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.
48 ** GDB now puts template parameters in scope when debugging in an
49 instantiation. For example, if you have:
51 template<int X> int func (void) { return X; }
53 then if you step into func<5>, "print X" will show "5". This
54 feature requires proper debuginfo support from the compiler; it
57 ** The motion commands "next", "finish", "until", and "advance" now
58 work better when exceptions are thrown. In particular, GDB will
59 no longer lose control of the inferior; instead, the GDB will
60 stop the inferior at the point at which the exception is caught.
61 This functionality requires a change in the exception handling
62 code that was introduced in GCC 4.5.
64 * GDB now follows GCC's rules on accessing volatile objects when
65 reading or writing target state during expression evaluation.
66 One notable difference to prior behavior is that "print x = 0"
67 no longer generates a read of x; the value of the assignment is
68 now always taken directly from the value being assigned.
70 * GDB now has some support for using labels in the program's source in
71 linespecs. For instance, you can use "advance label" to continue
74 * GDB now has support for reading and writing a new .gdb_index
75 section. This section holds a fast index of DWARF debugging
76 information and can be used to greatly speed up GDB startup and
77 operation. See the documentation for `save gdb-index' for details.
79 * The "watch" command now accepts an optional "-location" argument.
80 When used, this causes GDB to watch the memory referred to by the
81 expression. Such a watchpoint is never deleted due to it going out
84 * GDB now supports thread debugging of core dumps on GNU/Linux.
86 GDB now activates thread debugging using the libthread_db library
87 when debugging GNU/Linux core dumps, similarly to when debugging
88 live processes. As a result, when debugging a core dump file, GDB
89 is now able to display pthread_t ids of threads. For example, "info
90 threads" shows the same output as when debugging the process when it
91 was live. In earlier releases, you'd see something like this:
94 * 1 LWP 6780 main () at main.c:10
96 While now you see this:
99 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
101 It is also now possible to inspect TLS variables when debugging core
104 When debugging a core dump generated on a machine other than the one
105 used to run GDB, you may need to point GDB at the correct
106 libthread_db library with the "set libthread-db-search-path"
107 command. See the user manual for more details on this command.
109 * New features in the GDB remote stub, GDBserver
111 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
112 and i686 LynxOS (version 5.x).
114 ** GDBserver is now supported on Blackfin Linux.
118 Analog Devices, Inc. Blackfin Processor bfin-*
120 * Ada task switching is now supported on sparc-elf targets when
121 debugging a program using the Ravenscar Profile. For more information,
122 see the "Tasking Support when using the Ravenscar Profile" section
123 in the GDB user manual.
125 * Guile support was removed.
127 * New features in the GNU simulator
129 ** The --map-info flag lists all known core mappings.
131 *** Changes in GDB 7.2
133 * Shared library support for remote targets by default
135 When GDB is configured for a generic, non-OS specific target, like
136 for example, --target=arm-eabi or one of the many *-*-elf targets,
137 GDB now queries remote stubs for loaded shared libraries using the
138 `qXfer:libraries:read' packet. Previously, shared library support
139 was always disabled for such configurations.
143 ** Argument Dependent Lookup (ADL)
145 In C++ ADL lookup directs function search to the namespaces of its
146 arguments even if the namespace has not been imported.
156 Here the compiler will search for `foo' in the namespace of 'b'
157 and find A::foo. GDB now supports this. This construct is commonly
158 used in the Standard Template Library for operators.
160 ** Improved User Defined Operator Support
162 In addition to member operators, GDB now supports lookup of operators
163 defined in a namespace and imported with a `using' directive, operators
164 defined in the global scope, operators imported implicitly from an
165 anonymous namespace, and the ADL operators mentioned in the previous
167 GDB now also supports proper overload resolution for all the previously
168 mentioned flavors of operators.
170 ** static const class members
172 Printing of static const class members that are initialized in the
173 class definition has been fixed.
175 * Windows Thread Information Block access.
177 On Windows targets, GDB now supports displaying the Windows Thread
178 Information Block (TIB) structure. This structure is visible either
179 by using the new command `info w32 thread-information-block' or, by
180 dereferencing the new convenience variable named `$_tlb', a
181 thread-specific pointer to the TIB. This feature is also supported
182 when remote debugging using GDBserver.
186 Static tracepoints are calls in the user program into a tracing
187 library. One such library is a port of the LTTng kernel tracer to
188 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
189 When debugging with GDBserver, GDB now supports combining the GDB
190 tracepoint machinery with such libraries. For example: the user can
191 use GDB to probe a static tracepoint marker (a call from the user
192 program into the tracing library) with the new "strace" command (see
193 "New commands" below). This creates a "static tracepoint" in the
194 breakpoint list, that can be manipulated with the same feature set
195 as fast and regular tracepoints. E.g., collect registers, local and
196 global variables, collect trace state variables, and define
197 tracepoint conditions. In addition, the user can collect extra
198 static tracepoint marker specific data, by collecting the new
199 $_sdata internal variable. When analyzing the trace buffer, you can
200 inspect $_sdata like any other variable available to GDB. For more
201 information, see the "Tracepoints" chapter in GDB user manual. New
202 remote packets have been defined to support static tracepoints, see
203 the "New remote packets" section below.
205 * Better reconstruction of tracepoints after disconnected tracing
207 GDB will attempt to download the original source form of tracepoint
208 definitions when starting a trace run, and then will upload these
209 upon reconnection to the target, resulting in a more accurate
210 reconstruction of the tracepoints that are in use on the target.
214 You can now exercise direct control over the ways that GDB can
215 affect your program. For instance, you can disallow the setting of
216 breakpoints, so that the program can run continuously (assuming
217 non-stop mode). In addition, the "observer" variable is available
218 to switch all of the different controls; in observer mode, GDB
219 cannot affect the target's behavior at all, which is useful for
220 tasks like diagnosing live systems in the field.
222 * The new convenience variable $_thread holds the number of the
229 Return the address of the Windows Thread Information Block of a given thread.
233 In response to several of the tracepoint packets, the target may now
234 also respond with a number of intermediate `qRelocInsn' request
235 packets before the final result packet, to have GDB handle
236 relocating an instruction to execute at a different address. This
237 is particularly useful for stubs that support fast tracepoints. GDB
238 reports support for this feature in the qSupported packet.
242 List static tracepoint markers in the target program.
246 List static tracepoint markers at a given address in the target
249 qXfer:statictrace:read
251 Read the static trace data collected (by a `collect $_sdata'
252 tracepoint action). The remote stub reports support for this packet
253 to gdb's qSupported query.
257 Send the current settings of GDB's permission flags.
261 Send part of the source (textual) form of a tracepoint definition,
262 which includes location, conditional, and action list.
264 * The source command now accepts a -s option to force searching for the
265 script in the source search path even if the script name specifies
268 * New features in the GDB remote stub, GDBserver
270 - GDBserver now support tracepoints (including fast tracepoints, and
271 static tracepoints). The feature is currently supported by the
272 i386-linux and amd64-linux builds. See the "Tracepoints support
273 in gdbserver" section in the manual for more information.
275 GDBserver JIT compiles the tracepoint's conditional agent
276 expression bytecode into native code whenever possible for low
277 overhead dynamic tracepoints conditionals. For such tracepoints,
278 an expression that examines program state is evaluated when the
279 tracepoint is reached, in order to determine whether to capture
280 trace data. If the condition is simple and false, processing the
281 tracepoint finishes very quickly and no data is gathered.
283 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
284 for static tracepoints support.
286 - GDBserver now supports x86_64 Windows 64-bit debugging.
288 * GDB now sends xmlRegisters= in qSupported packet to indicate that
289 it understands register description.
291 * The --batch flag now disables pagination and queries.
293 * X86 general purpose registers
295 GDB now supports reading/writing byte, word and double-word x86
296 general purpose registers directly. This means you can use, say,
297 $ah or $ax to refer, respectively, to the byte register AH and
298 16-bit word register AX that are actually portions of the 32-bit
299 register EAX or 64-bit register RAX.
301 * The `commands' command now accepts a range of breakpoints to modify.
302 A plain `commands' following a command that creates multiple
303 breakpoints affects all the breakpoints set by that command. This
304 applies to breakpoints set by `rbreak', and also applies when a
305 single `break' command creates multiple breakpoints (e.g.,
306 breakpoints on overloaded c++ functions).
308 * The `rbreak' command now accepts a filename specification as part of
309 its argument, limiting the functions selected by the regex to those
310 in the specified file.
312 * Support for remote debugging Windows and SymbianOS shared libraries
313 from Unix hosts has been improved. Non Windows GDB builds now can
314 understand target reported file names that follow MS-DOS based file
315 system semantics, such as file names that include drive letters and
316 use the backslash character as directory separator. This makes it
317 possible to transparently use the "set sysroot" and "set
318 solib-search-path" on Unix hosts to point as host copies of the
319 target's shared libraries. See the new command "set
320 target-file-system-kind" described below, and the "Commands to
321 specify files" section in the user manual for more information.
325 eval template, expressions...
326 Convert the values of one or more expressions under the control
327 of the string template to a command line, and call it.
329 set target-file-system-kind unix|dos-based|auto
330 show target-file-system-kind
331 Set or show the assumed file system kind for target reported file
334 save breakpoints <filename>
335 Save all current breakpoint definitions to a file suitable for use
336 in a later debugging session. To read the saved breakpoint
337 definitions, use the `source' command.
339 `save tracepoints' is a new alias for `save-tracepoints'. The latter
342 info static-tracepoint-markers
343 Display information about static tracepoint markers in the target.
345 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
346 Define a static tracepoint by probing a marker at the given
347 function, line, address, or marker ID.
351 Enable and disable observer mode.
353 set may-write-registers on|off
354 set may-write-memory on|off
355 set may-insert-breakpoints on|off
356 set may-insert-tracepoints on|off
357 set may-insert-fast-tracepoints on|off
358 set may-interrupt on|off
359 Set individual permissions for GDB effects on the target. Note that
360 some of these settings can have undesirable or surprising
361 consequences, particularly when changed in the middle of a session.
362 For instance, disabling the writing of memory can prevent
363 breakpoints from being inserted, cause single-stepping to fail, or
364 even crash your program, if you disable after breakpoints have been
365 inserted. However, GDB should not crash.
367 set record memory-query on|off
368 show record memory-query
369 Control whether to stop the inferior if memory changes caused
370 by an instruction cannot be recorded.
375 The disassemble command now supports "start,+length" form of two arguments.
379 ** GDB now provides a new directory location, called the python directory,
380 where Python scripts written for GDB can be installed. The location
381 of that directory is <data-directory>/python, where <data-directory>
382 is the GDB data directory. For more details, see section `Scripting
383 GDB using Python' in the manual.
385 ** The GDB Python API now has access to breakpoints, symbols, symbol
386 tables, program spaces, inferiors, threads and frame's code blocks.
387 Additionally, GDB Parameters can now be created from the API, and
388 manipulated via set/show in the CLI.
390 ** New functions gdb.target_charset, gdb.target_wide_charset,
391 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
393 ** New exception gdb.GdbError.
395 ** Pretty-printers are now also looked up in the current program space.
397 ** Pretty-printers can now be individually enabled and disabled.
399 ** GDB now looks for names of Python scripts to auto-load in a
400 special section named `.debug_gdb_scripts', in addition to looking
401 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
403 * Tracepoint actions were unified with breakpoint commands. In particular,
404 there are no longer differences in "info break" output for breakpoints and
405 tracepoints and the "commands" command can be used for both tracepoints and
410 ARM Symbian arm*-*-symbianelf*
412 * D language support.
413 GDB now supports debugging programs written in the D programming
416 * GDB now supports the extended ptrace interface for PowerPC which is
417 available since Linux kernel version 2.6.34. This automatically enables
418 any hardware breakpoints and additional hardware watchpoints available in
419 the processor. The old ptrace interface exposes just one hardware
420 watchpoint and no hardware breakpoints.
422 * GDB is now able to use the Data Value Compare (DVC) register available on
423 embedded PowerPC processors to implement in hardware simple watchpoint
424 conditions of the form:
426 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
428 This works in native GDB running on Linux kernels with the extended ptrace
429 interface mentioned above.
431 *** Changes in GDB 7.1
437 GDB now supports importing of namespaces in C++. This enables the
438 user to inspect variables from imported namespaces. Support for
439 namepace aliasing has also been added. So, if a namespace is
440 aliased in the current scope (e.g. namepace C=A; ) the user can
441 print variables using the alias (e.g. (gdb) print C::x).
445 All known bugs relating to the printing of virtual base class were
446 fixed. It is now possible to call overloaded static methods using a
451 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
452 and reinterpret_cast<> are now handled by the C++ expression parser.
456 Xilinx MicroBlaze microblaze-*-*
461 Xilinx MicroBlaze microblaze
464 * Multi-program debugging.
466 GDB now has support for multi-program (a.k.a. multi-executable or
467 multi-exec) debugging. This allows for debugging multiple inferiors
468 simultaneously each running a different program under the same GDB
469 session. See "Debugging Multiple Inferiors and Programs" in the
470 manual for more information. This implied some user visible changes
471 in the multi-inferior support. For example, "info inferiors" now
472 lists inferiors that are not running yet or that have exited
473 already. See also "New commands" and "New options" below.
475 * New tracing features
477 GDB's tracepoint facility now includes several new features:
479 ** Trace state variables
481 GDB tracepoints now include support for trace state variables, which
482 are variables managed by the target agent during a tracing
483 experiment. They are useful for tracepoints that trigger each
484 other, so for instance one tracepoint can count hits in a variable,
485 and then a second tracepoint has a condition that is true when the
486 count reaches a particular value. Trace state variables share the
487 $-syntax of GDB convenience variables, and can appear in both
488 tracepoint actions and condition expressions. Use the "tvariable"
489 command to create, and "info tvariables" to view; see "Trace State
490 Variables" in the manual for more detail.
494 GDB now includes an option for defining fast tracepoints, which
495 targets may implement more efficiently, such as by installing a jump
496 into the target agent rather than a trap instruction. The resulting
497 speedup can be by two orders of magnitude or more, although the
498 tradeoff is that some program locations on some target architectures
499 might not allow fast tracepoint installation, for instance if the
500 instruction to be replaced is shorter than the jump. To request a
501 fast tracepoint, use the "ftrace" command, with syntax identical to
502 the regular trace command.
504 ** Disconnected tracing
506 It is now possible to detach GDB from the target while it is running
507 a trace experiment, then reconnect later to see how the experiment
508 is going. In addition, a new variable disconnected-tracing lets you
509 tell the target agent whether to continue running a trace if the
510 connection is lost unexpectedly.
514 GDB now has the ability to save the trace buffer into a file, and
515 then use that file as a target, similarly to you can do with
516 corefiles. You can select trace frames, print data that was
517 collected in them, and use tstatus to display the state of the
518 tracing run at the moment that it was saved. To create a trace
519 file, use "tsave <filename>", and to use it, do "target tfile
522 ** Circular trace buffer
524 You can ask the target agent to handle the trace buffer as a
525 circular buffer, discarding the oldest trace frames to make room for
526 newer ones, by setting circular-trace-buffer to on. This feature may
527 not be available for all target agents.
532 The disassemble command, when invoked with two arguments, now requires
533 the arguments to be comma-separated.
536 The info variables command now displays variable definitions. Files
537 which only declare a variable are not shown.
540 The source command is now capable of sourcing Python scripts.
541 This feature is dependent on the debugger being build with Python
544 Related to this enhancement is also the introduction of a new command
545 "set script-extension" (see below).
547 * New commands (for set/show, see "New options" below)
549 record save [<FILENAME>]
550 Save a file (in core file format) containing the process record
551 execution log for replay debugging at a later time.
553 record restore <FILENAME>
554 Restore the process record execution log that was saved at an
555 earlier time, for replay debugging.
557 add-inferior [-copies <N>] [-exec <FILENAME>]
560 clone-inferior [-copies <N>] [ID]
561 Make a new inferior ready to execute the same program another
567 maint info program-spaces
568 List the program spaces loaded into GDB.
570 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
571 show remote interrupt-sequence
572 Allow the user to select one of ^C, a BREAK signal or BREAK-g
573 as the sequence to the remote target in order to interrupt the execution.
574 Ctrl-C is a default. Some system prefers BREAK which is high level of
575 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
576 Magic SysRq g. It is BREAK signal and character 'g'.
578 set remote interrupt-on-connect [on | off]
579 show remote interrupt-on-connect
580 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
581 remote target when gdb connects to it. This is needed when you debug
584 set remotebreak [on | off]
586 Deprecated. Use "set/show remote interrupt-sequence" instead.
588 tvariable $NAME [ = EXP ]
589 Create or modify a trace state variable.
592 List trace state variables and their values.
594 delete tvariable $NAME ...
595 Delete one or more trace state variables.
598 Evaluate the given expressions without collecting anything into the
599 trace buffer. (Valid in tracepoint actions only.)
