1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.4
6 * GDB now supports reversible debugging on ARM, it allows you to
7 debug basic ARM and THUMB instructions, and provides
10 * The option "symbol-reloading" has been deleted as it is no longer used.
14 ** GDB commands implemented in Python can now be put in command class
17 ** The "maint set python print-stack on|off" is now deleted.
19 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
20 apply "flag enum"-style pretty-printing to any enum.
22 ** gdb.lookup_symbol can now work when there is no current frame.
24 ** gdb.Symbol now has a 'line' attribute, holding the line number in
25 the source at which the symbol was defined.
27 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
28 method 'value'. The former indicates whether the symbol needs a
29 frame in order to compute its value, and the latter computes the
32 ** A new method 'referenced_value' on gdb.Value objects which can
33 dereference pointer as well as C++ reference values.
35 * GDBserver now supports stdio connections.
36 E.g. (gdb) target remote | ssh myhost gdbserver - hello
38 * The binary "gdbtui" can no longer be built or installed.
39 Use "gdb -tui" instead.
41 * GDB will now print "flag" enums specially. A flag enum is one where
42 all the enumerator values have no bits in common when pairwise
43 "and"ed. When printing a value whose type is a flag enum, GDB will
44 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
45 (gdb) print (enum E) 3
48 * The filename part of a linespec will now match trailing components
49 of a source file name. For example, "break gcc/expr.c:1000" will
50 now set a breakpoint in build/gcc/expr.c, but not
53 * The "info proc" and "generate-core-file" commands will now also
54 work on remote targets connected to GDBserver on Linux.
56 * The command "info catch" has been removed. It has been disabled
59 * The "catch exception" and "catch assert" commands now accept
60 a condition at the end of the command, much like the "break"
61 command does. For instance:
63 (gdb) catch exception Constraint_Error if Barrier = True
65 Previously, it was possible to add a condition to such catchpoints,
66 but it had to be done as a second step, after the catchpoint had been
67 created, using the "condition" command.
69 * The "info static-tracepoint-marker" command will now also work on
70 native Linux targets with in-process agent.
72 * GDB can now set breakpoints on inlined functions.
74 * The .gdb_index section has been updated to include symbols for
75 inlined functions. GDB will ignore older .gdb_index sections by
76 default, which could cause symbol files to be loaded more slowly
77 until their .gdb_index sections can be recreated. The new option
78 --use-deprecated-index-sections will cause GDB to use any older
79 .gdb_index sections it finds. This will restore performance, but
80 the ability to set breakpoints on inlined functions will be lost
81 in symbol files with older .gdb_index sections.
83 * Ada support for GDB/MI Variable Objects has been added.
85 * GDB can now support 'breakpoint always-inserted mode' in 'record'
90 ** "catch load" and "catch unload" can be used to stop when a shared
91 library is loaded or unloaded, respectively.
93 ** "enable count" can be used to auto-disable a breakpoint after
96 ** "info vtbl" can be used to show the virtual method tables for
99 ** "explore" and its sub commands "explore value" and "explore type"
100 can be used to reccursively explore values and types of
101 expressions. These commands are available only if GDB is
102 configured with '--with-python'.
104 ** "info auto-load" shows status of all kinds of auto-loaded files,
105 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
106 sequences of commands files, "info auto-load python-scripts"
107 shows status of auto-loading Python script files,
108 "info auto-load local-gdbinit" shows status of loading init file
109 (.gdbinit) from current directory and "info auto-load libthread-db" shows
110 status of inferior specific thread debugging shared library loading.
112 ** "info auto-load-scripts", "set auto-load-scripts on|off"
113 and "show auto-load-scripts" commands have been deprecated, use their
114 "info auto-load python-scripts", "set auto-load python-scripts on|off"
115 and "show auto-load python-scripts" counterparts instead.
119 Renesas RL78 rl78-*-elf
120 HP OpenVMS ia64 ia64-hp-openvms*
122 * GDBserver supports evaluation of breakpoint conditions. When
123 support is advertised by GDBserver, GDB may be told to send the
124 breakpoint conditions in bytecode form to GDBserver. GDBserver
125 will only report the breakpoint trigger to GDB when its condition
130 set breakpoint condition-evaluation
131 show breakpoint condition-evaluation
132 Control whether breakpoint conditions are evaluated by GDB ("host") or by
133 GDBserver ("target"). Default option "auto" chooses the most efficient
135 This option can improve debugger efficiency depending on the speed of the
139 Disable auto-loading globally.
142 Show auto-loading setting of all kinds of auto-loaded files.
144 set auto-load gdb-scripts on|off
145 show auto-load gdb-scripts
146 Control auto-loading of GDB canned sequences of commands files.
148 set auto-load python-scripts on|off
149 show auto-load python-scripts
150 Control auto-loading of Python script files.
152 set auto-load local-gdbinit on|off
153 show auto-load local-gdbinit
154 Control loading of init file (.gdbinit) from current directory.
156 set auto-load libthread-db on|off
157 show auto-load libthread-db
158 Control auto-loading of inferior specific thread debugging shared library.
160 set auto-load safe-path <dir1>[:<dir2>...]
161 show auto-load safe-path
162 Set a list of directories from which it is safe to auto-load files.
163 The delimiter (':' above) may differ according to the host platform.
165 set debug auto-load on|off
167 Control display of debugging info for auto-loading the files above.
171 z0/z1 conditional breakpoints extension
173 The z0/z1 breakpoint insertion packets have been extended to carry
174 a list of conditional expressions over to the remote stub depending on the
175 condition evaluation mode. The use of this extension can be controlled
176 via the "set remote conditional-breakpoints-packet" command.
180 Specify the signals which the remote stub may pass to the debugged
181 program without GDB involvement.
183 * New command line options
185 --init-command=FILE, -ix Like --command, -x but execute it
186 before loading inferior.
187 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
188 execute it before loading inferior.
190 *** Changes in GDB 7.4
192 * GDB now handles ambiguous linespecs more consistently; the existing
193 FILE:LINE support has been expanded to other types of linespecs. A
194 breakpoint will now be set on all matching locations in all
195 inferiors, and locations will be added or removed according to
198 * GDB now allows you to skip uninteresting functions and files when
199 stepping with the "skip function" and "skip file" commands.
201 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
202 and "show remote hardware-watchpoint-length-limit". These allows to
203 set or show the maximum length limit (in bytes) of a remote
204 target hardware watchpoint.
206 This allows e.g. to use "unlimited" hardware watchpoints with the
207 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
208 watchpoints are slower than real hardware watchpoints but are
209 significantly faster than gdb software watchpoints.
213 ** The register_pretty_printer function in module gdb.printing now takes
214 an optional `replace' argument. If True, the new printer replaces any
217 ** The "maint set python print-stack on|off" command has been
218 deprecated and will be deleted in GDB 7.5.
219 A new command: "set python print-stack none|full|message" has
220 replaced it. Additionally, the default for "print-stack" is
221 now "message", which just prints the error message without
224 ** A prompt substitution hook (prompt_hook) is now available to the
227 ** A new Python module, gdb.prompt has been added to the GDB Python
228 modules library. This module provides functionality for
229 escape sequences in prompts (used by set/show
230 extended-prompt). These escape sequences are replaced by their
233 ** Python commands and convenience-functions located in
234 'data-directory'/python/gdb/command and
235 'data-directory'/python/gdb/function are now automatically loaded
238 ** Blocks now provide four new attributes. global_block and
239 static_block will return the global and static blocks
240 respectively. is_static and is_global are boolean attributes
241 that indicate if the block is one of those two types.
243 ** Symbols now provide the "type" attribute, the type of the symbol.
245 ** The "gdb.breakpoint" function has been deprecated in favor of
248 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
249 of a function. This class is based on the "finish" command
250 available in the CLI.
252 ** Type objects for struct and union types now allow access to
253 the fields using standard Python dictionary (mapping) methods.
254 For example, "some_type['myfield']" now works, as does
257 ** A new event "gdb.new_objfile" has been added, triggered by loading a
260 ** A new function, "deep_items" has been added to the gdb.types
261 module in the GDB Python modules library. This function returns
262 an iterator over the fields of a struct or union type. Unlike
263 the standard Python "iteritems" method, it will recursively traverse
264 any anonymous fields.
268 ** "*stopped" events can report several new "reason"s, such as
271 ** Breakpoint changes are now notified using new async records, like
272 "=breakpoint-modified".
274 ** New command -ada-task-info.
276 * libthread-db-search-path now supports two special values: $sdir and $pdir.
277 $sdir specifies the default system locations of shared libraries.
278 $pdir specifies the directory where the libpthread used by the application
281 GDB no longer looks in $sdir and $pdir after it has searched the directories
282 mentioned in libthread-db-search-path. If you want to search those
283 directories, they must be specified in libthread-db-search-path.
284 The default value of libthread-db-search-path on GNU/Linux and Solaris
285 systems is now "$sdir:$pdir".
287 $pdir is not supported by gdbserver, it is currently ignored.
288 $sdir is supported by gdbserver.
290 * New configure option --with-iconv-bin.
291 When using the internationalization support like the one in the GNU C
292 library, GDB will invoke the "iconv" program to get a list of supported
293 character sets. If this program lives in a non-standard location, one can
294 use this option to specify where to find it.
296 * When natively debugging programs on PowerPC BookE processors running
297 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
298 watchpoints, which specify a mask in addition to an address to watch.
299 The mask specifies that some bits of an address (the bits which are
300 reset in the mask) should be ignored when matching the address accessed
301 by the inferior against the watchpoint address. See the "PowerPC Embedded"
302 section in the user manual for more details.
304 * The new option --once causes GDBserver to stop listening for connections once
305 the first connection is made. The listening port used by GDBserver will
306 become available after that.
308 * New commands "info macros" and "alias" have been added.
310 * New function parameters suffix @entry specifies value of function parameter
311 at the time the function got called. Entry values are available only since
317 "!" is now an alias of the "shell" command.
318 Note that no space is needed between "!" and SHELL COMMAND.
322 watch EXPRESSION mask MASK_VALUE
323 The watch command now supports the mask argument which allows creation
324 of masked watchpoints, if the current architecture supports this feature.
326 info auto-load-scripts [REGEXP]
327 This command was formerly named "maintenance print section-scripts".
328 It is now generally useful and is no longer a maintenance-only command.
330 info macro [-all] [--] MACRO
331 The info macro command has new options `-all' and `--'. The first for
332 printing all definitions of a macro. The second for explicitly specifying
333 the end of arguments and the beginning of the macro name in case the macro
334 name starts with a hyphen.
336 collect[/s] EXPRESSIONS
337 The tracepoint collect command now takes an optional modifier "/s"
338 that directs it to dereference pointer-to-character types and
339 collect the bytes of memory up to a zero byte. The behavior is
340 similar to what you see when you use the regular print command on a
341 string. An optional integer following the "/s" sets a bound on the
342 number of bytes that will be collected.
345 The trace start command now interprets any supplied arguments as a
346 note to be recorded with the trace run, with an effect similar to
347 setting the variable trace-notes.
350 The trace stop command now interprets any arguments as a note to be
351 mentioned along with the tstatus report that the trace was stopped
352 with a command. The effect is similar to setting the variable
355 * Tracepoints can now be enabled and disabled at any time after a trace
356 experiment has been started using the standard "enable" and "disable"
357 commands. It is now possible to start a trace experiment with no enabled
358 tracepoints; GDB will display a warning, but will allow the experiment to
359 begin, assuming that tracepoints will be enabled as needed while the trace
362 * Fast tracepoints on 32-bit x86-architectures can now be placed at
363 locations with 4-byte instructions, when they were previously
364 limited to locations with instructions of 5 bytes or longer.
370 Set the GDB prompt, and allow escape sequences to be inserted to
371 display miscellaneous information (see 'help set extended-prompt'
372 for the list of sequences). This prompt (and any information
373 accessed through the escape sequences) is updated every time the
376 set print entry-values (both|compact|default|if-needed|no|only|preferred)
377 show print entry-values
378 Set printing of frame argument values at function entry. In some cases
379 GDB can determine the value of function argument which was passed by the
380 function caller, even if the value was modified inside the called function.
382 set debug entry-values
383 show debug entry-values
384 Control display of debugging info for determining frame argument values at
385 function entry and virtual tail call frames.
387 set basenames-may-differ
388 show basenames-may-differ
389 Set whether a source file may have multiple base names.
390 (A "base name" is the name of a file with the directory part removed.
391 Example: The base name of "/home/user/hello.c" is "hello.c".)
392 If set, GDB will canonicalize file names (e.g., expand symlinks)
393 before comparing them. Canonicalization is an expensive operation,
394 but it allows the same file be known by more than one base name.
395 If not set (the default), all source files are assumed to have just
396 one base name, and gdb will do file name comparisons more efficiently.
402 Set a user name and notes for the current and any future trace runs.
403 This is useful for long-running and/or disconnected traces, to
404 inform others (or yourself) as to who is running the trace, supply
405 contact information, or otherwise explain what is going on.
408 show trace-stop-notes
409 Set a note attached to the trace run, that is displayed when the
410 trace has been stopped by a tstop command. This is useful for
411 instance as an explanation, if you are stopping a trace run that was
412 started by someone else.
418 Dynamically enable a tracepoint in a started trace experiment.
422 Dynamically disable a tracepoint in a started trace experiment.
426 Set the user and notes of the trace run.
430 Query the current status of a tracepoint.
434 Query the minimum length of instruction at which a fast tracepoint may
437 * Dcache size (number of lines) and line-size are now runtime-configurable
438 via "set dcache line" and "set dcache line-size" commands.
442 Texas Instruments TMS320C6x tic6x-*-*
446 Renesas RL78 rl78-*-elf
448 *** Changes in GDB 7.3.1
450 * The build failure for NetBSD and OpenBSD targets have now been fixed.
452 *** Changes in GDB 7.3
454 * GDB has a new command: "thread find [REGEXP]".
455 It finds the thread id whose name, target id, or thread extra info
456 matches the given regular expression.
458 * The "catch syscall" command now works on mips*-linux* targets.
460 * The -data-disassemble MI command now supports modes 2 and 3 for
461 dumping the instruction opcodes.
463 * New command line options
465 -data-directory DIR Specify DIR as the "data-directory".
466 This is mostly for testing purposes.
468 * The "maint set python auto-load on|off" command has been renamed to
469 "set auto-load-scripts on|off".
471 * GDB has a new command: "set directories".
472 It is like the "dir" command except that it replaces the
473 source path list instead of augmenting it.
475 * GDB now understands thread names.
477 On GNU/Linux, "info threads" will display the thread name as set by
478 prctl or pthread_setname_np.
480 There is also a new command, "thread name", which can be used to
481 assign a name internally for GDB to display.
484 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
485 has been integrated into GDB.
489 ** The function gdb.Write now accepts an optional keyword 'stream'.
490 This keyword, when provided, will direct the output to either
491 stdout, stderr, or GDB's logging output.
493 ** Parameters can now be be sub-classed in Python, and in particular
494 you may implement the get_set_doc and get_show_doc functions.
495 This improves how Parameter set/show documentation is processed
496 and allows for more dynamic content.
498 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
499 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
500 have an is_valid method.
502 ** Breakpoints can now be sub-classed in Python, and in particular
503 you may implement a 'stop' function that is executed each time
504 the inferior reaches that breakpoint.
506 ** New function gdb.lookup_global_symbol looks up a global symbol.
508 ** GDB values in Python are now callable if the value represents a
509 function. For example, if 'some_value' represents a function that
510 takes two integer parameters and returns a value, you can call
511 that function like so:
513 result = some_value (10,20)
515 ** Module gdb.types has been added.
516 It contains a collection of utilities for working with gdb.Types objects:
517 get_basic_type, has_field, make_enum_dict.
519 ** Module gdb.printing has been added.
520 It contains utilities for writing and registering pretty-printers.
521 New classes: PrettyPrinter, SubPrettyPrinter,
522 RegexpCollectionPrettyPrinter.
523 New function: register_pretty_printer.
525 ** New commands "info pretty-printers", "enable pretty-printer" and
526 "disable pretty-printer" have been added.
528 ** gdb.parameter("directories") is now available.
530 ** New function gdb.newest_frame returns the newest frame in the
533 ** The gdb.InferiorThread class has a new "name" attribute. This
534 holds the thread's name.
536 ** Python Support for Inferior events.
537 Python scripts can add observers to be notified of events
538 occurring in the process being debugged.
539 The following events are currently supported:
540 - gdb.events.cont Continue event.
541 - gdb.events.exited Inferior exited event.
542 - gdb.events.stop Signal received, and Breakpoint hit events.
546 ** GDB now puts template parameters in scope when debugging in an
547 instantiation. For example, if you have:
549 template<int X> int func (void) { return X; }
551 then if you step into func<5>, "print X" will show "5". This
552 feature requires proper debuginfo support from the compiler; it
553 was added to GCC 4.5.
555 ** The motion commands "next", "finish", "until", and "advance" now
556 work better when exceptions are thrown. In particular, GDB will
557 no longer lose control of the inferior; instead, the GDB will
558 stop the inferior at the point at which the exception is caught.
559 This functionality requires a change in the exception handling
560 code that was introduced in GCC 4.5.
562 * GDB now follows GCC's rules on accessing volatile objects when
563 reading or writing target state during expression evaluation.
564 One notable difference to prior behavior is that "print x = 0"
565 no longer generates a read of x; the value of the assignment is
566 now always taken directly from the value being assigned.
568 * GDB now has some support for using labels in the program's source in
569 linespecs. For instance, you can use "advance label" to continue
570 execution to a label.
572 * GDB now has support for reading and writing a new .gdb_index
573 section. This section holds a fast index of DWARF debugging
574 information and can be used to greatly speed up GDB startup and
575 operation. See the documentation for `save gdb-index' for details.
577 * The "watch" command now accepts an optional "-location" argument.
578 When used, this causes GDB to watch the memory referred to by the
579 expression. Such a watchpoint is never deleted due to it going out
582 * GDB now supports thread debugging of core dumps on GNU/Linux.
584 GDB now activates thread debugging using the libthread_db library
585 when debugging GNU/Linux core dumps, similarly to when debugging
586 live processes. As a result, when debugging a core dump file, GDB
587 is now able to display pthread_t ids of threads. For example, "info
588 threads" shows the same output as when debugging the process when it
589 was live. In earlier releases, you'd see something like this:
592 * 1 LWP 6780 main () at main.c:10
594 While now you see this:
597 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
599 It is also now possible to inspect TLS variables when debugging core
602 When debugging a core dump generated on a machine other than the one
603 used to run GDB, you may need to point GDB at the correct
604 libthread_db library with the "set libthread-db-search-path"
605 command. See the user manual for more details on this command.
607 * When natively debugging programs on PowerPC BookE processors running
608 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
609 which stop execution of the inferior whenever it executes an instruction
610 at any address within the specified range. See the "PowerPC Embedded"
611 section in the user manual for more details.
613 * New features in the GDB remote stub, GDBserver
615 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
616 and i686 LynxOS (version 5.x).
618 ** GDBserver is now supported on Blackfin Linux.
