1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.3
6 * The new option --once causes GDBserver to stop listening for connections once
7 the first connection is made. The listening port used by GDBserver will
8 become available after that.
10 *** Changes in GDB 7.3
12 * GDB has a new command: "thread find [REGEXP]".
13 It finds the thread id whose name, target id, or thread extra info
14 matches the given regular expression.
16 * The "catch syscall" command now works on mips*-linux* targets.
18 * The -data-disassemble MI command now supports modes 2 and 3 for
19 dumping the instruction opcodes.
21 * New command line options
23 -data-directory DIR Specify DIR as the "data-directory".
24 This is mostly for testing purposes.
26 * The "maint set python auto-load on|off" command has been renamed to
27 "set auto-load-scripts on|off".
29 * GDB has a new command: "set directories".
30 It is like the "dir" command except that it replaces the
31 source path list instead of augmenting it.
33 * GDB now understands thread names.
35 On GNU/Linux, "info threads" will display the thread name as set by
36 prctl or pthread_setname_np.
38 There is also a new command, "thread name", which can be used to
39 assign a name internally for GDB to display.
42 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
43 has been integrated into GDB.
47 ** The function gdb.Write now accepts an optional keyword 'stream'.
48 This keyword, when provided, will direct the output to either
49 stdout, stderr, or GDB's logging output.
51 ** Parameters can now be be sub-classed in Python, and in particular
52 you may implement the get_set_doc and get_show_doc functions.
53 This improves how Parameter set/show documentation is processed
54 and allows for more dynamic content.
56 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
57 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
58 have an is_valid method.
60 ** Breakpoints can now be sub-classed in Python, and in particular
61 you may implement a 'stop' function that is executed each time
62 the inferior reaches that breakpoint.
64 ** New function gdb.lookup_global_symbol looks up a global symbol.
66 ** GDB values in Python are now callable if the value represents a
67 function. For example, if 'some_value' represents a function that
68 takes two integer parameters and returns a value, you can call
69 that function like so:
71 result = some_value (10,20)
73 ** Module gdb.types has been added.
74 It contains a collection of utilities for working with gdb.Types objects:
75 get_basic_type, has_field, make_enum_dict.
77 ** Module gdb.printing has been added.
78 It contains utilities for writing and registering pretty-printers.
79 New classes: PrettyPrinter, SubPrettyPrinter,
80 RegexpCollectionPrettyPrinter.
81 New function: register_pretty_printer.
83 ** New commands "info pretty-printers", "enable pretty-printer" and
84 "disable pretty-printer" have been added.
86 ** gdb.parameter("directories") is now available.
88 ** New function gdb.newest_frame returns the newest frame in the
91 ** The gdb.InferiorThread class has a new "name" attribute. This
92 holds the thread's name.
94 ** Python Support for Inferior events.
95 Python scripts can add observers to be notified of events
96 occurring in the process being debugged.
97 The following events are currently supported:
98 - gdb.events.cont Continue event.
99 - gdb.events.exited Inferior exited event.
100 - gdb.events.stop Signal received, and Breakpoint hit events.
104 ** GDB now puts template parameters in scope when debugging in an
105 instantiation. For example, if you have:
107 template<int X> int func (void) { return X; }
109 then if you step into func<5>, "print X" will show "5". This
110 feature requires proper debuginfo support from the compiler; it
111 was added to GCC 4.5.
113 ** The motion commands "next", "finish", "until", and "advance" now
114 work better when exceptions are thrown. In particular, GDB will
115 no longer lose control of the inferior; instead, the GDB will
116 stop the inferior at the point at which the exception is caught.
117 This functionality requires a change in the exception handling
118 code that was introduced in GCC 4.5.
120 * GDB now follows GCC's rules on accessing volatile objects when
121 reading or writing target state during expression evaluation.
122 One notable difference to prior behavior is that "print x = 0"
123 no longer generates a read of x; the value of the assignment is
124 now always taken directly from the value being assigned.
126 * GDB now has some support for using labels in the program's source in
127 linespecs. For instance, you can use "advance label" to continue
128 execution to a label.
130 * GDB now has support for reading and writing a new .gdb_index
131 section. This section holds a fast index of DWARF debugging
132 information and can be used to greatly speed up GDB startup and
133 operation. See the documentation for `save gdb-index' for details.
135 * The "watch" command now accepts an optional "-location" argument.
136 When used, this causes GDB to watch the memory referred to by the
137 expression. Such a watchpoint is never deleted due to it going out
140 * GDB now supports thread debugging of core dumps on GNU/Linux.
142 GDB now activates thread debugging using the libthread_db library
143 when debugging GNU/Linux core dumps, similarly to when debugging
144 live processes. As a result, when debugging a core dump file, GDB
145 is now able to display pthread_t ids of threads. For example, "info
146 threads" shows the same output as when debugging the process when it
147 was live. In earlier releases, you'd see something like this:
150 * 1 LWP 6780 main () at main.c:10
152 While now you see this:
155 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
157 It is also now possible to inspect TLS variables when debugging core
160 When debugging a core dump generated on a machine other than the one
161 used to run GDB, you may need to point GDB at the correct
162 libthread_db library with the "set libthread-db-search-path"
163 command. See the user manual for more details on this command.
165 * When natively debugging programs on PowerPC BookE processors running
166 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
167 which stop execution of the inferior whenever it executes an instruction
168 at any address within the specified range. See the "PowerPC Embedded"
169 section in the user manual for more details.
171 * New features in the GDB remote stub, GDBserver
173 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
174 and i686 LynxOS (version 5.x).
176 ** GDBserver is now supported on Blackfin Linux.
178 * New native configurations
180 ia64 HP-UX ia64-*-hpux*
184 Analog Devices, Inc. Blackfin Processor bfin-*
186 * Ada task switching is now supported on sparc-elf targets when
187 debugging a program using the Ravenscar Profile. For more information,
188 see the "Tasking Support when using the Ravenscar Profile" section
189 in the GDB user manual.
191 * Guile support was removed.
193 * New features in the GNU simulator
195 ** The --map-info flag lists all known core mappings.
197 ** CFI flashes may be simulated via the "cfi" device.
199 *** Changes in GDB 7.2
201 * Shared library support for remote targets by default
203 When GDB is configured for a generic, non-OS specific target, like
204 for example, --target=arm-eabi or one of the many *-*-elf targets,
205 GDB now queries remote stubs for loaded shared libraries using the
206 `qXfer:libraries:read' packet. Previously, shared library support
207 was always disabled for such configurations.
211 ** Argument Dependent Lookup (ADL)
213 In C++ ADL lookup directs function search to the namespaces of its
214 arguments even if the namespace has not been imported.
224 Here the compiler will search for `foo' in the namespace of 'b'
225 and find A::foo. GDB now supports this. This construct is commonly
226 used in the Standard Template Library for operators.
228 ** Improved User Defined Operator Support
230 In addition to member operators, GDB now supports lookup of operators
231 defined in a namespace and imported with a `using' directive, operators
232 defined in the global scope, operators imported implicitly from an
233 anonymous namespace, and the ADL operators mentioned in the previous
235 GDB now also supports proper overload resolution for all the previously
236 mentioned flavors of operators.
238 ** static const class members
240 Printing of static const class members that are initialized in the
241 class definition has been fixed.
243 * Windows Thread Information Block access.
245 On Windows targets, GDB now supports displaying the Windows Thread
246 Information Block (TIB) structure. This structure is visible either
247 by using the new command `info w32 thread-information-block' or, by
248 dereferencing the new convenience variable named `$_tlb', a
249 thread-specific pointer to the TIB. This feature is also supported
250 when remote debugging using GDBserver.
254 Static tracepoints are calls in the user program into a tracing
255 library. One such library is a port of the LTTng kernel tracer to
256 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
257 When debugging with GDBserver, GDB now supports combining the GDB
258 tracepoint machinery with such libraries. For example: the user can
259 use GDB to probe a static tracepoint marker (a call from the user
260 program into the tracing library) with the new "strace" command (see
261 "New commands" below). This creates a "static tracepoint" in the
262 breakpoint list, that can be manipulated with the same feature set
263 as fast and regular tracepoints. E.g., collect registers, local and
264 global variables, collect trace state variables, and define
265 tracepoint conditions. In addition, the user can collect extra
266 static tracepoint marker specific data, by collecting the new
267 $_sdata internal variable. When analyzing the trace buffer, you can
268 inspect $_sdata like any other variable available to GDB. For more
269 information, see the "Tracepoints" chapter in GDB user manual. New
270 remote packets have been defined to support static tracepoints, see
271 the "New remote packets" section below.
273 * Better reconstruction of tracepoints after disconnected tracing
275 GDB will attempt to download the original source form of tracepoint
276 definitions when starting a trace run, and then will upload these
277 upon reconnection to the target, resulting in a more accurate
278 reconstruction of the tracepoints that are in use on the target.
282 You can now exercise direct control over the ways that GDB can
283 affect your program. For instance, you can disallow the setting of
284 breakpoints, so that the program can run continuously (assuming
285 non-stop mode). In addition, the "observer" variable is available
286 to switch all of the different controls; in observer mode, GDB
287 cannot affect the target's behavior at all, which is useful for
288 tasks like diagnosing live systems in the field.
290 * The new convenience variable $_thread holds the number of the
297 Return the address of the Windows Thread Information Block of a given thread.
301 In response to several of the tracepoint packets, the target may now
302 also respond with a number of intermediate `qRelocInsn' request
303 packets before the final result packet, to have GDB handle
304 relocating an instruction to execute at a different address. This
305 is particularly useful for stubs that support fast tracepoints. GDB
306 reports support for this feature in the qSupported packet.
310 List static tracepoint markers in the target program.
314 List static tracepoint markers at a given address in the target
317 qXfer:statictrace:read
319 Read the static trace data collected (by a `collect $_sdata'
320 tracepoint action). The remote stub reports support for this packet
321 to gdb's qSupported query.
325 Send the current settings of GDB's permission flags.
329 Send part of the source (textual) form of a tracepoint definition,
330 which includes location, conditional, and action list.
332 * The source command now accepts a -s option to force searching for the
333 script in the source search path even if the script name specifies
336 * New features in the GDB remote stub, GDBserver
338 - GDBserver now support tracepoints (including fast tracepoints, and
339 static tracepoints). The feature is currently supported by the
340 i386-linux and amd64-linux builds. See the "Tracepoints support
341 in gdbserver" section in the manual for more information.
343 GDBserver JIT compiles the tracepoint's conditional agent
344 expression bytecode into native code whenever possible for low
345 overhead dynamic tracepoints conditionals. For such tracepoints,
346 an expression that examines program state is evaluated when the
347 tracepoint is reached, in order to determine whether to capture
348 trace data. If the condition is simple and false, processing the
349 tracepoint finishes very quickly and no data is gathered.
351 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
352 for static tracepoints support.
354 - GDBserver now supports x86_64 Windows 64-bit debugging.
356 * GDB now sends xmlRegisters= in qSupported packet to indicate that
357 it understands register description.
359 * The --batch flag now disables pagination and queries.
361 * X86 general purpose registers
363 GDB now supports reading/writing byte, word and double-word x86
364 general purpose registers directly. This means you can use, say,
365 $ah or $ax to refer, respectively, to the byte register AH and
366 16-bit word register AX that are actually portions of the 32-bit
367 register EAX or 64-bit register RAX.
369 * The `commands' command now accepts a range of breakpoints to modify.
370 A plain `commands' following a command that creates multiple
371 breakpoints affects all the breakpoints set by that command. This
372 applies to breakpoints set by `rbreak', and also applies when a
373 single `break' command creates multiple breakpoints (e.g.,
374 breakpoints on overloaded c++ functions).
376 * The `rbreak' command now accepts a filename specification as part of
377 its argument, limiting the functions selected by the regex to those
378 in the specified file.
380 * Support for remote debugging Windows and SymbianOS shared libraries
381 from Unix hosts has been improved. Non Windows GDB builds now can
382 understand target reported file names that follow MS-DOS based file
383 system semantics, such as file names that include drive letters and
384 use the backslash character as directory separator. This makes it
385 possible to transparently use the "set sysroot" and "set
386 solib-search-path" on Unix hosts to point as host copies of the
387 target's shared libraries. See the new command "set
388 target-file-system-kind" described below, and the "Commands to
389 specify files" section in the user manual for more information.
393 eval template, expressions...
394 Convert the values of one or more expressions under the control
395 of the string template to a command line, and call it.
397 set target-file-system-kind unix|dos-based|auto
398 show target-file-system-kind
399 Set or show the assumed file system kind for target reported file
402 save breakpoints <filename>
403 Save all current breakpoint definitions to a file suitable for use
404 in a later debugging session. To read the saved breakpoint
405 definitions, use the `source' command.
407 `save tracepoints' is a new alias for `save-tracepoints'. The latter
410 info static-tracepoint-markers
411 Display information about static tracepoint markers in the target.
413 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
414 Define a static tracepoint by probing a marker at the given
415 function, line, address, or marker ID.
419 Enable and disable observer mode.
421 set may-write-registers on|off
422 set may-write-memory on|off
423 set may-insert-breakpoints on|off
424 set may-insert-tracepoints on|off
425 set may-insert-fast-tracepoints on|off
426 set may-interrupt on|off
427 Set individual permissions for GDB effects on the target. Note that
428 some of these settings can have undesirable or surprising
429 consequences, particularly when changed in the middle of a session.
430 For instance, disabling the writing of memory can prevent
431 breakpoints from being inserted, cause single-stepping to fail, or
432 even crash your program, if you disable after breakpoints have been
433 inserted. However, GDB should not crash.
435 set record memory-query on|off
436 show record memory-query
437 Control whether to stop the inferior if memory changes caused
438 by an instruction cannot be recorded.
443 The disassemble command now supports "start,+length" form of two arguments.
447 ** GDB now provides a new directory location, called the python directory,
448 where Python scripts written for GDB can be installed. The location
449 of that directory is <data-directory>/python, where <data-directory>
450 is the GDB data directory. For more details, see section `Scripting
451 GDB using Python' in the manual.
453 ** The GDB Python API now has access to breakpoints, symbols, symbol
454 tables, program spaces, inferiors, threads and frame's code blocks.
455 Additionally, GDB Parameters can now be created from the API, and
456 manipulated via set/show in the CLI.
458 ** New functions gdb.target_charset, gdb.target_wide_charset,
459 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
461 ** New exception gdb.GdbError.
463 ** Pretty-printers are now also looked up in the current program space.
465 ** Pretty-printers can now be individually enabled and disabled.
467 ** GDB now looks for names of Python scripts to auto-load in a
468 special section named `.debug_gdb_scripts', in addition to looking
469 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
471 * Tracepoint actions were unified with breakpoint commands. In particular,
472 there are no longer differences in "info break" output for breakpoints and
473 tracepoints and the "commands" command can be used for both tracepoints and
478 ARM Symbian arm*-*-symbianelf*
480 * D language support.
481 GDB now supports debugging programs written in the D programming
484 * GDB now supports the extended ptrace interface for PowerPC which is
485 available since Linux kernel version 2.6.34. This automatically enables
486 any hardware breakpoints and additional hardware watchpoints available in
487 the processor. The old ptrace interface exposes just one hardware
488 watchpoint and no hardware breakpoints.
490 * GDB is now able to use the Data Value Compare (DVC) register available on
491 embedded PowerPC processors to implement in hardware simple watchpoint
492 conditions of the form:
494 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
496 This works in native GDB running on Linux kernels with the extended ptrace
497 interface mentioned above.
499 *** Changes in GDB 7.1
505 GDB now supports importing of namespaces in C++. This enables the
506 user to inspect variables from imported namespaces. Support for
507 namepace aliasing has also been added. So, if a namespace is
508 aliased in the current scope (e.g. namepace C=A; ) the user can
509 print variables using the alias (e.g. (gdb) print C::x).
513 All known bugs relating to the printing of virtual base class were
514 fixed. It is now possible to call overloaded static methods using a
519 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
520 and reinterpret_cast<> are now handled by the C++ expression parser.
524 Xilinx MicroBlaze microblaze-*-*
529 Xilinx MicroBlaze microblaze
532 * Multi-program debugging.
534 GDB now has support for multi-program (a.k.a. multi-executable or
535 multi-exec) debugging. This allows for debugging multiple inferiors
536 simultaneously each running a different program under the same GDB
537 session. See "Debugging Multiple Inferiors and Programs" in the
538 manual for more information. This implied some user visible changes
539 in the multi-inferior support. For example, "info inferiors" now
540 lists inferiors that are not running yet or that have exited
541 already. See also "New commands" and "New options" below.
543 * New tracing features
545 GDB's tracepoint facility now includes several new features:
547 ** Trace state variables
549 GDB tracepoints now include support for trace state variables, which
550 are variables managed by the target agent during a tracing
551 experiment. They are useful for tracepoints that trigger each
552 other, so for instance one tracepoint can count hits in a variable,
553 and then a second tracepoint has a condition that is true when the
554 count reaches a particular value. Trace state variables share the
555 $-syntax of GDB convenience variables, and can appear in both
556 tracepoint actions and condition expressions. Use the "tvariable"
557 command to create, and "info tvariables" to view; see "Trace State
558 Variables" in the manual for more detail.
562 GDB now includes an option for defining fast tracepoints, which
563 targets may implement more efficiently, such as by installing a jump
564 into the target agent rather than a trap instruction. The resulting
565 speedup can be by two orders of magnitude or more, although the
566 tradeoff is that some program locations on some target architectures
567 might not allow fast tracepoint installation, for instance if the
568 instruction to be replaced is shorter than the jump. To request a
569 fast tracepoint, use the "ftrace" command, with syntax identical to
570 the regular trace command.
