1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.2
6 * The -data-disassemble MI command now supports modes 2 and 3 for
7 dumping the instruction opcodes.
9 * New command line options
11 -data-directory DIR Specify DIR as the "data-directory".
12 This is mostly for testing purposes.
14 * The "maint set python auto-load on|off" command has been renamed to
15 "set auto-load-scripts on|off".
17 * GDB has a new command: "set directories".
18 It is like the "dir" command except that it replaces the
19 source path list instead of augmenting it.
22 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
23 has been integrated into GDB.
27 ** GDB values in Python are now callable if the value represents a
28 function. For example, if 'some_value' represents a function that
29 takes two integer parameters and returns a value, you can call
30 that function like so:
32 result = some_value (10,20)
34 ** Module gdb.types has been added.
35 It contains a collection of utilities for working with gdb.Types objects:
36 get_basic_type, has_field, make_enum_dict.
38 ** Module gdb.printing has been added.
39 It contains utilities for writing and registering pretty-printers.
40 New classes: PrettyPrinter, SubPrettyPrinter,
41 RegexpCollectionPrettyPrinter.
42 New function: register_pretty_printer.
44 ** New commands "info pretty-printers", "enable pretty-printer" and
45 "disable pretty-printer" have been added.
47 ** gdb.parameter("directories") is now available.
49 ** New function gdb.newest_frame returns the newest frame in the
54 ** GDB now puts template parameters in scope when debugging in an
55 instantiation. For example, if you have:
57 template<int X> int func (void) { return X; }
59 then if you step into func<5>, "print X" will show "5". This
60 feature requires proper debuginfo support from the compiler; it
63 ** The motion commands "next", "finish", "until", and "advance" now
64 work better when exceptions are thrown. In particular, GDB will
65 no longer lose control of the inferior; instead, the GDB will
66 stop the inferior at the point at which the exception is caught.
67 This functionality requires a change in the exception handling
68 code that was introduced in GCC 4.5.
70 * GDB now follows GCC's rules on accessing volatile objects when
71 reading or writing target state during expression evaluation.
72 One notable difference to prior behavior is that "print x = 0"
73 no longer generates a read of x; the value of the assignment is
74 now always taken directly from the value being assigned.
76 * GDB now has some support for using labels in the program's source in
77 linespecs. For instance, you can use "advance label" to continue
80 * GDB now has support for reading and writing a new .gdb_index
81 section. This section holds a fast index of DWARF debugging
82 information and can be used to greatly speed up GDB startup and
83 operation. See the documentation for `save gdb-index' for details.
85 * The "watch" command now accepts an optional "-location" argument.
86 When used, this causes GDB to watch the memory referred to by the
87 expression. Such a watchpoint is never deleted due to it going out
90 * GDB now supports thread debugging of core dumps on GNU/Linux.
92 GDB now activates thread debugging using the libthread_db library
93 when debugging GNU/Linux core dumps, similarly to when debugging
94 live processes. As a result, when debugging a core dump file, GDB
95 is now able to display pthread_t ids of threads. For example, "info
96 threads" shows the same output as when debugging the process when it
97 was live. In earlier releases, you'd see something like this:
100 * 1 LWP 6780 main () at main.c:10
102 While now you see this:
105 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
107 It is also now possible to inspect TLS variables when debugging core
110 When debugging a core dump generated on a machine other than the one
111 used to run GDB, you may need to point GDB at the correct
112 libthread_db library with the "set libthread-db-search-path"
113 command. See the user manual for more details on this command.
115 * New features in the GDB remote stub, GDBserver
117 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
118 and i686 LynxOS (version 5.x).
120 ** GDBserver is now supported on Blackfin Linux.
124 Analog Devices, Inc. Blackfin Processor bfin-*
126 * Ada task switching is now supported on sparc-elf targets when
127 debugging a program using the Ravenscar Profile. For more information,
128 see the "Tasking Support when using the Ravenscar Profile" section
129 in the GDB user manual.
131 * Guile support was removed.
133 * New features in the GNU simulator
135 ** The --map-info flag lists all known core mappings.
137 *** Changes in GDB 7.2
139 * Shared library support for remote targets by default
141 When GDB is configured for a generic, non-OS specific target, like
142 for example, --target=arm-eabi or one of the many *-*-elf targets,
143 GDB now queries remote stubs for loaded shared libraries using the
144 `qXfer:libraries:read' packet. Previously, shared library support
145 was always disabled for such configurations.
149 ** Argument Dependent Lookup (ADL)
151 In C++ ADL lookup directs function search to the namespaces of its
152 arguments even if the namespace has not been imported.
162 Here the compiler will search for `foo' in the namespace of 'b'
163 and find A::foo. GDB now supports this. This construct is commonly
164 used in the Standard Template Library for operators.
166 ** Improved User Defined Operator Support
168 In addition to member operators, GDB now supports lookup of operators
169 defined in a namespace and imported with a `using' directive, operators
170 defined in the global scope, operators imported implicitly from an
171 anonymous namespace, and the ADL operators mentioned in the previous
173 GDB now also supports proper overload resolution for all the previously
174 mentioned flavors of operators.
176 ** static const class members
178 Printing of static const class members that are initialized in the
179 class definition has been fixed.
181 * Windows Thread Information Block access.
183 On Windows targets, GDB now supports displaying the Windows Thread
184 Information Block (TIB) structure. This structure is visible either
185 by using the new command `info w32 thread-information-block' or, by
186 dereferencing the new convenience variable named `$_tlb', a
187 thread-specific pointer to the TIB. This feature is also supported
188 when remote debugging using GDBserver.
192 Static tracepoints are calls in the user program into a tracing
193 library. One such library is a port of the LTTng kernel tracer to
194 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
195 When debugging with GDBserver, GDB now supports combining the GDB
196 tracepoint machinery with such libraries. For example: the user can
197 use GDB to probe a static tracepoint marker (a call from the user
198 program into the tracing library) with the new "strace" command (see
199 "New commands" below). This creates a "static tracepoint" in the
200 breakpoint list, that can be manipulated with the same feature set
201 as fast and regular tracepoints. E.g., collect registers, local and
202 global variables, collect trace state variables, and define
203 tracepoint conditions. In addition, the user can collect extra
204 static tracepoint marker specific data, by collecting the new
205 $_sdata internal variable. When analyzing the trace buffer, you can
206 inspect $_sdata like any other variable available to GDB. For more
207 information, see the "Tracepoints" chapter in GDB user manual. New
208 remote packets have been defined to support static tracepoints, see
209 the "New remote packets" section below.
211 * Better reconstruction of tracepoints after disconnected tracing
213 GDB will attempt to download the original source form of tracepoint
214 definitions when starting a trace run, and then will upload these
215 upon reconnection to the target, resulting in a more accurate
216 reconstruction of the tracepoints that are in use on the target.
220 You can now exercise direct control over the ways that GDB can
221 affect your program. For instance, you can disallow the setting of
222 breakpoints, so that the program can run continuously (assuming
223 non-stop mode). In addition, the "observer" variable is available
224 to switch all of the different controls; in observer mode, GDB
225 cannot affect the target's behavior at all, which is useful for
226 tasks like diagnosing live systems in the field.
228 * The new convenience variable $_thread holds the number of the
235 Return the address of the Windows Thread Information Block of a given thread.
239 In response to several of the tracepoint packets, the target may now
240 also respond with a number of intermediate `qRelocInsn' request
241 packets before the final result packet, to have GDB handle
242 relocating an instruction to execute at a different address. This
243 is particularly useful for stubs that support fast tracepoints. GDB
244 reports support for this feature in the qSupported packet.
248 List static tracepoint markers in the target program.
252 List static tracepoint markers at a given address in the target
255 qXfer:statictrace:read
257 Read the static trace data collected (by a `collect $_sdata'
258 tracepoint action). The remote stub reports support for this packet
259 to gdb's qSupported query.
263 Send the current settings of GDB's permission flags.
267 Send part of the source (textual) form of a tracepoint definition,
268 which includes location, conditional, and action list.
270 * The source command now accepts a -s option to force searching for the
271 script in the source search path even if the script name specifies
274 * New features in the GDB remote stub, GDBserver
276 - GDBserver now support tracepoints (including fast tracepoints, and
277 static tracepoints). The feature is currently supported by the
278 i386-linux and amd64-linux builds. See the "Tracepoints support
279 in gdbserver" section in the manual for more information.
281 GDBserver JIT compiles the tracepoint's conditional agent
282 expression bytecode into native code whenever possible for low
283 overhead dynamic tracepoints conditionals. For such tracepoints,
284 an expression that examines program state is evaluated when the
285 tracepoint is reached, in order to determine whether to capture
286 trace data. If the condition is simple and false, processing the
287 tracepoint finishes very quickly and no data is gathered.
289 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
290 for static tracepoints support.
292 - GDBserver now supports x86_64 Windows 64-bit debugging.
294 * GDB now sends xmlRegisters= in qSupported packet to indicate that
295 it understands register description.
297 * The --batch flag now disables pagination and queries.
299 * X86 general purpose registers
301 GDB now supports reading/writing byte, word and double-word x86
302 general purpose registers directly. This means you can use, say,
303 $ah or $ax to refer, respectively, to the byte register AH and
304 16-bit word register AX that are actually portions of the 32-bit
305 register EAX or 64-bit register RAX.
307 * The `commands' command now accepts a range of breakpoints to modify.
308 A plain `commands' following a command that creates multiple
309 breakpoints affects all the breakpoints set by that command. This
310 applies to breakpoints set by `rbreak', and also applies when a
311 single `break' command creates multiple breakpoints (e.g.,
312 breakpoints on overloaded c++ functions).
314 * The `rbreak' command now accepts a filename specification as part of
315 its argument, limiting the functions selected by the regex to those
316 in the specified file.
318 * Support for remote debugging Windows and SymbianOS shared libraries
319 from Unix hosts has been improved. Non Windows GDB builds now can
320 understand target reported file names that follow MS-DOS based file
321 system semantics, such as file names that include drive letters and
322 use the backslash character as directory separator. This makes it
323 possible to transparently use the "set sysroot" and "set
324 solib-search-path" on Unix hosts to point as host copies of the
325 target's shared libraries. See the new command "set
326 target-file-system-kind" described below, and the "Commands to
327 specify files" section in the user manual for more information.
331 eval template, expressions...
332 Convert the values of one or more expressions under the control
333 of the string template to a command line, and call it.
335 set target-file-system-kind unix|dos-based|auto
336 show target-file-system-kind
337 Set or show the assumed file system kind for target reported file
340 save breakpoints <filename>
341 Save all current breakpoint definitions to a file suitable for use
342 in a later debugging session. To read the saved breakpoint
343 definitions, use the `source' command.
345 `save tracepoints' is a new alias for `save-tracepoints'. The latter
348 info static-tracepoint-markers
349 Display information about static tracepoint markers in the target.
351 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
352 Define a static tracepoint by probing a marker at the given
353 function, line, address, or marker ID.
357 Enable and disable observer mode.
359 set may-write-registers on|off
360 set may-write-memory on|off
361 set may-insert-breakpoints on|off
362 set may-insert-tracepoints on|off
363 set may-insert-fast-tracepoints on|off
364 set may-interrupt on|off
365 Set individual permissions for GDB effects on the target. Note that
366 some of these settings can have undesirable or surprising
367 consequences, particularly when changed in the middle of a session.
368 For instance, disabling the writing of memory can prevent
369 breakpoints from being inserted, cause single-stepping to fail, or
370 even crash your program, if you disable after breakpoints have been
371 inserted. However, GDB should not crash.
373 set record memory-query on|off
374 show record memory-query
375 Control whether to stop the inferior if memory changes caused
376 by an instruction cannot be recorded.
381 The disassemble command now supports "start,+length" form of two arguments.
385 ** GDB now provides a new directory location, called the python directory,
386 where Python scripts written for GDB can be installed. The location
387 of that directory is <data-directory>/python, where <data-directory>
388 is the GDB data directory. For more details, see section `Scripting
389 GDB using Python' in the manual.
391 ** The GDB Python API now has access to breakpoints, symbols, symbol
392 tables, program spaces, inferiors, threads and frame's code blocks.
393 Additionally, GDB Parameters can now be created from the API, and
394 manipulated via set/show in the CLI.
396 ** New functions gdb.target_charset, gdb.target_wide_charset,
397 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
399 ** New exception gdb.GdbError.
401 ** Pretty-printers are now also looked up in the current program space.
403 ** Pretty-printers can now be individually enabled and disabled.
405 ** GDB now looks for names of Python scripts to auto-load in a
406 special section named `.debug_gdb_scripts', in addition to looking
407 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
409 * Tracepoint actions were unified with breakpoint commands. In particular,
410 there are no longer differences in "info break" output for breakpoints and
411 tracepoints and the "commands" command can be used for both tracepoints and
416 ARM Symbian arm*-*-symbianelf*
418 * D language support.
419 GDB now supports debugging programs written in the D programming
422 * GDB now supports the extended ptrace interface for PowerPC which is
423 available since Linux kernel version 2.6.34. This automatically enables
424 any hardware breakpoints and additional hardware watchpoints available in
425 the processor. The old ptrace interface exposes just one hardware
426 watchpoint and no hardware breakpoints.
428 * GDB is now able to use the Data Value Compare (DVC) register available on
429 embedded PowerPC processors to implement in hardware simple watchpoint
430 conditions of the form:
432 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
434 This works in native GDB running on Linux kernels with the extended ptrace
435 interface mentioned above.
437 *** Changes in GDB 7.1
443 GDB now supports importing of namespaces in C++. This enables the
444 user to inspect variables from imported namespaces. Support for
445 namepace aliasing has also been added. So, if a namespace is
446 aliased in the current scope (e.g. namepace C=A; ) the user can
447 print variables using the alias (e.g. (gdb) print C::x).
451 All known bugs relating to the printing of virtual base class were
452 fixed. It is now possible to call overloaded static methods using a
457 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
458 and reinterpret_cast<> are now handled by the C++ expression parser.
462 Xilinx MicroBlaze microblaze-*-*
467 Xilinx MicroBlaze microblaze
470 * Multi-program debugging.
472 GDB now has support for multi-program (a.k.a. multi-executable or
473 multi-exec) debugging. This allows for debugging multiple inferiors
474 simultaneously each running a different program under the same GDB
475 session. See "Debugging Multiple Inferiors and Programs" in the
476 manual for more information. This implied some user visible changes
477 in the multi-inferior support. For example, "info inferiors" now
478 lists inferiors that are not running yet or that have exited
479 already. See also "New commands" and "New options" below.
481 * New tracing features
483 GDB's tracepoint facility now includes several new features:
485 ** Trace state variables
487 GDB tracepoints now include support for trace state variables, which
488 are variables managed by the target agent during a tracing
489 experiment. They are useful for tracepoints that trigger each
490 other, so for instance one tracepoint can count hits in a variable,
491 and then a second tracepoint has a condition that is true when the
492 count reaches a particular value. Trace state variables share the
493 $-syntax of GDB convenience variables, and can appear in both
494 tracepoint actions and condition expressions. Use the "tvariable"
495 command to create, and "info tvariables" to view; see "Trace State
496 Variables" in the manual for more detail.
500 GDB now includes an option for defining fast tracepoints, which
501 targets may implement more efficiently, such as by installing a jump
502 into the target agent rather than a trap instruction. The resulting
503 speedup can be by two orders of magnitude or more, although the
504 tradeoff is that some program locations on some target architectures
505 might not allow fast tracepoint installation, for instance if the
506 instruction to be replaced is shorter than the jump. To request a
507 fast tracepoint, use the "ftrace" command, with syntax identical to
508 the regular trace command.
510 ** Disconnected tracing
512 It is now possible to detach GDB from the target while it is running
513 a trace experiment, then reconnect later to see how the experiment
514 is going. In addition, a new variable disconnected-tracing lets you
515 tell the target agent whether to continue running a trace if the
516 connection is lost unexpectedly.
520 GDB now has the ability to save the trace buffer into a file, and
521 then use that file as a target, similarly to you can do with
522 corefiles. You can select trace frames, print data that was
523 collected in them, and use tstatus to display the state of the
524 tracing run at the moment that it was saved. To create a trace
525 file, use "tsave <filename>", and to use it, do "target tfile
528 ** Circular trace buffer
530 You can ask the target agent to handle the trace buffer as a
531 circular buffer, discarding the oldest trace frames to make room for
532 newer ones, by setting circular-trace-buffer to on. This feature may
533 not be available for all target agents.
538 The disassemble command, when invoked with two arguments, now requires
539 the arguments to be comma-separated.
542 The info variables command now displays variable definitions. Files
543 which only declare a variable are not shown.
546 The source command is now capable of sourcing Python scripts.
547 This feature is dependent on the debugger being build with Python
550 Related to this enhancement is also the introduction of a new command
551 "set script-extension" (see below).
553 * New commands (for set/show, see "New options" below)
555 record save [<FILENAME>]
556 Save a file (in core file format) containing the process record
557 execution log for replay debugging at a later time.
559 record restore <FILENAME>
560 Restore the process record execution log that was saved at an
561 earlier time, for replay debugging.