620 * New native configurations
622 ia64 HP-UX ia64-*-hpux*
626 Analog Devices, Inc. Blackfin Processor bfin-*
628 * Ada task switching is now supported on sparc-elf targets when
629 debugging a program using the Ravenscar Profile. For more information,
630 see the "Tasking Support when using the Ravenscar Profile" section
631 in the GDB user manual.
633 * Guile support was removed.
635 * New features in the GNU simulator
637 ** The --map-info flag lists all known core mappings.
639 ** CFI flashes may be simulated via the "cfi" device.
641 *** Changes in GDB 7.2
643 * Shared library support for remote targets by default
645 When GDB is configured for a generic, non-OS specific target, like
646 for example, --target=arm-eabi or one of the many *-*-elf targets,
647 GDB now queries remote stubs for loaded shared libraries using the
648 `qXfer:libraries:read' packet. Previously, shared library support
649 was always disabled for such configurations.
653 ** Argument Dependent Lookup (ADL)
655 In C++ ADL lookup directs function search to the namespaces of its
656 arguments even if the namespace has not been imported.
666 Here the compiler will search for `foo' in the namespace of 'b'
667 and find A::foo. GDB now supports this. This construct is commonly
668 used in the Standard Template Library for operators.
670 ** Improved User Defined Operator Support
672 In addition to member operators, GDB now supports lookup of operators
673 defined in a namespace and imported with a `using' directive, operators
674 defined in the global scope, operators imported implicitly from an
675 anonymous namespace, and the ADL operators mentioned in the previous
677 GDB now also supports proper overload resolution for all the previously
678 mentioned flavors of operators.
680 ** static const class members
682 Printing of static const class members that are initialized in the
683 class definition has been fixed.
685 * Windows Thread Information Block access.
687 On Windows targets, GDB now supports displaying the Windows Thread
688 Information Block (TIB) structure. This structure is visible either
689 by using the new command `info w32 thread-information-block' or, by
690 dereferencing the new convenience variable named `$_tlb', a
691 thread-specific pointer to the TIB. This feature is also supported
692 when remote debugging using GDBserver.
696 Static tracepoints are calls in the user program into a tracing
697 library. One such library is a port of the LTTng kernel tracer to
698 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
699 When debugging with GDBserver, GDB now supports combining the GDB
700 tracepoint machinery with such libraries. For example: the user can
701 use GDB to probe a static tracepoint marker (a call from the user
702 program into the tracing library) with the new "strace" command (see
703 "New commands" below). This creates a "static tracepoint" in the
704 breakpoint list, that can be manipulated with the same feature set
705 as fast and regular tracepoints. E.g., collect registers, local and
706 global variables, collect trace state variables, and define
707 tracepoint conditions. In addition, the user can collect extra
708 static tracepoint marker specific data, by collecting the new
709 $_sdata internal variable. When analyzing the trace buffer, you can
710 inspect $_sdata like any other variable available to GDB. For more
711 information, see the "Tracepoints" chapter in GDB user manual. New
712 remote packets have been defined to support static tracepoints, see
713 the "New remote packets" section below.
715 * Better reconstruction of tracepoints after disconnected tracing
717 GDB will attempt to download the original source form of tracepoint
718 definitions when starting a trace run, and then will upload these
719 upon reconnection to the target, resulting in a more accurate
720 reconstruction of the tracepoints that are in use on the target.
724 You can now exercise direct control over the ways that GDB can
725 affect your program. For instance, you can disallow the setting of
726 breakpoints, so that the program can run continuously (assuming
727 non-stop mode). In addition, the "observer" variable is available
728 to switch all of the different controls; in observer mode, GDB
729 cannot affect the target's behavior at all, which is useful for
730 tasks like diagnosing live systems in the field.
732 * The new convenience variable $_thread holds the number of the
739 Return the address of the Windows Thread Information Block of a given thread.
743 In response to several of the tracepoint packets, the target may now
744 also respond with a number of intermediate `qRelocInsn' request
745 packets before the final result packet, to have GDB handle
746 relocating an instruction to execute at a different address. This
747 is particularly useful for stubs that support fast tracepoints. GDB
748 reports support for this feature in the qSupported packet.
752 List static tracepoint markers in the target program.
756 List static tracepoint markers at a given address in the target
759 qXfer:statictrace:read
761 Read the static trace data collected (by a `collect $_sdata'
762 tracepoint action). The remote stub reports support for this packet
763 to gdb's qSupported query.
767 Send the current settings of GDB's permission flags.
771 Send part of the source (textual) form of a tracepoint definition,
772 which includes location, conditional, and action list.
774 * The source command now accepts a -s option to force searching for the
775 script in the source search path even if the script name specifies
778 * New features in the GDB remote stub, GDBserver
780 - GDBserver now support tracepoints (including fast tracepoints, and
781 static tracepoints). The feature is currently supported by the
782 i386-linux and amd64-linux builds. See the "Tracepoints support
783 in gdbserver" section in the manual for more information.
785 GDBserver JIT compiles the tracepoint's conditional agent
786 expression bytecode into native code whenever possible for low
787 overhead dynamic tracepoints conditionals. For such tracepoints,
788 an expression that examines program state is evaluated when the
789 tracepoint is reached, in order to determine whether to capture
790 trace data. If the condition is simple and false, processing the
791 tracepoint finishes very quickly and no data is gathered.
793 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
794 for static tracepoints support.
796 - GDBserver now supports x86_64 Windows 64-bit debugging.
798 * GDB now sends xmlRegisters= in qSupported packet to indicate that
799 it understands register description.
801 * The --batch flag now disables pagination and queries.
803 * X86 general purpose registers
805 GDB now supports reading/writing byte, word and double-word x86
806 general purpose registers directly. This means you can use, say,
807 $ah or $ax to refer, respectively, to the byte register AH and
808 16-bit word register AX that are actually portions of the 32-bit
809 register EAX or 64-bit register RAX.
811 * The `commands' command now accepts a range of breakpoints to modify.
812 A plain `commands' following a command that creates multiple
813 breakpoints affects all the breakpoints set by that command. This
814 applies to breakpoints set by `rbreak', and also applies when a
815 single `break' command creates multiple breakpoints (e.g.,
816 breakpoints on overloaded c++ functions).
818 * The `rbreak' command now accepts a filename specification as part of
819 its argument, limiting the functions selected by the regex to those
820 in the specified file.
822 * Support for remote debugging Windows and SymbianOS shared libraries
823 from Unix hosts has been improved. Non Windows GDB builds now can
824 understand target reported file names that follow MS-DOS based file
825 system semantics, such as file names that include drive letters and
826 use the backslash character as directory separator. This makes it
827 possible to transparently use the "set sysroot" and "set
828 solib-search-path" on Unix hosts to point as host copies of the
829 target's shared libraries. See the new command "set
830 target-file-system-kind" described below, and the "Commands to
831 specify files" section in the user manual for more information.
835 eval template, expressions...
836 Convert the values of one or more expressions under the control
837 of the string template to a command line, and call it.
839 set target-file-system-kind unix|dos-based|auto
840 show target-file-system-kind
841 Set or show the assumed file system kind for target reported file
844 save breakpoints <filename>
845 Save all current breakpoint definitions to a file suitable for use
846 in a later debugging session. To read the saved breakpoint
847 definitions, use the `source' command.
849 `save tracepoints' is a new alias for `save-tracepoints'. The latter
852 info static-tracepoint-markers
853 Display information about static tracepoint markers in the target.
855 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
856 Define a static tracepoint by probing a marker at the given
857 function, line, address, or marker ID.
861 Enable and disable observer mode.
863 set may-write-registers on|off
864 set may-write-memory on|off
865 set may-insert-breakpoints on|off
866 set may-insert-tracepoints on|off
867 set may-insert-fast-tracepoints on|off
868 set may-interrupt on|off
869 Set individual permissions for GDB effects on the target. Note that
870 some of these settings can have undesirable or surprising
871 consequences, particularly when changed in the middle of a session.
872 For instance, disabling the writing of memory can prevent
873 breakpoints from being inserted, cause single-stepping to fail, or
874 even crash your program, if you disable after breakpoints have been
875 inserted. However, GDB should not crash.
877 set record memory-query on|off
878 show record memory-query
879 Control whether to stop the inferior if memory changes caused
880 by an instruction cannot be recorded.
885 The disassemble command now supports "start,+length" form of two arguments.
889 ** GDB now provides a new directory location, called the python directory,
890 where Python scripts written for GDB can be installed. The location
891 of that directory is <data-directory>/python, where <data-directory>
892 is the GDB data directory. For more details, see section `Scripting
893 GDB using Python' in the manual.
895 ** The GDB Python API now has access to breakpoints, symbols, symbol
896 tables, program spaces, inferiors, threads and frame's code blocks.
897 Additionally, GDB Parameters can now be created from the API, and
898 manipulated via set/show in the CLI.
900 ** New functions gdb.target_charset, gdb.target_wide_charset,
901 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
903 ** New exception gdb.GdbError.
905 ** Pretty-printers are now also looked up in the current program space.
907 ** Pretty-printers can now be individually enabled and disabled.
909 ** GDB now looks for names of Python scripts to auto-load in a
910 special section named `.debug_gdb_scripts', in addition to looking
911 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
913 * Tracepoint actions were unified with breakpoint commands. In particular,
914 there are no longer differences in "info break" output for breakpoints and
915 tracepoints and the "commands" command can be used for both tracepoints and
920 ARM Symbian arm*-*-symbianelf*
922 * D language support.
923 GDB now supports debugging programs written in the D programming
926 * GDB now supports the extended ptrace interface for PowerPC which is
927 available since Linux kernel version 2.6.34. This automatically enables
928 any hardware breakpoints and additional hardware watchpoints available in
929 the processor. The old ptrace interface exposes just one hardware
930 watchpoint and no hardware breakpoints.
932 * GDB is now able to use the Data Value Compare (DVC) register available on
933 embedded PowerPC processors to implement in hardware simple watchpoint
934 conditions of the form:
936 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
938 This works in native GDB running on Linux kernels with the extended ptrace
939 interface mentioned above.
941 *** Changes in GDB 7.1
947 GDB now supports importing of namespaces in C++. This enables the
948 user to inspect variables from imported namespaces. Support for
949 namepace aliasing has also been added. So, if a namespace is
950 aliased in the current scope (e.g. namepace C=A; ) the user can
951 print variables using the alias (e.g. (gdb) print C::x).
955 All known bugs relating to the printing of virtual base class were
956 fixed. It is now possible to call overloaded static methods using a
961 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
962 and reinterpret_cast<> are now handled by the C++ expression parser.
966 Xilinx MicroBlaze microblaze-*-*
971 Xilinx MicroBlaze microblaze
974 * Multi-program debugging.
976 GDB now has support for multi-program (a.k.a. multi-executable or
977 multi-exec) debugging. This allows for debugging multiple inferiors
978 simultaneously each running a different program under the same GDB
979 session. See "Debugging Multiple Inferiors and Programs" in the
980 manual for more information. This implied some user visible changes
981 in the multi-inferior support. For example, "info inferiors" now
982 lists inferiors that are not running yet or that have exited
983 already. See also "New commands" and "New options" below.
985 * New tracing features
987 GDB's tracepoint facility now includes several new features:
989 ** Trace state variables
991 GDB tracepoints now include support for trace state variables, which
992 are variables managed by the target agent during a tracing
993 experiment. They are useful for tracepoints that trigger each
994 other, so for instance one tracepoint can count hits in a variable,
995 and then a second tracepoint has a condition that is true when the
996 count reaches a particular value. Trace state variables share the
997 $-syntax of GDB convenience variables, and can appear in both
998 tracepoint actions and condition expressions. Use the "tvariable"
999 command to create, and "info tvariables" to view; see "Trace State
1000 Variables" in the manual for more detail.
1004 GDB now includes an option for defining fast tracepoints, which
1005 targets may implement more efficiently, such as by installing a jump
1006 into the target agent rather than a trap instruction. The resulting
1007 speedup can be by two orders of magnitude or more, although the
1008 tradeoff is that some program locations on some target architectures
1009 might not allow fast tracepoint installation, for instance if the
1010 instruction to be replaced is shorter than the jump. To request a
1011 fast tracepoint, use the "ftrace" command, with syntax identical to
1012 the regular trace command.
1014 ** Disconnected tracing
1016 It is now possible to detach GDB from the target while it is running
1017 a trace experiment, then reconnect later to see how the experiment
1018 is going. In addition, a new variable disconnected-tracing lets you
1019 tell the target agent whether to continue running a trace if the
1020 connection is lost unexpectedly.
1024 GDB now has the ability to save the trace buffer into a file, and
1025 then use that file as a target, similarly to you can do with
1026 corefiles. You can select trace frames, print data that was
1027 collected in them, and use tstatus to display the state of the
1028 tracing run at the moment that it was saved. To create a trace
1029 file, use "tsave <filename>", and to use it, do "target tfile
1032 ** Circular trace buffer
1034 You can ask the target agent to handle the trace buffer as a
1035 circular buffer, discarding the oldest trace frames to make room for
1036 newer ones, by setting circular-trace-buffer to on. This feature may
1037 not be available for all target agents.
1042 The disassemble command, when invoked with two arguments, now requires
1043 the arguments to be comma-separated.
1046 The info variables command now displays variable definitions. Files
1047 which only declare a variable are not shown.
1050 The source command is now capable of sourcing Python scripts.
1051 This feature is dependent on the debugger being build with Python
1054 Related to this enhancement is also the introduction of a new command
1055 "set script-extension" (see below).
1057 * New commands (for set/show, see "New options" below)
1059 record save [<FILENAME>]
1060 Save a file (in core file format) containing the process record
1061 execution log for replay debugging at a later time.
1063 record restore <FILENAME>
1064 Restore the process record execution log that was saved at an
1065 earlier time, for replay debugging.
1067 add-inferior [-copies <N>] [-exec <FILENAME>]
1070 clone-inferior [-copies <N>] [ID]
1071 Make a new inferior ready to execute the same program another
1072 inferior has loaded.
1077 maint info program-spaces
1078 List the program spaces loaded into GDB.
1080 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1081 show remote interrupt-sequence
1082 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1083 as the sequence to the remote target in order to interrupt the execution.
1084 Ctrl-C is a default. Some system prefers BREAK which is high level of
1085 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1086 Magic SysRq g. It is BREAK signal and character 'g'.
1088 set remote interrupt-on-connect [on | off]
1089 show remote interrupt-on-connect
1090 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1091 remote target when gdb connects to it. This is needed when you debug
1094 set remotebreak [on | off]
1096 Deprecated. Use "set/show remote interrupt-sequence" instead.
1098 tvariable $NAME [ = EXP ]
1099 Create or modify a trace state variable.
1102 List trace state variables and their values.
1104 delete tvariable $NAME ...
1105 Delete one or more trace state variables.
1108 Evaluate the given expressions without collecting anything into the
1109 trace buffer. (Valid in tracepoint actions only.)
1111 ftrace FN / FILE:LINE / *ADDR
1112 Define a fast tracepoint at the given function, line, or address.
1114 * New expression syntax
1116 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1117 GDB now parses 0b101010 identically with 42.
1121 set follow-exec-mode new|same
1122 show follow-exec-mode
1123 Control whether GDB reuses the same inferior across an exec call or
1124 creates a new one. This is useful to be able to restart the old
1125 executable after the inferior having done an exec call.
1127 set default-collect EXPR, ...
1128 show default-collect
1129 Define a list of expressions to be collected at each tracepoint.
1130 This is a useful way to ensure essential items are not overlooked,
1131 such as registers or a critical global variable.
1133 set disconnected-tracing
1134 show disconnected-tracing
1135 If set to 1, the target is instructed to continue tracing if it
1136 loses its connection to GDB. If 0, the target is to stop tracing
1139 set circular-trace-buffer
1140 show circular-trace-buffer
1141 If set to on, the target is instructed to use a circular trace buffer
1142 and discard the oldest trace frames instead of stopping the trace due
1143 to a full trace buffer. If set to off, the trace stops when the buffer
1144 fills up. Some targets may not support this.
1146 set script-extension off|soft|strict
1147 show script-extension
1148 If set to "off", the debugger does not perform any script language
1149 recognition, and all sourced files are assumed to be GDB scripts.
1150 If set to "soft" (the default), files are sourced according to
1151 filename extension, falling back to GDB scripts if the first
1153 If set to "strict", files are sourced according to filename extension.
1155 set ada trust-PAD-over-XVS on|off
1156 show ada trust-PAD-over-XVS
1157 If off, activate a workaround against a bug in the debugging information
1158 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1159 the GCC sources for more information about the GNAT encoding and
1160 PAD types in particular). It is always safe to set this option to
1161 off, but this introduces a slight performance penalty. The default
1164 * Python API Improvements
1166 ** GDB provides the new class gdb.LazyString. This is useful in
1167 some pretty-printing cases. The new method gdb.Value.lazy_string
1168 provides a simple way to create objects of this type.
1170 ** The fields returned by gdb.Type.fields now have an
1171 `is_base_class' attribute.
1173 ** The new method gdb.Type.range returns the range of an array type.
1175 ** The new method gdb.parse_and_eval can be used to parse and
1176 evaluate an expression.
1178 * New remote packets
1181 Define a trace state variable.
1184 Get the current value of a trace state variable.
1187 Set desired tracing behavior upon disconnection.
1190 Set the trace buffer to be linear or circular.
1193 Get data about the tracepoints currently in use.
1197 Process record now works correctly with hardware watchpoints.
1199 Multiple bug fixes have been made to the mips-irix port, making it
1200 much more reliable. In particular:
1201 - Debugging threaded applications is now possible again. Previously,
1202 GDB would hang while starting the program, or while waiting for
1203 the program to stop at a breakpoint.
1204 - Attaching to a running process no longer hangs.
1205 - An error occurring while loading a core file has been fixed.
1206 - Changing the value of the PC register now works again. This fixes
1207 problems observed when using the "jump" command, or when calling
1208 a function from GDB, or even when assigning a new value to $pc.
1209 - With the "finish" and "return" commands, the return value for functions
1210 returning a small array is now correctly printed.
1211 - It is now possible to break on shared library code which gets executed
1212 during a shared library init phase (code executed while executing
1213 their .init section). Previously, the breakpoint would have no effect.
1214 - GDB is now able to backtrace through the signal handler for
1215 non-threaded programs.
1217 PIE (Position Independent Executable) programs debugging is now supported.
1218 This includes debugging execution of PIC (Position Independent Code) shared
1219 libraries although for that, it should be possible to run such libraries as an
1222 *** Changes in GDB 7.0
1224 * GDB now has an interface for JIT compilation. Applications that
1225 dynamically generate code can create symbol files in memory and register
1226 them with GDB. For users, the feature should work transparently, and
1227 for JIT developers, the interface is documented in the GDB manual in the
1228 "JIT Compilation Interface" chapter.
1230 * Tracepoints may now be conditional. The syntax is as for
1231 breakpoints; either an "if" clause appended to the "trace" command,
1232 or the "condition" command is available. GDB sends the condition to
1233 the target for evaluation using the same bytecode format as is used
1234 for tracepoint actions.
