1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.2
6 * New command line options
8 -data-directory DIR Specify DIR as the "data-directory".
9 This is mostly for testing purposes.
11 * The "maint set python auto-load on|off" command has been renamed to
12 "set auto-load-scripts on|off".
14 * GDB has a new command: "set directories".
15 It is like the "dir" command except that it replaces the
16 source path list instead of augmenting it.
19 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
20 has been integrated into GDB.
24 ** GDB values in Python are now callable if the value represents a
25 function. For example, if 'some_value' represents a function that
26 takes two integer parameters and returns a value, you can call
27 that function like so:
29 result = some_value (10,20)
31 ** Module gdb.types has been added.
32 It contains a collection of utilities for working with gdb.Types objects:
33 get_basic_type, has_field, make_enum_dict.
35 ** Module gdb.printing has been added.
36 It contains utilities for writing and registering pretty-printers.
37 New classes: PrettyPrinter, SubPrettyPrinter,
38 RegexpCollectionPrettyPrinter.
39 New function: register_pretty_printer.
41 ** New commands "info pretty-printers", "enable pretty-printer" and
42 "disable pretty-printer" have been added.
44 ** gdb.parameter("directories") is now available.
46 ** New function gdb.newest_frame returns the newest frame in the
51 ** GDB now puts template parameters in scope when debugging in an
52 instantiation. For example, if you have:
54 template<int X> int func (void) { return X; }
56 then if you step into func<5>, "print X" will show "5". This
57 feature requires proper debuginfo support from the compiler; it
60 ** The motion commands "next", "finish", "until", and "advance" now
61 work better when exceptions are thrown. In particular, GDB will
62 no longer lose control of the inferior; instead, the GDB will
63 stop the inferior at the point at which the exception is caught.
64 This functionality requires a change in the exception handling
65 code that was introduced in GCC 4.5.
67 * GDB now follows GCC's rules on accessing volatile objects when
68 reading or writing target state during expression evaluation.
69 One notable difference to prior behavior is that "print x = 0"
70 no longer generates a read of x; the value of the assignment is
71 now always taken directly from the value being assigned.
73 * GDB now has some support for using labels in the program's source in
74 linespecs. For instance, you can use "advance label" to continue
77 * GDB now has support for reading and writing a new .gdb_index
78 section. This section holds a fast index of DWARF debugging
79 information and can be used to greatly speed up GDB startup and
80 operation. See the documentation for `save gdb-index' for details.
82 * The "watch" command now accepts an optional "-location" argument.
83 When used, this causes GDB to watch the memory referred to by the
84 expression. Such a watchpoint is never deleted due to it going out
87 * GDB now supports thread debugging of core dumps on GNU/Linux.
89 GDB now activates thread debugging using the libthread_db library
90 when debugging GNU/Linux core dumps, similarly to when debugging
91 live processes. As a result, when debugging a core dump file, GDB
92 is now able to display pthread_t ids of threads. For example, "info
93 threads" shows the same output as when debugging the process when it
94 was live. In earlier releases, you'd see something like this:
97 * 1 LWP 6780 main () at main.c:10
99 While now you see this:
102 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
104 It is also now possible to inspect TLS variables when debugging core
107 When debugging a core dump generated on a machine other than the one
108 used to run GDB, you may need to point GDB at the correct
109 libthread_db library with the "set libthread-db-search-path"
110 command. See the user manual for more details on this command.
112 * New features in the GDB remote stub, GDBserver
114 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
115 and i686 LynxOS (version 5.x).
117 ** GDBserver is now supported on Blackfin Linux.
121 Analog Devices, Inc. Blackfin Processor bfin-*
123 * Ada task switching is now supported on sparc-elf targets when
124 debugging a program using the Ravenscar Profile. For more information,
125 see the "Tasking Support when using the Ravenscar Profile" section
126 in the GDB user manual.
128 * Guile support was removed.
130 * New features in the GNU simulator
132 ** The --map-info flag lists all known core mappings.
134 *** Changes in GDB 7.2
136 * Shared library support for remote targets by default
138 When GDB is configured for a generic, non-OS specific target, like
139 for example, --target=arm-eabi or one of the many *-*-elf targets,
140 GDB now queries remote stubs for loaded shared libraries using the
141 `qXfer:libraries:read' packet. Previously, shared library support
142 was always disabled for such configurations.
146 ** Argument Dependent Lookup (ADL)
148 In C++ ADL lookup directs function search to the namespaces of its
149 arguments even if the namespace has not been imported.
159 Here the compiler will search for `foo' in the namespace of 'b'
160 and find A::foo. GDB now supports this. This construct is commonly
161 used in the Standard Template Library for operators.
163 ** Improved User Defined Operator Support
165 In addition to member operators, GDB now supports lookup of operators
166 defined in a namespace and imported with a `using' directive, operators
167 defined in the global scope, operators imported implicitly from an
168 anonymous namespace, and the ADL operators mentioned in the previous
170 GDB now also supports proper overload resolution for all the previously
171 mentioned flavors of operators.
173 ** static const class members
175 Printing of static const class members that are initialized in the
176 class definition has been fixed.
178 * Windows Thread Information Block access.
180 On Windows targets, GDB now supports displaying the Windows Thread
181 Information Block (TIB) structure. This structure is visible either
182 by using the new command `info w32 thread-information-block' or, by
183 dereferencing the new convenience variable named `$_tlb', a
184 thread-specific pointer to the TIB. This feature is also supported
185 when remote debugging using GDBserver.
189 Static tracepoints are calls in the user program into a tracing
190 library. One such library is a port of the LTTng kernel tracer to
191 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
192 When debugging with GDBserver, GDB now supports combining the GDB
193 tracepoint machinery with such libraries. For example: the user can
194 use GDB to probe a static tracepoint marker (a call from the user
195 program into the tracing library) with the new "strace" command (see
196 "New commands" below). This creates a "static tracepoint" in the
197 breakpoint list, that can be manipulated with the same feature set
198 as fast and regular tracepoints. E.g., collect registers, local and
199 global variables, collect trace state variables, and define
200 tracepoint conditions. In addition, the user can collect extra
201 static tracepoint marker specific data, by collecting the new
202 $_sdata internal variable. When analyzing the trace buffer, you can
203 inspect $_sdata like any other variable available to GDB. For more
204 information, see the "Tracepoints" chapter in GDB user manual. New
205 remote packets have been defined to support static tracepoints, see
206 the "New remote packets" section below.
208 * Better reconstruction of tracepoints after disconnected tracing
210 GDB will attempt to download the original source form of tracepoint
211 definitions when starting a trace run, and then will upload these
212 upon reconnection to the target, resulting in a more accurate
213 reconstruction of the tracepoints that are in use on the target.
217 You can now exercise direct control over the ways that GDB can
218 affect your program. For instance, you can disallow the setting of
219 breakpoints, so that the program can run continuously (assuming
220 non-stop mode). In addition, the "observer" variable is available
221 to switch all of the different controls; in observer mode, GDB
222 cannot affect the target's behavior at all, which is useful for
223 tasks like diagnosing live systems in the field.
225 * The new convenience variable $_thread holds the number of the
232 Return the address of the Windows Thread Information Block of a given thread.
236 In response to several of the tracepoint packets, the target may now
237 also respond with a number of intermediate `qRelocInsn' request
238 packets before the final result packet, to have GDB handle
239 relocating an instruction to execute at a different address. This
240 is particularly useful for stubs that support fast tracepoints. GDB
241 reports support for this feature in the qSupported packet.
245 List static tracepoint markers in the target program.
249 List static tracepoint markers at a given address in the target
252 qXfer:statictrace:read
254 Read the static trace data collected (by a `collect $_sdata'
255 tracepoint action). The remote stub reports support for this packet
256 to gdb's qSupported query.
260 Send the current settings of GDB's permission flags.
264 Send part of the source (textual) form of a tracepoint definition,
265 which includes location, conditional, and action list.
267 * The source command now accepts a -s option to force searching for the
268 script in the source search path even if the script name specifies
271 * New features in the GDB remote stub, GDBserver
273 - GDBserver now support tracepoints (including fast tracepoints, and
274 static tracepoints). The feature is currently supported by the
275 i386-linux and amd64-linux builds. See the "Tracepoints support
276 in gdbserver" section in the manual for more information.
278 GDBserver JIT compiles the tracepoint's conditional agent
279 expression bytecode into native code whenever possible for low
280 overhead dynamic tracepoints conditionals. For such tracepoints,
281 an expression that examines program state is evaluated when the
282 tracepoint is reached, in order to determine whether to capture
283 trace data. If the condition is simple and false, processing the
284 tracepoint finishes very quickly and no data is gathered.
286 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
287 for static tracepoints support.
289 - GDBserver now supports x86_64 Windows 64-bit debugging.
291 * GDB now sends xmlRegisters= in qSupported packet to indicate that
292 it understands register description.
294 * The --batch flag now disables pagination and queries.
296 * X86 general purpose registers
298 GDB now supports reading/writing byte, word and double-word x86
299 general purpose registers directly. This means you can use, say,
300 $ah or $ax to refer, respectively, to the byte register AH and
301 16-bit word register AX that are actually portions of the 32-bit
302 register EAX or 64-bit register RAX.
304 * The `commands' command now accepts a range of breakpoints to modify.
305 A plain `commands' following a command that creates multiple
306 breakpoints affects all the breakpoints set by that command. This
307 applies to breakpoints set by `rbreak', and also applies when a
308 single `break' command creates multiple breakpoints (e.g.,
309 breakpoints on overloaded c++ functions).
311 * The `rbreak' command now accepts a filename specification as part of
312 its argument, limiting the functions selected by the regex to those
313 in the specified file.
315 * Support for remote debugging Windows and SymbianOS shared libraries
316 from Unix hosts has been improved. Non Windows GDB builds now can
317 understand target reported file names that follow MS-DOS based file
318 system semantics, such as file names that include drive letters and
319 use the backslash character as directory separator. This makes it
320 possible to transparently use the "set sysroot" and "set
321 solib-search-path" on Unix hosts to point as host copies of the
322 target's shared libraries. See the new command "set
323 target-file-system-kind" described below, and the "Commands to
324 specify files" section in the user manual for more information.
328 eval template, expressions...
329 Convert the values of one or more expressions under the control
330 of the string template to a command line, and call it.
332 set target-file-system-kind unix|dos-based|auto
333 show target-file-system-kind
334 Set or show the assumed file system kind for target reported file
337 save breakpoints <filename>
338 Save all current breakpoint definitions to a file suitable for use
339 in a later debugging session. To read the saved breakpoint
340 definitions, use the `source' command.
342 `save tracepoints' is a new alias for `save-tracepoints'. The latter
345 info static-tracepoint-markers
346 Display information about static tracepoint markers in the target.
348 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
349 Define a static tracepoint by probing a marker at the given
350 function, line, address, or marker ID.
354 Enable and disable observer mode.
356 set may-write-registers on|off
357 set may-write-memory on|off
358 set may-insert-breakpoints on|off
359 set may-insert-tracepoints on|off
360 set may-insert-fast-tracepoints on|off
361 set may-interrupt on|off
362 Set individual permissions for GDB effects on the target. Note that
363 some of these settings can have undesirable or surprising
364 consequences, particularly when changed in the middle of a session.
365 For instance, disabling the writing of memory can prevent
366 breakpoints from being inserted, cause single-stepping to fail, or
367 even crash your program, if you disable after breakpoints have been
368 inserted. However, GDB should not crash.
370 set record memory-query on|off
371 show record memory-query
372 Control whether to stop the inferior if memory changes caused
373 by an instruction cannot be recorded.
378 The disassemble command now supports "start,+length" form of two arguments.
382 ** GDB now provides a new directory location, called the python directory,
383 where Python scripts written for GDB can be installed. The location
384 of that directory is <data-directory>/python, where <data-directory>
385 is the GDB data directory. For more details, see section `Scripting
386 GDB using Python' in the manual.
388 ** The GDB Python API now has access to breakpoints, symbols, symbol
389 tables, program spaces, inferiors, threads and frame's code blocks.
390 Additionally, GDB Parameters can now be created from the API, and
391 manipulated via set/show in the CLI.
393 ** New functions gdb.target_charset, gdb.target_wide_charset,
394 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
396 ** New exception gdb.GdbError.
398 ** Pretty-printers are now also looked up in the current program space.
400 ** Pretty-printers can now be individually enabled and disabled.
402 ** GDB now looks for names of Python scripts to auto-load in a
403 special section named `.debug_gdb_scripts', in addition to looking
404 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
406 * Tracepoint actions were unified with breakpoint commands. In particular,
407 there are no longer differences in "info break" output for breakpoints and
408 tracepoints and the "commands" command can be used for both tracepoints and
413 ARM Symbian arm*-*-symbianelf*
415 * D language support.
416 GDB now supports debugging programs written in the D programming
419 * GDB now supports the extended ptrace interface for PowerPC which is
420 available since Linux kernel version 2.6.34. This automatically enables
421 any hardware breakpoints and additional hardware watchpoints available in
422 the processor. The old ptrace interface exposes just one hardware
423 watchpoint and no hardware breakpoints.
425 * GDB is now able to use the Data Value Compare (DVC) register available on
426 embedded PowerPC processors to implement in hardware simple watchpoint
427 conditions of the form:
429 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
431 This works in native GDB running on Linux kernels with the extended ptrace
432 interface mentioned above.
434 *** Changes in GDB 7.1
440 GDB now supports importing of namespaces in C++. This enables the
441 user to inspect variables from imported namespaces. Support for
442 namepace aliasing has also been added. So, if a namespace is
443 aliased in the current scope (e.g. namepace C=A; ) the user can
444 print variables using the alias (e.g. (gdb) print C::x).
448 All known bugs relating to the printing of virtual base class were
449 fixed. It is now possible to call overloaded static methods using a
454 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
455 and reinterpret_cast<> are now handled by the C++ expression parser.
459 Xilinx MicroBlaze microblaze-*-*
464 Xilinx MicroBlaze microblaze
467 * Multi-program debugging.
469 GDB now has support for multi-program (a.k.a. multi-executable or
470 multi-exec) debugging. This allows for debugging multiple inferiors
471 simultaneously each running a different program under the same GDB
472 session. See "Debugging Multiple Inferiors and Programs" in the
473 manual for more information. This implied some user visible changes
474 in the multi-inferior support. For example, "info inferiors" now
475 lists inferiors that are not running yet or that have exited
476 already. See also "New commands" and "New options" below.
478 * New tracing features
480 GDB's tracepoint facility now includes several new features:
482 ** Trace state variables
484 GDB tracepoints now include support for trace state variables, which
485 are variables managed by the target agent during a tracing
486 experiment. They are useful for tracepoints that trigger each
487 other, so for instance one tracepoint can count hits in a variable,
488 and then a second tracepoint has a condition that is true when the
489 count reaches a particular value. Trace state variables share the
490 $-syntax of GDB convenience variables, and can appear in both
491 tracepoint actions and condition expressions. Use the "tvariable"
492 command to create, and "info tvariables" to view; see "Trace State
493 Variables" in the manual for more detail.
497 GDB now includes an option for defining fast tracepoints, which
498 targets may implement more efficiently, such as by installing a jump
499 into the target agent rather than a trap instruction. The resulting
500 speedup can be by two orders of magnitude or more, although the
501 tradeoff is that some program locations on some target architectures
502 might not allow fast tracepoint installation, for instance if the
503 instruction to be replaced is shorter than the jump. To request a
504 fast tracepoint, use the "ftrace" command, with syntax identical to
505 the regular trace command.
507 ** Disconnected tracing
509 It is now possible to detach GDB from the target while it is running
510 a trace experiment, then reconnect later to see how the experiment
511 is going. In addition, a new variable disconnected-tracing lets you
512 tell the target agent whether to continue running a trace if the
513 connection is lost unexpectedly.
517 GDB now has the ability to save the trace buffer into a file, and
518 then use that file as a target, similarly to you can do with
519 corefiles. You can select trace frames, print data that was
520 collected in them, and use tstatus to display the state of the
521 tracing run at the moment that it was saved. To create a trace
522 file, use "tsave <filename>", and to use it, do "target tfile
525 ** Circular trace buffer
527 You can ask the target agent to handle the trace buffer as a
528 circular buffer, discarding the oldest trace frames to make room for
529 newer ones, by setting circular-trace-buffer to on. This feature may
530 not be available for all target agents.
535 The disassemble command, when invoked with two arguments, now requires
536 the arguments to be comma-separated.
539 The info variables command now displays variable definitions. Files
540 which only declare a variable are not shown.
543 The source command is now capable of sourcing Python scripts.
544 This feature is dependent on the debugger being build with Python
547 Related to this enhancement is also the introduction of a new command
548 "set script-extension" (see below).
550 * New commands (for set/show, see "New options" below)
552 record save [<FILENAME>]
553 Save a file (in core file format) containing the process record
554 execution log for replay debugging at a later time.
556 record restore <FILENAME>
557 Restore the process record execution log that was saved at an
558 earlier time, for replay debugging.
