1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.4
6 * The option "symbol-reloading" has been deleted as it is no longer used.
10 ** GDB commands implemented in Python can now be put in command class
13 ** The "maint set python print-stack on|off" is now deleted.
15 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
16 apply "flag enum"-style pretty-printing to any enum.
18 ** gdb.lookup_symbol can now work when there is no current frame.
20 ** gdb.Symbol now has a 'line' attribute, holding the line number in
21 the source at which the symbol was defined.
23 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
24 method 'value'. The former indicates whether the symbol needs a
25 frame in order to compute its value, and the latter computes the
28 * GDBserver now supports stdio connections.
29 E.g. (gdb) target remote | ssh myhost gdbserver - hello
31 * The binary "gdbtui" can no longer be built or installed.
32 Use "gdb -tui" instead.
34 * GDB will now print "flag" enums specially. A flag enum is one where
35 all the enumerator values have no bits in common when pairwise
36 "and"ed. When printing a value whose type is a flag enum, GDB will
37 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
38 (gdb) print (enum E) 3
41 * The filename part of a linespec will now match trailing components
42 of a source file name. For example, "break gcc/expr.c:1000" will
43 now set a breakpoint in build/gcc/expr.c, but not
46 * The "info proc" and "generate-core-file" commands will now also
47 work on remote targets connected to GDBserver on Linux.
49 * The command "info catch" has been removed. It has been disabled
52 * The "catch exception" and "catch assert" commands now accept
53 a condition at the end of the command, much like the "break"
54 command does. For instance:
56 (gdb) catch exception Constraint_Error if Barrier = True
58 Previously, it was possible to add a condition to such catchpoints,
59 but it had to be done as a second step, after the catchpoint had been
60 created, using the "condition" command.
62 * The "info static-tracepoint-marker" command will now also work on
63 native Linux targets with in-process agent.
65 * GDB can now set breakpoints on inlined functions.
67 * The .gdb_index section has been updated to include symbols for
68 inlined functions. GDB will ignore older .gdb_index sections by
69 default, which could cause symbol files to be loaded more slowly
70 until their .gdb_index sections can be recreated. The new option
71 --use-deprecated-index-sections will cause GDB to use any older
72 .gdb_index sections it finds. This will restore performance, but
73 the ability to set breakpoints on inlined functions will be lost
74 in symbol files with older .gdb_index sections.
78 ** "catch load" and "catch unload" can be used to stop when a shared
79 library is loaded or unloaded, respectively.
81 ** "enable count" can be used to auto-disable a breakpoint after
84 ** "info vtbl" can be used to show the virtual method tables for
89 Renesas RL78 rl78-*-elf
90 HP OpenVMS ia64 ia64-hp-openvms*
92 * GDBserver supports evaluation of breakpoint conditions. When
93 support is advertised by GDBserver, GDB may be told to send the
94 breakpoint conditions in bytecode form to GDBserver. GDBserver
95 will only report the breakpoint trigger to GDB when its condition
100 set breakpoint condition-evaluation
101 show breakpoint condition-evaluation
102 Controls whether breakpoint conditions are evaluated by GDB ("gdb") or by
103 GDBserver ("target").
104 This option can improve debugger efficiency depending on the speed of the
109 z0/z1 conditional breakpoints extension
111 The z0/z1 breakpoint insertion packets have been extended to carry
112 a list of conditional expressions over to the remote stub depending on the
113 condition evaluation mode. The use of this extension can be controlled
114 via the "set remote conditional-breakpoints-packet" command.
118 Specify the signals which the remote stub may pass to the debugged
119 program without GDB involvement.
121 *** Changes in GDB 7.4
123 * GDB now handles ambiguous linespecs more consistently; the existing
124 FILE:LINE support has been expanded to other types of linespecs. A
125 breakpoint will now be set on all matching locations in all
126 inferiors, and locations will be added or removed according to
129 * GDB now allows you to skip uninteresting functions and files when
130 stepping with the "skip function" and "skip file" commands.
132 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
133 and "show remote hardware-watchpoint-length-limit". These allows to
134 set or show the maximum length limit (in bytes) of a remote
135 target hardware watchpoint.
137 This allows e.g. to use "unlimited" hardware watchpoints with the
138 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
139 watchpoints are slower than real hardware watchpoints but are
140 significantly faster than gdb software watchpoints.
144 ** The register_pretty_printer function in module gdb.printing now takes
145 an optional `replace' argument. If True, the new printer replaces any
148 ** The "maint set python print-stack on|off" command has been
149 deprecated and will be deleted in GDB 7.5.
150 A new command: "set python print-stack none|full|message" has
151 replaced it. Additionally, the default for "print-stack" is
152 now "message", which just prints the error message without
155 ** A prompt substitution hook (prompt_hook) is now available to the
158 ** A new Python module, gdb.prompt has been added to the GDB Python
159 modules library. This module provides functionality for
160 escape sequences in prompts (used by set/show
161 extended-prompt). These escape sequences are replaced by their
164 ** Python commands and convenience-functions located in
165 'data-directory'/python/gdb/command and
166 'data-directory'/python/gdb/function are now automatically loaded
169 ** Blocks now provide four new attributes. global_block and
170 static_block will return the global and static blocks
171 respectively. is_static and is_global are boolean attributes
172 that indicate if the block is one of those two types.
174 ** Symbols now provide the "type" attribute, the type of the symbol.
176 ** The "gdb.breakpoint" function has been deprecated in favor of
179 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
180 of a function. This class is based on the "finish" command
181 available in the CLI.
183 ** Type objects for struct and union types now allow access to
184 the fields using standard Python dictionary (mapping) methods.
185 For example, "some_type['myfield']" now works, as does
188 ** A new event "gdb.new_objfile" has been added, triggered by loading a
191 ** A new function, "deep_items" has been added to the gdb.types
192 module in the GDB Python modules library. This function returns
193 an iterator over the fields of a struct or union type. Unlike
194 the standard Python "iteritems" method, it will recursively traverse
195 any anonymous fields.
199 ** "*stopped" events can report several new "reason"s, such as
202 ** Breakpoint changes are now notified using new async records, like
203 "=breakpoint-modified".
205 ** New command -ada-task-info.
207 * libthread-db-search-path now supports two special values: $sdir and $pdir.
208 $sdir specifies the default system locations of shared libraries.
209 $pdir specifies the directory where the libpthread used by the application
212 GDB no longer looks in $sdir and $pdir after it has searched the directories
213 mentioned in libthread-db-search-path. If you want to search those
214 directories, they must be specified in libthread-db-search-path.
215 The default value of libthread-db-search-path on GNU/Linux and Solaris
216 systems is now "$sdir:$pdir".
218 $pdir is not supported by gdbserver, it is currently ignored.
219 $sdir is supported by gdbserver.
221 * New configure option --with-iconv-bin.
222 When using the internationalization support like the one in the GNU C
223 library, GDB will invoke the "iconv" program to get a list of supported
224 character sets. If this program lives in a non-standard location, one can
225 use this option to specify where to find it.
227 * When natively debugging programs on PowerPC BookE processors running
228 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
229 watchpoints, which specify a mask in addition to an address to watch.
230 The mask specifies that some bits of an address (the bits which are
231 reset in the mask) should be ignored when matching the address accessed
232 by the inferior against the watchpoint address. See the "PowerPC Embedded"
233 section in the user manual for more details.
235 * The new option --once causes GDBserver to stop listening for connections once
236 the first connection is made. The listening port used by GDBserver will
237 become available after that.
239 * New commands "info macros" and "alias" have been added.
241 * New function parameters suffix @entry specifies value of function parameter
242 at the time the function got called. Entry values are available only since
248 "!" is now an alias of the "shell" command.
249 Note that no space is needed between "!" and SHELL COMMAND.
253 watch EXPRESSION mask MASK_VALUE
254 The watch command now supports the mask argument which allows creation
255 of masked watchpoints, if the current architecture supports this feature.
257 info auto-load-scripts [REGEXP]
258 This command was formerly named "maintenance print section-scripts".
259 It is now generally useful and is no longer a maintenance-only command.
261 info macro [-all] [--] MACRO
262 The info macro command has new options `-all' and `--'. The first for
263 printing all definitions of a macro. The second for explicitly specifying
264 the end of arguments and the beginning of the macro name in case the macro
265 name starts with a hyphen.
267 collect[/s] EXPRESSIONS
268 The tracepoint collect command now takes an optional modifier "/s"
269 that directs it to dereference pointer-to-character types and
270 collect the bytes of memory up to a zero byte. The behavior is
271 similar to what you see when you use the regular print command on a
272 string. An optional integer following the "/s" sets a bound on the
273 number of bytes that will be collected.
276 The trace start command now interprets any supplied arguments as a
277 note to be recorded with the trace run, with an effect similar to
278 setting the variable trace-notes.
281 The trace stop command now interprets any arguments as a note to be
282 mentioned along with the tstatus report that the trace was stopped
283 with a command. The effect is similar to setting the variable
286 * Tracepoints can now be enabled and disabled at any time after a trace
287 experiment has been started using the standard "enable" and "disable"
288 commands. It is now possible to start a trace experiment with no enabled
289 tracepoints; GDB will display a warning, but will allow the experiment to
290 begin, assuming that tracepoints will be enabled as needed while the trace
293 * Fast tracepoints on 32-bit x86-architectures can now be placed at
294 locations with 4-byte instructions, when they were previously
295 limited to locations with instructions of 5 bytes or longer.
301 Set the GDB prompt, and allow escape sequences to be inserted to
302 display miscellaneous information (see 'help set extended-prompt'
303 for the list of sequences). This prompt (and any information
304 accessed through the escape sequences) is updated every time the
307 set print entry-values (both|compact|default|if-needed|no|only|preferred)
308 show print entry-values
309 Set printing of frame argument values at function entry. In some cases
310 GDB can determine the value of function argument which was passed by the
311 function caller, even if the value was modified inside the called function.
313 set debug entry-values
314 show debug entry-values
315 Control display of debugging info for determining frame argument values at
316 function entry and virtual tail call frames.
318 set basenames-may-differ
319 show basenames-may-differ
320 Set whether a source file may have multiple base names.
321 (A "base name" is the name of a file with the directory part removed.
322 Example: The base name of "/home/user/hello.c" is "hello.c".)
323 If set, GDB will canonicalize file names (e.g., expand symlinks)
324 before comparing them. Canonicalization is an expensive operation,
325 but it allows the same file be known by more than one base name.
326 If not set (the default), all source files are assumed to have just
327 one base name, and gdb will do file name comparisons more efficiently.
333 Set a user name and notes for the current and any future trace runs.
334 This is useful for long-running and/or disconnected traces, to
335 inform others (or yourself) as to who is running the trace, supply
336 contact information, or otherwise explain what is going on.
339 show trace-stop-notes
340 Set a note attached to the trace run, that is displayed when the
341 trace has been stopped by a tstop command. This is useful for
342 instance as an explanation, if you are stopping a trace run that was
343 started by someone else.
349 Dynamically enable a tracepoint in a started trace experiment.
353 Dynamically disable a tracepoint in a started trace experiment.
357 Set the user and notes of the trace run.
361 Query the current status of a tracepoint.
365 Query the minimum length of instruction at which a fast tracepoint may
368 * Dcache size (number of lines) and line-size are now runtime-configurable
369 via "set dcache line" and "set dcache line-size" commands.
373 Texas Instruments TMS320C6x tic6x-*-*
377 Renesas RL78 rl78-*-elf
379 *** Changes in GDB 7.3.1
381 * The build failure for NetBSD and OpenBSD targets have now been fixed.
383 *** Changes in GDB 7.3
385 * GDB has a new command: "thread find [REGEXP]".
386 It finds the thread id whose name, target id, or thread extra info
387 matches the given regular expression.
389 * The "catch syscall" command now works on mips*-linux* targets.
391 * The -data-disassemble MI command now supports modes 2 and 3 for
392 dumping the instruction opcodes.
394 * New command line options
396 -data-directory DIR Specify DIR as the "data-directory".
397 This is mostly for testing purposes.
399 * The "maint set python auto-load on|off" command has been renamed to
400 "set auto-load-scripts on|off".
402 * GDB has a new command: "set directories".
403 It is like the "dir" command except that it replaces the
404 source path list instead of augmenting it.
406 * GDB now understands thread names.
408 On GNU/Linux, "info threads" will display the thread name as set by
409 prctl or pthread_setname_np.
411 There is also a new command, "thread name", which can be used to
412 assign a name internally for GDB to display.
415 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
416 has been integrated into GDB.
420 ** The function gdb.Write now accepts an optional keyword 'stream'.
421 This keyword, when provided, will direct the output to either
422 stdout, stderr, or GDB's logging output.
424 ** Parameters can now be be sub-classed in Python, and in particular
425 you may implement the get_set_doc and get_show_doc functions.
426 This improves how Parameter set/show documentation is processed
427 and allows for more dynamic content.
429 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
430 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
431 have an is_valid method.
433 ** Breakpoints can now be sub-classed in Python, and in particular
434 you may implement a 'stop' function that is executed each time
435 the inferior reaches that breakpoint.
437 ** New function gdb.lookup_global_symbol looks up a global symbol.
439 ** GDB values in Python are now callable if the value represents a
440 function. For example, if 'some_value' represents a function that
441 takes two integer parameters and returns a value, you can call
442 that function like so:
444 result = some_value (10,20)
446 ** Module gdb.types has been added.
447 It contains a collection of utilities for working with gdb.Types objects:
448 get_basic_type, has_field, make_enum_dict.
450 ** Module gdb.printing has been added.
451 It contains utilities for writing and registering pretty-printers.
452 New classes: PrettyPrinter, SubPrettyPrinter,
453 RegexpCollectionPrettyPrinter.
454 New function: register_pretty_printer.
456 ** New commands "info pretty-printers", "enable pretty-printer" and
457 "disable pretty-printer" have been added.
459 ** gdb.parameter("directories") is now available.
461 ** New function gdb.newest_frame returns the newest frame in the
464 ** The gdb.InferiorThread class has a new "name" attribute. This
465 holds the thread's name.
467 ** Python Support for Inferior events.
468 Python scripts can add observers to be notified of events
469 occurring in the process being debugged.
470 The following events are currently supported:
471 - gdb.events.cont Continue event.
472 - gdb.events.exited Inferior exited event.
473 - gdb.events.stop Signal received, and Breakpoint hit events.
477 ** GDB now puts template parameters in scope when debugging in an
478 instantiation. For example, if you have:
480 template<int X> int func (void) { return X; }
482 then if you step into func<5>, "print X" will show "5". This
483 feature requires proper debuginfo support from the compiler; it
484 was added to GCC 4.5.
486 ** The motion commands "next", "finish", "until", and "advance" now
487 work better when exceptions are thrown. In particular, GDB will
488 no longer lose control of the inferior; instead, the GDB will
489 stop the inferior at the point at which the exception is caught.
490 This functionality requires a change in the exception handling
491 code that was introduced in GCC 4.5.
493 * GDB now follows GCC's rules on accessing volatile objects when
494 reading or writing target state during expression evaluation.
495 One notable difference to prior behavior is that "print x = 0"
496 no longer generates a read of x; the value of the assignment is
497 now always taken directly from the value being assigned.
499 * GDB now has some support for using labels in the program's source in
500 linespecs. For instance, you can use "advance label" to continue
501 execution to a label.
503 * GDB now has support for reading and writing a new .gdb_index
504 section. This section holds a fast index of DWARF debugging
505 information and can be used to greatly speed up GDB startup and
506 operation. See the documentation for `save gdb-index' for details.
508 * The "watch" command now accepts an optional "-location" argument.
509 When used, this causes GDB to watch the memory referred to by the
510 expression. Such a watchpoint is never deleted due to it going out
513 * GDB now supports thread debugging of core dumps on GNU/Linux.
515 GDB now activates thread debugging using the libthread_db library
516 when debugging GNU/Linux core dumps, similarly to when debugging
517 live processes. As a result, when debugging a core dump file, GDB
518 is now able to display pthread_t ids of threads. For example, "info
519 threads" shows the same output as when debugging the process when it
520 was live. In earlier releases, you'd see something like this:
523 * 1 LWP 6780 main () at main.c:10
525 While now you see this:
528 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
530 It is also now possible to inspect TLS variables when debugging core
533 When debugging a core dump generated on a machine other than the one
534 used to run GDB, you may need to point GDB at the correct
535 libthread_db library with the "set libthread-db-search-path"
536 command. See the user manual for more details on this command.
538 * When natively debugging programs on PowerPC BookE processors running
539 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
540 which stop execution of the inferior whenever it executes an instruction
541 at any address within the specified range. See the "PowerPC Embedded"
542 section in the user manual for more details.
544 * New features in the GDB remote stub, GDBserver
546 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
547 and i686 LynxOS (version 5.x).
549 ** GDBserver is now supported on Blackfin Linux.
551 * New native configurations
553 ia64 HP-UX ia64-*-hpux*
557 Analog Devices, Inc. Blackfin Processor bfin-*
559 * Ada task switching is now supported on sparc-elf targets when
560 debugging a program using the Ravenscar Profile. For more information,
561 see the "Tasking Support when using the Ravenscar Profile" section
562 in the GDB user manual.
564 * Guile support was removed.
566 * New features in the GNU simulator
568 ** The --map-info flag lists all known core mappings.
570 ** CFI flashes may be simulated via the "cfi" device.
572 *** Changes in GDB 7.2
574 * Shared library support for remote targets by default
576 When GDB is configured for a generic, non-OS specific target, like
577 for example, --target=arm-eabi or one of the many *-*-elf targets,
578 GDB now queries remote stubs for loaded shared libraries using the
579 `qXfer:libraries:read' packet. Previously, shared library support
580 was always disabled for such configurations.
584 ** Argument Dependent Lookup (ADL)
586 In C++ ADL lookup directs function search to the namespaces of its
587 arguments even if the namespace has not been imported.
597 Here the compiler will search for `foo' in the namespace of 'b'
598 and find A::foo. GDB now supports this. This construct is commonly
599 used in the Standard Template Library for operators.
601 ** Improved User Defined Operator Support
603 In addition to member operators, GDB now supports lookup of operators
604 defined in a namespace and imported with a `using' directive, operators
605 defined in the global scope, operators imported implicitly from an
606 anonymous namespace, and the ADL operators mentioned in the previous
608 GDB now also supports proper overload resolution for all the previously
609 mentioned flavors of operators.
611 ** static const class members
613 Printing of static const class members that are initialized in the
614 class definition has been fixed.
616 * Windows Thread Information Block access.
618 On Windows targets, GDB now supports displaying the Windows Thread
619 Information Block (TIB) structure. This structure is visible either
620 by using the new command `info w32 thread-information-block' or, by
621 dereferencing the new convenience variable named `$_tlb', a
622 thread-specific pointer to the TIB. This feature is also supported
623 when remote debugging using GDBserver.