1236 * The disassemble command now supports: an optional /r modifier, print the
1237 raw instructions in hex as well as in symbolic form, and an optional /m
1238 modifier to print mixed source+assembly.
1240 * Process record and replay
1242 In a architecture environment that supports ``process record and
1243 replay'', ``process record and replay'' target can record a log of
1244 the process execution, and replay it with both forward and reverse
1247 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
1248 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
1249 set execution-direction {forward|reverse}, for targets that support
1252 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
1253 feature is available with a native GDB running on kernel version
1256 * GDB now has support for multi-byte and wide character sets on the
1257 target. Strings whose character type is wchar_t, char16_t, or
1258 char32_t are now correctly printed. GDB supports wide- and unicode-
1259 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
1260 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
1261 `printf'. This feature requires iconv to work properly; if your
1262 system does not have a working iconv, GDB can use GNU libiconv. See
1263 the installation instructions for more information.
1265 * GDB now supports automatic retrieval of shared library files from
1266 remote targets. To use this feature, specify a system root that begins
1267 with the `remote:' prefix, either via the `set sysroot' command or via
1268 the `--with-sysroot' configure-time option.
1270 * "info sharedlibrary" now takes an optional regex of libraries to show,
1271 and it now reports if a shared library has no debugging information.
1273 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
1274 now complete on file names.
1276 * When completing in expressions, gdb will attempt to limit
1277 completions to allowable structure or union fields, where appropriate.
1278 For instance, consider:
1280 # struct example { int f1; double f2; };
1281 # struct example variable;
1284 If the user types TAB at the end of this command line, the available
1285 completions will be "f1" and "f2".
1287 * Inlined functions are now supported. They show up in backtraces, and
1288 the "step", "next", and "finish" commands handle them automatically.
1290 * GDB now supports the token-splicing (##) and stringification (#)
1291 operators when expanding macros. It also supports variable-arity
1294 * GDB now supports inspecting extra signal information, exported by
1295 the new $_siginfo convenience variable. The feature is currently
1296 implemented on linux ARM, i386 and amd64.
1298 * GDB can now display the VFP floating point registers and NEON vector
1299 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
1300 can provide these registers (requires Linux 2.6.30 or later). Remote
1301 and simulator targets may also provide them.
1303 * New remote packets
1306 Search memory for a sequence of bytes.
1309 Turn off `+'/`-' protocol acknowledgments to permit more efficient
1310 operation over reliable transport links. Use of this packet is
1311 controlled by the `set remote noack-packet' command.
1314 Kill the process with the specified process ID. Use this in preference
1315 to `k' when multiprocess protocol extensions are supported.
1318 Obtains additional operating system information
1322 Read or write additional signal information.
1324 * Removed remote protocol undocumented extension
1326 An undocumented extension to the remote protocol's `S' stop reply
1327 packet that permited the stub to pass a process id was removed.
1328 Remote servers should use the `T' stop reply packet instead.
1330 * GDB now supports multiple function calling conventions according to the
1331 DWARF-2 DW_AT_calling_convention function attribute.
1333 * The SH target utilizes the aforementioned change to distinguish between gcc
1334 and Renesas calling convention. It also adds the new CLI commands
1335 `set/show sh calling-convention'.
1337 * GDB can now read compressed debug sections, as produced by GNU gold
1338 with the --compress-debug-sections=zlib flag.
1340 * 64-bit core files are now supported on AIX.
1342 * Thread switching is now supported on Tru64.
1344 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
1345 which will be allocated using malloc later in program execution.
1347 * The qXfer:libraries:read remote procotol packet now allows passing a
1348 list of section offsets.
1350 * On GNU/Linux, GDB can now attach to stopped processes. Several race
1351 conditions handling signals delivered during attach or thread creation
1352 have also been fixed.
1354 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
1355 From the user's standpoint, all unqualified instances of True and False
1356 are treated as the standard definitions, regardless of context.
1358 * GDB now parses C++ symbol and type names more flexibly. For
1361 template<typename T> class C { };
1364 GDB will now correctly handle all of:
1366 ptype C<char const *>
1367 ptype C<char const*>
1368 ptype C<const char *>
1369 ptype C<const char*>
1371 * New features in the GDB remote stub, gdbserver
1373 - The "--wrapper" command-line argument tells gdbserver to use a
1374 wrapper program to launch programs for debugging.
1376 - On PowerPC and S/390 targets, it is now possible to use a single
1377 gdbserver executable to debug both 32-bit and 64-bit programs.
1378 (This requires gdbserver itself to be built as a 64-bit executable.)
1380 - gdbserver uses the new noack protocol mode for TCP connections to
1381 reduce communications latency, if also supported and enabled in GDB.
1383 - Support for the sparc64-linux-gnu target is now included in
1386 - The amd64-linux build of gdbserver now supports debugging both
1387 32-bit and 64-bit programs.
1389 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
1390 now support hardware watchpoints, and will use them automatically
1395 GDB now has support for scripting using Python. Whether this is
1396 available is determined at configure time.
1398 New GDB commands can now be written in Python.
1400 * Ada tasking support
1402 Ada tasks can now be inspected in GDB. The following commands have
1406 Print the list of Ada tasks.
1408 Print detailed information about task number N.
1410 Print the task number of the current task.
1412 Switch the context of debugging to task number N.
1414 * Support for user-defined prefixed commands. The "define" command can
1415 add new commands to existing prefixes, e.g. "target".
1417 * Multi-inferior, multi-process debugging.
1419 GDB now has generalized support for multi-inferior debugging. See
1420 "Debugging Multiple Inferiors" in the manual for more information.
1421 Although availability still depends on target support, the command
1422 set is more uniform now. The GNU/Linux specific multi-forks support
1423 has been migrated to this new framework. This implied some user
1424 visible changes; see "New commands" and also "Removed commands"
1427 * Target descriptions can now describe the target OS ABI. See the
1428 "Target Description Format" section in the user manual for more
1431 * Target descriptions can now describe "compatible" architectures
1432 to indicate that the target can execute applications for a different
1433 architecture in addition to those for the main target architecture.
1434 See the "Target Description Format" section in the user manual for
1437 * Multi-architecture debugging.
1439 GDB now includes general supports for debugging applications on
1440 hybrid systems that use more than one single processor architecture
1441 at the same time. Each such hybrid architecture still requires
1442 specific support to be added. The only hybrid architecture supported
1443 in this version of GDB is the Cell Broadband Engine.
1445 * GDB now supports integrated debugging of Cell/B.E. applications that
1446 use both the PPU and SPU architectures. To enable support for hybrid
1447 Cell/B.E. debugging, you need to configure GDB to support both the
1448 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
1449 --enable-targets configure option.
1451 * Non-stop mode debugging.
1453 For some targets, GDB now supports an optional mode of operation in
1454 which you can examine stopped threads while other threads continue
1455 to execute freely. This is referred to as non-stop mode, with the
1456 old mode referred to as all-stop mode. See the "Non-Stop Mode"
1457 section in the user manual for more information.
1459 To be able to support remote non-stop debugging, a remote stub needs
1460 to implement the non-stop mode remote protocol extensions, as
1461 described in the "Remote Non-Stop" section of the user manual. The
1462 GDB remote stub, gdbserver, has been adjusted to support these
1463 extensions on linux targets.
1465 * New commands (for set/show, see "New options" below)
1467 catch syscall [NAME(S) | NUMBER(S)]
1468 Catch system calls. Arguments, which should be names of system
1469 calls or their numbers, mean catch only those syscalls. Without
1470 arguments, every syscall will be caught. When the inferior issues
1471 any of the specified syscalls, GDB will stop and announce the system
1472 call, both when it is called and when its call returns. This
1473 feature is currently available with a native GDB running on the
1474 Linux Kernel, under the following architectures: x86, x86_64,
1475 PowerPC and PowerPC64.
1477 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
1479 Search memory for a sequence of bytes.
1481 maint set python print-stack
1482 maint show python print-stack
1483 Show a stack trace when an error is encountered in a Python script.
1486 Invoke CODE by passing it to the Python interpreter.
1491 These allow macros to be defined, undefined, and listed
1495 Show operating system information about processes.
1498 List the inferiors currently under GDB's control.
1501 Switch focus to inferior number NUM.
1504 Detach from inferior number NUM.
1507 Kill inferior number NUM.
1511 set spu stop-on-load
1512 show spu stop-on-load
1513 Control whether to stop for new SPE threads during Cell/B.E. debugging.
1515 set spu auto-flush-cache
1516 show spu auto-flush-cache
1517 Control whether to automatically flush the software-managed cache
1518 during Cell/B.E. debugging.
1520 set sh calling-convention
1521 show sh calling-convention
1522 Control the calling convention used when calling SH target functions.
1525 show debug timestamp
1526 Control display of timestamps with GDB debugging output.
1528 set disassemble-next-line
1529 show disassemble-next-line
1530 Control display of disassembled source lines or instructions when
1533 set remote noack-packet
1534 show remote noack-packet
1535 Set/show the use of remote protocol QStartNoAckMode packet. See above
1536 under "New remote packets."
1538 set remote query-attached-packet
1539 show remote query-attached-packet
1540 Control use of remote protocol `qAttached' (query-attached) packet.
1542 set remote read-siginfo-object
1543 show remote read-siginfo-object
1544 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
1547 set remote write-siginfo-object
1548 show remote write-siginfo-object
1549 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
1552 set remote reverse-continue
1553 show remote reverse-continue
1554 Control use of remote protocol 'bc' (reverse-continue) packet.
1556 set remote reverse-step
1557 show remote reverse-step
1558 Control use of remote protocol 'bs' (reverse-step) packet.
1560 set displaced-stepping
1561 show displaced-stepping
1562 Control displaced stepping mode. Displaced stepping is a way to
1563 single-step over breakpoints without removing them from the debuggee.
1564 Also known as "out-of-line single-stepping".
1567 show debug displaced
1568 Control display of debugging info for displaced stepping.
1570 maint set internal-error
1571 maint show internal-error
1572 Control what GDB does when an internal error is detected.
1574 maint set internal-warning
1575 maint show internal-warning
1576 Control what GDB does when an internal warning is detected.
1581 Use a wrapper program to launch programs for debugging.
1583 set multiple-symbols (all|ask|cancel)
1584 show multiple-symbols
1585 The value of this variable can be changed to adjust the debugger behavior
1586 when an expression or a breakpoint location contains an ambiguous symbol
1587 name (an overloaded function name, for instance).
1589 set breakpoint always-inserted
1590 show breakpoint always-inserted
1591 Keep breakpoints always inserted in the target, as opposed to inserting
1592 them when resuming the target, and removing them when the target stops.
1593 This option can improve debugger performance on slow remote targets.
1595 set arm fallback-mode (arm|thumb|auto)
1596 show arm fallback-mode
1597 set arm force-mode (arm|thumb|auto)
1599 These commands control how ARM GDB determines whether instructions
1600 are ARM or Thumb. The default for both settings is auto, which uses
1601 the current CPSR value for instructions without symbols; previous
1602 versions of GDB behaved as if "set arm fallback-mode arm".
1604 set disable-randomization
1605 show disable-randomization
1606 Standalone programs run with the virtual address space randomization enabled
1607 by default on some platforms. This option keeps the addresses stable across
1608 multiple debugging sessions.
1612 Control whether other threads are stopped or not when some thread hits
1617 Requests that asynchronous execution is enabled in the target, if available.
1618 In this case, it's possible to resume target in the background, and interact
1619 with GDB while the target is running. "show target-async" displays the
1620 current state of asynchronous execution of the target.
1622 set target-wide-charset
1623 show target-wide-charset
1624 The target-wide-charset is the name of the character set that GDB
1625 uses when printing characters whose type is wchar_t.
1627 set tcp auto-retry (on|off)
1629 set tcp connect-timeout
1630 show tcp connect-timeout
1631 These commands allow GDB to retry failed TCP connections to a remote stub
1632 with a specified timeout period; this is useful if the stub is launched
1633 in parallel with GDB but may not be ready to accept connections immediately.
1635 set libthread-db-search-path
1636 show libthread-db-search-path
1637 Control list of directories which GDB will search for appropriate
1640 set schedule-multiple (on|off)
1641 show schedule-multiple
1642 Allow GDB to resume all threads of all processes or only threads of
1643 the current process.
1647 Use more aggressive caching for accesses to the stack. This improves
1648 performance of remote debugging (particularly backtraces) without
1649 affecting correctness.
1651 set interactive-mode (on|off|auto)
1652 show interactive-mode
1653 Control whether GDB runs in interactive mode (on) or not (off).
1654 When in interactive mode, GDB waits for the user to answer all
1655 queries. Otherwise, GDB does not wait and assumes the default
1656 answer. When set to auto (the default), GDB determines which
1657 mode to use based on the stdin settings.
1662 For program forks, this is replaced by the new more generic `info
1663 inferiors' command. To list checkpoints, you can still use the
1664 `info checkpoints' command, which was an alias for the `info forks'
1668 Replaced by the new `inferior' command. To switch between
1669 checkpoints, you can still use the `restart' command, which was an
1670 alias for the `fork' command.
1673 This is removed, since some targets don't have a notion of
1674 processes. To switch between processes, you can still use the
1675 `inferior' command using GDB's own inferior number.
1678 For program forks, this is replaced by the new more generic `kill
1679 inferior' command. To delete a checkpoint, you can still use the
1680 `delete checkpoint' command, which was an alias for the `delete
1684 For program forks, this is replaced by the new more generic `detach
1685 inferior' command. To detach a checkpoint, you can still use the
1686 `detach checkpoint' command, which was an alias for the `detach
1689 * New native configurations
1691 x86/x86_64 Darwin i[34567]86-*-darwin*
1693 x86_64 MinGW x86_64-*-mingw*
1697 Lattice Mico32 lm32-*
1698 x86 DICOS i[34567]86-*-dicos*
1699 x86_64 DICOS x86_64-*-dicos*
1702 * The GDB remote stub, gdbserver, now supports x86 Windows CE
1703 (mingw32ce) debugging.
1709 These commands were actually not implemented on any target.
1711 *** Changes in GDB 6.8
1713 * New native configurations
1715 NetBSD/hppa hppa*-*netbsd*
1716 Xtensa GNU/Linux xtensa*-*-linux*
1720 NetBSD/hppa hppa*-*-netbsd*
1721 Xtensa GNU/Lunux xtensa*-*-linux*
1723 * Change in command line behavior -- corefiles vs. process ids.
1725 When the '-p NUMBER' or '--pid NUMBER' options are used, and
1726 attaching to process NUMBER fails, GDB no longer attempts to open a
1727 core file named NUMBER. Attaching to a program using the -c option
1728 is no longer supported. Instead, use the '-p' or '--pid' options.
1730 * GDB can now be built as a native debugger for debugging Windows x86
1731 (mingw32) Portable Executable (PE) programs.
1733 * Pending breakpoints no longer change their number when their address
1736 * GDB now supports breakpoints with multiple locations,
1737 including breakpoints on C++ constructors, inside C++ templates,
1738 and in inlined functions.
1740 * GDB's ability to debug optimized code has been improved. GDB more
1741 accurately identifies function bodies and lexical blocks that occupy
1742 more than one contiguous range of addresses.
1744 * Target descriptions can now describe registers for PowerPC.
1746 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
1747 registers on PowerPC targets.
1749 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
1750 targets even when the libthread_db library is not available.
1752 * The GDB remote stub, gdbserver, now supports the new file transfer
1753 commands (remote put, remote get, and remote delete).
1755 * The GDB remote stub, gdbserver, now supports run and attach in
1756 extended-remote mode.
1758 * hppa*64*-*-hpux11* target broken
1759 The debugger is unable to start a program and fails with the following
1760 error: "Error trying to get information about dynamic linker".
1761 The gdb-6.7 release is also affected.
1763 * GDB now supports the --enable-targets= configure option to allow
1764 building a single GDB executable that supports multiple remote
1765 target architectures.
1767 * GDB now supports debugging C and C++ programs which use the
1768 Decimal Floating Point extension. In addition, the PowerPC target
1769 now has a set of pseudo-registers to inspect decimal float values
1770 stored in two consecutive float registers.
1772 * The -break-insert MI command can optionally create pending
1775 * Improved support for debugging Ada
1776 Many improvements to the Ada language support have been made. These
1778 - Better support for Ada2005 interface types
1779 - Improved handling of arrays and slices in general
1780 - Better support for Taft-amendment types
1781 - The '{type} ADDRESS' expression is now allowed on the left hand-side
1783 - Improved command completion in Ada
1786 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
1791 set print frame-arguments (all|scalars|none)
1792 show print frame-arguments
1793 The value of this variable can be changed to control which argument
1794 values should be printed by the debugger when displaying a frame.
1799 Transfer files to and from a remote target, and delete remote files.
1806 Transfer files to and from a remote target, and delete remote files.
1808 * New remote packets
1815 Open, close, read, write, and delete files on the remote system.
1818 Attach to an existing process on the remote system, in extended-remote
1822 Run a new process on the remote system, in extended-remote mode.
1824 *** Changes in GDB 6.7
1826 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
1827 bfd, libiberty and opcodes, as revealed by static analysis donated by
1828 Coverity, Inc. (http://scan.coverity.com).
1830 * When looking up multiply-defined global symbols, GDB will now prefer the
1831 symbol definition in the current shared library if it was built using the
1832 -Bsymbolic linker option.
1834 * When the Text User Interface (TUI) is not configured, GDB will now
1835 recognize the -tui command-line option and print a message that the TUI
1838 * The GDB remote stub, gdbserver, now has lower overhead for high
1839 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
1841 * GDB for MIPS targets now autodetects whether a remote target provides
1842 32-bit or 64-bit register values.
1844 * Support for C++ member pointers has been improved.
1846 * GDB now understands XML target descriptions, which specify the
1847 target's overall architecture. GDB can read a description from
1848 a local file or over the remote serial protocol.
1850 * Vectors of single-byte data use a new integer type which is not
1851 automatically displayed as character or string data.
1853 * The /s format now works with the print command. It displays
1854 arrays of single-byte integers and pointers to single-byte integers
1857 * Target descriptions can now describe target-specific registers,
1858 for architectures which have implemented the support (currently
1859 only ARM, M68K, and MIPS).
1861 * GDB and the GDB remote stub, gdbserver, now support the XScale
1864 * The GDB remote stub, gdbserver, has been updated to support
1865 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
1866 has been rewritten to use the standard GDB remote protocol.
1868 * GDB can now step into C++ functions which are called through thunks.
1870 * GDB for the Cell/B.E. SPU now supports overlay debugging.
1872 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
1873 layout. It also supports a TextSeg= and DataSeg= response when only
1874 segment base addresses (rather than offsets) are available.
1876 * The /i format now outputs any trailing branch delay slot instructions
1877 immediately following the last instruction within the count specified.
1879 * The GDB remote protocol "T" stop reply packet now supports a
1880 "library" response. Combined with the new "qXfer:libraries:read"
1881 packet, this response allows GDB to debug shared libraries on targets
1882 where the operating system manages the list of loaded libraries (e.g.
