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).
116 Analog Devices, Inc. Blackfin Processor bfin-*
118 * Ada task switching is now supported on sparc-elf targets when
119 debugging a program using the Ravenscar Profile. For more information,
120 see the "Tasking Support when using the Ravenscar Profile" section
121 in the GDB user manual.
123 * Guile support was removed.
125 * New features in the GNU simulator
127 ** The --map-info flag lists all known core mappings.
129 *** Changes in GDB 7.2
131 * Shared library support for remote targets by default
133 When GDB is configured for a generic, non-OS specific target, like
134 for example, --target=arm-eabi or one of the many *-*-elf targets,
135 GDB now queries remote stubs for loaded shared libraries using the
136 `qXfer:libraries:read' packet. Previously, shared library support
137 was always disabled for such configurations.
141 ** Argument Dependent Lookup (ADL)
143 In C++ ADL lookup directs function search to the namespaces of its
144 arguments even if the namespace has not been imported.
154 Here the compiler will search for `foo' in the namespace of 'b'
155 and find A::foo. GDB now supports this. This construct is commonly
156 used in the Standard Template Library for operators.
158 ** Improved User Defined Operator Support
160 In addition to member operators, GDB now supports lookup of operators
161 defined in a namespace and imported with a `using' directive, operators
162 defined in the global scope, operators imported implicitly from an
163 anonymous namespace, and the ADL operators mentioned in the previous
165 GDB now also supports proper overload resolution for all the previously
166 mentioned flavors of operators.
168 ** static const class members
170 Printing of static const class members that are initialized in the
171 class definition has been fixed.
173 * Windows Thread Information Block access.
175 On Windows targets, GDB now supports displaying the Windows Thread
176 Information Block (TIB) structure. This structure is visible either
177 by using the new command `info w32 thread-information-block' or, by
178 dereferencing the new convenience variable named `$_tlb', a
179 thread-specific pointer to the TIB. This feature is also supported
180 when remote debugging using GDBserver.
184 Static tracepoints are calls in the user program into a tracing
185 library. One such library is a port of the LTTng kernel tracer to
186 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
187 When debugging with GDBserver, GDB now supports combining the GDB
188 tracepoint machinery with such libraries. For example: the user can
189 use GDB to probe a static tracepoint marker (a call from the user
190 program into the tracing library) with the new "strace" command (see
191 "New commands" below). This creates a "static tracepoint" in the
192 breakpoint list, that can be manipulated with the same feature set
193 as fast and regular tracepoints. E.g., collect registers, local and
194 global variables, collect trace state variables, and define
195 tracepoint conditions. In addition, the user can collect extra
196 static tracepoint marker specific data, by collecting the new
197 $_sdata internal variable. When analyzing the trace buffer, you can
198 inspect $_sdata like any other variable available to GDB. For more
199 information, see the "Tracepoints" chapter in GDB user manual. New
200 remote packets have been defined to support static tracepoints, see
201 the "New remote packets" section below.
203 * Better reconstruction of tracepoints after disconnected tracing
205 GDB will attempt to download the original source form of tracepoint
206 definitions when starting a trace run, and then will upload these
207 upon reconnection to the target, resulting in a more accurate
208 reconstruction of the tracepoints that are in use on the target.
212 You can now exercise direct control over the ways that GDB can
213 affect your program. For instance, you can disallow the setting of
214 breakpoints, so that the program can run continuously (assuming
215 non-stop mode). In addition, the "observer" variable is available
216 to switch all of the different controls; in observer mode, GDB
217 cannot affect the target's behavior at all, which is useful for
218 tasks like diagnosing live systems in the field.
220 * The new convenience variable $_thread holds the number of the
227 Return the address of the Windows Thread Information Block of a given thread.
231 In response to several of the tracepoint packets, the target may now
232 also respond with a number of intermediate `qRelocInsn' request
233 packets before the final result packet, to have GDB handle
234 relocating an instruction to execute at a different address. This
235 is particularly useful for stubs that support fast tracepoints. GDB
236 reports support for this feature in the qSupported packet.
240 List static tracepoint markers in the target program.
244 List static tracepoint markers at a given address in the target
247 qXfer:statictrace:read
249 Read the static trace data collected (by a `collect $_sdata'
250 tracepoint action). The remote stub reports support for this packet
251 to gdb's qSupported query.
255 Send the current settings of GDB's permission flags.
259 Send part of the source (textual) form of a tracepoint definition,
260 which includes location, conditional, and action list.
262 * The source command now accepts a -s option to force searching for the
263 script in the source search path even if the script name specifies
266 * New features in the GDB remote stub, GDBserver
268 - GDBserver now support tracepoints (including fast tracepoints, and
269 static tracepoints). The feature is currently supported by the
270 i386-linux and amd64-linux builds. See the "Tracepoints support
271 in gdbserver" section in the manual for more information.
273 GDBserver JIT compiles the tracepoint's conditional agent
274 expression bytecode into native code whenever possible for low
275 overhead dynamic tracepoints conditionals. For such tracepoints,
276 an expression that examines program state is evaluated when the
277 tracepoint is reached, in order to determine whether to capture
278 trace data. If the condition is simple and false, processing the
279 tracepoint finishes very quickly and no data is gathered.
281 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
282 for static tracepoints support.
284 - GDBserver now supports x86_64 Windows 64-bit debugging.
286 * GDB now sends xmlRegisters= in qSupported packet to indicate that
287 it understands register description.
289 * The --batch flag now disables pagination and queries.
291 * X86 general purpose registers
293 GDB now supports reading/writing byte, word and double-word x86
294 general purpose registers directly. This means you can use, say,
295 $ah or $ax to refer, respectively, to the byte register AH and
296 16-bit word register AX that are actually portions of the 32-bit
297 register EAX or 64-bit register RAX.
299 * The `commands' command now accepts a range of breakpoints to modify.
300 A plain `commands' following a command that creates multiple
301 breakpoints affects all the breakpoints set by that command. This
302 applies to breakpoints set by `rbreak', and also applies when a
303 single `break' command creates multiple breakpoints (e.g.,
304 breakpoints on overloaded c++ functions).
306 * The `rbreak' command now accepts a filename specification as part of
307 its argument, limiting the functions selected by the regex to those
308 in the specified file.
310 * Support for remote debugging Windows and SymbianOS shared libraries
311 from Unix hosts has been improved. Non Windows GDB builds now can
312 understand target reported file names that follow MS-DOS based file
313 system semantics, such as file names that include drive letters and
314 use the backslash character as directory separator. This makes it
315 possible to transparently use the "set sysroot" and "set
316 solib-search-path" on Unix hosts to point as host copies of the
317 target's shared libraries. See the new command "set
318 target-file-system-kind" described below, and the "Commands to
319 specify files" section in the user manual for more information.
323 eval template, expressions...
324 Convert the values of one or more expressions under the control
325 of the string template to a command line, and call it.
327 set target-file-system-kind unix|dos-based|auto
328 show target-file-system-kind
329 Set or show the assumed file system kind for target reported file
332 save breakpoints <filename>
333 Save all current breakpoint definitions to a file suitable for use
334 in a later debugging session. To read the saved breakpoint
335 definitions, use the `source' command.
337 `save tracepoints' is a new alias for `save-tracepoints'. The latter
340 info static-tracepoint-markers
341 Display information about static tracepoint markers in the target.
343 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
344 Define a static tracepoint by probing a marker at the given
345 function, line, address, or marker ID.
349 Enable and disable observer mode.
351 set may-write-registers on|off
352 set may-write-memory on|off
353 set may-insert-breakpoints on|off
354 set may-insert-tracepoints on|off
355 set may-insert-fast-tracepoints on|off
356 set may-interrupt on|off
357 Set individual permissions for GDB effects on the target. Note that
358 some of these settings can have undesirable or surprising
359 consequences, particularly when changed in the middle of a session.
360 For instance, disabling the writing of memory can prevent
361 breakpoints from being inserted, cause single-stepping to fail, or
362 even crash your program, if you disable after breakpoints have been
363 inserted. However, GDB should not crash.
365 set record memory-query on|off
366 show record memory-query
367 Control whether to stop the inferior if memory changes caused
368 by an instruction cannot be recorded.
373 The disassemble command now supports "start,+length" form of two arguments.
377 ** GDB now provides a new directory location, called the python directory,
378 where Python scripts written for GDB can be installed. The location
379 of that directory is <data-directory>/python, where <data-directory>
380 is the GDB data directory. For more details, see section `Scripting
381 GDB using Python' in the manual.
383 ** The GDB Python API now has access to breakpoints, symbols, symbol
384 tables, program spaces, inferiors, threads and frame's code blocks.
385 Additionally, GDB Parameters can now be created from the API, and
386 manipulated via set/show in the CLI.
388 ** New functions gdb.target_charset, gdb.target_wide_charset,
389 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
391 ** New exception gdb.GdbError.
393 ** Pretty-printers are now also looked up in the current program space.
395 ** Pretty-printers can now be individually enabled and disabled.
397 ** GDB now looks for names of Python scripts to auto-load in a
398 special section named `.debug_gdb_scripts', in addition to looking
399 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
401 * Tracepoint actions were unified with breakpoint commands. In particular,
402 there are no longer differences in "info break" output for breakpoints and
403 tracepoints and the "commands" command can be used for both tracepoints and
408 ARM Symbian arm*-*-symbianelf*
410 * D language support.
411 GDB now supports debugging programs written in the D programming
414 * GDB now supports the extended ptrace interface for PowerPC which is
415 available since Linux kernel version 2.6.34. This automatically enables
416 any hardware breakpoints and additional hardware watchpoints available in
417 the processor. The old ptrace interface exposes just one hardware
418 watchpoint and no hardware breakpoints.
420 * GDB is now able to use the Data Value Compare (DVC) register available on
421 embedded PowerPC processors to implement in hardware simple watchpoint
422 conditions of the form:
424 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
426 This works in native GDB running on Linux kernels with the extended ptrace
427 interface mentioned above.
429 *** Changes in GDB 7.1
435 GDB now supports importing of namespaces in C++. This enables the
436 user to inspect variables from imported namespaces. Support for
437 namepace aliasing has also been added. So, if a namespace is
438 aliased in the current scope (e.g. namepace C=A; ) the user can
439 print variables using the alias (e.g. (gdb) print C::x).
443 All known bugs relating to the printing of virtual base class were
444 fixed. It is now possible to call overloaded static methods using a
449 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
450 and reinterpret_cast<> are now handled by the C++ expression parser.
454 Xilinx MicroBlaze microblaze-*-*
459 Xilinx MicroBlaze microblaze
462 * Multi-program debugging.
464 GDB now has support for multi-program (a.k.a. multi-executable or
465 multi-exec) debugging. This allows for debugging multiple inferiors
466 simultaneously each running a different program under the same GDB
467 session. See "Debugging Multiple Inferiors and Programs" in the
468 manual for more information. This implied some user visible changes
469 in the multi-inferior support. For example, "info inferiors" now
470 lists inferiors that are not running yet or that have exited
471 already. See also "New commands" and "New options" below.
473 * New tracing features
475 GDB's tracepoint facility now includes several new features:
477 ** Trace state variables
479 GDB tracepoints now include support for trace state variables, which
480 are variables managed by the target agent during a tracing
481 experiment. They are useful for tracepoints that trigger each
482 other, so for instance one tracepoint can count hits in a variable,
483 and then a second tracepoint has a condition that is true when the
484 count reaches a particular value. Trace state variables share the
485 $-syntax of GDB convenience variables, and can appear in both
486 tracepoint actions and condition expressions. Use the "tvariable"
487 command to create, and "info tvariables" to view; see "Trace State
488 Variables" in the manual for more detail.
492 GDB now includes an option for defining fast tracepoints, which
493 targets may implement more efficiently, such as by installing a jump
494 into the target agent rather than a trap instruction. The resulting
495 speedup can be by two orders of magnitude or more, although the
496 tradeoff is that some program locations on some target architectures
497 might not allow fast tracepoint installation, for instance if the
498 instruction to be replaced is shorter than the jump. To request a
499 fast tracepoint, use the "ftrace" command, with syntax identical to
500 the regular trace command.
502 ** Disconnected tracing
504 It is now possible to detach GDB from the target while it is running
505 a trace experiment, then reconnect later to see how the experiment
506 is going. In addition, a new variable disconnected-tracing lets you
507 tell the target agent whether to continue running a trace if the
508 connection is lost unexpectedly.
512 GDB now has the ability to save the trace buffer into a file, and
513 then use that file as a target, similarly to you can do with
514 corefiles. You can select trace frames, print data that was
515 collected in them, and use tstatus to display the state of the
516 tracing run at the moment that it was saved. To create a trace
517 file, use "tsave <filename>", and to use it, do "target tfile
520 ** Circular trace buffer
522 You can ask the target agent to handle the trace buffer as a
523 circular buffer, discarding the oldest trace frames to make room for
524 newer ones, by setting circular-trace-buffer to on. This feature may
525 not be available for all target agents.
530 The disassemble command, when invoked with two arguments, now requires
531 the arguments to be comma-separated.
534 The info variables command now displays variable definitions. Files
535 which only declare a variable are not shown.
538 The source command is now capable of sourcing Python scripts.
539 This feature is dependent on the debugger being build with Python
542 Related to this enhancement is also the introduction of a new command
543 "set script-extension" (see below).
545 * New commands (for set/show, see "New options" below)
547 record save [<FILENAME>]
548 Save a file (in core file format) containing the process record
549 execution log for replay debugging at a later time.
551 record restore <FILENAME>
552 Restore the process record execution log that was saved at an
553 earlier time, for replay debugging.
555 add-inferior [-copies <N>] [-exec <FILENAME>]
558 clone-inferior [-copies <N>] [ID]
559 Make a new inferior ready to execute the same program another
565 maint info program-spaces
566 List the program spaces loaded into GDB.
568 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
569 show remote interrupt-sequence
570 Allow the user to select one of ^C, a BREAK signal or BREAK-g
571 as the sequence to the remote target in order to interrupt the execution.
572 Ctrl-C is a default. Some system prefers BREAK which is high level of
573 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
574 Magic SysRq g. It is BREAK signal and character 'g'.
576 set remote interrupt-on-connect [on | off]
577 show remote interrupt-on-connect
578 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
579 remote target when gdb connects to it. This is needed when you debug
582 set remotebreak [on | off]
584 Deprecated. Use "set/show remote interrupt-sequence" instead.
586 tvariable $NAME [ = EXP ]
587 Create or modify a trace state variable.
590 List trace state variables and their values.
592 delete tvariable $NAME ...
593 Delete one or more trace state variables.
596 Evaluate the given expressions without collecting anything into the
597 trace buffer. (Valid in tracepoint actions only.)
599 ftrace FN / FILE:LINE / *ADDR
600 Define a fast tracepoint at the given function, line, or address.
602 * New expression syntax
604 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
605 GDB now parses 0b101010 identically with 42.
609 set follow-exec-mode new|same
610 show follow-exec-mode
611 Control whether GDB reuses the same inferior across an exec call or
612 creates a new one. This is useful to be able to restart the old
613 executable after the inferior having done an exec call.
615 set default-collect EXPR, ...
617 Define a list of expressions to be collected at each tracepoint.
618 This is a useful way to ensure essential items are not overlooked,
619 such as registers or a critical global variable.
621 set disconnected-tracing
622 show disconnected-tracing
623 If set to 1, the target is instructed to continue tracing if it
624 loses its connection to GDB. If 0, the target is to stop tracing
627 set circular-trace-buffer
628 show circular-trace-buffer
629 If set to on, the target is instructed to use a circular trace buffer
630 and discard the oldest trace frames instead of stopping the trace due
631 to a full trace buffer. If set to off, the trace stops when the buffer
632 fills up. Some targets may not support this.
634 set script-extension off|soft|strict
635 show script-extension
636 If set to "off", the debugger does not perform any script language
637 recognition, and all sourced files are assumed to be GDB scripts.
638 If set to "soft" (the default), files are sourced according to
639 filename extension, falling back to GDB scripts if the first
641 If set to "strict", files are sourced according to filename extension.
643 set ada trust-PAD-over-XVS on|off
644 show ada trust-PAD-over-XVS
645 If off, activate a workaround against a bug in the debugging information
646 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
647 the GCC sources for more information about the GNAT encoding and
648 PAD types in particular). It is always safe to set this option to
649 off, but this introduces a slight performance penalty. The default
652 * Python API Improvements
654 ** GDB provides the new class gdb.LazyString. This is useful in
655 some pretty-printing cases. The new method gdb.Value.lazy_string
656 provides a simple way to create objects of this type.
658 ** The fields returned by gdb.Type.fields now have an
659 `is_base_class' attribute.
