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 The .gdb_index section has also been updated to record more information
116 about each symbol. This speeds up the "info variables", "info functions"
117 and "info types" commands when used with programs having the .gdb_index
118 section, as well as speeding up debugging with shared libraries using
119 the .gdb_index section.
121 * Ada support for GDB/MI Variable Objects has been added.
123 * GDB can now support 'breakpoint always-inserted mode' in 'record'
128 ** New command -info-os is the MI equivalent of "info os".
132 ** "catch load" and "catch unload" can be used to stop when a shared
133 library is loaded or unloaded, respectively.
135 ** "enable count" can be used to auto-disable a breakpoint after
138 ** "info vtbl" can be used to show the virtual method tables for
139 C++ and Java objects.
141 ** "explore" and its sub commands "explore value" and "explore type"
142 can be used to reccursively explore values and types of
143 expressions. These commands are available only if GDB is
144 configured with '--with-python'.
146 ** "info auto-load" shows status of all kinds of auto-loaded files,
147 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
148 sequences of commands files, "info auto-load python-scripts"
149 shows status of auto-loading Python script files,
150 "info auto-load local-gdbinit" shows status of loading init file
151 (.gdbinit) from current directory and "info auto-load libthread-db" shows
152 status of inferior specific thread debugging shared library loading.
154 ** "info auto-load-scripts", "set auto-load-scripts on|off"
155 and "show auto-load-scripts" commands have been deprecated, use their
156 "info auto-load python-scripts", "set auto-load python-scripts on|off"
157 and "show auto-load python-scripts" counterparts instead.
159 ** "dprintf location,format,args..." creates a dynamic printf, which
160 is basically a breakpoint that does a printf and immediately
161 resumes your program's execution, so it is like a printf that you
162 can insert dynamically at runtime instead of at compiletime.
164 ** "set print symbol"
166 Controls whether GDB attempts to display the symbol, if any,
167 corresponding to addresses it prints. This defaults to "on", but
168 you can set it to "off" to restore GDB's previous behavior.
170 * Deprecated commands
172 ** For the Renesas Super-H architecture, the "regs" command has been
173 deprecated, and "info all-registers" should be used instead.
177 Renesas RL78 rl78-*-elf
178 HP OpenVMS ia64 ia64-hp-openvms*
180 * GDBserver supports evaluation of breakpoint conditions. When
181 support is advertised by GDBserver, GDB may be told to send the
182 breakpoint conditions in bytecode form to GDBserver. GDBserver
183 will only report the breakpoint trigger to GDB when its condition
189 show mips compression
190 Select the compressed ISA encoding used in functions that have no symbol
191 information available. The encoding can be set to either of:
194 and is updated automatically from ELF file flags if available.
196 set breakpoint condition-evaluation
197 show breakpoint condition-evaluation
198 Control whether breakpoint conditions are evaluated by GDB ("host") or by
199 GDBserver ("target"). Default option "auto" chooses the most efficient
201 This option can improve debugger efficiency depending on the speed of the
205 Disable auto-loading globally.
208 Show auto-loading setting of all kinds of auto-loaded files.
210 set auto-load gdb-scripts on|off
211 show auto-load gdb-scripts
212 Control auto-loading of GDB canned sequences of commands files.
214 set auto-load python-scripts on|off
215 show auto-load python-scripts
216 Control auto-loading of Python script files.
218 set auto-load local-gdbinit on|off
219 show auto-load local-gdbinit
220 Control loading of init file (.gdbinit) from current directory.
222 set auto-load libthread-db on|off
223 show auto-load libthread-db
224 Control auto-loading of inferior specific thread debugging shared library.
226 set auto-load scripts-directory <dir1>[:<dir2>...]
227 show auto-load scripts-directory
228 Set a list of directories from which to load auto-loaded scripts.
229 Automatically loaded Python scripts and GDB scripts are located in one
230 of the directories listed by this option.
231 The delimiter (':' above) may differ according to the host platform.
233 set auto-load safe-path <dir1>[:<dir2>...]
234 show auto-load safe-path
235 Set a list of directories from which it is safe to auto-load files.
236 The delimiter (':' above) may differ according to the host platform.
238 set debug auto-load on|off
240 Control display of debugging info for auto-loading the files above.
242 set dprintf-style gdb|call
244 Control the way in which a dynamic printf is performed; "gdb" requests
245 a GDB printf command, while "call" causes dprintf to call a function
248 set dprintf-function <expr>
249 show dprintf-function
250 set dprintf-channel <expr>
252 Set the function and optional first argument to the call when using
253 the "call" style of dynamic printf.
255 * New configure options
258 Configure default value for the 'set auto-load scripts-directory'
259 setting above. It defaults to '$debugdir:$datadir/auto-load',
260 $debugdir representing global debugging info directories (available
261 via 'show debug-file-directory') and $datadir representing GDB's data
262 directory (available via 'show data-directory').
264 --with-auto-load-safe-path
265 Configure default value for the 'set auto-load safe-path' setting
266 above. It defaults to the --with-auto-load-dir setting.
268 --without-auto-load-safe-path
269 Set 'set auto-load safe-path' to '/', effectively disabling this
274 z0/z1 conditional breakpoints extension
276 The z0/z1 breakpoint insertion packets have been extended to carry
277 a list of conditional expressions over to the remote stub depending on the
278 condition evaluation mode. The use of this extension can be controlled
279 via the "set remote conditional-breakpoints-packet" command.
283 Specify the signals which the remote stub may pass to the debugged
284 program without GDB involvement.
286 * New command line options
288 --init-command=FILE, -ix Like --command, -x but execute it
289 before loading inferior.
290 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
291 execute it before loading inferior.
293 *** Changes in GDB 7.4
295 * GDB now handles ambiguous linespecs more consistently; the existing
296 FILE:LINE support has been expanded to other types of linespecs. A
297 breakpoint will now be set on all matching locations in all
298 inferiors, and locations will be added or removed according to
301 * GDB now allows you to skip uninteresting functions and files when
302 stepping with the "skip function" and "skip file" commands.
304 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
305 and "show remote hardware-watchpoint-length-limit". These allows to
306 set or show the maximum length limit (in bytes) of a remote
307 target hardware watchpoint.
309 This allows e.g. to use "unlimited" hardware watchpoints with the
310 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
311 watchpoints are slower than real hardware watchpoints but are
312 significantly faster than gdb software watchpoints.
316 ** The register_pretty_printer function in module gdb.printing now takes
317 an optional `replace' argument. If True, the new printer replaces any
320 ** The "maint set python print-stack on|off" command has been
321 deprecated and will be deleted in GDB 7.5.
322 A new command: "set python print-stack none|full|message" has
323 replaced it. Additionally, the default for "print-stack" is
324 now "message", which just prints the error message without
327 ** A prompt substitution hook (prompt_hook) is now available to the
330 ** A new Python module, gdb.prompt has been added to the GDB Python
331 modules library. This module provides functionality for
332 escape sequences in prompts (used by set/show
333 extended-prompt). These escape sequences are replaced by their
336 ** Python commands and convenience-functions located in
337 'data-directory'/python/gdb/command and
338 'data-directory'/python/gdb/function are now automatically loaded
341 ** Blocks now provide four new attributes. global_block and
342 static_block will return the global and static blocks
343 respectively. is_static and is_global are boolean attributes
344 that indicate if the block is one of those two types.
346 ** Symbols now provide the "type" attribute, the type of the symbol.
348 ** The "gdb.breakpoint" function has been deprecated in favor of
351 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
352 of a function. This class is based on the "finish" command
353 available in the CLI.
355 ** Type objects for struct and union types now allow access to
356 the fields using standard Python dictionary (mapping) methods.
357 For example, "some_type['myfield']" now works, as does
360 ** A new event "gdb.new_objfile" has been added, triggered by loading a
363 ** A new function, "deep_items" has been added to the gdb.types
364 module in the GDB Python modules library. This function returns
365 an iterator over the fields of a struct or union type. Unlike
366 the standard Python "iteritems" method, it will recursively traverse
367 any anonymous fields.
371 ** "*stopped" events can report several new "reason"s, such as
374 ** Breakpoint changes are now notified using new async records, like
375 "=breakpoint-modified".
377 ** New command -ada-task-info.
379 * libthread-db-search-path now supports two special values: $sdir and $pdir.
380 $sdir specifies the default system locations of shared libraries.
381 $pdir specifies the directory where the libpthread used by the application
384 GDB no longer looks in $sdir and $pdir after it has searched the directories
385 mentioned in libthread-db-search-path. If you want to search those
386 directories, they must be specified in libthread-db-search-path.
387 The default value of libthread-db-search-path on GNU/Linux and Solaris
388 systems is now "$sdir:$pdir".
390 $pdir is not supported by gdbserver, it is currently ignored.
391 $sdir is supported by gdbserver.
393 * New configure option --with-iconv-bin.
394 When using the internationalization support like the one in the GNU C
395 library, GDB will invoke the "iconv" program to get a list of supported
396 character sets. If this program lives in a non-standard location, one can
397 use this option to specify where to find it.
399 * When natively debugging programs on PowerPC BookE processors running
400 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
401 watchpoints, which specify a mask in addition to an address to watch.
402 The mask specifies that some bits of an address (the bits which are
403 reset in the mask) should be ignored when matching the address accessed
404 by the inferior against the watchpoint address. See the "PowerPC Embedded"
405 section in the user manual for more details.
407 * The new option --once causes GDBserver to stop listening for connections once
408 the first connection is made. The listening port used by GDBserver will
409 become available after that.
411 * New commands "info macros" and "alias" have been added.
413 * New function parameters suffix @entry specifies value of function parameter
414 at the time the function got called. Entry values are available only since
420 "!" is now an alias of the "shell" command.
421 Note that no space is needed between "!" and SHELL COMMAND.
425 watch EXPRESSION mask MASK_VALUE
426 The watch command now supports the mask argument which allows creation
427 of masked watchpoints, if the current architecture supports this feature.
429 info auto-load-scripts [REGEXP]
430 This command was formerly named "maintenance print section-scripts".
431 It is now generally useful and is no longer a maintenance-only command.
433 info macro [-all] [--] MACRO
434 The info macro command has new options `-all' and `--'. The first for
435 printing all definitions of a macro. The second for explicitly specifying
436 the end of arguments and the beginning of the macro name in case the macro
437 name starts with a hyphen.
439 collect[/s] EXPRESSIONS
440 The tracepoint collect command now takes an optional modifier "/s"
441 that directs it to dereference pointer-to-character types and
442 collect the bytes of memory up to a zero byte. The behavior is
443 similar to what you see when you use the regular print command on a
444 string. An optional integer following the "/s" sets a bound on the
445 number of bytes that will be collected.
448 The trace start command now interprets any supplied arguments as a
449 note to be recorded with the trace run, with an effect similar to
450 setting the variable trace-notes.
453 The trace stop command now interprets any arguments as a note to be
454 mentioned along with the tstatus report that the trace was stopped
455 with a command. The effect is similar to setting the variable
458 * Tracepoints can now be enabled and disabled at any time after a trace
459 experiment has been started using the standard "enable" and "disable"
460 commands. It is now possible to start a trace experiment with no enabled
461 tracepoints; GDB will display a warning, but will allow the experiment to
462 begin, assuming that tracepoints will be enabled as needed while the trace
465 * Fast tracepoints on 32-bit x86-architectures can now be placed at
466 locations with 4-byte instructions, when they were previously
467 limited to locations with instructions of 5 bytes or longer.
473 Set the GDB prompt, and allow escape sequences to be inserted to
474 display miscellaneous information (see 'help set extended-prompt'
475 for the list of sequences). This prompt (and any information
476 accessed through the escape sequences) is updated every time the
479 set print entry-values (both|compact|default|if-needed|no|only|preferred)
480 show print entry-values
481 Set printing of frame argument values at function entry. In some cases
482 GDB can determine the value of function argument which was passed by the
483 function caller, even if the value was modified inside the called function.
485 set debug entry-values
486 show debug entry-values
487 Control display of debugging info for determining frame argument values at
488 function entry and virtual tail call frames.
490 set basenames-may-differ
491 show basenames-may-differ
492 Set whether a source file may have multiple base names.
493 (A "base name" is the name of a file with the directory part removed.
494 Example: The base name of "/home/user/hello.c" is "hello.c".)
495 If set, GDB will canonicalize file names (e.g., expand symlinks)
496 before comparing them. Canonicalization is an expensive operation,
497 but it allows the same file be known by more than one base name.
498 If not set (the default), all source files are assumed to have just
499 one base name, and gdb will do file name comparisons more efficiently.
505 Set a user name and notes for the current and any future trace runs.
506 This is useful for long-running and/or disconnected traces, to
507 inform others (or yourself) as to who is running the trace, supply
508 contact information, or otherwise explain what is going on.
511 show trace-stop-notes
512 Set a note attached to the trace run, that is displayed when the
513 trace has been stopped by a tstop command. This is useful for
514 instance as an explanation, if you are stopping a trace run that was
515 started by someone else.
521 Dynamically enable a tracepoint in a started trace experiment.
525 Dynamically disable a tracepoint in a started trace experiment.
529 Set the user and notes of the trace run.
533 Query the current status of a tracepoint.
537 Query the minimum length of instruction at which a fast tracepoint may
540 * Dcache size (number of lines) and line-size are now runtime-configurable
541 via "set dcache line" and "set dcache line-size" commands.
545 Texas Instruments TMS320C6x tic6x-*-*
549 Renesas RL78 rl78-*-elf
551 *** Changes in GDB 7.3.1
553 * The build failure for NetBSD and OpenBSD targets have now been fixed.
555 *** Changes in GDB 7.3
557 * GDB has a new command: "thread find [REGEXP]".
558 It finds the thread id whose name, target id, or thread extra info
559 matches the given regular expression.
561 * The "catch syscall" command now works on mips*-linux* targets.
563 * The -data-disassemble MI command now supports modes 2 and 3 for
564 dumping the instruction opcodes.
566 * New command line options
568 -data-directory DIR Specify DIR as the "data-directory".
569 This is mostly for testing purposes.
571 * The "maint set python auto-load on|off" command has been renamed to
572 "set auto-load-scripts on|off".
574 * GDB has a new command: "set directories".
575 It is like the "dir" command except that it replaces the
576 source path list instead of augmenting it.
578 * GDB now understands thread names.
580 On GNU/Linux, "info threads" will display the thread name as set by
581 prctl or pthread_setname_np.
583 There is also a new command, "thread name", which can be used to
584 assign a name internally for GDB to display.
587 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
588 has been integrated into GDB.
592 ** The function gdb.Write now accepts an optional keyword 'stream'.
593 This keyword, when provided, will direct the output to either
594 stdout, stderr, or GDB's logging output.
596 ** Parameters can now be be sub-classed in Python, and in particular
597 you may implement the get_set_doc and get_show_doc functions.
598 This improves how Parameter set/show documentation is processed
599 and allows for more dynamic content.
601 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
602 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
603 have an is_valid method.
605 ** Breakpoints can now be sub-classed in Python, and in particular
606 you may implement a 'stop' function that is executed each time
607 the inferior reaches that breakpoint.
609 ** New function gdb.lookup_global_symbol looks up a global symbol.
611 ** GDB values in Python are now callable if the value represents a
612 function. For example, if 'some_value' represents a function that
613 takes two integer parameters and returns a value, you can call
614 that function like so:
616 result = some_value (10,20)
618 ** Module gdb.types has been added.
619 It contains a collection of utilities for working with gdb.Types objects:
620 get_basic_type, has_field, make_enum_dict.
622 ** Module gdb.printing has been added.
623 It contains utilities for writing and registering pretty-printers.
624 New classes: PrettyPrinter, SubPrettyPrinter,
625 RegexpCollectionPrettyPrinter.
626 New function: register_pretty_printer.
628 ** New commands "info pretty-printers", "enable pretty-printer" and
629 "disable pretty-printer" have been added.
631 ** gdb.parameter("directories") is now available.
633 ** New function gdb.newest_frame returns the newest frame in the
636 ** The gdb.InferiorThread class has a new "name" attribute. This
637 holds the thread's name.
639 ** Python Support for Inferior events.
640 Python scripts can add observers to be notified of events
641 occurring in the process being debugged.
642 The following events are currently supported:
643 - gdb.events.cont Continue event.
644 - gdb.events.exited Inferior exited event.
645 - gdb.events.stop Signal received, and Breakpoint hit events.
649 ** GDB now puts template parameters in scope when debugging in an
650 instantiation. For example, if you have:
652 template<int X> int func (void) { return X; }
654 then if you step into func<5>, "print X" will show "5". This
655 feature requires proper debuginfo support from the compiler; it
656 was added to GCC 4.5.
658 ** The motion commands "next", "finish", "until", and "advance" now
659 work better when exceptions are thrown. In particular, GDB will
660 no longer lose control of the inferior; instead, the GDB will
661 stop the inferior at the point at which the exception is caught.
662 This functionality requires a change in the exception handling
663 code that was introduced in GCC 4.5.
665 * GDB now follows GCC's rules on accessing volatile objects when
666 reading or writing target state during expression evaluation.
667 One notable difference to prior behavior is that "print x = 0"
668 no longer generates a read of x; the value of the assignment is
669 now always taken directly from the value being assigned.
671 * GDB now has some support for using labels in the program's source in
672 linespecs. For instance, you can use "advance label" to continue
673 execution to a label.
675 * GDB now has support for reading and writing a new .gdb_index
676 section. This section holds a fast index of DWARF debugging
677 information and can be used to greatly speed up GDB startup and
678 operation. See the documentation for `save gdb-index' for details.
680 * The "watch" command now accepts an optional "-location" argument.
681 When used, this causes GDB to watch the memory referred to by the
682 expression. Such a watchpoint is never deleted due to it going out
685 * GDB now supports thread debugging of core dumps on GNU/Linux.
687 GDB now activates thread debugging using the libthread_db library
688 when debugging GNU/Linux core dumps, similarly to when debugging
689 live processes. As a result, when debugging a core dump file, GDB
690 is now able to display pthread_t ids of threads. For example, "info
691 threads" shows the same output as when debugging the process when it
692 was live. In earlier releases, you'd see something like this:
695 * 1 LWP 6780 main () at main.c:10
697 While now you see this:
700 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
702 It is also now possible to inspect TLS variables when debugging core
705 When debugging a core dump generated on a machine other than the one
706 used to run GDB, you may need to point GDB at the correct
707 libthread_db library with the "set libthread-db-search-path"
708 command. See the user manual for more details on this command.
710 * When natively debugging programs on PowerPC BookE processors running
711 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
712 which stop execution of the inferior whenever it executes an instruction
713 at any address within the specified range. See the "PowerPC Embedded"
714 section in the user manual for more details.
716 * New features in the GDB remote stub, GDBserver
718 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
719 and i686 LynxOS (version 5.x).
721 ** GDBserver is now supported on Blackfin Linux.
723 * New native configurations
725 ia64 HP-UX ia64-*-hpux*
729 Analog Devices, Inc. Blackfin Processor bfin-*
731 * Ada task switching is now supported on sparc-elf targets when
732 debugging a program using the Ravenscar Profile. For more information,
733 see the "Tasking Support when using the Ravenscar Profile" section
734 in the GDB user manual.