1883 Windows and SymbianOS).
1885 * The GDB remote stub, gdbserver, now supports dynamic link libraries
1886 (DLLs) on Windows and Windows CE targets.
1888 * GDB now supports a faster verification that a .debug file matches its binary
1889 according to its build-id signature, if the signature is present.
1895 Enable or disable hardware flow control (RTS/CTS) on the serial port
1896 when debugging using remote targets.
1898 set mem inaccessible-by-default
1899 show mem inaccessible-by-default
1900 If the target supplies a memory map, for instance via the remote
1901 protocol's "qXfer:memory-map:read" packet, setting this variable
1902 prevents GDB from accessing memory outside the memory map. This
1903 is useful for targets with memory mapped registers or which react
1904 badly to accesses of unmapped address space.
1906 set breakpoint auto-hw
1907 show breakpoint auto-hw
1908 If the target supplies a memory map, for instance via the remote
1909 protocol's "qXfer:memory-map:read" packet, setting this variable
1910 lets GDB use hardware breakpoints automatically for memory regions
1911 where it can not use software breakpoints. This covers both the
1912 "break" command and internal breakpoints used for other commands
1913 including "next" and "finish".
1916 catch exception unhandled
1917 Stop the program execution when Ada exceptions are raised.
1920 Stop the program execution when an Ada assertion failed.
1924 Set an alternate system root for target files. This is a more
1925 general version of "set solib-absolute-prefix", which is now
1926 an alias to "set sysroot".
1929 Provide extended SPU facility status information. This set of
1930 commands is available only when debugging the Cell/B.E. SPU
1933 * New native configurations
1935 OpenBSD/sh sh*-*openbsd*
1938 unset tdesc filename
1940 Use the specified local file as an XML target description, and do
1941 not query the target for its built-in description.
1945 OpenBSD/sh sh*-*-openbsd*
1946 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
1947 Toshiba Media Processor mep-elf
1949 * New remote packets
1952 Ignore the specified signals; pass them directly to the debugged program
1953 without stopping other threads or reporting them to GDB.
1955 qXfer:features:read:
1956 Read an XML target description from the target, which describes its
1961 Read or write contents of an spufs file on the target system. These
1962 packets are available only on the Cell/B.E. SPU architecture.
1964 qXfer:libraries:read:
1965 Report the loaded shared libraries. Combined with new "T" packet
1966 response, this packet allows GDB to debug shared libraries on
1967 targets where the operating system manages the list of loaded
1968 libraries (e.g. Windows and SymbianOS).
1972 Support for these obsolete configurations has been removed.
1980 i[34567]86-*-lynxos*
1981 i[34567]86-*-netware*
1982 i[34567]86-*-sco3.2v5*
1983 i[34567]86-*-sco3.2v4*
1985 i[34567]86-*-sysv4.2*
1988 i[34567]86-*-unixware2*
1989 i[34567]86-*-unixware*
1998 * Other removed features
2005 Various m68k-only ROM monitors.
2012 Various Renesas ROM monitors and debugging interfaces for SH and
2017 Support for a Macraigor serial interface to on-chip debugging.
2018 GDB does not directly support the newer parallel or USB
2023 A debug information format. The predecessor to DWARF 2 and
2024 DWARF 3, which are still supported.
2026 Support for the HP aCC compiler on HP-UX/PA-RISC
2028 SOM-encapsulated symbolic debugging information, automatic
2029 invocation of pxdb, and the aCC custom C++ ABI. This does not
2030 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2031 with aCC can still be debugged on an assembly level.
2033 MIPS ".pdr" sections
2035 A MIPS-specific format used to describe stack frame layout
2036 in debugging information.
2040 GDB could work with an older version of Guile to debug
2041 the interpreter and Scheme programs running in it.
2043 set mips stack-arg-size
2044 set mips saved-gpreg-size
2046 Use "set mips abi" to control parameter passing for MIPS.
2048 *** Changes in GDB 6.6
2053 Cell Broadband Engine SPU spu-elf
2055 * GDB can now be configured as a cross-debugger targeting native Windows
2056 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2057 running on a Windows system over TCP/IP to debug Windows programs.
2059 * The GDB remote stub, gdbserver, has been updated to support Windows and
2060 Cygwin debugging. Both single-threaded and multi-threaded programs are
2063 * The "set trust-readonly-sections" command works again. This command was
2064 broken in GDB 6.3, 6.4, and 6.5.
2066 * The "load" command now supports writing to flash memory, if the remote
2067 stub provides the required support.
2069 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2070 longer requires symbolic debug information (e.g. DWARF-2).
2075 unset substitute-path
2076 show substitute-path
2077 Manage a list of substitution rules that GDB uses to rewrite the name
2078 of the directories where the sources are located. This can be useful
2079 for instance when the sources were moved to a different location
2080 between compilation and debugging.
2084 Print each CLI command as it is executed. Each command is prefixed with
2085 a number of `+' symbols representing the nesting depth.
2086 The source command now has a `-v' option to enable the same feature.
2090 The ARM Demon monitor support (RDP protocol, "target rdp").
2092 Kernel Object Display, an embedded debugging feature which only worked with
2093 an obsolete version of Cisco IOS.
2095 The 'set download-write-size' and 'show download-write-size' commands.
2097 * New remote packets
2100 Tell a stub about GDB client features, and request remote target features.
2101 The first feature implemented is PacketSize, which allows the target to
2102 specify the size of packets it can handle - to minimize the number of
2103 packets required and improve performance when connected to a remote
2107 Fetch an OS auxilliary vector from the remote stub. This packet is a
2108 more efficient replacement for qPart:auxv:read.
2110 qXfer:memory-map:read:
2111 Fetch a memory map from the remote stub, including information about
2112 RAM, ROM, and flash memory devices.
2117 Erase and program a flash memory device.
2119 * Removed remote packets
2122 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2123 used it, and only gdbserver implemented it.
2125 *** Changes in GDB 6.5
2129 Renesas M32C/M16C m32c-elf
2131 Morpho Technologies ms1 ms1-elf
2135 init-if-undefined Initialize a convenience variable, but
2136 only if it doesn't already have a value.
2138 The following commands are presently only implemented for native GNU/Linux:
2140 checkpoint Save a snapshot of the program state.
2142 restart <n> Return the program state to a
2143 previously saved state.
2145 info checkpoints List currently saved checkpoints.
2147 delete-checkpoint <n> Delete a previously saved checkpoint.
2149 set|show detach-on-fork Tell gdb whether to detach from a newly
2150 forked process, or to keep debugging it.
2152 info forks List forks of the user program that
2153 are available to be debugged.
2155 fork <n> Switch to debugging one of several
2156 forks of the user program that are
2157 available to be debugged.
2159 delete-fork <n> Delete a fork from the list of forks
2160 that are available to be debugged (and
2161 kill the forked process).
2163 detach-fork <n> Delete a fork from the list of forks
2164 that are available to be debugged (and
2165 allow the process to continue).
2169 Morpho Technologies ms2 ms1-elf
2171 * Improved Windows host support
2173 GDB now builds as a cross debugger hosted on i686-mingw32, including
2174 native console support, and remote communications using either
2175 network sockets or serial ports.
2177 * Improved Modula-2 language support
2179 GDB can now print most types in the Modula-2 syntax. This includes:
2180 basic types, set types, record types, enumerated types, range types,
2181 pointer types and ARRAY types. Procedure var parameters are correctly
2182 printed and hexadecimal addresses and character constants are also
2183 written in the Modula-2 syntax. Best results can be obtained by using
2184 GNU Modula-2 together with the -gdwarf-2 command line option.
2188 The ARM rdi-share module.
2190 The Netware NLM debug server.
2192 *** Changes in GDB 6.4
2194 * New native configurations
2196 OpenBSD/arm arm*-*-openbsd*
2197 OpenBSD/mips64 mips64-*-openbsd*
2201 Morpho Technologies ms1 ms1-elf
2203 * New command line options
2205 --batch-silent As for --batch, but totally silent.
2206 --return-child-result The debugger will exist with the same value
2207 the child (debugged) program exited with.
2208 --eval-command COMMAND, -ex COMMAND
2209 Execute a single GDB CLI command. This may be
2210 specified multiple times and in conjunction
2211 with the --command (-x) option.
2213 * Deprecated commands removed
2215 The following commands, that were deprecated in 2000, have been
2219 set|show arm disassembly-flavor set|show arm disassembler
2220 othernames set arm disassembler
2221 set|show remotedebug set|show debug remote
2222 set|show archdebug set|show debug arch
2223 set|show eventdebug set|show debug event
2226 * New BSD user-level threads support
2228 It is now possible to debug programs using the user-level threads
2229 library on OpenBSD and FreeBSD. Currently supported (target)
2232 FreeBSD/amd64 x86_64-*-freebsd*
2233 FreeBSD/i386 i386-*-freebsd*
2234 OpenBSD/i386 i386-*-openbsd*
2236 Note that the new kernel threads libraries introduced in FreeBSD 5.x
2237 are not yet supported.
2239 * New support for Matsushita MN10300 w/sim added
2240 (Work in progress). mn10300-elf.
2242 * REMOVED configurations and files
2244 VxWorks and the XDR protocol *-*-vxworks
2245 Motorola MCORE mcore-*-*
2246 National Semiconductor NS32000 ns32k-*-*
2248 * New "set print array-indexes" command
2250 After turning this setting "on", GDB prints the index of each element
2251 when displaying arrays. The default is "off" to preserve the previous
2254 * VAX floating point support
2256 GDB now supports the not-quite-ieee VAX F and D floating point formats.
2258 * User-defined command support
2260 In addition to using $arg0..$arg9 for argument passing, it is now possible
2261 to use $argc to determine now many arguments have been passed. See the
2262 section on user-defined commands in the user manual for more information.
2264 *** Changes in GDB 6.3:
2266 * New command line option
2268 GDB now accepts -l followed by a number to set the timeout for remote
2271 * GDB works with GCC -feliminate-dwarf2-dups
2273 GDB now supports a more compact representation of DWARF-2 debug
2274 information using DW_FORM_ref_addr references. These are produced
2275 by GCC with the option -feliminate-dwarf2-dups and also by some
2276 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
2277 to use -feliminate-dwarf2-dups.
2279 * Internationalization
2281 When supported by the host system, GDB will be built with
2282 internationalization (libintl). The task of marking up the sources is
2283 continued, we're looking forward to our first translation.
2287 Initial support for debugging programs compiled with the GNAT
2288 implementation of the Ada programming language has been integrated
2289 into GDB. In this release, support is limited to expression evaluation.
2291 * New native configurations
2293 GNU/Linux/m32r m32r-*-linux-gnu
2297 GDB's remote protocol now includes support for the 'p' packet. This
2298 packet is used to fetch individual registers from a remote inferior.
2300 * END-OF-LIFE registers[] compatibility module
2302 GDB's internal register infrastructure has been completely rewritten.
2303 The new infrastructure making possible the implementation of key new
2304 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
2307 GDB 6.3 will be the last release to include the the registers[]
2308 compatibility module that allowed out-of-date configurations to
2309 continue to work. This change directly impacts the following
2319 powerpc bdm protocol
2321 Unless there is activity to revive these configurations, they will be
2322 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
2324 * OBSOLETE configurations and files
2326 Configurations that have been declared obsolete in this release have
2327 been commented out. Unless there is activity to revive these
2328 configurations, the next release of GDB will have their sources
2329 permanently REMOVED.
2338 *** Changes in GDB 6.2.1:
2340 * MIPS `break main; run' gave an heuristic-fence-post warning
2342 When attempting to run even a simple program, a warning about
2343 heuristic-fence-post being hit would be reported. This problem has
2346 * MIPS IRIX 'long double' crashed GDB
2348 When examining a long double variable, GDB would get a segmentation
2349 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
2350 IRIX long double values).
2354 A bug in the VAX stack code was causing problems with the "next"
2355 command. This problem has been fixed.
2357 *** Changes in GDB 6.2:
2359 * Fix for ``many threads''
2361 On GNU/Linux systems that use the NPTL threads library, a program
2362 rapidly creating and deleting threads would confuse GDB leading to the
2365 ptrace: No such process.
2366 thread_db_get_info: cannot get thread info: generic error
2368 This problem has been fixed.
2370 * "-async" and "-noasync" options removed.
2372 Support for the broken "-noasync" option has been removed (it caused
2375 * New ``start'' command.
2377 This command runs the program until the begining of the main procedure.
2379 * New BSD Kernel Data Access Library (libkvm) interface
2381 Using ``target kvm'' it is now possible to debug kernel core dumps and
2382 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
2383 platforms. Currently supported (native-only) configurations are:
2385 FreeBSD/amd64 x86_64-*-freebsd*
2386 FreeBSD/i386 i?86-*-freebsd*
2387 NetBSD/i386 i?86-*-netbsd*
2388 NetBSD/m68k m68*-*-netbsd*
2389 NetBSD/sparc sparc-*-netbsd*
2390 OpenBSD/amd64 x86_64-*-openbsd*
2391 OpenBSD/i386 i?86-*-openbsd*
2392 OpenBSD/m68k m68*-openbsd*
2393 OpenBSD/sparc sparc-*-openbsd*
2395 * Signal trampoline code overhauled
2397 Many generic problems with GDB's signal handling code have been fixed.
2398 These include: backtraces through non-contiguous stacks; recognition
2399 of sa_sigaction signal trampolines; backtrace from a NULL pointer
2400 call; backtrace through a signal trampoline; step into and out of
2401 signal handlers; and single-stepping in the signal trampoline.
2403 Please note that kernel bugs are a limiting factor here. These
2404 features have been shown to work on an s390 GNU/Linux system that
2405 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
2407 * Cygwin support for DWARF 2 added.
2409 * New native configurations
2411 GNU/Linux/hppa hppa*-*-linux*
2412 OpenBSD/hppa hppa*-*-openbsd*
2413 OpenBSD/m68k m68*-*-openbsd*
2414 OpenBSD/m88k m88*-*-openbsd*
2415 OpenBSD/powerpc powerpc-*-openbsd*
2416 NetBSD/vax vax-*-netbsd*
2417 OpenBSD/vax vax-*-openbsd*
2419 * END-OF-LIFE frame compatibility module
2421 GDB's internal frame infrastructure has been completely rewritten.
2422 The new infrastructure making it possible to support key new features
2423 including DWARF 2 Call Frame Information. To aid in the task of
2424 migrating old configurations to this new infrastructure, a
2425 compatibility module, that allowed old configurations to continue to
2426 work, was also included.
2428 GDB 6.2 will be the last release to include this frame compatibility
2429 module. This change directly impacts the following configurations:
2439 Unless there is activity to revive these configurations, they will be
2440 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
2442 * REMOVED configurations and files
2444 Sun 3, running SunOS 3 m68*-*-sunos3*
2445 Sun 3, running SunOS 4 m68*-*-sunos4*
2446 Sun 2, running SunOS 3 m68000-*-sunos3*
2447 Sun 2, running SunOS 4 m68000-*-sunos4*
2448 Motorola 680x0 running LynxOS m68*-*-lynxos*
2449 AT&T 3b1/Unix pc m68*-att-*
2450 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2451 decstation mips-dec-* mips-little-*
2452 riscos mips-*-riscos* mips-*-sysv*
2453 sonymips mips-sony-*
2454 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2456 *** Changes in GDB 6.1.1:
2458 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
2460 The TUI (Text-mode User Interface) is now built as part of a default
2461 GDB configuration. It is enabled by either selecting the TUI with the
2462 command line option "-i=tui" or by running the separate "gdbtui"
2463 program. For more information on the TUI, see the manual "Debugging
2466 * Pending breakpoint support (also included in GDB 6.1)
2468 Support has been added to allow you to specify breakpoints in shared
2469 libraries that have not yet been loaded. If a breakpoint location
2470 cannot be found, and the "breakpoint pending" option is set to auto,
2471 GDB queries you if you wish to make the breakpoint pending on a future
2472 shared-library load. If and when GDB resolves the breakpoint symbol,
2473 the pending breakpoint is removed as one or more regular breakpoints
2476 Pending breakpoints are very useful for GCJ Java debugging.
2478 * Fixed ISO-C build problems
2480 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
2481 non ISO-C code that stopped them being built using a more strict ISO-C
2482 compiler (e.g., IBM's C compiler).
2484 * Fixed build problem on IRIX 5
2486 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
2487 wasn't able to compile compile on an IRIX 5 system.
2489 * Added execute permission to gdb/gdbserver/configure
2491 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
2492 permission. This bug would cause configure to fail on a number of
2493 systems (Solaris, IRIX). Ref: server/519.
2495 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
2497 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
2498 has been updated to use constant array sizes.
2500 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
2502 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
2503 its generated DWARF Call Frame Info. This encoding was causing GDB to
2504 panic, that panic has been fixed. Ref: gdb/1628.
2506 * Fixed a problem when examining parameters in shared library code.
2508 When examining parameters in optimized shared library code generated
2509 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
2510 not available''. GDB now correctly displays the variable's value.
2512 *** Changes in GDB 6.1:
2514 * Removed --with-mmalloc
2516 Support for the mmalloc memory manager has been removed, as it
2517 conflicted with the internal gdb byte cache.
2519 * Changes in AMD64 configurations
2521 The AMD64 target now includes the %cs and %ss registers. As a result
2522 the AMD64 remote protocol has changed; this affects the floating-point
2523 and SSE registers. If you rely on those registers for your debugging,
2524 you should upgrade gdbserver on the remote side.
2526 * Revised SPARC target
2528 The SPARC target has been completely revised, incorporating the
2529 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
2530 support for LynxOS and SunOS 4 has been dropped. Calling functions
2531 from within GDB on operating systems with a non-executable stack
2532 (Solaris, OpenBSD) now works.
2536 GDB has a new C++ demangler which does a better job on the mangled
2537 names generated by current versions of g++. It also runs faster, so
2538 with this and other changes gdb should now start faster on large C++
2541 * DWARF 2 Location Expressions
2543 GDB support for location expressions has been extended to support function
2544 arguments and frame bases. Older versions of GDB could crash when they
2547 * C++ nested types and namespaces
2549 GDB's support for nested types and namespaces in C++ has been
2550 improved, especially if you use the DWARF 2 debugging format. (This
2551 is the default for recent versions of GCC on most platforms.)
2552 Specifically, if you have a class "Inner" defined within a class or
2553 namespace "Outer", then GDB realizes that the class's name is
2554 "Outer::Inner", not simply "Inner". This should greatly reduce the
2555 frequency of complaints about not finding RTTI symbols. In addition,
2556 if you are stopped at inside of a function defined within a namespace,
2557 GDB modifies its name lookup accordingly.
2559 * New native configurations
2561 NetBSD/amd64 x86_64-*-netbsd*
2562 OpenBSD/amd64 x86_64-*-openbsd*
2563 OpenBSD/alpha alpha*-*-openbsd*
2564 OpenBSD/sparc sparc-*-openbsd*
2565 OpenBSD/sparc64 sparc64-*-openbsd*
2567 * New debugging protocols
2569 M32R with SDI protocol m32r-*-elf*
2571 * "set prompt-escape-char" command deleted.