563 add-inferior [-copies <N>] [-exec <FILENAME>]
566 clone-inferior [-copies <N>] [ID]
567 Make a new inferior ready to execute the same program another
573 maint info program-spaces
574 List the program spaces loaded into GDB.
576 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
577 show remote interrupt-sequence
578 Allow the user to select one of ^C, a BREAK signal or BREAK-g
579 as the sequence to the remote target in order to interrupt the execution.
580 Ctrl-C is a default. Some system prefers BREAK which is high level of
581 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
582 Magic SysRq g. It is BREAK signal and character 'g'.
584 set remote interrupt-on-connect [on | off]
585 show remote interrupt-on-connect
586 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
587 remote target when gdb connects to it. This is needed when you debug
590 set remotebreak [on | off]
592 Deprecated. Use "set/show remote interrupt-sequence" instead.
594 tvariable $NAME [ = EXP ]
595 Create or modify a trace state variable.
598 List trace state variables and their values.
600 delete tvariable $NAME ...
601 Delete one or more trace state variables.
604 Evaluate the given expressions without collecting anything into the
605 trace buffer. (Valid in tracepoint actions only.)
607 ftrace FN / FILE:LINE / *ADDR
608 Define a fast tracepoint at the given function, line, or address.
610 * New expression syntax
612 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
613 GDB now parses 0b101010 identically with 42.
617 set follow-exec-mode new|same
618 show follow-exec-mode
619 Control whether GDB reuses the same inferior across an exec call or
620 creates a new one. This is useful to be able to restart the old
621 executable after the inferior having done an exec call.
623 set default-collect EXPR, ...
625 Define a list of expressions to be collected at each tracepoint.
626 This is a useful way to ensure essential items are not overlooked,
627 such as registers or a critical global variable.
629 set disconnected-tracing
630 show disconnected-tracing
631 If set to 1, the target is instructed to continue tracing if it
632 loses its connection to GDB. If 0, the target is to stop tracing
635 set circular-trace-buffer
636 show circular-trace-buffer
637 If set to on, the target is instructed to use a circular trace buffer
638 and discard the oldest trace frames instead of stopping the trace due
639 to a full trace buffer. If set to off, the trace stops when the buffer
640 fills up. Some targets may not support this.
642 set script-extension off|soft|strict
643 show script-extension
644 If set to "off", the debugger does not perform any script language
645 recognition, and all sourced files are assumed to be GDB scripts.
646 If set to "soft" (the default), files are sourced according to
647 filename extension, falling back to GDB scripts if the first
649 If set to "strict", files are sourced according to filename extension.
651 set ada trust-PAD-over-XVS on|off
652 show ada trust-PAD-over-XVS
653 If off, activate a workaround against a bug in the debugging information
654 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
655 the GCC sources for more information about the GNAT encoding and
656 PAD types in particular). It is always safe to set this option to
657 off, but this introduces a slight performance penalty. The default
660 * Python API Improvements
662 ** GDB provides the new class gdb.LazyString. This is useful in
663 some pretty-printing cases. The new method gdb.Value.lazy_string
664 provides a simple way to create objects of this type.
666 ** The fields returned by gdb.Type.fields now have an
667 `is_base_class' attribute.
669 ** The new method gdb.Type.range returns the range of an array type.
671 ** The new method gdb.parse_and_eval can be used to parse and
672 evaluate an expression.
677 Define a trace state variable.
680 Get the current value of a trace state variable.
683 Set desired tracing behavior upon disconnection.
686 Set the trace buffer to be linear or circular.
689 Get data about the tracepoints currently in use.
693 Process record now works correctly with hardware watchpoints.
695 Multiple bug fixes have been made to the mips-irix port, making it
696 much more reliable. In particular:
697 - Debugging threaded applications is now possible again. Previously,
698 GDB would hang while starting the program, or while waiting for
699 the program to stop at a breakpoint.
700 - Attaching to a running process no longer hangs.
701 - An error occurring while loading a core file has been fixed.
702 - Changing the value of the PC register now works again. This fixes
703 problems observed when using the "jump" command, or when calling
704 a function from GDB, or even when assigning a new value to $pc.
705 - With the "finish" and "return" commands, the return value for functions
706 returning a small array is now correctly printed.
707 - It is now possible to break on shared library code which gets executed
708 during a shared library init phase (code executed while executing
709 their .init section). Previously, the breakpoint would have no effect.
710 - GDB is now able to backtrace through the signal handler for
711 non-threaded programs.
713 PIE (Position Independent Executable) programs debugging is now supported.
714 This includes debugging execution of PIC (Position Independent Code) shared
715 libraries although for that, it should be possible to run such libraries as an
718 *** Changes in GDB 7.0
720 * GDB now has an interface for JIT compilation. Applications that
721 dynamically generate code can create symbol files in memory and register
722 them with GDB. For users, the feature should work transparently, and
723 for JIT developers, the interface is documented in the GDB manual in the
724 "JIT Compilation Interface" chapter.
726 * Tracepoints may now be conditional. The syntax is as for
727 breakpoints; either an "if" clause appended to the "trace" command,
728 or the "condition" command is available. GDB sends the condition to
729 the target for evaluation using the same bytecode format as is used
730 for tracepoint actions.
732 * The disassemble command now supports: an optional /r modifier, print the
733 raw instructions in hex as well as in symbolic form, and an optional /m
734 modifier to print mixed source+assembly.
736 * Process record and replay
738 In a architecture environment that supports ``process record and
739 replay'', ``process record and replay'' target can record a log of
740 the process execution, and replay it with both forward and reverse
743 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
744 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
745 set execution-direction {forward|reverse}, for targets that support
748 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
749 feature is available with a native GDB running on kernel version
752 * GDB now has support for multi-byte and wide character sets on the
753 target. Strings whose character type is wchar_t, char16_t, or
754 char32_t are now correctly printed. GDB supports wide- and unicode-
755 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
756 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
757 `printf'. This feature requires iconv to work properly; if your
758 system does not have a working iconv, GDB can use GNU libiconv. See
759 the installation instructions for more information.
761 * GDB now supports automatic retrieval of shared library files from
762 remote targets. To use this feature, specify a system root that begins
763 with the `remote:' prefix, either via the `set sysroot' command or via
764 the `--with-sysroot' configure-time option.
766 * "info sharedlibrary" now takes an optional regex of libraries to show,
767 and it now reports if a shared library has no debugging information.
769 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
770 now complete on file names.
772 * When completing in expressions, gdb will attempt to limit
773 completions to allowable structure or union fields, where appropriate.
774 For instance, consider:
776 # struct example { int f1; double f2; };
777 # struct example variable;
780 If the user types TAB at the end of this command line, the available
781 completions will be "f1" and "f2".
783 * Inlined functions are now supported. They show up in backtraces, and
784 the "step", "next", and "finish" commands handle them automatically.
786 * GDB now supports the token-splicing (##) and stringification (#)
787 operators when expanding macros. It also supports variable-arity
790 * GDB now supports inspecting extra signal information, exported by
791 the new $_siginfo convenience variable. The feature is currently
792 implemented on linux ARM, i386 and amd64.
794 * GDB can now display the VFP floating point registers and NEON vector
795 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
796 can provide these registers (requires Linux 2.6.30 or later). Remote
797 and simulator targets may also provide them.
802 Search memory for a sequence of bytes.
805 Turn off `+'/`-' protocol acknowledgments to permit more efficient
806 operation over reliable transport links. Use of this packet is
807 controlled by the `set remote noack-packet' command.
810 Kill the process with the specified process ID. Use this in preference
811 to `k' when multiprocess protocol extensions are supported.
814 Obtains additional operating system information
818 Read or write additional signal information.
820 * Removed remote protocol undocumented extension
822 An undocumented extension to the remote protocol's `S' stop reply
823 packet that permited the stub to pass a process id was removed.
824 Remote servers should use the `T' stop reply packet instead.
826 * GDB now supports multiple function calling conventions according to the
827 DWARF-2 DW_AT_calling_convention function attribute.
829 * The SH target utilizes the aforementioned change to distinguish between gcc
830 and Renesas calling convention. It also adds the new CLI commands
831 `set/show sh calling-convention'.
833 * GDB can now read compressed debug sections, as produced by GNU gold
834 with the --compress-debug-sections=zlib flag.
836 * 64-bit core files are now supported on AIX.
838 * Thread switching is now supported on Tru64.
840 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
841 which will be allocated using malloc later in program execution.
843 * The qXfer:libraries:read remote procotol packet now allows passing a
844 list of section offsets.
846 * On GNU/Linux, GDB can now attach to stopped processes. Several race
847 conditions handling signals delivered during attach or thread creation
848 have also been fixed.
850 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
851 From the user's standpoint, all unqualified instances of True and False
852 are treated as the standard definitions, regardless of context.
854 * GDB now parses C++ symbol and type names more flexibly. For
857 template<typename T> class C { };
860 GDB will now correctly handle all of:
862 ptype C<char const *>
864 ptype C<const char *>
867 * New features in the GDB remote stub, gdbserver
869 - The "--wrapper" command-line argument tells gdbserver to use a
870 wrapper program to launch programs for debugging.
872 - On PowerPC and S/390 targets, it is now possible to use a single
873 gdbserver executable to debug both 32-bit and 64-bit programs.
874 (This requires gdbserver itself to be built as a 64-bit executable.)
876 - gdbserver uses the new noack protocol mode for TCP connections to
877 reduce communications latency, if also supported and enabled in GDB.
879 - Support for the sparc64-linux-gnu target is now included in
882 - The amd64-linux build of gdbserver now supports debugging both
883 32-bit and 64-bit programs.
885 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
886 now support hardware watchpoints, and will use them automatically
891 GDB now has support for scripting using Python. Whether this is
892 available is determined at configure time.
894 New GDB commands can now be written in Python.
896 * Ada tasking support
898 Ada tasks can now be inspected in GDB. The following commands have
902 Print the list of Ada tasks.
904 Print detailed information about task number N.
906 Print the task number of the current task.
908 Switch the context of debugging to task number N.
910 * Support for user-defined prefixed commands. The "define" command can
911 add new commands to existing prefixes, e.g. "target".
913 * Multi-inferior, multi-process debugging.
915 GDB now has generalized support for multi-inferior debugging. See
916 "Debugging Multiple Inferiors" in the manual for more information.
917 Although availability still depends on target support, the command
918 set is more uniform now. The GNU/Linux specific multi-forks support
919 has been migrated to this new framework. This implied some user
920 visible changes; see "New commands" and also "Removed commands"
923 * Target descriptions can now describe the target OS ABI. See the
924 "Target Description Format" section in the user manual for more
927 * Target descriptions can now describe "compatible" architectures
928 to indicate that the target can execute applications for a different
929 architecture in addition to those for the main target architecture.
930 See the "Target Description Format" section in the user manual for
933 * Multi-architecture debugging.
935 GDB now includes general supports for debugging applications on
936 hybrid systems that use more than one single processor architecture
937 at the same time. Each such hybrid architecture still requires
938 specific support to be added. The only hybrid architecture supported
939 in this version of GDB is the Cell Broadband Engine.
941 * GDB now supports integrated debugging of Cell/B.E. applications that
942 use both the PPU and SPU architectures. To enable support for hybrid
943 Cell/B.E. debugging, you need to configure GDB to support both the
944 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
945 --enable-targets configure option.
947 * Non-stop mode debugging.
949 For some targets, GDB now supports an optional mode of operation in
950 which you can examine stopped threads while other threads continue
951 to execute freely. This is referred to as non-stop mode, with the
952 old mode referred to as all-stop mode. See the "Non-Stop Mode"
953 section in the user manual for more information.
955 To be able to support remote non-stop debugging, a remote stub needs
956 to implement the non-stop mode remote protocol extensions, as
957 described in the "Remote Non-Stop" section of the user manual. The
958 GDB remote stub, gdbserver, has been adjusted to support these
959 extensions on linux targets.
961 * New commands (for set/show, see "New options" below)
963 catch syscall [NAME(S) | NUMBER(S)]
964 Catch system calls. Arguments, which should be names of system
965 calls or their numbers, mean catch only those syscalls. Without
966 arguments, every syscall will be caught. When the inferior issues
967 any of the specified syscalls, GDB will stop and announce the system
968 call, both when it is called and when its call returns. This
969 feature is currently available with a native GDB running on the
970 Linux Kernel, under the following architectures: x86, x86_64,
971 PowerPC and PowerPC64.
973 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
975 Search memory for a sequence of bytes.
977 maint set python print-stack
978 maint show python print-stack
979 Show a stack trace when an error is encountered in a Python script.
982 Invoke CODE by passing it to the Python interpreter.
987 These allow macros to be defined, undefined, and listed
991 Show operating system information about processes.
994 List the inferiors currently under GDB's control.
997 Switch focus to inferior number NUM.
1000 Detach from inferior number NUM.
1003 Kill inferior number NUM.
1007 set spu stop-on-load
1008 show spu stop-on-load
1009 Control whether to stop for new SPE threads during Cell/B.E. debugging.
1011 set spu auto-flush-cache
1012 show spu auto-flush-cache
1013 Control whether to automatically flush the software-managed cache
1014 during Cell/B.E. debugging.
1016 set sh calling-convention
1017 show sh calling-convention
1018 Control the calling convention used when calling SH target functions.
1021 show debug timestamp
1022 Control display of timestamps with GDB debugging output.
1024 set disassemble-next-line
1025 show disassemble-next-line
1026 Control display of disassembled source lines or instructions when
1029 set remote noack-packet
1030 show remote noack-packet
1031 Set/show the use of remote protocol QStartNoAckMode packet. See above
1032 under "New remote packets."
1034 set remote query-attached-packet
1035 show remote query-attached-packet
1036 Control use of remote protocol `qAttached' (query-attached) packet.
1038 set remote read-siginfo-object
1039 show remote read-siginfo-object
1040 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
1043 set remote write-siginfo-object
1044 show remote write-siginfo-object
1045 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
1048 set remote reverse-continue
1049 show remote reverse-continue
1050 Control use of remote protocol 'bc' (reverse-continue) packet.
1052 set remote reverse-step
1053 show remote reverse-step
1054 Control use of remote protocol 'bs' (reverse-step) packet.
1056 set displaced-stepping
1057 show displaced-stepping
1058 Control displaced stepping mode. Displaced stepping is a way to
1059 single-step over breakpoints without removing them from the debuggee.
1060 Also known as "out-of-line single-stepping".
1063 show debug displaced
1064 Control display of debugging info for displaced stepping.
1066 maint set internal-error
1067 maint show internal-error
1068 Control what GDB does when an internal error is detected.
1070 maint set internal-warning
1071 maint show internal-warning
1072 Control what GDB does when an internal warning is detected.
1077 Use a wrapper program to launch programs for debugging.
1079 set multiple-symbols (all|ask|cancel)
1080 show multiple-symbols
1081 The value of this variable can be changed to adjust the debugger behavior
1082 when an expression or a breakpoint location contains an ambiguous symbol
1083 name (an overloaded function name, for instance).
1085 set breakpoint always-inserted
1086 show breakpoint always-inserted
1087 Keep breakpoints always inserted in the target, as opposed to inserting
1088 them when resuming the target, and removing them when the target stops.
1089 This option can improve debugger performance on slow remote targets.
1091 set arm fallback-mode (arm|thumb|auto)
1092 show arm fallback-mode
1093 set arm force-mode (arm|thumb|auto)
1095 These commands control how ARM GDB determines whether instructions
1096 are ARM or Thumb. The default for both settings is auto, which uses
1097 the current CPSR value for instructions without symbols; previous
1098 versions of GDB behaved as if "set arm fallback-mode arm".
1100 set disable-randomization
1101 show disable-randomization
1102 Standalone programs run with the virtual address space randomization enabled
1103 by default on some platforms. This option keeps the addresses stable across
1104 multiple debugging sessions.
1108 Control whether other threads are stopped or not when some thread hits
1113 Requests that asynchronous execution is enabled in the target, if available.
1114 In this case, it's possible to resume target in the background, and interact
1115 with GDB while the target is running. "show target-async" displays the
1116 current state of asynchronous execution of the target.
1118 set target-wide-charset
1119 show target-wide-charset
1120 The target-wide-charset is the name of the character set that GDB
1121 uses when printing characters whose type is wchar_t.
1123 set tcp auto-retry (on|off)
1125 set tcp connect-timeout
1126 show tcp connect-timeout
1127 These commands allow GDB to retry failed TCP connections to a remote stub
1128 with a specified timeout period; this is useful if the stub is launched
1129 in parallel with GDB but may not be ready to accept connections immediately.
1131 set libthread-db-search-path
1132 show libthread-db-search-path
1133 Control list of directories which GDB will search for appropriate
1136 set schedule-multiple (on|off)
1137 show schedule-multiple
1138 Allow GDB to resume all threads of all processes or only threads of
1139 the current process.
1143 Use more aggressive caching for accesses to the stack. This improves
1144 performance of remote debugging (particularly backtraces) without
1145 affecting correctness.