627 Static tracepoints are calls in the user program into a tracing
628 library. One such library is a port of the LTTng kernel tracer to
629 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
630 When debugging with GDBserver, GDB now supports combining the GDB
631 tracepoint machinery with such libraries. For example: the user can
632 use GDB to probe a static tracepoint marker (a call from the user
633 program into the tracing library) with the new "strace" command (see
634 "New commands" below). This creates a "static tracepoint" in the
635 breakpoint list, that can be manipulated with the same feature set
636 as fast and regular tracepoints. E.g., collect registers, local and
637 global variables, collect trace state variables, and define
638 tracepoint conditions. In addition, the user can collect extra
639 static tracepoint marker specific data, by collecting the new
640 $_sdata internal variable. When analyzing the trace buffer, you can
641 inspect $_sdata like any other variable available to GDB. For more
642 information, see the "Tracepoints" chapter in GDB user manual. New
643 remote packets have been defined to support static tracepoints, see
644 the "New remote packets" section below.
646 * Better reconstruction of tracepoints after disconnected tracing
648 GDB will attempt to download the original source form of tracepoint
649 definitions when starting a trace run, and then will upload these
650 upon reconnection to the target, resulting in a more accurate
651 reconstruction of the tracepoints that are in use on the target.
655 You can now exercise direct control over the ways that GDB can
656 affect your program. For instance, you can disallow the setting of
657 breakpoints, so that the program can run continuously (assuming
658 non-stop mode). In addition, the "observer" variable is available
659 to switch all of the different controls; in observer mode, GDB
660 cannot affect the target's behavior at all, which is useful for
661 tasks like diagnosing live systems in the field.
663 * The new convenience variable $_thread holds the number of the
670 Return the address of the Windows Thread Information Block of a given thread.
674 In response to several of the tracepoint packets, the target may now
675 also respond with a number of intermediate `qRelocInsn' request
676 packets before the final result packet, to have GDB handle
677 relocating an instruction to execute at a different address. This
678 is particularly useful for stubs that support fast tracepoints. GDB
679 reports support for this feature in the qSupported packet.
683 List static tracepoint markers in the target program.
687 List static tracepoint markers at a given address in the target
690 qXfer:statictrace:read
692 Read the static trace data collected (by a `collect $_sdata'
693 tracepoint action). The remote stub reports support for this packet
694 to gdb's qSupported query.
698 Send the current settings of GDB's permission flags.
702 Send part of the source (textual) form of a tracepoint definition,
703 which includes location, conditional, and action list.
705 * The source command now accepts a -s option to force searching for the
706 script in the source search path even if the script name specifies
709 * New features in the GDB remote stub, GDBserver
711 - GDBserver now support tracepoints (including fast tracepoints, and
712 static tracepoints). The feature is currently supported by the
713 i386-linux and amd64-linux builds. See the "Tracepoints support
714 in gdbserver" section in the manual for more information.
716 GDBserver JIT compiles the tracepoint's conditional agent
717 expression bytecode into native code whenever possible for low
718 overhead dynamic tracepoints conditionals. For such tracepoints,
719 an expression that examines program state is evaluated when the
720 tracepoint is reached, in order to determine whether to capture
721 trace data. If the condition is simple and false, processing the
722 tracepoint finishes very quickly and no data is gathered.
724 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
725 for static tracepoints support.
727 - GDBserver now supports x86_64 Windows 64-bit debugging.
729 * GDB now sends xmlRegisters= in qSupported packet to indicate that
730 it understands register description.
732 * The --batch flag now disables pagination and queries.
734 * X86 general purpose registers
736 GDB now supports reading/writing byte, word and double-word x86
737 general purpose registers directly. This means you can use, say,
738 $ah or $ax to refer, respectively, to the byte register AH and
739 16-bit word register AX that are actually portions of the 32-bit
740 register EAX or 64-bit register RAX.
742 * The `commands' command now accepts a range of breakpoints to modify.
743 A plain `commands' following a command that creates multiple
744 breakpoints affects all the breakpoints set by that command. This
745 applies to breakpoints set by `rbreak', and also applies when a
746 single `break' command creates multiple breakpoints (e.g.,
747 breakpoints on overloaded c++ functions).
749 * The `rbreak' command now accepts a filename specification as part of
750 its argument, limiting the functions selected by the regex to those
751 in the specified file.
753 * Support for remote debugging Windows and SymbianOS shared libraries
754 from Unix hosts has been improved. Non Windows GDB builds now can
755 understand target reported file names that follow MS-DOS based file
756 system semantics, such as file names that include drive letters and
757 use the backslash character as directory separator. This makes it
758 possible to transparently use the "set sysroot" and "set
759 solib-search-path" on Unix hosts to point as host copies of the
760 target's shared libraries. See the new command "set
761 target-file-system-kind" described below, and the "Commands to
762 specify files" section in the user manual for more information.
766 eval template, expressions...
767 Convert the values of one or more expressions under the control
768 of the string template to a command line, and call it.
770 set target-file-system-kind unix|dos-based|auto
771 show target-file-system-kind
772 Set or show the assumed file system kind for target reported file
775 save breakpoints <filename>
776 Save all current breakpoint definitions to a file suitable for use
777 in a later debugging session. To read the saved breakpoint
778 definitions, use the `source' command.
780 `save tracepoints' is a new alias for `save-tracepoints'. The latter
783 info static-tracepoint-markers
784 Display information about static tracepoint markers in the target.
786 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
787 Define a static tracepoint by probing a marker at the given
788 function, line, address, or marker ID.
792 Enable and disable observer mode.
794 set may-write-registers on|off
795 set may-write-memory on|off
796 set may-insert-breakpoints on|off
797 set may-insert-tracepoints on|off
798 set may-insert-fast-tracepoints on|off
799 set may-interrupt on|off
800 Set individual permissions for GDB effects on the target. Note that
801 some of these settings can have undesirable or surprising
802 consequences, particularly when changed in the middle of a session.
803 For instance, disabling the writing of memory can prevent
804 breakpoints from being inserted, cause single-stepping to fail, or
805 even crash your program, if you disable after breakpoints have been
806 inserted. However, GDB should not crash.
808 set record memory-query on|off
809 show record memory-query
810 Control whether to stop the inferior if memory changes caused
811 by an instruction cannot be recorded.
816 The disassemble command now supports "start,+length" form of two arguments.
820 ** GDB now provides a new directory location, called the python directory,
821 where Python scripts written for GDB can be installed. The location
822 of that directory is <data-directory>/python, where <data-directory>
823 is the GDB data directory. For more details, see section `Scripting
824 GDB using Python' in the manual.
826 ** The GDB Python API now has access to breakpoints, symbols, symbol
827 tables, program spaces, inferiors, threads and frame's code blocks.
828 Additionally, GDB Parameters can now be created from the API, and
829 manipulated via set/show in the CLI.
831 ** New functions gdb.target_charset, gdb.target_wide_charset,
832 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
834 ** New exception gdb.GdbError.
836 ** Pretty-printers are now also looked up in the current program space.
838 ** Pretty-printers can now be individually enabled and disabled.
840 ** GDB now looks for names of Python scripts to auto-load in a
841 special section named `.debug_gdb_scripts', in addition to looking
842 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
844 * Tracepoint actions were unified with breakpoint commands. In particular,
845 there are no longer differences in "info break" output for breakpoints and
846 tracepoints and the "commands" command can be used for both tracepoints and
851 ARM Symbian arm*-*-symbianelf*
853 * D language support.
854 GDB now supports debugging programs written in the D programming
857 * GDB now supports the extended ptrace interface for PowerPC which is
858 available since Linux kernel version 2.6.34. This automatically enables
859 any hardware breakpoints and additional hardware watchpoints available in
860 the processor. The old ptrace interface exposes just one hardware
861 watchpoint and no hardware breakpoints.
863 * GDB is now able to use the Data Value Compare (DVC) register available on
864 embedded PowerPC processors to implement in hardware simple watchpoint
865 conditions of the form:
867 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
869 This works in native GDB running on Linux kernels with the extended ptrace
870 interface mentioned above.
872 *** Changes in GDB 7.1
878 GDB now supports importing of namespaces in C++. This enables the
879 user to inspect variables from imported namespaces. Support for
880 namepace aliasing has also been added. So, if a namespace is
881 aliased in the current scope (e.g. namepace C=A; ) the user can
882 print variables using the alias (e.g. (gdb) print C::x).
886 All known bugs relating to the printing of virtual base class were
887 fixed. It is now possible to call overloaded static methods using a
892 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
893 and reinterpret_cast<> are now handled by the C++ expression parser.
897 Xilinx MicroBlaze microblaze-*-*
902 Xilinx MicroBlaze microblaze
905 * Multi-program debugging.
907 GDB now has support for multi-program (a.k.a. multi-executable or
908 multi-exec) debugging. This allows for debugging multiple inferiors
909 simultaneously each running a different program under the same GDB
910 session. See "Debugging Multiple Inferiors and Programs" in the
911 manual for more information. This implied some user visible changes
912 in the multi-inferior support. For example, "info inferiors" now
913 lists inferiors that are not running yet or that have exited
914 already. See also "New commands" and "New options" below.
916 * New tracing features
918 GDB's tracepoint facility now includes several new features:
920 ** Trace state variables
922 GDB tracepoints now include support for trace state variables, which
923 are variables managed by the target agent during a tracing
924 experiment. They are useful for tracepoints that trigger each
925 other, so for instance one tracepoint can count hits in a variable,
926 and then a second tracepoint has a condition that is true when the
927 count reaches a particular value. Trace state variables share the
928 $-syntax of GDB convenience variables, and can appear in both
929 tracepoint actions and condition expressions. Use the "tvariable"
930 command to create, and "info tvariables" to view; see "Trace State
931 Variables" in the manual for more detail.
935 GDB now includes an option for defining fast tracepoints, which
936 targets may implement more efficiently, such as by installing a jump
937 into the target agent rather than a trap instruction. The resulting
938 speedup can be by two orders of magnitude or more, although the
939 tradeoff is that some program locations on some target architectures
940 might not allow fast tracepoint installation, for instance if the
941 instruction to be replaced is shorter than the jump. To request a
942 fast tracepoint, use the "ftrace" command, with syntax identical to
943 the regular trace command.
945 ** Disconnected tracing
947 It is now possible to detach GDB from the target while it is running
948 a trace experiment, then reconnect later to see how the experiment
949 is going. In addition, a new variable disconnected-tracing lets you
950 tell the target agent whether to continue running a trace if the
951 connection is lost unexpectedly.
955 GDB now has the ability to save the trace buffer into a file, and
956 then use that file as a target, similarly to you can do with
957 corefiles. You can select trace frames, print data that was
958 collected in them, and use tstatus to display the state of the
959 tracing run at the moment that it was saved. To create a trace
960 file, use "tsave <filename>", and to use it, do "target tfile
963 ** Circular trace buffer
965 You can ask the target agent to handle the trace buffer as a
966 circular buffer, discarding the oldest trace frames to make room for
967 newer ones, by setting circular-trace-buffer to on. This feature may
968 not be available for all target agents.
973 The disassemble command, when invoked with two arguments, now requires
974 the arguments to be comma-separated.
977 The info variables command now displays variable definitions. Files
978 which only declare a variable are not shown.
981 The source command is now capable of sourcing Python scripts.
982 This feature is dependent on the debugger being build with Python
985 Related to this enhancement is also the introduction of a new command
986 "set script-extension" (see below).
988 * New commands (for set/show, see "New options" below)
990 record save [<FILENAME>]
991 Save a file (in core file format) containing the process record
992 execution log for replay debugging at a later time.
994 record restore <FILENAME>
995 Restore the process record execution log that was saved at an
996 earlier time, for replay debugging.
998 add-inferior [-copies <N>] [-exec <FILENAME>]
1001 clone-inferior [-copies <N>] [ID]
1002 Make a new inferior ready to execute the same program another
1003 inferior has loaded.
1008 maint info program-spaces
1009 List the program spaces loaded into GDB.
1011 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1012 show remote interrupt-sequence
1013 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1014 as the sequence to the remote target in order to interrupt the execution.
1015 Ctrl-C is a default. Some system prefers BREAK which is high level of
1016 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1017 Magic SysRq g. It is BREAK signal and character 'g'.
1019 set remote interrupt-on-connect [on | off]
1020 show remote interrupt-on-connect
1021 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1022 remote target when gdb connects to it. This is needed when you debug
1025 set remotebreak [on | off]
1027 Deprecated. Use "set/show remote interrupt-sequence" instead.
1029 tvariable $NAME [ = EXP ]
1030 Create or modify a trace state variable.
1033 List trace state variables and their values.
1035 delete tvariable $NAME ...
1036 Delete one or more trace state variables.
1039 Evaluate the given expressions without collecting anything into the
1040 trace buffer. (Valid in tracepoint actions only.)
1042 ftrace FN / FILE:LINE / *ADDR
1043 Define a fast tracepoint at the given function, line, or address.
1045 * New expression syntax
1047 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1048 GDB now parses 0b101010 identically with 42.
1052 set follow-exec-mode new|same
1053 show follow-exec-mode
1054 Control whether GDB reuses the same inferior across an exec call or
1055 creates a new one. This is useful to be able to restart the old
1056 executable after the inferior having done an exec call.
1058 set default-collect EXPR, ...
1059 show default-collect
1060 Define a list of expressions to be collected at each tracepoint.
1061 This is a useful way to ensure essential items are not overlooked,
1062 such as registers or a critical global variable.
1064 set disconnected-tracing
1065 show disconnected-tracing
1066 If set to 1, the target is instructed to continue tracing if it
1067 loses its connection to GDB. If 0, the target is to stop tracing
1070 set circular-trace-buffer
1071 show circular-trace-buffer
1072 If set to on, the target is instructed to use a circular trace buffer
1073 and discard the oldest trace frames instead of stopping the trace due
1074 to a full trace buffer. If set to off, the trace stops when the buffer
1075 fills up. Some targets may not support this.
1077 set script-extension off|soft|strict
1078 show script-extension
1079 If set to "off", the debugger does not perform any script language
1080 recognition, and all sourced files are assumed to be GDB scripts.
1081 If set to "soft" (the default), files are sourced according to
1082 filename extension, falling back to GDB scripts if the first
1084 If set to "strict", files are sourced according to filename extension.
1086 set ada trust-PAD-over-XVS on|off
1087 show ada trust-PAD-over-XVS
1088 If off, activate a workaround against a bug in the debugging information
1089 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1090 the GCC sources for more information about the GNAT encoding and
1091 PAD types in particular). It is always safe to set this option to
1092 off, but this introduces a slight performance penalty. The default
1095 * Python API Improvements
1097 ** GDB provides the new class gdb.LazyString. This is useful in
1098 some pretty-printing cases. The new method gdb.Value.lazy_string
1099 provides a simple way to create objects of this type.
1101 ** The fields returned by gdb.Type.fields now have an
1102 `is_base_class' attribute.
1104 ** The new method gdb.Type.range returns the range of an array type.
1106 ** The new method gdb.parse_and_eval can be used to parse and
1107 evaluate an expression.
1109 * New remote packets
1112 Define a trace state variable.
1115 Get the current value of a trace state variable.
1118 Set desired tracing behavior upon disconnection.
1121 Set the trace buffer to be linear or circular.
1124 Get data about the tracepoints currently in use.
1128 Process record now works correctly with hardware watchpoints.
1130 Multiple bug fixes have been made to the mips-irix port, making it
1131 much more reliable. In particular:
1132 - Debugging threaded applications is now possible again. Previously,
1133 GDB would hang while starting the program, or while waiting for
1134 the program to stop at a breakpoint.
1135 - Attaching to a running process no longer hangs.
1136 - An error occurring while loading a core file has been fixed.
1137 - Changing the value of the PC register now works again. This fixes
1138 problems observed when using the "jump" command, or when calling
1139 a function from GDB, or even when assigning a new value to $pc.
1140 - With the "finish" and "return" commands, the return value for functions
1141 returning a small array is now correctly printed.
1142 - It is now possible to break on shared library code which gets executed
1143 during a shared library init phase (code executed while executing
1144 their .init section). Previously, the breakpoint would have no effect.
1145 - GDB is now able to backtrace through the signal handler for
1146 non-threaded programs.
1148 PIE (Position Independent Executable) programs debugging is now supported.
1149 This includes debugging execution of PIC (Position Independent Code) shared
1150 libraries although for that, it should be possible to run such libraries as an
1153 *** Changes in GDB 7.0
1155 * GDB now has an interface for JIT compilation. Applications that
1156 dynamically generate code can create symbol files in memory and register
1157 them with GDB. For users, the feature should work transparently, and
1158 for JIT developers, the interface is documented in the GDB manual in the
1159 "JIT Compilation Interface" chapter.
1161 * Tracepoints may now be conditional. The syntax is as for
1162 breakpoints; either an "if" clause appended to the "trace" command,
1163 or the "condition" command is available. GDB sends the condition to
1164 the target for evaluation using the same bytecode format as is used
1165 for tracepoint actions.
1167 * The disassemble command now supports: an optional /r modifier, print the
1168 raw instructions in hex as well as in symbolic form, and an optional /m
1169 modifier to print mixed source+assembly.
1171 * Process record and replay
1173 In a architecture environment that supports ``process record and
1174 replay'', ``process record and replay'' target can record a log of
1175 the process execution, and replay it with both forward and reverse
1178 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
1179 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
1180 set execution-direction {forward|reverse}, for targets that support
1183 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
1184 feature is available with a native GDB running on kernel version
1187 * GDB now has support for multi-byte and wide character sets on the
1188 target. Strings whose character type is wchar_t, char16_t, or
1189 char32_t are now correctly printed. GDB supports wide- and unicode-
1190 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
1191 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
1192 `printf'. This feature requires iconv to work properly; if your
1193 system does not have a working iconv, GDB can use GNU libiconv. See
1194 the installation instructions for more information.
1196 * GDB now supports automatic retrieval of shared library files from
1197 remote targets. To use this feature, specify a system root that begins
1198 with the `remote:' prefix, either via the `set sysroot' command or via
1199 the `--with-sysroot' configure-time option.
1201 * "info sharedlibrary" now takes an optional regex of libraries to show,
1202 and it now reports if a shared library has no debugging information.
1204 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
1205 now complete on file names.
1207 * When completing in expressions, gdb will attempt to limit
1208 completions to allowable structure or union fields, where appropriate.
1209 For instance, consider:
1211 # struct example { int f1; double f2; };
1212 # struct example variable;
1215 If the user types TAB at the end of this command line, the available
1216 completions will be "f1" and "f2".
1218 * Inlined functions are now supported. They show up in backtraces, and
1219 the "step", "next", and "finish" commands handle them automatically.