661 ** The new method gdb.Type.range returns the range of an array type.
663 ** The new method gdb.parse_and_eval can be used to parse and
664 evaluate an expression.
669 Define a trace state variable.
672 Get the current value of a trace state variable.
675 Set desired tracing behavior upon disconnection.
678 Set the trace buffer to be linear or circular.
681 Get data about the tracepoints currently in use.
685 Process record now works correctly with hardware watchpoints.
687 Multiple bug fixes have been made to the mips-irix port, making it
688 much more reliable. In particular:
689 - Debugging threaded applications is now possible again. Previously,
690 GDB would hang while starting the program, or while waiting for
691 the program to stop at a breakpoint.
692 - Attaching to a running process no longer hangs.
693 - An error occurring while loading a core file has been fixed.
694 - Changing the value of the PC register now works again. This fixes
695 problems observed when using the "jump" command, or when calling
696 a function from GDB, or even when assigning a new value to $pc.
697 - With the "finish" and "return" commands, the return value for functions
698 returning a small array is now correctly printed.
699 - It is now possible to break on shared library code which gets executed
700 during a shared library init phase (code executed while executing
701 their .init section). Previously, the breakpoint would have no effect.
702 - GDB is now able to backtrace through the signal handler for
703 non-threaded programs.
705 PIE (Position Independent Executable) programs debugging is now supported.
706 This includes debugging execution of PIC (Position Independent Code) shared
707 libraries although for that, it should be possible to run such libraries as an
710 *** Changes in GDB 7.0
712 * GDB now has an interface for JIT compilation. Applications that
713 dynamically generate code can create symbol files in memory and register
714 them with GDB. For users, the feature should work transparently, and
715 for JIT developers, the interface is documented in the GDB manual in the
716 "JIT Compilation Interface" chapter.
718 * Tracepoints may now be conditional. The syntax is as for
719 breakpoints; either an "if" clause appended to the "trace" command,
720 or the "condition" command is available. GDB sends the condition to
721 the target for evaluation using the same bytecode format as is used
722 for tracepoint actions.
724 * The disassemble command now supports: an optional /r modifier, print the
725 raw instructions in hex as well as in symbolic form, and an optional /m
726 modifier to print mixed source+assembly.
728 * Process record and replay
730 In a architecture environment that supports ``process record and
731 replay'', ``process record and replay'' target can record a log of
732 the process execution, and replay it with both forward and reverse
735 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
736 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
737 set execution-direction {forward|reverse}, for targets that support
740 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
741 feature is available with a native GDB running on kernel version
744 * GDB now has support for multi-byte and wide character sets on the
745 target. Strings whose character type is wchar_t, char16_t, or
746 char32_t are now correctly printed. GDB supports wide- and unicode-
747 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
748 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
749 `printf'. This feature requires iconv to work properly; if your
750 system does not have a working iconv, GDB can use GNU libiconv. See
751 the installation instructions for more information.
753 * GDB now supports automatic retrieval of shared library files from
754 remote targets. To use this feature, specify a system root that begins
755 with the `remote:' prefix, either via the `set sysroot' command or via
756 the `--with-sysroot' configure-time option.
758 * "info sharedlibrary" now takes an optional regex of libraries to show,
759 and it now reports if a shared library has no debugging information.
761 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
762 now complete on file names.
764 * When completing in expressions, gdb will attempt to limit
765 completions to allowable structure or union fields, where appropriate.
766 For instance, consider:
768 # struct example { int f1; double f2; };
769 # struct example variable;
772 If the user types TAB at the end of this command line, the available
773 completions will be "f1" and "f2".
775 * Inlined functions are now supported. They show up in backtraces, and
776 the "step", "next", and "finish" commands handle them automatically.
778 * GDB now supports the token-splicing (##) and stringification (#)
779 operators when expanding macros. It also supports variable-arity
782 * GDB now supports inspecting extra signal information, exported by
783 the new $_siginfo convenience variable. The feature is currently
784 implemented on linux ARM, i386 and amd64.
786 * GDB can now display the VFP floating point registers and NEON vector
787 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
788 can provide these registers (requires Linux 2.6.30 or later). Remote
789 and simulator targets may also provide them.
794 Search memory for a sequence of bytes.
797 Turn off `+'/`-' protocol acknowledgments to permit more efficient
798 operation over reliable transport links. Use of this packet is
799 controlled by the `set remote noack-packet' command.
802 Kill the process with the specified process ID. Use this in preference
803 to `k' when multiprocess protocol extensions are supported.
806 Obtains additional operating system information
810 Read or write additional signal information.
812 * Removed remote protocol undocumented extension
814 An undocumented extension to the remote protocol's `S' stop reply
815 packet that permited the stub to pass a process id was removed.
816 Remote servers should use the `T' stop reply packet instead.
818 * GDB now supports multiple function calling conventions according to the
819 DWARF-2 DW_AT_calling_convention function attribute.
821 * The SH target utilizes the aforementioned change to distinguish between gcc
822 and Renesas calling convention. It also adds the new CLI commands
823 `set/show sh calling-convention'.
825 * GDB can now read compressed debug sections, as produced by GNU gold
826 with the --compress-debug-sections=zlib flag.
828 * 64-bit core files are now supported on AIX.
830 * Thread switching is now supported on Tru64.
832 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
833 which will be allocated using malloc later in program execution.
835 * The qXfer:libraries:read remote procotol packet now allows passing a
836 list of section offsets.
838 * On GNU/Linux, GDB can now attach to stopped processes. Several race
839 conditions handling signals delivered during attach or thread creation
840 have also been fixed.
842 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
843 From the user's standpoint, all unqualified instances of True and False
844 are treated as the standard definitions, regardless of context.
846 * GDB now parses C++ symbol and type names more flexibly. For
849 template<typename T> class C { };
852 GDB will now correctly handle all of:
854 ptype C<char const *>
856 ptype C<const char *>
859 * New features in the GDB remote stub, gdbserver
861 - The "--wrapper" command-line argument tells gdbserver to use a
862 wrapper program to launch programs for debugging.
864 - On PowerPC and S/390 targets, it is now possible to use a single
865 gdbserver executable to debug both 32-bit and 64-bit programs.
866 (This requires gdbserver itself to be built as a 64-bit executable.)
868 - gdbserver uses the new noack protocol mode for TCP connections to
869 reduce communications latency, if also supported and enabled in GDB.
871 - Support for the sparc64-linux-gnu target is now included in
874 - The amd64-linux build of gdbserver now supports debugging both
875 32-bit and 64-bit programs.
877 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
878 now support hardware watchpoints, and will use them automatically
883 GDB now has support for scripting using Python. Whether this is
884 available is determined at configure time.
886 New GDB commands can now be written in Python.
888 * Ada tasking support
890 Ada tasks can now be inspected in GDB. The following commands have
894 Print the list of Ada tasks.
896 Print detailed information about task number N.
898 Print the task number of the current task.
900 Switch the context of debugging to task number N.
902 * Support for user-defined prefixed commands. The "define" command can
903 add new commands to existing prefixes, e.g. "target".
905 * Multi-inferior, multi-process debugging.
907 GDB now has generalized support for multi-inferior debugging. See
908 "Debugging Multiple Inferiors" in the manual for more information.
909 Although availability still depends on target support, the command
910 set is more uniform now. The GNU/Linux specific multi-forks support
911 has been migrated to this new framework. This implied some user
912 visible changes; see "New commands" and also "Removed commands"
915 * Target descriptions can now describe the target OS ABI. See the
916 "Target Description Format" section in the user manual for more
919 * Target descriptions can now describe "compatible" architectures
920 to indicate that the target can execute applications for a different
921 architecture in addition to those for the main target architecture.
922 See the "Target Description Format" section in the user manual for
925 * Multi-architecture debugging.
927 GDB now includes general supports for debugging applications on
928 hybrid systems that use more than one single processor architecture
929 at the same time. Each such hybrid architecture still requires
930 specific support to be added. The only hybrid architecture supported
931 in this version of GDB is the Cell Broadband Engine.
933 * GDB now supports integrated debugging of Cell/B.E. applications that
934 use both the PPU and SPU architectures. To enable support for hybrid
935 Cell/B.E. debugging, you need to configure GDB to support both the
936 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
937 --enable-targets configure option.
939 * Non-stop mode debugging.
941 For some targets, GDB now supports an optional mode of operation in
942 which you can examine stopped threads while other threads continue
943 to execute freely. This is referred to as non-stop mode, with the
944 old mode referred to as all-stop mode. See the "Non-Stop Mode"
945 section in the user manual for more information.
947 To be able to support remote non-stop debugging, a remote stub needs
948 to implement the non-stop mode remote protocol extensions, as
949 described in the "Remote Non-Stop" section of the user manual. The
950 GDB remote stub, gdbserver, has been adjusted to support these
951 extensions on linux targets.
953 * New commands (for set/show, see "New options" below)
955 catch syscall [NAME(S) | NUMBER(S)]
956 Catch system calls. Arguments, which should be names of system
957 calls or their numbers, mean catch only those syscalls. Without
958 arguments, every syscall will be caught. When the inferior issues
959 any of the specified syscalls, GDB will stop and announce the system
960 call, both when it is called and when its call returns. This
961 feature is currently available with a native GDB running on the
962 Linux Kernel, under the following architectures: x86, x86_64,
963 PowerPC and PowerPC64.
965 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
967 Search memory for a sequence of bytes.
969 maint set python print-stack
970 maint show python print-stack
971 Show a stack trace when an error is encountered in a Python script.
974 Invoke CODE by passing it to the Python interpreter.
979 These allow macros to be defined, undefined, and listed
983 Show operating system information about processes.
986 List the inferiors currently under GDB's control.
989 Switch focus to inferior number NUM.
992 Detach from inferior number NUM.
995 Kill inferior number NUM.
1000 show spu stop-on-load
1001 Control whether to stop for new SPE threads during Cell/B.E. debugging.
1003 set spu auto-flush-cache
1004 show spu auto-flush-cache
1005 Control whether to automatically flush the software-managed cache
1006 during Cell/B.E. debugging.
1008 set sh calling-convention
1009 show sh calling-convention
1010 Control the calling convention used when calling SH target functions.
1013 show debug timestamp
1014 Control display of timestamps with GDB debugging output.
1016 set disassemble-next-line
1017 show disassemble-next-line
1018 Control display of disassembled source lines or instructions when
1021 set remote noack-packet
1022 show remote noack-packet
1023 Set/show the use of remote protocol QStartNoAckMode packet. See above
1024 under "New remote packets."
1026 set remote query-attached-packet
1027 show remote query-attached-packet
1028 Control use of remote protocol `qAttached' (query-attached) packet.
1030 set remote read-siginfo-object
1031 show remote read-siginfo-object
1032 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
1035 set remote write-siginfo-object
1036 show remote write-siginfo-object
1037 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
1040 set remote reverse-continue
1041 show remote reverse-continue
1042 Control use of remote protocol 'bc' (reverse-continue) packet.
1044 set remote reverse-step
1045 show remote reverse-step
1046 Control use of remote protocol 'bs' (reverse-step) packet.
1048 set displaced-stepping
1049 show displaced-stepping
1050 Control displaced stepping mode. Displaced stepping is a way to
1051 single-step over breakpoints without removing them from the debuggee.
1052 Also known as "out-of-line single-stepping".
1055 show debug displaced
1056 Control display of debugging info for displaced stepping.
1058 maint set internal-error
1059 maint show internal-error
1060 Control what GDB does when an internal error is detected.
1062 maint set internal-warning
1063 maint show internal-warning
1064 Control what GDB does when an internal warning is detected.
1069 Use a wrapper program to launch programs for debugging.
1071 set multiple-symbols (all|ask|cancel)
1072 show multiple-symbols
1073 The value of this variable can be changed to adjust the debugger behavior
1074 when an expression or a breakpoint location contains an ambiguous symbol
1075 name (an overloaded function name, for instance).
1077 set breakpoint always-inserted
1078 show breakpoint always-inserted
1079 Keep breakpoints always inserted in the target, as opposed to inserting
1080 them when resuming the target, and removing them when the target stops.
1081 This option can improve debugger performance on slow remote targets.
1083 set arm fallback-mode (arm|thumb|auto)
1084 show arm fallback-mode
1085 set arm force-mode (arm|thumb|auto)
1087 These commands control how ARM GDB determines whether instructions
1088 are ARM or Thumb. The default for both settings is auto, which uses
1089 the current CPSR value for instructions without symbols; previous
1090 versions of GDB behaved as if "set arm fallback-mode arm".
1092 set disable-randomization
1093 show disable-randomization
1094 Standalone programs run with the virtual address space randomization enabled
1095 by default on some platforms. This option keeps the addresses stable across
1096 multiple debugging sessions.
1100 Control whether other threads are stopped or not when some thread hits
1105 Requests that asynchronous execution is enabled in the target, if available.
1106 In this case, it's possible to resume target in the background, and interact
1107 with GDB while the target is running. "show target-async" displays the
1108 current state of asynchronous execution of the target.
1110 set target-wide-charset
1111 show target-wide-charset
1112 The target-wide-charset is the name of the character set that GDB
1113 uses when printing characters whose type is wchar_t.
1115 set tcp auto-retry (on|off)
1117 set tcp connect-timeout
1118 show tcp connect-timeout
1119 These commands allow GDB to retry failed TCP connections to a remote stub
1120 with a specified timeout period; this is useful if the stub is launched
1121 in parallel with GDB but may not be ready to accept connections immediately.
1123 set libthread-db-search-path
1124 show libthread-db-search-path
1125 Control list of directories which GDB will search for appropriate
1128 set schedule-multiple (on|off)
1129 show schedule-multiple
1130 Allow GDB to resume all threads of all processes or only threads of
1131 the current process.
1135 Use more aggressive caching for accesses to the stack. This improves
1136 performance of remote debugging (particularly backtraces) without
1137 affecting correctness.
1139 set interactive-mode (on|off|auto)
1140 show interactive-mode
1141 Control whether GDB runs in interactive mode (on) or not (off).
1142 When in interactive mode, GDB waits for the user to answer all
1143 queries. Otherwise, GDB does not wait and assumes the default
1144 answer. When set to auto (the default), GDB determines which
1145 mode to use based on the stdin settings.
1150 For program forks, this is replaced by the new more generic `info
1151 inferiors' command. To list checkpoints, you can still use the
1152 `info checkpoints' command, which was an alias for the `info forks'
1156 Replaced by the new `inferior' command. To switch between
1157 checkpoints, you can still use the `restart' command, which was an
1158 alias for the `fork' command.
1161 This is removed, since some targets don't have a notion of
1162 processes. To switch between processes, you can still use the
1163 `inferior' command using GDB's own inferior number.
1166 For program forks, this is replaced by the new more generic `kill
1167 inferior' command. To delete a checkpoint, you can still use the
1168 `delete checkpoint' command, which was an alias for the `delete
1172 For program forks, this is replaced by the new more generic `detach
1173 inferior' command. To detach a checkpoint, you can still use the
1174 `detach checkpoint' command, which was an alias for the `detach
1177 * New native configurations
1179 x86/x86_64 Darwin i[34567]86-*-darwin*
1181 x86_64 MinGW x86_64-*-mingw*
1185 Lattice Mico32 lm32-*
1186 x86 DICOS i[34567]86-*-dicos*
1187 x86_64 DICOS x86_64-*-dicos*
1190 * The GDB remote stub, gdbserver, now supports x86 Windows CE
1191 (mingw32ce) debugging.
1197 These commands were actually not implemented on any target.
1199 *** Changes in GDB 6.8
1201 * New native configurations
1203 NetBSD/hppa hppa*-*netbsd*
1204 Xtensa GNU/Linux xtensa*-*-linux*
1208 NetBSD/hppa hppa*-*-netbsd*
1209 Xtensa GNU/Lunux xtensa*-*-linux*
1211 * Change in command line behavior -- corefiles vs. process ids.
1213 When the '-p NUMBER' or '--pid NUMBER' options are used, and
1214 attaching to process NUMBER fails, GDB no longer attempts to open a
1215 core file named NUMBER. Attaching to a program using the -c option
1216 is no longer supported. Instead, use the '-p' or '--pid' options.
1218 * GDB can now be built as a native debugger for debugging Windows x86
1219 (mingw32) Portable Executable (PE) programs.
1221 * Pending breakpoints no longer change their number when their address
1224 * GDB now supports breakpoints with multiple locations,
1225 including breakpoints on C++ constructors, inside C++ templates,
1226 and in inlined functions.
1228 * GDB's ability to debug optimized code has been improved. GDB more
1229 accurately identifies function bodies and lexical blocks that occupy
1230 more than one contiguous range of addresses.
1232 * Target descriptions can now describe registers for PowerPC.
