1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.2
8 ** GDB values in Python are now callable if the value represents a
9 function. For example, if 'some_value' represents a function that
10 takes two integer parameters and returns a value, you can call
11 that function like so:
13 result = some_value (10,20)
17 ** GDB now puts template parameters in scope when debugging in an
18 instantiation. For example, if you have:
20 template<int X> int func (void) { return X; }
22 then if you step into func<5>, "print X" will show "5". This
23 feature requires proper debuginfo support from the compiler; it
26 * GDB now has some support for using labels in the program's source in
27 linespecs. For instance, you can use "advance label" to continue
30 * GDB now has support for reading and writing a new .gdb_index
31 section. This section holds a fast index of DWARF debugging
32 information and can be used to greatly speed up GDB startup and
33 operation. See the documentation for `save gdb-index' for details.
35 * The "watch" command now accepts an optional "-location" argument.
36 When used, this causes GDB to watch the memory referred to by the
37 expression. Such a watchpoint is never deleted due to it going out
40 *** Changes in GDB 7.2
42 * Shared library support for remote targets by default
44 When GDB is configured for a generic, non-OS specific target, like
45 for example, --target=arm-eabi or one of the many *-*-elf targets,
46 GDB now queries remote stubs for loaded shared libraries using the
47 `qXfer:libraries:read' packet. Previously, shared library support
48 was always disabled for such configurations.
52 ** Argument Dependent Lookup (ADL)
54 In C++ ADL lookup directs function search to the namespaces of its
55 arguments even if the namespace has not been imported.
65 Here the compiler will search for `foo' in the namespace of 'b'
66 and find A::foo. GDB now supports this. This construct is commonly
67 used in the Standard Template Library for operators.
69 ** Improved User Defined Operator Support
71 In addition to member operators, GDB now supports lookup of operators
72 defined in a namespace and imported with a `using' directive, operators
73 defined in the global scope, operators imported implicitly from an
74 anonymous namespace, and the ADL operators mentioned in the previous
76 GDB now also supports proper overload resolution for all the previously
77 mentioned flavors of operators.
79 ** static const class members
81 Printing of static const class members that are initialized in the
82 class definition has been fixed.
84 * Windows Thread Information Block access.
86 On Windows targets, GDB now supports displaying the Windows Thread
87 Information Block (TIB) structure. This structure is visible either
88 by using the new command `info w32 thread-information-block' or, by
89 dereferencing the new convenience variable named `$_tlb', a
90 thread-specific pointer to the TIB. This feature is also supported
91 when remote debugging using GDBserver.
95 Static tracepoints are calls in the user program into a tracing
96 library. One such library is a port of the LTTng kernel tracer to
97 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
98 When debugging with GDBserver, GDB now supports combining the GDB
99 tracepoint machinery with such libraries. For example: the user can
100 use GDB to probe a static tracepoint marker (a call from the user
101 program into the tracing library) with the new "strace" command (see
102 "New commands" below). This creates a "static tracepoint" in the
103 breakpoint list, that can be manipulated with the same feature set
104 as fast and regular tracepoints. E.g., collect registers, local and
105 global variables, collect trace state variables, and define
106 tracepoint conditions. In addition, the user can collect extra
107 static tracepoint marker specific data, by collecting the new
108 $_sdata internal variable. When analyzing the trace buffer, you can
109 inspect $_sdata like any other variable available to GDB. For more
110 information, see the "Tracepoints" chapter in GDB user manual. New
111 remote packets have been defined to support static tracepoints, see
112 the "New remote packets" section below.
114 * Better reconstruction of tracepoints after disconnected tracing
116 GDB will attempt to download the original source form of tracepoint
117 definitions when starting a trace run, and then will upload these
118 upon reconnection to the target, resulting in a more accurate
119 reconstruction of the tracepoints that are in use on the target.
123 You can now exercise direct control over the ways that GDB can
124 affect your program. For instance, you can disallow the setting of
125 breakpoints, so that the program can run continuously (assuming
126 non-stop mode). In addition, the "observer" variable is available
127 to switch all of the different controls; in observer mode, GDB
128 cannot affect the target's behavior at all, which is useful for
129 tasks like diagnosing live systems in the field.