560 add-inferior [-copies <N>] [-exec <FILENAME>]
563 clone-inferior [-copies <N>] [ID]
564 Make a new inferior ready to execute the same program another
570 maint info program-spaces
571 List the program spaces loaded into GDB.
573 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
574 show remote interrupt-sequence
575 Allow the user to select one of ^C, a BREAK signal or BREAK-g
576 as the sequence to the remote target in order to interrupt the execution.
577 Ctrl-C is a default. Some system prefers BREAK which is high level of
578 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
579 Magic SysRq g. It is BREAK signal and character 'g'.
581 set remote interrupt-on-connect [on | off]
582 show remote interrupt-on-connect
583 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
584 remote target when gdb connects to it. This is needed when you debug
587 set remotebreak [on | off]
589 Deprecated. Use "set/show remote interrupt-sequence" instead.
591 tvariable $NAME [ = EXP ]
592 Create or modify a trace state variable.
595 List trace state variables and their values.
597 delete tvariable $NAME ...
598 Delete one or more trace state variables.
601 Evaluate the given expressions without collecting anything into the
602 trace buffer. (Valid in tracepoint actions only.)
604 ftrace FN / FILE:LINE / *ADDR
605 Define a fast tracepoint at the given function, line, or address.
607 * New expression syntax
609 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
610 GDB now parses 0b101010 identically with 42.
614 set follow-exec-mode new|same
615 show follow-exec-mode
616 Control whether GDB reuses the same inferior across an exec call or
617 creates a new one. This is useful to be able to restart the old
618 executable after the inferior having done an exec call.
620 set default-collect EXPR, ...
622 Define a list of expressions to be collected at each tracepoint.
623 This is a useful way to ensure essential items are not overlooked,
624 such as registers or a critical global variable.
626 set disconnected-tracing
627 show disconnected-tracing
628 If set to 1, the target is instructed to continue tracing if it
629 loses its connection to GDB. If 0, the target is to stop tracing
632 set circular-trace-buffer
633 show circular-trace-buffer
634 If set to on, the target is instructed to use a circular trace buffer
635 and discard the oldest trace frames instead of stopping the trace due
636 to a full trace buffer. If set to off, the trace stops when the buffer
637 fills up. Some targets may not support this.
639 set script-extension off|soft|strict
640 show script-extension
641 If set to "off", the debugger does not perform any script language
642 recognition, and all sourced files are assumed to be GDB scripts.
643 If set to "soft" (the default), files are sourced according to
644 filename extension, falling back to GDB scripts if the first
646 If set to "strict", files are sourced according to filename extension.
648 set ada trust-PAD-over-XVS on|off
649 show ada trust-PAD-over-XVS
650 If off, activate a workaround against a bug in the debugging information
651 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
652 the GCC sources for more information about the GNAT encoding and
653 PAD types in particular). It is always safe to set this option to
654 off, but this introduces a slight performance penalty. The default
657 * Python API Improvements
659 ** GDB provides the new class gdb.LazyString. This is useful in
660 some pretty-printing cases. The new method gdb.Value.lazy_string
661 provides a simple way to create objects of this type.
663 ** The fields returned by gdb.Type.fields now have an
664 `is_base_class' attribute.
666 ** The new method gdb.Type.range returns the range of an array type.
668 ** The new method gdb.parse_and_eval can be used to parse and
669 evaluate an expression.
674 Define a trace state variable.
677 Get the current value of a trace state variable.
680 Set desired tracing behavior upon disconnection.
683 Set the trace buffer to be linear or circular.
686 Get data about the tracepoints currently in use.
690 Process record now works correctly with hardware watchpoints.
692 Multiple bug fixes have been made to the mips-irix port, making it
693 much more reliable. In particular:
694 - Debugging threaded applications is now possible again. Previously,
695 GDB would hang while starting the program, or while waiting for
696 the program to stop at a breakpoint.
697 - Attaching to a running process no longer hangs.
698 - An error occurring while loading a core file has been fixed.
699 - Changing the value of the PC register now works again. This fixes
700 problems observed when using the "jump" command, or when calling
701 a function from GDB, or even when assigning a new value to $pc.
702 - With the "finish" and "return" commands, the return value for functions
703 returning a small array is now correctly printed.
704 - It is now possible to break on shared library code which gets executed
705 during a shared library init phase (code executed while executing
706 their .init section). Previously, the breakpoint would have no effect.
707 - GDB is now able to backtrace through the signal handler for
708 non-threaded programs.
710 PIE (Position Independent Executable) programs debugging is now supported.
711 This includes debugging execution of PIC (Position Independent Code) shared
712 libraries although for that, it should be possible to run such libraries as an
715 *** Changes in GDB 7.0
717 * GDB now has an interface for JIT compilation. Applications that
718 dynamically generate code can create symbol files in memory and register
719 them with GDB. For users, the feature should work transparently, and
720 for JIT developers, the interface is documented in the GDB manual in the
721 "JIT Compilation Interface" chapter.
723 * Tracepoints may now be conditional. The syntax is as for
724 breakpoints; either an "if" clause appended to the "trace" command,
725 or the "condition" command is available. GDB sends the condition to
726 the target for evaluation using the same bytecode format as is used
727 for tracepoint actions.
729 * The disassemble command now supports: an optional /r modifier, print the
730 raw instructions in hex as well as in symbolic form, and an optional /m
731 modifier to print mixed source+assembly.
733 * Process record and replay
735 In a architecture environment that supports ``process record and
736 replay'', ``process record and replay'' target can record a log of
737 the process execution, and replay it with both forward and reverse
740 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
741 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
742 set execution-direction {forward|reverse}, for targets that support
745 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
746 feature is available with a native GDB running on kernel version
749 * GDB now has support for multi-byte and wide character sets on the
750 target. Strings whose character type is wchar_t, char16_t, or
751 char32_t are now correctly printed. GDB supports wide- and unicode-
752 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
753 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
754 `printf'. This feature requires iconv to work properly; if your
755 system does not have a working iconv, GDB can use GNU libiconv. See
756 the installation instructions for more information.
758 * GDB now supports automatic retrieval of shared library files from
759 remote targets. To use this feature, specify a system root that begins
760 with the `remote:' prefix, either via the `set sysroot' command or via
761 the `--with-sysroot' configure-time option.
763 * "info sharedlibrary" now takes an optional regex of libraries to show,
764 and it now reports if a shared library has no debugging information.
766 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
767 now complete on file names.
769 * When completing in expressions, gdb will attempt to limit
770 completions to allowable structure or union fields, where appropriate.
771 For instance, consider:
773 # struct example { int f1; double f2; };
774 # struct example variable;
777 If the user types TAB at the end of this command line, the available
778 completions will be "f1" and "f2".
780 * Inlined functions are now supported. They show up in backtraces, and
781 the "step", "next", and "finish" commands handle them automatically.
783 * GDB now supports the token-splicing (##) and stringification (#)
784 operators when expanding macros. It also supports variable-arity
787 * GDB now supports inspecting extra signal information, exported by
788 the new $_siginfo convenience variable. The feature is currently
789 implemented on linux ARM, i386 and amd64.
791 * GDB can now display the VFP floating point registers and NEON vector
792 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
793 can provide these registers (requires Linux 2.6.30 or later). Remote
794 and simulator targets may also provide them.
799 Search memory for a sequence of bytes.
802 Turn off `+'/`-' protocol acknowledgments to permit more efficient
803 operation over reliable transport links. Use of this packet is
804 controlled by the `set remote noack-packet' command.
807 Kill the process with the specified process ID. Use this in preference
808 to `k' when multiprocess protocol extensions are supported.
811 Obtains additional operating system information
815 Read or write additional signal information.
817 * Removed remote protocol undocumented extension
819 An undocumented extension to the remote protocol's `S' stop reply
820 packet that permited the stub to pass a process id was removed.
821 Remote servers should use the `T' stop reply packet instead.
823 * GDB now supports multiple function calling conventions according to the
824 DWARF-2 DW_AT_calling_convention function attribute.
826 * The SH target utilizes the aforementioned change to distinguish between gcc
827 and Renesas calling convention. It also adds the new CLI commands
828 `set/show sh calling-convention'.
830 * GDB can now read compressed debug sections, as produced by GNU gold
831 with the --compress-debug-sections=zlib flag.
833 * 64-bit core files are now supported on AIX.
835 * Thread switching is now supported on Tru64.
837 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
838 which will be allocated using malloc later in program execution.
840 * The qXfer:libraries:read remote procotol packet now allows passing a
841 list of section offsets.
843 * On GNU/Linux, GDB can now attach to stopped processes. Several race
844 conditions handling signals delivered during attach or thread creation
845 have also been fixed.
847 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
848 From the user's standpoint, all unqualified instances of True and False
849 are treated as the standard definitions, regardless of context.
851 * GDB now parses C++ symbol and type names more flexibly. For
854 template<typename T> class C { };
857 GDB will now correctly handle all of:
859 ptype C<char const *>
861 ptype C<const char *>
864 * New features in the GDB remote stub, gdbserver
866 - The "--wrapper" command-line argument tells gdbserver to use a
867 wrapper program to launch programs for debugging.
869 - On PowerPC and S/390 targets, it is now possible to use a single
870 gdbserver executable to debug both 32-bit and 64-bit programs.
871 (This requires gdbserver itself to be built as a 64-bit executable.)
873 - gdbserver uses the new noack protocol mode for TCP connections to
874 reduce communications latency, if also supported and enabled in GDB.
876 - Support for the sparc64-linux-gnu target is now included in
879 - The amd64-linux build of gdbserver now supports debugging both
880 32-bit and 64-bit programs.
882 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
883 now support hardware watchpoints, and will use them automatically
888 GDB now has support for scripting using Python. Whether this is
889 available is determined at configure time.
891 New GDB commands can now be written in Python.
893 * Ada tasking support
895 Ada tasks can now be inspected in GDB. The following commands have
899 Print the list of Ada tasks.
901 Print detailed information about task number N.
903 Print the task number of the current task.
905 Switch the context of debugging to task number N.
907 * Support for user-defined prefixed commands. The "define" command can
908 add new commands to existing prefixes, e.g. "target".
910 * Multi-inferior, multi-process debugging.
912 GDB now has generalized support for multi-inferior debugging. See
913 "Debugging Multiple Inferiors" in the manual for more information.
914 Although availability still depends on target support, the command
915 set is more uniform now. The GNU/Linux specific multi-forks support
916 has been migrated to this new framework. This implied some user
917 visible changes; see "New commands" and also "Removed commands"
920 * Target descriptions can now describe the target OS ABI. See the
921 "Target Description Format" section in the user manual for more
924 * Target descriptions can now describe "compatible" architectures
925 to indicate that the target can execute applications for a different
926 architecture in addition to those for the main target architecture.
927 See the "Target Description Format" section in the user manual for
930 * Multi-architecture debugging.
932 GDB now includes general supports for debugging applications on
933 hybrid systems that use more than one single processor architecture
934 at the same time. Each such hybrid architecture still requires
935 specific support to be added. The only hybrid architecture supported
936 in this version of GDB is the Cell Broadband Engine.
938 * GDB now supports integrated debugging of Cell/B.E. applications that
939 use both the PPU and SPU architectures. To enable support for hybrid
940 Cell/B.E. debugging, you need to configure GDB to support both the
941 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
942 --enable-targets configure option.
944 * Non-stop mode debugging.
946 For some targets, GDB now supports an optional mode of operation in
947 which you can examine stopped threads while other threads continue
948 to execute freely. This is referred to as non-stop mode, with the
949 old mode referred to as all-stop mode. See the "Non-Stop Mode"
950 section in the user manual for more information.
952 To be able to support remote non-stop debugging, a remote stub needs
953 to implement the non-stop mode remote protocol extensions, as
954 described in the "Remote Non-Stop" section of the user manual. The
955 GDB remote stub, gdbserver, has been adjusted to support these
956 extensions on linux targets.
958 * New commands (for set/show, see "New options" below)
960 catch syscall [NAME(S) | NUMBER(S)]
961 Catch system calls. Arguments, which should be names of system
962 calls or their numbers, mean catch only those syscalls. Without
963 arguments, every syscall will be caught. When the inferior issues
964 any of the specified syscalls, GDB will stop and announce the system
965 call, both when it is called and when its call returns. This
966 feature is currently available with a native GDB running on the
967 Linux Kernel, under the following architectures: x86, x86_64,
968 PowerPC and PowerPC64.
970 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
972 Search memory for a sequence of bytes.
974 maint set python print-stack
975 maint show python print-stack
976 Show a stack trace when an error is encountered in a Python script.
979 Invoke CODE by passing it to the Python interpreter.
984 These allow macros to be defined, undefined, and listed
988 Show operating system information about processes.
991 List the inferiors currently under GDB's control.
994 Switch focus to inferior number NUM.
997 Detach from inferior number NUM.
1000 Kill inferior number NUM.
1004 set spu stop-on-load
1005 show spu stop-on-load
1006 Control whether to stop for new SPE threads during Cell/B.E. debugging.
1008 set spu auto-flush-cache
1009 show spu auto-flush-cache
1010 Control whether to automatically flush the software-managed cache
1011 during Cell/B.E. debugging.
1013 set sh calling-convention
1014 show sh calling-convention
1015 Control the calling convention used when calling SH target functions.
1018 show debug timestamp
1019 Control display of timestamps with GDB debugging output.
1021 set disassemble-next-line
1022 show disassemble-next-line
1023 Control display of disassembled source lines or instructions when
1026 set remote noack-packet
1027 show remote noack-packet
1028 Set/show the use of remote protocol QStartNoAckMode packet. See above
1029 under "New remote packets."
1031 set remote query-attached-packet
1032 show remote query-attached-packet
1033 Control use of remote protocol `qAttached' (query-attached) packet.
1035 set remote read-siginfo-object
1036 show remote read-siginfo-object
1037 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
1040 set remote write-siginfo-object
1041 show remote write-siginfo-object
1042 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
1045 set remote reverse-continue
1046 show remote reverse-continue
1047 Control use of remote protocol 'bc' (reverse-continue) packet.
1049 set remote reverse-step
1050 show remote reverse-step
1051 Control use of remote protocol 'bs' (reverse-step) packet.
1053 set displaced-stepping
1054 show displaced-stepping
1055 Control displaced stepping mode. Displaced stepping is a way to
1056 single-step over breakpoints without removing them from the debuggee.
1057 Also known as "out-of-line single-stepping".
1060 show debug displaced
1061 Control display of debugging info for displaced stepping.
1063 maint set internal-error
1064 maint show internal-error
1065 Control what GDB does when an internal error is detected.
1067 maint set internal-warning
1068 maint show internal-warning
1069 Control what GDB does when an internal warning is detected.
1074 Use a wrapper program to launch programs for debugging.
1076 set multiple-symbols (all|ask|cancel)
1077 show multiple-symbols
1078 The value of this variable can be changed to adjust the debugger behavior
1079 when an expression or a breakpoint location contains an ambiguous symbol
1080 name (an overloaded function name, for instance).
1082 set breakpoint always-inserted
1083 show breakpoint always-inserted
1084 Keep breakpoints always inserted in the target, as opposed to inserting
1085 them when resuming the target, and removing them when the target stops.
1086 This option can improve debugger performance on slow remote targets.
1088 set arm fallback-mode (arm|thumb|auto)
1089 show arm fallback-mode
1090 set arm force-mode (arm|thumb|auto)
1092 These commands control how ARM GDB determines whether instructions
1093 are ARM or Thumb. The default for both settings is auto, which uses
1094 the current CPSR value for instructions without symbols; previous
1095 versions of GDB behaved as if "set arm fallback-mode arm".
1097 set disable-randomization
1098 show disable-randomization
1099 Standalone programs run with the virtual address space randomization enabled
1100 by default on some platforms. This option keeps the addresses stable across
1101 multiple debugging sessions.
1105 Control whether other threads are stopped or not when some thread hits
1110 Requests that asynchronous execution is enabled in the target, if available.
1111 In this case, it's possible to resume target in the background, and interact
1112 with GDB while the target is running. "show target-async" displays the
1113 current state of asynchronous execution of the target.
1115 set target-wide-charset
1116 show target-wide-charset
1117 The target-wide-charset is the name of the character set that GDB
1118 uses when printing characters whose type is wchar_t.
1120 set tcp auto-retry (on|off)
1122 set tcp connect-timeout
1123 show tcp connect-timeout
1124 These commands allow GDB to retry failed TCP connections to a remote stub
1125 with a specified timeout period; this is useful if the stub is launched
1126 in parallel with GDB but may not be ready to accept connections immediately.
1128 set libthread-db-search-path
1129 show libthread-db-search-path
1130 Control list of directories which GDB will search for appropriate
1133 set schedule-multiple (on|off)
1134 show schedule-multiple
1135 Allow GDB to resume all threads of all processes or only threads of
1136 the current process.
1140 Use more aggressive caching for accesses to the stack. This improves
1141 performance of remote debugging (particularly backtraces) without
1142 affecting correctness.
1144 set interactive-mode (on|off|auto)
1145 show interactive-mode
1146 Control whether GDB runs in interactive mode (on) or not (off).
1147 When in interactive mode, GDB waits for the user to answer all
1148 queries. Otherwise, GDB does not wait and assumes the default
1149 answer. When set to auto (the default), GDB determines which
1150 mode to use based on the stdin settings.