2573 The command "set prompt-escape-char" has been deleted. This command,
2574 and its very obscure effet on GDB's prompt, was never documented,
2575 tested, nor mentioned in the NEWS file.
2577 * OBSOLETE configurations and files
2579 Configurations that have been declared obsolete in this release have
2580 been commented out. Unless there is activity to revive these
2581 configurations, the next release of GDB will have their sources
2582 permanently REMOVED.
2584 Sun 3, running SunOS 3 m68*-*-sunos3*
2585 Sun 3, running SunOS 4 m68*-*-sunos4*
2586 Sun 2, running SunOS 3 m68000-*-sunos3*
2587 Sun 2, running SunOS 4 m68000-*-sunos4*
2588 Motorola 680x0 running LynxOS m68*-*-lynxos*
2589 AT&T 3b1/Unix pc m68*-att-*
2590 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2591 decstation mips-dec-* mips-little-*
2592 riscos mips-*-riscos* mips-*-sysv*
2593 sonymips mips-sony-*
2594 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2596 * REMOVED configurations and files
2598 SGI Irix-4.x mips-sgi-irix4 or iris4
2599 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
2600 Z8000 simulator z8k-zilog-none or z8ksim
2601 Matsushita MN10200 w/simulator mn10200-*-*
2602 H8/500 simulator h8500-hitachi-hms or h8500hms
2603 HP/PA running BSD hppa*-*-bsd*
2604 HP/PA running OSF/1 hppa*-*-osf*
2605 HP/PA Pro target hppa*-*-pro*
2606 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2607 386BSD i[3456]86-*-bsd*
2608 Sequent family i[3456]86-sequent-sysv4*
2609 i[3456]86-sequent-sysv*
2610 i[3456]86-sequent-bsd*
2611 SPARC running LynxOS sparc-*-lynxos*
2612 SPARC running SunOS 4 sparc-*-sunos4*
2613 Tsqware Sparclet sparclet-*-*
2614 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2616 *** Changes in GDB 6.0:
2620 Support for debugging the Objective-C programming language has been
2621 integrated into GDB.
2623 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
2625 DWARF 2's Call Frame Information makes available compiler generated
2626 information that more exactly describes the program's run-time stack.
2627 By using this information, GDB is able to provide more robust stack
2630 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
2631 have been updated to use a new backtrace mechanism which includes
2632 DWARF 2 CFI support.
2636 GDB's remote protocol has been extended to include support for hosted
2637 file I/O (where the remote target uses GDB's file system). See GDB's
2638 remote protocol documentation for details.
2640 * All targets using the new architecture framework.
2642 All of GDB's targets have been updated to use the new internal
2643 architecture framework. The way is now open for future GDB releases
2644 to include cross-architecture native debugging support (i386 on amd64,
2647 * GNU/Linux's Thread Local Storage (TLS)
2649 GDB now includes support for for the GNU/Linux implementation of
2650 per-thread variables.
2652 * GNU/Linux's Native POSIX Thread Library (NPTL)
2654 GDB's thread code has been updated to work with either the new
2655 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
2657 * Separate debug info.
2659 GDB, in conjunction with BINUTILS, now supports a mechanism for
2660 automatically loading debug information from a separate file. Instead
2661 of shipping full debug and non-debug versions of system libraries,
2662 system integrators can now instead ship just the stripped libraries
2663 and optional debug files.
2665 * DWARF 2 Location Expressions
2667 DWARF 2 Location Expressions allow the compiler to more completely
2668 describe the location of variables (even in optimized code) to the
2671 GDB now includes preliminary support for location expressions (support
2672 for DW_OP_piece is still missing).
2676 A number of long standing bugs that caused GDB to die while starting a
2677 Java application have been fixed. GDB's Java support is now
2678 considered "useable".
2680 * GNU/Linux support for fork, vfork, and exec.
2682 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
2683 commands are now implemented for GNU/Linux. They require a 2.5.x or later
2686 * GDB supports logging output to a file
2688 There are two new commands, "set logging" and "show logging", which can be
2689 used to capture GDB's output to a file.
2691 * The meaning of "detach" has changed for gdbserver
2693 The "detach" command will now resume the application, as documented. To
2694 disconnect from gdbserver and leave it stopped, use the new "disconnect"
2697 * d10v, m68hc11 `regs' command deprecated
2699 The `info registers' command has been updated so that it displays the
2700 registers using a format identical to the old `regs' command.
2704 A new command, "maint set profile on/off", has been added. This command can
2705 be used to enable or disable profiling while running GDB, to profile a
2706 session or a set of commands. In addition there is a new configure switch,
2707 "--enable-profiling", which will cause GDB to be compiled with profiling
2708 data, for more informative profiling results.
2710 * Default MI syntax changed to "mi2".
2712 The default MI (machine interface) syntax, enabled by the command line
2713 option "-i=mi", has been changed to "mi2". The previous MI syntax,
2714 "mi1", can be enabled by specifying the option "-i=mi1".
2716 Support for the original "mi0" syntax (included in GDB 5.0) has been
2719 Fix for gdb/192: removed extraneous space when displaying frame level.
2720 Fix for gdb/672: update changelist is now output in mi list format.
2721 Fix for gdb/702: a -var-assign that updates the value now shows up
2722 in a subsequent -var-update.
2724 * New native configurations.
2726 FreeBSD/amd64 x86_64-*-freebsd*
2728 * Multi-arched targets.
2730 HP/PA HPUX11 hppa*-*-hpux*
2731 Renesas M32R/D w/simulator m32r-*-elf*
2733 * OBSOLETE configurations and files
2735 Configurations that have been declared obsolete in this release have
2736 been commented out. Unless there is activity to revive these
2737 configurations, the next release of GDB will have their sources
2738 permanently REMOVED.
2740 Z8000 simulator z8k-zilog-none or z8ksim
2741 Matsushita MN10200 w/simulator mn10200-*-*
2742 H8/500 simulator h8500-hitachi-hms or h8500hms
2743 HP/PA running BSD hppa*-*-bsd*
2744 HP/PA running OSF/1 hppa*-*-osf*
2745 HP/PA Pro target hppa*-*-pro*
2746 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2747 Sequent family i[3456]86-sequent-sysv4*
2748 i[3456]86-sequent-sysv*
2749 i[3456]86-sequent-bsd*
2750 Tsqware Sparclet sparclet-*-*
2751 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2753 * REMOVED configurations and files
2756 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2757 IBM AIX PS/2 i[3456]86-*-aix
2758 i386 running Mach 3.0 i[3456]86-*-mach3*
2759 i386 running Mach i[3456]86-*-mach*
2760 i386 running OSF/1 i[3456]86-*osf1mk*
2761 HP/Apollo 68k Family m68*-apollo*-sysv*,
2763 m68*-hp-bsd*, m68*-hp-hpux*
2764 Argonaut Risc Chip (ARC) arc-*-*
2765 Mitsubishi D30V d30v-*-*
2766 Fujitsu FR30 fr30-*-elf*
2767 OS/9000 i[34]86-*-os9k
2768 I960 with MON960 i960-*-coff
2770 * MIPS $fp behavior changed
2772 The convenience variable $fp, for the MIPS, now consistently returns
2773 the address of the current frame's base. Previously, depending on the
2774 context, $fp could refer to either $sp or the current frame's base
2775 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
2776 The GNU Source-Level Debugger''.
2778 *** Changes in GDB 5.3:
2780 * GNU/Linux shared library multi-threaded performance improved.
2782 When debugging a multi-threaded application on GNU/Linux, GDB now uses
2783 `/proc', in preference to `ptrace' for memory reads. This may result
2784 in an improvement in the start-up time of multi-threaded, shared
2785 library applications when run under GDB. One GDB user writes: ``loads
2786 shared libs like mad''.
2788 * ``gdbserver'' now supports multi-threaded applications on some targets
2790 Support for debugging multi-threaded applications which use
2791 the GNU/Linux LinuxThreads package has been added for
2792 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
2793 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
2795 * GDB now supports C/C++ preprocessor macros.
2797 GDB now expands preprocessor macro invocations in C/C++ expressions,
2798 and provides various commands for showing macro definitions and how
2801 The new command `macro expand EXPRESSION' expands any macro
2802 invocations in expression, and shows the result.
2804 The new command `show macro MACRO-NAME' shows the definition of the
2805 macro named MACRO-NAME, and where it was defined.
2807 Most compilers don't include information about macros in the debugging
2808 information by default. In GCC 3.1, for example, you need to compile
2809 your program with the options `-gdwarf-2 -g3'. If the macro
2810 information is present in the executable, GDB will read it.
2812 * Multi-arched targets.
2814 DEC Alpha (partial) alpha*-*-*
2815 DEC VAX (partial) vax-*-*
2817 National Semiconductor NS32000 (partial) ns32k-*-*
2818 Motorola 68000 (partial) m68k-*-*
2819 Motorola MCORE mcore-*-*
2823 Fujitsu FRV architecture added by Red Hat frv*-*-*
2826 * New native configurations
2828 Alpha NetBSD alpha*-*-netbsd*
2829 SH NetBSD sh*-*-netbsdelf*
2830 MIPS NetBSD mips*-*-netbsd*
2831 UltraSPARC NetBSD sparc64-*-netbsd*
2833 * OBSOLETE configurations and files
2835 Configurations that have been declared obsolete in this release have
2836 been commented out. Unless there is activity to revive these
2837 configurations, the next release of GDB will have their sources
2838 permanently REMOVED.
2840 Mitsubishi D30V d30v-*-*
2841 OS/9000 i[34]86-*-os9k
2842 IBM AIX PS/2 i[3456]86-*-aix
2843 Fujitsu FR30 fr30-*-elf*
2844 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2845 Argonaut Risc Chip (ARC) arc-*-*
2846 i386 running Mach 3.0 i[3456]86-*-mach3*
2847 i386 running Mach i[3456]86-*-mach*
2848 i386 running OSF/1 i[3456]86-*osf1mk*
2849 HP/Apollo 68k Family m68*-apollo*-sysv*,
2851 m68*-hp-bsd*, m68*-hp-hpux*
2852 I960 with MON960 i960-*-coff
2854 * OBSOLETE languages
2856 CHILL, a Pascal like language used by telecommunications companies.
2858 * REMOVED configurations and files
2860 AMD 29k family via UDI a29k-amd-udi, udi29k
2861 A29K VxWorks a29k-*-vxworks
2862 AMD 29000 embedded, using EBMON a29k-none-none
2863 AMD 29000 embedded with COFF a29k-none-coff
2864 AMD 29000 embedded with a.out a29k-none-aout
2866 testsuite/gdb.hp/gdb.threads-hp/ directory
2868 * New command "set max-user-call-depth <nnn>"
2870 This command allows the user to limit the call depth of user-defined
2871 commands. The default is 1024.
2873 * Changes in FreeBSD/i386 native debugging.
2875 Support for the "generate-core-file" has been added.
2877 * New commands "dump", "append", and "restore".
2879 These commands allow data to be copied from target memory
2880 to a bfd-format or binary file (dump and append), and back
2881 from a file into memory (restore).
2883 * Improved "next/step" support on multi-processor Alpha Tru64.
2885 The previous single-step mechanism could cause unpredictable problems,
2886 including the random appearance of SIGSEGV or SIGTRAP signals. The use
2887 of a software single-step mechanism prevents this.
2889 *** Changes in GDB 5.2.1:
2897 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
2898 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
2899 Fix, by Joel Brobecker imported from mainline.
2901 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
2902 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
2903 Fix, by Fred Fish, imported from mainline.
2905 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
2906 Surprisingly enough, it works now.
2907 By Michal Ludvig, imported from mainline.
2909 i386 hardware watchpoint support:
2910 avoid misses on second run for some targets.
2911 By Pierre Muller, imported from mainline.
2913 *** Changes in GDB 5.2:
2915 * New command "set trust-readonly-sections on[off]".
2917 This command is a hint that tells gdb that read-only sections
2918 really are read-only (ie. that their contents will not change).
2919 In this mode, gdb will go to the object file rather than the
2920 target to read memory from read-only sections (such as ".text").
2921 This can be a significant performance improvement on some
2922 (notably embedded) targets.
2924 * New command "generate-core-file" (or "gcore").
2926 This new gdb command allows the user to drop a core file of the child
2927 process state at any time. So far it's been implemented only for
2928 GNU/Linux and Solaris, but should be relatively easily ported to other
2929 hosts. Argument is core file name (defaults to core.<pid>).
2931 * New command line option
2933 GDB now accepts --pid or -p followed by a process id.
2935 * Change in command line behavior -- corefiles vs. process ids.
2937 There is a subtle behavior in the way in which GDB handles
2938 command line arguments. The first non-flag argument is always
2939 a program to debug, but the second non-flag argument may either
2940 be a corefile or a process id. Previously, GDB would attempt to
2941 open the second argument as a corefile, and if that failed, would
2942 issue a superfluous error message and then attempt to attach it as
2943 a process. Now, if the second argument begins with a non-digit,
2944 it will be treated as a corefile. If it begins with a digit,
2945 GDB will attempt to attach it as a process, and if no such process
2946 is found, will then attempt to open it as a corefile.
2948 * Changes in ARM configurations.
2950 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
2951 configuration is fully multi-arch.
2953 * New native configurations
2955 ARM NetBSD arm*-*-netbsd*
2956 x86 OpenBSD i[3456]86-*-openbsd*
2957 AMD x86-64 running GNU/Linux x86_64-*-linux-*
2958 Sparc64 running FreeBSD sparc64-*-freebsd*
2962 Sanyo XStormy16 xstormy16-elf
2964 * OBSOLETE configurations and files
2966 Configurations that have been declared obsolete in this release have
2967 been commented out. Unless there is activity to revive these
2968 configurations, the next release of GDB will have their sources
2969 permanently REMOVED.
2971 AMD 29k family via UDI a29k-amd-udi, udi29k
2972 A29K VxWorks a29k-*-vxworks
2973 AMD 29000 embedded, using EBMON a29k-none-none
2974 AMD 29000 embedded with COFF a29k-none-coff
2975 AMD 29000 embedded with a.out a29k-none-aout
2977 testsuite/gdb.hp/gdb.threads-hp/ directory
2979 * REMOVED configurations and files
2981 TI TMS320C80 tic80-*-*
2983 PowerPC Solaris powerpcle-*-solaris*
2984 PowerPC Windows NT powerpcle-*-cygwin32
2985 PowerPC Netware powerpc-*-netware*
2986 Harris/CXUX m88k m88*-harris-cxux*
2987 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
2988 ns32k-utek-sysv* ns32k-utek-*
2989 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
2990 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
2991 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
2992 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
2993 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
2995 * Changes to command line processing
2997 The new `--args' feature can be used to specify command-line arguments
2998 for the inferior from gdb's command line.
3000 * Changes to key bindings
3002 There is a new `operate-and-get-next' function bound to `C-o'.
3004 *** Changes in GDB 5.1.1
3006 Fix compile problem on DJGPP.
3008 Fix a problem with floating-point registers on the i386 being
3011 Fix to stop GDB crashing on .debug_str debug info.
3013 Numerous documentation fixes.
3015 Numerous testsuite fixes.
3017 *** Changes in GDB 5.1:
3019 * New native configurations
3021 Alpha FreeBSD alpha*-*-freebsd*
3022 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3023 MIPS GNU/Linux mips*-*-linux*
3024 MIPS SGI Irix 6.x mips*-sgi-irix6*
3025 ia64 AIX ia64-*-aix*
3026 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3030 Motorola 68HC11 and 68HC12 m68hc11-elf
3032 UltraSparc running GNU/Linux sparc64-*-linux*
3034 * OBSOLETE configurations and files
3036 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3037 Harris/CXUX m88k m88*-harris-cxux*
3038 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3039 ns32k-utek-sysv* ns32k-utek-*
3040 TI TMS320C80 tic80-*-*
3042 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3043 PowerPC Solaris powerpcle-*-solaris*
3044 PowerPC Windows NT powerpcle-*-cygwin32
3045 PowerPC Netware powerpc-*-netware*
3046 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3047 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3048 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3049 Apple Macintosh (MPW) host N/A
3051 stuff.c (Program to stuff files into a specially prepared space in kdb)
3052 kdb-start.c (Main loop for the standalone kernel debugger)
3054 Configurations that have been declared obsolete in this release have
3055 been commented out. Unless there is activity to revive these
3056 configurations, the next release of GDB will have their sources
3057 permanently REMOVED.
3059 * REMOVED configurations and files
3061 Altos 3068 m68*-altos-*
3062 Convex c1-*-*, c2-*-*
3064 ARM RISCix arm-*-* (as host)
3068 * GDB has been converted to ISO C.
3070 GDB's source code has been converted to ISO C. In particular, the
3071 sources are fully protoized, and rely on standard headers being
3076 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3078 * The MI enabled by default.
3080 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3081 revised and enabled by default. Packages which use GDB as a debugging
3082 engine behind a UI or another front end are encouraged to switch to
3083 using the GDB/MI interface, instead of the old annotations interface
3084 which is now deprecated.
3086 * Support for debugging Pascal programs.
3088 GDB now includes support for debugging Pascal programs. The following
3089 main features are supported:
3091 - Pascal-specific data types such as sets;
3093 - automatic recognition of Pascal sources based on file-name
3096 - Pascal-style display of data types, variables, and functions;
3098 - a Pascal expression parser.
3100 However, some important features are not yet supported.
3102 - Pascal string operations are not supported at all;
3104 - there are some problems with boolean types;
3106 - Pascal type hexadecimal constants are not supported
3107 because they conflict with the internal variables format;
3109 - support for Pascal objects and classes is not full yet;
3111 - unlike Pascal, GDB is case-sensitive for symbol names.
3113 * Changes in completion.
3115 Commands such as `shell', `run' and `set args', which pass arguments
3116 to inferior programs, now complete on file names, similar to what
3117 users expect at the shell prompt.
3119 Commands which accept locations, such as `disassemble', `print',
3120 `breakpoint', `until', etc. now complete on filenames as well as
3121 program symbols. Thus, if you type "break foob TAB", and the source
3122 files linked into the programs include `foobar.c', that file name will
3123 be one of the candidates for completion. However, file names are not
3124 considered for completion after you typed a colon that delimits a file
3125 name from a name of a function in that file, as in "break foo.c:bar".
3127 `set demangle-style' completes on available demangling styles.
3129 * New platform-independent commands:
3131 It is now possible to define a post-hook for a command as well as a
3132 hook that runs before the command. For more details, see the
3133 documentation of `hookpost' in the GDB manual.
3135 * Changes in GNU/Linux native debugging.
3137 Support for debugging multi-threaded programs has been completely
3138 revised for all platforms except m68k and sparc. You can now debug as
3139 many threads as your system allows you to have.
3141 Attach/detach is supported for multi-threaded programs.
3143 Support for SSE registers was added for x86. This doesn't work for
3144 multi-threaded programs though.
3146 * Changes in MIPS configurations.
3148 Multi-arch support is enabled for all MIPS configurations.
3150 GDB can now be built as native debugger on SGI Irix 6.x systems for
3151 debugging n32 executables. (Debugging 64-bit executables is not yet
3154 * Unified support for hardware watchpoints in all x86 configurations.