131 * The new convenience variable $_thread holds the number of the
138 Return the address of the Windows Thread Information Block of a given thread.
142 In response to several of the tracepoint packets, the target may now
143 also respond with a number of intermediate `qRelocInsn' request
144 packets before the final result packet, to have GDB handle
145 relocating an instruction to execute at a different address. This
146 is particularly useful for stubs that support fast tracepoints. GDB
147 reports support for this feature in the qSupported packet.
151 List static tracepoint markers in the target program.
155 List static tracepoint markers at a given address in the target
158 qXfer:statictrace:read
160 Read the static trace data collected (by a `collect $_sdata'
161 tracepoint action). The remote stub reports support for this packet
162 to gdb's qSupported query.
166 Send the current settings of GDB's permission flags.
170 Send part of the source (textual) form of a tracepoint definition,
171 which includes location, conditional, and action list.
173 * The source command now accepts a -s option to force searching for the
174 script in the source search path even if the script name specifies
177 * New features in the GDB remote stub, GDBserver
179 - GDBserver now support tracepoints (including fast tracepoints, and
180 static tracepoints). The feature is currently supported by the
181 i386-linux and amd64-linux builds. See the "Tracepoints support
182 in gdbserver" section in the manual for more information.
184 GDBserver JIT compiles the tracepoint's conditional agent
185 expression bytecode into native code whenever possible for low
186 overhead dynamic tracepoints conditionals. For such tracepoints,
187 an expression that examines program state is evaluated when the
188 tracepoint is reached, in order to determine whether to capture
189 trace data. If the condition is simple and false, processing the
190 tracepoint finishes very quickly and no data is gathered.
192 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
193 for static tracepoints support.
195 - GDBserver now supports x86_64 Windows 64-bit debugging.
197 * GDB now sends xmlRegisters= in qSupported packet to indicate that
198 it understands register description.
200 * The --batch flag now disables pagination and queries.
202 * X86 general purpose registers
204 GDB now supports reading/writing byte, word and double-word x86
205 general purpose registers directly. This means you can use, say,
206 $ah or $ax to refer, respectively, to the byte register AH and
207 16-bit word register AX that are actually portions of the 32-bit
208 register EAX or 64-bit register RAX.
210 * The `commands' command now accepts a range of breakpoints to modify.
211 A plain `commands' following a command that creates multiple
212 breakpoints affects all the breakpoints set by that command. This
213 applies to breakpoints set by `rbreak', and also applies when a
214 single `break' command creates multiple breakpoints (e.g.,
215 breakpoints on overloaded c++ functions).
217 * The `rbreak' command now accepts a filename specification as part of
218 its argument, limiting the functions selected by the regex to those
219 in the specified file.
221 * Support for remote debugging Windows and SymbianOS shared libraries
222 from Unix hosts has been improved. Non Windows GDB builds now can
223 understand target reported file names that follow MS-DOS based file
224 system semantics, such as file names that include drive letters and
225 use the backslash character as directory separator. This makes it
226 possible to transparently use the "set sysroot" and "set
227 solib-search-path" on Unix hosts to point as host copies of the
228 target's shared libraries. See the new command "set
229 target-file-system-kind" described below, and the "Commands to
230 specify files" section in the user manual for more information.
234 eval template, expressions...
235 Convert the values of one or more expressions under the control
236 of the string template to a command line, and call it.
238 set target-file-system-kind unix|dos-based|auto
239 show target-file-system-kind
240 Set or show the assumed file system kind for target reported file
243 save breakpoints <filename>
244 Save all current breakpoint definitions to a file suitable for use
245 in a later debugging session. To read the saved breakpoint
246 definitions, use the `source' command.
248 `save tracepoints' is a new alias for `save-tracepoints'. The latter
251 info static-tracepoint-markers
252 Display information about static tracepoint markers in the target.
254 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
255 Define a static tracepoint by probing a marker at the given
256 function, line, address, or marker ID.
260 Enable and disable observer mode.
262 set may-write-registers on|off
263 set may-write-memory on|off
264 set may-insert-breakpoints on|off
265 set may-insert-tracepoints on|off
266 set may-insert-fast-tracepoints on|off
267 set may-interrupt on|off
268 Set individual permissions for GDB effects on the target. Note that
269 some of these settings can have undesirable or surprising
270 consequences, particularly when changed in the middle of a session.