1147 set interactive-mode (on|off|auto)
1148 show interactive-mode
1149 Control whether GDB runs in interactive mode (on) or not (off).
1150 When in interactive mode, GDB waits for the user to answer all
1151 queries. Otherwise, GDB does not wait and assumes the default
1152 answer. When set to auto (the default), GDB determines which
1153 mode to use based on the stdin settings.
1158 For program forks, this is replaced by the new more generic `info
1159 inferiors' command. To list checkpoints, you can still use the
1160 `info checkpoints' command, which was an alias for the `info forks'
1164 Replaced by the new `inferior' command. To switch between
1165 checkpoints, you can still use the `restart' command, which was an
1166 alias for the `fork' command.
1169 This is removed, since some targets don't have a notion of
1170 processes. To switch between processes, you can still use the
1171 `inferior' command using GDB's own inferior number.
1174 For program forks, this is replaced by the new more generic `kill
1175 inferior' command. To delete a checkpoint, you can still use the
1176 `delete checkpoint' command, which was an alias for the `delete
1180 For program forks, this is replaced by the new more generic `detach
1181 inferior' command. To detach a checkpoint, you can still use the
1182 `detach checkpoint' command, which was an alias for the `detach
1185 * New native configurations
1187 x86/x86_64 Darwin i[34567]86-*-darwin*
1189 x86_64 MinGW x86_64-*-mingw*
1193 Lattice Mico32 lm32-*
1194 x86 DICOS i[34567]86-*-dicos*
1195 x86_64 DICOS x86_64-*-dicos*
1198 * The GDB remote stub, gdbserver, now supports x86 Windows CE
1199 (mingw32ce) debugging.
1205 These commands were actually not implemented on any target.
1207 *** Changes in GDB 6.8
1209 * New native configurations
1211 NetBSD/hppa hppa*-*netbsd*
1212 Xtensa GNU/Linux xtensa*-*-linux*
1216 NetBSD/hppa hppa*-*-netbsd*
1217 Xtensa GNU/Lunux xtensa*-*-linux*
1219 * Change in command line behavior -- corefiles vs. process ids.
1221 When the '-p NUMBER' or '--pid NUMBER' options are used, and
1222 attaching to process NUMBER fails, GDB no longer attempts to open a
1223 core file named NUMBER. Attaching to a program using the -c option
1224 is no longer supported. Instead, use the '-p' or '--pid' options.
1226 * GDB can now be built as a native debugger for debugging Windows x86
1227 (mingw32) Portable Executable (PE) programs.
1229 * Pending breakpoints no longer change their number when their address
1232 * GDB now supports breakpoints with multiple locations,
1233 including breakpoints on C++ constructors, inside C++ templates,
1234 and in inlined functions.
1236 * GDB's ability to debug optimized code has been improved. GDB more
1237 accurately identifies function bodies and lexical blocks that occupy
1238 more than one contiguous range of addresses.
1240 * Target descriptions can now describe registers for PowerPC.
1242 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
1243 registers on PowerPC targets.
1245 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
1246 targets even when the libthread_db library is not available.
1248 * The GDB remote stub, gdbserver, now supports the new file transfer
1249 commands (remote put, remote get, and remote delete).
1251 * The GDB remote stub, gdbserver, now supports run and attach in
1252 extended-remote mode.
1254 * hppa*64*-*-hpux11* target broken
1255 The debugger is unable to start a program and fails with the following
1256 error: "Error trying to get information about dynamic linker".
1257 The gdb-6.7 release is also affected.
1259 * GDB now supports the --enable-targets= configure option to allow
1260 building a single GDB executable that supports multiple remote
1261 target architectures.
1263 * GDB now supports debugging C and C++ programs which use the
1264 Decimal Floating Point extension. In addition, the PowerPC target
1265 now has a set of pseudo-registers to inspect decimal float values
1266 stored in two consecutive float registers.
1268 * The -break-insert MI command can optionally create pending
1271 * Improved support for debugging Ada
1272 Many improvements to the Ada language support have been made. These
1274 - Better support for Ada2005 interface types
1275 - Improved handling of arrays and slices in general
1276 - Better support for Taft-amendment types
1277 - The '{type} ADDRESS' expression is now allowed on the left hand-side
1279 - Improved command completion in Ada
1282 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
1287 set print frame-arguments (all|scalars|none)
1288 show print frame-arguments
1289 The value of this variable can be changed to control which argument
1290 values should be printed by the debugger when displaying a frame.
1295 Transfer files to and from a remote target, and delete remote files.
1302 Transfer files to and from a remote target, and delete remote files.
1304 * New remote packets
1311 Open, close, read, write, and delete files on the remote system.
1314 Attach to an existing process on the remote system, in extended-remote
1318 Run a new process on the remote system, in extended-remote mode.
1320 *** Changes in GDB 6.7
1322 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
1323 bfd, libiberty and opcodes, as revealed by static analysis donated by
1324 Coverity, Inc. (http://scan.coverity.com).
1326 * When looking up multiply-defined global symbols, GDB will now prefer the
1327 symbol definition in the current shared library if it was built using the
1328 -Bsymbolic linker option.
1330 * When the Text User Interface (TUI) is not configured, GDB will now
1331 recognize the -tui command-line option and print a message that the TUI
1334 * The GDB remote stub, gdbserver, now has lower overhead for high
1335 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
1337 * GDB for MIPS targets now autodetects whether a remote target provides
1338 32-bit or 64-bit register values.
1340 * Support for C++ member pointers has been improved.
1342 * GDB now understands XML target descriptions, which specify the
1343 target's overall architecture. GDB can read a description from
1344 a local file or over the remote serial protocol.
1346 * Vectors of single-byte data use a new integer type which is not
1347 automatically displayed as character or string data.
1349 * The /s format now works with the print command. It displays
1350 arrays of single-byte integers and pointers to single-byte integers
1353 * Target descriptions can now describe target-specific registers,
1354 for architectures which have implemented the support (currently
1355 only ARM, M68K, and MIPS).
1357 * GDB and the GDB remote stub, gdbserver, now support the XScale
1360 * The GDB remote stub, gdbserver, has been updated to support
1361 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
1362 has been rewritten to use the standard GDB remote protocol.
1364 * GDB can now step into C++ functions which are called through thunks.
1366 * GDB for the Cell/B.E. SPU now supports overlay debugging.
1368 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
1369 layout. It also supports a TextSeg= and DataSeg= response when only
1370 segment base addresses (rather than offsets) are available.
1372 * The /i format now outputs any trailing branch delay slot instructions
1373 immediately following the last instruction within the count specified.
1375 * The GDB remote protocol "T" stop reply packet now supports a
1376 "library" response. Combined with the new "qXfer:libraries:read"
1377 packet, this response allows GDB to debug shared libraries on targets
1378 where the operating system manages the list of loaded libraries (e.g.
1379 Windows and SymbianOS).
1381 * The GDB remote stub, gdbserver, now supports dynamic link libraries
1382 (DLLs) on Windows and Windows CE targets.
1384 * GDB now supports a faster verification that a .debug file matches its binary
1385 according to its build-id signature, if the signature is present.
1391 Enable or disable hardware flow control (RTS/CTS) on the serial port
1392 when debugging using remote targets.
1394 set mem inaccessible-by-default
1395 show mem inaccessible-by-default
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 prevents GDB from accessing memory outside the memory map. This
1399 is useful for targets with memory mapped registers or which react
1400 badly to accesses of unmapped address space.
1402 set breakpoint auto-hw
1403 show breakpoint auto-hw
1404 If the target supplies a memory map, for instance via the remote
1405 protocol's "qXfer:memory-map:read" packet, setting this variable
1406 lets GDB use hardware breakpoints automatically for memory regions
1407 where it can not use software breakpoints. This covers both the
1408 "break" command and internal breakpoints used for other commands
1409 including "next" and "finish".
1412 catch exception unhandled
1413 Stop the program execution when Ada exceptions are raised.
1416 Stop the program execution when an Ada assertion failed.
1420 Set an alternate system root for target files. This is a more
1421 general version of "set solib-absolute-prefix", which is now
1422 an alias to "set sysroot".
1425 Provide extended SPU facility status information. This set of
1426 commands is available only when debugging the Cell/B.E. SPU
1429 * New native configurations
1431 OpenBSD/sh sh*-*openbsd*
1434 unset tdesc filename
1436 Use the specified local file as an XML target description, and do
1437 not query the target for its built-in description.
1441 OpenBSD/sh sh*-*-openbsd*
1442 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
1443 Toshiba Media Processor mep-elf
1445 * New remote packets
1448 Ignore the specified signals; pass them directly to the debugged program
1449 without stopping other threads or reporting them to GDB.
1451 qXfer:features:read:
1452 Read an XML target description from the target, which describes its
1457 Read or write contents of an spufs file on the target system. These
1458 packets are available only on the Cell/B.E. SPU architecture.
1460 qXfer:libraries:read:
1461 Report the loaded shared libraries. Combined with new "T" packet
1462 response, this packet allows GDB to debug shared libraries on
1463 targets where the operating system manages the list of loaded
1464 libraries (e.g. Windows and SymbianOS).
1468 Support for these obsolete configurations has been removed.
1476 i[34567]86-*-lynxos*
1477 i[34567]86-*-netware*
1478 i[34567]86-*-sco3.2v5*
1479 i[34567]86-*-sco3.2v4*
1481 i[34567]86-*-sysv4.2*
1484 i[34567]86-*-unixware2*
1485 i[34567]86-*-unixware*
1494 * Other removed features
1501 Various m68k-only ROM monitors.
1508 Various Renesas ROM monitors and debugging interfaces for SH and
1513 Support for a Macraigor serial interface to on-chip debugging.
1514 GDB does not directly support the newer parallel or USB
1519 A debug information format. The predecessor to DWARF 2 and
1520 DWARF 3, which are still supported.
1522 Support for the HP aCC compiler on HP-UX/PA-RISC
1524 SOM-encapsulated symbolic debugging information, automatic
1525 invocation of pxdb, and the aCC custom C++ ABI. This does not
1526 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
1527 with aCC can still be debugged on an assembly level.
1529 MIPS ".pdr" sections
1531 A MIPS-specific format used to describe stack frame layout
1532 in debugging information.
1536 GDB could work with an older version of Guile to debug
1537 the interpreter and Scheme programs running in it.
1539 set mips stack-arg-size
1540 set mips saved-gpreg-size
1542 Use "set mips abi" to control parameter passing for MIPS.
1544 *** Changes in GDB 6.6
1549 Cell Broadband Engine SPU spu-elf
1551 * GDB can now be configured as a cross-debugger targeting native Windows
1552 (mingw32) or Cygwin. It can communicate with a remote debugging stub
1553 running on a Windows system over TCP/IP to debug Windows programs.
1555 * The GDB remote stub, gdbserver, has been updated to support Windows and
1556 Cygwin debugging. Both single-threaded and multi-threaded programs are
1559 * The "set trust-readonly-sections" command works again. This command was
1560 broken in GDB 6.3, 6.4, and 6.5.
1562 * The "load" command now supports writing to flash memory, if the remote
1563 stub provides the required support.
1565 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
1566 longer requires symbolic debug information (e.g. DWARF-2).
1571 unset substitute-path
1572 show substitute-path
1573 Manage a list of substitution rules that GDB uses to rewrite the name
1574 of the directories where the sources are located. This can be useful
1575 for instance when the sources were moved to a different location
1576 between compilation and debugging.
1580 Print each CLI command as it is executed. Each command is prefixed with
1581 a number of `+' symbols representing the nesting depth.
1582 The source command now has a `-v' option to enable the same feature.
1586 The ARM Demon monitor support (RDP protocol, "target rdp").
1588 Kernel Object Display, an embedded debugging feature which only worked with
1589 an obsolete version of Cisco IOS.
1591 The 'set download-write-size' and 'show download-write-size' commands.
1593 * New remote packets
1596 Tell a stub about GDB client features, and request remote target features.
1597 The first feature implemented is PacketSize, which allows the target to
1598 specify the size of packets it can handle - to minimize the number of
1599 packets required and improve performance when connected to a remote
1603 Fetch an OS auxilliary vector from the remote stub. This packet is a
1604 more efficient replacement for qPart:auxv:read.
1606 qXfer:memory-map:read:
1607 Fetch a memory map from the remote stub, including information about
1608 RAM, ROM, and flash memory devices.
1613 Erase and program a flash memory device.
1615 * Removed remote packets
1618 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
1619 used it, and only gdbserver implemented it.
1621 *** Changes in GDB 6.5
1625 Renesas M32C/M16C m32c-elf
1627 Morpho Technologies ms1 ms1-elf
1631 init-if-undefined Initialize a convenience variable, but
1632 only if it doesn't already have a value.
1634 The following commands are presently only implemented for native GNU/Linux:
1636 checkpoint Save a snapshot of the program state.
1638 restart <n> Return the program state to a
1639 previously saved state.
1641 info checkpoints List currently saved checkpoints.
1643 delete-checkpoint <n> Delete a previously saved checkpoint.
1645 set|show detach-on-fork Tell gdb whether to detach from a newly
1646 forked process, or to keep debugging it.
1648 info forks List forks of the user program that
1649 are available to be debugged.
1651 fork <n> Switch to debugging one of several
1652 forks of the user program that are
1653 available to be debugged.
1655 delete-fork <n> Delete a fork from the list of forks
1656 that are available to be debugged (and
1657 kill the forked process).
1659 detach-fork <n> Delete a fork from the list of forks
1660 that are available to be debugged (and
1661 allow the process to continue).
1665 Morpho Technologies ms2 ms1-elf
1667 * Improved Windows host support
1669 GDB now builds as a cross debugger hosted on i686-mingw32, including
1670 native console support, and remote communications using either
1671 network sockets or serial ports.
1673 * Improved Modula-2 language support
1675 GDB can now print most types in the Modula-2 syntax. This includes:
1676 basic types, set types, record types, enumerated types, range types,
1677 pointer types and ARRAY types. Procedure var parameters are correctly
1678 printed and hexadecimal addresses and character constants are also
1679 written in the Modula-2 syntax. Best results can be obtained by using
1680 GNU Modula-2 together with the -gdwarf-2 command line option.
1684 The ARM rdi-share module.
1686 The Netware NLM debug server.
1688 *** Changes in GDB 6.4
1690 * New native configurations
1692 OpenBSD/arm arm*-*-openbsd*
1693 OpenBSD/mips64 mips64-*-openbsd*
1697 Morpho Technologies ms1 ms1-elf
1699 * New command line options
1701 --batch-silent As for --batch, but totally silent.
1702 --return-child-result The debugger will exist with the same value
1703 the child (debugged) program exited with.
1704 --eval-command COMMAND, -ex COMMAND
1705 Execute a single GDB CLI command. This may be
1706 specified multiple times and in conjunction
1707 with the --command (-x) option.
1709 * Deprecated commands removed
1711 The following commands, that were deprecated in 2000, have been
1715 set|show arm disassembly-flavor set|show arm disassembler
1716 othernames set arm disassembler
1717 set|show remotedebug set|show debug remote
1718 set|show archdebug set|show debug arch
1719 set|show eventdebug set|show debug event
1722 * New BSD user-level threads support
1724 It is now possible to debug programs using the user-level threads
1725 library on OpenBSD and FreeBSD. Currently supported (target)
1728 FreeBSD/amd64 x86_64-*-freebsd*
1729 FreeBSD/i386 i386-*-freebsd*
1730 OpenBSD/i386 i386-*-openbsd*
1732 Note that the new kernel threads libraries introduced in FreeBSD 5.x
1733 are not yet supported.
1735 * New support for Matsushita MN10300 w/sim added
1736 (Work in progress). mn10300-elf.
1738 * REMOVED configurations and files
1740 VxWorks and the XDR protocol *-*-vxworks
1741 Motorola MCORE mcore-*-*
1742 National Semiconductor NS32000 ns32k-*-*
1744 * New "set print array-indexes" command
1746 After turning this setting "on", GDB prints the index of each element
1747 when displaying arrays. The default is "off" to preserve the previous
1750 * VAX floating point support
1752 GDB now supports the not-quite-ieee VAX F and D floating point formats.
1754 * User-defined command support
1756 In addition to using $arg0..$arg9 for argument passing, it is now possible
1757 to use $argc to determine now many arguments have been passed. See the
1758 section on user-defined commands in the user manual for more information.
1760 *** Changes in GDB 6.3:
1762 * New command line option
1764 GDB now accepts -l followed by a number to set the timeout for remote
1767 * GDB works with GCC -feliminate-dwarf2-dups
1769 GDB now supports a more compact representation of DWARF-2 debug
1770 information using DW_FORM_ref_addr references. These are produced
1771 by GCC with the option -feliminate-dwarf2-dups and also by some
1772 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
1773 to use -feliminate-dwarf2-dups.
1775 * Internationalization
1777 When supported by the host system, GDB will be built with
1778 internationalization (libintl). The task of marking up the sources is
1779 continued, we're looking forward to our first translation.
1783 Initial support for debugging programs compiled with the GNAT
1784 implementation of the Ada programming language has been integrated
1785 into GDB. In this release, support is limited to expression evaluation.