1221 * GDB now supports the token-splicing (##) and stringification (#)
1222 operators when expanding macros. It also supports variable-arity
1225 * GDB now supports inspecting extra signal information, exported by
1226 the new $_siginfo convenience variable. The feature is currently
1227 implemented on linux ARM, i386 and amd64.
1229 * GDB can now display the VFP floating point registers and NEON vector
1230 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
1231 can provide these registers (requires Linux 2.6.30 or later). Remote
1232 and simulator targets may also provide them.
1234 * New remote packets
1237 Search memory for a sequence of bytes.
1240 Turn off `+'/`-' protocol acknowledgments to permit more efficient
1241 operation over reliable transport links. Use of this packet is
1242 controlled by the `set remote noack-packet' command.
1245 Kill the process with the specified process ID. Use this in preference
1246 to `k' when multiprocess protocol extensions are supported.
1249 Obtains additional operating system information
1253 Read or write additional signal information.
1255 * Removed remote protocol undocumented extension
1257 An undocumented extension to the remote protocol's `S' stop reply
1258 packet that permited the stub to pass a process id was removed.
1259 Remote servers should use the `T' stop reply packet instead.
1261 * GDB now supports multiple function calling conventions according to the
1262 DWARF-2 DW_AT_calling_convention function attribute.
1264 * The SH target utilizes the aforementioned change to distinguish between gcc
1265 and Renesas calling convention. It also adds the new CLI commands
1266 `set/show sh calling-convention'.
1268 * GDB can now read compressed debug sections, as produced by GNU gold
1269 with the --compress-debug-sections=zlib flag.
1271 * 64-bit core files are now supported on AIX.
1273 * Thread switching is now supported on Tru64.
1275 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
1276 which will be allocated using malloc later in program execution.
1278 * The qXfer:libraries:read remote procotol packet now allows passing a
1279 list of section offsets.
1281 * On GNU/Linux, GDB can now attach to stopped processes. Several race
1282 conditions handling signals delivered during attach or thread creation
1283 have also been fixed.
1285 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
1286 From the user's standpoint, all unqualified instances of True and False
1287 are treated as the standard definitions, regardless of context.
1289 * GDB now parses C++ symbol and type names more flexibly. For
1292 template<typename T> class C { };
1295 GDB will now correctly handle all of:
1297 ptype C<char const *>
1298 ptype C<char const*>
1299 ptype C<const char *>
1300 ptype C<const char*>
1302 * New features in the GDB remote stub, gdbserver
1304 - The "--wrapper" command-line argument tells gdbserver to use a
1305 wrapper program to launch programs for debugging.
1307 - On PowerPC and S/390 targets, it is now possible to use a single
1308 gdbserver executable to debug both 32-bit and 64-bit programs.
1309 (This requires gdbserver itself to be built as a 64-bit executable.)
1311 - gdbserver uses the new noack protocol mode for TCP connections to
1312 reduce communications latency, if also supported and enabled in GDB.
1314 - Support for the sparc64-linux-gnu target is now included in
1317 - The amd64-linux build of gdbserver now supports debugging both
1318 32-bit and 64-bit programs.
1320 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
1321 now support hardware watchpoints, and will use them automatically
1326 GDB now has support for scripting using Python. Whether this is
1327 available is determined at configure time.
1329 New GDB commands can now be written in Python.
1331 * Ada tasking support
1333 Ada tasks can now be inspected in GDB. The following commands have
1337 Print the list of Ada tasks.
1339 Print detailed information about task number N.
1341 Print the task number of the current task.
1343 Switch the context of debugging to task number N.
1345 * Support for user-defined prefixed commands. The "define" command can
1346 add new commands to existing prefixes, e.g. "target".
1348 * Multi-inferior, multi-process debugging.
1350 GDB now has generalized support for multi-inferior debugging. See
1351 "Debugging Multiple Inferiors" in the manual for more information.
1352 Although availability still depends on target support, the command
1353 set is more uniform now. The GNU/Linux specific multi-forks support
1354 has been migrated to this new framework. This implied some user
1355 visible changes; see "New commands" and also "Removed commands"
1358 * Target descriptions can now describe the target OS ABI. See the
1359 "Target Description Format" section in the user manual for more
1362 * Target descriptions can now describe "compatible" architectures
1363 to indicate that the target can execute applications for a different
1364 architecture in addition to those for the main target architecture.
1365 See the "Target Description Format" section in the user manual for
1368 * Multi-architecture debugging.
1370 GDB now includes general supports for debugging applications on
1371 hybrid systems that use more than one single processor architecture
1372 at the same time. Each such hybrid architecture still requires
1373 specific support to be added. The only hybrid architecture supported
1374 in this version of GDB is the Cell Broadband Engine.
1376 * GDB now supports integrated debugging of Cell/B.E. applications that
1377 use both the PPU and SPU architectures. To enable support for hybrid
1378 Cell/B.E. debugging, you need to configure GDB to support both the
1379 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
1380 --enable-targets configure option.
1382 * Non-stop mode debugging.
1384 For some targets, GDB now supports an optional mode of operation in
1385 which you can examine stopped threads while other threads continue
1386 to execute freely. This is referred to as non-stop mode, with the
1387 old mode referred to as all-stop mode. See the "Non-Stop Mode"
1388 section in the user manual for more information.
1390 To be able to support remote non-stop debugging, a remote stub needs
1391 to implement the non-stop mode remote protocol extensions, as
1392 described in the "Remote Non-Stop" section of the user manual. The
1393 GDB remote stub, gdbserver, has been adjusted to support these
1394 extensions on linux targets.
1396 * New commands (for set/show, see "New options" below)
1398 catch syscall [NAME(S) | NUMBER(S)]
1399 Catch system calls. Arguments, which should be names of system
1400 calls or their numbers, mean catch only those syscalls. Without
1401 arguments, every syscall will be caught. When the inferior issues
1402 any of the specified syscalls, GDB will stop and announce the system
1403 call, both when it is called and when its call returns. This
1404 feature is currently available with a native GDB running on the
1405 Linux Kernel, under the following architectures: x86, x86_64,
1406 PowerPC and PowerPC64.
1408 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
1410 Search memory for a sequence of bytes.
1412 maint set python print-stack
1413 maint show python print-stack
1414 Show a stack trace when an error is encountered in a Python script.
1417 Invoke CODE by passing it to the Python interpreter.
1422 These allow macros to be defined, undefined, and listed
1426 Show operating system information about processes.
1429 List the inferiors currently under GDB's control.
1432 Switch focus to inferior number NUM.
1435 Detach from inferior number NUM.
1438 Kill inferior number NUM.
1442 set spu stop-on-load
1443 show spu stop-on-load
1444 Control whether to stop for new SPE threads during Cell/B.E. debugging.
1446 set spu auto-flush-cache
1447 show spu auto-flush-cache
1448 Control whether to automatically flush the software-managed cache
1449 during Cell/B.E. debugging.
1451 set sh calling-convention
1452 show sh calling-convention
1453 Control the calling convention used when calling SH target functions.
1456 show debug timestamp
1457 Control display of timestamps with GDB debugging output.
1459 set disassemble-next-line
1460 show disassemble-next-line
1461 Control display of disassembled source lines or instructions when
1464 set remote noack-packet
1465 show remote noack-packet
1466 Set/show the use of remote protocol QStartNoAckMode packet. See above
1467 under "New remote packets."
1469 set remote query-attached-packet
1470 show remote query-attached-packet
1471 Control use of remote protocol `qAttached' (query-attached) packet.
1473 set remote read-siginfo-object
1474 show remote read-siginfo-object
1475 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
1478 set remote write-siginfo-object
1479 show remote write-siginfo-object
1480 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
1483 set remote reverse-continue
1484 show remote reverse-continue
1485 Control use of remote protocol 'bc' (reverse-continue) packet.
1487 set remote reverse-step
1488 show remote reverse-step
1489 Control use of remote protocol 'bs' (reverse-step) packet.
1491 set displaced-stepping
1492 show displaced-stepping
1493 Control displaced stepping mode. Displaced stepping is a way to
1494 single-step over breakpoints without removing them from the debuggee.
1495 Also known as "out-of-line single-stepping".
1498 show debug displaced
1499 Control display of debugging info for displaced stepping.
1501 maint set internal-error
1502 maint show internal-error
1503 Control what GDB does when an internal error is detected.
1505 maint set internal-warning
1506 maint show internal-warning
1507 Control what GDB does when an internal warning is detected.
1512 Use a wrapper program to launch programs for debugging.
1514 set multiple-symbols (all|ask|cancel)
1515 show multiple-symbols
1516 The value of this variable can be changed to adjust the debugger behavior
1517 when an expression or a breakpoint location contains an ambiguous symbol
1518 name (an overloaded function name, for instance).
1520 set breakpoint always-inserted
1521 show breakpoint always-inserted
1522 Keep breakpoints always inserted in the target, as opposed to inserting
1523 them when resuming the target, and removing them when the target stops.
1524 This option can improve debugger performance on slow remote targets.
1526 set arm fallback-mode (arm|thumb|auto)
1527 show arm fallback-mode
1528 set arm force-mode (arm|thumb|auto)
1530 These commands control how ARM GDB determines whether instructions
1531 are ARM or Thumb. The default for both settings is auto, which uses
1532 the current CPSR value for instructions without symbols; previous
1533 versions of GDB behaved as if "set arm fallback-mode arm".
1535 set disable-randomization
1536 show disable-randomization
1537 Standalone programs run with the virtual address space randomization enabled
1538 by default on some platforms. This option keeps the addresses stable across
1539 multiple debugging sessions.
1543 Control whether other threads are stopped or not when some thread hits
1548 Requests that asynchronous execution is enabled in the target, if available.
1549 In this case, it's possible to resume target in the background, and interact
1550 with GDB while the target is running. "show target-async" displays the
1551 current state of asynchronous execution of the target.
1553 set target-wide-charset
1554 show target-wide-charset
1555 The target-wide-charset is the name of the character set that GDB
1556 uses when printing characters whose type is wchar_t.
1558 set tcp auto-retry (on|off)
1560 set tcp connect-timeout
1561 show tcp connect-timeout
1562 These commands allow GDB to retry failed TCP connections to a remote stub
1563 with a specified timeout period; this is useful if the stub is launched
1564 in parallel with GDB but may not be ready to accept connections immediately.
1566 set libthread-db-search-path
1567 show libthread-db-search-path
1568 Control list of directories which GDB will search for appropriate
1571 set schedule-multiple (on|off)
1572 show schedule-multiple
1573 Allow GDB to resume all threads of all processes or only threads of
1574 the current process.
1578 Use more aggressive caching for accesses to the stack. This improves
1579 performance of remote debugging (particularly backtraces) without
1580 affecting correctness.
1582 set interactive-mode (on|off|auto)
1583 show interactive-mode
1584 Control whether GDB runs in interactive mode (on) or not (off).
1585 When in interactive mode, GDB waits for the user to answer all
1586 queries. Otherwise, GDB does not wait and assumes the default
1587 answer. When set to auto (the default), GDB determines which
1588 mode to use based on the stdin settings.
1593 For program forks, this is replaced by the new more generic `info
1594 inferiors' command. To list checkpoints, you can still use the
1595 `info checkpoints' command, which was an alias for the `info forks'
1599 Replaced by the new `inferior' command. To switch between
1600 checkpoints, you can still use the `restart' command, which was an
1601 alias for the `fork' command.
1604 This is removed, since some targets don't have a notion of
1605 processes. To switch between processes, you can still use the
1606 `inferior' command using GDB's own inferior number.
1609 For program forks, this is replaced by the new more generic `kill
1610 inferior' command. To delete a checkpoint, you can still use the
1611 `delete checkpoint' command, which was an alias for the `delete
1615 For program forks, this is replaced by the new more generic `detach
1616 inferior' command. To detach a checkpoint, you can still use the
1617 `detach checkpoint' command, which was an alias for the `detach
1620 * New native configurations
1622 x86/x86_64 Darwin i[34567]86-*-darwin*
1624 x86_64 MinGW x86_64-*-mingw*
1628 Lattice Mico32 lm32-*
1629 x86 DICOS i[34567]86-*-dicos*
1630 x86_64 DICOS x86_64-*-dicos*
1633 * The GDB remote stub, gdbserver, now supports x86 Windows CE
1634 (mingw32ce) debugging.
1640 These commands were actually not implemented on any target.
1642 *** Changes in GDB 6.8
1644 * New native configurations
1646 NetBSD/hppa hppa*-*netbsd*
1647 Xtensa GNU/Linux xtensa*-*-linux*
1651 NetBSD/hppa hppa*-*-netbsd*
1652 Xtensa GNU/Lunux xtensa*-*-linux*
1654 * Change in command line behavior -- corefiles vs. process ids.
1656 When the '-p NUMBER' or '--pid NUMBER' options are used, and
1657 attaching to process NUMBER fails, GDB no longer attempts to open a
1658 core file named NUMBER. Attaching to a program using the -c option
1659 is no longer supported. Instead, use the '-p' or '--pid' options.
1661 * GDB can now be built as a native debugger for debugging Windows x86
1662 (mingw32) Portable Executable (PE) programs.
1664 * Pending breakpoints no longer change their number when their address
1667 * GDB now supports breakpoints with multiple locations,
1668 including breakpoints on C++ constructors, inside C++ templates,
1669 and in inlined functions.
1671 * GDB's ability to debug optimized code has been improved. GDB more
1672 accurately identifies function bodies and lexical blocks that occupy
1673 more than one contiguous range of addresses.
1675 * Target descriptions can now describe registers for PowerPC.
1677 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
1678 registers on PowerPC targets.
1680 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
1681 targets even when the libthread_db library is not available.
1683 * The GDB remote stub, gdbserver, now supports the new file transfer
1684 commands (remote put, remote get, and remote delete).
1686 * The GDB remote stub, gdbserver, now supports run and attach in
1687 extended-remote mode.
1689 * hppa*64*-*-hpux11* target broken
1690 The debugger is unable to start a program and fails with the following
1691 error: "Error trying to get information about dynamic linker".
1692 The gdb-6.7 release is also affected.
1694 * GDB now supports the --enable-targets= configure option to allow
1695 building a single GDB executable that supports multiple remote
1696 target architectures.
1698 * GDB now supports debugging C and C++ programs which use the
1699 Decimal Floating Point extension. In addition, the PowerPC target
1700 now has a set of pseudo-registers to inspect decimal float values
1701 stored in two consecutive float registers.
1703 * The -break-insert MI command can optionally create pending
1706 * Improved support for debugging Ada
1707 Many improvements to the Ada language support have been made. These
1709 - Better support for Ada2005 interface types
1710 - Improved handling of arrays and slices in general
1711 - Better support for Taft-amendment types
1712 - The '{type} ADDRESS' expression is now allowed on the left hand-side
1714 - Improved command completion in Ada
1717 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
1722 set print frame-arguments (all|scalars|none)
1723 show print frame-arguments
1724 The value of this variable can be changed to control which argument
1725 values should be printed by the debugger when displaying a frame.
1730 Transfer files to and from a remote target, and delete remote files.
1737 Transfer files to and from a remote target, and delete remote files.
1739 * New remote packets
1746 Open, close, read, write, and delete files on the remote system.
1749 Attach to an existing process on the remote system, in extended-remote
1753 Run a new process on the remote system, in extended-remote mode.
1755 *** Changes in GDB 6.7
1757 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
1758 bfd, libiberty and opcodes, as revealed by static analysis donated by
1759 Coverity, Inc. (http://scan.coverity.com).
1761 * When looking up multiply-defined global symbols, GDB will now prefer the
1762 symbol definition in the current shared library if it was built using the
1763 -Bsymbolic linker option.
1765 * When the Text User Interface (TUI) is not configured, GDB will now
1766 recognize the -tui command-line option and print a message that the TUI
1769 * The GDB remote stub, gdbserver, now has lower overhead for high
1770 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
1772 * GDB for MIPS targets now autodetects whether a remote target provides
1773 32-bit or 64-bit register values.
1775 * Support for C++ member pointers has been improved.
1777 * GDB now understands XML target descriptions, which specify the
1778 target's overall architecture. GDB can read a description from
1779 a local file or over the remote serial protocol.
1781 * Vectors of single-byte data use a new integer type which is not
1782 automatically displayed as character or string data.
1784 * The /s format now works with the print command. It displays
1785 arrays of single-byte integers and pointers to single-byte integers
1788 * Target descriptions can now describe target-specific registers,
1789 for architectures which have implemented the support (currently
1790 only ARM, M68K, and MIPS).
1792 * GDB and the GDB remote stub, gdbserver, now support the XScale
1795 * The GDB remote stub, gdbserver, has been updated to support
1796 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
1797 has been rewritten to use the standard GDB remote protocol.
1799 * GDB can now step into C++ functions which are called through thunks.
1801 * GDB for the Cell/B.E. SPU now supports overlay debugging.
1803 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
1804 layout. It also supports a TextSeg= and DataSeg= response when only
1805 segment base addresses (rather than offsets) are available.
1807 * The /i format now outputs any trailing branch delay slot instructions
1808 immediately following the last instruction within the count specified.
1810 * The GDB remote protocol "T" stop reply packet now supports a
1811 "library" response. Combined with the new "qXfer:libraries:read"
1812 packet, this response allows GDB to debug shared libraries on targets
1813 where the operating system manages the list of loaded libraries (e.g.
1814 Windows and SymbianOS).
1816 * The GDB remote stub, gdbserver, now supports dynamic link libraries
1817 (DLLs) on Windows and Windows CE targets.
1819 * GDB now supports a faster verification that a .debug file matches its binary
1820 according to its build-id signature, if the signature is present.
1826 Enable or disable hardware flow control (RTS/CTS) on the serial port
1827 when debugging using remote targets.
1829 set mem inaccessible-by-default
1830 show mem inaccessible-by-default
1831 If the target supplies a memory map, for instance via the remote
1832 protocol's "qXfer:memory-map:read" packet, setting this variable
1833 prevents GDB from accessing memory outside the memory map. This
1834 is useful for targets with memory mapped registers or which react
1835 badly to accesses of unmapped address space.
1837 set breakpoint auto-hw
1838 show breakpoint auto-hw
1839 If the target supplies a memory map, for instance via the remote
1840 protocol's "qXfer:memory-map:read" packet, setting this variable
1841 lets GDB use hardware breakpoints automatically for memory regions
1842 where it can not use software breakpoints. This covers both the
1843 "break" command and internal breakpoints used for other commands
1844 including "next" and "finish".
1847 catch exception unhandled
1848 Stop the program execution when Ada exceptions are raised.
1851 Stop the program execution when an Ada assertion failed.
1855 Set an alternate system root for target files. This is a more
1856 general version of "set solib-absolute-prefix", which is now
1857 an alias to "set sysroot".
