1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.2
6 * New command line options
8 -data-directory DIR Specify DIR as the "data-directory".
9 This is mostly for testing purposes.
11 * GDB has a new command: "set directories".
12 It is like the "dir" command except that it replaces the
13 source path list instead of augmenting it.
16 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
17 has been integrated into GDB.
21 ** GDB values in Python are now callable if the value represents a
22 function. For example, if 'some_value' represents a function that
23 takes two integer parameters and returns a value, you can call
24 that function like so:
26 result = some_value (10,20)
28 ** Module gdb.types has been added.
29 It contains a collection of utilities for working with gdb.Types objects:
30 get_basic_type, has_field, make_enum_dict.
32 ** Module gdb.printing has been added.
33 It contains utilities for writing and registering pretty-printers.
34 New classes: PrettyPrinter, SubPrettyPrinter,
35 RegexpCollectionPrettyPrinter.
36 New function: register_pretty_printer.
38 ** New commands "info pretty-printers", "enable pretty-printer" and
39 "disable pretty-printer" have been added.
41 ** gdb.parameter("directories") is now available.
45 ** GDB now puts template parameters in scope when debugging in an
46 instantiation. For example, if you have:
48 template<int X> int func (void) { return X; }
50 then if you step into func<5>, "print X" will show "5". This
51 feature requires proper debuginfo support from the compiler; it
54 * GDB now follows GCC's rules on accessing volatile objects when
55 reading or writing target state during expression evaluation.
56 One notable difference to prior behavior is that "print x = 0"
57 no longer generates a read of x; the value of the assignment is
58 now always taken directly from the value being assigned.
60 * GDB now has some support for using labels in the program's source in
61 linespecs. For instance, you can use "advance label" to continue
64 * GDB now has support for reading and writing a new .gdb_index
65 section. This section holds a fast index of DWARF debugging
66 information and can be used to greatly speed up GDB startup and
67 operation. See the documentation for `save gdb-index' for details.
69 * The "watch" command now accepts an optional "-location" argument.
70 When used, this causes GDB to watch the memory referred to by the
71 expression. Such a watchpoint is never deleted due to it going out
74 * GDB now supports thread debugging of core dumps on GNU/Linux.
76 GDB now activates thread debugging using the libthread_db library
77 when debugging GNU/Linux core dumps, similarly to when debugging
78 live processes. As a result, when debugging a core dump file, GDB
79 is now able to display pthread_t ids of threads. For example, "info
80 threads" shows the same output as when debugging the process when it
81 was live. In earlier releases, you'd see something like this:
84 * 1 LWP 6780 main () at main.c:10
86 While now you see this:
89 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
91 It is also now possible to inspect TLS variables when debugging core
94 When debugging a core dump generated on a machine other than the one
95 used to run GDB, you may need to point GDB at the correct
96 libthread_db library with the "set libthread-db-search-path"
97 command. See the user manual for more details on this command.
99 * New features in the GDB remote stub, GDBserver
101 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
102 and i686 LynxOS (version 5.x).
104 * Ada task switching is now supported on sparc-elf targets when
105 debugging a program using the Ravenscar Profile. For more information,
106 see the "Tasking Support when using the Ravenscar Profile" section
107 in the GDB user manual.
109 * Guile support was removed.
111 *** Changes in GDB 7.2
113 * Shared library support for remote targets by default
115 When GDB is configured for a generic, non-OS specific target, like
116 for example, --target=arm-eabi or one of the many *-*-elf targets,
117 GDB now queries remote stubs for loaded shared libraries using the
118 `qXfer:libraries:read' packet. Previously, shared library support
119 was always disabled for such configurations.
123 ** Argument Dependent Lookup (ADL)
125 In C++ ADL lookup directs function search to the namespaces of its
126 arguments even if the namespace has not been imported.
136 Here the compiler will search for `foo' in the namespace of 'b'
137 and find A::foo. GDB now supports this. This construct is commonly
138 used in the Standard Template Library for operators.
140 ** Improved User Defined Operator Support
142 In addition to member operators, GDB now supports lookup of operators
143 defined in a namespace and imported with a `using' directive, operators
144 defined in the global scope, operators imported implicitly from an
145 anonymous namespace, and the ADL operators mentioned in the previous
147 GDB now also supports proper overload resolution for all the previously
148 mentioned flavors of operators.
150 ** static const class members
152 Printing of static const class members that are initialized in the
153 class definition has been fixed.
155 * Windows Thread Information Block access.
157 On Windows targets, GDB now supports displaying the Windows Thread
158 Information Block (TIB) structure. This structure is visible either
159 by using the new command `info w32 thread-information-block' or, by
160 dereferencing the new convenience variable named `$_tlb', a
161 thread-specific pointer to the TIB. This feature is also supported
162 when remote debugging using GDBserver.
166 Static tracepoints are calls in the user program into a tracing
167 library. One such library is a port of the LTTng kernel tracer to
168 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
169 When debugging with GDBserver, GDB now supports combining the GDB
170 tracepoint machinery with such libraries. For example: the user can
171 use GDB to probe a static tracepoint marker (a call from the user
172 program into the tracing library) with the new "strace" command (see
173 "New commands" below). This creates a "static tracepoint" in the
174 breakpoint list, that can be manipulated with the same feature set
175 as fast and regular tracepoints. E.g., collect registers, local and
176 global variables, collect trace state variables, and define
177 tracepoint conditions. In addition, the user can collect extra
178 static tracepoint marker specific data, by collecting the new
179 $_sdata internal variable. When analyzing the trace buffer, you can
180 inspect $_sdata like any other variable available to GDB. For more
181 information, see the "Tracepoints" chapter in GDB user manual. New
182 remote packets have been defined to support static tracepoints, see
183 the "New remote packets" section below.
185 * Better reconstruction of tracepoints after disconnected tracing
187 GDB will attempt to download the original source form of tracepoint
188 definitions when starting a trace run, and then will upload these
189 upon reconnection to the target, resulting in a more accurate
190 reconstruction of the tracepoints that are in use on the target.
194 You can now exercise direct control over the ways that GDB can
195 affect your program. For instance, you can disallow the setting of
196 breakpoints, so that the program can run continuously (assuming
197 non-stop mode). In addition, the "observer" variable is available
198 to switch all of the different controls; in observer mode, GDB
199 cannot affect the target's behavior at all, which is useful for
200 tasks like diagnosing live systems in the field.
202 * The new convenience variable $_thread holds the number of the
209 Return the address of the Windows Thread Information Block of a given thread.
213 In response to several of the tracepoint packets, the target may now
214 also respond with a number of intermediate `qRelocInsn' request
215 packets before the final result packet, to have GDB handle
216 relocating an instruction to execute at a different address. This
217 is particularly useful for stubs that support fast tracepoints. GDB
218 reports support for this feature in the qSupported packet.
222 List static tracepoint markers in the target program.
226 List static tracepoint markers at a given address in the target
229 qXfer:statictrace:read
231 Read the static trace data collected (by a `collect $_sdata'
232 tracepoint action). The remote stub reports support for this packet
233 to gdb's qSupported query.
237 Send the current settings of GDB's permission flags.
241 Send part of the source (textual) form of a tracepoint definition,
242 which includes location, conditional, and action list.
244 * The source command now accepts a -s option to force searching for the
245 script in the source search path even if the script name specifies
248 * New features in the GDB remote stub, GDBserver
250 - GDBserver now support tracepoints (including fast tracepoints, and
251 static tracepoints). The feature is currently supported by the
252 i386-linux and amd64-linux builds. See the "Tracepoints support
253 in gdbserver" section in the manual for more information.
255 GDBserver JIT compiles the tracepoint's conditional agent
256 expression bytecode into native code whenever possible for low
257 overhead dynamic tracepoints conditionals. For such tracepoints,
258 an expression that examines program state is evaluated when the
259 tracepoint is reached, in order to determine whether to capture
260 trace data. If the condition is simple and false, processing the
261 tracepoint finishes very quickly and no data is gathered.
263 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
264 for static tracepoints support.
266 - GDBserver now supports x86_64 Windows 64-bit debugging.
268 * GDB now sends xmlRegisters= in qSupported packet to indicate that
269 it understands register description.
271 * The --batch flag now disables pagination and queries.
273 * X86 general purpose registers
275 GDB now supports reading/writing byte, word and double-word x86
276 general purpose registers directly. This means you can use, say,
277 $ah or $ax to refer, respectively, to the byte register AH and
278 16-bit word register AX that are actually portions of the 32-bit
279 register EAX or 64-bit register RAX.
281 * The `commands' command now accepts a range of breakpoints to modify.
282 A plain `commands' following a command that creates multiple
283 breakpoints affects all the breakpoints set by that command. This
284 applies to breakpoints set by `rbreak', and also applies when a
285 single `break' command creates multiple breakpoints (e.g.,
286 breakpoints on overloaded c++ functions).
288 * The `rbreak' command now accepts a filename specification as part of
289 its argument, limiting the functions selected by the regex to those
290 in the specified file.
292 * Support for remote debugging Windows and SymbianOS shared libraries
293 from Unix hosts has been improved. Non Windows GDB builds now can
294 understand target reported file names that follow MS-DOS based file
295 system semantics, such as file names that include drive letters and
296 use the backslash character as directory separator. This makes it
297 possible to transparently use the "set sysroot" and "set
298 solib-search-path" on Unix hosts to point as host copies of the
299 target's shared libraries. See the new command "set
300 target-file-system-kind" described below, and the "Commands to
301 specify files" section in the user manual for more information.
305 eval template, expressions...
306 Convert the values of one or more expressions under the control
307 of the string template to a command line, and call it.
309 set target-file-system-kind unix|dos-based|auto
310 show target-file-system-kind
311 Set or show the assumed file system kind for target reported file
314 save breakpoints <filename>
315 Save all current breakpoint definitions to a file suitable for use
316 in a later debugging session. To read the saved breakpoint
317 definitions, use the `source' command.
319 `save tracepoints' is a new alias for `save-tracepoints'. The latter
322 info static-tracepoint-markers
323 Display information about static tracepoint markers in the target.
325 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
326 Define a static tracepoint by probing a marker at the given
327 function, line, address, or marker ID.
331 Enable and disable observer mode.
333 set may-write-registers on|off
334 set may-write-memory on|off
335 set may-insert-breakpoints on|off
336 set may-insert-tracepoints on|off
337 set may-insert-fast-tracepoints on|off
338 set may-interrupt on|off
339 Set individual permissions for GDB effects on the target. Note that
340 some of these settings can have undesirable or surprising
341 consequences, particularly when changed in the middle of a session.
342 For instance, disabling the writing of memory can prevent
343 breakpoints from being inserted, cause single-stepping to fail, or
344 even crash your program, if you disable after breakpoints have been
345 inserted. However, GDB should not crash.
347 set record memory-query on|off
348 show record memory-query
349 Control whether to stop the inferior if memory changes caused
350 by an instruction cannot be recorded.
355 The disassemble command now supports "start,+length" form of two arguments.
359 ** GDB now provides a new directory location, called the python directory,
360 where Python scripts written for GDB can be installed. The location
361 of that directory is <data-directory>/python, where <data-directory>
362 is the GDB data directory. For more details, see section `Scripting
363 GDB using Python' in the manual.
365 ** The GDB Python API now has access to breakpoints, symbols, symbol
366 tables, program spaces, inferiors, threads and frame's code blocks.
367 Additionally, GDB Parameters can now be created from the API, and
368 manipulated via set/show in the CLI.
370 ** New functions gdb.target_charset, gdb.target_wide_charset,
371 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
373 ** New exception gdb.GdbError.
375 ** Pretty-printers are now also looked up in the current program space.
377 ** Pretty-printers can now be individually enabled and disabled.
379 ** GDB now looks for names of Python scripts to auto-load in a
380 special section named `.debug_gdb_scripts', in addition to looking
381 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
383 * Tracepoint actions were unified with breakpoint commands. In particular,
384 there are no longer differences in "info break" output for breakpoints and
385 tracepoints and the "commands" command can be used for both tracepoints and
390 ARM Symbian arm*-*-symbianelf*
392 * D language support.
393 GDB now supports debugging programs written in the D programming
396 * GDB now supports the extended ptrace interface for PowerPC which is
397 available since Linux kernel version 2.6.34. This automatically enables
398 any hardware breakpoints and additional hardware watchpoints available in
399 the processor. The old ptrace interface exposes just one hardware
400 watchpoint and no hardware breakpoints.
402 * GDB is now able to use the Data Value Compare (DVC) register available on
403 embedded PowerPC processors to implement in hardware simple watchpoint
404 conditions of the form:
406 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
408 This works in native GDB running on Linux kernels with the extended ptrace
409 interface mentioned above.
411 *** Changes in GDB 7.1
417 GDB now supports importing of namespaces in C++. This enables the
418 user to inspect variables from imported namespaces. Support for
419 namepace aliasing has also been added. So, if a namespace is
420 aliased in the current scope (e.g. namepace C=A; ) the user can
421 print variables using the alias (e.g. (gdb) print C::x).
425 All known bugs relating to the printing of virtual base class were
426 fixed. It is now possible to call overloaded static methods using a
431 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
432 and reinterpret_cast<> are now handled by the C++ expression parser.
436 Xilinx MicroBlaze microblaze-*-*
441 Xilinx MicroBlaze microblaze
444 * Multi-program debugging.
446 GDB now has support for multi-program (a.k.a. multi-executable or
447 multi-exec) debugging. This allows for debugging multiple inferiors
448 simultaneously each running a different program under the same GDB
449 session. See "Debugging Multiple Inferiors and Programs" in the
450 manual for more information. This implied some user visible changes
451 in the multi-inferior support. For example, "info inferiors" now
452 lists inferiors that are not running yet or that have exited
453 already. See also "New commands" and "New options" below.
455 * New tracing features
457 GDB's tracepoint facility now includes several new features:
459 ** Trace state variables
461 GDB tracepoints now include support for trace state variables, which
462 are variables managed by the target agent during a tracing
463 experiment. They are useful for tracepoints that trigger each
464 other, so for instance one tracepoint can count hits in a variable,
465 and then a second tracepoint has a condition that is true when the
466 count reaches a particular value. Trace state variables share the
467 $-syntax of GDB convenience variables, and can appear in both
468 tracepoint actions and condition expressions. Use the "tvariable"
469 command to create, and "info tvariables" to view; see "Trace State
470 Variables" in the manual for more detail.
474 GDB now includes an option for defining fast tracepoints, which
475 targets may implement more efficiently, such as by installing a jump
476 into the target agent rather than a trap instruction. The resulting
477 speedup can be by two orders of magnitude or more, although the
478 tradeoff is that some program locations on some target architectures
479 might not allow fast tracepoint installation, for instance if the
480 instruction to be replaced is shorter than the jump. To request a
481 fast tracepoint, use the "ftrace" command, with syntax identical to
482 the regular trace command.
484 ** Disconnected tracing
486 It is now possible to detach GDB from the target while it is running
487 a trace experiment, then reconnect later to see how the experiment
488 is going. In addition, a new variable disconnected-tracing lets you
489 tell the target agent whether to continue running a trace if the
490 connection is lost unexpectedly.
494 GDB now has the ability to save the trace buffer into a file, and
495 then use that file as a target, similarly to you can do with
496 corefiles. You can select trace frames, print data that was
497 collected in them, and use tstatus to display the state of the
498 tracing run at the moment that it was saved. To create a trace
499 file, use "tsave <filename>", and to use it, do "target tfile
502 ** Circular trace buffer
504 You can ask the target agent to handle the trace buffer as a
505 circular buffer, discarding the oldest trace frames to make room for
506 newer ones, by setting circular-trace-buffer to on. This feature may
507 not be available for all target agents.
512 The disassemble command, when invoked with two arguments, now requires
513 the arguments to be comma-separated.
516 The info variables command now displays variable definitions. Files
517 which only declare a variable are not shown.
520 The source command is now capable of sourcing Python scripts.
521 This feature is dependent on the debugger being build with Python
524 Related to this enhancement is also the introduction of a new command
525 "set script-extension" (see below).
527 * New commands (for set/show, see "New options" below)
529 record save [<FILENAME>]
530 Save a file (in core file format) containing the process record
531 execution log for replay debugging at a later time.
533 record restore <FILENAME>
534 Restore the process record execution log that was saved at an
535 earlier time, for replay debugging.
537 add-inferior [-copies <N>] [-exec <FILENAME>]
540 clone-inferior [-copies <N>] [ID]
541 Make a new inferior ready to execute the same program another
547 maint info program-spaces
548 List the program spaces loaded into GDB.
550 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
551 show remote interrupt-sequence
552 Allow the user to select one of ^C, a BREAK signal or BREAK-g
553 as the sequence to the remote target in order to interrupt the execution.
554 Ctrl-C is a default. Some system prefers BREAK which is high level of
555 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
556 Magic SysRq g. It is BREAK signal and character 'g'.
558 set remote interrupt-on-connect [on | off]
559 show remote interrupt-on-connect
560 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
561 remote target when gdb connects to it. This is needed when you debug
564 set remotebreak [on | off]
566 Deprecated. Use "set/show remote interrupt-sequence" instead.
568 tvariable $NAME [ = EXP ]
569 Create or modify a trace state variable.
572 List trace state variables and their values.
574 delete tvariable $NAME ...