736 * Guile support was removed.
738 * New features in the GNU simulator
740 ** The --map-info flag lists all known core mappings.
742 ** CFI flashes may be simulated via the "cfi" device.
744 *** Changes in GDB 7.2
746 * Shared library support for remote targets by default
748 When GDB is configured for a generic, non-OS specific target, like
749 for example, --target=arm-eabi or one of the many *-*-elf targets,
750 GDB now queries remote stubs for loaded shared libraries using the
751 `qXfer:libraries:read' packet. Previously, shared library support
752 was always disabled for such configurations.
756 ** Argument Dependent Lookup (ADL)
758 In C++ ADL lookup directs function search to the namespaces of its
759 arguments even if the namespace has not been imported.
769 Here the compiler will search for `foo' in the namespace of 'b'
770 and find A::foo. GDB now supports this. This construct is commonly
771 used in the Standard Template Library for operators.
773 ** Improved User Defined Operator Support
775 In addition to member operators, GDB now supports lookup of operators
776 defined in a namespace and imported with a `using' directive, operators
777 defined in the global scope, operators imported implicitly from an
778 anonymous namespace, and the ADL operators mentioned in the previous
780 GDB now also supports proper overload resolution for all the previously
781 mentioned flavors of operators.
783 ** static const class members
785 Printing of static const class members that are initialized in the
786 class definition has been fixed.
788 * Windows Thread Information Block access.
790 On Windows targets, GDB now supports displaying the Windows Thread
791 Information Block (TIB) structure. This structure is visible either
792 by using the new command `info w32 thread-information-block' or, by
793 dereferencing the new convenience variable named `$_tlb', a
794 thread-specific pointer to the TIB. This feature is also supported
795 when remote debugging using GDBserver.
799 Static tracepoints are calls in the user program into a tracing
800 library. One such library is a port of the LTTng kernel tracer to
801 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
802 When debugging with GDBserver, GDB now supports combining the GDB
803 tracepoint machinery with such libraries. For example: the user can
804 use GDB to probe a static tracepoint marker (a call from the user
805 program into the tracing library) with the new "strace" command (see
806 "New commands" below). This creates a "static tracepoint" in the
807 breakpoint list, that can be manipulated with the same feature set
808 as fast and regular tracepoints. E.g., collect registers, local and
809 global variables, collect trace state variables, and define
810 tracepoint conditions. In addition, the user can collect extra
811 static tracepoint marker specific data, by collecting the new
812 $_sdata internal variable. When analyzing the trace buffer, you can
813 inspect $_sdata like any other variable available to GDB. For more
814 information, see the "Tracepoints" chapter in GDB user manual. New
815 remote packets have been defined to support static tracepoints, see
816 the "New remote packets" section below.
818 * Better reconstruction of tracepoints after disconnected tracing
820 GDB will attempt to download the original source form of tracepoint
821 definitions when starting a trace run, and then will upload these
822 upon reconnection to the target, resulting in a more accurate
823 reconstruction of the tracepoints that are in use on the target.
827 You can now exercise direct control over the ways that GDB can
828 affect your program. For instance, you can disallow the setting of
829 breakpoints, so that the program can run continuously (assuming
830 non-stop mode). In addition, the "observer" variable is available
831 to switch all of the different controls; in observer mode, GDB
832 cannot affect the target's behavior at all, which is useful for
833 tasks like diagnosing live systems in the field.
835 * The new convenience variable $_thread holds the number of the
842 Return the address of the Windows Thread Information Block of a given thread.
846 In response to several of the tracepoint packets, the target may now
847 also respond with a number of intermediate `qRelocInsn' request
848 packets before the final result packet, to have GDB handle
849 relocating an instruction to execute at a different address. This
850 is particularly useful for stubs that support fast tracepoints. GDB
851 reports support for this feature in the qSupported packet.
855 List static tracepoint markers in the target program.
859 List static tracepoint markers at a given address in the target
862 qXfer:statictrace:read
864 Read the static trace data collected (by a `collect $_sdata'
865 tracepoint action). The remote stub reports support for this packet
866 to gdb's qSupported query.
870 Send the current settings of GDB's permission flags.
874 Send part of the source (textual) form of a tracepoint definition,
875 which includes location, conditional, and action list.
877 * The source command now accepts a -s option to force searching for the
878 script in the source search path even if the script name specifies
881 * New features in the GDB remote stub, GDBserver
883 - GDBserver now support tracepoints (including fast tracepoints, and
884 static tracepoints). The feature is currently supported by the
885 i386-linux and amd64-linux builds. See the "Tracepoints support
886 in gdbserver" section in the manual for more information.
888 GDBserver JIT compiles the tracepoint's conditional agent
889 expression bytecode into native code whenever possible for low
890 overhead dynamic tracepoints conditionals. For such tracepoints,
891 an expression that examines program state is evaluated when the
892 tracepoint is reached, in order to determine whether to capture
893 trace data. If the condition is simple and false, processing the
894 tracepoint finishes very quickly and no data is gathered.
896 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
897 for static tracepoints support.
899 - GDBserver now supports x86_64 Windows 64-bit debugging.
901 * GDB now sends xmlRegisters= in qSupported packet to indicate that
902 it understands register description.
904 * The --batch flag now disables pagination and queries.
906 * X86 general purpose registers
908 GDB now supports reading/writing byte, word and double-word x86
909 general purpose registers directly. This means you can use, say,
910 $ah or $ax to refer, respectively, to the byte register AH and
911 16-bit word register AX that are actually portions of the 32-bit
912 register EAX or 64-bit register RAX.
914 * The `commands' command now accepts a range of breakpoints to modify.
915 A plain `commands' following a command that creates multiple
916 breakpoints affects all the breakpoints set by that command. This
917 applies to breakpoints set by `rbreak', and also applies when a
918 single `break' command creates multiple breakpoints (e.g.,
919 breakpoints on overloaded c++ functions).
921 * The `rbreak' command now accepts a filename specification as part of
922 its argument, limiting the functions selected by the regex to those
923 in the specified file.
925 * Support for remote debugging Windows and SymbianOS shared libraries
926 from Unix hosts has been improved. Non Windows GDB builds now can
927 understand target reported file names that follow MS-DOS based file
928 system semantics, such as file names that include drive letters and
929 use the backslash character as directory separator. This makes it
930 possible to transparently use the "set sysroot" and "set
931 solib-search-path" on Unix hosts to point as host copies of the
932 target's shared libraries. See the new command "set
933 target-file-system-kind" described below, and the "Commands to
934 specify files" section in the user manual for more information.
938 eval template, expressions...
939 Convert the values of one or more expressions under the control
940 of the string template to a command line, and call it.
942 set target-file-system-kind unix|dos-based|auto
943 show target-file-system-kind
944 Set or show the assumed file system kind for target reported file
947 save breakpoints <filename>
948 Save all current breakpoint definitions to a file suitable for use
949 in a later debugging session. To read the saved breakpoint
950 definitions, use the `source' command.
952 `save tracepoints' is a new alias for `save-tracepoints'. The latter
955 info static-tracepoint-markers
956 Display information about static tracepoint markers in the target.
958 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
959 Define a static tracepoint by probing a marker at the given
960 function, line, address, or marker ID.
964 Enable and disable observer mode.
966 set may-write-registers on|off
967 set may-write-memory on|off
968 set may-insert-breakpoints on|off
969 set may-insert-tracepoints on|off
970 set may-insert-fast-tracepoints on|off
971 set may-interrupt on|off
972 Set individual permissions for GDB effects on the target. Note that
973 some of these settings can have undesirable or surprising
974 consequences, particularly when changed in the middle of a session.
975 For instance, disabling the writing of memory can prevent
976 breakpoints from being inserted, cause single-stepping to fail, or
977 even crash your program, if you disable after breakpoints have been
978 inserted. However, GDB should not crash.
980 set record memory-query on|off
981 show record memory-query
982 Control whether to stop the inferior if memory changes caused
983 by an instruction cannot be recorded.
988 The disassemble command now supports "start,+length" form of two arguments.
992 ** GDB now provides a new directory location, called the python directory,
993 where Python scripts written for GDB can be installed. The location
994 of that directory is <data-directory>/python, where <data-directory>
995 is the GDB data directory. For more details, see section `Scripting
996 GDB using Python' in the manual.
998 ** The GDB Python API now has access to breakpoints, symbols, symbol
999 tables, program spaces, inferiors, threads and frame's code blocks.
1000 Additionally, GDB Parameters can now be created from the API, and
1001 manipulated via set/show in the CLI.
1003 ** New functions gdb.target_charset, gdb.target_wide_charset,
1004 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1006 ** New exception gdb.GdbError.
1008 ** Pretty-printers are now also looked up in the current program space.
1010 ** Pretty-printers can now be individually enabled and disabled.
1012 ** GDB now looks for names of Python scripts to auto-load in a
1013 special section named `.debug_gdb_scripts', in addition to looking
1014 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1016 * Tracepoint actions were unified with breakpoint commands. In particular,
1017 there are no longer differences in "info break" output for breakpoints and
1018 tracepoints and the "commands" command can be used for both tracepoints and
1019 regular breakpoints.
1023 ARM Symbian arm*-*-symbianelf*
1025 * D language support.
1026 GDB now supports debugging programs written in the D programming
1029 * GDB now supports the extended ptrace interface for PowerPC which is
1030 available since Linux kernel version 2.6.34. This automatically enables
1031 any hardware breakpoints and additional hardware watchpoints available in
1032 the processor. The old ptrace interface exposes just one hardware
1033 watchpoint and no hardware breakpoints.
1035 * GDB is now able to use the Data Value Compare (DVC) register available on
1036 embedded PowerPC processors to implement in hardware simple watchpoint
1037 conditions of the form:
1039 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1041 This works in native GDB running on Linux kernels with the extended ptrace
1042 interface mentioned above.
1044 *** Changes in GDB 7.1
1048 ** Namespace Support
1050 GDB now supports importing of namespaces in C++. This enables the
1051 user to inspect variables from imported namespaces. Support for
1052 namepace aliasing has also been added. So, if a namespace is
1053 aliased in the current scope (e.g. namepace C=A; ) the user can
1054 print variables using the alias (e.g. (gdb) print C::x).
1058 All known bugs relating to the printing of virtual base class were
1059 fixed. It is now possible to call overloaded static methods using a
1064 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1065 and reinterpret_cast<> are now handled by the C++ expression parser.
1069 Xilinx MicroBlaze microblaze-*-*
1074 Xilinx MicroBlaze microblaze
1077 * Multi-program debugging.
1079 GDB now has support for multi-program (a.k.a. multi-executable or
1080 multi-exec) debugging. This allows for debugging multiple inferiors
1081 simultaneously each running a different program under the same GDB
1082 session. See "Debugging Multiple Inferiors and Programs" in the
1083 manual for more information. This implied some user visible changes
1084 in the multi-inferior support. For example, "info inferiors" now
1085 lists inferiors that are not running yet or that have exited
1086 already. See also "New commands" and "New options" below.
1088 * New tracing features
1090 GDB's tracepoint facility now includes several new features:
1092 ** Trace state variables
1094 GDB tracepoints now include support for trace state variables, which
1095 are variables managed by the target agent during a tracing
1096 experiment. They are useful for tracepoints that trigger each
1097 other, so for instance one tracepoint can count hits in a variable,
1098 and then a second tracepoint has a condition that is true when the
1099 count reaches a particular value. Trace state variables share the
1100 $-syntax of GDB convenience variables, and can appear in both
1101 tracepoint actions and condition expressions. Use the "tvariable"
1102 command to create, and "info tvariables" to view; see "Trace State
1103 Variables" in the manual for more detail.
1107 GDB now includes an option for defining fast tracepoints, which
1108 targets may implement more efficiently, such as by installing a jump
1109 into the target agent rather than a trap instruction. The resulting
1110 speedup can be by two orders of magnitude or more, although the
1111 tradeoff is that some program locations on some target architectures
1112 might not allow fast tracepoint installation, for instance if the
1113 instruction to be replaced is shorter than the jump. To request a
1114 fast tracepoint, use the "ftrace" command, with syntax identical to
1115 the regular trace command.
1117 ** Disconnected tracing
1119 It is now possible to detach GDB from the target while it is running
1120 a trace experiment, then reconnect later to see how the experiment
1121 is going. In addition, a new variable disconnected-tracing lets you
1122 tell the target agent whether to continue running a trace if the
1123 connection is lost unexpectedly.
1127 GDB now has the ability to save the trace buffer into a file, and
1128 then use that file as a target, similarly to you can do with
1129 corefiles. You can select trace frames, print data that was
1130 collected in them, and use tstatus to display the state of the
1131 tracing run at the moment that it was saved. To create a trace
1132 file, use "tsave <filename>", and to use it, do "target tfile
1135 ** Circular trace buffer
1137 You can ask the target agent to handle the trace buffer as a
1138 circular buffer, discarding the oldest trace frames to make room for
1139 newer ones, by setting circular-trace-buffer to on. This feature may
1140 not be available for all target agents.
1145 The disassemble command, when invoked with two arguments, now requires
1146 the arguments to be comma-separated.
1149 The info variables command now displays variable definitions. Files
1150 which only declare a variable are not shown.
1153 The source command is now capable of sourcing Python scripts.
1154 This feature is dependent on the debugger being build with Python
1157 Related to this enhancement is also the introduction of a new command
1158 "set script-extension" (see below).
1160 * New commands (for set/show, see "New options" below)
1162 record save [<FILENAME>]
1163 Save a file (in core file format) containing the process record
1164 execution log for replay debugging at a later time.
1166 record restore <FILENAME>
1167 Restore the process record execution log that was saved at an
1168 earlier time, for replay debugging.
1170 add-inferior [-copies <N>] [-exec <FILENAME>]
1173 clone-inferior [-copies <N>] [ID]
1174 Make a new inferior ready to execute the same program another
1175 inferior has loaded.
1180 maint info program-spaces
1181 List the program spaces loaded into GDB.
1183 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1184 show remote interrupt-sequence
1185 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1186 as the sequence to the remote target in order to interrupt the execution.
1187 Ctrl-C is a default. Some system prefers BREAK which is high level of
1188 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1189 Magic SysRq g. It is BREAK signal and character 'g'.
1191 set remote interrupt-on-connect [on | off]
1192 show remote interrupt-on-connect
1193 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1194 remote target when gdb connects to it. This is needed when you debug
1197 set remotebreak [on | off]
1199 Deprecated. Use "set/show remote interrupt-sequence" instead.
1201 tvariable $NAME [ = EXP ]
1202 Create or modify a trace state variable.
1205 List trace state variables and their values.
1207 delete tvariable $NAME ...
1208 Delete one or more trace state variables.
1211 Evaluate the given expressions without collecting anything into the
1212 trace buffer. (Valid in tracepoint actions only.)
1214 ftrace FN / FILE:LINE / *ADDR
1215 Define a fast tracepoint at the given function, line, or address.
1217 * New expression syntax
1219 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1220 GDB now parses 0b101010 identically with 42.
1224 set follow-exec-mode new|same
1225 show follow-exec-mode
1226 Control whether GDB reuses the same inferior across an exec call or
1227 creates a new one. This is useful to be able to restart the old
1228 executable after the inferior having done an exec call.
1230 set default-collect EXPR, ...
1231 show default-collect
1232 Define a list of expressions to be collected at each tracepoint.
1233 This is a useful way to ensure essential items are not overlooked,
1234 such as registers or a critical global variable.
1236 set disconnected-tracing
1237 show disconnected-tracing
1238 If set to 1, the target is instructed to continue tracing if it
1239 loses its connection to GDB. If 0, the target is to stop tracing
1242 set circular-trace-buffer
1243 show circular-trace-buffer
1244 If set to on, the target is instructed to use a circular trace buffer
1245 and discard the oldest trace frames instead of stopping the trace due
1246 to a full trace buffer. If set to off, the trace stops when the buffer
1247 fills up. Some targets may not support this.
1249 set script-extension off|soft|strict
1250 show script-extension
1251 If set to "off", the debugger does not perform any script language
1252 recognition, and all sourced files are assumed to be GDB scripts.
1253 If set to "soft" (the default), files are sourced according to
1254 filename extension, falling back to GDB scripts if the first
1256 If set to "strict", files are sourced according to filename extension.
1258 set ada trust-PAD-over-XVS on|off
1259 show ada trust-PAD-over-XVS
1260 If off, activate a workaround against a bug in the debugging information
1261 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1262 the GCC sources for more information about the GNAT encoding and
1263 PAD types in particular). It is always safe to set this option to
1264 off, but this introduces a slight performance penalty. The default
1267 * Python API Improvements
1269 ** GDB provides the new class gdb.LazyString. This is useful in
1270 some pretty-printing cases. The new method gdb.Value.lazy_string
1271 provides a simple way to create objects of this type.
1273 ** The fields returned by gdb.Type.fields now have an
1274 `is_base_class' attribute.
1276 ** The new method gdb.Type.range returns the range of an array type.
1278 ** The new method gdb.parse_and_eval can be used to parse and
1279 evaluate an expression.
1281 * New remote packets
1284 Define a trace state variable.
1287 Get the current value of a trace state variable.
1290 Set desired tracing behavior upon disconnection.
1293 Set the trace buffer to be linear or circular.
1296 Get data about the tracepoints currently in use.
1300 Process record now works correctly with hardware watchpoints.
1302 Multiple bug fixes have been made to the mips-irix port, making it
1303 much more reliable. In particular:
1304 - Debugging threaded applications is now possible again. Previously,
1305 GDB would hang while starting the program, or while waiting for
1306 the program to stop at a breakpoint.
1307 - Attaching to a running process no longer hangs.
1308 - An error occurring while loading a core file has been fixed.
1309 - Changing the value of the PC register now works again. This fixes
1310 problems observed when using the "jump" command, or when calling
1311 a function from GDB, or even when assigning a new value to $pc.
1312 - With the "finish" and "return" commands, the return value for functions
1313 returning a small array is now correctly printed.
1314 - It is now possible to break on shared library code which gets executed
1315 during a shared library init phase (code executed while executing
1316 their .init section). Previously, the breakpoint would have no effect.
1317 - GDB is now able to backtrace through the signal handler for
1318 non-threaded programs.
1320 PIE (Position Independent Executable) programs debugging is now supported.
1321 This includes debugging execution of PIC (Position Independent Code) shared
1322 libraries although for that, it should be possible to run such libraries as an
1325 *** Changes in GDB 7.0
1327 * GDB now has an interface for JIT compilation. Applications that
1328 dynamically generate code can create symbol files in memory and register
1329 them with GDB. For users, the feature should work transparently, and
1330 for JIT developers, the interface is documented in the GDB manual in the
1331 "JIT Compilation Interface" chapter.
1333 * Tracepoints may now be conditional. The syntax is as for
1334 breakpoints; either an "if" clause appended to the "trace" command,
1335 or the "condition" command is available. GDB sends the condition to
1336 the target for evaluation using the same bytecode format as is used
1337 for tracepoint actions.