3156 Most (if not all) native x86 configurations support hardware-assisted
3157 breakpoints and watchpoints in a unified manner. This support
3158 implements debug register sharing between watchpoints, which allows to
3159 put a virtually infinite number of watchpoints on the same address,
3160 and also supports watching regions up to 16 bytes with several debug
3163 The new maintenance command `maintenance show-debug-regs' toggles
3164 debugging print-outs in functions that insert, remove, and test
3165 watchpoints and hardware breakpoints.
3167 * Changes in the DJGPP native configuration.
3169 New command ``info dos sysinfo'' displays assorted information about
3170 the CPU, OS, memory, and DPMI server.
3172 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
3173 display information about segment descriptors stored in GDT, LDT, and
3176 New commands ``info dos pde'' and ``info dos pte'' display entries
3177 from Page Directory and Page Tables (for now works with CWSDPMI only).
3178 New command ``info dos address-pte'' displays the Page Table entry for
3179 a given linear address.
3181 GDB can now pass command lines longer than 126 characters to the
3182 program being debugged (requires an update to the libdbg.a library
3183 which is part of the DJGPP development kit).
3185 DWARF2 debug info is now supported.
3187 It is now possible to `step' and `next' through calls to `longjmp'.
3189 * Changes in documentation.
3191 All GDB documentation was converted to GFDL, the GNU Free
3192 Documentation License.
3194 Tracepoints-related commands are now fully documented in the GDB
3197 TUI, the Text-mode User Interface, is now documented in the manual.
3199 Tracepoints-related commands are now fully documented in the GDB
3202 The "GDB Internals" manual now has an index. It also includes
3203 documentation of `ui_out' functions, GDB coding standards, x86
3204 hardware watchpoints, and memory region attributes.
3206 * GDB's version number moved to ``version.in''
3208 The Makefile variable VERSION has been replaced by the file
3209 ``version.in''. People creating GDB distributions should update the
3210 contents of this file.
3214 GUD support is now a standard part of the EMACS distribution.
3216 *** Changes in GDB 5.0:
3218 * Improved support for debugging FP programs on x86 targets
3220 Unified and much-improved support for debugging floating-point
3221 programs on all x86 targets. In particular, ``info float'' now
3222 displays the FP registers in the same format on all x86 targets, with
3223 greater level of detail.
3225 * Improvements and bugfixes in hardware-assisted watchpoints
3227 It is now possible to watch array elements, struct members, and
3228 bitfields with hardware-assisted watchpoints. Data-read watchpoints
3229 on x86 targets no longer erroneously trigger when the address is
3232 * Improvements in the native DJGPP version of GDB
3234 The distribution now includes all the scripts and auxiliary files
3235 necessary to build the native DJGPP version on MS-DOS/MS-Windows
3236 machines ``out of the box''.
3238 The DJGPP version can now debug programs that use signals. It is
3239 possible to catch signals that happened in the debuggee, deliver
3240 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
3241 would kill the program being debugged.) Programs that hook hardware
3242 interrupts (keyboard, timer, etc.) can also be debugged.
3244 It is now possible to debug DJGPP programs that redirect their
3245 standard handles or switch them to raw (as opposed to cooked) mode, or
3246 even close them. The command ``run < foo > bar'' works as expected,
3247 and ``info terminal'' reports useful information about the debuggee's
3248 terminal, including raw/cooked mode, redirection, etc.
3250 The DJGPP version now uses termios functions for console I/O, which
3251 enables debugging graphics programs. Interrupting GDB with Ctrl-C
3254 DOS-style file names with drive letters are now fully supported by
3257 It is now possible to debug DJGPP programs that switch their working
3258 directory. It is also possible to rerun the debuggee any number of
3259 times without restarting GDB; thus, you can use the same setup,
3260 breakpoints, etc. for many debugging sessions.
3262 * New native configurations
3264 ARM GNU/Linux arm*-*-linux*
3265 PowerPC GNU/Linux powerpc-*-linux*
3269 Motorola MCore mcore-*-*
3270 x86 VxWorks i[3456]86-*-vxworks*
3271 PowerPC VxWorks powerpc-*-vxworks*
3272 TI TMS320C80 tic80-*-*
3274 * OBSOLETE configurations
3276 Altos 3068 m68*-altos-*
3277 Convex c1-*-*, c2-*-*
3279 ARM RISCix arm-*-* (as host)
3282 Configurations that have been declared obsolete will be commented out,
3283 but the code will be left in place. If there is no activity to revive
3284 these configurations before the next release of GDB, the sources will
3285 be permanently REMOVED.
3287 * Gould support removed
3289 Support for the Gould PowerNode and NP1 has been removed.
3291 * New features for SVR4
3293 On SVR4 native platforms (such as Solaris), if you attach to a process
3294 without first loading a symbol file, GDB will now attempt to locate and
3295 load symbols from the running process's executable file.
3297 * Many C++ enhancements
3299 C++ support has been greatly improved. Overload resolution now works properly
3300 in almost all cases. RTTI support is on the way.
3302 * Remote targets can connect to a sub-program
3304 A popen(3) style serial-device has been added. This device starts a
3305 sub-process (such as a stand-alone simulator) and then communicates
3306 with that. The sub-program to run is specified using the syntax
3307 ``|<program> <args>'' vis:
3309 (gdb) set remotedebug 1
3310 (gdb) target extended-remote |mn10300-elf-sim program-args
3312 * MIPS 64 remote protocol
3314 A long standing bug in the mips64 remote protocol where by GDB
3315 expected certain 32 bit registers (ex SR) to be transfered as 32
3316 instead of 64 bits has been fixed.
3318 The command ``set remote-mips64-transfers-32bit-regs on'' has been
3319 added to provide backward compatibility with older versions of GDB.
3321 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
3323 The command ``set remotebinarydownload'' command has been replaced by
3324 ``set remote X-packet''. Other commands in ``set remote'' family
3325 include ``set remote P-packet''.
3327 * Breakpoint commands accept ranges.
3329 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
3330 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
3331 ``tracepoint passcount'' also accepts a range of tracepoints.
3333 * ``apropos'' command added.
3335 The ``apropos'' command searches through command names and
3336 documentation strings, printing out matches, making it much easier to
3337 try to find a command that does what you are looking for.
3341 A new machine oriented interface (MI) has been added to GDB. This
3342 interface is designed for debug environments running GDB as a separate
3343 process. This is part of the long term libGDB project. See the
3344 "GDB/MI" chapter of the GDB manual for further information. It can be
3345 enabled by configuring with:
3347 .../configure --enable-gdbmi
3349 *** Changes in GDB-4.18:
3351 * New native configurations
3353 HP-UX 10.20 hppa*-*-hpux10.20
3354 HP-UX 11.x hppa*-*-hpux11.0*
3355 M68K GNU/Linux m68*-*-linux*
3359 Fujitsu FR30 fr30-*-elf*
3360 Intel StrongARM strongarm-*-*
3361 Mitsubishi D30V d30v-*-*
3363 * OBSOLETE configurations
3365 Gould PowerNode, NP1 np1-*-*, pn-*-*
3367 Configurations that have been declared obsolete will be commented out,
3368 but the code will be left in place. If there is no activity to revive
3369 these configurations before the next release of GDB, the sources will
3370 be permanently REMOVED.
3374 As a compatibility experiment, GDB's source files buildsym.h and
3375 buildsym.c have been converted to pure standard C, no longer
3376 containing any K&R compatibility code. We believe that all systems in
3377 use today either come with a standard C compiler, or have a GCC port
3378 available. If this is not true, please report the affected
3379 configuration to bug-gdb@gnu.org immediately. See the README file for
3380 information about getting a standard C compiler if you don't have one
3385 GDB now uses readline 2.2.
3387 * set extension-language
3389 You can now control the mapping between filename extensions and source
3390 languages by using the `set extension-language' command. For instance,
3391 you can ask GDB to treat .c files as C++ by saying
3392 set extension-language .c c++
3393 The command `info extensions' lists all of the recognized extensions
3394 and their associated languages.
3396 * Setting processor type for PowerPC and RS/6000
3398 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
3399 you can use the `set processor' command to specify what variant of the
3400 PowerPC family you are debugging. The command
3404 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
3405 following PowerPC and RS6000 variants:
3407 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
3408 rs6000 IBM RS6000 ("POWER") architecture, user-level view
3410 403GC IBM PowerPC 403GC
3411 505 Motorola PowerPC 505
3412 860 Motorola PowerPC 860 or 850
3413 601 Motorola PowerPC 601
3414 602 Motorola PowerPC 602
3415 603 Motorola/IBM PowerPC 603 or 603e
3416 604 Motorola PowerPC 604 or 604e
3417 750 Motorola/IBM PowerPC 750 or 750
3419 At the moment, this command just tells GDB what to name the
3420 special-purpose processor registers. Since almost all the affected
3421 registers are inaccessible to user-level programs, this command is
3422 only useful for remote debugging in its present form.
3426 Thanks to a major code donation from Hewlett-Packard, GDB now has much
3427 more extensive support for HP-UX. Added features include shared
3428 library support, kernel threads and hardware watchpoints for 11.00,
3429 support for HP's ANSI C and C++ compilers, and a compatibility mode
3430 for xdb and dbx commands.
3434 HP's donation includes the new concept of catchpoints, which is a
3435 generalization of the old catch command. On HP-UX, it is now possible
3436 to catch exec, fork, and vfork, as well as library loading.
3438 This means that the existing catch command has changed; its first
3439 argument now specifies the type of catch to be set up. See the
3440 output of "help catch" for a list of catchpoint types.
3442 * Debugging across forks
3444 On HP-UX, you can choose which process to debug when a fork() happens
3449 HP has donated a curses-based terminal user interface (TUI). To get
3450 it, build with --enable-tui. Although this can be enabled for any
3451 configuration, at present it only works for native HP debugging.
3453 * GDB remote protocol additions
3455 A new protocol packet 'X' that writes binary data is now available.
3456 Default behavior is to try 'X', then drop back to 'M' if the stub
3457 fails to respond. The settable variable `remotebinarydownload'
3458 allows explicit control over the use of 'X'.
3460 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
3461 full 64-bit address. The command
3463 set remoteaddresssize 32
3465 can be used to revert to the old behaviour. For existing remote stubs
3466 the change should not be noticed, as the additional address information
3469 In order to assist in debugging stubs, you may use the maintenance
3470 command `packet' to send any text string to the stub. For instance,
3472 maint packet heythere
3474 sends the packet "$heythere#<checksum>". Note that it is very easy to
3475 disrupt a debugging session by sending the wrong packet at the wrong
3478 The compare-sections command allows you to compare section data on the
3479 target to what is in the executable file without uploading or
3480 downloading, by comparing CRC checksums.
3482 * Tracing can collect general expressions
3484 You may now collect general expressions at tracepoints. This requires
3485 further additions to the target-side stub; see tracepoint.c and
3486 doc/agentexpr.texi for further details.
3488 * mask-address variable for Mips
3490 For Mips targets, you may control the zeroing of the upper 32 bits of
3491 a 64-bit address by entering `set mask-address on'. This is mainly
3492 of interest to users of embedded R4xxx and R5xxx processors.
3494 * Higher serial baud rates
3496 GDB's serial code now allows you to specify baud rates 57600, 115200,
3497 230400, and 460800 baud. (Note that your host system may not be able
3498 to achieve all of these rates.)
3502 The i960 configuration now includes an initial implementation of a
3503 builtin simulator, contributed by Jim Wilson.
3506 *** Changes in GDB-4.17:
3508 * New native configurations
3510 Alpha GNU/Linux alpha*-*-linux*
3511 Unixware 2.x i[3456]86-unixware2*
3512 Irix 6.x mips*-sgi-irix6*
3513 PowerPC GNU/Linux powerpc-*-linux*
3514 PowerPC Solaris powerpcle-*-solaris*
3515 Sparc GNU/Linux sparc-*-linux*
3516 Motorola sysV68 R3V7.1 m68k-motorola-sysv
3520 Argonaut Risc Chip (ARC) arc-*-*
3521 Hitachi H8/300S h8300*-*-*
3522 Matsushita MN10200 w/simulator mn10200-*-*
3523 Matsushita MN10300 w/simulator mn10300-*-*
3524 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
3525 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
3526 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
3527 Mitsubishi D10V w/simulator d10v-*-*
3528 Mitsubishi M32R/D w/simulator m32r-*-elf*
3529 Tsqware Sparclet sparclet-*-*
3530 NEC V850 w/simulator v850-*-*
3532 * New debugging protocols
3534 ARM with RDI protocol arm*-*-*
3535 M68K with dBUG monitor m68*-*-{aout,coff,elf}
3536 DDB and LSI variants of PMON protocol mips*-*-*
3537 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
3538 PowerPC with SDS protocol powerpc{,le}-*-eabi
3539 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
3543 All configurations can now understand and use the DWARF 2 debugging
3544 format. The choice is automatic, if the symbol file contains DWARF 2
3549 GDB now includes basic Java language support. This support is
3550 only useful with Java compilers that produce native machine code.
3552 * solib-absolute-prefix and solib-search-path
3554 For SunOS and SVR4 shared libraries, you may now set the prefix for
3555 loading absolute shared library symbol files, and the search path for
3556 locating non-absolute shared library symbol files.
3558 * Live range splitting
3560 GDB can now effectively debug code for which GCC has performed live
3561 range splitting as part of its optimization. See gdb/doc/LRS for
3562 more details on the expected format of the stabs information.
3566 GDB's support for the GNU Hurd, including thread debugging, has been
3567 updated to work with current versions of the Hurd.
3571 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
3572 instruction set. ARM GDB automatically detects when Thumb
3573 instructions are in use, and adjusts disassembly and backtracing
3578 GDB's MIPS target configurations now handle the MIP16 16-bit
3583 GDB now includes support for overlays; if an executable has been
3584 linked such that multiple sections are based at the same address, GDB
3585 will decide which section to use for symbolic info. You can choose to
3586 control the decision manually, using overlay commands, or implement
3587 additional target-side support and use "overlay load-target" to bring
3588 in the overlay mapping. Do "help overlay" for more detail.
3592 The command "info symbol <address>" displays information about
3593 the symbol at the specified address.
3597 The standard remote protocol now includes an extension that allows
3598 asynchronous collection and display of trace data. This requires
3599 extensive support in the target-side debugging stub. Tracing mode
3600 includes a new interaction mode in GDB and new commands: see the
3601 file tracepoint.c for more details.
3605 Configurations for embedded MIPS now include a simulator contributed
3606 by Cygnus Solutions. The simulator supports the instruction sets
3607 of most MIPS variants.
3611 Sparc configurations may now include the ERC32 simulator contributed
3612 by the European Space Agency. The simulator is not built into
3613 Sparc targets by default; configure with --enable-sim to include it.
3617 For target configurations that may include multiple variants of a
3618 basic architecture (such as MIPS and SH), you may now set the
3619 architecture explicitly. "set arch" sets, "info arch" lists
3620 the possible architectures.
3622 *** Changes in GDB-4.16:
3624 * New native configurations
3626 Windows 95, x86 Windows NT i[345]86-*-cygwin32
3627 M68K NetBSD m68k-*-netbsd*
3628 PowerPC AIX 4.x powerpc-*-aix*
3629 PowerPC MacOS powerpc-*-macos*
3630 PowerPC Windows NT powerpcle-*-cygwin32
3631 RS/6000 AIX 4.x rs6000-*-aix4*
3635 ARM with RDP protocol arm-*-*
3636 I960 with MON960 i960-*-coff
3637 MIPS VxWorks mips*-*-vxworks*
3638 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
3639 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
3641 Matra Sparclet sparclet-*-*
3645 The powerpc-eabi configuration now includes the PSIM simulator,
3646 contributed by Andrew Cagney, with assistance from Mike Meissner.
3647 PSIM is a very elaborate model of the PowerPC, including not only
3648 basic instruction set execution, but also details of execution unit
3649 performance and I/O hardware. See sim/ppc/README for more details.
3653 GDB now works with Solaris 2.5.
3655 * Windows 95/NT native
3657 GDB will now work as a native debugger on Windows 95 and Windows NT.
3658 To build it from source, you must use the "gnu-win32" environment,
3659 which uses a DLL to emulate enough of Unix to run the GNU tools.
3660 Further information, binaries, and sources are available at
3661 ftp.cygnus.com, under pub/gnu-win32.
3663 * dont-repeat command
3665 If a user-defined command includes the command `dont-repeat', then the
3666 command will not be repeated if the user just types return. This is
3667 useful if the command is time-consuming to run, so that accidental
3668 extra keystrokes don't run the same command many times.
3670 * Send break instead of ^C
3672 The standard remote protocol now includes an option to send a break
3673 rather than a ^C to the target in order to interrupt it. By default,
3674 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
3676 * Remote protocol timeout
3678 The standard remote protocol includes a new variable `remotetimeout'
3679 that allows you to set the number of seconds before GDB gives up trying
3680 to read from the target. The default value is 2.
3682 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
3684 By default GDB will automatically keep track of objects as they are
3685 loaded and unloaded by the dynamic linker. By using the command `set
3686 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
3687 when shared library events occur, thus allowing you to set breakpoints
3688 in shared libraries which are explicitly loaded by the inferior.
3690 Note this feature does not work on hpux8. On hpux9 you must link
3691 /usr/lib/end.o into your program. This feature should work
3692 automatically on hpux10.
3694 * Irix 5.x hardware watchpoint support
3696 Irix 5 configurations now support the use of hardware watchpoints.
3698 * Mips protocol "SYN garbage limit"
3700 When debugging a Mips target using the `target mips' protocol, you
3701 may set the number of characters that GDB will ignore by setting
3702 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
3703 every character. The default value is 1050.
3705 * Recording and replaying remote debug sessions
3707 If you set `remotelogfile' to the name of a file, gdb will write to it
3708 a recording of a remote debug session. This recording may then be
3709 replayed back to gdb using "gdbreplay". See gdbserver/README for
3710 details. This is useful when you have a problem with GDB while doing
3711 remote debugging; you can make a recording of the session and send it
3712 to someone else, who can then recreate the problem.
3714 * Speedups for remote debugging
3716 GDB includes speedups for downloading and stepping MIPS systems using
3717 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
3718 and more efficient S-record downloading.
3720 * Memory use reductions and statistics collection
3722 GDB now uses less memory and reports statistics about memory usage.
3723 Try the `maint print statistics' command, for example.
3725 *** Changes in GDB-4.15:
3727 * Psymtabs for XCOFF
3729 The symbol reader for AIX GDB now uses partial symbol tables. This
3730 can greatly improve startup time, especially for large executables.
3732 * Remote targets use caching
3734 Remote targets now use a data cache to speed up communication with the
3735 remote side. The data cache could lead to incorrect results because
3736 it doesn't know about volatile variables, thus making it impossible to
3737 debug targets which use memory mapped I/O devices. `set remotecache
3738 off' turns the the data cache off.