575 Delete one or more trace state variables.
578 Evaluate the given expressions without collecting anything into the
579 trace buffer. (Valid in tracepoint actions only.)
581 ftrace FN / FILE:LINE / *ADDR
582 Define a fast tracepoint at the given function, line, or address.
584 * New expression syntax
586 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
587 GDB now parses 0b101010 identically with 42.
591 set follow-exec-mode new|same
592 show follow-exec-mode
593 Control whether GDB reuses the same inferior across an exec call or
594 creates a new one. This is useful to be able to restart the old
595 executable after the inferior having done an exec call.
597 set default-collect EXPR, ...
599 Define a list of expressions to be collected at each tracepoint.
600 This is a useful way to ensure essential items are not overlooked,
601 such as registers or a critical global variable.
603 set disconnected-tracing
604 show disconnected-tracing
605 If set to 1, the target is instructed to continue tracing if it
606 loses its connection to GDB. If 0, the target is to stop tracing
609 set circular-trace-buffer
610 show circular-trace-buffer
611 If set to on, the target is instructed to use a circular trace buffer
612 and discard the oldest trace frames instead of stopping the trace due
613 to a full trace buffer. If set to off, the trace stops when the buffer
614 fills up. Some targets may not support this.
616 set script-extension off|soft|strict
617 show script-extension
618 If set to "off", the debugger does not perform any script language
619 recognition, and all sourced files are assumed to be GDB scripts.
620 If set to "soft" (the default), files are sourced according to
621 filename extension, falling back to GDB scripts if the first
623 If set to "strict", files are sourced according to filename extension.
625 set ada trust-PAD-over-XVS on|off
626 show ada trust-PAD-over-XVS
627 If off, activate a workaround against a bug in the debugging information
628 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
629 the GCC sources for more information about the GNAT encoding and
630 PAD types in particular). It is always safe to set this option to
631 off, but this introduces a slight performance penalty. The default
634 * Python API Improvements
636 ** GDB provides the new class gdb.LazyString. This is useful in
637 some pretty-printing cases. The new method gdb.Value.lazy_string
638 provides a simple way to create objects of this type.
640 ** The fields returned by gdb.Type.fields now have an
641 `is_base_class' attribute.
643 ** The new method gdb.Type.range returns the range of an array type.
645 ** The new method gdb.parse_and_eval can be used to parse and
646 evaluate an expression.
651 Define a trace state variable.
654 Get the current value of a trace state variable.
657 Set desired tracing behavior upon disconnection.
660 Set the trace buffer to be linear or circular.
663 Get data about the tracepoints currently in use.
667 Process record now works correctly with hardware watchpoints.
669 Multiple bug fixes have been made to the mips-irix port, making it
670 much more reliable. In particular:
671 - Debugging threaded applications is now possible again. Previously,
672 GDB would hang while starting the program, or while waiting for
673 the program to stop at a breakpoint.
674 - Attaching to a running process no longer hangs.
675 - An error occurring while loading a core file has been fixed.
676 - Changing the value of the PC register now works again. This fixes
677 problems observed when using the "jump" command, or when calling
678 a function from GDB, or even when assigning a new value to $pc.
679 - With the "finish" and "return" commands, the return value for functions
680 returning a small array is now correctly printed.
681 - It is now possible to break on shared library code which gets executed
682 during a shared library init phase (code executed while executing
683 their .init section). Previously, the breakpoint would have no effect.
684 - GDB is now able to backtrace through the signal handler for
685 non-threaded programs.
687 PIE (Position Independent Executable) programs debugging is now supported.
688 This includes debugging execution of PIC (Position Independent Code) shared
689 libraries although for that, it should be possible to run such libraries as an
692 *** Changes in GDB 7.0
694 * GDB now has an interface for JIT compilation. Applications that
695 dynamically generate code can create symbol files in memory and register
696 them with GDB. For users, the feature should work transparently, and
697 for JIT developers, the interface is documented in the GDB manual in the
698 "JIT Compilation Interface" chapter.
700 * Tracepoints may now be conditional. The syntax is as for
701 breakpoints; either an "if" clause appended to the "trace" command,
702 or the "condition" command is available. GDB sends the condition to
703 the target for evaluation using the same bytecode format as is used
704 for tracepoint actions.
706 * The disassemble command now supports: an optional /r modifier, print the
707 raw instructions in hex as well as in symbolic form, and an optional /m
708 modifier to print mixed source+assembly.
710 * Process record and replay
712 In a architecture environment that supports ``process record and
713 replay'', ``process record and replay'' target can record a log of
714 the process execution, and replay it with both forward and reverse
717 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
718 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
719 set execution-direction {forward|reverse}, for targets that support
722 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
723 feature is available with a native GDB running on kernel version
726 * GDB now has support for multi-byte and wide character sets on the
727 target. Strings whose character type is wchar_t, char16_t, or
728 char32_t are now correctly printed. GDB supports wide- and unicode-
729 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
730 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
731 `printf'. This feature requires iconv to work properly; if your
732 system does not have a working iconv, GDB can use GNU libiconv. See
733 the installation instructions for more information.
735 * GDB now supports automatic retrieval of shared library files from
736 remote targets. To use this feature, specify a system root that begins
737 with the `remote:' prefix, either via the `set sysroot' command or via
738 the `--with-sysroot' configure-time option.
740 * "info sharedlibrary" now takes an optional regex of libraries to show,
741 and it now reports if a shared library has no debugging information.
743 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
744 now complete on file names.
746 * When completing in expressions, gdb will attempt to limit
747 completions to allowable structure or union fields, where appropriate.
748 For instance, consider:
750 # struct example { int f1; double f2; };
751 # struct example variable;
754 If the user types TAB at the end of this command line, the available
755 completions will be "f1" and "f2".
757 * Inlined functions are now supported. They show up in backtraces, and
758 the "step", "next", and "finish" commands handle them automatically.
760 * GDB now supports the token-splicing (##) and stringification (#)
761 operators when expanding macros. It also supports variable-arity
764 * GDB now supports inspecting extra signal information, exported by
765 the new $_siginfo convenience variable. The feature is currently
766 implemented on linux ARM, i386 and amd64.
768 * GDB can now display the VFP floating point registers and NEON vector
769 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
770 can provide these registers (requires Linux 2.6.30 or later). Remote
771 and simulator targets may also provide them.
776 Search memory for a sequence of bytes.
779 Turn off `+'/`-' protocol acknowledgments to permit more efficient
780 operation over reliable transport links. Use of this packet is
781 controlled by the `set remote noack-packet' command.
784 Kill the process with the specified process ID. Use this in preference
785 to `k' when multiprocess protocol extensions are supported.
788 Obtains additional operating system information
792 Read or write additional signal information.
794 * Removed remote protocol undocumented extension
796 An undocumented extension to the remote protocol's `S' stop reply
797 packet that permited the stub to pass a process id was removed.
798 Remote servers should use the `T' stop reply packet instead.
800 * GDB now supports multiple function calling conventions according to the
801 DWARF-2 DW_AT_calling_convention function attribute.
803 * The SH target utilizes the aforementioned change to distinguish between gcc
804 and Renesas calling convention. It also adds the new CLI commands
805 `set/show sh calling-convention'.
807 * GDB can now read compressed debug sections, as produced by GNU gold
808 with the --compress-debug-sections=zlib flag.
810 * 64-bit core files are now supported on AIX.
812 * Thread switching is now supported on Tru64.
814 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
815 which will be allocated using malloc later in program execution.
817 * The qXfer:libraries:read remote procotol packet now allows passing a
818 list of section offsets.
820 * On GNU/Linux, GDB can now attach to stopped processes. Several race
821 conditions handling signals delivered during attach or thread creation
822 have also been fixed.
824 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
825 From the user's standpoint, all unqualified instances of True and False
826 are treated as the standard definitions, regardless of context.
828 * GDB now parses C++ symbol and type names more flexibly. For
831 template<typename T> class C { };
834 GDB will now correctly handle all of:
836 ptype C<char const *>
838 ptype C<const char *>
841 * New features in the GDB remote stub, gdbserver
843 - The "--wrapper" command-line argument tells gdbserver to use a
844 wrapper program to launch programs for debugging.
846 - On PowerPC and S/390 targets, it is now possible to use a single
847 gdbserver executable to debug both 32-bit and 64-bit programs.
848 (This requires gdbserver itself to be built as a 64-bit executable.)
850 - gdbserver uses the new noack protocol mode for TCP connections to
851 reduce communications latency, if also supported and enabled in GDB.
853 - Support for the sparc64-linux-gnu target is now included in
856 - The amd64-linux build of gdbserver now supports debugging both
857 32-bit and 64-bit programs.
859 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
860 now support hardware watchpoints, and will use them automatically
865 GDB now has support for scripting using Python. Whether this is
866 available is determined at configure time.
868 New GDB commands can now be written in Python.
870 * Ada tasking support
872 Ada tasks can now be inspected in GDB. The following commands have
876 Print the list of Ada tasks.
878 Print detailed information about task number N.
880 Print the task number of the current task.
882 Switch the context of debugging to task number N.
884 * Support for user-defined prefixed commands. The "define" command can
885 add new commands to existing prefixes, e.g. "target".
887 * Multi-inferior, multi-process debugging.
889 GDB now has generalized support for multi-inferior debugging. See
890 "Debugging Multiple Inferiors" in the manual for more information.
891 Although availability still depends on target support, the command
892 set is more uniform now. The GNU/Linux specific multi-forks support
893 has been migrated to this new framework. This implied some user
894 visible changes; see "New commands" and also "Removed commands"
897 * Target descriptions can now describe the target OS ABI. See the
898 "Target Description Format" section in the user manual for more
901 * Target descriptions can now describe "compatible" architectures
902 to indicate that the target can execute applications for a different
903 architecture in addition to those for the main target architecture.
904 See the "Target Description Format" section in the user manual for
907 * Multi-architecture debugging.
909 GDB now includes general supports for debugging applications on
910 hybrid systems that use more than one single processor architecture
911 at the same time. Each such hybrid architecture still requires
912 specific support to be added. The only hybrid architecture supported
913 in this version of GDB is the Cell Broadband Engine.
915 * GDB now supports integrated debugging of Cell/B.E. applications that
916 use both the PPU and SPU architectures. To enable support for hybrid
917 Cell/B.E. debugging, you need to configure GDB to support both the
918 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
919 --enable-targets configure option.
921 * Non-stop mode debugging.
923 For some targets, GDB now supports an optional mode of operation in
924 which you can examine stopped threads while other threads continue
925 to execute freely. This is referred to as non-stop mode, with the
926 old mode referred to as all-stop mode. See the "Non-Stop Mode"
927 section in the user manual for more information.
929 To be able to support remote non-stop debugging, a remote stub needs
930 to implement the non-stop mode remote protocol extensions, as
931 described in the "Remote Non-Stop" section of the user manual. The
932 GDB remote stub, gdbserver, has been adjusted to support these
933 extensions on linux targets.
935 * New commands (for set/show, see "New options" below)
937 catch syscall [NAME(S) | NUMBER(S)]
938 Catch system calls. Arguments, which should be names of system
939 calls or their numbers, mean catch only those syscalls. Without
940 arguments, every syscall will be caught. When the inferior issues
941 any of the specified syscalls, GDB will stop and announce the system
942 call, both when it is called and when its call returns. This
943 feature is currently available with a native GDB running on the
944 Linux Kernel, under the following architectures: x86, x86_64,
945 PowerPC and PowerPC64.
947 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
949 Search memory for a sequence of bytes.
951 maint set python print-stack
952 maint show python print-stack
953 Show a stack trace when an error is encountered in a Python script.
956 Invoke CODE by passing it to the Python interpreter.
961 These allow macros to be defined, undefined, and listed
965 Show operating system information about processes.
968 List the inferiors currently under GDB's control.
971 Switch focus to inferior number NUM.
974 Detach from inferior number NUM.
977 Kill inferior number NUM.
982 show spu stop-on-load
983 Control whether to stop for new SPE threads during Cell/B.E. debugging.
985 set spu auto-flush-cache
986 show spu auto-flush-cache
987 Control whether to automatically flush the software-managed cache
988 during Cell/B.E. debugging.
990 set sh calling-convention
991 show sh calling-convention
992 Control the calling convention used when calling SH target functions.
996 Control display of timestamps with GDB debugging output.
998 set disassemble-next-line
999 show disassemble-next-line
1000 Control display of disassembled source lines or instructions when
1003 set remote noack-packet
1004 show remote noack-packet
1005 Set/show the use of remote protocol QStartNoAckMode packet. See above
1006 under "New remote packets."
1008 set remote query-attached-packet
1009 show remote query-attached-packet
1010 Control use of remote protocol `qAttached' (query-attached) packet.
1012 set remote read-siginfo-object
1013 show remote read-siginfo-object
1014 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
1017 set remote write-siginfo-object
1018 show remote write-siginfo-object
1019 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
1022 set remote reverse-continue
1023 show remote reverse-continue
1024 Control use of remote protocol 'bc' (reverse-continue) packet.
1026 set remote reverse-step
1027 show remote reverse-step
1028 Control use of remote protocol 'bs' (reverse-step) packet.
1030 set displaced-stepping
1031 show displaced-stepping
1032 Control displaced stepping mode. Displaced stepping is a way to
1033 single-step over breakpoints without removing them from the debuggee.
1034 Also known as "out-of-line single-stepping".
1037 show debug displaced
1038 Control display of debugging info for displaced stepping.
1040 maint set internal-error
1041 maint show internal-error
1042 Control what GDB does when an internal error is detected.
1044 maint set internal-warning
1045 maint show internal-warning
1046 Control what GDB does when an internal warning is detected.
1051 Use a wrapper program to launch programs for debugging.
1053 set multiple-symbols (all|ask|cancel)
1054 show multiple-symbols
1055 The value of this variable can be changed to adjust the debugger behavior
1056 when an expression or a breakpoint location contains an ambiguous symbol
1057 name (an overloaded function name, for instance).
1059 set breakpoint always-inserted
1060 show breakpoint always-inserted
1061 Keep breakpoints always inserted in the target, as opposed to inserting
1062 them when resuming the target, and removing them when the target stops.
1063 This option can improve debugger performance on slow remote targets.
1065 set arm fallback-mode (arm|thumb|auto)
1066 show arm fallback-mode
1067 set arm force-mode (arm|thumb|auto)
1069 These commands control how ARM GDB determines whether instructions
1070 are ARM or Thumb. The default for both settings is auto, which uses
1071 the current CPSR value for instructions without symbols; previous
1072 versions of GDB behaved as if "set arm fallback-mode arm".
1074 set disable-randomization
1075 show disable-randomization
1076 Standalone programs run with the virtual address space randomization enabled
1077 by default on some platforms. This option keeps the addresses stable across
1078 multiple debugging sessions.
1082 Control whether other threads are stopped or not when some thread hits
1087 Requests that asynchronous execution is enabled in the target, if available.
1088 In this case, it's possible to resume target in the background, and interact
1089 with GDB while the target is running. "show target-async" displays the
1090 current state of asynchronous execution of the target.
1092 set target-wide-charset
1093 show target-wide-charset
1094 The target-wide-charset is the name of the character set that GDB
1095 uses when printing characters whose type is wchar_t.
1097 set tcp auto-retry (on|off)
1099 set tcp connect-timeout
1100 show tcp connect-timeout
1101 These commands allow GDB to retry failed TCP connections to a remote stub
1102 with a specified timeout period; this is useful if the stub is launched
1103 in parallel with GDB but may not be ready to accept connections immediately.
1105 set libthread-db-search-path
1106 show libthread-db-search-path
1107 Control list of directories which GDB will search for appropriate
1110 set schedule-multiple (on|off)
1111 show schedule-multiple
1112 Allow GDB to resume all threads of all processes or only threads of
1113 the current process.
1117 Use more aggressive caching for accesses to the stack. This improves
1118 performance of remote debugging (particularly backtraces) without
1119 affecting correctness.
1121 set interactive-mode (on|off|auto)
1122 show interactive-mode
1123 Control whether GDB runs in interactive mode (on) or not (off).
1124 When in interactive mode, GDB waits for the user to answer all
1125 queries. Otherwise, GDB does not wait and assumes the default
1126 answer. When set to auto (the default), GDB determines which
1127 mode to use based on the stdin settings.
1132 For program forks, this is replaced by the new more generic `info
1133 inferiors' command. To list checkpoints, you can still use the
1134 `info checkpoints' command, which was an alias for the `info forks'
1138 Replaced by the new `inferior' command. To switch between
1139 checkpoints, you can still use the `restart' command, which was an
1140 alias for the `fork' command.
1143 This is removed, since some targets don't have a notion of
1144 processes. To switch between processes, you can still use the
1145 `inferior' command using GDB's own inferior number.