1155 For program forks, this is replaced by the new more generic `info
1156 inferiors' command. To list checkpoints, you can still use the
1157 `info checkpoints' command, which was an alias for the `info forks'
1161 Replaced by the new `inferior' command. To switch between
1162 checkpoints, you can still use the `restart' command, which was an
1163 alias for the `fork' command.
1166 This is removed, since some targets don't have a notion of
1167 processes. To switch between processes, you can still use the
1168 `inferior' command using GDB's own inferior number.
1171 For program forks, this is replaced by the new more generic `kill
1172 inferior' command. To delete a checkpoint, you can still use the
1173 `delete checkpoint' command, which was an alias for the `delete
1177 For program forks, this is replaced by the new more generic `detach
1178 inferior' command. To detach a checkpoint, you can still use the
1179 `detach checkpoint' command, which was an alias for the `detach
1182 * New native configurations
1184 x86/x86_64 Darwin i[34567]86-*-darwin*
1186 x86_64 MinGW x86_64-*-mingw*
1190 Lattice Mico32 lm32-*
1191 x86 DICOS i[34567]86-*-dicos*
1192 x86_64 DICOS x86_64-*-dicos*
1195 * The GDB remote stub, gdbserver, now supports x86 Windows CE
1196 (mingw32ce) debugging.
1202 These commands were actually not implemented on any target.
1204 *** Changes in GDB 6.8
1206 * New native configurations
1208 NetBSD/hppa hppa*-*netbsd*
1209 Xtensa GNU/Linux xtensa*-*-linux*
1213 NetBSD/hppa hppa*-*-netbsd*
1214 Xtensa GNU/Lunux xtensa*-*-linux*
1216 * Change in command line behavior -- corefiles vs. process ids.
1218 When the '-p NUMBER' or '--pid NUMBER' options are used, and
1219 attaching to process NUMBER fails, GDB no longer attempts to open a
1220 core file named NUMBER. Attaching to a program using the -c option
1221 is no longer supported. Instead, use the '-p' or '--pid' options.
1223 * GDB can now be built as a native debugger for debugging Windows x86
1224 (mingw32) Portable Executable (PE) programs.
1226 * Pending breakpoints no longer change their number when their address
1229 * GDB now supports breakpoints with multiple locations,
1230 including breakpoints on C++ constructors, inside C++ templates,
1231 and in inlined functions.
1233 * GDB's ability to debug optimized code has been improved. GDB more
1234 accurately identifies function bodies and lexical blocks that occupy
1235 more than one contiguous range of addresses.
1237 * Target descriptions can now describe registers for PowerPC.
1239 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
1240 registers on PowerPC targets.
1242 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
1243 targets even when the libthread_db library is not available.
1245 * The GDB remote stub, gdbserver, now supports the new file transfer
1246 commands (remote put, remote get, and remote delete).
1248 * The GDB remote stub, gdbserver, now supports run and attach in
1249 extended-remote mode.
1251 * hppa*64*-*-hpux11* target broken
1252 The debugger is unable to start a program and fails with the following
1253 error: "Error trying to get information about dynamic linker".
1254 The gdb-6.7 release is also affected.
1256 * GDB now supports the --enable-targets= configure option to allow
1257 building a single GDB executable that supports multiple remote
1258 target architectures.
1260 * GDB now supports debugging C and C++ programs which use the
1261 Decimal Floating Point extension. In addition, the PowerPC target
1262 now has a set of pseudo-registers to inspect decimal float values
1263 stored in two consecutive float registers.
1265 * The -break-insert MI command can optionally create pending
1268 * Improved support for debugging Ada
1269 Many improvements to the Ada language support have been made. These
1271 - Better support for Ada2005 interface types
1272 - Improved handling of arrays and slices in general
1273 - Better support for Taft-amendment types
1274 - The '{type} ADDRESS' expression is now allowed on the left hand-side
1276 - Improved command completion in Ada
1279 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
1284 set print frame-arguments (all|scalars|none)
1285 show print frame-arguments
1286 The value of this variable can be changed to control which argument
1287 values should be printed by the debugger when displaying a frame.
1292 Transfer files to and from a remote target, and delete remote files.
1299 Transfer files to and from a remote target, and delete remote files.
1301 * New remote packets
1308 Open, close, read, write, and delete files on the remote system.
1311 Attach to an existing process on the remote system, in extended-remote
1315 Run a new process on the remote system, in extended-remote mode.
1317 *** Changes in GDB 6.7
1319 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
1320 bfd, libiberty and opcodes, as revealed by static analysis donated by
1321 Coverity, Inc. (http://scan.coverity.com).
1323 * When looking up multiply-defined global symbols, GDB will now prefer the
1324 symbol definition in the current shared library if it was built using the
1325 -Bsymbolic linker option.
1327 * When the Text User Interface (TUI) is not configured, GDB will now
1328 recognize the -tui command-line option and print a message that the TUI
1331 * The GDB remote stub, gdbserver, now has lower overhead for high
1332 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
1334 * GDB for MIPS targets now autodetects whether a remote target provides
1335 32-bit or 64-bit register values.
1337 * Support for C++ member pointers has been improved.
1339 * GDB now understands XML target descriptions, which specify the
1340 target's overall architecture. GDB can read a description from
1341 a local file or over the remote serial protocol.
1343 * Vectors of single-byte data use a new integer type which is not
1344 automatically displayed as character or string data.
1346 * The /s format now works with the print command. It displays
1347 arrays of single-byte integers and pointers to single-byte integers
1350 * Target descriptions can now describe target-specific registers,
1351 for architectures which have implemented the support (currently
1352 only ARM, M68K, and MIPS).
1354 * GDB and the GDB remote stub, gdbserver, now support the XScale
1357 * The GDB remote stub, gdbserver, has been updated to support
1358 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
1359 has been rewritten to use the standard GDB remote protocol.
1361 * GDB can now step into C++ functions which are called through thunks.
1363 * GDB for the Cell/B.E. SPU now supports overlay debugging.
1365 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
1366 layout. It also supports a TextSeg= and DataSeg= response when only
1367 segment base addresses (rather than offsets) are available.
1369 * The /i format now outputs any trailing branch delay slot instructions
1370 immediately following the last instruction within the count specified.
1372 * The GDB remote protocol "T" stop reply packet now supports a
1373 "library" response. Combined with the new "qXfer:libraries:read"
1374 packet, this response allows GDB to debug shared libraries on targets
1375 where the operating system manages the list of loaded libraries (e.g.
1376 Windows and SymbianOS).
1378 * The GDB remote stub, gdbserver, now supports dynamic link libraries
1379 (DLLs) on Windows and Windows CE targets.
1381 * GDB now supports a faster verification that a .debug file matches its binary
1382 according to its build-id signature, if the signature is present.
1388 Enable or disable hardware flow control (RTS/CTS) on the serial port
1389 when debugging using remote targets.
1391 set mem inaccessible-by-default
1392 show mem inaccessible-by-default
1393 If the target supplies a memory map, for instance via the remote
1394 protocol's "qXfer:memory-map:read" packet, setting this variable
1395 prevents GDB from accessing memory outside the memory map. This
1396 is useful for targets with memory mapped registers or which react
1397 badly to accesses of unmapped address space.
1399 set breakpoint auto-hw
1400 show breakpoint auto-hw
1401 If the target supplies a memory map, for instance via the remote
1402 protocol's "qXfer:memory-map:read" packet, setting this variable
1403 lets GDB use hardware breakpoints automatically for memory regions
1404 where it can not use software breakpoints. This covers both the
1405 "break" command and internal breakpoints used for other commands
1406 including "next" and "finish".
1409 catch exception unhandled
1410 Stop the program execution when Ada exceptions are raised.
1413 Stop the program execution when an Ada assertion failed.
1417 Set an alternate system root for target files. This is a more
1418 general version of "set solib-absolute-prefix", which is now
1419 an alias to "set sysroot".
1422 Provide extended SPU facility status information. This set of
1423 commands is available only when debugging the Cell/B.E. SPU
1426 * New native configurations
1428 OpenBSD/sh sh*-*openbsd*
1431 unset tdesc filename
1433 Use the specified local file as an XML target description, and do
1434 not query the target for its built-in description.
1438 OpenBSD/sh sh*-*-openbsd*
1439 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
1440 Toshiba Media Processor mep-elf
1442 * New remote packets
1445 Ignore the specified signals; pass them directly to the debugged program
1446 without stopping other threads or reporting them to GDB.
1448 qXfer:features:read:
1449 Read an XML target description from the target, which describes its
1454 Read or write contents of an spufs file on the target system. These
1455 packets are available only on the Cell/B.E. SPU architecture.
1457 qXfer:libraries:read:
1458 Report the loaded shared libraries. Combined with new "T" packet
1459 response, this packet allows GDB to debug shared libraries on
1460 targets where the operating system manages the list of loaded
1461 libraries (e.g. Windows and SymbianOS).
1465 Support for these obsolete configurations has been removed.
1473 i[34567]86-*-lynxos*
1474 i[34567]86-*-netware*
1475 i[34567]86-*-sco3.2v5*
1476 i[34567]86-*-sco3.2v4*
1478 i[34567]86-*-sysv4.2*
1481 i[34567]86-*-unixware2*
1482 i[34567]86-*-unixware*
1491 * Other removed features
1498 Various m68k-only ROM monitors.
1505 Various Renesas ROM monitors and debugging interfaces for SH and
1510 Support for a Macraigor serial interface to on-chip debugging.
1511 GDB does not directly support the newer parallel or USB
1516 A debug information format. The predecessor to DWARF 2 and
1517 DWARF 3, which are still supported.
1519 Support for the HP aCC compiler on HP-UX/PA-RISC
1521 SOM-encapsulated symbolic debugging information, automatic
1522 invocation of pxdb, and the aCC custom C++ ABI. This does not
1523 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
1524 with aCC can still be debugged on an assembly level.
1526 MIPS ".pdr" sections
1528 A MIPS-specific format used to describe stack frame layout
1529 in debugging information.
1533 GDB could work with an older version of Guile to debug
1534 the interpreter and Scheme programs running in it.
1536 set mips stack-arg-size
1537 set mips saved-gpreg-size
1539 Use "set mips abi" to control parameter passing for MIPS.
1541 *** Changes in GDB 6.6
1546 Cell Broadband Engine SPU spu-elf
1548 * GDB can now be configured as a cross-debugger targeting native Windows
1549 (mingw32) or Cygwin. It can communicate with a remote debugging stub
1550 running on a Windows system over TCP/IP to debug Windows programs.
1552 * The GDB remote stub, gdbserver, has been updated to support Windows and
1553 Cygwin debugging. Both single-threaded and multi-threaded programs are
1556 * The "set trust-readonly-sections" command works again. This command was
1557 broken in GDB 6.3, 6.4, and 6.5.
1559 * The "load" command now supports writing to flash memory, if the remote
1560 stub provides the required support.
1562 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
1563 longer requires symbolic debug information (e.g. DWARF-2).
1568 unset substitute-path
1569 show substitute-path
1570 Manage a list of substitution rules that GDB uses to rewrite the name
1571 of the directories where the sources are located. This can be useful
1572 for instance when the sources were moved to a different location
1573 between compilation and debugging.
1577 Print each CLI command as it is executed. Each command is prefixed with
1578 a number of `+' symbols representing the nesting depth.
1579 The source command now has a `-v' option to enable the same feature.
1583 The ARM Demon monitor support (RDP protocol, "target rdp").
1585 Kernel Object Display, an embedded debugging feature which only worked with
1586 an obsolete version of Cisco IOS.
1588 The 'set download-write-size' and 'show download-write-size' commands.
1590 * New remote packets
1593 Tell a stub about GDB client features, and request remote target features.
1594 The first feature implemented is PacketSize, which allows the target to
1595 specify the size of packets it can handle - to minimize the number of
1596 packets required and improve performance when connected to a remote
1600 Fetch an OS auxilliary vector from the remote stub. This packet is a
1601 more efficient replacement for qPart:auxv:read.
1603 qXfer:memory-map:read:
1604 Fetch a memory map from the remote stub, including information about
1605 RAM, ROM, and flash memory devices.
1610 Erase and program a flash memory device.
1612 * Removed remote packets
1615 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
1616 used it, and only gdbserver implemented it.
1618 *** Changes in GDB 6.5
1622 Renesas M32C/M16C m32c-elf
1624 Morpho Technologies ms1 ms1-elf
1628 init-if-undefined Initialize a convenience variable, but
1629 only if it doesn't already have a value.
1631 The following commands are presently only implemented for native GNU/Linux:
1633 checkpoint Save a snapshot of the program state.
1635 restart <n> Return the program state to a
1636 previously saved state.
1638 info checkpoints List currently saved checkpoints.
1640 delete-checkpoint <n> Delete a previously saved checkpoint.
1642 set|show detach-on-fork Tell gdb whether to detach from a newly
1643 forked process, or to keep debugging it.
1645 info forks List forks of the user program that
1646 are available to be debugged.
1648 fork <n> Switch to debugging one of several
1649 forks of the user program that are
1650 available to be debugged.
1652 delete-fork <n> Delete a fork from the list of forks
1653 that are available to be debugged (and
1654 kill the forked process).
1656 detach-fork <n> Delete a fork from the list of forks
1657 that are available to be debugged (and
1658 allow the process to continue).
1662 Morpho Technologies ms2 ms1-elf
1664 * Improved Windows host support
1666 GDB now builds as a cross debugger hosted on i686-mingw32, including
1667 native console support, and remote communications using either
1668 network sockets or serial ports.
1670 * Improved Modula-2 language support
1672 GDB can now print most types in the Modula-2 syntax. This includes:
1673 basic types, set types, record types, enumerated types, range types,
1674 pointer types and ARRAY types. Procedure var parameters are correctly
1675 printed and hexadecimal addresses and character constants are also
1676 written in the Modula-2 syntax. Best results can be obtained by using
1677 GNU Modula-2 together with the -gdwarf-2 command line option.
1681 The ARM rdi-share module.
1683 The Netware NLM debug server.
1685 *** Changes in GDB 6.4
1687 * New native configurations
1689 OpenBSD/arm arm*-*-openbsd*
1690 OpenBSD/mips64 mips64-*-openbsd*
1694 Morpho Technologies ms1 ms1-elf
1696 * New command line options
1698 --batch-silent As for --batch, but totally silent.
1699 --return-child-result The debugger will exist with the same value
1700 the child (debugged) program exited with.
1701 --eval-command COMMAND, -ex COMMAND
1702 Execute a single GDB CLI command. This may be
1703 specified multiple times and in conjunction
1704 with the --command (-x) option.
1706 * Deprecated commands removed
1708 The following commands, that were deprecated in 2000, have been
1712 set|show arm disassembly-flavor set|show arm disassembler
1713 othernames set arm disassembler
1714 set|show remotedebug set|show debug remote
1715 set|show archdebug set|show debug arch
1716 set|show eventdebug set|show debug event
1719 * New BSD user-level threads support
1721 It is now possible to debug programs using the user-level threads
1722 library on OpenBSD and FreeBSD. Currently supported (target)
1725 FreeBSD/amd64 x86_64-*-freebsd*
1726 FreeBSD/i386 i386-*-freebsd*
1727 OpenBSD/i386 i386-*-openbsd*
1729 Note that the new kernel threads libraries introduced in FreeBSD 5.x
1730 are not yet supported.
1732 * New support for Matsushita MN10300 w/sim added
1733 (Work in progress). mn10300-elf.
1735 * REMOVED configurations and files
1737 VxWorks and the XDR protocol *-*-vxworks
1738 Motorola MCORE mcore-*-*
1739 National Semiconductor NS32000 ns32k-*-*
1741 * New "set print array-indexes" command
1743 After turning this setting "on", GDB prints the index of each element
1744 when displaying arrays. The default is "off" to preserve the previous
1747 * VAX floating point support
1749 GDB now supports the not-quite-ieee VAX F and D floating point formats.
1751 * User-defined command support
1753 In addition to using $arg0..$arg9 for argument passing, it is now possible
1754 to use $argc to determine now many arguments have been passed. See the
1755 section on user-defined commands in the user manual for more information.
1757 *** Changes in GDB 6.3:
1759 * New command line option
1761 GDB now accepts -l followed by a number to set the timeout for remote
1764 * GDB works with GCC -feliminate-dwarf2-dups
1766 GDB now supports a more compact representation of DWARF-2 debug
1767 information using DW_FORM_ref_addr references. These are produced
1768 by GCC with the option -feliminate-dwarf2-dups and also by some
1769 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
1770 to use -feliminate-dwarf2-dups.
1772 * Internationalization
1774 When supported by the host system, GDB will be built with
1775 internationalization (libintl). The task of marking up the sources is
1776 continued, we're looking forward to our first translation.
1780 Initial support for debugging programs compiled with the GNAT
1781 implementation of the Ada programming language has been integrated
1782 into GDB. In this release, support is limited to expression evaluation.