1234 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
1235 registers on PowerPC targets.
1237 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
1238 targets even when the libthread_db library is not available.
1240 * The GDB remote stub, gdbserver, now supports the new file transfer
1241 commands (remote put, remote get, and remote delete).
1243 * The GDB remote stub, gdbserver, now supports run and attach in
1244 extended-remote mode.
1246 * hppa*64*-*-hpux11* target broken
1247 The debugger is unable to start a program and fails with the following
1248 error: "Error trying to get information about dynamic linker".
1249 The gdb-6.7 release is also affected.
1251 * GDB now supports the --enable-targets= configure option to allow
1252 building a single GDB executable that supports multiple remote
1253 target architectures.
1255 * GDB now supports debugging C and C++ programs which use the
1256 Decimal Floating Point extension. In addition, the PowerPC target
1257 now has a set of pseudo-registers to inspect decimal float values
1258 stored in two consecutive float registers.
1260 * The -break-insert MI command can optionally create pending
1263 * Improved support for debugging Ada
1264 Many improvements to the Ada language support have been made. These
1266 - Better support for Ada2005 interface types
1267 - Improved handling of arrays and slices in general
1268 - Better support for Taft-amendment types
1269 - The '{type} ADDRESS' expression is now allowed on the left hand-side
1271 - Improved command completion in Ada
1274 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
1279 set print frame-arguments (all|scalars|none)
1280 show print frame-arguments
1281 The value of this variable can be changed to control which argument
1282 values should be printed by the debugger when displaying a frame.
1287 Transfer files to and from a remote target, and delete remote files.
1294 Transfer files to and from a remote target, and delete remote files.
1296 * New remote packets
1303 Open, close, read, write, and delete files on the remote system.
1306 Attach to an existing process on the remote system, in extended-remote
1310 Run a new process on the remote system, in extended-remote mode.
1312 *** Changes in GDB 6.7
1314 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
1315 bfd, libiberty and opcodes, as revealed by static analysis donated by
1316 Coverity, Inc. (http://scan.coverity.com).
1318 * When looking up multiply-defined global symbols, GDB will now prefer the
1319 symbol definition in the current shared library if it was built using the
1320 -Bsymbolic linker option.
1322 * When the Text User Interface (TUI) is not configured, GDB will now
1323 recognize the -tui command-line option and print a message that the TUI
1326 * The GDB remote stub, gdbserver, now has lower overhead for high
1327 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
1329 * GDB for MIPS targets now autodetects whether a remote target provides
1330 32-bit or 64-bit register values.
1332 * Support for C++ member pointers has been improved.
1334 * GDB now understands XML target descriptions, which specify the
1335 target's overall architecture. GDB can read a description from
1336 a local file or over the remote serial protocol.
1338 * Vectors of single-byte data use a new integer type which is not
1339 automatically displayed as character or string data.
1341 * The /s format now works with the print command. It displays
1342 arrays of single-byte integers and pointers to single-byte integers
1345 * Target descriptions can now describe target-specific registers,
1346 for architectures which have implemented the support (currently
1347 only ARM, M68K, and MIPS).
1349 * GDB and the GDB remote stub, gdbserver, now support the XScale
1352 * The GDB remote stub, gdbserver, has been updated to support
1353 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
1354 has been rewritten to use the standard GDB remote protocol.
1356 * GDB can now step into C++ functions which are called through thunks.
1358 * GDB for the Cell/B.E. SPU now supports overlay debugging.
1360 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
1361 layout. It also supports a TextSeg= and DataSeg= response when only
1362 segment base addresses (rather than offsets) are available.
1364 * The /i format now outputs any trailing branch delay slot instructions
1365 immediately following the last instruction within the count specified.
1367 * The GDB remote protocol "T" stop reply packet now supports a
1368 "library" response. Combined with the new "qXfer:libraries:read"
1369 packet, this response allows GDB to debug shared libraries on targets
1370 where the operating system manages the list of loaded libraries (e.g.
1371 Windows and SymbianOS).
1373 * The GDB remote stub, gdbserver, now supports dynamic link libraries
1374 (DLLs) on Windows and Windows CE targets.
1376 * GDB now supports a faster verification that a .debug file matches its binary
1377 according to its build-id signature, if the signature is present.
1383 Enable or disable hardware flow control (RTS/CTS) on the serial port
1384 when debugging using remote targets.
1386 set mem inaccessible-by-default
1387 show mem inaccessible-by-default
1388 If the target supplies a memory map, for instance via the remote
1389 protocol's "qXfer:memory-map:read" packet, setting this variable
1390 prevents GDB from accessing memory outside the memory map. This
1391 is useful for targets with memory mapped registers or which react
1392 badly to accesses of unmapped address space.
1394 set breakpoint auto-hw
1395 show breakpoint auto-hw
1396 If the target supplies a memory map, for instance via the remote
1397 protocol's "qXfer:memory-map:read" packet, setting this variable
1398 lets GDB use hardware breakpoints automatically for memory regions
1399 where it can not use software breakpoints. This covers both the
1400 "break" command and internal breakpoints used for other commands
1401 including "next" and "finish".
1404 catch exception unhandled
1405 Stop the program execution when Ada exceptions are raised.
1408 Stop the program execution when an Ada assertion failed.
1412 Set an alternate system root for target files. This is a more
1413 general version of "set solib-absolute-prefix", which is now
1414 an alias to "set sysroot".
1417 Provide extended SPU facility status information. This set of
1418 commands is available only when debugging the Cell/B.E. SPU
1421 * New native configurations
1423 OpenBSD/sh sh*-*openbsd*
1426 unset tdesc filename
1428 Use the specified local file as an XML target description, and do
1429 not query the target for its built-in description.
1433 OpenBSD/sh sh*-*-openbsd*
1434 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
1435 Toshiba Media Processor mep-elf
1437 * New remote packets
1440 Ignore the specified signals; pass them directly to the debugged program
1441 without stopping other threads or reporting them to GDB.
1443 qXfer:features:read:
1444 Read an XML target description from the target, which describes its
1449 Read or write contents of an spufs file on the target system. These
1450 packets are available only on the Cell/B.E. SPU architecture.
1452 qXfer:libraries:read:
1453 Report the loaded shared libraries. Combined with new "T" packet
1454 response, this packet allows GDB to debug shared libraries on
1455 targets where the operating system manages the list of loaded
1456 libraries (e.g. Windows and SymbianOS).
1460 Support for these obsolete configurations has been removed.
1468 i[34567]86-*-lynxos*
1469 i[34567]86-*-netware*
1470 i[34567]86-*-sco3.2v5*
1471 i[34567]86-*-sco3.2v4*
1473 i[34567]86-*-sysv4.2*
1476 i[34567]86-*-unixware2*
1477 i[34567]86-*-unixware*
1486 * Other removed features
1493 Various m68k-only ROM monitors.
1500 Various Renesas ROM monitors and debugging interfaces for SH and
1505 Support for a Macraigor serial interface to on-chip debugging.
1506 GDB does not directly support the newer parallel or USB
1511 A debug information format. The predecessor to DWARF 2 and
1512 DWARF 3, which are still supported.
1514 Support for the HP aCC compiler on HP-UX/PA-RISC
1516 SOM-encapsulated symbolic debugging information, automatic
1517 invocation of pxdb, and the aCC custom C++ ABI. This does not
1518 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
1519 with aCC can still be debugged on an assembly level.
1521 MIPS ".pdr" sections
1523 A MIPS-specific format used to describe stack frame layout
1524 in debugging information.
1528 GDB could work with an older version of Guile to debug
1529 the interpreter and Scheme programs running in it.
1531 set mips stack-arg-size
1532 set mips saved-gpreg-size
1534 Use "set mips abi" to control parameter passing for MIPS.
1536 *** Changes in GDB 6.6
1541 Cell Broadband Engine SPU spu-elf
1543 * GDB can now be configured as a cross-debugger targeting native Windows
1544 (mingw32) or Cygwin. It can communicate with a remote debugging stub
1545 running on a Windows system over TCP/IP to debug Windows programs.
1547 * The GDB remote stub, gdbserver, has been updated to support Windows and
1548 Cygwin debugging. Both single-threaded and multi-threaded programs are
1551 * The "set trust-readonly-sections" command works again. This command was
1552 broken in GDB 6.3, 6.4, and 6.5.
1554 * The "load" command now supports writing to flash memory, if the remote
1555 stub provides the required support.
1557 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
1558 longer requires symbolic debug information (e.g. DWARF-2).
1563 unset substitute-path
1564 show substitute-path
1565 Manage a list of substitution rules that GDB uses to rewrite the name
1566 of the directories where the sources are located. This can be useful
1567 for instance when the sources were moved to a different location
1568 between compilation and debugging.
1572 Print each CLI command as it is executed. Each command is prefixed with
1573 a number of `+' symbols representing the nesting depth.
1574 The source command now has a `-v' option to enable the same feature.
1578 The ARM Demon monitor support (RDP protocol, "target rdp").
1580 Kernel Object Display, an embedded debugging feature which only worked with
1581 an obsolete version of Cisco IOS.
1583 The 'set download-write-size' and 'show download-write-size' commands.
1585 * New remote packets
1588 Tell a stub about GDB client features, and request remote target features.
1589 The first feature implemented is PacketSize, which allows the target to
1590 specify the size of packets it can handle - to minimize the number of
1591 packets required and improve performance when connected to a remote
1595 Fetch an OS auxilliary vector from the remote stub. This packet is a
1596 more efficient replacement for qPart:auxv:read.
1598 qXfer:memory-map:read:
1599 Fetch a memory map from the remote stub, including information about
1600 RAM, ROM, and flash memory devices.
1605 Erase and program a flash memory device.
1607 * Removed remote packets
1610 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
1611 used it, and only gdbserver implemented it.
1613 *** Changes in GDB 6.5
1617 Renesas M32C/M16C m32c-elf
1619 Morpho Technologies ms1 ms1-elf
1623 init-if-undefined Initialize a convenience variable, but
1624 only if it doesn't already have a value.
1626 The following commands are presently only implemented for native GNU/Linux:
1628 checkpoint Save a snapshot of the program state.
1630 restart <n> Return the program state to a
1631 previously saved state.
1633 info checkpoints List currently saved checkpoints.
1635 delete-checkpoint <n> Delete a previously saved checkpoint.
1637 set|show detach-on-fork Tell gdb whether to detach from a newly
1638 forked process, or to keep debugging it.
1640 info forks List forks of the user program that
1641 are available to be debugged.
1643 fork <n> Switch to debugging one of several
1644 forks of the user program that are
1645 available to be debugged.
1647 delete-fork <n> Delete a fork from the list of forks
1648 that are available to be debugged (and
1649 kill the forked process).
1651 detach-fork <n> Delete a fork from the list of forks
1652 that are available to be debugged (and
1653 allow the process to continue).
1657 Morpho Technologies ms2 ms1-elf
1659 * Improved Windows host support
1661 GDB now builds as a cross debugger hosted on i686-mingw32, including
1662 native console support, and remote communications using either
1663 network sockets or serial ports.
1665 * Improved Modula-2 language support
1667 GDB can now print most types in the Modula-2 syntax. This includes:
1668 basic types, set types, record types, enumerated types, range types,
1669 pointer types and ARRAY types. Procedure var parameters are correctly
1670 printed and hexadecimal addresses and character constants are also
1671 written in the Modula-2 syntax. Best results can be obtained by using
1672 GNU Modula-2 together with the -gdwarf-2 command line option.
1676 The ARM rdi-share module.
1678 The Netware NLM debug server.
1680 *** Changes in GDB 6.4
1682 * New native configurations
1684 OpenBSD/arm arm*-*-openbsd*
1685 OpenBSD/mips64 mips64-*-openbsd*
1689 Morpho Technologies ms1 ms1-elf
1691 * New command line options
1693 --batch-silent As for --batch, but totally silent.
1694 --return-child-result The debugger will exist with the same value
1695 the child (debugged) program exited with.
1696 --eval-command COMMAND, -ex COMMAND
1697 Execute a single GDB CLI command. This may be
1698 specified multiple times and in conjunction
1699 with the --command (-x) option.
1701 * Deprecated commands removed
1703 The following commands, that were deprecated in 2000, have been
1707 set|show arm disassembly-flavor set|show arm disassembler
1708 othernames set arm disassembler
1709 set|show remotedebug set|show debug remote
1710 set|show archdebug set|show debug arch
1711 set|show eventdebug set|show debug event
1714 * New BSD user-level threads support
1716 It is now possible to debug programs using the user-level threads
1717 library on OpenBSD and FreeBSD. Currently supported (target)
1720 FreeBSD/amd64 x86_64-*-freebsd*
1721 FreeBSD/i386 i386-*-freebsd*
1722 OpenBSD/i386 i386-*-openbsd*
1724 Note that the new kernel threads libraries introduced in FreeBSD 5.x
1725 are not yet supported.
1727 * New support for Matsushita MN10300 w/sim added
1728 (Work in progress). mn10300-elf.
1730 * REMOVED configurations and files
1732 VxWorks and the XDR protocol *-*-vxworks
1733 Motorola MCORE mcore-*-*
1734 National Semiconductor NS32000 ns32k-*-*
1736 * New "set print array-indexes" command
1738 After turning this setting "on", GDB prints the index of each element
1739 when displaying arrays. The default is "off" to preserve the previous
1742 * VAX floating point support
1744 GDB now supports the not-quite-ieee VAX F and D floating point formats.
1746 * User-defined command support
1748 In addition to using $arg0..$arg9 for argument passing, it is now possible
1749 to use $argc to determine now many arguments have been passed. See the
1750 section on user-defined commands in the user manual for more information.
1752 *** Changes in GDB 6.3:
1754 * New command line option
1756 GDB now accepts -l followed by a number to set the timeout for remote
1759 * GDB works with GCC -feliminate-dwarf2-dups
1761 GDB now supports a more compact representation of DWARF-2 debug
1762 information using DW_FORM_ref_addr references. These are produced
1763 by GCC with the option -feliminate-dwarf2-dups and also by some
1764 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
1765 to use -feliminate-dwarf2-dups.
1767 * Internationalization
1769 When supported by the host system, GDB will be built with
1770 internationalization (libintl). The task of marking up the sources is
1771 continued, we're looking forward to our first translation.
1775 Initial support for debugging programs compiled with the GNAT
1776 implementation of the Ada programming language has been integrated
1777 into GDB. In this release, support is limited to expression evaluation.
1779 * New native configurations
1781 GNU/Linux/m32r m32r-*-linux-gnu
1785 GDB's remote protocol now includes support for the 'p' packet. This
1786 packet is used to fetch individual registers from a remote inferior.
1788 * END-OF-LIFE registers[] compatibility module
1790 GDB's internal register infrastructure has been completely rewritten.
1791 The new infrastructure making possible the implementation of key new
1792 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
1795 GDB 6.3 will be the last release to include the the registers[]
1796 compatibility module that allowed out-of-date configurations to
1797 continue to work. This change directly impacts the following
1807 powerpc bdm protocol
1809 Unless there is activity to revive these configurations, they will be
1810 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
1812 * OBSOLETE configurations and files
1814 Configurations that have been declared obsolete in this release have
1815 been commented out. Unless there is activity to revive these
1816 configurations, the next release of GDB will have their sources
1817 permanently REMOVED.
1826 *** Changes in GDB 6.2.1:
1828 * MIPS `break main; run' gave an heuristic-fence-post warning
1830 When attempting to run even a simple program, a warning about
1831 heuristic-fence-post being hit would be reported. This problem has
1834 * MIPS IRIX 'long double' crashed GDB
1836 When examining a long double variable, GDB would get a segmentation
1837 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
1838 IRIX long double values).
1842 A bug in the VAX stack code was causing problems with the "next"
1843 command. This problem has been fixed.
1845 *** Changes in GDB 6.2:
1847 * Fix for ``many threads''
1849 On GNU/Linux systems that use the NPTL threads library, a program
1850 rapidly creating and deleting threads would confuse GDB leading to the
1853 ptrace: No such process.
1854 thread_db_get_info: cannot get thread info: generic error
1856 This problem has been fixed.
1858 * "-async" and "-noasync" options removed.
1860 Support for the broken "-noasync" option has been removed (it caused
1863 * New ``start'' command.