1339 * The disassemble command now supports: an optional /r modifier, print the
1340 raw instructions in hex as well as in symbolic form, and an optional /m
1341 modifier to print mixed source+assembly.
1343 * Process record and replay
1345 In a architecture environment that supports ``process record and
1346 replay'', ``process record and replay'' target can record a log of
1347 the process execution, and replay it with both forward and reverse
1350 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
1351 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
1352 set execution-direction {forward|reverse}, for targets that support
1355 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
1356 feature is available with a native GDB running on kernel version
1359 * GDB now has support for multi-byte and wide character sets on the
1360 target. Strings whose character type is wchar_t, char16_t, or
1361 char32_t are now correctly printed. GDB supports wide- and unicode-
1362 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
1363 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
1364 `printf'. This feature requires iconv to work properly; if your
1365 system does not have a working iconv, GDB can use GNU libiconv. See
1366 the installation instructions for more information.
1368 * GDB now supports automatic retrieval of shared library files from
1369 remote targets. To use this feature, specify a system root that begins
1370 with the `remote:' prefix, either via the `set sysroot' command or via
1371 the `--with-sysroot' configure-time option.
1373 * "info sharedlibrary" now takes an optional regex of libraries to show,
1374 and it now reports if a shared library has no debugging information.
1376 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
1377 now complete on file names.
1379 * When completing in expressions, gdb will attempt to limit
1380 completions to allowable structure or union fields, where appropriate.
1381 For instance, consider:
1383 # struct example { int f1; double f2; };
1384 # struct example variable;
1387 If the user types TAB at the end of this command line, the available
1388 completions will be "f1" and "f2".
1390 * Inlined functions are now supported. They show up in backtraces, and
1391 the "step", "next", and "finish" commands handle them automatically.
1393 * GDB now supports the token-splicing (##) and stringification (#)
1394 operators when expanding macros. It also supports variable-arity
1397 * GDB now supports inspecting extra signal information, exported by
1398 the new $_siginfo convenience variable. The feature is currently
1399 implemented on linux ARM, i386 and amd64.
1401 * GDB can now display the VFP floating point registers and NEON vector
1402 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
1403 can provide these registers (requires Linux 2.6.30 or later). Remote
1404 and simulator targets may also provide them.
1406 * New remote packets
1409 Search memory for a sequence of bytes.
1412 Turn off `+'/`-' protocol acknowledgments to permit more efficient
1413 operation over reliable transport links. Use of this packet is
1414 controlled by the `set remote noack-packet' command.
1417 Kill the process with the specified process ID. Use this in preference
1418 to `k' when multiprocess protocol extensions are supported.
1421 Obtains additional operating system information
1425 Read or write additional signal information.
1427 * Removed remote protocol undocumented extension
1429 An undocumented extension to the remote protocol's `S' stop reply
1430 packet that permited the stub to pass a process id was removed.
1431 Remote servers should use the `T' stop reply packet instead.
1433 * GDB now supports multiple function calling conventions according to the
1434 DWARF-2 DW_AT_calling_convention function attribute.
1436 * The SH target utilizes the aforementioned change to distinguish between gcc
1437 and Renesas calling convention. It also adds the new CLI commands
1438 `set/show sh calling-convention'.
1440 * GDB can now read compressed debug sections, as produced by GNU gold
1441 with the --compress-debug-sections=zlib flag.
1443 * 64-bit core files are now supported on AIX.
1445 * Thread switching is now supported on Tru64.
1447 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
1448 which will be allocated using malloc later in program execution.
1450 * The qXfer:libraries:read remote procotol packet now allows passing a
1451 list of section offsets.
1453 * On GNU/Linux, GDB can now attach to stopped processes. Several race
1454 conditions handling signals delivered during attach or thread creation
1455 have also been fixed.
1457 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
1458 From the user's standpoint, all unqualified instances of True and False
1459 are treated as the standard definitions, regardless of context.
1461 * GDB now parses C++ symbol and type names more flexibly. For
1464 template<typename T> class C { };
1467 GDB will now correctly handle all of:
1469 ptype C<char const *>
1470 ptype C<char const*>
1471 ptype C<const char *>
1472 ptype C<const char*>
1474 * New features in the GDB remote stub, gdbserver
1476 - The "--wrapper" command-line argument tells gdbserver to use a
1477 wrapper program to launch programs for debugging.
1479 - On PowerPC and S/390 targets, it is now possible to use a single
1480 gdbserver executable to debug both 32-bit and 64-bit programs.
1481 (This requires gdbserver itself to be built as a 64-bit executable.)
1483 - gdbserver uses the new noack protocol mode for TCP connections to
1484 reduce communications latency, if also supported and enabled in GDB.
1486 - Support for the sparc64-linux-gnu target is now included in
1489 - The amd64-linux build of gdbserver now supports debugging both
1490 32-bit and 64-bit programs.
1492 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
1493 now support hardware watchpoints, and will use them automatically
1498 GDB now has support for scripting using Python. Whether this is
1499 available is determined at configure time.
1501 New GDB commands can now be written in Python.
1503 * Ada tasking support
1505 Ada tasks can now be inspected in GDB. The following commands have
1509 Print the list of Ada tasks.
1511 Print detailed information about task number N.
1513 Print the task number of the current task.
1515 Switch the context of debugging to task number N.
1517 * Support for user-defined prefixed commands. The "define" command can
1518 add new commands to existing prefixes, e.g. "target".
1520 * Multi-inferior, multi-process debugging.
1522 GDB now has generalized support for multi-inferior debugging. See
1523 "Debugging Multiple Inferiors" in the manual for more information.
1524 Although availability still depends on target support, the command
1525 set is more uniform now. The GNU/Linux specific multi-forks support
1526 has been migrated to this new framework. This implied some user
1527 visible changes; see "New commands" and also "Removed commands"
1530 * Target descriptions can now describe the target OS ABI. See the
1531 "Target Description Format" section in the user manual for more
1534 * Target descriptions can now describe "compatible" architectures
1535 to indicate that the target can execute applications for a different
1536 architecture in addition to those for the main target architecture.
1537 See the "Target Description Format" section in the user manual for
1540 * Multi-architecture debugging.
1542 GDB now includes general supports for debugging applications on
1543 hybrid systems that use more than one single processor architecture
1544 at the same time. Each such hybrid architecture still requires
1545 specific support to be added. The only hybrid architecture supported
1546 in this version of GDB is the Cell Broadband Engine.
1548 * GDB now supports integrated debugging of Cell/B.E. applications that
1549 use both the PPU and SPU architectures. To enable support for hybrid
1550 Cell/B.E. debugging, you need to configure GDB to support both the
1551 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
1552 --enable-targets configure option.
1554 * Non-stop mode debugging.
1556 For some targets, GDB now supports an optional mode of operation in
1557 which you can examine stopped threads while other threads continue
1558 to execute freely. This is referred to as non-stop mode, with the
1559 old mode referred to as all-stop mode. See the "Non-Stop Mode"
1560 section in the user manual for more information.
1562 To be able to support remote non-stop debugging, a remote stub needs
1563 to implement the non-stop mode remote protocol extensions, as
1564 described in the "Remote Non-Stop" section of the user manual. The
1565 GDB remote stub, gdbserver, has been adjusted to support these
1566 extensions on linux targets.
1568 * New commands (for set/show, see "New options" below)
1570 catch syscall [NAME(S) | NUMBER(S)]
1571 Catch system calls. Arguments, which should be names of system
1572 calls or their numbers, mean catch only those syscalls. Without
1573 arguments, every syscall will be caught. When the inferior issues
1574 any of the specified syscalls, GDB will stop and announce the system
1575 call, both when it is called and when its call returns. This
1576 feature is currently available with a native GDB running on the
1577 Linux Kernel, under the following architectures: x86, x86_64,
1578 PowerPC and PowerPC64.
1580 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
1582 Search memory for a sequence of bytes.
1584 maint set python print-stack
1585 maint show python print-stack
1586 Show a stack trace when an error is encountered in a Python script.
1589 Invoke CODE by passing it to the Python interpreter.
1594 These allow macros to be defined, undefined, and listed
1598 Show operating system information about processes.
1601 List the inferiors currently under GDB's control.
1604 Switch focus to inferior number NUM.
1607 Detach from inferior number NUM.
1610 Kill inferior number NUM.
1614 set spu stop-on-load
1615 show spu stop-on-load
1616 Control whether to stop for new SPE threads during Cell/B.E. debugging.
1618 set spu auto-flush-cache
1619 show spu auto-flush-cache
1620 Control whether to automatically flush the software-managed cache
1621 during Cell/B.E. debugging.
1623 set sh calling-convention
1624 show sh calling-convention
1625 Control the calling convention used when calling SH target functions.
1628 show debug timestamp
1629 Control display of timestamps with GDB debugging output.
1631 set disassemble-next-line
1632 show disassemble-next-line
1633 Control display of disassembled source lines or instructions when
1636 set remote noack-packet
1637 show remote noack-packet
1638 Set/show the use of remote protocol QStartNoAckMode packet. See above
1639 under "New remote packets."
1641 set remote query-attached-packet
1642 show remote query-attached-packet
1643 Control use of remote protocol `qAttached' (query-attached) packet.
1645 set remote read-siginfo-object
1646 show remote read-siginfo-object
1647 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
1650 set remote write-siginfo-object
1651 show remote write-siginfo-object
1652 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
1655 set remote reverse-continue
1656 show remote reverse-continue
1657 Control use of remote protocol 'bc' (reverse-continue) packet.
1659 set remote reverse-step
1660 show remote reverse-step
1661 Control use of remote protocol 'bs' (reverse-step) packet.
1663 set displaced-stepping
1664 show displaced-stepping
1665 Control displaced stepping mode. Displaced stepping is a way to
1666 single-step over breakpoints without removing them from the debuggee.
1667 Also known as "out-of-line single-stepping".
1670 show debug displaced
1671 Control display of debugging info for displaced stepping.
1673 maint set internal-error
1674 maint show internal-error
1675 Control what GDB does when an internal error is detected.
1677 maint set internal-warning
1678 maint show internal-warning
1679 Control what GDB does when an internal warning is detected.
1684 Use a wrapper program to launch programs for debugging.
1686 set multiple-symbols (all|ask|cancel)
1687 show multiple-symbols
1688 The value of this variable can be changed to adjust the debugger behavior
1689 when an expression or a breakpoint location contains an ambiguous symbol
1690 name (an overloaded function name, for instance).
1692 set breakpoint always-inserted
1693 show breakpoint always-inserted
1694 Keep breakpoints always inserted in the target, as opposed to inserting
1695 them when resuming the target, and removing them when the target stops.
1696 This option can improve debugger performance on slow remote targets.
1698 set arm fallback-mode (arm|thumb|auto)
1699 show arm fallback-mode
1700 set arm force-mode (arm|thumb|auto)
1702 These commands control how ARM GDB determines whether instructions
1703 are ARM or Thumb. The default for both settings is auto, which uses
1704 the current CPSR value for instructions without symbols; previous
1705 versions of GDB behaved as if "set arm fallback-mode arm".
1707 set disable-randomization
1708 show disable-randomization
1709 Standalone programs run with the virtual address space randomization enabled
1710 by default on some platforms. This option keeps the addresses stable across
1711 multiple debugging sessions.
1715 Control whether other threads are stopped or not when some thread hits
1720 Requests that asynchronous execution is enabled in the target, if available.
1721 In this case, it's possible to resume target in the background, and interact
1722 with GDB while the target is running. "show target-async" displays the
1723 current state of asynchronous execution of the target.
1725 set target-wide-charset
1726 show target-wide-charset
1727 The target-wide-charset is the name of the character set that GDB
1728 uses when printing characters whose type is wchar_t.
1730 set tcp auto-retry (on|off)
1732 set tcp connect-timeout
1733 show tcp connect-timeout
1734 These commands allow GDB to retry failed TCP connections to a remote stub
1735 with a specified timeout period; this is useful if the stub is launched
1736 in parallel with GDB but may not be ready to accept connections immediately.
1738 set libthread-db-search-path
1739 show libthread-db-search-path
1740 Control list of directories which GDB will search for appropriate
1743 set schedule-multiple (on|off)
1744 show schedule-multiple
1745 Allow GDB to resume all threads of all processes or only threads of
1746 the current process.
1750 Use more aggressive caching for accesses to the stack. This improves
1751 performance of remote debugging (particularly backtraces) without
1752 affecting correctness.
1754 set interactive-mode (on|off|auto)
1755 show interactive-mode
1756 Control whether GDB runs in interactive mode (on) or not (off).
1757 When in interactive mode, GDB waits for the user to answer all
1758 queries. Otherwise, GDB does not wait and assumes the default
1759 answer. When set to auto (the default), GDB determines which
1760 mode to use based on the stdin settings.
1765 For program forks, this is replaced by the new more generic `info
1766 inferiors' command. To list checkpoints, you can still use the
1767 `info checkpoints' command, which was an alias for the `info forks'
1771 Replaced by the new `inferior' command. To switch between
1772 checkpoints, you can still use the `restart' command, which was an
1773 alias for the `fork' command.
1776 This is removed, since some targets don't have a notion of
1777 processes. To switch between processes, you can still use the
1778 `inferior' command using GDB's own inferior number.
1781 For program forks, this is replaced by the new more generic `kill
1782 inferior' command. To delete a checkpoint, you can still use the
1783 `delete checkpoint' command, which was an alias for the `delete
1787 For program forks, this is replaced by the new more generic `detach
1788 inferior' command. To detach a checkpoint, you can still use the
1789 `detach checkpoint' command, which was an alias for the `detach
1792 * New native configurations
1794 x86/x86_64 Darwin i[34567]86-*-darwin*
1796 x86_64 MinGW x86_64-*-mingw*
1800 Lattice Mico32 lm32-*
1801 x86 DICOS i[34567]86-*-dicos*
1802 x86_64 DICOS x86_64-*-dicos*
1805 * The GDB remote stub, gdbserver, now supports x86 Windows CE
1806 (mingw32ce) debugging.
1812 These commands were actually not implemented on any target.
1814 *** Changes in GDB 6.8
1816 * New native configurations
1818 NetBSD/hppa hppa*-*netbsd*
1819 Xtensa GNU/Linux xtensa*-*-linux*
1823 NetBSD/hppa hppa*-*-netbsd*
1824 Xtensa GNU/Lunux xtensa*-*-linux*
1826 * Change in command line behavior -- corefiles vs. process ids.
1828 When the '-p NUMBER' or '--pid NUMBER' options are used, and
1829 attaching to process NUMBER fails, GDB no longer attempts to open a
1830 core file named NUMBER. Attaching to a program using the -c option
1831 is no longer supported. Instead, use the '-p' or '--pid' options.
1833 * GDB can now be built as a native debugger for debugging Windows x86
1834 (mingw32) Portable Executable (PE) programs.
1836 * Pending breakpoints no longer change their number when their address
1839 * GDB now supports breakpoints with multiple locations,
1840 including breakpoints on C++ constructors, inside C++ templates,
1841 and in inlined functions.
1843 * GDB's ability to debug optimized code has been improved. GDB more
1844 accurately identifies function bodies and lexical blocks that occupy
1845 more than one contiguous range of addresses.
1847 * Target descriptions can now describe registers for PowerPC.
1849 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
1850 registers on PowerPC targets.
1852 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
1853 targets even when the libthread_db library is not available.
1855 * The GDB remote stub, gdbserver, now supports the new file transfer
1856 commands (remote put, remote get, and remote delete).
1858 * The GDB remote stub, gdbserver, now supports run and attach in
1859 extended-remote mode.
1861 * hppa*64*-*-hpux11* target broken
1862 The debugger is unable to start a program and fails with the following
1863 error: "Error trying to get information about dynamic linker".
1864 The gdb-6.7 release is also affected.
1866 * GDB now supports the --enable-targets= configure option to allow
1867 building a single GDB executable that supports multiple remote
1868 target architectures.
1870 * GDB now supports debugging C and C++ programs which use the
1871 Decimal Floating Point extension. In addition, the PowerPC target
1872 now has a set of pseudo-registers to inspect decimal float values
1873 stored in two consecutive float registers.
1875 * The -break-insert MI command can optionally create pending
1878 * Improved support for debugging Ada
1879 Many improvements to the Ada language support have been made. These
1881 - Better support for Ada2005 interface types
1882 - Improved handling of arrays and slices in general
1883 - Better support for Taft-amendment types
1884 - The '{type} ADDRESS' expression is now allowed on the left hand-side
1886 - Improved command completion in Ada
1889 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
1894 set print frame-arguments (all|scalars|none)
1895 show print frame-arguments
1896 The value of this variable can be changed to control which argument
1897 values should be printed by the debugger when displaying a frame.
1902 Transfer files to and from a remote target, and delete remote files.
1909 Transfer files to and from a remote target, and delete remote files.
1911 * New remote packets
1918 Open, close, read, write, and delete files on the remote system.
1921 Attach to an existing process on the remote system, in extended-remote
1925 Run a new process on the remote system, in extended-remote mode.
1927 *** Changes in GDB 6.7
1929 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
1930 bfd, libiberty and opcodes, as revealed by static analysis donated by
1931 Coverity, Inc. (http://scan.coverity.com).
1933 * When looking up multiply-defined global symbols, GDB will now prefer the
1934 symbol definition in the current shared library if it was built using the
1935 -Bsymbolic linker option.
1937 * When the Text User Interface (TUI) is not configured, GDB will now
1938 recognize the -tui command-line option and print a message that the TUI
1941 * The GDB remote stub, gdbserver, now has lower overhead for high
1942 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
1944 * GDB for MIPS targets now autodetects whether a remote target provides
1945 32-bit or 64-bit register values.
1947 * Support for C++ member pointers has been improved.
1949 * GDB now understands XML target descriptions, which specify the
1950 target's overall architecture. GDB can read a description from
1951 a local file or over the remote serial protocol.
1953 * Vectors of single-byte data use a new integer type which is not
1954 automatically displayed as character or string data.
1956 * The /s format now works with the print command. It displays
1957 arrays of single-byte integers and pointers to single-byte integers
1960 * Target descriptions can now describe target-specific registers,
1961 for architectures which have implemented the support (currently
1962 only ARM, M68K, and MIPS).
1964 * GDB and the GDB remote stub, gdbserver, now support the XScale
1967 * The GDB remote stub, gdbserver, has been updated to support
1968 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
1969 has been rewritten to use the standard GDB remote protocol.
1971 * GDB can now step into C++ functions which are called through thunks.
1973 * GDB for the Cell/B.E. SPU now supports overlay debugging.
1975 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
1976 layout. It also supports a TextSeg= and DataSeg= response when only
1977 segment base addresses (rather than offsets) are available.
1979 * The /i format now outputs any trailing branch delay slot instructions
1980 immediately following the last instruction within the count specified.
1982 * The GDB remote protocol "T" stop reply packet now supports a
1983 "library" response. Combined with the new "qXfer:libraries:read"
1984 packet, this response allows GDB to debug shared libraries on targets
1985 where the operating system manages the list of loaded libraries (e.g.