572 ** Disconnected tracing
574 It is now possible to detach GDB from the target while it is running
575 a trace experiment, then reconnect later to see how the experiment
576 is going. In addition, a new variable disconnected-tracing lets you
577 tell the target agent whether to continue running a trace if the
578 connection is lost unexpectedly.
582 GDB now has the ability to save the trace buffer into a file, and
583 then use that file as a target, similarly to you can do with
584 corefiles. You can select trace frames, print data that was
585 collected in them, and use tstatus to display the state of the
586 tracing run at the moment that it was saved. To create a trace
587 file, use "tsave <filename>", and to use it, do "target tfile
590 ** Circular trace buffer
592 You can ask the target agent to handle the trace buffer as a
593 circular buffer, discarding the oldest trace frames to make room for
594 newer ones, by setting circular-trace-buffer to on. This feature may
595 not be available for all target agents.
600 The disassemble command, when invoked with two arguments, now requires
601 the arguments to be comma-separated.
604 The info variables command now displays variable definitions. Files
605 which only declare a variable are not shown.
608 The source command is now capable of sourcing Python scripts.
609 This feature is dependent on the debugger being build with Python
612 Related to this enhancement is also the introduction of a new command
613 "set script-extension" (see below).
615 * New commands (for set/show, see "New options" below)
617 record save [<FILENAME>]
618 Save a file (in core file format) containing the process record
619 execution log for replay debugging at a later time.
621 record restore <FILENAME>
622 Restore the process record execution log that was saved at an
623 earlier time, for replay debugging.
625 add-inferior [-copies <N>] [-exec <FILENAME>]
628 clone-inferior [-copies <N>] [ID]
629 Make a new inferior ready to execute the same program another
635 maint info program-spaces
636 List the program spaces loaded into GDB.
638 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
639 show remote interrupt-sequence
640 Allow the user to select one of ^C, a BREAK signal or BREAK-g
641 as the sequence to the remote target in order to interrupt the execution.
642 Ctrl-C is a default. Some system prefers BREAK which is high level of
643 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
644 Magic SysRq g. It is BREAK signal and character 'g'.
646 set remote interrupt-on-connect [on | off]
647 show remote interrupt-on-connect
648 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
649 remote target when gdb connects to it. This is needed when you debug
652 set remotebreak [on | off]
654 Deprecated. Use "set/show remote interrupt-sequence" instead.
656 tvariable $NAME [ = EXP ]
657 Create or modify a trace state variable.
660 List trace state variables and their values.
662 delete tvariable $NAME ...
663 Delete one or more trace state variables.
666 Evaluate the given expressions without collecting anything into the
667 trace buffer. (Valid in tracepoint actions only.)
669 ftrace FN / FILE:LINE / *ADDR
670 Define a fast tracepoint at the given function, line, or address.
672 * New expression syntax
674 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
675 GDB now parses 0b101010 identically with 42.
679 set follow-exec-mode new|same
680 show follow-exec-mode
681 Control whether GDB reuses the same inferior across an exec call or
682 creates a new one. This is useful to be able to restart the old
683 executable after the inferior having done an exec call.
685 set default-collect EXPR, ...
687 Define a list of expressions to be collected at each tracepoint.
688 This is a useful way to ensure essential items are not overlooked,
689 such as registers or a critical global variable.
691 set disconnected-tracing
692 show disconnected-tracing
693 If set to 1, the target is instructed to continue tracing if it
694 loses its connection to GDB. If 0, the target is to stop tracing
697 set circular-trace-buffer
698 show circular-trace-buffer
699 If set to on, the target is instructed to use a circular trace buffer
700 and discard the oldest trace frames instead of stopping the trace due
701 to a full trace buffer. If set to off, the trace stops when the buffer
702 fills up. Some targets may not support this.
704 set script-extension off|soft|strict
705 show script-extension
706 If set to "off", the debugger does not perform any script language
707 recognition, and all sourced files are assumed to be GDB scripts.
708 If set to "soft" (the default), files are sourced according to
709 filename extension, falling back to GDB scripts if the first
711 If set to "strict", files are sourced according to filename extension.
713 set ada trust-PAD-over-XVS on|off
714 show ada trust-PAD-over-XVS
715 If off, activate a workaround against a bug in the debugging information
716 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
717 the GCC sources for more information about the GNAT encoding and
718 PAD types in particular). It is always safe to set this option to
719 off, but this introduces a slight performance penalty. The default
722 * Python API Improvements
724 ** GDB provides the new class gdb.LazyString. This is useful in
725 some pretty-printing cases. The new method gdb.Value.lazy_string
726 provides a simple way to create objects of this type.
728 ** The fields returned by gdb.Type.fields now have an
729 `is_base_class' attribute.
731 ** The new method gdb.Type.range returns the range of an array type.
733 ** The new method gdb.parse_and_eval can be used to parse and
734 evaluate an expression.
739 Define a trace state variable.
742 Get the current value of a trace state variable.
745 Set desired tracing behavior upon disconnection.
748 Set the trace buffer to be linear or circular.
751 Get data about the tracepoints currently in use.
755 Process record now works correctly with hardware watchpoints.
757 Multiple bug fixes have been made to the mips-irix port, making it
758 much more reliable. In particular:
759 - Debugging threaded applications is now possible again. Previously,
760 GDB would hang while starting the program, or while waiting for
761 the program to stop at a breakpoint.
762 - Attaching to a running process no longer hangs.
763 - An error occurring while loading a core file has been fixed.
764 - Changing the value of the PC register now works again. This fixes
765 problems observed when using the "jump" command, or when calling
766 a function from GDB, or even when assigning a new value to $pc.
767 - With the "finish" and "return" commands, the return value for functions
768 returning a small array is now correctly printed.
769 - It is now possible to break on shared library code which gets executed
770 during a shared library init phase (code executed while executing
771 their .init section). Previously, the breakpoint would have no effect.
772 - GDB is now able to backtrace through the signal handler for
773 non-threaded programs.
775 PIE (Position Independent Executable) programs debugging is now supported.
776 This includes debugging execution of PIC (Position Independent Code) shared
777 libraries although for that, it should be possible to run such libraries as an
780 *** Changes in GDB 7.0
782 * GDB now has an interface for JIT compilation. Applications that
783 dynamically generate code can create symbol files in memory and register
784 them with GDB. For users, the feature should work transparently, and
785 for JIT developers, the interface is documented in the GDB manual in the
786 "JIT Compilation Interface" chapter.
788 * Tracepoints may now be conditional. The syntax is as for
789 breakpoints; either an "if" clause appended to the "trace" command,
790 or the "condition" command is available. GDB sends the condition to
791 the target for evaluation using the same bytecode format as is used
792 for tracepoint actions.
794 * The disassemble command now supports: an optional /r modifier, print the
795 raw instructions in hex as well as in symbolic form, and an optional /m
796 modifier to print mixed source+assembly.
798 * Process record and replay
800 In a architecture environment that supports ``process record and
801 replay'', ``process record and replay'' target can record a log of
802 the process execution, and replay it with both forward and reverse
805 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
806 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
807 set execution-direction {forward|reverse}, for targets that support
810 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
811 feature is available with a native GDB running on kernel version
814 * GDB now has support for multi-byte and wide character sets on the
815 target. Strings whose character type is wchar_t, char16_t, or
816 char32_t are now correctly printed. GDB supports wide- and unicode-
817 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
818 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
819 `printf'. This feature requires iconv to work properly; if your
820 system does not have a working iconv, GDB can use GNU libiconv. See
821 the installation instructions for more information.
823 * GDB now supports automatic retrieval of shared library files from
824 remote targets. To use this feature, specify a system root that begins
825 with the `remote:' prefix, either via the `set sysroot' command or via
826 the `--with-sysroot' configure-time option.
828 * "info sharedlibrary" now takes an optional regex of libraries to show,
829 and it now reports if a shared library has no debugging information.
831 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
832 now complete on file names.
834 * When completing in expressions, gdb will attempt to limit
835 completions to allowable structure or union fields, where appropriate.
836 For instance, consider:
838 # struct example { int f1; double f2; };
839 # struct example variable;
842 If the user types TAB at the end of this command line, the available
843 completions will be "f1" and "f2".
845 * Inlined functions are now supported. They show up in backtraces, and
846 the "step", "next", and "finish" commands handle them automatically.
848 * GDB now supports the token-splicing (##) and stringification (#)
849 operators when expanding macros. It also supports variable-arity
852 * GDB now supports inspecting extra signal information, exported by
853 the new $_siginfo convenience variable. The feature is currently
854 implemented on linux ARM, i386 and amd64.
856 * GDB can now display the VFP floating point registers and NEON vector
857 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
858 can provide these registers (requires Linux 2.6.30 or later). Remote
859 and simulator targets may also provide them.
864 Search memory for a sequence of bytes.
867 Turn off `+'/`-' protocol acknowledgments to permit more efficient
868 operation over reliable transport links. Use of this packet is
869 controlled by the `set remote noack-packet' command.
872 Kill the process with the specified process ID. Use this in preference
873 to `k' when multiprocess protocol extensions are supported.
876 Obtains additional operating system information
880 Read or write additional signal information.
882 * Removed remote protocol undocumented extension
884 An undocumented extension to the remote protocol's `S' stop reply
885 packet that permited the stub to pass a process id was removed.
886 Remote servers should use the `T' stop reply packet instead.
888 * GDB now supports multiple function calling conventions according to the
889 DWARF-2 DW_AT_calling_convention function attribute.
891 * The SH target utilizes the aforementioned change to distinguish between gcc
892 and Renesas calling convention. It also adds the new CLI commands
893 `set/show sh calling-convention'.
895 * GDB can now read compressed debug sections, as produced by GNU gold
896 with the --compress-debug-sections=zlib flag.
898 * 64-bit core files are now supported on AIX.
900 * Thread switching is now supported on Tru64.
902 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
903 which will be allocated using malloc later in program execution.
905 * The qXfer:libraries:read remote procotol packet now allows passing a
906 list of section offsets.
908 * On GNU/Linux, GDB can now attach to stopped processes. Several race
909 conditions handling signals delivered during attach or thread creation
910 have also been fixed.
912 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
913 From the user's standpoint, all unqualified instances of True and False
914 are treated as the standard definitions, regardless of context.
916 * GDB now parses C++ symbol and type names more flexibly. For
919 template<typename T> class C { };
922 GDB will now correctly handle all of:
924 ptype C<char const *>
926 ptype C<const char *>
929 * New features in the GDB remote stub, gdbserver
931 - The "--wrapper" command-line argument tells gdbserver to use a
932 wrapper program to launch programs for debugging.
934 - On PowerPC and S/390 targets, it is now possible to use a single
935 gdbserver executable to debug both 32-bit and 64-bit programs.
936 (This requires gdbserver itself to be built as a 64-bit executable.)
938 - gdbserver uses the new noack protocol mode for TCP connections to
939 reduce communications latency, if also supported and enabled in GDB.
941 - Support for the sparc64-linux-gnu target is now included in
944 - The amd64-linux build of gdbserver now supports debugging both
945 32-bit and 64-bit programs.
947 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
948 now support hardware watchpoints, and will use them automatically
953 GDB now has support for scripting using Python. Whether this is
954 available is determined at configure time.
956 New GDB commands can now be written in Python.
958 * Ada tasking support
960 Ada tasks can now be inspected in GDB. The following commands have
964 Print the list of Ada tasks.
966 Print detailed information about task number N.
968 Print the task number of the current task.
970 Switch the context of debugging to task number N.
972 * Support for user-defined prefixed commands. The "define" command can
973 add new commands to existing prefixes, e.g. "target".
975 * Multi-inferior, multi-process debugging.
977 GDB now has generalized support for multi-inferior debugging. See
978 "Debugging Multiple Inferiors" in the manual for more information.
979 Although availability still depends on target support, the command
980 set is more uniform now. The GNU/Linux specific multi-forks support
981 has been migrated to this new framework. This implied some user
982 visible changes; see "New commands" and also "Removed commands"
985 * Target descriptions can now describe the target OS ABI. See the
986 "Target Description Format" section in the user manual for more
989 * Target descriptions can now describe "compatible" architectures
990 to indicate that the target can execute applications for a different
991 architecture in addition to those for the main target architecture.
992 See the "Target Description Format" section in the user manual for
995 * Multi-architecture debugging.
997 GDB now includes general supports for debugging applications on
998 hybrid systems that use more than one single processor architecture
999 at the same time. Each such hybrid architecture still requires
1000 specific support to be added. The only hybrid architecture supported
1001 in this version of GDB is the Cell Broadband Engine.
1003 * GDB now supports integrated debugging of Cell/B.E. applications that
1004 use both the PPU and SPU architectures. To enable support for hybrid
1005 Cell/B.E. debugging, you need to configure GDB to support both the
1006 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
1007 --enable-targets configure option.
1009 * Non-stop mode debugging.
1011 For some targets, GDB now supports an optional mode of operation in
1012 which you can examine stopped threads while other threads continue
1013 to execute freely. This is referred to as non-stop mode, with the
1014 old mode referred to as all-stop mode. See the "Non-Stop Mode"
1015 section in the user manual for more information.
1017 To be able to support remote non-stop debugging, a remote stub needs
1018 to implement the non-stop mode remote protocol extensions, as
1019 described in the "Remote Non-Stop" section of the user manual. The
1020 GDB remote stub, gdbserver, has been adjusted to support these
1021 extensions on linux targets.
1023 * New commands (for set/show, see "New options" below)
1025 catch syscall [NAME(S) | NUMBER(S)]
1026 Catch system calls. Arguments, which should be names of system
1027 calls or their numbers, mean catch only those syscalls. Without
1028 arguments, every syscall will be caught. When the inferior issues
1029 any of the specified syscalls, GDB will stop and announce the system
1030 call, both when it is called and when its call returns. This
1031 feature is currently available with a native GDB running on the
1032 Linux Kernel, under the following architectures: x86, x86_64,
1033 PowerPC and PowerPC64.
1035 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
1037 Search memory for a sequence of bytes.
1039 maint set python print-stack
1040 maint show python print-stack
1041 Show a stack trace when an error is encountered in a Python script.
1044 Invoke CODE by passing it to the Python interpreter.
1049 These allow macros to be defined, undefined, and listed
1053 Show operating system information about processes.
1056 List the inferiors currently under GDB's control.
1059 Switch focus to inferior number NUM.
1062 Detach from inferior number NUM.
1065 Kill inferior number NUM.
1069 set spu stop-on-load
1070 show spu stop-on-load
1071 Control whether to stop for new SPE threads during Cell/B.E. debugging.
1073 set spu auto-flush-cache
1074 show spu auto-flush-cache
1075 Control whether to automatically flush the software-managed cache
1076 during Cell/B.E. debugging.
1078 set sh calling-convention
1079 show sh calling-convention
1080 Control the calling convention used when calling SH target functions.
1083 show debug timestamp
1084 Control display of timestamps with GDB debugging output.
1086 set disassemble-next-line
1087 show disassemble-next-line
1088 Control display of disassembled source lines or instructions when
1091 set remote noack-packet
1092 show remote noack-packet
1093 Set/show the use of remote protocol QStartNoAckMode packet. See above
1094 under "New remote packets."
1096 set remote query-attached-packet
1097 show remote query-attached-packet
1098 Control use of remote protocol `qAttached' (query-attached) packet.
1100 set remote read-siginfo-object
1101 show remote read-siginfo-object
1102 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
1105 set remote write-siginfo-object
1106 show remote write-siginfo-object
1107 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
1110 set remote reverse-continue
1111 show remote reverse-continue
1112 Control use of remote protocol 'bc' (reverse-continue) packet.
1114 set remote reverse-step
1115 show remote reverse-step
1116 Control use of remote protocol 'bs' (reverse-step) packet.
1118 set displaced-stepping
1119 show displaced-stepping
1120 Control displaced stepping mode. Displaced stepping is a way to
1121 single-step over breakpoints without removing them from the debuggee.
1122 Also known as "out-of-line single-stepping".
1125 show debug displaced
1126 Control display of debugging info for displaced stepping.
1128 maint set internal-error
1129 maint show internal-error
1130 Control what GDB does when an internal error is detected.
1132 maint set internal-warning
1133 maint show internal-warning
1134 Control what GDB does when an internal warning is detected.
1139 Use a wrapper program to launch programs for debugging.
1141 set multiple-symbols (all|ask|cancel)
1142 show multiple-symbols
1143 The value of this variable can be changed to adjust the debugger behavior
1144 when an expression or a breakpoint location contains an ambiguous symbol
1145 name (an overloaded function name, for instance).
1147 set breakpoint always-inserted
1148 show breakpoint always-inserted
1149 Keep breakpoints always inserted in the target, as opposed to inserting
1150 them when resuming the target, and removing them when the target stops.
1151 This option can improve debugger performance on slow remote targets.
1153 set arm fallback-mode (arm|thumb|auto)
1154 show arm fallback-mode
1155 set arm force-mode (arm|thumb|auto)
1157 These commands control how ARM GDB determines whether instructions
1158 are ARM or Thumb. The default for both settings is auto, which uses
1159 the current CPSR value for instructions without symbols; previous
1160 versions of GDB behaved as if "set arm fallback-mode arm".