1865 This command runs the program until the begining of the main procedure.
1867 * New BSD Kernel Data Access Library (libkvm) interface
1869 Using ``target kvm'' it is now possible to debug kernel core dumps and
1870 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
1871 platforms. Currently supported (native-only) configurations are:
1873 FreeBSD/amd64 x86_64-*-freebsd*
1874 FreeBSD/i386 i?86-*-freebsd*
1875 NetBSD/i386 i?86-*-netbsd*
1876 NetBSD/m68k m68*-*-netbsd*
1877 NetBSD/sparc sparc-*-netbsd*
1878 OpenBSD/amd64 x86_64-*-openbsd*
1879 OpenBSD/i386 i?86-*-openbsd*
1880 OpenBSD/m68k m68*-openbsd*
1881 OpenBSD/sparc sparc-*-openbsd*
1883 * Signal trampoline code overhauled
1885 Many generic problems with GDB's signal handling code have been fixed.
1886 These include: backtraces through non-contiguous stacks; recognition
1887 of sa_sigaction signal trampolines; backtrace from a NULL pointer
1888 call; backtrace through a signal trampoline; step into and out of
1889 signal handlers; and single-stepping in the signal trampoline.
1891 Please note that kernel bugs are a limiting factor here. These
1892 features have been shown to work on an s390 GNU/Linux system that
1893 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
1895 * Cygwin support for DWARF 2 added.
1897 * New native configurations
1899 GNU/Linux/hppa hppa*-*-linux*
1900 OpenBSD/hppa hppa*-*-openbsd*
1901 OpenBSD/m68k m68*-*-openbsd*
1902 OpenBSD/m88k m88*-*-openbsd*
1903 OpenBSD/powerpc powerpc-*-openbsd*
1904 NetBSD/vax vax-*-netbsd*
1905 OpenBSD/vax vax-*-openbsd*
1907 * END-OF-LIFE frame compatibility module
1909 GDB's internal frame infrastructure has been completely rewritten.
1910 The new infrastructure making it possible to support key new features
1911 including DWARF 2 Call Frame Information. To aid in the task of
1912 migrating old configurations to this new infrastructure, a
1913 compatibility module, that allowed old configurations to continue to
1914 work, was also included.
1916 GDB 6.2 will be the last release to include this frame compatibility
1917 module. This change directly impacts the following configurations:
1927 Unless there is activity to revive these configurations, they will be
1928 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
1930 * REMOVED configurations and files
1932 Sun 3, running SunOS 3 m68*-*-sunos3*
1933 Sun 3, running SunOS 4 m68*-*-sunos4*
1934 Sun 2, running SunOS 3 m68000-*-sunos3*
1935 Sun 2, running SunOS 4 m68000-*-sunos4*
1936 Motorola 680x0 running LynxOS m68*-*-lynxos*
1937 AT&T 3b1/Unix pc m68*-att-*
1938 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
1939 decstation mips-dec-* mips-little-*
1940 riscos mips-*-riscos* mips-*-sysv*
1941 sonymips mips-sony-*
1942 sysv mips*-*-sysv4* (IRIX 5/6 not included)
1944 *** Changes in GDB 6.1.1:
1946 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
1948 The TUI (Text-mode User Interface) is now built as part of a default
1949 GDB configuration. It is enabled by either selecting the TUI with the
1950 command line option "-i=tui" or by running the separate "gdbtui"
1951 program. For more information on the TUI, see the manual "Debugging
1954 * Pending breakpoint support (also included in GDB 6.1)
1956 Support has been added to allow you to specify breakpoints in shared
1957 libraries that have not yet been loaded. If a breakpoint location
1958 cannot be found, and the "breakpoint pending" option is set to auto,
1959 GDB queries you if you wish to make the breakpoint pending on a future
1960 shared-library load. If and when GDB resolves the breakpoint symbol,
1961 the pending breakpoint is removed as one or more regular breakpoints
1964 Pending breakpoints are very useful for GCJ Java debugging.
1966 * Fixed ISO-C build problems
1968 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
1969 non ISO-C code that stopped them being built using a more strict ISO-C
1970 compiler (e.g., IBM's C compiler).
1972 * Fixed build problem on IRIX 5
1974 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
1975 wasn't able to compile compile on an IRIX 5 system.
1977 * Added execute permission to gdb/gdbserver/configure
1979 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
1980 permission. This bug would cause configure to fail on a number of
1981 systems (Solaris, IRIX). Ref: server/519.
1983 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
1985 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
1986 has been updated to use constant array sizes.
1988 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
1990 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
1991 its generated DWARF Call Frame Info. This encoding was causing GDB to
1992 panic, that panic has been fixed. Ref: gdb/1628.
1994 * Fixed a problem when examining parameters in shared library code.
1996 When examining parameters in optimized shared library code generated
1997 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
1998 not available''. GDB now correctly displays the variable's value.
2000 *** Changes in GDB 6.1:
2002 * Removed --with-mmalloc
2004 Support for the mmalloc memory manager has been removed, as it
2005 conflicted with the internal gdb byte cache.
2007 * Changes in AMD64 configurations
2009 The AMD64 target now includes the %cs and %ss registers. As a result
2010 the AMD64 remote protocol has changed; this affects the floating-point
2011 and SSE registers. If you rely on those registers for your debugging,
2012 you should upgrade gdbserver on the remote side.
2014 * Revised SPARC target
2016 The SPARC target has been completely revised, incorporating the
2017 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
2018 support for LynxOS and SunOS 4 has been dropped. Calling functions
2019 from within GDB on operating systems with a non-executable stack
2020 (Solaris, OpenBSD) now works.
2024 GDB has a new C++ demangler which does a better job on the mangled
2025 names generated by current versions of g++. It also runs faster, so
2026 with this and other changes gdb should now start faster on large C++
2029 * DWARF 2 Location Expressions
2031 GDB support for location expressions has been extended to support function
2032 arguments and frame bases. Older versions of GDB could crash when they
2035 * C++ nested types and namespaces
2037 GDB's support for nested types and namespaces in C++ has been
2038 improved, especially if you use the DWARF 2 debugging format. (This
2039 is the default for recent versions of GCC on most platforms.)
2040 Specifically, if you have a class "Inner" defined within a class or
2041 namespace "Outer", then GDB realizes that the class's name is
2042 "Outer::Inner", not simply "Inner". This should greatly reduce the
2043 frequency of complaints about not finding RTTI symbols. In addition,
2044 if you are stopped at inside of a function defined within a namespace,
2045 GDB modifies its name lookup accordingly.
2047 * New native configurations
2049 NetBSD/amd64 x86_64-*-netbsd*
2050 OpenBSD/amd64 x86_64-*-openbsd*
2051 OpenBSD/alpha alpha*-*-openbsd*
2052 OpenBSD/sparc sparc-*-openbsd*
2053 OpenBSD/sparc64 sparc64-*-openbsd*
2055 * New debugging protocols
2057 M32R with SDI protocol m32r-*-elf*
2059 * "set prompt-escape-char" command deleted.
2061 The command "set prompt-escape-char" has been deleted. This command,
2062 and its very obscure effet on GDB's prompt, was never documented,
2063 tested, nor mentioned in the NEWS file.
2065 * OBSOLETE configurations and files
2067 Configurations that have been declared obsolete in this release have
2068 been commented out. Unless there is activity to revive these
2069 configurations, the next release of GDB will have their sources
2070 permanently REMOVED.
2072 Sun 3, running SunOS 3 m68*-*-sunos3*
2073 Sun 3, running SunOS 4 m68*-*-sunos4*
2074 Sun 2, running SunOS 3 m68000-*-sunos3*
2075 Sun 2, running SunOS 4 m68000-*-sunos4*
2076 Motorola 680x0 running LynxOS m68*-*-lynxos*
2077 AT&T 3b1/Unix pc m68*-att-*
2078 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2079 decstation mips-dec-* mips-little-*
2080 riscos mips-*-riscos* mips-*-sysv*
2081 sonymips mips-sony-*
2082 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2084 * REMOVED configurations and files
2086 SGI Irix-4.x mips-sgi-irix4 or iris4
2087 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
2088 Z8000 simulator z8k-zilog-none or z8ksim
2089 Matsushita MN10200 w/simulator mn10200-*-*
2090 H8/500 simulator h8500-hitachi-hms or h8500hms
2091 HP/PA running BSD hppa*-*-bsd*
2092 HP/PA running OSF/1 hppa*-*-osf*
2093 HP/PA Pro target hppa*-*-pro*
2094 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2095 386BSD i[3456]86-*-bsd*
2096 Sequent family i[3456]86-sequent-sysv4*
2097 i[3456]86-sequent-sysv*
2098 i[3456]86-sequent-bsd*
2099 SPARC running LynxOS sparc-*-lynxos*
2100 SPARC running SunOS 4 sparc-*-sunos4*
2101 Tsqware Sparclet sparclet-*-*
2102 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2104 *** Changes in GDB 6.0:
2108 Support for debugging the Objective-C programming language has been
2109 integrated into GDB.
2111 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
2113 DWARF 2's Call Frame Information makes available compiler generated
2114 information that more exactly describes the program's run-time stack.
2115 By using this information, GDB is able to provide more robust stack
2118 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
2119 have been updated to use a new backtrace mechanism which includes
2120 DWARF 2 CFI support.
2124 GDB's remote protocol has been extended to include support for hosted
2125 file I/O (where the remote target uses GDB's file system). See GDB's
2126 remote protocol documentation for details.
2128 * All targets using the new architecture framework.
2130 All of GDB's targets have been updated to use the new internal
2131 architecture framework. The way is now open for future GDB releases
2132 to include cross-architecture native debugging support (i386 on amd64,
2135 * GNU/Linux's Thread Local Storage (TLS)
2137 GDB now includes support for for the GNU/Linux implementation of
2138 per-thread variables.
2140 * GNU/Linux's Native POSIX Thread Library (NPTL)
2142 GDB's thread code has been updated to work with either the new
2143 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
2145 * Separate debug info.
2147 GDB, in conjunction with BINUTILS, now supports a mechanism for
2148 automatically loading debug information from a separate file. Instead
2149 of shipping full debug and non-debug versions of system libraries,
2150 system integrators can now instead ship just the stripped libraries
2151 and optional debug files.
2153 * DWARF 2 Location Expressions
2155 DWARF 2 Location Expressions allow the compiler to more completely
2156 describe the location of variables (even in optimized code) to the
2159 GDB now includes preliminary support for location expressions (support
2160 for DW_OP_piece is still missing).
2164 A number of long standing bugs that caused GDB to die while starting a
2165 Java application have been fixed. GDB's Java support is now
2166 considered "useable".
2168 * GNU/Linux support for fork, vfork, and exec.
2170 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
2171 commands are now implemented for GNU/Linux. They require a 2.5.x or later
2174 * GDB supports logging output to a file
2176 There are two new commands, "set logging" and "show logging", which can be
2177 used to capture GDB's output to a file.
2179 * The meaning of "detach" has changed for gdbserver
2181 The "detach" command will now resume the application, as documented. To
2182 disconnect from gdbserver and leave it stopped, use the new "disconnect"
2185 * d10v, m68hc11 `regs' command deprecated
2187 The `info registers' command has been updated so that it displays the
2188 registers using a format identical to the old `regs' command.
2192 A new command, "maint set profile on/off", has been added. This command can
2193 be used to enable or disable profiling while running GDB, to profile a
2194 session or a set of commands. In addition there is a new configure switch,
2195 "--enable-profiling", which will cause GDB to be compiled with profiling
2196 data, for more informative profiling results.
2198 * Default MI syntax changed to "mi2".
2200 The default MI (machine interface) syntax, enabled by the command line
2201 option "-i=mi", has been changed to "mi2". The previous MI syntax,
2202 "mi1", can be enabled by specifying the option "-i=mi1".
2204 Support for the original "mi0" syntax (included in GDB 5.0) has been
2207 Fix for gdb/192: removed extraneous space when displaying frame level.
2208 Fix for gdb/672: update changelist is now output in mi list format.
2209 Fix for gdb/702: a -var-assign that updates the value now shows up
2210 in a subsequent -var-update.
2212 * New native configurations.
2214 FreeBSD/amd64 x86_64-*-freebsd*
2216 * Multi-arched targets.
2218 HP/PA HPUX11 hppa*-*-hpux*
2219 Renesas M32R/D w/simulator m32r-*-elf*
2221 * OBSOLETE configurations and files
2223 Configurations that have been declared obsolete in this release have
2224 been commented out. Unless there is activity to revive these
2225 configurations, the next release of GDB will have their sources
2226 permanently REMOVED.
2228 Z8000 simulator z8k-zilog-none or z8ksim
2229 Matsushita MN10200 w/simulator mn10200-*-*
2230 H8/500 simulator h8500-hitachi-hms or h8500hms
2231 HP/PA running BSD hppa*-*-bsd*
2232 HP/PA running OSF/1 hppa*-*-osf*
2233 HP/PA Pro target hppa*-*-pro*
2234 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2235 Sequent family i[3456]86-sequent-sysv4*
2236 i[3456]86-sequent-sysv*
2237 i[3456]86-sequent-bsd*
2238 Tsqware Sparclet sparclet-*-*
2239 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2241 * REMOVED configurations and files
2244 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2245 IBM AIX PS/2 i[3456]86-*-aix
2246 i386 running Mach 3.0 i[3456]86-*-mach3*
2247 i386 running Mach i[3456]86-*-mach*
2248 i386 running OSF/1 i[3456]86-*osf1mk*
2249 HP/Apollo 68k Family m68*-apollo*-sysv*,
2251 m68*-hp-bsd*, m68*-hp-hpux*
2252 Argonaut Risc Chip (ARC) arc-*-*
2253 Mitsubishi D30V d30v-*-*
2254 Fujitsu FR30 fr30-*-elf*
2255 OS/9000 i[34]86-*-os9k
2256 I960 with MON960 i960-*-coff
2258 * MIPS $fp behavior changed
2260 The convenience variable $fp, for the MIPS, now consistently returns
2261 the address of the current frame's base. Previously, depending on the
2262 context, $fp could refer to either $sp or the current frame's base
2263 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
2264 The GNU Source-Level Debugger''.
2266 *** Changes in GDB 5.3:
2268 * GNU/Linux shared library multi-threaded performance improved.
2270 When debugging a multi-threaded application on GNU/Linux, GDB now uses
2271 `/proc', in preference to `ptrace' for memory reads. This may result
2272 in an improvement in the start-up time of multi-threaded, shared
2273 library applications when run under GDB. One GDB user writes: ``loads
2274 shared libs like mad''.
2276 * ``gdbserver'' now supports multi-threaded applications on some targets
2278 Support for debugging multi-threaded applications which use
2279 the GNU/Linux LinuxThreads package has been added for
2280 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
2281 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
2283 * GDB now supports C/C++ preprocessor macros.
2285 GDB now expands preprocessor macro invocations in C/C++ expressions,
2286 and provides various commands for showing macro definitions and how
2289 The new command `macro expand EXPRESSION' expands any macro
2290 invocations in expression, and shows the result.
2292 The new command `show macro MACRO-NAME' shows the definition of the
2293 macro named MACRO-NAME, and where it was defined.
2295 Most compilers don't include information about macros in the debugging
2296 information by default. In GCC 3.1, for example, you need to compile
2297 your program with the options `-gdwarf-2 -g3'. If the macro
2298 information is present in the executable, GDB will read it.
2300 * Multi-arched targets.
2302 DEC Alpha (partial) alpha*-*-*
2303 DEC VAX (partial) vax-*-*
2305 National Semiconductor NS32000 (partial) ns32k-*-*
2306 Motorola 68000 (partial) m68k-*-*
2307 Motorola MCORE mcore-*-*
2311 Fujitsu FRV architecture added by Red Hat frv*-*-*
2314 * New native configurations
2316 Alpha NetBSD alpha*-*-netbsd*
2317 SH NetBSD sh*-*-netbsdelf*
2318 MIPS NetBSD mips*-*-netbsd*
2319 UltraSPARC NetBSD sparc64-*-netbsd*
2321 * OBSOLETE configurations and files
2323 Configurations that have been declared obsolete in this release have
2324 been commented out. Unless there is activity to revive these
2325 configurations, the next release of GDB will have their sources
2326 permanently REMOVED.
2328 Mitsubishi D30V d30v-*-*
2329 OS/9000 i[34]86-*-os9k
2330 IBM AIX PS/2 i[3456]86-*-aix
2331 Fujitsu FR30 fr30-*-elf*
2332 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2333 Argonaut Risc Chip (ARC) arc-*-*
2334 i386 running Mach 3.0 i[3456]86-*-mach3*
2335 i386 running Mach i[3456]86-*-mach*
2336 i386 running OSF/1 i[3456]86-*osf1mk*
2337 HP/Apollo 68k Family m68*-apollo*-sysv*,
2339 m68*-hp-bsd*, m68*-hp-hpux*
2340 I960 with MON960 i960-*-coff
2342 * OBSOLETE languages
2344 CHILL, a Pascal like language used by telecommunications companies.
2346 * REMOVED configurations and files
2348 AMD 29k family via UDI a29k-amd-udi, udi29k
2349 A29K VxWorks a29k-*-vxworks
2350 AMD 29000 embedded, using EBMON a29k-none-none
2351 AMD 29000 embedded with COFF a29k-none-coff
2352 AMD 29000 embedded with a.out a29k-none-aout
2354 testsuite/gdb.hp/gdb.threads-hp/ directory
2356 * New command "set max-user-call-depth <nnn>"
2358 This command allows the user to limit the call depth of user-defined
2359 commands. The default is 1024.