1986 Windows and SymbianOS).
1988 * The GDB remote stub, gdbserver, now supports dynamic link libraries
1989 (DLLs) on Windows and Windows CE targets.
1991 * GDB now supports a faster verification that a .debug file matches its binary
1992 according to its build-id signature, if the signature is present.
1998 Enable or disable hardware flow control (RTS/CTS) on the serial port
1999 when debugging using remote targets.
2001 set mem inaccessible-by-default
2002 show mem inaccessible-by-default
2003 If the target supplies a memory map, for instance via the remote
2004 protocol's "qXfer:memory-map:read" packet, setting this variable
2005 prevents GDB from accessing memory outside the memory map. This
2006 is useful for targets with memory mapped registers or which react
2007 badly to accesses of unmapped address space.
2009 set breakpoint auto-hw
2010 show breakpoint auto-hw
2011 If the target supplies a memory map, for instance via the remote
2012 protocol's "qXfer:memory-map:read" packet, setting this variable
2013 lets GDB use hardware breakpoints automatically for memory regions
2014 where it can not use software breakpoints. This covers both the
2015 "break" command and internal breakpoints used for other commands
2016 including "next" and "finish".
2019 catch exception unhandled
2020 Stop the program execution when Ada exceptions are raised.
2023 Stop the program execution when an Ada assertion failed.
2027 Set an alternate system root for target files. This is a more
2028 general version of "set solib-absolute-prefix", which is now
2029 an alias to "set sysroot".
2032 Provide extended SPU facility status information. This set of
2033 commands is available only when debugging the Cell/B.E. SPU
2036 * New native configurations
2038 OpenBSD/sh sh*-*openbsd*
2041 unset tdesc filename
2043 Use the specified local file as an XML target description, and do
2044 not query the target for its built-in description.
2048 OpenBSD/sh sh*-*-openbsd*
2049 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2050 Toshiba Media Processor mep-elf
2052 * New remote packets
2055 Ignore the specified signals; pass them directly to the debugged program
2056 without stopping other threads or reporting them to GDB.
2058 qXfer:features:read:
2059 Read an XML target description from the target, which describes its
2064 Read or write contents of an spufs file on the target system. These
2065 packets are available only on the Cell/B.E. SPU architecture.
2067 qXfer:libraries:read:
2068 Report the loaded shared libraries. Combined with new "T" packet
2069 response, this packet allows GDB to debug shared libraries on
2070 targets where the operating system manages the list of loaded
2071 libraries (e.g. Windows and SymbianOS).
2075 Support for these obsolete configurations has been removed.
2083 i[34567]86-*-lynxos*
2084 i[34567]86-*-netware*
2085 i[34567]86-*-sco3.2v5*
2086 i[34567]86-*-sco3.2v4*
2088 i[34567]86-*-sysv4.2*
2091 i[34567]86-*-unixware2*
2092 i[34567]86-*-unixware*
2101 * Other removed features
2108 Various m68k-only ROM monitors.
2115 Various Renesas ROM monitors and debugging interfaces for SH and
2120 Support for a Macraigor serial interface to on-chip debugging.
2121 GDB does not directly support the newer parallel or USB
2126 A debug information format. The predecessor to DWARF 2 and
2127 DWARF 3, which are still supported.
2129 Support for the HP aCC compiler on HP-UX/PA-RISC
2131 SOM-encapsulated symbolic debugging information, automatic
2132 invocation of pxdb, and the aCC custom C++ ABI. This does not
2133 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2134 with aCC can still be debugged on an assembly level.
2136 MIPS ".pdr" sections
2138 A MIPS-specific format used to describe stack frame layout
2139 in debugging information.
2143 GDB could work with an older version of Guile to debug
2144 the interpreter and Scheme programs running in it.
2146 set mips stack-arg-size
2147 set mips saved-gpreg-size
2149 Use "set mips abi" to control parameter passing for MIPS.
2151 *** Changes in GDB 6.6
2156 Cell Broadband Engine SPU spu-elf
2158 * GDB can now be configured as a cross-debugger targeting native Windows
2159 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2160 running on a Windows system over TCP/IP to debug Windows programs.
2162 * The GDB remote stub, gdbserver, has been updated to support Windows and
2163 Cygwin debugging. Both single-threaded and multi-threaded programs are
2166 * The "set trust-readonly-sections" command works again. This command was
2167 broken in GDB 6.3, 6.4, and 6.5.
2169 * The "load" command now supports writing to flash memory, if the remote
2170 stub provides the required support.
2172 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2173 longer requires symbolic debug information (e.g. DWARF-2).
2178 unset substitute-path
2179 show substitute-path
2180 Manage a list of substitution rules that GDB uses to rewrite the name
2181 of the directories where the sources are located. This can be useful
2182 for instance when the sources were moved to a different location
2183 between compilation and debugging.
2187 Print each CLI command as it is executed. Each command is prefixed with
2188 a number of `+' symbols representing the nesting depth.
2189 The source command now has a `-v' option to enable the same feature.
2193 The ARM Demon monitor support (RDP protocol, "target rdp").
2195 Kernel Object Display, an embedded debugging feature which only worked with
2196 an obsolete version of Cisco IOS.
2198 The 'set download-write-size' and 'show download-write-size' commands.
2200 * New remote packets
2203 Tell a stub about GDB client features, and request remote target features.
2204 The first feature implemented is PacketSize, which allows the target to
2205 specify the size of packets it can handle - to minimize the number of
2206 packets required and improve performance when connected to a remote
2210 Fetch an OS auxilliary vector from the remote stub. This packet is a
2211 more efficient replacement for qPart:auxv:read.
2213 qXfer:memory-map:read:
2214 Fetch a memory map from the remote stub, including information about
2215 RAM, ROM, and flash memory devices.
2220 Erase and program a flash memory device.
2222 * Removed remote packets
2225 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2226 used it, and only gdbserver implemented it.
2228 *** Changes in GDB 6.5
2232 Renesas M32C/M16C m32c-elf
2234 Morpho Technologies ms1 ms1-elf
2238 init-if-undefined Initialize a convenience variable, but
2239 only if it doesn't already have a value.
2241 The following commands are presently only implemented for native GNU/Linux:
2243 checkpoint Save a snapshot of the program state.
2245 restart <n> Return the program state to a
2246 previously saved state.
2248 info checkpoints List currently saved checkpoints.
2250 delete-checkpoint <n> Delete a previously saved checkpoint.
2252 set|show detach-on-fork Tell gdb whether to detach from a newly
2253 forked process, or to keep debugging it.
2255 info forks List forks of the user program that
2256 are available to be debugged.
2258 fork <n> Switch to debugging one of several
2259 forks of the user program that are
2260 available to be debugged.
2262 delete-fork <n> Delete a fork from the list of forks
2263 that are available to be debugged (and
2264 kill the forked process).
2266 detach-fork <n> Delete a fork from the list of forks
2267 that are available to be debugged (and
2268 allow the process to continue).
2272 Morpho Technologies ms2 ms1-elf
2274 * Improved Windows host support
2276 GDB now builds as a cross debugger hosted on i686-mingw32, including
2277 native console support, and remote communications using either
2278 network sockets or serial ports.
2280 * Improved Modula-2 language support
2282 GDB can now print most types in the Modula-2 syntax. This includes:
2283 basic types, set types, record types, enumerated types, range types,
2284 pointer types and ARRAY types. Procedure var parameters are correctly
2285 printed and hexadecimal addresses and character constants are also
2286 written in the Modula-2 syntax. Best results can be obtained by using
2287 GNU Modula-2 together with the -gdwarf-2 command line option.
2291 The ARM rdi-share module.
2293 The Netware NLM debug server.
2295 *** Changes in GDB 6.4
2297 * New native configurations
2299 OpenBSD/arm arm*-*-openbsd*
2300 OpenBSD/mips64 mips64-*-openbsd*
2304 Morpho Technologies ms1 ms1-elf
2306 * New command line options
2308 --batch-silent As for --batch, but totally silent.
2309 --return-child-result The debugger will exist with the same value
2310 the child (debugged) program exited with.
2311 --eval-command COMMAND, -ex COMMAND
2312 Execute a single GDB CLI command. This may be
2313 specified multiple times and in conjunction
2314 with the --command (-x) option.
2316 * Deprecated commands removed
2318 The following commands, that were deprecated in 2000, have been
2322 set|show arm disassembly-flavor set|show arm disassembler
2323 othernames set arm disassembler
2324 set|show remotedebug set|show debug remote
2325 set|show archdebug set|show debug arch
2326 set|show eventdebug set|show debug event
2329 * New BSD user-level threads support
2331 It is now possible to debug programs using the user-level threads
2332 library on OpenBSD and FreeBSD. Currently supported (target)
2335 FreeBSD/amd64 x86_64-*-freebsd*
2336 FreeBSD/i386 i386-*-freebsd*
2337 OpenBSD/i386 i386-*-openbsd*
2339 Note that the new kernel threads libraries introduced in FreeBSD 5.x
2340 are not yet supported.
2342 * New support for Matsushita MN10300 w/sim added
2343 (Work in progress). mn10300-elf.
2345 * REMOVED configurations and files
2347 VxWorks and the XDR protocol *-*-vxworks
2348 Motorola MCORE mcore-*-*
2349 National Semiconductor NS32000 ns32k-*-*
2351 * New "set print array-indexes" command
2353 After turning this setting "on", GDB prints the index of each element
2354 when displaying arrays. The default is "off" to preserve the previous
2357 * VAX floating point support
2359 GDB now supports the not-quite-ieee VAX F and D floating point formats.
2361 * User-defined command support
2363 In addition to using $arg0..$arg9 for argument passing, it is now possible
2364 to use $argc to determine now many arguments have been passed. See the
2365 section on user-defined commands in the user manual for more information.
2367 *** Changes in GDB 6.3:
2369 * New command line option
2371 GDB now accepts -l followed by a number to set the timeout for remote
2374 * GDB works with GCC -feliminate-dwarf2-dups
2376 GDB now supports a more compact representation of DWARF-2 debug
2377 information using DW_FORM_ref_addr references. These are produced
2378 by GCC with the option -feliminate-dwarf2-dups and also by some
2379 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
2380 to use -feliminate-dwarf2-dups.
2382 * Internationalization
2384 When supported by the host system, GDB will be built with
2385 internationalization (libintl). The task of marking up the sources is
2386 continued, we're looking forward to our first translation.
2390 Initial support for debugging programs compiled with the GNAT
2391 implementation of the Ada programming language has been integrated
2392 into GDB. In this release, support is limited to expression evaluation.
2394 * New native configurations
2396 GNU/Linux/m32r m32r-*-linux-gnu
2400 GDB's remote protocol now includes support for the 'p' packet. This
2401 packet is used to fetch individual registers from a remote inferior.
2403 * END-OF-LIFE registers[] compatibility module
2405 GDB's internal register infrastructure has been completely rewritten.
2406 The new infrastructure making possible the implementation of key new
2407 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
2410 GDB 6.3 will be the last release to include the the registers[]
2411 compatibility module that allowed out-of-date configurations to
2412 continue to work. This change directly impacts the following
2422 powerpc bdm protocol
2424 Unless there is activity to revive these configurations, they will be
2425 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
2427 * OBSOLETE configurations and files
2429 Configurations that have been declared obsolete in this release have
2430 been commented out. Unless there is activity to revive these
2431 configurations, the next release of GDB will have their sources
2432 permanently REMOVED.
2441 *** Changes in GDB 6.2.1:
2443 * MIPS `break main; run' gave an heuristic-fence-post warning
2445 When attempting to run even a simple program, a warning about
2446 heuristic-fence-post being hit would be reported. This problem has
2449 * MIPS IRIX 'long double' crashed GDB
2451 When examining a long double variable, GDB would get a segmentation
2452 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
2453 IRIX long double values).
2457 A bug in the VAX stack code was causing problems with the "next"
2458 command. This problem has been fixed.
2460 *** Changes in GDB 6.2:
2462 * Fix for ``many threads''
2464 On GNU/Linux systems that use the NPTL threads library, a program
2465 rapidly creating and deleting threads would confuse GDB leading to the
2468 ptrace: No such process.
2469 thread_db_get_info: cannot get thread info: generic error
2471 This problem has been fixed.
2473 * "-async" and "-noasync" options removed.
2475 Support for the broken "-noasync" option has been removed (it caused
2478 * New ``start'' command.
2480 This command runs the program until the begining of the main procedure.
2482 * New BSD Kernel Data Access Library (libkvm) interface
2484 Using ``target kvm'' it is now possible to debug kernel core dumps and
2485 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
2486 platforms. Currently supported (native-only) configurations are:
2488 FreeBSD/amd64 x86_64-*-freebsd*
2489 FreeBSD/i386 i?86-*-freebsd*
2490 NetBSD/i386 i?86-*-netbsd*
2491 NetBSD/m68k m68*-*-netbsd*
2492 NetBSD/sparc sparc-*-netbsd*
2493 OpenBSD/amd64 x86_64-*-openbsd*
2494 OpenBSD/i386 i?86-*-openbsd*
2495 OpenBSD/m68k m68*-openbsd*
2496 OpenBSD/sparc sparc-*-openbsd*
2498 * Signal trampoline code overhauled
2500 Many generic problems with GDB's signal handling code have been fixed.
2501 These include: backtraces through non-contiguous stacks; recognition
2502 of sa_sigaction signal trampolines; backtrace from a NULL pointer
2503 call; backtrace through a signal trampoline; step into and out of
2504 signal handlers; and single-stepping in the signal trampoline.
2506 Please note that kernel bugs are a limiting factor here. These
2507 features have been shown to work on an s390 GNU/Linux system that
2508 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
2510 * Cygwin support for DWARF 2 added.
2512 * New native configurations
2514 GNU/Linux/hppa hppa*-*-linux*
2515 OpenBSD/hppa hppa*-*-openbsd*
2516 OpenBSD/m68k m68*-*-openbsd*
2517 OpenBSD/m88k m88*-*-openbsd*
2518 OpenBSD/powerpc powerpc-*-openbsd*
2519 NetBSD/vax vax-*-netbsd*
2520 OpenBSD/vax vax-*-openbsd*
2522 * END-OF-LIFE frame compatibility module
2524 GDB's internal frame infrastructure has been completely rewritten.
2525 The new infrastructure making it possible to support key new features
2526 including DWARF 2 Call Frame Information. To aid in the task of
2527 migrating old configurations to this new infrastructure, a
2528 compatibility module, that allowed old configurations to continue to
2529 work, was also included.
2531 GDB 6.2 will be the last release to include this frame compatibility
2532 module. This change directly impacts the following configurations:
2542 Unless there is activity to revive these configurations, they will be
2543 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
2545 * REMOVED configurations and files
2547 Sun 3, running SunOS 3 m68*-*-sunos3*
2548 Sun 3, running SunOS 4 m68*-*-sunos4*
2549 Sun 2, running SunOS 3 m68000-*-sunos3*
2550 Sun 2, running SunOS 4 m68000-*-sunos4*
2551 Motorola 680x0 running LynxOS m68*-*-lynxos*
2552 AT&T 3b1/Unix pc m68*-att-*
2553 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2554 decstation mips-dec-* mips-little-*
2555 riscos mips-*-riscos* mips-*-sysv*
2556 sonymips mips-sony-*
2557 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2559 *** Changes in GDB 6.1.1:
2561 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
2563 The TUI (Text-mode User Interface) is now built as part of a default
2564 GDB configuration. It is enabled by either selecting the TUI with the
2565 command line option "-i=tui" or by running the separate "gdbtui"
2566 program. For more information on the TUI, see the manual "Debugging
2569 * Pending breakpoint support (also included in GDB 6.1)
2571 Support has been added to allow you to specify breakpoints in shared
2572 libraries that have not yet been loaded. If a breakpoint location
2573 cannot be found, and the "breakpoint pending" option is set to auto,
2574 GDB queries you if you wish to make the breakpoint pending on a future
2575 shared-library load. If and when GDB resolves the breakpoint symbol,
2576 the pending breakpoint is removed as one or more regular breakpoints
2579 Pending breakpoints are very useful for GCJ Java debugging.
2581 * Fixed ISO-C build problems
2583 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
2584 non ISO-C code that stopped them being built using a more strict ISO-C
2585 compiler (e.g., IBM's C compiler).
2587 * Fixed build problem on IRIX 5
2589 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
2590 wasn't able to compile compile on an IRIX 5 system.
2592 * Added execute permission to gdb/gdbserver/configure
2594 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
2595 permission. This bug would cause configure to fail on a number of
2596 systems (Solaris, IRIX). Ref: server/519.
2598 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
2600 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
2601 has been updated to use constant array sizes.
2603 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
2605 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
2606 its generated DWARF Call Frame Info. This encoding was causing GDB to
2607 panic, that panic has been fixed. Ref: gdb/1628.
2609 * Fixed a problem when examining parameters in shared library code.
2611 When examining parameters in optimized shared library code generated
2612 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
2613 not available''. GDB now correctly displays the variable's value.
2615 *** Changes in GDB 6.1:
2617 * Removed --with-mmalloc
2619 Support for the mmalloc memory manager has been removed, as it
2620 conflicted with the internal gdb byte cache.
2622 * Changes in AMD64 configurations
2624 The AMD64 target now includes the %cs and %ss registers. As a result
2625 the AMD64 remote protocol has changed; this affects the floating-point
2626 and SSE registers. If you rely on those registers for your debugging,
2627 you should upgrade gdbserver on the remote side.
2629 * Revised SPARC target
2631 The SPARC target has been completely revised, incorporating the
2632 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
2633 support for LynxOS and SunOS 4 has been dropped. Calling functions
2634 from within GDB on operating systems with a non-executable stack
2635 (Solaris, OpenBSD) now works.
2639 GDB has a new C++ demangler which does a better job on the mangled
2640 names generated by current versions of g++. It also runs faster, so
2641 with this and other changes gdb should now start faster on large C++
2644 * DWARF 2 Location Expressions
2646 GDB support for location expressions has been extended to support function
2647 arguments and frame bases. Older versions of GDB could crash when they
2650 * C++ nested types and namespaces
2652 GDB's support for nested types and namespaces in C++ has been
2653 improved, especially if you use the DWARF 2 debugging format. (This
2654 is the default for recent versions of GCC on most platforms.)
2655 Specifically, if you have a class "Inner" defined within a class or
2656 namespace "Outer", then GDB realizes that the class's name is
2657 "Outer::Inner", not simply "Inner". This should greatly reduce the
2658 frequency of complaints about not finding RTTI symbols. In addition,
2659 if you are stopped at inside of a function defined within a namespace,
2660 GDB modifies its name lookup accordingly.
2662 * New native configurations
2664 NetBSD/amd64 x86_64-*-netbsd*
2665 OpenBSD/amd64 x86_64-*-openbsd*
2666 OpenBSD/alpha alpha*-*-openbsd*
2667 OpenBSD/sparc sparc-*-openbsd*
2668 OpenBSD/sparc64 sparc64-*-openbsd*
2670 * New debugging protocols
2672 M32R with SDI protocol m32r-*-elf*
2674 * "set prompt-escape-char" command deleted.