1787 * New native configurations
1789 GNU/Linux/m32r m32r-*-linux-gnu
1793 GDB's remote protocol now includes support for the 'p' packet. This
1794 packet is used to fetch individual registers from a remote inferior.
1796 * END-OF-LIFE registers[] compatibility module
1798 GDB's internal register infrastructure has been completely rewritten.
1799 The new infrastructure making possible the implementation of key new
1800 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
1803 GDB 6.3 will be the last release to include the the registers[]
1804 compatibility module that allowed out-of-date configurations to
1805 continue to work. This change directly impacts the following
1815 powerpc bdm protocol
1817 Unless there is activity to revive these configurations, they will be
1818 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
1820 * OBSOLETE configurations and files
1822 Configurations that have been declared obsolete in this release have
1823 been commented out. Unless there is activity to revive these
1824 configurations, the next release of GDB will have their sources
1825 permanently REMOVED.
1834 *** Changes in GDB 6.2.1:
1836 * MIPS `break main; run' gave an heuristic-fence-post warning
1838 When attempting to run even a simple program, a warning about
1839 heuristic-fence-post being hit would be reported. This problem has
1842 * MIPS IRIX 'long double' crashed GDB
1844 When examining a long double variable, GDB would get a segmentation
1845 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
1846 IRIX long double values).
1850 A bug in the VAX stack code was causing problems with the "next"
1851 command. This problem has been fixed.
1853 *** Changes in GDB 6.2:
1855 * Fix for ``many threads''
1857 On GNU/Linux systems that use the NPTL threads library, a program
1858 rapidly creating and deleting threads would confuse GDB leading to the
1861 ptrace: No such process.
1862 thread_db_get_info: cannot get thread info: generic error
1864 This problem has been fixed.
1866 * "-async" and "-noasync" options removed.
1868 Support for the broken "-noasync" option has been removed (it caused
1871 * New ``start'' command.
1873 This command runs the program until the begining of the main procedure.
1875 * New BSD Kernel Data Access Library (libkvm) interface
1877 Using ``target kvm'' it is now possible to debug kernel core dumps and
1878 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
1879 platforms. Currently supported (native-only) configurations are:
1881 FreeBSD/amd64 x86_64-*-freebsd*
1882 FreeBSD/i386 i?86-*-freebsd*
1883 NetBSD/i386 i?86-*-netbsd*
1884 NetBSD/m68k m68*-*-netbsd*
1885 NetBSD/sparc sparc-*-netbsd*
1886 OpenBSD/amd64 x86_64-*-openbsd*
1887 OpenBSD/i386 i?86-*-openbsd*
1888 OpenBSD/m68k m68*-openbsd*
1889 OpenBSD/sparc sparc-*-openbsd*
1891 * Signal trampoline code overhauled
1893 Many generic problems with GDB's signal handling code have been fixed.
1894 These include: backtraces through non-contiguous stacks; recognition
1895 of sa_sigaction signal trampolines; backtrace from a NULL pointer
1896 call; backtrace through a signal trampoline; step into and out of
1897 signal handlers; and single-stepping in the signal trampoline.
1899 Please note that kernel bugs are a limiting factor here. These
1900 features have been shown to work on an s390 GNU/Linux system that
1901 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
1903 * Cygwin support for DWARF 2 added.
1905 * New native configurations
1907 GNU/Linux/hppa hppa*-*-linux*
1908 OpenBSD/hppa hppa*-*-openbsd*
1909 OpenBSD/m68k m68*-*-openbsd*
1910 OpenBSD/m88k m88*-*-openbsd*
1911 OpenBSD/powerpc powerpc-*-openbsd*
1912 NetBSD/vax vax-*-netbsd*
1913 OpenBSD/vax vax-*-openbsd*
1915 * END-OF-LIFE frame compatibility module
1917 GDB's internal frame infrastructure has been completely rewritten.
1918 The new infrastructure making it possible to support key new features
1919 including DWARF 2 Call Frame Information. To aid in the task of
1920 migrating old configurations to this new infrastructure, a
1921 compatibility module, that allowed old configurations to continue to
1922 work, was also included.
1924 GDB 6.2 will be the last release to include this frame compatibility
1925 module. This change directly impacts the following configurations:
1935 Unless there is activity to revive these configurations, they will be
1936 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
1938 * REMOVED configurations and files
1940 Sun 3, running SunOS 3 m68*-*-sunos3*
1941 Sun 3, running SunOS 4 m68*-*-sunos4*
1942 Sun 2, running SunOS 3 m68000-*-sunos3*
1943 Sun 2, running SunOS 4 m68000-*-sunos4*
1944 Motorola 680x0 running LynxOS m68*-*-lynxos*
1945 AT&T 3b1/Unix pc m68*-att-*
1946 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
1947 decstation mips-dec-* mips-little-*
1948 riscos mips-*-riscos* mips-*-sysv*
1949 sonymips mips-sony-*
1950 sysv mips*-*-sysv4* (IRIX 5/6 not included)
1952 *** Changes in GDB 6.1.1:
1954 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
1956 The TUI (Text-mode User Interface) is now built as part of a default
1957 GDB configuration. It is enabled by either selecting the TUI with the
1958 command line option "-i=tui" or by running the separate "gdbtui"
1959 program. For more information on the TUI, see the manual "Debugging
1962 * Pending breakpoint support (also included in GDB 6.1)
1964 Support has been added to allow you to specify breakpoints in shared
1965 libraries that have not yet been loaded. If a breakpoint location
1966 cannot be found, and the "breakpoint pending" option is set to auto,
1967 GDB queries you if you wish to make the breakpoint pending on a future
1968 shared-library load. If and when GDB resolves the breakpoint symbol,
1969 the pending breakpoint is removed as one or more regular breakpoints
1972 Pending breakpoints are very useful for GCJ Java debugging.
1974 * Fixed ISO-C build problems
1976 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
1977 non ISO-C code that stopped them being built using a more strict ISO-C
1978 compiler (e.g., IBM's C compiler).
1980 * Fixed build problem on IRIX 5
1982 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
1983 wasn't able to compile compile on an IRIX 5 system.
1985 * Added execute permission to gdb/gdbserver/configure
1987 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
1988 permission. This bug would cause configure to fail on a number of
1989 systems (Solaris, IRIX). Ref: server/519.
1991 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
1993 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
1994 has been updated to use constant array sizes.
1996 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
1998 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
1999 its generated DWARF Call Frame Info. This encoding was causing GDB to
2000 panic, that panic has been fixed. Ref: gdb/1628.
2002 * Fixed a problem when examining parameters in shared library code.
2004 When examining parameters in optimized shared library code generated
2005 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
2006 not available''. GDB now correctly displays the variable's value.
2008 *** Changes in GDB 6.1:
2010 * Removed --with-mmalloc
2012 Support for the mmalloc memory manager has been removed, as it
2013 conflicted with the internal gdb byte cache.
2015 * Changes in AMD64 configurations
2017 The AMD64 target now includes the %cs and %ss registers. As a result
2018 the AMD64 remote protocol has changed; this affects the floating-point
2019 and SSE registers. If you rely on those registers for your debugging,
2020 you should upgrade gdbserver on the remote side.
2022 * Revised SPARC target
2024 The SPARC target has been completely revised, incorporating the
2025 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
2026 support for LynxOS and SunOS 4 has been dropped. Calling functions
2027 from within GDB on operating systems with a non-executable stack
2028 (Solaris, OpenBSD) now works.
2032 GDB has a new C++ demangler which does a better job on the mangled
2033 names generated by current versions of g++. It also runs faster, so
2034 with this and other changes gdb should now start faster on large C++
2037 * DWARF 2 Location Expressions
2039 GDB support for location expressions has been extended to support function
2040 arguments and frame bases. Older versions of GDB could crash when they
2043 * C++ nested types and namespaces
2045 GDB's support for nested types and namespaces in C++ has been
2046 improved, especially if you use the DWARF 2 debugging format. (This
2047 is the default for recent versions of GCC on most platforms.)
2048 Specifically, if you have a class "Inner" defined within a class or
2049 namespace "Outer", then GDB realizes that the class's name is
2050 "Outer::Inner", not simply "Inner". This should greatly reduce the
2051 frequency of complaints about not finding RTTI symbols. In addition,
2052 if you are stopped at inside of a function defined within a namespace,
2053 GDB modifies its name lookup accordingly.
2055 * New native configurations
2057 NetBSD/amd64 x86_64-*-netbsd*
2058 OpenBSD/amd64 x86_64-*-openbsd*
2059 OpenBSD/alpha alpha*-*-openbsd*
2060 OpenBSD/sparc sparc-*-openbsd*
2061 OpenBSD/sparc64 sparc64-*-openbsd*
2063 * New debugging protocols
2065 M32R with SDI protocol m32r-*-elf*
2067 * "set prompt-escape-char" command deleted.
2069 The command "set prompt-escape-char" has been deleted. This command,
2070 and its very obscure effet on GDB's prompt, was never documented,
2071 tested, nor mentioned in the NEWS file.
2073 * OBSOLETE configurations and files
2075 Configurations that have been declared obsolete in this release have
2076 been commented out. Unless there is activity to revive these
2077 configurations, the next release of GDB will have their sources
2078 permanently REMOVED.
2080 Sun 3, running SunOS 3 m68*-*-sunos3*
2081 Sun 3, running SunOS 4 m68*-*-sunos4*
2082 Sun 2, running SunOS 3 m68000-*-sunos3*
2083 Sun 2, running SunOS 4 m68000-*-sunos4*
2084 Motorola 680x0 running LynxOS m68*-*-lynxos*
2085 AT&T 3b1/Unix pc m68*-att-*
2086 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2087 decstation mips-dec-* mips-little-*
2088 riscos mips-*-riscos* mips-*-sysv*
2089 sonymips mips-sony-*
2090 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2092 * REMOVED configurations and files
2094 SGI Irix-4.x mips-sgi-irix4 or iris4
2095 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
2096 Z8000 simulator z8k-zilog-none or z8ksim
2097 Matsushita MN10200 w/simulator mn10200-*-*
2098 H8/500 simulator h8500-hitachi-hms or h8500hms
2099 HP/PA running BSD hppa*-*-bsd*
2100 HP/PA running OSF/1 hppa*-*-osf*
2101 HP/PA Pro target hppa*-*-pro*
2102 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2103 386BSD i[3456]86-*-bsd*
2104 Sequent family i[3456]86-sequent-sysv4*
2105 i[3456]86-sequent-sysv*
2106 i[3456]86-sequent-bsd*
2107 SPARC running LynxOS sparc-*-lynxos*
2108 SPARC running SunOS 4 sparc-*-sunos4*
2109 Tsqware Sparclet sparclet-*-*
2110 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2112 *** Changes in GDB 6.0:
2116 Support for debugging the Objective-C programming language has been
2117 integrated into GDB.
2119 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
2121 DWARF 2's Call Frame Information makes available compiler generated
2122 information that more exactly describes the program's run-time stack.
2123 By using this information, GDB is able to provide more robust stack
2126 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
2127 have been updated to use a new backtrace mechanism which includes
2128 DWARF 2 CFI support.
2132 GDB's remote protocol has been extended to include support for hosted
2133 file I/O (where the remote target uses GDB's file system). See GDB's
2134 remote protocol documentation for details.
2136 * All targets using the new architecture framework.
2138 All of GDB's targets have been updated to use the new internal
2139 architecture framework. The way is now open for future GDB releases
2140 to include cross-architecture native debugging support (i386 on amd64,
2143 * GNU/Linux's Thread Local Storage (TLS)
2145 GDB now includes support for for the GNU/Linux implementation of
2146 per-thread variables.
2148 * GNU/Linux's Native POSIX Thread Library (NPTL)
2150 GDB's thread code has been updated to work with either the new
2151 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
2153 * Separate debug info.
2155 GDB, in conjunction with BINUTILS, now supports a mechanism for
2156 automatically loading debug information from a separate file. Instead
2157 of shipping full debug and non-debug versions of system libraries,
2158 system integrators can now instead ship just the stripped libraries
2159 and optional debug files.
2161 * DWARF 2 Location Expressions
2163 DWARF 2 Location Expressions allow the compiler to more completely
2164 describe the location of variables (even in optimized code) to the
2167 GDB now includes preliminary support for location expressions (support
2168 for DW_OP_piece is still missing).
2172 A number of long standing bugs that caused GDB to die while starting a
2173 Java application have been fixed. GDB's Java support is now
2174 considered "useable".
2176 * GNU/Linux support for fork, vfork, and exec.
2178 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
2179 commands are now implemented for GNU/Linux. They require a 2.5.x or later
2182 * GDB supports logging output to a file
2184 There are two new commands, "set logging" and "show logging", which can be
2185 used to capture GDB's output to a file.
2187 * The meaning of "detach" has changed for gdbserver
2189 The "detach" command will now resume the application, as documented. To
2190 disconnect from gdbserver and leave it stopped, use the new "disconnect"
2193 * d10v, m68hc11 `regs' command deprecated
2195 The `info registers' command has been updated so that it displays the
2196 registers using a format identical to the old `regs' command.
2200 A new command, "maint set profile on/off", has been added. This command can
2201 be used to enable or disable profiling while running GDB, to profile a
2202 session or a set of commands. In addition there is a new configure switch,
2203 "--enable-profiling", which will cause GDB to be compiled with profiling
2204 data, for more informative profiling results.
2206 * Default MI syntax changed to "mi2".
2208 The default MI (machine interface) syntax, enabled by the command line
2209 option "-i=mi", has been changed to "mi2". The previous MI syntax,
2210 "mi1", can be enabled by specifying the option "-i=mi1".
2212 Support for the original "mi0" syntax (included in GDB 5.0) has been
2215 Fix for gdb/192: removed extraneous space when displaying frame level.
2216 Fix for gdb/672: update changelist is now output in mi list format.
2217 Fix for gdb/702: a -var-assign that updates the value now shows up
2218 in a subsequent -var-update.
2220 * New native configurations.
2222 FreeBSD/amd64 x86_64-*-freebsd*
2224 * Multi-arched targets.
2226 HP/PA HPUX11 hppa*-*-hpux*
2227 Renesas M32R/D w/simulator m32r-*-elf*
2229 * OBSOLETE configurations and files
2231 Configurations that have been declared obsolete in this release have
2232 been commented out. Unless there is activity to revive these
2233 configurations, the next release of GDB will have their sources
2234 permanently REMOVED.
2236 Z8000 simulator z8k-zilog-none or z8ksim
2237 Matsushita MN10200 w/simulator mn10200-*-*
2238 H8/500 simulator h8500-hitachi-hms or h8500hms
2239 HP/PA running BSD hppa*-*-bsd*
2240 HP/PA running OSF/1 hppa*-*-osf*
2241 HP/PA Pro target hppa*-*-pro*
2242 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2243 Sequent family i[3456]86-sequent-sysv4*
2244 i[3456]86-sequent-sysv*
2245 i[3456]86-sequent-bsd*
2246 Tsqware Sparclet sparclet-*-*
2247 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2249 * REMOVED configurations and files
2252 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2253 IBM AIX PS/2 i[3456]86-*-aix
2254 i386 running Mach 3.0 i[3456]86-*-mach3*
2255 i386 running Mach i[3456]86-*-mach*
2256 i386 running OSF/1 i[3456]86-*osf1mk*
2257 HP/Apollo 68k Family m68*-apollo*-sysv*,
2259 m68*-hp-bsd*, m68*-hp-hpux*
2260 Argonaut Risc Chip (ARC) arc-*-*
2261 Mitsubishi D30V d30v-*-*
2262 Fujitsu FR30 fr30-*-elf*
2263 OS/9000 i[34]86-*-os9k
2264 I960 with MON960 i960-*-coff
2266 * MIPS $fp behavior changed
2268 The convenience variable $fp, for the MIPS, now consistently returns
2269 the address of the current frame's base. Previously, depending on the
2270 context, $fp could refer to either $sp or the current frame's base
2271 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
2272 The GNU Source-Level Debugger''.
2274 *** Changes in GDB 5.3:
2276 * GNU/Linux shared library multi-threaded performance improved.
2278 When debugging a multi-threaded application on GNU/Linux, GDB now uses
2279 `/proc', in preference to `ptrace' for memory reads. This may result
2280 in an improvement in the start-up time of multi-threaded, shared
2281 library applications when run under GDB. One GDB user writes: ``loads
2282 shared libs like mad''.
2284 * ``gdbserver'' now supports multi-threaded applications on some targets
2286 Support for debugging multi-threaded applications which use
2287 the GNU/Linux LinuxThreads package has been added for
2288 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
2289 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
2291 * GDB now supports C/C++ preprocessor macros.
2293 GDB now expands preprocessor macro invocations in C/C++ expressions,
2294 and provides various commands for showing macro definitions and how
2297 The new command `macro expand EXPRESSION' expands any macro
2298 invocations in expression, and shows the result.
2300 The new command `show macro MACRO-NAME' shows the definition of the
2301 macro named MACRO-NAME, and where it was defined.
2303 Most compilers don't include information about macros in the debugging
2304 information by default. In GCC 3.1, for example, you need to compile
2305 your program with the options `-gdwarf-2 -g3'. If the macro
2306 information is present in the executable, GDB will read it.