601 ftrace FN / FILE:LINE / *ADDR
602 Define a fast tracepoint at the given function, line, or address.
604 * New expression syntax
606 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
607 GDB now parses 0b101010 identically with 42.
611 set follow-exec-mode new|same
612 show follow-exec-mode
613 Control whether GDB reuses the same inferior across an exec call or
614 creates a new one. This is useful to be able to restart the old
615 executable after the inferior having done an exec call.
617 set default-collect EXPR, ...
619 Define a list of expressions to be collected at each tracepoint.
620 This is a useful way to ensure essential items are not overlooked,
621 such as registers or a critical global variable.
623 set disconnected-tracing
624 show disconnected-tracing
625 If set to 1, the target is instructed to continue tracing if it
626 loses its connection to GDB. If 0, the target is to stop tracing
629 set circular-trace-buffer
630 show circular-trace-buffer
631 If set to on, the target is instructed to use a circular trace buffer
632 and discard the oldest trace frames instead of stopping the trace due
633 to a full trace buffer. If set to off, the trace stops when the buffer
634 fills up. Some targets may not support this.
636 set script-extension off|soft|strict
637 show script-extension
638 If set to "off", the debugger does not perform any script language
639 recognition, and all sourced files are assumed to be GDB scripts.
640 If set to "soft" (the default), files are sourced according to
641 filename extension, falling back to GDB scripts if the first
643 If set to "strict", files are sourced according to filename extension.
645 set ada trust-PAD-over-XVS on|off
646 show ada trust-PAD-over-XVS
647 If off, activate a workaround against a bug in the debugging information
648 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
649 the GCC sources for more information about the GNAT encoding and
650 PAD types in particular). It is always safe to set this option to
651 off, but this introduces a slight performance penalty. The default
654 * Python API Improvements
656 ** GDB provides the new class gdb.LazyString. This is useful in
657 some pretty-printing cases. The new method gdb.Value.lazy_string
658 provides a simple way to create objects of this type.
660 ** The fields returned by gdb.Type.fields now have an
661 `is_base_class' attribute.
663 ** The new method gdb.Type.range returns the range of an array type.
665 ** The new method gdb.parse_and_eval can be used to parse and
666 evaluate an expression.
671 Define a trace state variable.
674 Get the current value of a trace state variable.
677 Set desired tracing behavior upon disconnection.
680 Set the trace buffer to be linear or circular.
683 Get data about the tracepoints currently in use.
687 Process record now works correctly with hardware watchpoints.
689 Multiple bug fixes have been made to the mips-irix port, making it
690 much more reliable. In particular:
691 - Debugging threaded applications is now possible again. Previously,
692 GDB would hang while starting the program, or while waiting for
693 the program to stop at a breakpoint.
694 - Attaching to a running process no longer hangs.
695 - An error occurring while loading a core file has been fixed.
696 - Changing the value of the PC register now works again. This fixes
697 problems observed when using the "jump" command, or when calling
698 a function from GDB, or even when assigning a new value to $pc.
699 - With the "finish" and "return" commands, the return value for functions
700 returning a small array is now correctly printed.
701 - It is now possible to break on shared library code which gets executed
702 during a shared library init phase (code executed while executing
703 their .init section). Previously, the breakpoint would have no effect.
704 - GDB is now able to backtrace through the signal handler for
705 non-threaded programs.
707 PIE (Position Independent Executable) programs debugging is now supported.
708 This includes debugging execution of PIC (Position Independent Code) shared
709 libraries although for that, it should be possible to run such libraries as an
712 *** Changes in GDB 7.0
714 * GDB now has an interface for JIT compilation. Applications that
715 dynamically generate code can create symbol files in memory and register
716 them with GDB. For users, the feature should work transparently, and
717 for JIT developers, the interface is documented in the GDB manual in the
718 "JIT Compilation Interface" chapter.
720 * Tracepoints may now be conditional. The syntax is as for
721 breakpoints; either an "if" clause appended to the "trace" command,
722 or the "condition" command is available. GDB sends the condition to
723 the target for evaluation using the same bytecode format as is used
724 for tracepoint actions.
726 * The disassemble command now supports: an optional /r modifier, print the
727 raw instructions in hex as well as in symbolic form, and an optional /m
728 modifier to print mixed source+assembly.
730 * Process record and replay
732 In a architecture environment that supports ``process record and
733 replay'', ``process record and replay'' target can record a log of
734 the process execution, and replay it with both forward and reverse
737 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
738 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
739 set execution-direction {forward|reverse}, for targets that support
742 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
743 feature is available with a native GDB running on kernel version
746 * GDB now has support for multi-byte and wide character sets on the
747 target. Strings whose character type is wchar_t, char16_t, or
748 char32_t are now correctly printed. GDB supports wide- and unicode-
749 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
750 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
751 `printf'. This feature requires iconv to work properly; if your
752 system does not have a working iconv, GDB can use GNU libiconv. See
753 the installation instructions for more information.
755 * GDB now supports automatic retrieval of shared library files from
756 remote targets. To use this feature, specify a system root that begins
757 with the `remote:' prefix, either via the `set sysroot' command or via
758 the `--with-sysroot' configure-time option.
760 * "info sharedlibrary" now takes an optional regex of libraries to show,
761 and it now reports if a shared library has no debugging information.
763 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
764 now complete on file names.
766 * When completing in expressions, gdb will attempt to limit
767 completions to allowable structure or union fields, where appropriate.
768 For instance, consider:
770 # struct example { int f1; double f2; };
771 # struct example variable;
774 If the user types TAB at the end of this command line, the available
775 completions will be "f1" and "f2".
777 * Inlined functions are now supported. They show up in backtraces, and
778 the "step", "next", and "finish" commands handle them automatically.
780 * GDB now supports the token-splicing (##) and stringification (#)
781 operators when expanding macros. It also supports variable-arity
784 * GDB now supports inspecting extra signal information, exported by
785 the new $_siginfo convenience variable. The feature is currently
786 implemented on linux ARM, i386 and amd64.
788 * GDB can now display the VFP floating point registers and NEON vector
789 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
790 can provide these registers (requires Linux 2.6.30 or later). Remote
791 and simulator targets may also provide them.
796 Search memory for a sequence of bytes.
799 Turn off `+'/`-' protocol acknowledgments to permit more efficient
800 operation over reliable transport links. Use of this packet is
801 controlled by the `set remote noack-packet' command.
804 Kill the process with the specified process ID. Use this in preference
805 to `k' when multiprocess protocol extensions are supported.
808 Obtains additional operating system information
812 Read or write additional signal information.
814 * Removed remote protocol undocumented extension
816 An undocumented extension to the remote protocol's `S' stop reply
817 packet that permited the stub to pass a process id was removed.
818 Remote servers should use the `T' stop reply packet instead.
820 * GDB now supports multiple function calling conventions according to the
821 DWARF-2 DW_AT_calling_convention function attribute.
823 * The SH target utilizes the aforementioned change to distinguish between gcc
824 and Renesas calling convention. It also adds the new CLI commands
825 `set/show sh calling-convention'.
827 * GDB can now read compressed debug sections, as produced by GNU gold
828 with the --compress-debug-sections=zlib flag.
830 * 64-bit core files are now supported on AIX.
832 * Thread switching is now supported on Tru64.
834 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
835 which will be allocated using malloc later in program execution.
837 * The qXfer:libraries:read remote procotol packet now allows passing a
838 list of section offsets.
840 * On GNU/Linux, GDB can now attach to stopped processes. Several race
841 conditions handling signals delivered during attach or thread creation
842 have also been fixed.
844 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
845 From the user's standpoint, all unqualified instances of True and False
846 are treated as the standard definitions, regardless of context.
848 * GDB now parses C++ symbol and type names more flexibly. For
851 template<typename T> class C { };
854 GDB will now correctly handle all of:
856 ptype C<char const *>
858 ptype C<const char *>
861 * New features in the GDB remote stub, gdbserver
863 - The "--wrapper" command-line argument tells gdbserver to use a
864 wrapper program to launch programs for debugging.
866 - On PowerPC and S/390 targets, it is now possible to use a single
867 gdbserver executable to debug both 32-bit and 64-bit programs.
868 (This requires gdbserver itself to be built as a 64-bit executable.)
870 - gdbserver uses the new noack protocol mode for TCP connections to
871 reduce communications latency, if also supported and enabled in GDB.
873 - Support for the sparc64-linux-gnu target is now included in
876 - The amd64-linux build of gdbserver now supports debugging both
877 32-bit and 64-bit programs.
879 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
880 now support hardware watchpoints, and will use them automatically
885 GDB now has support for scripting using Python. Whether this is
886 available is determined at configure time.
888 New GDB commands can now be written in Python.
890 * Ada tasking support
892 Ada tasks can now be inspected in GDB. The following commands have
896 Print the list of Ada tasks.
898 Print detailed information about task number N.
900 Print the task number of the current task.
902 Switch the context of debugging to task number N.
904 * Support for user-defined prefixed commands. The "define" command can
905 add new commands to existing prefixes, e.g. "target".
907 * Multi-inferior, multi-process debugging.
909 GDB now has generalized support for multi-inferior debugging. See
910 "Debugging Multiple Inferiors" in the manual for more information.
911 Although availability still depends on target support, the command
912 set is more uniform now. The GNU/Linux specific multi-forks support
913 has been migrated to this new framework. This implied some user
914 visible changes; see "New commands" and also "Removed commands"
917 * Target descriptions can now describe the target OS ABI. See the
918 "Target Description Format" section in the user manual for more
921 * Target descriptions can now describe "compatible" architectures
922 to indicate that the target can execute applications for a different
923 architecture in addition to those for the main target architecture.
924 See the "Target Description Format" section in the user manual for
927 * Multi-architecture debugging.
929 GDB now includes general supports for debugging applications on
930 hybrid systems that use more than one single processor architecture
931 at the same time. Each such hybrid architecture still requires
932 specific support to be added. The only hybrid architecture supported
933 in this version of GDB is the Cell Broadband Engine.
935 * GDB now supports integrated debugging of Cell/B.E. applications that
936 use both the PPU and SPU architectures. To enable support for hybrid
937 Cell/B.E. debugging, you need to configure GDB to support both the
938 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
939 --enable-targets configure option.
941 * Non-stop mode debugging.
943 For some targets, GDB now supports an optional mode of operation in
944 which you can examine stopped threads while other threads continue
945 to execute freely. This is referred to as non-stop mode, with the
946 old mode referred to as all-stop mode. See the "Non-Stop Mode"
947 section in the user manual for more information.
949 To be able to support remote non-stop debugging, a remote stub needs
950 to implement the non-stop mode remote protocol extensions, as
951 described in the "Remote Non-Stop" section of the user manual. The
952 GDB remote stub, gdbserver, has been adjusted to support these
953 extensions on linux targets.
955 * New commands (for set/show, see "New options" below)
957 catch syscall [NAME(S) | NUMBER(S)]
958 Catch system calls. Arguments, which should be names of system
959 calls or their numbers, mean catch only those syscalls. Without
960 arguments, every syscall will be caught. When the inferior issues
961 any of the specified syscalls, GDB will stop and announce the system
962 call, both when it is called and when its call returns. This
963 feature is currently available with a native GDB running on the
964 Linux Kernel, under the following architectures: x86, x86_64,
965 PowerPC and PowerPC64.
967 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
969 Search memory for a sequence of bytes.
971 maint set python print-stack
972 maint show python print-stack
973 Show a stack trace when an error is encountered in a Python script.
976 Invoke CODE by passing it to the Python interpreter.
981 These allow macros to be defined, undefined, and listed
985 Show operating system information about processes.
988 List the inferiors currently under GDB's control.
991 Switch focus to inferior number NUM.
994 Detach from inferior number NUM.
997 Kill inferior number NUM.
1001 set spu stop-on-load
1002 show spu stop-on-load
1003 Control whether to stop for new SPE threads during Cell/B.E. debugging.
1005 set spu auto-flush-cache
1006 show spu auto-flush-cache
1007 Control whether to automatically flush the software-managed cache
1008 during Cell/B.E. debugging.
1010 set sh calling-convention
1011 show sh calling-convention
1012 Control the calling convention used when calling SH target functions.
1015 show debug timestamp
1016 Control display of timestamps with GDB debugging output.
1018 set disassemble-next-line
1019 show disassemble-next-line
1020 Control display of disassembled source lines or instructions when
1023 set remote noack-packet
1024 show remote noack-packet
1025 Set/show the use of remote protocol QStartNoAckMode packet. See above
1026 under "New remote packets."
1028 set remote query-attached-packet
1029 show remote query-attached-packet
1030 Control use of remote protocol `qAttached' (query-attached) packet.
1032 set remote read-siginfo-object
1033 show remote read-siginfo-object
1034 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
1037 set remote write-siginfo-object
1038 show remote write-siginfo-object
1039 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
1042 set remote reverse-continue
1043 show remote reverse-continue
1044 Control use of remote protocol 'bc' (reverse-continue) packet.
1046 set remote reverse-step
1047 show remote reverse-step
1048 Control use of remote protocol 'bs' (reverse-step) packet.
1050 set displaced-stepping
1051 show displaced-stepping
1052 Control displaced stepping mode. Displaced stepping is a way to
1053 single-step over breakpoints without removing them from the debuggee.
1054 Also known as "out-of-line single-stepping".
1057 show debug displaced
1058 Control display of debugging info for displaced stepping.
1060 maint set internal-error
1061 maint show internal-error
1062 Control what GDB does when an internal error is detected.
1064 maint set internal-warning
1065 maint show internal-warning
1066 Control what GDB does when an internal warning is detected.
1071 Use a wrapper program to launch programs for debugging.
1073 set multiple-symbols (all|ask|cancel)
1074 show multiple-symbols
1075 The value of this variable can be changed to adjust the debugger behavior
1076 when an expression or a breakpoint location contains an ambiguous symbol
1077 name (an overloaded function name, for instance).
1079 set breakpoint always-inserted
1080 show breakpoint always-inserted
1081 Keep breakpoints always inserted in the target, as opposed to inserting
1082 them when resuming the target, and removing them when the target stops.
1083 This option can improve debugger performance on slow remote targets.
1085 set arm fallback-mode (arm|thumb|auto)
1086 show arm fallback-mode
1087 set arm force-mode (arm|thumb|auto)
1089 These commands control how ARM GDB determines whether instructions
1090 are ARM or Thumb. The default for both settings is auto, which uses
1091 the current CPSR value for instructions without symbols; previous
1092 versions of GDB behaved as if "set arm fallback-mode arm".
1094 set disable-randomization
1095 show disable-randomization
1096 Standalone programs run with the virtual address space randomization enabled
1097 by default on some platforms. This option keeps the addresses stable across
1098 multiple debugging sessions.
1102 Control whether other threads are stopped or not when some thread hits
1107 Requests that asynchronous execution is enabled in the target, if available.
1108 In this case, it's possible to resume target in the background, and interact
1109 with GDB while the target is running. "show target-async" displays the
1110 current state of asynchronous execution of the target.
1112 set target-wide-charset
1113 show target-wide-charset
1114 The target-wide-charset is the name of the character set that GDB
1115 uses when printing characters whose type is wchar_t.
1117 set tcp auto-retry (on|off)
1119 set tcp connect-timeout
1120 show tcp connect-timeout
1121 These commands allow GDB to retry failed TCP connections to a remote stub
1122 with a specified timeout period; this is useful if the stub is launched
1123 in parallel with GDB but may not be ready to accept connections immediately.
1125 set libthread-db-search-path
1126 show libthread-db-search-path
1127 Control list of directories which GDB will search for appropriate
1130 set schedule-multiple (on|off)
1131 show schedule-multiple
1132 Allow GDB to resume all threads of all processes or only threads of
1133 the current process.
1137 Use more aggressive caching for accesses to the stack. This improves
1138 performance of remote debugging (particularly backtraces) without
1139 affecting correctness.
1141 set interactive-mode (on|off|auto)
1142 show interactive-mode
1143 Control whether GDB runs in interactive mode (on) or not (off).
1144 When in interactive mode, GDB waits for the user to answer all
1145 queries. Otherwise, GDB does not wait and assumes the default
1146 answer. When set to auto (the default), GDB determines which
1147 mode to use based on the stdin settings.
1152 For program forks, this is replaced by the new more generic `info
1153 inferiors' command. To list checkpoints, you can still use the
1154 `info checkpoints' command, which was an alias for the `info forks'
1158 Replaced by the new `inferior' command. To switch between
1159 checkpoints, you can still use the `restart' command, which was an
1160 alias for the `fork' command.
1163 This is removed, since some targets don't have a notion of
1164 processes. To switch between processes, you can still use the
1165 `inferior' command using GDB's own inferior number.
