1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.3
6 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
7 and "show remote hardware-watchpoint-length-limit". These allows to
8 set or show the maximum length limit (in bytes) of a remote
9 target hardware watchpoint.
11 This allows e.g. to use "unlimited" hardware watchpoints with the
12 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
13 watchpoints are slower than real hardware watchpoints but are
14 significantly faster than gdb software watchpoints.
18 ** The "maint set python print-stack on|off" command has been
19 deprecated, and a new command: "set python print-stack on|off" has
20 replaced it. Additionally, the default for "print-stack" is now
23 ** A prompt subsitution hook (prompt_hook) is now available to the
26 ** Python commands and convenience-functions located in
27 'data-directory'/python/gdb/command and
28 'data-directory'/python/gdb/function are now automatically loaded
31 * libthread-db-search-path now supports two special values: $sdir and $pdir.
32 $sdir specifies the default system locations of shared libraries.
33 $pdir specifies the directory where the libpthread used by the application
36 GDB no longer looks in $sdir and $pdir after it has searched the directories
37 mentioned in libthread-db-search-path. If you want to search those
38 directories, they must be specified in libthread-db-search-path.
39 The default value of libthread-db-search-path on GNU/Linux and Solaris
40 systems is now "$sdir:$pdir".
42 $pdir is not supported by gdbserver, it is currently ignored.
43 $sdir is supported by gdbserver.
45 * New configure option --with-iconv-bin.
46 When using the internationalization support like the one in the GNU C
47 library, GDB will invoke the "iconv" program to get a list of supported
48 character sets. If this program lives in a non-standard location, one can
49 use this option to specify where to find it.
51 * When natively debugging programs on PowerPC BookE processors running
52 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
53 watchpoints, which specify a mask in addition to an address to watch.
54 The mask specifies that some bits of an address (the bits which are
55 reset in the mask) should be ignored when matching the address accessed
56 by the inferior against the watchpoint address. See the "PowerPC Embedded"
57 section in the user manual for more details.
59 * The new option --once causes GDBserver to stop listening for connections once
60 the first connection is made. The listening port used by GDBserver will
61 become available after that.
63 * New commands "info macros", and "info definitions" have been added.
67 watch EXPRESSION mask MASK_VALUE
68 The watch command now supports the mask argument which allows creation
69 of masked watchpoints, if the current architecture supports this feature.
71 info auto-load-scripts [REGEXP]
72 This command was formerly named "maintenance print section-scripts".
73 It is now generally useful and is no longer a maintenance-only command.
75 * Tracepoints can now be enabled and disabled at any time after a trace
76 experiment has been started using the standard "enable" and "disable"
77 commands. It is now possible to start a trace experiment with no enabled
78 tracepoints; GDB will display a warning, but will allow the experiment to
79 begin, assuming that tracepoints will be enabled as needed while the trace
86 Dynamically enable a tracepoint in a started trace experiment.
90 Dynamically disable a tracepoint in a started trace experiment.
92 * Dcache size (number of lines) and line-size are now runtime-configurable
93 via "set dcache line" and "set dcache line-size" commands.
95 *** Changes in GDB 7.3
97 * GDB has a new command: "thread find [REGEXP]".
98 It finds the thread id whose name, target id, or thread extra info
99 matches the given regular expression.
101 * The "catch syscall" command now works on mips*-linux* targets.
103 * The -data-disassemble MI command now supports modes 2 and 3 for
104 dumping the instruction opcodes.
106 * New command line options
108 -data-directory DIR Specify DIR as the "data-directory".
109 This is mostly for testing purposes.
111 * The "maint set python auto-load on|off" command has been renamed to
112 "set auto-load-scripts on|off".
114 * GDB has a new command: "set directories".
115 It is like the "dir" command except that it replaces the
116 source path list instead of augmenting it.
118 * GDB now understands thread names.
120 On GNU/Linux, "info threads" will display the thread name as set by
121 prctl or pthread_setname_np.
123 There is also a new command, "thread name", which can be used to
124 assign a name internally for GDB to display.
127 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
128 has been integrated into GDB.
132 ** The function gdb.Write now accepts an optional keyword 'stream'.
133 This keyword, when provided, will direct the output to either
134 stdout, stderr, or GDB's logging output.
136 ** Parameters can now be be sub-classed in Python, and in particular
137 you may implement the get_set_doc and get_show_doc functions.
138 This improves how Parameter set/show documentation is processed
139 and allows for more dynamic content.
141 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
142 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
143 have an is_valid method.
145 ** Breakpoints can now be sub-classed in Python, and in particular
146 you may implement a 'stop' function that is executed each time
147 the inferior reaches that breakpoint.
149 ** New function gdb.lookup_global_symbol looks up a global symbol.
151 ** GDB values in Python are now callable if the value represents a
152 function. For example, if 'some_value' represents a function that
153 takes two integer parameters and returns a value, you can call
154 that function like so:
156 result = some_value (10,20)
158 ** Module gdb.types has been added.
159 It contains a collection of utilities for working with gdb.Types objects:
160 get_basic_type, has_field, make_enum_dict.
162 ** Module gdb.printing has been added.
163 It contains utilities for writing and registering pretty-printers.
164 New classes: PrettyPrinter, SubPrettyPrinter,
165 RegexpCollectionPrettyPrinter.
166 New function: register_pretty_printer.
168 ** New commands "info pretty-printers", "enable pretty-printer" and
169 "disable pretty-printer" have been added.
171 ** gdb.parameter("directories") is now available.
173 ** New function gdb.newest_frame returns the newest frame in the
176 ** The gdb.InferiorThread class has a new "name" attribute. This
177 holds the thread's name.
179 ** Python Support for Inferior events.
180 Python scripts can add observers to be notified of events
181 occurring in the process being debugged.
182 The following events are currently supported:
183 - gdb.events.cont Continue event.
184 - gdb.events.exited Inferior exited event.
185 - gdb.events.stop Signal received, and Breakpoint hit events.
189 ** GDB now puts template parameters in scope when debugging in an
190 instantiation. For example, if you have:
192 template<int X> int func (void) { return X; }
194 then if you step into func<5>, "print X" will show "5". This
195 feature requires proper debuginfo support from the compiler; it
196 was added to GCC 4.5.
198 ** The motion commands "next", "finish", "until", and "advance" now
199 work better when exceptions are thrown. In particular, GDB will
200 no longer lose control of the inferior; instead, the GDB will
201 stop the inferior at the point at which the exception is caught.
202 This functionality requires a change in the exception handling
203 code that was introduced in GCC 4.5.
205 * GDB now follows GCC's rules on accessing volatile objects when
206 reading or writing target state during expression evaluation.
207 One notable difference to prior behavior is that "print x = 0"
208 no longer generates a read of x; the value of the assignment is
209 now always taken directly from the value being assigned.
211 * GDB now has some support for using labels in the program's source in
212 linespecs. For instance, you can use "advance label" to continue
213 execution to a label.
215 * GDB now has support for reading and writing a new .gdb_index
216 section. This section holds a fast index of DWARF debugging
217 information and can be used to greatly speed up GDB startup and
218 operation. See the documentation for `save gdb-index' for details.
220 * The "watch" command now accepts an optional "-location" argument.
221 When used, this causes GDB to watch the memory referred to by the
222 expression. Such a watchpoint is never deleted due to it going out
225 * GDB now supports thread debugging of core dumps on GNU/Linux.
227 GDB now activates thread debugging using the libthread_db library
228 when debugging GNU/Linux core dumps, similarly to when debugging
229 live processes. As a result, when debugging a core dump file, GDB
230 is now able to display pthread_t ids of threads. For example, "info
231 threads" shows the same output as when debugging the process when it
232 was live. In earlier releases, you'd see something like this:
235 * 1 LWP 6780 main () at main.c:10
237 While now you see this:
240 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
242 It is also now possible to inspect TLS variables when debugging core
245 When debugging a core dump generated on a machine other than the one
246 used to run GDB, you may need to point GDB at the correct
247 libthread_db library with the "set libthread-db-search-path"
248 command. See the user manual for more details on this command.
250 * When natively debugging programs on PowerPC BookE processors running
251 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
252 which stop execution of the inferior whenever it executes an instruction
253 at any address within the specified range. See the "PowerPC Embedded"
254 section in the user manual for more details.
256 * New features in the GDB remote stub, GDBserver
258 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
259 and i686 LynxOS (version 5.x).
261 ** GDBserver is now supported on Blackfin Linux.
263 * New native configurations
265 ia64 HP-UX ia64-*-hpux*
269 Analog Devices, Inc. Blackfin Processor bfin-*
271 * Ada task switching is now supported on sparc-elf targets when
272 debugging a program using the Ravenscar Profile. For more information,
273 see the "Tasking Support when using the Ravenscar Profile" section
274 in the GDB user manual.
276 * Guile support was removed.
278 * New features in the GNU simulator
280 ** The --map-info flag lists all known core mappings.
282 ** CFI flashes may be simulated via the "cfi" device.
284 *** Changes in GDB 7.2
286 * Shared library support for remote targets by default
288 When GDB is configured for a generic, non-OS specific target, like
289 for example, --target=arm-eabi or one of the many *-*-elf targets,
290 GDB now queries remote stubs for loaded shared libraries using the
291 `qXfer:libraries:read' packet. Previously, shared library support
292 was always disabled for such configurations.
296 ** Argument Dependent Lookup (ADL)
298 In C++ ADL lookup directs function search to the namespaces of its
299 arguments even if the namespace has not been imported.
309 Here the compiler will search for `foo' in the namespace of 'b'
310 and find A::foo. GDB now supports this. This construct is commonly
311 used in the Standard Template Library for operators.
313 ** Improved User Defined Operator Support
315 In addition to member operators, GDB now supports lookup of operators
316 defined in a namespace and imported with a `using' directive, operators
317 defined in the global scope, operators imported implicitly from an
318 anonymous namespace, and the ADL operators mentioned in the previous
320 GDB now also supports proper overload resolution for all the previously
321 mentioned flavors of operators.
323 ** static const class members
325 Printing of static const class members that are initialized in the
326 class definition has been fixed.
328 * Windows Thread Information Block access.
330 On Windows targets, GDB now supports displaying the Windows Thread
331 Information Block (TIB) structure. This structure is visible either
332 by using the new command `info w32 thread-information-block' or, by
333 dereferencing the new convenience variable named `$_tlb', a
334 thread-specific pointer to the TIB. This feature is also supported
335 when remote debugging using GDBserver.
339 Static tracepoints are calls in the user program into a tracing
340 library. One such library is a port of the LTTng kernel tracer to
341 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
342 When debugging with GDBserver, GDB now supports combining the GDB
343 tracepoint machinery with such libraries. For example: the user can
344 use GDB to probe a static tracepoint marker (a call from the user
345 program into the tracing library) with the new "strace" command (see
346 "New commands" below). This creates a "static tracepoint" in the
347 breakpoint list, that can be manipulated with the same feature set
348 as fast and regular tracepoints. E.g., collect registers, local and
349 global variables, collect trace state variables, and define
350 tracepoint conditions. In addition, the user can collect extra
351 static tracepoint marker specific data, by collecting the new
352 $_sdata internal variable. When analyzing the trace buffer, you can
353 inspect $_sdata like any other variable available to GDB. For more
354 information, see the "Tracepoints" chapter in GDB user manual. New
355 remote packets have been defined to support static tracepoints, see
356 the "New remote packets" section below.
358 * Better reconstruction of tracepoints after disconnected tracing
360 GDB will attempt to download the original source form of tracepoint
361 definitions when starting a trace run, and then will upload these
362 upon reconnection to the target, resulting in a more accurate
363 reconstruction of the tracepoints that are in use on the target.
367 You can now exercise direct control over the ways that GDB can
368 affect your program. For instance, you can disallow the setting of
369 breakpoints, so that the program can run continuously (assuming
370 non-stop mode). In addition, the "observer" variable is available
371 to switch all of the different controls; in observer mode, GDB
372 cannot affect the target's behavior at all, which is useful for
373 tasks like diagnosing live systems in the field.
375 * The new convenience variable $_thread holds the number of the
382 Return the address of the Windows Thread Information Block of a given thread.
386 In response to several of the tracepoint packets, the target may now
387 also respond with a number of intermediate `qRelocInsn' request
388 packets before the final result packet, to have GDB handle
389 relocating an instruction to execute at a different address. This
390 is particularly useful for stubs that support fast tracepoints. GDB
391 reports support for this feature in the qSupported packet.
395 List static tracepoint markers in the target program.
399 List static tracepoint markers at a given address in the target
402 qXfer:statictrace:read
404 Read the static trace data collected (by a `collect $_sdata'
405 tracepoint action). The remote stub reports support for this packet
406 to gdb's qSupported query.
410 Send the current settings of GDB's permission flags.
414 Send part of the source (textual) form of a tracepoint definition,
415 which includes location, conditional, and action list.
417 * The source command now accepts a -s option to force searching for the
418 script in the source search path even if the script name specifies
421 * New features in the GDB remote stub, GDBserver
423 - GDBserver now support tracepoints (including fast tracepoints, and
424 static tracepoints). The feature is currently supported by the
425 i386-linux and amd64-linux builds. See the "Tracepoints support
426 in gdbserver" section in the manual for more information.
428 GDBserver JIT compiles the tracepoint's conditional agent
429 expression bytecode into native code whenever possible for low
430 overhead dynamic tracepoints conditionals. For such tracepoints,
431 an expression that examines program state is evaluated when the
432 tracepoint is reached, in order to determine whether to capture
433 trace data. If the condition is simple and false, processing the
434 tracepoint finishes very quickly and no data is gathered.
436 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
437 for static tracepoints support.
439 - GDBserver now supports x86_64 Windows 64-bit debugging.
441 * GDB now sends xmlRegisters= in qSupported packet to indicate that
442 it understands register description.
444 * The --batch flag now disables pagination and queries.
446 * X86 general purpose registers
448 GDB now supports reading/writing byte, word and double-word x86
449 general purpose registers directly. This means you can use, say,
450 $ah or $ax to refer, respectively, to the byte register AH and
451 16-bit word register AX that are actually portions of the 32-bit
452 register EAX or 64-bit register RAX.
454 * The `commands' command now accepts a range of breakpoints to modify.
455 A plain `commands' following a command that creates multiple
456 breakpoints affects all the breakpoints set by that command. This
457 applies to breakpoints set by `rbreak', and also applies when a
458 single `break' command creates multiple breakpoints (e.g.,
459 breakpoints on overloaded c++ functions).
461 * The `rbreak' command now accepts a filename specification as part of
462 its argument, limiting the functions selected by the regex to those
463 in the specified file.
465 * Support for remote debugging Windows and SymbianOS shared libraries
466 from Unix hosts has been improved. Non Windows GDB builds now can
467 understand target reported file names that follow MS-DOS based file
468 system semantics, such as file names that include drive letters and
469 use the backslash character as directory separator. This makes it
470 possible to transparently use the "set sysroot" and "set
471 solib-search-path" on Unix hosts to point as host copies of the
472 target's shared libraries. See the new command "set
473 target-file-system-kind" described below, and the "Commands to
474 specify files" section in the user manual for more information.
478 eval template, expressions...
479 Convert the values of one or more expressions under the control
480 of the string template to a command line, and call it.
482 set target-file-system-kind unix|dos-based|auto
483 show target-file-system-kind
484 Set or show the assumed file system kind for target reported file
487 save breakpoints <filename>
488 Save all current breakpoint definitions to a file suitable for use
489 in a later debugging session. To read the saved breakpoint
490 definitions, use the `source' command.
492 `save tracepoints' is a new alias for `save-tracepoints'. The latter
495 info static-tracepoint-markers
496 Display information about static tracepoint markers in the target.
498 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
499 Define a static tracepoint by probing a marker at the given
500 function, line, address, or marker ID.
504 Enable and disable observer mode.
506 set may-write-registers on|off
507 set may-write-memory on|off
508 set may-insert-breakpoints on|off
509 set may-insert-tracepoints on|off
510 set may-insert-fast-tracepoints on|off
511 set may-interrupt on|off
512 Set individual permissions for GDB effects on the target. Note that
513 some of these settings can have undesirable or surprising
514 consequences, particularly when changed in the middle of a session.
515 For instance, disabling the writing of memory can prevent
516 breakpoints from being inserted, cause single-stepping to fail, or
517 even crash your program, if you disable after breakpoints have been
518 inserted. However, GDB should not crash.
520 set record memory-query on|off
521 show record memory-query
522 Control whether to stop the inferior if memory changes caused
523 by an instruction cannot be recorded.
528 The disassemble command now supports "start,+length" form of two arguments.
532 ** GDB now provides a new directory location, called the python directory,
533 where Python scripts written for GDB can be installed. The location
534 of that directory is <data-directory>/python, where <data-directory>
535 is the GDB data directory. For more details, see section `Scripting
536 GDB using Python' in the manual.
538 ** The GDB Python API now has access to breakpoints, symbols, symbol
539 tables, program spaces, inferiors, threads and frame's code blocks.
540 Additionally, GDB Parameters can now be created from the API, and
541 manipulated via set/show in the CLI.
543 ** New functions gdb.target_charset, gdb.target_wide_charset,
544 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
546 ** New exception gdb.GdbError.
548 ** Pretty-printers are now also looked up in the current program space.
550 ** Pretty-printers can now be individually enabled and disabled.
552 ** GDB now looks for names of Python scripts to auto-load in a
553 special section named `.debug_gdb_scripts', in addition to looking
554 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
556 * Tracepoint actions were unified with breakpoint commands. In particular,
557 there are no longer differences in "info break" output for breakpoints and
558 tracepoints and the "commands" command can be used for both tracepoints and
563 ARM Symbian arm*-*-symbianelf*
565 * D language support.