2361 * Changes in FreeBSD/i386 native debugging.
2363 Support for the "generate-core-file" has been added.
2365 * New commands "dump", "append", and "restore".
2367 These commands allow data to be copied from target memory
2368 to a bfd-format or binary file (dump and append), and back
2369 from a file into memory (restore).
2371 * Improved "next/step" support on multi-processor Alpha Tru64.
2373 The previous single-step mechanism could cause unpredictable problems,
2374 including the random appearance of SIGSEGV or SIGTRAP signals. The use
2375 of a software single-step mechanism prevents this.
2377 *** Changes in GDB 5.2.1:
2385 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
2386 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
2387 Fix, by Joel Brobecker imported from mainline.
2389 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
2390 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
2391 Fix, by Fred Fish, imported from mainline.
2393 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
2394 Surprisingly enough, it works now.
2395 By Michal Ludvig, imported from mainline.
2397 i386 hardware watchpoint support:
2398 avoid misses on second run for some targets.
2399 By Pierre Muller, imported from mainline.
2401 *** Changes in GDB 5.2:
2403 * New command "set trust-readonly-sections on[off]".
2405 This command is a hint that tells gdb that read-only sections
2406 really are read-only (ie. that their contents will not change).
2407 In this mode, gdb will go to the object file rather than the
2408 target to read memory from read-only sections (such as ".text").
2409 This can be a significant performance improvement on some
2410 (notably embedded) targets.
2412 * New command "generate-core-file" (or "gcore").
2414 This new gdb command allows the user to drop a core file of the child
2415 process state at any time. So far it's been implemented only for
2416 GNU/Linux and Solaris, but should be relatively easily ported to other
2417 hosts. Argument is core file name (defaults to core.<pid>).
2419 * New command line option
2421 GDB now accepts --pid or -p followed by a process id.
2423 * Change in command line behavior -- corefiles vs. process ids.
2425 There is a subtle behavior in the way in which GDB handles
2426 command line arguments. The first non-flag argument is always
2427 a program to debug, but the second non-flag argument may either
2428 be a corefile or a process id. Previously, GDB would attempt to
2429 open the second argument as a corefile, and if that failed, would
2430 issue a superfluous error message and then attempt to attach it as
2431 a process. Now, if the second argument begins with a non-digit,
2432 it will be treated as a corefile. If it begins with a digit,
2433 GDB will attempt to attach it as a process, and if no such process
2434 is found, will then attempt to open it as a corefile.
2436 * Changes in ARM configurations.
2438 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
2439 configuration is fully multi-arch.
2441 * New native configurations
2443 ARM NetBSD arm*-*-netbsd*
2444 x86 OpenBSD i[3456]86-*-openbsd*
2445 AMD x86-64 running GNU/Linux x86_64-*-linux-*
2446 Sparc64 running FreeBSD sparc64-*-freebsd*
2450 Sanyo XStormy16 xstormy16-elf
2452 * OBSOLETE configurations and files
2454 Configurations that have been declared obsolete in this release have
2455 been commented out. Unless there is activity to revive these
2456 configurations, the next release of GDB will have their sources
2457 permanently REMOVED.
2459 AMD 29k family via UDI a29k-amd-udi, udi29k
2460 A29K VxWorks a29k-*-vxworks
2461 AMD 29000 embedded, using EBMON a29k-none-none
2462 AMD 29000 embedded with COFF a29k-none-coff
2463 AMD 29000 embedded with a.out a29k-none-aout
2465 testsuite/gdb.hp/gdb.threads-hp/ directory
2467 * REMOVED configurations and files
2469 TI TMS320C80 tic80-*-*
2471 PowerPC Solaris powerpcle-*-solaris*
2472 PowerPC Windows NT powerpcle-*-cygwin32
2473 PowerPC Netware powerpc-*-netware*
2474 Harris/CXUX m88k m88*-harris-cxux*
2475 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
2476 ns32k-utek-sysv* ns32k-utek-*
2477 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
2478 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
2479 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
2480 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
2481 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
2483 * Changes to command line processing
2485 The new `--args' feature can be used to specify command-line arguments
2486 for the inferior from gdb's command line.
2488 * Changes to key bindings
2490 There is a new `operate-and-get-next' function bound to `C-o'.
2492 *** Changes in GDB 5.1.1
2494 Fix compile problem on DJGPP.
2496 Fix a problem with floating-point registers on the i386 being
2499 Fix to stop GDB crashing on .debug_str debug info.
2501 Numerous documentation fixes.
2503 Numerous testsuite fixes.
2505 *** Changes in GDB 5.1:
2507 * New native configurations
2509 Alpha FreeBSD alpha*-*-freebsd*
2510 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
2511 MIPS GNU/Linux mips*-*-linux*
2512 MIPS SGI Irix 6.x mips*-sgi-irix6*
2513 ia64 AIX ia64-*-aix*
2514 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
2518 Motorola 68HC11 and 68HC12 m68hc11-elf
2520 UltraSparc running GNU/Linux sparc64-*-linux*
2522 * OBSOLETE configurations and files
2524 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
2525 Harris/CXUX m88k m88*-harris-cxux*
2526 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
2527 ns32k-utek-sysv* ns32k-utek-*
2528 TI TMS320C80 tic80-*-*
2530 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
2531 PowerPC Solaris powerpcle-*-solaris*
2532 PowerPC Windows NT powerpcle-*-cygwin32
2533 PowerPC Netware powerpc-*-netware*
2534 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
2535 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
2536 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
2537 Apple Macintosh (MPW) host N/A
2539 stuff.c (Program to stuff files into a specially prepared space in kdb)
2540 kdb-start.c (Main loop for the standalone kernel debugger)
2542 Configurations that have been declared obsolete in this release have
2543 been commented out. Unless there is activity to revive these
2544 configurations, the next release of GDB will have their sources
2545 permanently REMOVED.
2547 * REMOVED configurations and files
2549 Altos 3068 m68*-altos-*
2550 Convex c1-*-*, c2-*-*
2552 ARM RISCix arm-*-* (as host)
2556 * GDB has been converted to ISO C.
2558 GDB's source code has been converted to ISO C. In particular, the
2559 sources are fully protoized, and rely on standard headers being
2564 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
2566 * The MI enabled by default.
2568 The new machine oriented interface (MI) introduced in GDB 5.0 has been
2569 revised and enabled by default. Packages which use GDB as a debugging
2570 engine behind a UI or another front end are encouraged to switch to
2571 using the GDB/MI interface, instead of the old annotations interface
2572 which is now deprecated.
2574 * Support for debugging Pascal programs.
2576 GDB now includes support for debugging Pascal programs. The following
2577 main features are supported:
2579 - Pascal-specific data types such as sets;
2581 - automatic recognition of Pascal sources based on file-name
2584 - Pascal-style display of data types, variables, and functions;
2586 - a Pascal expression parser.
2588 However, some important features are not yet supported.
2590 - Pascal string operations are not supported at all;
2592 - there are some problems with boolean types;
2594 - Pascal type hexadecimal constants are not supported
2595 because they conflict with the internal variables format;
2597 - support for Pascal objects and classes is not full yet;
2599 - unlike Pascal, GDB is case-sensitive for symbol names.
2601 * Changes in completion.
2603 Commands such as `shell', `run' and `set args', which pass arguments
2604 to inferior programs, now complete on file names, similar to what
2605 users expect at the shell prompt.
2607 Commands which accept locations, such as `disassemble', `print',
2608 `breakpoint', `until', etc. now complete on filenames as well as
2609 program symbols. Thus, if you type "break foob TAB", and the source
2610 files linked into the programs include `foobar.c', that file name will
2611 be one of the candidates for completion. However, file names are not
2612 considered for completion after you typed a colon that delimits a file
2613 name from a name of a function in that file, as in "break foo.c:bar".
2615 `set demangle-style' completes on available demangling styles.
2617 * New platform-independent commands:
2619 It is now possible to define a post-hook for a command as well as a
2620 hook that runs before the command. For more details, see the
2621 documentation of `hookpost' in the GDB manual.
2623 * Changes in GNU/Linux native debugging.
2625 Support for debugging multi-threaded programs has been completely
2626 revised for all platforms except m68k and sparc. You can now debug as
2627 many threads as your system allows you to have.
2629 Attach/detach is supported for multi-threaded programs.
2631 Support for SSE registers was added for x86. This doesn't work for
2632 multi-threaded programs though.
2634 * Changes in MIPS configurations.
2636 Multi-arch support is enabled for all MIPS configurations.
2638 GDB can now be built as native debugger on SGI Irix 6.x systems for
2639 debugging n32 executables. (Debugging 64-bit executables is not yet
2642 * Unified support for hardware watchpoints in all x86 configurations.
2644 Most (if not all) native x86 configurations support hardware-assisted
2645 breakpoints and watchpoints in a unified manner. This support
2646 implements debug register sharing between watchpoints, which allows to
2647 put a virtually infinite number of watchpoints on the same address,
2648 and also supports watching regions up to 16 bytes with several debug
2651 The new maintenance command `maintenance show-debug-regs' toggles
2652 debugging print-outs in functions that insert, remove, and test
2653 watchpoints and hardware breakpoints.
2655 * Changes in the DJGPP native configuration.
2657 New command ``info dos sysinfo'' displays assorted information about
2658 the CPU, OS, memory, and DPMI server.
2660 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
2661 display information about segment descriptors stored in GDT, LDT, and
2664 New commands ``info dos pde'' and ``info dos pte'' display entries
2665 from Page Directory and Page Tables (for now works with CWSDPMI only).
2666 New command ``info dos address-pte'' displays the Page Table entry for
2667 a given linear address.
2669 GDB can now pass command lines longer than 126 characters to the
2670 program being debugged (requires an update to the libdbg.a library
2671 which is part of the DJGPP development kit).
2673 DWARF2 debug info is now supported.
2675 It is now possible to `step' and `next' through calls to `longjmp'.
2677 * Changes in documentation.
2679 All GDB documentation was converted to GFDL, the GNU Free
2680 Documentation License.
2682 Tracepoints-related commands are now fully documented in the GDB
2685 TUI, the Text-mode User Interface, is now documented in the manual.
2687 Tracepoints-related commands are now fully documented in the GDB
2690 The "GDB Internals" manual now has an index. It also includes
2691 documentation of `ui_out' functions, GDB coding standards, x86
2692 hardware watchpoints, and memory region attributes.
2694 * GDB's version number moved to ``version.in''
2696 The Makefile variable VERSION has been replaced by the file
2697 ``version.in''. People creating GDB distributions should update the
2698 contents of this file.
2702 GUD support is now a standard part of the EMACS distribution.
2704 *** Changes in GDB 5.0:
2706 * Improved support for debugging FP programs on x86 targets
2708 Unified and much-improved support for debugging floating-point
2709 programs on all x86 targets. In particular, ``info float'' now
2710 displays the FP registers in the same format on all x86 targets, with
2711 greater level of detail.
2713 * Improvements and bugfixes in hardware-assisted watchpoints
2715 It is now possible to watch array elements, struct members, and
2716 bitfields with hardware-assisted watchpoints. Data-read watchpoints
2717 on x86 targets no longer erroneously trigger when the address is
2720 * Improvements in the native DJGPP version of GDB
2722 The distribution now includes all the scripts and auxiliary files
2723 necessary to build the native DJGPP version on MS-DOS/MS-Windows
2724 machines ``out of the box''.
2726 The DJGPP version can now debug programs that use signals. It is
2727 possible to catch signals that happened in the debuggee, deliver
2728 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
2729 would kill the program being debugged.) Programs that hook hardware
2730 interrupts (keyboard, timer, etc.) can also be debugged.
2732 It is now possible to debug DJGPP programs that redirect their
2733 standard handles or switch them to raw (as opposed to cooked) mode, or
2734 even close them. The command ``run < foo > bar'' works as expected,
2735 and ``info terminal'' reports useful information about the debuggee's
2736 terminal, including raw/cooked mode, redirection, etc.
2738 The DJGPP version now uses termios functions for console I/O, which
2739 enables debugging graphics programs. Interrupting GDB with Ctrl-C
2742 DOS-style file names with drive letters are now fully supported by
2745 It is now possible to debug DJGPP programs that switch their working
2746 directory. It is also possible to rerun the debuggee any number of
2747 times without restarting GDB; thus, you can use the same setup,
2748 breakpoints, etc. for many debugging sessions.
2750 * New native configurations
2752 ARM GNU/Linux arm*-*-linux*
2753 PowerPC GNU/Linux powerpc-*-linux*
2757 Motorola MCore mcore-*-*
2758 x86 VxWorks i[3456]86-*-vxworks*
2759 PowerPC VxWorks powerpc-*-vxworks*
2760 TI TMS320C80 tic80-*-*
2762 * OBSOLETE configurations
2764 Altos 3068 m68*-altos-*
2765 Convex c1-*-*, c2-*-*
2767 ARM RISCix arm-*-* (as host)
2770 Configurations that have been declared obsolete will be commented out,
2771 but the code will be left in place. If there is no activity to revive
2772 these configurations before the next release of GDB, the sources will
2773 be permanently REMOVED.
2775 * Gould support removed
2777 Support for the Gould PowerNode and NP1 has been removed.
2779 * New features for SVR4
2781 On SVR4 native platforms (such as Solaris), if you attach to a process
2782 without first loading a symbol file, GDB will now attempt to locate and
2783 load symbols from the running process's executable file.
2785 * Many C++ enhancements
2787 C++ support has been greatly improved. Overload resolution now works properly
2788 in almost all cases. RTTI support is on the way.
2790 * Remote targets can connect to a sub-program
2792 A popen(3) style serial-device has been added. This device starts a
2793 sub-process (such as a stand-alone simulator) and then communicates
2794 with that. The sub-program to run is specified using the syntax
2795 ``|<program> <args>'' vis:
2797 (gdb) set remotedebug 1
2798 (gdb) target extended-remote |mn10300-elf-sim program-args
2800 * MIPS 64 remote protocol
2802 A long standing bug in the mips64 remote protocol where by GDB
2803 expected certain 32 bit registers (ex SR) to be transfered as 32
2804 instead of 64 bits has been fixed.
2806 The command ``set remote-mips64-transfers-32bit-regs on'' has been
2807 added to provide backward compatibility with older versions of GDB.
2809 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
2811 The command ``set remotebinarydownload'' command has been replaced by
2812 ``set remote X-packet''. Other commands in ``set remote'' family
2813 include ``set remote P-packet''.
2815 * Breakpoint commands accept ranges.
2817 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
2818 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
2819 ``tracepoint passcount'' also accepts a range of tracepoints.
2821 * ``apropos'' command added.
2823 The ``apropos'' command searches through command names and
2824 documentation strings, printing out matches, making it much easier to
2825 try to find a command that does what you are looking for.
2829 A new machine oriented interface (MI) has been added to GDB. This
2830 interface is designed for debug environments running GDB as a separate
2831 process. This is part of the long term libGDB project. See the
2832 "GDB/MI" chapter of the GDB manual for further information. It can be
2833 enabled by configuring with:
2835 .../configure --enable-gdbmi
2837 *** Changes in GDB-4.18:
2839 * New native configurations
2841 HP-UX 10.20 hppa*-*-hpux10.20
2842 HP-UX 11.x hppa*-*-hpux11.0*
2843 M68K GNU/Linux m68*-*-linux*
2847 Fujitsu FR30 fr30-*-elf*
2848 Intel StrongARM strongarm-*-*
2849 Mitsubishi D30V d30v-*-*
2851 * OBSOLETE configurations
2853 Gould PowerNode, NP1 np1-*-*, pn-*-*
2855 Configurations that have been declared obsolete will be commented out,
2856 but the code will be left in place. If there is no activity to revive
2857 these configurations before the next release of GDB, the sources will
2858 be permanently REMOVED.
2862 As a compatibility experiment, GDB's source files buildsym.h and
2863 buildsym.c have been converted to pure standard C, no longer
2864 containing any K&R compatibility code. We believe that all systems in
2865 use today either come with a standard C compiler, or have a GCC port
2866 available. If this is not true, please report the affected
2867 configuration to bug-gdb@gnu.org immediately. See the README file for
2868 information about getting a standard C compiler if you don't have one
2873 GDB now uses readline 2.2.
2875 * set extension-language
2877 You can now control the mapping between filename extensions and source
2878 languages by using the `set extension-language' command. For instance,
2879 you can ask GDB to treat .c files as C++ by saying
2880 set extension-language .c c++
2881 The command `info extensions' lists all of the recognized extensions
2882 and their associated languages.