2308 * Multi-arched targets.
2310 DEC Alpha (partial) alpha*-*-*
2311 DEC VAX (partial) vax-*-*
2313 National Semiconductor NS32000 (partial) ns32k-*-*
2314 Motorola 68000 (partial) m68k-*-*
2315 Motorola MCORE mcore-*-*
2319 Fujitsu FRV architecture added by Red Hat frv*-*-*
2322 * New native configurations
2324 Alpha NetBSD alpha*-*-netbsd*
2325 SH NetBSD sh*-*-netbsdelf*
2326 MIPS NetBSD mips*-*-netbsd*
2327 UltraSPARC NetBSD sparc64-*-netbsd*
2329 * OBSOLETE configurations and files
2331 Configurations that have been declared obsolete in this release have
2332 been commented out. Unless there is activity to revive these
2333 configurations, the next release of GDB will have their sources
2334 permanently REMOVED.
2336 Mitsubishi D30V d30v-*-*
2337 OS/9000 i[34]86-*-os9k
2338 IBM AIX PS/2 i[3456]86-*-aix
2339 Fujitsu FR30 fr30-*-elf*
2340 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2341 Argonaut Risc Chip (ARC) arc-*-*
2342 i386 running Mach 3.0 i[3456]86-*-mach3*
2343 i386 running Mach i[3456]86-*-mach*
2344 i386 running OSF/1 i[3456]86-*osf1mk*
2345 HP/Apollo 68k Family m68*-apollo*-sysv*,
2347 m68*-hp-bsd*, m68*-hp-hpux*
2348 I960 with MON960 i960-*-coff
2350 * OBSOLETE languages
2352 CHILL, a Pascal like language used by telecommunications companies.
2354 * REMOVED configurations and files
2356 AMD 29k family via UDI a29k-amd-udi, udi29k
2357 A29K VxWorks a29k-*-vxworks
2358 AMD 29000 embedded, using EBMON a29k-none-none
2359 AMD 29000 embedded with COFF a29k-none-coff
2360 AMD 29000 embedded with a.out a29k-none-aout
2362 testsuite/gdb.hp/gdb.threads-hp/ directory
2364 * New command "set max-user-call-depth <nnn>"
2366 This command allows the user to limit the call depth of user-defined
2367 commands. The default is 1024.
2369 * Changes in FreeBSD/i386 native debugging.
2371 Support for the "generate-core-file" has been added.
2373 * New commands "dump", "append", and "restore".
2375 These commands allow data to be copied from target memory
2376 to a bfd-format or binary file (dump and append), and back
2377 from a file into memory (restore).
2379 * Improved "next/step" support on multi-processor Alpha Tru64.
2381 The previous single-step mechanism could cause unpredictable problems,
2382 including the random appearance of SIGSEGV or SIGTRAP signals. The use
2383 of a software single-step mechanism prevents this.
2385 *** Changes in GDB 5.2.1:
2393 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
2394 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
2395 Fix, by Joel Brobecker imported from mainline.
2397 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
2398 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
2399 Fix, by Fred Fish, imported from mainline.
2401 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
2402 Surprisingly enough, it works now.
2403 By Michal Ludvig, imported from mainline.
2405 i386 hardware watchpoint support:
2406 avoid misses on second run for some targets.
2407 By Pierre Muller, imported from mainline.
2409 *** Changes in GDB 5.2:
2411 * New command "set trust-readonly-sections on[off]".
2413 This command is a hint that tells gdb that read-only sections
2414 really are read-only (ie. that their contents will not change).
2415 In this mode, gdb will go to the object file rather than the
2416 target to read memory from read-only sections (such as ".text").
2417 This can be a significant performance improvement on some
2418 (notably embedded) targets.
2420 * New command "generate-core-file" (or "gcore").
2422 This new gdb command allows the user to drop a core file of the child
2423 process state at any time. So far it's been implemented only for
2424 GNU/Linux and Solaris, but should be relatively easily ported to other
2425 hosts. Argument is core file name (defaults to core.<pid>).
2427 * New command line option
2429 GDB now accepts --pid or -p followed by a process id.
2431 * Change in command line behavior -- corefiles vs. process ids.
2433 There is a subtle behavior in the way in which GDB handles
2434 command line arguments. The first non-flag argument is always
2435 a program to debug, but the second non-flag argument may either
2436 be a corefile or a process id. Previously, GDB would attempt to
2437 open the second argument as a corefile, and if that failed, would
2438 issue a superfluous error message and then attempt to attach it as
2439 a process. Now, if the second argument begins with a non-digit,
2440 it will be treated as a corefile. If it begins with a digit,
2441 GDB will attempt to attach it as a process, and if no such process
2442 is found, will then attempt to open it as a corefile.
2444 * Changes in ARM configurations.
2446 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
2447 configuration is fully multi-arch.
2449 * New native configurations
2451 ARM NetBSD arm*-*-netbsd*
2452 x86 OpenBSD i[3456]86-*-openbsd*
2453 AMD x86-64 running GNU/Linux x86_64-*-linux-*
2454 Sparc64 running FreeBSD sparc64-*-freebsd*
2458 Sanyo XStormy16 xstormy16-elf
2460 * OBSOLETE configurations and files
2462 Configurations that have been declared obsolete in this release have
2463 been commented out. Unless there is activity to revive these
2464 configurations, the next release of GDB will have their sources
2465 permanently REMOVED.
2467 AMD 29k family via UDI a29k-amd-udi, udi29k
2468 A29K VxWorks a29k-*-vxworks
2469 AMD 29000 embedded, using EBMON a29k-none-none
2470 AMD 29000 embedded with COFF a29k-none-coff
2471 AMD 29000 embedded with a.out a29k-none-aout
2473 testsuite/gdb.hp/gdb.threads-hp/ directory
2475 * REMOVED configurations and files
2477 TI TMS320C80 tic80-*-*
2479 PowerPC Solaris powerpcle-*-solaris*
2480 PowerPC Windows NT powerpcle-*-cygwin32
2481 PowerPC Netware powerpc-*-netware*
2482 Harris/CXUX m88k m88*-harris-cxux*
2483 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
2484 ns32k-utek-sysv* ns32k-utek-*
2485 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
2486 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
2487 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
2488 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
2489 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
2491 * Changes to command line processing
2493 The new `--args' feature can be used to specify command-line arguments
2494 for the inferior from gdb's command line.
2496 * Changes to key bindings
2498 There is a new `operate-and-get-next' function bound to `C-o'.
2500 *** Changes in GDB 5.1.1
2502 Fix compile problem on DJGPP.
2504 Fix a problem with floating-point registers on the i386 being
2507 Fix to stop GDB crashing on .debug_str debug info.
2509 Numerous documentation fixes.
2511 Numerous testsuite fixes.
2513 *** Changes in GDB 5.1:
2515 * New native configurations
2517 Alpha FreeBSD alpha*-*-freebsd*
2518 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
2519 MIPS GNU/Linux mips*-*-linux*
2520 MIPS SGI Irix 6.x mips*-sgi-irix6*
2521 ia64 AIX ia64-*-aix*
2522 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
2526 Motorola 68HC11 and 68HC12 m68hc11-elf
2528 UltraSparc running GNU/Linux sparc64-*-linux*
2530 * OBSOLETE configurations and files
2532 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
2533 Harris/CXUX m88k m88*-harris-cxux*
2534 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
2535 ns32k-utek-sysv* ns32k-utek-*
2536 TI TMS320C80 tic80-*-*
2538 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
2539 PowerPC Solaris powerpcle-*-solaris*
2540 PowerPC Windows NT powerpcle-*-cygwin32
2541 PowerPC Netware powerpc-*-netware*
2542 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
2543 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
2544 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
2545 Apple Macintosh (MPW) host N/A
2547 stuff.c (Program to stuff files into a specially prepared space in kdb)
2548 kdb-start.c (Main loop for the standalone kernel debugger)
2550 Configurations that have been declared obsolete in this release have
2551 been commented out. Unless there is activity to revive these
2552 configurations, the next release of GDB will have their sources
2553 permanently REMOVED.
2555 * REMOVED configurations and files
2557 Altos 3068 m68*-altos-*
2558 Convex c1-*-*, c2-*-*
2560 ARM RISCix arm-*-* (as host)
2564 * GDB has been converted to ISO C.
2566 GDB's source code has been converted to ISO C. In particular, the
2567 sources are fully protoized, and rely on standard headers being
2572 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
2574 * The MI enabled by default.
2576 The new machine oriented interface (MI) introduced in GDB 5.0 has been
2577 revised and enabled by default. Packages which use GDB as a debugging
2578 engine behind a UI or another front end are encouraged to switch to
2579 using the GDB/MI interface, instead of the old annotations interface
2580 which is now deprecated.
2582 * Support for debugging Pascal programs.
2584 GDB now includes support for debugging Pascal programs. The following
2585 main features are supported:
2587 - Pascal-specific data types such as sets;
2589 - automatic recognition of Pascal sources based on file-name
2592 - Pascal-style display of data types, variables, and functions;
2594 - a Pascal expression parser.
2596 However, some important features are not yet supported.
2598 - Pascal string operations are not supported at all;
2600 - there are some problems with boolean types;
2602 - Pascal type hexadecimal constants are not supported
2603 because they conflict with the internal variables format;
2605 - support for Pascal objects and classes is not full yet;
2607 - unlike Pascal, GDB is case-sensitive for symbol names.
2609 * Changes in completion.
2611 Commands such as `shell', `run' and `set args', which pass arguments
2612 to inferior programs, now complete on file names, similar to what
2613 users expect at the shell prompt.
2615 Commands which accept locations, such as `disassemble', `print',
2616 `breakpoint', `until', etc. now complete on filenames as well as
2617 program symbols. Thus, if you type "break foob TAB", and the source
2618 files linked into the programs include `foobar.c', that file name will
2619 be one of the candidates for completion. However, file names are not
2620 considered for completion after you typed a colon that delimits a file
2621 name from a name of a function in that file, as in "break foo.c:bar".
2623 `set demangle-style' completes on available demangling styles.
2625 * New platform-independent commands:
2627 It is now possible to define a post-hook for a command as well as a
2628 hook that runs before the command. For more details, see the
2629 documentation of `hookpost' in the GDB manual.
2631 * Changes in GNU/Linux native debugging.
2633 Support for debugging multi-threaded programs has been completely
2634 revised for all platforms except m68k and sparc. You can now debug as
2635 many threads as your system allows you to have.
2637 Attach/detach is supported for multi-threaded programs.
2639 Support for SSE registers was added for x86. This doesn't work for
2640 multi-threaded programs though.
2642 * Changes in MIPS configurations.
2644 Multi-arch support is enabled for all MIPS configurations.
2646 GDB can now be built as native debugger on SGI Irix 6.x systems for
2647 debugging n32 executables. (Debugging 64-bit executables is not yet
2650 * Unified support for hardware watchpoints in all x86 configurations.
2652 Most (if not all) native x86 configurations support hardware-assisted
2653 breakpoints and watchpoints in a unified manner. This support
2654 implements debug register sharing between watchpoints, which allows to
2655 put a virtually infinite number of watchpoints on the same address,
2656 and also supports watching regions up to 16 bytes with several debug
2659 The new maintenance command `maintenance show-debug-regs' toggles
2660 debugging print-outs in functions that insert, remove, and test
2661 watchpoints and hardware breakpoints.
2663 * Changes in the DJGPP native configuration.
2665 New command ``info dos sysinfo'' displays assorted information about
2666 the CPU, OS, memory, and DPMI server.
2668 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
2669 display information about segment descriptors stored in GDT, LDT, and
2672 New commands ``info dos pde'' and ``info dos pte'' display entries
2673 from Page Directory and Page Tables (for now works with CWSDPMI only).
2674 New command ``info dos address-pte'' displays the Page Table entry for
2675 a given linear address.
2677 GDB can now pass command lines longer than 126 characters to the
2678 program being debugged (requires an update to the libdbg.a library
2679 which is part of the DJGPP development kit).
2681 DWARF2 debug info is now supported.
2683 It is now possible to `step' and `next' through calls to `longjmp'.
2685 * Changes in documentation.
2687 All GDB documentation was converted to GFDL, the GNU Free
2688 Documentation License.
2690 Tracepoints-related commands are now fully documented in the GDB
2693 TUI, the Text-mode User Interface, is now documented in the manual.
2695 Tracepoints-related commands are now fully documented in the GDB
2698 The "GDB Internals" manual now has an index. It also includes
2699 documentation of `ui_out' functions, GDB coding standards, x86
2700 hardware watchpoints, and memory region attributes.
2702 * GDB's version number moved to ``version.in''
2704 The Makefile variable VERSION has been replaced by the file
2705 ``version.in''. People creating GDB distributions should update the
2706 contents of this file.
2710 GUD support is now a standard part of the EMACS distribution.
2712 *** Changes in GDB 5.0:
2714 * Improved support for debugging FP programs on x86 targets
2716 Unified and much-improved support for debugging floating-point
2717 programs on all x86 targets. In particular, ``info float'' now
2718 displays the FP registers in the same format on all x86 targets, with
2719 greater level of detail.
2721 * Improvements and bugfixes in hardware-assisted watchpoints
2723 It is now possible to watch array elements, struct members, and
2724 bitfields with hardware-assisted watchpoints. Data-read watchpoints
2725 on x86 targets no longer erroneously trigger when the address is
2728 * Improvements in the native DJGPP version of GDB
2730 The distribution now includes all the scripts and auxiliary files
2731 necessary to build the native DJGPP version on MS-DOS/MS-Windows
2732 machines ``out of the box''.
2734 The DJGPP version can now debug programs that use signals. It is
2735 possible to catch signals that happened in the debuggee, deliver
2736 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
2737 would kill the program being debugged.) Programs that hook hardware
2738 interrupts (keyboard, timer, etc.) can also be debugged.
2740 It is now possible to debug DJGPP programs that redirect their
2741 standard handles or switch them to raw (as opposed to cooked) mode, or
2742 even close them. The command ``run < foo > bar'' works as expected,
2743 and ``info terminal'' reports useful information about the debuggee's
2744 terminal, including raw/cooked mode, redirection, etc.
2746 The DJGPP version now uses termios functions for console I/O, which
2747 enables debugging graphics programs. Interrupting GDB with Ctrl-C
2750 DOS-style file names with drive letters are now fully supported by
2753 It is now possible to debug DJGPP programs that switch their working
2754 directory. It is also possible to rerun the debuggee any number of
2755 times without restarting GDB; thus, you can use the same setup,
2756 breakpoints, etc. for many debugging sessions.
2758 * New native configurations
2760 ARM GNU/Linux arm*-*-linux*
2761 PowerPC GNU/Linux powerpc-*-linux*
2765 Motorola MCore mcore-*-*
2766 x86 VxWorks i[3456]86-*-vxworks*
2767 PowerPC VxWorks powerpc-*-vxworks*
2768 TI TMS320C80 tic80-*-*
2770 * OBSOLETE configurations
2772 Altos 3068 m68*-altos-*
2773 Convex c1-*-*, c2-*-*
2775 ARM RISCix arm-*-* (as host)
2778 Configurations that have been declared obsolete will be commented out,
2779 but the code will be left in place. If there is no activity to revive
2780 these configurations before the next release of GDB, the sources will
2781 be permanently REMOVED.
2783 * Gould support removed
2785 Support for the Gould PowerNode and NP1 has been removed.
2787 * New features for SVR4
2789 On SVR4 native platforms (such as Solaris), if you attach to a process
2790 without first loading a symbol file, GDB will now attempt to locate and
2791 load symbols from the running process's executable file.
2793 * Many C++ enhancements
2795 C++ support has been greatly improved. Overload resolution now works properly
2796 in almost all cases. RTTI support is on the way.
2798 * Remote targets can connect to a sub-program
2800 A popen(3) style serial-device has been added. This device starts a
2801 sub-process (such as a stand-alone simulator) and then communicates
2802 with that. The sub-program to run is specified using the syntax
2803 ``|<program> <args>'' vis:
2805 (gdb) set remotedebug 1
2806 (gdb) target extended-remote |mn10300-elf-sim program-args
2808 * MIPS 64 remote protocol
2810 A long standing bug in the mips64 remote protocol where by GDB
2811 expected certain 32 bit registers (ex SR) to be transfered as 32
2812 instead of 64 bits has been fixed.
2814 The command ``set remote-mips64-transfers-32bit-regs on'' has been
2815 added to provide backward compatibility with older versions of GDB.
2817 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
2819 The command ``set remotebinarydownload'' command has been replaced by
2820 ``set remote X-packet''. Other commands in ``set remote'' family
2821 include ``set remote P-packet''.
2823 * Breakpoint commands accept ranges.
2825 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
2826 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
2827 ``tracepoint passcount'' also accepts a range of tracepoints.
2829 * ``apropos'' command added.
2831 The ``apropos'' command searches through command names and
2832 documentation strings, printing out matches, making it much easier to
2833 try to find a command that does what you are looking for.