566 GDB now supports debugging programs written in the D programming
569 * GDB now supports the extended ptrace interface for PowerPC which is
570 available since Linux kernel version 2.6.34. This automatically enables
571 any hardware breakpoints and additional hardware watchpoints available in
572 the processor. The old ptrace interface exposes just one hardware
573 watchpoint and no hardware breakpoints.
575 * GDB is now able to use the Data Value Compare (DVC) register available on
576 embedded PowerPC processors to implement in hardware simple watchpoint
577 conditions of the form:
579 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
581 This works in native GDB running on Linux kernels with the extended ptrace
582 interface mentioned above.
584 *** Changes in GDB 7.1
590 GDB now supports importing of namespaces in C++. This enables the
591 user to inspect variables from imported namespaces. Support for
592 namepace aliasing has also been added. So, if a namespace is
593 aliased in the current scope (e.g. namepace C=A; ) the user can
594 print variables using the alias (e.g. (gdb) print C::x).
598 All known bugs relating to the printing of virtual base class were
599 fixed. It is now possible to call overloaded static methods using a
604 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
605 and reinterpret_cast<> are now handled by the C++ expression parser.
609 Xilinx MicroBlaze microblaze-*-*
614 Xilinx MicroBlaze microblaze
617 * Multi-program debugging.
619 GDB now has support for multi-program (a.k.a. multi-executable or
620 multi-exec) debugging. This allows for debugging multiple inferiors
621 simultaneously each running a different program under the same GDB
622 session. See "Debugging Multiple Inferiors and Programs" in the
623 manual for more information. This implied some user visible changes
624 in the multi-inferior support. For example, "info inferiors" now
625 lists inferiors that are not running yet or that have exited
626 already. See also "New commands" and "New options" below.
628 * New tracing features
630 GDB's tracepoint facility now includes several new features:
632 ** Trace state variables
634 GDB tracepoints now include support for trace state variables, which
635 are variables managed by the target agent during a tracing
636 experiment. They are useful for tracepoints that trigger each
637 other, so for instance one tracepoint can count hits in a variable,
638 and then a second tracepoint has a condition that is true when the
639 count reaches a particular value. Trace state variables share the
640 $-syntax of GDB convenience variables, and can appear in both
641 tracepoint actions and condition expressions. Use the "tvariable"
642 command to create, and "info tvariables" to view; see "Trace State
643 Variables" in the manual for more detail.
647 GDB now includes an option for defining fast tracepoints, which
648 targets may implement more efficiently, such as by installing a jump
649 into the target agent rather than a trap instruction. The resulting
650 speedup can be by two orders of magnitude or more, although the
651 tradeoff is that some program locations on some target architectures
652 might not allow fast tracepoint installation, for instance if the
653 instruction to be replaced is shorter than the jump. To request a
654 fast tracepoint, use the "ftrace" command, with syntax identical to
655 the regular trace command.
657 ** Disconnected tracing
659 It is now possible to detach GDB from the target while it is running
660 a trace experiment, then reconnect later to see how the experiment
661 is going. In addition, a new variable disconnected-tracing lets you
662 tell the target agent whether to continue running a trace if the
663 connection is lost unexpectedly.
667 GDB now has the ability to save the trace buffer into a file, and
668 then use that file as a target, similarly to you can do with
669 corefiles. You can select trace frames, print data that was
670 collected in them, and use tstatus to display the state of the
671 tracing run at the moment that it was saved. To create a trace
672 file, use "tsave <filename>", and to use it, do "target tfile
675 ** Circular trace buffer
677 You can ask the target agent to handle the trace buffer as a
678 circular buffer, discarding the oldest trace frames to make room for
679 newer ones, by setting circular-trace-buffer to on. This feature may
680 not be available for all target agents.
685 The disassemble command, when invoked with two arguments, now requires
686 the arguments to be comma-separated.
689 The info variables command now displays variable definitions. Files
690 which only declare a variable are not shown.
693 The source command is now capable of sourcing Python scripts.
694 This feature is dependent on the debugger being build with Python
697 Related to this enhancement is also the introduction of a new command
698 "set script-extension" (see below).
700 * New commands (for set/show, see "New options" below)
702 record save [<FILENAME>]
703 Save a file (in core file format) containing the process record
704 execution log for replay debugging at a later time.
706 record restore <FILENAME>
707 Restore the process record execution log that was saved at an
708 earlier time, for replay debugging.
710 add-inferior [-copies <N>] [-exec <FILENAME>]
713 clone-inferior [-copies <N>] [ID]
714 Make a new inferior ready to execute the same program another
720 maint info program-spaces
721 List the program spaces loaded into GDB.
723 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
724 show remote interrupt-sequence
725 Allow the user to select one of ^C, a BREAK signal or BREAK-g
726 as the sequence to the remote target in order to interrupt the execution.
727 Ctrl-C is a default. Some system prefers BREAK which is high level of
728 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
729 Magic SysRq g. It is BREAK signal and character 'g'.
731 set remote interrupt-on-connect [on | off]
732 show remote interrupt-on-connect
733 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
734 remote target when gdb connects to it. This is needed when you debug
737 set remotebreak [on | off]
739 Deprecated. Use "set/show remote interrupt-sequence" instead.
741 tvariable $NAME [ = EXP ]
742 Create or modify a trace state variable.
745 List trace state variables and their values.
747 delete tvariable $NAME ...
748 Delete one or more trace state variables.
751 Evaluate the given expressions without collecting anything into the
752 trace buffer. (Valid in tracepoint actions only.)
754 ftrace FN / FILE:LINE / *ADDR
755 Define a fast tracepoint at the given function, line, or address.
757 * New expression syntax
759 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
760 GDB now parses 0b101010 identically with 42.
764 set follow-exec-mode new|same
765 show follow-exec-mode
766 Control whether GDB reuses the same inferior across an exec call or
767 creates a new one. This is useful to be able to restart the old
768 executable after the inferior having done an exec call.
770 set default-collect EXPR, ...
772 Define a list of expressions to be collected at each tracepoint.
773 This is a useful way to ensure essential items are not overlooked,
774 such as registers or a critical global variable.
776 set disconnected-tracing
777 show disconnected-tracing
778 If set to 1, the target is instructed to continue tracing if it
779 loses its connection to GDB. If 0, the target is to stop tracing
782 set circular-trace-buffer
783 show circular-trace-buffer
784 If set to on, the target is instructed to use a circular trace buffer
785 and discard the oldest trace frames instead of stopping the trace due
786 to a full trace buffer. If set to off, the trace stops when the buffer
787 fills up. Some targets may not support this.
789 set script-extension off|soft|strict
790 show script-extension
791 If set to "off", the debugger does not perform any script language
792 recognition, and all sourced files are assumed to be GDB scripts.
793 If set to "soft" (the default), files are sourced according to
794 filename extension, falling back to GDB scripts if the first
796 If set to "strict", files are sourced according to filename extension.
798 set ada trust-PAD-over-XVS on|off
799 show ada trust-PAD-over-XVS
800 If off, activate a workaround against a bug in the debugging information
801 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
802 the GCC sources for more information about the GNAT encoding and
803 PAD types in particular). It is always safe to set this option to
804 off, but this introduces a slight performance penalty. The default
807 * Python API Improvements
809 ** GDB provides the new class gdb.LazyString. This is useful in
810 some pretty-printing cases. The new method gdb.Value.lazy_string
811 provides a simple way to create objects of this type.
813 ** The fields returned by gdb.Type.fields now have an
814 `is_base_class' attribute.
816 ** The new method gdb.Type.range returns the range of an array type.
818 ** The new method gdb.parse_and_eval can be used to parse and
819 evaluate an expression.
824 Define a trace state variable.
827 Get the current value of a trace state variable.
830 Set desired tracing behavior upon disconnection.
833 Set the trace buffer to be linear or circular.
836 Get data about the tracepoints currently in use.
840 Process record now works correctly with hardware watchpoints.
842 Multiple bug fixes have been made to the mips-irix port, making it
843 much more reliable. In particular:
844 - Debugging threaded applications is now possible again. Previously,
845 GDB would hang while starting the program, or while waiting for
846 the program to stop at a breakpoint.
847 - Attaching to a running process no longer hangs.
848 - An error occurring while loading a core file has been fixed.
849 - Changing the value of the PC register now works again. This fixes
850 problems observed when using the "jump" command, or when calling
851 a function from GDB, or even when assigning a new value to $pc.
852 - With the "finish" and "return" commands, the return value for functions
853 returning a small array is now correctly printed.
854 - It is now possible to break on shared library code which gets executed
855 during a shared library init phase (code executed while executing
856 their .init section). Previously, the breakpoint would have no effect.
857 - GDB is now able to backtrace through the signal handler for
858 non-threaded programs.
860 PIE (Position Independent Executable) programs debugging is now supported.
861 This includes debugging execution of PIC (Position Independent Code) shared
862 libraries although for that, it should be possible to run such libraries as an
865 *** Changes in GDB 7.0
867 * GDB now has an interface for JIT compilation. Applications that
868 dynamically generate code can create symbol files in memory and register
869 them with GDB. For users, the feature should work transparently, and
870 for JIT developers, the interface is documented in the GDB manual in the
871 "JIT Compilation Interface" chapter.
873 * Tracepoints may now be conditional. The syntax is as for
874 breakpoints; either an "if" clause appended to the "trace" command,
875 or the "condition" command is available. GDB sends the condition to
876 the target for evaluation using the same bytecode format as is used
877 for tracepoint actions.
879 * The disassemble command now supports: an optional /r modifier, print the
880 raw instructions in hex as well as in symbolic form, and an optional /m
881 modifier to print mixed source+assembly.
883 * Process record and replay
885 In a architecture environment that supports ``process record and
886 replay'', ``process record and replay'' target can record a log of
887 the process execution, and replay it with both forward and reverse
890 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
891 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
892 set execution-direction {forward|reverse}, for targets that support
895 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
896 feature is available with a native GDB running on kernel version
899 * GDB now has support for multi-byte and wide character sets on the
900 target. Strings whose character type is wchar_t, char16_t, or
901 char32_t are now correctly printed. GDB supports wide- and unicode-
902 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
903 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
904 `printf'. This feature requires iconv to work properly; if your
905 system does not have a working iconv, GDB can use GNU libiconv. See
906 the installation instructions for more information.
908 * GDB now supports automatic retrieval of shared library files from
909 remote targets. To use this feature, specify a system root that begins
910 with the `remote:' prefix, either via the `set sysroot' command or via
911 the `--with-sysroot' configure-time option.
913 * "info sharedlibrary" now takes an optional regex of libraries to show,
914 and it now reports if a shared library has no debugging information.
916 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
917 now complete on file names.
919 * When completing in expressions, gdb will attempt to limit
920 completions to allowable structure or union fields, where appropriate.
921 For instance, consider:
923 # struct example { int f1; double f2; };
924 # struct example variable;
927 If the user types TAB at the end of this command line, the available
928 completions will be "f1" and "f2".
930 * Inlined functions are now supported. They show up in backtraces, and
931 the "step", "next", and "finish" commands handle them automatically.
933 * GDB now supports the token-splicing (##) and stringification (#)
934 operators when expanding macros. It also supports variable-arity
937 * GDB now supports inspecting extra signal information, exported by
938 the new $_siginfo convenience variable. The feature is currently
939 implemented on linux ARM, i386 and amd64.
941 * GDB can now display the VFP floating point registers and NEON vector
942 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
943 can provide these registers (requires Linux 2.6.30 or later). Remote
944 and simulator targets may also provide them.
949 Search memory for a sequence of bytes.
952 Turn off `+'/`-' protocol acknowledgments to permit more efficient
953 operation over reliable transport links. Use of this packet is
954 controlled by the `set remote noack-packet' command.
957 Kill the process with the specified process ID. Use this in preference
958 to `k' when multiprocess protocol extensions are supported.
961 Obtains additional operating system information
965 Read or write additional signal information.
967 * Removed remote protocol undocumented extension
969 An undocumented extension to the remote protocol's `S' stop reply
970 packet that permited the stub to pass a process id was removed.
971 Remote servers should use the `T' stop reply packet instead.
973 * GDB now supports multiple function calling conventions according to the
974 DWARF-2 DW_AT_calling_convention function attribute.
976 * The SH target utilizes the aforementioned change to distinguish between gcc
977 and Renesas calling convention. It also adds the new CLI commands
978 `set/show sh calling-convention'.
980 * GDB can now read compressed debug sections, as produced by GNU gold
981 with the --compress-debug-sections=zlib flag.
983 * 64-bit core files are now supported on AIX.
985 * Thread switching is now supported on Tru64.
987 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
988 which will be allocated using malloc later in program execution.
990 * The qXfer:libraries:read remote procotol packet now allows passing a
991 list of section offsets.
993 * On GNU/Linux, GDB can now attach to stopped processes. Several race
994 conditions handling signals delivered during attach or thread creation
995 have also been fixed.
997 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
998 From the user's standpoint, all unqualified instances of True and False
999 are treated as the standard definitions, regardless of context.
1001 * GDB now parses C++ symbol and type names more flexibly. For
1004 template<typename T> class C { };
1007 GDB will now correctly handle all of:
1009 ptype C<char const *>
1010 ptype C<char const*>
1011 ptype C<const char *>
1012 ptype C<const char*>
1014 * New features in the GDB remote stub, gdbserver
1016 - The "--wrapper" command-line argument tells gdbserver to use a
1017 wrapper program to launch programs for debugging.
1019 - On PowerPC and S/390 targets, it is now possible to use a single
1020 gdbserver executable to debug both 32-bit and 64-bit programs.
1021 (This requires gdbserver itself to be built as a 64-bit executable.)
1023 - gdbserver uses the new noack protocol mode for TCP connections to
1024 reduce communications latency, if also supported and enabled in GDB.
1026 - Support for the sparc64-linux-gnu target is now included in
1029 - The amd64-linux build of gdbserver now supports debugging both
1030 32-bit and 64-bit programs.
1032 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
1033 now support hardware watchpoints, and will use them automatically
1038 GDB now has support for scripting using Python. Whether this is
1039 available is determined at configure time.
1041 New GDB commands can now be written in Python.
1043 * Ada tasking support
1045 Ada tasks can now be inspected in GDB. The following commands have
1049 Print the list of Ada tasks.
1051 Print detailed information about task number N.
1053 Print the task number of the current task.
1055 Switch the context of debugging to task number N.
1057 * Support for user-defined prefixed commands. The "define" command can
1058 add new commands to existing prefixes, e.g. "target".
1060 * Multi-inferior, multi-process debugging.
1062 GDB now has generalized support for multi-inferior debugging. See
1063 "Debugging Multiple Inferiors" in the manual for more information.
1064 Although availability still depends on target support, the command
1065 set is more uniform now. The GNU/Linux specific multi-forks support
1066 has been migrated to this new framework. This implied some user
1067 visible changes; see "New commands" and also "Removed commands"
1070 * Target descriptions can now describe the target OS ABI. See the
1071 "Target Description Format" section in the user manual for more
1074 * Target descriptions can now describe "compatible" architectures
1075 to indicate that the target can execute applications for a different
1076 architecture in addition to those for the main target architecture.
1077 See the "Target Description Format" section in the user manual for
1080 * Multi-architecture debugging.
1082 GDB now includes general supports for debugging applications on
1083 hybrid systems that use more than one single processor architecture
1084 at the same time. Each such hybrid architecture still requires
1085 specific support to be added. The only hybrid architecture supported
1086 in this version of GDB is the Cell Broadband Engine.
1088 * GDB now supports integrated debugging of Cell/B.E. applications that
1089 use both the PPU and SPU architectures. To enable support for hybrid
1090 Cell/B.E. debugging, you need to configure GDB to support both the
1091 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
1092 --enable-targets configure option.
1094 * Non-stop mode debugging.
1096 For some targets, GDB now supports an optional mode of operation in
1097 which you can examine stopped threads while other threads continue
1098 to execute freely. This is referred to as non-stop mode, with the
1099 old mode referred to as all-stop mode. See the "Non-Stop Mode"
1100 section in the user manual for more information.
1102 To be able to support remote non-stop debugging, a remote stub needs
1103 to implement the non-stop mode remote protocol extensions, as
1104 described in the "Remote Non-Stop" section of the user manual. The
1105 GDB remote stub, gdbserver, has been adjusted to support these
1106 extensions on linux targets.
1108 * New commands (for set/show, see "New options" below)
1110 catch syscall [NAME(S) | NUMBER(S)]
1111 Catch system calls. Arguments, which should be names of system
1112 calls or their numbers, mean catch only those syscalls. Without
1113 arguments, every syscall will be caught. When the inferior issues
1114 any of the specified syscalls, GDB will stop and announce the system
1115 call, both when it is called and when its call returns. This
1116 feature is currently available with a native GDB running on the
1117 Linux Kernel, under the following architectures: x86, x86_64,
1118 PowerPC and PowerPC64.
1120 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
1122 Search memory for a sequence of bytes.
1124 maint set python print-stack
1125 maint show python print-stack
1126 Show a stack trace when an error is encountered in a Python script.
1129 Invoke CODE by passing it to the Python interpreter.
1134 These allow macros to be defined, undefined, and listed
1138 Show operating system information about processes.
1141 List the inferiors currently under GDB's control.
1144 Switch focus to inferior number NUM.
1147 Detach from inferior number NUM.
1150 Kill inferior number NUM.
1154 set spu stop-on-load
1155 show spu stop-on-load
1156 Control whether to stop for new SPE threads during Cell/B.E. debugging.
1158 set spu auto-flush-cache
1159 show spu auto-flush-cache
1160 Control whether to automatically flush the software-managed cache
1161 during Cell/B.E. debugging.