1784 * New native configurations
1786 GNU/Linux/m32r m32r-*-linux-gnu
1790 GDB's remote protocol now includes support for the 'p' packet. This
1791 packet is used to fetch individual registers from a remote inferior.
1793 * END-OF-LIFE registers[] compatibility module
1795 GDB's internal register infrastructure has been completely rewritten.
1796 The new infrastructure making possible the implementation of key new
1797 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
1800 GDB 6.3 will be the last release to include the the registers[]
1801 compatibility module that allowed out-of-date configurations to
1802 continue to work. This change directly impacts the following
1812 powerpc bdm protocol
1814 Unless there is activity to revive these configurations, they will be
1815 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
1817 * OBSOLETE configurations and files
1819 Configurations that have been declared obsolete in this release have
1820 been commented out. Unless there is activity to revive these
1821 configurations, the next release of GDB will have their sources
1822 permanently REMOVED.
1831 *** Changes in GDB 6.2.1:
1833 * MIPS `break main; run' gave an heuristic-fence-post warning
1835 When attempting to run even a simple program, a warning about
1836 heuristic-fence-post being hit would be reported. This problem has
1839 * MIPS IRIX 'long double' crashed GDB
1841 When examining a long double variable, GDB would get a segmentation
1842 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
1843 IRIX long double values).
1847 A bug in the VAX stack code was causing problems with the "next"
1848 command. This problem has been fixed.
1850 *** Changes in GDB 6.2:
1852 * Fix for ``many threads''
1854 On GNU/Linux systems that use the NPTL threads library, a program
1855 rapidly creating and deleting threads would confuse GDB leading to the
1858 ptrace: No such process.
1859 thread_db_get_info: cannot get thread info: generic error
1861 This problem has been fixed.
1863 * "-async" and "-noasync" options removed.
1865 Support for the broken "-noasync" option has been removed (it caused
1868 * New ``start'' command.
1870 This command runs the program until the begining of the main procedure.
1872 * New BSD Kernel Data Access Library (libkvm) interface
1874 Using ``target kvm'' it is now possible to debug kernel core dumps and
1875 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
1876 platforms. Currently supported (native-only) configurations are:
1878 FreeBSD/amd64 x86_64-*-freebsd*
1879 FreeBSD/i386 i?86-*-freebsd*
1880 NetBSD/i386 i?86-*-netbsd*
1881 NetBSD/m68k m68*-*-netbsd*
1882 NetBSD/sparc sparc-*-netbsd*
1883 OpenBSD/amd64 x86_64-*-openbsd*
1884 OpenBSD/i386 i?86-*-openbsd*
1885 OpenBSD/m68k m68*-openbsd*
1886 OpenBSD/sparc sparc-*-openbsd*
1888 * Signal trampoline code overhauled
1890 Many generic problems with GDB's signal handling code have been fixed.
1891 These include: backtraces through non-contiguous stacks; recognition
1892 of sa_sigaction signal trampolines; backtrace from a NULL pointer
1893 call; backtrace through a signal trampoline; step into and out of
1894 signal handlers; and single-stepping in the signal trampoline.
1896 Please note that kernel bugs are a limiting factor here. These
1897 features have been shown to work on an s390 GNU/Linux system that
1898 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
1900 * Cygwin support for DWARF 2 added.
1902 * New native configurations
1904 GNU/Linux/hppa hppa*-*-linux*
1905 OpenBSD/hppa hppa*-*-openbsd*
1906 OpenBSD/m68k m68*-*-openbsd*
1907 OpenBSD/m88k m88*-*-openbsd*
1908 OpenBSD/powerpc powerpc-*-openbsd*
1909 NetBSD/vax vax-*-netbsd*
1910 OpenBSD/vax vax-*-openbsd*
1912 * END-OF-LIFE frame compatibility module
1914 GDB's internal frame infrastructure has been completely rewritten.
1915 The new infrastructure making it possible to support key new features
1916 including DWARF 2 Call Frame Information. To aid in the task of
1917 migrating old configurations to this new infrastructure, a
1918 compatibility module, that allowed old configurations to continue to
1919 work, was also included.
1921 GDB 6.2 will be the last release to include this frame compatibility
1922 module. This change directly impacts the following configurations:
1932 Unless there is activity to revive these configurations, they will be
1933 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
1935 * REMOVED configurations and files
1937 Sun 3, running SunOS 3 m68*-*-sunos3*
1938 Sun 3, running SunOS 4 m68*-*-sunos4*
1939 Sun 2, running SunOS 3 m68000-*-sunos3*
1940 Sun 2, running SunOS 4 m68000-*-sunos4*
1941 Motorola 680x0 running LynxOS m68*-*-lynxos*
1942 AT&T 3b1/Unix pc m68*-att-*
1943 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
1944 decstation mips-dec-* mips-little-*
1945 riscos mips-*-riscos* mips-*-sysv*
1946 sonymips mips-sony-*
1947 sysv mips*-*-sysv4* (IRIX 5/6 not included)
1949 *** Changes in GDB 6.1.1:
1951 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
1953 The TUI (Text-mode User Interface) is now built as part of a default
1954 GDB configuration. It is enabled by either selecting the TUI with the
1955 command line option "-i=tui" or by running the separate "gdbtui"
1956 program. For more information on the TUI, see the manual "Debugging
1959 * Pending breakpoint support (also included in GDB 6.1)
1961 Support has been added to allow you to specify breakpoints in shared
1962 libraries that have not yet been loaded. If a breakpoint location
1963 cannot be found, and the "breakpoint pending" option is set to auto,
1964 GDB queries you if you wish to make the breakpoint pending on a future
1965 shared-library load. If and when GDB resolves the breakpoint symbol,
1966 the pending breakpoint is removed as one or more regular breakpoints
1969 Pending breakpoints are very useful for GCJ Java debugging.
1971 * Fixed ISO-C build problems
1973 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
1974 non ISO-C code that stopped them being built using a more strict ISO-C
1975 compiler (e.g., IBM's C compiler).
1977 * Fixed build problem on IRIX 5
1979 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
1980 wasn't able to compile compile on an IRIX 5 system.
1982 * Added execute permission to gdb/gdbserver/configure
1984 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
1985 permission. This bug would cause configure to fail on a number of
1986 systems (Solaris, IRIX). Ref: server/519.
1988 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
1990 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
1991 has been updated to use constant array sizes.
1993 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
1995 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
1996 its generated DWARF Call Frame Info. This encoding was causing GDB to
1997 panic, that panic has been fixed. Ref: gdb/1628.
1999 * Fixed a problem when examining parameters in shared library code.
2001 When examining parameters in optimized shared library code generated
2002 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
2003 not available''. GDB now correctly displays the variable's value.
2005 *** Changes in GDB 6.1:
2007 * Removed --with-mmalloc
2009 Support for the mmalloc memory manager has been removed, as it
2010 conflicted with the internal gdb byte cache.
2012 * Changes in AMD64 configurations
2014 The AMD64 target now includes the %cs and %ss registers. As a result
2015 the AMD64 remote protocol has changed; this affects the floating-point
2016 and SSE registers. If you rely on those registers for your debugging,
2017 you should upgrade gdbserver on the remote side.
2019 * Revised SPARC target
2021 The SPARC target has been completely revised, incorporating the
2022 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
2023 support for LynxOS and SunOS 4 has been dropped. Calling functions
2024 from within GDB on operating systems with a non-executable stack
2025 (Solaris, OpenBSD) now works.
2029 GDB has a new C++ demangler which does a better job on the mangled
2030 names generated by current versions of g++. It also runs faster, so
2031 with this and other changes gdb should now start faster on large C++
2034 * DWARF 2 Location Expressions
2036 GDB support for location expressions has been extended to support function
2037 arguments and frame bases. Older versions of GDB could crash when they
2040 * C++ nested types and namespaces
2042 GDB's support for nested types and namespaces in C++ has been
2043 improved, especially if you use the DWARF 2 debugging format. (This
2044 is the default for recent versions of GCC on most platforms.)
2045 Specifically, if you have a class "Inner" defined within a class or
2046 namespace "Outer", then GDB realizes that the class's name is
2047 "Outer::Inner", not simply "Inner". This should greatly reduce the
2048 frequency of complaints about not finding RTTI symbols. In addition,
2049 if you are stopped at inside of a function defined within a namespace,
2050 GDB modifies its name lookup accordingly.
2052 * New native configurations
2054 NetBSD/amd64 x86_64-*-netbsd*
2055 OpenBSD/amd64 x86_64-*-openbsd*
2056 OpenBSD/alpha alpha*-*-openbsd*
2057 OpenBSD/sparc sparc-*-openbsd*
2058 OpenBSD/sparc64 sparc64-*-openbsd*
2060 * New debugging protocols
2062 M32R with SDI protocol m32r-*-elf*
2064 * "set prompt-escape-char" command deleted.
2066 The command "set prompt-escape-char" has been deleted. This command,
2067 and its very obscure effet on GDB's prompt, was never documented,
2068 tested, nor mentioned in the NEWS file.
2070 * OBSOLETE configurations and files
2072 Configurations that have been declared obsolete in this release have
2073 been commented out. Unless there is activity to revive these
2074 configurations, the next release of GDB will have their sources
2075 permanently REMOVED.
2077 Sun 3, running SunOS 3 m68*-*-sunos3*
2078 Sun 3, running SunOS 4 m68*-*-sunos4*
2079 Sun 2, running SunOS 3 m68000-*-sunos3*
2080 Sun 2, running SunOS 4 m68000-*-sunos4*
2081 Motorola 680x0 running LynxOS m68*-*-lynxos*
2082 AT&T 3b1/Unix pc m68*-att-*
2083 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2084 decstation mips-dec-* mips-little-*
2085 riscos mips-*-riscos* mips-*-sysv*
2086 sonymips mips-sony-*
2087 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2089 * REMOVED configurations and files
2091 SGI Irix-4.x mips-sgi-irix4 or iris4
2092 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
2093 Z8000 simulator z8k-zilog-none or z8ksim
2094 Matsushita MN10200 w/simulator mn10200-*-*
2095 H8/500 simulator h8500-hitachi-hms or h8500hms
2096 HP/PA running BSD hppa*-*-bsd*
2097 HP/PA running OSF/1 hppa*-*-osf*
2098 HP/PA Pro target hppa*-*-pro*
2099 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2100 386BSD i[3456]86-*-bsd*
2101 Sequent family i[3456]86-sequent-sysv4*
2102 i[3456]86-sequent-sysv*
2103 i[3456]86-sequent-bsd*
2104 SPARC running LynxOS sparc-*-lynxos*
2105 SPARC running SunOS 4 sparc-*-sunos4*
2106 Tsqware Sparclet sparclet-*-*
2107 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2109 *** Changes in GDB 6.0:
2113 Support for debugging the Objective-C programming language has been
2114 integrated into GDB.
2116 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
2118 DWARF 2's Call Frame Information makes available compiler generated
2119 information that more exactly describes the program's run-time stack.
2120 By using this information, GDB is able to provide more robust stack
2123 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
2124 have been updated to use a new backtrace mechanism which includes
2125 DWARF 2 CFI support.
2129 GDB's remote protocol has been extended to include support for hosted
2130 file I/O (where the remote target uses GDB's file system). See GDB's
2131 remote protocol documentation for details.
2133 * All targets using the new architecture framework.
2135 All of GDB's targets have been updated to use the new internal
2136 architecture framework. The way is now open for future GDB releases
2137 to include cross-architecture native debugging support (i386 on amd64,
2140 * GNU/Linux's Thread Local Storage (TLS)
2142 GDB now includes support for for the GNU/Linux implementation of
2143 per-thread variables.
2145 * GNU/Linux's Native POSIX Thread Library (NPTL)
2147 GDB's thread code has been updated to work with either the new
2148 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
2150 * Separate debug info.
2152 GDB, in conjunction with BINUTILS, now supports a mechanism for
2153 automatically loading debug information from a separate file. Instead
2154 of shipping full debug and non-debug versions of system libraries,
2155 system integrators can now instead ship just the stripped libraries
2156 and optional debug files.
2158 * DWARF 2 Location Expressions
2160 DWARF 2 Location Expressions allow the compiler to more completely
2161 describe the location of variables (even in optimized code) to the
2164 GDB now includes preliminary support for location expressions (support
2165 for DW_OP_piece is still missing).
2169 A number of long standing bugs that caused GDB to die while starting a
2170 Java application have been fixed. GDB's Java support is now
2171 considered "useable".
2173 * GNU/Linux support for fork, vfork, and exec.
2175 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
2176 commands are now implemented for GNU/Linux. They require a 2.5.x or later
2179 * GDB supports logging output to a file
2181 There are two new commands, "set logging" and "show logging", which can be
2182 used to capture GDB's output to a file.
2184 * The meaning of "detach" has changed for gdbserver
2186 The "detach" command will now resume the application, as documented. To
2187 disconnect from gdbserver and leave it stopped, use the new "disconnect"
2190 * d10v, m68hc11 `regs' command deprecated
2192 The `info registers' command has been updated so that it displays the
2193 registers using a format identical to the old `regs' command.
2197 A new command, "maint set profile on/off", has been added. This command can
2198 be used to enable or disable profiling while running GDB, to profile a
2199 session or a set of commands. In addition there is a new configure switch,
2200 "--enable-profiling", which will cause GDB to be compiled with profiling
2201 data, for more informative profiling results.
2203 * Default MI syntax changed to "mi2".
2205 The default MI (machine interface) syntax, enabled by the command line
2206 option "-i=mi", has been changed to "mi2". The previous MI syntax,
2207 "mi1", can be enabled by specifying the option "-i=mi1".
2209 Support for the original "mi0" syntax (included in GDB 5.0) has been
2212 Fix for gdb/192: removed extraneous space when displaying frame level.
2213 Fix for gdb/672: update changelist is now output in mi list format.
2214 Fix for gdb/702: a -var-assign that updates the value now shows up
2215 in a subsequent -var-update.
2217 * New native configurations.
2219 FreeBSD/amd64 x86_64-*-freebsd*
2221 * Multi-arched targets.
2223 HP/PA HPUX11 hppa*-*-hpux*
2224 Renesas M32R/D w/simulator m32r-*-elf*
2226 * OBSOLETE configurations and files
2228 Configurations that have been declared obsolete in this release have
2229 been commented out. Unless there is activity to revive these
2230 configurations, the next release of GDB will have their sources
2231 permanently REMOVED.
2233 Z8000 simulator z8k-zilog-none or z8ksim
2234 Matsushita MN10200 w/simulator mn10200-*-*
2235 H8/500 simulator h8500-hitachi-hms or h8500hms
2236 HP/PA running BSD hppa*-*-bsd*
2237 HP/PA running OSF/1 hppa*-*-osf*
2238 HP/PA Pro target hppa*-*-pro*
2239 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2240 Sequent family i[3456]86-sequent-sysv4*
2241 i[3456]86-sequent-sysv*
2242 i[3456]86-sequent-bsd*
2243 Tsqware Sparclet sparclet-*-*
2244 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2246 * REMOVED configurations and files
2249 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2250 IBM AIX PS/2 i[3456]86-*-aix
2251 i386 running Mach 3.0 i[3456]86-*-mach3*
2252 i386 running Mach i[3456]86-*-mach*
2253 i386 running OSF/1 i[3456]86-*osf1mk*
2254 HP/Apollo 68k Family m68*-apollo*-sysv*,
2256 m68*-hp-bsd*, m68*-hp-hpux*
2257 Argonaut Risc Chip (ARC) arc-*-*
2258 Mitsubishi D30V d30v-*-*
2259 Fujitsu FR30 fr30-*-elf*
2260 OS/9000 i[34]86-*-os9k
2261 I960 with MON960 i960-*-coff
2263 * MIPS $fp behavior changed
2265 The convenience variable $fp, for the MIPS, now consistently returns
2266 the address of the current frame's base. Previously, depending on the
2267 context, $fp could refer to either $sp or the current frame's base
2268 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
2269 The GNU Source-Level Debugger''.
2271 *** Changes in GDB 5.3:
2273 * GNU/Linux shared library multi-threaded performance improved.
2275 When debugging a multi-threaded application on GNU/Linux, GDB now uses
2276 `/proc', in preference to `ptrace' for memory reads. This may result
2277 in an improvement in the start-up time of multi-threaded, shared
2278 library applications when run under GDB. One GDB user writes: ``loads
2279 shared libs like mad''.
2281 * ``gdbserver'' now supports multi-threaded applications on some targets
2283 Support for debugging multi-threaded applications which use
2284 the GNU/Linux LinuxThreads package has been added for
2285 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
2286 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
2288 * GDB now supports C/C++ preprocessor macros.
2290 GDB now expands preprocessor macro invocations in C/C++ expressions,
2291 and provides various commands for showing macro definitions and how
2294 The new command `macro expand EXPRESSION' expands any macro
2295 invocations in expression, and shows the result.
2297 The new command `show macro MACRO-NAME' shows the definition of the
2298 macro named MACRO-NAME, and where it was defined.
2300 Most compilers don't include information about macros in the debugging
2301 information by default. In GCC 3.1, for example, you need to compile
2302 your program with the options `-gdwarf-2 -g3'. If the macro
2303 information is present in the executable, GDB will read it.