1860 Provide extended SPU facility status information. This set of
1861 commands is available only when debugging the Cell/B.E. SPU
1864 * New native configurations
1866 OpenBSD/sh sh*-*openbsd*
1869 unset tdesc filename
1871 Use the specified local file as an XML target description, and do
1872 not query the target for its built-in description.
1876 OpenBSD/sh sh*-*-openbsd*
1877 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
1878 Toshiba Media Processor mep-elf
1880 * New remote packets
1883 Ignore the specified signals; pass them directly to the debugged program
1884 without stopping other threads or reporting them to GDB.
1886 qXfer:features:read:
1887 Read an XML target description from the target, which describes its
1892 Read or write contents of an spufs file on the target system. These
1893 packets are available only on the Cell/B.E. SPU architecture.
1895 qXfer:libraries:read:
1896 Report the loaded shared libraries. Combined with new "T" packet
1897 response, this packet allows GDB to debug shared libraries on
1898 targets where the operating system manages the list of loaded
1899 libraries (e.g. Windows and SymbianOS).
1903 Support for these obsolete configurations has been removed.
1911 i[34567]86-*-lynxos*
1912 i[34567]86-*-netware*
1913 i[34567]86-*-sco3.2v5*
1914 i[34567]86-*-sco3.2v4*
1916 i[34567]86-*-sysv4.2*
1919 i[34567]86-*-unixware2*
1920 i[34567]86-*-unixware*
1929 * Other removed features
1936 Various m68k-only ROM monitors.
1943 Various Renesas ROM monitors and debugging interfaces for SH and
1948 Support for a Macraigor serial interface to on-chip debugging.
1949 GDB does not directly support the newer parallel or USB
1954 A debug information format. The predecessor to DWARF 2 and
1955 DWARF 3, which are still supported.
1957 Support for the HP aCC compiler on HP-UX/PA-RISC
1959 SOM-encapsulated symbolic debugging information, automatic
1960 invocation of pxdb, and the aCC custom C++ ABI. This does not
1961 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
1962 with aCC can still be debugged on an assembly level.
1964 MIPS ".pdr" sections
1966 A MIPS-specific format used to describe stack frame layout
1967 in debugging information.
1971 GDB could work with an older version of Guile to debug
1972 the interpreter and Scheme programs running in it.
1974 set mips stack-arg-size
1975 set mips saved-gpreg-size
1977 Use "set mips abi" to control parameter passing for MIPS.
1979 *** Changes in GDB 6.6
1984 Cell Broadband Engine SPU spu-elf
1986 * GDB can now be configured as a cross-debugger targeting native Windows
1987 (mingw32) or Cygwin. It can communicate with a remote debugging stub
1988 running on a Windows system over TCP/IP to debug Windows programs.
1990 * The GDB remote stub, gdbserver, has been updated to support Windows and
1991 Cygwin debugging. Both single-threaded and multi-threaded programs are
1994 * The "set trust-readonly-sections" command works again. This command was
1995 broken in GDB 6.3, 6.4, and 6.5.
1997 * The "load" command now supports writing to flash memory, if the remote
1998 stub provides the required support.
2000 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2001 longer requires symbolic debug information (e.g. DWARF-2).
2006 unset substitute-path
2007 show substitute-path
2008 Manage a list of substitution rules that GDB uses to rewrite the name
2009 of the directories where the sources are located. This can be useful
2010 for instance when the sources were moved to a different location
2011 between compilation and debugging.
2015 Print each CLI command as it is executed. Each command is prefixed with
2016 a number of `+' symbols representing the nesting depth.
2017 The source command now has a `-v' option to enable the same feature.
2021 The ARM Demon monitor support (RDP protocol, "target rdp").
2023 Kernel Object Display, an embedded debugging feature which only worked with
2024 an obsolete version of Cisco IOS.
2026 The 'set download-write-size' and 'show download-write-size' commands.
2028 * New remote packets
2031 Tell a stub about GDB client features, and request remote target features.
2032 The first feature implemented is PacketSize, which allows the target to
2033 specify the size of packets it can handle - to minimize the number of
2034 packets required and improve performance when connected to a remote
2038 Fetch an OS auxilliary vector from the remote stub. This packet is a
2039 more efficient replacement for qPart:auxv:read.
2041 qXfer:memory-map:read:
2042 Fetch a memory map from the remote stub, including information about
2043 RAM, ROM, and flash memory devices.
2048 Erase and program a flash memory device.
2050 * Removed remote packets
2053 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2054 used it, and only gdbserver implemented it.
2056 *** Changes in GDB 6.5
2060 Renesas M32C/M16C m32c-elf
2062 Morpho Technologies ms1 ms1-elf
2066 init-if-undefined Initialize a convenience variable, but
2067 only if it doesn't already have a value.
2069 The following commands are presently only implemented for native GNU/Linux:
2071 checkpoint Save a snapshot of the program state.
2073 restart <n> Return the program state to a
2074 previously saved state.
2076 info checkpoints List currently saved checkpoints.
2078 delete-checkpoint <n> Delete a previously saved checkpoint.
2080 set|show detach-on-fork Tell gdb whether to detach from a newly
2081 forked process, or to keep debugging it.
2083 info forks List forks of the user program that
2084 are available to be debugged.
2086 fork <n> Switch to debugging one of several
2087 forks of the user program that are
2088 available to be debugged.
2090 delete-fork <n> Delete a fork from the list of forks
2091 that are available to be debugged (and
2092 kill the forked process).
2094 detach-fork <n> Delete a fork from the list of forks
2095 that are available to be debugged (and
2096 allow the process to continue).
2100 Morpho Technologies ms2 ms1-elf
2102 * Improved Windows host support
2104 GDB now builds as a cross debugger hosted on i686-mingw32, including
2105 native console support, and remote communications using either
2106 network sockets or serial ports.
2108 * Improved Modula-2 language support
2110 GDB can now print most types in the Modula-2 syntax. This includes:
2111 basic types, set types, record types, enumerated types, range types,
2112 pointer types and ARRAY types. Procedure var parameters are correctly
2113 printed and hexadecimal addresses and character constants are also
2114 written in the Modula-2 syntax. Best results can be obtained by using
2115 GNU Modula-2 together with the -gdwarf-2 command line option.
2119 The ARM rdi-share module.
2121 The Netware NLM debug server.
2123 *** Changes in GDB 6.4
2125 * New native configurations
2127 OpenBSD/arm arm*-*-openbsd*
2128 OpenBSD/mips64 mips64-*-openbsd*
2132 Morpho Technologies ms1 ms1-elf
2134 * New command line options
2136 --batch-silent As for --batch, but totally silent.
2137 --return-child-result The debugger will exist with the same value
2138 the child (debugged) program exited with.
2139 --eval-command COMMAND, -ex COMMAND
2140 Execute a single GDB CLI command. This may be
2141 specified multiple times and in conjunction
2142 with the --command (-x) option.
2144 * Deprecated commands removed
2146 The following commands, that were deprecated in 2000, have been
2150 set|show arm disassembly-flavor set|show arm disassembler
2151 othernames set arm disassembler
2152 set|show remotedebug set|show debug remote
2153 set|show archdebug set|show debug arch
2154 set|show eventdebug set|show debug event
2157 * New BSD user-level threads support
2159 It is now possible to debug programs using the user-level threads
2160 library on OpenBSD and FreeBSD. Currently supported (target)
2163 FreeBSD/amd64 x86_64-*-freebsd*
2164 FreeBSD/i386 i386-*-freebsd*
2165 OpenBSD/i386 i386-*-openbsd*
2167 Note that the new kernel threads libraries introduced in FreeBSD 5.x
2168 are not yet supported.
2170 * New support for Matsushita MN10300 w/sim added
2171 (Work in progress). mn10300-elf.
2173 * REMOVED configurations and files
2175 VxWorks and the XDR protocol *-*-vxworks
2176 Motorola MCORE mcore-*-*
2177 National Semiconductor NS32000 ns32k-*-*
2179 * New "set print array-indexes" command
2181 After turning this setting "on", GDB prints the index of each element
2182 when displaying arrays. The default is "off" to preserve the previous
2185 * VAX floating point support
2187 GDB now supports the not-quite-ieee VAX F and D floating point formats.
2189 * User-defined command support
2191 In addition to using $arg0..$arg9 for argument passing, it is now possible
2192 to use $argc to determine now many arguments have been passed. See the
2193 section on user-defined commands in the user manual for more information.
2195 *** Changes in GDB 6.3:
2197 * New command line option
2199 GDB now accepts -l followed by a number to set the timeout for remote
2202 * GDB works with GCC -feliminate-dwarf2-dups
2204 GDB now supports a more compact representation of DWARF-2 debug
2205 information using DW_FORM_ref_addr references. These are produced
2206 by GCC with the option -feliminate-dwarf2-dups and also by some
2207 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
2208 to use -feliminate-dwarf2-dups.
2210 * Internationalization
2212 When supported by the host system, GDB will be built with
2213 internationalization (libintl). The task of marking up the sources is
2214 continued, we're looking forward to our first translation.
2218 Initial support for debugging programs compiled with the GNAT
2219 implementation of the Ada programming language has been integrated
2220 into GDB. In this release, support is limited to expression evaluation.
2222 * New native configurations
2224 GNU/Linux/m32r m32r-*-linux-gnu
2228 GDB's remote protocol now includes support for the 'p' packet. This
2229 packet is used to fetch individual registers from a remote inferior.
2231 * END-OF-LIFE registers[] compatibility module
2233 GDB's internal register infrastructure has been completely rewritten.
2234 The new infrastructure making possible the implementation of key new
2235 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
2238 GDB 6.3 will be the last release to include the the registers[]
2239 compatibility module that allowed out-of-date configurations to
2240 continue to work. This change directly impacts the following
2250 powerpc bdm protocol
2252 Unless there is activity to revive these configurations, they will be
2253 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
2255 * OBSOLETE configurations and files
2257 Configurations that have been declared obsolete in this release have
2258 been commented out. Unless there is activity to revive these
2259 configurations, the next release of GDB will have their sources
2260 permanently REMOVED.
2269 *** Changes in GDB 6.2.1:
2271 * MIPS `break main; run' gave an heuristic-fence-post warning
2273 When attempting to run even a simple program, a warning about
2274 heuristic-fence-post being hit would be reported. This problem has
2277 * MIPS IRIX 'long double' crashed GDB
2279 When examining a long double variable, GDB would get a segmentation
2280 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
2281 IRIX long double values).
2285 A bug in the VAX stack code was causing problems with the "next"
2286 command. This problem has been fixed.
2288 *** Changes in GDB 6.2:
2290 * Fix for ``many threads''
2292 On GNU/Linux systems that use the NPTL threads library, a program
2293 rapidly creating and deleting threads would confuse GDB leading to the
2296 ptrace: No such process.
2297 thread_db_get_info: cannot get thread info: generic error
2299 This problem has been fixed.
2301 * "-async" and "-noasync" options removed.
2303 Support for the broken "-noasync" option has been removed (it caused
2306 * New ``start'' command.
2308 This command runs the program until the begining of the main procedure.
2310 * New BSD Kernel Data Access Library (libkvm) interface
2312 Using ``target kvm'' it is now possible to debug kernel core dumps and
2313 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
2314 platforms. Currently supported (native-only) configurations are:
2316 FreeBSD/amd64 x86_64-*-freebsd*
2317 FreeBSD/i386 i?86-*-freebsd*
2318 NetBSD/i386 i?86-*-netbsd*
2319 NetBSD/m68k m68*-*-netbsd*
2320 NetBSD/sparc sparc-*-netbsd*
2321 OpenBSD/amd64 x86_64-*-openbsd*
2322 OpenBSD/i386 i?86-*-openbsd*
2323 OpenBSD/m68k m68*-openbsd*
2324 OpenBSD/sparc sparc-*-openbsd*
2326 * Signal trampoline code overhauled
2328 Many generic problems with GDB's signal handling code have been fixed.
2329 These include: backtraces through non-contiguous stacks; recognition
2330 of sa_sigaction signal trampolines; backtrace from a NULL pointer
2331 call; backtrace through a signal trampoline; step into and out of
2332 signal handlers; and single-stepping in the signal trampoline.
2334 Please note that kernel bugs are a limiting factor here. These
2335 features have been shown to work on an s390 GNU/Linux system that
2336 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
2338 * Cygwin support for DWARF 2 added.
2340 * New native configurations
2342 GNU/Linux/hppa hppa*-*-linux*
2343 OpenBSD/hppa hppa*-*-openbsd*
2344 OpenBSD/m68k m68*-*-openbsd*
2345 OpenBSD/m88k m88*-*-openbsd*
2346 OpenBSD/powerpc powerpc-*-openbsd*
2347 NetBSD/vax vax-*-netbsd*
2348 OpenBSD/vax vax-*-openbsd*
2350 * END-OF-LIFE frame compatibility module
2352 GDB's internal frame infrastructure has been completely rewritten.
2353 The new infrastructure making it possible to support key new features
2354 including DWARF 2 Call Frame Information. To aid in the task of
2355 migrating old configurations to this new infrastructure, a
2356 compatibility module, that allowed old configurations to continue to
2357 work, was also included.
2359 GDB 6.2 will be the last release to include this frame compatibility
2360 module. This change directly impacts the following configurations:
2370 Unless there is activity to revive these configurations, they will be
2371 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
2373 * REMOVED configurations and files
2375 Sun 3, running SunOS 3 m68*-*-sunos3*
2376 Sun 3, running SunOS 4 m68*-*-sunos4*
2377 Sun 2, running SunOS 3 m68000-*-sunos3*
2378 Sun 2, running SunOS 4 m68000-*-sunos4*
2379 Motorola 680x0 running LynxOS m68*-*-lynxos*
2380 AT&T 3b1/Unix pc m68*-att-*
2381 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2382 decstation mips-dec-* mips-little-*
2383 riscos mips-*-riscos* mips-*-sysv*
2384 sonymips mips-sony-*
2385 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2387 *** Changes in GDB 6.1.1:
2389 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
2391 The TUI (Text-mode User Interface) is now built as part of a default
2392 GDB configuration. It is enabled by either selecting the TUI with the
2393 command line option "-i=tui" or by running the separate "gdbtui"
2394 program. For more information on the TUI, see the manual "Debugging
2397 * Pending breakpoint support (also included in GDB 6.1)
2399 Support has been added to allow you to specify breakpoints in shared
2400 libraries that have not yet been loaded. If a breakpoint location
2401 cannot be found, and the "breakpoint pending" option is set to auto,
2402 GDB queries you if you wish to make the breakpoint pending on a future
2403 shared-library load. If and when GDB resolves the breakpoint symbol,
2404 the pending breakpoint is removed as one or more regular breakpoints
2407 Pending breakpoints are very useful for GCJ Java debugging.
2409 * Fixed ISO-C build problems
2411 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
2412 non ISO-C code that stopped them being built using a more strict ISO-C
2413 compiler (e.g., IBM's C compiler).
2415 * Fixed build problem on IRIX 5
2417 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
2418 wasn't able to compile compile on an IRIX 5 system.
2420 * Added execute permission to gdb/gdbserver/configure
2422 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
2423 permission. This bug would cause configure to fail on a number of
2424 systems (Solaris, IRIX). Ref: server/519.
2426 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
2428 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
2429 has been updated to use constant array sizes.
2431 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
2433 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
2434 its generated DWARF Call Frame Info. This encoding was causing GDB to
2435 panic, that panic has been fixed. Ref: gdb/1628.
2437 * Fixed a problem when examining parameters in shared library code.
2439 When examining parameters in optimized shared library code generated
2440 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
2441 not available''. GDB now correctly displays the variable's value.
2443 *** Changes in GDB 6.1:
2445 * Removed --with-mmalloc
2447 Support for the mmalloc memory manager has been removed, as it
2448 conflicted with the internal gdb byte cache.
2450 * Changes in AMD64 configurations
2452 The AMD64 target now includes the %cs and %ss registers. As a result
2453 the AMD64 remote protocol has changed; this affects the floating-point
2454 and SSE registers. If you rely on those registers for your debugging,
2455 you should upgrade gdbserver on the remote side.
2457 * Revised SPARC target
2459 The SPARC target has been completely revised, incorporating the
2460 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
2461 support for LynxOS and SunOS 4 has been dropped. Calling functions
2462 from within GDB on operating systems with a non-executable stack
2463 (Solaris, OpenBSD) now works.
2467 GDB has a new C++ demangler which does a better job on the mangled
2468 names generated by current versions of g++. It also runs faster, so
2469 with this and other changes gdb should now start faster on large C++
2472 * DWARF 2 Location Expressions
2474 GDB support for location expressions has been extended to support function
2475 arguments and frame bases. Older versions of GDB could crash when they
2478 * C++ nested types and namespaces
2480 GDB's support for nested types and namespaces in C++ has been
2481 improved, especially if you use the DWARF 2 debugging format. (This
2482 is the default for recent versions of GCC on most platforms.)
2483 Specifically, if you have a class "Inner" defined within a class or
2484 namespace "Outer", then GDB realizes that the class's name is
2485 "Outer::Inner", not simply "Inner". This should greatly reduce the
2486 frequency of complaints about not finding RTTI symbols. In addition,
2487 if you are stopped at inside of a function defined within a namespace,
2488 GDB modifies its name lookup accordingly.
2490 * New native configurations
2492 NetBSD/amd64 x86_64-*-netbsd*
2493 OpenBSD/amd64 x86_64-*-openbsd*
2494 OpenBSD/alpha alpha*-*-openbsd*
2495 OpenBSD/sparc sparc-*-openbsd*
2496 OpenBSD/sparc64 sparc64-*-openbsd*
2498 * New debugging protocols
2500 M32R with SDI protocol m32r-*-elf*
2502 * "set prompt-escape-char" command deleted.
2504 The command "set prompt-escape-char" has been deleted. This command,
2505 and its very obscure effet on GDB's prompt, was never documented,
2506 tested, nor mentioned in the NEWS file.
2508 * OBSOLETE configurations and files
2510 Configurations that have been declared obsolete in this release have
2511 been commented out. Unless there is activity to revive these
2512 configurations, the next release of GDB will have their sources
2513 permanently REMOVED.