1148 For program forks, this is replaced by the new more generic `kill
1149 inferior' command. To delete a checkpoint, you can still use the
1150 `delete checkpoint' command, which was an alias for the `delete
1154 For program forks, this is replaced by the new more generic `detach
1155 inferior' command. To detach a checkpoint, you can still use the
1156 `detach checkpoint' command, which was an alias for the `detach
1159 * New native configurations
1161 x86/x86_64 Darwin i[34567]86-*-darwin*
1163 x86_64 MinGW x86_64-*-mingw*
1167 Lattice Mico32 lm32-*
1168 x86 DICOS i[34567]86-*-dicos*
1169 x86_64 DICOS x86_64-*-dicos*
1172 * The GDB remote stub, gdbserver, now supports x86 Windows CE
1173 (mingw32ce) debugging.
1179 These commands were actually not implemented on any target.
1181 *** Changes in GDB 6.8
1183 * New native configurations
1185 NetBSD/hppa hppa*-*netbsd*
1186 Xtensa GNU/Linux xtensa*-*-linux*
1190 NetBSD/hppa hppa*-*-netbsd*
1191 Xtensa GNU/Lunux xtensa*-*-linux*
1193 * Change in command line behavior -- corefiles vs. process ids.
1195 When the '-p NUMBER' or '--pid NUMBER' options are used, and
1196 attaching to process NUMBER fails, GDB no longer attempts to open a
1197 core file named NUMBER. Attaching to a program using the -c option
1198 is no longer supported. Instead, use the '-p' or '--pid' options.
1200 * GDB can now be built as a native debugger for debugging Windows x86
1201 (mingw32) Portable Executable (PE) programs.
1203 * Pending breakpoints no longer change their number when their address
1206 * GDB now supports breakpoints with multiple locations,
1207 including breakpoints on C++ constructors, inside C++ templates,
1208 and in inlined functions.
1210 * GDB's ability to debug optimized code has been improved. GDB more
1211 accurately identifies function bodies and lexical blocks that occupy
1212 more than one contiguous range of addresses.
1214 * Target descriptions can now describe registers for PowerPC.
1216 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
1217 registers on PowerPC targets.
1219 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
1220 targets even when the libthread_db library is not available.
1222 * The GDB remote stub, gdbserver, now supports the new file transfer
1223 commands (remote put, remote get, and remote delete).
1225 * The GDB remote stub, gdbserver, now supports run and attach in
1226 extended-remote mode.
1228 * hppa*64*-*-hpux11* target broken
1229 The debugger is unable to start a program and fails with the following
1230 error: "Error trying to get information about dynamic linker".
1231 The gdb-6.7 release is also affected.
1233 * GDB now supports the --enable-targets= configure option to allow
1234 building a single GDB executable that supports multiple remote
1235 target architectures.
1237 * GDB now supports debugging C and C++ programs which use the
1238 Decimal Floating Point extension. In addition, the PowerPC target
1239 now has a set of pseudo-registers to inspect decimal float values
1240 stored in two consecutive float registers.
1242 * The -break-insert MI command can optionally create pending
1245 * Improved support for debugging Ada
1246 Many improvements to the Ada language support have been made. These
1248 - Better support for Ada2005 interface types
1249 - Improved handling of arrays and slices in general
1250 - Better support for Taft-amendment types
1251 - The '{type} ADDRESS' expression is now allowed on the left hand-side
1253 - Improved command completion in Ada
1256 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
1261 set print frame-arguments (all|scalars|none)
1262 show print frame-arguments
1263 The value of this variable can be changed to control which argument
1264 values should be printed by the debugger when displaying a frame.
1269 Transfer files to and from a remote target, and delete remote files.
1276 Transfer files to and from a remote target, and delete remote files.
1278 * New remote packets
1285 Open, close, read, write, and delete files on the remote system.
1288 Attach to an existing process on the remote system, in extended-remote
1292 Run a new process on the remote system, in extended-remote mode.
1294 *** Changes in GDB 6.7
1296 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
1297 bfd, libiberty and opcodes, as revealed by static analysis donated by
1298 Coverity, Inc. (http://scan.coverity.com).
1300 * When looking up multiply-defined global symbols, GDB will now prefer the
1301 symbol definition in the current shared library if it was built using the
1302 -Bsymbolic linker option.
1304 * When the Text User Interface (TUI) is not configured, GDB will now
1305 recognize the -tui command-line option and print a message that the TUI
1308 * The GDB remote stub, gdbserver, now has lower overhead for high
1309 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
1311 * GDB for MIPS targets now autodetects whether a remote target provides
1312 32-bit or 64-bit register values.
1314 * Support for C++ member pointers has been improved.
1316 * GDB now understands XML target descriptions, which specify the
1317 target's overall architecture. GDB can read a description from
1318 a local file or over the remote serial protocol.
1320 * Vectors of single-byte data use a new integer type which is not
1321 automatically displayed as character or string data.
1323 * The /s format now works with the print command. It displays
1324 arrays of single-byte integers and pointers to single-byte integers
1327 * Target descriptions can now describe target-specific registers,
1328 for architectures which have implemented the support (currently
1329 only ARM, M68K, and MIPS).
1331 * GDB and the GDB remote stub, gdbserver, now support the XScale
1334 * The GDB remote stub, gdbserver, has been updated to support
1335 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
1336 has been rewritten to use the standard GDB remote protocol.
1338 * GDB can now step into C++ functions which are called through thunks.
1340 * GDB for the Cell/B.E. SPU now supports overlay debugging.
1342 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
1343 layout. It also supports a TextSeg= and DataSeg= response when only
1344 segment base addresses (rather than offsets) are available.
1346 * The /i format now outputs any trailing branch delay slot instructions
1347 immediately following the last instruction within the count specified.
1349 * The GDB remote protocol "T" stop reply packet now supports a
1350 "library" response. Combined with the new "qXfer:libraries:read"
1351 packet, this response allows GDB to debug shared libraries on targets
1352 where the operating system manages the list of loaded libraries (e.g.
1353 Windows and SymbianOS).
1355 * The GDB remote stub, gdbserver, now supports dynamic link libraries
1356 (DLLs) on Windows and Windows CE targets.
1358 * GDB now supports a faster verification that a .debug file matches its binary
1359 according to its build-id signature, if the signature is present.
1365 Enable or disable hardware flow control (RTS/CTS) on the serial port
1366 when debugging using remote targets.
1368 set mem inaccessible-by-default
1369 show mem inaccessible-by-default
1370 If the target supplies a memory map, for instance via the remote
1371 protocol's "qXfer:memory-map:read" packet, setting this variable
1372 prevents GDB from accessing memory outside the memory map. This
1373 is useful for targets with memory mapped registers or which react
1374 badly to accesses of unmapped address space.
1376 set breakpoint auto-hw
1377 show breakpoint auto-hw
1378 If the target supplies a memory map, for instance via the remote
1379 protocol's "qXfer:memory-map:read" packet, setting this variable
1380 lets GDB use hardware breakpoints automatically for memory regions
1381 where it can not use software breakpoints. This covers both the
1382 "break" command and internal breakpoints used for other commands
1383 including "next" and "finish".
1386 catch exception unhandled
1387 Stop the program execution when Ada exceptions are raised.
1390 Stop the program execution when an Ada assertion failed.
1394 Set an alternate system root for target files. This is a more
1395 general version of "set solib-absolute-prefix", which is now
1396 an alias to "set sysroot".
1399 Provide extended SPU facility status information. This set of
1400 commands is available only when debugging the Cell/B.E. SPU
1403 * New native configurations
1405 OpenBSD/sh sh*-*openbsd*
1408 unset tdesc filename
1410 Use the specified local file as an XML target description, and do
1411 not query the target for its built-in description.
1415 OpenBSD/sh sh*-*-openbsd*
1416 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
1417 Toshiba Media Processor mep-elf
1419 * New remote packets
1422 Ignore the specified signals; pass them directly to the debugged program
1423 without stopping other threads or reporting them to GDB.
1425 qXfer:features:read:
1426 Read an XML target description from the target, which describes its
1431 Read or write contents of an spufs file on the target system. These
1432 packets are available only on the Cell/B.E. SPU architecture.
1434 qXfer:libraries:read:
1435 Report the loaded shared libraries. Combined with new "T" packet
1436 response, this packet allows GDB to debug shared libraries on
1437 targets where the operating system manages the list of loaded
1438 libraries (e.g. Windows and SymbianOS).
1442 Support for these obsolete configurations has been removed.
1450 i[34567]86-*-lynxos*
1451 i[34567]86-*-netware*
1452 i[34567]86-*-sco3.2v5*
1453 i[34567]86-*-sco3.2v4*
1455 i[34567]86-*-sysv4.2*
1458 i[34567]86-*-unixware2*
1459 i[34567]86-*-unixware*
1468 * Other removed features
1475 Various m68k-only ROM monitors.
1482 Various Renesas ROM monitors and debugging interfaces for SH and
1487 Support for a Macraigor serial interface to on-chip debugging.
1488 GDB does not directly support the newer parallel or USB
1493 A debug information format. The predecessor to DWARF 2 and
1494 DWARF 3, which are still supported.
1496 Support for the HP aCC compiler on HP-UX/PA-RISC
1498 SOM-encapsulated symbolic debugging information, automatic
1499 invocation of pxdb, and the aCC custom C++ ABI. This does not
1500 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
1501 with aCC can still be debugged on an assembly level.
1503 MIPS ".pdr" sections
1505 A MIPS-specific format used to describe stack frame layout
1506 in debugging information.
1510 GDB could work with an older version of Guile to debug
1511 the interpreter and Scheme programs running in it.
1513 set mips stack-arg-size
1514 set mips saved-gpreg-size
1516 Use "set mips abi" to control parameter passing for MIPS.
1518 *** Changes in GDB 6.6
1523 Cell Broadband Engine SPU spu-elf
1525 * GDB can now be configured as a cross-debugger targeting native Windows
1526 (mingw32) or Cygwin. It can communicate with a remote debugging stub
1527 running on a Windows system over TCP/IP to debug Windows programs.
1529 * The GDB remote stub, gdbserver, has been updated to support Windows and
1530 Cygwin debugging. Both single-threaded and multi-threaded programs are
1533 * The "set trust-readonly-sections" command works again. This command was
1534 broken in GDB 6.3, 6.4, and 6.5.
1536 * The "load" command now supports writing to flash memory, if the remote
1537 stub provides the required support.
1539 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
1540 longer requires symbolic debug information (e.g. DWARF-2).
1545 unset substitute-path
1546 show substitute-path
1547 Manage a list of substitution rules that GDB uses to rewrite the name
1548 of the directories where the sources are located. This can be useful
1549 for instance when the sources were moved to a different location
1550 between compilation and debugging.
1554 Print each CLI command as it is executed. Each command is prefixed with
1555 a number of `+' symbols representing the nesting depth.
1556 The source command now has a `-v' option to enable the same feature.
1560 The ARM Demon monitor support (RDP protocol, "target rdp").
1562 Kernel Object Display, an embedded debugging feature which only worked with
1563 an obsolete version of Cisco IOS.
1565 The 'set download-write-size' and 'show download-write-size' commands.
1567 * New remote packets
1570 Tell a stub about GDB client features, and request remote target features.
1571 The first feature implemented is PacketSize, which allows the target to
1572 specify the size of packets it can handle - to minimize the number of
1573 packets required and improve performance when connected to a remote
1577 Fetch an OS auxilliary vector from the remote stub. This packet is a
1578 more efficient replacement for qPart:auxv:read.
1580 qXfer:memory-map:read:
1581 Fetch a memory map from the remote stub, including information about
1582 RAM, ROM, and flash memory devices.
1587 Erase and program a flash memory device.
1589 * Removed remote packets
1592 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
1593 used it, and only gdbserver implemented it.
1595 *** Changes in GDB 6.5
1599 Renesas M32C/M16C m32c-elf
1601 Morpho Technologies ms1 ms1-elf
1605 init-if-undefined Initialize a convenience variable, but
1606 only if it doesn't already have a value.
1608 The following commands are presently only implemented for native GNU/Linux:
1610 checkpoint Save a snapshot of the program state.
1612 restart <n> Return the program state to a
1613 previously saved state.
1615 info checkpoints List currently saved checkpoints.
1617 delete-checkpoint <n> Delete a previously saved checkpoint.
1619 set|show detach-on-fork Tell gdb whether to detach from a newly
1620 forked process, or to keep debugging it.
1622 info forks List forks of the user program that
1623 are available to be debugged.
1625 fork <n> Switch to debugging one of several
1626 forks of the user program that are
1627 available to be debugged.
1629 delete-fork <n> Delete a fork from the list of forks
1630 that are available to be debugged (and
1631 kill the forked process).
1633 detach-fork <n> Delete a fork from the list of forks
1634 that are available to be debugged (and
1635 allow the process to continue).
1639 Morpho Technologies ms2 ms1-elf
1641 * Improved Windows host support
1643 GDB now builds as a cross debugger hosted on i686-mingw32, including
1644 native console support, and remote communications using either
1645 network sockets or serial ports.
1647 * Improved Modula-2 language support
1649 GDB can now print most types in the Modula-2 syntax. This includes:
1650 basic types, set types, record types, enumerated types, range types,
1651 pointer types and ARRAY types. Procedure var parameters are correctly
1652 printed and hexadecimal addresses and character constants are also
1653 written in the Modula-2 syntax. Best results can be obtained by using
1654 GNU Modula-2 together with the -gdwarf-2 command line option.
1658 The ARM rdi-share module.
1660 The Netware NLM debug server.
1662 *** Changes in GDB 6.4
1664 * New native configurations
1666 OpenBSD/arm arm*-*-openbsd*
1667 OpenBSD/mips64 mips64-*-openbsd*
1671 Morpho Technologies ms1 ms1-elf
1673 * New command line options
1675 --batch-silent As for --batch, but totally silent.
1676 --return-child-result The debugger will exist with the same value
1677 the child (debugged) program exited with.
1678 --eval-command COMMAND, -ex COMMAND
1679 Execute a single GDB CLI command. This may be
1680 specified multiple times and in conjunction
1681 with the --command (-x) option.
1683 * Deprecated commands removed
1685 The following commands, that were deprecated in 2000, have been
1689 set|show arm disassembly-flavor set|show arm disassembler
1690 othernames set arm disassembler
1691 set|show remotedebug set|show debug remote
1692 set|show archdebug set|show debug arch
1693 set|show eventdebug set|show debug event
1696 * New BSD user-level threads support
1698 It is now possible to debug programs using the user-level threads
1699 library on OpenBSD and FreeBSD. Currently supported (target)
1702 FreeBSD/amd64 x86_64-*-freebsd*
1703 FreeBSD/i386 i386-*-freebsd*
1704 OpenBSD/i386 i386-*-openbsd*
1706 Note that the new kernel threads libraries introduced in FreeBSD 5.x
1707 are not yet supported.
1709 * New support for Matsushita MN10300 w/sim added
1710 (Work in progress). mn10300-elf.
1712 * REMOVED configurations and files
1714 VxWorks and the XDR protocol *-*-vxworks
1715 Motorola MCORE mcore-*-*
1716 National Semiconductor NS32000 ns32k-*-*
1718 * New "set print array-indexes" command
1720 After turning this setting "on", GDB prints the index of each element
1721 when displaying arrays. The default is "off" to preserve the previous
1724 * VAX floating point support
1726 GDB now supports the not-quite-ieee VAX F and D floating point formats.
1728 * User-defined command support
1730 In addition to using $arg0..$arg9 for argument passing, it is now possible
1731 to use $argc to determine now many arguments have been passed. See the
1732 section on user-defined commands in the user manual for more information.
1734 *** Changes in GDB 6.3:
1736 * New command line option
1738 GDB now accepts -l followed by a number to set the timeout for remote
1741 * GDB works with GCC -feliminate-dwarf2-dups
1743 GDB now supports a more compact representation of DWARF-2 debug
1744 information using DW_FORM_ref_addr references. These are produced
1745 by GCC with the option -feliminate-dwarf2-dups and also by some
1746 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
1747 to use -feliminate-dwarf2-dups.
1749 * Internationalization
1751 When supported by the host system, GDB will be built with
1752 internationalization (libintl). The task of marking up the sources is
1753 continued, we're looking forward to our first translation.
1757 Initial support for debugging programs compiled with the GNAT
1758 implementation of the Ada programming language has been integrated
1759 into GDB. In this release, support is limited to expression evaluation.
1761 * New native configurations
1763 GNU/Linux/m32r m32r-*-linux-gnu
1767 GDB's remote protocol now includes support for the 'p' packet. This
1768 packet is used to fetch individual registers from a remote inferior.
1770 * END-OF-LIFE registers[] compatibility module
1772 GDB's internal register infrastructure has been completely rewritten.
1773 The new infrastructure making possible the implementation of key new
1774 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
1777 GDB 6.3 will be the last release to include the the registers[]
1778 compatibility module that allowed out-of-date configurations to
1779 continue to work. This change directly impacts the following
1789 powerpc bdm protocol
1791 Unless there is activity to revive these configurations, they will be
1792 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
1794 * OBSOLETE configurations and files
1796 Configurations that have been declared obsolete in this release have
1797 been commented out. Unless there is activity to revive these
1798 configurations, the next release of GDB will have their sources
1799 permanently REMOVED.