1162 set disable-randomization
1163 show disable-randomization
1164 Standalone programs run with the virtual address space randomization enabled
1165 by default on some platforms. This option keeps the addresses stable across
1166 multiple debugging sessions.
1170 Control whether other threads are stopped or not when some thread hits
1175 Requests that asynchronous execution is enabled in the target, if available.
1176 In this case, it's possible to resume target in the background, and interact
1177 with GDB while the target is running. "show target-async" displays the
1178 current state of asynchronous execution of the target.
1180 set target-wide-charset
1181 show target-wide-charset
1182 The target-wide-charset is the name of the character set that GDB
1183 uses when printing characters whose type is wchar_t.
1185 set tcp auto-retry (on|off)
1187 set tcp connect-timeout
1188 show tcp connect-timeout
1189 These commands allow GDB to retry failed TCP connections to a remote stub
1190 with a specified timeout period; this is useful if the stub is launched
1191 in parallel with GDB but may not be ready to accept connections immediately.
1193 set libthread-db-search-path
1194 show libthread-db-search-path
1195 Control list of directories which GDB will search for appropriate
1198 set schedule-multiple (on|off)
1199 show schedule-multiple
1200 Allow GDB to resume all threads of all processes or only threads of
1201 the current process.
1205 Use more aggressive caching for accesses to the stack. This improves
1206 performance of remote debugging (particularly backtraces) without
1207 affecting correctness.
1209 set interactive-mode (on|off|auto)
1210 show interactive-mode
1211 Control whether GDB runs in interactive mode (on) or not (off).
1212 When in interactive mode, GDB waits for the user to answer all
1213 queries. Otherwise, GDB does not wait and assumes the default
1214 answer. When set to auto (the default), GDB determines which
1215 mode to use based on the stdin settings.
1220 For program forks, this is replaced by the new more generic `info
1221 inferiors' command. To list checkpoints, you can still use the
1222 `info checkpoints' command, which was an alias for the `info forks'
1226 Replaced by the new `inferior' command. To switch between
1227 checkpoints, you can still use the `restart' command, which was an
1228 alias for the `fork' command.
1231 This is removed, since some targets don't have a notion of
1232 processes. To switch between processes, you can still use the
1233 `inferior' command using GDB's own inferior number.
1236 For program forks, this is replaced by the new more generic `kill
1237 inferior' command. To delete a checkpoint, you can still use the
1238 `delete checkpoint' command, which was an alias for the `delete
1242 For program forks, this is replaced by the new more generic `detach
1243 inferior' command. To detach a checkpoint, you can still use the
1244 `detach checkpoint' command, which was an alias for the `detach
1247 * New native configurations
1249 x86/x86_64 Darwin i[34567]86-*-darwin*
1251 x86_64 MinGW x86_64-*-mingw*
1255 Lattice Mico32 lm32-*
1256 x86 DICOS i[34567]86-*-dicos*
1257 x86_64 DICOS x86_64-*-dicos*
1260 * The GDB remote stub, gdbserver, now supports x86 Windows CE
1261 (mingw32ce) debugging.
1267 These commands were actually not implemented on any target.
1269 *** Changes in GDB 6.8
1271 * New native configurations
1273 NetBSD/hppa hppa*-*netbsd*
1274 Xtensa GNU/Linux xtensa*-*-linux*
1278 NetBSD/hppa hppa*-*-netbsd*
1279 Xtensa GNU/Lunux xtensa*-*-linux*
1281 * Change in command line behavior -- corefiles vs. process ids.
1283 When the '-p NUMBER' or '--pid NUMBER' options are used, and
1284 attaching to process NUMBER fails, GDB no longer attempts to open a
1285 core file named NUMBER. Attaching to a program using the -c option
1286 is no longer supported. Instead, use the '-p' or '--pid' options.
1288 * GDB can now be built as a native debugger for debugging Windows x86
1289 (mingw32) Portable Executable (PE) programs.
1291 * Pending breakpoints no longer change their number when their address
1294 * GDB now supports breakpoints with multiple locations,
1295 including breakpoints on C++ constructors, inside C++ templates,
1296 and in inlined functions.
1298 * GDB's ability to debug optimized code has been improved. GDB more
1299 accurately identifies function bodies and lexical blocks that occupy
1300 more than one contiguous range of addresses.
1302 * Target descriptions can now describe registers for PowerPC.
1304 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
1305 registers on PowerPC targets.
1307 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
1308 targets even when the libthread_db library is not available.
1310 * The GDB remote stub, gdbserver, now supports the new file transfer
1311 commands (remote put, remote get, and remote delete).
1313 * The GDB remote stub, gdbserver, now supports run and attach in
1314 extended-remote mode.
1316 * hppa*64*-*-hpux11* target broken
1317 The debugger is unable to start a program and fails with the following
1318 error: "Error trying to get information about dynamic linker".
1319 The gdb-6.7 release is also affected.
1321 * GDB now supports the --enable-targets= configure option to allow
1322 building a single GDB executable that supports multiple remote
1323 target architectures.
1325 * GDB now supports debugging C and C++ programs which use the
1326 Decimal Floating Point extension. In addition, the PowerPC target
1327 now has a set of pseudo-registers to inspect decimal float values
1328 stored in two consecutive float registers.
1330 * The -break-insert MI command can optionally create pending
1333 * Improved support for debugging Ada
1334 Many improvements to the Ada language support have been made. These
1336 - Better support for Ada2005 interface types
1337 - Improved handling of arrays and slices in general
1338 - Better support for Taft-amendment types
1339 - The '{type} ADDRESS' expression is now allowed on the left hand-side
1341 - Improved command completion in Ada
1344 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
1349 set print frame-arguments (all|scalars|none)
1350 show print frame-arguments
1351 The value of this variable can be changed to control which argument
1352 values should be printed by the debugger when displaying a frame.
1357 Transfer files to and from a remote target, and delete remote files.
1364 Transfer files to and from a remote target, and delete remote files.
1366 * New remote packets
1373 Open, close, read, write, and delete files on the remote system.
1376 Attach to an existing process on the remote system, in extended-remote
1380 Run a new process on the remote system, in extended-remote mode.
1382 *** Changes in GDB 6.7
1384 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
1385 bfd, libiberty and opcodes, as revealed by static analysis donated by
1386 Coverity, Inc. (http://scan.coverity.com).
1388 * When looking up multiply-defined global symbols, GDB will now prefer the
1389 symbol definition in the current shared library if it was built using the
1390 -Bsymbolic linker option.
1392 * When the Text User Interface (TUI) is not configured, GDB will now
1393 recognize the -tui command-line option and print a message that the TUI
1396 * The GDB remote stub, gdbserver, now has lower overhead for high
1397 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
1399 * GDB for MIPS targets now autodetects whether a remote target provides
1400 32-bit or 64-bit register values.
1402 * Support for C++ member pointers has been improved.
1404 * GDB now understands XML target descriptions, which specify the
1405 target's overall architecture. GDB can read a description from
1406 a local file or over the remote serial protocol.
1408 * Vectors of single-byte data use a new integer type which is not
1409 automatically displayed as character or string data.
1411 * The /s format now works with the print command. It displays
1412 arrays of single-byte integers and pointers to single-byte integers
1415 * Target descriptions can now describe target-specific registers,
1416 for architectures which have implemented the support (currently
1417 only ARM, M68K, and MIPS).
1419 * GDB and the GDB remote stub, gdbserver, now support the XScale
1422 * The GDB remote stub, gdbserver, has been updated to support
1423 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
1424 has been rewritten to use the standard GDB remote protocol.
1426 * GDB can now step into C++ functions which are called through thunks.
1428 * GDB for the Cell/B.E. SPU now supports overlay debugging.
1430 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
1431 layout. It also supports a TextSeg= and DataSeg= response when only
1432 segment base addresses (rather than offsets) are available.
1434 * The /i format now outputs any trailing branch delay slot instructions
1435 immediately following the last instruction within the count specified.
1437 * The GDB remote protocol "T" stop reply packet now supports a
1438 "library" response. Combined with the new "qXfer:libraries:read"
1439 packet, this response allows GDB to debug shared libraries on targets
1440 where the operating system manages the list of loaded libraries (e.g.
1441 Windows and SymbianOS).
1443 * The GDB remote stub, gdbserver, now supports dynamic link libraries
1444 (DLLs) on Windows and Windows CE targets.
1446 * GDB now supports a faster verification that a .debug file matches its binary
1447 according to its build-id signature, if the signature is present.
1453 Enable or disable hardware flow control (RTS/CTS) on the serial port
1454 when debugging using remote targets.
1456 set mem inaccessible-by-default
1457 show mem inaccessible-by-default
1458 If the target supplies a memory map, for instance via the remote
1459 protocol's "qXfer:memory-map:read" packet, setting this variable
1460 prevents GDB from accessing memory outside the memory map. This
1461 is useful for targets with memory mapped registers or which react
1462 badly to accesses of unmapped address space.
1464 set breakpoint auto-hw
1465 show breakpoint auto-hw
1466 If the target supplies a memory map, for instance via the remote
1467 protocol's "qXfer:memory-map:read" packet, setting this variable
1468 lets GDB use hardware breakpoints automatically for memory regions
1469 where it can not use software breakpoints. This covers both the
1470 "break" command and internal breakpoints used for other commands
1471 including "next" and "finish".
1474 catch exception unhandled
1475 Stop the program execution when Ada exceptions are raised.
1478 Stop the program execution when an Ada assertion failed.
1482 Set an alternate system root for target files. This is a more
1483 general version of "set solib-absolute-prefix", which is now
1484 an alias to "set sysroot".
1487 Provide extended SPU facility status information. This set of
1488 commands is available only when debugging the Cell/B.E. SPU
1491 * New native configurations
1493 OpenBSD/sh sh*-*openbsd*
1496 unset tdesc filename
1498 Use the specified local file as an XML target description, and do
1499 not query the target for its built-in description.
1503 OpenBSD/sh sh*-*-openbsd*
1504 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
1505 Toshiba Media Processor mep-elf
1507 * New remote packets
1510 Ignore the specified signals; pass them directly to the debugged program
1511 without stopping other threads or reporting them to GDB.
1513 qXfer:features:read:
1514 Read an XML target description from the target, which describes its
1519 Read or write contents of an spufs file on the target system. These
1520 packets are available only on the Cell/B.E. SPU architecture.
1522 qXfer:libraries:read:
1523 Report the loaded shared libraries. Combined with new "T" packet
1524 response, this packet allows GDB to debug shared libraries on
1525 targets where the operating system manages the list of loaded
1526 libraries (e.g. Windows and SymbianOS).
1530 Support for these obsolete configurations has been removed.
1538 i[34567]86-*-lynxos*
1539 i[34567]86-*-netware*
1540 i[34567]86-*-sco3.2v5*
1541 i[34567]86-*-sco3.2v4*
1543 i[34567]86-*-sysv4.2*
1546 i[34567]86-*-unixware2*
1547 i[34567]86-*-unixware*
1556 * Other removed features
1563 Various m68k-only ROM monitors.
1570 Various Renesas ROM monitors and debugging interfaces for SH and
1575 Support for a Macraigor serial interface to on-chip debugging.
1576 GDB does not directly support the newer parallel or USB
1581 A debug information format. The predecessor to DWARF 2 and
1582 DWARF 3, which are still supported.
1584 Support for the HP aCC compiler on HP-UX/PA-RISC
1586 SOM-encapsulated symbolic debugging information, automatic
1587 invocation of pxdb, and the aCC custom C++ ABI. This does not
1588 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
1589 with aCC can still be debugged on an assembly level.
1591 MIPS ".pdr" sections
1593 A MIPS-specific format used to describe stack frame layout
1594 in debugging information.
1598 GDB could work with an older version of Guile to debug
1599 the interpreter and Scheme programs running in it.
1601 set mips stack-arg-size
1602 set mips saved-gpreg-size
1604 Use "set mips abi" to control parameter passing for MIPS.
1606 *** Changes in GDB 6.6
1611 Cell Broadband Engine SPU spu-elf
1613 * GDB can now be configured as a cross-debugger targeting native Windows
1614 (mingw32) or Cygwin. It can communicate with a remote debugging stub
1615 running on a Windows system over TCP/IP to debug Windows programs.
1617 * The GDB remote stub, gdbserver, has been updated to support Windows and
1618 Cygwin debugging. Both single-threaded and multi-threaded programs are
1621 * The "set trust-readonly-sections" command works again. This command was
1622 broken in GDB 6.3, 6.4, and 6.5.
1624 * The "load" command now supports writing to flash memory, if the remote
1625 stub provides the required support.
1627 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
1628 longer requires symbolic debug information (e.g. DWARF-2).
1633 unset substitute-path
1634 show substitute-path
1635 Manage a list of substitution rules that GDB uses to rewrite the name
1636 of the directories where the sources are located. This can be useful
1637 for instance when the sources were moved to a different location
1638 between compilation and debugging.
1642 Print each CLI command as it is executed. Each command is prefixed with
1643 a number of `+' symbols representing the nesting depth.
1644 The source command now has a `-v' option to enable the same feature.
1648 The ARM Demon monitor support (RDP protocol, "target rdp").
1650 Kernel Object Display, an embedded debugging feature which only worked with
1651 an obsolete version of Cisco IOS.
1653 The 'set download-write-size' and 'show download-write-size' commands.
1655 * New remote packets
1658 Tell a stub about GDB client features, and request remote target features.
1659 The first feature implemented is PacketSize, which allows the target to
1660 specify the size of packets it can handle - to minimize the number of
1661 packets required and improve performance when connected to a remote
1665 Fetch an OS auxilliary vector from the remote stub. This packet is a
1666 more efficient replacement for qPart:auxv:read.
1668 qXfer:memory-map:read:
1669 Fetch a memory map from the remote stub, including information about
1670 RAM, ROM, and flash memory devices.
1675 Erase and program a flash memory device.
1677 * Removed remote packets
1680 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
1681 used it, and only gdbserver implemented it.
1683 *** Changes in GDB 6.5
1687 Renesas M32C/M16C m32c-elf
1689 Morpho Technologies ms1 ms1-elf
1693 init-if-undefined Initialize a convenience variable, but
1694 only if it doesn't already have a value.
1696 The following commands are presently only implemented for native GNU/Linux:
1698 checkpoint Save a snapshot of the program state.
1700 restart <n> Return the program state to a
1701 previously saved state.
1703 info checkpoints List currently saved checkpoints.
1705 delete-checkpoint <n> Delete a previously saved checkpoint.
1707 set|show detach-on-fork Tell gdb whether to detach from a newly
1708 forked process, or to keep debugging it.
1710 info forks List forks of the user program that
1711 are available to be debugged.
1713 fork <n> Switch to debugging one of several
1714 forks of the user program that are
1715 available to be debugged.
1717 delete-fork <n> Delete a fork from the list of forks
1718 that are available to be debugged (and
1719 kill the forked process).
1721 detach-fork <n> Delete a fork from the list of forks
1722 that are available to be debugged (and
1723 allow the process to continue).
1727 Morpho Technologies ms2 ms1-elf
1729 * Improved Windows host support
1731 GDB now builds as a cross debugger hosted on i686-mingw32, including
1732 native console support, and remote communications using either
1733 network sockets or serial ports.
1735 * Improved Modula-2 language support
1737 GDB can now print most types in the Modula-2 syntax. This includes:
1738 basic types, set types, record types, enumerated types, range types,
1739 pointer types and ARRAY types. Procedure var parameters are correctly
1740 printed and hexadecimal addresses and character constants are also
1741 written in the Modula-2 syntax. Best results can be obtained by using
1742 GNU Modula-2 together with the -gdwarf-2 command line option.
1746 The ARM rdi-share module.
1748 The Netware NLM debug server.
1750 *** Changes in GDB 6.4
1752 * New native configurations
1754 OpenBSD/arm arm*-*-openbsd*
1755 OpenBSD/mips64 mips64-*-openbsd*
1759 Morpho Technologies ms1 ms1-elf
1761 * New command line options
1763 --batch-silent As for --batch, but totally silent.
1764 --return-child-result The debugger will exist with the same value
1765 the child (debugged) program exited with.
1766 --eval-command COMMAND, -ex COMMAND
1767 Execute a single GDB CLI command. This may be
1768 specified multiple times and in conjunction
1769 with the --command (-x) option.
1771 * Deprecated commands removed
1773 The following commands, that were deprecated in 2000, have been
1777 set|show arm disassembly-flavor set|show arm disassembler
1778 othernames set arm disassembler
1779 set|show remotedebug set|show debug remote
1780 set|show archdebug set|show debug arch
1781 set|show eventdebug set|show debug event
1784 * New BSD user-level threads support
1786 It is now possible to debug programs using the user-level threads
1787 library on OpenBSD and FreeBSD. Currently supported (target)
1790 FreeBSD/amd64 x86_64-*-freebsd*
1791 FreeBSD/i386 i386-*-freebsd*
1792 OpenBSD/i386 i386-*-openbsd*
1794 Note that the new kernel threads libraries introduced in FreeBSD 5.x
1795 are not yet supported.
1797 * New support for Matsushita MN10300 w/sim added
1798 (Work in progress). mn10300-elf.