2515 Sun 3, running SunOS 3 m68*-*-sunos3*
2516 Sun 3, running SunOS 4 m68*-*-sunos4*
2517 Sun 2, running SunOS 3 m68000-*-sunos3*
2518 Sun 2, running SunOS 4 m68000-*-sunos4*
2519 Motorola 680x0 running LynxOS m68*-*-lynxos*
2520 AT&T 3b1/Unix pc m68*-att-*
2521 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2522 decstation mips-dec-* mips-little-*
2523 riscos mips-*-riscos* mips-*-sysv*
2524 sonymips mips-sony-*
2525 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2527 * REMOVED configurations and files
2529 SGI Irix-4.x mips-sgi-irix4 or iris4
2530 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
2531 Z8000 simulator z8k-zilog-none or z8ksim
2532 Matsushita MN10200 w/simulator mn10200-*-*
2533 H8/500 simulator h8500-hitachi-hms or h8500hms
2534 HP/PA running BSD hppa*-*-bsd*
2535 HP/PA running OSF/1 hppa*-*-osf*
2536 HP/PA Pro target hppa*-*-pro*
2537 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2538 386BSD i[3456]86-*-bsd*
2539 Sequent family i[3456]86-sequent-sysv4*
2540 i[3456]86-sequent-sysv*
2541 i[3456]86-sequent-bsd*
2542 SPARC running LynxOS sparc-*-lynxos*
2543 SPARC running SunOS 4 sparc-*-sunos4*
2544 Tsqware Sparclet sparclet-*-*
2545 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2547 *** Changes in GDB 6.0:
2551 Support for debugging the Objective-C programming language has been
2552 integrated into GDB.
2554 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
2556 DWARF 2's Call Frame Information makes available compiler generated
2557 information that more exactly describes the program's run-time stack.
2558 By using this information, GDB is able to provide more robust stack
2561 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
2562 have been updated to use a new backtrace mechanism which includes
2563 DWARF 2 CFI support.
2567 GDB's remote protocol has been extended to include support for hosted
2568 file I/O (where the remote target uses GDB's file system). See GDB's
2569 remote protocol documentation for details.
2571 * All targets using the new architecture framework.
2573 All of GDB's targets have been updated to use the new internal
2574 architecture framework. The way is now open for future GDB releases
2575 to include cross-architecture native debugging support (i386 on amd64,
2578 * GNU/Linux's Thread Local Storage (TLS)
2580 GDB now includes support for for the GNU/Linux implementation of
2581 per-thread variables.
2583 * GNU/Linux's Native POSIX Thread Library (NPTL)
2585 GDB's thread code has been updated to work with either the new
2586 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
2588 * Separate debug info.
2590 GDB, in conjunction with BINUTILS, now supports a mechanism for
2591 automatically loading debug information from a separate file. Instead
2592 of shipping full debug and non-debug versions of system libraries,
2593 system integrators can now instead ship just the stripped libraries
2594 and optional debug files.
2596 * DWARF 2 Location Expressions
2598 DWARF 2 Location Expressions allow the compiler to more completely
2599 describe the location of variables (even in optimized code) to the
2602 GDB now includes preliminary support for location expressions (support
2603 for DW_OP_piece is still missing).
2607 A number of long standing bugs that caused GDB to die while starting a
2608 Java application have been fixed. GDB's Java support is now
2609 considered "useable".
2611 * GNU/Linux support for fork, vfork, and exec.
2613 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
2614 commands are now implemented for GNU/Linux. They require a 2.5.x or later
2617 * GDB supports logging output to a file
2619 There are two new commands, "set logging" and "show logging", which can be
2620 used to capture GDB's output to a file.
2622 * The meaning of "detach" has changed for gdbserver
2624 The "detach" command will now resume the application, as documented. To
2625 disconnect from gdbserver and leave it stopped, use the new "disconnect"
2628 * d10v, m68hc11 `regs' command deprecated
2630 The `info registers' command has been updated so that it displays the
2631 registers using a format identical to the old `regs' command.
2635 A new command, "maint set profile on/off", has been added. This command can
2636 be used to enable or disable profiling while running GDB, to profile a
2637 session or a set of commands. In addition there is a new configure switch,
2638 "--enable-profiling", which will cause GDB to be compiled with profiling
2639 data, for more informative profiling results.
2641 * Default MI syntax changed to "mi2".
2643 The default MI (machine interface) syntax, enabled by the command line
2644 option "-i=mi", has been changed to "mi2". The previous MI syntax,
2645 "mi1", can be enabled by specifying the option "-i=mi1".
2647 Support for the original "mi0" syntax (included in GDB 5.0) has been
2650 Fix for gdb/192: removed extraneous space when displaying frame level.
2651 Fix for gdb/672: update changelist is now output in mi list format.
2652 Fix for gdb/702: a -var-assign that updates the value now shows up
2653 in a subsequent -var-update.
2655 * New native configurations.
2657 FreeBSD/amd64 x86_64-*-freebsd*
2659 * Multi-arched targets.
2661 HP/PA HPUX11 hppa*-*-hpux*
2662 Renesas M32R/D w/simulator m32r-*-elf*
2664 * OBSOLETE configurations and files
2666 Configurations that have been declared obsolete in this release have
2667 been commented out. Unless there is activity to revive these
2668 configurations, the next release of GDB will have their sources
2669 permanently REMOVED.
2671 Z8000 simulator z8k-zilog-none or z8ksim
2672 Matsushita MN10200 w/simulator mn10200-*-*
2673 H8/500 simulator h8500-hitachi-hms or h8500hms
2674 HP/PA running BSD hppa*-*-bsd*
2675 HP/PA running OSF/1 hppa*-*-osf*
2676 HP/PA Pro target hppa*-*-pro*
2677 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2678 Sequent family i[3456]86-sequent-sysv4*
2679 i[3456]86-sequent-sysv*
2680 i[3456]86-sequent-bsd*
2681 Tsqware Sparclet sparclet-*-*
2682 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2684 * REMOVED configurations and files
2687 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2688 IBM AIX PS/2 i[3456]86-*-aix
2689 i386 running Mach 3.0 i[3456]86-*-mach3*
2690 i386 running Mach i[3456]86-*-mach*
2691 i386 running OSF/1 i[3456]86-*osf1mk*
2692 HP/Apollo 68k Family m68*-apollo*-sysv*,
2694 m68*-hp-bsd*, m68*-hp-hpux*
2695 Argonaut Risc Chip (ARC) arc-*-*
2696 Mitsubishi D30V d30v-*-*
2697 Fujitsu FR30 fr30-*-elf*
2698 OS/9000 i[34]86-*-os9k
2699 I960 with MON960 i960-*-coff
2701 * MIPS $fp behavior changed
2703 The convenience variable $fp, for the MIPS, now consistently returns
2704 the address of the current frame's base. Previously, depending on the
2705 context, $fp could refer to either $sp or the current frame's base
2706 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
2707 The GNU Source-Level Debugger''.
2709 *** Changes in GDB 5.3:
2711 * GNU/Linux shared library multi-threaded performance improved.
2713 When debugging a multi-threaded application on GNU/Linux, GDB now uses
2714 `/proc', in preference to `ptrace' for memory reads. This may result
2715 in an improvement in the start-up time of multi-threaded, shared
2716 library applications when run under GDB. One GDB user writes: ``loads
2717 shared libs like mad''.
2719 * ``gdbserver'' now supports multi-threaded applications on some targets
2721 Support for debugging multi-threaded applications which use
2722 the GNU/Linux LinuxThreads package has been added for
2723 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
2724 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
2726 * GDB now supports C/C++ preprocessor macros.
2728 GDB now expands preprocessor macro invocations in C/C++ expressions,
2729 and provides various commands for showing macro definitions and how
2732 The new command `macro expand EXPRESSION' expands any macro
2733 invocations in expression, and shows the result.
2735 The new command `show macro MACRO-NAME' shows the definition of the
2736 macro named MACRO-NAME, and where it was defined.
2738 Most compilers don't include information about macros in the debugging
2739 information by default. In GCC 3.1, for example, you need to compile
2740 your program with the options `-gdwarf-2 -g3'. If the macro
2741 information is present in the executable, GDB will read it.
2743 * Multi-arched targets.
2745 DEC Alpha (partial) alpha*-*-*
2746 DEC VAX (partial) vax-*-*
2748 National Semiconductor NS32000 (partial) ns32k-*-*
2749 Motorola 68000 (partial) m68k-*-*
2750 Motorola MCORE mcore-*-*
2754 Fujitsu FRV architecture added by Red Hat frv*-*-*
2757 * New native configurations
2759 Alpha NetBSD alpha*-*-netbsd*
2760 SH NetBSD sh*-*-netbsdelf*
2761 MIPS NetBSD mips*-*-netbsd*
2762 UltraSPARC NetBSD sparc64-*-netbsd*
2764 * OBSOLETE configurations and files
2766 Configurations that have been declared obsolete in this release have
2767 been commented out. Unless there is activity to revive these
2768 configurations, the next release of GDB will have their sources
2769 permanently REMOVED.
2771 Mitsubishi D30V d30v-*-*
2772 OS/9000 i[34]86-*-os9k
2773 IBM AIX PS/2 i[3456]86-*-aix
2774 Fujitsu FR30 fr30-*-elf*
2775 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2776 Argonaut Risc Chip (ARC) arc-*-*
2777 i386 running Mach 3.0 i[3456]86-*-mach3*
2778 i386 running Mach i[3456]86-*-mach*
2779 i386 running OSF/1 i[3456]86-*osf1mk*
2780 HP/Apollo 68k Family m68*-apollo*-sysv*,
2782 m68*-hp-bsd*, m68*-hp-hpux*
2783 I960 with MON960 i960-*-coff
2785 * OBSOLETE languages
2787 CHILL, a Pascal like language used by telecommunications companies.
2789 * REMOVED configurations and files
2791 AMD 29k family via UDI a29k-amd-udi, udi29k
2792 A29K VxWorks a29k-*-vxworks
2793 AMD 29000 embedded, using EBMON a29k-none-none
2794 AMD 29000 embedded with COFF a29k-none-coff
2795 AMD 29000 embedded with a.out a29k-none-aout
2797 testsuite/gdb.hp/gdb.threads-hp/ directory
2799 * New command "set max-user-call-depth <nnn>"
2801 This command allows the user to limit the call depth of user-defined
2802 commands. The default is 1024.
2804 * Changes in FreeBSD/i386 native debugging.
2806 Support for the "generate-core-file" has been added.
2808 * New commands "dump", "append", and "restore".
2810 These commands allow data to be copied from target memory
2811 to a bfd-format or binary file (dump and append), and back
2812 from a file into memory (restore).
2814 * Improved "next/step" support on multi-processor Alpha Tru64.
2816 The previous single-step mechanism could cause unpredictable problems,
2817 including the random appearance of SIGSEGV or SIGTRAP signals. The use
2818 of a software single-step mechanism prevents this.
2820 *** Changes in GDB 5.2.1:
2828 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
2829 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
2830 Fix, by Joel Brobecker imported from mainline.
2832 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
2833 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
2834 Fix, by Fred Fish, imported from mainline.
2836 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
2837 Surprisingly enough, it works now.
2838 By Michal Ludvig, imported from mainline.
2840 i386 hardware watchpoint support:
2841 avoid misses on second run for some targets.
2842 By Pierre Muller, imported from mainline.
2844 *** Changes in GDB 5.2:
2846 * New command "set trust-readonly-sections on[off]".
2848 This command is a hint that tells gdb that read-only sections
2849 really are read-only (ie. that their contents will not change).
2850 In this mode, gdb will go to the object file rather than the
2851 target to read memory from read-only sections (such as ".text").
2852 This can be a significant performance improvement on some
2853 (notably embedded) targets.
2855 * New command "generate-core-file" (or "gcore").
2857 This new gdb command allows the user to drop a core file of the child
2858 process state at any time. So far it's been implemented only for
2859 GNU/Linux and Solaris, but should be relatively easily ported to other
2860 hosts. Argument is core file name (defaults to core.<pid>).
2862 * New command line option
2864 GDB now accepts --pid or -p followed by a process id.
2866 * Change in command line behavior -- corefiles vs. process ids.
2868 There is a subtle behavior in the way in which GDB handles
2869 command line arguments. The first non-flag argument is always
2870 a program to debug, but the second non-flag argument may either
2871 be a corefile or a process id. Previously, GDB would attempt to
2872 open the second argument as a corefile, and if that failed, would
2873 issue a superfluous error message and then attempt to attach it as
2874 a process. Now, if the second argument begins with a non-digit,
2875 it will be treated as a corefile. If it begins with a digit,
2876 GDB will attempt to attach it as a process, and if no such process
2877 is found, will then attempt to open it as a corefile.
2879 * Changes in ARM configurations.
2881 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
2882 configuration is fully multi-arch.
2884 * New native configurations
2886 ARM NetBSD arm*-*-netbsd*
2887 x86 OpenBSD i[3456]86-*-openbsd*
2888 AMD x86-64 running GNU/Linux x86_64-*-linux-*
2889 Sparc64 running FreeBSD sparc64-*-freebsd*
2893 Sanyo XStormy16 xstormy16-elf
2895 * OBSOLETE configurations and files
2897 Configurations that have been declared obsolete in this release have
2898 been commented out. Unless there is activity to revive these
2899 configurations, the next release of GDB will have their sources
2900 permanently REMOVED.
2902 AMD 29k family via UDI a29k-amd-udi, udi29k
2903 A29K VxWorks a29k-*-vxworks
2904 AMD 29000 embedded, using EBMON a29k-none-none
2905 AMD 29000 embedded with COFF a29k-none-coff
2906 AMD 29000 embedded with a.out a29k-none-aout
2908 testsuite/gdb.hp/gdb.threads-hp/ directory
2910 * REMOVED configurations and files
2912 TI TMS320C80 tic80-*-*
2914 PowerPC Solaris powerpcle-*-solaris*
2915 PowerPC Windows NT powerpcle-*-cygwin32
2916 PowerPC Netware powerpc-*-netware*
2917 Harris/CXUX m88k m88*-harris-cxux*
2918 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
2919 ns32k-utek-sysv* ns32k-utek-*
2920 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
2921 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
2922 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
2923 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
2924 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
2926 * Changes to command line processing
2928 The new `--args' feature can be used to specify command-line arguments
2929 for the inferior from gdb's command line.
2931 * Changes to key bindings
2933 There is a new `operate-and-get-next' function bound to `C-o'.
2935 *** Changes in GDB 5.1.1
2937 Fix compile problem on DJGPP.
2939 Fix a problem with floating-point registers on the i386 being
2942 Fix to stop GDB crashing on .debug_str debug info.
2944 Numerous documentation fixes.
2946 Numerous testsuite fixes.
2948 *** Changes in GDB 5.1:
2950 * New native configurations
2952 Alpha FreeBSD alpha*-*-freebsd*
2953 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
2954 MIPS GNU/Linux mips*-*-linux*
2955 MIPS SGI Irix 6.x mips*-sgi-irix6*
2956 ia64 AIX ia64-*-aix*
2957 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
2961 Motorola 68HC11 and 68HC12 m68hc11-elf
2963 UltraSparc running GNU/Linux sparc64-*-linux*
2965 * OBSOLETE configurations and files
2967 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
2968 Harris/CXUX m88k m88*-harris-cxux*
2969 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
2970 ns32k-utek-sysv* ns32k-utek-*
2971 TI TMS320C80 tic80-*-*
2973 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
2974 PowerPC Solaris powerpcle-*-solaris*
2975 PowerPC Windows NT powerpcle-*-cygwin32
2976 PowerPC Netware powerpc-*-netware*
2977 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
2978 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
2979 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
2980 Apple Macintosh (MPW) host N/A
2982 stuff.c (Program to stuff files into a specially prepared space in kdb)
2983 kdb-start.c (Main loop for the standalone kernel debugger)
2985 Configurations that have been declared obsolete in this release have
2986 been commented out. Unless there is activity to revive these
2987 configurations, the next release of GDB will have their sources
2988 permanently REMOVED.
2990 * REMOVED configurations and files
2992 Altos 3068 m68*-altos-*
2993 Convex c1-*-*, c2-*-*
2995 ARM RISCix arm-*-* (as host)
2999 * GDB has been converted to ISO C.
3001 GDB's source code has been converted to ISO C. In particular, the
3002 sources are fully protoized, and rely on standard headers being
3007 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3009 * The MI enabled by default.
3011 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3012 revised and enabled by default. Packages which use GDB as a debugging
3013 engine behind a UI or another front end are encouraged to switch to
3014 using the GDB/MI interface, instead of the old annotations interface
3015 which is now deprecated.
3017 * Support for debugging Pascal programs.
3019 GDB now includes support for debugging Pascal programs. The following
3020 main features are supported:
3022 - Pascal-specific data types such as sets;
3024 - automatic recognition of Pascal sources based on file-name
3027 - Pascal-style display of data types, variables, and functions;
3029 - a Pascal expression parser.
3031 However, some important features are not yet supported.
3033 - Pascal string operations are not supported at all;
3035 - there are some problems with boolean types;
3037 - Pascal type hexadecimal constants are not supported
3038 because they conflict with the internal variables format;
3040 - support for Pascal objects and classes is not full yet;
3042 - unlike Pascal, GDB is case-sensitive for symbol names.
3044 * Changes in completion.
3046 Commands such as `shell', `run' and `set args', which pass arguments
3047 to inferior programs, now complete on file names, similar to what
3048 users expect at the shell prompt.
3050 Commands which accept locations, such as `disassemble', `print',
3051 `breakpoint', `until', etc. now complete on filenames as well as
3052 program symbols. Thus, if you type "break foob TAB", and the source
3053 files linked into the programs include `foobar.c', that file name will
3054 be one of the candidates for completion. However, file names are not
3055 considered for completion after you typed a colon that delimits a file
3056 name from a name of a function in that file, as in "break foo.c:bar".
3058 `set demangle-style' completes on available demangling styles.
3060 * New platform-independent commands:
3062 It is now possible to define a post-hook for a command as well as a
3063 hook that runs before the command. For more details, see the
3064 documentation of `hookpost' in the GDB manual.
3066 * Changes in GNU/Linux native debugging.
3068 Support for debugging multi-threaded programs has been completely
3069 revised for all platforms except m68k and sparc. You can now debug as
3070 many threads as your system allows you to have.
3072 Attach/detach is supported for multi-threaded programs.
3074 Support for SSE registers was added for x86. This doesn't work for
3075 multi-threaded programs though.
3077 * Changes in MIPS configurations.
3079 Multi-arch support is enabled for all MIPS configurations.
3081 GDB can now be built as native debugger on SGI Irix 6.x systems for
3082 debugging n32 executables. (Debugging 64-bit executables is not yet
3085 * Unified support for hardware watchpoints in all x86 configurations.
3087 Most (if not all) native x86 configurations support hardware-assisted
3088 breakpoints and watchpoints in a unified manner. This support
3089 implements debug register sharing between watchpoints, which allows to
3090 put a virtually infinite number of watchpoints on the same address,
3091 and also supports watching regions up to 16 bytes with several debug
3094 The new maintenance command `maintenance show-debug-regs' toggles
3095 debugging print-outs in functions that insert, remove, and test
3096 watchpoints and hardware breakpoints.
3098 * Changes in the DJGPP native configuration.
3100 New command ``info dos sysinfo'' displays assorted information about
3101 the CPU, OS, memory, and DPMI server.
3103 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
3104 display information about segment descriptors stored in GDT, LDT, and
3107 New commands ``info dos pde'' and ``info dos pte'' display entries
3108 from Page Directory and Page Tables (for now works with CWSDPMI only).