2676 The command "set prompt-escape-char" has been deleted. This command,
2677 and its very obscure effet on GDB's prompt, was never documented,
2678 tested, nor mentioned in the NEWS file.
2680 * OBSOLETE configurations and files
2682 Configurations that have been declared obsolete in this release have
2683 been commented out. Unless there is activity to revive these
2684 configurations, the next release of GDB will have their sources
2685 permanently REMOVED.
2687 Sun 3, running SunOS 3 m68*-*-sunos3*
2688 Sun 3, running SunOS 4 m68*-*-sunos4*
2689 Sun 2, running SunOS 3 m68000-*-sunos3*
2690 Sun 2, running SunOS 4 m68000-*-sunos4*
2691 Motorola 680x0 running LynxOS m68*-*-lynxos*
2692 AT&T 3b1/Unix pc m68*-att-*
2693 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2694 decstation mips-dec-* mips-little-*
2695 riscos mips-*-riscos* mips-*-sysv*
2696 sonymips mips-sony-*
2697 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2699 * REMOVED configurations and files
2701 SGI Irix-4.x mips-sgi-irix4 or iris4
2702 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
2703 Z8000 simulator z8k-zilog-none or z8ksim
2704 Matsushita MN10200 w/simulator mn10200-*-*
2705 H8/500 simulator h8500-hitachi-hms or h8500hms
2706 HP/PA running BSD hppa*-*-bsd*
2707 HP/PA running OSF/1 hppa*-*-osf*
2708 HP/PA Pro target hppa*-*-pro*
2709 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2710 386BSD i[3456]86-*-bsd*
2711 Sequent family i[3456]86-sequent-sysv4*
2712 i[3456]86-sequent-sysv*
2713 i[3456]86-sequent-bsd*
2714 SPARC running LynxOS sparc-*-lynxos*
2715 SPARC running SunOS 4 sparc-*-sunos4*
2716 Tsqware Sparclet sparclet-*-*
2717 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2719 *** Changes in GDB 6.0:
2723 Support for debugging the Objective-C programming language has been
2724 integrated into GDB.
2726 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
2728 DWARF 2's Call Frame Information makes available compiler generated
2729 information that more exactly describes the program's run-time stack.
2730 By using this information, GDB is able to provide more robust stack
2733 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
2734 have been updated to use a new backtrace mechanism which includes
2735 DWARF 2 CFI support.
2739 GDB's remote protocol has been extended to include support for hosted
2740 file I/O (where the remote target uses GDB's file system). See GDB's
2741 remote protocol documentation for details.
2743 * All targets using the new architecture framework.
2745 All of GDB's targets have been updated to use the new internal
2746 architecture framework. The way is now open for future GDB releases
2747 to include cross-architecture native debugging support (i386 on amd64,
2750 * GNU/Linux's Thread Local Storage (TLS)
2752 GDB now includes support for for the GNU/Linux implementation of
2753 per-thread variables.
2755 * GNU/Linux's Native POSIX Thread Library (NPTL)
2757 GDB's thread code has been updated to work with either the new
2758 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
2760 * Separate debug info.
2762 GDB, in conjunction with BINUTILS, now supports a mechanism for
2763 automatically loading debug information from a separate file. Instead
2764 of shipping full debug and non-debug versions of system libraries,
2765 system integrators can now instead ship just the stripped libraries
2766 and optional debug files.
2768 * DWARF 2 Location Expressions
2770 DWARF 2 Location Expressions allow the compiler to more completely
2771 describe the location of variables (even in optimized code) to the
2774 GDB now includes preliminary support for location expressions (support
2775 for DW_OP_piece is still missing).
2779 A number of long standing bugs that caused GDB to die while starting a
2780 Java application have been fixed. GDB's Java support is now
2781 considered "useable".
2783 * GNU/Linux support for fork, vfork, and exec.
2785 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
2786 commands are now implemented for GNU/Linux. They require a 2.5.x or later
2789 * GDB supports logging output to a file
2791 There are two new commands, "set logging" and "show logging", which can be
2792 used to capture GDB's output to a file.
2794 * The meaning of "detach" has changed for gdbserver
2796 The "detach" command will now resume the application, as documented. To
2797 disconnect from gdbserver and leave it stopped, use the new "disconnect"
2800 * d10v, m68hc11 `regs' command deprecated
2802 The `info registers' command has been updated so that it displays the
2803 registers using a format identical to the old `regs' command.
2807 A new command, "maint set profile on/off", has been added. This command can
2808 be used to enable or disable profiling while running GDB, to profile a
2809 session or a set of commands. In addition there is a new configure switch,
2810 "--enable-profiling", which will cause GDB to be compiled with profiling
2811 data, for more informative profiling results.
2813 * Default MI syntax changed to "mi2".
2815 The default MI (machine interface) syntax, enabled by the command line
2816 option "-i=mi", has been changed to "mi2". The previous MI syntax,
2817 "mi1", can be enabled by specifying the option "-i=mi1".
2819 Support for the original "mi0" syntax (included in GDB 5.0) has been
2822 Fix for gdb/192: removed extraneous space when displaying frame level.
2823 Fix for gdb/672: update changelist is now output in mi list format.
2824 Fix for gdb/702: a -var-assign that updates the value now shows up
2825 in a subsequent -var-update.
2827 * New native configurations.
2829 FreeBSD/amd64 x86_64-*-freebsd*
2831 * Multi-arched targets.
2833 HP/PA HPUX11 hppa*-*-hpux*
2834 Renesas M32R/D w/simulator m32r-*-elf*
2836 * OBSOLETE configurations and files
2838 Configurations that have been declared obsolete in this release have
2839 been commented out. Unless there is activity to revive these
2840 configurations, the next release of GDB will have their sources
2841 permanently REMOVED.
2843 Z8000 simulator z8k-zilog-none or z8ksim
2844 Matsushita MN10200 w/simulator mn10200-*-*
2845 H8/500 simulator h8500-hitachi-hms or h8500hms
2846 HP/PA running BSD hppa*-*-bsd*
2847 HP/PA running OSF/1 hppa*-*-osf*
2848 HP/PA Pro target hppa*-*-pro*
2849 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2850 Sequent family i[3456]86-sequent-sysv4*
2851 i[3456]86-sequent-sysv*
2852 i[3456]86-sequent-bsd*
2853 Tsqware Sparclet sparclet-*-*
2854 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2856 * REMOVED configurations and files
2859 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2860 IBM AIX PS/2 i[3456]86-*-aix
2861 i386 running Mach 3.0 i[3456]86-*-mach3*
2862 i386 running Mach i[3456]86-*-mach*
2863 i386 running OSF/1 i[3456]86-*osf1mk*
2864 HP/Apollo 68k Family m68*-apollo*-sysv*,
2866 m68*-hp-bsd*, m68*-hp-hpux*
2867 Argonaut Risc Chip (ARC) arc-*-*
2868 Mitsubishi D30V d30v-*-*
2869 Fujitsu FR30 fr30-*-elf*
2870 OS/9000 i[34]86-*-os9k
2871 I960 with MON960 i960-*-coff
2873 * MIPS $fp behavior changed
2875 The convenience variable $fp, for the MIPS, now consistently returns
2876 the address of the current frame's base. Previously, depending on the
2877 context, $fp could refer to either $sp or the current frame's base
2878 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
2879 The GNU Source-Level Debugger''.
2881 *** Changes in GDB 5.3:
2883 * GNU/Linux shared library multi-threaded performance improved.
2885 When debugging a multi-threaded application on GNU/Linux, GDB now uses
2886 `/proc', in preference to `ptrace' for memory reads. This may result
2887 in an improvement in the start-up time of multi-threaded, shared
2888 library applications when run under GDB. One GDB user writes: ``loads
2889 shared libs like mad''.
2891 * ``gdbserver'' now supports multi-threaded applications on some targets
2893 Support for debugging multi-threaded applications which use
2894 the GNU/Linux LinuxThreads package has been added for
2895 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
2896 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
2898 * GDB now supports C/C++ preprocessor macros.
2900 GDB now expands preprocessor macro invocations in C/C++ expressions,
2901 and provides various commands for showing macro definitions and how
2904 The new command `macro expand EXPRESSION' expands any macro
2905 invocations in expression, and shows the result.
2907 The new command `show macro MACRO-NAME' shows the definition of the
2908 macro named MACRO-NAME, and where it was defined.
2910 Most compilers don't include information about macros in the debugging
2911 information by default. In GCC 3.1, for example, you need to compile
2912 your program with the options `-gdwarf-2 -g3'. If the macro
2913 information is present in the executable, GDB will read it.
2915 * Multi-arched targets.
2917 DEC Alpha (partial) alpha*-*-*
2918 DEC VAX (partial) vax-*-*
2920 National Semiconductor NS32000 (partial) ns32k-*-*
2921 Motorola 68000 (partial) m68k-*-*
2922 Motorola MCORE mcore-*-*
2926 Fujitsu FRV architecture added by Red Hat frv*-*-*
2929 * New native configurations
2931 Alpha NetBSD alpha*-*-netbsd*
2932 SH NetBSD sh*-*-netbsdelf*
2933 MIPS NetBSD mips*-*-netbsd*
2934 UltraSPARC NetBSD sparc64-*-netbsd*
2936 * OBSOLETE configurations and files
2938 Configurations that have been declared obsolete in this release have
2939 been commented out. Unless there is activity to revive these
2940 configurations, the next release of GDB will have their sources
2941 permanently REMOVED.
2943 Mitsubishi D30V d30v-*-*
2944 OS/9000 i[34]86-*-os9k
2945 IBM AIX PS/2 i[3456]86-*-aix
2946 Fujitsu FR30 fr30-*-elf*
2947 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2948 Argonaut Risc Chip (ARC) arc-*-*
2949 i386 running Mach 3.0 i[3456]86-*-mach3*
2950 i386 running Mach i[3456]86-*-mach*
2951 i386 running OSF/1 i[3456]86-*osf1mk*
2952 HP/Apollo 68k Family m68*-apollo*-sysv*,
2954 m68*-hp-bsd*, m68*-hp-hpux*
2955 I960 with MON960 i960-*-coff
2957 * OBSOLETE languages
2959 CHILL, a Pascal like language used by telecommunications companies.
2961 * REMOVED configurations and files
2963 AMD 29k family via UDI a29k-amd-udi, udi29k
2964 A29K VxWorks a29k-*-vxworks
2965 AMD 29000 embedded, using EBMON a29k-none-none
2966 AMD 29000 embedded with COFF a29k-none-coff
2967 AMD 29000 embedded with a.out a29k-none-aout
2969 testsuite/gdb.hp/gdb.threads-hp/ directory
2971 * New command "set max-user-call-depth <nnn>"
2973 This command allows the user to limit the call depth of user-defined
2974 commands. The default is 1024.
2976 * Changes in FreeBSD/i386 native debugging.
2978 Support for the "generate-core-file" has been added.
2980 * New commands "dump", "append", and "restore".
2982 These commands allow data to be copied from target memory
2983 to a bfd-format or binary file (dump and append), and back
2984 from a file into memory (restore).
2986 * Improved "next/step" support on multi-processor Alpha Tru64.
2988 The previous single-step mechanism could cause unpredictable problems,
2989 including the random appearance of SIGSEGV or SIGTRAP signals. The use
2990 of a software single-step mechanism prevents this.
2992 *** Changes in GDB 5.2.1:
3000 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3001 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3002 Fix, by Joel Brobecker imported from mainline.
3004 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3005 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3006 Fix, by Fred Fish, imported from mainline.
3008 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3009 Surprisingly enough, it works now.
3010 By Michal Ludvig, imported from mainline.
3012 i386 hardware watchpoint support:
3013 avoid misses on second run for some targets.
3014 By Pierre Muller, imported from mainline.
3016 *** Changes in GDB 5.2:
3018 * New command "set trust-readonly-sections on[off]".
3020 This command is a hint that tells gdb that read-only sections
3021 really are read-only (ie. that their contents will not change).
3022 In this mode, gdb will go to the object file rather than the
3023 target to read memory from read-only sections (such as ".text").
3024 This can be a significant performance improvement on some
3025 (notably embedded) targets.
3027 * New command "generate-core-file" (or "gcore").
3029 This new gdb command allows the user to drop a core file of the child
3030 process state at any time. So far it's been implemented only for
3031 GNU/Linux and Solaris, but should be relatively easily ported to other
3032 hosts. Argument is core file name (defaults to core.<pid>).
3034 * New command line option
3036 GDB now accepts --pid or -p followed by a process id.
3038 * Change in command line behavior -- corefiles vs. process ids.
3040 There is a subtle behavior in the way in which GDB handles
3041 command line arguments. The first non-flag argument is always
3042 a program to debug, but the second non-flag argument may either
3043 be a corefile or a process id. Previously, GDB would attempt to
3044 open the second argument as a corefile, and if that failed, would
3045 issue a superfluous error message and then attempt to attach it as
3046 a process. Now, if the second argument begins with a non-digit,
3047 it will be treated as a corefile. If it begins with a digit,
3048 GDB will attempt to attach it as a process, and if no such process
3049 is found, will then attempt to open it as a corefile.
3051 * Changes in ARM configurations.
3053 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3054 configuration is fully multi-arch.
3056 * New native configurations
3058 ARM NetBSD arm*-*-netbsd*
3059 x86 OpenBSD i[3456]86-*-openbsd*
3060 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3061 Sparc64 running FreeBSD sparc64-*-freebsd*
3065 Sanyo XStormy16 xstormy16-elf
3067 * OBSOLETE configurations and files
3069 Configurations that have been declared obsolete in this release have
3070 been commented out. Unless there is activity to revive these
3071 configurations, the next release of GDB will have their sources
3072 permanently REMOVED.
3074 AMD 29k family via UDI a29k-amd-udi, udi29k
3075 A29K VxWorks a29k-*-vxworks
3076 AMD 29000 embedded, using EBMON a29k-none-none
3077 AMD 29000 embedded with COFF a29k-none-coff
3078 AMD 29000 embedded with a.out a29k-none-aout
3080 testsuite/gdb.hp/gdb.threads-hp/ directory
3082 * REMOVED configurations and files
3084 TI TMS320C80 tic80-*-*
3086 PowerPC Solaris powerpcle-*-solaris*
3087 PowerPC Windows NT powerpcle-*-cygwin32
3088 PowerPC Netware powerpc-*-netware*
3089 Harris/CXUX m88k m88*-harris-cxux*
3090 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3091 ns32k-utek-sysv* ns32k-utek-*
3092 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3093 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3094 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3095 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3096 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3098 * Changes to command line processing
3100 The new `--args' feature can be used to specify command-line arguments
3101 for the inferior from gdb's command line.
3103 * Changes to key bindings
3105 There is a new `operate-and-get-next' function bound to `C-o'.
3107 *** Changes in GDB 5.1.1
3109 Fix compile problem on DJGPP.
3111 Fix a problem with floating-point registers on the i386 being
3114 Fix to stop GDB crashing on .debug_str debug info.
3116 Numerous documentation fixes.
3118 Numerous testsuite fixes.
3120 *** Changes in GDB 5.1:
3122 * New native configurations
3124 Alpha FreeBSD alpha*-*-freebsd*
3125 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3126 MIPS GNU/Linux mips*-*-linux*
3127 MIPS SGI Irix 6.x mips*-sgi-irix6*
3128 ia64 AIX ia64-*-aix*
3129 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3133 Motorola 68HC11 and 68HC12 m68hc11-elf
3135 UltraSparc running GNU/Linux sparc64-*-linux*
3137 * OBSOLETE configurations and files
3139 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3140 Harris/CXUX m88k m88*-harris-cxux*
3141 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3142 ns32k-utek-sysv* ns32k-utek-*
3143 TI TMS320C80 tic80-*-*
3145 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3146 PowerPC Solaris powerpcle-*-solaris*
3147 PowerPC Windows NT powerpcle-*-cygwin32
3148 PowerPC Netware powerpc-*-netware*
3149 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3150 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3151 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3152 Apple Macintosh (MPW) host N/A
3154 stuff.c (Program to stuff files into a specially prepared space in kdb)
3155 kdb-start.c (Main loop for the standalone kernel debugger)
3157 Configurations that have been declared obsolete in this release have
3158 been commented out. Unless there is activity to revive these
3159 configurations, the next release of GDB will have their sources
3160 permanently REMOVED.
3162 * REMOVED configurations and files
3164 Altos 3068 m68*-altos-*
3165 Convex c1-*-*, c2-*-*
3167 ARM RISCix arm-*-* (as host)
3171 * GDB has been converted to ISO C.
3173 GDB's source code has been converted to ISO C. In particular, the
3174 sources are fully protoized, and rely on standard headers being
3179 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3181 * The MI enabled by default.
3183 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3184 revised and enabled by default. Packages which use GDB as a debugging
3185 engine behind a UI or another front end are encouraged to switch to
3186 using the GDB/MI interface, instead of the old annotations interface
3187 which is now deprecated.
3189 * Support for debugging Pascal programs.
3191 GDB now includes support for debugging Pascal programs. The following
3192 main features are supported:
3194 - Pascal-specific data types such as sets;
3196 - automatic recognition of Pascal sources based on file-name
3199 - Pascal-style display of data types, variables, and functions;
3201 - a Pascal expression parser.
3203 However, some important features are not yet supported.
3205 - Pascal string operations are not supported at all;
3207 - there are some problems with boolean types;
3209 - Pascal type hexadecimal constants are not supported
3210 because they conflict with the internal variables format;
3212 - support for Pascal objects and classes is not full yet;
3214 - unlike Pascal, GDB is case-sensitive for symbol names.
3216 * Changes in completion.
3218 Commands such as `shell', `run' and `set args', which pass arguments
3219 to inferior programs, now complete on file names, similar to what
3220 users expect at the shell prompt.
3222 Commands which accept locations, such as `disassemble', `print',
3223 `breakpoint', `until', etc. now complete on filenames as well as
3224 program symbols. Thus, if you type "break foob TAB", and the source
3225 files linked into the programs include `foobar.c', that file name will
3226 be one of the candidates for completion. However, file names are not
3227 considered for completion after you typed a colon that delimits a file
3228 name from a name of a function in that file, as in "break foo.c:bar".
3230 `set demangle-style' completes on available demangling styles.
3232 * New platform-independent commands:
3234 It is now possible to define a post-hook for a command as well as a
3235 hook that runs before the command. For more details, see the
3236 documentation of `hookpost' in the GDB manual.
3238 * Changes in GNU/Linux native debugging.
3240 Support for debugging multi-threaded programs has been completely
3241 revised for all platforms except m68k and sparc. You can now debug as
3242 many threads as your system allows you to have.
3244 Attach/detach is supported for multi-threaded programs.
3246 Support for SSE registers was added for x86. This doesn't work for
3247 multi-threaded programs though.
3249 * Changes in MIPS configurations.