2305 * Multi-arched targets.
2307 DEC Alpha (partial) alpha*-*-*
2308 DEC VAX (partial) vax-*-*
2310 National Semiconductor NS32000 (partial) ns32k-*-*
2311 Motorola 68000 (partial) m68k-*-*
2312 Motorola MCORE mcore-*-*
2316 Fujitsu FRV architecture added by Red Hat frv*-*-*
2319 * New native configurations
2321 Alpha NetBSD alpha*-*-netbsd*
2322 SH NetBSD sh*-*-netbsdelf*
2323 MIPS NetBSD mips*-*-netbsd*
2324 UltraSPARC NetBSD sparc64-*-netbsd*
2326 * OBSOLETE configurations and files
2328 Configurations that have been declared obsolete in this release have
2329 been commented out. Unless there is activity to revive these
2330 configurations, the next release of GDB will have their sources
2331 permanently REMOVED.
2333 Mitsubishi D30V d30v-*-*
2334 OS/9000 i[34]86-*-os9k
2335 IBM AIX PS/2 i[3456]86-*-aix
2336 Fujitsu FR30 fr30-*-elf*
2337 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2338 Argonaut Risc Chip (ARC) arc-*-*
2339 i386 running Mach 3.0 i[3456]86-*-mach3*
2340 i386 running Mach i[3456]86-*-mach*
2341 i386 running OSF/1 i[3456]86-*osf1mk*
2342 HP/Apollo 68k Family m68*-apollo*-sysv*,
2344 m68*-hp-bsd*, m68*-hp-hpux*
2345 I960 with MON960 i960-*-coff
2347 * OBSOLETE languages
2349 CHILL, a Pascal like language used by telecommunications companies.
2351 * REMOVED configurations and files
2353 AMD 29k family via UDI a29k-amd-udi, udi29k
2354 A29K VxWorks a29k-*-vxworks
2355 AMD 29000 embedded, using EBMON a29k-none-none
2356 AMD 29000 embedded with COFF a29k-none-coff
2357 AMD 29000 embedded with a.out a29k-none-aout
2359 testsuite/gdb.hp/gdb.threads-hp/ directory
2361 * New command "set max-user-call-depth <nnn>"
2363 This command allows the user to limit the call depth of user-defined
2364 commands. The default is 1024.
2366 * Changes in FreeBSD/i386 native debugging.
2368 Support for the "generate-core-file" has been added.
2370 * New commands "dump", "append", and "restore".
2372 These commands allow data to be copied from target memory
2373 to a bfd-format or binary file (dump and append), and back
2374 from a file into memory (restore).
2376 * Improved "next/step" support on multi-processor Alpha Tru64.
2378 The previous single-step mechanism could cause unpredictable problems,
2379 including the random appearance of SIGSEGV or SIGTRAP signals. The use
2380 of a software single-step mechanism prevents this.
2382 *** Changes in GDB 5.2.1:
2390 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
2391 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
2392 Fix, by Joel Brobecker imported from mainline.
2394 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
2395 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
2396 Fix, by Fred Fish, imported from mainline.
2398 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
2399 Surprisingly enough, it works now.
2400 By Michal Ludvig, imported from mainline.
2402 i386 hardware watchpoint support:
2403 avoid misses on second run for some targets.
2404 By Pierre Muller, imported from mainline.
2406 *** Changes in GDB 5.2:
2408 * New command "set trust-readonly-sections on[off]".
2410 This command is a hint that tells gdb that read-only sections
2411 really are read-only (ie. that their contents will not change).
2412 In this mode, gdb will go to the object file rather than the
2413 target to read memory from read-only sections (such as ".text").
2414 This can be a significant performance improvement on some
2415 (notably embedded) targets.
2417 * New command "generate-core-file" (or "gcore").
2419 This new gdb command allows the user to drop a core file of the child
2420 process state at any time. So far it's been implemented only for
2421 GNU/Linux and Solaris, but should be relatively easily ported to other
2422 hosts. Argument is core file name (defaults to core.<pid>).
2424 * New command line option
2426 GDB now accepts --pid or -p followed by a process id.
2428 * Change in command line behavior -- corefiles vs. process ids.
2430 There is a subtle behavior in the way in which GDB handles
2431 command line arguments. The first non-flag argument is always
2432 a program to debug, but the second non-flag argument may either
2433 be a corefile or a process id. Previously, GDB would attempt to
2434 open the second argument as a corefile, and if that failed, would
2435 issue a superfluous error message and then attempt to attach it as
2436 a process. Now, if the second argument begins with a non-digit,
2437 it will be treated as a corefile. If it begins with a digit,
2438 GDB will attempt to attach it as a process, and if no such process
2439 is found, will then attempt to open it as a corefile.
2441 * Changes in ARM configurations.
2443 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
2444 configuration is fully multi-arch.
2446 * New native configurations
2448 ARM NetBSD arm*-*-netbsd*
2449 x86 OpenBSD i[3456]86-*-openbsd*
2450 AMD x86-64 running GNU/Linux x86_64-*-linux-*
2451 Sparc64 running FreeBSD sparc64-*-freebsd*
2455 Sanyo XStormy16 xstormy16-elf
2457 * OBSOLETE configurations and files
2459 Configurations that have been declared obsolete in this release have
2460 been commented out. Unless there is activity to revive these
2461 configurations, the next release of GDB will have their sources
2462 permanently REMOVED.
2464 AMD 29k family via UDI a29k-amd-udi, udi29k
2465 A29K VxWorks a29k-*-vxworks
2466 AMD 29000 embedded, using EBMON a29k-none-none
2467 AMD 29000 embedded with COFF a29k-none-coff
2468 AMD 29000 embedded with a.out a29k-none-aout
2470 testsuite/gdb.hp/gdb.threads-hp/ directory
2472 * REMOVED configurations and files
2474 TI TMS320C80 tic80-*-*
2476 PowerPC Solaris powerpcle-*-solaris*
2477 PowerPC Windows NT powerpcle-*-cygwin32
2478 PowerPC Netware powerpc-*-netware*
2479 Harris/CXUX m88k m88*-harris-cxux*
2480 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
2481 ns32k-utek-sysv* ns32k-utek-*
2482 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
2483 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
2484 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
2485 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
2486 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
2488 * Changes to command line processing
2490 The new `--args' feature can be used to specify command-line arguments
2491 for the inferior from gdb's command line.
2493 * Changes to key bindings
2495 There is a new `operate-and-get-next' function bound to `C-o'.
2497 *** Changes in GDB 5.1.1
2499 Fix compile problem on DJGPP.
2501 Fix a problem with floating-point registers on the i386 being
2504 Fix to stop GDB crashing on .debug_str debug info.
2506 Numerous documentation fixes.
2508 Numerous testsuite fixes.
2510 *** Changes in GDB 5.1:
2512 * New native configurations
2514 Alpha FreeBSD alpha*-*-freebsd*
2515 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
2516 MIPS GNU/Linux mips*-*-linux*
2517 MIPS SGI Irix 6.x mips*-sgi-irix6*
2518 ia64 AIX ia64-*-aix*
2519 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
2523 Motorola 68HC11 and 68HC12 m68hc11-elf
2525 UltraSparc running GNU/Linux sparc64-*-linux*
2527 * OBSOLETE configurations and files
2529 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
2530 Harris/CXUX m88k m88*-harris-cxux*
2531 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
2532 ns32k-utek-sysv* ns32k-utek-*
2533 TI TMS320C80 tic80-*-*
2535 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
2536 PowerPC Solaris powerpcle-*-solaris*
2537 PowerPC Windows NT powerpcle-*-cygwin32
2538 PowerPC Netware powerpc-*-netware*
2539 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
2540 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
2541 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
2542 Apple Macintosh (MPW) host N/A
2544 stuff.c (Program to stuff files into a specially prepared space in kdb)
2545 kdb-start.c (Main loop for the standalone kernel debugger)
2547 Configurations that have been declared obsolete in this release have
2548 been commented out. Unless there is activity to revive these
2549 configurations, the next release of GDB will have their sources
2550 permanently REMOVED.
2552 * REMOVED configurations and files
2554 Altos 3068 m68*-altos-*
2555 Convex c1-*-*, c2-*-*
2557 ARM RISCix arm-*-* (as host)
2561 * GDB has been converted to ISO C.
2563 GDB's source code has been converted to ISO C. In particular, the
2564 sources are fully protoized, and rely on standard headers being
2569 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
2571 * The MI enabled by default.
2573 The new machine oriented interface (MI) introduced in GDB 5.0 has been
2574 revised and enabled by default. Packages which use GDB as a debugging
2575 engine behind a UI or another front end are encouraged to switch to
2576 using the GDB/MI interface, instead of the old annotations interface
2577 which is now deprecated.
2579 * Support for debugging Pascal programs.
2581 GDB now includes support for debugging Pascal programs. The following
2582 main features are supported:
2584 - Pascal-specific data types such as sets;
2586 - automatic recognition of Pascal sources based on file-name
2589 - Pascal-style display of data types, variables, and functions;
2591 - a Pascal expression parser.
2593 However, some important features are not yet supported.
2595 - Pascal string operations are not supported at all;
2597 - there are some problems with boolean types;
2599 - Pascal type hexadecimal constants are not supported
2600 because they conflict with the internal variables format;
2602 - support for Pascal objects and classes is not full yet;
2604 - unlike Pascal, GDB is case-sensitive for symbol names.
2606 * Changes in completion.
2608 Commands such as `shell', `run' and `set args', which pass arguments
2609 to inferior programs, now complete on file names, similar to what
2610 users expect at the shell prompt.
2612 Commands which accept locations, such as `disassemble', `print',
2613 `breakpoint', `until', etc. now complete on filenames as well as
2614 program symbols. Thus, if you type "break foob TAB", and the source
2615 files linked into the programs include `foobar.c', that file name will
2616 be one of the candidates for completion. However, file names are not
2617 considered for completion after you typed a colon that delimits a file
2618 name from a name of a function in that file, as in "break foo.c:bar".
2620 `set demangle-style' completes on available demangling styles.
2622 * New platform-independent commands:
2624 It is now possible to define a post-hook for a command as well as a
2625 hook that runs before the command. For more details, see the
2626 documentation of `hookpost' in the GDB manual.
2628 * Changes in GNU/Linux native debugging.
2630 Support for debugging multi-threaded programs has been completely
2631 revised for all platforms except m68k and sparc. You can now debug as
2632 many threads as your system allows you to have.
2634 Attach/detach is supported for multi-threaded programs.
2636 Support for SSE registers was added for x86. This doesn't work for
2637 multi-threaded programs though.
2639 * Changes in MIPS configurations.
2641 Multi-arch support is enabled for all MIPS configurations.
2643 GDB can now be built as native debugger on SGI Irix 6.x systems for
2644 debugging n32 executables. (Debugging 64-bit executables is not yet
2647 * Unified support for hardware watchpoints in all x86 configurations.
2649 Most (if not all) native x86 configurations support hardware-assisted
2650 breakpoints and watchpoints in a unified manner. This support
2651 implements debug register sharing between watchpoints, which allows to
2652 put a virtually infinite number of watchpoints on the same address,
2653 and also supports watching regions up to 16 bytes with several debug
2656 The new maintenance command `maintenance show-debug-regs' toggles
2657 debugging print-outs in functions that insert, remove, and test
2658 watchpoints and hardware breakpoints.
2660 * Changes in the DJGPP native configuration.
2662 New command ``info dos sysinfo'' displays assorted information about
2663 the CPU, OS, memory, and DPMI server.
2665 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
2666 display information about segment descriptors stored in GDT, LDT, and
2669 New commands ``info dos pde'' and ``info dos pte'' display entries
2670 from Page Directory and Page Tables (for now works with CWSDPMI only).
2671 New command ``info dos address-pte'' displays the Page Table entry for
2672 a given linear address.
2674 GDB can now pass command lines longer than 126 characters to the
2675 program being debugged (requires an update to the libdbg.a library
2676 which is part of the DJGPP development kit).
2678 DWARF2 debug info is now supported.
2680 It is now possible to `step' and `next' through calls to `longjmp'.
2682 * Changes in documentation.
2684 All GDB documentation was converted to GFDL, the GNU Free
2685 Documentation License.
2687 Tracepoints-related commands are now fully documented in the GDB
2690 TUI, the Text-mode User Interface, is now documented in the manual.
2692 Tracepoints-related commands are now fully documented in the GDB
2695 The "GDB Internals" manual now has an index. It also includes
2696 documentation of `ui_out' functions, GDB coding standards, x86
2697 hardware watchpoints, and memory region attributes.
2699 * GDB's version number moved to ``version.in''
2701 The Makefile variable VERSION has been replaced by the file
2702 ``version.in''. People creating GDB distributions should update the
2703 contents of this file.
2707 GUD support is now a standard part of the EMACS distribution.
2709 *** Changes in GDB 5.0:
2711 * Improved support for debugging FP programs on x86 targets
2713 Unified and much-improved support for debugging floating-point
2714 programs on all x86 targets. In particular, ``info float'' now
2715 displays the FP registers in the same format on all x86 targets, with
2716 greater level of detail.
2718 * Improvements and bugfixes in hardware-assisted watchpoints
2720 It is now possible to watch array elements, struct members, and
2721 bitfields with hardware-assisted watchpoints. Data-read watchpoints
2722 on x86 targets no longer erroneously trigger when the address is
2725 * Improvements in the native DJGPP version of GDB
2727 The distribution now includes all the scripts and auxiliary files
2728 necessary to build the native DJGPP version on MS-DOS/MS-Windows
2729 machines ``out of the box''.
2731 The DJGPP version can now debug programs that use signals. It is
2732 possible to catch signals that happened in the debuggee, deliver
2733 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
2734 would kill the program being debugged.) Programs that hook hardware
2735 interrupts (keyboard, timer, etc.) can also be debugged.
2737 It is now possible to debug DJGPP programs that redirect their
2738 standard handles or switch them to raw (as opposed to cooked) mode, or
2739 even close them. The command ``run < foo > bar'' works as expected,
2740 and ``info terminal'' reports useful information about the debuggee's
2741 terminal, including raw/cooked mode, redirection, etc.
2743 The DJGPP version now uses termios functions for console I/O, which
2744 enables debugging graphics programs. Interrupting GDB with Ctrl-C
2747 DOS-style file names with drive letters are now fully supported by
2750 It is now possible to debug DJGPP programs that switch their working
2751 directory. It is also possible to rerun the debuggee any number of
2752 times without restarting GDB; thus, you can use the same setup,
2753 breakpoints, etc. for many debugging sessions.
2755 * New native configurations
2757 ARM GNU/Linux arm*-*-linux*
2758 PowerPC GNU/Linux powerpc-*-linux*
2762 Motorola MCore mcore-*-*
2763 x86 VxWorks i[3456]86-*-vxworks*
2764 PowerPC VxWorks powerpc-*-vxworks*
2765 TI TMS320C80 tic80-*-*
2767 * OBSOLETE configurations
2769 Altos 3068 m68*-altos-*
2770 Convex c1-*-*, c2-*-*
2772 ARM RISCix arm-*-* (as host)
2775 Configurations that have been declared obsolete will be commented out,
2776 but the code will be left in place. If there is no activity to revive
2777 these configurations before the next release of GDB, the sources will
2778 be permanently REMOVED.
2780 * Gould support removed
2782 Support for the Gould PowerNode and NP1 has been removed.
2784 * New features for SVR4
2786 On SVR4 native platforms (such as Solaris), if you attach to a process
2787 without first loading a symbol file, GDB will now attempt to locate and
2788 load symbols from the running process's executable file.
2790 * Many C++ enhancements
2792 C++ support has been greatly improved. Overload resolution now works properly
2793 in almost all cases. RTTI support is on the way.
2795 * Remote targets can connect to a sub-program
2797 A popen(3) style serial-device has been added. This device starts a
2798 sub-process (such as a stand-alone simulator) and then communicates
2799 with that. The sub-program to run is specified using the syntax
2800 ``|<program> <args>'' vis:
2802 (gdb) set remotedebug 1
2803 (gdb) target extended-remote |mn10300-elf-sim program-args
2805 * MIPS 64 remote protocol
2807 A long standing bug in the mips64 remote protocol where by GDB
2808 expected certain 32 bit registers (ex SR) to be transfered as 32
2809 instead of 64 bits has been fixed.
2811 The command ``set remote-mips64-transfers-32bit-regs on'' has been
2812 added to provide backward compatibility with older versions of GDB.
2814 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
2816 The command ``set remotebinarydownload'' command has been replaced by
2817 ``set remote X-packet''. Other commands in ``set remote'' family
2818 include ``set remote P-packet''.
2820 * Breakpoint commands accept ranges.
2822 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
2823 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
2824 ``tracepoint passcount'' also accepts a range of tracepoints.
2826 * ``apropos'' command added.
2828 The ``apropos'' command searches through command names and
2829 documentation strings, printing out matches, making it much easier to
2830 try to find a command that does what you are looking for.