1168 For program forks, this is replaced by the new more generic `kill
1169 inferior' command. To delete a checkpoint, you can still use the
1170 `delete checkpoint' command, which was an alias for the `delete
1174 For program forks, this is replaced by the new more generic `detach
1175 inferior' command. To detach a checkpoint, you can still use the
1176 `detach checkpoint' command, which was an alias for the `detach
1179 * New native configurations
1181 x86/x86_64 Darwin i[34567]86-*-darwin*
1183 x86_64 MinGW x86_64-*-mingw*
1187 Lattice Mico32 lm32-*
1188 x86 DICOS i[34567]86-*-dicos*
1189 x86_64 DICOS x86_64-*-dicos*
1192 * The GDB remote stub, gdbserver, now supports x86 Windows CE
1193 (mingw32ce) debugging.
1199 These commands were actually not implemented on any target.
1201 *** Changes in GDB 6.8
1203 * New native configurations
1205 NetBSD/hppa hppa*-*netbsd*
1206 Xtensa GNU/Linux xtensa*-*-linux*
1210 NetBSD/hppa hppa*-*-netbsd*
1211 Xtensa GNU/Lunux xtensa*-*-linux*
1213 * Change in command line behavior -- corefiles vs. process ids.
1215 When the '-p NUMBER' or '--pid NUMBER' options are used, and
1216 attaching to process NUMBER fails, GDB no longer attempts to open a
1217 core file named NUMBER. Attaching to a program using the -c option
1218 is no longer supported. Instead, use the '-p' or '--pid' options.
1220 * GDB can now be built as a native debugger for debugging Windows x86
1221 (mingw32) Portable Executable (PE) programs.
1223 * Pending breakpoints no longer change their number when their address
1226 * GDB now supports breakpoints with multiple locations,
1227 including breakpoints on C++ constructors, inside C++ templates,
1228 and in inlined functions.
1230 * GDB's ability to debug optimized code has been improved. GDB more
1231 accurately identifies function bodies and lexical blocks that occupy
1232 more than one contiguous range of addresses.
1234 * Target descriptions can now describe registers for PowerPC.
1236 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
1237 registers on PowerPC targets.
1239 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
1240 targets even when the libthread_db library is not available.
1242 * The GDB remote stub, gdbserver, now supports the new file transfer
1243 commands (remote put, remote get, and remote delete).
1245 * The GDB remote stub, gdbserver, now supports run and attach in
1246 extended-remote mode.
1248 * hppa*64*-*-hpux11* target broken
1249 The debugger is unable to start a program and fails with the following
1250 error: "Error trying to get information about dynamic linker".
1251 The gdb-6.7 release is also affected.
1253 * GDB now supports the --enable-targets= configure option to allow
1254 building a single GDB executable that supports multiple remote
1255 target architectures.
1257 * GDB now supports debugging C and C++ programs which use the
1258 Decimal Floating Point extension. In addition, the PowerPC target
1259 now has a set of pseudo-registers to inspect decimal float values
1260 stored in two consecutive float registers.
1262 * The -break-insert MI command can optionally create pending
1265 * Improved support for debugging Ada
1266 Many improvements to the Ada language support have been made. These
1268 - Better support for Ada2005 interface types
1269 - Improved handling of arrays and slices in general
1270 - Better support for Taft-amendment types
1271 - The '{type} ADDRESS' expression is now allowed on the left hand-side
1273 - Improved command completion in Ada
1276 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
1281 set print frame-arguments (all|scalars|none)
1282 show print frame-arguments
1283 The value of this variable can be changed to control which argument
1284 values should be printed by the debugger when displaying a frame.
1289 Transfer files to and from a remote target, and delete remote files.
1296 Transfer files to and from a remote target, and delete remote files.
1298 * New remote packets
1305 Open, close, read, write, and delete files on the remote system.
1308 Attach to an existing process on the remote system, in extended-remote
1312 Run a new process on the remote system, in extended-remote mode.
1314 *** Changes in GDB 6.7
1316 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
1317 bfd, libiberty and opcodes, as revealed by static analysis donated by
1318 Coverity, Inc. (http://scan.coverity.com).
1320 * When looking up multiply-defined global symbols, GDB will now prefer the
1321 symbol definition in the current shared library if it was built using the
1322 -Bsymbolic linker option.
1324 * When the Text User Interface (TUI) is not configured, GDB will now
1325 recognize the -tui command-line option and print a message that the TUI
1328 * The GDB remote stub, gdbserver, now has lower overhead for high
1329 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
1331 * GDB for MIPS targets now autodetects whether a remote target provides
1332 32-bit or 64-bit register values.
1334 * Support for C++ member pointers has been improved.
1336 * GDB now understands XML target descriptions, which specify the
1337 target's overall architecture. GDB can read a description from
1338 a local file or over the remote serial protocol.
1340 * Vectors of single-byte data use a new integer type which is not
1341 automatically displayed as character or string data.
1343 * The /s format now works with the print command. It displays
1344 arrays of single-byte integers and pointers to single-byte integers
1347 * Target descriptions can now describe target-specific registers,
1348 for architectures which have implemented the support (currently
1349 only ARM, M68K, and MIPS).
1351 * GDB and the GDB remote stub, gdbserver, now support the XScale
1354 * The GDB remote stub, gdbserver, has been updated to support
1355 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
1356 has been rewritten to use the standard GDB remote protocol.
1358 * GDB can now step into C++ functions which are called through thunks.
1360 * GDB for the Cell/B.E. SPU now supports overlay debugging.
1362 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
1363 layout. It also supports a TextSeg= and DataSeg= response when only
1364 segment base addresses (rather than offsets) are available.
1366 * The /i format now outputs any trailing branch delay slot instructions
1367 immediately following the last instruction within the count specified.
1369 * The GDB remote protocol "T" stop reply packet now supports a
1370 "library" response. Combined with the new "qXfer:libraries:read"
1371 packet, this response allows GDB to debug shared libraries on targets
1372 where the operating system manages the list of loaded libraries (e.g.
1373 Windows and SymbianOS).
1375 * The GDB remote stub, gdbserver, now supports dynamic link libraries
1376 (DLLs) on Windows and Windows CE targets.
1378 * GDB now supports a faster verification that a .debug file matches its binary
1379 according to its build-id signature, if the signature is present.
1385 Enable or disable hardware flow control (RTS/CTS) on the serial port
1386 when debugging using remote targets.
1388 set mem inaccessible-by-default
1389 show mem inaccessible-by-default
1390 If the target supplies a memory map, for instance via the remote
1391 protocol's "qXfer:memory-map:read" packet, setting this variable
1392 prevents GDB from accessing memory outside the memory map. This
1393 is useful for targets with memory mapped registers or which react
1394 badly to accesses of unmapped address space.
1396 set breakpoint auto-hw
1397 show breakpoint auto-hw
1398 If the target supplies a memory map, for instance via the remote
1399 protocol's "qXfer:memory-map:read" packet, setting this variable
1400 lets GDB use hardware breakpoints automatically for memory regions
1401 where it can not use software breakpoints. This covers both the
1402 "break" command and internal breakpoints used for other commands
1403 including "next" and "finish".
1406 catch exception unhandled
1407 Stop the program execution when Ada exceptions are raised.
1410 Stop the program execution when an Ada assertion failed.
1414 Set an alternate system root for target files. This is a more
1415 general version of "set solib-absolute-prefix", which is now
1416 an alias to "set sysroot".
1419 Provide extended SPU facility status information. This set of
1420 commands is available only when debugging the Cell/B.E. SPU
1423 * New native configurations
1425 OpenBSD/sh sh*-*openbsd*
1428 unset tdesc filename
1430 Use the specified local file as an XML target description, and do
1431 not query the target for its built-in description.
1435 OpenBSD/sh sh*-*-openbsd*
1436 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
1437 Toshiba Media Processor mep-elf
1439 * New remote packets
1442 Ignore the specified signals; pass them directly to the debugged program
1443 without stopping other threads or reporting them to GDB.
1445 qXfer:features:read:
1446 Read an XML target description from the target, which describes its
1451 Read or write contents of an spufs file on the target system. These
1452 packets are available only on the Cell/B.E. SPU architecture.
1454 qXfer:libraries:read:
1455 Report the loaded shared libraries. Combined with new "T" packet
1456 response, this packet allows GDB to debug shared libraries on
1457 targets where the operating system manages the list of loaded
1458 libraries (e.g. Windows and SymbianOS).
1462 Support for these obsolete configurations has been removed.
1470 i[34567]86-*-lynxos*
1471 i[34567]86-*-netware*
1472 i[34567]86-*-sco3.2v5*
1473 i[34567]86-*-sco3.2v4*
1475 i[34567]86-*-sysv4.2*
1478 i[34567]86-*-unixware2*
1479 i[34567]86-*-unixware*
1488 * Other removed features
1495 Various m68k-only ROM monitors.
1502 Various Renesas ROM monitors and debugging interfaces for SH and
1507 Support for a Macraigor serial interface to on-chip debugging.
1508 GDB does not directly support the newer parallel or USB
1513 A debug information format. The predecessor to DWARF 2 and
1514 DWARF 3, which are still supported.
1516 Support for the HP aCC compiler on HP-UX/PA-RISC
1518 SOM-encapsulated symbolic debugging information, automatic
1519 invocation of pxdb, and the aCC custom C++ ABI. This does not
1520 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
1521 with aCC can still be debugged on an assembly level.
1523 MIPS ".pdr" sections
1525 A MIPS-specific format used to describe stack frame layout
1526 in debugging information.
1530 GDB could work with an older version of Guile to debug
1531 the interpreter and Scheme programs running in it.
1533 set mips stack-arg-size
1534 set mips saved-gpreg-size
1536 Use "set mips abi" to control parameter passing for MIPS.
1538 *** Changes in GDB 6.6
1543 Cell Broadband Engine SPU spu-elf
1545 * GDB can now be configured as a cross-debugger targeting native Windows
1546 (mingw32) or Cygwin. It can communicate with a remote debugging stub
1547 running on a Windows system over TCP/IP to debug Windows programs.
1549 * The GDB remote stub, gdbserver, has been updated to support Windows and
1550 Cygwin debugging. Both single-threaded and multi-threaded programs are
1553 * The "set trust-readonly-sections" command works again. This command was
1554 broken in GDB 6.3, 6.4, and 6.5.
1556 * The "load" command now supports writing to flash memory, if the remote
1557 stub provides the required support.
1559 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
1560 longer requires symbolic debug information (e.g. DWARF-2).
1565 unset substitute-path
1566 show substitute-path
1567 Manage a list of substitution rules that GDB uses to rewrite the name
1568 of the directories where the sources are located. This can be useful
1569 for instance when the sources were moved to a different location
1570 between compilation and debugging.
1574 Print each CLI command as it is executed. Each command is prefixed with
1575 a number of `+' symbols representing the nesting depth.
1576 The source command now has a `-v' option to enable the same feature.
1580 The ARM Demon monitor support (RDP protocol, "target rdp").
1582 Kernel Object Display, an embedded debugging feature which only worked with
1583 an obsolete version of Cisco IOS.
1585 The 'set download-write-size' and 'show download-write-size' commands.
1587 * New remote packets
1590 Tell a stub about GDB client features, and request remote target features.
1591 The first feature implemented is PacketSize, which allows the target to
1592 specify the size of packets it can handle - to minimize the number of
1593 packets required and improve performance when connected to a remote
1597 Fetch an OS auxilliary vector from the remote stub. This packet is a
1598 more efficient replacement for qPart:auxv:read.
1600 qXfer:memory-map:read:
1601 Fetch a memory map from the remote stub, including information about
1602 RAM, ROM, and flash memory devices.
1607 Erase and program a flash memory device.
1609 * Removed remote packets
1612 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
1613 used it, and only gdbserver implemented it.
1615 *** Changes in GDB 6.5
1619 Renesas M32C/M16C m32c-elf
1621 Morpho Technologies ms1 ms1-elf
1625 init-if-undefined Initialize a convenience variable, but
1626 only if it doesn't already have a value.
1628 The following commands are presently only implemented for native GNU/Linux:
1630 checkpoint Save a snapshot of the program state.
1632 restart <n> Return the program state to a
1633 previously saved state.
1635 info checkpoints List currently saved checkpoints.
1637 delete-checkpoint <n> Delete a previously saved checkpoint.
1639 set|show detach-on-fork Tell gdb whether to detach from a newly
1640 forked process, or to keep debugging it.
1642 info forks List forks of the user program that
1643 are available to be debugged.
1645 fork <n> Switch to debugging one of several
1646 forks of the user program that are
1647 available to be debugged.
1649 delete-fork <n> Delete a fork from the list of forks
1650 that are available to be debugged (and
1651 kill the forked process).
1653 detach-fork <n> Delete a fork from the list of forks
1654 that are available to be debugged (and
1655 allow the process to continue).
1659 Morpho Technologies ms2 ms1-elf
1661 * Improved Windows host support
1663 GDB now builds as a cross debugger hosted on i686-mingw32, including
1664 native console support, and remote communications using either
1665 network sockets or serial ports.
1667 * Improved Modula-2 language support
1669 GDB can now print most types in the Modula-2 syntax. This includes:
1670 basic types, set types, record types, enumerated types, range types,
1671 pointer types and ARRAY types. Procedure var parameters are correctly
1672 printed and hexadecimal addresses and character constants are also
1673 written in the Modula-2 syntax. Best results can be obtained by using
1674 GNU Modula-2 together with the -gdwarf-2 command line option.
1678 The ARM rdi-share module.
1680 The Netware NLM debug server.
1682 *** Changes in GDB 6.4
1684 * New native configurations
1686 OpenBSD/arm arm*-*-openbsd*
1687 OpenBSD/mips64 mips64-*-openbsd*
1691 Morpho Technologies ms1 ms1-elf
1693 * New command line options
1695 --batch-silent As for --batch, but totally silent.
1696 --return-child-result The debugger will exist with the same value
1697 the child (debugged) program exited with.
1698 --eval-command COMMAND, -ex COMMAND
1699 Execute a single GDB CLI command. This may be
1700 specified multiple times and in conjunction
1701 with the --command (-x) option.
1703 * Deprecated commands removed
1705 The following commands, that were deprecated in 2000, have been
1709 set|show arm disassembly-flavor set|show arm disassembler
1710 othernames set arm disassembler
1711 set|show remotedebug set|show debug remote
1712 set|show archdebug set|show debug arch
1713 set|show eventdebug set|show debug event
1716 * New BSD user-level threads support
1718 It is now possible to debug programs using the user-level threads
1719 library on OpenBSD and FreeBSD. Currently supported (target)
1722 FreeBSD/amd64 x86_64-*-freebsd*
1723 FreeBSD/i386 i386-*-freebsd*
1724 OpenBSD/i386 i386-*-openbsd*
1726 Note that the new kernel threads libraries introduced in FreeBSD 5.x
1727 are not yet supported.
1729 * New support for Matsushita MN10300 w/sim added
1730 (Work in progress). mn10300-elf.
1732 * REMOVED configurations and files
1734 VxWorks and the XDR protocol *-*-vxworks
1735 Motorola MCORE mcore-*-*
1736 National Semiconductor NS32000 ns32k-*-*
1738 * New "set print array-indexes" command
1740 After turning this setting "on", GDB prints the index of each element
1741 when displaying arrays. The default is "off" to preserve the previous
1744 * VAX floating point support
1746 GDB now supports the not-quite-ieee VAX F and D floating point formats.
1748 * User-defined command support
1750 In addition to using $arg0..$arg9 for argument passing, it is now possible
1751 to use $argc to determine now many arguments have been passed. See the
1752 section on user-defined commands in the user manual for more information.
1754 *** Changes in GDB 6.3:
1756 * New command line option
1758 GDB now accepts -l followed by a number to set the timeout for remote
1761 * GDB works with GCC -feliminate-dwarf2-dups
1763 GDB now supports a more compact representation of DWARF-2 debug
1764 information using DW_FORM_ref_addr references. These are produced
1765 by GCC with the option -feliminate-dwarf2-dups and also by some
1766 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
1767 to use -feliminate-dwarf2-dups.
1769 * Internationalization
1771 When supported by the host system, GDB will be built with
1772 internationalization (libintl). The task of marking up the sources is
1773 continued, we're looking forward to our first translation.
1777 Initial support for debugging programs compiled with the GNAT
1778 implementation of the Ada programming language has been integrated
1779 into GDB. In this release, support is limited to expression evaluation.
1781 * New native configurations
1783 GNU/Linux/m32r m32r-*-linux-gnu
1787 GDB's remote protocol now includes support for the 'p' packet. This
1788 packet is used to fetch individual registers from a remote inferior.
1790 * END-OF-LIFE registers[] compatibility module
1792 GDB's internal register infrastructure has been completely rewritten.
1793 The new infrastructure making possible the implementation of key new
1794 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
1797 GDB 6.3 will be the last release to include the the registers[]
1798 compatibility module that allowed out-of-date configurations to
1799 continue to work. This change directly impacts the following
1809 powerpc bdm protocol
1811 Unless there is activity to revive these configurations, they will be
1812 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
1814 * OBSOLETE configurations and files
1816 Configurations that have been declared obsolete in this release have
1817 been commented out. Unless there is activity to revive these
1818 configurations, the next release of GDB will have their sources
1819 permanently REMOVED.