1800 * REMOVED configurations and files
1802 VxWorks and the XDR protocol *-*-vxworks
1803 Motorola MCORE mcore-*-*
1804 National Semiconductor NS32000 ns32k-*-*
1806 * New "set print array-indexes" command
1808 After turning this setting "on", GDB prints the index of each element
1809 when displaying arrays. The default is "off" to preserve the previous
1812 * VAX floating point support
1814 GDB now supports the not-quite-ieee VAX F and D floating point formats.
1816 * User-defined command support
1818 In addition to using $arg0..$arg9 for argument passing, it is now possible
1819 to use $argc to determine now many arguments have been passed. See the
1820 section on user-defined commands in the user manual for more information.
1822 *** Changes in GDB 6.3:
1824 * New command line option
1826 GDB now accepts -l followed by a number to set the timeout for remote
1829 * GDB works with GCC -feliminate-dwarf2-dups
1831 GDB now supports a more compact representation of DWARF-2 debug
1832 information using DW_FORM_ref_addr references. These are produced
1833 by GCC with the option -feliminate-dwarf2-dups and also by some
1834 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
1835 to use -feliminate-dwarf2-dups.
1837 * Internationalization
1839 When supported by the host system, GDB will be built with
1840 internationalization (libintl). The task of marking up the sources is
1841 continued, we're looking forward to our first translation.
1845 Initial support for debugging programs compiled with the GNAT
1846 implementation of the Ada programming language has been integrated
1847 into GDB. In this release, support is limited to expression evaluation.
1849 * New native configurations
1851 GNU/Linux/m32r m32r-*-linux-gnu
1855 GDB's remote protocol now includes support for the 'p' packet. This
1856 packet is used to fetch individual registers from a remote inferior.
1858 * END-OF-LIFE registers[] compatibility module
1860 GDB's internal register infrastructure has been completely rewritten.
1861 The new infrastructure making possible the implementation of key new
1862 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
1865 GDB 6.3 will be the last release to include the the registers[]
1866 compatibility module that allowed out-of-date configurations to
1867 continue to work. This change directly impacts the following
1877 powerpc bdm protocol
1879 Unless there is activity to revive these configurations, they will be
1880 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
1882 * OBSOLETE configurations and files
1884 Configurations that have been declared obsolete in this release have
1885 been commented out. Unless there is activity to revive these
1886 configurations, the next release of GDB will have their sources
1887 permanently REMOVED.
1896 *** Changes in GDB 6.2.1:
1898 * MIPS `break main; run' gave an heuristic-fence-post warning
1900 When attempting to run even a simple program, a warning about
1901 heuristic-fence-post being hit would be reported. This problem has
1904 * MIPS IRIX 'long double' crashed GDB
1906 When examining a long double variable, GDB would get a segmentation
1907 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
1908 IRIX long double values).
1912 A bug in the VAX stack code was causing problems with the "next"
1913 command. This problem has been fixed.
1915 *** Changes in GDB 6.2:
1917 * Fix for ``many threads''
1919 On GNU/Linux systems that use the NPTL threads library, a program
1920 rapidly creating and deleting threads would confuse GDB leading to the
1923 ptrace: No such process.
1924 thread_db_get_info: cannot get thread info: generic error
1926 This problem has been fixed.
1928 * "-async" and "-noasync" options removed.
1930 Support for the broken "-noasync" option has been removed (it caused
1933 * New ``start'' command.
1935 This command runs the program until the begining of the main procedure.
1937 * New BSD Kernel Data Access Library (libkvm) interface
1939 Using ``target kvm'' it is now possible to debug kernel core dumps and
1940 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
1941 platforms. Currently supported (native-only) configurations are:
1943 FreeBSD/amd64 x86_64-*-freebsd*
1944 FreeBSD/i386 i?86-*-freebsd*
1945 NetBSD/i386 i?86-*-netbsd*
1946 NetBSD/m68k m68*-*-netbsd*
1947 NetBSD/sparc sparc-*-netbsd*
1948 OpenBSD/amd64 x86_64-*-openbsd*
1949 OpenBSD/i386 i?86-*-openbsd*
1950 OpenBSD/m68k m68*-openbsd*
1951 OpenBSD/sparc sparc-*-openbsd*
1953 * Signal trampoline code overhauled
1955 Many generic problems with GDB's signal handling code have been fixed.
1956 These include: backtraces through non-contiguous stacks; recognition
1957 of sa_sigaction signal trampolines; backtrace from a NULL pointer
1958 call; backtrace through a signal trampoline; step into and out of
1959 signal handlers; and single-stepping in the signal trampoline.
1961 Please note that kernel bugs are a limiting factor here. These
1962 features have been shown to work on an s390 GNU/Linux system that
1963 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
1965 * Cygwin support for DWARF 2 added.
1967 * New native configurations
1969 GNU/Linux/hppa hppa*-*-linux*
1970 OpenBSD/hppa hppa*-*-openbsd*
1971 OpenBSD/m68k m68*-*-openbsd*
1972 OpenBSD/m88k m88*-*-openbsd*
1973 OpenBSD/powerpc powerpc-*-openbsd*
1974 NetBSD/vax vax-*-netbsd*
1975 OpenBSD/vax vax-*-openbsd*
1977 * END-OF-LIFE frame compatibility module
1979 GDB's internal frame infrastructure has been completely rewritten.
1980 The new infrastructure making it possible to support key new features
1981 including DWARF 2 Call Frame Information. To aid in the task of
1982 migrating old configurations to this new infrastructure, a
1983 compatibility module, that allowed old configurations to continue to
1984 work, was also included.
1986 GDB 6.2 will be the last release to include this frame compatibility
1987 module. This change directly impacts the following configurations:
1997 Unless there is activity to revive these configurations, they will be
1998 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
2000 * REMOVED configurations and files
2002 Sun 3, running SunOS 3 m68*-*-sunos3*
2003 Sun 3, running SunOS 4 m68*-*-sunos4*
2004 Sun 2, running SunOS 3 m68000-*-sunos3*
2005 Sun 2, running SunOS 4 m68000-*-sunos4*
2006 Motorola 680x0 running LynxOS m68*-*-lynxos*
2007 AT&T 3b1/Unix pc m68*-att-*
2008 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2009 decstation mips-dec-* mips-little-*
2010 riscos mips-*-riscos* mips-*-sysv*
2011 sonymips mips-sony-*
2012 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2014 *** Changes in GDB 6.1.1:
2016 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
2018 The TUI (Text-mode User Interface) is now built as part of a default
2019 GDB configuration. It is enabled by either selecting the TUI with the
2020 command line option "-i=tui" or by running the separate "gdbtui"
2021 program. For more information on the TUI, see the manual "Debugging
2024 * Pending breakpoint support (also included in GDB 6.1)
2026 Support has been added to allow you to specify breakpoints in shared
2027 libraries that have not yet been loaded. If a breakpoint location
2028 cannot be found, and the "breakpoint pending" option is set to auto,
2029 GDB queries you if you wish to make the breakpoint pending on a future
2030 shared-library load. If and when GDB resolves the breakpoint symbol,
2031 the pending breakpoint is removed as one or more regular breakpoints
2034 Pending breakpoints are very useful for GCJ Java debugging.
2036 * Fixed ISO-C build problems
2038 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
2039 non ISO-C code that stopped them being built using a more strict ISO-C
2040 compiler (e.g., IBM's C compiler).
2042 * Fixed build problem on IRIX 5
2044 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
2045 wasn't able to compile compile on an IRIX 5 system.
2047 * Added execute permission to gdb/gdbserver/configure
2049 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
2050 permission. This bug would cause configure to fail on a number of
2051 systems (Solaris, IRIX). Ref: server/519.
2053 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
2055 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
2056 has been updated to use constant array sizes.
2058 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
2060 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
2061 its generated DWARF Call Frame Info. This encoding was causing GDB to
2062 panic, that panic has been fixed. Ref: gdb/1628.
2064 * Fixed a problem when examining parameters in shared library code.
2066 When examining parameters in optimized shared library code generated
2067 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
2068 not available''. GDB now correctly displays the variable's value.
2070 *** Changes in GDB 6.1:
2072 * Removed --with-mmalloc
2074 Support for the mmalloc memory manager has been removed, as it
2075 conflicted with the internal gdb byte cache.
2077 * Changes in AMD64 configurations
2079 The AMD64 target now includes the %cs and %ss registers. As a result
2080 the AMD64 remote protocol has changed; this affects the floating-point
2081 and SSE registers. If you rely on those registers for your debugging,
2082 you should upgrade gdbserver on the remote side.
2084 * Revised SPARC target
2086 The SPARC target has been completely revised, incorporating the
2087 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
2088 support for LynxOS and SunOS 4 has been dropped. Calling functions
2089 from within GDB on operating systems with a non-executable stack
2090 (Solaris, OpenBSD) now works.
2094 GDB has a new C++ demangler which does a better job on the mangled
2095 names generated by current versions of g++. It also runs faster, so
2096 with this and other changes gdb should now start faster on large C++
2099 * DWARF 2 Location Expressions
2101 GDB support for location expressions has been extended to support function
2102 arguments and frame bases. Older versions of GDB could crash when they
2105 * C++ nested types and namespaces
2107 GDB's support for nested types and namespaces in C++ has been
2108 improved, especially if you use the DWARF 2 debugging format. (This
2109 is the default for recent versions of GCC on most platforms.)
2110 Specifically, if you have a class "Inner" defined within a class or
2111 namespace "Outer", then GDB realizes that the class's name is
2112 "Outer::Inner", not simply "Inner". This should greatly reduce the
2113 frequency of complaints about not finding RTTI symbols. In addition,
2114 if you are stopped at inside of a function defined within a namespace,
2115 GDB modifies its name lookup accordingly.
2117 * New native configurations
2119 NetBSD/amd64 x86_64-*-netbsd*
2120 OpenBSD/amd64 x86_64-*-openbsd*
2121 OpenBSD/alpha alpha*-*-openbsd*
2122 OpenBSD/sparc sparc-*-openbsd*
2123 OpenBSD/sparc64 sparc64-*-openbsd*
2125 * New debugging protocols
2127 M32R with SDI protocol m32r-*-elf*
2129 * "set prompt-escape-char" command deleted.
2131 The command "set prompt-escape-char" has been deleted. This command,
2132 and its very obscure effet on GDB's prompt, was never documented,
2133 tested, nor mentioned in the NEWS file.
2135 * OBSOLETE configurations and files
2137 Configurations that have been declared obsolete in this release have
2138 been commented out. Unless there is activity to revive these
2139 configurations, the next release of GDB will have their sources
2140 permanently REMOVED.
2142 Sun 3, running SunOS 3 m68*-*-sunos3*
2143 Sun 3, running SunOS 4 m68*-*-sunos4*
2144 Sun 2, running SunOS 3 m68000-*-sunos3*
2145 Sun 2, running SunOS 4 m68000-*-sunos4*
2146 Motorola 680x0 running LynxOS m68*-*-lynxos*
2147 AT&T 3b1/Unix pc m68*-att-*
2148 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2149 decstation mips-dec-* mips-little-*
2150 riscos mips-*-riscos* mips-*-sysv*
2151 sonymips mips-sony-*
2152 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2154 * REMOVED configurations and files
2156 SGI Irix-4.x mips-sgi-irix4 or iris4
2157 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
2158 Z8000 simulator z8k-zilog-none or z8ksim
2159 Matsushita MN10200 w/simulator mn10200-*-*
2160 H8/500 simulator h8500-hitachi-hms or h8500hms
2161 HP/PA running BSD hppa*-*-bsd*
2162 HP/PA running OSF/1 hppa*-*-osf*
2163 HP/PA Pro target hppa*-*-pro*
2164 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2165 386BSD i[3456]86-*-bsd*
2166 Sequent family i[3456]86-sequent-sysv4*
2167 i[3456]86-sequent-sysv*
2168 i[3456]86-sequent-bsd*
2169 SPARC running LynxOS sparc-*-lynxos*
2170 SPARC running SunOS 4 sparc-*-sunos4*
2171 Tsqware Sparclet sparclet-*-*
2172 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2174 *** Changes in GDB 6.0:
2178 Support for debugging the Objective-C programming language has been
2179 integrated into GDB.
2181 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
2183 DWARF 2's Call Frame Information makes available compiler generated
2184 information that more exactly describes the program's run-time stack.
2185 By using this information, GDB is able to provide more robust stack
2188 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
2189 have been updated to use a new backtrace mechanism which includes
2190 DWARF 2 CFI support.
2194 GDB's remote protocol has been extended to include support for hosted
2195 file I/O (where the remote target uses GDB's file system). See GDB's
2196 remote protocol documentation for details.
2198 * All targets using the new architecture framework.
2200 All of GDB's targets have been updated to use the new internal
2201 architecture framework. The way is now open for future GDB releases
2202 to include cross-architecture native debugging support (i386 on amd64,
2205 * GNU/Linux's Thread Local Storage (TLS)
2207 GDB now includes support for for the GNU/Linux implementation of
2208 per-thread variables.
2210 * GNU/Linux's Native POSIX Thread Library (NPTL)
2212 GDB's thread code has been updated to work with either the new
2213 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
2215 * Separate debug info.
2217 GDB, in conjunction with BINUTILS, now supports a mechanism for
2218 automatically loading debug information from a separate file. Instead
2219 of shipping full debug and non-debug versions of system libraries,
2220 system integrators can now instead ship just the stripped libraries
2221 and optional debug files.
2223 * DWARF 2 Location Expressions
2225 DWARF 2 Location Expressions allow the compiler to more completely
2226 describe the location of variables (even in optimized code) to the
2229 GDB now includes preliminary support for location expressions (support
2230 for DW_OP_piece is still missing).
2234 A number of long standing bugs that caused GDB to die while starting a
2235 Java application have been fixed. GDB's Java support is now
2236 considered "useable".
2238 * GNU/Linux support for fork, vfork, and exec.
2240 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
2241 commands are now implemented for GNU/Linux. They require a 2.5.x or later
2244 * GDB supports logging output to a file
2246 There are two new commands, "set logging" and "show logging", which can be
2247 used to capture GDB's output to a file.
2249 * The meaning of "detach" has changed for gdbserver
2251 The "detach" command will now resume the application, as documented. To
2252 disconnect from gdbserver and leave it stopped, use the new "disconnect"
2255 * d10v, m68hc11 `regs' command deprecated
2257 The `info registers' command has been updated so that it displays the
2258 registers using a format identical to the old `regs' command.
2262 A new command, "maint set profile on/off", has been added. This command can
2263 be used to enable or disable profiling while running GDB, to profile a
2264 session or a set of commands. In addition there is a new configure switch,
2265 "--enable-profiling", which will cause GDB to be compiled with profiling
2266 data, for more informative profiling results.
2268 * Default MI syntax changed to "mi2".
2270 The default MI (machine interface) syntax, enabled by the command line
2271 option "-i=mi", has been changed to "mi2". The previous MI syntax,
2272 "mi1", can be enabled by specifying the option "-i=mi1".
2274 Support for the original "mi0" syntax (included in GDB 5.0) has been
2277 Fix for gdb/192: removed extraneous space when displaying frame level.
2278 Fix for gdb/672: update changelist is now output in mi list format.
2279 Fix for gdb/702: a -var-assign that updates the value now shows up
2280 in a subsequent -var-update.
2282 * New native configurations.
2284 FreeBSD/amd64 x86_64-*-freebsd*
2286 * Multi-arched targets.
2288 HP/PA HPUX11 hppa*-*-hpux*
2289 Renesas M32R/D w/simulator m32r-*-elf*
2291 * OBSOLETE configurations and files
2293 Configurations that have been declared obsolete in this release have
2294 been commented out. Unless there is activity to revive these
2295 configurations, the next release of GDB will have their sources
2296 permanently REMOVED.
2298 Z8000 simulator z8k-zilog-none or z8ksim
2299 Matsushita MN10200 w/simulator mn10200-*-*
2300 H8/500 simulator h8500-hitachi-hms or h8500hms
2301 HP/PA running BSD hppa*-*-bsd*
2302 HP/PA running OSF/1 hppa*-*-osf*
2303 HP/PA Pro target hppa*-*-pro*
2304 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2305 Sequent family i[3456]86-sequent-sysv4*
2306 i[3456]86-sequent-sysv*
2307 i[3456]86-sequent-bsd*
2308 Tsqware Sparclet sparclet-*-*
2309 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2311 * REMOVED configurations and files
2314 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2315 IBM AIX PS/2 i[3456]86-*-aix
2316 i386 running Mach 3.0 i[3456]86-*-mach3*
2317 i386 running Mach i[3456]86-*-mach*
2318 i386 running OSF/1 i[3456]86-*osf1mk*
2319 HP/Apollo 68k Family m68*-apollo*-sysv*,
2321 m68*-hp-bsd*, m68*-hp-hpux*
2322 Argonaut Risc Chip (ARC) arc-*-*
2323 Mitsubishi D30V d30v-*-*
2324 Fujitsu FR30 fr30-*-elf*
2325 OS/9000 i[34]86-*-os9k
2326 I960 with MON960 i960-*-coff
2328 * MIPS $fp behavior changed
2330 The convenience variable $fp, for the MIPS, now consistently returns
2331 the address of the current frame's base. Previously, depending on the
2332 context, $fp could refer to either $sp or the current frame's base
2333 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
2334 The GNU Source-Level Debugger''.
2336 *** Changes in GDB 5.3:
2338 * GNU/Linux shared library multi-threaded performance improved.