3740 * Remote targets may have threads
3742 The standard remote protocol now includes support for multiple threads
3743 in the target system, using new protocol commands 'H' and 'T'. See
3744 gdb/remote.c for details.
3748 If GDB is configured with `--enable-netrom', then it will include
3749 support for the NetROM ROM emulator from XLNT Designs. The NetROM
3750 acts as though it is a bank of ROM on the target board, but you can
3751 write into it over the network. GDB's support consists only of
3752 support for fast loading into the emulated ROM; to debug, you must use
3753 another protocol, such as standard remote protocol. The usual
3754 sequence is something like
3756 target nrom <netrom-hostname>
3758 target remote <netrom-hostname>:1235
3762 GDB now includes support for the Apple Macintosh, as a host only. It
3763 may be run as either an MPW tool or as a standalone application, and
3764 it can debug through the serial port. All the usual GDB commands are
3765 available, but to the target command, you must supply "serial" as the
3766 device type instead of "/dev/ttyXX". See mpw-README in the main
3767 directory for more information on how to build. The MPW configuration
3768 scripts */mpw-config.in support only a few targets, and only the
3769 mips-idt-ecoff target has been tested.
3773 GDB configuration now uses autoconf. This is not user-visible,
3774 but does simplify configuration and building.
3778 GDB now supports hpux10.
3780 *** Changes in GDB-4.14:
3782 * New native configurations
3784 x86 FreeBSD i[345]86-*-freebsd
3785 x86 NetBSD i[345]86-*-netbsd
3786 NS32k NetBSD ns32k-*-netbsd
3787 Sparc NetBSD sparc-*-netbsd
3791 A29K VxWorks a29k-*-vxworks
3792 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
3793 CPU32 EST-300 emulator m68*-*-est*
3794 PowerPC ELF powerpc-*-elf
3797 * Alpha OSF/1 support for procfs
3799 GDB now supports procfs under OSF/1-2.x and higher, which makes it
3800 possible to attach to running processes. As the mounting of the /proc
3801 filesystem is optional on the Alpha, GDB automatically determines
3802 the availability of /proc during startup. This can lead to problems
3803 if /proc is unmounted after GDB has been started.
3805 * Arguments to user-defined commands
3807 User commands may accept up to 10 arguments separated by whitespace.
3808 Arguments are accessed within the user command via $arg0..$arg9. A
3811 print $arg0 + $arg1 + $arg2
3813 To execute the command use:
3816 Defines the command "adder" which prints the sum of its three arguments.
3817 Note the arguments are text substitutions, so they may reference variables,
3818 use complex expressions, or even perform inferior function calls.
3820 * New `if' and `while' commands
3822 This makes it possible to write more sophisticated user-defined
3823 commands. Both commands take a single argument, which is the
3824 expression to evaluate, and must be followed by the commands to
3825 execute, one per line, if the expression is nonzero, the list being
3826 terminated by the word `end'. The `if' command list may include an
3827 `else' word, which causes the following commands to be executed only
3828 if the expression is zero.
3830 * Fortran source language mode
3832 GDB now includes partial support for Fortran 77. It will recognize
3833 Fortran programs and can evaluate a subset of Fortran expressions, but
3834 variables and functions may not be handled correctly. GDB will work
3835 with G77, but does not yet know much about symbols emitted by other
3838 * Better HPUX support
3840 Most debugging facilities now work on dynamic executables for HPPAs
3841 running hpux9 or later. You can attach to running dynamically linked
3842 processes, but by default the dynamic libraries will be read-only, so
3843 for instance you won't be able to put breakpoints in them. To change
3844 that behavior do the following before running the program:
3850 This will cause the libraries to be mapped private and read-write.
3851 To revert to the normal behavior, do this:
3857 You cannot set breakpoints or examine data in the library until after
3858 the library is loaded if the function/data symbols do not have
3861 GDB can now also read debug symbols produced by the HP C compiler on
3862 HPPAs (sorry, no C++, Fortran or 68k support).
3864 * Target byte order now dynamically selectable
3866 You can choose which byte order to use with a target system, via the
3867 commands "set endian big" and "set endian little", and you can see the
3868 current setting by using "show endian". You can also give the command
3869 "set endian auto", in which case GDB will use the byte order
3870 associated with the executable. Currently, only embedded MIPS
3871 configurations support dynamic selection of target byte order.
3873 * New DOS host serial code
3875 This version uses DPMI interrupts to handle buffered I/O, so you
3876 no longer need to run asynctsr when debugging boards connected to
3879 *** Changes in GDB-4.13:
3881 * New "complete" command
3883 This lists all the possible completions for the rest of the line, if it
3884 were to be given as a command itself. This is intended for use by emacs.
3886 * Trailing space optional in prompt
3888 "set prompt" no longer adds a space for you after the prompt you set. This
3889 allows you to set a prompt which ends in a space or one that does not.
3891 * Breakpoint hit counts
3893 "info break" now displays a count of the number of times the breakpoint
3894 has been hit. This is especially useful in conjunction with "ignore"; you
3895 can ignore a large number of breakpoint hits, look at the breakpoint info
3896 to see how many times the breakpoint was hit, then run again, ignoring one
3897 less than that number, and this will get you quickly to the last hit of
3900 * Ability to stop printing at NULL character
3902 "set print null-stop" will cause GDB to stop printing the characters of
3903 an array when the first NULL is encountered. This is useful when large
3904 arrays actually contain only short strings.
3906 * Shared library breakpoints
3908 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
3909 breakpoints in shared libraries before the executable is run.
3911 * Hardware watchpoints
3913 There is a new hardware breakpoint for the watch command for sparclite
3914 targets. See gdb/sparclite/hw_breakpoint.note.
3916 Hardware watchpoints are also now supported under GNU/Linux.
3920 Annotations have been added. These are for use with graphical interfaces,
3921 and are still experimental. Currently only gdba.el uses these.
3923 * Improved Irix 5 support
3925 GDB now works properly with Irix 5.2.
3927 * Improved HPPA support
3929 GDB now works properly with the latest GCC and GAS.
3931 * New native configurations
3933 Sequent PTX4 i[34]86-sequent-ptx4
3934 HPPA running OSF/1 hppa*-*-osf*
3935 Atari TT running SVR4 m68*-*-sysv4*
3936 RS/6000 LynxOS rs6000-*-lynxos*
3940 OS/9000 i[34]86-*-os9k
3941 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
3944 * Hitachi SH7000 and E7000-PC ICE support
3946 There is now support for communicating with the Hitachi E7000-PC ICE.
3947 This is available automatically when GDB is configured for the SH.
3951 As usual, a variety of small fixes and improvements, both generic
3952 and configuration-specific. See the ChangeLog for more detail.
3954 *** Changes in GDB-4.12:
3956 * Irix 5 is now supported
3960 GDB-4.12 on the HPPA has a number of changes which make it unable
3961 to debug the output from the currently released versions of GCC and
3962 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
3963 of GCC and GAS, versions of these tools designed to work with GDB-4.12
3964 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
3967 *** Changes in GDB-4.11:
3969 * User visible changes:
3973 The "set remotedebug" option is now consistent between the mips remote
3974 target, remote targets using the gdb-specific protocol, UDI (AMD's
3975 debug protocol for the 29k) and the 88k bug monitor. It is now an
3976 integer specifying a debug level (normally 0 or 1, but 2 means more
3977 debugging info for the mips target).
3979 * DEC Alpha native support
3981 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
3982 debug info, but GDB works fairly well with the DEC compiler and should
3983 work with a future GCC release. See the README file for a few
3984 Alpha-specific notes.
3986 * Preliminary thread implementation
3988 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
3990 * LynxOS native and target support for 386
3992 This release has been hosted on LynxOS 2.2, and also can be configured
3993 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
3996 * Improvements in C++ mangling/demangling.
3998 This release has much better g++ debugging, specifically in name
3999 mangling/demangling, virtual function calls, print virtual table,
4000 call methods, ...etc.
4002 *** Changes in GDB-4.10:
4004 * User visible changes:
4006 Remote debugging using the GDB-specific (`target remote') protocol now
4007 supports the `load' command. This is only useful if you have some
4008 other way of getting the stub to the target system, and you can put it
4009 somewhere in memory where it won't get clobbered by the download.
4011 Filename completion now works.
4013 When run under emacs mode, the "info line" command now causes the
4014 arrow to point to the line specified. Also, "info line" prints
4015 addresses in symbolic form (as well as hex).
4017 All vxworks based targets now support a user settable option, called
4018 vxworks-timeout. This option represents the number of seconds gdb
4019 should wait for responses to rpc's. You might want to use this if
4020 your vxworks target is, perhaps, a slow software simulator or happens
4021 to be on the far side of a thin network line.
4025 This release contains support for using a DEC alpha as a GDB host for
4026 cross debugging. Native alpha debugging is not supported yet.
4029 *** Changes in GDB-4.9:
4033 This is the first GDB release which is accompanied by a matching testsuite.
4034 The testsuite requires installation of dejagnu, which should be available
4035 via ftp from most sites that carry GNU software.
4039 'Cfront' style demangling has had its name changed to 'ARM' style, to
4040 emphasize that it was written from the specifications in the C++ Annotated
4041 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4042 disclaimers, it still generated too much confusion with users attempting to
4043 use gdb with AT&T cfront.
4047 GDB now uses a standard remote interface to a simulator library.
4048 So far, the library contains simulators for the Zilog Z8001/2, the
4049 Hitachi H8/300, H8/500 and Super-H.
4051 * New targets supported
4053 H8/300 simulator h8300-hitachi-hms or h8300hms
4054 H8/500 simulator h8500-hitachi-hms or h8500hms
4055 SH simulator sh-hitachi-hms or sh
4056 Z8000 simulator z8k-zilog-none or z8ksim
4057 IDT MIPS board over serial line mips-idt-ecoff
4059 Cross-debugging to GO32 targets is supported. It requires a custom
4060 version of the i386-stub.c module which is integrated with the
4061 GO32 memory extender.
4063 * New remote protocols
4065 MIPS remote debugging protocol.
4067 * New source languages supported
4069 This version includes preliminary support for Chill, a Pascal like language
4070 used by telecommunications companies. Chill support is also being integrated
4071 into the GNU compiler, but we don't know when it will be publically available.
4074 *** Changes in GDB-4.8:
4076 * HP Precision Architecture supported
4078 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4079 version of this support was available as a set of patches from the
4080 University of Utah. GDB does not support debugging of programs
4081 compiled with the HP compiler, because HP will not document their file
4082 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4083 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4085 Many problems in the preliminary version have been fixed.
4087 * Faster and better demangling
4089 We have improved template demangling and fixed numerous bugs in the GNU style
4090 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4091 character types (wchar_t) are now supported. Demangling of each symbol is now
4092 only done once, and is cached when the symbol table for a file is read in.
4093 This results in a small increase in memory usage for C programs, a moderate
4094 increase in memory usage for C++ programs, and a fantastic speedup in
4097 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4098 from the specifications in the Annotated Reference Manual, which AT&T's
4099 compiler does not actually implement.
4101 * G++ multiple inheritance compiler problem
4103 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4104 inheritance lattices was reworked to properly discover ambiguities. We
4105 recently found an example which causes this new algorithm to fail in a
4106 very subtle way, producing bad debug information for those classes.
4107 The file 'gcc.patch' (in this directory) can be applied to gcc to
4108 circumvent the problem. A future GCC release will contain a complete
4111 The previous G++ debug info problem (mentioned below for the gdb-4.7
4112 release) is fixed in gcc version 2.3.2.
4114 * Improved configure script
4116 The `configure' script will now attempt to guess your system type if
4117 you don't supply a host system type. The old scheme of supplying a
4118 host system triplet is preferable over using this. All the magic is
4119 done in the new `config.guess' script. Examine it for details.
4121 We have also brought our configure script much more in line with the FSF's
4122 version. It now supports the --with-xxx options. In particular,
4123 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4124 The resulting GDB will not be able to read arbitrary object file formats --
4125 only the format ``expected'' to be used on the configured target system.
4126 We hope to make this the default in a future release.
4128 * Documentation improvements
4130 There's new internal documentation on how to modify GDB, and how to
4131 produce clean changes to the code. We implore people to read it
4132 before submitting changes.
4134 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4135 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4136 `info' files are also provided. To build `info' files from scratch,
4137 you will need the latest `makeinfo' release, which will be available in
4138 a future texinfo-X.Y release.
4140 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4141 We're not sure exactly which versions have this problem, but it has
4142 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4143 or better. If that isn't possible, there is a patch in
4144 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4145 around this problem.
4149 GDB now supports array constants that can be used in expressions typed in by
4150 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4151 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4154 The new directory `gdb/sparclite' contains a program that demonstrates
4155 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4157 * New native hosts supported
4159 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4160 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4162 * New targets supported
4164 AMD 29k family via UDI a29k-amd-udi or udi29k
4166 * New file formats supported
4168 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4169 HPUX core files, and SCO 3.2v2 core files.
4173 Attaching to processes now works again; thanks for the many bug reports.
4175 We have also stomped on a bunch of core dumps caused by
4176 printf_filtered("%s") problems.
4178 We eliminated a copyright problem on the rpc and ptrace header files
4179 for VxWorks, which was discovered at the last minute during the 4.7
4180 release. You should now be able to build a VxWorks GDB.
4182 You can now interrupt gdb while an attached process is running. This
4183 will cause the attached process to stop, and give control back to GDB.
4185 We fixed problems caused by using too many file descriptors
4186 for reading symbols from object files and libraries. This was
4187 especially a problem for programs that used many (~100) shared
4190 The `step' command now only enters a subroutine if there is line number
4191 information for the subroutine. Otherwise it acts like the `next'
4192 command. Previously, `step' would enter subroutines if there was
4193 any debugging information about the routine. This avoids problems
4194 when using `cc -g1' on MIPS machines.
4196 * Internal improvements
4198 GDB's internal interfaces have been improved to make it easier to support
4199 debugging of multiple languages in the future.
4201 GDB now uses a common structure for symbol information internally.
4202 Minimal symbols (derived from linkage symbols in object files), partial
4203 symbols (from a quick scan of debug information), and full symbols
4204 contain a common subset of information, making it easier to write
4205 shared code that handles any of them.
4207 * New command line options
4209 We now accept --silent as an alias for --quiet.
4213 The memory-mapped-malloc library is now licensed under the GNU Library
4214 General Public License.
4216 *** Changes in GDB-4.7:
4218 * Host/native/target split
4220 GDB has had some major internal surgery to untangle the support for
4221 hosts and remote targets. Now, when you configure GDB for a remote
4222 target, it will no longer load in all of the support for debugging
4223 local programs on the host. When fully completed and tested, this will
4224 ensure that arbitrary host/target combinations are possible.
4226 The primary conceptual shift is to separate the non-portable code in
4227 GDB into three categories. Host specific code is required any time GDB
4228 is compiled on that host, regardless of the target. Target specific
4229 code relates to the peculiarities of the target, but can be compiled on
4230 any host. Native specific code is everything else: it can only be
4231 built when the host and target are the same system. Child process
4232 handling and core file support are two common `native' examples.
4234 GDB's use of /proc for controlling Unix child processes is now cleaner.
4235 It has been split out into a single module under the `target_ops' vector,
4236 plus two native-dependent functions for each system that uses /proc.
4238 * New hosts supported
4240 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
4241 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4242 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
4244 * New targets supported
4246 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4247 68030 and CPU32 m68030-*-*, m68332-*-*
4249 * New native hosts supported
4251 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4252 (386bsd is not well tested yet)
4253 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
4255 * New file formats supported
4257 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
4258 supports reading of `a.out.adobe' object files, which are an a.out
4259 format extended with minimal information about multiple sections.
4263 `show copying' is the same as the old `info copying'.
4264 `show warranty' is the same as `info warrantee'.
4265 These were renamed for consistency. The old commands continue to work.
4267 `info handle' is a new alias for `info signals'.
4269 You can now define pre-command hooks, which attach arbitrary command
4270 scripts to any command. The commands in the hook will be executed
4271 prior to the user's command. You can also create a hook which will be
4272 executed whenever the program stops. See gdb.texinfo.
4276 We now deal with Cfront style name mangling, and can even extract type
4277 info from mangled symbols. GDB can automatically figure out which
4278 symbol mangling style your C++ compiler uses.
4280 Calling of methods and virtual functions has been improved as well.
4284 The crash that occured when debugging Sun Ansi-C compiled binaries is
4285 fixed. This was due to mishandling of the extra N_SO stabs output
4288 We also finally got Ultrix 4.2 running in house, and fixed core file
4289 support, with help from a dozen people on the net.
4291 John M. Farrell discovered that the reason that single-stepping was so
4292 slow on all of the Mips based platforms (primarily SGI and DEC) was
4293 that we were trying to demangle and lookup a symbol used for internal
4294 purposes on every instruction that was being stepped through. Changing
4295 the name of that symbol so that it couldn't be mistaken for a C++
4296 mangled symbol sped things up a great deal.
4298 Rich Pixley sped up symbol lookups in general by getting much smarter
4299 about when C++ symbol mangling is necessary. This should make symbol
4300 completion (TAB on the command line) much faster. It's not as fast as
4301 we'd like, but it's significantly faster than gdb-4.6.
4305 A new user controllable variable 'call_scratch_address' can
4306 specify the location of a scratch area to be used when GDB
4307 calls a function in the target. This is necessary because the
4308 usual method of putting the scratch area on the stack does not work
4309 in systems that have separate instruction and data spaces.
4311 We integrated changes to support the 29k UDI (Universal Debugger
4312 Interface), but discovered at the last minute that we didn't have all
4313 of the appropriate copyright paperwork. We are working with AMD to
4314 resolve this, and hope to have it available soon.
4318 We have sped up the remote serial line protocol, especially for targets
4319 with lots of registers. It now supports a new `expedited status' ('T')
4320 message which can be used in place of the existing 'S' status message.
4321 This allows the remote stub to send only the registers that GDB
4322 needs to make a quick decision about single-stepping or conditional
4323 breakpoints, eliminating the need to fetch the entire register set for
4324 each instruction being stepped through.
4326 The GDB remote serial protocol now implements a write-through cache for
4327 registers, only re-reading the registers if the target has run.
4329 There is also a new remote serial stub for SPARC processors. You can
4330 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
4331 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
4332 processor with a serial port.
4336 Configure.in files have become much easier to read and modify. A new
4337 `table driven' format makes it more obvious what configurations are
4338 supported, and what files each one uses.
4342 There is a new opcodes library which will eventually contain all of the
4343 disassembly routines and opcode tables. At present, it only contains
4344 Sparc and Z8000 routines. This will allow the assembler, debugger, and
4345 disassembler (binutils/objdump) to share these routines.
4347 The libiberty library is now copylefted under the GNU Library General
4348 Public License. This allows more liberal use, and was done so libg++
4349 can use it. This makes no difference to GDB, since the Library License
4350 grants all the rights from the General Public License.
4354 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
4355 reference to the stabs symbol info used by the debugger. It is (as far
4356 as we know) the only published document on this fascinating topic. We
4357 encourage you to read it, compare it to the stabs information on your
4358 system, and send improvements on the document in general (to
4359 bug-gdb@prep.ai.mit.edu).