3251 Multi-arch support is enabled for all MIPS configurations.
3253 GDB can now be built as native debugger on SGI Irix 6.x systems for
3254 debugging n32 executables. (Debugging 64-bit executables is not yet
3257 * Unified support for hardware watchpoints in all x86 configurations.
3259 Most (if not all) native x86 configurations support hardware-assisted
3260 breakpoints and watchpoints in a unified manner. This support
3261 implements debug register sharing between watchpoints, which allows to
3262 put a virtually infinite number of watchpoints on the same address,
3263 and also supports watching regions up to 16 bytes with several debug
3266 The new maintenance command `maintenance show-debug-regs' toggles
3267 debugging print-outs in functions that insert, remove, and test
3268 watchpoints and hardware breakpoints.
3270 * Changes in the DJGPP native configuration.
3272 New command ``info dos sysinfo'' displays assorted information about
3273 the CPU, OS, memory, and DPMI server.
3275 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
3276 display information about segment descriptors stored in GDT, LDT, and
3279 New commands ``info dos pde'' and ``info dos pte'' display entries
3280 from Page Directory and Page Tables (for now works with CWSDPMI only).
3281 New command ``info dos address-pte'' displays the Page Table entry for
3282 a given linear address.
3284 GDB can now pass command lines longer than 126 characters to the
3285 program being debugged (requires an update to the libdbg.a library
3286 which is part of the DJGPP development kit).
3288 DWARF2 debug info is now supported.
3290 It is now possible to `step' and `next' through calls to `longjmp'.
3292 * Changes in documentation.
3294 All GDB documentation was converted to GFDL, the GNU Free
3295 Documentation License.
3297 Tracepoints-related commands are now fully documented in the GDB
3300 TUI, the Text-mode User Interface, is now documented in the manual.
3302 Tracepoints-related commands are now fully documented in the GDB
3305 The "GDB Internals" manual now has an index. It also includes
3306 documentation of `ui_out' functions, GDB coding standards, x86
3307 hardware watchpoints, and memory region attributes.
3309 * GDB's version number moved to ``version.in''
3311 The Makefile variable VERSION has been replaced by the file
3312 ``version.in''. People creating GDB distributions should update the
3313 contents of this file.
3317 GUD support is now a standard part of the EMACS distribution.
3319 *** Changes in GDB 5.0:
3321 * Improved support for debugging FP programs on x86 targets
3323 Unified and much-improved support for debugging floating-point
3324 programs on all x86 targets. In particular, ``info float'' now
3325 displays the FP registers in the same format on all x86 targets, with
3326 greater level of detail.
3328 * Improvements and bugfixes in hardware-assisted watchpoints
3330 It is now possible to watch array elements, struct members, and
3331 bitfields with hardware-assisted watchpoints. Data-read watchpoints
3332 on x86 targets no longer erroneously trigger when the address is
3335 * Improvements in the native DJGPP version of GDB
3337 The distribution now includes all the scripts and auxiliary files
3338 necessary to build the native DJGPP version on MS-DOS/MS-Windows
3339 machines ``out of the box''.
3341 The DJGPP version can now debug programs that use signals. It is
3342 possible to catch signals that happened in the debuggee, deliver
3343 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
3344 would kill the program being debugged.) Programs that hook hardware
3345 interrupts (keyboard, timer, etc.) can also be debugged.
3347 It is now possible to debug DJGPP programs that redirect their
3348 standard handles or switch them to raw (as opposed to cooked) mode, or
3349 even close them. The command ``run < foo > bar'' works as expected,
3350 and ``info terminal'' reports useful information about the debuggee's
3351 terminal, including raw/cooked mode, redirection, etc.
3353 The DJGPP version now uses termios functions for console I/O, which
3354 enables debugging graphics programs. Interrupting GDB with Ctrl-C
3357 DOS-style file names with drive letters are now fully supported by
3360 It is now possible to debug DJGPP programs that switch their working
3361 directory. It is also possible to rerun the debuggee any number of
3362 times without restarting GDB; thus, you can use the same setup,
3363 breakpoints, etc. for many debugging sessions.
3365 * New native configurations
3367 ARM GNU/Linux arm*-*-linux*
3368 PowerPC GNU/Linux powerpc-*-linux*
3372 Motorola MCore mcore-*-*
3373 x86 VxWorks i[3456]86-*-vxworks*
3374 PowerPC VxWorks powerpc-*-vxworks*
3375 TI TMS320C80 tic80-*-*
3377 * OBSOLETE configurations
3379 Altos 3068 m68*-altos-*
3380 Convex c1-*-*, c2-*-*
3382 ARM RISCix arm-*-* (as host)
3385 Configurations that have been declared obsolete will be commented out,
3386 but the code will be left in place. If there is no activity to revive
3387 these configurations before the next release of GDB, the sources will
3388 be permanently REMOVED.
3390 * Gould support removed
3392 Support for the Gould PowerNode and NP1 has been removed.
3394 * New features for SVR4
3396 On SVR4 native platforms (such as Solaris), if you attach to a process
3397 without first loading a symbol file, GDB will now attempt to locate and
3398 load symbols from the running process's executable file.
3400 * Many C++ enhancements
3402 C++ support has been greatly improved. Overload resolution now works properly
3403 in almost all cases. RTTI support is on the way.
3405 * Remote targets can connect to a sub-program
3407 A popen(3) style serial-device has been added. This device starts a
3408 sub-process (such as a stand-alone simulator) and then communicates
3409 with that. The sub-program to run is specified using the syntax
3410 ``|<program> <args>'' vis:
3412 (gdb) set remotedebug 1
3413 (gdb) target extended-remote |mn10300-elf-sim program-args
3415 * MIPS 64 remote protocol
3417 A long standing bug in the mips64 remote protocol where by GDB
3418 expected certain 32 bit registers (ex SR) to be transfered as 32
3419 instead of 64 bits has been fixed.
3421 The command ``set remote-mips64-transfers-32bit-regs on'' has been
3422 added to provide backward compatibility with older versions of GDB.
3424 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
3426 The command ``set remotebinarydownload'' command has been replaced by
3427 ``set remote X-packet''. Other commands in ``set remote'' family
3428 include ``set remote P-packet''.
3430 * Breakpoint commands accept ranges.
3432 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
3433 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
3434 ``tracepoint passcount'' also accepts a range of tracepoints.
3436 * ``apropos'' command added.
3438 The ``apropos'' command searches through command names and
3439 documentation strings, printing out matches, making it much easier to
3440 try to find a command that does what you are looking for.
3444 A new machine oriented interface (MI) has been added to GDB. This
3445 interface is designed for debug environments running GDB as a separate
3446 process. This is part of the long term libGDB project. See the
3447 "GDB/MI" chapter of the GDB manual for further information. It can be
3448 enabled by configuring with:
3450 .../configure --enable-gdbmi
3452 *** Changes in GDB-4.18:
3454 * New native configurations
3456 HP-UX 10.20 hppa*-*-hpux10.20
3457 HP-UX 11.x hppa*-*-hpux11.0*
3458 M68K GNU/Linux m68*-*-linux*
3462 Fujitsu FR30 fr30-*-elf*
3463 Intel StrongARM strongarm-*-*
3464 Mitsubishi D30V d30v-*-*
3466 * OBSOLETE configurations
3468 Gould PowerNode, NP1 np1-*-*, pn-*-*
3470 Configurations that have been declared obsolete will be commented out,
3471 but the code will be left in place. If there is no activity to revive
3472 these configurations before the next release of GDB, the sources will
3473 be permanently REMOVED.
3477 As a compatibility experiment, GDB's source files buildsym.h and
3478 buildsym.c have been converted to pure standard C, no longer
3479 containing any K&R compatibility code. We believe that all systems in
3480 use today either come with a standard C compiler, or have a GCC port
3481 available. If this is not true, please report the affected
3482 configuration to bug-gdb@gnu.org immediately. See the README file for
3483 information about getting a standard C compiler if you don't have one
3488 GDB now uses readline 2.2.
3490 * set extension-language
3492 You can now control the mapping between filename extensions and source
3493 languages by using the `set extension-language' command. For instance,
3494 you can ask GDB to treat .c files as C++ by saying
3495 set extension-language .c c++
3496 The command `info extensions' lists all of the recognized extensions
3497 and their associated languages.
3499 * Setting processor type for PowerPC and RS/6000
3501 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
3502 you can use the `set processor' command to specify what variant of the
3503 PowerPC family you are debugging. The command
3507 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
3508 following PowerPC and RS6000 variants:
3510 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
3511 rs6000 IBM RS6000 ("POWER") architecture, user-level view
3513 403GC IBM PowerPC 403GC
3514 505 Motorola PowerPC 505
3515 860 Motorola PowerPC 860 or 850
3516 601 Motorola PowerPC 601
3517 602 Motorola PowerPC 602
3518 603 Motorola/IBM PowerPC 603 or 603e
3519 604 Motorola PowerPC 604 or 604e
3520 750 Motorola/IBM PowerPC 750 or 750
3522 At the moment, this command just tells GDB what to name the
3523 special-purpose processor registers. Since almost all the affected
3524 registers are inaccessible to user-level programs, this command is
3525 only useful for remote debugging in its present form.
3529 Thanks to a major code donation from Hewlett-Packard, GDB now has much
3530 more extensive support for HP-UX. Added features include shared
3531 library support, kernel threads and hardware watchpoints for 11.00,
3532 support for HP's ANSI C and C++ compilers, and a compatibility mode
3533 for xdb and dbx commands.
3537 HP's donation includes the new concept of catchpoints, which is a
3538 generalization of the old catch command. On HP-UX, it is now possible
3539 to catch exec, fork, and vfork, as well as library loading.
3541 This means that the existing catch command has changed; its first
3542 argument now specifies the type of catch to be set up. See the
3543 output of "help catch" for a list of catchpoint types.
3545 * Debugging across forks
3547 On HP-UX, you can choose which process to debug when a fork() happens
3552 HP has donated a curses-based terminal user interface (TUI). To get
3553 it, build with --enable-tui. Although this can be enabled for any
3554 configuration, at present it only works for native HP debugging.
3556 * GDB remote protocol additions
3558 A new protocol packet 'X' that writes binary data is now available.
3559 Default behavior is to try 'X', then drop back to 'M' if the stub
3560 fails to respond. The settable variable `remotebinarydownload'
3561 allows explicit control over the use of 'X'.
3563 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
3564 full 64-bit address. The command
3566 set remoteaddresssize 32
3568 can be used to revert to the old behaviour. For existing remote stubs
3569 the change should not be noticed, as the additional address information
3572 In order to assist in debugging stubs, you may use the maintenance
3573 command `packet' to send any text string to the stub. For instance,
3575 maint packet heythere
3577 sends the packet "$heythere#<checksum>". Note that it is very easy to
3578 disrupt a debugging session by sending the wrong packet at the wrong
3581 The compare-sections command allows you to compare section data on the
3582 target to what is in the executable file without uploading or
3583 downloading, by comparing CRC checksums.
3585 * Tracing can collect general expressions
3587 You may now collect general expressions at tracepoints. This requires
3588 further additions to the target-side stub; see tracepoint.c and
3589 doc/agentexpr.texi for further details.
3591 * mask-address variable for Mips
3593 For Mips targets, you may control the zeroing of the upper 32 bits of
3594 a 64-bit address by entering `set mask-address on'. This is mainly
3595 of interest to users of embedded R4xxx and R5xxx processors.
3597 * Higher serial baud rates
3599 GDB's serial code now allows you to specify baud rates 57600, 115200,
3600 230400, and 460800 baud. (Note that your host system may not be able
3601 to achieve all of these rates.)
3605 The i960 configuration now includes an initial implementation of a
3606 builtin simulator, contributed by Jim Wilson.
3609 *** Changes in GDB-4.17:
3611 * New native configurations
3613 Alpha GNU/Linux alpha*-*-linux*
3614 Unixware 2.x i[3456]86-unixware2*
3615 Irix 6.x mips*-sgi-irix6*
3616 PowerPC GNU/Linux powerpc-*-linux*
3617 PowerPC Solaris powerpcle-*-solaris*
3618 Sparc GNU/Linux sparc-*-linux*
3619 Motorola sysV68 R3V7.1 m68k-motorola-sysv
3623 Argonaut Risc Chip (ARC) arc-*-*
3624 Hitachi H8/300S h8300*-*-*
3625 Matsushita MN10200 w/simulator mn10200-*-*
3626 Matsushita MN10300 w/simulator mn10300-*-*
3627 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
3628 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
3629 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
3630 Mitsubishi D10V w/simulator d10v-*-*
3631 Mitsubishi M32R/D w/simulator m32r-*-elf*
3632 Tsqware Sparclet sparclet-*-*
3633 NEC V850 w/simulator v850-*-*
3635 * New debugging protocols
3637 ARM with RDI protocol arm*-*-*
3638 M68K with dBUG monitor m68*-*-{aout,coff,elf}
3639 DDB and LSI variants of PMON protocol mips*-*-*
3640 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
3641 PowerPC with SDS protocol powerpc{,le}-*-eabi
3642 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
3646 All configurations can now understand and use the DWARF 2 debugging
3647 format. The choice is automatic, if the symbol file contains DWARF 2
3652 GDB now includes basic Java language support. This support is
3653 only useful with Java compilers that produce native machine code.
3655 * solib-absolute-prefix and solib-search-path
3657 For SunOS and SVR4 shared libraries, you may now set the prefix for
3658 loading absolute shared library symbol files, and the search path for
3659 locating non-absolute shared library symbol files.
3661 * Live range splitting
3663 GDB can now effectively debug code for which GCC has performed live
3664 range splitting as part of its optimization. See gdb/doc/LRS for
3665 more details on the expected format of the stabs information.
3669 GDB's support for the GNU Hurd, including thread debugging, has been
3670 updated to work with current versions of the Hurd.
3674 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
3675 instruction set. ARM GDB automatically detects when Thumb
3676 instructions are in use, and adjusts disassembly and backtracing
3681 GDB's MIPS target configurations now handle the MIP16 16-bit
3686 GDB now includes support for overlays; if an executable has been
3687 linked such that multiple sections are based at the same address, GDB
3688 will decide which section to use for symbolic info. You can choose to
3689 control the decision manually, using overlay commands, or implement
3690 additional target-side support and use "overlay load-target" to bring
3691 in the overlay mapping. Do "help overlay" for more detail.
3695 The command "info symbol <address>" displays information about
3696 the symbol at the specified address.
3700 The standard remote protocol now includes an extension that allows
3701 asynchronous collection and display of trace data. This requires
3702 extensive support in the target-side debugging stub. Tracing mode
3703 includes a new interaction mode in GDB and new commands: see the
3704 file tracepoint.c for more details.
3708 Configurations for embedded MIPS now include a simulator contributed
3709 by Cygnus Solutions. The simulator supports the instruction sets
3710 of most MIPS variants.
3714 Sparc configurations may now include the ERC32 simulator contributed
3715 by the European Space Agency. The simulator is not built into
3716 Sparc targets by default; configure with --enable-sim to include it.
3720 For target configurations that may include multiple variants of a
3721 basic architecture (such as MIPS and SH), you may now set the
3722 architecture explicitly. "set arch" sets, "info arch" lists
3723 the possible architectures.
3725 *** Changes in GDB-4.16:
3727 * New native configurations
3729 Windows 95, x86 Windows NT i[345]86-*-cygwin32
3730 M68K NetBSD m68k-*-netbsd*
3731 PowerPC AIX 4.x powerpc-*-aix*
3732 PowerPC MacOS powerpc-*-macos*
3733 PowerPC Windows NT powerpcle-*-cygwin32
3734 RS/6000 AIX 4.x rs6000-*-aix4*
3738 ARM with RDP protocol arm-*-*
3739 I960 with MON960 i960-*-coff
3740 MIPS VxWorks mips*-*-vxworks*
3741 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
3742 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
3744 Matra Sparclet sparclet-*-*
3748 The powerpc-eabi configuration now includes the PSIM simulator,
3749 contributed by Andrew Cagney, with assistance from Mike Meissner.
3750 PSIM is a very elaborate model of the PowerPC, including not only
3751 basic instruction set execution, but also details of execution unit
3752 performance and I/O hardware. See sim/ppc/README for more details.
3756 GDB now works with Solaris 2.5.
3758 * Windows 95/NT native
3760 GDB will now work as a native debugger on Windows 95 and Windows NT.
3761 To build it from source, you must use the "gnu-win32" environment,
3762 which uses a DLL to emulate enough of Unix to run the GNU tools.
3763 Further information, binaries, and sources are available at
3764 ftp.cygnus.com, under pub/gnu-win32.
3766 * dont-repeat command
3768 If a user-defined command includes the command `dont-repeat', then the
3769 command will not be repeated if the user just types return. This is
3770 useful if the command is time-consuming to run, so that accidental
3771 extra keystrokes don't run the same command many times.
3773 * Send break instead of ^C
3775 The standard remote protocol now includes an option to send a break
3776 rather than a ^C to the target in order to interrupt it. By default,
3777 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
3779 * Remote protocol timeout
3781 The standard remote protocol includes a new variable `remotetimeout'
3782 that allows you to set the number of seconds before GDB gives up trying
3783 to read from the target. The default value is 2.
3785 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
3787 By default GDB will automatically keep track of objects as they are
3788 loaded and unloaded by the dynamic linker. By using the command `set
3789 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
3790 when shared library events occur, thus allowing you to set breakpoints
3791 in shared libraries which are explicitly loaded by the inferior.
3793 Note this feature does not work on hpux8. On hpux9 you must link
3794 /usr/lib/end.o into your program. This feature should work
3795 automatically on hpux10.
3797 * Irix 5.x hardware watchpoint support
3799 Irix 5 configurations now support the use of hardware watchpoints.
3801 * Mips protocol "SYN garbage limit"
3803 When debugging a Mips target using the `target mips' protocol, you
3804 may set the number of characters that GDB will ignore by setting
3805 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
3806 every character. The default value is 1050.
3808 * Recording and replaying remote debug sessions
3810 If you set `remotelogfile' to the name of a file, gdb will write to it
3811 a recording of a remote debug session. This recording may then be
3812 replayed back to gdb using "gdbreplay". See gdbserver/README for
3813 details. This is useful when you have a problem with GDB while doing
3814 remote debugging; you can make a recording of the session and send it
3815 to someone else, who can then recreate the problem.
3817 * Speedups for remote debugging
3819 GDB includes speedups for downloading and stepping MIPS systems using
3820 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
3821 and more efficient S-record downloading.
3823 * Memory use reductions and statistics collection
3825 GDB now uses less memory and reports statistics about memory usage.
3826 Try the `maint print statistics' command, for example.
3828 *** Changes in GDB-4.15:
3830 * Psymtabs for XCOFF
3832 The symbol reader for AIX GDB now uses partial symbol tables. This
3833 can greatly improve startup time, especially for large executables.
3835 * Remote targets use caching
3837 Remote targets now use a data cache to speed up communication with the
3838 remote side. The data cache could lead to incorrect results because
3839 it doesn't know about volatile variables, thus making it impossible to
3840 debug targets which use memory mapped I/O devices. `set remotecache
3841 off' turns the the data cache off.