2340 When debugging a multi-threaded application on GNU/Linux, GDB now uses
2341 `/proc', in preference to `ptrace' for memory reads. This may result
2342 in an improvement in the start-up time of multi-threaded, shared
2343 library applications when run under GDB. One GDB user writes: ``loads
2344 shared libs like mad''.
2346 * ``gdbserver'' now supports multi-threaded applications on some targets
2348 Support for debugging multi-threaded applications which use
2349 the GNU/Linux LinuxThreads package has been added for
2350 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
2351 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
2353 * GDB now supports C/C++ preprocessor macros.
2355 GDB now expands preprocessor macro invocations in C/C++ expressions,
2356 and provides various commands for showing macro definitions and how
2359 The new command `macro expand EXPRESSION' expands any macro
2360 invocations in expression, and shows the result.
2362 The new command `show macro MACRO-NAME' shows the definition of the
2363 macro named MACRO-NAME, and where it was defined.
2365 Most compilers don't include information about macros in the debugging
2366 information by default. In GCC 3.1, for example, you need to compile
2367 your program with the options `-gdwarf-2 -g3'. If the macro
2368 information is present in the executable, GDB will read it.
2370 * Multi-arched targets.
2372 DEC Alpha (partial) alpha*-*-*
2373 DEC VAX (partial) vax-*-*
2375 National Semiconductor NS32000 (partial) ns32k-*-*
2376 Motorola 68000 (partial) m68k-*-*
2377 Motorola MCORE mcore-*-*
2381 Fujitsu FRV architecture added by Red Hat frv*-*-*
2384 * New native configurations
2386 Alpha NetBSD alpha*-*-netbsd*
2387 SH NetBSD sh*-*-netbsdelf*
2388 MIPS NetBSD mips*-*-netbsd*
2389 UltraSPARC NetBSD sparc64-*-netbsd*
2391 * OBSOLETE configurations and files
2393 Configurations that have been declared obsolete in this release have
2394 been commented out. Unless there is activity to revive these
2395 configurations, the next release of GDB will have their sources
2396 permanently REMOVED.
2398 Mitsubishi D30V d30v-*-*
2399 OS/9000 i[34]86-*-os9k
2400 IBM AIX PS/2 i[3456]86-*-aix
2401 Fujitsu FR30 fr30-*-elf*
2402 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2403 Argonaut Risc Chip (ARC) arc-*-*
2404 i386 running Mach 3.0 i[3456]86-*-mach3*
2405 i386 running Mach i[3456]86-*-mach*
2406 i386 running OSF/1 i[3456]86-*osf1mk*
2407 HP/Apollo 68k Family m68*-apollo*-sysv*,
2409 m68*-hp-bsd*, m68*-hp-hpux*
2410 I960 with MON960 i960-*-coff
2412 * OBSOLETE languages
2414 CHILL, a Pascal like language used by telecommunications companies.
2416 * REMOVED configurations and files
2418 AMD 29k family via UDI a29k-amd-udi, udi29k
2419 A29K VxWorks a29k-*-vxworks
2420 AMD 29000 embedded, using EBMON a29k-none-none
2421 AMD 29000 embedded with COFF a29k-none-coff
2422 AMD 29000 embedded with a.out a29k-none-aout
2424 testsuite/gdb.hp/gdb.threads-hp/ directory
2426 * New command "set max-user-call-depth <nnn>"
2428 This command allows the user to limit the call depth of user-defined
2429 commands. The default is 1024.
2431 * Changes in FreeBSD/i386 native debugging.
2433 Support for the "generate-core-file" has been added.
2435 * New commands "dump", "append", and "restore".
2437 These commands allow data to be copied from target memory
2438 to a bfd-format or binary file (dump and append), and back
2439 from a file into memory (restore).
2441 * Improved "next/step" support on multi-processor Alpha Tru64.
2443 The previous single-step mechanism could cause unpredictable problems,
2444 including the random appearance of SIGSEGV or SIGTRAP signals. The use
2445 of a software single-step mechanism prevents this.
2447 *** Changes in GDB 5.2.1:
2455 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
2456 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
2457 Fix, by Joel Brobecker imported from mainline.
2459 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
2460 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
2461 Fix, by Fred Fish, imported from mainline.
2463 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
2464 Surprisingly enough, it works now.
2465 By Michal Ludvig, imported from mainline.
2467 i386 hardware watchpoint support:
2468 avoid misses on second run for some targets.
2469 By Pierre Muller, imported from mainline.
2471 *** Changes in GDB 5.2:
2473 * New command "set trust-readonly-sections on[off]".
2475 This command is a hint that tells gdb that read-only sections
2476 really are read-only (ie. that their contents will not change).
2477 In this mode, gdb will go to the object file rather than the
2478 target to read memory from read-only sections (such as ".text").
2479 This can be a significant performance improvement on some
2480 (notably embedded) targets.
2482 * New command "generate-core-file" (or "gcore").
2484 This new gdb command allows the user to drop a core file of the child
2485 process state at any time. So far it's been implemented only for
2486 GNU/Linux and Solaris, but should be relatively easily ported to other
2487 hosts. Argument is core file name (defaults to core.<pid>).
2489 * New command line option
2491 GDB now accepts --pid or -p followed by a process id.
2493 * Change in command line behavior -- corefiles vs. process ids.
2495 There is a subtle behavior in the way in which GDB handles
2496 command line arguments. The first non-flag argument is always
2497 a program to debug, but the second non-flag argument may either
2498 be a corefile or a process id. Previously, GDB would attempt to
2499 open the second argument as a corefile, and if that failed, would
2500 issue a superfluous error message and then attempt to attach it as
2501 a process. Now, if the second argument begins with a non-digit,
2502 it will be treated as a corefile. If it begins with a digit,
2503 GDB will attempt to attach it as a process, and if no such process
2504 is found, will then attempt to open it as a corefile.
2506 * Changes in ARM configurations.
2508 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
2509 configuration is fully multi-arch.
2511 * New native configurations
2513 ARM NetBSD arm*-*-netbsd*
2514 x86 OpenBSD i[3456]86-*-openbsd*
2515 AMD x86-64 running GNU/Linux x86_64-*-linux-*
2516 Sparc64 running FreeBSD sparc64-*-freebsd*
2520 Sanyo XStormy16 xstormy16-elf
2522 * OBSOLETE configurations and files
2524 Configurations that have been declared obsolete in this release have
2525 been commented out. Unless there is activity to revive these
2526 configurations, the next release of GDB will have their sources
2527 permanently REMOVED.
2529 AMD 29k family via UDI a29k-amd-udi, udi29k
2530 A29K VxWorks a29k-*-vxworks
2531 AMD 29000 embedded, using EBMON a29k-none-none
2532 AMD 29000 embedded with COFF a29k-none-coff
2533 AMD 29000 embedded with a.out a29k-none-aout
2535 testsuite/gdb.hp/gdb.threads-hp/ directory
2537 * REMOVED configurations and files
2539 TI TMS320C80 tic80-*-*
2541 PowerPC Solaris powerpcle-*-solaris*
2542 PowerPC Windows NT powerpcle-*-cygwin32
2543 PowerPC Netware powerpc-*-netware*
2544 Harris/CXUX m88k m88*-harris-cxux*
2545 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
2546 ns32k-utek-sysv* ns32k-utek-*
2547 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
2548 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
2549 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
2550 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
2551 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
2553 * Changes to command line processing
2555 The new `--args' feature can be used to specify command-line arguments
2556 for the inferior from gdb's command line.
2558 * Changes to key bindings
2560 There is a new `operate-and-get-next' function bound to `C-o'.
2562 *** Changes in GDB 5.1.1
2564 Fix compile problem on DJGPP.
2566 Fix a problem with floating-point registers on the i386 being
2569 Fix to stop GDB crashing on .debug_str debug info.
2571 Numerous documentation fixes.
2573 Numerous testsuite fixes.
2575 *** Changes in GDB 5.1:
2577 * New native configurations
2579 Alpha FreeBSD alpha*-*-freebsd*
2580 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
2581 MIPS GNU/Linux mips*-*-linux*
2582 MIPS SGI Irix 6.x mips*-sgi-irix6*
2583 ia64 AIX ia64-*-aix*
2584 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
2588 Motorola 68HC11 and 68HC12 m68hc11-elf
2590 UltraSparc running GNU/Linux sparc64-*-linux*
2592 * OBSOLETE configurations and files
2594 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
2595 Harris/CXUX m88k m88*-harris-cxux*
2596 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
2597 ns32k-utek-sysv* ns32k-utek-*
2598 TI TMS320C80 tic80-*-*
2600 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
2601 PowerPC Solaris powerpcle-*-solaris*
2602 PowerPC Windows NT powerpcle-*-cygwin32
2603 PowerPC Netware powerpc-*-netware*
2604 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
2605 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
2606 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
2607 Apple Macintosh (MPW) host N/A
2609 stuff.c (Program to stuff files into a specially prepared space in kdb)
2610 kdb-start.c (Main loop for the standalone kernel debugger)
2612 Configurations that have been declared obsolete in this release have
2613 been commented out. Unless there is activity to revive these
2614 configurations, the next release of GDB will have their sources
2615 permanently REMOVED.
2617 * REMOVED configurations and files
2619 Altos 3068 m68*-altos-*
2620 Convex c1-*-*, c2-*-*
2622 ARM RISCix arm-*-* (as host)
2626 * GDB has been converted to ISO C.
2628 GDB's source code has been converted to ISO C. In particular, the
2629 sources are fully protoized, and rely on standard headers being
2634 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
2636 * The MI enabled by default.
2638 The new machine oriented interface (MI) introduced in GDB 5.0 has been
2639 revised and enabled by default. Packages which use GDB as a debugging
2640 engine behind a UI or another front end are encouraged to switch to
2641 using the GDB/MI interface, instead of the old annotations interface
2642 which is now deprecated.
2644 * Support for debugging Pascal programs.
2646 GDB now includes support for debugging Pascal programs. The following
2647 main features are supported:
2649 - Pascal-specific data types such as sets;
2651 - automatic recognition of Pascal sources based on file-name
2654 - Pascal-style display of data types, variables, and functions;
2656 - a Pascal expression parser.
2658 However, some important features are not yet supported.
2660 - Pascal string operations are not supported at all;
2662 - there are some problems with boolean types;
2664 - Pascal type hexadecimal constants are not supported
2665 because they conflict with the internal variables format;
2667 - support for Pascal objects and classes is not full yet;
2669 - unlike Pascal, GDB is case-sensitive for symbol names.
2671 * Changes in completion.
2673 Commands such as `shell', `run' and `set args', which pass arguments
2674 to inferior programs, now complete on file names, similar to what
2675 users expect at the shell prompt.
2677 Commands which accept locations, such as `disassemble', `print',
2678 `breakpoint', `until', etc. now complete on filenames as well as
2679 program symbols. Thus, if you type "break foob TAB", and the source
2680 files linked into the programs include `foobar.c', that file name will
2681 be one of the candidates for completion. However, file names are not
2682 considered for completion after you typed a colon that delimits a file
2683 name from a name of a function in that file, as in "break foo.c:bar".
2685 `set demangle-style' completes on available demangling styles.
2687 * New platform-independent commands:
2689 It is now possible to define a post-hook for a command as well as a
2690 hook that runs before the command. For more details, see the
2691 documentation of `hookpost' in the GDB manual.
2693 * Changes in GNU/Linux native debugging.
2695 Support for debugging multi-threaded programs has been completely
2696 revised for all platforms except m68k and sparc. You can now debug as
2697 many threads as your system allows you to have.
2699 Attach/detach is supported for multi-threaded programs.
2701 Support for SSE registers was added for x86. This doesn't work for
2702 multi-threaded programs though.
2704 * Changes in MIPS configurations.
2706 Multi-arch support is enabled for all MIPS configurations.
2708 GDB can now be built as native debugger on SGI Irix 6.x systems for
2709 debugging n32 executables. (Debugging 64-bit executables is not yet
2712 * Unified support for hardware watchpoints in all x86 configurations.
2714 Most (if not all) native x86 configurations support hardware-assisted
2715 breakpoints and watchpoints in a unified manner. This support
2716 implements debug register sharing between watchpoints, which allows to
2717 put a virtually infinite number of watchpoints on the same address,
2718 and also supports watching regions up to 16 bytes with several debug
2721 The new maintenance command `maintenance show-debug-regs' toggles
2722 debugging print-outs in functions that insert, remove, and test
2723 watchpoints and hardware breakpoints.
2725 * Changes in the DJGPP native configuration.
2727 New command ``info dos sysinfo'' displays assorted information about
2728 the CPU, OS, memory, and DPMI server.
2730 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
2731 display information about segment descriptors stored in GDT, LDT, and
2734 New commands ``info dos pde'' and ``info dos pte'' display entries
2735 from Page Directory and Page Tables (for now works with CWSDPMI only).
2736 New command ``info dos address-pte'' displays the Page Table entry for
2737 a given linear address.
2739 GDB can now pass command lines longer than 126 characters to the
2740 program being debugged (requires an update to the libdbg.a library
2741 which is part of the DJGPP development kit).
2743 DWARF2 debug info is now supported.
2745 It is now possible to `step' and `next' through calls to `longjmp'.
2747 * Changes in documentation.
2749 All GDB documentation was converted to GFDL, the GNU Free
2750 Documentation License.
2752 Tracepoints-related commands are now fully documented in the GDB
2755 TUI, the Text-mode User Interface, is now documented in the manual.
2757 Tracepoints-related commands are now fully documented in the GDB
2760 The "GDB Internals" manual now has an index. It also includes
2761 documentation of `ui_out' functions, GDB coding standards, x86
2762 hardware watchpoints, and memory region attributes.
2764 * GDB's version number moved to ``version.in''
2766 The Makefile variable VERSION has been replaced by the file
2767 ``version.in''. People creating GDB distributions should update the
2768 contents of this file.
2772 GUD support is now a standard part of the EMACS distribution.
2774 *** Changes in GDB 5.0:
2776 * Improved support for debugging FP programs on x86 targets
2778 Unified and much-improved support for debugging floating-point
2779 programs on all x86 targets. In particular, ``info float'' now
2780 displays the FP registers in the same format on all x86 targets, with
2781 greater level of detail.
2783 * Improvements and bugfixes in hardware-assisted watchpoints
2785 It is now possible to watch array elements, struct members, and
2786 bitfields with hardware-assisted watchpoints. Data-read watchpoints
2787 on x86 targets no longer erroneously trigger when the address is
2790 * Improvements in the native DJGPP version of GDB
2792 The distribution now includes all the scripts and auxiliary files
2793 necessary to build the native DJGPP version on MS-DOS/MS-Windows
2794 machines ``out of the box''.
2796 The DJGPP version can now debug programs that use signals. It is
2797 possible to catch signals that happened in the debuggee, deliver
2798 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
2799 would kill the program being debugged.) Programs that hook hardware
2800 interrupts (keyboard, timer, etc.) can also be debugged.
2802 It is now possible to debug DJGPP programs that redirect their
2803 standard handles or switch them to raw (as opposed to cooked) mode, or
2804 even close them. The command ``run < foo > bar'' works as expected,
2805 and ``info terminal'' reports useful information about the debuggee's
2806 terminal, including raw/cooked mode, redirection, etc.
2808 The DJGPP version now uses termios functions for console I/O, which
2809 enables debugging graphics programs. Interrupting GDB with Ctrl-C
2812 DOS-style file names with drive letters are now fully supported by
2815 It is now possible to debug DJGPP programs that switch their working
2816 directory. It is also possible to rerun the debuggee any number of
2817 times without restarting GDB; thus, you can use the same setup,
2818 breakpoints, etc. for many debugging sessions.
2820 * New native configurations
2822 ARM GNU/Linux arm*-*-linux*
2823 PowerPC GNU/Linux powerpc-*-linux*
2827 Motorola MCore mcore-*-*
2828 x86 VxWorks i[3456]86-*-vxworks*
2829 PowerPC VxWorks powerpc-*-vxworks*
2830 TI TMS320C80 tic80-*-*
2832 * OBSOLETE configurations
2834 Altos 3068 m68*-altos-*
2835 Convex c1-*-*, c2-*-*
2837 ARM RISCix arm-*-* (as host)
2840 Configurations that have been declared obsolete will be commented out,
2841 but the code will be left in place. If there is no activity to revive
2842 these configurations before the next release of GDB, the sources will
2843 be permanently REMOVED.
2845 * Gould support removed
2847 Support for the Gould PowerNode and NP1 has been removed.
2849 * New features for SVR4
2851 On SVR4 native platforms (such as Solaris), if you attach to a process
2852 without first loading a symbol file, GDB will now attempt to locate and
2853 load symbols from the running process's executable file.
2855 * Many C++ enhancements
2857 C++ support has been greatly improved. Overload resolution now works properly
2858 in almost all cases. RTTI support is on the way.
2860 * Remote targets can connect to a sub-program
2862 A popen(3) style serial-device has been added. This device starts a
2863 sub-process (such as a stand-alone simulator) and then communicates
2864 with that. The sub-program to run is specified using the syntax
2865 ``|<program> <args>'' vis:
2867 (gdb) set remotedebug 1
2868 (gdb) target extended-remote |mn10300-elf-sim program-args
2870 * MIPS 64 remote protocol
2872 A long standing bug in the mips64 remote protocol where by GDB
2873 expected certain 32 bit registers (ex SR) to be transfered as 32
2874 instead of 64 bits has been fixed.