1808 *** Changes in GDB 6.2.1:
1810 * MIPS `break main; run' gave an heuristic-fence-post warning
1812 When attempting to run even a simple program, a warning about
1813 heuristic-fence-post being hit would be reported. This problem has
1816 * MIPS IRIX 'long double' crashed GDB
1818 When examining a long double variable, GDB would get a segmentation
1819 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
1820 IRIX long double values).
1824 A bug in the VAX stack code was causing problems with the "next"
1825 command. This problem has been fixed.
1827 *** Changes in GDB 6.2:
1829 * Fix for ``many threads''
1831 On GNU/Linux systems that use the NPTL threads library, a program
1832 rapidly creating and deleting threads would confuse GDB leading to the
1835 ptrace: No such process.
1836 thread_db_get_info: cannot get thread info: generic error
1838 This problem has been fixed.
1840 * "-async" and "-noasync" options removed.
1842 Support for the broken "-noasync" option has been removed (it caused
1845 * New ``start'' command.
1847 This command runs the program until the begining of the main procedure.
1849 * New BSD Kernel Data Access Library (libkvm) interface
1851 Using ``target kvm'' it is now possible to debug kernel core dumps and
1852 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
1853 platforms. Currently supported (native-only) configurations are:
1855 FreeBSD/amd64 x86_64-*-freebsd*
1856 FreeBSD/i386 i?86-*-freebsd*
1857 NetBSD/i386 i?86-*-netbsd*
1858 NetBSD/m68k m68*-*-netbsd*
1859 NetBSD/sparc sparc-*-netbsd*
1860 OpenBSD/amd64 x86_64-*-openbsd*
1861 OpenBSD/i386 i?86-*-openbsd*
1862 OpenBSD/m68k m68*-openbsd*
1863 OpenBSD/sparc sparc-*-openbsd*
1865 * Signal trampoline code overhauled
1867 Many generic problems with GDB's signal handling code have been fixed.
1868 These include: backtraces through non-contiguous stacks; recognition
1869 of sa_sigaction signal trampolines; backtrace from a NULL pointer
1870 call; backtrace through a signal trampoline; step into and out of
1871 signal handlers; and single-stepping in the signal trampoline.
1873 Please note that kernel bugs are a limiting factor here. These
1874 features have been shown to work on an s390 GNU/Linux system that
1875 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
1877 * Cygwin support for DWARF 2 added.
1879 * New native configurations
1881 GNU/Linux/hppa hppa*-*-linux*
1882 OpenBSD/hppa hppa*-*-openbsd*
1883 OpenBSD/m68k m68*-*-openbsd*
1884 OpenBSD/m88k m88*-*-openbsd*
1885 OpenBSD/powerpc powerpc-*-openbsd*
1886 NetBSD/vax vax-*-netbsd*
1887 OpenBSD/vax vax-*-openbsd*
1889 * END-OF-LIFE frame compatibility module
1891 GDB's internal frame infrastructure has been completely rewritten.
1892 The new infrastructure making it possible to support key new features
1893 including DWARF 2 Call Frame Information. To aid in the task of
1894 migrating old configurations to this new infrastructure, a
1895 compatibility module, that allowed old configurations to continue to
1896 work, was also included.
1898 GDB 6.2 will be the last release to include this frame compatibility
1899 module. This change directly impacts the following configurations:
1909 Unless there is activity to revive these configurations, they will be
1910 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
1912 * REMOVED configurations and files
1914 Sun 3, running SunOS 3 m68*-*-sunos3*
1915 Sun 3, running SunOS 4 m68*-*-sunos4*
1916 Sun 2, running SunOS 3 m68000-*-sunos3*
1917 Sun 2, running SunOS 4 m68000-*-sunos4*
1918 Motorola 680x0 running LynxOS m68*-*-lynxos*
1919 AT&T 3b1/Unix pc m68*-att-*
1920 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
1921 decstation mips-dec-* mips-little-*
1922 riscos mips-*-riscos* mips-*-sysv*
1923 sonymips mips-sony-*
1924 sysv mips*-*-sysv4* (IRIX 5/6 not included)
1926 *** Changes in GDB 6.1.1:
1928 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
1930 The TUI (Text-mode User Interface) is now built as part of a default
1931 GDB configuration. It is enabled by either selecting the TUI with the
1932 command line option "-i=tui" or by running the separate "gdbtui"
1933 program. For more information on the TUI, see the manual "Debugging
1936 * Pending breakpoint support (also included in GDB 6.1)
1938 Support has been added to allow you to specify breakpoints in shared
1939 libraries that have not yet been loaded. If a breakpoint location
1940 cannot be found, and the "breakpoint pending" option is set to auto,
1941 GDB queries you if you wish to make the breakpoint pending on a future
1942 shared-library load. If and when GDB resolves the breakpoint symbol,
1943 the pending breakpoint is removed as one or more regular breakpoints
1946 Pending breakpoints are very useful for GCJ Java debugging.
1948 * Fixed ISO-C build problems
1950 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
1951 non ISO-C code that stopped them being built using a more strict ISO-C
1952 compiler (e.g., IBM's C compiler).
1954 * Fixed build problem on IRIX 5
1956 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
1957 wasn't able to compile compile on an IRIX 5 system.
1959 * Added execute permission to gdb/gdbserver/configure
1961 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
1962 permission. This bug would cause configure to fail on a number of
1963 systems (Solaris, IRIX). Ref: server/519.
1965 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
1967 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
1968 has been updated to use constant array sizes.
1970 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
1972 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
1973 its generated DWARF Call Frame Info. This encoding was causing GDB to
1974 panic, that panic has been fixed. Ref: gdb/1628.
1976 * Fixed a problem when examining parameters in shared library code.
1978 When examining parameters in optimized shared library code generated
1979 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
1980 not available''. GDB now correctly displays the variable's value.
1982 *** Changes in GDB 6.1:
1984 * Removed --with-mmalloc
1986 Support for the mmalloc memory manager has been removed, as it
1987 conflicted with the internal gdb byte cache.
1989 * Changes in AMD64 configurations
1991 The AMD64 target now includes the %cs and %ss registers. As a result
1992 the AMD64 remote protocol has changed; this affects the floating-point
1993 and SSE registers. If you rely on those registers for your debugging,
1994 you should upgrade gdbserver on the remote side.
1996 * Revised SPARC target
1998 The SPARC target has been completely revised, incorporating the
1999 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
2000 support for LynxOS and SunOS 4 has been dropped. Calling functions
2001 from within GDB on operating systems with a non-executable stack
2002 (Solaris, OpenBSD) now works.
2006 GDB has a new C++ demangler which does a better job on the mangled
2007 names generated by current versions of g++. It also runs faster, so
2008 with this and other changes gdb should now start faster on large C++
2011 * DWARF 2 Location Expressions
2013 GDB support for location expressions has been extended to support function
2014 arguments and frame bases. Older versions of GDB could crash when they
2017 * C++ nested types and namespaces
2019 GDB's support for nested types and namespaces in C++ has been
2020 improved, especially if you use the DWARF 2 debugging format. (This
2021 is the default for recent versions of GCC on most platforms.)
2022 Specifically, if you have a class "Inner" defined within a class or
2023 namespace "Outer", then GDB realizes that the class's name is
2024 "Outer::Inner", not simply "Inner". This should greatly reduce the
2025 frequency of complaints about not finding RTTI symbols. In addition,
2026 if you are stopped at inside of a function defined within a namespace,
2027 GDB modifies its name lookup accordingly.
2029 * New native configurations
2031 NetBSD/amd64 x86_64-*-netbsd*
2032 OpenBSD/amd64 x86_64-*-openbsd*
2033 OpenBSD/alpha alpha*-*-openbsd*
2034 OpenBSD/sparc sparc-*-openbsd*
2035 OpenBSD/sparc64 sparc64-*-openbsd*
2037 * New debugging protocols
2039 M32R with SDI protocol m32r-*-elf*
2041 * "set prompt-escape-char" command deleted.
2043 The command "set prompt-escape-char" has been deleted. This command,
2044 and its very obscure effet on GDB's prompt, was never documented,
2045 tested, nor mentioned in the NEWS file.
2047 * OBSOLETE configurations and files
2049 Configurations that have been declared obsolete in this release have
2050 been commented out. Unless there is activity to revive these
2051 configurations, the next release of GDB will have their sources
2052 permanently REMOVED.
2054 Sun 3, running SunOS 3 m68*-*-sunos3*
2055 Sun 3, running SunOS 4 m68*-*-sunos4*
2056 Sun 2, running SunOS 3 m68000-*-sunos3*
2057 Sun 2, running SunOS 4 m68000-*-sunos4*
2058 Motorola 680x0 running LynxOS m68*-*-lynxos*
2059 AT&T 3b1/Unix pc m68*-att-*
2060 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2061 decstation mips-dec-* mips-little-*
2062 riscos mips-*-riscos* mips-*-sysv*
2063 sonymips mips-sony-*
2064 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2066 * REMOVED configurations and files
2068 SGI Irix-4.x mips-sgi-irix4 or iris4
2069 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
2070 Z8000 simulator z8k-zilog-none or z8ksim
2071 Matsushita MN10200 w/simulator mn10200-*-*
2072 H8/500 simulator h8500-hitachi-hms or h8500hms
2073 HP/PA running BSD hppa*-*-bsd*
2074 HP/PA running OSF/1 hppa*-*-osf*
2075 HP/PA Pro target hppa*-*-pro*
2076 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2077 386BSD i[3456]86-*-bsd*
2078 Sequent family i[3456]86-sequent-sysv4*
2079 i[3456]86-sequent-sysv*
2080 i[3456]86-sequent-bsd*
2081 SPARC running LynxOS sparc-*-lynxos*
2082 SPARC running SunOS 4 sparc-*-sunos4*
2083 Tsqware Sparclet sparclet-*-*
2084 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2086 *** Changes in GDB 6.0:
2090 Support for debugging the Objective-C programming language has been
2091 integrated into GDB.
2093 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
2095 DWARF 2's Call Frame Information makes available compiler generated
2096 information that more exactly describes the program's run-time stack.
2097 By using this information, GDB is able to provide more robust stack
2100 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
2101 have been updated to use a new backtrace mechanism which includes
2102 DWARF 2 CFI support.
2106 GDB's remote protocol has been extended to include support for hosted
2107 file I/O (where the remote target uses GDB's file system). See GDB's
2108 remote protocol documentation for details.
2110 * All targets using the new architecture framework.
2112 All of GDB's targets have been updated to use the new internal
2113 architecture framework. The way is now open for future GDB releases
2114 to include cross-architecture native debugging support (i386 on amd64,
2117 * GNU/Linux's Thread Local Storage (TLS)
2119 GDB now includes support for for the GNU/Linux implementation of
2120 per-thread variables.
2122 * GNU/Linux's Native POSIX Thread Library (NPTL)
2124 GDB's thread code has been updated to work with either the new
2125 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
2127 * Separate debug info.
2129 GDB, in conjunction with BINUTILS, now supports a mechanism for
2130 automatically loading debug information from a separate file. Instead
2131 of shipping full debug and non-debug versions of system libraries,
2132 system integrators can now instead ship just the stripped libraries
2133 and optional debug files.
2135 * DWARF 2 Location Expressions
2137 DWARF 2 Location Expressions allow the compiler to more completely
2138 describe the location of variables (even in optimized code) to the
2141 GDB now includes preliminary support for location expressions (support
2142 for DW_OP_piece is still missing).
2146 A number of long standing bugs that caused GDB to die while starting a
2147 Java application have been fixed. GDB's Java support is now
2148 considered "useable".
2150 * GNU/Linux support for fork, vfork, and exec.
2152 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
2153 commands are now implemented for GNU/Linux. They require a 2.5.x or later
2156 * GDB supports logging output to a file
2158 There are two new commands, "set logging" and "show logging", which can be
2159 used to capture GDB's output to a file.
2161 * The meaning of "detach" has changed for gdbserver
2163 The "detach" command will now resume the application, as documented. To
2164 disconnect from gdbserver and leave it stopped, use the new "disconnect"
2167 * d10v, m68hc11 `regs' command deprecated
2169 The `info registers' command has been updated so that it displays the
2170 registers using a format identical to the old `regs' command.
2174 A new command, "maint set profile on/off", has been added. This command can
2175 be used to enable or disable profiling while running GDB, to profile a
2176 session or a set of commands. In addition there is a new configure switch,
2177 "--enable-profiling", which will cause GDB to be compiled with profiling
2178 data, for more informative profiling results.
2180 * Default MI syntax changed to "mi2".
2182 The default MI (machine interface) syntax, enabled by the command line
2183 option "-i=mi", has been changed to "mi2". The previous MI syntax,
2184 "mi1", can be enabled by specifying the option "-i=mi1".
2186 Support for the original "mi0" syntax (included in GDB 5.0) has been
2189 Fix for gdb/192: removed extraneous space when displaying frame level.
2190 Fix for gdb/672: update changelist is now output in mi list format.
2191 Fix for gdb/702: a -var-assign that updates the value now shows up
2192 in a subsequent -var-update.
2194 * New native configurations.
2196 FreeBSD/amd64 x86_64-*-freebsd*
2198 * Multi-arched targets.
2200 HP/PA HPUX11 hppa*-*-hpux*
2201 Renesas M32R/D w/simulator m32r-*-elf*
2203 * OBSOLETE configurations and files
2205 Configurations that have been declared obsolete in this release have
2206 been commented out. Unless there is activity to revive these
2207 configurations, the next release of GDB will have their sources
2208 permanently REMOVED.
2210 Z8000 simulator z8k-zilog-none or z8ksim
2211 Matsushita MN10200 w/simulator mn10200-*-*
2212 H8/500 simulator h8500-hitachi-hms or h8500hms
2213 HP/PA running BSD hppa*-*-bsd*
2214 HP/PA running OSF/1 hppa*-*-osf*
2215 HP/PA Pro target hppa*-*-pro*
2216 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2217 Sequent family i[3456]86-sequent-sysv4*
2218 i[3456]86-sequent-sysv*
2219 i[3456]86-sequent-bsd*
2220 Tsqware Sparclet sparclet-*-*
2221 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2223 * REMOVED configurations and files
2226 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2227 IBM AIX PS/2 i[3456]86-*-aix
2228 i386 running Mach 3.0 i[3456]86-*-mach3*
2229 i386 running Mach i[3456]86-*-mach*
2230 i386 running OSF/1 i[3456]86-*osf1mk*
2231 HP/Apollo 68k Family m68*-apollo*-sysv*,
2233 m68*-hp-bsd*, m68*-hp-hpux*
2234 Argonaut Risc Chip (ARC) arc-*-*
2235 Mitsubishi D30V d30v-*-*
2236 Fujitsu FR30 fr30-*-elf*
2237 OS/9000 i[34]86-*-os9k
2238 I960 with MON960 i960-*-coff
2240 * MIPS $fp behavior changed
2242 The convenience variable $fp, for the MIPS, now consistently returns
2243 the address of the current frame's base. Previously, depending on the
2244 context, $fp could refer to either $sp or the current frame's base
2245 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
2246 The GNU Source-Level Debugger''.
2248 *** Changes in GDB 5.3:
2250 * GNU/Linux shared library multi-threaded performance improved.
2252 When debugging a multi-threaded application on GNU/Linux, GDB now uses
2253 `/proc', in preference to `ptrace' for memory reads. This may result
2254 in an improvement in the start-up time of multi-threaded, shared
2255 library applications when run under GDB. One GDB user writes: ``loads
2256 shared libs like mad''.
2258 * ``gdbserver'' now supports multi-threaded applications on some targets
2260 Support for debugging multi-threaded applications which use
2261 the GNU/Linux LinuxThreads package has been added for
2262 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
2263 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
2265 * GDB now supports C/C++ preprocessor macros.
2267 GDB now expands preprocessor macro invocations in C/C++ expressions,
2268 and provides various commands for showing macro definitions and how
2271 The new command `macro expand EXPRESSION' expands any macro
2272 invocations in expression, and shows the result.
2274 The new command `show macro MACRO-NAME' shows the definition of the
2275 macro named MACRO-NAME, and where it was defined.
2277 Most compilers don't include information about macros in the debugging
2278 information by default. In GCC 3.1, for example, you need to compile
2279 your program with the options `-gdwarf-2 -g3'. If the macro
2280 information is present in the executable, GDB will read it.
2282 * Multi-arched targets.