2834 A new machine oriented interface (MI) has been added to GDB. This
2835 interface is designed for debug environments running GDB as a separate
2836 process. This is part of the long term libGDB project. See the
2837 "GDB/MI" chapter of the GDB manual for further information. It can be
2838 enabled by configuring with:
2840 .../configure --enable-gdbmi
2842 *** Changes in GDB-4.18:
2844 * New native configurations
2846 HP-UX 10.20 hppa*-*-hpux10.20
2847 HP-UX 11.x hppa*-*-hpux11.0*
2848 M68K GNU/Linux m68*-*-linux*
2852 Fujitsu FR30 fr30-*-elf*
2853 Intel StrongARM strongarm-*-*
2854 Mitsubishi D30V d30v-*-*
2856 * OBSOLETE configurations
2858 Gould PowerNode, NP1 np1-*-*, pn-*-*
2860 Configurations that have been declared obsolete will be commented out,
2861 but the code will be left in place. If there is no activity to revive
2862 these configurations before the next release of GDB, the sources will
2863 be permanently REMOVED.
2867 As a compatibility experiment, GDB's source files buildsym.h and
2868 buildsym.c have been converted to pure standard C, no longer
2869 containing any K&R compatibility code. We believe that all systems in
2870 use today either come with a standard C compiler, or have a GCC port
2871 available. If this is not true, please report the affected
2872 configuration to bug-gdb@gnu.org immediately. See the README file for
2873 information about getting a standard C compiler if you don't have one
2878 GDB now uses readline 2.2.
2880 * set extension-language
2882 You can now control the mapping between filename extensions and source
2883 languages by using the `set extension-language' command. For instance,
2884 you can ask GDB to treat .c files as C++ by saying
2885 set extension-language .c c++
2886 The command `info extensions' lists all of the recognized extensions
2887 and their associated languages.
2889 * Setting processor type for PowerPC and RS/6000
2891 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
2892 you can use the `set processor' command to specify what variant of the
2893 PowerPC family you are debugging. The command
2897 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
2898 following PowerPC and RS6000 variants:
2900 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
2901 rs6000 IBM RS6000 ("POWER") architecture, user-level view
2903 403GC IBM PowerPC 403GC
2904 505 Motorola PowerPC 505
2905 860 Motorola PowerPC 860 or 850
2906 601 Motorola PowerPC 601
2907 602 Motorola PowerPC 602
2908 603 Motorola/IBM PowerPC 603 or 603e
2909 604 Motorola PowerPC 604 or 604e
2910 750 Motorola/IBM PowerPC 750 or 750
2912 At the moment, this command just tells GDB what to name the
2913 special-purpose processor registers. Since almost all the affected
2914 registers are inaccessible to user-level programs, this command is
2915 only useful for remote debugging in its present form.
2919 Thanks to a major code donation from Hewlett-Packard, GDB now has much
2920 more extensive support for HP-UX. Added features include shared
2921 library support, kernel threads and hardware watchpoints for 11.00,
2922 support for HP's ANSI C and C++ compilers, and a compatibility mode
2923 for xdb and dbx commands.
2927 HP's donation includes the new concept of catchpoints, which is a
2928 generalization of the old catch command. On HP-UX, it is now possible
2929 to catch exec, fork, and vfork, as well as library loading.
2931 This means that the existing catch command has changed; its first
2932 argument now specifies the type of catch to be set up. See the
2933 output of "help catch" for a list of catchpoint types.
2935 * Debugging across forks
2937 On HP-UX, you can choose which process to debug when a fork() happens
2942 HP has donated a curses-based terminal user interface (TUI). To get
2943 it, build with --enable-tui. Although this can be enabled for any
2944 configuration, at present it only works for native HP debugging.
2946 * GDB remote protocol additions
2948 A new protocol packet 'X' that writes binary data is now available.
2949 Default behavior is to try 'X', then drop back to 'M' if the stub
2950 fails to respond. The settable variable `remotebinarydownload'
2951 allows explicit control over the use of 'X'.
2953 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
2954 full 64-bit address. The command
2956 set remoteaddresssize 32
2958 can be used to revert to the old behaviour. For existing remote stubs
2959 the change should not be noticed, as the additional address information
2962 In order to assist in debugging stubs, you may use the maintenance
2963 command `packet' to send any text string to the stub. For instance,
2965 maint packet heythere
2967 sends the packet "$heythere#<checksum>". Note that it is very easy to
2968 disrupt a debugging session by sending the wrong packet at the wrong
2971 The compare-sections command allows you to compare section data on the
2972 target to what is in the executable file without uploading or
2973 downloading, by comparing CRC checksums.
2975 * Tracing can collect general expressions
2977 You may now collect general expressions at tracepoints. This requires
2978 further additions to the target-side stub; see tracepoint.c and
2979 doc/agentexpr.texi for further details.
2981 * mask-address variable for Mips
2983 For Mips targets, you may control the zeroing of the upper 32 bits of
2984 a 64-bit address by entering `set mask-address on'. This is mainly
2985 of interest to users of embedded R4xxx and R5xxx processors.
2987 * Higher serial baud rates
2989 GDB's serial code now allows you to specify baud rates 57600, 115200,
2990 230400, and 460800 baud. (Note that your host system may not be able
2991 to achieve all of these rates.)
2995 The i960 configuration now includes an initial implementation of a
2996 builtin simulator, contributed by Jim Wilson.
2999 *** Changes in GDB-4.17:
3001 * New native configurations
3003 Alpha GNU/Linux alpha*-*-linux*
3004 Unixware 2.x i[3456]86-unixware2*
3005 Irix 6.x mips*-sgi-irix6*
3006 PowerPC GNU/Linux powerpc-*-linux*
3007 PowerPC Solaris powerpcle-*-solaris*
3008 Sparc GNU/Linux sparc-*-linux*
3009 Motorola sysV68 R3V7.1 m68k-motorola-sysv
3013 Argonaut Risc Chip (ARC) arc-*-*
3014 Hitachi H8/300S h8300*-*-*
3015 Matsushita MN10200 w/simulator mn10200-*-*
3016 Matsushita MN10300 w/simulator mn10300-*-*
3017 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
3018 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
3019 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
3020 Mitsubishi D10V w/simulator d10v-*-*
3021 Mitsubishi M32R/D w/simulator m32r-*-elf*
3022 Tsqware Sparclet sparclet-*-*
3023 NEC V850 w/simulator v850-*-*
3025 * New debugging protocols
3027 ARM with RDI protocol arm*-*-*
3028 M68K with dBUG monitor m68*-*-{aout,coff,elf}
3029 DDB and LSI variants of PMON protocol mips*-*-*
3030 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
3031 PowerPC with SDS protocol powerpc{,le}-*-eabi
3032 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
3036 All configurations can now understand and use the DWARF 2 debugging
3037 format. The choice is automatic, if the symbol file contains DWARF 2
3042 GDB now includes basic Java language support. This support is
3043 only useful with Java compilers that produce native machine code.
3045 * solib-absolute-prefix and solib-search-path
3047 For SunOS and SVR4 shared libraries, you may now set the prefix for
3048 loading absolute shared library symbol files, and the search path for
3049 locating non-absolute shared library symbol files.
3051 * Live range splitting
3053 GDB can now effectively debug code for which GCC has performed live
3054 range splitting as part of its optimization. See gdb/doc/LRS for
3055 more details on the expected format of the stabs information.
3059 GDB's support for the GNU Hurd, including thread debugging, has been
3060 updated to work with current versions of the Hurd.
3064 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
3065 instruction set. ARM GDB automatically detects when Thumb
3066 instructions are in use, and adjusts disassembly and backtracing
3071 GDB's MIPS target configurations now handle the MIP16 16-bit
3076 GDB now includes support for overlays; if an executable has been
3077 linked such that multiple sections are based at the same address, GDB
3078 will decide which section to use for symbolic info. You can choose to
3079 control the decision manually, using overlay commands, or implement
3080 additional target-side support and use "overlay load-target" to bring
3081 in the overlay mapping. Do "help overlay" for more detail.
3085 The command "info symbol <address>" displays information about
3086 the symbol at the specified address.
3090 The standard remote protocol now includes an extension that allows
3091 asynchronous collection and display of trace data. This requires
3092 extensive support in the target-side debugging stub. Tracing mode
3093 includes a new interaction mode in GDB and new commands: see the
3094 file tracepoint.c for more details.
3098 Configurations for embedded MIPS now include a simulator contributed
3099 by Cygnus Solutions. The simulator supports the instruction sets
3100 of most MIPS variants.
3104 Sparc configurations may now include the ERC32 simulator contributed
3105 by the European Space Agency. The simulator is not built into
3106 Sparc targets by default; configure with --enable-sim to include it.
3110 For target configurations that may include multiple variants of a
3111 basic architecture (such as MIPS and SH), you may now set the
3112 architecture explicitly. "set arch" sets, "info arch" lists
3113 the possible architectures.
3115 *** Changes in GDB-4.16:
3117 * New native configurations
3119 Windows 95, x86 Windows NT i[345]86-*-cygwin32
3120 M68K NetBSD m68k-*-netbsd*
3121 PowerPC AIX 4.x powerpc-*-aix*
3122 PowerPC MacOS powerpc-*-macos*
3123 PowerPC Windows NT powerpcle-*-cygwin32
3124 RS/6000 AIX 4.x rs6000-*-aix4*
3128 ARM with RDP protocol arm-*-*
3129 I960 with MON960 i960-*-coff
3130 MIPS VxWorks mips*-*-vxworks*
3131 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
3132 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
3134 Matra Sparclet sparclet-*-*
3138 The powerpc-eabi configuration now includes the PSIM simulator,
3139 contributed by Andrew Cagney, with assistance from Mike Meissner.
3140 PSIM is a very elaborate model of the PowerPC, including not only
3141 basic instruction set execution, but also details of execution unit
3142 performance and I/O hardware. See sim/ppc/README for more details.
3146 GDB now works with Solaris 2.5.
3148 * Windows 95/NT native
3150 GDB will now work as a native debugger on Windows 95 and Windows NT.
3151 To build it from source, you must use the "gnu-win32" environment,
3152 which uses a DLL to emulate enough of Unix to run the GNU tools.
3153 Further information, binaries, and sources are available at
3154 ftp.cygnus.com, under pub/gnu-win32.
3156 * dont-repeat command
3158 If a user-defined command includes the command `dont-repeat', then the
3159 command will not be repeated if the user just types return. This is
3160 useful if the command is time-consuming to run, so that accidental
3161 extra keystrokes don't run the same command many times.
3163 * Send break instead of ^C
3165 The standard remote protocol now includes an option to send a break
3166 rather than a ^C to the target in order to interrupt it. By default,
3167 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
3169 * Remote protocol timeout
3171 The standard remote protocol includes a new variable `remotetimeout'
3172 that allows you to set the number of seconds before GDB gives up trying
3173 to read from the target. The default value is 2.
3175 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
3177 By default GDB will automatically keep track of objects as they are
3178 loaded and unloaded by the dynamic linker. By using the command `set
3179 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
3180 when shared library events occur, thus allowing you to set breakpoints
3181 in shared libraries which are explicitly loaded by the inferior.
3183 Note this feature does not work on hpux8. On hpux9 you must link
3184 /usr/lib/end.o into your program. This feature should work
3185 automatically on hpux10.
3187 * Irix 5.x hardware watchpoint support
3189 Irix 5 configurations now support the use of hardware watchpoints.
3191 * Mips protocol "SYN garbage limit"
3193 When debugging a Mips target using the `target mips' protocol, you
3194 may set the number of characters that GDB will ignore by setting
3195 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
3196 every character. The default value is 1050.
3198 * Recording and replaying remote debug sessions
3200 If you set `remotelogfile' to the name of a file, gdb will write to it
3201 a recording of a remote debug session. This recording may then be
3202 replayed back to gdb using "gdbreplay". See gdbserver/README for
3203 details. This is useful when you have a problem with GDB while doing
3204 remote debugging; you can make a recording of the session and send it
3205 to someone else, who can then recreate the problem.
3207 * Speedups for remote debugging
3209 GDB includes speedups for downloading and stepping MIPS systems using
3210 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
3211 and more efficient S-record downloading.
3213 * Memory use reductions and statistics collection
3215 GDB now uses less memory and reports statistics about memory usage.
3216 Try the `maint print statistics' command, for example.
3218 *** Changes in GDB-4.15:
3220 * Psymtabs for XCOFF
3222 The symbol reader for AIX GDB now uses partial symbol tables. This
3223 can greatly improve startup time, especially for large executables.
3225 * Remote targets use caching
3227 Remote targets now use a data cache to speed up communication with the
3228 remote side. The data cache could lead to incorrect results because
3229 it doesn't know about volatile variables, thus making it impossible to
3230 debug targets which use memory mapped I/O devices. `set remotecache
3231 off' turns the the data cache off.
3233 * Remote targets may have threads
3235 The standard remote protocol now includes support for multiple threads
3236 in the target system, using new protocol commands 'H' and 'T'. See
3237 gdb/remote.c for details.
3241 If GDB is configured with `--enable-netrom', then it will include
3242 support for the NetROM ROM emulator from XLNT Designs. The NetROM
3243 acts as though it is a bank of ROM on the target board, but you can
3244 write into it over the network. GDB's support consists only of
3245 support for fast loading into the emulated ROM; to debug, you must use
3246 another protocol, such as standard remote protocol. The usual
3247 sequence is something like
3249 target nrom <netrom-hostname>
3251 target remote <netrom-hostname>:1235
3255 GDB now includes support for the Apple Macintosh, as a host only. It
3256 may be run as either an MPW tool or as a standalone application, and
3257 it can debug through the serial port. All the usual GDB commands are
3258 available, but to the target command, you must supply "serial" as the
3259 device type instead of "/dev/ttyXX". See mpw-README in the main
3260 directory for more information on how to build. The MPW configuration
3261 scripts */mpw-config.in support only a few targets, and only the
3262 mips-idt-ecoff target has been tested.
3266 GDB configuration now uses autoconf. This is not user-visible,
3267 but does simplify configuration and building.
3271 GDB now supports hpux10.
3273 *** Changes in GDB-4.14:
3275 * New native configurations
3277 x86 FreeBSD i[345]86-*-freebsd
3278 x86 NetBSD i[345]86-*-netbsd
3279 NS32k NetBSD ns32k-*-netbsd
3280 Sparc NetBSD sparc-*-netbsd
3284 A29K VxWorks a29k-*-vxworks
3285 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
3286 CPU32 EST-300 emulator m68*-*-est*
3287 PowerPC ELF powerpc-*-elf
3290 * Alpha OSF/1 support for procfs
3292 GDB now supports procfs under OSF/1-2.x and higher, which makes it
3293 possible to attach to running processes. As the mounting of the /proc
3294 filesystem is optional on the Alpha, GDB automatically determines
3295 the availability of /proc during startup. This can lead to problems
3296 if /proc is unmounted after GDB has been started.
3298 * Arguments to user-defined commands
3300 User commands may accept up to 10 arguments separated by whitespace.
3301 Arguments are accessed within the user command via $arg0..$arg9. A
3304 print $arg0 + $arg1 + $arg2
3306 To execute the command use:
3309 Defines the command "adder" which prints the sum of its three arguments.
3310 Note the arguments are text substitutions, so they may reference variables,
3311 use complex expressions, or even perform inferior function calls.
3313 * New `if' and `while' commands
3315 This makes it possible to write more sophisticated user-defined
3316 commands. Both commands take a single argument, which is the
3317 expression to evaluate, and must be followed by the commands to
3318 execute, one per line, if the expression is nonzero, the list being
3319 terminated by the word `end'. The `if' command list may include an
3320 `else' word, which causes the following commands to be executed only
3321 if the expression is zero.
3323 * Fortran source language mode
3325 GDB now includes partial support for Fortran 77. It will recognize
3326 Fortran programs and can evaluate a subset of Fortran expressions, but
3327 variables and functions may not be handled correctly. GDB will work
3328 with G77, but does not yet know much about symbols emitted by other
3331 * Better HPUX support
3333 Most debugging facilities now work on dynamic executables for HPPAs
3334 running hpux9 or later. You can attach to running dynamically linked
3335 processes, but by default the dynamic libraries will be read-only, so
3336 for instance you won't be able to put breakpoints in them. To change
3337 that behavior do the following before running the program:
3343 This will cause the libraries to be mapped private and read-write.
3344 To revert to the normal behavior, do this:
3350 You cannot set breakpoints or examine data in the library until after
3351 the library is loaded if the function/data symbols do not have
3354 GDB can now also read debug symbols produced by the HP C compiler on
3355 HPPAs (sorry, no C++, Fortran or 68k support).
3357 * Target byte order now dynamically selectable
3359 You can choose which byte order to use with a target system, via the
3360 commands "set endian big" and "set endian little", and you can see the
3361 current setting by using "show endian". You can also give the command
3362 "set endian auto", in which case GDB will use the byte order
3363 associated with the executable. Currently, only embedded MIPS
3364 configurations support dynamic selection of target byte order.
3366 * New DOS host serial code
3368 This version uses DPMI interrupts to handle buffered I/O, so you
3369 no longer need to run asynctsr when debugging boards connected to
3372 *** Changes in GDB-4.13:
3374 * New "complete" command
3376 This lists all the possible completions for the rest of the line, if it
3377 were to be given as a command itself. This is intended for use by emacs.