2876 The command ``set remote-mips64-transfers-32bit-regs on'' has been
2877 added to provide backward compatibility with older versions of GDB.
2879 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
2881 The command ``set remotebinarydownload'' command has been replaced by
2882 ``set remote X-packet''. Other commands in ``set remote'' family
2883 include ``set remote P-packet''.
2885 * Breakpoint commands accept ranges.
2887 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
2888 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
2889 ``tracepoint passcount'' also accepts a range of tracepoints.
2891 * ``apropos'' command added.
2893 The ``apropos'' command searches through command names and
2894 documentation strings, printing out matches, making it much easier to
2895 try to find a command that does what you are looking for.
2899 A new machine oriented interface (MI) has been added to GDB. This
2900 interface is designed for debug environments running GDB as a separate
2901 process. This is part of the long term libGDB project. See the
2902 "GDB/MI" chapter of the GDB manual for further information. It can be
2903 enabled by configuring with:
2905 .../configure --enable-gdbmi
2907 *** Changes in GDB-4.18:
2909 * New native configurations
2911 HP-UX 10.20 hppa*-*-hpux10.20
2912 HP-UX 11.x hppa*-*-hpux11.0*
2913 M68K GNU/Linux m68*-*-linux*
2917 Fujitsu FR30 fr30-*-elf*
2918 Intel StrongARM strongarm-*-*
2919 Mitsubishi D30V d30v-*-*
2921 * OBSOLETE configurations
2923 Gould PowerNode, NP1 np1-*-*, pn-*-*
2925 Configurations that have been declared obsolete will be commented out,
2926 but the code will be left in place. If there is no activity to revive
2927 these configurations before the next release of GDB, the sources will
2928 be permanently REMOVED.
2932 As a compatibility experiment, GDB's source files buildsym.h and
2933 buildsym.c have been converted to pure standard C, no longer
2934 containing any K&R compatibility code. We believe that all systems in
2935 use today either come with a standard C compiler, or have a GCC port
2936 available. If this is not true, please report the affected
2937 configuration to bug-gdb@gnu.org immediately. See the README file for
2938 information about getting a standard C compiler if you don't have one
2943 GDB now uses readline 2.2.
2945 * set extension-language
2947 You can now control the mapping between filename extensions and source
2948 languages by using the `set extension-language' command. For instance,
2949 you can ask GDB to treat .c files as C++ by saying
2950 set extension-language .c c++
2951 The command `info extensions' lists all of the recognized extensions
2952 and their associated languages.
2954 * Setting processor type for PowerPC and RS/6000
2956 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
2957 you can use the `set processor' command to specify what variant of the
2958 PowerPC family you are debugging. The command
2962 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
2963 following PowerPC and RS6000 variants:
2965 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
2966 rs6000 IBM RS6000 ("POWER") architecture, user-level view
2968 403GC IBM PowerPC 403GC
2969 505 Motorola PowerPC 505
2970 860 Motorola PowerPC 860 or 850
2971 601 Motorola PowerPC 601
2972 602 Motorola PowerPC 602
2973 603 Motorola/IBM PowerPC 603 or 603e
2974 604 Motorola PowerPC 604 or 604e
2975 750 Motorola/IBM PowerPC 750 or 750
2977 At the moment, this command just tells GDB what to name the
2978 special-purpose processor registers. Since almost all the affected
2979 registers are inaccessible to user-level programs, this command is
2980 only useful for remote debugging in its present form.
2984 Thanks to a major code donation from Hewlett-Packard, GDB now has much
2985 more extensive support for HP-UX. Added features include shared
2986 library support, kernel threads and hardware watchpoints for 11.00,
2987 support for HP's ANSI C and C++ compilers, and a compatibility mode
2988 for xdb and dbx commands.
2992 HP's donation includes the new concept of catchpoints, which is a
2993 generalization of the old catch command. On HP-UX, it is now possible
2994 to catch exec, fork, and vfork, as well as library loading.
2996 This means that the existing catch command has changed; its first
2997 argument now specifies the type of catch to be set up. See the
2998 output of "help catch" for a list of catchpoint types.
3000 * Debugging across forks
3002 On HP-UX, you can choose which process to debug when a fork() happens
3007 HP has donated a curses-based terminal user interface (TUI). To get
3008 it, build with --enable-tui. Although this can be enabled for any
3009 configuration, at present it only works for native HP debugging.
3011 * GDB remote protocol additions
3013 A new protocol packet 'X' that writes binary data is now available.
3014 Default behavior is to try 'X', then drop back to 'M' if the stub
3015 fails to respond. The settable variable `remotebinarydownload'
3016 allows explicit control over the use of 'X'.
3018 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
3019 full 64-bit address. The command
3021 set remoteaddresssize 32
3023 can be used to revert to the old behaviour. For existing remote stubs
3024 the change should not be noticed, as the additional address information
3027 In order to assist in debugging stubs, you may use the maintenance
3028 command `packet' to send any text string to the stub. For instance,
3030 maint packet heythere
3032 sends the packet "$heythere#<checksum>". Note that it is very easy to
3033 disrupt a debugging session by sending the wrong packet at the wrong
3036 The compare-sections command allows you to compare section data on the
3037 target to what is in the executable file without uploading or
3038 downloading, by comparing CRC checksums.
3040 * Tracing can collect general expressions
3042 You may now collect general expressions at tracepoints. This requires
3043 further additions to the target-side stub; see tracepoint.c and
3044 doc/agentexpr.texi for further details.
3046 * mask-address variable for Mips
3048 For Mips targets, you may control the zeroing of the upper 32 bits of
3049 a 64-bit address by entering `set mask-address on'. This is mainly
3050 of interest to users of embedded R4xxx and R5xxx processors.
3052 * Higher serial baud rates
3054 GDB's serial code now allows you to specify baud rates 57600, 115200,
3055 230400, and 460800 baud. (Note that your host system may not be able
3056 to achieve all of these rates.)
3060 The i960 configuration now includes an initial implementation of a
3061 builtin simulator, contributed by Jim Wilson.
3064 *** Changes in GDB-4.17:
3066 * New native configurations
3068 Alpha GNU/Linux alpha*-*-linux*
3069 Unixware 2.x i[3456]86-unixware2*
3070 Irix 6.x mips*-sgi-irix6*
3071 PowerPC GNU/Linux powerpc-*-linux*
3072 PowerPC Solaris powerpcle-*-solaris*
3073 Sparc GNU/Linux sparc-*-linux*
3074 Motorola sysV68 R3V7.1 m68k-motorola-sysv
3078 Argonaut Risc Chip (ARC) arc-*-*
3079 Hitachi H8/300S h8300*-*-*
3080 Matsushita MN10200 w/simulator mn10200-*-*
3081 Matsushita MN10300 w/simulator mn10300-*-*
3082 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
3083 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
3084 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
3085 Mitsubishi D10V w/simulator d10v-*-*
3086 Mitsubishi M32R/D w/simulator m32r-*-elf*
3087 Tsqware Sparclet sparclet-*-*
3088 NEC V850 w/simulator v850-*-*
3090 * New debugging protocols
3092 ARM with RDI protocol arm*-*-*
3093 M68K with dBUG monitor m68*-*-{aout,coff,elf}
3094 DDB and LSI variants of PMON protocol mips*-*-*
3095 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
3096 PowerPC with SDS protocol powerpc{,le}-*-eabi
3097 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
3101 All configurations can now understand and use the DWARF 2 debugging
3102 format. The choice is automatic, if the symbol file contains DWARF 2
3107 GDB now includes basic Java language support. This support is
3108 only useful with Java compilers that produce native machine code.
3110 * solib-absolute-prefix and solib-search-path
3112 For SunOS and SVR4 shared libraries, you may now set the prefix for
3113 loading absolute shared library symbol files, and the search path for
3114 locating non-absolute shared library symbol files.
3116 * Live range splitting
3118 GDB can now effectively debug code for which GCC has performed live
3119 range splitting as part of its optimization. See gdb/doc/LRS for
3120 more details on the expected format of the stabs information.
3124 GDB's support for the GNU Hurd, including thread debugging, has been
3125 updated to work with current versions of the Hurd.
3129 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
3130 instruction set. ARM GDB automatically detects when Thumb
3131 instructions are in use, and adjusts disassembly and backtracing
3136 GDB's MIPS target configurations now handle the MIP16 16-bit
3141 GDB now includes support for overlays; if an executable has been
3142 linked such that multiple sections are based at the same address, GDB
3143 will decide which section to use for symbolic info. You can choose to
3144 control the decision manually, using overlay commands, or implement
3145 additional target-side support and use "overlay load-target" to bring
3146 in the overlay mapping. Do "help overlay" for more detail.
3150 The command "info symbol <address>" displays information about
3151 the symbol at the specified address.
3155 The standard remote protocol now includes an extension that allows
3156 asynchronous collection and display of trace data. This requires
3157 extensive support in the target-side debugging stub. Tracing mode
3158 includes a new interaction mode in GDB and new commands: see the
3159 file tracepoint.c for more details.
3163 Configurations for embedded MIPS now include a simulator contributed
3164 by Cygnus Solutions. The simulator supports the instruction sets
3165 of most MIPS variants.
3169 Sparc configurations may now include the ERC32 simulator contributed
3170 by the European Space Agency. The simulator is not built into
3171 Sparc targets by default; configure with --enable-sim to include it.
3175 For target configurations that may include multiple variants of a
3176 basic architecture (such as MIPS and SH), you may now set the
3177 architecture explicitly. "set arch" sets, "info arch" lists
3178 the possible architectures.
3180 *** Changes in GDB-4.16:
3182 * New native configurations
3184 Windows 95, x86 Windows NT i[345]86-*-cygwin32
3185 M68K NetBSD m68k-*-netbsd*
3186 PowerPC AIX 4.x powerpc-*-aix*
3187 PowerPC MacOS powerpc-*-macos*
3188 PowerPC Windows NT powerpcle-*-cygwin32
3189 RS/6000 AIX 4.x rs6000-*-aix4*
3193 ARM with RDP protocol arm-*-*
3194 I960 with MON960 i960-*-coff
3195 MIPS VxWorks mips*-*-vxworks*
3196 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
3197 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
3199 Matra Sparclet sparclet-*-*
3203 The powerpc-eabi configuration now includes the PSIM simulator,
3204 contributed by Andrew Cagney, with assistance from Mike Meissner.
3205 PSIM is a very elaborate model of the PowerPC, including not only
3206 basic instruction set execution, but also details of execution unit
3207 performance and I/O hardware. See sim/ppc/README for more details.
3211 GDB now works with Solaris 2.5.
3213 * Windows 95/NT native
3215 GDB will now work as a native debugger on Windows 95 and Windows NT.
3216 To build it from source, you must use the "gnu-win32" environment,
3217 which uses a DLL to emulate enough of Unix to run the GNU tools.
3218 Further information, binaries, and sources are available at
3219 ftp.cygnus.com, under pub/gnu-win32.
3221 * dont-repeat command
3223 If a user-defined command includes the command `dont-repeat', then the
3224 command will not be repeated if the user just types return. This is
3225 useful if the command is time-consuming to run, so that accidental
3226 extra keystrokes don't run the same command many times.
3228 * Send break instead of ^C
3230 The standard remote protocol now includes an option to send a break
3231 rather than a ^C to the target in order to interrupt it. By default,
3232 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
3234 * Remote protocol timeout
3236 The standard remote protocol includes a new variable `remotetimeout'
3237 that allows you to set the number of seconds before GDB gives up trying
3238 to read from the target. The default value is 2.
3240 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
3242 By default GDB will automatically keep track of objects as they are
3243 loaded and unloaded by the dynamic linker. By using the command `set
3244 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
3245 when shared library events occur, thus allowing you to set breakpoints
3246 in shared libraries which are explicitly loaded by the inferior.
3248 Note this feature does not work on hpux8. On hpux9 you must link
3249 /usr/lib/end.o into your program. This feature should work
3250 automatically on hpux10.
3252 * Irix 5.x hardware watchpoint support
3254 Irix 5 configurations now support the use of hardware watchpoints.
3256 * Mips protocol "SYN garbage limit"
3258 When debugging a Mips target using the `target mips' protocol, you
3259 may set the number of characters that GDB will ignore by setting
3260 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
3261 every character. The default value is 1050.
3263 * Recording and replaying remote debug sessions
3265 If you set `remotelogfile' to the name of a file, gdb will write to it
3266 a recording of a remote debug session. This recording may then be
3267 replayed back to gdb using "gdbreplay". See gdbserver/README for
3268 details. This is useful when you have a problem with GDB while doing
3269 remote debugging; you can make a recording of the session and send it
3270 to someone else, who can then recreate the problem.
3272 * Speedups for remote debugging
3274 GDB includes speedups for downloading and stepping MIPS systems using
3275 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
3276 and more efficient S-record downloading.
3278 * Memory use reductions and statistics collection
3280 GDB now uses less memory and reports statistics about memory usage.
3281 Try the `maint print statistics' command, for example.
3283 *** Changes in GDB-4.15:
3285 * Psymtabs for XCOFF
3287 The symbol reader for AIX GDB now uses partial symbol tables. This
3288 can greatly improve startup time, especially for large executables.
3290 * Remote targets use caching
3292 Remote targets now use a data cache to speed up communication with the
3293 remote side. The data cache could lead to incorrect results because
3294 it doesn't know about volatile variables, thus making it impossible to
3295 debug targets which use memory mapped I/O devices. `set remotecache
3296 off' turns the the data cache off.
3298 * Remote targets may have threads
3300 The standard remote protocol now includes support for multiple threads
3301 in the target system, using new protocol commands 'H' and 'T'. See
3302 gdb/remote.c for details.
3306 If GDB is configured with `--enable-netrom', then it will include
3307 support for the NetROM ROM emulator from XLNT Designs. The NetROM
3308 acts as though it is a bank of ROM on the target board, but you can
3309 write into it over the network. GDB's support consists only of
3310 support for fast loading into the emulated ROM; to debug, you must use
3311 another protocol, such as standard remote protocol. The usual
3312 sequence is something like
3314 target nrom <netrom-hostname>
3316 target remote <netrom-hostname>:1235
3320 GDB now includes support for the Apple Macintosh, as a host only. It
3321 may be run as either an MPW tool or as a standalone application, and
3322 it can debug through the serial port. All the usual GDB commands are
3323 available, but to the target command, you must supply "serial" as the
3324 device type instead of "/dev/ttyXX". See mpw-README in the main
3325 directory for more information on how to build. The MPW configuration
3326 scripts */mpw-config.in support only a few targets, and only the
3327 mips-idt-ecoff target has been tested.
3331 GDB configuration now uses autoconf. This is not user-visible,
3332 but does simplify configuration and building.
3336 GDB now supports hpux10.
3338 *** Changes in GDB-4.14:
3340 * New native configurations
3342 x86 FreeBSD i[345]86-*-freebsd
3343 x86 NetBSD i[345]86-*-netbsd
3344 NS32k NetBSD ns32k-*-netbsd
3345 Sparc NetBSD sparc-*-netbsd
3349 A29K VxWorks a29k-*-vxworks
3350 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
3351 CPU32 EST-300 emulator m68*-*-est*
3352 PowerPC ELF powerpc-*-elf
3355 * Alpha OSF/1 support for procfs
3357 GDB now supports procfs under OSF/1-2.x and higher, which makes it
3358 possible to attach to running processes. As the mounting of the /proc
3359 filesystem is optional on the Alpha, GDB automatically determines
3360 the availability of /proc during startup. This can lead to problems
3361 if /proc is unmounted after GDB has been started.
3363 * Arguments to user-defined commands
3365 User commands may accept up to 10 arguments separated by whitespace.
3366 Arguments are accessed within the user command via $arg0..$arg9. A
3369 print $arg0 + $arg1 + $arg2
3371 To execute the command use:
3374 Defines the command "adder" which prints the sum of its three arguments.
3375 Note the arguments are text substitutions, so they may reference variables,
3376 use complex expressions, or even perform inferior function calls.
3378 * New `if' and `while' commands
3380 This makes it possible to write more sophisticated user-defined
3381 commands. Both commands take a single argument, which is the
3382 expression to evaluate, and must be followed by the commands to
3383 execute, one per line, if the expression is nonzero, the list being
3384 terminated by the word `end'. The `if' command list may include an
3385 `else' word, which causes the following commands to be executed only
3386 if the expression is zero.
3388 * Fortran source language mode
3390 GDB now includes partial support for Fortran 77. It will recognize
3391 Fortran programs and can evaluate a subset of Fortran expressions, but
3392 variables and functions may not be handled correctly. GDB will work
3393 with G77, but does not yet know much about symbols emitted by other
3396 * Better HPUX support
3398 Most debugging facilities now work on dynamic executables for HPPAs
3399 running hpux9 or later. You can attach to running dynamically linked
3400 processes, but by default the dynamic libraries will be read-only, so
3401 for instance you won't be able to put breakpoints in them. To change
3402 that behavior do the following before running the program:
3408 This will cause the libraries to be mapped private and read-write.
3409 To revert to the normal behavior, do this:
3415 You cannot set breakpoints or examine data in the library until after
3416 the library is loaded if the function/data symbols do not have
3419 GDB can now also read debug symbols produced by the HP C compiler on
3420 HPPAs (sorry, no C++, Fortran or 68k support).
3422 * Target byte order now dynamically selectable
3424 You can choose which byte order to use with a target system, via the
3425 commands "set endian big" and "set endian little", and you can see the
3426 current setting by using "show endian". You can also give the command
3427 "set endian auto", in which case GDB will use the byte order
3428 associated with the executable. Currently, only embedded MIPS
3429 configurations support dynamic selection of target byte order.