1163 set sh calling-convention
1164 show sh calling-convention
1165 Control the calling convention used when calling SH target functions.
1168 show debug timestamp
1169 Control display of timestamps with GDB debugging output.
1171 set disassemble-next-line
1172 show disassemble-next-line
1173 Control display of disassembled source lines or instructions when
1176 set remote noack-packet
1177 show remote noack-packet
1178 Set/show the use of remote protocol QStartNoAckMode packet. See above
1179 under "New remote packets."
1181 set remote query-attached-packet
1182 show remote query-attached-packet
1183 Control use of remote protocol `qAttached' (query-attached) packet.
1185 set remote read-siginfo-object
1186 show remote read-siginfo-object
1187 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
1190 set remote write-siginfo-object
1191 show remote write-siginfo-object
1192 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
1195 set remote reverse-continue
1196 show remote reverse-continue
1197 Control use of remote protocol 'bc' (reverse-continue) packet.
1199 set remote reverse-step
1200 show remote reverse-step
1201 Control use of remote protocol 'bs' (reverse-step) packet.
1203 set displaced-stepping
1204 show displaced-stepping
1205 Control displaced stepping mode. Displaced stepping is a way to
1206 single-step over breakpoints without removing them from the debuggee.
1207 Also known as "out-of-line single-stepping".
1210 show debug displaced
1211 Control display of debugging info for displaced stepping.
1213 maint set internal-error
1214 maint show internal-error
1215 Control what GDB does when an internal error is detected.
1217 maint set internal-warning
1218 maint show internal-warning
1219 Control what GDB does when an internal warning is detected.
1224 Use a wrapper program to launch programs for debugging.
1226 set multiple-symbols (all|ask|cancel)
1227 show multiple-symbols
1228 The value of this variable can be changed to adjust the debugger behavior
1229 when an expression or a breakpoint location contains an ambiguous symbol
1230 name (an overloaded function name, for instance).
1232 set breakpoint always-inserted
1233 show breakpoint always-inserted
1234 Keep breakpoints always inserted in the target, as opposed to inserting
1235 them when resuming the target, and removing them when the target stops.
1236 This option can improve debugger performance on slow remote targets.
1238 set arm fallback-mode (arm|thumb|auto)
1239 show arm fallback-mode
1240 set arm force-mode (arm|thumb|auto)
1242 These commands control how ARM GDB determines whether instructions
1243 are ARM or Thumb. The default for both settings is auto, which uses
1244 the current CPSR value for instructions without symbols; previous
1245 versions of GDB behaved as if "set arm fallback-mode arm".
1247 set disable-randomization
1248 show disable-randomization
1249 Standalone programs run with the virtual address space randomization enabled
1250 by default on some platforms. This option keeps the addresses stable across
1251 multiple debugging sessions.
1255 Control whether other threads are stopped or not when some thread hits
1260 Requests that asynchronous execution is enabled in the target, if available.
1261 In this case, it's possible to resume target in the background, and interact
1262 with GDB while the target is running. "show target-async" displays the
1263 current state of asynchronous execution of the target.
1265 set target-wide-charset
1266 show target-wide-charset
1267 The target-wide-charset is the name of the character set that GDB
1268 uses when printing characters whose type is wchar_t.
1270 set tcp auto-retry (on|off)
1272 set tcp connect-timeout
1273 show tcp connect-timeout
1274 These commands allow GDB to retry failed TCP connections to a remote stub
1275 with a specified timeout period; this is useful if the stub is launched
1276 in parallel with GDB but may not be ready to accept connections immediately.
1278 set libthread-db-search-path
1279 show libthread-db-search-path
1280 Control list of directories which GDB will search for appropriate
1283 set schedule-multiple (on|off)
1284 show schedule-multiple
1285 Allow GDB to resume all threads of all processes or only threads of
1286 the current process.
1290 Use more aggressive caching for accesses to the stack. This improves
1291 performance of remote debugging (particularly backtraces) without
1292 affecting correctness.
1294 set interactive-mode (on|off|auto)
1295 show interactive-mode
1296 Control whether GDB runs in interactive mode (on) or not (off).
1297 When in interactive mode, GDB waits for the user to answer all
1298 queries. Otherwise, GDB does not wait and assumes the default
1299 answer. When set to auto (the default), GDB determines which
1300 mode to use based on the stdin settings.
1305 For program forks, this is replaced by the new more generic `info
1306 inferiors' command. To list checkpoints, you can still use the
1307 `info checkpoints' command, which was an alias for the `info forks'
1311 Replaced by the new `inferior' command. To switch between
1312 checkpoints, you can still use the `restart' command, which was an
1313 alias for the `fork' command.
1316 This is removed, since some targets don't have a notion of
1317 processes. To switch between processes, you can still use the
1318 `inferior' command using GDB's own inferior number.
1321 For program forks, this is replaced by the new more generic `kill
1322 inferior' command. To delete a checkpoint, you can still use the
1323 `delete checkpoint' command, which was an alias for the `delete
1327 For program forks, this is replaced by the new more generic `detach
1328 inferior' command. To detach a checkpoint, you can still use the
1329 `detach checkpoint' command, which was an alias for the `detach
1332 * New native configurations
1334 x86/x86_64 Darwin i[34567]86-*-darwin*
1336 x86_64 MinGW x86_64-*-mingw*
1340 Lattice Mico32 lm32-*
1341 x86 DICOS i[34567]86-*-dicos*
1342 x86_64 DICOS x86_64-*-dicos*
1345 * The GDB remote stub, gdbserver, now supports x86 Windows CE
1346 (mingw32ce) debugging.
1352 These commands were actually not implemented on any target.
1354 *** Changes in GDB 6.8
1356 * New native configurations
1358 NetBSD/hppa hppa*-*netbsd*
1359 Xtensa GNU/Linux xtensa*-*-linux*
1363 NetBSD/hppa hppa*-*-netbsd*
1364 Xtensa GNU/Lunux xtensa*-*-linux*
1366 * Change in command line behavior -- corefiles vs. process ids.
1368 When the '-p NUMBER' or '--pid NUMBER' options are used, and
1369 attaching to process NUMBER fails, GDB no longer attempts to open a
1370 core file named NUMBER. Attaching to a program using the -c option
1371 is no longer supported. Instead, use the '-p' or '--pid' options.
1373 * GDB can now be built as a native debugger for debugging Windows x86
1374 (mingw32) Portable Executable (PE) programs.
1376 * Pending breakpoints no longer change their number when their address
1379 * GDB now supports breakpoints with multiple locations,
1380 including breakpoints on C++ constructors, inside C++ templates,
1381 and in inlined functions.
1383 * GDB's ability to debug optimized code has been improved. GDB more
1384 accurately identifies function bodies and lexical blocks that occupy
1385 more than one contiguous range of addresses.
1387 * Target descriptions can now describe registers for PowerPC.
1389 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
1390 registers on PowerPC targets.
1392 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
1393 targets even when the libthread_db library is not available.
1395 * The GDB remote stub, gdbserver, now supports the new file transfer
1396 commands (remote put, remote get, and remote delete).
1398 * The GDB remote stub, gdbserver, now supports run and attach in
1399 extended-remote mode.
1401 * hppa*64*-*-hpux11* target broken
1402 The debugger is unable to start a program and fails with the following
1403 error: "Error trying to get information about dynamic linker".
1404 The gdb-6.7 release is also affected.
1406 * GDB now supports the --enable-targets= configure option to allow
1407 building a single GDB executable that supports multiple remote
1408 target architectures.
1410 * GDB now supports debugging C and C++ programs which use the
1411 Decimal Floating Point extension. In addition, the PowerPC target
1412 now has a set of pseudo-registers to inspect decimal float values
1413 stored in two consecutive float registers.
1415 * The -break-insert MI command can optionally create pending
1418 * Improved support for debugging Ada
1419 Many improvements to the Ada language support have been made. These
1421 - Better support for Ada2005 interface types
1422 - Improved handling of arrays and slices in general
1423 - Better support for Taft-amendment types
1424 - The '{type} ADDRESS' expression is now allowed on the left hand-side
1426 - Improved command completion in Ada
1429 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
1434 set print frame-arguments (all|scalars|none)
1435 show print frame-arguments
1436 The value of this variable can be changed to control which argument
1437 values should be printed by the debugger when displaying a frame.
1442 Transfer files to and from a remote target, and delete remote files.
1449 Transfer files to and from a remote target, and delete remote files.
1451 * New remote packets
1458 Open, close, read, write, and delete files on the remote system.
1461 Attach to an existing process on the remote system, in extended-remote
1465 Run a new process on the remote system, in extended-remote mode.
1467 *** Changes in GDB 6.7
1469 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
1470 bfd, libiberty and opcodes, as revealed by static analysis donated by
1471 Coverity, Inc. (http://scan.coverity.com).
1473 * When looking up multiply-defined global symbols, GDB will now prefer the
1474 symbol definition in the current shared library if it was built using the
1475 -Bsymbolic linker option.
1477 * When the Text User Interface (TUI) is not configured, GDB will now
1478 recognize the -tui command-line option and print a message that the TUI
1481 * The GDB remote stub, gdbserver, now has lower overhead for high
1482 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
1484 * GDB for MIPS targets now autodetects whether a remote target provides
1485 32-bit or 64-bit register values.
1487 * Support for C++ member pointers has been improved.
1489 * GDB now understands XML target descriptions, which specify the
1490 target's overall architecture. GDB can read a description from
1491 a local file or over the remote serial protocol.
1493 * Vectors of single-byte data use a new integer type which is not
1494 automatically displayed as character or string data.
1496 * The /s format now works with the print command. It displays
1497 arrays of single-byte integers and pointers to single-byte integers
1500 * Target descriptions can now describe target-specific registers,
1501 for architectures which have implemented the support (currently
1502 only ARM, M68K, and MIPS).
1504 * GDB and the GDB remote stub, gdbserver, now support the XScale
1507 * The GDB remote stub, gdbserver, has been updated to support
1508 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
1509 has been rewritten to use the standard GDB remote protocol.
1511 * GDB can now step into C++ functions which are called through thunks.
1513 * GDB for the Cell/B.E. SPU now supports overlay debugging.
1515 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
1516 layout. It also supports a TextSeg= and DataSeg= response when only
1517 segment base addresses (rather than offsets) are available.
1519 * The /i format now outputs any trailing branch delay slot instructions
1520 immediately following the last instruction within the count specified.
1522 * The GDB remote protocol "T" stop reply packet now supports a
1523 "library" response. Combined with the new "qXfer:libraries:read"
1524 packet, this response allows GDB to debug shared libraries on targets
1525 where the operating system manages the list of loaded libraries (e.g.
1526 Windows and SymbianOS).
1528 * The GDB remote stub, gdbserver, now supports dynamic link libraries
1529 (DLLs) on Windows and Windows CE targets.
1531 * GDB now supports a faster verification that a .debug file matches its binary
1532 according to its build-id signature, if the signature is present.
1538 Enable or disable hardware flow control (RTS/CTS) on the serial port
1539 when debugging using remote targets.
1541 set mem inaccessible-by-default
1542 show mem inaccessible-by-default
1543 If the target supplies a memory map, for instance via the remote
1544 protocol's "qXfer:memory-map:read" packet, setting this variable
1545 prevents GDB from accessing memory outside the memory map. This
1546 is useful for targets with memory mapped registers or which react
1547 badly to accesses of unmapped address space.
1549 set breakpoint auto-hw
1550 show breakpoint auto-hw
1551 If the target supplies a memory map, for instance via the remote
1552 protocol's "qXfer:memory-map:read" packet, setting this variable
1553 lets GDB use hardware breakpoints automatically for memory regions
1554 where it can not use software breakpoints. This covers both the
1555 "break" command and internal breakpoints used for other commands
1556 including "next" and "finish".
1559 catch exception unhandled
1560 Stop the program execution when Ada exceptions are raised.
1563 Stop the program execution when an Ada assertion failed.
1567 Set an alternate system root for target files. This is a more
1568 general version of "set solib-absolute-prefix", which is now
1569 an alias to "set sysroot".
1572 Provide extended SPU facility status information. This set of
1573 commands is available only when debugging the Cell/B.E. SPU
1576 * New native configurations
1578 OpenBSD/sh sh*-*openbsd*
1581 unset tdesc filename
1583 Use the specified local file as an XML target description, and do
1584 not query the target for its built-in description.
1588 OpenBSD/sh sh*-*-openbsd*
1589 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
1590 Toshiba Media Processor mep-elf
1592 * New remote packets
1595 Ignore the specified signals; pass them directly to the debugged program
1596 without stopping other threads or reporting them to GDB.
1598 qXfer:features:read:
1599 Read an XML target description from the target, which describes its
1604 Read or write contents of an spufs file on the target system. These
1605 packets are available only on the Cell/B.E. SPU architecture.
1607 qXfer:libraries:read:
1608 Report the loaded shared libraries. Combined with new "T" packet
1609 response, this packet allows GDB to debug shared libraries on
1610 targets where the operating system manages the list of loaded
1611 libraries (e.g. Windows and SymbianOS).
1615 Support for these obsolete configurations has been removed.
1623 i[34567]86-*-lynxos*
1624 i[34567]86-*-netware*
1625 i[34567]86-*-sco3.2v5*
1626 i[34567]86-*-sco3.2v4*
1628 i[34567]86-*-sysv4.2*
1631 i[34567]86-*-unixware2*
1632 i[34567]86-*-unixware*
1641 * Other removed features
1648 Various m68k-only ROM monitors.
1655 Various Renesas ROM monitors and debugging interfaces for SH and
1660 Support for a Macraigor serial interface to on-chip debugging.
1661 GDB does not directly support the newer parallel or USB
1666 A debug information format. The predecessor to DWARF 2 and
1667 DWARF 3, which are still supported.
1669 Support for the HP aCC compiler on HP-UX/PA-RISC
1671 SOM-encapsulated symbolic debugging information, automatic
1672 invocation of pxdb, and the aCC custom C++ ABI. This does not
1673 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
1674 with aCC can still be debugged on an assembly level.
1676 MIPS ".pdr" sections
1678 A MIPS-specific format used to describe stack frame layout
1679 in debugging information.
1683 GDB could work with an older version of Guile to debug
1684 the interpreter and Scheme programs running in it.
1686 set mips stack-arg-size
1687 set mips saved-gpreg-size
1689 Use "set mips abi" to control parameter passing for MIPS.
1691 *** Changes in GDB 6.6
1696 Cell Broadband Engine SPU spu-elf
1698 * GDB can now be configured as a cross-debugger targeting native Windows
1699 (mingw32) or Cygwin. It can communicate with a remote debugging stub
1700 running on a Windows system over TCP/IP to debug Windows programs.
1702 * The GDB remote stub, gdbserver, has been updated to support Windows and
1703 Cygwin debugging. Both single-threaded and multi-threaded programs are
1706 * The "set trust-readonly-sections" command works again. This command was
1707 broken in GDB 6.3, 6.4, and 6.5.
1709 * The "load" command now supports writing to flash memory, if the remote
1710 stub provides the required support.
1712 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
1713 longer requires symbolic debug information (e.g. DWARF-2).
1718 unset substitute-path
1719 show substitute-path
1720 Manage a list of substitution rules that GDB uses to rewrite the name
1721 of the directories where the sources are located. This can be useful
1722 for instance when the sources were moved to a different location
1723 between compilation and debugging.
1727 Print each CLI command as it is executed. Each command is prefixed with
1728 a number of `+' symbols representing the nesting depth.
1729 The source command now has a `-v' option to enable the same feature.
1733 The ARM Demon monitor support (RDP protocol, "target rdp").
1735 Kernel Object Display, an embedded debugging feature which only worked with
1736 an obsolete version of Cisco IOS.
1738 The 'set download-write-size' and 'show download-write-size' commands.
1740 * New remote packets
1743 Tell a stub about GDB client features, and request remote target features.
1744 The first feature implemented is PacketSize, which allows the target to
1745 specify the size of packets it can handle - to minimize the number of
1746 packets required and improve performance when connected to a remote
1750 Fetch an OS auxilliary vector from the remote stub. This packet is a
1751 more efficient replacement for qPart:auxv:read.
1753 qXfer:memory-map:read:
1754 Fetch a memory map from the remote stub, including information about
1755 RAM, ROM, and flash memory devices.
1760 Erase and program a flash memory device.
1762 * Removed remote packets
1765 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
1766 used it, and only gdbserver implemented it.
1768 *** Changes in GDB 6.5
1772 Renesas M32C/M16C m32c-elf
1774 Morpho Technologies ms1 ms1-elf
1778 init-if-undefined Initialize a convenience variable, but
1779 only if it doesn't already have a value.
1781 The following commands are presently only implemented for native GNU/Linux:
1783 checkpoint Save a snapshot of the program state.
1785 restart <n> Return the program state to a
1786 previously saved state.
1788 info checkpoints List currently saved checkpoints.
1790 delete-checkpoint <n> Delete a previously saved checkpoint.
1792 set|show detach-on-fork Tell gdb whether to detach from a newly
1793 forked process, or to keep debugging it.
1795 info forks List forks of the user program that
1796 are available to be debugged.
1798 fork <n> Switch to debugging one of several
1799 forks of the user program that are
1800 available to be debugged.
1802 delete-fork <n> Delete a fork from the list of forks
1803 that are available to be debugged (and
1804 kill the forked process).
1806 detach-fork <n> Delete a fork from the list of forks
1807 that are available to be debugged (and
1808 allow the process to continue).
1812 Morpho Technologies ms2 ms1-elf
1814 * Improved Windows host support
1816 GDB now builds as a cross debugger hosted on i686-mingw32, including
1817 native console support, and remote communications using either
1818 network sockets or serial ports.