2884 * Setting processor type for PowerPC and RS/6000
2886 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
2887 you can use the `set processor' command to specify what variant of the
2888 PowerPC family you are debugging. The command
2892 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
2893 following PowerPC and RS6000 variants:
2895 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
2896 rs6000 IBM RS6000 ("POWER") architecture, user-level view
2898 403GC IBM PowerPC 403GC
2899 505 Motorola PowerPC 505
2900 860 Motorola PowerPC 860 or 850
2901 601 Motorola PowerPC 601
2902 602 Motorola PowerPC 602
2903 603 Motorola/IBM PowerPC 603 or 603e
2904 604 Motorola PowerPC 604 or 604e
2905 750 Motorola/IBM PowerPC 750 or 750
2907 At the moment, this command just tells GDB what to name the
2908 special-purpose processor registers. Since almost all the affected
2909 registers are inaccessible to user-level programs, this command is
2910 only useful for remote debugging in its present form.
2914 Thanks to a major code donation from Hewlett-Packard, GDB now has much
2915 more extensive support for HP-UX. Added features include shared
2916 library support, kernel threads and hardware watchpoints for 11.00,
2917 support for HP's ANSI C and C++ compilers, and a compatibility mode
2918 for xdb and dbx commands.
2922 HP's donation includes the new concept of catchpoints, which is a
2923 generalization of the old catch command. On HP-UX, it is now possible
2924 to catch exec, fork, and vfork, as well as library loading.
2926 This means that the existing catch command has changed; its first
2927 argument now specifies the type of catch to be set up. See the
2928 output of "help catch" for a list of catchpoint types.
2930 * Debugging across forks
2932 On HP-UX, you can choose which process to debug when a fork() happens
2937 HP has donated a curses-based terminal user interface (TUI). To get
2938 it, build with --enable-tui. Although this can be enabled for any
2939 configuration, at present it only works for native HP debugging.
2941 * GDB remote protocol additions
2943 A new protocol packet 'X' that writes binary data is now available.
2944 Default behavior is to try 'X', then drop back to 'M' if the stub
2945 fails to respond. The settable variable `remotebinarydownload'
2946 allows explicit control over the use of 'X'.
2948 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
2949 full 64-bit address. The command
2951 set remoteaddresssize 32
2953 can be used to revert to the old behaviour. For existing remote stubs
2954 the change should not be noticed, as the additional address information
2957 In order to assist in debugging stubs, you may use the maintenance
2958 command `packet' to send any text string to the stub. For instance,
2960 maint packet heythere
2962 sends the packet "$heythere#<checksum>". Note that it is very easy to
2963 disrupt a debugging session by sending the wrong packet at the wrong
2966 The compare-sections command allows you to compare section data on the
2967 target to what is in the executable file without uploading or
2968 downloading, by comparing CRC checksums.
2970 * Tracing can collect general expressions
2972 You may now collect general expressions at tracepoints. This requires
2973 further additions to the target-side stub; see tracepoint.c and
2974 doc/agentexpr.texi for further details.
2976 * mask-address variable for Mips
2978 For Mips targets, you may control the zeroing of the upper 32 bits of
2979 a 64-bit address by entering `set mask-address on'. This is mainly
2980 of interest to users of embedded R4xxx and R5xxx processors.
2982 * Higher serial baud rates
2984 GDB's serial code now allows you to specify baud rates 57600, 115200,
2985 230400, and 460800 baud. (Note that your host system may not be able
2986 to achieve all of these rates.)
2990 The i960 configuration now includes an initial implementation of a
2991 builtin simulator, contributed by Jim Wilson.
2994 *** Changes in GDB-4.17:
2996 * New native configurations
2998 Alpha GNU/Linux alpha*-*-linux*
2999 Unixware 2.x i[3456]86-unixware2*
3000 Irix 6.x mips*-sgi-irix6*
3001 PowerPC GNU/Linux powerpc-*-linux*
3002 PowerPC Solaris powerpcle-*-solaris*
3003 Sparc GNU/Linux sparc-*-linux*
3004 Motorola sysV68 R3V7.1 m68k-motorola-sysv
3008 Argonaut Risc Chip (ARC) arc-*-*
3009 Hitachi H8/300S h8300*-*-*
3010 Matsushita MN10200 w/simulator mn10200-*-*
3011 Matsushita MN10300 w/simulator mn10300-*-*
3012 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
3013 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
3014 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
3015 Mitsubishi D10V w/simulator d10v-*-*
3016 Mitsubishi M32R/D w/simulator m32r-*-elf*
3017 Tsqware Sparclet sparclet-*-*
3018 NEC V850 w/simulator v850-*-*
3020 * New debugging protocols
3022 ARM with RDI protocol arm*-*-*
3023 M68K with dBUG monitor m68*-*-{aout,coff,elf}
3024 DDB and LSI variants of PMON protocol mips*-*-*
3025 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
3026 PowerPC with SDS protocol powerpc{,le}-*-eabi
3027 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
3031 All configurations can now understand and use the DWARF 2 debugging
3032 format. The choice is automatic, if the symbol file contains DWARF 2
3037 GDB now includes basic Java language support. This support is
3038 only useful with Java compilers that produce native machine code.
3040 * solib-absolute-prefix and solib-search-path
3042 For SunOS and SVR4 shared libraries, you may now set the prefix for
3043 loading absolute shared library symbol files, and the search path for
3044 locating non-absolute shared library symbol files.
3046 * Live range splitting
3048 GDB can now effectively debug code for which GCC has performed live
3049 range splitting as part of its optimization. See gdb/doc/LRS for
3050 more details on the expected format of the stabs information.
3054 GDB's support for the GNU Hurd, including thread debugging, has been
3055 updated to work with current versions of the Hurd.
3059 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
3060 instruction set. ARM GDB automatically detects when Thumb
3061 instructions are in use, and adjusts disassembly and backtracing
3066 GDB's MIPS target configurations now handle the MIP16 16-bit
3071 GDB now includes support for overlays; if an executable has been
3072 linked such that multiple sections are based at the same address, GDB
3073 will decide which section to use for symbolic info. You can choose to
3074 control the decision manually, using overlay commands, or implement
3075 additional target-side support and use "overlay load-target" to bring
3076 in the overlay mapping. Do "help overlay" for more detail.
3080 The command "info symbol <address>" displays information about
3081 the symbol at the specified address.
3085 The standard remote protocol now includes an extension that allows
3086 asynchronous collection and display of trace data. This requires
3087 extensive support in the target-side debugging stub. Tracing mode
3088 includes a new interaction mode in GDB and new commands: see the
3089 file tracepoint.c for more details.
3093 Configurations for embedded MIPS now include a simulator contributed
3094 by Cygnus Solutions. The simulator supports the instruction sets
3095 of most MIPS variants.
3099 Sparc configurations may now include the ERC32 simulator contributed
3100 by the European Space Agency. The simulator is not built into
3101 Sparc targets by default; configure with --enable-sim to include it.
3105 For target configurations that may include multiple variants of a
3106 basic architecture (such as MIPS and SH), you may now set the
3107 architecture explicitly. "set arch" sets, "info arch" lists
3108 the possible architectures.
3110 *** Changes in GDB-4.16:
3112 * New native configurations
3114 Windows 95, x86 Windows NT i[345]86-*-cygwin32
3115 M68K NetBSD m68k-*-netbsd*
3116 PowerPC AIX 4.x powerpc-*-aix*
3117 PowerPC MacOS powerpc-*-macos*
3118 PowerPC Windows NT powerpcle-*-cygwin32
3119 RS/6000 AIX 4.x rs6000-*-aix4*
3123 ARM with RDP protocol arm-*-*
3124 I960 with MON960 i960-*-coff
3125 MIPS VxWorks mips*-*-vxworks*
3126 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
3127 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
3129 Matra Sparclet sparclet-*-*
3133 The powerpc-eabi configuration now includes the PSIM simulator,
3134 contributed by Andrew Cagney, with assistance from Mike Meissner.
3135 PSIM is a very elaborate model of the PowerPC, including not only
3136 basic instruction set execution, but also details of execution unit
3137 performance and I/O hardware. See sim/ppc/README for more details.
3141 GDB now works with Solaris 2.5.
3143 * Windows 95/NT native
3145 GDB will now work as a native debugger on Windows 95 and Windows NT.
3146 To build it from source, you must use the "gnu-win32" environment,
3147 which uses a DLL to emulate enough of Unix to run the GNU tools.
3148 Further information, binaries, and sources are available at
3149 ftp.cygnus.com, under pub/gnu-win32.
3151 * dont-repeat command
3153 If a user-defined command includes the command `dont-repeat', then the
3154 command will not be repeated if the user just types return. This is
3155 useful if the command is time-consuming to run, so that accidental
3156 extra keystrokes don't run the same command many times.
3158 * Send break instead of ^C
3160 The standard remote protocol now includes an option to send a break
3161 rather than a ^C to the target in order to interrupt it. By default,
3162 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
3164 * Remote protocol timeout
3166 The standard remote protocol includes a new variable `remotetimeout'
3167 that allows you to set the number of seconds before GDB gives up trying
3168 to read from the target. The default value is 2.
3170 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
3172 By default GDB will automatically keep track of objects as they are
3173 loaded and unloaded by the dynamic linker. By using the command `set
3174 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
3175 when shared library events occur, thus allowing you to set breakpoints
3176 in shared libraries which are explicitly loaded by the inferior.
3178 Note this feature does not work on hpux8. On hpux9 you must link
3179 /usr/lib/end.o into your program. This feature should work
3180 automatically on hpux10.
3182 * Irix 5.x hardware watchpoint support
3184 Irix 5 configurations now support the use of hardware watchpoints.
3186 * Mips protocol "SYN garbage limit"
3188 When debugging a Mips target using the `target mips' protocol, you
3189 may set the number of characters that GDB will ignore by setting
3190 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
3191 every character. The default value is 1050.
3193 * Recording and replaying remote debug sessions
3195 If you set `remotelogfile' to the name of a file, gdb will write to it
3196 a recording of a remote debug session. This recording may then be
3197 replayed back to gdb using "gdbreplay". See gdbserver/README for
3198 details. This is useful when you have a problem with GDB while doing
3199 remote debugging; you can make a recording of the session and send it
3200 to someone else, who can then recreate the problem.
3202 * Speedups for remote debugging
3204 GDB includes speedups for downloading and stepping MIPS systems using
3205 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
3206 and more efficient S-record downloading.
3208 * Memory use reductions and statistics collection
3210 GDB now uses less memory and reports statistics about memory usage.
3211 Try the `maint print statistics' command, for example.
3213 *** Changes in GDB-4.15:
3215 * Psymtabs for XCOFF
3217 The symbol reader for AIX GDB now uses partial symbol tables. This
3218 can greatly improve startup time, especially for large executables.
3220 * Remote targets use caching
3222 Remote targets now use a data cache to speed up communication with the
3223 remote side. The data cache could lead to incorrect results because
3224 it doesn't know about volatile variables, thus making it impossible to
3225 debug targets which use memory mapped I/O devices. `set remotecache
3226 off' turns the the data cache off.
3228 * Remote targets may have threads
3230 The standard remote protocol now includes support for multiple threads
3231 in the target system, using new protocol commands 'H' and 'T'. See
3232 gdb/remote.c for details.
3236 If GDB is configured with `--enable-netrom', then it will include
3237 support for the NetROM ROM emulator from XLNT Designs. The NetROM
3238 acts as though it is a bank of ROM on the target board, but you can
3239 write into it over the network. GDB's support consists only of
3240 support for fast loading into the emulated ROM; to debug, you must use
3241 another protocol, such as standard remote protocol. The usual
3242 sequence is something like
3244 target nrom <netrom-hostname>
3246 target remote <netrom-hostname>:1235
3250 GDB now includes support for the Apple Macintosh, as a host only. It
3251 may be run as either an MPW tool or as a standalone application, and
3252 it can debug through the serial port. All the usual GDB commands are
3253 available, but to the target command, you must supply "serial" as the
3254 device type instead of "/dev/ttyXX". See mpw-README in the main
3255 directory for more information on how to build. The MPW configuration
3256 scripts */mpw-config.in support only a few targets, and only the
3257 mips-idt-ecoff target has been tested.
3261 GDB configuration now uses autoconf. This is not user-visible,
3262 but does simplify configuration and building.
3266 GDB now supports hpux10.
3268 *** Changes in GDB-4.14:
3270 * New native configurations
3272 x86 FreeBSD i[345]86-*-freebsd
3273 x86 NetBSD i[345]86-*-netbsd
3274 NS32k NetBSD ns32k-*-netbsd
3275 Sparc NetBSD sparc-*-netbsd
3279 A29K VxWorks a29k-*-vxworks
3280 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
3281 CPU32 EST-300 emulator m68*-*-est*
3282 PowerPC ELF powerpc-*-elf
3285 * Alpha OSF/1 support for procfs
3287 GDB now supports procfs under OSF/1-2.x and higher, which makes it
3288 possible to attach to running processes. As the mounting of the /proc
3289 filesystem is optional on the Alpha, GDB automatically determines
3290 the availability of /proc during startup. This can lead to problems
3291 if /proc is unmounted after GDB has been started.
3293 * Arguments to user-defined commands
3295 User commands may accept up to 10 arguments separated by whitespace.
3296 Arguments are accessed within the user command via $arg0..$arg9. A
3299 print $arg0 + $arg1 + $arg2
3301 To execute the command use:
3304 Defines the command "adder" which prints the sum of its three arguments.
3305 Note the arguments are text substitutions, so they may reference variables,
3306 use complex expressions, or even perform inferior function calls.
3308 * New `if' and `while' commands
3310 This makes it possible to write more sophisticated user-defined
3311 commands. Both commands take a single argument, which is the
3312 expression to evaluate, and must be followed by the commands to
3313 execute, one per line, if the expression is nonzero, the list being
3314 terminated by the word `end'. The `if' command list may include an
3315 `else' word, which causes the following commands to be executed only
3316 if the expression is zero.
3318 * Fortran source language mode
3320 GDB now includes partial support for Fortran 77. It will recognize
3321 Fortran programs and can evaluate a subset of Fortran expressions, but
3322 variables and functions may not be handled correctly. GDB will work
3323 with G77, but does not yet know much about symbols emitted by other
3326 * Better HPUX support
3328 Most debugging facilities now work on dynamic executables for HPPAs
3329 running hpux9 or later. You can attach to running dynamically linked
3330 processes, but by default the dynamic libraries will be read-only, so
3331 for instance you won't be able to put breakpoints in them. To change
3332 that behavior do the following before running the program:
3338 This will cause the libraries to be mapped private and read-write.
3339 To revert to the normal behavior, do this:
3345 You cannot set breakpoints or examine data in the library until after
3346 the library is loaded if the function/data symbols do not have
3349 GDB can now also read debug symbols produced by the HP C compiler on
3350 HPPAs (sorry, no C++, Fortran or 68k support).
3352 * Target byte order now dynamically selectable
3354 You can choose which byte order to use with a target system, via the
3355 commands "set endian big" and "set endian little", and you can see the
3356 current setting by using "show endian". You can also give the command
3357 "set endian auto", in which case GDB will use the byte order
3358 associated with the executable. Currently, only embedded MIPS
3359 configurations support dynamic selection of target byte order.
3361 * New DOS host serial code
3363 This version uses DPMI interrupts to handle buffered I/O, so you
3364 no longer need to run asynctsr when debugging boards connected to
3367 *** Changes in GDB-4.13:
3369 * New "complete" command
3371 This lists all the possible completions for the rest of the line, if it
3372 were to be given as a command itself. This is intended for use by emacs.
3374 * Trailing space optional in prompt
3376 "set prompt" no longer adds a space for you after the prompt you set. This
3377 allows you to set a prompt which ends in a space or one that does not.
3379 * Breakpoint hit counts
3381 "info break" now displays a count of the number of times the breakpoint
3382 has been hit. This is especially useful in conjunction with "ignore"; you
3383 can ignore a large number of breakpoint hits, look at the breakpoint info
3384 to see how many times the breakpoint was hit, then run again, ignoring one
3385 less than that number, and this will get you quickly to the last hit of
3388 * Ability to stop printing at NULL character
3390 "set print null-stop" will cause GDB to stop printing the characters of
3391 an array when the first NULL is encountered. This is useful when large
3392 arrays actually contain only short strings.