3379 * Trailing space optional in prompt
3381 "set prompt" no longer adds a space for you after the prompt you set. This
3382 allows you to set a prompt which ends in a space or one that does not.
3384 * Breakpoint hit counts
3386 "info break" now displays a count of the number of times the breakpoint
3387 has been hit. This is especially useful in conjunction with "ignore"; you
3388 can ignore a large number of breakpoint hits, look at the breakpoint info
3389 to see how many times the breakpoint was hit, then run again, ignoring one
3390 less than that number, and this will get you quickly to the last hit of
3393 * Ability to stop printing at NULL character
3395 "set print null-stop" will cause GDB to stop printing the characters of
3396 an array when the first NULL is encountered. This is useful when large
3397 arrays actually contain only short strings.
3399 * Shared library breakpoints
3401 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
3402 breakpoints in shared libraries before the executable is run.
3404 * Hardware watchpoints
3406 There is a new hardware breakpoint for the watch command for sparclite
3407 targets. See gdb/sparclite/hw_breakpoint.note.
3409 Hardware watchpoints are also now supported under GNU/Linux.
3413 Annotations have been added. These are for use with graphical interfaces,
3414 and are still experimental. Currently only gdba.el uses these.
3416 * Improved Irix 5 support
3418 GDB now works properly with Irix 5.2.
3420 * Improved HPPA support
3422 GDB now works properly with the latest GCC and GAS.
3424 * New native configurations
3426 Sequent PTX4 i[34]86-sequent-ptx4
3427 HPPA running OSF/1 hppa*-*-osf*
3428 Atari TT running SVR4 m68*-*-sysv4*
3429 RS/6000 LynxOS rs6000-*-lynxos*
3433 OS/9000 i[34]86-*-os9k
3434 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
3437 * Hitachi SH7000 and E7000-PC ICE support
3439 There is now support for communicating with the Hitachi E7000-PC ICE.
3440 This is available automatically when GDB is configured for the SH.
3444 As usual, a variety of small fixes and improvements, both generic
3445 and configuration-specific. See the ChangeLog for more detail.
3447 *** Changes in GDB-4.12:
3449 * Irix 5 is now supported
3453 GDB-4.12 on the HPPA has a number of changes which make it unable
3454 to debug the output from the currently released versions of GCC and
3455 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
3456 of GCC and GAS, versions of these tools designed to work with GDB-4.12
3457 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
3460 *** Changes in GDB-4.11:
3462 * User visible changes:
3466 The "set remotedebug" option is now consistent between the mips remote
3467 target, remote targets using the gdb-specific protocol, UDI (AMD's
3468 debug protocol for the 29k) and the 88k bug monitor. It is now an
3469 integer specifying a debug level (normally 0 or 1, but 2 means more
3470 debugging info for the mips target).
3472 * DEC Alpha native support
3474 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
3475 debug info, but GDB works fairly well with the DEC compiler and should
3476 work with a future GCC release. See the README file for a few
3477 Alpha-specific notes.
3479 * Preliminary thread implementation
3481 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
3483 * LynxOS native and target support for 386
3485 This release has been hosted on LynxOS 2.2, and also can be configured
3486 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
3489 * Improvements in C++ mangling/demangling.
3491 This release has much better g++ debugging, specifically in name
3492 mangling/demangling, virtual function calls, print virtual table,
3493 call methods, ...etc.
3495 *** Changes in GDB-4.10:
3497 * User visible changes:
3499 Remote debugging using the GDB-specific (`target remote') protocol now
3500 supports the `load' command. This is only useful if you have some
3501 other way of getting the stub to the target system, and you can put it
3502 somewhere in memory where it won't get clobbered by the download.
3504 Filename completion now works.
3506 When run under emacs mode, the "info line" command now causes the
3507 arrow to point to the line specified. Also, "info line" prints
3508 addresses in symbolic form (as well as hex).
3510 All vxworks based targets now support a user settable option, called
3511 vxworks-timeout. This option represents the number of seconds gdb
3512 should wait for responses to rpc's. You might want to use this if
3513 your vxworks target is, perhaps, a slow software simulator or happens
3514 to be on the far side of a thin network line.
3518 This release contains support for using a DEC alpha as a GDB host for
3519 cross debugging. Native alpha debugging is not supported yet.
3522 *** Changes in GDB-4.9:
3526 This is the first GDB release which is accompanied by a matching testsuite.
3527 The testsuite requires installation of dejagnu, which should be available
3528 via ftp from most sites that carry GNU software.
3532 'Cfront' style demangling has had its name changed to 'ARM' style, to
3533 emphasize that it was written from the specifications in the C++ Annotated
3534 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
3535 disclaimers, it still generated too much confusion with users attempting to
3536 use gdb with AT&T cfront.
3540 GDB now uses a standard remote interface to a simulator library.
3541 So far, the library contains simulators for the Zilog Z8001/2, the
3542 Hitachi H8/300, H8/500 and Super-H.
3544 * New targets supported
3546 H8/300 simulator h8300-hitachi-hms or h8300hms
3547 H8/500 simulator h8500-hitachi-hms or h8500hms
3548 SH simulator sh-hitachi-hms or sh
3549 Z8000 simulator z8k-zilog-none or z8ksim
3550 IDT MIPS board over serial line mips-idt-ecoff
3552 Cross-debugging to GO32 targets is supported. It requires a custom
3553 version of the i386-stub.c module which is integrated with the
3554 GO32 memory extender.
3556 * New remote protocols
3558 MIPS remote debugging protocol.
3560 * New source languages supported
3562 This version includes preliminary support for Chill, a Pascal like language
3563 used by telecommunications companies. Chill support is also being integrated
3564 into the GNU compiler, but we don't know when it will be publically available.
3567 *** Changes in GDB-4.8:
3569 * HP Precision Architecture supported
3571 GDB now supports HP PA-RISC machines running HPUX. A preliminary
3572 version of this support was available as a set of patches from the
3573 University of Utah. GDB does not support debugging of programs
3574 compiled with the HP compiler, because HP will not document their file
3575 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
3576 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
3578 Many problems in the preliminary version have been fixed.
3580 * Faster and better demangling
3582 We have improved template demangling and fixed numerous bugs in the GNU style
3583 demangler. It can now handle type modifiers such as `static' or `const'. Wide
3584 character types (wchar_t) are now supported. Demangling of each symbol is now
3585 only done once, and is cached when the symbol table for a file is read in.
3586 This results in a small increase in memory usage for C programs, a moderate
3587 increase in memory usage for C++ programs, and a fantastic speedup in
3590 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
3591 from the specifications in the Annotated Reference Manual, which AT&T's
3592 compiler does not actually implement.
3594 * G++ multiple inheritance compiler problem
3596 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
3597 inheritance lattices was reworked to properly discover ambiguities. We
3598 recently found an example which causes this new algorithm to fail in a
3599 very subtle way, producing bad debug information for those classes.
3600 The file 'gcc.patch' (in this directory) can be applied to gcc to
3601 circumvent the problem. A future GCC release will contain a complete
3604 The previous G++ debug info problem (mentioned below for the gdb-4.7
3605 release) is fixed in gcc version 2.3.2.
3607 * Improved configure script
3609 The `configure' script will now attempt to guess your system type if
3610 you don't supply a host system type. The old scheme of supplying a
3611 host system triplet is preferable over using this. All the magic is
3612 done in the new `config.guess' script. Examine it for details.
3614 We have also brought our configure script much more in line with the FSF's
3615 version. It now supports the --with-xxx options. In particular,
3616 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
3617 The resulting GDB will not be able to read arbitrary object file formats --
3618 only the format ``expected'' to be used on the configured target system.
3619 We hope to make this the default in a future release.
3621 * Documentation improvements
3623 There's new internal documentation on how to modify GDB, and how to
3624 produce clean changes to the code. We implore people to read it
3625 before submitting changes.
3627 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
3628 M4 macros. The new texinfo.tex is provided in this release. Pre-built
3629 `info' files are also provided. To build `info' files from scratch,
3630 you will need the latest `makeinfo' release, which will be available in
3631 a future texinfo-X.Y release.
3633 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
3634 We're not sure exactly which versions have this problem, but it has
3635 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
3636 or better. If that isn't possible, there is a patch in
3637 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
3638 around this problem.
3642 GDB now supports array constants that can be used in expressions typed in by
3643 the user. The syntax is `{element, element, ...}'. Ie: you can now type
3644 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
3647 The new directory `gdb/sparclite' contains a program that demonstrates
3648 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
3650 * New native hosts supported
3652 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
3653 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
3655 * New targets supported
3657 AMD 29k family via UDI a29k-amd-udi or udi29k
3659 * New file formats supported
3661 BFD now supports reading HP/PA-RISC executables (SOM file format?),
3662 HPUX core files, and SCO 3.2v2 core files.
3666 Attaching to processes now works again; thanks for the many bug reports.
3668 We have also stomped on a bunch of core dumps caused by
3669 printf_filtered("%s") problems.
3671 We eliminated a copyright problem on the rpc and ptrace header files
3672 for VxWorks, which was discovered at the last minute during the 4.7
3673 release. You should now be able to build a VxWorks GDB.
3675 You can now interrupt gdb while an attached process is running. This
3676 will cause the attached process to stop, and give control back to GDB.
3678 We fixed problems caused by using too many file descriptors
3679 for reading symbols from object files and libraries. This was
3680 especially a problem for programs that used many (~100) shared
3683 The `step' command now only enters a subroutine if there is line number
3684 information for the subroutine. Otherwise it acts like the `next'
3685 command. Previously, `step' would enter subroutines if there was
3686 any debugging information about the routine. This avoids problems
3687 when using `cc -g1' on MIPS machines.
3689 * Internal improvements
3691 GDB's internal interfaces have been improved to make it easier to support
3692 debugging of multiple languages in the future.
3694 GDB now uses a common structure for symbol information internally.
3695 Minimal symbols (derived from linkage symbols in object files), partial
3696 symbols (from a quick scan of debug information), and full symbols
3697 contain a common subset of information, making it easier to write
3698 shared code that handles any of them.
3700 * New command line options
3702 We now accept --silent as an alias for --quiet.
3706 The memory-mapped-malloc library is now licensed under the GNU Library
3707 General Public License.
3709 *** Changes in GDB-4.7:
3711 * Host/native/target split
3713 GDB has had some major internal surgery to untangle the support for
3714 hosts and remote targets. Now, when you configure GDB for a remote
3715 target, it will no longer load in all of the support for debugging
3716 local programs on the host. When fully completed and tested, this will
3717 ensure that arbitrary host/target combinations are possible.
3719 The primary conceptual shift is to separate the non-portable code in
3720 GDB into three categories. Host specific code is required any time GDB
3721 is compiled on that host, regardless of the target. Target specific
3722 code relates to the peculiarities of the target, but can be compiled on
3723 any host. Native specific code is everything else: it can only be
3724 built when the host and target are the same system. Child process
3725 handling and core file support are two common `native' examples.
3727 GDB's use of /proc for controlling Unix child processes is now cleaner.
3728 It has been split out into a single module under the `target_ops' vector,
3729 plus two native-dependent functions for each system that uses /proc.
3731 * New hosts supported
3733 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
3734 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
3735 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
3737 * New targets supported
3739 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3740 68030 and CPU32 m68030-*-*, m68332-*-*
3742 * New native hosts supported
3744 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
3745 (386bsd is not well tested yet)
3746 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
3748 * New file formats supported
3750 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
3751 supports reading of `a.out.adobe' object files, which are an a.out
3752 format extended with minimal information about multiple sections.
3756 `show copying' is the same as the old `info copying'.
3757 `show warranty' is the same as `info warrantee'.
3758 These were renamed for consistency. The old commands continue to work.
3760 `info handle' is a new alias for `info signals'.
3762 You can now define pre-command hooks, which attach arbitrary command
3763 scripts to any command. The commands in the hook will be executed
3764 prior to the user's command. You can also create a hook which will be
3765 executed whenever the program stops. See gdb.texinfo.
3769 We now deal with Cfront style name mangling, and can even extract type
3770 info from mangled symbols. GDB can automatically figure out which
3771 symbol mangling style your C++ compiler uses.
3773 Calling of methods and virtual functions has been improved as well.
3777 The crash that occured when debugging Sun Ansi-C compiled binaries is
3778 fixed. This was due to mishandling of the extra N_SO stabs output
3781 We also finally got Ultrix 4.2 running in house, and fixed core file
3782 support, with help from a dozen people on the net.
3784 John M. Farrell discovered that the reason that single-stepping was so
3785 slow on all of the Mips based platforms (primarily SGI and DEC) was
3786 that we were trying to demangle and lookup a symbol used for internal
3787 purposes on every instruction that was being stepped through. Changing
3788 the name of that symbol so that it couldn't be mistaken for a C++
3789 mangled symbol sped things up a great deal.
3791 Rich Pixley sped up symbol lookups in general by getting much smarter
3792 about when C++ symbol mangling is necessary. This should make symbol
3793 completion (TAB on the command line) much faster. It's not as fast as
3794 we'd like, but it's significantly faster than gdb-4.6.
3798 A new user controllable variable 'call_scratch_address' can
3799 specify the location of a scratch area to be used when GDB
3800 calls a function in the target. This is necessary because the
3801 usual method of putting the scratch area on the stack does not work
3802 in systems that have separate instruction and data spaces.
3804 We integrated changes to support the 29k UDI (Universal Debugger
3805 Interface), but discovered at the last minute that we didn't have all
3806 of the appropriate copyright paperwork. We are working with AMD to
3807 resolve this, and hope to have it available soon.
3811 We have sped up the remote serial line protocol, especially for targets
3812 with lots of registers. It now supports a new `expedited status' ('T')
3813 message which can be used in place of the existing 'S' status message.
3814 This allows the remote stub to send only the registers that GDB
3815 needs to make a quick decision about single-stepping or conditional
3816 breakpoints, eliminating the need to fetch the entire register set for
3817 each instruction being stepped through.
3819 The GDB remote serial protocol now implements a write-through cache for
3820 registers, only re-reading the registers if the target has run.
3822 There is also a new remote serial stub for SPARC processors. You can
3823 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
3824 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
3825 processor with a serial port.
3829 Configure.in files have become much easier to read and modify. A new
3830 `table driven' format makes it more obvious what configurations are
3831 supported, and what files each one uses.
3835 There is a new opcodes library which will eventually contain all of the
3836 disassembly routines and opcode tables. At present, it only contains
3837 Sparc and Z8000 routines. This will allow the assembler, debugger, and
3838 disassembler (binutils/objdump) to share these routines.
3840 The libiberty library is now copylefted under the GNU Library General
3841 Public License. This allows more liberal use, and was done so libg++
3842 can use it. This makes no difference to GDB, since the Library License
3843 grants all the rights from the General Public License.
3847 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
3848 reference to the stabs symbol info used by the debugger. It is (as far
3849 as we know) the only published document on this fascinating topic. We
3850 encourage you to read it, compare it to the stabs information on your
3851 system, and send improvements on the document in general (to
3852 bug-gdb@prep.ai.mit.edu).
3854 And, of course, many bugs have been fixed.
3857 *** Changes in GDB-4.6:
3859 * Better support for C++ function names
3861 GDB now accepts as input the "demangled form" of C++ overloaded function
3862 names and member function names, and can do command completion on such names
3863 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
3864 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
3865 Make use of command completion, it is your friend.
3867 GDB also now accepts a variety of C++ mangled symbol formats. They are
3868 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
3869 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
3870 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
3871 for the list of formats.
3873 * G++ symbol mangling problem
3875 Recent versions of gcc have a bug in how they emit debugging information for
3876 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
3877 directory) can be applied to gcc to fix the problem. Alternatively, if you
3878 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
3879 usual symptom is difficulty with setting breakpoints on methods. GDB complains
3880 about the method being non-existent. (We believe that version 2.2.2 of GCC has
3883 * New 'maintenance' command
3885 All of the commands related to hacking GDB internals have been moved out of
3886 the main command set, and now live behind the 'maintenance' command. This
3887 can also be abbreviated as 'mt'. The following changes were made:
3889 dump-me -> maintenance dump-me
3890 info all-breakpoints -> maintenance info breakpoints
3891 printmsyms -> maintenance print msyms
3892 printobjfiles -> maintenance print objfiles
3893 printpsyms -> maintenance print psymbols
3894 printsyms -> maintenance print symbols
3896 The following commands are new:
3898 maintenance demangle Call internal GDB demangler routine to
3899 demangle a C++ link name and prints the result.
3900 maintenance print type Print a type chain for a given symbol
3902 * Change to .gdbinit file processing
3904 We now read the $HOME/.gdbinit file before processing the argv arguments
3905 (e.g. reading symbol files or core files). This allows global parameters to
3906 be set, which will apply during the symbol reading. The ./.gdbinit is still
3907 read after argv processing.