2837 A new machine oriented interface (MI) has been added to GDB. This
2838 interface is designed for debug environments running GDB as a separate
2839 process. This is part of the long term libGDB project. See the
2840 "GDB/MI" chapter of the GDB manual for further information. It can be
2841 enabled by configuring with:
2843 .../configure --enable-gdbmi
2845 *** Changes in GDB-4.18:
2847 * New native configurations
2849 HP-UX 10.20 hppa*-*-hpux10.20
2850 HP-UX 11.x hppa*-*-hpux11.0*
2851 M68K GNU/Linux m68*-*-linux*
2855 Fujitsu FR30 fr30-*-elf*
2856 Intel StrongARM strongarm-*-*
2857 Mitsubishi D30V d30v-*-*
2859 * OBSOLETE configurations
2861 Gould PowerNode, NP1 np1-*-*, pn-*-*
2863 Configurations that have been declared obsolete will be commented out,
2864 but the code will be left in place. If there is no activity to revive
2865 these configurations before the next release of GDB, the sources will
2866 be permanently REMOVED.
2870 As a compatibility experiment, GDB's source files buildsym.h and
2871 buildsym.c have been converted to pure standard C, no longer
2872 containing any K&R compatibility code. We believe that all systems in
2873 use today either come with a standard C compiler, or have a GCC port
2874 available. If this is not true, please report the affected
2875 configuration to bug-gdb@gnu.org immediately. See the README file for
2876 information about getting a standard C compiler if you don't have one
2881 GDB now uses readline 2.2.
2883 * set extension-language
2885 You can now control the mapping between filename extensions and source
2886 languages by using the `set extension-language' command. For instance,
2887 you can ask GDB to treat .c files as C++ by saying
2888 set extension-language .c c++
2889 The command `info extensions' lists all of the recognized extensions
2890 and their associated languages.
2892 * Setting processor type for PowerPC and RS/6000
2894 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
2895 you can use the `set processor' command to specify what variant of the
2896 PowerPC family you are debugging. The command
2900 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
2901 following PowerPC and RS6000 variants:
2903 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
2904 rs6000 IBM RS6000 ("POWER") architecture, user-level view
2906 403GC IBM PowerPC 403GC
2907 505 Motorola PowerPC 505
2908 860 Motorola PowerPC 860 or 850
2909 601 Motorola PowerPC 601
2910 602 Motorola PowerPC 602
2911 603 Motorola/IBM PowerPC 603 or 603e
2912 604 Motorola PowerPC 604 or 604e
2913 750 Motorola/IBM PowerPC 750 or 750
2915 At the moment, this command just tells GDB what to name the
2916 special-purpose processor registers. Since almost all the affected
2917 registers are inaccessible to user-level programs, this command is
2918 only useful for remote debugging in its present form.
2922 Thanks to a major code donation from Hewlett-Packard, GDB now has much
2923 more extensive support for HP-UX. Added features include shared
2924 library support, kernel threads and hardware watchpoints for 11.00,
2925 support for HP's ANSI C and C++ compilers, and a compatibility mode
2926 for xdb and dbx commands.
2930 HP's donation includes the new concept of catchpoints, which is a
2931 generalization of the old catch command. On HP-UX, it is now possible
2932 to catch exec, fork, and vfork, as well as library loading.
2934 This means that the existing catch command has changed; its first
2935 argument now specifies the type of catch to be set up. See the
2936 output of "help catch" for a list of catchpoint types.
2938 * Debugging across forks
2940 On HP-UX, you can choose which process to debug when a fork() happens
2945 HP has donated a curses-based terminal user interface (TUI). To get
2946 it, build with --enable-tui. Although this can be enabled for any
2947 configuration, at present it only works for native HP debugging.
2949 * GDB remote protocol additions
2951 A new protocol packet 'X' that writes binary data is now available.
2952 Default behavior is to try 'X', then drop back to 'M' if the stub
2953 fails to respond. The settable variable `remotebinarydownload'
2954 allows explicit control over the use of 'X'.
2956 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
2957 full 64-bit address. The command
2959 set remoteaddresssize 32
2961 can be used to revert to the old behaviour. For existing remote stubs
2962 the change should not be noticed, as the additional address information
2965 In order to assist in debugging stubs, you may use the maintenance
2966 command `packet' to send any text string to the stub. For instance,
2968 maint packet heythere
2970 sends the packet "$heythere#<checksum>". Note that it is very easy to
2971 disrupt a debugging session by sending the wrong packet at the wrong
2974 The compare-sections command allows you to compare section data on the
2975 target to what is in the executable file without uploading or
2976 downloading, by comparing CRC checksums.
2978 * Tracing can collect general expressions
2980 You may now collect general expressions at tracepoints. This requires
2981 further additions to the target-side stub; see tracepoint.c and
2982 doc/agentexpr.texi for further details.
2984 * mask-address variable for Mips
2986 For Mips targets, you may control the zeroing of the upper 32 bits of
2987 a 64-bit address by entering `set mask-address on'. This is mainly
2988 of interest to users of embedded R4xxx and R5xxx processors.
2990 * Higher serial baud rates
2992 GDB's serial code now allows you to specify baud rates 57600, 115200,
2993 230400, and 460800 baud. (Note that your host system may not be able
2994 to achieve all of these rates.)
2998 The i960 configuration now includes an initial implementation of a
2999 builtin simulator, contributed by Jim Wilson.
3002 *** Changes in GDB-4.17:
3004 * New native configurations
3006 Alpha GNU/Linux alpha*-*-linux*
3007 Unixware 2.x i[3456]86-unixware2*
3008 Irix 6.x mips*-sgi-irix6*
3009 PowerPC GNU/Linux powerpc-*-linux*
3010 PowerPC Solaris powerpcle-*-solaris*
3011 Sparc GNU/Linux sparc-*-linux*
3012 Motorola sysV68 R3V7.1 m68k-motorola-sysv
3016 Argonaut Risc Chip (ARC) arc-*-*
3017 Hitachi H8/300S h8300*-*-*
3018 Matsushita MN10200 w/simulator mn10200-*-*
3019 Matsushita MN10300 w/simulator mn10300-*-*
3020 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
3021 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
3022 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
3023 Mitsubishi D10V w/simulator d10v-*-*
3024 Mitsubishi M32R/D w/simulator m32r-*-elf*
3025 Tsqware Sparclet sparclet-*-*
3026 NEC V850 w/simulator v850-*-*
3028 * New debugging protocols
3030 ARM with RDI protocol arm*-*-*
3031 M68K with dBUG monitor m68*-*-{aout,coff,elf}
3032 DDB and LSI variants of PMON protocol mips*-*-*
3033 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
3034 PowerPC with SDS protocol powerpc{,le}-*-eabi
3035 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
3039 All configurations can now understand and use the DWARF 2 debugging
3040 format. The choice is automatic, if the symbol file contains DWARF 2
3045 GDB now includes basic Java language support. This support is
3046 only useful with Java compilers that produce native machine code.
3048 * solib-absolute-prefix and solib-search-path
3050 For SunOS and SVR4 shared libraries, you may now set the prefix for
3051 loading absolute shared library symbol files, and the search path for
3052 locating non-absolute shared library symbol files.
3054 * Live range splitting
3056 GDB can now effectively debug code for which GCC has performed live
3057 range splitting as part of its optimization. See gdb/doc/LRS for
3058 more details on the expected format of the stabs information.
3062 GDB's support for the GNU Hurd, including thread debugging, has been
3063 updated to work with current versions of the Hurd.
3067 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
3068 instruction set. ARM GDB automatically detects when Thumb
3069 instructions are in use, and adjusts disassembly and backtracing
3074 GDB's MIPS target configurations now handle the MIP16 16-bit
3079 GDB now includes support for overlays; if an executable has been
3080 linked such that multiple sections are based at the same address, GDB
3081 will decide which section to use for symbolic info. You can choose to
3082 control the decision manually, using overlay commands, or implement
3083 additional target-side support and use "overlay load-target" to bring
3084 in the overlay mapping. Do "help overlay" for more detail.
3088 The command "info symbol <address>" displays information about
3089 the symbol at the specified address.
3093 The standard remote protocol now includes an extension that allows
3094 asynchronous collection and display of trace data. This requires
3095 extensive support in the target-side debugging stub. Tracing mode
3096 includes a new interaction mode in GDB and new commands: see the
3097 file tracepoint.c for more details.
3101 Configurations for embedded MIPS now include a simulator contributed
3102 by Cygnus Solutions. The simulator supports the instruction sets
3103 of most MIPS variants.
3107 Sparc configurations may now include the ERC32 simulator contributed
3108 by the European Space Agency. The simulator is not built into
3109 Sparc targets by default; configure with --enable-sim to include it.
3113 For target configurations that may include multiple variants of a
3114 basic architecture (such as MIPS and SH), you may now set the
3115 architecture explicitly. "set arch" sets, "info arch" lists
3116 the possible architectures.
3118 *** Changes in GDB-4.16:
3120 * New native configurations
3122 Windows 95, x86 Windows NT i[345]86-*-cygwin32
3123 M68K NetBSD m68k-*-netbsd*
3124 PowerPC AIX 4.x powerpc-*-aix*
3125 PowerPC MacOS powerpc-*-macos*
3126 PowerPC Windows NT powerpcle-*-cygwin32
3127 RS/6000 AIX 4.x rs6000-*-aix4*
3131 ARM with RDP protocol arm-*-*
3132 I960 with MON960 i960-*-coff
3133 MIPS VxWorks mips*-*-vxworks*
3134 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
3135 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
3137 Matra Sparclet sparclet-*-*
3141 The powerpc-eabi configuration now includes the PSIM simulator,
3142 contributed by Andrew Cagney, with assistance from Mike Meissner.
3143 PSIM is a very elaborate model of the PowerPC, including not only
3144 basic instruction set execution, but also details of execution unit
3145 performance and I/O hardware. See sim/ppc/README for more details.
3149 GDB now works with Solaris 2.5.
3151 * Windows 95/NT native
3153 GDB will now work as a native debugger on Windows 95 and Windows NT.
3154 To build it from source, you must use the "gnu-win32" environment,
3155 which uses a DLL to emulate enough of Unix to run the GNU tools.
3156 Further information, binaries, and sources are available at
3157 ftp.cygnus.com, under pub/gnu-win32.
3159 * dont-repeat command
3161 If a user-defined command includes the command `dont-repeat', then the
3162 command will not be repeated if the user just types return. This is
3163 useful if the command is time-consuming to run, so that accidental
3164 extra keystrokes don't run the same command many times.
3166 * Send break instead of ^C
3168 The standard remote protocol now includes an option to send a break
3169 rather than a ^C to the target in order to interrupt it. By default,
3170 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
3172 * Remote protocol timeout
3174 The standard remote protocol includes a new variable `remotetimeout'
3175 that allows you to set the number of seconds before GDB gives up trying
3176 to read from the target. The default value is 2.
3178 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
3180 By default GDB will automatically keep track of objects as they are
3181 loaded and unloaded by the dynamic linker. By using the command `set
3182 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
3183 when shared library events occur, thus allowing you to set breakpoints
3184 in shared libraries which are explicitly loaded by the inferior.
3186 Note this feature does not work on hpux8. On hpux9 you must link
3187 /usr/lib/end.o into your program. This feature should work
3188 automatically on hpux10.
3190 * Irix 5.x hardware watchpoint support
3192 Irix 5 configurations now support the use of hardware watchpoints.
3194 * Mips protocol "SYN garbage limit"
3196 When debugging a Mips target using the `target mips' protocol, you
3197 may set the number of characters that GDB will ignore by setting
3198 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
3199 every character. The default value is 1050.
3201 * Recording and replaying remote debug sessions
3203 If you set `remotelogfile' to the name of a file, gdb will write to it
3204 a recording of a remote debug session. This recording may then be
3205 replayed back to gdb using "gdbreplay". See gdbserver/README for
3206 details. This is useful when you have a problem with GDB while doing
3207 remote debugging; you can make a recording of the session and send it
3208 to someone else, who can then recreate the problem.
3210 * Speedups for remote debugging
3212 GDB includes speedups for downloading and stepping MIPS systems using
3213 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
3214 and more efficient S-record downloading.
3216 * Memory use reductions and statistics collection
3218 GDB now uses less memory and reports statistics about memory usage.
3219 Try the `maint print statistics' command, for example.
3221 *** Changes in GDB-4.15:
3223 * Psymtabs for XCOFF
3225 The symbol reader for AIX GDB now uses partial symbol tables. This
3226 can greatly improve startup time, especially for large executables.
3228 * Remote targets use caching
3230 Remote targets now use a data cache to speed up communication with the
3231 remote side. The data cache could lead to incorrect results because
3232 it doesn't know about volatile variables, thus making it impossible to
3233 debug targets which use memory mapped I/O devices. `set remotecache
3234 off' turns the the data cache off.
3236 * Remote targets may have threads
3238 The standard remote protocol now includes support for multiple threads
3239 in the target system, using new protocol commands 'H' and 'T'. See
3240 gdb/remote.c for details.
3244 If GDB is configured with `--enable-netrom', then it will include
3245 support for the NetROM ROM emulator from XLNT Designs. The NetROM
3246 acts as though it is a bank of ROM on the target board, but you can
3247 write into it over the network. GDB's support consists only of
3248 support for fast loading into the emulated ROM; to debug, you must use
3249 another protocol, such as standard remote protocol. The usual
3250 sequence is something like
3252 target nrom <netrom-hostname>
3254 target remote <netrom-hostname>:1235
3258 GDB now includes support for the Apple Macintosh, as a host only. It
3259 may be run as either an MPW tool or as a standalone application, and
3260 it can debug through the serial port. All the usual GDB commands are
3261 available, but to the target command, you must supply "serial" as the
3262 device type instead of "/dev/ttyXX". See mpw-README in the main
3263 directory for more information on how to build. The MPW configuration
3264 scripts */mpw-config.in support only a few targets, and only the
3265 mips-idt-ecoff target has been tested.
3269 GDB configuration now uses autoconf. This is not user-visible,
3270 but does simplify configuration and building.
3274 GDB now supports hpux10.
3276 *** Changes in GDB-4.14:
3278 * New native configurations
3280 x86 FreeBSD i[345]86-*-freebsd
3281 x86 NetBSD i[345]86-*-netbsd
3282 NS32k NetBSD ns32k-*-netbsd
3283 Sparc NetBSD sparc-*-netbsd
3287 A29K VxWorks a29k-*-vxworks
3288 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
3289 CPU32 EST-300 emulator m68*-*-est*
3290 PowerPC ELF powerpc-*-elf
3293 * Alpha OSF/1 support for procfs
3295 GDB now supports procfs under OSF/1-2.x and higher, which makes it
3296 possible to attach to running processes. As the mounting of the /proc
3297 filesystem is optional on the Alpha, GDB automatically determines
3298 the availability of /proc during startup. This can lead to problems
3299 if /proc is unmounted after GDB has been started.
3301 * Arguments to user-defined commands
3303 User commands may accept up to 10 arguments separated by whitespace.
3304 Arguments are accessed within the user command via $arg0..$arg9. A
3307 print $arg0 + $arg1 + $arg2
3309 To execute the command use:
3312 Defines the command "adder" which prints the sum of its three arguments.
3313 Note the arguments are text substitutions, so they may reference variables,
3314 use complex expressions, or even perform inferior function calls.
3316 * New `if' and `while' commands
3318 This makes it possible to write more sophisticated user-defined
3319 commands. Both commands take a single argument, which is the
3320 expression to evaluate, and must be followed by the commands to
3321 execute, one per line, if the expression is nonzero, the list being
3322 terminated by the word `end'. The `if' command list may include an
3323 `else' word, which causes the following commands to be executed only
3324 if the expression is zero.
3326 * Fortran source language mode
3328 GDB now includes partial support for Fortran 77. It will recognize
3329 Fortran programs and can evaluate a subset of Fortran expressions, but
3330 variables and functions may not be handled correctly. GDB will work
3331 with G77, but does not yet know much about symbols emitted by other
3334 * Better HPUX support
3336 Most debugging facilities now work on dynamic executables for HPPAs
3337 running hpux9 or later. You can attach to running dynamically linked
3338 processes, but by default the dynamic libraries will be read-only, so
3339 for instance you won't be able to put breakpoints in them. To change
3340 that behavior do the following before running the program:
3346 This will cause the libraries to be mapped private and read-write.
3347 To revert to the normal behavior, do this:
3353 You cannot set breakpoints or examine data in the library until after
3354 the library is loaded if the function/data symbols do not have
3357 GDB can now also read debug symbols produced by the HP C compiler on
3358 HPPAs (sorry, no C++, Fortran or 68k support).
3360 * Target byte order now dynamically selectable
3362 You can choose which byte order to use with a target system, via the
3363 commands "set endian big" and "set endian little", and you can see the
3364 current setting by using "show endian". You can also give the command
3365 "set endian auto", in which case GDB will use the byte order
3366 associated with the executable. Currently, only embedded MIPS
3367 configurations support dynamic selection of target byte order.
3369 * New DOS host serial code
3371 This version uses DPMI interrupts to handle buffered I/O, so you
3372 no longer need to run asynctsr when debugging boards connected to
3375 *** Changes in GDB-4.13:
3377 * New "complete" command
3379 This lists all the possible completions for the rest of the line, if it
3380 were to be given as a command itself. This is intended for use by emacs.