1828 *** Changes in GDB 6.2.1:
1830 * MIPS `break main; run' gave an heuristic-fence-post warning
1832 When attempting to run even a simple program, a warning about
1833 heuristic-fence-post being hit would be reported. This problem has
1836 * MIPS IRIX 'long double' crashed GDB
1838 When examining a long double variable, GDB would get a segmentation
1839 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
1840 IRIX long double values).
1844 A bug in the VAX stack code was causing problems with the "next"
1845 command. This problem has been fixed.
1847 *** Changes in GDB 6.2:
1849 * Fix for ``many threads''
1851 On GNU/Linux systems that use the NPTL threads library, a program
1852 rapidly creating and deleting threads would confuse GDB leading to the
1855 ptrace: No such process.
1856 thread_db_get_info: cannot get thread info: generic error
1858 This problem has been fixed.
1860 * "-async" and "-noasync" options removed.
1862 Support for the broken "-noasync" option has been removed (it caused
1865 * New ``start'' command.
1867 This command runs the program until the begining of the main procedure.
1869 * New BSD Kernel Data Access Library (libkvm) interface
1871 Using ``target kvm'' it is now possible to debug kernel core dumps and
1872 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
1873 platforms. Currently supported (native-only) configurations are:
1875 FreeBSD/amd64 x86_64-*-freebsd*
1876 FreeBSD/i386 i?86-*-freebsd*
1877 NetBSD/i386 i?86-*-netbsd*
1878 NetBSD/m68k m68*-*-netbsd*
1879 NetBSD/sparc sparc-*-netbsd*
1880 OpenBSD/amd64 x86_64-*-openbsd*
1881 OpenBSD/i386 i?86-*-openbsd*
1882 OpenBSD/m68k m68*-openbsd*
1883 OpenBSD/sparc sparc-*-openbsd*
1885 * Signal trampoline code overhauled
1887 Many generic problems with GDB's signal handling code have been fixed.
1888 These include: backtraces through non-contiguous stacks; recognition
1889 of sa_sigaction signal trampolines; backtrace from a NULL pointer
1890 call; backtrace through a signal trampoline; step into and out of
1891 signal handlers; and single-stepping in the signal trampoline.
1893 Please note that kernel bugs are a limiting factor here. These
1894 features have been shown to work on an s390 GNU/Linux system that
1895 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
1897 * Cygwin support for DWARF 2 added.
1899 * New native configurations
1901 GNU/Linux/hppa hppa*-*-linux*
1902 OpenBSD/hppa hppa*-*-openbsd*
1903 OpenBSD/m68k m68*-*-openbsd*
1904 OpenBSD/m88k m88*-*-openbsd*
1905 OpenBSD/powerpc powerpc-*-openbsd*
1906 NetBSD/vax vax-*-netbsd*
1907 OpenBSD/vax vax-*-openbsd*
1909 * END-OF-LIFE frame compatibility module
1911 GDB's internal frame infrastructure has been completely rewritten.
1912 The new infrastructure making it possible to support key new features
1913 including DWARF 2 Call Frame Information. To aid in the task of
1914 migrating old configurations to this new infrastructure, a
1915 compatibility module, that allowed old configurations to continue to
1916 work, was also included.
1918 GDB 6.2 will be the last release to include this frame compatibility
1919 module. This change directly impacts the following configurations:
1929 Unless there is activity to revive these configurations, they will be
1930 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
1932 * REMOVED configurations and files
1934 Sun 3, running SunOS 3 m68*-*-sunos3*
1935 Sun 3, running SunOS 4 m68*-*-sunos4*
1936 Sun 2, running SunOS 3 m68000-*-sunos3*
1937 Sun 2, running SunOS 4 m68000-*-sunos4*
1938 Motorola 680x0 running LynxOS m68*-*-lynxos*
1939 AT&T 3b1/Unix pc m68*-att-*
1940 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
1941 decstation mips-dec-* mips-little-*
1942 riscos mips-*-riscos* mips-*-sysv*
1943 sonymips mips-sony-*
1944 sysv mips*-*-sysv4* (IRIX 5/6 not included)
1946 *** Changes in GDB 6.1.1:
1948 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
1950 The TUI (Text-mode User Interface) is now built as part of a default
1951 GDB configuration. It is enabled by either selecting the TUI with the
1952 command line option "-i=tui" or by running the separate "gdbtui"
1953 program. For more information on the TUI, see the manual "Debugging
1956 * Pending breakpoint support (also included in GDB 6.1)
1958 Support has been added to allow you to specify breakpoints in shared
1959 libraries that have not yet been loaded. If a breakpoint location
1960 cannot be found, and the "breakpoint pending" option is set to auto,
1961 GDB queries you if you wish to make the breakpoint pending on a future
1962 shared-library load. If and when GDB resolves the breakpoint symbol,
1963 the pending breakpoint is removed as one or more regular breakpoints
1966 Pending breakpoints are very useful for GCJ Java debugging.
1968 * Fixed ISO-C build problems
1970 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
1971 non ISO-C code that stopped them being built using a more strict ISO-C
1972 compiler (e.g., IBM's C compiler).
1974 * Fixed build problem on IRIX 5
1976 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
1977 wasn't able to compile compile on an IRIX 5 system.
1979 * Added execute permission to gdb/gdbserver/configure
1981 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
1982 permission. This bug would cause configure to fail on a number of
1983 systems (Solaris, IRIX). Ref: server/519.
1985 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
1987 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
1988 has been updated to use constant array sizes.
1990 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
1992 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
1993 its generated DWARF Call Frame Info. This encoding was causing GDB to
1994 panic, that panic has been fixed. Ref: gdb/1628.
1996 * Fixed a problem when examining parameters in shared library code.
1998 When examining parameters in optimized shared library code generated
1999 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
2000 not available''. GDB now correctly displays the variable's value.
2002 *** Changes in GDB 6.1:
2004 * Removed --with-mmalloc
2006 Support for the mmalloc memory manager has been removed, as it
2007 conflicted with the internal gdb byte cache.
2009 * Changes in AMD64 configurations
2011 The AMD64 target now includes the %cs and %ss registers. As a result
2012 the AMD64 remote protocol has changed; this affects the floating-point
2013 and SSE registers. If you rely on those registers for your debugging,
2014 you should upgrade gdbserver on the remote side.
2016 * Revised SPARC target
2018 The SPARC target has been completely revised, incorporating the
2019 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
2020 support for LynxOS and SunOS 4 has been dropped. Calling functions
2021 from within GDB on operating systems with a non-executable stack
2022 (Solaris, OpenBSD) now works.
2026 GDB has a new C++ demangler which does a better job on the mangled
2027 names generated by current versions of g++. It also runs faster, so
2028 with this and other changes gdb should now start faster on large C++
2031 * DWARF 2 Location Expressions
2033 GDB support for location expressions has been extended to support function
2034 arguments and frame bases. Older versions of GDB could crash when they
2037 * C++ nested types and namespaces
2039 GDB's support for nested types and namespaces in C++ has been
2040 improved, especially if you use the DWARF 2 debugging format. (This
2041 is the default for recent versions of GCC on most platforms.)
2042 Specifically, if you have a class "Inner" defined within a class or
2043 namespace "Outer", then GDB realizes that the class's name is
2044 "Outer::Inner", not simply "Inner". This should greatly reduce the
2045 frequency of complaints about not finding RTTI symbols. In addition,
2046 if you are stopped at inside of a function defined within a namespace,
2047 GDB modifies its name lookup accordingly.
2049 * New native configurations
2051 NetBSD/amd64 x86_64-*-netbsd*
2052 OpenBSD/amd64 x86_64-*-openbsd*
2053 OpenBSD/alpha alpha*-*-openbsd*
2054 OpenBSD/sparc sparc-*-openbsd*
2055 OpenBSD/sparc64 sparc64-*-openbsd*
2057 * New debugging protocols
2059 M32R with SDI protocol m32r-*-elf*
2061 * "set prompt-escape-char" command deleted.
2063 The command "set prompt-escape-char" has been deleted. This command,
2064 and its very obscure effet on GDB's prompt, was never documented,
2065 tested, nor mentioned in the NEWS file.
2067 * OBSOLETE configurations and files
2069 Configurations that have been declared obsolete in this release have
2070 been commented out. Unless there is activity to revive these
2071 configurations, the next release of GDB will have their sources
2072 permanently REMOVED.
2074 Sun 3, running SunOS 3 m68*-*-sunos3*
2075 Sun 3, running SunOS 4 m68*-*-sunos4*
2076 Sun 2, running SunOS 3 m68000-*-sunos3*
2077 Sun 2, running SunOS 4 m68000-*-sunos4*
2078 Motorola 680x0 running LynxOS m68*-*-lynxos*
2079 AT&T 3b1/Unix pc m68*-att-*
2080 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2081 decstation mips-dec-* mips-little-*
2082 riscos mips-*-riscos* mips-*-sysv*
2083 sonymips mips-sony-*
2084 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2086 * REMOVED configurations and files
2088 SGI Irix-4.x mips-sgi-irix4 or iris4
2089 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
2090 Z8000 simulator z8k-zilog-none or z8ksim
2091 Matsushita MN10200 w/simulator mn10200-*-*
2092 H8/500 simulator h8500-hitachi-hms or h8500hms
2093 HP/PA running BSD hppa*-*-bsd*
2094 HP/PA running OSF/1 hppa*-*-osf*
2095 HP/PA Pro target hppa*-*-pro*
2096 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2097 386BSD i[3456]86-*-bsd*
2098 Sequent family i[3456]86-sequent-sysv4*
2099 i[3456]86-sequent-sysv*
2100 i[3456]86-sequent-bsd*
2101 SPARC running LynxOS sparc-*-lynxos*
2102 SPARC running SunOS 4 sparc-*-sunos4*
2103 Tsqware Sparclet sparclet-*-*
2104 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2106 *** Changes in GDB 6.0:
2110 Support for debugging the Objective-C programming language has been
2111 integrated into GDB.
2113 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
2115 DWARF 2's Call Frame Information makes available compiler generated
2116 information that more exactly describes the program's run-time stack.
2117 By using this information, GDB is able to provide more robust stack
2120 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
2121 have been updated to use a new backtrace mechanism which includes
2122 DWARF 2 CFI support.
2126 GDB's remote protocol has been extended to include support for hosted
2127 file I/O (where the remote target uses GDB's file system). See GDB's
2128 remote protocol documentation for details.
2130 * All targets using the new architecture framework.
2132 All of GDB's targets have been updated to use the new internal
2133 architecture framework. The way is now open for future GDB releases
2134 to include cross-architecture native debugging support (i386 on amd64,
2137 * GNU/Linux's Thread Local Storage (TLS)
2139 GDB now includes support for for the GNU/Linux implementation of
2140 per-thread variables.
2142 * GNU/Linux's Native POSIX Thread Library (NPTL)
2144 GDB's thread code has been updated to work with either the new
2145 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
2147 * Separate debug info.
2149 GDB, in conjunction with BINUTILS, now supports a mechanism for
2150 automatically loading debug information from a separate file. Instead
2151 of shipping full debug and non-debug versions of system libraries,
2152 system integrators can now instead ship just the stripped libraries
2153 and optional debug files.
2155 * DWARF 2 Location Expressions
2157 DWARF 2 Location Expressions allow the compiler to more completely
2158 describe the location of variables (even in optimized code) to the
2161 GDB now includes preliminary support for location expressions (support
2162 for DW_OP_piece is still missing).
2166 A number of long standing bugs that caused GDB to die while starting a
2167 Java application have been fixed. GDB's Java support is now
2168 considered "useable".
2170 * GNU/Linux support for fork, vfork, and exec.
2172 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
2173 commands are now implemented for GNU/Linux. They require a 2.5.x or later
2176 * GDB supports logging output to a file
2178 There are two new commands, "set logging" and "show logging", which can be
2179 used to capture GDB's output to a file.
2181 * The meaning of "detach" has changed for gdbserver
2183 The "detach" command will now resume the application, as documented. To
2184 disconnect from gdbserver and leave it stopped, use the new "disconnect"
2187 * d10v, m68hc11 `regs' command deprecated
2189 The `info registers' command has been updated so that it displays the
2190 registers using a format identical to the old `regs' command.
2194 A new command, "maint set profile on/off", has been added. This command can
2195 be used to enable or disable profiling while running GDB, to profile a
2196 session or a set of commands. In addition there is a new configure switch,
2197 "--enable-profiling", which will cause GDB to be compiled with profiling
2198 data, for more informative profiling results.
2200 * Default MI syntax changed to "mi2".
2202 The default MI (machine interface) syntax, enabled by the command line
2203 option "-i=mi", has been changed to "mi2". The previous MI syntax,
2204 "mi1", can be enabled by specifying the option "-i=mi1".
2206 Support for the original "mi0" syntax (included in GDB 5.0) has been
2209 Fix for gdb/192: removed extraneous space when displaying frame level.
2210 Fix for gdb/672: update changelist is now output in mi list format.
2211 Fix for gdb/702: a -var-assign that updates the value now shows up
2212 in a subsequent -var-update.
2214 * New native configurations.
2216 FreeBSD/amd64 x86_64-*-freebsd*
2218 * Multi-arched targets.
2220 HP/PA HPUX11 hppa*-*-hpux*
2221 Renesas M32R/D w/simulator m32r-*-elf*
2223 * OBSOLETE configurations and files
2225 Configurations that have been declared obsolete in this release have
2226 been commented out. Unless there is activity to revive these
2227 configurations, the next release of GDB will have their sources
2228 permanently REMOVED.
2230 Z8000 simulator z8k-zilog-none or z8ksim
2231 Matsushita MN10200 w/simulator mn10200-*-*
2232 H8/500 simulator h8500-hitachi-hms or h8500hms
2233 HP/PA running BSD hppa*-*-bsd*
2234 HP/PA running OSF/1 hppa*-*-osf*
2235 HP/PA Pro target hppa*-*-pro*
2236 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2237 Sequent family i[3456]86-sequent-sysv4*
2238 i[3456]86-sequent-sysv*
2239 i[3456]86-sequent-bsd*
2240 Tsqware Sparclet sparclet-*-*
2241 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2243 * REMOVED configurations and files
2246 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2247 IBM AIX PS/2 i[3456]86-*-aix
2248 i386 running Mach 3.0 i[3456]86-*-mach3*
2249 i386 running Mach i[3456]86-*-mach*
2250 i386 running OSF/1 i[3456]86-*osf1mk*
2251 HP/Apollo 68k Family m68*-apollo*-sysv*,
2253 m68*-hp-bsd*, m68*-hp-hpux*
2254 Argonaut Risc Chip (ARC) arc-*-*
2255 Mitsubishi D30V d30v-*-*
2256 Fujitsu FR30 fr30-*-elf*
2257 OS/9000 i[34]86-*-os9k
2258 I960 with MON960 i960-*-coff
2260 * MIPS $fp behavior changed
2262 The convenience variable $fp, for the MIPS, now consistently returns
2263 the address of the current frame's base. Previously, depending on the
2264 context, $fp could refer to either $sp or the current frame's base
2265 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
2266 The GNU Source-Level Debugger''.
2268 *** Changes in GDB 5.3:
2270 * GNU/Linux shared library multi-threaded performance improved.
2272 When debugging a multi-threaded application on GNU/Linux, GDB now uses
2273 `/proc', in preference to `ptrace' for memory reads. This may result
2274 in an improvement in the start-up time of multi-threaded, shared
2275 library applications when run under GDB. One GDB user writes: ``loads
2276 shared libs like mad''.
2278 * ``gdbserver'' now supports multi-threaded applications on some targets
2280 Support for debugging multi-threaded applications which use
2281 the GNU/Linux LinuxThreads package has been added for
2282 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
2283 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
2285 * GDB now supports C/C++ preprocessor macros.
2287 GDB now expands preprocessor macro invocations in C/C++ expressions,
2288 and provides various commands for showing macro definitions and how
2291 The new command `macro expand EXPRESSION' expands any macro
2292 invocations in expression, and shows the result.
2294 The new command `show macro MACRO-NAME' shows the definition of the
2295 macro named MACRO-NAME, and where it was defined.
2297 Most compilers don't include information about macros in the debugging
2298 information by default. In GCC 3.1, for example, you need to compile
2299 your program with the options `-gdwarf-2 -g3'. If the macro
2300 information is present in the executable, GDB will read it.
2302 * Multi-arched targets.
2304 DEC Alpha (partial) alpha*-*-*
2305 DEC VAX (partial) vax-*-*
2307 National Semiconductor NS32000 (partial) ns32k-*-*
2308 Motorola 68000 (partial) m68k-*-*
2309 Motorola MCORE mcore-*-*
2313 Fujitsu FRV architecture added by Red Hat frv*-*-*
2316 * New native configurations
2318 Alpha NetBSD alpha*-*-netbsd*
2319 SH NetBSD sh*-*-netbsdelf*
2320 MIPS NetBSD mips*-*-netbsd*
2321 UltraSPARC NetBSD sparc64-*-netbsd*
2323 * OBSOLETE configurations and files
2325 Configurations that have been declared obsolete in this release have
2326 been commented out. Unless there is activity to revive these
2327 configurations, the next release of GDB will have their sources
2328 permanently REMOVED.