3109 New command ``info dos address-pte'' displays the Page Table entry for
3110 a given linear address.
3112 GDB can now pass command lines longer than 126 characters to the
3113 program being debugged (requires an update to the libdbg.a library
3114 which is part of the DJGPP development kit).
3116 DWARF2 debug info is now supported.
3118 It is now possible to `step' and `next' through calls to `longjmp'.
3120 * Changes in documentation.
3122 All GDB documentation was converted to GFDL, the GNU Free
3123 Documentation License.
3125 Tracepoints-related commands are now fully documented in the GDB
3128 TUI, the Text-mode User Interface, is now documented in the manual.
3130 Tracepoints-related commands are now fully documented in the GDB
3133 The "GDB Internals" manual now has an index. It also includes
3134 documentation of `ui_out' functions, GDB coding standards, x86
3135 hardware watchpoints, and memory region attributes.
3137 * GDB's version number moved to ``version.in''
3139 The Makefile variable VERSION has been replaced by the file
3140 ``version.in''. People creating GDB distributions should update the
3141 contents of this file.
3145 GUD support is now a standard part of the EMACS distribution.
3147 *** Changes in GDB 5.0:
3149 * Improved support for debugging FP programs on x86 targets
3151 Unified and much-improved support for debugging floating-point
3152 programs on all x86 targets. In particular, ``info float'' now
3153 displays the FP registers in the same format on all x86 targets, with
3154 greater level of detail.
3156 * Improvements and bugfixes in hardware-assisted watchpoints
3158 It is now possible to watch array elements, struct members, and
3159 bitfields with hardware-assisted watchpoints. Data-read watchpoints
3160 on x86 targets no longer erroneously trigger when the address is
3163 * Improvements in the native DJGPP version of GDB
3165 The distribution now includes all the scripts and auxiliary files
3166 necessary to build the native DJGPP version on MS-DOS/MS-Windows
3167 machines ``out of the box''.
3169 The DJGPP version can now debug programs that use signals. It is
3170 possible to catch signals that happened in the debuggee, deliver
3171 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
3172 would kill the program being debugged.) Programs that hook hardware
3173 interrupts (keyboard, timer, etc.) can also be debugged.
3175 It is now possible to debug DJGPP programs that redirect their
3176 standard handles or switch them to raw (as opposed to cooked) mode, or
3177 even close them. The command ``run < foo > bar'' works as expected,
3178 and ``info terminal'' reports useful information about the debuggee's
3179 terminal, including raw/cooked mode, redirection, etc.
3181 The DJGPP version now uses termios functions for console I/O, which
3182 enables debugging graphics programs. Interrupting GDB with Ctrl-C
3185 DOS-style file names with drive letters are now fully supported by
3188 It is now possible to debug DJGPP programs that switch their working
3189 directory. It is also possible to rerun the debuggee any number of
3190 times without restarting GDB; thus, you can use the same setup,
3191 breakpoints, etc. for many debugging sessions.
3193 * New native configurations
3195 ARM GNU/Linux arm*-*-linux*
3196 PowerPC GNU/Linux powerpc-*-linux*
3200 Motorola MCore mcore-*-*
3201 x86 VxWorks i[3456]86-*-vxworks*
3202 PowerPC VxWorks powerpc-*-vxworks*
3203 TI TMS320C80 tic80-*-*
3205 * OBSOLETE configurations
3207 Altos 3068 m68*-altos-*
3208 Convex c1-*-*, c2-*-*
3210 ARM RISCix arm-*-* (as host)
3213 Configurations that have been declared obsolete will be commented out,
3214 but the code will be left in place. If there is no activity to revive
3215 these configurations before the next release of GDB, the sources will
3216 be permanently REMOVED.
3218 * Gould support removed
3220 Support for the Gould PowerNode and NP1 has been removed.
3222 * New features for SVR4
3224 On SVR4 native platforms (such as Solaris), if you attach to a process
3225 without first loading a symbol file, GDB will now attempt to locate and
3226 load symbols from the running process's executable file.
3228 * Many C++ enhancements
3230 C++ support has been greatly improved. Overload resolution now works properly
3231 in almost all cases. RTTI support is on the way.
3233 * Remote targets can connect to a sub-program
3235 A popen(3) style serial-device has been added. This device starts a
3236 sub-process (such as a stand-alone simulator) and then communicates
3237 with that. The sub-program to run is specified using the syntax
3238 ``|<program> <args>'' vis:
3240 (gdb) set remotedebug 1
3241 (gdb) target extended-remote |mn10300-elf-sim program-args
3243 * MIPS 64 remote protocol
3245 A long standing bug in the mips64 remote protocol where by GDB
3246 expected certain 32 bit registers (ex SR) to be transfered as 32
3247 instead of 64 bits has been fixed.
3249 The command ``set remote-mips64-transfers-32bit-regs on'' has been
3250 added to provide backward compatibility with older versions of GDB.
3252 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
3254 The command ``set remotebinarydownload'' command has been replaced by
3255 ``set remote X-packet''. Other commands in ``set remote'' family
3256 include ``set remote P-packet''.
3258 * Breakpoint commands accept ranges.
3260 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
3261 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
3262 ``tracepoint passcount'' also accepts a range of tracepoints.
3264 * ``apropos'' command added.
3266 The ``apropos'' command searches through command names and
3267 documentation strings, printing out matches, making it much easier to
3268 try to find a command that does what you are looking for.
3272 A new machine oriented interface (MI) has been added to GDB. This
3273 interface is designed for debug environments running GDB as a separate
3274 process. This is part of the long term libGDB project. See the
3275 "GDB/MI" chapter of the GDB manual for further information. It can be
3276 enabled by configuring with:
3278 .../configure --enable-gdbmi
3280 *** Changes in GDB-4.18:
3282 * New native configurations
3284 HP-UX 10.20 hppa*-*-hpux10.20
3285 HP-UX 11.x hppa*-*-hpux11.0*
3286 M68K GNU/Linux m68*-*-linux*
3290 Fujitsu FR30 fr30-*-elf*
3291 Intel StrongARM strongarm-*-*
3292 Mitsubishi D30V d30v-*-*
3294 * OBSOLETE configurations
3296 Gould PowerNode, NP1 np1-*-*, pn-*-*
3298 Configurations that have been declared obsolete will be commented out,
3299 but the code will be left in place. If there is no activity to revive
3300 these configurations before the next release of GDB, the sources will
3301 be permanently REMOVED.
3305 As a compatibility experiment, GDB's source files buildsym.h and
3306 buildsym.c have been converted to pure standard C, no longer
3307 containing any K&R compatibility code. We believe that all systems in
3308 use today either come with a standard C compiler, or have a GCC port
3309 available. If this is not true, please report the affected
3310 configuration to bug-gdb@gnu.org immediately. See the README file for
3311 information about getting a standard C compiler if you don't have one
3316 GDB now uses readline 2.2.
3318 * set extension-language
3320 You can now control the mapping between filename extensions and source
3321 languages by using the `set extension-language' command. For instance,
3322 you can ask GDB to treat .c files as C++ by saying
3323 set extension-language .c c++
3324 The command `info extensions' lists all of the recognized extensions
3325 and their associated languages.
3327 * Setting processor type for PowerPC and RS/6000
3329 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
3330 you can use the `set processor' command to specify what variant of the
3331 PowerPC family you are debugging. The command
3335 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
3336 following PowerPC and RS6000 variants:
3338 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
3339 rs6000 IBM RS6000 ("POWER") architecture, user-level view
3341 403GC IBM PowerPC 403GC
3342 505 Motorola PowerPC 505
3343 860 Motorola PowerPC 860 or 850
3344 601 Motorola PowerPC 601
3345 602 Motorola PowerPC 602
3346 603 Motorola/IBM PowerPC 603 or 603e
3347 604 Motorola PowerPC 604 or 604e
3348 750 Motorola/IBM PowerPC 750 or 750
3350 At the moment, this command just tells GDB what to name the
3351 special-purpose processor registers. Since almost all the affected
3352 registers are inaccessible to user-level programs, this command is
3353 only useful for remote debugging in its present form.
3357 Thanks to a major code donation from Hewlett-Packard, GDB now has much
3358 more extensive support for HP-UX. Added features include shared
3359 library support, kernel threads and hardware watchpoints for 11.00,
3360 support for HP's ANSI C and C++ compilers, and a compatibility mode
3361 for xdb and dbx commands.
3365 HP's donation includes the new concept of catchpoints, which is a
3366 generalization of the old catch command. On HP-UX, it is now possible
3367 to catch exec, fork, and vfork, as well as library loading.
3369 This means that the existing catch command has changed; its first
3370 argument now specifies the type of catch to be set up. See the
3371 output of "help catch" for a list of catchpoint types.
3373 * Debugging across forks
3375 On HP-UX, you can choose which process to debug when a fork() happens
3380 HP has donated a curses-based terminal user interface (TUI). To get
3381 it, build with --enable-tui. Although this can be enabled for any
3382 configuration, at present it only works for native HP debugging.
3384 * GDB remote protocol additions
3386 A new protocol packet 'X' that writes binary data is now available.
3387 Default behavior is to try 'X', then drop back to 'M' if the stub
3388 fails to respond. The settable variable `remotebinarydownload'
3389 allows explicit control over the use of 'X'.
3391 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
3392 full 64-bit address. The command
3394 set remoteaddresssize 32
3396 can be used to revert to the old behaviour. For existing remote stubs
3397 the change should not be noticed, as the additional address information
3400 In order to assist in debugging stubs, you may use the maintenance
3401 command `packet' to send any text string to the stub. For instance,
3403 maint packet heythere
3405 sends the packet "$heythere#<checksum>". Note that it is very easy to
3406 disrupt a debugging session by sending the wrong packet at the wrong
3409 The compare-sections command allows you to compare section data on the
3410 target to what is in the executable file without uploading or
3411 downloading, by comparing CRC checksums.
3413 * Tracing can collect general expressions
3415 You may now collect general expressions at tracepoints. This requires
3416 further additions to the target-side stub; see tracepoint.c and
3417 doc/agentexpr.texi for further details.
3419 * mask-address variable for Mips
3421 For Mips targets, you may control the zeroing of the upper 32 bits of
3422 a 64-bit address by entering `set mask-address on'. This is mainly
3423 of interest to users of embedded R4xxx and R5xxx processors.
3425 * Higher serial baud rates
3427 GDB's serial code now allows you to specify baud rates 57600, 115200,
3428 230400, and 460800 baud. (Note that your host system may not be able
3429 to achieve all of these rates.)
3433 The i960 configuration now includes an initial implementation of a
3434 builtin simulator, contributed by Jim Wilson.
3437 *** Changes in GDB-4.17:
3439 * New native configurations
3441 Alpha GNU/Linux alpha*-*-linux*
3442 Unixware 2.x i[3456]86-unixware2*
3443 Irix 6.x mips*-sgi-irix6*
3444 PowerPC GNU/Linux powerpc-*-linux*
3445 PowerPC Solaris powerpcle-*-solaris*
3446 Sparc GNU/Linux sparc-*-linux*
3447 Motorola sysV68 R3V7.1 m68k-motorola-sysv
3451 Argonaut Risc Chip (ARC) arc-*-*
3452 Hitachi H8/300S h8300*-*-*
3453 Matsushita MN10200 w/simulator mn10200-*-*
3454 Matsushita MN10300 w/simulator mn10300-*-*
3455 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
3456 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
3457 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
3458 Mitsubishi D10V w/simulator d10v-*-*
3459 Mitsubishi M32R/D w/simulator m32r-*-elf*
3460 Tsqware Sparclet sparclet-*-*
3461 NEC V850 w/simulator v850-*-*
3463 * New debugging protocols
3465 ARM with RDI protocol arm*-*-*
3466 M68K with dBUG monitor m68*-*-{aout,coff,elf}
3467 DDB and LSI variants of PMON protocol mips*-*-*
3468 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
3469 PowerPC with SDS protocol powerpc{,le}-*-eabi
3470 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
3474 All configurations can now understand and use the DWARF 2 debugging
3475 format. The choice is automatic, if the symbol file contains DWARF 2
3480 GDB now includes basic Java language support. This support is
3481 only useful with Java compilers that produce native machine code.
3483 * solib-absolute-prefix and solib-search-path
3485 For SunOS and SVR4 shared libraries, you may now set the prefix for
3486 loading absolute shared library symbol files, and the search path for
3487 locating non-absolute shared library symbol files.
3489 * Live range splitting
3491 GDB can now effectively debug code for which GCC has performed live
3492 range splitting as part of its optimization. See gdb/doc/LRS for
3493 more details on the expected format of the stabs information.
3497 GDB's support for the GNU Hurd, including thread debugging, has been
3498 updated to work with current versions of the Hurd.
3502 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
3503 instruction set. ARM GDB automatically detects when Thumb
3504 instructions are in use, and adjusts disassembly and backtracing
3509 GDB's MIPS target configurations now handle the MIP16 16-bit
3514 GDB now includes support for overlays; if an executable has been
3515 linked such that multiple sections are based at the same address, GDB
3516 will decide which section to use for symbolic info. You can choose to
3517 control the decision manually, using overlay commands, or implement
3518 additional target-side support and use "overlay load-target" to bring
3519 in the overlay mapping. Do "help overlay" for more detail.
3523 The command "info symbol <address>" displays information about
3524 the symbol at the specified address.
3528 The standard remote protocol now includes an extension that allows
3529 asynchronous collection and display of trace data. This requires
3530 extensive support in the target-side debugging stub. Tracing mode
3531 includes a new interaction mode in GDB and new commands: see the
3532 file tracepoint.c for more details.
3536 Configurations for embedded MIPS now include a simulator contributed
3537 by Cygnus Solutions. The simulator supports the instruction sets
3538 of most MIPS variants.
3542 Sparc configurations may now include the ERC32 simulator contributed
3543 by the European Space Agency. The simulator is not built into
3544 Sparc targets by default; configure with --enable-sim to include it.
3548 For target configurations that may include multiple variants of a
3549 basic architecture (such as MIPS and SH), you may now set the
3550 architecture explicitly. "set arch" sets, "info arch" lists
3551 the possible architectures.
3553 *** Changes in GDB-4.16:
3555 * New native configurations
3557 Windows 95, x86 Windows NT i[345]86-*-cygwin32
3558 M68K NetBSD m68k-*-netbsd*
3559 PowerPC AIX 4.x powerpc-*-aix*
3560 PowerPC MacOS powerpc-*-macos*
3561 PowerPC Windows NT powerpcle-*-cygwin32
3562 RS/6000 AIX 4.x rs6000-*-aix4*
3566 ARM with RDP protocol arm-*-*
3567 I960 with MON960 i960-*-coff
3568 MIPS VxWorks mips*-*-vxworks*
3569 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
3570 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
3572 Matra Sparclet sparclet-*-*
3576 The powerpc-eabi configuration now includes the PSIM simulator,
3577 contributed by Andrew Cagney, with assistance from Mike Meissner.
3578 PSIM is a very elaborate model of the PowerPC, including not only
3579 basic instruction set execution, but also details of execution unit
3580 performance and I/O hardware. See sim/ppc/README for more details.
3584 GDB now works with Solaris 2.5.
3586 * Windows 95/NT native
3588 GDB will now work as a native debugger on Windows 95 and Windows NT.
3589 To build it from source, you must use the "gnu-win32" environment,
3590 which uses a DLL to emulate enough of Unix to run the GNU tools.
3591 Further information, binaries, and sources are available at
3592 ftp.cygnus.com, under pub/gnu-win32.
3594 * dont-repeat command
3596 If a user-defined command includes the command `dont-repeat', then the
3597 command will not be repeated if the user just types return. This is
3598 useful if the command is time-consuming to run, so that accidental
3599 extra keystrokes don't run the same command many times.
3601 * Send break instead of ^C
3603 The standard remote protocol now includes an option to send a break
3604 rather than a ^C to the target in order to interrupt it. By default,
3605 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
3607 * Remote protocol timeout
3609 The standard remote protocol includes a new variable `remotetimeout'
3610 that allows you to set the number of seconds before GDB gives up trying
3611 to read from the target. The default value is 2.
3613 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
3615 By default GDB will automatically keep track of objects as they are
3616 loaded and unloaded by the dynamic linker. By using the command `set
3617 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
3618 when shared library events occur, thus allowing you to set breakpoints
3619 in shared libraries which are explicitly loaded by the inferior.
3621 Note this feature does not work on hpux8. On hpux9 you must link
3622 /usr/lib/end.o into your program. This feature should work
3623 automatically on hpux10.
3625 * Irix 5.x hardware watchpoint support
3627 Irix 5 configurations now support the use of hardware watchpoints.
3629 * Mips protocol "SYN garbage limit"
3631 When debugging a Mips target using the `target mips' protocol, you
3632 may set the number of characters that GDB will ignore by setting
3633 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
3634 every character. The default value is 1050.
3636 * Recording and replaying remote debug sessions
3638 If you set `remotelogfile' to the name of a file, gdb will write to it
3639 a recording of a remote debug session. This recording may then be
3640 replayed back to gdb using "gdbreplay". See gdbserver/README for
3641 details. This is useful when you have a problem with GDB while doing
3642 remote debugging; you can make a recording of the session and send it
3643 to someone else, who can then recreate the problem.
3645 * Speedups for remote debugging
3647 GDB includes speedups for downloading and stepping MIPS systems using
3648 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
3649 and more efficient S-record downloading.
3651 * Memory use reductions and statistics collection
3653 GDB now uses less memory and reports statistics about memory usage.
3654 Try the `maint print statistics' command, for example.
3656 *** Changes in GDB-4.15:
3658 * Psymtabs for XCOFF
3660 The symbol reader for AIX GDB now uses partial symbol tables. This
3661 can greatly improve startup time, especially for large executables.
3663 * Remote targets use caching
3665 Remote targets now use a data cache to speed up communication with the
3666 remote side. The data cache could lead to incorrect results because
3667 it doesn't know about volatile variables, thus making it impossible to
3668 debug targets which use memory mapped I/O devices. `set remotecache
3669 off' turns the the data cache off.
3671 * Remote targets may have threads
3673 The standard remote protocol now includes support for multiple threads
3674 in the target system, using new protocol commands 'H' and 'T'. See
3675 gdb/remote.c for details.