3843 * Remote targets may have threads
3845 The standard remote protocol now includes support for multiple threads
3846 in the target system, using new protocol commands 'H' and 'T'. See
3847 gdb/remote.c for details.
3851 If GDB is configured with `--enable-netrom', then it will include
3852 support for the NetROM ROM emulator from XLNT Designs. The NetROM
3853 acts as though it is a bank of ROM on the target board, but you can
3854 write into it over the network. GDB's support consists only of
3855 support for fast loading into the emulated ROM; to debug, you must use
3856 another protocol, such as standard remote protocol. The usual
3857 sequence is something like
3859 target nrom <netrom-hostname>
3861 target remote <netrom-hostname>:1235
3865 GDB now includes support for the Apple Macintosh, as a host only. It
3866 may be run as either an MPW tool or as a standalone application, and
3867 it can debug through the serial port. All the usual GDB commands are
3868 available, but to the target command, you must supply "serial" as the
3869 device type instead of "/dev/ttyXX". See mpw-README in the main
3870 directory for more information on how to build. The MPW configuration
3871 scripts */mpw-config.in support only a few targets, and only the
3872 mips-idt-ecoff target has been tested.
3876 GDB configuration now uses autoconf. This is not user-visible,
3877 but does simplify configuration and building.
3881 GDB now supports hpux10.
3883 *** Changes in GDB-4.14:
3885 * New native configurations
3887 x86 FreeBSD i[345]86-*-freebsd
3888 x86 NetBSD i[345]86-*-netbsd
3889 NS32k NetBSD ns32k-*-netbsd
3890 Sparc NetBSD sparc-*-netbsd
3894 A29K VxWorks a29k-*-vxworks
3895 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
3896 CPU32 EST-300 emulator m68*-*-est*
3897 PowerPC ELF powerpc-*-elf
3900 * Alpha OSF/1 support for procfs
3902 GDB now supports procfs under OSF/1-2.x and higher, which makes it
3903 possible to attach to running processes. As the mounting of the /proc
3904 filesystem is optional on the Alpha, GDB automatically determines
3905 the availability of /proc during startup. This can lead to problems
3906 if /proc is unmounted after GDB has been started.
3908 * Arguments to user-defined commands
3910 User commands may accept up to 10 arguments separated by whitespace.
3911 Arguments are accessed within the user command via $arg0..$arg9. A
3914 print $arg0 + $arg1 + $arg2
3916 To execute the command use:
3919 Defines the command "adder" which prints the sum of its three arguments.
3920 Note the arguments are text substitutions, so they may reference variables,
3921 use complex expressions, or even perform inferior function calls.
3923 * New `if' and `while' commands
3925 This makes it possible to write more sophisticated user-defined
3926 commands. Both commands take a single argument, which is the
3927 expression to evaluate, and must be followed by the commands to
3928 execute, one per line, if the expression is nonzero, the list being
3929 terminated by the word `end'. The `if' command list may include an
3930 `else' word, which causes the following commands to be executed only
3931 if the expression is zero.
3933 * Fortran source language mode
3935 GDB now includes partial support for Fortran 77. It will recognize
3936 Fortran programs and can evaluate a subset of Fortran expressions, but
3937 variables and functions may not be handled correctly. GDB will work
3938 with G77, but does not yet know much about symbols emitted by other
3941 * Better HPUX support
3943 Most debugging facilities now work on dynamic executables for HPPAs
3944 running hpux9 or later. You can attach to running dynamically linked
3945 processes, but by default the dynamic libraries will be read-only, so
3946 for instance you won't be able to put breakpoints in them. To change
3947 that behavior do the following before running the program:
3953 This will cause the libraries to be mapped private and read-write.
3954 To revert to the normal behavior, do this:
3960 You cannot set breakpoints or examine data in the library until after
3961 the library is loaded if the function/data symbols do not have
3964 GDB can now also read debug symbols produced by the HP C compiler on
3965 HPPAs (sorry, no C++, Fortran or 68k support).
3967 * Target byte order now dynamically selectable
3969 You can choose which byte order to use with a target system, via the
3970 commands "set endian big" and "set endian little", and you can see the
3971 current setting by using "show endian". You can also give the command
3972 "set endian auto", in which case GDB will use the byte order
3973 associated with the executable. Currently, only embedded MIPS
3974 configurations support dynamic selection of target byte order.
3976 * New DOS host serial code
3978 This version uses DPMI interrupts to handle buffered I/O, so you
3979 no longer need to run asynctsr when debugging boards connected to
3982 *** Changes in GDB-4.13:
3984 * New "complete" command
3986 This lists all the possible completions for the rest of the line, if it
3987 were to be given as a command itself. This is intended for use by emacs.
3989 * Trailing space optional in prompt
3991 "set prompt" no longer adds a space for you after the prompt you set. This
3992 allows you to set a prompt which ends in a space or one that does not.
3994 * Breakpoint hit counts
3996 "info break" now displays a count of the number of times the breakpoint
3997 has been hit. This is especially useful in conjunction with "ignore"; you
3998 can ignore a large number of breakpoint hits, look at the breakpoint info
3999 to see how many times the breakpoint was hit, then run again, ignoring one
4000 less than that number, and this will get you quickly to the last hit of
4003 * Ability to stop printing at NULL character
4005 "set print null-stop" will cause GDB to stop printing the characters of
4006 an array when the first NULL is encountered. This is useful when large
4007 arrays actually contain only short strings.
4009 * Shared library breakpoints
4011 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4012 breakpoints in shared libraries before the executable is run.
4014 * Hardware watchpoints
4016 There is a new hardware breakpoint for the watch command for sparclite
4017 targets. See gdb/sparclite/hw_breakpoint.note.
4019 Hardware watchpoints are also now supported under GNU/Linux.
4023 Annotations have been added. These are for use with graphical interfaces,
4024 and are still experimental. Currently only gdba.el uses these.
4026 * Improved Irix 5 support
4028 GDB now works properly with Irix 5.2.
4030 * Improved HPPA support
4032 GDB now works properly with the latest GCC and GAS.
4034 * New native configurations
4036 Sequent PTX4 i[34]86-sequent-ptx4
4037 HPPA running OSF/1 hppa*-*-osf*
4038 Atari TT running SVR4 m68*-*-sysv4*
4039 RS/6000 LynxOS rs6000-*-lynxos*
4043 OS/9000 i[34]86-*-os9k
4044 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4047 * Hitachi SH7000 and E7000-PC ICE support
4049 There is now support for communicating with the Hitachi E7000-PC ICE.
4050 This is available automatically when GDB is configured for the SH.
4054 As usual, a variety of small fixes and improvements, both generic
4055 and configuration-specific. See the ChangeLog for more detail.
4057 *** Changes in GDB-4.12:
4059 * Irix 5 is now supported
4063 GDB-4.12 on the HPPA has a number of changes which make it unable
4064 to debug the output from the currently released versions of GCC and
4065 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4066 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4067 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4070 *** Changes in GDB-4.11:
4072 * User visible changes:
4076 The "set remotedebug" option is now consistent between the mips remote
4077 target, remote targets using the gdb-specific protocol, UDI (AMD's
4078 debug protocol for the 29k) and the 88k bug monitor. It is now an
4079 integer specifying a debug level (normally 0 or 1, but 2 means more
4080 debugging info for the mips target).
4082 * DEC Alpha native support
4084 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4085 debug info, but GDB works fairly well with the DEC compiler and should
4086 work with a future GCC release. See the README file for a few
4087 Alpha-specific notes.
4089 * Preliminary thread implementation
4091 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4093 * LynxOS native and target support for 386
4095 This release has been hosted on LynxOS 2.2, and also can be configured
4096 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4099 * Improvements in C++ mangling/demangling.
4101 This release has much better g++ debugging, specifically in name
4102 mangling/demangling, virtual function calls, print virtual table,
4103 call methods, ...etc.
4105 *** Changes in GDB-4.10:
4107 * User visible changes:
4109 Remote debugging using the GDB-specific (`target remote') protocol now
4110 supports the `load' command. This is only useful if you have some
4111 other way of getting the stub to the target system, and you can put it
4112 somewhere in memory where it won't get clobbered by the download.
4114 Filename completion now works.
4116 When run under emacs mode, the "info line" command now causes the
4117 arrow to point to the line specified. Also, "info line" prints
4118 addresses in symbolic form (as well as hex).
4120 All vxworks based targets now support a user settable option, called
4121 vxworks-timeout. This option represents the number of seconds gdb
4122 should wait for responses to rpc's. You might want to use this if
4123 your vxworks target is, perhaps, a slow software simulator or happens
4124 to be on the far side of a thin network line.
4128 This release contains support for using a DEC alpha as a GDB host for
4129 cross debugging. Native alpha debugging is not supported yet.
4132 *** Changes in GDB-4.9:
4136 This is the first GDB release which is accompanied by a matching testsuite.
4137 The testsuite requires installation of dejagnu, which should be available
4138 via ftp from most sites that carry GNU software.
4142 'Cfront' style demangling has had its name changed to 'ARM' style, to
4143 emphasize that it was written from the specifications in the C++ Annotated
4144 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4145 disclaimers, it still generated too much confusion with users attempting to
4146 use gdb with AT&T cfront.
4150 GDB now uses a standard remote interface to a simulator library.
4151 So far, the library contains simulators for the Zilog Z8001/2, the
4152 Hitachi H8/300, H8/500 and Super-H.
4154 * New targets supported
4156 H8/300 simulator h8300-hitachi-hms or h8300hms
4157 H8/500 simulator h8500-hitachi-hms or h8500hms
4158 SH simulator sh-hitachi-hms or sh
4159 Z8000 simulator z8k-zilog-none or z8ksim
4160 IDT MIPS board over serial line mips-idt-ecoff
4162 Cross-debugging to GO32 targets is supported. It requires a custom
4163 version of the i386-stub.c module which is integrated with the
4164 GO32 memory extender.
4166 * New remote protocols
4168 MIPS remote debugging protocol.
4170 * New source languages supported
4172 This version includes preliminary support for Chill, a Pascal like language
4173 used by telecommunications companies. Chill support is also being integrated
4174 into the GNU compiler, but we don't know when it will be publically available.
4177 *** Changes in GDB-4.8:
4179 * HP Precision Architecture supported
4181 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4182 version of this support was available as a set of patches from the
4183 University of Utah. GDB does not support debugging of programs
4184 compiled with the HP compiler, because HP will not document their file
4185 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4186 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4188 Many problems in the preliminary version have been fixed.
4190 * Faster and better demangling
4192 We have improved template demangling and fixed numerous bugs in the GNU style
4193 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4194 character types (wchar_t) are now supported. Demangling of each symbol is now
4195 only done once, and is cached when the symbol table for a file is read in.
4196 This results in a small increase in memory usage for C programs, a moderate
4197 increase in memory usage for C++ programs, and a fantastic speedup in
4200 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4201 from the specifications in the Annotated Reference Manual, which AT&T's
4202 compiler does not actually implement.
4204 * G++ multiple inheritance compiler problem
4206 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4207 inheritance lattices was reworked to properly discover ambiguities. We
4208 recently found an example which causes this new algorithm to fail in a
4209 very subtle way, producing bad debug information for those classes.
4210 The file 'gcc.patch' (in this directory) can be applied to gcc to
4211 circumvent the problem. A future GCC release will contain a complete
4214 The previous G++ debug info problem (mentioned below for the gdb-4.7
4215 release) is fixed in gcc version 2.3.2.
4217 * Improved configure script
4219 The `configure' script will now attempt to guess your system type if
4220 you don't supply a host system type. The old scheme of supplying a
4221 host system triplet is preferable over using this. All the magic is
4222 done in the new `config.guess' script. Examine it for details.
4224 We have also brought our configure script much more in line with the FSF's
4225 version. It now supports the --with-xxx options. In particular,
4226 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4227 The resulting GDB will not be able to read arbitrary object file formats --
4228 only the format ``expected'' to be used on the configured target system.
4229 We hope to make this the default in a future release.
4231 * Documentation improvements
4233 There's new internal documentation on how to modify GDB, and how to
4234 produce clean changes to the code. We implore people to read it
4235 before submitting changes.
4237 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4238 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4239 `info' files are also provided. To build `info' files from scratch,
4240 you will need the latest `makeinfo' release, which will be available in
4241 a future texinfo-X.Y release.
4243 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4244 We're not sure exactly which versions have this problem, but it has
4245 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4246 or better. If that isn't possible, there is a patch in
4247 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4248 around this problem.
4252 GDB now supports array constants that can be used in expressions typed in by
4253 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4254 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4257 The new directory `gdb/sparclite' contains a program that demonstrates
4258 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4260 * New native hosts supported
4262 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4263 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4265 * New targets supported
4267 AMD 29k family via UDI a29k-amd-udi or udi29k
4269 * New file formats supported
4271 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4272 HPUX core files, and SCO 3.2v2 core files.
4276 Attaching to processes now works again; thanks for the many bug reports.
4278 We have also stomped on a bunch of core dumps caused by
4279 printf_filtered("%s") problems.
4281 We eliminated a copyright problem on the rpc and ptrace header files
4282 for VxWorks, which was discovered at the last minute during the 4.7
4283 release. You should now be able to build a VxWorks GDB.
4285 You can now interrupt gdb while an attached process is running. This
4286 will cause the attached process to stop, and give control back to GDB.
4288 We fixed problems caused by using too many file descriptors
4289 for reading symbols from object files and libraries. This was
4290 especially a problem for programs that used many (~100) shared
4293 The `step' command now only enters a subroutine if there is line number
4294 information for the subroutine. Otherwise it acts like the `next'
4295 command. Previously, `step' would enter subroutines if there was
4296 any debugging information about the routine. This avoids problems
4297 when using `cc -g1' on MIPS machines.
4299 * Internal improvements
4301 GDB's internal interfaces have been improved to make it easier to support
4302 debugging of multiple languages in the future.
4304 GDB now uses a common structure for symbol information internally.
4305 Minimal symbols (derived from linkage symbols in object files), partial
4306 symbols (from a quick scan of debug information), and full symbols
4307 contain a common subset of information, making it easier to write
4308 shared code that handles any of them.
4310 * New command line options
4312 We now accept --silent as an alias for --quiet.
4316 The memory-mapped-malloc library is now licensed under the GNU Library
4317 General Public License.
4319 *** Changes in GDB-4.7:
4321 * Host/native/target split
4323 GDB has had some major internal surgery to untangle the support for
4324 hosts and remote targets. Now, when you configure GDB for a remote
4325 target, it will no longer load in all of the support for debugging
4326 local programs on the host. When fully completed and tested, this will
4327 ensure that arbitrary host/target combinations are possible.
4329 The primary conceptual shift is to separate the non-portable code in
4330 GDB into three categories. Host specific code is required any time GDB
4331 is compiled on that host, regardless of the target. Target specific
4332 code relates to the peculiarities of the target, but can be compiled on
4333 any host. Native specific code is everything else: it can only be
4334 built when the host and target are the same system. Child process
4335 handling and core file support are two common `native' examples.
4337 GDB's use of /proc for controlling Unix child processes is now cleaner.
4338 It has been split out into a single module under the `target_ops' vector,
4339 plus two native-dependent functions for each system that uses /proc.
4341 * New hosts supported
4343 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
4344 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4345 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
4347 * New targets supported
4349 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4350 68030 and CPU32 m68030-*-*, m68332-*-*
4352 * New native hosts supported
4354 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4355 (386bsd is not well tested yet)
4356 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
4358 * New file formats supported
4360 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
4361 supports reading of `a.out.adobe' object files, which are an a.out
4362 format extended with minimal information about multiple sections.
4366 `show copying' is the same as the old `info copying'.
4367 `show warranty' is the same as `info warrantee'.
4368 These were renamed for consistency. The old commands continue to work.
4370 `info handle' is a new alias for `info signals'.
4372 You can now define pre-command hooks, which attach arbitrary command
4373 scripts to any command. The commands in the hook will be executed
4374 prior to the user's command. You can also create a hook which will be
4375 executed whenever the program stops. See gdb.texinfo.
4379 We now deal with Cfront style name mangling, and can even extract type
4380 info from mangled symbols. GDB can automatically figure out which
4381 symbol mangling style your C++ compiler uses.
4383 Calling of methods and virtual functions has been improved as well.
4387 The crash that occured when debugging Sun Ansi-C compiled binaries is
4388 fixed. This was due to mishandling of the extra N_SO stabs output
4391 We also finally got Ultrix 4.2 running in house, and fixed core file
4392 support, with help from a dozen people on the net.
4394 John M. Farrell discovered that the reason that single-stepping was so
4395 slow on all of the Mips based platforms (primarily SGI and DEC) was
4396 that we were trying to demangle and lookup a symbol used for internal
4397 purposes on every instruction that was being stepped through. Changing
4398 the name of that symbol so that it couldn't be mistaken for a C++
4399 mangled symbol sped things up a great deal.
4401 Rich Pixley sped up symbol lookups in general by getting much smarter
4402 about when C++ symbol mangling is necessary. This should make symbol
4403 completion (TAB on the command line) much faster. It's not as fast as
4404 we'd like, but it's significantly faster than gdb-4.6.
4408 A new user controllable variable 'call_scratch_address' can
4409 specify the location of a scratch area to be used when GDB
4410 calls a function in the target. This is necessary because the
4411 usual method of putting the scratch area on the stack does not work
4412 in systems that have separate instruction and data spaces.
4414 We integrated changes to support the 29k UDI (Universal Debugger
4415 Interface), but discovered at the last minute that we didn't have all
4416 of the appropriate copyright paperwork. We are working with AMD to
4417 resolve this, and hope to have it available soon.
4421 We have sped up the remote serial line protocol, especially for targets
4422 with lots of registers. It now supports a new `expedited status' ('T')
4423 message which can be used in place of the existing 'S' status message.
4424 This allows the remote stub to send only the registers that GDB
4425 needs to make a quick decision about single-stepping or conditional
4426 breakpoints, eliminating the need to fetch the entire register set for
4427 each instruction being stepped through.
4429 The GDB remote serial protocol now implements a write-through cache for
4430 registers, only re-reading the registers if the target has run.
4432 There is also a new remote serial stub for SPARC processors. You can
4433 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
4434 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
4435 processor with a serial port.
4439 Configure.in files have become much easier to read and modify. A new
4440 `table driven' format makes it more obvious what configurations are
4441 supported, and what files each one uses.
4445 There is a new opcodes library which will eventually contain all of the
4446 disassembly routines and opcode tables. At present, it only contains
4447 Sparc and Z8000 routines. This will allow the assembler, debugger, and
4448 disassembler (binutils/objdump) to share these routines.
4450 The libiberty library is now copylefted under the GNU Library General
4451 Public License. This allows more liberal use, and was done so libg++
4452 can use it. This makes no difference to GDB, since the Library License
4453 grants all the rights from the General Public License.
4457 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
4458 reference to the stabs symbol info used by the debugger. It is (as far
4459 as we know) the only published document on this fascinating topic. We
4460 encourage you to read it, compare it to the stabs information on your
4461 system, and send improvements on the document in general (to
4462 bug-gdb@prep.ai.mit.edu).