2330 Mitsubishi D30V d30v-*-*
2331 OS/9000 i[34]86-*-os9k
2332 IBM AIX PS/2 i[3456]86-*-aix
2333 Fujitsu FR30 fr30-*-elf*
2334 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2335 Argonaut Risc Chip (ARC) arc-*-*
2336 i386 running Mach 3.0 i[3456]86-*-mach3*
2337 i386 running Mach i[3456]86-*-mach*
2338 i386 running OSF/1 i[3456]86-*osf1mk*
2339 HP/Apollo 68k Family m68*-apollo*-sysv*,
2341 m68*-hp-bsd*, m68*-hp-hpux*
2342 I960 with MON960 i960-*-coff
2344 * OBSOLETE languages
2346 CHILL, a Pascal like language used by telecommunications companies.
2348 * REMOVED configurations and files
2350 AMD 29k family via UDI a29k-amd-udi, udi29k
2351 A29K VxWorks a29k-*-vxworks
2352 AMD 29000 embedded, using EBMON a29k-none-none
2353 AMD 29000 embedded with COFF a29k-none-coff
2354 AMD 29000 embedded with a.out a29k-none-aout
2356 testsuite/gdb.hp/gdb.threads-hp/ directory
2358 * New command "set max-user-call-depth <nnn>"
2360 This command allows the user to limit the call depth of user-defined
2361 commands. The default is 1024.
2363 * Changes in FreeBSD/i386 native debugging.
2365 Support for the "generate-core-file" has been added.
2367 * New commands "dump", "append", and "restore".
2369 These commands allow data to be copied from target memory
2370 to a bfd-format or binary file (dump and append), and back
2371 from a file into memory (restore).
2373 * Improved "next/step" support on multi-processor Alpha Tru64.
2375 The previous single-step mechanism could cause unpredictable problems,
2376 including the random appearance of SIGSEGV or SIGTRAP signals. The use
2377 of a software single-step mechanism prevents this.
2379 *** Changes in GDB 5.2.1:
2387 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
2388 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
2389 Fix, by Joel Brobecker imported from mainline.
2391 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
2392 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
2393 Fix, by Fred Fish, imported from mainline.
2395 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
2396 Surprisingly enough, it works now.
2397 By Michal Ludvig, imported from mainline.
2399 i386 hardware watchpoint support:
2400 avoid misses on second run for some targets.
2401 By Pierre Muller, imported from mainline.
2403 *** Changes in GDB 5.2:
2405 * New command "set trust-readonly-sections on[off]".
2407 This command is a hint that tells gdb that read-only sections
2408 really are read-only (ie. that their contents will not change).
2409 In this mode, gdb will go to the object file rather than the
2410 target to read memory from read-only sections (such as ".text").
2411 This can be a significant performance improvement on some
2412 (notably embedded) targets.
2414 * New command "generate-core-file" (or "gcore").
2416 This new gdb command allows the user to drop a core file of the child
2417 process state at any time. So far it's been implemented only for
2418 GNU/Linux and Solaris, but should be relatively easily ported to other
2419 hosts. Argument is core file name (defaults to core.<pid>).
2421 * New command line option
2423 GDB now accepts --pid or -p followed by a process id.
2425 * Change in command line behavior -- corefiles vs. process ids.
2427 There is a subtle behavior in the way in which GDB handles
2428 command line arguments. The first non-flag argument is always
2429 a program to debug, but the second non-flag argument may either
2430 be a corefile or a process id. Previously, GDB would attempt to
2431 open the second argument as a corefile, and if that failed, would
2432 issue a superfluous error message and then attempt to attach it as
2433 a process. Now, if the second argument begins with a non-digit,
2434 it will be treated as a corefile. If it begins with a digit,
2435 GDB will attempt to attach it as a process, and if no such process
2436 is found, will then attempt to open it as a corefile.
2438 * Changes in ARM configurations.
2440 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
2441 configuration is fully multi-arch.
2443 * New native configurations
2445 ARM NetBSD arm*-*-netbsd*
2446 x86 OpenBSD i[3456]86-*-openbsd*
2447 AMD x86-64 running GNU/Linux x86_64-*-linux-*
2448 Sparc64 running FreeBSD sparc64-*-freebsd*
2452 Sanyo XStormy16 xstormy16-elf
2454 * OBSOLETE configurations and files
2456 Configurations that have been declared obsolete in this release have
2457 been commented out. Unless there is activity to revive these
2458 configurations, the next release of GDB will have their sources
2459 permanently REMOVED.
2461 AMD 29k family via UDI a29k-amd-udi, udi29k
2462 A29K VxWorks a29k-*-vxworks
2463 AMD 29000 embedded, using EBMON a29k-none-none
2464 AMD 29000 embedded with COFF a29k-none-coff
2465 AMD 29000 embedded with a.out a29k-none-aout
2467 testsuite/gdb.hp/gdb.threads-hp/ directory
2469 * REMOVED configurations and files
2471 TI TMS320C80 tic80-*-*
2473 PowerPC Solaris powerpcle-*-solaris*
2474 PowerPC Windows NT powerpcle-*-cygwin32
2475 PowerPC Netware powerpc-*-netware*
2476 Harris/CXUX m88k m88*-harris-cxux*
2477 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
2478 ns32k-utek-sysv* ns32k-utek-*
2479 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
2480 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
2481 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
2482 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
2483 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
2485 * Changes to command line processing
2487 The new `--args' feature can be used to specify command-line arguments
2488 for the inferior from gdb's command line.
2490 * Changes to key bindings
2492 There is a new `operate-and-get-next' function bound to `C-o'.
2494 *** Changes in GDB 5.1.1
2496 Fix compile problem on DJGPP.
2498 Fix a problem with floating-point registers on the i386 being
2501 Fix to stop GDB crashing on .debug_str debug info.
2503 Numerous documentation fixes.
2505 Numerous testsuite fixes.
2507 *** Changes in GDB 5.1:
2509 * New native configurations
2511 Alpha FreeBSD alpha*-*-freebsd*
2512 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
2513 MIPS GNU/Linux mips*-*-linux*
2514 MIPS SGI Irix 6.x mips*-sgi-irix6*
2515 ia64 AIX ia64-*-aix*
2516 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
2520 Motorola 68HC11 and 68HC12 m68hc11-elf
2522 UltraSparc running GNU/Linux sparc64-*-linux*
2524 * OBSOLETE configurations and files
2526 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
2527 Harris/CXUX m88k m88*-harris-cxux*
2528 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
2529 ns32k-utek-sysv* ns32k-utek-*
2530 TI TMS320C80 tic80-*-*
2532 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
2533 PowerPC Solaris powerpcle-*-solaris*
2534 PowerPC Windows NT powerpcle-*-cygwin32
2535 PowerPC Netware powerpc-*-netware*
2536 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
2537 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
2538 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
2539 Apple Macintosh (MPW) host N/A
2541 stuff.c (Program to stuff files into a specially prepared space in kdb)
2542 kdb-start.c (Main loop for the standalone kernel debugger)
2544 Configurations that have been declared obsolete in this release have
2545 been commented out. Unless there is activity to revive these
2546 configurations, the next release of GDB will have their sources
2547 permanently REMOVED.
2549 * REMOVED configurations and files
2551 Altos 3068 m68*-altos-*
2552 Convex c1-*-*, c2-*-*
2554 ARM RISCix arm-*-* (as host)
2558 * GDB has been converted to ISO C.
2560 GDB's source code has been converted to ISO C. In particular, the
2561 sources are fully protoized, and rely on standard headers being
2566 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
2568 * The MI enabled by default.
2570 The new machine oriented interface (MI) introduced in GDB 5.0 has been
2571 revised and enabled by default. Packages which use GDB as a debugging
2572 engine behind a UI or another front end are encouraged to switch to
2573 using the GDB/MI interface, instead of the old annotations interface
2574 which is now deprecated.
2576 * Support for debugging Pascal programs.
2578 GDB now includes support for debugging Pascal programs. The following
2579 main features are supported:
2581 - Pascal-specific data types such as sets;
2583 - automatic recognition of Pascal sources based on file-name
2586 - Pascal-style display of data types, variables, and functions;
2588 - a Pascal expression parser.
2590 However, some important features are not yet supported.
2592 - Pascal string operations are not supported at all;
2594 - there are some problems with boolean types;
2596 - Pascal type hexadecimal constants are not supported
2597 because they conflict with the internal variables format;
2599 - support for Pascal objects and classes is not full yet;
2601 - unlike Pascal, GDB is case-sensitive for symbol names.
2603 * Changes in completion.
2605 Commands such as `shell', `run' and `set args', which pass arguments
2606 to inferior programs, now complete on file names, similar to what
2607 users expect at the shell prompt.
2609 Commands which accept locations, such as `disassemble', `print',
2610 `breakpoint', `until', etc. now complete on filenames as well as
2611 program symbols. Thus, if you type "break foob TAB", and the source
2612 files linked into the programs include `foobar.c', that file name will
2613 be one of the candidates for completion. However, file names are not
2614 considered for completion after you typed a colon that delimits a file
2615 name from a name of a function in that file, as in "break foo.c:bar".
2617 `set demangle-style' completes on available demangling styles.
2619 * New platform-independent commands:
2621 It is now possible to define a post-hook for a command as well as a
2622 hook that runs before the command. For more details, see the
2623 documentation of `hookpost' in the GDB manual.
2625 * Changes in GNU/Linux native debugging.
2627 Support for debugging multi-threaded programs has been completely
2628 revised for all platforms except m68k and sparc. You can now debug as
2629 many threads as your system allows you to have.
2631 Attach/detach is supported for multi-threaded programs.
2633 Support for SSE registers was added for x86. This doesn't work for
2634 multi-threaded programs though.
2636 * Changes in MIPS configurations.
2638 Multi-arch support is enabled for all MIPS configurations.
2640 GDB can now be built as native debugger on SGI Irix 6.x systems for
2641 debugging n32 executables. (Debugging 64-bit executables is not yet
2644 * Unified support for hardware watchpoints in all x86 configurations.
2646 Most (if not all) native x86 configurations support hardware-assisted
2647 breakpoints and watchpoints in a unified manner. This support
2648 implements debug register sharing between watchpoints, which allows to
2649 put a virtually infinite number of watchpoints on the same address,
2650 and also supports watching regions up to 16 bytes with several debug
2653 The new maintenance command `maintenance show-debug-regs' toggles
2654 debugging print-outs in functions that insert, remove, and test
2655 watchpoints and hardware breakpoints.
2657 * Changes in the DJGPP native configuration.
2659 New command ``info dos sysinfo'' displays assorted information about
2660 the CPU, OS, memory, and DPMI server.
2662 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
2663 display information about segment descriptors stored in GDT, LDT, and
2666 New commands ``info dos pde'' and ``info dos pte'' display entries
2667 from Page Directory and Page Tables (for now works with CWSDPMI only).
2668 New command ``info dos address-pte'' displays the Page Table entry for
2669 a given linear address.
2671 GDB can now pass command lines longer than 126 characters to the
2672 program being debugged (requires an update to the libdbg.a library
2673 which is part of the DJGPP development kit).
2675 DWARF2 debug info is now supported.
2677 It is now possible to `step' and `next' through calls to `longjmp'.
2679 * Changes in documentation.
2681 All GDB documentation was converted to GFDL, the GNU Free
2682 Documentation License.
2684 Tracepoints-related commands are now fully documented in the GDB
2687 TUI, the Text-mode User Interface, is now documented in the manual.
2689 Tracepoints-related commands are now fully documented in the GDB
2692 The "GDB Internals" manual now has an index. It also includes
2693 documentation of `ui_out' functions, GDB coding standards, x86
2694 hardware watchpoints, and memory region attributes.
2696 * GDB's version number moved to ``version.in''
2698 The Makefile variable VERSION has been replaced by the file
2699 ``version.in''. People creating GDB distributions should update the
2700 contents of this file.
2704 GUD support is now a standard part of the EMACS distribution.
2706 *** Changes in GDB 5.0:
2708 * Improved support for debugging FP programs on x86 targets
2710 Unified and much-improved support for debugging floating-point
2711 programs on all x86 targets. In particular, ``info float'' now
2712 displays the FP registers in the same format on all x86 targets, with
2713 greater level of detail.
2715 * Improvements and bugfixes in hardware-assisted watchpoints
2717 It is now possible to watch array elements, struct members, and
2718 bitfields with hardware-assisted watchpoints. Data-read watchpoints
2719 on x86 targets no longer erroneously trigger when the address is
2722 * Improvements in the native DJGPP version of GDB
2724 The distribution now includes all the scripts and auxiliary files
2725 necessary to build the native DJGPP version on MS-DOS/MS-Windows
2726 machines ``out of the box''.
2728 The DJGPP version can now debug programs that use signals. It is
2729 possible to catch signals that happened in the debuggee, deliver
2730 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
2731 would kill the program being debugged.) Programs that hook hardware
2732 interrupts (keyboard, timer, etc.) can also be debugged.
2734 It is now possible to debug DJGPP programs that redirect their
2735 standard handles or switch them to raw (as opposed to cooked) mode, or
2736 even close them. The command ``run < foo > bar'' works as expected,
2737 and ``info terminal'' reports useful information about the debuggee's
2738 terminal, including raw/cooked mode, redirection, etc.
2740 The DJGPP version now uses termios functions for console I/O, which
2741 enables debugging graphics programs. Interrupting GDB with Ctrl-C
2744 DOS-style file names with drive letters are now fully supported by
2747 It is now possible to debug DJGPP programs that switch their working
2748 directory. It is also possible to rerun the debuggee any number of
2749 times without restarting GDB; thus, you can use the same setup,
2750 breakpoints, etc. for many debugging sessions.
2752 * New native configurations
2754 ARM GNU/Linux arm*-*-linux*
2755 PowerPC GNU/Linux powerpc-*-linux*
2759 Motorola MCore mcore-*-*
2760 x86 VxWorks i[3456]86-*-vxworks*
2761 PowerPC VxWorks powerpc-*-vxworks*
2762 TI TMS320C80 tic80-*-*
2764 * OBSOLETE configurations
2766 Altos 3068 m68*-altos-*
2767 Convex c1-*-*, c2-*-*
2769 ARM RISCix arm-*-* (as host)
2772 Configurations that have been declared obsolete will be commented out,
2773 but the code will be left in place. If there is no activity to revive
2774 these configurations before the next release of GDB, the sources will
2775 be permanently REMOVED.
2777 * Gould support removed
2779 Support for the Gould PowerNode and NP1 has been removed.
2781 * New features for SVR4
2783 On SVR4 native platforms (such as Solaris), if you attach to a process
2784 without first loading a symbol file, GDB will now attempt to locate and
2785 load symbols from the running process's executable file.
2787 * Many C++ enhancements
2789 C++ support has been greatly improved. Overload resolution now works properly
2790 in almost all cases. RTTI support is on the way.
2792 * Remote targets can connect to a sub-program
2794 A popen(3) style serial-device has been added. This device starts a
2795 sub-process (such as a stand-alone simulator) and then communicates
2796 with that. The sub-program to run is specified using the syntax
2797 ``|<program> <args>'' vis:
2799 (gdb) set remotedebug 1
2800 (gdb) target extended-remote |mn10300-elf-sim program-args
2802 * MIPS 64 remote protocol
2804 A long standing bug in the mips64 remote protocol where by GDB
2805 expected certain 32 bit registers (ex SR) to be transfered as 32
2806 instead of 64 bits has been fixed.
2808 The command ``set remote-mips64-transfers-32bit-regs on'' has been
2809 added to provide backward compatibility with older versions of GDB.
2811 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
2813 The command ``set remotebinarydownload'' command has been replaced by
2814 ``set remote X-packet''. Other commands in ``set remote'' family
2815 include ``set remote P-packet''.
2817 * Breakpoint commands accept ranges.
2819 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
2820 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
2821 ``tracepoint passcount'' also accepts a range of tracepoints.
2823 * ``apropos'' command added.
2825 The ``apropos'' command searches through command names and
2826 documentation strings, printing out matches, making it much easier to
2827 try to find a command that does what you are looking for.
2831 A new machine oriented interface (MI) has been added to GDB. This
2832 interface is designed for debug environments running GDB as a separate
2833 process. This is part of the long term libGDB project. See the
2834 "GDB/MI" chapter of the GDB manual for further information. It can be
2835 enabled by configuring with:
2837 .../configure --enable-gdbmi
2839 *** Changes in GDB-4.18:
2841 * New native configurations
2843 HP-UX 10.20 hppa*-*-hpux10.20
2844 HP-UX 11.x hppa*-*-hpux11.0*
2845 M68K GNU/Linux m68*-*-linux*
2849 Fujitsu FR30 fr30-*-elf*
2850 Intel StrongARM strongarm-*-*
2851 Mitsubishi D30V d30v-*-*
2853 * OBSOLETE configurations
2855 Gould PowerNode, NP1 np1-*-*, pn-*-*
2857 Configurations that have been declared obsolete will be commented out,
2858 but the code will be left in place. If there is no activity to revive
2859 these configurations before the next release of GDB, the sources will
2860 be permanently REMOVED.