3679 If GDB is configured with `--enable-netrom', then it will include
3680 support for the NetROM ROM emulator from XLNT Designs. The NetROM
3681 acts as though it is a bank of ROM on the target board, but you can
3682 write into it over the network. GDB's support consists only of
3683 support for fast loading into the emulated ROM; to debug, you must use
3684 another protocol, such as standard remote protocol. The usual
3685 sequence is something like
3687 target nrom <netrom-hostname>
3689 target remote <netrom-hostname>:1235
3693 GDB now includes support for the Apple Macintosh, as a host only. It
3694 may be run as either an MPW tool or as a standalone application, and
3695 it can debug through the serial port. All the usual GDB commands are
3696 available, but to the target command, you must supply "serial" as the
3697 device type instead of "/dev/ttyXX". See mpw-README in the main
3698 directory for more information on how to build. The MPW configuration
3699 scripts */mpw-config.in support only a few targets, and only the
3700 mips-idt-ecoff target has been tested.
3704 GDB configuration now uses autoconf. This is not user-visible,
3705 but does simplify configuration and building.
3709 GDB now supports hpux10.
3711 *** Changes in GDB-4.14:
3713 * New native configurations
3715 x86 FreeBSD i[345]86-*-freebsd
3716 x86 NetBSD i[345]86-*-netbsd
3717 NS32k NetBSD ns32k-*-netbsd
3718 Sparc NetBSD sparc-*-netbsd
3722 A29K VxWorks a29k-*-vxworks
3723 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
3724 CPU32 EST-300 emulator m68*-*-est*
3725 PowerPC ELF powerpc-*-elf
3728 * Alpha OSF/1 support for procfs
3730 GDB now supports procfs under OSF/1-2.x and higher, which makes it
3731 possible to attach to running processes. As the mounting of the /proc
3732 filesystem is optional on the Alpha, GDB automatically determines
3733 the availability of /proc during startup. This can lead to problems
3734 if /proc is unmounted after GDB has been started.
3736 * Arguments to user-defined commands
3738 User commands may accept up to 10 arguments separated by whitespace.
3739 Arguments are accessed within the user command via $arg0..$arg9. A
3742 print $arg0 + $arg1 + $arg2
3744 To execute the command use:
3747 Defines the command "adder" which prints the sum of its three arguments.
3748 Note the arguments are text substitutions, so they may reference variables,
3749 use complex expressions, or even perform inferior function calls.
3751 * New `if' and `while' commands
3753 This makes it possible to write more sophisticated user-defined
3754 commands. Both commands take a single argument, which is the
3755 expression to evaluate, and must be followed by the commands to
3756 execute, one per line, if the expression is nonzero, the list being
3757 terminated by the word `end'. The `if' command list may include an
3758 `else' word, which causes the following commands to be executed only
3759 if the expression is zero.
3761 * Fortran source language mode
3763 GDB now includes partial support for Fortran 77. It will recognize
3764 Fortran programs and can evaluate a subset of Fortran expressions, but
3765 variables and functions may not be handled correctly. GDB will work
3766 with G77, but does not yet know much about symbols emitted by other
3769 * Better HPUX support
3771 Most debugging facilities now work on dynamic executables for HPPAs
3772 running hpux9 or later. You can attach to running dynamically linked
3773 processes, but by default the dynamic libraries will be read-only, so
3774 for instance you won't be able to put breakpoints in them. To change
3775 that behavior do the following before running the program:
3781 This will cause the libraries to be mapped private and read-write.
3782 To revert to the normal behavior, do this:
3788 You cannot set breakpoints or examine data in the library until after
3789 the library is loaded if the function/data symbols do not have
3792 GDB can now also read debug symbols produced by the HP C compiler on
3793 HPPAs (sorry, no C++, Fortran or 68k support).
3795 * Target byte order now dynamically selectable
3797 You can choose which byte order to use with a target system, via the
3798 commands "set endian big" and "set endian little", and you can see the
3799 current setting by using "show endian". You can also give the command
3800 "set endian auto", in which case GDB will use the byte order
3801 associated with the executable. Currently, only embedded MIPS
3802 configurations support dynamic selection of target byte order.
3804 * New DOS host serial code
3806 This version uses DPMI interrupts to handle buffered I/O, so you
3807 no longer need to run asynctsr when debugging boards connected to
3810 *** Changes in GDB-4.13:
3812 * New "complete" command
3814 This lists all the possible completions for the rest of the line, if it
3815 were to be given as a command itself. This is intended for use by emacs.
3817 * Trailing space optional in prompt
3819 "set prompt" no longer adds a space for you after the prompt you set. This
3820 allows you to set a prompt which ends in a space or one that does not.
3822 * Breakpoint hit counts
3824 "info break" now displays a count of the number of times the breakpoint
3825 has been hit. This is especially useful in conjunction with "ignore"; you
3826 can ignore a large number of breakpoint hits, look at the breakpoint info
3827 to see how many times the breakpoint was hit, then run again, ignoring one
3828 less than that number, and this will get you quickly to the last hit of
3831 * Ability to stop printing at NULL character
3833 "set print null-stop" will cause GDB to stop printing the characters of
3834 an array when the first NULL is encountered. This is useful when large
3835 arrays actually contain only short strings.
3837 * Shared library breakpoints
3839 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
3840 breakpoints in shared libraries before the executable is run.
3842 * Hardware watchpoints
3844 There is a new hardware breakpoint for the watch command for sparclite
3845 targets. See gdb/sparclite/hw_breakpoint.note.
3847 Hardware watchpoints are also now supported under GNU/Linux.
3851 Annotations have been added. These are for use with graphical interfaces,
3852 and are still experimental. Currently only gdba.el uses these.
3854 * Improved Irix 5 support
3856 GDB now works properly with Irix 5.2.
3858 * Improved HPPA support
3860 GDB now works properly with the latest GCC and GAS.
3862 * New native configurations
3864 Sequent PTX4 i[34]86-sequent-ptx4
3865 HPPA running OSF/1 hppa*-*-osf*
3866 Atari TT running SVR4 m68*-*-sysv4*
3867 RS/6000 LynxOS rs6000-*-lynxos*
3871 OS/9000 i[34]86-*-os9k
3872 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
3875 * Hitachi SH7000 and E7000-PC ICE support
3877 There is now support for communicating with the Hitachi E7000-PC ICE.
3878 This is available automatically when GDB is configured for the SH.
3882 As usual, a variety of small fixes and improvements, both generic
3883 and configuration-specific. See the ChangeLog for more detail.
3885 *** Changes in GDB-4.12:
3887 * Irix 5 is now supported
3891 GDB-4.12 on the HPPA has a number of changes which make it unable
3892 to debug the output from the currently released versions of GCC and
3893 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
3894 of GCC and GAS, versions of these tools designed to work with GDB-4.12
3895 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
3898 *** Changes in GDB-4.11:
3900 * User visible changes:
3904 The "set remotedebug" option is now consistent between the mips remote
3905 target, remote targets using the gdb-specific protocol, UDI (AMD's
3906 debug protocol for the 29k) and the 88k bug monitor. It is now an
3907 integer specifying a debug level (normally 0 or 1, but 2 means more
3908 debugging info for the mips target).
3910 * DEC Alpha native support
3912 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
3913 debug info, but GDB works fairly well with the DEC compiler and should
3914 work with a future GCC release. See the README file for a few
3915 Alpha-specific notes.
3917 * Preliminary thread implementation
3919 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
3921 * LynxOS native and target support for 386
3923 This release has been hosted on LynxOS 2.2, and also can be configured
3924 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
3927 * Improvements in C++ mangling/demangling.
3929 This release has much better g++ debugging, specifically in name
3930 mangling/demangling, virtual function calls, print virtual table,
3931 call methods, ...etc.
3933 *** Changes in GDB-4.10:
3935 * User visible changes:
3937 Remote debugging using the GDB-specific (`target remote') protocol now
3938 supports the `load' command. This is only useful if you have some
3939 other way of getting the stub to the target system, and you can put it
3940 somewhere in memory where it won't get clobbered by the download.
3942 Filename completion now works.
3944 When run under emacs mode, the "info line" command now causes the
3945 arrow to point to the line specified. Also, "info line" prints
3946 addresses in symbolic form (as well as hex).
3948 All vxworks based targets now support a user settable option, called
3949 vxworks-timeout. This option represents the number of seconds gdb
3950 should wait for responses to rpc's. You might want to use this if
3951 your vxworks target is, perhaps, a slow software simulator or happens
3952 to be on the far side of a thin network line.
3956 This release contains support for using a DEC alpha as a GDB host for
3957 cross debugging. Native alpha debugging is not supported yet.
3960 *** Changes in GDB-4.9:
3964 This is the first GDB release which is accompanied by a matching testsuite.
3965 The testsuite requires installation of dejagnu, which should be available
3966 via ftp from most sites that carry GNU software.
3970 'Cfront' style demangling has had its name changed to 'ARM' style, to
3971 emphasize that it was written from the specifications in the C++ Annotated
3972 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
3973 disclaimers, it still generated too much confusion with users attempting to
3974 use gdb with AT&T cfront.
3978 GDB now uses a standard remote interface to a simulator library.
3979 So far, the library contains simulators for the Zilog Z8001/2, the
3980 Hitachi H8/300, H8/500 and Super-H.
3982 * New targets supported
3984 H8/300 simulator h8300-hitachi-hms or h8300hms
3985 H8/500 simulator h8500-hitachi-hms or h8500hms
3986 SH simulator sh-hitachi-hms or sh
3987 Z8000 simulator z8k-zilog-none or z8ksim
3988 IDT MIPS board over serial line mips-idt-ecoff
3990 Cross-debugging to GO32 targets is supported. It requires a custom
3991 version of the i386-stub.c module which is integrated with the
3992 GO32 memory extender.
3994 * New remote protocols
3996 MIPS remote debugging protocol.
3998 * New source languages supported
4000 This version includes preliminary support for Chill, a Pascal like language
4001 used by telecommunications companies. Chill support is also being integrated
4002 into the GNU compiler, but we don't know when it will be publically available.
4005 *** Changes in GDB-4.8:
4007 * HP Precision Architecture supported
4009 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4010 version of this support was available as a set of patches from the
4011 University of Utah. GDB does not support debugging of programs
4012 compiled with the HP compiler, because HP will not document their file
4013 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4014 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4016 Many problems in the preliminary version have been fixed.
4018 * Faster and better demangling
4020 We have improved template demangling and fixed numerous bugs in the GNU style
4021 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4022 character types (wchar_t) are now supported. Demangling of each symbol is now
4023 only done once, and is cached when the symbol table for a file is read in.
4024 This results in a small increase in memory usage for C programs, a moderate
4025 increase in memory usage for C++ programs, and a fantastic speedup in
4028 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4029 from the specifications in the Annotated Reference Manual, which AT&T's
4030 compiler does not actually implement.
4032 * G++ multiple inheritance compiler problem
4034 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4035 inheritance lattices was reworked to properly discover ambiguities. We
4036 recently found an example which causes this new algorithm to fail in a
4037 very subtle way, producing bad debug information for those classes.
4038 The file 'gcc.patch' (in this directory) can be applied to gcc to
4039 circumvent the problem. A future GCC release will contain a complete
4042 The previous G++ debug info problem (mentioned below for the gdb-4.7
4043 release) is fixed in gcc version 2.3.2.
4045 * Improved configure script
4047 The `configure' script will now attempt to guess your system type if
4048 you don't supply a host system type. The old scheme of supplying a
4049 host system triplet is preferable over using this. All the magic is
4050 done in the new `config.guess' script. Examine it for details.
4052 We have also brought our configure script much more in line with the FSF's
4053 version. It now supports the --with-xxx options. In particular,
4054 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4055 The resulting GDB will not be able to read arbitrary object file formats --
4056 only the format ``expected'' to be used on the configured target system.
4057 We hope to make this the default in a future release.
4059 * Documentation improvements
4061 There's new internal documentation on how to modify GDB, and how to
4062 produce clean changes to the code. We implore people to read it
4063 before submitting changes.
4065 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4066 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4067 `info' files are also provided. To build `info' files from scratch,
4068 you will need the latest `makeinfo' release, which will be available in
4069 a future texinfo-X.Y release.
4071 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4072 We're not sure exactly which versions have this problem, but it has
4073 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4074 or better. If that isn't possible, there is a patch in
4075 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4076 around this problem.
4080 GDB now supports array constants that can be used in expressions typed in by
4081 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4082 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4085 The new directory `gdb/sparclite' contains a program that demonstrates
4086 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4088 * New native hosts supported
4090 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4091 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4093 * New targets supported
4095 AMD 29k family via UDI a29k-amd-udi or udi29k
4097 * New file formats supported
4099 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4100 HPUX core files, and SCO 3.2v2 core files.
4104 Attaching to processes now works again; thanks for the many bug reports.
4106 We have also stomped on a bunch of core dumps caused by
4107 printf_filtered("%s") problems.
4109 We eliminated a copyright problem on the rpc and ptrace header files
4110 for VxWorks, which was discovered at the last minute during the 4.7
4111 release. You should now be able to build a VxWorks GDB.
4113 You can now interrupt gdb while an attached process is running. This
4114 will cause the attached process to stop, and give control back to GDB.
4116 We fixed problems caused by using too many file descriptors
4117 for reading symbols from object files and libraries. This was
4118 especially a problem for programs that used many (~100) shared
4121 The `step' command now only enters a subroutine if there is line number
4122 information for the subroutine. Otherwise it acts like the `next'
4123 command. Previously, `step' would enter subroutines if there was
4124 any debugging information about the routine. This avoids problems
4125 when using `cc -g1' on MIPS machines.
4127 * Internal improvements
4129 GDB's internal interfaces have been improved to make it easier to support
4130 debugging of multiple languages in the future.
4132 GDB now uses a common structure for symbol information internally.
4133 Minimal symbols (derived from linkage symbols in object files), partial
4134 symbols (from a quick scan of debug information), and full symbols
4135 contain a common subset of information, making it easier to write
4136 shared code that handles any of them.
4138 * New command line options
4140 We now accept --silent as an alias for --quiet.
4144 The memory-mapped-malloc library is now licensed under the GNU Library
4145 General Public License.
4147 *** Changes in GDB-4.7:
4149 * Host/native/target split
4151 GDB has had some major internal surgery to untangle the support for
4152 hosts and remote targets. Now, when you configure GDB for a remote
4153 target, it will no longer load in all of the support for debugging
4154 local programs on the host. When fully completed and tested, this will
4155 ensure that arbitrary host/target combinations are possible.
4157 The primary conceptual shift is to separate the non-portable code in
4158 GDB into three categories. Host specific code is required any time GDB
4159 is compiled on that host, regardless of the target. Target specific
4160 code relates to the peculiarities of the target, but can be compiled on
4161 any host. Native specific code is everything else: it can only be
4162 built when the host and target are the same system. Child process
4163 handling and core file support are two common `native' examples.
4165 GDB's use of /proc for controlling Unix child processes is now cleaner.
4166 It has been split out into a single module under the `target_ops' vector,
4167 plus two native-dependent functions for each system that uses /proc.
4169 * New hosts supported
4171 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
4172 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4173 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
4175 * New targets supported
4177 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4178 68030 and CPU32 m68030-*-*, m68332-*-*
4180 * New native hosts supported
4182 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4183 (386bsd is not well tested yet)
4184 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
4186 * New file formats supported
4188 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
4189 supports reading of `a.out.adobe' object files, which are an a.out
4190 format extended with minimal information about multiple sections.
4194 `show copying' is the same as the old `info copying'.
4195 `show warranty' is the same as `info warrantee'.
4196 These were renamed for consistency. The old commands continue to work.
4198 `info handle' is a new alias for `info signals'.
4200 You can now define pre-command hooks, which attach arbitrary command
4201 scripts to any command. The commands in the hook will be executed
4202 prior to the user's command. You can also create a hook which will be
4203 executed whenever the program stops. See gdb.texinfo.
4207 We now deal with Cfront style name mangling, and can even extract type
4208 info from mangled symbols. GDB can automatically figure out which
4209 symbol mangling style your C++ compiler uses.
4211 Calling of methods and virtual functions has been improved as well.
4215 The crash that occured when debugging Sun Ansi-C compiled binaries is
4216 fixed. This was due to mishandling of the extra N_SO stabs output
4219 We also finally got Ultrix 4.2 running in house, and fixed core file
4220 support, with help from a dozen people on the net.
4222 John M. Farrell discovered that the reason that single-stepping was so
4223 slow on all of the Mips based platforms (primarily SGI and DEC) was
4224 that we were trying to demangle and lookup a symbol used for internal
4225 purposes on every instruction that was being stepped through. Changing
4226 the name of that symbol so that it couldn't be mistaken for a C++
4227 mangled symbol sped things up a great deal.
4229 Rich Pixley sped up symbol lookups in general by getting much smarter
4230 about when C++ symbol mangling is necessary. This should make symbol
4231 completion (TAB on the command line) much faster. It's not as fast as
4232 we'd like, but it's significantly faster than gdb-4.6.
4236 A new user controllable variable 'call_scratch_address' can
4237 specify the location of a scratch area to be used when GDB
4238 calls a function in the target. This is necessary because the
4239 usual method of putting the scratch area on the stack does not work
4240 in systems that have separate instruction and data spaces.
4242 We integrated changes to support the 29k UDI (Universal Debugger
4243 Interface), but discovered at the last minute that we didn't have all
4244 of the appropriate copyright paperwork. We are working with AMD to
4245 resolve this, and hope to have it available soon.
4249 We have sped up the remote serial line protocol, especially for targets
4250 with lots of registers. It now supports a new `expedited status' ('T')
4251 message which can be used in place of the existing 'S' status message.
4252 This allows the remote stub to send only the registers that GDB
4253 needs to make a quick decision about single-stepping or conditional
4254 breakpoints, eliminating the need to fetch the entire register set for
4255 each instruction being stepped through.
4257 The GDB remote serial protocol now implements a write-through cache for
4258 registers, only re-reading the registers if the target has run.
4260 There is also a new remote serial stub for SPARC processors. You can
4261 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
4262 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
4263 processor with a serial port.
4267 Configure.in files have become much easier to read and modify. A new
4268 `table driven' format makes it more obvious what configurations are
4269 supported, and what files each one uses.
4273 There is a new opcodes library which will eventually contain all of the
4274 disassembly routines and opcode tables. At present, it only contains
4275 Sparc and Z8000 routines. This will allow the assembler, debugger, and
4276 disassembler (binutils/objdump) to share these routines.
4278 The libiberty library is now copylefted under the GNU Library General
4279 Public License. This allows more liberal use, and was done so libg++
4280 can use it. This makes no difference to GDB, since the Library License
4281 grants all the rights from the General Public License.
4285 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
4286 reference to the stabs symbol info used by the debugger. It is (as far
4287 as we know) the only published document on this fascinating topic. We
4288 encourage you to read it, compare it to the stabs information on your
4289 system, and send improvements on the document in general (to
4290 bug-gdb@prep.ai.mit.edu).
4292 And, of course, many bugs have been fixed.
4295 *** Changes in GDB-4.6:
4297 * Better support for C++ function names
4299 GDB now accepts as input the "demangled form" of C++ overloaded function
4300 names and member function names, and can do command completion on such names
4301 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
4302 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
4303 Make use of command completion, it is your friend.
4305 GDB also now accepts a variety of C++ mangled symbol formats. They are
4306 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
4307 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
4308 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
4309 for the list of formats.