2284 DEC Alpha (partial) alpha*-*-*
2285 DEC VAX (partial) vax-*-*
2287 National Semiconductor NS32000 (partial) ns32k-*-*
2288 Motorola 68000 (partial) m68k-*-*
2289 Motorola MCORE mcore-*-*
2293 Fujitsu FRV architecture added by Red Hat frv*-*-*
2296 * New native configurations
2298 Alpha NetBSD alpha*-*-netbsd*
2299 SH NetBSD sh*-*-netbsdelf*
2300 MIPS NetBSD mips*-*-netbsd*
2301 UltraSPARC NetBSD sparc64-*-netbsd*
2303 * OBSOLETE configurations and files
2305 Configurations that have been declared obsolete in this release have
2306 been commented out. Unless there is activity to revive these
2307 configurations, the next release of GDB will have their sources
2308 permanently REMOVED.
2310 Mitsubishi D30V d30v-*-*
2311 OS/9000 i[34]86-*-os9k
2312 IBM AIX PS/2 i[3456]86-*-aix
2313 Fujitsu FR30 fr30-*-elf*
2314 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2315 Argonaut Risc Chip (ARC) arc-*-*
2316 i386 running Mach 3.0 i[3456]86-*-mach3*
2317 i386 running Mach i[3456]86-*-mach*
2318 i386 running OSF/1 i[3456]86-*osf1mk*
2319 HP/Apollo 68k Family m68*-apollo*-sysv*,
2321 m68*-hp-bsd*, m68*-hp-hpux*
2322 I960 with MON960 i960-*-coff
2324 * OBSOLETE languages
2326 CHILL, a Pascal like language used by telecommunications companies.
2328 * REMOVED configurations and files
2330 AMD 29k family via UDI a29k-amd-udi, udi29k
2331 A29K VxWorks a29k-*-vxworks
2332 AMD 29000 embedded, using EBMON a29k-none-none
2333 AMD 29000 embedded with COFF a29k-none-coff
2334 AMD 29000 embedded with a.out a29k-none-aout
2336 testsuite/gdb.hp/gdb.threads-hp/ directory
2338 * New command "set max-user-call-depth <nnn>"
2340 This command allows the user to limit the call depth of user-defined
2341 commands. The default is 1024.
2343 * Changes in FreeBSD/i386 native debugging.
2345 Support for the "generate-core-file" has been added.
2347 * New commands "dump", "append", and "restore".
2349 These commands allow data to be copied from target memory
2350 to a bfd-format or binary file (dump and append), and back
2351 from a file into memory (restore).
2353 * Improved "next/step" support on multi-processor Alpha Tru64.
2355 The previous single-step mechanism could cause unpredictable problems,
2356 including the random appearance of SIGSEGV or SIGTRAP signals. The use
2357 of a software single-step mechanism prevents this.
2359 *** Changes in GDB 5.2.1:
2367 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
2368 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
2369 Fix, by Joel Brobecker imported from mainline.
2371 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
2372 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
2373 Fix, by Fred Fish, imported from mainline.
2375 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
2376 Surprisingly enough, it works now.
2377 By Michal Ludvig, imported from mainline.
2379 i386 hardware watchpoint support:
2380 avoid misses on second run for some targets.
2381 By Pierre Muller, imported from mainline.
2383 *** Changes in GDB 5.2:
2385 * New command "set trust-readonly-sections on[off]".
2387 This command is a hint that tells gdb that read-only sections
2388 really are read-only (ie. that their contents will not change).
2389 In this mode, gdb will go to the object file rather than the
2390 target to read memory from read-only sections (such as ".text").
2391 This can be a significant performance improvement on some
2392 (notably embedded) targets.
2394 * New command "generate-core-file" (or "gcore").
2396 This new gdb command allows the user to drop a core file of the child
2397 process state at any time. So far it's been implemented only for
2398 GNU/Linux and Solaris, but should be relatively easily ported to other
2399 hosts. Argument is core file name (defaults to core.<pid>).
2401 * New command line option
2403 GDB now accepts --pid or -p followed by a process id.
2405 * Change in command line behavior -- corefiles vs. process ids.
2407 There is a subtle behavior in the way in which GDB handles
2408 command line arguments. The first non-flag argument is always
2409 a program to debug, but the second non-flag argument may either
2410 be a corefile or a process id. Previously, GDB would attempt to
2411 open the second argument as a corefile, and if that failed, would
2412 issue a superfluous error message and then attempt to attach it as
2413 a process. Now, if the second argument begins with a non-digit,
2414 it will be treated as a corefile. If it begins with a digit,
2415 GDB will attempt to attach it as a process, and if no such process
2416 is found, will then attempt to open it as a corefile.
2418 * Changes in ARM configurations.
2420 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
2421 configuration is fully multi-arch.
2423 * New native configurations
2425 ARM NetBSD arm*-*-netbsd*
2426 x86 OpenBSD i[3456]86-*-openbsd*
2427 AMD x86-64 running GNU/Linux x86_64-*-linux-*
2428 Sparc64 running FreeBSD sparc64-*-freebsd*
2432 Sanyo XStormy16 xstormy16-elf
2434 * OBSOLETE configurations and files
2436 Configurations that have been declared obsolete in this release have
2437 been commented out. Unless there is activity to revive these
2438 configurations, the next release of GDB will have their sources
2439 permanently REMOVED.
2441 AMD 29k family via UDI a29k-amd-udi, udi29k
2442 A29K VxWorks a29k-*-vxworks
2443 AMD 29000 embedded, using EBMON a29k-none-none
2444 AMD 29000 embedded with COFF a29k-none-coff
2445 AMD 29000 embedded with a.out a29k-none-aout
2447 testsuite/gdb.hp/gdb.threads-hp/ directory
2449 * REMOVED configurations and files
2451 TI TMS320C80 tic80-*-*
2453 PowerPC Solaris powerpcle-*-solaris*
2454 PowerPC Windows NT powerpcle-*-cygwin32
2455 PowerPC Netware powerpc-*-netware*
2456 Harris/CXUX m88k m88*-harris-cxux*
2457 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
2458 ns32k-utek-sysv* ns32k-utek-*
2459 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
2460 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
2461 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
2462 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
2463 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
2465 * Changes to command line processing
2467 The new `--args' feature can be used to specify command-line arguments
2468 for the inferior from gdb's command line.
2470 * Changes to key bindings
2472 There is a new `operate-and-get-next' function bound to `C-o'.
2474 *** Changes in GDB 5.1.1
2476 Fix compile problem on DJGPP.
2478 Fix a problem with floating-point registers on the i386 being
2481 Fix to stop GDB crashing on .debug_str debug info.
2483 Numerous documentation fixes.
2485 Numerous testsuite fixes.
2487 *** Changes in GDB 5.1:
2489 * New native configurations
2491 Alpha FreeBSD alpha*-*-freebsd*
2492 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
2493 MIPS GNU/Linux mips*-*-linux*
2494 MIPS SGI Irix 6.x mips*-sgi-irix6*
2495 ia64 AIX ia64-*-aix*
2496 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
2500 Motorola 68HC11 and 68HC12 m68hc11-elf
2502 UltraSparc running GNU/Linux sparc64-*-linux*
2504 * OBSOLETE configurations and files
2506 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
2507 Harris/CXUX m88k m88*-harris-cxux*
2508 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
2509 ns32k-utek-sysv* ns32k-utek-*
2510 TI TMS320C80 tic80-*-*
2512 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
2513 PowerPC Solaris powerpcle-*-solaris*
2514 PowerPC Windows NT powerpcle-*-cygwin32
2515 PowerPC Netware powerpc-*-netware*
2516 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
2517 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
2518 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
2519 Apple Macintosh (MPW) host N/A
2521 stuff.c (Program to stuff files into a specially prepared space in kdb)
2522 kdb-start.c (Main loop for the standalone kernel debugger)
2524 Configurations that have been declared obsolete in this release have
2525 been commented out. Unless there is activity to revive these
2526 configurations, the next release of GDB will have their sources
2527 permanently REMOVED.
2529 * REMOVED configurations and files
2531 Altos 3068 m68*-altos-*
2532 Convex c1-*-*, c2-*-*
2534 ARM RISCix arm-*-* (as host)
2538 * GDB has been converted to ISO C.
2540 GDB's source code has been converted to ISO C. In particular, the
2541 sources are fully protoized, and rely on standard headers being
2546 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
2548 * The MI enabled by default.
2550 The new machine oriented interface (MI) introduced in GDB 5.0 has been
2551 revised and enabled by default. Packages which use GDB as a debugging
2552 engine behind a UI or another front end are encouraged to switch to
2553 using the GDB/MI interface, instead of the old annotations interface
2554 which is now deprecated.
2556 * Support for debugging Pascal programs.
2558 GDB now includes support for debugging Pascal programs. The following
2559 main features are supported:
2561 - Pascal-specific data types such as sets;
2563 - automatic recognition of Pascal sources based on file-name
2566 - Pascal-style display of data types, variables, and functions;
2568 - a Pascal expression parser.
2570 However, some important features are not yet supported.
2572 - Pascal string operations are not supported at all;
2574 - there are some problems with boolean types;
2576 - Pascal type hexadecimal constants are not supported
2577 because they conflict with the internal variables format;
2579 - support for Pascal objects and classes is not full yet;
2581 - unlike Pascal, GDB is case-sensitive for symbol names.
2583 * Changes in completion.
2585 Commands such as `shell', `run' and `set args', which pass arguments
2586 to inferior programs, now complete on file names, similar to what
2587 users expect at the shell prompt.
2589 Commands which accept locations, such as `disassemble', `print',
2590 `breakpoint', `until', etc. now complete on filenames as well as
2591 program symbols. Thus, if you type "break foob TAB", and the source
2592 files linked into the programs include `foobar.c', that file name will
2593 be one of the candidates for completion. However, file names are not
2594 considered for completion after you typed a colon that delimits a file
2595 name from a name of a function in that file, as in "break foo.c:bar".
2597 `set demangle-style' completes on available demangling styles.
2599 * New platform-independent commands:
2601 It is now possible to define a post-hook for a command as well as a
2602 hook that runs before the command. For more details, see the
2603 documentation of `hookpost' in the GDB manual.
2605 * Changes in GNU/Linux native debugging.
2607 Support for debugging multi-threaded programs has been completely
2608 revised for all platforms except m68k and sparc. You can now debug as
2609 many threads as your system allows you to have.
2611 Attach/detach is supported for multi-threaded programs.
2613 Support for SSE registers was added for x86. This doesn't work for
2614 multi-threaded programs though.
2616 * Changes in MIPS configurations.
2618 Multi-arch support is enabled for all MIPS configurations.
2620 GDB can now be built as native debugger on SGI Irix 6.x systems for
2621 debugging n32 executables. (Debugging 64-bit executables is not yet
2624 * Unified support for hardware watchpoints in all x86 configurations.
2626 Most (if not all) native x86 configurations support hardware-assisted
2627 breakpoints and watchpoints in a unified manner. This support
2628 implements debug register sharing between watchpoints, which allows to
2629 put a virtually infinite number of watchpoints on the same address,
2630 and also supports watching regions up to 16 bytes with several debug
2633 The new maintenance command `maintenance show-debug-regs' toggles
2634 debugging print-outs in functions that insert, remove, and test
2635 watchpoints and hardware breakpoints.
2637 * Changes in the DJGPP native configuration.
2639 New command ``info dos sysinfo'' displays assorted information about
2640 the CPU, OS, memory, and DPMI server.
2642 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
2643 display information about segment descriptors stored in GDT, LDT, and
2646 New commands ``info dos pde'' and ``info dos pte'' display entries
2647 from Page Directory and Page Tables (for now works with CWSDPMI only).
2648 New command ``info dos address-pte'' displays the Page Table entry for
2649 a given linear address.
2651 GDB can now pass command lines longer than 126 characters to the
2652 program being debugged (requires an update to the libdbg.a library
2653 which is part of the DJGPP development kit).
2655 DWARF2 debug info is now supported.
2657 It is now possible to `step' and `next' through calls to `longjmp'.
2659 * Changes in documentation.
2661 All GDB documentation was converted to GFDL, the GNU Free
2662 Documentation License.
2664 Tracepoints-related commands are now fully documented in the GDB
2667 TUI, the Text-mode User Interface, is now documented in the manual.
2669 Tracepoints-related commands are now fully documented in the GDB
2672 The "GDB Internals" manual now has an index. It also includes
2673 documentation of `ui_out' functions, GDB coding standards, x86
2674 hardware watchpoints, and memory region attributes.
2676 * GDB's version number moved to ``version.in''
2678 The Makefile variable VERSION has been replaced by the file
2679 ``version.in''. People creating GDB distributions should update the
2680 contents of this file.
2684 GUD support is now a standard part of the EMACS distribution.
2686 *** Changes in GDB 5.0:
2688 * Improved support for debugging FP programs on x86 targets
2690 Unified and much-improved support for debugging floating-point
2691 programs on all x86 targets. In particular, ``info float'' now
2692 displays the FP registers in the same format on all x86 targets, with
2693 greater level of detail.
2695 * Improvements and bugfixes in hardware-assisted watchpoints
2697 It is now possible to watch array elements, struct members, and
2698 bitfields with hardware-assisted watchpoints. Data-read watchpoints
2699 on x86 targets no longer erroneously trigger when the address is
2702 * Improvements in the native DJGPP version of GDB
2704 The distribution now includes all the scripts and auxiliary files
2705 necessary to build the native DJGPP version on MS-DOS/MS-Windows
2706 machines ``out of the box''.
2708 The DJGPP version can now debug programs that use signals. It is
2709 possible to catch signals that happened in the debuggee, deliver
2710 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
2711 would kill the program being debugged.) Programs that hook hardware
2712 interrupts (keyboard, timer, etc.) can also be debugged.
2714 It is now possible to debug DJGPP programs that redirect their
2715 standard handles or switch them to raw (as opposed to cooked) mode, or
2716 even close them. The command ``run < foo > bar'' works as expected,
2717 and ``info terminal'' reports useful information about the debuggee's
2718 terminal, including raw/cooked mode, redirection, etc.
2720 The DJGPP version now uses termios functions for console I/O, which
2721 enables debugging graphics programs. Interrupting GDB with Ctrl-C
2724 DOS-style file names with drive letters are now fully supported by
2727 It is now possible to debug DJGPP programs that switch their working
2728 directory. It is also possible to rerun the debuggee any number of
2729 times without restarting GDB; thus, you can use the same setup,
2730 breakpoints, etc. for many debugging sessions.
2732 * New native configurations
2734 ARM GNU/Linux arm*-*-linux*
2735 PowerPC GNU/Linux powerpc-*-linux*
2739 Motorola MCore mcore-*-*
2740 x86 VxWorks i[3456]86-*-vxworks*
2741 PowerPC VxWorks powerpc-*-vxworks*
2742 TI TMS320C80 tic80-*-*
2744 * OBSOLETE configurations
2746 Altos 3068 m68*-altos-*
2747 Convex c1-*-*, c2-*-*
2749 ARM RISCix arm-*-* (as host)
2752 Configurations that have been declared obsolete will be commented out,
2753 but the code will be left in place. If there is no activity to revive
2754 these configurations before the next release of GDB, the sources will
2755 be permanently REMOVED.
2757 * Gould support removed
2759 Support for the Gould PowerNode and NP1 has been removed.
2761 * New features for SVR4
2763 On SVR4 native platforms (such as Solaris), if you attach to a process
2764 without first loading a symbol file, GDB will now attempt to locate and
2765 load symbols from the running process's executable file.
2767 * Many C++ enhancements
2769 C++ support has been greatly improved. Overload resolution now works properly
2770 in almost all cases. RTTI support is on the way.
2772 * Remote targets can connect to a sub-program
2774 A popen(3) style serial-device has been added. This device starts a
2775 sub-process (such as a stand-alone simulator) and then communicates
2776 with that. The sub-program to run is specified using the syntax
2777 ``|<program> <args>'' vis:
2779 (gdb) set remotedebug 1
2780 (gdb) target extended-remote |mn10300-elf-sim program-args
2782 * MIPS 64 remote protocol
2784 A long standing bug in the mips64 remote protocol where by GDB
2785 expected certain 32 bit registers (ex SR) to be transfered as 32
2786 instead of 64 bits has been fixed.
2788 The command ``set remote-mips64-transfers-32bit-regs on'' has been
2789 added to provide backward compatibility with older versions of GDB.
2791 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
2793 The command ``set remotebinarydownload'' command has been replaced by
2794 ``set remote X-packet''. Other commands in ``set remote'' family
2795 include ``set remote P-packet''.
2797 * Breakpoint commands accept ranges.
2799 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
2800 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
2801 ``tracepoint passcount'' also accepts a range of tracepoints.
2803 * ``apropos'' command added.
2805 The ``apropos'' command searches through command names and
2806 documentation strings, printing out matches, making it much easier to
2807 try to find a command that does what you are looking for.