2864 As a compatibility experiment, GDB's source files buildsym.h and
2865 buildsym.c have been converted to pure standard C, no longer
2866 containing any K&R compatibility code. We believe that all systems in
2867 use today either come with a standard C compiler, or have a GCC port
2868 available. If this is not true, please report the affected
2869 configuration to bug-gdb@gnu.org immediately. See the README file for
2870 information about getting a standard C compiler if you don't have one
2875 GDB now uses readline 2.2.
2877 * set extension-language
2879 You can now control the mapping between filename extensions and source
2880 languages by using the `set extension-language' command. For instance,
2881 you can ask GDB to treat .c files as C++ by saying
2882 set extension-language .c c++
2883 The command `info extensions' lists all of the recognized extensions
2884 and their associated languages.
2886 * Setting processor type for PowerPC and RS/6000
2888 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
2889 you can use the `set processor' command to specify what variant of the
2890 PowerPC family you are debugging. The command
2894 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
2895 following PowerPC and RS6000 variants:
2897 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
2898 rs6000 IBM RS6000 ("POWER") architecture, user-level view
2900 403GC IBM PowerPC 403GC
2901 505 Motorola PowerPC 505
2902 860 Motorola PowerPC 860 or 850
2903 601 Motorola PowerPC 601
2904 602 Motorola PowerPC 602
2905 603 Motorola/IBM PowerPC 603 or 603e
2906 604 Motorola PowerPC 604 or 604e
2907 750 Motorola/IBM PowerPC 750 or 750
2909 At the moment, this command just tells GDB what to name the
2910 special-purpose processor registers. Since almost all the affected
2911 registers are inaccessible to user-level programs, this command is
2912 only useful for remote debugging in its present form.
2916 Thanks to a major code donation from Hewlett-Packard, GDB now has much
2917 more extensive support for HP-UX. Added features include shared
2918 library support, kernel threads and hardware watchpoints for 11.00,
2919 support for HP's ANSI C and C++ compilers, and a compatibility mode
2920 for xdb and dbx commands.
2924 HP's donation includes the new concept of catchpoints, which is a
2925 generalization of the old catch command. On HP-UX, it is now possible
2926 to catch exec, fork, and vfork, as well as library loading.
2928 This means that the existing catch command has changed; its first
2929 argument now specifies the type of catch to be set up. See the
2930 output of "help catch" for a list of catchpoint types.
2932 * Debugging across forks
2934 On HP-UX, you can choose which process to debug when a fork() happens
2939 HP has donated a curses-based terminal user interface (TUI). To get
2940 it, build with --enable-tui. Although this can be enabled for any
2941 configuration, at present it only works for native HP debugging.
2943 * GDB remote protocol additions
2945 A new protocol packet 'X' that writes binary data is now available.
2946 Default behavior is to try 'X', then drop back to 'M' if the stub
2947 fails to respond. The settable variable `remotebinarydownload'
2948 allows explicit control over the use of 'X'.
2950 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
2951 full 64-bit address. The command
2953 set remoteaddresssize 32
2955 can be used to revert to the old behaviour. For existing remote stubs
2956 the change should not be noticed, as the additional address information
2959 In order to assist in debugging stubs, you may use the maintenance
2960 command `packet' to send any text string to the stub. For instance,
2962 maint packet heythere
2964 sends the packet "$heythere#<checksum>". Note that it is very easy to
2965 disrupt a debugging session by sending the wrong packet at the wrong
2968 The compare-sections command allows you to compare section data on the
2969 target to what is in the executable file without uploading or
2970 downloading, by comparing CRC checksums.
2972 * Tracing can collect general expressions
2974 You may now collect general expressions at tracepoints. This requires
2975 further additions to the target-side stub; see tracepoint.c and
2976 doc/agentexpr.texi for further details.
2978 * mask-address variable for Mips
2980 For Mips targets, you may control the zeroing of the upper 32 bits of
2981 a 64-bit address by entering `set mask-address on'. This is mainly
2982 of interest to users of embedded R4xxx and R5xxx processors.
2984 * Higher serial baud rates
2986 GDB's serial code now allows you to specify baud rates 57600, 115200,
2987 230400, and 460800 baud. (Note that your host system may not be able
2988 to achieve all of these rates.)
2992 The i960 configuration now includes an initial implementation of a
2993 builtin simulator, contributed by Jim Wilson.
2996 *** Changes in GDB-4.17:
2998 * New native configurations
3000 Alpha GNU/Linux alpha*-*-linux*
3001 Unixware 2.x i[3456]86-unixware2*
3002 Irix 6.x mips*-sgi-irix6*
3003 PowerPC GNU/Linux powerpc-*-linux*
3004 PowerPC Solaris powerpcle-*-solaris*
3005 Sparc GNU/Linux sparc-*-linux*
3006 Motorola sysV68 R3V7.1 m68k-motorola-sysv
3010 Argonaut Risc Chip (ARC) arc-*-*
3011 Hitachi H8/300S h8300*-*-*
3012 Matsushita MN10200 w/simulator mn10200-*-*
3013 Matsushita MN10300 w/simulator mn10300-*-*
3014 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
3015 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
3016 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
3017 Mitsubishi D10V w/simulator d10v-*-*
3018 Mitsubishi M32R/D w/simulator m32r-*-elf*
3019 Tsqware Sparclet sparclet-*-*
3020 NEC V850 w/simulator v850-*-*
3022 * New debugging protocols
3024 ARM with RDI protocol arm*-*-*
3025 M68K with dBUG monitor m68*-*-{aout,coff,elf}
3026 DDB and LSI variants of PMON protocol mips*-*-*
3027 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
3028 PowerPC with SDS protocol powerpc{,le}-*-eabi
3029 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
3033 All configurations can now understand and use the DWARF 2 debugging
3034 format. The choice is automatic, if the symbol file contains DWARF 2
3039 GDB now includes basic Java language support. This support is
3040 only useful with Java compilers that produce native machine code.
3042 * solib-absolute-prefix and solib-search-path
3044 For SunOS and SVR4 shared libraries, you may now set the prefix for
3045 loading absolute shared library symbol files, and the search path for
3046 locating non-absolute shared library symbol files.
3048 * Live range splitting
3050 GDB can now effectively debug code for which GCC has performed live
3051 range splitting as part of its optimization. See gdb/doc/LRS for
3052 more details on the expected format of the stabs information.
3056 GDB's support for the GNU Hurd, including thread debugging, has been
3057 updated to work with current versions of the Hurd.
3061 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
3062 instruction set. ARM GDB automatically detects when Thumb
3063 instructions are in use, and adjusts disassembly and backtracing
3068 GDB's MIPS target configurations now handle the MIP16 16-bit
3073 GDB now includes support for overlays; if an executable has been
3074 linked such that multiple sections are based at the same address, GDB
3075 will decide which section to use for symbolic info. You can choose to
3076 control the decision manually, using overlay commands, or implement
3077 additional target-side support and use "overlay load-target" to bring
3078 in the overlay mapping. Do "help overlay" for more detail.
3082 The command "info symbol <address>" displays information about
3083 the symbol at the specified address.
3087 The standard remote protocol now includes an extension that allows
3088 asynchronous collection and display of trace data. This requires
3089 extensive support in the target-side debugging stub. Tracing mode
3090 includes a new interaction mode in GDB and new commands: see the
3091 file tracepoint.c for more details.
3095 Configurations for embedded MIPS now include a simulator contributed
3096 by Cygnus Solutions. The simulator supports the instruction sets
3097 of most MIPS variants.
3101 Sparc configurations may now include the ERC32 simulator contributed
3102 by the European Space Agency. The simulator is not built into
3103 Sparc targets by default; configure with --enable-sim to include it.
3107 For target configurations that may include multiple variants of a
3108 basic architecture (such as MIPS and SH), you may now set the
3109 architecture explicitly. "set arch" sets, "info arch" lists
3110 the possible architectures.
3112 *** Changes in GDB-4.16:
3114 * New native configurations
3116 Windows 95, x86 Windows NT i[345]86-*-cygwin32
3117 M68K NetBSD m68k-*-netbsd*
3118 PowerPC AIX 4.x powerpc-*-aix*
3119 PowerPC MacOS powerpc-*-macos*
3120 PowerPC Windows NT powerpcle-*-cygwin32
3121 RS/6000 AIX 4.x rs6000-*-aix4*
3125 ARM with RDP protocol arm-*-*
3126 I960 with MON960 i960-*-coff
3127 MIPS VxWorks mips*-*-vxworks*
3128 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
3129 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
3131 Matra Sparclet sparclet-*-*
3135 The powerpc-eabi configuration now includes the PSIM simulator,
3136 contributed by Andrew Cagney, with assistance from Mike Meissner.
3137 PSIM is a very elaborate model of the PowerPC, including not only
3138 basic instruction set execution, but also details of execution unit
3139 performance and I/O hardware. See sim/ppc/README for more details.
3143 GDB now works with Solaris 2.5.
3145 * Windows 95/NT native
3147 GDB will now work as a native debugger on Windows 95 and Windows NT.
3148 To build it from source, you must use the "gnu-win32" environment,
3149 which uses a DLL to emulate enough of Unix to run the GNU tools.
3150 Further information, binaries, and sources are available at
3151 ftp.cygnus.com, under pub/gnu-win32.
3153 * dont-repeat command
3155 If a user-defined command includes the command `dont-repeat', then the
3156 command will not be repeated if the user just types return. This is
3157 useful if the command is time-consuming to run, so that accidental
3158 extra keystrokes don't run the same command many times.
3160 * Send break instead of ^C
3162 The standard remote protocol now includes an option to send a break
3163 rather than a ^C to the target in order to interrupt it. By default,
3164 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
3166 * Remote protocol timeout
3168 The standard remote protocol includes a new variable `remotetimeout'
3169 that allows you to set the number of seconds before GDB gives up trying
3170 to read from the target. The default value is 2.
3172 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
3174 By default GDB will automatically keep track of objects as they are
3175 loaded and unloaded by the dynamic linker. By using the command `set
3176 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
3177 when shared library events occur, thus allowing you to set breakpoints
3178 in shared libraries which are explicitly loaded by the inferior.
3180 Note this feature does not work on hpux8. On hpux9 you must link
3181 /usr/lib/end.o into your program. This feature should work
3182 automatically on hpux10.
3184 * Irix 5.x hardware watchpoint support
3186 Irix 5 configurations now support the use of hardware watchpoints.
3188 * Mips protocol "SYN garbage limit"
3190 When debugging a Mips target using the `target mips' protocol, you
3191 may set the number of characters that GDB will ignore by setting
3192 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
3193 every character. The default value is 1050.
3195 * Recording and replaying remote debug sessions
3197 If you set `remotelogfile' to the name of a file, gdb will write to it
3198 a recording of a remote debug session. This recording may then be
3199 replayed back to gdb using "gdbreplay". See gdbserver/README for
3200 details. This is useful when you have a problem with GDB while doing
3201 remote debugging; you can make a recording of the session and send it
3202 to someone else, who can then recreate the problem.
3204 * Speedups for remote debugging
3206 GDB includes speedups for downloading and stepping MIPS systems using
3207 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
3208 and more efficient S-record downloading.
3210 * Memory use reductions and statistics collection
3212 GDB now uses less memory and reports statistics about memory usage.
3213 Try the `maint print statistics' command, for example.
3215 *** Changes in GDB-4.15:
3217 * Psymtabs for XCOFF
3219 The symbol reader for AIX GDB now uses partial symbol tables. This
3220 can greatly improve startup time, especially for large executables.
3222 * Remote targets use caching
3224 Remote targets now use a data cache to speed up communication with the
3225 remote side. The data cache could lead to incorrect results because
3226 it doesn't know about volatile variables, thus making it impossible to
3227 debug targets which use memory mapped I/O devices. `set remotecache
3228 off' turns the the data cache off.
3230 * Remote targets may have threads
3232 The standard remote protocol now includes support for multiple threads
3233 in the target system, using new protocol commands 'H' and 'T'. See
3234 gdb/remote.c for details.
3238 If GDB is configured with `--enable-netrom', then it will include
3239 support for the NetROM ROM emulator from XLNT Designs. The NetROM
3240 acts as though it is a bank of ROM on the target board, but you can
3241 write into it over the network. GDB's support consists only of
3242 support for fast loading into the emulated ROM; to debug, you must use
3243 another protocol, such as standard remote protocol. The usual
3244 sequence is something like
3246 target nrom <netrom-hostname>
3248 target remote <netrom-hostname>:1235
3252 GDB now includes support for the Apple Macintosh, as a host only. It
3253 may be run as either an MPW tool or as a standalone application, and
3254 it can debug through the serial port. All the usual GDB commands are
3255 available, but to the target command, you must supply "serial" as the
3256 device type instead of "/dev/ttyXX". See mpw-README in the main
3257 directory for more information on how to build. The MPW configuration
3258 scripts */mpw-config.in support only a few targets, and only the
3259 mips-idt-ecoff target has been tested.
3263 GDB configuration now uses autoconf. This is not user-visible,
3264 but does simplify configuration and building.
3268 GDB now supports hpux10.
3270 *** Changes in GDB-4.14:
3272 * New native configurations
3274 x86 FreeBSD i[345]86-*-freebsd
3275 x86 NetBSD i[345]86-*-netbsd
3276 NS32k NetBSD ns32k-*-netbsd
3277 Sparc NetBSD sparc-*-netbsd
3281 A29K VxWorks a29k-*-vxworks
3282 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
3283 CPU32 EST-300 emulator m68*-*-est*
3284 PowerPC ELF powerpc-*-elf
3287 * Alpha OSF/1 support for procfs
3289 GDB now supports procfs under OSF/1-2.x and higher, which makes it
3290 possible to attach to running processes. As the mounting of the /proc
3291 filesystem is optional on the Alpha, GDB automatically determines
3292 the availability of /proc during startup. This can lead to problems
3293 if /proc is unmounted after GDB has been started.
3295 * Arguments to user-defined commands
3297 User commands may accept up to 10 arguments separated by whitespace.
3298 Arguments are accessed within the user command via $arg0..$arg9. A
3301 print $arg0 + $arg1 + $arg2
3303 To execute the command use:
3306 Defines the command "adder" which prints the sum of its three arguments.
3307 Note the arguments are text substitutions, so they may reference variables,
3308 use complex expressions, or even perform inferior function calls.
3310 * New `if' and `while' commands
3312 This makes it possible to write more sophisticated user-defined
3313 commands. Both commands take a single argument, which is the
3314 expression to evaluate, and must be followed by the commands to
3315 execute, one per line, if the expression is nonzero, the list being
3316 terminated by the word `end'. The `if' command list may include an
3317 `else' word, which causes the following commands to be executed only
3318 if the expression is zero.
3320 * Fortran source language mode
3322 GDB now includes partial support for Fortran 77. It will recognize
3323 Fortran programs and can evaluate a subset of Fortran expressions, but
3324 variables and functions may not be handled correctly. GDB will work
3325 with G77, but does not yet know much about symbols emitted by other
3328 * Better HPUX support
3330 Most debugging facilities now work on dynamic executables for HPPAs
3331 running hpux9 or later. You can attach to running dynamically linked
3332 processes, but by default the dynamic libraries will be read-only, so
3333 for instance you won't be able to put breakpoints in them. To change
3334 that behavior do the following before running the program:
3340 This will cause the libraries to be mapped private and read-write.
3341 To revert to the normal behavior, do this:
3347 You cannot set breakpoints or examine data in the library until after
3348 the library is loaded if the function/data symbols do not have
3351 GDB can now also read debug symbols produced by the HP C compiler on
3352 HPPAs (sorry, no C++, Fortran or 68k support).
3354 * Target byte order now dynamically selectable
3356 You can choose which byte order to use with a target system, via the
3357 commands "set endian big" and "set endian little", and you can see the
3358 current setting by using "show endian". You can also give the command
3359 "set endian auto", in which case GDB will use the byte order
3360 associated with the executable. Currently, only embedded MIPS
3361 configurations support dynamic selection of target byte order.
3363 * New DOS host serial code
3365 This version uses DPMI interrupts to handle buffered I/O, so you
3366 no longer need to run asynctsr when debugging boards connected to
3369 *** Changes in GDB-4.13:
3371 * New "complete" command
3373 This lists all the possible completions for the rest of the line, if it
3374 were to be given as a command itself. This is intended for use by emacs.
3376 * Trailing space optional in prompt
3378 "set prompt" no longer adds a space for you after the prompt you set. This
3379 allows you to set a prompt which ends in a space or one that does not.