3394 * Shared library breakpoints
3396 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
3397 breakpoints in shared libraries before the executable is run.
3399 * Hardware watchpoints
3401 There is a new hardware breakpoint for the watch command for sparclite
3402 targets. See gdb/sparclite/hw_breakpoint.note.
3404 Hardware watchpoints are also now supported under GNU/Linux.
3408 Annotations have been added. These are for use with graphical interfaces,
3409 and are still experimental. Currently only gdba.el uses these.
3411 * Improved Irix 5 support
3413 GDB now works properly with Irix 5.2.
3415 * Improved HPPA support
3417 GDB now works properly with the latest GCC and GAS.
3419 * New native configurations
3421 Sequent PTX4 i[34]86-sequent-ptx4
3422 HPPA running OSF/1 hppa*-*-osf*
3423 Atari TT running SVR4 m68*-*-sysv4*
3424 RS/6000 LynxOS rs6000-*-lynxos*
3428 OS/9000 i[34]86-*-os9k
3429 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
3432 * Hitachi SH7000 and E7000-PC ICE support
3434 There is now support for communicating with the Hitachi E7000-PC ICE.
3435 This is available automatically when GDB is configured for the SH.
3439 As usual, a variety of small fixes and improvements, both generic
3440 and configuration-specific. See the ChangeLog for more detail.
3442 *** Changes in GDB-4.12:
3444 * Irix 5 is now supported
3448 GDB-4.12 on the HPPA has a number of changes which make it unable
3449 to debug the output from the currently released versions of GCC and
3450 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
3451 of GCC and GAS, versions of these tools designed to work with GDB-4.12
3452 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
3455 *** Changes in GDB-4.11:
3457 * User visible changes:
3461 The "set remotedebug" option is now consistent between the mips remote
3462 target, remote targets using the gdb-specific protocol, UDI (AMD's
3463 debug protocol for the 29k) and the 88k bug monitor. It is now an
3464 integer specifying a debug level (normally 0 or 1, but 2 means more
3465 debugging info for the mips target).
3467 * DEC Alpha native support
3469 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
3470 debug info, but GDB works fairly well with the DEC compiler and should
3471 work with a future GCC release. See the README file for a few
3472 Alpha-specific notes.
3474 * Preliminary thread implementation
3476 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
3478 * LynxOS native and target support for 386
3480 This release has been hosted on LynxOS 2.2, and also can be configured
3481 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
3484 * Improvements in C++ mangling/demangling.
3486 This release has much better g++ debugging, specifically in name
3487 mangling/demangling, virtual function calls, print virtual table,
3488 call methods, ...etc.
3490 *** Changes in GDB-4.10:
3492 * User visible changes:
3494 Remote debugging using the GDB-specific (`target remote') protocol now
3495 supports the `load' command. This is only useful if you have some
3496 other way of getting the stub to the target system, and you can put it
3497 somewhere in memory where it won't get clobbered by the download.
3499 Filename completion now works.
3501 When run under emacs mode, the "info line" command now causes the
3502 arrow to point to the line specified. Also, "info line" prints
3503 addresses in symbolic form (as well as hex).
3505 All vxworks based targets now support a user settable option, called
3506 vxworks-timeout. This option represents the number of seconds gdb
3507 should wait for responses to rpc's. You might want to use this if
3508 your vxworks target is, perhaps, a slow software simulator or happens
3509 to be on the far side of a thin network line.
3513 This release contains support for using a DEC alpha as a GDB host for
3514 cross debugging. Native alpha debugging is not supported yet.
3517 *** Changes in GDB-4.9:
3521 This is the first GDB release which is accompanied by a matching testsuite.
3522 The testsuite requires installation of dejagnu, which should be available
3523 via ftp from most sites that carry GNU software.
3527 'Cfront' style demangling has had its name changed to 'ARM' style, to
3528 emphasize that it was written from the specifications in the C++ Annotated
3529 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
3530 disclaimers, it still generated too much confusion with users attempting to
3531 use gdb with AT&T cfront.
3535 GDB now uses a standard remote interface to a simulator library.
3536 So far, the library contains simulators for the Zilog Z8001/2, the
3537 Hitachi H8/300, H8/500 and Super-H.
3539 * New targets supported
3541 H8/300 simulator h8300-hitachi-hms or h8300hms
3542 H8/500 simulator h8500-hitachi-hms or h8500hms
3543 SH simulator sh-hitachi-hms or sh
3544 Z8000 simulator z8k-zilog-none or z8ksim
3545 IDT MIPS board over serial line mips-idt-ecoff
3547 Cross-debugging to GO32 targets is supported. It requires a custom
3548 version of the i386-stub.c module which is integrated with the
3549 GO32 memory extender.
3551 * New remote protocols
3553 MIPS remote debugging protocol.
3555 * New source languages supported
3557 This version includes preliminary support for Chill, a Pascal like language
3558 used by telecommunications companies. Chill support is also being integrated
3559 into the GNU compiler, but we don't know when it will be publically available.
3562 *** Changes in GDB-4.8:
3564 * HP Precision Architecture supported
3566 GDB now supports HP PA-RISC machines running HPUX. A preliminary
3567 version of this support was available as a set of patches from the
3568 University of Utah. GDB does not support debugging of programs
3569 compiled with the HP compiler, because HP will not document their file
3570 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
3571 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
3573 Many problems in the preliminary version have been fixed.
3575 * Faster and better demangling
3577 We have improved template demangling and fixed numerous bugs in the GNU style
3578 demangler. It can now handle type modifiers such as `static' or `const'. Wide
3579 character types (wchar_t) are now supported. Demangling of each symbol is now
3580 only done once, and is cached when the symbol table for a file is read in.
3581 This results in a small increase in memory usage for C programs, a moderate
3582 increase in memory usage for C++ programs, and a fantastic speedup in
3585 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
3586 from the specifications in the Annotated Reference Manual, which AT&T's
3587 compiler does not actually implement.
3589 * G++ multiple inheritance compiler problem
3591 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
3592 inheritance lattices was reworked to properly discover ambiguities. We
3593 recently found an example which causes this new algorithm to fail in a
3594 very subtle way, producing bad debug information for those classes.
3595 The file 'gcc.patch' (in this directory) can be applied to gcc to
3596 circumvent the problem. A future GCC release will contain a complete
3599 The previous G++ debug info problem (mentioned below for the gdb-4.7
3600 release) is fixed in gcc version 2.3.2.
3602 * Improved configure script
3604 The `configure' script will now attempt to guess your system type if
3605 you don't supply a host system type. The old scheme of supplying a
3606 host system triplet is preferable over using this. All the magic is
3607 done in the new `config.guess' script. Examine it for details.
3609 We have also brought our configure script much more in line with the FSF's
3610 version. It now supports the --with-xxx options. In particular,
3611 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
3612 The resulting GDB will not be able to read arbitrary object file formats --
3613 only the format ``expected'' to be used on the configured target system.
3614 We hope to make this the default in a future release.
3616 * Documentation improvements
3618 There's new internal documentation on how to modify GDB, and how to
3619 produce clean changes to the code. We implore people to read it
3620 before submitting changes.
3622 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
3623 M4 macros. The new texinfo.tex is provided in this release. Pre-built
3624 `info' files are also provided. To build `info' files from scratch,
3625 you will need the latest `makeinfo' release, which will be available in
3626 a future texinfo-X.Y release.
3628 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
3629 We're not sure exactly which versions have this problem, but it has
3630 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
3631 or better. If that isn't possible, there is a patch in
3632 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
3633 around this problem.
3637 GDB now supports array constants that can be used in expressions typed in by
3638 the user. The syntax is `{element, element, ...}'. Ie: you can now type
3639 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
3642 The new directory `gdb/sparclite' contains a program that demonstrates
3643 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
3645 * New native hosts supported
3647 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
3648 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
3650 * New targets supported
3652 AMD 29k family via UDI a29k-amd-udi or udi29k
3654 * New file formats supported
3656 BFD now supports reading HP/PA-RISC executables (SOM file format?),
3657 HPUX core files, and SCO 3.2v2 core files.
3661 Attaching to processes now works again; thanks for the many bug reports.
3663 We have also stomped on a bunch of core dumps caused by
3664 printf_filtered("%s") problems.
3666 We eliminated a copyright problem on the rpc and ptrace header files
3667 for VxWorks, which was discovered at the last minute during the 4.7
3668 release. You should now be able to build a VxWorks GDB.
3670 You can now interrupt gdb while an attached process is running. This
3671 will cause the attached process to stop, and give control back to GDB.
3673 We fixed problems caused by using too many file descriptors
3674 for reading symbols from object files and libraries. This was
3675 especially a problem for programs that used many (~100) shared
3678 The `step' command now only enters a subroutine if there is line number
3679 information for the subroutine. Otherwise it acts like the `next'
3680 command. Previously, `step' would enter subroutines if there was
3681 any debugging information about the routine. This avoids problems
3682 when using `cc -g1' on MIPS machines.
3684 * Internal improvements
3686 GDB's internal interfaces have been improved to make it easier to support
3687 debugging of multiple languages in the future.
3689 GDB now uses a common structure for symbol information internally.
3690 Minimal symbols (derived from linkage symbols in object files), partial
3691 symbols (from a quick scan of debug information), and full symbols
3692 contain a common subset of information, making it easier to write
3693 shared code that handles any of them.
3695 * New command line options
3697 We now accept --silent as an alias for --quiet.
3701 The memory-mapped-malloc library is now licensed under the GNU Library
3702 General Public License.
3704 *** Changes in GDB-4.7:
3706 * Host/native/target split
3708 GDB has had some major internal surgery to untangle the support for
3709 hosts and remote targets. Now, when you configure GDB for a remote
3710 target, it will no longer load in all of the support for debugging
3711 local programs on the host. When fully completed and tested, this will
3712 ensure that arbitrary host/target combinations are possible.
3714 The primary conceptual shift is to separate the non-portable code in
3715 GDB into three categories. Host specific code is required any time GDB
3716 is compiled on that host, regardless of the target. Target specific
3717 code relates to the peculiarities of the target, but can be compiled on
3718 any host. Native specific code is everything else: it can only be
3719 built when the host and target are the same system. Child process
3720 handling and core file support are two common `native' examples.
3722 GDB's use of /proc for controlling Unix child processes is now cleaner.
3723 It has been split out into a single module under the `target_ops' vector,
3724 plus two native-dependent functions for each system that uses /proc.
3726 * New hosts supported
3728 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
3729 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
3730 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
3732 * New targets supported
3734 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3735 68030 and CPU32 m68030-*-*, m68332-*-*
3737 * New native hosts supported
3739 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
3740 (386bsd is not well tested yet)
3741 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
3743 * New file formats supported
3745 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
3746 supports reading of `a.out.adobe' object files, which are an a.out
3747 format extended with minimal information about multiple sections.
3751 `show copying' is the same as the old `info copying'.
3752 `show warranty' is the same as `info warrantee'.
3753 These were renamed for consistency. The old commands continue to work.
3755 `info handle' is a new alias for `info signals'.
3757 You can now define pre-command hooks, which attach arbitrary command
3758 scripts to any command. The commands in the hook will be executed
3759 prior to the user's command. You can also create a hook which will be
3760 executed whenever the program stops. See gdb.texinfo.
3764 We now deal with Cfront style name mangling, and can even extract type
3765 info from mangled symbols. GDB can automatically figure out which
3766 symbol mangling style your C++ compiler uses.
3768 Calling of methods and virtual functions has been improved as well.
3772 The crash that occured when debugging Sun Ansi-C compiled binaries is
3773 fixed. This was due to mishandling of the extra N_SO stabs output
3776 We also finally got Ultrix 4.2 running in house, and fixed core file
3777 support, with help from a dozen people on the net.
3779 John M. Farrell discovered that the reason that single-stepping was so
3780 slow on all of the Mips based platforms (primarily SGI and DEC) was
3781 that we were trying to demangle and lookup a symbol used for internal
3782 purposes on every instruction that was being stepped through. Changing
3783 the name of that symbol so that it couldn't be mistaken for a C++
3784 mangled symbol sped things up a great deal.
3786 Rich Pixley sped up symbol lookups in general by getting much smarter
3787 about when C++ symbol mangling is necessary. This should make symbol
3788 completion (TAB on the command line) much faster. It's not as fast as
3789 we'd like, but it's significantly faster than gdb-4.6.
3793 A new user controllable variable 'call_scratch_address' can
3794 specify the location of a scratch area to be used when GDB
3795 calls a function in the target. This is necessary because the
3796 usual method of putting the scratch area on the stack does not work
3797 in systems that have separate instruction and data spaces.
3799 We integrated changes to support the 29k UDI (Universal Debugger
3800 Interface), but discovered at the last minute that we didn't have all
3801 of the appropriate copyright paperwork. We are working with AMD to
3802 resolve this, and hope to have it available soon.
3806 We have sped up the remote serial line protocol, especially for targets
3807 with lots of registers. It now supports a new `expedited status' ('T')
3808 message which can be used in place of the existing 'S' status message.
3809 This allows the remote stub to send only the registers that GDB
3810 needs to make a quick decision about single-stepping or conditional
3811 breakpoints, eliminating the need to fetch the entire register set for
3812 each instruction being stepped through.
3814 The GDB remote serial protocol now implements a write-through cache for
3815 registers, only re-reading the registers if the target has run.
3817 There is also a new remote serial stub for SPARC processors. You can
3818 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
3819 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
3820 processor with a serial port.
3824 Configure.in files have become much easier to read and modify. A new
3825 `table driven' format makes it more obvious what configurations are
3826 supported, and what files each one uses.
3830 There is a new opcodes library which will eventually contain all of the
3831 disassembly routines and opcode tables. At present, it only contains
3832 Sparc and Z8000 routines. This will allow the assembler, debugger, and
3833 disassembler (binutils/objdump) to share these routines.
3835 The libiberty library is now copylefted under the GNU Library General
3836 Public License. This allows more liberal use, and was done so libg++
3837 can use it. This makes no difference to GDB, since the Library License
3838 grants all the rights from the General Public License.
3842 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
3843 reference to the stabs symbol info used by the debugger. It is (as far
3844 as we know) the only published document on this fascinating topic. We
3845 encourage you to read it, compare it to the stabs information on your
3846 system, and send improvements on the document in general (to
3847 bug-gdb@prep.ai.mit.edu).
3849 And, of course, many bugs have been fixed.
3852 *** Changes in GDB-4.6:
3854 * Better support for C++ function names
3856 GDB now accepts as input the "demangled form" of C++ overloaded function
3857 names and member function names, and can do command completion on such names
3858 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
3859 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
3860 Make use of command completion, it is your friend.
3862 GDB also now accepts a variety of C++ mangled symbol formats. They are
3863 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
3864 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
3865 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
3866 for the list of formats.
3868 * G++ symbol mangling problem
3870 Recent versions of gcc have a bug in how they emit debugging information for
3871 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
3872 directory) can be applied to gcc to fix the problem. Alternatively, if you
3873 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
3874 usual symptom is difficulty with setting breakpoints on methods. GDB complains
3875 about the method being non-existent. (We believe that version 2.2.2 of GCC has
3878 * New 'maintenance' command
3880 All of the commands related to hacking GDB internals have been moved out of
3881 the main command set, and now live behind the 'maintenance' command. This
3882 can also be abbreviated as 'mt'. The following changes were made:
3884 dump-me -> maintenance dump-me
3885 info all-breakpoints -> maintenance info breakpoints
3886 printmsyms -> maintenance print msyms
3887 printobjfiles -> maintenance print objfiles
3888 printpsyms -> maintenance print psymbols
3889 printsyms -> maintenance print symbols
3891 The following commands are new:
3893 maintenance demangle Call internal GDB demangler routine to
3894 demangle a C++ link name and prints the result.
3895 maintenance print type Print a type chain for a given symbol
3897 * Change to .gdbinit file processing
3899 We now read the $HOME/.gdbinit file before processing the argv arguments
3900 (e.g. reading symbol files or core files). This allows global parameters to
3901 be set, which will apply during the symbol reading. The ./.gdbinit is still
3902 read after argv processing.
3904 * New hosts supported
3906 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
3908 GNU/Linux support i386-unknown-linux or linux
3910 We are also including code to support the HP/PA running BSD and HPUX. This
3911 is almost guaranteed not to work, as we didn't have time to test or build it
3912 for this release. We are including it so that the more adventurous (or
3913 masochistic) of you can play with it. We also had major problems with the
3914 fact that the compiler that we got from HP doesn't support the -g option.
3917 * New targets supported
3919 Hitachi H8/300 h8300-hitachi-hms or h8300hms
3921 * More smarts about finding #include files
3923 GDB now remembers the compilation directory for all include files, and for
3924 all files from which C is generated (like yacc and lex sources). This
3925 greatly improves GDB's ability to find yacc/lex sources, and include files,
3926 especially if you are debugging your program from a directory different from
3927 the one that contains your sources.