1820 * Improved Modula-2 language support
1822 GDB can now print most types in the Modula-2 syntax. This includes:
1823 basic types, set types, record types, enumerated types, range types,
1824 pointer types and ARRAY types. Procedure var parameters are correctly
1825 printed and hexadecimal addresses and character constants are also
1826 written in the Modula-2 syntax. Best results can be obtained by using
1827 GNU Modula-2 together with the -gdwarf-2 command line option.
1831 The ARM rdi-share module.
1833 The Netware NLM debug server.
1835 *** Changes in GDB 6.4
1837 * New native configurations
1839 OpenBSD/arm arm*-*-openbsd*
1840 OpenBSD/mips64 mips64-*-openbsd*
1844 Morpho Technologies ms1 ms1-elf
1846 * New command line options
1848 --batch-silent As for --batch, but totally silent.
1849 --return-child-result The debugger will exist with the same value
1850 the child (debugged) program exited with.
1851 --eval-command COMMAND, -ex COMMAND
1852 Execute a single GDB CLI command. This may be
1853 specified multiple times and in conjunction
1854 with the --command (-x) option.
1856 * Deprecated commands removed
1858 The following commands, that were deprecated in 2000, have been
1862 set|show arm disassembly-flavor set|show arm disassembler
1863 othernames set arm disassembler
1864 set|show remotedebug set|show debug remote
1865 set|show archdebug set|show debug arch
1866 set|show eventdebug set|show debug event
1869 * New BSD user-level threads support
1871 It is now possible to debug programs using the user-level threads
1872 library on OpenBSD and FreeBSD. Currently supported (target)
1875 FreeBSD/amd64 x86_64-*-freebsd*
1876 FreeBSD/i386 i386-*-freebsd*
1877 OpenBSD/i386 i386-*-openbsd*
1879 Note that the new kernel threads libraries introduced in FreeBSD 5.x
1880 are not yet supported.
1882 * New support for Matsushita MN10300 w/sim added
1883 (Work in progress). mn10300-elf.
1885 * REMOVED configurations and files
1887 VxWorks and the XDR protocol *-*-vxworks
1888 Motorola MCORE mcore-*-*
1889 National Semiconductor NS32000 ns32k-*-*
1891 * New "set print array-indexes" command
1893 After turning this setting "on", GDB prints the index of each element
1894 when displaying arrays. The default is "off" to preserve the previous
1897 * VAX floating point support
1899 GDB now supports the not-quite-ieee VAX F and D floating point formats.
1901 * User-defined command support
1903 In addition to using $arg0..$arg9 for argument passing, it is now possible
1904 to use $argc to determine now many arguments have been passed. See the
1905 section on user-defined commands in the user manual for more information.
1907 *** Changes in GDB 6.3:
1909 * New command line option
1911 GDB now accepts -l followed by a number to set the timeout for remote
1914 * GDB works with GCC -feliminate-dwarf2-dups
1916 GDB now supports a more compact representation of DWARF-2 debug
1917 information using DW_FORM_ref_addr references. These are produced
1918 by GCC with the option -feliminate-dwarf2-dups and also by some
1919 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
1920 to use -feliminate-dwarf2-dups.
1922 * Internationalization
1924 When supported by the host system, GDB will be built with
1925 internationalization (libintl). The task of marking up the sources is
1926 continued, we're looking forward to our first translation.
1930 Initial support for debugging programs compiled with the GNAT
1931 implementation of the Ada programming language has been integrated
1932 into GDB. In this release, support is limited to expression evaluation.
1934 * New native configurations
1936 GNU/Linux/m32r m32r-*-linux-gnu
1940 GDB's remote protocol now includes support for the 'p' packet. This
1941 packet is used to fetch individual registers from a remote inferior.
1943 * END-OF-LIFE registers[] compatibility module
1945 GDB's internal register infrastructure has been completely rewritten.
1946 The new infrastructure making possible the implementation of key new
1947 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
1950 GDB 6.3 will be the last release to include the the registers[]
1951 compatibility module that allowed out-of-date configurations to
1952 continue to work. This change directly impacts the following
1962 powerpc bdm protocol
1964 Unless there is activity to revive these configurations, they will be
1965 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
1967 * OBSOLETE configurations and files
1969 Configurations that have been declared obsolete in this release have
1970 been commented out. Unless there is activity to revive these
1971 configurations, the next release of GDB will have their sources
1972 permanently REMOVED.
1981 *** Changes in GDB 6.2.1:
1983 * MIPS `break main; run' gave an heuristic-fence-post warning
1985 When attempting to run even a simple program, a warning about
1986 heuristic-fence-post being hit would be reported. This problem has
1989 * MIPS IRIX 'long double' crashed GDB
1991 When examining a long double variable, GDB would get a segmentation
1992 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
1993 IRIX long double values).
1997 A bug in the VAX stack code was causing problems with the "next"
1998 command. This problem has been fixed.
2000 *** Changes in GDB 6.2:
2002 * Fix for ``many threads''
2004 On GNU/Linux systems that use the NPTL threads library, a program
2005 rapidly creating and deleting threads would confuse GDB leading to the
2008 ptrace: No such process.
2009 thread_db_get_info: cannot get thread info: generic error
2011 This problem has been fixed.
2013 * "-async" and "-noasync" options removed.
2015 Support for the broken "-noasync" option has been removed (it caused
2018 * New ``start'' command.
2020 This command runs the program until the begining of the main procedure.
2022 * New BSD Kernel Data Access Library (libkvm) interface
2024 Using ``target kvm'' it is now possible to debug kernel core dumps and
2025 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
2026 platforms. Currently supported (native-only) configurations are:
2028 FreeBSD/amd64 x86_64-*-freebsd*
2029 FreeBSD/i386 i?86-*-freebsd*
2030 NetBSD/i386 i?86-*-netbsd*
2031 NetBSD/m68k m68*-*-netbsd*
2032 NetBSD/sparc sparc-*-netbsd*
2033 OpenBSD/amd64 x86_64-*-openbsd*
2034 OpenBSD/i386 i?86-*-openbsd*
2035 OpenBSD/m68k m68*-openbsd*
2036 OpenBSD/sparc sparc-*-openbsd*
2038 * Signal trampoline code overhauled
2040 Many generic problems with GDB's signal handling code have been fixed.
2041 These include: backtraces through non-contiguous stacks; recognition
2042 of sa_sigaction signal trampolines; backtrace from a NULL pointer
2043 call; backtrace through a signal trampoline; step into and out of
2044 signal handlers; and single-stepping in the signal trampoline.
2046 Please note that kernel bugs are a limiting factor here. These
2047 features have been shown to work on an s390 GNU/Linux system that
2048 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
2050 * Cygwin support for DWARF 2 added.
2052 * New native configurations
2054 GNU/Linux/hppa hppa*-*-linux*
2055 OpenBSD/hppa hppa*-*-openbsd*
2056 OpenBSD/m68k m68*-*-openbsd*
2057 OpenBSD/m88k m88*-*-openbsd*
2058 OpenBSD/powerpc powerpc-*-openbsd*
2059 NetBSD/vax vax-*-netbsd*
2060 OpenBSD/vax vax-*-openbsd*
2062 * END-OF-LIFE frame compatibility module
2064 GDB's internal frame infrastructure has been completely rewritten.
2065 The new infrastructure making it possible to support key new features
2066 including DWARF 2 Call Frame Information. To aid in the task of
2067 migrating old configurations to this new infrastructure, a
2068 compatibility module, that allowed old configurations to continue to
2069 work, was also included.
2071 GDB 6.2 will be the last release to include this frame compatibility
2072 module. This change directly impacts the following configurations:
2082 Unless there is activity to revive these configurations, they will be
2083 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
2085 * REMOVED configurations and files
2087 Sun 3, running SunOS 3 m68*-*-sunos3*
2088 Sun 3, running SunOS 4 m68*-*-sunos4*
2089 Sun 2, running SunOS 3 m68000-*-sunos3*
2090 Sun 2, running SunOS 4 m68000-*-sunos4*
2091 Motorola 680x0 running LynxOS m68*-*-lynxos*
2092 AT&T 3b1/Unix pc m68*-att-*
2093 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2094 decstation mips-dec-* mips-little-*
2095 riscos mips-*-riscos* mips-*-sysv*
2096 sonymips mips-sony-*
2097 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2099 *** Changes in GDB 6.1.1:
2101 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
2103 The TUI (Text-mode User Interface) is now built as part of a default
2104 GDB configuration. It is enabled by either selecting the TUI with the
2105 command line option "-i=tui" or by running the separate "gdbtui"
2106 program. For more information on the TUI, see the manual "Debugging
2109 * Pending breakpoint support (also included in GDB 6.1)
2111 Support has been added to allow you to specify breakpoints in shared
2112 libraries that have not yet been loaded. If a breakpoint location
2113 cannot be found, and the "breakpoint pending" option is set to auto,
2114 GDB queries you if you wish to make the breakpoint pending on a future
2115 shared-library load. If and when GDB resolves the breakpoint symbol,
2116 the pending breakpoint is removed as one or more regular breakpoints
2119 Pending breakpoints are very useful for GCJ Java debugging.
2121 * Fixed ISO-C build problems
2123 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
2124 non ISO-C code that stopped them being built using a more strict ISO-C
2125 compiler (e.g., IBM's C compiler).
2127 * Fixed build problem on IRIX 5
2129 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
2130 wasn't able to compile compile on an IRIX 5 system.
2132 * Added execute permission to gdb/gdbserver/configure
2134 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
2135 permission. This bug would cause configure to fail on a number of
2136 systems (Solaris, IRIX). Ref: server/519.
2138 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
2140 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
2141 has been updated to use constant array sizes.
2143 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
2145 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
2146 its generated DWARF Call Frame Info. This encoding was causing GDB to
2147 panic, that panic has been fixed. Ref: gdb/1628.
2149 * Fixed a problem when examining parameters in shared library code.
2151 When examining parameters in optimized shared library code generated
2152 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
2153 not available''. GDB now correctly displays the variable's value.
2155 *** Changes in GDB 6.1:
2157 * Removed --with-mmalloc
2159 Support for the mmalloc memory manager has been removed, as it
2160 conflicted with the internal gdb byte cache.
2162 * Changes in AMD64 configurations
2164 The AMD64 target now includes the %cs and %ss registers. As a result
2165 the AMD64 remote protocol has changed; this affects the floating-point
2166 and SSE registers. If you rely on those registers for your debugging,
2167 you should upgrade gdbserver on the remote side.
2169 * Revised SPARC target
2171 The SPARC target has been completely revised, incorporating the
2172 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
2173 support for LynxOS and SunOS 4 has been dropped. Calling functions
2174 from within GDB on operating systems with a non-executable stack
2175 (Solaris, OpenBSD) now works.
2179 GDB has a new C++ demangler which does a better job on the mangled
2180 names generated by current versions of g++. It also runs faster, so
2181 with this and other changes gdb should now start faster on large C++
2184 * DWARF 2 Location Expressions
2186 GDB support for location expressions has been extended to support function
2187 arguments and frame bases. Older versions of GDB could crash when they
2190 * C++ nested types and namespaces
2192 GDB's support for nested types and namespaces in C++ has been
2193 improved, especially if you use the DWARF 2 debugging format. (This
2194 is the default for recent versions of GCC on most platforms.)
2195 Specifically, if you have a class "Inner" defined within a class or
2196 namespace "Outer", then GDB realizes that the class's name is
2197 "Outer::Inner", not simply "Inner". This should greatly reduce the
2198 frequency of complaints about not finding RTTI symbols. In addition,
2199 if you are stopped at inside of a function defined within a namespace,
2200 GDB modifies its name lookup accordingly.
2202 * New native configurations
2204 NetBSD/amd64 x86_64-*-netbsd*
2205 OpenBSD/amd64 x86_64-*-openbsd*
2206 OpenBSD/alpha alpha*-*-openbsd*
2207 OpenBSD/sparc sparc-*-openbsd*
2208 OpenBSD/sparc64 sparc64-*-openbsd*
2210 * New debugging protocols
2212 M32R with SDI protocol m32r-*-elf*
2214 * "set prompt-escape-char" command deleted.
2216 The command "set prompt-escape-char" has been deleted. This command,
2217 and its very obscure effet on GDB's prompt, was never documented,
2218 tested, nor mentioned in the NEWS file.
2220 * OBSOLETE configurations and files
2222 Configurations that have been declared obsolete in this release have
2223 been commented out. Unless there is activity to revive these
2224 configurations, the next release of GDB will have their sources
2225 permanently REMOVED.
2227 Sun 3, running SunOS 3 m68*-*-sunos3*
2228 Sun 3, running SunOS 4 m68*-*-sunos4*
2229 Sun 2, running SunOS 3 m68000-*-sunos3*
2230 Sun 2, running SunOS 4 m68000-*-sunos4*
2231 Motorola 680x0 running LynxOS m68*-*-lynxos*
2232 AT&T 3b1/Unix pc m68*-att-*
2233 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2234 decstation mips-dec-* mips-little-*
2235 riscos mips-*-riscos* mips-*-sysv*
2236 sonymips mips-sony-*
2237 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2239 * REMOVED configurations and files
2241 SGI Irix-4.x mips-sgi-irix4 or iris4
2242 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
2243 Z8000 simulator z8k-zilog-none or z8ksim
2244 Matsushita MN10200 w/simulator mn10200-*-*
2245 H8/500 simulator h8500-hitachi-hms or h8500hms
2246 HP/PA running BSD hppa*-*-bsd*
2247 HP/PA running OSF/1 hppa*-*-osf*
2248 HP/PA Pro target hppa*-*-pro*
2249 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2250 386BSD i[3456]86-*-bsd*
2251 Sequent family i[3456]86-sequent-sysv4*
2252 i[3456]86-sequent-sysv*
2253 i[3456]86-sequent-bsd*
2254 SPARC running LynxOS sparc-*-lynxos*
2255 SPARC running SunOS 4 sparc-*-sunos4*
2256 Tsqware Sparclet sparclet-*-*
2257 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2259 *** Changes in GDB 6.0:
2263 Support for debugging the Objective-C programming language has been
2264 integrated into GDB.
2266 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
2268 DWARF 2's Call Frame Information makes available compiler generated
2269 information that more exactly describes the program's run-time stack.
2270 By using this information, GDB is able to provide more robust stack
2273 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
2274 have been updated to use a new backtrace mechanism which includes
2275 DWARF 2 CFI support.
2279 GDB's remote protocol has been extended to include support for hosted
2280 file I/O (where the remote target uses GDB's file system). See GDB's
2281 remote protocol documentation for details.
2283 * All targets using the new architecture framework.
2285 All of GDB's targets have been updated to use the new internal
2286 architecture framework. The way is now open for future GDB releases
2287 to include cross-architecture native debugging support (i386 on amd64,
2290 * GNU/Linux's Thread Local Storage (TLS)
2292 GDB now includes support for for the GNU/Linux implementation of
2293 per-thread variables.
2295 * GNU/Linux's Native POSIX Thread Library (NPTL)
2297 GDB's thread code has been updated to work with either the new
2298 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
2300 * Separate debug info.
2302 GDB, in conjunction with BINUTILS, now supports a mechanism for
2303 automatically loading debug information from a separate file. Instead
2304 of shipping full debug and non-debug versions of system libraries,
2305 system integrators can now instead ship just the stripped libraries
2306 and optional debug files.
2308 * DWARF 2 Location Expressions
2310 DWARF 2 Location Expressions allow the compiler to more completely
2311 describe the location of variables (even in optimized code) to the
2314 GDB now includes preliminary support for location expressions (support
2315 for DW_OP_piece is still missing).
2319 A number of long standing bugs that caused GDB to die while starting a
2320 Java application have been fixed. GDB's Java support is now
2321 considered "useable".
2323 * GNU/Linux support for fork, vfork, and exec.
2325 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
2326 commands are now implemented for GNU/Linux. They require a 2.5.x or later
2329 * GDB supports logging output to a file
2331 There are two new commands, "set logging" and "show logging", which can be
2332 used to capture GDB's output to a file.
2334 * The meaning of "detach" has changed for gdbserver
2336 The "detach" command will now resume the application, as documented. To
2337 disconnect from gdbserver and leave it stopped, use the new "disconnect"
2340 * d10v, m68hc11 `regs' command deprecated
2342 The `info registers' command has been updated so that it displays the
2343 registers using a format identical to the old `regs' command.
2347 A new command, "maint set profile on/off", has been added. This command can
2348 be used to enable or disable profiling while running GDB, to profile a
2349 session or a set of commands. In addition there is a new configure switch,
2350 "--enable-profiling", which will cause GDB to be compiled with profiling
2351 data, for more informative profiling results.
2353 * Default MI syntax changed to "mi2".
2355 The default MI (machine interface) syntax, enabled by the command line
2356 option "-i=mi", has been changed to "mi2". The previous MI syntax,
2357 "mi1", can be enabled by specifying the option "-i=mi1".
2359 Support for the original "mi0" syntax (included in GDB 5.0) has been
2362 Fix for gdb/192: removed extraneous space when displaying frame level.
2363 Fix for gdb/672: update changelist is now output in mi list format.
2364 Fix for gdb/702: a -var-assign that updates the value now shows up
2365 in a subsequent -var-update.
2367 * New native configurations.
2369 FreeBSD/amd64 x86_64-*-freebsd*
2371 * Multi-arched targets.
2373 HP/PA HPUX11 hppa*-*-hpux*
2374 Renesas M32R/D w/simulator m32r-*-elf*
2376 * OBSOLETE configurations and files
2378 Configurations that have been declared obsolete in this release have
2379 been commented out. Unless there is activity to revive these
2380 configurations, the next release of GDB will have their sources
2381 permanently REMOVED.