3431 * New DOS host serial code
3433 This version uses DPMI interrupts to handle buffered I/O, so you
3434 no longer need to run asynctsr when debugging boards connected to
3437 *** Changes in GDB-4.13:
3439 * New "complete" command
3441 This lists all the possible completions for the rest of the line, if it
3442 were to be given as a command itself. This is intended for use by emacs.
3444 * Trailing space optional in prompt
3446 "set prompt" no longer adds a space for you after the prompt you set. This
3447 allows you to set a prompt which ends in a space or one that does not.
3449 * Breakpoint hit counts
3451 "info break" now displays a count of the number of times the breakpoint
3452 has been hit. This is especially useful in conjunction with "ignore"; you
3453 can ignore a large number of breakpoint hits, look at the breakpoint info
3454 to see how many times the breakpoint was hit, then run again, ignoring one
3455 less than that number, and this will get you quickly to the last hit of
3458 * Ability to stop printing at NULL character
3460 "set print null-stop" will cause GDB to stop printing the characters of
3461 an array when the first NULL is encountered. This is useful when large
3462 arrays actually contain only short strings.
3464 * Shared library breakpoints
3466 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
3467 breakpoints in shared libraries before the executable is run.
3469 * Hardware watchpoints
3471 There is a new hardware breakpoint for the watch command for sparclite
3472 targets. See gdb/sparclite/hw_breakpoint.note.
3474 Hardware watchpoints are also now supported under GNU/Linux.
3478 Annotations have been added. These are for use with graphical interfaces,
3479 and are still experimental. Currently only gdba.el uses these.
3481 * Improved Irix 5 support
3483 GDB now works properly with Irix 5.2.
3485 * Improved HPPA support
3487 GDB now works properly with the latest GCC and GAS.
3489 * New native configurations
3491 Sequent PTX4 i[34]86-sequent-ptx4
3492 HPPA running OSF/1 hppa*-*-osf*
3493 Atari TT running SVR4 m68*-*-sysv4*
3494 RS/6000 LynxOS rs6000-*-lynxos*
3498 OS/9000 i[34]86-*-os9k
3499 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
3502 * Hitachi SH7000 and E7000-PC ICE support
3504 There is now support for communicating with the Hitachi E7000-PC ICE.
3505 This is available automatically when GDB is configured for the SH.
3509 As usual, a variety of small fixes and improvements, both generic
3510 and configuration-specific. See the ChangeLog for more detail.
3512 *** Changes in GDB-4.12:
3514 * Irix 5 is now supported
3518 GDB-4.12 on the HPPA has a number of changes which make it unable
3519 to debug the output from the currently released versions of GCC and
3520 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
3521 of GCC and GAS, versions of these tools designed to work with GDB-4.12
3522 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
3525 *** Changes in GDB-4.11:
3527 * User visible changes:
3531 The "set remotedebug" option is now consistent between the mips remote
3532 target, remote targets using the gdb-specific protocol, UDI (AMD's
3533 debug protocol for the 29k) and the 88k bug monitor. It is now an
3534 integer specifying a debug level (normally 0 or 1, but 2 means more
3535 debugging info for the mips target).
3537 * DEC Alpha native support
3539 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
3540 debug info, but GDB works fairly well with the DEC compiler and should
3541 work with a future GCC release. See the README file for a few
3542 Alpha-specific notes.
3544 * Preliminary thread implementation
3546 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
3548 * LynxOS native and target support for 386
3550 This release has been hosted on LynxOS 2.2, and also can be configured
3551 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
3554 * Improvements in C++ mangling/demangling.
3556 This release has much better g++ debugging, specifically in name
3557 mangling/demangling, virtual function calls, print virtual table,
3558 call methods, ...etc.
3560 *** Changes in GDB-4.10:
3562 * User visible changes:
3564 Remote debugging using the GDB-specific (`target remote') protocol now
3565 supports the `load' command. This is only useful if you have some
3566 other way of getting the stub to the target system, and you can put it
3567 somewhere in memory where it won't get clobbered by the download.
3569 Filename completion now works.
3571 When run under emacs mode, the "info line" command now causes the
3572 arrow to point to the line specified. Also, "info line" prints
3573 addresses in symbolic form (as well as hex).
3575 All vxworks based targets now support a user settable option, called
3576 vxworks-timeout. This option represents the number of seconds gdb
3577 should wait for responses to rpc's. You might want to use this if
3578 your vxworks target is, perhaps, a slow software simulator or happens
3579 to be on the far side of a thin network line.
3583 This release contains support for using a DEC alpha as a GDB host for
3584 cross debugging. Native alpha debugging is not supported yet.
3587 *** Changes in GDB-4.9:
3591 This is the first GDB release which is accompanied by a matching testsuite.
3592 The testsuite requires installation of dejagnu, which should be available
3593 via ftp from most sites that carry GNU software.
3597 'Cfront' style demangling has had its name changed to 'ARM' style, to
3598 emphasize that it was written from the specifications in the C++ Annotated
3599 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
3600 disclaimers, it still generated too much confusion with users attempting to
3601 use gdb with AT&T cfront.
3605 GDB now uses a standard remote interface to a simulator library.
3606 So far, the library contains simulators for the Zilog Z8001/2, the
3607 Hitachi H8/300, H8/500 and Super-H.
3609 * New targets supported
3611 H8/300 simulator h8300-hitachi-hms or h8300hms
3612 H8/500 simulator h8500-hitachi-hms or h8500hms
3613 SH simulator sh-hitachi-hms or sh
3614 Z8000 simulator z8k-zilog-none or z8ksim
3615 IDT MIPS board over serial line mips-idt-ecoff
3617 Cross-debugging to GO32 targets is supported. It requires a custom
3618 version of the i386-stub.c module which is integrated with the
3619 GO32 memory extender.
3621 * New remote protocols
3623 MIPS remote debugging protocol.
3625 * New source languages supported
3627 This version includes preliminary support for Chill, a Pascal like language
3628 used by telecommunications companies. Chill support is also being integrated
3629 into the GNU compiler, but we don't know when it will be publically available.
3632 *** Changes in GDB-4.8:
3634 * HP Precision Architecture supported
3636 GDB now supports HP PA-RISC machines running HPUX. A preliminary
3637 version of this support was available as a set of patches from the
3638 University of Utah. GDB does not support debugging of programs
3639 compiled with the HP compiler, because HP will not document their file
3640 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
3641 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
3643 Many problems in the preliminary version have been fixed.
3645 * Faster and better demangling
3647 We have improved template demangling and fixed numerous bugs in the GNU style
3648 demangler. It can now handle type modifiers such as `static' or `const'. Wide
3649 character types (wchar_t) are now supported. Demangling of each symbol is now
3650 only done once, and is cached when the symbol table for a file is read in.
3651 This results in a small increase in memory usage for C programs, a moderate
3652 increase in memory usage for C++ programs, and a fantastic speedup in
3655 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
3656 from the specifications in the Annotated Reference Manual, which AT&T's
3657 compiler does not actually implement.
3659 * G++ multiple inheritance compiler problem
3661 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
3662 inheritance lattices was reworked to properly discover ambiguities. We
3663 recently found an example which causes this new algorithm to fail in a
3664 very subtle way, producing bad debug information for those classes.
3665 The file 'gcc.patch' (in this directory) can be applied to gcc to
3666 circumvent the problem. A future GCC release will contain a complete
3669 The previous G++ debug info problem (mentioned below for the gdb-4.7
3670 release) is fixed in gcc version 2.3.2.
3672 * Improved configure script
3674 The `configure' script will now attempt to guess your system type if
3675 you don't supply a host system type. The old scheme of supplying a
3676 host system triplet is preferable over using this. All the magic is
3677 done in the new `config.guess' script. Examine it for details.
3679 We have also brought our configure script much more in line with the FSF's
3680 version. It now supports the --with-xxx options. In particular,
3681 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
3682 The resulting GDB will not be able to read arbitrary object file formats --
3683 only the format ``expected'' to be used on the configured target system.
3684 We hope to make this the default in a future release.
3686 * Documentation improvements
3688 There's new internal documentation on how to modify GDB, and how to
3689 produce clean changes to the code. We implore people to read it
3690 before submitting changes.
3692 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
3693 M4 macros. The new texinfo.tex is provided in this release. Pre-built
3694 `info' files are also provided. To build `info' files from scratch,
3695 you will need the latest `makeinfo' release, which will be available in
3696 a future texinfo-X.Y release.
3698 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
3699 We're not sure exactly which versions have this problem, but it has
3700 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
3701 or better. If that isn't possible, there is a patch in
3702 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
3703 around this problem.
3707 GDB now supports array constants that can be used in expressions typed in by
3708 the user. The syntax is `{element, element, ...}'. Ie: you can now type
3709 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
3712 The new directory `gdb/sparclite' contains a program that demonstrates
3713 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
3715 * New native hosts supported
3717 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
3718 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
3720 * New targets supported
3722 AMD 29k family via UDI a29k-amd-udi or udi29k
3724 * New file formats supported
3726 BFD now supports reading HP/PA-RISC executables (SOM file format?),
3727 HPUX core files, and SCO 3.2v2 core files.
3731 Attaching to processes now works again; thanks for the many bug reports.
3733 We have also stomped on a bunch of core dumps caused by
3734 printf_filtered("%s") problems.
3736 We eliminated a copyright problem on the rpc and ptrace header files
3737 for VxWorks, which was discovered at the last minute during the 4.7
3738 release. You should now be able to build a VxWorks GDB.
3740 You can now interrupt gdb while an attached process is running. This
3741 will cause the attached process to stop, and give control back to GDB.
3743 We fixed problems caused by using too many file descriptors
3744 for reading symbols from object files and libraries. This was
3745 especially a problem for programs that used many (~100) shared
3748 The `step' command now only enters a subroutine if there is line number
3749 information for the subroutine. Otherwise it acts like the `next'
3750 command. Previously, `step' would enter subroutines if there was
3751 any debugging information about the routine. This avoids problems
3752 when using `cc -g1' on MIPS machines.
3754 * Internal improvements
3756 GDB's internal interfaces have been improved to make it easier to support
3757 debugging of multiple languages in the future.
3759 GDB now uses a common structure for symbol information internally.
3760 Minimal symbols (derived from linkage symbols in object files), partial
3761 symbols (from a quick scan of debug information), and full symbols
3762 contain a common subset of information, making it easier to write
3763 shared code that handles any of them.
3765 * New command line options
3767 We now accept --silent as an alias for --quiet.
3771 The memory-mapped-malloc library is now licensed under the GNU Library
3772 General Public License.
3774 *** Changes in GDB-4.7:
3776 * Host/native/target split
3778 GDB has had some major internal surgery to untangle the support for
3779 hosts and remote targets. Now, when you configure GDB for a remote
3780 target, it will no longer load in all of the support for debugging
3781 local programs on the host. When fully completed and tested, this will
3782 ensure that arbitrary host/target combinations are possible.
3784 The primary conceptual shift is to separate the non-portable code in
3785 GDB into three categories. Host specific code is required any time GDB
3786 is compiled on that host, regardless of the target. Target specific
3787 code relates to the peculiarities of the target, but can be compiled on
3788 any host. Native specific code is everything else: it can only be
3789 built when the host and target are the same system. Child process
3790 handling and core file support are two common `native' examples.
3792 GDB's use of /proc for controlling Unix child processes is now cleaner.
3793 It has been split out into a single module under the `target_ops' vector,
3794 plus two native-dependent functions for each system that uses /proc.
3796 * New hosts supported
3798 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
3799 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
3800 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
3802 * New targets supported
3804 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3805 68030 and CPU32 m68030-*-*, m68332-*-*
3807 * New native hosts supported
3809 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
3810 (386bsd is not well tested yet)
3811 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
3813 * New file formats supported
3815 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
3816 supports reading of `a.out.adobe' object files, which are an a.out
3817 format extended with minimal information about multiple sections.
3821 `show copying' is the same as the old `info copying'.
3822 `show warranty' is the same as `info warrantee'.
3823 These were renamed for consistency. The old commands continue to work.
3825 `info handle' is a new alias for `info signals'.
3827 You can now define pre-command hooks, which attach arbitrary command
3828 scripts to any command. The commands in the hook will be executed
3829 prior to the user's command. You can also create a hook which will be
3830 executed whenever the program stops. See gdb.texinfo.
3834 We now deal with Cfront style name mangling, and can even extract type
3835 info from mangled symbols. GDB can automatically figure out which
3836 symbol mangling style your C++ compiler uses.
3838 Calling of methods and virtual functions has been improved as well.
3842 The crash that occured when debugging Sun Ansi-C compiled binaries is
3843 fixed. This was due to mishandling of the extra N_SO stabs output
3846 We also finally got Ultrix 4.2 running in house, and fixed core file
3847 support, with help from a dozen people on the net.
3849 John M. Farrell discovered that the reason that single-stepping was so
3850 slow on all of the Mips based platforms (primarily SGI and DEC) was
3851 that we were trying to demangle and lookup a symbol used for internal
3852 purposes on every instruction that was being stepped through. Changing
3853 the name of that symbol so that it couldn't be mistaken for a C++
3854 mangled symbol sped things up a great deal.
3856 Rich Pixley sped up symbol lookups in general by getting much smarter
3857 about when C++ symbol mangling is necessary. This should make symbol
3858 completion (TAB on the command line) much faster. It's not as fast as
3859 we'd like, but it's significantly faster than gdb-4.6.
3863 A new user controllable variable 'call_scratch_address' can
3864 specify the location of a scratch area to be used when GDB
3865 calls a function in the target. This is necessary because the
3866 usual method of putting the scratch area on the stack does not work
3867 in systems that have separate instruction and data spaces.
3869 We integrated changes to support the 29k UDI (Universal Debugger
3870 Interface), but discovered at the last minute that we didn't have all
3871 of the appropriate copyright paperwork. We are working with AMD to
3872 resolve this, and hope to have it available soon.
3876 We have sped up the remote serial line protocol, especially for targets
3877 with lots of registers. It now supports a new `expedited status' ('T')
3878 message which can be used in place of the existing 'S' status message.
3879 This allows the remote stub to send only the registers that GDB
3880 needs to make a quick decision about single-stepping or conditional
3881 breakpoints, eliminating the need to fetch the entire register set for
3882 each instruction being stepped through.
3884 The GDB remote serial protocol now implements a write-through cache for
3885 registers, only re-reading the registers if the target has run.
3887 There is also a new remote serial stub for SPARC processors. You can
3888 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
3889 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
3890 processor with a serial port.
3894 Configure.in files have become much easier to read and modify. A new
3895 `table driven' format makes it more obvious what configurations are
3896 supported, and what files each one uses.
3900 There is a new opcodes library which will eventually contain all of the
3901 disassembly routines and opcode tables. At present, it only contains
3902 Sparc and Z8000 routines. This will allow the assembler, debugger, and
3903 disassembler (binutils/objdump) to share these routines.
3905 The libiberty library is now copylefted under the GNU Library General
3906 Public License. This allows more liberal use, and was done so libg++
3907 can use it. This makes no difference to GDB, since the Library License
3908 grants all the rights from the General Public License.
3912 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
3913 reference to the stabs symbol info used by the debugger. It is (as far
3914 as we know) the only published document on this fascinating topic. We
3915 encourage you to read it, compare it to the stabs information on your
3916 system, and send improvements on the document in general (to
3917 bug-gdb@prep.ai.mit.edu).
3919 And, of course, many bugs have been fixed.
3922 *** Changes in GDB-4.6:
3924 * Better support for C++ function names
3926 GDB now accepts as input the "demangled form" of C++ overloaded function
3927 names and member function names, and can do command completion on such names
3928 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
3929 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
3930 Make use of command completion, it is your friend.
3932 GDB also now accepts a variety of C++ mangled symbol formats. They are
3933 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
3934 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
3935 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
3936 for the list of formats.
3938 * G++ symbol mangling problem
3940 Recent versions of gcc have a bug in how they emit debugging information for
3941 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
3942 directory) can be applied to gcc to fix the problem. Alternatively, if you
3943 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
3944 usual symptom is difficulty with setting breakpoints on methods. GDB complains
3945 about the method being non-existent. (We believe that version 2.2.2 of GCC has
3948 * New 'maintenance' command
3950 All of the commands related to hacking GDB internals have been moved out of
3951 the main command set, and now live behind the 'maintenance' command. This
3952 can also be abbreviated as 'mt'. The following changes were made:
3954 dump-me -> maintenance dump-me
3955 info all-breakpoints -> maintenance info breakpoints
3956 printmsyms -> maintenance print msyms
3957 printobjfiles -> maintenance print objfiles
3958 printpsyms -> maintenance print psymbols
3959 printsyms -> maintenance print symbols
3961 The following commands are new:
3963 maintenance demangle Call internal GDB demangler routine to
3964 demangle a C++ link name and prints the result.
3965 maintenance print type Print a type chain for a given symbol
3967 * Change to .gdbinit file processing
3969 We now read the $HOME/.gdbinit file before processing the argv arguments
3970 (e.g. reading symbol files or core files). This allows global parameters to
3971 be set, which will apply during the symbol reading. The ./.gdbinit is still
3972 read after argv processing.