4311 * G++ symbol mangling problem
4313 Recent versions of gcc have a bug in how they emit debugging information for
4314 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
4315 directory) can be applied to gcc to fix the problem. Alternatively, if you
4316 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
4317 usual symptom is difficulty with setting breakpoints on methods. GDB complains
4318 about the method being non-existent. (We believe that version 2.2.2 of GCC has
4321 * New 'maintenance' command
4323 All of the commands related to hacking GDB internals have been moved out of
4324 the main command set, and now live behind the 'maintenance' command. This
4325 can also be abbreviated as 'mt'. The following changes were made:
4327 dump-me -> maintenance dump-me
4328 info all-breakpoints -> maintenance info breakpoints
4329 printmsyms -> maintenance print msyms
4330 printobjfiles -> maintenance print objfiles
4331 printpsyms -> maintenance print psymbols
4332 printsyms -> maintenance print symbols
4334 The following commands are new:
4336 maintenance demangle Call internal GDB demangler routine to
4337 demangle a C++ link name and prints the result.
4338 maintenance print type Print a type chain for a given symbol
4340 * Change to .gdbinit file processing
4342 We now read the $HOME/.gdbinit file before processing the argv arguments
4343 (e.g. reading symbol files or core files). This allows global parameters to
4344 be set, which will apply during the symbol reading. The ./.gdbinit is still
4345 read after argv processing.
4347 * New hosts supported
4349 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
4351 GNU/Linux support i386-unknown-linux or linux
4353 We are also including code to support the HP/PA running BSD and HPUX. This
4354 is almost guaranteed not to work, as we didn't have time to test or build it
4355 for this release. We are including it so that the more adventurous (or
4356 masochistic) of you can play with it. We also had major problems with the
4357 fact that the compiler that we got from HP doesn't support the -g option.
4360 * New targets supported
4362 Hitachi H8/300 h8300-hitachi-hms or h8300hms
4364 * More smarts about finding #include files
4366 GDB now remembers the compilation directory for all include files, and for
4367 all files from which C is generated (like yacc and lex sources). This
4368 greatly improves GDB's ability to find yacc/lex sources, and include files,
4369 especially if you are debugging your program from a directory different from
4370 the one that contains your sources.
4372 We also fixed a bug which caused difficulty with listing and setting
4373 breakpoints in include files which contain C code. (In the past, you had to
4374 try twice in order to list an include file that you hadn't looked at before.)
4376 * Interesting infernals change
4378 GDB now deals with arbitrary numbers of sections, where the symbols for each
4379 section must be relocated relative to that section's landing place in the
4380 target's address space. This work was needed to support ELF with embedded
4381 stabs used by Solaris-2.0.
4383 * Bug fixes (of course!)
4385 There have been loads of fixes for the following things:
4386 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
4387 i960, stabs, DOS(GO32), procfs, etc...
4389 See the ChangeLog for details.
4391 *** Changes in GDB-4.5:
4393 * New machines supported (host and target)
4395 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
4397 SGI Irix-4.x mips-sgi-irix4 or iris4
4399 * New malloc package
4401 GDB now uses a new memory manager called mmalloc, based on gmalloc.
4402 Mmalloc is capable of handling mutiple heaps of memory. It is also
4403 capable of saving a heap to a file, and then mapping it back in later.
4404 This can be used to greatly speedup the startup of GDB by using a
4405 pre-parsed symbol table which lives in a mmalloc managed heap. For
4406 more details, please read mmalloc/mmalloc.texi.
4410 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
4411 'help info proc' for details.
4413 * MIPS ecoff symbol table format
4415 The code that reads MIPS symbol table format is now supported on all hosts.
4416 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
4419 * File name changes for MS-DOS
4421 Many files in the config directories have been renamed to make it easier to
4422 support GDB on MS-DOSe systems (which have very restrictive file name
4423 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
4424 environment) is close to working but has some remaining problems. Note
4425 that debugging of DOS programs is not supported, due to limitations
4426 in the ``operating system'', but it can be used to host cross-debugging.
4428 * Cross byte order fixes
4430 Many fixes have been made to support cross debugging of Sparc and MIPS
4431 targets from hosts whose byte order differs.
4433 * New -mapped and -readnow options
4435 If memory-mapped files are available on your system through the 'mmap'
4436 system call, you can use the -mapped option on the `file' or
4437 `symbol-file' commands to cause GDB to write the symbols from your
4438 program into a reusable file. If the program you are debugging is
4439 called `/path/fred', the mapped symbol file will be `./fred.syms'.
4440 Future GDB debugging sessions will notice the presence of this file,
4441 and will quickly map in symbol information from it, rather than reading
4442 the symbol table from the executable program. Using the '-mapped'
4443 option in a GDB `file' or `symbol-file' command has the same effect as
4444 starting GDB with the '-mapped' command-line option.
4446 You can cause GDB to read the entire symbol table immediately by using
4447 the '-readnow' option with any of the commands that load symbol table
4448 information (or on the GDB command line). This makes the command
4449 slower, but makes future operations faster.
4451 The -mapped and -readnow options are typically combined in order to
4452 build a `fred.syms' file that contains complete symbol information.
4453 A simple GDB invocation to do nothing but build a `.syms' file for future
4456 gdb -batch -nx -mapped -readnow programname
4458 The `.syms' file is specific to the host machine on which GDB is run.
4459 It holds an exact image of GDB's internal symbol table. It cannot be
4460 shared across multiple host platforms.
4462 * longjmp() handling
4464 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
4465 siglongjmp() without losing control. This feature has not yet been ported to
4466 all systems. It currently works on many 386 platforms, all MIPS-based
4467 platforms (SGI, DECstation, etc), and Sun3/4.
4471 Preliminary work has been put in to support the new Solaris OS from Sun. At
4472 this time, it can control and debug processes, but it is not capable of
4477 As always, many many bug fixes. The major areas were with g++, and mipsread.
4478 People using the MIPS-based platforms should experience fewer mysterious
4479 crashes and trashed symbol tables.
4481 *** Changes in GDB-4.4:
4483 * New machines supported (host and target)
4485 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4487 BSD Reno on Vax vax-dec-bsd
4488 Ultrix on Vax vax-dec-ultrix
4490 * New machines supported (target)
4492 AMD 29000 embedded, using EBMON a29k-none-none
4496 GDB continues to improve its handling of C++. `References' work better.
4497 The demangler has also been improved, and now deals with symbols mangled as
4498 per the Annotated C++ Reference Guide.
4500 GDB also now handles `stabs' symbol information embedded in MIPS
4501 `ecoff' symbol tables. Since the ecoff format was not easily
4502 extensible to handle new languages such as C++, this appeared to be a
4503 good way to put C++ debugging info into MIPS binaries. This option
4504 will be supported in the GNU C compiler, version 2, when it is
4507 * New features for SVR4
4509 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
4510 shared libraries. Debugging dynamically linked programs should present
4511 only minor differences from debugging statically linked programs.
4513 The `info proc' command will print out information about any process
4514 on an SVR4 system (including the one you are debugging). At the moment,
4515 it prints the address mappings of the process.
4517 If you bring up GDB on another SVR4 system, please send mail to
4518 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
4520 * Better dynamic linking support in SunOS
4522 Reading symbols from shared libraries which contain debugging symbols
4523 now works properly. However, there remain issues such as automatic
4524 skipping of `transfer vector' code during function calls, which
4525 make it harder to debug code in a shared library, than to debug the
4526 same code linked statically.
4530 GDB is now using the latest `getopt' routines from the FSF. This
4531 version accepts the -- prefix for options with long names. GDB will
4532 continue to accept the old forms (-option and +option) as well.
4533 Various single letter abbreviations for options have been explicity
4534 added to the option table so that they won't get overshadowed in the
4535 future by other options that begin with the same letter.
4539 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
4540 Many assorted bugs have been handled. Many more remain to be handled.
4541 See the various ChangeLog files (primarily in gdb and bfd) for details.
4544 *** Changes in GDB-4.3:
4546 * New machines supported (host and target)
4548 Amiga 3000 running Amix m68k-cbm-svr4 or amix
4549 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
4550 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4552 * Almost SCO Unix support
4554 We had hoped to support:
4555 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4556 (except for core file support), but we discovered very late in the release
4557 that it has problems with process groups that render gdb unusable. Sorry
4558 about that. I encourage people to fix it and post the fixes.
4560 * Preliminary ELF and DWARF support
4562 GDB can read ELF object files on System V Release 4, and can handle
4563 debugging records for C, in DWARF format, in ELF files. This support
4564 is preliminary. If you bring up GDB on another SVR4 system, please
4565 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
4570 GDB now uses the latest `readline' library. One user-visible change
4571 is that two tabs will list possible command completions, which previously
4572 required typing M-? (meta-question mark, or ESC ?).
4576 The `stepi' bug that many of you noticed has been squashed.
4577 Many bugs in C++ have been handled. Many more remain to be handled.
4578 See the various ChangeLog files (primarily in gdb and bfd) for details.
4580 * State of the MIPS world (in case you wondered):
4582 GDB can understand the symbol tables emitted by the compilers
4583 supplied by most vendors of MIPS-based machines, including DEC. These
4584 symbol tables are in a format that essentially nobody else uses.
4586 Some versions of gcc come with an assembler post-processor called
4587 mips-tfile. This program is required if you want to do source-level
4588 debugging of gcc-compiled programs. I believe FSF does not ship
4589 mips-tfile with gcc version 1, but it will eventually come with gcc
4592 Debugging of g++ output remains a problem. g++ version 1.xx does not
4593 really support it at all. (If you're lucky, you should be able to get
4594 line numbers and stack traces to work, but no parameters or local
4595 variables.) With some work it should be possible to improve the
4598 When gcc version 2 is released, you will have somewhat better luck.
4599 However, even then you will get confusing results for inheritance and
4602 We will eventually provide full debugging of g++ output on
4603 DECstations. This will probably involve some kind of stabs-in-ecoff
4604 encapulation, but the details have not been worked out yet.
4607 *** Changes in GDB-4.2:
4609 * Improved configuration
4611 Only one copy of `configure' exists now, and it is not self-modifying.
4612 Porting BFD is simpler.
4616 The `step' and `next' commands now only stop at the first instruction
4617 of a source line. This prevents the multiple stops that used to occur
4618 in switch statements, for-loops, etc. `Step' continues to stop if a
4619 function that has debugging information is called within the line.
4623 Lots of small bugs fixed. More remain.
4625 * New host supported (not target)
4627 Intel 386 PC clone running Mach i386-none-mach
4630 *** Changes in GDB-4.1:
4632 * Multiple source language support
4634 GDB now has internal scaffolding to handle several source languages.
4635 It determines the type of each source file from its filename extension,
4636 and will switch expression parsing and number formatting to match the
4637 language of the function in the currently selected stack frame.
4638 You can also specifically set the language to be used, with
4639 `set language c' or `set language modula-2'.
4643 GDB now has preliminary support for the GNU Modula-2 compiler,
4644 currently under development at the State University of New York at
4645 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
4646 continue through the fall of 1991 and into 1992.
4648 Other Modula-2 compilers are currently not supported, and attempting to
4649 debug programs compiled with them will likely result in an error as the
4650 symbol table is read. Feel free to work on it, though!
4652 There are hooks in GDB for strict type checking and range checking,
4653 in the `Modula-2 philosophy', but they do not currently work.
4657 GDB can now write to executable and core files (e.g. patch
4658 a variable's value). You must turn this switch on, specify
4659 the file ("exec foo" or "core foo"), *then* modify it, e.g.
4660 by assigning a new value to a variable. Modifications take
4663 * Automatic SunOS shared library reading
4665 When you run your program, GDB automatically determines where its
4666 shared libraries (if any) have been loaded, and reads their symbols.
4667 The `share' command is no longer needed. This also works when
4668 examining core files.
4672 You can specify the number of lines that the `list' command shows.
4675 * New machines supported (host and target)
4677 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4678 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
4679 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
4681 * New hosts supported (not targets)
4683 IBM RT/PC: romp-ibm-aix or rtpc
4685 * New targets supported (not hosts)
4687 AMD 29000 embedded with COFF a29k-none-coff
4688 AMD 29000 embedded with a.out a29k-none-aout
4689 Ultracomputer remote kernel debug a29k-nyu-kern
4691 * New remote interfaces
4697 *** Changes in GDB-4.0:
4701 Wide output is wrapped at good places to make the output more readable.
4703 Gdb now supports cross-debugging from a host machine of one type to a
4704 target machine of another type. Communication with the target system
4705 is over serial lines. The ``target'' command handles connecting to the
4706 remote system; the ``load'' command will download a program into the
4707 remote system. Serial stubs for the m68k and i386 are provided. Gdb
4708 also supports debugging of realtime processes running under VxWorks,
4709 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
4710 stub on the target system.
4712 New CPUs supported include the AMD 29000 and Intel 960.
4714 GDB now reads object files and symbol tables via a ``binary file''
4715 library, which allows a single copy of GDB to debug programs of multiple
4716 object file types such as a.out and coff.
4718 There is now a GDB reference card in "doc/refcard.tex". (Make targets
4719 refcard.dvi and refcard.ps are available to format it).
4722 * Control-Variable user interface simplified
4724 All variables that control the operation of the debugger can be set
4725 by the ``set'' command, and displayed by the ``show'' command.
4727 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
4728 ``Show prompt'' produces the response:
4729 Gdb's prompt is new-gdb=>.
4731 What follows are the NEW set commands. The command ``help set'' will
4732 print a complete list of old and new set commands. ``help set FOO''
4733 will give a longer description of the variable FOO. ``show'' will show
4734 all of the variable descriptions and their current settings.
4736 confirm on/off: Enables warning questions for operations that are
4737 hard to recover from, e.g. rerunning the program while
4738 it is already running. Default is ON.
4740 editing on/off: Enables EMACS style command line editing
4741 of input. Previous lines can be recalled with
4742 control-P, the current line can be edited with control-B,
4743 you can search for commands with control-R, etc.
4746 history filename NAME: NAME is where the gdb command history
4747 will be stored. The default is .gdb_history,
4748 or the value of the environment variable
4751 history size N: The size, in commands, of the command history. The
4752 default is 256, or the value of the environment variable
4755 history save on/off: If this value is set to ON, the history file will
4756 be saved after exiting gdb. If set to OFF, the
4757 file will not be saved. The default is OFF.
4759 history expansion on/off: If this value is set to ON, then csh-like
4760 history expansion will be performed on
4761 command line input. The default is OFF.
4763 radix N: Sets the default radix for input and output. It can be set
4764 to 8, 10, or 16. Note that the argument to "radix" is interpreted
4765 in the current radix, so "set radix 10" is always a no-op.
4767 height N: This integer value is the number of lines on a page. Default
4768 is 24, the current `stty rows'' setting, or the ``li#''
4769 setting from the termcap entry matching the environment
4772 width N: This integer value is the number of characters on a line.
4773 Default is 80, the current `stty cols'' setting, or the ``co#''
4774 setting from the termcap entry matching the environment
4777 Note: ``set screensize'' is obsolete. Use ``set height'' and
4778 ``set width'' instead.
4780 print address on/off: Print memory addresses in various command displays,
4781 such as stack traces and structure values. Gdb looks
4782 more ``symbolic'' if you turn this off; it looks more
4783 ``machine level'' with it on. Default is ON.
4785 print array on/off: Prettyprint arrays. New convenient format! Default
4788 print demangle on/off: Print C++ symbols in "source" form if on,
4791 print asm-demangle on/off: Same, for assembler level printouts
4794 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
4797 * Support for Epoch Environment.
4799 The epoch environment is a version of Emacs v18 with windowing. One
4800 new command, ``inspect'', is identical to ``print'', except that if you
4801 are running in the epoch environment, the value is printed in its own
4805 * Support for Shared Libraries
4807 GDB can now debug programs and core files that use SunOS shared libraries.
4808 Symbols from a shared library cannot be referenced
4809 before the shared library has been linked with the program (this
4810 happens after you type ``run'' and before the function main() is entered).
4811 At any time after this linking (including when examining core files
4812 from dynamically linked programs), gdb reads the symbols from each
4813 shared library when you type the ``sharedlibrary'' command.
4814 It can be abbreviated ``share''.
4816 sharedlibrary REGEXP: Load shared object library symbols for files
4817 matching a unix regular expression. No argument
4818 indicates to load symbols for all shared libraries.
4820 info sharedlibrary: Status of loaded shared libraries.
4825 A watchpoint stops execution of a program whenever the value of an
4826 expression changes. Checking for this slows down execution
4827 tremendously whenever you are in the scope of the expression, but is
4828 quite useful for catching tough ``bit-spreader'' or pointer misuse
4829 problems. Some machines such as the 386 have hardware for doing this
4830 more quickly, and future versions of gdb will use this hardware.
4832 watch EXP: Set a watchpoint (breakpoint) for an expression.
4834 info watchpoints: Information about your watchpoints.
4836 delete N: Deletes watchpoint number N (same as breakpoints).
4837 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
4838 enable N: Re-enables watchpoint number N (same as breakpoints).
4841 * C++ multiple inheritance
4843 When used with a GCC version 2 compiler, GDB supports multiple inheritance
4846 * C++ exception handling
4848 Gdb now supports limited C++ exception handling. Besides the existing
4849 ability to breakpoint on an exception handler, gdb can breakpoint on
4850 the raising of an exception (before the stack is peeled back to the
4853 catch FOO: If there is a FOO exception handler in the dynamic scope,
4854 set a breakpoint to catch exceptions which may be raised there.
4855 Multiple exceptions (``catch foo bar baz'') may be caught.
4857 info catch: Lists all exceptions which may be caught in the
4858 current stack frame.
4861 * Minor command changes
4863 The command ``call func (arg, arg, ...)'' now acts like the print
4864 command, except it does not print or save a value if the function's result
4865 is void. This is similar to dbx usage.
4867 The ``up'' and ``down'' commands now always print the frame they end up
4868 at; ``up-silently'' and `down-silently'' can be used in scripts to change
4869 frames without printing.
4871 * New directory command
4873 'dir' now adds directories to the FRONT of the source search path.
4874 The path starts off empty. Source files that contain debug information
4875 about the directory in which they were compiled can be found even
4876 with an empty path; Sun CC and GCC include this information. If GDB can't
4877 find your source file in the current directory, type "dir .".
4879 * Configuring GDB for compilation
4881 For normal use, type ``./configure host''. See README or gdb.texinfo
4884 GDB now handles cross debugging. If you are remotely debugging between
4885 two different machines, type ``./configure host -target=targ''.
4886 Host is the machine where GDB will run; targ is the machine
4887 where the program that you are debugging will run.