2383 Z8000 simulator z8k-zilog-none or z8ksim
2384 Matsushita MN10200 w/simulator mn10200-*-*
2385 H8/500 simulator h8500-hitachi-hms or h8500hms
2386 HP/PA running BSD hppa*-*-bsd*
2387 HP/PA running OSF/1 hppa*-*-osf*
2388 HP/PA Pro target hppa*-*-pro*
2389 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2390 Sequent family i[3456]86-sequent-sysv4*
2391 i[3456]86-sequent-sysv*
2392 i[3456]86-sequent-bsd*
2393 Tsqware Sparclet sparclet-*-*
2394 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2396 * REMOVED configurations and files
2399 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2400 IBM AIX PS/2 i[3456]86-*-aix
2401 i386 running Mach 3.0 i[3456]86-*-mach3*
2402 i386 running Mach i[3456]86-*-mach*
2403 i386 running OSF/1 i[3456]86-*osf1mk*
2404 HP/Apollo 68k Family m68*-apollo*-sysv*,
2406 m68*-hp-bsd*, m68*-hp-hpux*
2407 Argonaut Risc Chip (ARC) arc-*-*
2408 Mitsubishi D30V d30v-*-*
2409 Fujitsu FR30 fr30-*-elf*
2410 OS/9000 i[34]86-*-os9k
2411 I960 with MON960 i960-*-coff
2413 * MIPS $fp behavior changed
2415 The convenience variable $fp, for the MIPS, now consistently returns
2416 the address of the current frame's base. Previously, depending on the
2417 context, $fp could refer to either $sp or the current frame's base
2418 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
2419 The GNU Source-Level Debugger''.
2421 *** Changes in GDB 5.3:
2423 * GNU/Linux shared library multi-threaded performance improved.
2425 When debugging a multi-threaded application on GNU/Linux, GDB now uses
2426 `/proc', in preference to `ptrace' for memory reads. This may result
2427 in an improvement in the start-up time of multi-threaded, shared
2428 library applications when run under GDB. One GDB user writes: ``loads
2429 shared libs like mad''.
2431 * ``gdbserver'' now supports multi-threaded applications on some targets
2433 Support for debugging multi-threaded applications which use
2434 the GNU/Linux LinuxThreads package has been added for
2435 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
2436 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
2438 * GDB now supports C/C++ preprocessor macros.
2440 GDB now expands preprocessor macro invocations in C/C++ expressions,
2441 and provides various commands for showing macro definitions and how
2444 The new command `macro expand EXPRESSION' expands any macro
2445 invocations in expression, and shows the result.
2447 The new command `show macro MACRO-NAME' shows the definition of the
2448 macro named MACRO-NAME, and where it was defined.
2450 Most compilers don't include information about macros in the debugging
2451 information by default. In GCC 3.1, for example, you need to compile
2452 your program with the options `-gdwarf-2 -g3'. If the macro
2453 information is present in the executable, GDB will read it.
2455 * Multi-arched targets.
2457 DEC Alpha (partial) alpha*-*-*
2458 DEC VAX (partial) vax-*-*
2460 National Semiconductor NS32000 (partial) ns32k-*-*
2461 Motorola 68000 (partial) m68k-*-*
2462 Motorola MCORE mcore-*-*
2466 Fujitsu FRV architecture added by Red Hat frv*-*-*
2469 * New native configurations
2471 Alpha NetBSD alpha*-*-netbsd*
2472 SH NetBSD sh*-*-netbsdelf*
2473 MIPS NetBSD mips*-*-netbsd*
2474 UltraSPARC NetBSD sparc64-*-netbsd*
2476 * OBSOLETE configurations and files
2478 Configurations that have been declared obsolete in this release have
2479 been commented out. Unless there is activity to revive these
2480 configurations, the next release of GDB will have their sources
2481 permanently REMOVED.
2483 Mitsubishi D30V d30v-*-*
2484 OS/9000 i[34]86-*-os9k
2485 IBM AIX PS/2 i[3456]86-*-aix
2486 Fujitsu FR30 fr30-*-elf*
2487 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2488 Argonaut Risc Chip (ARC) arc-*-*
2489 i386 running Mach 3.0 i[3456]86-*-mach3*
2490 i386 running Mach i[3456]86-*-mach*
2491 i386 running OSF/1 i[3456]86-*osf1mk*
2492 HP/Apollo 68k Family m68*-apollo*-sysv*,
2494 m68*-hp-bsd*, m68*-hp-hpux*
2495 I960 with MON960 i960-*-coff
2497 * OBSOLETE languages
2499 CHILL, a Pascal like language used by telecommunications companies.
2501 * REMOVED configurations and files
2503 AMD 29k family via UDI a29k-amd-udi, udi29k
2504 A29K VxWorks a29k-*-vxworks
2505 AMD 29000 embedded, using EBMON a29k-none-none
2506 AMD 29000 embedded with COFF a29k-none-coff
2507 AMD 29000 embedded with a.out a29k-none-aout
2509 testsuite/gdb.hp/gdb.threads-hp/ directory
2511 * New command "set max-user-call-depth <nnn>"
2513 This command allows the user to limit the call depth of user-defined
2514 commands. The default is 1024.
2516 * Changes in FreeBSD/i386 native debugging.
2518 Support for the "generate-core-file" has been added.
2520 * New commands "dump", "append", and "restore".
2522 These commands allow data to be copied from target memory
2523 to a bfd-format or binary file (dump and append), and back
2524 from a file into memory (restore).
2526 * Improved "next/step" support on multi-processor Alpha Tru64.
2528 The previous single-step mechanism could cause unpredictable problems,
2529 including the random appearance of SIGSEGV or SIGTRAP signals. The use
2530 of a software single-step mechanism prevents this.
2532 *** Changes in GDB 5.2.1:
2540 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
2541 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
2542 Fix, by Joel Brobecker imported from mainline.
2544 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
2545 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
2546 Fix, by Fred Fish, imported from mainline.
2548 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
2549 Surprisingly enough, it works now.
2550 By Michal Ludvig, imported from mainline.
2552 i386 hardware watchpoint support:
2553 avoid misses on second run for some targets.
2554 By Pierre Muller, imported from mainline.
2556 *** Changes in GDB 5.2:
2558 * New command "set trust-readonly-sections on[off]".
2560 This command is a hint that tells gdb that read-only sections
2561 really are read-only (ie. that their contents will not change).
2562 In this mode, gdb will go to the object file rather than the
2563 target to read memory from read-only sections (such as ".text").
2564 This can be a significant performance improvement on some
2565 (notably embedded) targets.
2567 * New command "generate-core-file" (or "gcore").
2569 This new gdb command allows the user to drop a core file of the child
2570 process state at any time. So far it's been implemented only for
2571 GNU/Linux and Solaris, but should be relatively easily ported to other
2572 hosts. Argument is core file name (defaults to core.<pid>).
2574 * New command line option
2576 GDB now accepts --pid or -p followed by a process id.
2578 * Change in command line behavior -- corefiles vs. process ids.
2580 There is a subtle behavior in the way in which GDB handles
2581 command line arguments. The first non-flag argument is always
2582 a program to debug, but the second non-flag argument may either
2583 be a corefile or a process id. Previously, GDB would attempt to
2584 open the second argument as a corefile, and if that failed, would
2585 issue a superfluous error message and then attempt to attach it as
2586 a process. Now, if the second argument begins with a non-digit,
2587 it will be treated as a corefile. If it begins with a digit,
2588 GDB will attempt to attach it as a process, and if no such process
2589 is found, will then attempt to open it as a corefile.
2591 * Changes in ARM configurations.
2593 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
2594 configuration is fully multi-arch.
2596 * New native configurations
2598 ARM NetBSD arm*-*-netbsd*
2599 x86 OpenBSD i[3456]86-*-openbsd*
2600 AMD x86-64 running GNU/Linux x86_64-*-linux-*
2601 Sparc64 running FreeBSD sparc64-*-freebsd*
2605 Sanyo XStormy16 xstormy16-elf
2607 * OBSOLETE configurations and files
2609 Configurations that have been declared obsolete in this release have
2610 been commented out. Unless there is activity to revive these
2611 configurations, the next release of GDB will have their sources
2612 permanently REMOVED.
2614 AMD 29k family via UDI a29k-amd-udi, udi29k
2615 A29K VxWorks a29k-*-vxworks
2616 AMD 29000 embedded, using EBMON a29k-none-none
2617 AMD 29000 embedded with COFF a29k-none-coff
2618 AMD 29000 embedded with a.out a29k-none-aout
2620 testsuite/gdb.hp/gdb.threads-hp/ directory
2622 * REMOVED configurations and files
2624 TI TMS320C80 tic80-*-*
2626 PowerPC Solaris powerpcle-*-solaris*
2627 PowerPC Windows NT powerpcle-*-cygwin32
2628 PowerPC Netware powerpc-*-netware*
2629 Harris/CXUX m88k m88*-harris-cxux*
2630 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
2631 ns32k-utek-sysv* ns32k-utek-*
2632 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
2633 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
2634 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
2635 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
2636 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
2638 * Changes to command line processing
2640 The new `--args' feature can be used to specify command-line arguments
2641 for the inferior from gdb's command line.
2643 * Changes to key bindings
2645 There is a new `operate-and-get-next' function bound to `C-o'.
2647 *** Changes in GDB 5.1.1
2649 Fix compile problem on DJGPP.
2651 Fix a problem with floating-point registers on the i386 being
2654 Fix to stop GDB crashing on .debug_str debug info.
2656 Numerous documentation fixes.
2658 Numerous testsuite fixes.
2660 *** Changes in GDB 5.1:
2662 * New native configurations
2664 Alpha FreeBSD alpha*-*-freebsd*
2665 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
2666 MIPS GNU/Linux mips*-*-linux*
2667 MIPS SGI Irix 6.x mips*-sgi-irix6*
2668 ia64 AIX ia64-*-aix*
2669 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
2673 Motorola 68HC11 and 68HC12 m68hc11-elf
2675 UltraSparc running GNU/Linux sparc64-*-linux*
2677 * OBSOLETE configurations and files
2679 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
2680 Harris/CXUX m88k m88*-harris-cxux*
2681 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
2682 ns32k-utek-sysv* ns32k-utek-*
2683 TI TMS320C80 tic80-*-*
2685 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
2686 PowerPC Solaris powerpcle-*-solaris*
2687 PowerPC Windows NT powerpcle-*-cygwin32
2688 PowerPC Netware powerpc-*-netware*
2689 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
2690 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
2691 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
2692 Apple Macintosh (MPW) host N/A
2694 stuff.c (Program to stuff files into a specially prepared space in kdb)
2695 kdb-start.c (Main loop for the standalone kernel debugger)
2697 Configurations that have been declared obsolete in this release have
2698 been commented out. Unless there is activity to revive these
2699 configurations, the next release of GDB will have their sources
2700 permanently REMOVED.
2702 * REMOVED configurations and files
2704 Altos 3068 m68*-altos-*
2705 Convex c1-*-*, c2-*-*
2707 ARM RISCix arm-*-* (as host)
2711 * GDB has been converted to ISO C.
2713 GDB's source code has been converted to ISO C. In particular, the
2714 sources are fully protoized, and rely on standard headers being
2719 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
2721 * The MI enabled by default.
2723 The new machine oriented interface (MI) introduced in GDB 5.0 has been
2724 revised and enabled by default. Packages which use GDB as a debugging
2725 engine behind a UI or another front end are encouraged to switch to
2726 using the GDB/MI interface, instead of the old annotations interface
2727 which is now deprecated.
2729 * Support for debugging Pascal programs.
2731 GDB now includes support for debugging Pascal programs. The following
2732 main features are supported:
2734 - Pascal-specific data types such as sets;
2736 - automatic recognition of Pascal sources based on file-name
2739 - Pascal-style display of data types, variables, and functions;
2741 - a Pascal expression parser.
2743 However, some important features are not yet supported.
2745 - Pascal string operations are not supported at all;
2747 - there are some problems with boolean types;
2749 - Pascal type hexadecimal constants are not supported
2750 because they conflict with the internal variables format;
2752 - support for Pascal objects and classes is not full yet;
2754 - unlike Pascal, GDB is case-sensitive for symbol names.
2756 * Changes in completion.
2758 Commands such as `shell', `run' and `set args', which pass arguments
2759 to inferior programs, now complete on file names, similar to what
2760 users expect at the shell prompt.
2762 Commands which accept locations, such as `disassemble', `print',
2763 `breakpoint', `until', etc. now complete on filenames as well as
2764 program symbols. Thus, if you type "break foob TAB", and the source
2765 files linked into the programs include `foobar.c', that file name will
2766 be one of the candidates for completion. However, file names are not
2767 considered for completion after you typed a colon that delimits a file
2768 name from a name of a function in that file, as in "break foo.c:bar".
2770 `set demangle-style' completes on available demangling styles.
2772 * New platform-independent commands:
2774 It is now possible to define a post-hook for a command as well as a
2775 hook that runs before the command. For more details, see the
2776 documentation of `hookpost' in the GDB manual.
2778 * Changes in GNU/Linux native debugging.
2780 Support for debugging multi-threaded programs has been completely
2781 revised for all platforms except m68k and sparc. You can now debug as
2782 many threads as your system allows you to have.
2784 Attach/detach is supported for multi-threaded programs.
2786 Support for SSE registers was added for x86. This doesn't work for
2787 multi-threaded programs though.
2789 * Changes in MIPS configurations.
2791 Multi-arch support is enabled for all MIPS configurations.
2793 GDB can now be built as native debugger on SGI Irix 6.x systems for
2794 debugging n32 executables. (Debugging 64-bit executables is not yet
2797 * Unified support for hardware watchpoints in all x86 configurations.
2799 Most (if not all) native x86 configurations support hardware-assisted
2800 breakpoints and watchpoints in a unified manner. This support
2801 implements debug register sharing between watchpoints, which allows to
2802 put a virtually infinite number of watchpoints on the same address,
2803 and also supports watching regions up to 16 bytes with several debug
2806 The new maintenance command `maintenance show-debug-regs' toggles
2807 debugging print-outs in functions that insert, remove, and test
2808 watchpoints and hardware breakpoints.
2810 * Changes in the DJGPP native configuration.
2812 New command ``info dos sysinfo'' displays assorted information about
2813 the CPU, OS, memory, and DPMI server.
2815 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
2816 display information about segment descriptors stored in GDT, LDT, and
2819 New commands ``info dos pde'' and ``info dos pte'' display entries
2820 from Page Directory and Page Tables (for now works with CWSDPMI only).
2821 New command ``info dos address-pte'' displays the Page Table entry for
2822 a given linear address.
2824 GDB can now pass command lines longer than 126 characters to the
2825 program being debugged (requires an update to the libdbg.a library
2826 which is part of the DJGPP development kit).
2828 DWARF2 debug info is now supported.
2830 It is now possible to `step' and `next' through calls to `longjmp'.
2832 * Changes in documentation.
2834 All GDB documentation was converted to GFDL, the GNU Free
2835 Documentation License.
2837 Tracepoints-related commands are now fully documented in the GDB
2840 TUI, the Text-mode User Interface, is now documented in the manual.
2842 Tracepoints-related commands are now fully documented in the GDB
2845 The "GDB Internals" manual now has an index. It also includes
2846 documentation of `ui_out' functions, GDB coding standards, x86
2847 hardware watchpoints, and memory region attributes.
2849 * GDB's version number moved to ``version.in''
2851 The Makefile variable VERSION has been replaced by the file
2852 ``version.in''. People creating GDB distributions should update the
2853 contents of this file.
2857 GUD support is now a standard part of the EMACS distribution.
2859 *** Changes in GDB 5.0:
2861 * Improved support for debugging FP programs on x86 targets
2863 Unified and much-improved support for debugging floating-point
2864 programs on all x86 targets. In particular, ``info float'' now
2865 displays the FP registers in the same format on all x86 targets, with
2866 greater level of detail.
2868 * Improvements and bugfixes in hardware-assisted watchpoints
2870 It is now possible to watch array elements, struct members, and
2871 bitfields with hardware-assisted watchpoints. Data-read watchpoints
2872 on x86 targets no longer erroneously trigger when the address is
2875 * Improvements in the native DJGPP version of GDB
2877 The distribution now includes all the scripts and auxiliary files
2878 necessary to build the native DJGPP version on MS-DOS/MS-Windows
2879 machines ``out of the box''.
2881 The DJGPP version can now debug programs that use signals. It is
2882 possible to catch signals that happened in the debuggee, deliver
2883 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
2884 would kill the program being debugged.) Programs that hook hardware
2885 interrupts (keyboard, timer, etc.) can also be debugged.
2887 It is now possible to debug DJGPP programs that redirect their
2888 standard handles or switch them to raw (as opposed to cooked) mode, or
2889 even close them. The command ``run < foo > bar'' works as expected,
2890 and ``info terminal'' reports useful information about the debuggee's
2891 terminal, including raw/cooked mode, redirection, etc.
2893 The DJGPP version now uses termios functions for console I/O, which
2894 enables debugging graphics programs. Interrupting GDB with Ctrl-C
2897 DOS-style file names with drive letters are now fully supported by
2900 It is now possible to debug DJGPP programs that switch their working
2901 directory. It is also possible to rerun the debuggee any number of
2902 times without restarting GDB; thus, you can use the same setup,
2903 breakpoints, etc. for many debugging sessions.
2905 * New native configurations
2907 ARM GNU/Linux arm*-*-linux*
2908 PowerPC GNU/Linux powerpc-*-linux*
2912 Motorola MCore mcore-*-*
2913 x86 VxWorks i[3456]86-*-vxworks*
2914 PowerPC VxWorks powerpc-*-vxworks*
2915 TI TMS320C80 tic80-*-*
2917 * OBSOLETE configurations
2919 Altos 3068 m68*-altos-*
2920 Convex c1-*-*, c2-*-*
2922 ARM RISCix arm-*-* (as host)
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.