3381 * Breakpoint hit counts
3383 "info break" now displays a count of the number of times the breakpoint
3384 has been hit. This is especially useful in conjunction with "ignore"; you
3385 can ignore a large number of breakpoint hits, look at the breakpoint info
3386 to see how many times the breakpoint was hit, then run again, ignoring one
3387 less than that number, and this will get you quickly to the last hit of
3390 * Ability to stop printing at NULL character
3392 "set print null-stop" will cause GDB to stop printing the characters of
3393 an array when the first NULL is encountered. This is useful when large
3394 arrays actually contain only short strings.
3396 * Shared library breakpoints
3398 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
3399 breakpoints in shared libraries before the executable is run.
3401 * Hardware watchpoints
3403 There is a new hardware breakpoint for the watch command for sparclite
3404 targets. See gdb/sparclite/hw_breakpoint.note.
3406 Hardware watchpoints are also now supported under GNU/Linux.
3410 Annotations have been added. These are for use with graphical interfaces,
3411 and are still experimental. Currently only gdba.el uses these.
3413 * Improved Irix 5 support
3415 GDB now works properly with Irix 5.2.
3417 * Improved HPPA support
3419 GDB now works properly with the latest GCC and GAS.
3421 * New native configurations
3423 Sequent PTX4 i[34]86-sequent-ptx4
3424 HPPA running OSF/1 hppa*-*-osf*
3425 Atari TT running SVR4 m68*-*-sysv4*
3426 RS/6000 LynxOS rs6000-*-lynxos*
3430 OS/9000 i[34]86-*-os9k
3431 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
3434 * Hitachi SH7000 and E7000-PC ICE support
3436 There is now support for communicating with the Hitachi E7000-PC ICE.
3437 This is available automatically when GDB is configured for the SH.
3441 As usual, a variety of small fixes and improvements, both generic
3442 and configuration-specific. See the ChangeLog for more detail.
3444 *** Changes in GDB-4.12:
3446 * Irix 5 is now supported
3450 GDB-4.12 on the HPPA has a number of changes which make it unable
3451 to debug the output from the currently released versions of GCC and
3452 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
3453 of GCC and GAS, versions of these tools designed to work with GDB-4.12
3454 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
3457 *** Changes in GDB-4.11:
3459 * User visible changes:
3463 The "set remotedebug" option is now consistent between the mips remote
3464 target, remote targets using the gdb-specific protocol, UDI (AMD's
3465 debug protocol for the 29k) and the 88k bug monitor. It is now an
3466 integer specifying a debug level (normally 0 or 1, but 2 means more
3467 debugging info for the mips target).
3469 * DEC Alpha native support
3471 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
3472 debug info, but GDB works fairly well with the DEC compiler and should
3473 work with a future GCC release. See the README file for a few
3474 Alpha-specific notes.
3476 * Preliminary thread implementation
3478 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
3480 * LynxOS native and target support for 386
3482 This release has been hosted on LynxOS 2.2, and also can be configured
3483 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
3486 * Improvements in C++ mangling/demangling.
3488 This release has much better g++ debugging, specifically in name
3489 mangling/demangling, virtual function calls, print virtual table,
3490 call methods, ...etc.
3492 *** Changes in GDB-4.10:
3494 * User visible changes:
3496 Remote debugging using the GDB-specific (`target remote') protocol now
3497 supports the `load' command. This is only useful if you have some
3498 other way of getting the stub to the target system, and you can put it
3499 somewhere in memory where it won't get clobbered by the download.
3501 Filename completion now works.
3503 When run under emacs mode, the "info line" command now causes the
3504 arrow to point to the line specified. Also, "info line" prints
3505 addresses in symbolic form (as well as hex).
3507 All vxworks based targets now support a user settable option, called
3508 vxworks-timeout. This option represents the number of seconds gdb
3509 should wait for responses to rpc's. You might want to use this if
3510 your vxworks target is, perhaps, a slow software simulator or happens
3511 to be on the far side of a thin network line.
3515 This release contains support for using a DEC alpha as a GDB host for
3516 cross debugging. Native alpha debugging is not supported yet.
3519 *** Changes in GDB-4.9:
3523 This is the first GDB release which is accompanied by a matching testsuite.
3524 The testsuite requires installation of dejagnu, which should be available
3525 via ftp from most sites that carry GNU software.
3529 'Cfront' style demangling has had its name changed to 'ARM' style, to
3530 emphasize that it was written from the specifications in the C++ Annotated
3531 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
3532 disclaimers, it still generated too much confusion with users attempting to
3533 use gdb with AT&T cfront.
3537 GDB now uses a standard remote interface to a simulator library.
3538 So far, the library contains simulators for the Zilog Z8001/2, the
3539 Hitachi H8/300, H8/500 and Super-H.
3541 * New targets supported
3543 H8/300 simulator h8300-hitachi-hms or h8300hms
3544 H8/500 simulator h8500-hitachi-hms or h8500hms
3545 SH simulator sh-hitachi-hms or sh
3546 Z8000 simulator z8k-zilog-none or z8ksim
3547 IDT MIPS board over serial line mips-idt-ecoff
3549 Cross-debugging to GO32 targets is supported. It requires a custom
3550 version of the i386-stub.c module which is integrated with the
3551 GO32 memory extender.
3553 * New remote protocols
3555 MIPS remote debugging protocol.
3557 * New source languages supported
3559 This version includes preliminary support for Chill, a Pascal like language
3560 used by telecommunications companies. Chill support is also being integrated
3561 into the GNU compiler, but we don't know when it will be publically available.
3564 *** Changes in GDB-4.8:
3566 * HP Precision Architecture supported
3568 GDB now supports HP PA-RISC machines running HPUX. A preliminary
3569 version of this support was available as a set of patches from the
3570 University of Utah. GDB does not support debugging of programs
3571 compiled with the HP compiler, because HP will not document their file
3572 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
3573 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
3575 Many problems in the preliminary version have been fixed.
3577 * Faster and better demangling
3579 We have improved template demangling and fixed numerous bugs in the GNU style
3580 demangler. It can now handle type modifiers such as `static' or `const'. Wide
3581 character types (wchar_t) are now supported. Demangling of each symbol is now
3582 only done once, and is cached when the symbol table for a file is read in.
3583 This results in a small increase in memory usage for C programs, a moderate
3584 increase in memory usage for C++ programs, and a fantastic speedup in
3587 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
3588 from the specifications in the Annotated Reference Manual, which AT&T's
3589 compiler does not actually implement.
3591 * G++ multiple inheritance compiler problem
3593 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
3594 inheritance lattices was reworked to properly discover ambiguities. We
3595 recently found an example which causes this new algorithm to fail in a
3596 very subtle way, producing bad debug information for those classes.
3597 The file 'gcc.patch' (in this directory) can be applied to gcc to
3598 circumvent the problem. A future GCC release will contain a complete
3601 The previous G++ debug info problem (mentioned below for the gdb-4.7
3602 release) is fixed in gcc version 2.3.2.
3604 * Improved configure script
3606 The `configure' script will now attempt to guess your system type if
3607 you don't supply a host system type. The old scheme of supplying a
3608 host system triplet is preferable over using this. All the magic is
3609 done in the new `config.guess' script. Examine it for details.
3611 We have also brought our configure script much more in line with the FSF's
3612 version. It now supports the --with-xxx options. In particular,
3613 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
3614 The resulting GDB will not be able to read arbitrary object file formats --
3615 only the format ``expected'' to be used on the configured target system.
3616 We hope to make this the default in a future release.
3618 * Documentation improvements
3620 There's new internal documentation on how to modify GDB, and how to
3621 produce clean changes to the code. We implore people to read it
3622 before submitting changes.
3624 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
3625 M4 macros. The new texinfo.tex is provided in this release. Pre-built
3626 `info' files are also provided. To build `info' files from scratch,
3627 you will need the latest `makeinfo' release, which will be available in
3628 a future texinfo-X.Y release.
3630 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
3631 We're not sure exactly which versions have this problem, but it has
3632 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
3633 or better. If that isn't possible, there is a patch in
3634 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
3635 around this problem.
3639 GDB now supports array constants that can be used in expressions typed in by
3640 the user. The syntax is `{element, element, ...}'. Ie: you can now type
3641 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
3644 The new directory `gdb/sparclite' contains a program that demonstrates
3645 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
3647 * New native hosts supported
3649 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
3650 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
3652 * New targets supported
3654 AMD 29k family via UDI a29k-amd-udi or udi29k
3656 * New file formats supported
3658 BFD now supports reading HP/PA-RISC executables (SOM file format?),
3659 HPUX core files, and SCO 3.2v2 core files.
3663 Attaching to processes now works again; thanks for the many bug reports.
3665 We have also stomped on a bunch of core dumps caused by
3666 printf_filtered("%s") problems.
3668 We eliminated a copyright problem on the rpc and ptrace header files
3669 for VxWorks, which was discovered at the last minute during the 4.7
3670 release. You should now be able to build a VxWorks GDB.
3672 You can now interrupt gdb while an attached process is running. This
3673 will cause the attached process to stop, and give control back to GDB.
3675 We fixed problems caused by using too many file descriptors
3676 for reading symbols from object files and libraries. This was
3677 especially a problem for programs that used many (~100) shared
3680 The `step' command now only enters a subroutine if there is line number
3681 information for the subroutine. Otherwise it acts like the `next'
3682 command. Previously, `step' would enter subroutines if there was
3683 any debugging information about the routine. This avoids problems
3684 when using `cc -g1' on MIPS machines.
3686 * Internal improvements
3688 GDB's internal interfaces have been improved to make it easier to support
3689 debugging of multiple languages in the future.
3691 GDB now uses a common structure for symbol information internally.
3692 Minimal symbols (derived from linkage symbols in object files), partial
3693 symbols (from a quick scan of debug information), and full symbols
3694 contain a common subset of information, making it easier to write
3695 shared code that handles any of them.
3697 * New command line options
3699 We now accept --silent as an alias for --quiet.
3703 The memory-mapped-malloc library is now licensed under the GNU Library
3704 General Public License.
3706 *** Changes in GDB-4.7:
3708 * Host/native/target split
3710 GDB has had some major internal surgery to untangle the support for
3711 hosts and remote targets. Now, when you configure GDB for a remote
3712 target, it will no longer load in all of the support for debugging
3713 local programs on the host. When fully completed and tested, this will
3714 ensure that arbitrary host/target combinations are possible.
3716 The primary conceptual shift is to separate the non-portable code in
3717 GDB into three categories. Host specific code is required any time GDB
3718 is compiled on that host, regardless of the target. Target specific
3719 code relates to the peculiarities of the target, but can be compiled on
3720 any host. Native specific code is everything else: it can only be
3721 built when the host and target are the same system. Child process
3722 handling and core file support are two common `native' examples.
3724 GDB's use of /proc for controlling Unix child processes is now cleaner.
3725 It has been split out into a single module under the `target_ops' vector,
3726 plus two native-dependent functions for each system that uses /proc.
3728 * New hosts supported
3730 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
3731 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
3732 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
3734 * New targets supported
3736 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3737 68030 and CPU32 m68030-*-*, m68332-*-*
3739 * New native hosts supported
3741 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
3742 (386bsd is not well tested yet)
3743 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
3745 * New file formats supported
3747 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
3748 supports reading of `a.out.adobe' object files, which are an a.out
3749 format extended with minimal information about multiple sections.
3753 `show copying' is the same as the old `info copying'.
3754 `show warranty' is the same as `info warrantee'.
3755 These were renamed for consistency. The old commands continue to work.
3757 `info handle' is a new alias for `info signals'.
3759 You can now define pre-command hooks, which attach arbitrary command
3760 scripts to any command. The commands in the hook will be executed
3761 prior to the user's command. You can also create a hook which will be
3762 executed whenever the program stops. See gdb.texinfo.
3766 We now deal with Cfront style name mangling, and can even extract type
3767 info from mangled symbols. GDB can automatically figure out which
3768 symbol mangling style your C++ compiler uses.
3770 Calling of methods and virtual functions has been improved as well.
3774 The crash that occured when debugging Sun Ansi-C compiled binaries is
3775 fixed. This was due to mishandling of the extra N_SO stabs output
3778 We also finally got Ultrix 4.2 running in house, and fixed core file
3779 support, with help from a dozen people on the net.
3781 John M. Farrell discovered that the reason that single-stepping was so
3782 slow on all of the Mips based platforms (primarily SGI and DEC) was
3783 that we were trying to demangle and lookup a symbol used for internal
3784 purposes on every instruction that was being stepped through. Changing
3785 the name of that symbol so that it couldn't be mistaken for a C++
3786 mangled symbol sped things up a great deal.
3788 Rich Pixley sped up symbol lookups in general by getting much smarter
3789 about when C++ symbol mangling is necessary. This should make symbol
3790 completion (TAB on the command line) much faster. It's not as fast as
3791 we'd like, but it's significantly faster than gdb-4.6.
3795 A new user controllable variable 'call_scratch_address' can
3796 specify the location of a scratch area to be used when GDB
3797 calls a function in the target. This is necessary because the
3798 usual method of putting the scratch area on the stack does not work
3799 in systems that have separate instruction and data spaces.
3801 We integrated changes to support the 29k UDI (Universal Debugger
3802 Interface), but discovered at the last minute that we didn't have all
3803 of the appropriate copyright paperwork. We are working with AMD to
3804 resolve this, and hope to have it available soon.
3808 We have sped up the remote serial line protocol, especially for targets
3809 with lots of registers. It now supports a new `expedited status' ('T')
3810 message which can be used in place of the existing 'S' status message.
3811 This allows the remote stub to send only the registers that GDB
3812 needs to make a quick decision about single-stepping or conditional
3813 breakpoints, eliminating the need to fetch the entire register set for
3814 each instruction being stepped through.
3816 The GDB remote serial protocol now implements a write-through cache for
3817 registers, only re-reading the registers if the target has run.
3819 There is also a new remote serial stub for SPARC processors. You can
3820 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
3821 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
3822 processor with a serial port.
3826 Configure.in files have become much easier to read and modify. A new
3827 `table driven' format makes it more obvious what configurations are
3828 supported, and what files each one uses.
3832 There is a new opcodes library which will eventually contain all of the
3833 disassembly routines and opcode tables. At present, it only contains
3834 Sparc and Z8000 routines. This will allow the assembler, debugger, and
3835 disassembler (binutils/objdump) to share these routines.
3837 The libiberty library is now copylefted under the GNU Library General
3838 Public License. This allows more liberal use, and was done so libg++
3839 can use it. This makes no difference to GDB, since the Library License
3840 grants all the rights from the General Public License.
3844 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
3845 reference to the stabs symbol info used by the debugger. It is (as far
3846 as we know) the only published document on this fascinating topic. We
3847 encourage you to read it, compare it to the stabs information on your
3848 system, and send improvements on the document in general (to
3849 bug-gdb@prep.ai.mit.edu).
3851 And, of course, many bugs have been fixed.
3854 *** Changes in GDB-4.6:
3856 * Better support for C++ function names
3858 GDB now accepts as input the "demangled form" of C++ overloaded function
3859 names and member function names, and can do command completion on such names
3860 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
3861 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
3862 Make use of command completion, it is your friend.
3864 GDB also now accepts a variety of C++ mangled symbol formats. They are
3865 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
3866 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
3867 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
3868 for the list of formats.
3870 * G++ symbol mangling problem
3872 Recent versions of gcc have a bug in how they emit debugging information for
3873 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
3874 directory) can be applied to gcc to fix the problem. Alternatively, if you
3875 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
3876 usual symptom is difficulty with setting breakpoints on methods. GDB complains
3877 about the method being non-existent. (We believe that version 2.2.2 of GCC has
3880 * New 'maintenance' command
3882 All of the commands related to hacking GDB internals have been moved out of
3883 the main command set, and now live behind the 'maintenance' command. This
3884 can also be abbreviated as 'mt'. The following changes were made:
3886 dump-me -> maintenance dump-me
3887 info all-breakpoints -> maintenance info breakpoints
3888 printmsyms -> maintenance print msyms
3889 printobjfiles -> maintenance print objfiles
3890 printpsyms -> maintenance print psymbols
3891 printsyms -> maintenance print symbols
3893 The following commands are new:
3895 maintenance demangle Call internal GDB demangler routine to
3896 demangle a C++ link name and prints the result.
3897 maintenance print type Print a type chain for a given symbol
3899 * Change to .gdbinit file processing
3901 We now read the $HOME/.gdbinit file before processing the argv arguments
3902 (e.g. reading symbol files or core files). This allows global parameters to
3903 be set, which will apply during the symbol reading. The ./.gdbinit is still
3904 read after argv processing.
3906 * New hosts supported
3908 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
3910 GNU/Linux support i386-unknown-linux or linux
3912 We are also including code to support the HP/PA running BSD and HPUX. This
3913 is almost guaranteed not to work, as we didn't have time to test or build it
3914 for this release. We are including it so that the more adventurous (or
3915 masochistic) of you can play with it. We also had major problems with the
3916 fact that the compiler that we got from HP doesn't support the -g option.