3974 * New hosts supported
3976 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
3978 GNU/Linux support i386-unknown-linux or linux
3980 We are also including code to support the HP/PA running BSD and HPUX. This
3981 is almost guaranteed not to work, as we didn't have time to test or build it
3982 for this release. We are including it so that the more adventurous (or
3983 masochistic) of you can play with it. We also had major problems with the
3984 fact that the compiler that we got from HP doesn't support the -g option.
3987 * New targets supported
3989 Hitachi H8/300 h8300-hitachi-hms or h8300hms
3991 * More smarts about finding #include files
3993 GDB now remembers the compilation directory for all include files, and for
3994 all files from which C is generated (like yacc and lex sources). This
3995 greatly improves GDB's ability to find yacc/lex sources, and include files,
3996 especially if you are debugging your program from a directory different from
3997 the one that contains your sources.
3999 We also fixed a bug which caused difficulty with listing and setting
4000 breakpoints in include files which contain C code. (In the past, you had to
4001 try twice in order to list an include file that you hadn't looked at before.)
4003 * Interesting infernals change
4005 GDB now deals with arbitrary numbers of sections, where the symbols for each
4006 section must be relocated relative to that section's landing place in the
4007 target's address space. This work was needed to support ELF with embedded
4008 stabs used by Solaris-2.0.
4010 * Bug fixes (of course!)
4012 There have been loads of fixes for the following things:
4013 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
4014 i960, stabs, DOS(GO32), procfs, etc...
4016 See the ChangeLog for details.
4018 *** Changes in GDB-4.5:
4020 * New machines supported (host and target)
4022 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
4024 SGI Irix-4.x mips-sgi-irix4 or iris4
4026 * New malloc package
4028 GDB now uses a new memory manager called mmalloc, based on gmalloc.
4029 Mmalloc is capable of handling mutiple heaps of memory. It is also
4030 capable of saving a heap to a file, and then mapping it back in later.
4031 This can be used to greatly speedup the startup of GDB by using a
4032 pre-parsed symbol table which lives in a mmalloc managed heap. For
4033 more details, please read mmalloc/mmalloc.texi.
4037 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
4038 'help info proc' for details.
4040 * MIPS ecoff symbol table format
4042 The code that reads MIPS symbol table format is now supported on all hosts.
4043 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
4046 * File name changes for MS-DOS
4048 Many files in the config directories have been renamed to make it easier to
4049 support GDB on MS-DOSe systems (which have very restrictive file name
4050 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
4051 environment) is close to working but has some remaining problems. Note
4052 that debugging of DOS programs is not supported, due to limitations
4053 in the ``operating system'', but it can be used to host cross-debugging.
4055 * Cross byte order fixes
4057 Many fixes have been made to support cross debugging of Sparc and MIPS
4058 targets from hosts whose byte order differs.
4060 * New -mapped and -readnow options
4062 If memory-mapped files are available on your system through the 'mmap'
4063 system call, you can use the -mapped option on the `file' or
4064 `symbol-file' commands to cause GDB to write the symbols from your
4065 program into a reusable file. If the program you are debugging is
4066 called `/path/fred', the mapped symbol file will be `./fred.syms'.
4067 Future GDB debugging sessions will notice the presence of this file,
4068 and will quickly map in symbol information from it, rather than reading
4069 the symbol table from the executable program. Using the '-mapped'
4070 option in a GDB `file' or `symbol-file' command has the same effect as
4071 starting GDB with the '-mapped' command-line option.
4073 You can cause GDB to read the entire symbol table immediately by using
4074 the '-readnow' option with any of the commands that load symbol table
4075 information (or on the GDB command line). This makes the command
4076 slower, but makes future operations faster.
4078 The -mapped and -readnow options are typically combined in order to
4079 build a `fred.syms' file that contains complete symbol information.
4080 A simple GDB invocation to do nothing but build a `.syms' file for future
4083 gdb -batch -nx -mapped -readnow programname
4085 The `.syms' file is specific to the host machine on which GDB is run.
4086 It holds an exact image of GDB's internal symbol table. It cannot be
4087 shared across multiple host platforms.
4089 * longjmp() handling
4091 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
4092 siglongjmp() without losing control. This feature has not yet been ported to
4093 all systems. It currently works on many 386 platforms, all MIPS-based
4094 platforms (SGI, DECstation, etc), and Sun3/4.
4098 Preliminary work has been put in to support the new Solaris OS from Sun. At
4099 this time, it can control and debug processes, but it is not capable of
4104 As always, many many bug fixes. The major areas were with g++, and mipsread.
4105 People using the MIPS-based platforms should experience fewer mysterious
4106 crashes and trashed symbol tables.
4108 *** Changes in GDB-4.4:
4110 * New machines supported (host and target)
4112 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4114 BSD Reno on Vax vax-dec-bsd
4115 Ultrix on Vax vax-dec-ultrix
4117 * New machines supported (target)
4119 AMD 29000 embedded, using EBMON a29k-none-none
4123 GDB continues to improve its handling of C++. `References' work better.
4124 The demangler has also been improved, and now deals with symbols mangled as
4125 per the Annotated C++ Reference Guide.
4127 GDB also now handles `stabs' symbol information embedded in MIPS
4128 `ecoff' symbol tables. Since the ecoff format was not easily
4129 extensible to handle new languages such as C++, this appeared to be a
4130 good way to put C++ debugging info into MIPS binaries. This option
4131 will be supported in the GNU C compiler, version 2, when it is
4134 * New features for SVR4
4136 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
4137 shared libraries. Debugging dynamically linked programs should present
4138 only minor differences from debugging statically linked programs.
4140 The `info proc' command will print out information about any process
4141 on an SVR4 system (including the one you are debugging). At the moment,
4142 it prints the address mappings of the process.
4144 If you bring up GDB on another SVR4 system, please send mail to
4145 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
4147 * Better dynamic linking support in SunOS
4149 Reading symbols from shared libraries which contain debugging symbols
4150 now works properly. However, there remain issues such as automatic
4151 skipping of `transfer vector' code during function calls, which
4152 make it harder to debug code in a shared library, than to debug the
4153 same code linked statically.
4157 GDB is now using the latest `getopt' routines from the FSF. This
4158 version accepts the -- prefix for options with long names. GDB will
4159 continue to accept the old forms (-option and +option) as well.
4160 Various single letter abbreviations for options have been explicity
4161 added to the option table so that they won't get overshadowed in the
4162 future by other options that begin with the same letter.
4166 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
4167 Many assorted bugs have been handled. Many more remain to be handled.
4168 See the various ChangeLog files (primarily in gdb and bfd) for details.
4171 *** Changes in GDB-4.3:
4173 * New machines supported (host and target)
4175 Amiga 3000 running Amix m68k-cbm-svr4 or amix
4176 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
4177 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4179 * Almost SCO Unix support
4181 We had hoped to support:
4182 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4183 (except for core file support), but we discovered very late in the release
4184 that it has problems with process groups that render gdb unusable. Sorry
4185 about that. I encourage people to fix it and post the fixes.
4187 * Preliminary ELF and DWARF support
4189 GDB can read ELF object files on System V Release 4, and can handle
4190 debugging records for C, in DWARF format, in ELF files. This support
4191 is preliminary. If you bring up GDB on another SVR4 system, please
4192 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
4197 GDB now uses the latest `readline' library. One user-visible change
4198 is that two tabs will list possible command completions, which previously
4199 required typing M-? (meta-question mark, or ESC ?).
4203 The `stepi' bug that many of you noticed has been squashed.
4204 Many bugs in C++ have been handled. Many more remain to be handled.
4205 See the various ChangeLog files (primarily in gdb and bfd) for details.
4207 * State of the MIPS world (in case you wondered):
4209 GDB can understand the symbol tables emitted by the compilers
4210 supplied by most vendors of MIPS-based machines, including DEC. These
4211 symbol tables are in a format that essentially nobody else uses.
4213 Some versions of gcc come with an assembler post-processor called
4214 mips-tfile. This program is required if you want to do source-level
4215 debugging of gcc-compiled programs. I believe FSF does not ship
4216 mips-tfile with gcc version 1, but it will eventually come with gcc
4219 Debugging of g++ output remains a problem. g++ version 1.xx does not
4220 really support it at all. (If you're lucky, you should be able to get
4221 line numbers and stack traces to work, but no parameters or local
4222 variables.) With some work it should be possible to improve the
4225 When gcc version 2 is released, you will have somewhat better luck.
4226 However, even then you will get confusing results for inheritance and
4229 We will eventually provide full debugging of g++ output on
4230 DECstations. This will probably involve some kind of stabs-in-ecoff
4231 encapulation, but the details have not been worked out yet.
4234 *** Changes in GDB-4.2:
4236 * Improved configuration
4238 Only one copy of `configure' exists now, and it is not self-modifying.
4239 Porting BFD is simpler.
4243 The `step' and `next' commands now only stop at the first instruction
4244 of a source line. This prevents the multiple stops that used to occur
4245 in switch statements, for-loops, etc. `Step' continues to stop if a
4246 function that has debugging information is called within the line.
4250 Lots of small bugs fixed. More remain.
4252 * New host supported (not target)
4254 Intel 386 PC clone running Mach i386-none-mach
4257 *** Changes in GDB-4.1:
4259 * Multiple source language support
4261 GDB now has internal scaffolding to handle several source languages.
4262 It determines the type of each source file from its filename extension,
4263 and will switch expression parsing and number formatting to match the
4264 language of the function in the currently selected stack frame.
4265 You can also specifically set the language to be used, with
4266 `set language c' or `set language modula-2'.
4270 GDB now has preliminary support for the GNU Modula-2 compiler,
4271 currently under development at the State University of New York at
4272 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
4273 continue through the fall of 1991 and into 1992.
4275 Other Modula-2 compilers are currently not supported, and attempting to
4276 debug programs compiled with them will likely result in an error as the
4277 symbol table is read. Feel free to work on it, though!
4279 There are hooks in GDB for strict type checking and range checking,
4280 in the `Modula-2 philosophy', but they do not currently work.
4284 GDB can now write to executable and core files (e.g. patch
4285 a variable's value). You must turn this switch on, specify
4286 the file ("exec foo" or "core foo"), *then* modify it, e.g.
4287 by assigning a new value to a variable. Modifications take
4290 * Automatic SunOS shared library reading
4292 When you run your program, GDB automatically determines where its
4293 shared libraries (if any) have been loaded, and reads their symbols.
4294 The `share' command is no longer needed. This also works when
4295 examining core files.
4299 You can specify the number of lines that the `list' command shows.
4302 * New machines supported (host and target)
4304 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4305 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
4306 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
4308 * New hosts supported (not targets)
4310 IBM RT/PC: romp-ibm-aix or rtpc
4312 * New targets supported (not hosts)
4314 AMD 29000 embedded with COFF a29k-none-coff
4315 AMD 29000 embedded with a.out a29k-none-aout
4316 Ultracomputer remote kernel debug a29k-nyu-kern
4318 * New remote interfaces
4324 *** Changes in GDB-4.0:
4328 Wide output is wrapped at good places to make the output more readable.
4330 Gdb now supports cross-debugging from a host machine of one type to a
4331 target machine of another type. Communication with the target system
4332 is over serial lines. The ``target'' command handles connecting to the
4333 remote system; the ``load'' command will download a program into the
4334 remote system. Serial stubs for the m68k and i386 are provided. Gdb
4335 also supports debugging of realtime processes running under VxWorks,
4336 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
4337 stub on the target system.
4339 New CPUs supported include the AMD 29000 and Intel 960.
4341 GDB now reads object files and symbol tables via a ``binary file''
4342 library, which allows a single copy of GDB to debug programs of multiple
4343 object file types such as a.out and coff.
4345 There is now a GDB reference card in "doc/refcard.tex". (Make targets
4346 refcard.dvi and refcard.ps are available to format it).
4349 * Control-Variable user interface simplified
4351 All variables that control the operation of the debugger can be set
4352 by the ``set'' command, and displayed by the ``show'' command.
4354 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
4355 ``Show prompt'' produces the response:
4356 Gdb's prompt is new-gdb=>.
4358 What follows are the NEW set commands. The command ``help set'' will
4359 print a complete list of old and new set commands. ``help set FOO''
4360 will give a longer description of the variable FOO. ``show'' will show
4361 all of the variable descriptions and their current settings.
4363 confirm on/off: Enables warning questions for operations that are
4364 hard to recover from, e.g. rerunning the program while
4365 it is already running. Default is ON.
4367 editing on/off: Enables EMACS style command line editing
4368 of input. Previous lines can be recalled with
4369 control-P, the current line can be edited with control-B,
4370 you can search for commands with control-R, etc.
4373 history filename NAME: NAME is where the gdb command history
4374 will be stored. The default is .gdb_history,
4375 or the value of the environment variable
4378 history size N: The size, in commands, of the command history. The
4379 default is 256, or the value of the environment variable
4382 history save on/off: If this value is set to ON, the history file will
4383 be saved after exiting gdb. If set to OFF, the
4384 file will not be saved. The default is OFF.
4386 history expansion on/off: If this value is set to ON, then csh-like
4387 history expansion will be performed on
4388 command line input. The default is OFF.
4390 radix N: Sets the default radix for input and output. It can be set
4391 to 8, 10, or 16. Note that the argument to "radix" is interpreted
4392 in the current radix, so "set radix 10" is always a no-op.
4394 height N: This integer value is the number of lines on a page. Default
4395 is 24, the current `stty rows'' setting, or the ``li#''
4396 setting from the termcap entry matching the environment
4399 width N: This integer value is the number of characters on a line.
4400 Default is 80, the current `stty cols'' setting, or the ``co#''
4401 setting from the termcap entry matching the environment
4404 Note: ``set screensize'' is obsolete. Use ``set height'' and
4405 ``set width'' instead.
4407 print address on/off: Print memory addresses in various command displays,
4408 such as stack traces and structure values. Gdb looks
4409 more ``symbolic'' if you turn this off; it looks more
4410 ``machine level'' with it on. Default is ON.
4412 print array on/off: Prettyprint arrays. New convenient format! Default
4415 print demangle on/off: Print C++ symbols in "source" form if on,
4418 print asm-demangle on/off: Same, for assembler level printouts
4421 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
4424 * Support for Epoch Environment.
4426 The epoch environment is a version of Emacs v18 with windowing. One
4427 new command, ``inspect'', is identical to ``print'', except that if you
4428 are running in the epoch environment, the value is printed in its own
4432 * Support for Shared Libraries
4434 GDB can now debug programs and core files that use SunOS shared libraries.
4435 Symbols from a shared library cannot be referenced
4436 before the shared library has been linked with the program (this
4437 happens after you type ``run'' and before the function main() is entered).
4438 At any time after this linking (including when examining core files
4439 from dynamically linked programs), gdb reads the symbols from each
4440 shared library when you type the ``sharedlibrary'' command.
4441 It can be abbreviated ``share''.
4443 sharedlibrary REGEXP: Load shared object library symbols for files
4444 matching a unix regular expression. No argument
4445 indicates to load symbols for all shared libraries.
4447 info sharedlibrary: Status of loaded shared libraries.
4452 A watchpoint stops execution of a program whenever the value of an
4453 expression changes. Checking for this slows down execution
4454 tremendously whenever you are in the scope of the expression, but is
4455 quite useful for catching tough ``bit-spreader'' or pointer misuse
4456 problems. Some machines such as the 386 have hardware for doing this
4457 more quickly, and future versions of gdb will use this hardware.
4459 watch EXP: Set a watchpoint (breakpoint) for an expression.
4461 info watchpoints: Information about your watchpoints.
4463 delete N: Deletes watchpoint number N (same as breakpoints).
4464 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
4465 enable N: Re-enables watchpoint number N (same as breakpoints).
4468 * C++ multiple inheritance
4470 When used with a GCC version 2 compiler, GDB supports multiple inheritance
4473 * C++ exception handling
4475 Gdb now supports limited C++ exception handling. Besides the existing
4476 ability to breakpoint on an exception handler, gdb can breakpoint on
4477 the raising of an exception (before the stack is peeled back to the
4480 catch FOO: If there is a FOO exception handler in the dynamic scope,
4481 set a breakpoint to catch exceptions which may be raised there.
4482 Multiple exceptions (``catch foo bar baz'') may be caught.
4484 info catch: Lists all exceptions which may be caught in the
4485 current stack frame.
4488 * Minor command changes
4490 The command ``call func (arg, arg, ...)'' now acts like the print
4491 command, except it does not print or save a value if the function's result
4492 is void. This is similar to dbx usage.
4494 The ``up'' and ``down'' commands now always print the frame they end up
4495 at; ``up-silently'' and `down-silently'' can be used in scripts to change
4496 frames without printing.
4498 * New directory command
4500 'dir' now adds directories to the FRONT of the source search path.
4501 The path starts off empty. Source files that contain debug information
4502 about the directory in which they were compiled can be found even
4503 with an empty path; Sun CC and GCC include this information. If GDB can't
4504 find your source file in the current directory, type "dir .".
4506 * Configuring GDB for compilation
4508 For normal use, type ``./configure host''. See README or gdb.texinfo
4511 GDB now handles cross debugging. If you are remotely debugging between
4512 two different machines, type ``./configure host -target=targ''.
4513 Host is the machine where GDB will run; targ is the machine
4514 where the program that you are debugging will run.