2930 * Gould support removed
2932 Support for the Gould PowerNode and NP1 has been removed.
2934 * New features for SVR4
2936 On SVR4 native platforms (such as Solaris), if you attach to a process
2937 without first loading a symbol file, GDB will now attempt to locate and
2938 load symbols from the running process's executable file.
2940 * Many C++ enhancements
2942 C++ support has been greatly improved. Overload resolution now works properly
2943 in almost all cases. RTTI support is on the way.
2945 * Remote targets can connect to a sub-program
2947 A popen(3) style serial-device has been added. This device starts a
2948 sub-process (such as a stand-alone simulator) and then communicates
2949 with that. The sub-program to run is specified using the syntax
2950 ``|<program> <args>'' vis:
2952 (gdb) set remotedebug 1
2953 (gdb) target extended-remote |mn10300-elf-sim program-args
2955 * MIPS 64 remote protocol
2957 A long standing bug in the mips64 remote protocol where by GDB
2958 expected certain 32 bit registers (ex SR) to be transfered as 32
2959 instead of 64 bits has been fixed.
2961 The command ``set remote-mips64-transfers-32bit-regs on'' has been
2962 added to provide backward compatibility with older versions of GDB.
2964 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
2966 The command ``set remotebinarydownload'' command has been replaced by
2967 ``set remote X-packet''. Other commands in ``set remote'' family
2968 include ``set remote P-packet''.
2970 * Breakpoint commands accept ranges.
2972 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
2973 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
2974 ``tracepoint passcount'' also accepts a range of tracepoints.
2976 * ``apropos'' command added.
2978 The ``apropos'' command searches through command names and
2979 documentation strings, printing out matches, making it much easier to
2980 try to find a command that does what you are looking for.
2984 A new machine oriented interface (MI) has been added to GDB. This
2985 interface is designed for debug environments running GDB as a separate
2986 process. This is part of the long term libGDB project. See the
2987 "GDB/MI" chapter of the GDB manual for further information. It can be
2988 enabled by configuring with:
2990 .../configure --enable-gdbmi
2992 *** Changes in GDB-4.18:
2994 * New native configurations
2996 HP-UX 10.20 hppa*-*-hpux10.20
2997 HP-UX 11.x hppa*-*-hpux11.0*
2998 M68K GNU/Linux m68*-*-linux*
3002 Fujitsu FR30 fr30-*-elf*
3003 Intel StrongARM strongarm-*-*
3004 Mitsubishi D30V d30v-*-*
3006 * OBSOLETE configurations
3008 Gould PowerNode, NP1 np1-*-*, pn-*-*
3010 Configurations that have been declared obsolete will be commented out,
3011 but the code will be left in place. If there is no activity to revive
3012 these configurations before the next release of GDB, the sources will
3013 be permanently REMOVED.
3017 As a compatibility experiment, GDB's source files buildsym.h and
3018 buildsym.c have been converted to pure standard C, no longer
3019 containing any K&R compatibility code. We believe that all systems in
3020 use today either come with a standard C compiler, or have a GCC port
3021 available. If this is not true, please report the affected
3022 configuration to bug-gdb@gnu.org immediately. See the README file for
3023 information about getting a standard C compiler if you don't have one
3028 GDB now uses readline 2.2.
3030 * set extension-language
3032 You can now control the mapping between filename extensions and source
3033 languages by using the `set extension-language' command. For instance,
3034 you can ask GDB to treat .c files as C++ by saying
3035 set extension-language .c c++
3036 The command `info extensions' lists all of the recognized extensions
3037 and their associated languages.
3039 * Setting processor type for PowerPC and RS/6000
3041 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
3042 you can use the `set processor' command to specify what variant of the
3043 PowerPC family you are debugging. The command
3047 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
3048 following PowerPC and RS6000 variants:
3050 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
3051 rs6000 IBM RS6000 ("POWER") architecture, user-level view
3053 403GC IBM PowerPC 403GC
3054 505 Motorola PowerPC 505
3055 860 Motorola PowerPC 860 or 850
3056 601 Motorola PowerPC 601
3057 602 Motorola PowerPC 602
3058 603 Motorola/IBM PowerPC 603 or 603e
3059 604 Motorola PowerPC 604 or 604e
3060 750 Motorola/IBM PowerPC 750 or 750
3062 At the moment, this command just tells GDB what to name the
3063 special-purpose processor registers. Since almost all the affected
3064 registers are inaccessible to user-level programs, this command is
3065 only useful for remote debugging in its present form.
3069 Thanks to a major code donation from Hewlett-Packard, GDB now has much
3070 more extensive support for HP-UX. Added features include shared
3071 library support, kernel threads and hardware watchpoints for 11.00,
3072 support for HP's ANSI C and C++ compilers, and a compatibility mode
3073 for xdb and dbx commands.
3077 HP's donation includes the new concept of catchpoints, which is a
3078 generalization of the old catch command. On HP-UX, it is now possible
3079 to catch exec, fork, and vfork, as well as library loading.
3081 This means that the existing catch command has changed; its first
3082 argument now specifies the type of catch to be set up. See the
3083 output of "help catch" for a list of catchpoint types.
3085 * Debugging across forks
3087 On HP-UX, you can choose which process to debug when a fork() happens
3092 HP has donated a curses-based terminal user interface (TUI). To get
3093 it, build with --enable-tui. Although this can be enabled for any
3094 configuration, at present it only works for native HP debugging.
3096 * GDB remote protocol additions
3098 A new protocol packet 'X' that writes binary data is now available.
3099 Default behavior is to try 'X', then drop back to 'M' if the stub
3100 fails to respond. The settable variable `remotebinarydownload'
3101 allows explicit control over the use of 'X'.
3103 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
3104 full 64-bit address. The command
3106 set remoteaddresssize 32
3108 can be used to revert to the old behaviour. For existing remote stubs
3109 the change should not be noticed, as the additional address information
3112 In order to assist in debugging stubs, you may use the maintenance
3113 command `packet' to send any text string to the stub. For instance,
3115 maint packet heythere
3117 sends the packet "$heythere#<checksum>". Note that it is very easy to
3118 disrupt a debugging session by sending the wrong packet at the wrong
3121 The compare-sections command allows you to compare section data on the
3122 target to what is in the executable file without uploading or
3123 downloading, by comparing CRC checksums.
3125 * Tracing can collect general expressions
3127 You may now collect general expressions at tracepoints. This requires
3128 further additions to the target-side stub; see tracepoint.c and
3129 doc/agentexpr.texi for further details.
3131 * mask-address variable for Mips
3133 For Mips targets, you may control the zeroing of the upper 32 bits of
3134 a 64-bit address by entering `set mask-address on'. This is mainly
3135 of interest to users of embedded R4xxx and R5xxx processors.
3137 * Higher serial baud rates
3139 GDB's serial code now allows you to specify baud rates 57600, 115200,
3140 230400, and 460800 baud. (Note that your host system may not be able
3141 to achieve all of these rates.)
3145 The i960 configuration now includes an initial implementation of a
3146 builtin simulator, contributed by Jim Wilson.
3149 *** Changes in GDB-4.17:
3151 * New native configurations
3153 Alpha GNU/Linux alpha*-*-linux*
3154 Unixware 2.x i[3456]86-unixware2*
3155 Irix 6.x mips*-sgi-irix6*
3156 PowerPC GNU/Linux powerpc-*-linux*
3157 PowerPC Solaris powerpcle-*-solaris*
3158 Sparc GNU/Linux sparc-*-linux*
3159 Motorola sysV68 R3V7.1 m68k-motorola-sysv
3163 Argonaut Risc Chip (ARC) arc-*-*
3164 Hitachi H8/300S h8300*-*-*
3165 Matsushita MN10200 w/simulator mn10200-*-*
3166 Matsushita MN10300 w/simulator mn10300-*-*
3167 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
3168 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
3169 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
3170 Mitsubishi D10V w/simulator d10v-*-*
3171 Mitsubishi M32R/D w/simulator m32r-*-elf*
3172 Tsqware Sparclet sparclet-*-*
3173 NEC V850 w/simulator v850-*-*
3175 * New debugging protocols
3177 ARM with RDI protocol arm*-*-*
3178 M68K with dBUG monitor m68*-*-{aout,coff,elf}
3179 DDB and LSI variants of PMON protocol mips*-*-*
3180 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
3181 PowerPC with SDS protocol powerpc{,le}-*-eabi
3182 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
3186 All configurations can now understand and use the DWARF 2 debugging
3187 format. The choice is automatic, if the symbol file contains DWARF 2
3192 GDB now includes basic Java language support. This support is
3193 only useful with Java compilers that produce native machine code.
3195 * solib-absolute-prefix and solib-search-path
3197 For SunOS and SVR4 shared libraries, you may now set the prefix for
3198 loading absolute shared library symbol files, and the search path for
3199 locating non-absolute shared library symbol files.
3201 * Live range splitting
3203 GDB can now effectively debug code for which GCC has performed live
3204 range splitting as part of its optimization. See gdb/doc/LRS for
3205 more details on the expected format of the stabs information.
3209 GDB's support for the GNU Hurd, including thread debugging, has been
3210 updated to work with current versions of the Hurd.
3214 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
3215 instruction set. ARM GDB automatically detects when Thumb
3216 instructions are in use, and adjusts disassembly and backtracing
3221 GDB's MIPS target configurations now handle the MIP16 16-bit
3226 GDB now includes support for overlays; if an executable has been
3227 linked such that multiple sections are based at the same address, GDB
3228 will decide which section to use for symbolic info. You can choose to
3229 control the decision manually, using overlay commands, or implement
3230 additional target-side support and use "overlay load-target" to bring
3231 in the overlay mapping. Do "help overlay" for more detail.
3235 The command "info symbol <address>" displays information about
3236 the symbol at the specified address.
3240 The standard remote protocol now includes an extension that allows
3241 asynchronous collection and display of trace data. This requires
3242 extensive support in the target-side debugging stub. Tracing mode
3243 includes a new interaction mode in GDB and new commands: see the
3244 file tracepoint.c for more details.
3248 Configurations for embedded MIPS now include a simulator contributed
3249 by Cygnus Solutions. The simulator supports the instruction sets
3250 of most MIPS variants.
3254 Sparc configurations may now include the ERC32 simulator contributed
3255 by the European Space Agency. The simulator is not built into
3256 Sparc targets by default; configure with --enable-sim to include it.
3260 For target configurations that may include multiple variants of a
3261 basic architecture (such as MIPS and SH), you may now set the
3262 architecture explicitly. "set arch" sets, "info arch" lists
3263 the possible architectures.
3265 *** Changes in GDB-4.16:
3267 * New native configurations
3269 Windows 95, x86 Windows NT i[345]86-*-cygwin32
3270 M68K NetBSD m68k-*-netbsd*
3271 PowerPC AIX 4.x powerpc-*-aix*
3272 PowerPC MacOS powerpc-*-macos*
3273 PowerPC Windows NT powerpcle-*-cygwin32
3274 RS/6000 AIX 4.x rs6000-*-aix4*
3278 ARM with RDP protocol arm-*-*
3279 I960 with MON960 i960-*-coff
3280 MIPS VxWorks mips*-*-vxworks*
3281 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
3282 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
3284 Matra Sparclet sparclet-*-*
3288 The powerpc-eabi configuration now includes the PSIM simulator,
3289 contributed by Andrew Cagney, with assistance from Mike Meissner.
3290 PSIM is a very elaborate model of the PowerPC, including not only
3291 basic instruction set execution, but also details of execution unit
3292 performance and I/O hardware. See sim/ppc/README for more details.
3296 GDB now works with Solaris 2.5.
3298 * Windows 95/NT native
3300 GDB will now work as a native debugger on Windows 95 and Windows NT.
3301 To build it from source, you must use the "gnu-win32" environment,
3302 which uses a DLL to emulate enough of Unix to run the GNU tools.
3303 Further information, binaries, and sources are available at
3304 ftp.cygnus.com, under pub/gnu-win32.
3306 * dont-repeat command
3308 If a user-defined command includes the command `dont-repeat', then the
3309 command will not be repeated if the user just types return. This is
3310 useful if the command is time-consuming to run, so that accidental
3311 extra keystrokes don't run the same command many times.
3313 * Send break instead of ^C
3315 The standard remote protocol now includes an option to send a break
3316 rather than a ^C to the target in order to interrupt it. By default,
3317 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
3319 * Remote protocol timeout
3321 The standard remote protocol includes a new variable `remotetimeout'
3322 that allows you to set the number of seconds before GDB gives up trying
3323 to read from the target. The default value is 2.
3325 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
3327 By default GDB will automatically keep track of objects as they are
3328 loaded and unloaded by the dynamic linker. By using the command `set
3329 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
3330 when shared library events occur, thus allowing you to set breakpoints
3331 in shared libraries which are explicitly loaded by the inferior.
3333 Note this feature does not work on hpux8. On hpux9 you must link
3334 /usr/lib/end.o into your program. This feature should work
3335 automatically on hpux10.
3337 * Irix 5.x hardware watchpoint support
3339 Irix 5 configurations now support the use of hardware watchpoints.
3341 * Mips protocol "SYN garbage limit"
3343 When debugging a Mips target using the `target mips' protocol, you
3344 may set the number of characters that GDB will ignore by setting
3345 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
3346 every character. The default value is 1050.
3348 * Recording and replaying remote debug sessions
3350 If you set `remotelogfile' to the name of a file, gdb will write to it
3351 a recording of a remote debug session. This recording may then be
3352 replayed back to gdb using "gdbreplay". See gdbserver/README for
3353 details. This is useful when you have a problem with GDB while doing
3354 remote debugging; you can make a recording of the session and send it
3355 to someone else, who can then recreate the problem.
3357 * Speedups for remote debugging
3359 GDB includes speedups for downloading and stepping MIPS systems using
3360 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
3361 and more efficient S-record downloading.
3363 * Memory use reductions and statistics collection
3365 GDB now uses less memory and reports statistics about memory usage.
3366 Try the `maint print statistics' command, for example.
3368 *** Changes in GDB-4.15:
3370 * Psymtabs for XCOFF
3372 The symbol reader for AIX GDB now uses partial symbol tables. This
3373 can greatly improve startup time, especially for large executables.
3375 * Remote targets use caching
3377 Remote targets now use a data cache to speed up communication with the
3378 remote side. The data cache could lead to incorrect results because
3379 it doesn't know about volatile variables, thus making it impossible to
3380 debug targets which use memory mapped I/O devices. `set remotecache
3381 off' turns the the data cache off.
3383 * Remote targets may have threads
3385 The standard remote protocol now includes support for multiple threads
3386 in the target system, using new protocol commands 'H' and 'T'. See
3387 gdb/remote.c for details.
3391 If GDB is configured with `--enable-netrom', then it will include
3392 support for the NetROM ROM emulator from XLNT Designs. The NetROM
3393 acts as though it is a bank of ROM on the target board, but you can
3394 write into it over the network. GDB's support consists only of
3395 support for fast loading into the emulated ROM; to debug, you must use
3396 another protocol, such as standard remote protocol. The usual
3397 sequence is something like
3399 target nrom <netrom-hostname>
3401 target remote <netrom-hostname>:1235
3405 GDB now includes support for the Apple Macintosh, as a host only. It
3406 may be run as either an MPW tool or as a standalone application, and
3407 it can debug through the serial port. All the usual GDB commands are
3408 available, but to the target command, you must supply "serial" as the
3409 device type instead of "/dev/ttyXX". See mpw-README in the main
3410 directory for more information on how to build. The MPW configuration
3411 scripts */mpw-config.in support only a few targets, and only the
3412 mips-idt-ecoff target has been tested.
3416 GDB configuration now uses autoconf. This is not user-visible,
3417 but does simplify configuration and building.
3421 GDB now supports hpux10.
3423 *** Changes in GDB-4.14:
3425 * New native configurations
3427 x86 FreeBSD i[345]86-*-freebsd
3428 x86 NetBSD i[345]86-*-netbsd
3429 NS32k NetBSD ns32k-*-netbsd
3430 Sparc NetBSD sparc-*-netbsd
3434 A29K VxWorks a29k-*-vxworks
3435 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
3436 CPU32 EST-300 emulator m68*-*-est*
3437 PowerPC ELF powerpc-*-elf
3440 * Alpha OSF/1 support for procfs
3442 GDB now supports procfs under OSF/1-2.x and higher, which makes it
3443 possible to attach to running processes. As the mounting of the /proc
3444 filesystem is optional on the Alpha, GDB automatically determines
3445 the availability of /proc during startup. This can lead to problems
3446 if /proc is unmounted after GDB has been started.
3448 * Arguments to user-defined commands
3450 User commands may accept up to 10 arguments separated by whitespace.
3451 Arguments are accessed within the user command via $arg0..$arg9. A
3454 print $arg0 + $arg1 + $arg2
3456 To execute the command use:
3459 Defines the command "adder" which prints the sum of its three arguments.
3460 Note the arguments are text substitutions, so they may reference variables,
3461 use complex expressions, or even perform inferior function calls.
3463 * New `if' and `while' commands
3465 This makes it possible to write more sophisticated user-defined
3466 commands. Both commands take a single argument, which is the
3467 expression to evaluate, and must be followed by the commands to
3468 execute, one per line, if the expression is nonzero, the list being
3469 terminated by the word `end'. The `if' command list may include an
3470 `else' word, which causes the following commands to be executed only
3471 if the expression is zero.