4361 And, of course, many bugs have been fixed.
4364 *** Changes in GDB-4.6:
4366 * Better support for C++ function names
4368 GDB now accepts as input the "demangled form" of C++ overloaded function
4369 names and member function names, and can do command completion on such names
4370 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
4371 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
4372 Make use of command completion, it is your friend.
4374 GDB also now accepts a variety of C++ mangled symbol formats. They are
4375 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
4376 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
4377 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
4378 for the list of formats.
4380 * G++ symbol mangling problem
4382 Recent versions of gcc have a bug in how they emit debugging information for
4383 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
4384 directory) can be applied to gcc to fix the problem. Alternatively, if you
4385 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
4386 usual symptom is difficulty with setting breakpoints on methods. GDB complains
4387 about the method being non-existent. (We believe that version 2.2.2 of GCC has
4390 * New 'maintenance' command
4392 All of the commands related to hacking GDB internals have been moved out of
4393 the main command set, and now live behind the 'maintenance' command. This
4394 can also be abbreviated as 'mt'. The following changes were made:
4396 dump-me -> maintenance dump-me
4397 info all-breakpoints -> maintenance info breakpoints
4398 printmsyms -> maintenance print msyms
4399 printobjfiles -> maintenance print objfiles
4400 printpsyms -> maintenance print psymbols
4401 printsyms -> maintenance print symbols
4403 The following commands are new:
4405 maintenance demangle Call internal GDB demangler routine to
4406 demangle a C++ link name and prints the result.
4407 maintenance print type Print a type chain for a given symbol
4409 * Change to .gdbinit file processing
4411 We now read the $HOME/.gdbinit file before processing the argv arguments
4412 (e.g. reading symbol files or core files). This allows global parameters to
4413 be set, which will apply during the symbol reading. The ./.gdbinit is still
4414 read after argv processing.
4416 * New hosts supported
4418 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
4420 GNU/Linux support i386-unknown-linux or linux
4422 We are also including code to support the HP/PA running BSD and HPUX. This
4423 is almost guaranteed not to work, as we didn't have time to test or build it
4424 for this release. We are including it so that the more adventurous (or
4425 masochistic) of you can play with it. We also had major problems with the
4426 fact that the compiler that we got from HP doesn't support the -g option.
4429 * New targets supported
4431 Hitachi H8/300 h8300-hitachi-hms or h8300hms
4433 * More smarts about finding #include files
4435 GDB now remembers the compilation directory for all include files, and for
4436 all files from which C is generated (like yacc and lex sources). This
4437 greatly improves GDB's ability to find yacc/lex sources, and include files,
4438 especially if you are debugging your program from a directory different from
4439 the one that contains your sources.
4441 We also fixed a bug which caused difficulty with listing and setting
4442 breakpoints in include files which contain C code. (In the past, you had to
4443 try twice in order to list an include file that you hadn't looked at before.)
4445 * Interesting infernals change
4447 GDB now deals with arbitrary numbers of sections, where the symbols for each
4448 section must be relocated relative to that section's landing place in the
4449 target's address space. This work was needed to support ELF with embedded
4450 stabs used by Solaris-2.0.
4452 * Bug fixes (of course!)
4454 There have been loads of fixes for the following things:
4455 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
4456 i960, stabs, DOS(GO32), procfs, etc...
4458 See the ChangeLog for details.
4460 *** Changes in GDB-4.5:
4462 * New machines supported (host and target)
4464 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
4466 SGI Irix-4.x mips-sgi-irix4 or iris4
4468 * New malloc package
4470 GDB now uses a new memory manager called mmalloc, based on gmalloc.
4471 Mmalloc is capable of handling mutiple heaps of memory. It is also
4472 capable of saving a heap to a file, and then mapping it back in later.
4473 This can be used to greatly speedup the startup of GDB by using a
4474 pre-parsed symbol table which lives in a mmalloc managed heap. For
4475 more details, please read mmalloc/mmalloc.texi.
4479 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
4480 'help info proc' for details.
4482 * MIPS ecoff symbol table format
4484 The code that reads MIPS symbol table format is now supported on all hosts.
4485 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
4488 * File name changes for MS-DOS
4490 Many files in the config directories have been renamed to make it easier to
4491 support GDB on MS-DOSe systems (which have very restrictive file name
4492 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
4493 environment) is close to working but has some remaining problems. Note
4494 that debugging of DOS programs is not supported, due to limitations
4495 in the ``operating system'', but it can be used to host cross-debugging.
4497 * Cross byte order fixes
4499 Many fixes have been made to support cross debugging of Sparc and MIPS
4500 targets from hosts whose byte order differs.
4502 * New -mapped and -readnow options
4504 If memory-mapped files are available on your system through the 'mmap'
4505 system call, you can use the -mapped option on the `file' or
4506 `symbol-file' commands to cause GDB to write the symbols from your
4507 program into a reusable file. If the program you are debugging is
4508 called `/path/fred', the mapped symbol file will be `./fred.syms'.
4509 Future GDB debugging sessions will notice the presence of this file,
4510 and will quickly map in symbol information from it, rather than reading
4511 the symbol table from the executable program. Using the '-mapped'
4512 option in a GDB `file' or `symbol-file' command has the same effect as
4513 starting GDB with the '-mapped' command-line option.
4515 You can cause GDB to read the entire symbol table immediately by using
4516 the '-readnow' option with any of the commands that load symbol table
4517 information (or on the GDB command line). This makes the command
4518 slower, but makes future operations faster.
4520 The -mapped and -readnow options are typically combined in order to
4521 build a `fred.syms' file that contains complete symbol information.
4522 A simple GDB invocation to do nothing but build a `.syms' file for future
4525 gdb -batch -nx -mapped -readnow programname
4527 The `.syms' file is specific to the host machine on which GDB is run.
4528 It holds an exact image of GDB's internal symbol table. It cannot be
4529 shared across multiple host platforms.
4531 * longjmp() handling
4533 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
4534 siglongjmp() without losing control. This feature has not yet been ported to
4535 all systems. It currently works on many 386 platforms, all MIPS-based
4536 platforms (SGI, DECstation, etc), and Sun3/4.
4540 Preliminary work has been put in to support the new Solaris OS from Sun. At
4541 this time, it can control and debug processes, but it is not capable of
4546 As always, many many bug fixes. The major areas were with g++, and mipsread.
4547 People using the MIPS-based platforms should experience fewer mysterious
4548 crashes and trashed symbol tables.
4550 *** Changes in GDB-4.4:
4552 * New machines supported (host and target)
4554 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4556 BSD Reno on Vax vax-dec-bsd
4557 Ultrix on Vax vax-dec-ultrix
4559 * New machines supported (target)
4561 AMD 29000 embedded, using EBMON a29k-none-none
4565 GDB continues to improve its handling of C++. `References' work better.
4566 The demangler has also been improved, and now deals with symbols mangled as
4567 per the Annotated C++ Reference Guide.
4569 GDB also now handles `stabs' symbol information embedded in MIPS
4570 `ecoff' symbol tables. Since the ecoff format was not easily
4571 extensible to handle new languages such as C++, this appeared to be a
4572 good way to put C++ debugging info into MIPS binaries. This option
4573 will be supported in the GNU C compiler, version 2, when it is
4576 * New features for SVR4
4578 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
4579 shared libraries. Debugging dynamically linked programs should present
4580 only minor differences from debugging statically linked programs.
4582 The `info proc' command will print out information about any process
4583 on an SVR4 system (including the one you are debugging). At the moment,
4584 it prints the address mappings of the process.
4586 If you bring up GDB on another SVR4 system, please send mail to
4587 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
4589 * Better dynamic linking support in SunOS
4591 Reading symbols from shared libraries which contain debugging symbols
4592 now works properly. However, there remain issues such as automatic
4593 skipping of `transfer vector' code during function calls, which
4594 make it harder to debug code in a shared library, than to debug the
4595 same code linked statically.
4599 GDB is now using the latest `getopt' routines from the FSF. This
4600 version accepts the -- prefix for options with long names. GDB will
4601 continue to accept the old forms (-option and +option) as well.
4602 Various single letter abbreviations for options have been explicity
4603 added to the option table so that they won't get overshadowed in the
4604 future by other options that begin with the same letter.
4608 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
4609 Many assorted bugs have been handled. Many more remain to be handled.
4610 See the various ChangeLog files (primarily in gdb and bfd) for details.
4613 *** Changes in GDB-4.3:
4615 * New machines supported (host and target)
4617 Amiga 3000 running Amix m68k-cbm-svr4 or amix
4618 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
4619 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4621 * Almost SCO Unix support
4623 We had hoped to support:
4624 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4625 (except for core file support), but we discovered very late in the release
4626 that it has problems with process groups that render gdb unusable. Sorry
4627 about that. I encourage people to fix it and post the fixes.
4629 * Preliminary ELF and DWARF support
4631 GDB can read ELF object files on System V Release 4, and can handle
4632 debugging records for C, in DWARF format, in ELF files. This support
4633 is preliminary. If you bring up GDB on another SVR4 system, please
4634 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
4639 GDB now uses the latest `readline' library. One user-visible change
4640 is that two tabs will list possible command completions, which previously
4641 required typing M-? (meta-question mark, or ESC ?).
4645 The `stepi' bug that many of you noticed has been squashed.
4646 Many bugs in C++ have been handled. Many more remain to be handled.
4647 See the various ChangeLog files (primarily in gdb and bfd) for details.
4649 * State of the MIPS world (in case you wondered):
4651 GDB can understand the symbol tables emitted by the compilers
4652 supplied by most vendors of MIPS-based machines, including DEC. These
4653 symbol tables are in a format that essentially nobody else uses.
4655 Some versions of gcc come with an assembler post-processor called
4656 mips-tfile. This program is required if you want to do source-level
4657 debugging of gcc-compiled programs. I believe FSF does not ship
4658 mips-tfile with gcc version 1, but it will eventually come with gcc
4661 Debugging of g++ output remains a problem. g++ version 1.xx does not
4662 really support it at all. (If you're lucky, you should be able to get
4663 line numbers and stack traces to work, but no parameters or local
4664 variables.) With some work it should be possible to improve the
4667 When gcc version 2 is released, you will have somewhat better luck.
4668 However, even then you will get confusing results for inheritance and
4671 We will eventually provide full debugging of g++ output on
4672 DECstations. This will probably involve some kind of stabs-in-ecoff
4673 encapulation, but the details have not been worked out yet.
4676 *** Changes in GDB-4.2:
4678 * Improved configuration
4680 Only one copy of `configure' exists now, and it is not self-modifying.
4681 Porting BFD is simpler.
4685 The `step' and `next' commands now only stop at the first instruction
4686 of a source line. This prevents the multiple stops that used to occur
4687 in switch statements, for-loops, etc. `Step' continues to stop if a
4688 function that has debugging information is called within the line.
4692 Lots of small bugs fixed. More remain.
4694 * New host supported (not target)
4696 Intel 386 PC clone running Mach i386-none-mach
4699 *** Changes in GDB-4.1:
4701 * Multiple source language support
4703 GDB now has internal scaffolding to handle several source languages.
4704 It determines the type of each source file from its filename extension,
4705 and will switch expression parsing and number formatting to match the
4706 language of the function in the currently selected stack frame.
4707 You can also specifically set the language to be used, with
4708 `set language c' or `set language modula-2'.
4712 GDB now has preliminary support for the GNU Modula-2 compiler,
4713 currently under development at the State University of New York at
4714 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
4715 continue through the fall of 1991 and into 1992.
4717 Other Modula-2 compilers are currently not supported, and attempting to
4718 debug programs compiled with them will likely result in an error as the
4719 symbol table is read. Feel free to work on it, though!
4721 There are hooks in GDB for strict type checking and range checking,
4722 in the `Modula-2 philosophy', but they do not currently work.
4726 GDB can now write to executable and core files (e.g. patch
4727 a variable's value). You must turn this switch on, specify
4728 the file ("exec foo" or "core foo"), *then* modify it, e.g.
4729 by assigning a new value to a variable. Modifications take
4732 * Automatic SunOS shared library reading
4734 When you run your program, GDB automatically determines where its
4735 shared libraries (if any) have been loaded, and reads their symbols.
4736 The `share' command is no longer needed. This also works when
4737 examining core files.
4741 You can specify the number of lines that the `list' command shows.
4744 * New machines supported (host and target)
4746 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4747 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
4748 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
4750 * New hosts supported (not targets)
4752 IBM RT/PC: romp-ibm-aix or rtpc
4754 * New targets supported (not hosts)
4756 AMD 29000 embedded with COFF a29k-none-coff
4757 AMD 29000 embedded with a.out a29k-none-aout
4758 Ultracomputer remote kernel debug a29k-nyu-kern
4760 * New remote interfaces
4766 *** Changes in GDB-4.0:
4770 Wide output is wrapped at good places to make the output more readable.
4772 Gdb now supports cross-debugging from a host machine of one type to a
4773 target machine of another type. Communication with the target system
4774 is over serial lines. The ``target'' command handles connecting to the
4775 remote system; the ``load'' command will download a program into the
4776 remote system. Serial stubs for the m68k and i386 are provided. Gdb
4777 also supports debugging of realtime processes running under VxWorks,
4778 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
4779 stub on the target system.
4781 New CPUs supported include the AMD 29000 and Intel 960.
4783 GDB now reads object files and symbol tables via a ``binary file''
4784 library, which allows a single copy of GDB to debug programs of multiple
4785 object file types such as a.out and coff.
4787 There is now a GDB reference card in "doc/refcard.tex". (Make targets
4788 refcard.dvi and refcard.ps are available to format it).
4791 * Control-Variable user interface simplified
4793 All variables that control the operation of the debugger can be set
4794 by the ``set'' command, and displayed by the ``show'' command.
4796 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
4797 ``Show prompt'' produces the response:
4798 Gdb's prompt is new-gdb=>.
4800 What follows are the NEW set commands. The command ``help set'' will
4801 print a complete list of old and new set commands. ``help set FOO''
4802 will give a longer description of the variable FOO. ``show'' will show
4803 all of the variable descriptions and their current settings.
4805 confirm on/off: Enables warning questions for operations that are
4806 hard to recover from, e.g. rerunning the program while
4807 it is already running. Default is ON.
4809 editing on/off: Enables EMACS style command line editing
4810 of input. Previous lines can be recalled with
4811 control-P, the current line can be edited with control-B,
4812 you can search for commands with control-R, etc.
4815 history filename NAME: NAME is where the gdb command history
4816 will be stored. The default is .gdb_history,
4817 or the value of the environment variable
4820 history size N: The size, in commands, of the command history. The
4821 default is 256, or the value of the environment variable
4824 history save on/off: If this value is set to ON, the history file will
4825 be saved after exiting gdb. If set to OFF, the
4826 file will not be saved. The default is OFF.
4828 history expansion on/off: If this value is set to ON, then csh-like
4829 history expansion will be performed on
4830 command line input. The default is OFF.
4832 radix N: Sets the default radix for input and output. It can be set
4833 to 8, 10, or 16. Note that the argument to "radix" is interpreted
4834 in the current radix, so "set radix 10" is always a no-op.
4836 height N: This integer value is the number of lines on a page. Default
4837 is 24, the current `stty rows'' setting, or the ``li#''
4838 setting from the termcap entry matching the environment
4841 width N: This integer value is the number of characters on a line.
4842 Default is 80, the current `stty cols'' setting, or the ``co#''
4843 setting from the termcap entry matching the environment
4846 Note: ``set screensize'' is obsolete. Use ``set height'' and
4847 ``set width'' instead.
4849 print address on/off: Print memory addresses in various command displays,
4850 such as stack traces and structure values. Gdb looks
4851 more ``symbolic'' if you turn this off; it looks more
4852 ``machine level'' with it on. Default is ON.
4854 print array on/off: Prettyprint arrays. New convenient format! Default
4857 print demangle on/off: Print C++ symbols in "source" form if on,
4860 print asm-demangle on/off: Same, for assembler level printouts
4863 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
4866 * Support for Epoch Environment.
4868 The epoch environment is a version of Emacs v18 with windowing. One
4869 new command, ``inspect'', is identical to ``print'', except that if you
4870 are running in the epoch environment, the value is printed in its own
4874 * Support for Shared Libraries
4876 GDB can now debug programs and core files that use SunOS shared libraries.
4877 Symbols from a shared library cannot be referenced
4878 before the shared library has been linked with the program (this
4879 happens after you type ``run'' and before the function main() is entered).
4880 At any time after this linking (including when examining core files
4881 from dynamically linked programs), gdb reads the symbols from each
4882 shared library when you type the ``sharedlibrary'' command.
4883 It can be abbreviated ``share''.
4885 sharedlibrary REGEXP: Load shared object library symbols for files
4886 matching a unix regular expression. No argument
4887 indicates to load symbols for all shared libraries.
4889 info sharedlibrary: Status of loaded shared libraries.
4894 A watchpoint stops execution of a program whenever the value of an
4895 expression changes. Checking for this slows down execution
4896 tremendously whenever you are in the scope of the expression, but is
4897 quite useful for catching tough ``bit-spreader'' or pointer misuse
4898 problems. Some machines such as the 386 have hardware for doing this
4899 more quickly, and future versions of gdb will use this hardware.
4901 watch EXP: Set a watchpoint (breakpoint) for an expression.
4903 info watchpoints: Information about your watchpoints.
4905 delete N: Deletes watchpoint number N (same as breakpoints).
4906 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
4907 enable N: Re-enables watchpoint number N (same as breakpoints).
4910 * C++ multiple inheritance
4912 When used with a GCC version 2 compiler, GDB supports multiple inheritance
4915 * C++ exception handling
4917 Gdb now supports limited C++ exception handling. Besides the existing
4918 ability to breakpoint on an exception handler, gdb can breakpoint on
4919 the raising of an exception (before the stack is peeled back to the
4922 catch FOO: If there is a FOO exception handler in the dynamic scope,
4923 set a breakpoint to catch exceptions which may be raised there.
4924 Multiple exceptions (``catch foo bar baz'') may be caught.
4926 info catch: Lists all exceptions which may be caught in the
4927 current stack frame.
4930 * Minor command changes
4932 The command ``call func (arg, arg, ...)'' now acts like the print
4933 command, except it does not print or save a value if the function's result
4934 is void. This is similar to dbx usage.
4936 The ``up'' and ``down'' commands now always print the frame they end up
4937 at; ``up-silently'' and `down-silently'' can be used in scripts to change
4938 frames without printing.
4940 * New directory command
4942 'dir' now adds directories to the FRONT of the source search path.
4943 The path starts off empty. Source files that contain debug information
4944 about the directory in which they were compiled can be found even
4945 with an empty path; Sun CC and GCC include this information. If GDB can't
4946 find your source file in the current directory, type "dir .".
4948 * Configuring GDB for compilation
4950 For normal use, type ``./configure host''. See README or gdb.texinfo
4953 GDB now handles cross debugging. If you are remotely debugging between
4954 two different machines, type ``./configure host -target=targ''.
4955 Host is the machine where GDB will run; targ is the machine
4956 where the program that you are debugging will run.