2811 A new machine oriented interface (MI) has been added to GDB. This
2812 interface is designed for debug environments running GDB as a separate
2813 process. This is part of the long term libGDB project. See the
2814 "GDB/MI" chapter of the GDB manual for further information. It can be
2815 enabled by configuring with:
2817 .../configure --enable-gdbmi
2819 *** Changes in GDB-4.18:
2821 * New native configurations
2823 HP-UX 10.20 hppa*-*-hpux10.20
2824 HP-UX 11.x hppa*-*-hpux11.0*
2825 M68K GNU/Linux m68*-*-linux*
2829 Fujitsu FR30 fr30-*-elf*
2830 Intel StrongARM strongarm-*-*
2831 Mitsubishi D30V d30v-*-*
2833 * OBSOLETE configurations
2835 Gould PowerNode, NP1 np1-*-*, pn-*-*
2837 Configurations that have been declared obsolete will be commented out,
2838 but the code will be left in place. If there is no activity to revive
2839 these configurations before the next release of GDB, the sources will
2840 be permanently REMOVED.
2844 As a compatibility experiment, GDB's source files buildsym.h and
2845 buildsym.c have been converted to pure standard C, no longer
2846 containing any K&R compatibility code. We believe that all systems in
2847 use today either come with a standard C compiler, or have a GCC port
2848 available. If this is not true, please report the affected
2849 configuration to bug-gdb@gnu.org immediately. See the README file for
2850 information about getting a standard C compiler if you don't have one
2855 GDB now uses readline 2.2.
2857 * set extension-language
2859 You can now control the mapping between filename extensions and source
2860 languages by using the `set extension-language' command. For instance,
2861 you can ask GDB to treat .c files as C++ by saying
2862 set extension-language .c c++
2863 The command `info extensions' lists all of the recognized extensions
2864 and their associated languages.
2866 * Setting processor type for PowerPC and RS/6000
2868 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
2869 you can use the `set processor' command to specify what variant of the
2870 PowerPC family you are debugging. The command
2874 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
2875 following PowerPC and RS6000 variants:
2877 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
2878 rs6000 IBM RS6000 ("POWER") architecture, user-level view
2880 403GC IBM PowerPC 403GC
2881 505 Motorola PowerPC 505
2882 860 Motorola PowerPC 860 or 850
2883 601 Motorola PowerPC 601
2884 602 Motorola PowerPC 602
2885 603 Motorola/IBM PowerPC 603 or 603e
2886 604 Motorola PowerPC 604 or 604e
2887 750 Motorola/IBM PowerPC 750 or 750
2889 At the moment, this command just tells GDB what to name the
2890 special-purpose processor registers. Since almost all the affected
2891 registers are inaccessible to user-level programs, this command is
2892 only useful for remote debugging in its present form.
2896 Thanks to a major code donation from Hewlett-Packard, GDB now has much
2897 more extensive support for HP-UX. Added features include shared
2898 library support, kernel threads and hardware watchpoints for 11.00,
2899 support for HP's ANSI C and C++ compilers, and a compatibility mode
2900 for xdb and dbx commands.
2904 HP's donation includes the new concept of catchpoints, which is a
2905 generalization of the old catch command. On HP-UX, it is now possible
2906 to catch exec, fork, and vfork, as well as library loading.
2908 This means that the existing catch command has changed; its first
2909 argument now specifies the type of catch to be set up. See the
2910 output of "help catch" for a list of catchpoint types.
2912 * Debugging across forks
2914 On HP-UX, you can choose which process to debug when a fork() happens
2919 HP has donated a curses-based terminal user interface (TUI). To get
2920 it, build with --enable-tui. Although this can be enabled for any
2921 configuration, at present it only works for native HP debugging.
2923 * GDB remote protocol additions
2925 A new protocol packet 'X' that writes binary data is now available.
2926 Default behavior is to try 'X', then drop back to 'M' if the stub
2927 fails to respond. The settable variable `remotebinarydownload'
2928 allows explicit control over the use of 'X'.
2930 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
2931 full 64-bit address. The command
2933 set remoteaddresssize 32
2935 can be used to revert to the old behaviour. For existing remote stubs
2936 the change should not be noticed, as the additional address information
2939 In order to assist in debugging stubs, you may use the maintenance
2940 command `packet' to send any text string to the stub. For instance,
2942 maint packet heythere
2944 sends the packet "$heythere#<checksum>". Note that it is very easy to
2945 disrupt a debugging session by sending the wrong packet at the wrong
2948 The compare-sections command allows you to compare section data on the
2949 target to what is in the executable file without uploading or
2950 downloading, by comparing CRC checksums.
2952 * Tracing can collect general expressions
2954 You may now collect general expressions at tracepoints. This requires
2955 further additions to the target-side stub; see tracepoint.c and
2956 doc/agentexpr.texi for further details.
2958 * mask-address variable for Mips
2960 For Mips targets, you may control the zeroing of the upper 32 bits of
2961 a 64-bit address by entering `set mask-address on'. This is mainly
2962 of interest to users of embedded R4xxx and R5xxx processors.
2964 * Higher serial baud rates
2966 GDB's serial code now allows you to specify baud rates 57600, 115200,
2967 230400, and 460800 baud. (Note that your host system may not be able
2968 to achieve all of these rates.)
2972 The i960 configuration now includes an initial implementation of a
2973 builtin simulator, contributed by Jim Wilson.
2976 *** Changes in GDB-4.17:
2978 * New native configurations
2980 Alpha GNU/Linux alpha*-*-linux*
2981 Unixware 2.x i[3456]86-unixware2*
2982 Irix 6.x mips*-sgi-irix6*
2983 PowerPC GNU/Linux powerpc-*-linux*
2984 PowerPC Solaris powerpcle-*-solaris*
2985 Sparc GNU/Linux sparc-*-linux*
2986 Motorola sysV68 R3V7.1 m68k-motorola-sysv
2990 Argonaut Risc Chip (ARC) arc-*-*
2991 Hitachi H8/300S h8300*-*-*
2992 Matsushita MN10200 w/simulator mn10200-*-*
2993 Matsushita MN10300 w/simulator mn10300-*-*
2994 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
2995 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
2996 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
2997 Mitsubishi D10V w/simulator d10v-*-*
2998 Mitsubishi M32R/D w/simulator m32r-*-elf*
2999 Tsqware Sparclet sparclet-*-*
3000 NEC V850 w/simulator v850-*-*
3002 * New debugging protocols
3004 ARM with RDI protocol arm*-*-*
3005 M68K with dBUG monitor m68*-*-{aout,coff,elf}
3006 DDB and LSI variants of PMON protocol mips*-*-*
3007 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
3008 PowerPC with SDS protocol powerpc{,le}-*-eabi
3009 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
3013 All configurations can now understand and use the DWARF 2 debugging
3014 format. The choice is automatic, if the symbol file contains DWARF 2
3019 GDB now includes basic Java language support. This support is
3020 only useful with Java compilers that produce native machine code.
3022 * solib-absolute-prefix and solib-search-path
3024 For SunOS and SVR4 shared libraries, you may now set the prefix for
3025 loading absolute shared library symbol files, and the search path for
3026 locating non-absolute shared library symbol files.
3028 * Live range splitting
3030 GDB can now effectively debug code for which GCC has performed live
3031 range splitting as part of its optimization. See gdb/doc/LRS for
3032 more details on the expected format of the stabs information.
3036 GDB's support for the GNU Hurd, including thread debugging, has been
3037 updated to work with current versions of the Hurd.
3041 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
3042 instruction set. ARM GDB automatically detects when Thumb
3043 instructions are in use, and adjusts disassembly and backtracing
3048 GDB's MIPS target configurations now handle the MIP16 16-bit
3053 GDB now includes support for overlays; if an executable has been
3054 linked such that multiple sections are based at the same address, GDB
3055 will decide which section to use for symbolic info. You can choose to
3056 control the decision manually, using overlay commands, or implement
3057 additional target-side support and use "overlay load-target" to bring
3058 in the overlay mapping. Do "help overlay" for more detail.
3062 The command "info symbol <address>" displays information about
3063 the symbol at the specified address.
3067 The standard remote protocol now includes an extension that allows
3068 asynchronous collection and display of trace data. This requires
3069 extensive support in the target-side debugging stub. Tracing mode
3070 includes a new interaction mode in GDB and new commands: see the
3071 file tracepoint.c for more details.
3075 Configurations for embedded MIPS now include a simulator contributed
3076 by Cygnus Solutions. The simulator supports the instruction sets
3077 of most MIPS variants.
3081 Sparc configurations may now include the ERC32 simulator contributed
3082 by the European Space Agency. The simulator is not built into
3083 Sparc targets by default; configure with --enable-sim to include it.
3087 For target configurations that may include multiple variants of a
3088 basic architecture (such as MIPS and SH), you may now set the
3089 architecture explicitly. "set arch" sets, "info arch" lists
3090 the possible architectures.
3092 *** Changes in GDB-4.16:
3094 * New native configurations
3096 Windows 95, x86 Windows NT i[345]86-*-cygwin32
3097 M68K NetBSD m68k-*-netbsd*
3098 PowerPC AIX 4.x powerpc-*-aix*
3099 PowerPC MacOS powerpc-*-macos*
3100 PowerPC Windows NT powerpcle-*-cygwin32
3101 RS/6000 AIX 4.x rs6000-*-aix4*
3105 ARM with RDP protocol arm-*-*
3106 I960 with MON960 i960-*-coff
3107 MIPS VxWorks mips*-*-vxworks*
3108 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
3109 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
3111 Matra Sparclet sparclet-*-*
3115 The powerpc-eabi configuration now includes the PSIM simulator,
3116 contributed by Andrew Cagney, with assistance from Mike Meissner.
3117 PSIM is a very elaborate model of the PowerPC, including not only
3118 basic instruction set execution, but also details of execution unit
3119 performance and I/O hardware. See sim/ppc/README for more details.
3123 GDB now works with Solaris 2.5.
3125 * Windows 95/NT native
3127 GDB will now work as a native debugger on Windows 95 and Windows NT.
3128 To build it from source, you must use the "gnu-win32" environment,
3129 which uses a DLL to emulate enough of Unix to run the GNU tools.
3130 Further information, binaries, and sources are available at
3131 ftp.cygnus.com, under pub/gnu-win32.
3133 * dont-repeat command
3135 If a user-defined command includes the command `dont-repeat', then the
3136 command will not be repeated if the user just types return. This is
3137 useful if the command is time-consuming to run, so that accidental
3138 extra keystrokes don't run the same command many times.
3140 * Send break instead of ^C
3142 The standard remote protocol now includes an option to send a break
3143 rather than a ^C to the target in order to interrupt it. By default,
3144 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
3146 * Remote protocol timeout
3148 The standard remote protocol includes a new variable `remotetimeout'
3149 that allows you to set the number of seconds before GDB gives up trying
3150 to read from the target. The default value is 2.
3152 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
3154 By default GDB will automatically keep track of objects as they are
3155 loaded and unloaded by the dynamic linker. By using the command `set
3156 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
3157 when shared library events occur, thus allowing you to set breakpoints
3158 in shared libraries which are explicitly loaded by the inferior.
3160 Note this feature does not work on hpux8. On hpux9 you must link
3161 /usr/lib/end.o into your program. This feature should work
3162 automatically on hpux10.
3164 * Irix 5.x hardware watchpoint support
3166 Irix 5 configurations now support the use of hardware watchpoints.
3168 * Mips protocol "SYN garbage limit"
3170 When debugging a Mips target using the `target mips' protocol, you
3171 may set the number of characters that GDB will ignore by setting
3172 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
3173 every character. The default value is 1050.
3175 * Recording and replaying remote debug sessions
3177 If you set `remotelogfile' to the name of a file, gdb will write to it
3178 a recording of a remote debug session. This recording may then be
3179 replayed back to gdb using "gdbreplay". See gdbserver/README for
3180 details. This is useful when you have a problem with GDB while doing
3181 remote debugging; you can make a recording of the session and send it
3182 to someone else, who can then recreate the problem.
3184 * Speedups for remote debugging
3186 GDB includes speedups for downloading and stepping MIPS systems using
3187 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
3188 and more efficient S-record downloading.
3190 * Memory use reductions and statistics collection
3192 GDB now uses less memory and reports statistics about memory usage.
3193 Try the `maint print statistics' command, for example.
3195 *** Changes in GDB-4.15:
3197 * Psymtabs for XCOFF
3199 The symbol reader for AIX GDB now uses partial symbol tables. This
3200 can greatly improve startup time, especially for large executables.
3202 * Remote targets use caching
3204 Remote targets now use a data cache to speed up communication with the
3205 remote side. The data cache could lead to incorrect results because
3206 it doesn't know about volatile variables, thus making it impossible to
3207 debug targets which use memory mapped I/O devices. `set remotecache
3208 off' turns the the data cache off.
3210 * Remote targets may have threads
3212 The standard remote protocol now includes support for multiple threads
3213 in the target system, using new protocol commands 'H' and 'T'. See
3214 gdb/remote.c for details.
3218 If GDB is configured with `--enable-netrom', then it will include
3219 support for the NetROM ROM emulator from XLNT Designs. The NetROM
3220 acts as though it is a bank of ROM on the target board, but you can
3221 write into it over the network. GDB's support consists only of
3222 support for fast loading into the emulated ROM; to debug, you must use
3223 another protocol, such as standard remote protocol. The usual
3224 sequence is something like
3226 target nrom <netrom-hostname>
3228 target remote <netrom-hostname>:1235
3232 GDB now includes support for the Apple Macintosh, as a host only. It
3233 may be run as either an MPW tool or as a standalone application, and
3234 it can debug through the serial port. All the usual GDB commands are
3235 available, but to the target command, you must supply "serial" as the
3236 device type instead of "/dev/ttyXX". See mpw-README in the main
3237 directory for more information on how to build. The MPW configuration
3238 scripts */mpw-config.in support only a few targets, and only the
3239 mips-idt-ecoff target has been tested.
3243 GDB configuration now uses autoconf. This is not user-visible,
3244 but does simplify configuration and building.
3248 GDB now supports hpux10.
3250 *** Changes in GDB-4.14:
3252 * New native configurations
3254 x86 FreeBSD i[345]86-*-freebsd
3255 x86 NetBSD i[345]86-*-netbsd
3256 NS32k NetBSD ns32k-*-netbsd
3257 Sparc NetBSD sparc-*-netbsd
3261 A29K VxWorks a29k-*-vxworks
3262 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
3263 CPU32 EST-300 emulator m68*-*-est*
3264 PowerPC ELF powerpc-*-elf
3267 * Alpha OSF/1 support for procfs
3269 GDB now supports procfs under OSF/1-2.x and higher, which makes it
3270 possible to attach to running processes. As the mounting of the /proc
3271 filesystem is optional on the Alpha, GDB automatically determines
3272 the availability of /proc during startup. This can lead to problems
3273 if /proc is unmounted after GDB has been started.
3275 * Arguments to user-defined commands
3277 User commands may accept up to 10 arguments separated by whitespace.
3278 Arguments are accessed within the user command via $arg0..$arg9. A
3281 print $arg0 + $arg1 + $arg2
3283 To execute the command use:
3286 Defines the command "adder" which prints the sum of its three arguments.
3287 Note the arguments are text substitutions, so they may reference variables,
3288 use complex expressions, or even perform inferior function calls.
3290 * New `if' and `while' commands
3292 This makes it possible to write more sophisticated user-defined
3293 commands. Both commands take a single argument, which is the
3294 expression to evaluate, and must be followed by the commands to
3295 execute, one per line, if the expression is nonzero, the list being
3296 terminated by the word `end'. The `if' command list may include an
3297 `else' word, which causes the following commands to be executed only
3298 if the expression is zero.
3300 * Fortran source language mode
3302 GDB now includes partial support for Fortran 77. It will recognize
3303 Fortran programs and can evaluate a subset of Fortran expressions, but
3304 variables and functions may not be handled correctly. GDB will work
3305 with G77, but does not yet know much about symbols emitted by other
3308 * Better HPUX support
3310 Most debugging facilities now work on dynamic executables for HPPAs
3311 running hpux9 or later. You can attach to running dynamically linked
3312 processes, but by default the dynamic libraries will be read-only, so
3313 for instance you won't be able to put breakpoints in them. To change
3314 that behavior do the following before running the program:
3320 This will cause the libraries to be mapped private and read-write.
3321 To revert to the normal behavior, do this:
3327 You cannot set breakpoints or examine data in the library until after
3328 the library is loaded if the function/data symbols do not have
3331 GDB can now also read debug symbols produced by the HP C compiler on
3332 HPPAs (sorry, no C++, Fortran or 68k support).
3334 * Target byte order now dynamically selectable
3336 You can choose which byte order to use with a target system, via the
3337 commands "set endian big" and "set endian little", and you can see the
3338 current setting by using "show endian". You can also give the command
3339 "set endian auto", in which case GDB will use the byte order
3340 associated with the executable. Currently, only embedded MIPS
3341 configurations support dynamic selection of target byte order.
3343 * New DOS host serial code
3345 This version uses DPMI interrupts to handle buffered I/O, so you
3346 no longer need to run asynctsr when debugging boards connected to
3349 *** Changes in GDB-4.13:
3351 * New "complete" command
3353 This lists all the possible completions for the rest of the line, if it
3354 were to be given as a command itself. This is intended for use by emacs.
3356 * Trailing space optional in prompt
3358 "set prompt" no longer adds a space for you after the prompt you set. This
3359 allows you to set a prompt which ends in a space or one that does not.