3473 * Fortran source language mode
3475 GDB now includes partial support for Fortran 77. It will recognize
3476 Fortran programs and can evaluate a subset of Fortran expressions, but
3477 variables and functions may not be handled correctly. GDB will work
3478 with G77, but does not yet know much about symbols emitted by other
3481 * Better HPUX support
3483 Most debugging facilities now work on dynamic executables for HPPAs
3484 running hpux9 or later. You can attach to running dynamically linked
3485 processes, but by default the dynamic libraries will be read-only, so
3486 for instance you won't be able to put breakpoints in them. To change
3487 that behavior do the following before running the program:
3493 This will cause the libraries to be mapped private and read-write.
3494 To revert to the normal behavior, do this:
3500 You cannot set breakpoints or examine data in the library until after
3501 the library is loaded if the function/data symbols do not have
3504 GDB can now also read debug symbols produced by the HP C compiler on
3505 HPPAs (sorry, no C++, Fortran or 68k support).
3507 * Target byte order now dynamically selectable
3509 You can choose which byte order to use with a target system, via the
3510 commands "set endian big" and "set endian little", and you can see the
3511 current setting by using "show endian". You can also give the command
3512 "set endian auto", in which case GDB will use the byte order
3513 associated with the executable. Currently, only embedded MIPS
3514 configurations support dynamic selection of target byte order.
3516 * New DOS host serial code
3518 This version uses DPMI interrupts to handle buffered I/O, so you
3519 no longer need to run asynctsr when debugging boards connected to
3522 *** Changes in GDB-4.13:
3524 * New "complete" command
3526 This lists all the possible completions for the rest of the line, if it
3527 were to be given as a command itself. This is intended for use by emacs.
3529 * Trailing space optional in prompt
3531 "set prompt" no longer adds a space for you after the prompt you set. This
3532 allows you to set a prompt which ends in a space or one that does not.
3534 * Breakpoint hit counts
3536 "info break" now displays a count of the number of times the breakpoint
3537 has been hit. This is especially useful in conjunction with "ignore"; you
3538 can ignore a large number of breakpoint hits, look at the breakpoint info
3539 to see how many times the breakpoint was hit, then run again, ignoring one
3540 less than that number, and this will get you quickly to the last hit of
3543 * Ability to stop printing at NULL character
3545 "set print null-stop" will cause GDB to stop printing the characters of
3546 an array when the first NULL is encountered. This is useful when large
3547 arrays actually contain only short strings.
3549 * Shared library breakpoints
3551 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
3552 breakpoints in shared libraries before the executable is run.
3554 * Hardware watchpoints
3556 There is a new hardware breakpoint for the watch command for sparclite
3557 targets. See gdb/sparclite/hw_breakpoint.note.
3559 Hardware watchpoints are also now supported under GNU/Linux.
3563 Annotations have been added. These are for use with graphical interfaces,
3564 and are still experimental. Currently only gdba.el uses these.
3566 * Improved Irix 5 support
3568 GDB now works properly with Irix 5.2.
3570 * Improved HPPA support
3572 GDB now works properly with the latest GCC and GAS.
3574 * New native configurations
3576 Sequent PTX4 i[34]86-sequent-ptx4
3577 HPPA running OSF/1 hppa*-*-osf*
3578 Atari TT running SVR4 m68*-*-sysv4*
3579 RS/6000 LynxOS rs6000-*-lynxos*
3583 OS/9000 i[34]86-*-os9k
3584 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
3587 * Hitachi SH7000 and E7000-PC ICE support
3589 There is now support for communicating with the Hitachi E7000-PC ICE.
3590 This is available automatically when GDB is configured for the SH.
3594 As usual, a variety of small fixes and improvements, both generic
3595 and configuration-specific. See the ChangeLog for more detail.
3597 *** Changes in GDB-4.12:
3599 * Irix 5 is now supported
3603 GDB-4.12 on the HPPA has a number of changes which make it unable
3604 to debug the output from the currently released versions of GCC and
3605 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
3606 of GCC and GAS, versions of these tools designed to work with GDB-4.12
3607 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
3610 *** Changes in GDB-4.11:
3612 * User visible changes:
3616 The "set remotedebug" option is now consistent between the mips remote
3617 target, remote targets using the gdb-specific protocol, UDI (AMD's
3618 debug protocol for the 29k) and the 88k bug monitor. It is now an
3619 integer specifying a debug level (normally 0 or 1, but 2 means more
3620 debugging info for the mips target).
3622 * DEC Alpha native support
3624 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
3625 debug info, but GDB works fairly well with the DEC compiler and should
3626 work with a future GCC release. See the README file for a few
3627 Alpha-specific notes.
3629 * Preliminary thread implementation
3631 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
3633 * LynxOS native and target support for 386
3635 This release has been hosted on LynxOS 2.2, and also can be configured
3636 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
3639 * Improvements in C++ mangling/demangling.
3641 This release has much better g++ debugging, specifically in name
3642 mangling/demangling, virtual function calls, print virtual table,
3643 call methods, ...etc.
3645 *** Changes in GDB-4.10:
3647 * User visible changes:
3649 Remote debugging using the GDB-specific (`target remote') protocol now
3650 supports the `load' command. This is only useful if you have some
3651 other way of getting the stub to the target system, and you can put it
3652 somewhere in memory where it won't get clobbered by the download.
3654 Filename completion now works.
3656 When run under emacs mode, the "info line" command now causes the
3657 arrow to point to the line specified. Also, "info line" prints
3658 addresses in symbolic form (as well as hex).
3660 All vxworks based targets now support a user settable option, called
3661 vxworks-timeout. This option represents the number of seconds gdb
3662 should wait for responses to rpc's. You might want to use this if
3663 your vxworks target is, perhaps, a slow software simulator or happens
3664 to be on the far side of a thin network line.
3668 This release contains support for using a DEC alpha as a GDB host for
3669 cross debugging. Native alpha debugging is not supported yet.
3672 *** Changes in GDB-4.9:
3676 This is the first GDB release which is accompanied by a matching testsuite.
3677 The testsuite requires installation of dejagnu, which should be available
3678 via ftp from most sites that carry GNU software.
3682 'Cfront' style demangling has had its name changed to 'ARM' style, to
3683 emphasize that it was written from the specifications in the C++ Annotated
3684 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
3685 disclaimers, it still generated too much confusion with users attempting to
3686 use gdb with AT&T cfront.
3690 GDB now uses a standard remote interface to a simulator library.
3691 So far, the library contains simulators for the Zilog Z8001/2, the
3692 Hitachi H8/300, H8/500 and Super-H.
3694 * New targets supported
3696 H8/300 simulator h8300-hitachi-hms or h8300hms
3697 H8/500 simulator h8500-hitachi-hms or h8500hms
3698 SH simulator sh-hitachi-hms or sh
3699 Z8000 simulator z8k-zilog-none or z8ksim
3700 IDT MIPS board over serial line mips-idt-ecoff
3702 Cross-debugging to GO32 targets is supported. It requires a custom
3703 version of the i386-stub.c module which is integrated with the
3704 GO32 memory extender.
3706 * New remote protocols
3708 MIPS remote debugging protocol.
3710 * New source languages supported
3712 This version includes preliminary support for Chill, a Pascal like language
3713 used by telecommunications companies. Chill support is also being integrated
3714 into the GNU compiler, but we don't know when it will be publically available.
3717 *** Changes in GDB-4.8:
3719 * HP Precision Architecture supported
3721 GDB now supports HP PA-RISC machines running HPUX. A preliminary
3722 version of this support was available as a set of patches from the
3723 University of Utah. GDB does not support debugging of programs
3724 compiled with the HP compiler, because HP will not document their file
3725 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
3726 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
3728 Many problems in the preliminary version have been fixed.
3730 * Faster and better demangling
3732 We have improved template demangling and fixed numerous bugs in the GNU style
3733 demangler. It can now handle type modifiers such as `static' or `const'. Wide
3734 character types (wchar_t) are now supported. Demangling of each symbol is now
3735 only done once, and is cached when the symbol table for a file is read in.
3736 This results in a small increase in memory usage for C programs, a moderate
3737 increase in memory usage for C++ programs, and a fantastic speedup in
3740 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
3741 from the specifications in the Annotated Reference Manual, which AT&T's
3742 compiler does not actually implement.
3744 * G++ multiple inheritance compiler problem
3746 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
3747 inheritance lattices was reworked to properly discover ambiguities. We
3748 recently found an example which causes this new algorithm to fail in a
3749 very subtle way, producing bad debug information for those classes.
3750 The file 'gcc.patch' (in this directory) can be applied to gcc to
3751 circumvent the problem. A future GCC release will contain a complete
3754 The previous G++ debug info problem (mentioned below for the gdb-4.7
3755 release) is fixed in gcc version 2.3.2.
3757 * Improved configure script
3759 The `configure' script will now attempt to guess your system type if
3760 you don't supply a host system type. The old scheme of supplying a
3761 host system triplet is preferable over using this. All the magic is
3762 done in the new `config.guess' script. Examine it for details.
3764 We have also brought our configure script much more in line with the FSF's
3765 version. It now supports the --with-xxx options. In particular,
3766 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
3767 The resulting GDB will not be able to read arbitrary object file formats --
3768 only the format ``expected'' to be used on the configured target system.
3769 We hope to make this the default in a future release.
3771 * Documentation improvements
3773 There's new internal documentation on how to modify GDB, and how to
3774 produce clean changes to the code. We implore people to read it
3775 before submitting changes.
3777 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
3778 M4 macros. The new texinfo.tex is provided in this release. Pre-built
3779 `info' files are also provided. To build `info' files from scratch,
3780 you will need the latest `makeinfo' release, which will be available in
3781 a future texinfo-X.Y release.
3783 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
3784 We're not sure exactly which versions have this problem, but it has
3785 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
3786 or better. If that isn't possible, there is a patch in
3787 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
3788 around this problem.
3792 GDB now supports array constants that can be used in expressions typed in by
3793 the user. The syntax is `{element, element, ...}'. Ie: you can now type
3794 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
3797 The new directory `gdb/sparclite' contains a program that demonstrates
3798 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
3800 * New native hosts supported
3802 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
3803 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
3805 * New targets supported
3807 AMD 29k family via UDI a29k-amd-udi or udi29k
3809 * New file formats supported
3811 BFD now supports reading HP/PA-RISC executables (SOM file format?),
3812 HPUX core files, and SCO 3.2v2 core files.
3816 Attaching to processes now works again; thanks for the many bug reports.
3818 We have also stomped on a bunch of core dumps caused by
3819 printf_filtered("%s") problems.
3821 We eliminated a copyright problem on the rpc and ptrace header files
3822 for VxWorks, which was discovered at the last minute during the 4.7
3823 release. You should now be able to build a VxWorks GDB.
3825 You can now interrupt gdb while an attached process is running. This
3826 will cause the attached process to stop, and give control back to GDB.
3828 We fixed problems caused by using too many file descriptors
3829 for reading symbols from object files and libraries. This was
3830 especially a problem for programs that used many (~100) shared
3833 The `step' command now only enters a subroutine if there is line number
3834 information for the subroutine. Otherwise it acts like the `next'
3835 command. Previously, `step' would enter subroutines if there was
3836 any debugging information about the routine. This avoids problems
3837 when using `cc -g1' on MIPS machines.
3839 * Internal improvements
3841 GDB's internal interfaces have been improved to make it easier to support
3842 debugging of multiple languages in the future.
3844 GDB now uses a common structure for symbol information internally.
3845 Minimal symbols (derived from linkage symbols in object files), partial
3846 symbols (from a quick scan of debug information), and full symbols
3847 contain a common subset of information, making it easier to write
3848 shared code that handles any of them.
3850 * New command line options
3852 We now accept --silent as an alias for --quiet.
3856 The memory-mapped-malloc library is now licensed under the GNU Library
3857 General Public License.
3859 *** Changes in GDB-4.7:
3861 * Host/native/target split
3863 GDB has had some major internal surgery to untangle the support for
3864 hosts and remote targets. Now, when you configure GDB for a remote
3865 target, it will no longer load in all of the support for debugging
3866 local programs on the host. When fully completed and tested, this will
3867 ensure that arbitrary host/target combinations are possible.
3869 The primary conceptual shift is to separate the non-portable code in
3870 GDB into three categories. Host specific code is required any time GDB
3871 is compiled on that host, regardless of the target. Target specific
3872 code relates to the peculiarities of the target, but can be compiled on
3873 any host. Native specific code is everything else: it can only be
3874 built when the host and target are the same system. Child process
3875 handling and core file support are two common `native' examples.
3877 GDB's use of /proc for controlling Unix child processes is now cleaner.
3878 It has been split out into a single module under the `target_ops' vector,
3879 plus two native-dependent functions for each system that uses /proc.
3881 * New hosts supported
3883 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
3884 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
3885 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
3887 * New targets supported
3889 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3890 68030 and CPU32 m68030-*-*, m68332-*-*
3892 * New native hosts supported
3894 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
3895 (386bsd is not well tested yet)
3896 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
3898 * New file formats supported
3900 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
3901 supports reading of `a.out.adobe' object files, which are an a.out
3902 format extended with minimal information about multiple sections.
3906 `show copying' is the same as the old `info copying'.
3907 `show warranty' is the same as `info warrantee'.
3908 These were renamed for consistency. The old commands continue to work.
3910 `info handle' is a new alias for `info signals'.
3912 You can now define pre-command hooks, which attach arbitrary command
3913 scripts to any command. The commands in the hook will be executed
3914 prior to the user's command. You can also create a hook which will be
3915 executed whenever the program stops. See gdb.texinfo.
3919 We now deal with Cfront style name mangling, and can even extract type
3920 info from mangled symbols. GDB can automatically figure out which
3921 symbol mangling style your C++ compiler uses.
3923 Calling of methods and virtual functions has been improved as well.
3927 The crash that occured when debugging Sun Ansi-C compiled binaries is
3928 fixed. This was due to mishandling of the extra N_SO stabs output
3931 We also finally got Ultrix 4.2 running in house, and fixed core file
3932 support, with help from a dozen people on the net.
3934 John M. Farrell discovered that the reason that single-stepping was so
3935 slow on all of the Mips based platforms (primarily SGI and DEC) was
3936 that we were trying to demangle and lookup a symbol used for internal
3937 purposes on every instruction that was being stepped through. Changing
3938 the name of that symbol so that it couldn't be mistaken for a C++
3939 mangled symbol sped things up a great deal.
3941 Rich Pixley sped up symbol lookups in general by getting much smarter
3942 about when C++ symbol mangling is necessary. This should make symbol
3943 completion (TAB on the command line) much faster. It's not as fast as
3944 we'd like, but it's significantly faster than gdb-4.6.
3948 A new user controllable variable 'call_scratch_address' can
3949 specify the location of a scratch area to be used when GDB
3950 calls a function in the target. This is necessary because the
3951 usual method of putting the scratch area on the stack does not work
3952 in systems that have separate instruction and data spaces.
3954 We integrated changes to support the 29k UDI (Universal Debugger
3955 Interface), but discovered at the last minute that we didn't have all
3956 of the appropriate copyright paperwork. We are working with AMD to
3957 resolve this, and hope to have it available soon.
3961 We have sped up the remote serial line protocol, especially for targets
3962 with lots of registers. It now supports a new `expedited status' ('T')
3963 message which can be used in place of the existing 'S' status message.
3964 This allows the remote stub to send only the registers that GDB
3965 needs to make a quick decision about single-stepping or conditional
3966 breakpoints, eliminating the need to fetch the entire register set for
3967 each instruction being stepped through.
3969 The GDB remote serial protocol now implements a write-through cache for
3970 registers, only re-reading the registers if the target has run.
3972 There is also a new remote serial stub for SPARC processors. You can
3973 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
3974 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
3975 processor with a serial port.
3979 Configure.in files have become much easier to read and modify. A new
3980 `table driven' format makes it more obvious what configurations are
3981 supported, and what files each one uses.
3985 There is a new opcodes library which will eventually contain all of the
3986 disassembly routines and opcode tables. At present, it only contains
3987 Sparc and Z8000 routines. This will allow the assembler, debugger, and
3988 disassembler (binutils/objdump) to share these routines.
3990 The libiberty library is now copylefted under the GNU Library General
3991 Public License. This allows more liberal use, and was done so libg++
3992 can use it. This makes no difference to GDB, since the Library License
3993 grants all the rights from the General Public License.
3997 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
3998 reference to the stabs symbol info used by the debugger. It is (as far
3999 as we know) the only published document on this fascinating topic. We
4000 encourage you to read it, compare it to the stabs information on your
4001 system, and send improvements on the document in general (to
4002 bug-gdb@prep.ai.mit.edu).
4004 And, of course, many bugs have been fixed.
4007 *** Changes in GDB-4.6:
4009 * Better support for C++ function names
4011 GDB now accepts as input the "demangled form" of C++ overloaded function
4012 names and member function names, and can do command completion on such names
4013 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
4014 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
4015 Make use of command completion, it is your friend.
4017 GDB also now accepts a variety of C++ mangled symbol formats. They are
4018 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
4019 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
4020 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
4021 for the list of formats.
4023 * G++ symbol mangling problem
4025 Recent versions of gcc have a bug in how they emit debugging information for
4026 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
4027 directory) can be applied to gcc to fix the problem. Alternatively, if you
4028 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
4029 usual symptom is difficulty with setting breakpoints on methods. GDB complains
4030 about the method being non-existent. (We believe that version 2.2.2 of GCC has
4033 * New 'maintenance' command
4035 All of the commands related to hacking GDB internals have been moved out of
4036 the main command set, and now live behind the 'maintenance' command. This
4037 can also be abbreviated as 'mt'. The following changes were made:
4039 dump-me -> maintenance dump-me
4040 info all-breakpoints -> maintenance info breakpoints
4041 printmsyms -> maintenance print msyms
4042 printobjfiles -> maintenance print objfiles
4043 printpsyms -> maintenance print psymbols
4044 printsyms -> maintenance print symbols
4046 The following commands are new:
4048 maintenance demangle Call internal GDB demangler routine to
4049 demangle a C++ link name and prints the result.