3382 * Trailing space optional in prompt
3384 "set prompt" no longer adds a space for you after the prompt you set. This
3385 allows you to set a prompt which ends in a space or one that does not.
3387 * Breakpoint hit counts
3389 "info break" now displays a count of the number of times the breakpoint
3390 has been hit. This is especially useful in conjunction with "ignore"; you
3391 can ignore a large number of breakpoint hits, look at the breakpoint info
3392 to see how many times the breakpoint was hit, then run again, ignoring one
3393 less than that number, and this will get you quickly to the last hit of
3396 * Ability to stop printing at NULL character
3398 "set print null-stop" will cause GDB to stop printing the characters of
3399 an array when the first NULL is encountered. This is useful when large
3400 arrays actually contain only short strings.
3402 * Shared library breakpoints
3404 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
3405 breakpoints in shared libraries before the executable is run.
3407 * Hardware watchpoints
3409 There is a new hardware breakpoint for the watch command for sparclite
3410 targets. See gdb/sparclite/hw_breakpoint.note.
3412 Hardware watchpoints are also now supported under GNU/Linux.
3416 Annotations have been added. These are for use with graphical interfaces,
3417 and are still experimental. Currently only gdba.el uses these.
3419 * Improved Irix 5 support
3421 GDB now works properly with Irix 5.2.
3423 * Improved HPPA support
3425 GDB now works properly with the latest GCC and GAS.
3427 * New native configurations
3429 Sequent PTX4 i[34]86-sequent-ptx4
3430 HPPA running OSF/1 hppa*-*-osf*
3431 Atari TT running SVR4 m68*-*-sysv4*
3432 RS/6000 LynxOS rs6000-*-lynxos*
3436 OS/9000 i[34]86-*-os9k
3437 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
3440 * Hitachi SH7000 and E7000-PC ICE support
3442 There is now support for communicating with the Hitachi E7000-PC ICE.
3443 This is available automatically when GDB is configured for the SH.
3447 As usual, a variety of small fixes and improvements, both generic
3448 and configuration-specific. See the ChangeLog for more detail.
3450 *** Changes in GDB-4.12:
3452 * Irix 5 is now supported
3456 GDB-4.12 on the HPPA has a number of changes which make it unable
3457 to debug the output from the currently released versions of GCC and
3458 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
3459 of GCC and GAS, versions of these tools designed to work with GDB-4.12
3460 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
3463 *** Changes in GDB-4.11:
3465 * User visible changes:
3469 The "set remotedebug" option is now consistent between the mips remote
3470 target, remote targets using the gdb-specific protocol, UDI (AMD's
3471 debug protocol for the 29k) and the 88k bug monitor. It is now an
3472 integer specifying a debug level (normally 0 or 1, but 2 means more
3473 debugging info for the mips target).
3475 * DEC Alpha native support
3477 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
3478 debug info, but GDB works fairly well with the DEC compiler and should
3479 work with a future GCC release. See the README file for a few
3480 Alpha-specific notes.
3482 * Preliminary thread implementation
3484 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
3486 * LynxOS native and target support for 386
3488 This release has been hosted on LynxOS 2.2, and also can be configured
3489 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
3492 * Improvements in C++ mangling/demangling.
3494 This release has much better g++ debugging, specifically in name
3495 mangling/demangling, virtual function calls, print virtual table,
3496 call methods, ...etc.
3498 *** Changes in GDB-4.10:
3500 * User visible changes:
3502 Remote debugging using the GDB-specific (`target remote') protocol now
3503 supports the `load' command. This is only useful if you have some
3504 other way of getting the stub to the target system, and you can put it
3505 somewhere in memory where it won't get clobbered by the download.
3507 Filename completion now works.
3509 When run under emacs mode, the "info line" command now causes the
3510 arrow to point to the line specified. Also, "info line" prints
3511 addresses in symbolic form (as well as hex).
3513 All vxworks based targets now support a user settable option, called
3514 vxworks-timeout. This option represents the number of seconds gdb
3515 should wait for responses to rpc's. You might want to use this if
3516 your vxworks target is, perhaps, a slow software simulator or happens
3517 to be on the far side of a thin network line.
3521 This release contains support for using a DEC alpha as a GDB host for
3522 cross debugging. Native alpha debugging is not supported yet.
3525 *** Changes in GDB-4.9:
3529 This is the first GDB release which is accompanied by a matching testsuite.
3530 The testsuite requires installation of dejagnu, which should be available
3531 via ftp from most sites that carry GNU software.
3535 'Cfront' style demangling has had its name changed to 'ARM' style, to
3536 emphasize that it was written from the specifications in the C++ Annotated
3537 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
3538 disclaimers, it still generated too much confusion with users attempting to
3539 use gdb with AT&T cfront.
3543 GDB now uses a standard remote interface to a simulator library.
3544 So far, the library contains simulators for the Zilog Z8001/2, the
3545 Hitachi H8/300, H8/500 and Super-H.
3547 * New targets supported
3549 H8/300 simulator h8300-hitachi-hms or h8300hms
3550 H8/500 simulator h8500-hitachi-hms or h8500hms
3551 SH simulator sh-hitachi-hms or sh
3552 Z8000 simulator z8k-zilog-none or z8ksim
3553 IDT MIPS board over serial line mips-idt-ecoff
3555 Cross-debugging to GO32 targets is supported. It requires a custom
3556 version of the i386-stub.c module which is integrated with the
3557 GO32 memory extender.
3559 * New remote protocols
3561 MIPS remote debugging protocol.
3563 * New source languages supported
3565 This version includes preliminary support for Chill, a Pascal like language
3566 used by telecommunications companies. Chill support is also being integrated
3567 into the GNU compiler, but we don't know when it will be publically available.
3570 *** Changes in GDB-4.8:
3572 * HP Precision Architecture supported
3574 GDB now supports HP PA-RISC machines running HPUX. A preliminary
3575 version of this support was available as a set of patches from the
3576 University of Utah. GDB does not support debugging of programs
3577 compiled with the HP compiler, because HP will not document their file
3578 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
3579 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
3581 Many problems in the preliminary version have been fixed.
3583 * Faster and better demangling
3585 We have improved template demangling and fixed numerous bugs in the GNU style
3586 demangler. It can now handle type modifiers such as `static' or `const'. Wide
3587 character types (wchar_t) are now supported. Demangling of each symbol is now
3588 only done once, and is cached when the symbol table for a file is read in.
3589 This results in a small increase in memory usage for C programs, a moderate
3590 increase in memory usage for C++ programs, and a fantastic speedup in
3593 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
3594 from the specifications in the Annotated Reference Manual, which AT&T's
3595 compiler does not actually implement.
3597 * G++ multiple inheritance compiler problem
3599 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
3600 inheritance lattices was reworked to properly discover ambiguities. We
3601 recently found an example which causes this new algorithm to fail in a
3602 very subtle way, producing bad debug information for those classes.
3603 The file 'gcc.patch' (in this directory) can be applied to gcc to
3604 circumvent the problem. A future GCC release will contain a complete
3607 The previous G++ debug info problem (mentioned below for the gdb-4.7
3608 release) is fixed in gcc version 2.3.2.
3610 * Improved configure script
3612 The `configure' script will now attempt to guess your system type if
3613 you don't supply a host system type. The old scheme of supplying a
3614 host system triplet is preferable over using this. All the magic is
3615 done in the new `config.guess' script. Examine it for details.
3617 We have also brought our configure script much more in line with the FSF's
3618 version. It now supports the --with-xxx options. In particular,
3619 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
3620 The resulting GDB will not be able to read arbitrary object file formats --
3621 only the format ``expected'' to be used on the configured target system.
3622 We hope to make this the default in a future release.
3624 * Documentation improvements
3626 There's new internal documentation on how to modify GDB, and how to
3627 produce clean changes to the code. We implore people to read it
3628 before submitting changes.
3630 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
3631 M4 macros. The new texinfo.tex is provided in this release. Pre-built
3632 `info' files are also provided. To build `info' files from scratch,
3633 you will need the latest `makeinfo' release, which will be available in
3634 a future texinfo-X.Y release.
3636 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
3637 We're not sure exactly which versions have this problem, but it has
3638 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
3639 or better. If that isn't possible, there is a patch in
3640 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
3641 around this problem.
3645 GDB now supports array constants that can be used in expressions typed in by
3646 the user. The syntax is `{element, element, ...}'. Ie: you can now type
3647 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
3650 The new directory `gdb/sparclite' contains a program that demonstrates
3651 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
3653 * New native hosts supported
3655 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
3656 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
3658 * New targets supported
3660 AMD 29k family via UDI a29k-amd-udi or udi29k
3662 * New file formats supported
3664 BFD now supports reading HP/PA-RISC executables (SOM file format?),
3665 HPUX core files, and SCO 3.2v2 core files.
3669 Attaching to processes now works again; thanks for the many bug reports.
3671 We have also stomped on a bunch of core dumps caused by
3672 printf_filtered("%s") problems.
3674 We eliminated a copyright problem on the rpc and ptrace header files
3675 for VxWorks, which was discovered at the last minute during the 4.7
3676 release. You should now be able to build a VxWorks GDB.
3678 You can now interrupt gdb while an attached process is running. This
3679 will cause the attached process to stop, and give control back to GDB.
3681 We fixed problems caused by using too many file descriptors
3682 for reading symbols from object files and libraries. This was
3683 especially a problem for programs that used many (~100) shared
3686 The `step' command now only enters a subroutine if there is line number
3687 information for the subroutine. Otherwise it acts like the `next'
3688 command. Previously, `step' would enter subroutines if there was
3689 any debugging information about the routine. This avoids problems
3690 when using `cc -g1' on MIPS machines.
3692 * Internal improvements
3694 GDB's internal interfaces have been improved to make it easier to support
3695 debugging of multiple languages in the future.
3697 GDB now uses a common structure for symbol information internally.
3698 Minimal symbols (derived from linkage symbols in object files), partial
3699 symbols (from a quick scan of debug information), and full symbols
3700 contain a common subset of information, making it easier to write
3701 shared code that handles any of them.
3703 * New command line options
3705 We now accept --silent as an alias for --quiet.
3709 The memory-mapped-malloc library is now licensed under the GNU Library
3710 General Public License.
3712 *** Changes in GDB-4.7:
3714 * Host/native/target split
3716 GDB has had some major internal surgery to untangle the support for
3717 hosts and remote targets. Now, when you configure GDB for a remote
3718 target, it will no longer load in all of the support for debugging
3719 local programs on the host. When fully completed and tested, this will
3720 ensure that arbitrary host/target combinations are possible.
3722 The primary conceptual shift is to separate the non-portable code in
3723 GDB into three categories. Host specific code is required any time GDB
3724 is compiled on that host, regardless of the target. Target specific
3725 code relates to the peculiarities of the target, but can be compiled on
3726 any host. Native specific code is everything else: it can only be
3727 built when the host and target are the same system. Child process
3728 handling and core file support are two common `native' examples.
3730 GDB's use of /proc for controlling Unix child processes is now cleaner.
3731 It has been split out into a single module under the `target_ops' vector,
3732 plus two native-dependent functions for each system that uses /proc.
3734 * New hosts supported
3736 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
3737 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
3738 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
3740 * New targets supported
3742 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3743 68030 and CPU32 m68030-*-*, m68332-*-*
3745 * New native hosts supported
3747 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
3748 (386bsd is not well tested yet)
3749 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
3751 * New file formats supported
3753 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
3754 supports reading of `a.out.adobe' object files, which are an a.out
3755 format extended with minimal information about multiple sections.
3759 `show copying' is the same as the old `info copying'.
3760 `show warranty' is the same as `info warrantee'.
3761 These were renamed for consistency. The old commands continue to work.
3763 `info handle' is a new alias for `info signals'.
3765 You can now define pre-command hooks, which attach arbitrary command
3766 scripts to any command. The commands in the hook will be executed
3767 prior to the user's command. You can also create a hook which will be
3768 executed whenever the program stops. See gdb.texinfo.
3772 We now deal with Cfront style name mangling, and can even extract type
3773 info from mangled symbols. GDB can automatically figure out which
3774 symbol mangling style your C++ compiler uses.
3776 Calling of methods and virtual functions has been improved as well.
3780 The crash that occured when debugging Sun Ansi-C compiled binaries is
3781 fixed. This was due to mishandling of the extra N_SO stabs output
3784 We also finally got Ultrix 4.2 running in house, and fixed core file
3785 support, with help from a dozen people on the net.
3787 John M. Farrell discovered that the reason that single-stepping was so
3788 slow on all of the Mips based platforms (primarily SGI and DEC) was
3789 that we were trying to demangle and lookup a symbol used for internal
3790 purposes on every instruction that was being stepped through. Changing
3791 the name of that symbol so that it couldn't be mistaken for a C++
3792 mangled symbol sped things up a great deal.
3794 Rich Pixley sped up symbol lookups in general by getting much smarter
3795 about when C++ symbol mangling is necessary. This should make symbol
3796 completion (TAB on the command line) much faster. It's not as fast as
3797 we'd like, but it's significantly faster than gdb-4.6.
3801 A new user controllable variable 'call_scratch_address' can
3802 specify the location of a scratch area to be used when GDB
3803 calls a function in the target. This is necessary because the
3804 usual method of putting the scratch area on the stack does not work
3805 in systems that have separate instruction and data spaces.
3807 We integrated changes to support the 29k UDI (Universal Debugger
3808 Interface), but discovered at the last minute that we didn't have all
3809 of the appropriate copyright paperwork. We are working with AMD to
3810 resolve this, and hope to have it available soon.
3814 We have sped up the remote serial line protocol, especially for targets
3815 with lots of registers. It now supports a new `expedited status' ('T')
3816 message which can be used in place of the existing 'S' status message.
3817 This allows the remote stub to send only the registers that GDB
3818 needs to make a quick decision about single-stepping or conditional
3819 breakpoints, eliminating the need to fetch the entire register set for
3820 each instruction being stepped through.
3822 The GDB remote serial protocol now implements a write-through cache for
3823 registers, only re-reading the registers if the target has run.
3825 There is also a new remote serial stub for SPARC processors. You can
3826 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
3827 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
3828 processor with a serial port.
3832 Configure.in files have become much easier to read and modify. A new
3833 `table driven' format makes it more obvious what configurations are
3834 supported, and what files each one uses.
3838 There is a new opcodes library which will eventually contain all of the
3839 disassembly routines and opcode tables. At present, it only contains
3840 Sparc and Z8000 routines. This will allow the assembler, debugger, and
3841 disassembler (binutils/objdump) to share these routines.
3843 The libiberty library is now copylefted under the GNU Library General
3844 Public License. This allows more liberal use, and was done so libg++
3845 can use it. This makes no difference to GDB, since the Library License
3846 grants all the rights from the General Public License.
3850 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
3851 reference to the stabs symbol info used by the debugger. It is (as far
3852 as we know) the only published document on this fascinating topic. We
3853 encourage you to read it, compare it to the stabs information on your
3854 system, and send improvements on the document in general (to
3855 bug-gdb@prep.ai.mit.edu).
3857 And, of course, many bugs have been fixed.
3860 *** Changes in GDB-4.6:
3862 * Better support for C++ function names
3864 GDB now accepts as input the "demangled form" of C++ overloaded function
3865 names and member function names, and can do command completion on such names
3866 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
3867 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
3868 Make use of command completion, it is your friend.
3870 GDB also now accepts a variety of C++ mangled symbol formats. They are
3871 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
3872 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
3873 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
3874 for the list of formats.
3876 * G++ symbol mangling problem
3878 Recent versions of gcc have a bug in how they emit debugging information for
3879 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
3880 directory) can be applied to gcc to fix the problem. Alternatively, if you
3881 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
3882 usual symptom is difficulty with setting breakpoints on methods. GDB complains
3883 about the method being non-existent. (We believe that version 2.2.2 of GCC has
3886 * New 'maintenance' command
3888 All of the commands related to hacking GDB internals have been moved out of
3889 the main command set, and now live behind the 'maintenance' command. This
3890 can also be abbreviated as 'mt'. The following changes were made:
3892 dump-me -> maintenance dump-me
3893 info all-breakpoints -> maintenance info breakpoints
3894 printmsyms -> maintenance print msyms
3895 printobjfiles -> maintenance print objfiles
3896 printpsyms -> maintenance print psymbols
3897 printsyms -> maintenance print symbols
3899 The following commands are new:
3901 maintenance demangle Call internal GDB demangler routine to
3902 demangle a C++ link name and prints the result.
3903 maintenance print type Print a type chain for a given symbol
3905 * Change to .gdbinit file processing
3907 We now read the $HOME/.gdbinit file before processing the argv arguments
3908 (e.g. reading symbol files or core files). This allows global parameters to
3909 be set, which will apply during the symbol reading. The ./.gdbinit is still
3910 read after argv processing.