3919 * New targets supported
3921 Hitachi H8/300 h8300-hitachi-hms or h8300hms
3923 * More smarts about finding #include files
3925 GDB now remembers the compilation directory for all include files, and for
3926 all files from which C is generated (like yacc and lex sources). This
3927 greatly improves GDB's ability to find yacc/lex sources, and include files,
3928 especially if you are debugging your program from a directory different from
3929 the one that contains your sources.
3931 We also fixed a bug which caused difficulty with listing and setting
3932 breakpoints in include files which contain C code. (In the past, you had to
3933 try twice in order to list an include file that you hadn't looked at before.)
3935 * Interesting infernals change
3937 GDB now deals with arbitrary numbers of sections, where the symbols for each
3938 section must be relocated relative to that section's landing place in the
3939 target's address space. This work was needed to support ELF with embedded
3940 stabs used by Solaris-2.0.
3942 * Bug fixes (of course!)
3944 There have been loads of fixes for the following things:
3945 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
3946 i960, stabs, DOS(GO32), procfs, etc...
3948 See the ChangeLog for details.
3950 *** Changes in GDB-4.5:
3952 * New machines supported (host and target)
3954 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
3956 SGI Irix-4.x mips-sgi-irix4 or iris4
3958 * New malloc package
3960 GDB now uses a new memory manager called mmalloc, based on gmalloc.
3961 Mmalloc is capable of handling mutiple heaps of memory. It is also
3962 capable of saving a heap to a file, and then mapping it back in later.
3963 This can be used to greatly speedup the startup of GDB by using a
3964 pre-parsed symbol table which lives in a mmalloc managed heap. For
3965 more details, please read mmalloc/mmalloc.texi.
3969 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
3970 'help info proc' for details.
3972 * MIPS ecoff symbol table format
3974 The code that reads MIPS symbol table format is now supported on all hosts.
3975 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
3978 * File name changes for MS-DOS
3980 Many files in the config directories have been renamed to make it easier to
3981 support GDB on MS-DOSe systems (which have very restrictive file name
3982 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
3983 environment) is close to working but has some remaining problems. Note
3984 that debugging of DOS programs is not supported, due to limitations
3985 in the ``operating system'', but it can be used to host cross-debugging.
3987 * Cross byte order fixes
3989 Many fixes have been made to support cross debugging of Sparc and MIPS
3990 targets from hosts whose byte order differs.
3992 * New -mapped and -readnow options
3994 If memory-mapped files are available on your system through the 'mmap'
3995 system call, you can use the -mapped option on the `file' or
3996 `symbol-file' commands to cause GDB to write the symbols from your
3997 program into a reusable file. If the program you are debugging is
3998 called `/path/fred', the mapped symbol file will be `./fred.syms'.
3999 Future GDB debugging sessions will notice the presence of this file,
4000 and will quickly map in symbol information from it, rather than reading
4001 the symbol table from the executable program. Using the '-mapped'
4002 option in a GDB `file' or `symbol-file' command has the same effect as
4003 starting GDB with the '-mapped' command-line option.
4005 You can cause GDB to read the entire symbol table immediately by using
4006 the '-readnow' option with any of the commands that load symbol table
4007 information (or on the GDB command line). This makes the command
4008 slower, but makes future operations faster.
4010 The -mapped and -readnow options are typically combined in order to
4011 build a `fred.syms' file that contains complete symbol information.
4012 A simple GDB invocation to do nothing but build a `.syms' file for future
4015 gdb -batch -nx -mapped -readnow programname
4017 The `.syms' file is specific to the host machine on which GDB is run.
4018 It holds an exact image of GDB's internal symbol table. It cannot be
4019 shared across multiple host platforms.
4021 * longjmp() handling
4023 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
4024 siglongjmp() without losing control. This feature has not yet been ported to
4025 all systems. It currently works on many 386 platforms, all MIPS-based
4026 platforms (SGI, DECstation, etc), and Sun3/4.
4030 Preliminary work has been put in to support the new Solaris OS from Sun. At
4031 this time, it can control and debug processes, but it is not capable of
4036 As always, many many bug fixes. The major areas were with g++, and mipsread.
4037 People using the MIPS-based platforms should experience fewer mysterious
4038 crashes and trashed symbol tables.
4040 *** Changes in GDB-4.4:
4042 * New machines supported (host and target)
4044 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4046 BSD Reno on Vax vax-dec-bsd
4047 Ultrix on Vax vax-dec-ultrix
4049 * New machines supported (target)
4051 AMD 29000 embedded, using EBMON a29k-none-none
4055 GDB continues to improve its handling of C++. `References' work better.
4056 The demangler has also been improved, and now deals with symbols mangled as
4057 per the Annotated C++ Reference Guide.
4059 GDB also now handles `stabs' symbol information embedded in MIPS
4060 `ecoff' symbol tables. Since the ecoff format was not easily
4061 extensible to handle new languages such as C++, this appeared to be a
4062 good way to put C++ debugging info into MIPS binaries. This option
4063 will be supported in the GNU C compiler, version 2, when it is
4066 * New features for SVR4
4068 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
4069 shared libraries. Debugging dynamically linked programs should present
4070 only minor differences from debugging statically linked programs.
4072 The `info proc' command will print out information about any process
4073 on an SVR4 system (including the one you are debugging). At the moment,
4074 it prints the address mappings of the process.
4076 If you bring up GDB on another SVR4 system, please send mail to
4077 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
4079 * Better dynamic linking support in SunOS
4081 Reading symbols from shared libraries which contain debugging symbols
4082 now works properly. However, there remain issues such as automatic
4083 skipping of `transfer vector' code during function calls, which
4084 make it harder to debug code in a shared library, than to debug the
4085 same code linked statically.
4089 GDB is now using the latest `getopt' routines from the FSF. This
4090 version accepts the -- prefix for options with long names. GDB will
4091 continue to accept the old forms (-option and +option) as well.
4092 Various single letter abbreviations for options have been explicity
4093 added to the option table so that they won't get overshadowed in the
4094 future by other options that begin with the same letter.
4098 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
4099 Many assorted bugs have been handled. Many more remain to be handled.
4100 See the various ChangeLog files (primarily in gdb and bfd) for details.
4103 *** Changes in GDB-4.3:
4105 * New machines supported (host and target)
4107 Amiga 3000 running Amix m68k-cbm-svr4 or amix
4108 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
4109 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4111 * Almost SCO Unix support
4113 We had hoped to support:
4114 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4115 (except for core file support), but we discovered very late in the release
4116 that it has problems with process groups that render gdb unusable. Sorry
4117 about that. I encourage people to fix it and post the fixes.
4119 * Preliminary ELF and DWARF support
4121 GDB can read ELF object files on System V Release 4, and can handle
4122 debugging records for C, in DWARF format, in ELF files. This support
4123 is preliminary. If you bring up GDB on another SVR4 system, please
4124 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
4129 GDB now uses the latest `readline' library. One user-visible change
4130 is that two tabs will list possible command completions, which previously
4131 required typing M-? (meta-question mark, or ESC ?).
4135 The `stepi' bug that many of you noticed has been squashed.
4136 Many bugs in C++ have been handled. Many more remain to be handled.
4137 See the various ChangeLog files (primarily in gdb and bfd) for details.
4139 * State of the MIPS world (in case you wondered):
4141 GDB can understand the symbol tables emitted by the compilers
4142 supplied by most vendors of MIPS-based machines, including DEC. These
4143 symbol tables are in a format that essentially nobody else uses.
4145 Some versions of gcc come with an assembler post-processor called
4146 mips-tfile. This program is required if you want to do source-level
4147 debugging of gcc-compiled programs. I believe FSF does not ship
4148 mips-tfile with gcc version 1, but it will eventually come with gcc
4151 Debugging of g++ output remains a problem. g++ version 1.xx does not
4152 really support it at all. (If you're lucky, you should be able to get
4153 line numbers and stack traces to work, but no parameters or local
4154 variables.) With some work it should be possible to improve the
4157 When gcc version 2 is released, you will have somewhat better luck.
4158 However, even then you will get confusing results for inheritance and
4161 We will eventually provide full debugging of g++ output on
4162 DECstations. This will probably involve some kind of stabs-in-ecoff
4163 encapulation, but the details have not been worked out yet.
4166 *** Changes in GDB-4.2:
4168 * Improved configuration
4170 Only one copy of `configure' exists now, and it is not self-modifying.
4171 Porting BFD is simpler.
4175 The `step' and `next' commands now only stop at the first instruction
4176 of a source line. This prevents the multiple stops that used to occur
4177 in switch statements, for-loops, etc. `Step' continues to stop if a
4178 function that has debugging information is called within the line.
4182 Lots of small bugs fixed. More remain.
4184 * New host supported (not target)
4186 Intel 386 PC clone running Mach i386-none-mach
4189 *** Changes in GDB-4.1:
4191 * Multiple source language support
4193 GDB now has internal scaffolding to handle several source languages.
4194 It determines the type of each source file from its filename extension,
4195 and will switch expression parsing and number formatting to match the
4196 language of the function in the currently selected stack frame.
4197 You can also specifically set the language to be used, with
4198 `set language c' or `set language modula-2'.
4202 GDB now has preliminary support for the GNU Modula-2 compiler,
4203 currently under development at the State University of New York at
4204 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
4205 continue through the fall of 1991 and into 1992.
4207 Other Modula-2 compilers are currently not supported, and attempting to
4208 debug programs compiled with them will likely result in an error as the
4209 symbol table is read. Feel free to work on it, though!
4211 There are hooks in GDB for strict type checking and range checking,
4212 in the `Modula-2 philosophy', but they do not currently work.
4216 GDB can now write to executable and core files (e.g. patch
4217 a variable's value). You must turn this switch on, specify
4218 the file ("exec foo" or "core foo"), *then* modify it, e.g.
4219 by assigning a new value to a variable. Modifications take
4222 * Automatic SunOS shared library reading
4224 When you run your program, GDB automatically determines where its
4225 shared libraries (if any) have been loaded, and reads their symbols.
4226 The `share' command is no longer needed. This also works when
4227 examining core files.
4231 You can specify the number of lines that the `list' command shows.
4234 * New machines supported (host and target)
4236 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4237 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
4238 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
4240 * New hosts supported (not targets)
4242 IBM RT/PC: romp-ibm-aix or rtpc
4244 * New targets supported (not hosts)
4246 AMD 29000 embedded with COFF a29k-none-coff
4247 AMD 29000 embedded with a.out a29k-none-aout
4248 Ultracomputer remote kernel debug a29k-nyu-kern
4250 * New remote interfaces
4256 *** Changes in GDB-4.0:
4260 Wide output is wrapped at good places to make the output more readable.
4262 Gdb now supports cross-debugging from a host machine of one type to a
4263 target machine of another type. Communication with the target system
4264 is over serial lines. The ``target'' command handles connecting to the
4265 remote system; the ``load'' command will download a program into the
4266 remote system. Serial stubs for the m68k and i386 are provided. Gdb
4267 also supports debugging of realtime processes running under VxWorks,
4268 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
4269 stub on the target system.
4271 New CPUs supported include the AMD 29000 and Intel 960.
4273 GDB now reads object files and symbol tables via a ``binary file''
4274 library, which allows a single copy of GDB to debug programs of multiple
4275 object file types such as a.out and coff.
4277 There is now a GDB reference card in "doc/refcard.tex". (Make targets
4278 refcard.dvi and refcard.ps are available to format it).
4281 * Control-Variable user interface simplified
4283 All variables that control the operation of the debugger can be set
4284 by the ``set'' command, and displayed by the ``show'' command.
4286 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
4287 ``Show prompt'' produces the response:
4288 Gdb's prompt is new-gdb=>.
4290 What follows are the NEW set commands. The command ``help set'' will
4291 print a complete list of old and new set commands. ``help set FOO''
4292 will give a longer description of the variable FOO. ``show'' will show
4293 all of the variable descriptions and their current settings.
4295 confirm on/off: Enables warning questions for operations that are
4296 hard to recover from, e.g. rerunning the program while
4297 it is already running. Default is ON.
4299 editing on/off: Enables EMACS style command line editing
4300 of input. Previous lines can be recalled with
4301 control-P, the current line can be edited with control-B,
4302 you can search for commands with control-R, etc.
4305 history filename NAME: NAME is where the gdb command history
4306 will be stored. The default is .gdb_history,
4307 or the value of the environment variable
4310 history size N: The size, in commands, of the command history. The
4311 default is 256, or the value of the environment variable
4314 history save on/off: If this value is set to ON, the history file will
4315 be saved after exiting gdb. If set to OFF, the
4316 file will not be saved. The default is OFF.
4318 history expansion on/off: If this value is set to ON, then csh-like
4319 history expansion will be performed on
4320 command line input. The default is OFF.
4322 radix N: Sets the default radix for input and output. It can be set
4323 to 8, 10, or 16. Note that the argument to "radix" is interpreted
4324 in the current radix, so "set radix 10" is always a no-op.
4326 height N: This integer value is the number of lines on a page. Default
4327 is 24, the current `stty rows'' setting, or the ``li#''
4328 setting from the termcap entry matching the environment
4331 width N: This integer value is the number of characters on a line.
4332 Default is 80, the current `stty cols'' setting, or the ``co#''
4333 setting from the termcap entry matching the environment
4336 Note: ``set screensize'' is obsolete. Use ``set height'' and
4337 ``set width'' instead.
4339 print address on/off: Print memory addresses in various command displays,
4340 such as stack traces and structure values. Gdb looks
4341 more ``symbolic'' if you turn this off; it looks more
4342 ``machine level'' with it on. Default is ON.
4344 print array on/off: Prettyprint arrays. New convenient format! Default
4347 print demangle on/off: Print C++ symbols in "source" form if on,
4350 print asm-demangle on/off: Same, for assembler level printouts
4353 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
4356 * Support for Epoch Environment.
4358 The epoch environment is a version of Emacs v18 with windowing. One
4359 new command, ``inspect'', is identical to ``print'', except that if you
4360 are running in the epoch environment, the value is printed in its own
4364 * Support for Shared Libraries
4366 GDB can now debug programs and core files that use SunOS shared libraries.
4367 Symbols from a shared library cannot be referenced
4368 before the shared library has been linked with the program (this
4369 happens after you type ``run'' and before the function main() is entered).
4370 At any time after this linking (including when examining core files
4371 from dynamically linked programs), gdb reads the symbols from each
4372 shared library when you type the ``sharedlibrary'' command.
4373 It can be abbreviated ``share''.
4375 sharedlibrary REGEXP: Load shared object library symbols for files
4376 matching a unix regular expression. No argument
4377 indicates to load symbols for all shared libraries.
4379 info sharedlibrary: Status of loaded shared libraries.
4384 A watchpoint stops execution of a program whenever the value of an
4385 expression changes. Checking for this slows down execution
4386 tremendously whenever you are in the scope of the expression, but is
4387 quite useful for catching tough ``bit-spreader'' or pointer misuse
4388 problems. Some machines such as the 386 have hardware for doing this
4389 more quickly, and future versions of gdb will use this hardware.
4391 watch EXP: Set a watchpoint (breakpoint) for an expression.
4393 info watchpoints: Information about your watchpoints.
4395 delete N: Deletes watchpoint number N (same as breakpoints).
4396 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
4397 enable N: Re-enables watchpoint number N (same as breakpoints).
4400 * C++ multiple inheritance
4402 When used with a GCC version 2 compiler, GDB supports multiple inheritance
4405 * C++ exception handling
4407 Gdb now supports limited C++ exception handling. Besides the existing
4408 ability to breakpoint on an exception handler, gdb can breakpoint on
4409 the raising of an exception (before the stack is peeled back to the
4412 catch FOO: If there is a FOO exception handler in the dynamic scope,
4413 set a breakpoint to catch exceptions which may be raised there.
4414 Multiple exceptions (``catch foo bar baz'') may be caught.
4416 info catch: Lists all exceptions which may be caught in the
4417 current stack frame.
4420 * Minor command changes
4422 The command ``call func (arg, arg, ...)'' now acts like the print
4423 command, except it does not print or save a value if the function's result
4424 is void. This is similar to dbx usage.
4426 The ``up'' and ``down'' commands now always print the frame they end up
4427 at; ``up-silently'' and `down-silently'' can be used in scripts to change
4428 frames without printing.
4430 * New directory command
4432 'dir' now adds directories to the FRONT of the source search path.
4433 The path starts off empty. Source files that contain debug information
4434 about the directory in which they were compiled can be found even
4435 with an empty path; Sun CC and GCC include this information. If GDB can't
4436 find your source file in the current directory, type "dir .".
4438 * Configuring GDB for compilation
4440 For normal use, type ``./configure host''. See README or gdb.texinfo
4443 GDB now handles cross debugging. If you are remotely debugging between
4444 two different machines, type ``./configure host -target=targ''.
4445 Host is the machine where GDB will run; targ is the machine
4446 where the program that you are debugging will run.