3361 * Breakpoint hit counts
3363 "info break" now displays a count of the number of times the breakpoint
3364 has been hit. This is especially useful in conjunction with "ignore"; you
3365 can ignore a large number of breakpoint hits, look at the breakpoint info
3366 to see how many times the breakpoint was hit, then run again, ignoring one
3367 less than that number, and this will get you quickly to the last hit of
3370 * Ability to stop printing at NULL character
3372 "set print null-stop" will cause GDB to stop printing the characters of
3373 an array when the first NULL is encountered. This is useful when large
3374 arrays actually contain only short strings.
3376 * Shared library breakpoints
3378 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
3379 breakpoints in shared libraries before the executable is run.
3381 * Hardware watchpoints
3383 There is a new hardware breakpoint for the watch command for sparclite
3384 targets. See gdb/sparclite/hw_breakpoint.note.
3386 Hardware watchpoints are also now supported under GNU/Linux.
3390 Annotations have been added. These are for use with graphical interfaces,
3391 and are still experimental. Currently only gdba.el uses these.
3393 * Improved Irix 5 support
3395 GDB now works properly with Irix 5.2.
3397 * Improved HPPA support
3399 GDB now works properly with the latest GCC and GAS.
3401 * New native configurations
3403 Sequent PTX4 i[34]86-sequent-ptx4
3404 HPPA running OSF/1 hppa*-*-osf*
3405 Atari TT running SVR4 m68*-*-sysv4*
3406 RS/6000 LynxOS rs6000-*-lynxos*
3410 OS/9000 i[34]86-*-os9k
3411 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
3414 * Hitachi SH7000 and E7000-PC ICE support
3416 There is now support for communicating with the Hitachi E7000-PC ICE.
3417 This is available automatically when GDB is configured for the SH.
3421 As usual, a variety of small fixes and improvements, both generic
3422 and configuration-specific. See the ChangeLog for more detail.
3424 *** Changes in GDB-4.12:
3426 * Irix 5 is now supported
3430 GDB-4.12 on the HPPA has a number of changes which make it unable
3431 to debug the output from the currently released versions of GCC and
3432 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
3433 of GCC and GAS, versions of these tools designed to work with GDB-4.12
3434 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
3437 *** Changes in GDB-4.11:
3439 * User visible changes:
3443 The "set remotedebug" option is now consistent between the mips remote
3444 target, remote targets using the gdb-specific protocol, UDI (AMD's
3445 debug protocol for the 29k) and the 88k bug monitor. It is now an
3446 integer specifying a debug level (normally 0 or 1, but 2 means more
3447 debugging info for the mips target).
3449 * DEC Alpha native support
3451 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
3452 debug info, but GDB works fairly well with the DEC compiler and should
3453 work with a future GCC release. See the README file for a few
3454 Alpha-specific notes.
3456 * Preliminary thread implementation
3458 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
3460 * LynxOS native and target support for 386
3462 This release has been hosted on LynxOS 2.2, and also can be configured
3463 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
3466 * Improvements in C++ mangling/demangling.
3468 This release has much better g++ debugging, specifically in name
3469 mangling/demangling, virtual function calls, print virtual table,
3470 call methods, ...etc.
3472 *** Changes in GDB-4.10:
3474 * User visible changes:
3476 Remote debugging using the GDB-specific (`target remote') protocol now
3477 supports the `load' command. This is only useful if you have some
3478 other way of getting the stub to the target system, and you can put it
3479 somewhere in memory where it won't get clobbered by the download.
3481 Filename completion now works.
3483 When run under emacs mode, the "info line" command now causes the
3484 arrow to point to the line specified. Also, "info line" prints
3485 addresses in symbolic form (as well as hex).
3487 All vxworks based targets now support a user settable option, called
3488 vxworks-timeout. This option represents the number of seconds gdb
3489 should wait for responses to rpc's. You might want to use this if
3490 your vxworks target is, perhaps, a slow software simulator or happens
3491 to be on the far side of a thin network line.
3495 This release contains support for using a DEC alpha as a GDB host for
3496 cross debugging. Native alpha debugging is not supported yet.
3499 *** Changes in GDB-4.9:
3503 This is the first GDB release which is accompanied by a matching testsuite.
3504 The testsuite requires installation of dejagnu, which should be available
3505 via ftp from most sites that carry GNU software.
3509 'Cfront' style demangling has had its name changed to 'ARM' style, to
3510 emphasize that it was written from the specifications in the C++ Annotated
3511 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
3512 disclaimers, it still generated too much confusion with users attempting to
3513 use gdb with AT&T cfront.
3517 GDB now uses a standard remote interface to a simulator library.
3518 So far, the library contains simulators for the Zilog Z8001/2, the
3519 Hitachi H8/300, H8/500 and Super-H.
3521 * New targets supported
3523 H8/300 simulator h8300-hitachi-hms or h8300hms
3524 H8/500 simulator h8500-hitachi-hms or h8500hms
3525 SH simulator sh-hitachi-hms or sh
3526 Z8000 simulator z8k-zilog-none or z8ksim
3527 IDT MIPS board over serial line mips-idt-ecoff
3529 Cross-debugging to GO32 targets is supported. It requires a custom
3530 version of the i386-stub.c module which is integrated with the
3531 GO32 memory extender.
3533 * New remote protocols
3535 MIPS remote debugging protocol.
3537 * New source languages supported
3539 This version includes preliminary support for Chill, a Pascal like language
3540 used by telecommunications companies. Chill support is also being integrated
3541 into the GNU compiler, but we don't know when it will be publically available.
3544 *** Changes in GDB-4.8:
3546 * HP Precision Architecture supported
3548 GDB now supports HP PA-RISC machines running HPUX. A preliminary
3549 version of this support was available as a set of patches from the
3550 University of Utah. GDB does not support debugging of programs
3551 compiled with the HP compiler, because HP will not document their file
3552 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
3553 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
3555 Many problems in the preliminary version have been fixed.
3557 * Faster and better demangling
3559 We have improved template demangling and fixed numerous bugs in the GNU style
3560 demangler. It can now handle type modifiers such as `static' or `const'. Wide
3561 character types (wchar_t) are now supported. Demangling of each symbol is now
3562 only done once, and is cached when the symbol table for a file is read in.
3563 This results in a small increase in memory usage for C programs, a moderate
3564 increase in memory usage for C++ programs, and a fantastic speedup in
3567 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
3568 from the specifications in the Annotated Reference Manual, which AT&T's
3569 compiler does not actually implement.
3571 * G++ multiple inheritance compiler problem
3573 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
3574 inheritance lattices was reworked to properly discover ambiguities. We
3575 recently found an example which causes this new algorithm to fail in a
3576 very subtle way, producing bad debug information for those classes.
3577 The file 'gcc.patch' (in this directory) can be applied to gcc to
3578 circumvent the problem. A future GCC release will contain a complete
3581 The previous G++ debug info problem (mentioned below for the gdb-4.7
3582 release) is fixed in gcc version 2.3.2.
3584 * Improved configure script
3586 The `configure' script will now attempt to guess your system type if
3587 you don't supply a host system type. The old scheme of supplying a
3588 host system triplet is preferable over using this. All the magic is
3589 done in the new `config.guess' script. Examine it for details.
3591 We have also brought our configure script much more in line with the FSF's
3592 version. It now supports the --with-xxx options. In particular,
3593 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
3594 The resulting GDB will not be able to read arbitrary object file formats --
3595 only the format ``expected'' to be used on the configured target system.
3596 We hope to make this the default in a future release.
3598 * Documentation improvements
3600 There's new internal documentation on how to modify GDB, and how to
3601 produce clean changes to the code. We implore people to read it
3602 before submitting changes.
3604 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
3605 M4 macros. The new texinfo.tex is provided in this release. Pre-built
3606 `info' files are also provided. To build `info' files from scratch,
3607 you will need the latest `makeinfo' release, which will be available in
3608 a future texinfo-X.Y release.
3610 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
3611 We're not sure exactly which versions have this problem, but it has
3612 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
3613 or better. If that isn't possible, there is a patch in
3614 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
3615 around this problem.
3619 GDB now supports array constants that can be used in expressions typed in by
3620 the user. The syntax is `{element, element, ...}'. Ie: you can now type
3621 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
3624 The new directory `gdb/sparclite' contains a program that demonstrates
3625 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
3627 * New native hosts supported
3629 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
3630 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
3632 * New targets supported
3634 AMD 29k family via UDI a29k-amd-udi or udi29k
3636 * New file formats supported
3638 BFD now supports reading HP/PA-RISC executables (SOM file format?),
3639 HPUX core files, and SCO 3.2v2 core files.
3643 Attaching to processes now works again; thanks for the many bug reports.
3645 We have also stomped on a bunch of core dumps caused by
3646 printf_filtered("%s") problems.
3648 We eliminated a copyright problem on the rpc and ptrace header files
3649 for VxWorks, which was discovered at the last minute during the 4.7
3650 release. You should now be able to build a VxWorks GDB.
3652 You can now interrupt gdb while an attached process is running. This
3653 will cause the attached process to stop, and give control back to GDB.
3655 We fixed problems caused by using too many file descriptors
3656 for reading symbols from object files and libraries. This was
3657 especially a problem for programs that used many (~100) shared
3660 The `step' command now only enters a subroutine if there is line number
3661 information for the subroutine. Otherwise it acts like the `next'
3662 command. Previously, `step' would enter subroutines if there was
3663 any debugging information about the routine. This avoids problems
3664 when using `cc -g1' on MIPS machines.
3666 * Internal improvements
3668 GDB's internal interfaces have been improved to make it easier to support
3669 debugging of multiple languages in the future.
3671 GDB now uses a common structure for symbol information internally.
3672 Minimal symbols (derived from linkage symbols in object files), partial
3673 symbols (from a quick scan of debug information), and full symbols
3674 contain a common subset of information, making it easier to write
3675 shared code that handles any of them.
3677 * New command line options
3679 We now accept --silent as an alias for --quiet.
3683 The memory-mapped-malloc library is now licensed under the GNU Library
3684 General Public License.
3686 *** Changes in GDB-4.7:
3688 * Host/native/target split
3690 GDB has had some major internal surgery to untangle the support for
3691 hosts and remote targets. Now, when you configure GDB for a remote
3692 target, it will no longer load in all of the support for debugging
3693 local programs on the host. When fully completed and tested, this will
3694 ensure that arbitrary host/target combinations are possible.
3696 The primary conceptual shift is to separate the non-portable code in
3697 GDB into three categories. Host specific code is required any time GDB
3698 is compiled on that host, regardless of the target. Target specific
3699 code relates to the peculiarities of the target, but can be compiled on
3700 any host. Native specific code is everything else: it can only be
3701 built when the host and target are the same system. Child process
3702 handling and core file support are two common `native' examples.
3704 GDB's use of /proc for controlling Unix child processes is now cleaner.
3705 It has been split out into a single module under the `target_ops' vector,
3706 plus two native-dependent functions for each system that uses /proc.
3708 * New hosts supported
3710 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
3711 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
3712 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
3714 * New targets supported
3716 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3717 68030 and CPU32 m68030-*-*, m68332-*-*
3719 * New native hosts supported
3721 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
3722 (386bsd is not well tested yet)
3723 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
3725 * New file formats supported
3727 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
3728 supports reading of `a.out.adobe' object files, which are an a.out
3729 format extended with minimal information about multiple sections.
3733 `show copying' is the same as the old `info copying'.
3734 `show warranty' is the same as `info warrantee'.
3735 These were renamed for consistency. The old commands continue to work.
3737 `info handle' is a new alias for `info signals'.
3739 You can now define pre-command hooks, which attach arbitrary command
3740 scripts to any command. The commands in the hook will be executed
3741 prior to the user's command. You can also create a hook which will be
3742 executed whenever the program stops. See gdb.texinfo.
3746 We now deal with Cfront style name mangling, and can even extract type
3747 info from mangled symbols. GDB can automatically figure out which
3748 symbol mangling style your C++ compiler uses.
3750 Calling of methods and virtual functions has been improved as well.
3754 The crash that occured when debugging Sun Ansi-C compiled binaries is
3755 fixed. This was due to mishandling of the extra N_SO stabs output
3758 We also finally got Ultrix 4.2 running in house, and fixed core file
3759 support, with help from a dozen people on the net.
3761 John M. Farrell discovered that the reason that single-stepping was so
3762 slow on all of the Mips based platforms (primarily SGI and DEC) was
3763 that we were trying to demangle and lookup a symbol used for internal
3764 purposes on every instruction that was being stepped through. Changing
3765 the name of that symbol so that it couldn't be mistaken for a C++
3766 mangled symbol sped things up a great deal.
3768 Rich Pixley sped up symbol lookups in general by getting much smarter
3769 about when C++ symbol mangling is necessary. This should make symbol
3770 completion (TAB on the command line) much faster. It's not as fast as
3771 we'd like, but it's significantly faster than gdb-4.6.
3775 A new user controllable variable 'call_scratch_address' can
3776 specify the location of a scratch area to be used when GDB
3777 calls a function in the target. This is necessary because the
3778 usual method of putting the scratch area on the stack does not work
3779 in systems that have separate instruction and data spaces.
3781 We integrated changes to support the 29k UDI (Universal Debugger
3782 Interface), but discovered at the last minute that we didn't have all
3783 of the appropriate copyright paperwork. We are working with AMD to
3784 resolve this, and hope to have it available soon.
3788 We have sped up the remote serial line protocol, especially for targets
3789 with lots of registers. It now supports a new `expedited status' ('T')
3790 message which can be used in place of the existing 'S' status message.
3791 This allows the remote stub to send only the registers that GDB
3792 needs to make a quick decision about single-stepping or conditional
3793 breakpoints, eliminating the need to fetch the entire register set for
3794 each instruction being stepped through.
3796 The GDB remote serial protocol now implements a write-through cache for
3797 registers, only re-reading the registers if the target has run.
3799 There is also a new remote serial stub for SPARC processors. You can
3800 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
3801 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
3802 processor with a serial port.
3806 Configure.in files have become much easier to read and modify. A new
3807 `table driven' format makes it more obvious what configurations are
3808 supported, and what files each one uses.
3812 There is a new opcodes library which will eventually contain all of the
3813 disassembly routines and opcode tables. At present, it only contains
3814 Sparc and Z8000 routines. This will allow the assembler, debugger, and
3815 disassembler (binutils/objdump) to share these routines.
3817 The libiberty library is now copylefted under the GNU Library General
3818 Public License. This allows more liberal use, and was done so libg++
3819 can use it. This makes no difference to GDB, since the Library License
3820 grants all the rights from the General Public License.
3824 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
3825 reference to the stabs symbol info used by the debugger. It is (as far
3826 as we know) the only published document on this fascinating topic. We
3827 encourage you to read it, compare it to the stabs information on your
3828 system, and send improvements on the document in general (to
3829 bug-gdb@prep.ai.mit.edu).
3831 And, of course, many bugs have been fixed.
3834 *** Changes in GDB-4.6:
3836 * Better support for C++ function names
3838 GDB now accepts as input the "demangled form" of C++ overloaded function
3839 names and member function names, and can do command completion on such names
3840 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
3841 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
3842 Make use of command completion, it is your friend.
3844 GDB also now accepts a variety of C++ mangled symbol formats. They are
3845 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
3846 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
3847 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
3848 for the list of formats.
3850 * G++ symbol mangling problem
3852 Recent versions of gcc have a bug in how they emit debugging information for
3853 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
3854 directory) can be applied to gcc to fix the problem. Alternatively, if you
3855 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
3856 usual symptom is difficulty with setting breakpoints on methods. GDB complains
3857 about the method being non-existent. (We believe that version 2.2.2 of GCC has
3860 * New 'maintenance' command
3862 All of the commands related to hacking GDB internals have been moved out of
3863 the main command set, and now live behind the 'maintenance' command. This
3864 can also be abbreviated as 'mt'. The following changes were made:
3866 dump-me -> maintenance dump-me
3867 info all-breakpoints -> maintenance info breakpoints
3868 printmsyms -> maintenance print msyms
3869 printobjfiles -> maintenance print objfiles
3870 printpsyms -> maintenance print psymbols
3871 printsyms -> maintenance print symbols
3873 The following commands are new:
3875 maintenance demangle Call internal GDB demangler routine to
3876 demangle a C++ link name and prints the result.
3877 maintenance print type Print a type chain for a given symbol
3879 * Change to .gdbinit file processing
3881 We now read the $HOME/.gdbinit file before processing the argv arguments
3882 (e.g. reading symbol files or core files). This allows global parameters to
3883 be set, which will apply during the symbol reading. The ./.gdbinit is still
3884 read after argv processing.
3886 * New hosts supported
3888 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
3890 GNU/Linux support i386-unknown-linux or linux
3892 We are also including code to support the HP/PA running BSD and HPUX. This
3893 is almost guaranteed not to work, as we didn't have time to test or build it
3894 for this release. We are including it so that the more adventurous (or
3895 masochistic) of you can play with it. We also had major problems with the
3896 fact that the compiler that we got from HP doesn't support the -g option.