3912 * New hosts supported
3914 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
3916 GNU/Linux support i386-unknown-linux or linux
3918 We are also including code to support the HP/PA running BSD and HPUX. This
3919 is almost guaranteed not to work, as we didn't have time to test or build it
3920 for this release. We are including it so that the more adventurous (or
3921 masochistic) of you can play with it. We also had major problems with the
3922 fact that the compiler that we got from HP doesn't support the -g option.
3925 * New targets supported
3927 Hitachi H8/300 h8300-hitachi-hms or h8300hms
3929 * More smarts about finding #include files
3931 GDB now remembers the compilation directory for all include files, and for
3932 all files from which C is generated (like yacc and lex sources). This
3933 greatly improves GDB's ability to find yacc/lex sources, and include files,
3934 especially if you are debugging your program from a directory different from
3935 the one that contains your sources.
3937 We also fixed a bug which caused difficulty with listing and setting
3938 breakpoints in include files which contain C code. (In the past, you had to
3939 try twice in order to list an include file that you hadn't looked at before.)
3941 * Interesting infernals change
3943 GDB now deals with arbitrary numbers of sections, where the symbols for each
3944 section must be relocated relative to that section's landing place in the
3945 target's address space. This work was needed to support ELF with embedded
3946 stabs used by Solaris-2.0.
3948 * Bug fixes (of course!)
3950 There have been loads of fixes for the following things:
3951 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
3952 i960, stabs, DOS(GO32), procfs, etc...
3954 See the ChangeLog for details.
3956 *** Changes in GDB-4.5:
3958 * New machines supported (host and target)
3960 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
3962 SGI Irix-4.x mips-sgi-irix4 or iris4
3964 * New malloc package
3966 GDB now uses a new memory manager called mmalloc, based on gmalloc.
3967 Mmalloc is capable of handling mutiple heaps of memory. It is also
3968 capable of saving a heap to a file, and then mapping it back in later.
3969 This can be used to greatly speedup the startup of GDB by using a
3970 pre-parsed symbol table which lives in a mmalloc managed heap. For
3971 more details, please read mmalloc/mmalloc.texi.
3975 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
3976 'help info proc' for details.
3978 * MIPS ecoff symbol table format
3980 The code that reads MIPS symbol table format is now supported on all hosts.
3981 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
3984 * File name changes for MS-DOS
3986 Many files in the config directories have been renamed to make it easier to
3987 support GDB on MS-DOSe systems (which have very restrictive file name
3988 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
3989 environment) is close to working but has some remaining problems. Note
3990 that debugging of DOS programs is not supported, due to limitations
3991 in the ``operating system'', but it can be used to host cross-debugging.
3993 * Cross byte order fixes
3995 Many fixes have been made to support cross debugging of Sparc and MIPS
3996 targets from hosts whose byte order differs.
3998 * New -mapped and -readnow options
4000 If memory-mapped files are available on your system through the 'mmap'
4001 system call, you can use the -mapped option on the `file' or
4002 `symbol-file' commands to cause GDB to write the symbols from your
4003 program into a reusable file. If the program you are debugging is
4004 called `/path/fred', the mapped symbol file will be `./fred.syms'.
4005 Future GDB debugging sessions will notice the presence of this file,
4006 and will quickly map in symbol information from it, rather than reading
4007 the symbol table from the executable program. Using the '-mapped'
4008 option in a GDB `file' or `symbol-file' command has the same effect as
4009 starting GDB with the '-mapped' command-line option.
4011 You can cause GDB to read the entire symbol table immediately by using
4012 the '-readnow' option with any of the commands that load symbol table
4013 information (or on the GDB command line). This makes the command
4014 slower, but makes future operations faster.
4016 The -mapped and -readnow options are typically combined in order to
4017 build a `fred.syms' file that contains complete symbol information.
4018 A simple GDB invocation to do nothing but build a `.syms' file for future
4021 gdb -batch -nx -mapped -readnow programname
4023 The `.syms' file is specific to the host machine on which GDB is run.
4024 It holds an exact image of GDB's internal symbol table. It cannot be
4025 shared across multiple host platforms.
4027 * longjmp() handling
4029 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
4030 siglongjmp() without losing control. This feature has not yet been ported to
4031 all systems. It currently works on many 386 platforms, all MIPS-based
4032 platforms (SGI, DECstation, etc), and Sun3/4.
4036 Preliminary work has been put in to support the new Solaris OS from Sun. At
4037 this time, it can control and debug processes, but it is not capable of
4042 As always, many many bug fixes. The major areas were with g++, and mipsread.
4043 People using the MIPS-based platforms should experience fewer mysterious
4044 crashes and trashed symbol tables.
4046 *** Changes in GDB-4.4:
4048 * New machines supported (host and target)
4050 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4052 BSD Reno on Vax vax-dec-bsd
4053 Ultrix on Vax vax-dec-ultrix
4055 * New machines supported (target)
4057 AMD 29000 embedded, using EBMON a29k-none-none
4061 GDB continues to improve its handling of C++. `References' work better.
4062 The demangler has also been improved, and now deals with symbols mangled as
4063 per the Annotated C++ Reference Guide.
4065 GDB also now handles `stabs' symbol information embedded in MIPS
4066 `ecoff' symbol tables. Since the ecoff format was not easily
4067 extensible to handle new languages such as C++, this appeared to be a
4068 good way to put C++ debugging info into MIPS binaries. This option
4069 will be supported in the GNU C compiler, version 2, when it is
4072 * New features for SVR4
4074 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
4075 shared libraries. Debugging dynamically linked programs should present
4076 only minor differences from debugging statically linked programs.
4078 The `info proc' command will print out information about any process
4079 on an SVR4 system (including the one you are debugging). At the moment,
4080 it prints the address mappings of the process.
4082 If you bring up GDB on another SVR4 system, please send mail to
4083 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
4085 * Better dynamic linking support in SunOS
4087 Reading symbols from shared libraries which contain debugging symbols
4088 now works properly. However, there remain issues such as automatic
4089 skipping of `transfer vector' code during function calls, which
4090 make it harder to debug code in a shared library, than to debug the
4091 same code linked statically.
4095 GDB is now using the latest `getopt' routines from the FSF. This
4096 version accepts the -- prefix for options with long names. GDB will
4097 continue to accept the old forms (-option and +option) as well.
4098 Various single letter abbreviations for options have been explicity
4099 added to the option table so that they won't get overshadowed in the
4100 future by other options that begin with the same letter.
4104 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
4105 Many assorted bugs have been handled. Many more remain to be handled.
4106 See the various ChangeLog files (primarily in gdb and bfd) for details.
4109 *** Changes in GDB-4.3:
4111 * New machines supported (host and target)
4113 Amiga 3000 running Amix m68k-cbm-svr4 or amix
4114 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
4115 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4117 * Almost SCO Unix support
4119 We had hoped to support:
4120 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4121 (except for core file support), but we discovered very late in the release
4122 that it has problems with process groups that render gdb unusable. Sorry
4123 about that. I encourage people to fix it and post the fixes.
4125 * Preliminary ELF and DWARF support
4127 GDB can read ELF object files on System V Release 4, and can handle
4128 debugging records for C, in DWARF format, in ELF files. This support
4129 is preliminary. If you bring up GDB on another SVR4 system, please
4130 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
4135 GDB now uses the latest `readline' library. One user-visible change
4136 is that two tabs will list possible command completions, which previously
4137 required typing M-? (meta-question mark, or ESC ?).
4141 The `stepi' bug that many of you noticed has been squashed.
4142 Many bugs in C++ have been handled. Many more remain to be handled.
4143 See the various ChangeLog files (primarily in gdb and bfd) for details.
4145 * State of the MIPS world (in case you wondered):
4147 GDB can understand the symbol tables emitted by the compilers
4148 supplied by most vendors of MIPS-based machines, including DEC. These
4149 symbol tables are in a format that essentially nobody else uses.
4151 Some versions of gcc come with an assembler post-processor called
4152 mips-tfile. This program is required if you want to do source-level
4153 debugging of gcc-compiled programs. I believe FSF does not ship
4154 mips-tfile with gcc version 1, but it will eventually come with gcc
4157 Debugging of g++ output remains a problem. g++ version 1.xx does not
4158 really support it at all. (If you're lucky, you should be able to get
4159 line numbers and stack traces to work, but no parameters or local
4160 variables.) With some work it should be possible to improve the
4163 When gcc version 2 is released, you will have somewhat better luck.
4164 However, even then you will get confusing results for inheritance and
4167 We will eventually provide full debugging of g++ output on
4168 DECstations. This will probably involve some kind of stabs-in-ecoff
4169 encapulation, but the details have not been worked out yet.
4172 *** Changes in GDB-4.2:
4174 * Improved configuration
4176 Only one copy of `configure' exists now, and it is not self-modifying.
4177 Porting BFD is simpler.
4181 The `step' and `next' commands now only stop at the first instruction
4182 of a source line. This prevents the multiple stops that used to occur
4183 in switch statements, for-loops, etc. `Step' continues to stop if a
4184 function that has debugging information is called within the line.
4188 Lots of small bugs fixed. More remain.
4190 * New host supported (not target)
4192 Intel 386 PC clone running Mach i386-none-mach
4195 *** Changes in GDB-4.1:
4197 * Multiple source language support
4199 GDB now has internal scaffolding to handle several source languages.
4200 It determines the type of each source file from its filename extension,
4201 and will switch expression parsing and number formatting to match the
4202 language of the function in the currently selected stack frame.
4203 You can also specifically set the language to be used, with
4204 `set language c' or `set language modula-2'.
4208 GDB now has preliminary support for the GNU Modula-2 compiler,
4209 currently under development at the State University of New York at
4210 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
4211 continue through the fall of 1991 and into 1992.
4213 Other Modula-2 compilers are currently not supported, and attempting to
4214 debug programs compiled with them will likely result in an error as the
4215 symbol table is read. Feel free to work on it, though!
4217 There are hooks in GDB for strict type checking and range checking,
4218 in the `Modula-2 philosophy', but they do not currently work.
4222 GDB can now write to executable and core files (e.g. patch
4223 a variable's value). You must turn this switch on, specify
4224 the file ("exec foo" or "core foo"), *then* modify it, e.g.
4225 by assigning a new value to a variable. Modifications take
4228 * Automatic SunOS shared library reading
4230 When you run your program, GDB automatically determines where its
4231 shared libraries (if any) have been loaded, and reads their symbols.
4232 The `share' command is no longer needed. This also works when
4233 examining core files.
4237 You can specify the number of lines that the `list' command shows.
4240 * New machines supported (host and target)
4242 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4243 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
4244 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
4246 * New hosts supported (not targets)
4248 IBM RT/PC: romp-ibm-aix or rtpc
4250 * New targets supported (not hosts)
4252 AMD 29000 embedded with COFF a29k-none-coff
4253 AMD 29000 embedded with a.out a29k-none-aout
4254 Ultracomputer remote kernel debug a29k-nyu-kern
4256 * New remote interfaces
4262 *** Changes in GDB-4.0:
4266 Wide output is wrapped at good places to make the output more readable.
4268 Gdb now supports cross-debugging from a host machine of one type to a
4269 target machine of another type. Communication with the target system
4270 is over serial lines. The ``target'' command handles connecting to the
4271 remote system; the ``load'' command will download a program into the
4272 remote system. Serial stubs for the m68k and i386 are provided. Gdb
4273 also supports debugging of realtime processes running under VxWorks,
4274 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
4275 stub on the target system.
4277 New CPUs supported include the AMD 29000 and Intel 960.
4279 GDB now reads object files and symbol tables via a ``binary file''
4280 library, which allows a single copy of GDB to debug programs of multiple
4281 object file types such as a.out and coff.
4283 There is now a GDB reference card in "doc/refcard.tex". (Make targets
4284 refcard.dvi and refcard.ps are available to format it).
4287 * Control-Variable user interface simplified
4289 All variables that control the operation of the debugger can be set
4290 by the ``set'' command, and displayed by the ``show'' command.
4292 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
4293 ``Show prompt'' produces the response:
4294 Gdb's prompt is new-gdb=>.
4296 What follows are the NEW set commands. The command ``help set'' will
4297 print a complete list of old and new set commands. ``help set FOO''
4298 will give a longer description of the variable FOO. ``show'' will show
4299 all of the variable descriptions and their current settings.
4301 confirm on/off: Enables warning questions for operations that are
4302 hard to recover from, e.g. rerunning the program while
4303 it is already running. Default is ON.
4305 editing on/off: Enables EMACS style command line editing
4306 of input. Previous lines can be recalled with
4307 control-P, the current line can be edited with control-B,
4308 you can search for commands with control-R, etc.
4311 history filename NAME: NAME is where the gdb command history
4312 will be stored. The default is .gdb_history,
4313 or the value of the environment variable
4316 history size N: The size, in commands, of the command history. The
4317 default is 256, or the value of the environment variable
4320 history save on/off: If this value is set to ON, the history file will
4321 be saved after exiting gdb. If set to OFF, the
4322 file will not be saved. The default is OFF.
4324 history expansion on/off: If this value is set to ON, then csh-like
4325 history expansion will be performed on
4326 command line input. The default is OFF.
4328 radix N: Sets the default radix for input and output. It can be set
4329 to 8, 10, or 16. Note that the argument to "radix" is interpreted
4330 in the current radix, so "set radix 10" is always a no-op.
4332 height N: This integer value is the number of lines on a page. Default
4333 is 24, the current `stty rows'' setting, or the ``li#''
4334 setting from the termcap entry matching the environment
4337 width N: This integer value is the number of characters on a line.
4338 Default is 80, the current `stty cols'' setting, or the ``co#''
4339 setting from the termcap entry matching the environment
4342 Note: ``set screensize'' is obsolete. Use ``set height'' and
4343 ``set width'' instead.
4345 print address on/off: Print memory addresses in various command displays,
4346 such as stack traces and structure values. Gdb looks
4347 more ``symbolic'' if you turn this off; it looks more
4348 ``machine level'' with it on. Default is ON.
4350 print array on/off: Prettyprint arrays. New convenient format! Default
4353 print demangle on/off: Print C++ symbols in "source" form if on,
4356 print asm-demangle on/off: Same, for assembler level printouts
4359 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
4362 * Support for Epoch Environment.
4364 The epoch environment is a version of Emacs v18 with windowing. One
4365 new command, ``inspect'', is identical to ``print'', except that if you
4366 are running in the epoch environment, the value is printed in its own
4370 * Support for Shared Libraries
4372 GDB can now debug programs and core files that use SunOS shared libraries.
4373 Symbols from a shared library cannot be referenced
4374 before the shared library has been linked with the program (this
4375 happens after you type ``run'' and before the function main() is entered).
4376 At any time after this linking (including when examining core files
4377 from dynamically linked programs), gdb reads the symbols from each
4378 shared library when you type the ``sharedlibrary'' command.
4379 It can be abbreviated ``share''.
4381 sharedlibrary REGEXP: Load shared object library symbols for files
4382 matching a unix regular expression. No argument
4383 indicates to load symbols for all shared libraries.
4385 info sharedlibrary: Status of loaded shared libraries.
4390 A watchpoint stops execution of a program whenever the value of an
4391 expression changes. Checking for this slows down execution
4392 tremendously whenever you are in the scope of the expression, but is
4393 quite useful for catching tough ``bit-spreader'' or pointer misuse
4394 problems. Some machines such as the 386 have hardware for doing this
4395 more quickly, and future versions of gdb will use this hardware.
4397 watch EXP: Set a watchpoint (breakpoint) for an expression.
4399 info watchpoints: Information about your watchpoints.
4401 delete N: Deletes watchpoint number N (same as breakpoints).
4402 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
4403 enable N: Re-enables watchpoint number N (same as breakpoints).
4406 * C++ multiple inheritance
4408 When used with a GCC version 2 compiler, GDB supports multiple inheritance
4411 * C++ exception handling
4413 Gdb now supports limited C++ exception handling. Besides the existing
4414 ability to breakpoint on an exception handler, gdb can breakpoint on
4415 the raising of an exception (before the stack is peeled back to the
4418 catch FOO: If there is a FOO exception handler in the dynamic scope,
4419 set a breakpoint to catch exceptions which may be raised there.
4420 Multiple exceptions (``catch foo bar baz'') may be caught.
4422 info catch: Lists all exceptions which may be caught in the
4423 current stack frame.
4426 * Minor command changes
4428 The command ``call func (arg, arg, ...)'' now acts like the print
4429 command, except it does not print or save a value if the function's result
4430 is void. This is similar to dbx usage.
4432 The ``up'' and ``down'' commands now always print the frame they end up
4433 at; ``up-silently'' and `down-silently'' can be used in scripts to change
4434 frames without printing.
4436 * New directory command
4438 'dir' now adds directories to the FRONT of the source search path.
4439 The path starts off empty. Source files that contain debug information
4440 about the directory in which they were compiled can be found even
4441 with an empty path; Sun CC and GCC include this information. If GDB can't
4442 find your source file in the current directory, type "dir .".
4444 * Configuring GDB for compilation
4446 For normal use, type ``./configure host''. See README or gdb.texinfo
4449 GDB now handles cross debugging. If you are remotely debugging between
4450 two different machines, type ``./configure host -target=targ''.
4451 Host is the machine where GDB will run; targ is the machine
4452 where the program that you are debugging will run.