4050 maintenance print type Print a type chain for a given symbol
4052 * Change to .gdbinit file processing
4054 We now read the $HOME/.gdbinit file before processing the argv arguments
4055 (e.g. reading symbol files or core files). This allows global parameters to
4056 be set, which will apply during the symbol reading. The ./.gdbinit is still
4057 read after argv processing.
4059 * New hosts supported
4061 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
4063 GNU/Linux support i386-unknown-linux or linux
4065 We are also including code to support the HP/PA running BSD and HPUX. This
4066 is almost guaranteed not to work, as we didn't have time to test or build it
4067 for this release. We are including it so that the more adventurous (or
4068 masochistic) of you can play with it. We also had major problems with the
4069 fact that the compiler that we got from HP doesn't support the -g option.
4072 * New targets supported
4074 Hitachi H8/300 h8300-hitachi-hms or h8300hms
4076 * More smarts about finding #include files
4078 GDB now remembers the compilation directory for all include files, and for
4079 all files from which C is generated (like yacc and lex sources). This
4080 greatly improves GDB's ability to find yacc/lex sources, and include files,
4081 especially if you are debugging your program from a directory different from
4082 the one that contains your sources.
4084 We also fixed a bug which caused difficulty with listing and setting
4085 breakpoints in include files which contain C code. (In the past, you had to
4086 try twice in order to list an include file that you hadn't looked at before.)
4088 * Interesting infernals change
4090 GDB now deals with arbitrary numbers of sections, where the symbols for each
4091 section must be relocated relative to that section's landing place in the
4092 target's address space. This work was needed to support ELF with embedded
4093 stabs used by Solaris-2.0.
4095 * Bug fixes (of course!)
4097 There have been loads of fixes for the following things:
4098 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
4099 i960, stabs, DOS(GO32), procfs, etc...
4101 See the ChangeLog for details.
4103 *** Changes in GDB-4.5:
4105 * New machines supported (host and target)
4107 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
4109 SGI Irix-4.x mips-sgi-irix4 or iris4
4111 * New malloc package
4113 GDB now uses a new memory manager called mmalloc, based on gmalloc.
4114 Mmalloc is capable of handling mutiple heaps of memory. It is also
4115 capable of saving a heap to a file, and then mapping it back in later.
4116 This can be used to greatly speedup the startup of GDB by using a
4117 pre-parsed symbol table which lives in a mmalloc managed heap. For
4118 more details, please read mmalloc/mmalloc.texi.
4122 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
4123 'help info proc' for details.
4125 * MIPS ecoff symbol table format
4127 The code that reads MIPS symbol table format is now supported on all hosts.
4128 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
4131 * File name changes for MS-DOS
4133 Many files in the config directories have been renamed to make it easier to
4134 support GDB on MS-DOSe systems (which have very restrictive file name
4135 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
4136 environment) is close to working but has some remaining problems. Note
4137 that debugging of DOS programs is not supported, due to limitations
4138 in the ``operating system'', but it can be used to host cross-debugging.
4140 * Cross byte order fixes
4142 Many fixes have been made to support cross debugging of Sparc and MIPS
4143 targets from hosts whose byte order differs.
4145 * New -mapped and -readnow options
4147 If memory-mapped files are available on your system through the 'mmap'
4148 system call, you can use the -mapped option on the `file' or
4149 `symbol-file' commands to cause GDB to write the symbols from your
4150 program into a reusable file. If the program you are debugging is
4151 called `/path/fred', the mapped symbol file will be `./fred.syms'.
4152 Future GDB debugging sessions will notice the presence of this file,
4153 and will quickly map in symbol information from it, rather than reading
4154 the symbol table from the executable program. Using the '-mapped'
4155 option in a GDB `file' or `symbol-file' command has the same effect as
4156 starting GDB with the '-mapped' command-line option.
4158 You can cause GDB to read the entire symbol table immediately by using
4159 the '-readnow' option with any of the commands that load symbol table
4160 information (or on the GDB command line). This makes the command
4161 slower, but makes future operations faster.
4163 The -mapped and -readnow options are typically combined in order to
4164 build a `fred.syms' file that contains complete symbol information.
4165 A simple GDB invocation to do nothing but build a `.syms' file for future
4168 gdb -batch -nx -mapped -readnow programname
4170 The `.syms' file is specific to the host machine on which GDB is run.
4171 It holds an exact image of GDB's internal symbol table. It cannot be
4172 shared across multiple host platforms.
4174 * longjmp() handling
4176 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
4177 siglongjmp() without losing control. This feature has not yet been ported to
4178 all systems. It currently works on many 386 platforms, all MIPS-based
4179 platforms (SGI, DECstation, etc), and Sun3/4.
4183 Preliminary work has been put in to support the new Solaris OS from Sun. At
4184 this time, it can control and debug processes, but it is not capable of
4189 As always, many many bug fixes. The major areas were with g++, and mipsread.
4190 People using the MIPS-based platforms should experience fewer mysterious
4191 crashes and trashed symbol tables.
4193 *** Changes in GDB-4.4:
4195 * New machines supported (host and target)
4197 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4199 BSD Reno on Vax vax-dec-bsd
4200 Ultrix on Vax vax-dec-ultrix
4202 * New machines supported (target)
4204 AMD 29000 embedded, using EBMON a29k-none-none
4208 GDB continues to improve its handling of C++. `References' work better.
4209 The demangler has also been improved, and now deals with symbols mangled as
4210 per the Annotated C++ Reference Guide.
4212 GDB also now handles `stabs' symbol information embedded in MIPS
4213 `ecoff' symbol tables. Since the ecoff format was not easily
4214 extensible to handle new languages such as C++, this appeared to be a
4215 good way to put C++ debugging info into MIPS binaries. This option
4216 will be supported in the GNU C compiler, version 2, when it is
4219 * New features for SVR4
4221 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
4222 shared libraries. Debugging dynamically linked programs should present
4223 only minor differences from debugging statically linked programs.
4225 The `info proc' command will print out information about any process
4226 on an SVR4 system (including the one you are debugging). At the moment,
4227 it prints the address mappings of the process.
4229 If you bring up GDB on another SVR4 system, please send mail to
4230 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
4232 * Better dynamic linking support in SunOS
4234 Reading symbols from shared libraries which contain debugging symbols
4235 now works properly. However, there remain issues such as automatic
4236 skipping of `transfer vector' code during function calls, which
4237 make it harder to debug code in a shared library, than to debug the
4238 same code linked statically.
4242 GDB is now using the latest `getopt' routines from the FSF. This
4243 version accepts the -- prefix for options with long names. GDB will
4244 continue to accept the old forms (-option and +option) as well.
4245 Various single letter abbreviations for options have been explicity
4246 added to the option table so that they won't get overshadowed in the
4247 future by other options that begin with the same letter.
4251 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
4252 Many assorted bugs have been handled. Many more remain to be handled.
4253 See the various ChangeLog files (primarily in gdb and bfd) for details.
4256 *** Changes in GDB-4.3:
4258 * New machines supported (host and target)
4260 Amiga 3000 running Amix m68k-cbm-svr4 or amix
4261 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
4262 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4264 * Almost SCO Unix support
4266 We had hoped to support:
4267 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4268 (except for core file support), but we discovered very late in the release
4269 that it has problems with process groups that render gdb unusable. Sorry
4270 about that. I encourage people to fix it and post the fixes.
4272 * Preliminary ELF and DWARF support
4274 GDB can read ELF object files on System V Release 4, and can handle
4275 debugging records for C, in DWARF format, in ELF files. This support
4276 is preliminary. If you bring up GDB on another SVR4 system, please
4277 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
4282 GDB now uses the latest `readline' library. One user-visible change
4283 is that two tabs will list possible command completions, which previously
4284 required typing M-? (meta-question mark, or ESC ?).
4288 The `stepi' bug that many of you noticed has been squashed.
4289 Many bugs in C++ have been handled. Many more remain to be handled.
4290 See the various ChangeLog files (primarily in gdb and bfd) for details.
4292 * State of the MIPS world (in case you wondered):
4294 GDB can understand the symbol tables emitted by the compilers
4295 supplied by most vendors of MIPS-based machines, including DEC. These
4296 symbol tables are in a format that essentially nobody else uses.
4298 Some versions of gcc come with an assembler post-processor called
4299 mips-tfile. This program is required if you want to do source-level
4300 debugging of gcc-compiled programs. I believe FSF does not ship
4301 mips-tfile with gcc version 1, but it will eventually come with gcc
4304 Debugging of g++ output remains a problem. g++ version 1.xx does not
4305 really support it at all. (If you're lucky, you should be able to get
4306 line numbers and stack traces to work, but no parameters or local
4307 variables.) With some work it should be possible to improve the
4310 When gcc version 2 is released, you will have somewhat better luck.
4311 However, even then you will get confusing results for inheritance and
4314 We will eventually provide full debugging of g++ output on
4315 DECstations. This will probably involve some kind of stabs-in-ecoff
4316 encapulation, but the details have not been worked out yet.
4319 *** Changes in GDB-4.2:
4321 * Improved configuration
4323 Only one copy of `configure' exists now, and it is not self-modifying.
4324 Porting BFD is simpler.
4328 The `step' and `next' commands now only stop at the first instruction
4329 of a source line. This prevents the multiple stops that used to occur
4330 in switch statements, for-loops, etc. `Step' continues to stop if a
4331 function that has debugging information is called within the line.
4335 Lots of small bugs fixed. More remain.
4337 * New host supported (not target)
4339 Intel 386 PC clone running Mach i386-none-mach
4342 *** Changes in GDB-4.1:
4344 * Multiple source language support
4346 GDB now has internal scaffolding to handle several source languages.
4347 It determines the type of each source file from its filename extension,
4348 and will switch expression parsing and number formatting to match the
4349 language of the function in the currently selected stack frame.
4350 You can also specifically set the language to be used, with
4351 `set language c' or `set language modula-2'.
4355 GDB now has preliminary support for the GNU Modula-2 compiler,
4356 currently under development at the State University of New York at
4357 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
4358 continue through the fall of 1991 and into 1992.
4360 Other Modula-2 compilers are currently not supported, and attempting to
4361 debug programs compiled with them will likely result in an error as the
4362 symbol table is read. Feel free to work on it, though!
4364 There are hooks in GDB for strict type checking and range checking,
4365 in the `Modula-2 philosophy', but they do not currently work.
4369 GDB can now write to executable and core files (e.g. patch
4370 a variable's value). You must turn this switch on, specify
4371 the file ("exec foo" or "core foo"), *then* modify it, e.g.
4372 by assigning a new value to a variable. Modifications take
4375 * Automatic SunOS shared library reading
4377 When you run your program, GDB automatically determines where its
4378 shared libraries (if any) have been loaded, and reads their symbols.
4379 The `share' command is no longer needed. This also works when
4380 examining core files.
4384 You can specify the number of lines that the `list' command shows.
4387 * New machines supported (host and target)
4389 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4390 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
4391 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
4393 * New hosts supported (not targets)
4395 IBM RT/PC: romp-ibm-aix or rtpc
4397 * New targets supported (not hosts)
4399 AMD 29000 embedded with COFF a29k-none-coff
4400 AMD 29000 embedded with a.out a29k-none-aout
4401 Ultracomputer remote kernel debug a29k-nyu-kern
4403 * New remote interfaces
4409 *** Changes in GDB-4.0:
4413 Wide output is wrapped at good places to make the output more readable.
4415 Gdb now supports cross-debugging from a host machine of one type to a
4416 target machine of another type. Communication with the target system
4417 is over serial lines. The ``target'' command handles connecting to the
4418 remote system; the ``load'' command will download a program into the
4419 remote system. Serial stubs for the m68k and i386 are provided. Gdb
4420 also supports debugging of realtime processes running under VxWorks,
4421 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
4422 stub on the target system.
4424 New CPUs supported include the AMD 29000 and Intel 960.
4426 GDB now reads object files and symbol tables via a ``binary file''
4427 library, which allows a single copy of GDB to debug programs of multiple
4428 object file types such as a.out and coff.
4430 There is now a GDB reference card in "doc/refcard.tex". (Make targets
4431 refcard.dvi and refcard.ps are available to format it).
4434 * Control-Variable user interface simplified
4436 All variables that control the operation of the debugger can be set
4437 by the ``set'' command, and displayed by the ``show'' command.
4439 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
4440 ``Show prompt'' produces the response:
4441 Gdb's prompt is new-gdb=>.
4443 What follows are the NEW set commands. The command ``help set'' will
4444 print a complete list of old and new set commands. ``help set FOO''
4445 will give a longer description of the variable FOO. ``show'' will show
4446 all of the variable descriptions and their current settings.
4448 confirm on/off: Enables warning questions for operations that are
4449 hard to recover from, e.g. rerunning the program while
4450 it is already running. Default is ON.
4452 editing on/off: Enables EMACS style command line editing
4453 of input. Previous lines can be recalled with
4454 control-P, the current line can be edited with control-B,
4455 you can search for commands with control-R, etc.
4458 history filename NAME: NAME is where the gdb command history
4459 will be stored. The default is .gdb_history,
4460 or the value of the environment variable
4463 history size N: The size, in commands, of the command history. The
4464 default is 256, or the value of the environment variable
4467 history save on/off: If this value is set to ON, the history file will
4468 be saved after exiting gdb. If set to OFF, the
4469 file will not be saved. The default is OFF.
4471 history expansion on/off: If this value is set to ON, then csh-like
4472 history expansion will be performed on
4473 command line input. The default is OFF.
4475 radix N: Sets the default radix for input and output. It can be set
4476 to 8, 10, or 16. Note that the argument to "radix" is interpreted
4477 in the current radix, so "set radix 10" is always a no-op.
4479 height N: This integer value is the number of lines on a page. Default
4480 is 24, the current `stty rows'' setting, or the ``li#''
4481 setting from the termcap entry matching the environment
4484 width N: This integer value is the number of characters on a line.
4485 Default is 80, the current `stty cols'' setting, or the ``co#''
4486 setting from the termcap entry matching the environment
4489 Note: ``set screensize'' is obsolete. Use ``set height'' and
4490 ``set width'' instead.
4492 print address on/off: Print memory addresses in various command displays,
4493 such as stack traces and structure values. Gdb looks
4494 more ``symbolic'' if you turn this off; it looks more
4495 ``machine level'' with it on. Default is ON.
4497 print array on/off: Prettyprint arrays. New convenient format! Default
4500 print demangle on/off: Print C++ symbols in "source" form if on,
4503 print asm-demangle on/off: Same, for assembler level printouts
4506 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
4509 * Support for Epoch Environment.
4511 The epoch environment is a version of Emacs v18 with windowing. One
4512 new command, ``inspect'', is identical to ``print'', except that if you
4513 are running in the epoch environment, the value is printed in its own
4517 * Support for Shared Libraries
4519 GDB can now debug programs and core files that use SunOS shared libraries.
4520 Symbols from a shared library cannot be referenced
4521 before the shared library has been linked with the program (this
4522 happens after you type ``run'' and before the function main() is entered).
4523 At any time after this linking (including when examining core files
4524 from dynamically linked programs), gdb reads the symbols from each
4525 shared library when you type the ``sharedlibrary'' command.
4526 It can be abbreviated ``share''.
4528 sharedlibrary REGEXP: Load shared object library symbols for files
4529 matching a unix regular expression. No argument
4530 indicates to load symbols for all shared libraries.
4532 info sharedlibrary: Status of loaded shared libraries.
4537 A watchpoint stops execution of a program whenever the value of an
4538 expression changes. Checking for this slows down execution
4539 tremendously whenever you are in the scope of the expression, but is
4540 quite useful for catching tough ``bit-spreader'' or pointer misuse
4541 problems. Some machines such as the 386 have hardware for doing this
4542 more quickly, and future versions of gdb will use this hardware.
4544 watch EXP: Set a watchpoint (breakpoint) for an expression.
4546 info watchpoints: Information about your watchpoints.
4548 delete N: Deletes watchpoint number N (same as breakpoints).
4549 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
4550 enable N: Re-enables watchpoint number N (same as breakpoints).
4553 * C++ multiple inheritance
4555 When used with a GCC version 2 compiler, GDB supports multiple inheritance
4558 * C++ exception handling
4560 Gdb now supports limited C++ exception handling. Besides the existing
4561 ability to breakpoint on an exception handler, gdb can breakpoint on
4562 the raising of an exception (before the stack is peeled back to the
4565 catch FOO: If there is a FOO exception handler in the dynamic scope,
4566 set a breakpoint to catch exceptions which may be raised there.
4567 Multiple exceptions (``catch foo bar baz'') may be caught.
4569 info catch: Lists all exceptions which may be caught in the
4570 current stack frame.
4573 * Minor command changes
4575 The command ``call func (arg, arg, ...)'' now acts like the print
4576 command, except it does not print or save a value if the function's result
4577 is void. This is similar to dbx usage.
4579 The ``up'' and ``down'' commands now always print the frame they end up
4580 at; ``up-silently'' and `down-silently'' can be used in scripts to change
4581 frames without printing.
4583 * New directory command
4585 'dir' now adds directories to the FRONT of the source search path.
4586 The path starts off empty. Source files that contain debug information
4587 about the directory in which they were compiled can be found even
4588 with an empty path; Sun CC and GCC include this information. If GDB can't
4589 find your source file in the current directory, type "dir .".
4591 * Configuring GDB for compilation
4593 For normal use, type ``./configure host''. See README or gdb.texinfo
4596 GDB now handles cross debugging. If you are remotely debugging between
4597 two different machines, type ``./configure host -target=targ''.
4598 Host is the machine where GDB will run; targ is the machine
4599 where the program that you are debugging will run.