3909 * New hosts supported
3911 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
3913 GNU/Linux support i386-unknown-linux or linux
3915 We are also including code to support the HP/PA running BSD and HPUX. This
3916 is almost guaranteed not to work, as we didn't have time to test or build it
3917 for this release. We are including it so that the more adventurous (or
3918 masochistic) of you can play with it. We also had major problems with the
3919 fact that the compiler that we got from HP doesn't support the -g option.
3922 * New targets supported
3924 Hitachi H8/300 h8300-hitachi-hms or h8300hms
3926 * More smarts about finding #include files
3928 GDB now remembers the compilation directory for all include files, and for
3929 all files from which C is generated (like yacc and lex sources). This
3930 greatly improves GDB's ability to find yacc/lex sources, and include files,
3931 especially if you are debugging your program from a directory different from
3932 the one that contains your sources.
3934 We also fixed a bug which caused difficulty with listing and setting
3935 breakpoints in include files which contain C code. (In the past, you had to
3936 try twice in order to list an include file that you hadn't looked at before.)
3938 * Interesting infernals change
3940 GDB now deals with arbitrary numbers of sections, where the symbols for each
3941 section must be relocated relative to that section's landing place in the
3942 target's address space. This work was needed to support ELF with embedded
3943 stabs used by Solaris-2.0.
3945 * Bug fixes (of course!)
3947 There have been loads of fixes for the following things:
3948 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
3949 i960, stabs, DOS(GO32), procfs, etc...
3951 See the ChangeLog for details.
3953 *** Changes in GDB-4.5:
3955 * New machines supported (host and target)
3957 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
3959 SGI Irix-4.x mips-sgi-irix4 or iris4
3961 * New malloc package
3963 GDB now uses a new memory manager called mmalloc, based on gmalloc.
3964 Mmalloc is capable of handling mutiple heaps of memory. It is also
3965 capable of saving a heap to a file, and then mapping it back in later.
3966 This can be used to greatly speedup the startup of GDB by using a
3967 pre-parsed symbol table which lives in a mmalloc managed heap. For
3968 more details, please read mmalloc/mmalloc.texi.
3972 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
3973 'help info proc' for details.
3975 * MIPS ecoff symbol table format
3977 The code that reads MIPS symbol table format is now supported on all hosts.
3978 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
3981 * File name changes for MS-DOS
3983 Many files in the config directories have been renamed to make it easier to
3984 support GDB on MS-DOSe systems (which have very restrictive file name
3985 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
3986 environment) is close to working but has some remaining problems. Note
3987 that debugging of DOS programs is not supported, due to limitations
3988 in the ``operating system'', but it can be used to host cross-debugging.
3990 * Cross byte order fixes
3992 Many fixes have been made to support cross debugging of Sparc and MIPS
3993 targets from hosts whose byte order differs.
3995 * New -mapped and -readnow options
3997 If memory-mapped files are available on your system through the 'mmap'
3998 system call, you can use the -mapped option on the `file' or
3999 `symbol-file' commands to cause GDB to write the symbols from your
4000 program into a reusable file. If the program you are debugging is
4001 called `/path/fred', the mapped symbol file will be `./fred.syms'.
4002 Future GDB debugging sessions will notice the presence of this file,
4003 and will quickly map in symbol information from it, rather than reading
4004 the symbol table from the executable program. Using the '-mapped'
4005 option in a GDB `file' or `symbol-file' command has the same effect as
4006 starting GDB with the '-mapped' command-line option.
4008 You can cause GDB to read the entire symbol table immediately by using
4009 the '-readnow' option with any of the commands that load symbol table
4010 information (or on the GDB command line). This makes the command
4011 slower, but makes future operations faster.
4013 The -mapped and -readnow options are typically combined in order to
4014 build a `fred.syms' file that contains complete symbol information.
4015 A simple GDB invocation to do nothing but build a `.syms' file for future
4018 gdb -batch -nx -mapped -readnow programname
4020 The `.syms' file is specific to the host machine on which GDB is run.
4021 It holds an exact image of GDB's internal symbol table. It cannot be
4022 shared across multiple host platforms.
4024 * longjmp() handling
4026 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
4027 siglongjmp() without losing control. This feature has not yet been ported to
4028 all systems. It currently works on many 386 platforms, all MIPS-based
4029 platforms (SGI, DECstation, etc), and Sun3/4.
4033 Preliminary work has been put in to support the new Solaris OS from Sun. At
4034 this time, it can control and debug processes, but it is not capable of
4039 As always, many many bug fixes. The major areas were with g++, and mipsread.
4040 People using the MIPS-based platforms should experience fewer mysterious
4041 crashes and trashed symbol tables.
4043 *** Changes in GDB-4.4:
4045 * New machines supported (host and target)
4047 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4049 BSD Reno on Vax vax-dec-bsd
4050 Ultrix on Vax vax-dec-ultrix
4052 * New machines supported (target)
4054 AMD 29000 embedded, using EBMON a29k-none-none
4058 GDB continues to improve its handling of C++. `References' work better.
4059 The demangler has also been improved, and now deals with symbols mangled as
4060 per the Annotated C++ Reference Guide.
4062 GDB also now handles `stabs' symbol information embedded in MIPS
4063 `ecoff' symbol tables. Since the ecoff format was not easily
4064 extensible to handle new languages such as C++, this appeared to be a
4065 good way to put C++ debugging info into MIPS binaries. This option
4066 will be supported in the GNU C compiler, version 2, when it is
4069 * New features for SVR4
4071 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
4072 shared libraries. Debugging dynamically linked programs should present
4073 only minor differences from debugging statically linked programs.
4075 The `info proc' command will print out information about any process
4076 on an SVR4 system (including the one you are debugging). At the moment,
4077 it prints the address mappings of the process.
4079 If you bring up GDB on another SVR4 system, please send mail to
4080 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
4082 * Better dynamic linking support in SunOS
4084 Reading symbols from shared libraries which contain debugging symbols
4085 now works properly. However, there remain issues such as automatic
4086 skipping of `transfer vector' code during function calls, which
4087 make it harder to debug code in a shared library, than to debug the
4088 same code linked statically.
4092 GDB is now using the latest `getopt' routines from the FSF. This
4093 version accepts the -- prefix for options with long names. GDB will
4094 continue to accept the old forms (-option and +option) as well.
4095 Various single letter abbreviations for options have been explicity
4096 added to the option table so that they won't get overshadowed in the
4097 future by other options that begin with the same letter.
4101 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
4102 Many assorted bugs have been handled. Many more remain to be handled.
4103 See the various ChangeLog files (primarily in gdb and bfd) for details.
4106 *** Changes in GDB-4.3:
4108 * New machines supported (host and target)
4110 Amiga 3000 running Amix m68k-cbm-svr4 or amix
4111 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
4112 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4114 * Almost SCO Unix support
4116 We had hoped to support:
4117 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4118 (except for core file support), but we discovered very late in the release
4119 that it has problems with process groups that render gdb unusable. Sorry
4120 about that. I encourage people to fix it and post the fixes.
4122 * Preliminary ELF and DWARF support
4124 GDB can read ELF object files on System V Release 4, and can handle
4125 debugging records for C, in DWARF format, in ELF files. This support
4126 is preliminary. If you bring up GDB on another SVR4 system, please
4127 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
4132 GDB now uses the latest `readline' library. One user-visible change
4133 is that two tabs will list possible command completions, which previously
4134 required typing M-? (meta-question mark, or ESC ?).
4138 The `stepi' bug that many of you noticed has been squashed.
4139 Many bugs in C++ have been handled. Many more remain to be handled.
4140 See the various ChangeLog files (primarily in gdb and bfd) for details.
4142 * State of the MIPS world (in case you wondered):
4144 GDB can understand the symbol tables emitted by the compilers
4145 supplied by most vendors of MIPS-based machines, including DEC. These
4146 symbol tables are in a format that essentially nobody else uses.
4148 Some versions of gcc come with an assembler post-processor called
4149 mips-tfile. This program is required if you want to do source-level
4150 debugging of gcc-compiled programs. I believe FSF does not ship
4151 mips-tfile with gcc version 1, but it will eventually come with gcc
4154 Debugging of g++ output remains a problem. g++ version 1.xx does not
4155 really support it at all. (If you're lucky, you should be able to get
4156 line numbers and stack traces to work, but no parameters or local
4157 variables.) With some work it should be possible to improve the
4160 When gcc version 2 is released, you will have somewhat better luck.
4161 However, even then you will get confusing results for inheritance and
4164 We will eventually provide full debugging of g++ output on
4165 DECstations. This will probably involve some kind of stabs-in-ecoff
4166 encapulation, but the details have not been worked out yet.
4169 *** Changes in GDB-4.2:
4171 * Improved configuration
4173 Only one copy of `configure' exists now, and it is not self-modifying.
4174 Porting BFD is simpler.
4178 The `step' and `next' commands now only stop at the first instruction
4179 of a source line. This prevents the multiple stops that used to occur
4180 in switch statements, for-loops, etc. `Step' continues to stop if a
4181 function that has debugging information is called within the line.
4185 Lots of small bugs fixed. More remain.
4187 * New host supported (not target)
4189 Intel 386 PC clone running Mach i386-none-mach
4192 *** Changes in GDB-4.1:
4194 * Multiple source language support
4196 GDB now has internal scaffolding to handle several source languages.
4197 It determines the type of each source file from its filename extension,
4198 and will switch expression parsing and number formatting to match the
4199 language of the function in the currently selected stack frame.
4200 You can also specifically set the language to be used, with
4201 `set language c' or `set language modula-2'.
4205 GDB now has preliminary support for the GNU Modula-2 compiler,
4206 currently under development at the State University of New York at
4207 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
4208 continue through the fall of 1991 and into 1992.
4210 Other Modula-2 compilers are currently not supported, and attempting to
4211 debug programs compiled with them will likely result in an error as the
4212 symbol table is read. Feel free to work on it, though!
4214 There are hooks in GDB for strict type checking and range checking,
4215 in the `Modula-2 philosophy', but they do not currently work.
4219 GDB can now write to executable and core files (e.g. patch
4220 a variable's value). You must turn this switch on, specify
4221 the file ("exec foo" or "core foo"), *then* modify it, e.g.
4222 by assigning a new value to a variable. Modifications take
4225 * Automatic SunOS shared library reading
4227 When you run your program, GDB automatically determines where its
4228 shared libraries (if any) have been loaded, and reads their symbols.
4229 The `share' command is no longer needed. This also works when
4230 examining core files.
4234 You can specify the number of lines that the `list' command shows.
4237 * New machines supported (host and target)
4239 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4240 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
4241 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
4243 * New hosts supported (not targets)
4245 IBM RT/PC: romp-ibm-aix or rtpc
4247 * New targets supported (not hosts)
4249 AMD 29000 embedded with COFF a29k-none-coff
4250 AMD 29000 embedded with a.out a29k-none-aout
4251 Ultracomputer remote kernel debug a29k-nyu-kern
4253 * New remote interfaces
4259 *** Changes in GDB-4.0:
4263 Wide output is wrapped at good places to make the output more readable.
4265 Gdb now supports cross-debugging from a host machine of one type to a
4266 target machine of another type. Communication with the target system
4267 is over serial lines. The ``target'' command handles connecting to the
4268 remote system; the ``load'' command will download a program into the
4269 remote system. Serial stubs for the m68k and i386 are provided. Gdb
4270 also supports debugging of realtime processes running under VxWorks,
4271 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
4272 stub on the target system.
4274 New CPUs supported include the AMD 29000 and Intel 960.
4276 GDB now reads object files and symbol tables via a ``binary file''
4277 library, which allows a single copy of GDB to debug programs of multiple
4278 object file types such as a.out and coff.
4280 There is now a GDB reference card in "doc/refcard.tex". (Make targets
4281 refcard.dvi and refcard.ps are available to format it).
4284 * Control-Variable user interface simplified
4286 All variables that control the operation of the debugger can be set
4287 by the ``set'' command, and displayed by the ``show'' command.
4289 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
4290 ``Show prompt'' produces the response:
4291 Gdb's prompt is new-gdb=>.
4293 What follows are the NEW set commands. The command ``help set'' will
4294 print a complete list of old and new set commands. ``help set FOO''
4295 will give a longer description of the variable FOO. ``show'' will show
4296 all of the variable descriptions and their current settings.
4298 confirm on/off: Enables warning questions for operations that are
4299 hard to recover from, e.g. rerunning the program while
4300 it is already running. Default is ON.
4302 editing on/off: Enables EMACS style command line editing
4303 of input. Previous lines can be recalled with
4304 control-P, the current line can be edited with control-B,
4305 you can search for commands with control-R, etc.
4308 history filename NAME: NAME is where the gdb command history
4309 will be stored. The default is .gdb_history,
4310 or the value of the environment variable
4313 history size N: The size, in commands, of the command history. The
4314 default is 256, or the value of the environment variable
4317 history save on/off: If this value is set to ON, the history file will
4318 be saved after exiting gdb. If set to OFF, the
4319 file will not be saved. The default is OFF.
4321 history expansion on/off: If this value is set to ON, then csh-like
4322 history expansion will be performed on
4323 command line input. The default is OFF.
4325 radix N: Sets the default radix for input and output. It can be set
4326 to 8, 10, or 16. Note that the argument to "radix" is interpreted
4327 in the current radix, so "set radix 10" is always a no-op.
4329 height N: This integer value is the number of lines on a page. Default
4330 is 24, the current `stty rows'' setting, or the ``li#''
4331 setting from the termcap entry matching the environment
4334 width N: This integer value is the number of characters on a line.
4335 Default is 80, the current `stty cols'' setting, or the ``co#''
4336 setting from the termcap entry matching the environment
4339 Note: ``set screensize'' is obsolete. Use ``set height'' and
4340 ``set width'' instead.
4342 print address on/off: Print memory addresses in various command displays,
4343 such as stack traces and structure values. Gdb looks
4344 more ``symbolic'' if you turn this off; it looks more
4345 ``machine level'' with it on. Default is ON.
4347 print array on/off: Prettyprint arrays. New convenient format! Default
4350 print demangle on/off: Print C++ symbols in "source" form if on,
4353 print asm-demangle on/off: Same, for assembler level printouts
4356 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
4359 * Support for Epoch Environment.
4361 The epoch environment is a version of Emacs v18 with windowing. One
4362 new command, ``inspect'', is identical to ``print'', except that if you
4363 are running in the epoch environment, the value is printed in its own
4367 * Support for Shared Libraries
4369 GDB can now debug programs and core files that use SunOS shared libraries.
4370 Symbols from a shared library cannot be referenced
4371 before the shared library has been linked with the program (this
4372 happens after you type ``run'' and before the function main() is entered).
4373 At any time after this linking (including when examining core files
4374 from dynamically linked programs), gdb reads the symbols from each
4375 shared library when you type the ``sharedlibrary'' command.
4376 It can be abbreviated ``share''.
4378 sharedlibrary REGEXP: Load shared object library symbols for files
4379 matching a unix regular expression. No argument
4380 indicates to load symbols for all shared libraries.
4382 info sharedlibrary: Status of loaded shared libraries.
4387 A watchpoint stops execution of a program whenever the value of an
4388 expression changes. Checking for this slows down execution
4389 tremendously whenever you are in the scope of the expression, but is
4390 quite useful for catching tough ``bit-spreader'' or pointer misuse
4391 problems. Some machines such as the 386 have hardware for doing this
4392 more quickly, and future versions of gdb will use this hardware.
4394 watch EXP: Set a watchpoint (breakpoint) for an expression.
4396 info watchpoints: Information about your watchpoints.
4398 delete N: Deletes watchpoint number N (same as breakpoints).
4399 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
4400 enable N: Re-enables watchpoint number N (same as breakpoints).
4403 * C++ multiple inheritance
4405 When used with a GCC version 2 compiler, GDB supports multiple inheritance
4408 * C++ exception handling
4410 Gdb now supports limited C++ exception handling. Besides the existing
4411 ability to breakpoint on an exception handler, gdb can breakpoint on
4412 the raising of an exception (before the stack is peeled back to the
4415 catch FOO: If there is a FOO exception handler in the dynamic scope,
4416 set a breakpoint to catch exceptions which may be raised there.
4417 Multiple exceptions (``catch foo bar baz'') may be caught.
4419 info catch: Lists all exceptions which may be caught in the
4420 current stack frame.
4423 * Minor command changes
4425 The command ``call func (arg, arg, ...)'' now acts like the print
4426 command, except it does not print or save a value if the function's result
4427 is void. This is similar to dbx usage.
4429 The ``up'' and ``down'' commands now always print the frame they end up
4430 at; ``up-silently'' and `down-silently'' can be used in scripts to change
4431 frames without printing.
4433 * New directory command
4435 'dir' now adds directories to the FRONT of the source search path.
4436 The path starts off empty. Source files that contain debug information
4437 about the directory in which they were compiled can be found even
4438 with an empty path; Sun CC and GCC include this information. If GDB can't
4439 find your source file in the current directory, type "dir .".
4441 * Configuring GDB for compilation
4443 For normal use, type ``./configure host''. See README or gdb.texinfo
4446 GDB now handles cross debugging. If you are remotely debugging between
4447 two different machines, type ``./configure host -target=targ''.
4448 Host is the machine where GDB will run; targ is the machine
4449 where the program that you are debugging will run.