4464 And, of course, many bugs have been fixed.
4467 *** Changes in GDB-4.6:
4469 * Better support for C++ function names
4471 GDB now accepts as input the "demangled form" of C++ overloaded function
4472 names and member function names, and can do command completion on such names
4473 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
4474 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
4475 Make use of command completion, it is your friend.
4477 GDB also now accepts a variety of C++ mangled symbol formats. They are
4478 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
4479 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
4480 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
4481 for the list of formats.
4483 * G++ symbol mangling problem
4485 Recent versions of gcc have a bug in how they emit debugging information for
4486 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
4487 directory) can be applied to gcc to fix the problem. Alternatively, if you
4488 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
4489 usual symptom is difficulty with setting breakpoints on methods. GDB complains
4490 about the method being non-existent. (We believe that version 2.2.2 of GCC has
4493 * New 'maintenance' command
4495 All of the commands related to hacking GDB internals have been moved out of
4496 the main command set, and now live behind the 'maintenance' command. This
4497 can also be abbreviated as 'mt'. The following changes were made:
4499 dump-me -> maintenance dump-me
4500 info all-breakpoints -> maintenance info breakpoints
4501 printmsyms -> maintenance print msyms
4502 printobjfiles -> maintenance print objfiles
4503 printpsyms -> maintenance print psymbols
4504 printsyms -> maintenance print symbols
4506 The following commands are new:
4508 maintenance demangle Call internal GDB demangler routine to
4509 demangle a C++ link name and prints the result.
4510 maintenance print type Print a type chain for a given symbol
4512 * Change to .gdbinit file processing
4514 We now read the $HOME/.gdbinit file before processing the argv arguments
4515 (e.g. reading symbol files or core files). This allows global parameters to
4516 be set, which will apply during the symbol reading. The ./.gdbinit is still
4517 read after argv processing.
4519 * New hosts supported
4521 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
4523 GNU/Linux support i386-unknown-linux or linux
4525 We are also including code to support the HP/PA running BSD and HPUX. This
4526 is almost guaranteed not to work, as we didn't have time to test or build it
4527 for this release. We are including it so that the more adventurous (or
4528 masochistic) of you can play with it. We also had major problems with the
4529 fact that the compiler that we got from HP doesn't support the -g option.
4532 * New targets supported
4534 Hitachi H8/300 h8300-hitachi-hms or h8300hms
4536 * More smarts about finding #include files
4538 GDB now remembers the compilation directory for all include files, and for
4539 all files from which C is generated (like yacc and lex sources). This
4540 greatly improves GDB's ability to find yacc/lex sources, and include files,
4541 especially if you are debugging your program from a directory different from
4542 the one that contains your sources.
4544 We also fixed a bug which caused difficulty with listing and setting
4545 breakpoints in include files which contain C code. (In the past, you had to
4546 try twice in order to list an include file that you hadn't looked at before.)
4548 * Interesting infernals change
4550 GDB now deals with arbitrary numbers of sections, where the symbols for each
4551 section must be relocated relative to that section's landing place in the
4552 target's address space. This work was needed to support ELF with embedded
4553 stabs used by Solaris-2.0.
4555 * Bug fixes (of course!)
4557 There have been loads of fixes for the following things:
4558 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
4559 i960, stabs, DOS(GO32), procfs, etc...
4561 See the ChangeLog for details.
4563 *** Changes in GDB-4.5:
4565 * New machines supported (host and target)
4567 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
4569 SGI Irix-4.x mips-sgi-irix4 or iris4
4571 * New malloc package
4573 GDB now uses a new memory manager called mmalloc, based on gmalloc.
4574 Mmalloc is capable of handling mutiple heaps of memory. It is also
4575 capable of saving a heap to a file, and then mapping it back in later.
4576 This can be used to greatly speedup the startup of GDB by using a
4577 pre-parsed symbol table which lives in a mmalloc managed heap. For
4578 more details, please read mmalloc/mmalloc.texi.
4582 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
4583 'help info proc' for details.
4585 * MIPS ecoff symbol table format
4587 The code that reads MIPS symbol table format is now supported on all hosts.
4588 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
4591 * File name changes for MS-DOS
4593 Many files in the config directories have been renamed to make it easier to
4594 support GDB on MS-DOSe systems (which have very restrictive file name
4595 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
4596 environment) is close to working but has some remaining problems. Note
4597 that debugging of DOS programs is not supported, due to limitations
4598 in the ``operating system'', but it can be used to host cross-debugging.
4600 * Cross byte order fixes
4602 Many fixes have been made to support cross debugging of Sparc and MIPS
4603 targets from hosts whose byte order differs.
4605 * New -mapped and -readnow options
4607 If memory-mapped files are available on your system through the 'mmap'
4608 system call, you can use the -mapped option on the `file' or
4609 `symbol-file' commands to cause GDB to write the symbols from your
4610 program into a reusable file. If the program you are debugging is
4611 called `/path/fred', the mapped symbol file will be `./fred.syms'.
4612 Future GDB debugging sessions will notice the presence of this file,
4613 and will quickly map in symbol information from it, rather than reading
4614 the symbol table from the executable program. Using the '-mapped'
4615 option in a GDB `file' or `symbol-file' command has the same effect as
4616 starting GDB with the '-mapped' command-line option.
4618 You can cause GDB to read the entire symbol table immediately by using
4619 the '-readnow' option with any of the commands that load symbol table
4620 information (or on the GDB command line). This makes the command
4621 slower, but makes future operations faster.
4623 The -mapped and -readnow options are typically combined in order to
4624 build a `fred.syms' file that contains complete symbol information.
4625 A simple GDB invocation to do nothing but build a `.syms' file for future
4628 gdb -batch -nx -mapped -readnow programname
4630 The `.syms' file is specific to the host machine on which GDB is run.
4631 It holds an exact image of GDB's internal symbol table. It cannot be
4632 shared across multiple host platforms.
4634 * longjmp() handling
4636 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
4637 siglongjmp() without losing control. This feature has not yet been ported to
4638 all systems. It currently works on many 386 platforms, all MIPS-based
4639 platforms (SGI, DECstation, etc), and Sun3/4.
4643 Preliminary work has been put in to support the new Solaris OS from Sun. At
4644 this time, it can control and debug processes, but it is not capable of
4649 As always, many many bug fixes. The major areas were with g++, and mipsread.
4650 People using the MIPS-based platforms should experience fewer mysterious
4651 crashes and trashed symbol tables.
4653 *** Changes in GDB-4.4:
4655 * New machines supported (host and target)
4657 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4659 BSD Reno on Vax vax-dec-bsd
4660 Ultrix on Vax vax-dec-ultrix
4662 * New machines supported (target)
4664 AMD 29000 embedded, using EBMON a29k-none-none
4668 GDB continues to improve its handling of C++. `References' work better.
4669 The demangler has also been improved, and now deals with symbols mangled as
4670 per the Annotated C++ Reference Guide.
4672 GDB also now handles `stabs' symbol information embedded in MIPS
4673 `ecoff' symbol tables. Since the ecoff format was not easily
4674 extensible to handle new languages such as C++, this appeared to be a
4675 good way to put C++ debugging info into MIPS binaries. This option
4676 will be supported in the GNU C compiler, version 2, when it is
4679 * New features for SVR4
4681 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
4682 shared libraries. Debugging dynamically linked programs should present
4683 only minor differences from debugging statically linked programs.
4685 The `info proc' command will print out information about any process
4686 on an SVR4 system (including the one you are debugging). At the moment,
4687 it prints the address mappings of the process.
4689 If you bring up GDB on another SVR4 system, please send mail to
4690 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
4692 * Better dynamic linking support in SunOS
4694 Reading symbols from shared libraries which contain debugging symbols
4695 now works properly. However, there remain issues such as automatic
4696 skipping of `transfer vector' code during function calls, which
4697 make it harder to debug code in a shared library, than to debug the
4698 same code linked statically.
4702 GDB is now using the latest `getopt' routines from the FSF. This
4703 version accepts the -- prefix for options with long names. GDB will
4704 continue to accept the old forms (-option and +option) as well.
4705 Various single letter abbreviations for options have been explicity
4706 added to the option table so that they won't get overshadowed in the
4707 future by other options that begin with the same letter.
4711 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
4712 Many assorted bugs have been handled. Many more remain to be handled.
4713 See the various ChangeLog files (primarily in gdb and bfd) for details.
4716 *** Changes in GDB-4.3:
4718 * New machines supported (host and target)
4720 Amiga 3000 running Amix m68k-cbm-svr4 or amix
4721 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
4722 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4724 * Almost SCO Unix support
4726 We had hoped to support:
4727 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4728 (except for core file support), but we discovered very late in the release
4729 that it has problems with process groups that render gdb unusable. Sorry
4730 about that. I encourage people to fix it and post the fixes.
4732 * Preliminary ELF and DWARF support
4734 GDB can read ELF object files on System V Release 4, and can handle
4735 debugging records for C, in DWARF format, in ELF files. This support
4736 is preliminary. If you bring up GDB on another SVR4 system, please
4737 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
4742 GDB now uses the latest `readline' library. One user-visible change
4743 is that two tabs will list possible command completions, which previously
4744 required typing M-? (meta-question mark, or ESC ?).
4748 The `stepi' bug that many of you noticed has been squashed.
4749 Many bugs in C++ have been handled. Many more remain to be handled.
4750 See the various ChangeLog files (primarily in gdb and bfd) for details.
4752 * State of the MIPS world (in case you wondered):
4754 GDB can understand the symbol tables emitted by the compilers
4755 supplied by most vendors of MIPS-based machines, including DEC. These
4756 symbol tables are in a format that essentially nobody else uses.
4758 Some versions of gcc come with an assembler post-processor called
4759 mips-tfile. This program is required if you want to do source-level
4760 debugging of gcc-compiled programs. I believe FSF does not ship
4761 mips-tfile with gcc version 1, but it will eventually come with gcc
4764 Debugging of g++ output remains a problem. g++ version 1.xx does not
4765 really support it at all. (If you're lucky, you should be able to get
4766 line numbers and stack traces to work, but no parameters or local
4767 variables.) With some work it should be possible to improve the
4770 When gcc version 2 is released, you will have somewhat better luck.
4771 However, even then you will get confusing results for inheritance and
4774 We will eventually provide full debugging of g++ output on
4775 DECstations. This will probably involve some kind of stabs-in-ecoff
4776 encapulation, but the details have not been worked out yet.
4779 *** Changes in GDB-4.2:
4781 * Improved configuration
4783 Only one copy of `configure' exists now, and it is not self-modifying.
4784 Porting BFD is simpler.
4788 The `step' and `next' commands now only stop at the first instruction
4789 of a source line. This prevents the multiple stops that used to occur
4790 in switch statements, for-loops, etc. `Step' continues to stop if a
4791 function that has debugging information is called within the line.
4795 Lots of small bugs fixed. More remain.
4797 * New host supported (not target)
4799 Intel 386 PC clone running Mach i386-none-mach
4802 *** Changes in GDB-4.1:
4804 * Multiple source language support
4806 GDB now has internal scaffolding to handle several source languages.
4807 It determines the type of each source file from its filename extension,
4808 and will switch expression parsing and number formatting to match the
4809 language of the function in the currently selected stack frame.
4810 You can also specifically set the language to be used, with
4811 `set language c' or `set language modula-2'.
4815 GDB now has preliminary support for the GNU Modula-2 compiler,
4816 currently under development at the State University of New York at
4817 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
4818 continue through the fall of 1991 and into 1992.
4820 Other Modula-2 compilers are currently not supported, and attempting to
4821 debug programs compiled with them will likely result in an error as the
4822 symbol table is read. Feel free to work on it, though!
4824 There are hooks in GDB for strict type checking and range checking,
4825 in the `Modula-2 philosophy', but they do not currently work.
4829 GDB can now write to executable and core files (e.g. patch
4830 a variable's value). You must turn this switch on, specify
4831 the file ("exec foo" or "core foo"), *then* modify it, e.g.
4832 by assigning a new value to a variable. Modifications take
4835 * Automatic SunOS shared library reading
4837 When you run your program, GDB automatically determines where its
4838 shared libraries (if any) have been loaded, and reads their symbols.
4839 The `share' command is no longer needed. This also works when
4840 examining core files.
4844 You can specify the number of lines that the `list' command shows.
4847 * New machines supported (host and target)
4849 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4850 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
4851 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
4853 * New hosts supported (not targets)
4855 IBM RT/PC: romp-ibm-aix or rtpc
4857 * New targets supported (not hosts)
4859 AMD 29000 embedded with COFF a29k-none-coff
4860 AMD 29000 embedded with a.out a29k-none-aout
4861 Ultracomputer remote kernel debug a29k-nyu-kern
4863 * New remote interfaces
4869 *** Changes in GDB-4.0:
4873 Wide output is wrapped at good places to make the output more readable.
4875 Gdb now supports cross-debugging from a host machine of one type to a
4876 target machine of another type. Communication with the target system
4877 is over serial lines. The ``target'' command handles connecting to the
4878 remote system; the ``load'' command will download a program into the
4879 remote system. Serial stubs for the m68k and i386 are provided. Gdb
4880 also supports debugging of realtime processes running under VxWorks,
4881 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
4882 stub on the target system.
4884 New CPUs supported include the AMD 29000 and Intel 960.
4886 GDB now reads object files and symbol tables via a ``binary file''
4887 library, which allows a single copy of GDB to debug programs of multiple
4888 object file types such as a.out and coff.
4890 There is now a GDB reference card in "doc/refcard.tex". (Make targets
4891 refcard.dvi and refcard.ps are available to format it).
4894 * Control-Variable user interface simplified
4896 All variables that control the operation of the debugger can be set
4897 by the ``set'' command, and displayed by the ``show'' command.
4899 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
4900 ``Show prompt'' produces the response:
4901 Gdb's prompt is new-gdb=>.
4903 What follows are the NEW set commands. The command ``help set'' will
4904 print a complete list of old and new set commands. ``help set FOO''
4905 will give a longer description of the variable FOO. ``show'' will show
4906 all of the variable descriptions and their current settings.
4908 confirm on/off: Enables warning questions for operations that are
4909 hard to recover from, e.g. rerunning the program while
4910 it is already running. Default is ON.
4912 editing on/off: Enables EMACS style command line editing
4913 of input. Previous lines can be recalled with
4914 control-P, the current line can be edited with control-B,
4915 you can search for commands with control-R, etc.
4918 history filename NAME: NAME is where the gdb command history
4919 will be stored. The default is .gdb_history,
4920 or the value of the environment variable
4923 history size N: The size, in commands, of the command history. The
4924 default is 256, or the value of the environment variable
4927 history save on/off: If this value is set to ON, the history file will
4928 be saved after exiting gdb. If set to OFF, the
4929 file will not be saved. The default is OFF.
4931 history expansion on/off: If this value is set to ON, then csh-like
4932 history expansion will be performed on
4933 command line input. The default is OFF.
4935 radix N: Sets the default radix for input and output. It can be set
4936 to 8, 10, or 16. Note that the argument to "radix" is interpreted
4937 in the current radix, so "set radix 10" is always a no-op.
4939 height N: This integer value is the number of lines on a page. Default
4940 is 24, the current `stty rows'' setting, or the ``li#''
4941 setting from the termcap entry matching the environment
4944 width N: This integer value is the number of characters on a line.
4945 Default is 80, the current `stty cols'' setting, or the ``co#''
4946 setting from the termcap entry matching the environment
4949 Note: ``set screensize'' is obsolete. Use ``set height'' and
4950 ``set width'' instead.
4952 print address on/off: Print memory addresses in various command displays,
4953 such as stack traces and structure values. Gdb looks
4954 more ``symbolic'' if you turn this off; it looks more
4955 ``machine level'' with it on. Default is ON.
4957 print array on/off: Prettyprint arrays. New convenient format! Default
4960 print demangle on/off: Print C++ symbols in "source" form if on,
4963 print asm-demangle on/off: Same, for assembler level printouts
4966 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
4969 * Support for Epoch Environment.
4971 The epoch environment is a version of Emacs v18 with windowing. One
4972 new command, ``inspect'', is identical to ``print'', except that if you
4973 are running in the epoch environment, the value is printed in its own
4977 * Support for Shared Libraries
4979 GDB can now debug programs and core files that use SunOS shared libraries.
4980 Symbols from a shared library cannot be referenced
4981 before the shared library has been linked with the program (this
4982 happens after you type ``run'' and before the function main() is entered).
4983 At any time after this linking (including when examining core files
4984 from dynamically linked programs), gdb reads the symbols from each
4985 shared library when you type the ``sharedlibrary'' command.
4986 It can be abbreviated ``share''.
4988 sharedlibrary REGEXP: Load shared object library symbols for files
4989 matching a unix regular expression. No argument
4990 indicates to load symbols for all shared libraries.
4992 info sharedlibrary: Status of loaded shared libraries.
4997 A watchpoint stops execution of a program whenever the value of an
4998 expression changes. Checking for this slows down execution
4999 tremendously whenever you are in the scope of the expression, but is
5000 quite useful for catching tough ``bit-spreader'' or pointer misuse
5001 problems. Some machines such as the 386 have hardware for doing this
5002 more quickly, and future versions of gdb will use this hardware.
5004 watch EXP: Set a watchpoint (breakpoint) for an expression.
5006 info watchpoints: Information about your watchpoints.
5008 delete N: Deletes watchpoint number N (same as breakpoints).
5009 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5010 enable N: Re-enables watchpoint number N (same as breakpoints).
5013 * C++ multiple inheritance
5015 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5018 * C++ exception handling
5020 Gdb now supports limited C++ exception handling. Besides the existing
5021 ability to breakpoint on an exception handler, gdb can breakpoint on
5022 the raising of an exception (before the stack is peeled back to the
5025 catch FOO: If there is a FOO exception handler in the dynamic scope,
5026 set a breakpoint to catch exceptions which may be raised there.
5027 Multiple exceptions (``catch foo bar baz'') may be caught.
5029 info catch: Lists all exceptions which may be caught in the
5030 current stack frame.
5033 * Minor command changes
5035 The command ``call func (arg, arg, ...)'' now acts like the print
5036 command, except it does not print or save a value if the function's result
5037 is void. This is similar to dbx usage.
5039 The ``up'' and ``down'' commands now always print the frame they end up
5040 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5041 frames without printing.
5043 * New directory command
5045 'dir' now adds directories to the FRONT of the source search path.
5046 The path starts off empty. Source files that contain debug information
5047 about the directory in which they were compiled can be found even
5048 with an empty path; Sun CC and GCC include this information. If GDB can't
5049 find your source file in the current directory, type "dir .".
5051 * Configuring GDB for compilation
5053 For normal use, type ``./configure host''. See README or gdb.texinfo
5056 GDB now handles cross debugging. If you are remotely debugging between
5057 two different machines, type ``./configure host -target=targ''.
5058 Host is the machine where GDB will run; targ is the machine
5059 where the program that you are debugging will run.