3899 * New targets supported
3901 Hitachi H8/300 h8300-hitachi-hms or h8300hms
3903 * More smarts about finding #include files
3905 GDB now remembers the compilation directory for all include files, and for
3906 all files from which C is generated (like yacc and lex sources). This
3907 greatly improves GDB's ability to find yacc/lex sources, and include files,
3908 especially if you are debugging your program from a directory different from
3909 the one that contains your sources.
3911 We also fixed a bug which caused difficulty with listing and setting
3912 breakpoints in include files which contain C code. (In the past, you had to
3913 try twice in order to list an include file that you hadn't looked at before.)
3915 * Interesting infernals change
3917 GDB now deals with arbitrary numbers of sections, where the symbols for each
3918 section must be relocated relative to that section's landing place in the
3919 target's address space. This work was needed to support ELF with embedded
3920 stabs used by Solaris-2.0.
3922 * Bug fixes (of course!)
3924 There have been loads of fixes for the following things:
3925 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
3926 i960, stabs, DOS(GO32), procfs, etc...
3928 See the ChangeLog for details.
3930 *** Changes in GDB-4.5:
3932 * New machines supported (host and target)
3934 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
3936 SGI Irix-4.x mips-sgi-irix4 or iris4
3938 * New malloc package
3940 GDB now uses a new memory manager called mmalloc, based on gmalloc.
3941 Mmalloc is capable of handling mutiple heaps of memory. It is also
3942 capable of saving a heap to a file, and then mapping it back in later.
3943 This can be used to greatly speedup the startup of GDB by using a
3944 pre-parsed symbol table which lives in a mmalloc managed heap. For
3945 more details, please read mmalloc/mmalloc.texi.
3949 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
3950 'help info proc' for details.
3952 * MIPS ecoff symbol table format
3954 The code that reads MIPS symbol table format is now supported on all hosts.
3955 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
3958 * File name changes for MS-DOS
3960 Many files in the config directories have been renamed to make it easier to
3961 support GDB on MS-DOSe systems (which have very restrictive file name
3962 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
3963 environment) is close to working but has some remaining problems. Note
3964 that debugging of DOS programs is not supported, due to limitations
3965 in the ``operating system'', but it can be used to host cross-debugging.
3967 * Cross byte order fixes
3969 Many fixes have been made to support cross debugging of Sparc and MIPS
3970 targets from hosts whose byte order differs.
3972 * New -mapped and -readnow options
3974 If memory-mapped files are available on your system through the 'mmap'
3975 system call, you can use the -mapped option on the `file' or
3976 `symbol-file' commands to cause GDB to write the symbols from your
3977 program into a reusable file. If the program you are debugging is
3978 called `/path/fred', the mapped symbol file will be `./fred.syms'.
3979 Future GDB debugging sessions will notice the presence of this file,
3980 and will quickly map in symbol information from it, rather than reading
3981 the symbol table from the executable program. Using the '-mapped'
3982 option in a GDB `file' or `symbol-file' command has the same effect as
3983 starting GDB with the '-mapped' command-line option.
3985 You can cause GDB to read the entire symbol table immediately by using
3986 the '-readnow' option with any of the commands that load symbol table
3987 information (or on the GDB command line). This makes the command
3988 slower, but makes future operations faster.
3990 The -mapped and -readnow options are typically combined in order to
3991 build a `fred.syms' file that contains complete symbol information.
3992 A simple GDB invocation to do nothing but build a `.syms' file for future
3995 gdb -batch -nx -mapped -readnow programname
3997 The `.syms' file is specific to the host machine on which GDB is run.
3998 It holds an exact image of GDB's internal symbol table. It cannot be
3999 shared across multiple host platforms.
4001 * longjmp() handling
4003 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
4004 siglongjmp() without losing control. This feature has not yet been ported to
4005 all systems. It currently works on many 386 platforms, all MIPS-based
4006 platforms (SGI, DECstation, etc), and Sun3/4.
4010 Preliminary work has been put in to support the new Solaris OS from Sun. At
4011 this time, it can control and debug processes, but it is not capable of
4016 As always, many many bug fixes. The major areas were with g++, and mipsread.
4017 People using the MIPS-based platforms should experience fewer mysterious
4018 crashes and trashed symbol tables.
4020 *** Changes in GDB-4.4:
4022 * New machines supported (host and target)
4024 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4026 BSD Reno on Vax vax-dec-bsd
4027 Ultrix on Vax vax-dec-ultrix
4029 * New machines supported (target)
4031 AMD 29000 embedded, using EBMON a29k-none-none
4035 GDB continues to improve its handling of C++. `References' work better.
4036 The demangler has also been improved, and now deals with symbols mangled as
4037 per the Annotated C++ Reference Guide.
4039 GDB also now handles `stabs' symbol information embedded in MIPS
4040 `ecoff' symbol tables. Since the ecoff format was not easily
4041 extensible to handle new languages such as C++, this appeared to be a
4042 good way to put C++ debugging info into MIPS binaries. This option
4043 will be supported in the GNU C compiler, version 2, when it is
4046 * New features for SVR4
4048 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
4049 shared libraries. Debugging dynamically linked programs should present
4050 only minor differences from debugging statically linked programs.
4052 The `info proc' command will print out information about any process
4053 on an SVR4 system (including the one you are debugging). At the moment,
4054 it prints the address mappings of the process.
4056 If you bring up GDB on another SVR4 system, please send mail to
4057 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
4059 * Better dynamic linking support in SunOS
4061 Reading symbols from shared libraries which contain debugging symbols
4062 now works properly. However, there remain issues such as automatic
4063 skipping of `transfer vector' code during function calls, which
4064 make it harder to debug code in a shared library, than to debug the
4065 same code linked statically.
4069 GDB is now using the latest `getopt' routines from the FSF. This
4070 version accepts the -- prefix for options with long names. GDB will
4071 continue to accept the old forms (-option and +option) as well.
4072 Various single letter abbreviations for options have been explicity
4073 added to the option table so that they won't get overshadowed in the
4074 future by other options that begin with the same letter.
4078 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
4079 Many assorted bugs have been handled. Many more remain to be handled.
4080 See the various ChangeLog files (primarily in gdb and bfd) for details.
4083 *** Changes in GDB-4.3:
4085 * New machines supported (host and target)
4087 Amiga 3000 running Amix m68k-cbm-svr4 or amix
4088 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
4089 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4091 * Almost SCO Unix support
4093 We had hoped to support:
4094 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4095 (except for core file support), but we discovered very late in the release
4096 that it has problems with process groups that render gdb unusable. Sorry
4097 about that. I encourage people to fix it and post the fixes.
4099 * Preliminary ELF and DWARF support
4101 GDB can read ELF object files on System V Release 4, and can handle
4102 debugging records for C, in DWARF format, in ELF files. This support
4103 is preliminary. If you bring up GDB on another SVR4 system, please
4104 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
4109 GDB now uses the latest `readline' library. One user-visible change
4110 is that two tabs will list possible command completions, which previously
4111 required typing M-? (meta-question mark, or ESC ?).
4115 The `stepi' bug that many of you noticed has been squashed.
4116 Many bugs in C++ have been handled. Many more remain to be handled.
4117 See the various ChangeLog files (primarily in gdb and bfd) for details.
4119 * State of the MIPS world (in case you wondered):
4121 GDB can understand the symbol tables emitted by the compilers
4122 supplied by most vendors of MIPS-based machines, including DEC. These
4123 symbol tables are in a format that essentially nobody else uses.
4125 Some versions of gcc come with an assembler post-processor called
4126 mips-tfile. This program is required if you want to do source-level
4127 debugging of gcc-compiled programs. I believe FSF does not ship
4128 mips-tfile with gcc version 1, but it will eventually come with gcc
4131 Debugging of g++ output remains a problem. g++ version 1.xx does not
4132 really support it at all. (If you're lucky, you should be able to get
4133 line numbers and stack traces to work, but no parameters or local
4134 variables.) With some work it should be possible to improve the
4137 When gcc version 2 is released, you will have somewhat better luck.
4138 However, even then you will get confusing results for inheritance and
4141 We will eventually provide full debugging of g++ output on
4142 DECstations. This will probably involve some kind of stabs-in-ecoff
4143 encapulation, but the details have not been worked out yet.
4146 *** Changes in GDB-4.2:
4148 * Improved configuration
4150 Only one copy of `configure' exists now, and it is not self-modifying.
4151 Porting BFD is simpler.
4155 The `step' and `next' commands now only stop at the first instruction
4156 of a source line. This prevents the multiple stops that used to occur
4157 in switch statements, for-loops, etc. `Step' continues to stop if a
4158 function that has debugging information is called within the line.
4162 Lots of small bugs fixed. More remain.
4164 * New host supported (not target)
4166 Intel 386 PC clone running Mach i386-none-mach
4169 *** Changes in GDB-4.1:
4171 * Multiple source language support
4173 GDB now has internal scaffolding to handle several source languages.
4174 It determines the type of each source file from its filename extension,
4175 and will switch expression parsing and number formatting to match the
4176 language of the function in the currently selected stack frame.
4177 You can also specifically set the language to be used, with
4178 `set language c' or `set language modula-2'.
4182 GDB now has preliminary support for the GNU Modula-2 compiler,
4183 currently under development at the State University of New York at
4184 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
4185 continue through the fall of 1991 and into 1992.
4187 Other Modula-2 compilers are currently not supported, and attempting to
4188 debug programs compiled with them will likely result in an error as the
4189 symbol table is read. Feel free to work on it, though!
4191 There are hooks in GDB for strict type checking and range checking,
4192 in the `Modula-2 philosophy', but they do not currently work.
4196 GDB can now write to executable and core files (e.g. patch
4197 a variable's value). You must turn this switch on, specify
4198 the file ("exec foo" or "core foo"), *then* modify it, e.g.
4199 by assigning a new value to a variable. Modifications take
4202 * Automatic SunOS shared library reading
4204 When you run your program, GDB automatically determines where its
4205 shared libraries (if any) have been loaded, and reads their symbols.
4206 The `share' command is no longer needed. This also works when
4207 examining core files.
4211 You can specify the number of lines that the `list' command shows.
4214 * New machines supported (host and target)
4216 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4217 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
4218 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
4220 * New hosts supported (not targets)
4222 IBM RT/PC: romp-ibm-aix or rtpc
4224 * New targets supported (not hosts)
4226 AMD 29000 embedded with COFF a29k-none-coff
4227 AMD 29000 embedded with a.out a29k-none-aout
4228 Ultracomputer remote kernel debug a29k-nyu-kern
4230 * New remote interfaces
4236 *** Changes in GDB-4.0:
4240 Wide output is wrapped at good places to make the output more readable.
4242 Gdb now supports cross-debugging from a host machine of one type to a
4243 target machine of another type. Communication with the target system
4244 is over serial lines. The ``target'' command handles connecting to the
4245 remote system; the ``load'' command will download a program into the
4246 remote system. Serial stubs for the m68k and i386 are provided. Gdb
4247 also supports debugging of realtime processes running under VxWorks,
4248 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
4249 stub on the target system.
4251 New CPUs supported include the AMD 29000 and Intel 960.
4253 GDB now reads object files and symbol tables via a ``binary file''
4254 library, which allows a single copy of GDB to debug programs of multiple
4255 object file types such as a.out and coff.
4257 There is now a GDB reference card in "doc/refcard.tex". (Make targets
4258 refcard.dvi and refcard.ps are available to format it).
4261 * Control-Variable user interface simplified
4263 All variables that control the operation of the debugger can be set
4264 by the ``set'' command, and displayed by the ``show'' command.
4266 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
4267 ``Show prompt'' produces the response:
4268 Gdb's prompt is new-gdb=>.
4270 What follows are the NEW set commands. The command ``help set'' will
4271 print a complete list of old and new set commands. ``help set FOO''
4272 will give a longer description of the variable FOO. ``show'' will show
4273 all of the variable descriptions and their current settings.
4275 confirm on/off: Enables warning questions for operations that are
4276 hard to recover from, e.g. rerunning the program while
4277 it is already running. Default is ON.
4279 editing on/off: Enables EMACS style command line editing
4280 of input. Previous lines can be recalled with
4281 control-P, the current line can be edited with control-B,
4282 you can search for commands with control-R, etc.
4285 history filename NAME: NAME is where the gdb command history
4286 will be stored. The default is .gdb_history,
4287 or the value of the environment variable
4290 history size N: The size, in commands, of the command history. The
4291 default is 256, or the value of the environment variable
4294 history save on/off: If this value is set to ON, the history file will
4295 be saved after exiting gdb. If set to OFF, the
4296 file will not be saved. The default is OFF.
4298 history expansion on/off: If this value is set to ON, then csh-like
4299 history expansion will be performed on
4300 command line input. The default is OFF.
4302 radix N: Sets the default radix for input and output. It can be set
4303 to 8, 10, or 16. Note that the argument to "radix" is interpreted
4304 in the current radix, so "set radix 10" is always a no-op.
4306 height N: This integer value is the number of lines on a page. Default
4307 is 24, the current `stty rows'' setting, or the ``li#''
4308 setting from the termcap entry matching the environment
4311 width N: This integer value is the number of characters on a line.
4312 Default is 80, the current `stty cols'' setting, or the ``co#''
4313 setting from the termcap entry matching the environment
4316 Note: ``set screensize'' is obsolete. Use ``set height'' and
4317 ``set width'' instead.
4319 print address on/off: Print memory addresses in various command displays,
4320 such as stack traces and structure values. Gdb looks
4321 more ``symbolic'' if you turn this off; it looks more
4322 ``machine level'' with it on. Default is ON.
4324 print array on/off: Prettyprint arrays. New convenient format! Default
4327 print demangle on/off: Print C++ symbols in "source" form if on,
4330 print asm-demangle on/off: Same, for assembler level printouts
4333 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
4336 * Support for Epoch Environment.
4338 The epoch environment is a version of Emacs v18 with windowing. One
4339 new command, ``inspect'', is identical to ``print'', except that if you
4340 are running in the epoch environment, the value is printed in its own
4344 * Support for Shared Libraries
4346 GDB can now debug programs and core files that use SunOS shared libraries.
4347 Symbols from a shared library cannot be referenced
4348 before the shared library has been linked with the program (this
4349 happens after you type ``run'' and before the function main() is entered).
4350 At any time after this linking (including when examining core files
4351 from dynamically linked programs), gdb reads the symbols from each
4352 shared library when you type the ``sharedlibrary'' command.
4353 It can be abbreviated ``share''.
4355 sharedlibrary REGEXP: Load shared object library symbols for files
4356 matching a unix regular expression. No argument
4357 indicates to load symbols for all shared libraries.
4359 info sharedlibrary: Status of loaded shared libraries.
4364 A watchpoint stops execution of a program whenever the value of an
4365 expression changes. Checking for this slows down execution
4366 tremendously whenever you are in the scope of the expression, but is
4367 quite useful for catching tough ``bit-spreader'' or pointer misuse
4368 problems. Some machines such as the 386 have hardware for doing this
4369 more quickly, and future versions of gdb will use this hardware.
4371 watch EXP: Set a watchpoint (breakpoint) for an expression.
4373 info watchpoints: Information about your watchpoints.
4375 delete N: Deletes watchpoint number N (same as breakpoints).
4376 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
4377 enable N: Re-enables watchpoint number N (same as breakpoints).
4380 * C++ multiple inheritance
4382 When used with a GCC version 2 compiler, GDB supports multiple inheritance
4385 * C++ exception handling
4387 Gdb now supports limited C++ exception handling. Besides the existing
4388 ability to breakpoint on an exception handler, gdb can breakpoint on
4389 the raising of an exception (before the stack is peeled back to the
4392 catch FOO: If there is a FOO exception handler in the dynamic scope,
4393 set a breakpoint to catch exceptions which may be raised there.
4394 Multiple exceptions (``catch foo bar baz'') may be caught.
4396 info catch: Lists all exceptions which may be caught in the
4397 current stack frame.
4400 * Minor command changes
4402 The command ``call func (arg, arg, ...)'' now acts like the print
4403 command, except it does not print or save a value if the function's result
4404 is void. This is similar to dbx usage.
4406 The ``up'' and ``down'' commands now always print the frame they end up
4407 at; ``up-silently'' and `down-silently'' can be used in scripts to change
4408 frames without printing.
4410 * New directory command
4412 'dir' now adds directories to the FRONT of the source search path.
4413 The path starts off empty. Source files that contain debug information
4414 about the directory in which they were compiled can be found even
4415 with an empty path; Sun CC and GCC include this information. If GDB can't
4416 find your source file in the current directory, type "dir .".
4418 * Configuring GDB for compilation
4420 For normal use, type ``./configure host''. See README or gdb.texinfo
4423 GDB now handles cross debugging. If you are remotely debugging between
4424 two different machines, type ``./configure host -target=targ''.
4425 Host is the machine where GDB will run; targ is the machine
4426 where the program that you are debugging will run.