3929 We also fixed a bug which caused difficulty with listing and setting
3930 breakpoints in include files which contain C code. (In the past, you had to
3931 try twice in order to list an include file that you hadn't looked at before.)
3933 * Interesting infernals change
3935 GDB now deals with arbitrary numbers of sections, where the symbols for each
3936 section must be relocated relative to that section's landing place in the
3937 target's address space. This work was needed to support ELF with embedded
3938 stabs used by Solaris-2.0.
3940 * Bug fixes (of course!)
3942 There have been loads of fixes for the following things:
3943 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
3944 i960, stabs, DOS(GO32), procfs, etc...
3946 See the ChangeLog for details.
3948 *** Changes in GDB-4.5:
3950 * New machines supported (host and target)
3952 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
3954 SGI Irix-4.x mips-sgi-irix4 or iris4
3956 * New malloc package
3958 GDB now uses a new memory manager called mmalloc, based on gmalloc.
3959 Mmalloc is capable of handling mutiple heaps of memory. It is also
3960 capable of saving a heap to a file, and then mapping it back in later.
3961 This can be used to greatly speedup the startup of GDB by using a
3962 pre-parsed symbol table which lives in a mmalloc managed heap. For
3963 more details, please read mmalloc/mmalloc.texi.
3967 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
3968 'help info proc' for details.
3970 * MIPS ecoff symbol table format
3972 The code that reads MIPS symbol table format is now supported on all hosts.
3973 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
3976 * File name changes for MS-DOS
3978 Many files in the config directories have been renamed to make it easier to
3979 support GDB on MS-DOSe systems (which have very restrictive file name
3980 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
3981 environment) is close to working but has some remaining problems. Note
3982 that debugging of DOS programs is not supported, due to limitations
3983 in the ``operating system'', but it can be used to host cross-debugging.
3985 * Cross byte order fixes
3987 Many fixes have been made to support cross debugging of Sparc and MIPS
3988 targets from hosts whose byte order differs.
3990 * New -mapped and -readnow options
3992 If memory-mapped files are available on your system through the 'mmap'
3993 system call, you can use the -mapped option on the `file' or
3994 `symbol-file' commands to cause GDB to write the symbols from your
3995 program into a reusable file. If the program you are debugging is
3996 called `/path/fred', the mapped symbol file will be `./fred.syms'.
3997 Future GDB debugging sessions will notice the presence of this file,
3998 and will quickly map in symbol information from it, rather than reading
3999 the symbol table from the executable program. Using the '-mapped'
4000 option in a GDB `file' or `symbol-file' command has the same effect as
4001 starting GDB with the '-mapped' command-line option.
4003 You can cause GDB to read the entire symbol table immediately by using
4004 the '-readnow' option with any of the commands that load symbol table
4005 information (or on the GDB command line). This makes the command
4006 slower, but makes future operations faster.
4008 The -mapped and -readnow options are typically combined in order to
4009 build a `fred.syms' file that contains complete symbol information.
4010 A simple GDB invocation to do nothing but build a `.syms' file for future
4013 gdb -batch -nx -mapped -readnow programname
4015 The `.syms' file is specific to the host machine on which GDB is run.
4016 It holds an exact image of GDB's internal symbol table. It cannot be
4017 shared across multiple host platforms.
4019 * longjmp() handling
4021 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
4022 siglongjmp() without losing control. This feature has not yet been ported to
4023 all systems. It currently works on many 386 platforms, all MIPS-based
4024 platforms (SGI, DECstation, etc), and Sun3/4.
4028 Preliminary work has been put in to support the new Solaris OS from Sun. At
4029 this time, it can control and debug processes, but it is not capable of
4034 As always, many many bug fixes. The major areas were with g++, and mipsread.
4035 People using the MIPS-based platforms should experience fewer mysterious
4036 crashes and trashed symbol tables.
4038 *** Changes in GDB-4.4:
4040 * New machines supported (host and target)
4042 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4044 BSD Reno on Vax vax-dec-bsd
4045 Ultrix on Vax vax-dec-ultrix
4047 * New machines supported (target)
4049 AMD 29000 embedded, using EBMON a29k-none-none
4053 GDB continues to improve its handling of C++. `References' work better.
4054 The demangler has also been improved, and now deals with symbols mangled as
4055 per the Annotated C++ Reference Guide.
4057 GDB also now handles `stabs' symbol information embedded in MIPS
4058 `ecoff' symbol tables. Since the ecoff format was not easily
4059 extensible to handle new languages such as C++, this appeared to be a
4060 good way to put C++ debugging info into MIPS binaries. This option
4061 will be supported in the GNU C compiler, version 2, when it is
4064 * New features for SVR4
4066 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
4067 shared libraries. Debugging dynamically linked programs should present
4068 only minor differences from debugging statically linked programs.
4070 The `info proc' command will print out information about any process
4071 on an SVR4 system (including the one you are debugging). At the moment,
4072 it prints the address mappings of the process.
4074 If you bring up GDB on another SVR4 system, please send mail to
4075 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
4077 * Better dynamic linking support in SunOS
4079 Reading symbols from shared libraries which contain debugging symbols
4080 now works properly. However, there remain issues such as automatic
4081 skipping of `transfer vector' code during function calls, which
4082 make it harder to debug code in a shared library, than to debug the
4083 same code linked statically.
4087 GDB is now using the latest `getopt' routines from the FSF. This
4088 version accepts the -- prefix for options with long names. GDB will
4089 continue to accept the old forms (-option and +option) as well.
4090 Various single letter abbreviations for options have been explicity
4091 added to the option table so that they won't get overshadowed in the
4092 future by other options that begin with the same letter.
4096 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
4097 Many assorted bugs have been handled. Many more remain to be handled.
4098 See the various ChangeLog files (primarily in gdb and bfd) for details.
4101 *** Changes in GDB-4.3:
4103 * New machines supported (host and target)
4105 Amiga 3000 running Amix m68k-cbm-svr4 or amix
4106 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
4107 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4109 * Almost SCO Unix support
4111 We had hoped to support:
4112 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4113 (except for core file support), but we discovered very late in the release
4114 that it has problems with process groups that render gdb unusable. Sorry
4115 about that. I encourage people to fix it and post the fixes.
4117 * Preliminary ELF and DWARF support
4119 GDB can read ELF object files on System V Release 4, and can handle
4120 debugging records for C, in DWARF format, in ELF files. This support
4121 is preliminary. If you bring up GDB on another SVR4 system, please
4122 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
4127 GDB now uses the latest `readline' library. One user-visible change
4128 is that two tabs will list possible command completions, which previously
4129 required typing M-? (meta-question mark, or ESC ?).
4133 The `stepi' bug that many of you noticed has been squashed.
4134 Many bugs in C++ have been handled. Many more remain to be handled.
4135 See the various ChangeLog files (primarily in gdb and bfd) for details.
4137 * State of the MIPS world (in case you wondered):
4139 GDB can understand the symbol tables emitted by the compilers
4140 supplied by most vendors of MIPS-based machines, including DEC. These
4141 symbol tables are in a format that essentially nobody else uses.
4143 Some versions of gcc come with an assembler post-processor called
4144 mips-tfile. This program is required if you want to do source-level
4145 debugging of gcc-compiled programs. I believe FSF does not ship
4146 mips-tfile with gcc version 1, but it will eventually come with gcc
4149 Debugging of g++ output remains a problem. g++ version 1.xx does not
4150 really support it at all. (If you're lucky, you should be able to get
4151 line numbers and stack traces to work, but no parameters or local
4152 variables.) With some work it should be possible to improve the
4155 When gcc version 2 is released, you will have somewhat better luck.
4156 However, even then you will get confusing results for inheritance and
4159 We will eventually provide full debugging of g++ output on
4160 DECstations. This will probably involve some kind of stabs-in-ecoff
4161 encapulation, but the details have not been worked out yet.
4164 *** Changes in GDB-4.2:
4166 * Improved configuration
4168 Only one copy of `configure' exists now, and it is not self-modifying.
4169 Porting BFD is simpler.
4173 The `step' and `next' commands now only stop at the first instruction
4174 of a source line. This prevents the multiple stops that used to occur
4175 in switch statements, for-loops, etc. `Step' continues to stop if a
4176 function that has debugging information is called within the line.
4180 Lots of small bugs fixed. More remain.
4182 * New host supported (not target)
4184 Intel 386 PC clone running Mach i386-none-mach
4187 *** Changes in GDB-4.1:
4189 * Multiple source language support
4191 GDB now has internal scaffolding to handle several source languages.
4192 It determines the type of each source file from its filename extension,
4193 and will switch expression parsing and number formatting to match the
4194 language of the function in the currently selected stack frame.
4195 You can also specifically set the language to be used, with
4196 `set language c' or `set language modula-2'.
4200 GDB now has preliminary support for the GNU Modula-2 compiler,
4201 currently under development at the State University of New York at
4202 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
4203 continue through the fall of 1991 and into 1992.
4205 Other Modula-2 compilers are currently not supported, and attempting to
4206 debug programs compiled with them will likely result in an error as the
4207 symbol table is read. Feel free to work on it, though!
4209 There are hooks in GDB for strict type checking and range checking,
4210 in the `Modula-2 philosophy', but they do not currently work.
4214 GDB can now write to executable and core files (e.g. patch
4215 a variable's value). You must turn this switch on, specify
4216 the file ("exec foo" or "core foo"), *then* modify it, e.g.
4217 by assigning a new value to a variable. Modifications take
4220 * Automatic SunOS shared library reading
4222 When you run your program, GDB automatically determines where its
4223 shared libraries (if any) have been loaded, and reads their symbols.
4224 The `share' command is no longer needed. This also works when
4225 examining core files.
4229 You can specify the number of lines that the `list' command shows.
4232 * New machines supported (host and target)
4234 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4235 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
4236 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
4238 * New hosts supported (not targets)
4240 IBM RT/PC: romp-ibm-aix or rtpc
4242 * New targets supported (not hosts)
4244 AMD 29000 embedded with COFF a29k-none-coff
4245 AMD 29000 embedded with a.out a29k-none-aout
4246 Ultracomputer remote kernel debug a29k-nyu-kern
4248 * New remote interfaces
4254 *** Changes in GDB-4.0:
4258 Wide output is wrapped at good places to make the output more readable.
4260 Gdb now supports cross-debugging from a host machine of one type to a
4261 target machine of another type. Communication with the target system
4262 is over serial lines. The ``target'' command handles connecting to the
4263 remote system; the ``load'' command will download a program into the
4264 remote system. Serial stubs for the m68k and i386 are provided. Gdb
4265 also supports debugging of realtime processes running under VxWorks,
4266 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
4267 stub on the target system.
4269 New CPUs supported include the AMD 29000 and Intel 960.
4271 GDB now reads object files and symbol tables via a ``binary file''
4272 library, which allows a single copy of GDB to debug programs of multiple
4273 object file types such as a.out and coff.
4275 There is now a GDB reference card in "doc/refcard.tex". (Make targets
4276 refcard.dvi and refcard.ps are available to format it).
4279 * Control-Variable user interface simplified
4281 All variables that control the operation of the debugger can be set
4282 by the ``set'' command, and displayed by the ``show'' command.
4284 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
4285 ``Show prompt'' produces the response:
4286 Gdb's prompt is new-gdb=>.
4288 What follows are the NEW set commands. The command ``help set'' will
4289 print a complete list of old and new set commands. ``help set FOO''
4290 will give a longer description of the variable FOO. ``show'' will show
4291 all of the variable descriptions and their current settings.
4293 confirm on/off: Enables warning questions for operations that are
4294 hard to recover from, e.g. rerunning the program while
4295 it is already running. Default is ON.
4297 editing on/off: Enables EMACS style command line editing
4298 of input. Previous lines can be recalled with
4299 control-P, the current line can be edited with control-B,
4300 you can search for commands with control-R, etc.
4303 history filename NAME: NAME is where the gdb command history
4304 will be stored. The default is .gdb_history,
4305 or the value of the environment variable
4308 history size N: The size, in commands, of the command history. The
4309 default is 256, or the value of the environment variable
4312 history save on/off: If this value is set to ON, the history file will
4313 be saved after exiting gdb. If set to OFF, the
4314 file will not be saved. The default is OFF.
4316 history expansion on/off: If this value is set to ON, then csh-like
4317 history expansion will be performed on
4318 command line input. The default is OFF.
4320 radix N: Sets the default radix for input and output. It can be set
4321 to 8, 10, or 16. Note that the argument to "radix" is interpreted
4322 in the current radix, so "set radix 10" is always a no-op.
4324 height N: This integer value is the number of lines on a page. Default
4325 is 24, the current `stty rows'' setting, or the ``li#''
4326 setting from the termcap entry matching the environment
4329 width N: This integer value is the number of characters on a line.
4330 Default is 80, the current `stty cols'' setting, or the ``co#''
4331 setting from the termcap entry matching the environment
4334 Note: ``set screensize'' is obsolete. Use ``set height'' and
4335 ``set width'' instead.
4337 print address on/off: Print memory addresses in various command displays,
4338 such as stack traces and structure values. Gdb looks
4339 more ``symbolic'' if you turn this off; it looks more
4340 ``machine level'' with it on. Default is ON.
4342 print array on/off: Prettyprint arrays. New convenient format! Default
4345 print demangle on/off: Print C++ symbols in "source" form if on,
4348 print asm-demangle on/off: Same, for assembler level printouts
4351 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
4354 * Support for Epoch Environment.
4356 The epoch environment is a version of Emacs v18 with windowing. One
4357 new command, ``inspect'', is identical to ``print'', except that if you
4358 are running in the epoch environment, the value is printed in its own
4362 * Support for Shared Libraries
4364 GDB can now debug programs and core files that use SunOS shared libraries.
4365 Symbols from a shared library cannot be referenced
4366 before the shared library has been linked with the program (this
4367 happens after you type ``run'' and before the function main() is entered).
4368 At any time after this linking (including when examining core files
4369 from dynamically linked programs), gdb reads the symbols from each
4370 shared library when you type the ``sharedlibrary'' command.
4371 It can be abbreviated ``share''.
4373 sharedlibrary REGEXP: Load shared object library symbols for files
4374 matching a unix regular expression. No argument
4375 indicates to load symbols for all shared libraries.
4377 info sharedlibrary: Status of loaded shared libraries.
4382 A watchpoint stops execution of a program whenever the value of an
4383 expression changes. Checking for this slows down execution
4384 tremendously whenever you are in the scope of the expression, but is
4385 quite useful for catching tough ``bit-spreader'' or pointer misuse
4386 problems. Some machines such as the 386 have hardware for doing this
4387 more quickly, and future versions of gdb will use this hardware.
4389 watch EXP: Set a watchpoint (breakpoint) for an expression.
4391 info watchpoints: Information about your watchpoints.
4393 delete N: Deletes watchpoint number N (same as breakpoints).
4394 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
4395 enable N: Re-enables watchpoint number N (same as breakpoints).
4398 * C++ multiple inheritance
4400 When used with a GCC version 2 compiler, GDB supports multiple inheritance
4403 * C++ exception handling
4405 Gdb now supports limited C++ exception handling. Besides the existing
4406 ability to breakpoint on an exception handler, gdb can breakpoint on
4407 the raising of an exception (before the stack is peeled back to the
4410 catch FOO: If there is a FOO exception handler in the dynamic scope,
4411 set a breakpoint to catch exceptions which may be raised there.
4412 Multiple exceptions (``catch foo bar baz'') may be caught.
4414 info catch: Lists all exceptions which may be caught in the
4415 current stack frame.
4418 * Minor command changes
4420 The command ``call func (arg, arg, ...)'' now acts like the print
4421 command, except it does not print or save a value if the function's result
4422 is void. This is similar to dbx usage.
4424 The ``up'' and ``down'' commands now always print the frame they end up
4425 at; ``up-silently'' and `down-silently'' can be used in scripts to change
4426 frames without printing.
4428 * New directory command
4430 'dir' now adds directories to the FRONT of the source search path.
4431 The path starts off empty. Source files that contain debug information
4432 about the directory in which they were compiled can be found even
4433 with an empty path; Sun CC and GCC include this information. If GDB can't
4434 find your source file in the current directory, type "dir .".
4436 * Configuring GDB for compilation
4438 For normal use, type ``./configure host''. See README or gdb.texinfo
4441 GDB now handles cross debugging. If you are remotely debugging between
4442 two different machines, type ``./configure host -target=targ''.
4443 Host is the machine where GDB will run; targ is the machine
4444 where the program that you are debugging will run.