271 For instance, disabling the writing of memory can prevent
272 breakpoints from being inserted, cause single-stepping to fail, or
273 even crash your program, if you disable after breakpoints have been
274 inserted. However, GDB should not crash.
276 set record memory-query on|off
277 show record memory-query
278 Control whether to stop the inferior if memory changes caused
279 by an instruction cannot be recorded.
284 The disassemble command now supports "start,+length" form of two arguments.
288 ** GDB now provides a new directory location, called the python directory,
289 where Python scripts written for GDB can be installed. The location
290 of that directory is <data-directory>/python, where <data-directory>
291 is the GDB data directory. For more details, see section `Scripting
292 GDB using Python' in the manual.
294 ** The GDB Python API now has access to breakpoints, symbols, symbol
295 tables, program spaces, inferiors, threads and frame's code blocks.
296 Additionally, GDB Parameters can now be created from the API, and
297 manipulated via set/show in the CLI.
299 ** New functions gdb.target_charset, gdb.target_wide_charset,
300 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
302 ** New exception gdb.GdbError.
304 ** Pretty-printers are now also looked up in the current program space.
306 ** Pretty-printers can now be individually enabled and disabled.
308 ** GDB now looks for names of Python scripts to auto-load in a
309 special section named `.debug_gdb_scripts', in addition to looking
310 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
312 * Tracepoint actions were unified with breakpoint commands. In particular,
313 there are no longer differences in "info break" output for breakpoints and
314 tracepoints and the "commands" command can be used for both tracepoints and
319 ARM Symbian arm*-*-symbianelf*
321 * D language support.
322 GDB now supports debugging programs written in the D programming
325 * GDB now supports the extended ptrace interface for PowerPC which is
326 available since Linux kernel version 2.6.34. This automatically enables
327 any hardware breakpoints and additional hardware watchpoints available in
328 the processor. The old ptrace interface exposes just one hardware
329 watchpoint and no hardware breakpoints.
331 * GDB is now able to use the Data Value Compare (DVC) register available on
332 embedded PowerPC processors to implement in hardware simple watchpoint
333 conditions of the form:
335 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
337 This works in native GDB running on Linux kernels with the extended ptrace
338 interface mentioned above.
340 *** Changes in GDB 7.1
346 GDB now supports importing of namespaces in C++. This enables the
347 user to inspect variables from imported namespaces. Support for
348 namepace aliasing has also been added. So, if a namespace is
349 aliased in the current scope (e.g. namepace C=A; ) the user can
350 print variables using the alias (e.g. (gdb) print C::x).
354 All known bugs relating to the printing of virtual base class were
355 fixed. It is now possible to call overloaded static methods using a
360 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
361 and reinterpret_cast<> are now handled by the C++ expression parser.
365 Xilinx MicroBlaze microblaze-*-*
370 Xilinx MicroBlaze microblaze
373 * Multi-program debugging.
375 GDB now has support for multi-program (a.k.a. multi-executable or
376 multi-exec) debugging. This allows for debugging multiple inferiors
377 simultaneously each running a different program under the same GDB
378 session. See "Debugging Multiple Inferiors and Programs" in the
379 manual for more information. This implied some user visible changes
380 in the multi-inferior support. For example, "info inferiors" now
381 lists inferiors that are not running yet or that have exited
382 already. See also "New commands" and "New options" below.
384 * New tracing features
386 GDB's tracepoint facility now includes several new features:
388 ** Trace state variables
390 GDB tracepoints now include support for trace state variables, which
391 are variables managed by the target agent during a tracing
392 experiment. They are useful for tracepoints that trigger each
393 other, so for instance one tracepoint can count hits in a variable,
394 and then a second tracepoint has a condition that is true when the
395 count reaches a particular value. Trace state variables share the
396 $-syntax of GDB convenience variables, and can appear in both
397 tracepoint actions and condition expressions. Use the "tvariable"
398 command to create, and "info tvariables" to view; see "Trace State
399 Variables" in the manual for more detail.
403 GDB now includes an option for defining fast tracepoints, which
404 targets may implement more efficiently, such as by installing a jump
405 into the target agent rather than a trap instruction. The resulting
406 speedup can be by two orders of magnitude or more, although the
407 tradeoff is that some program locations on some target architectures
408 might not allow fast tracepoint installation, for instance if the
409 instruction to be replaced is shorter than the jump. To request a
410 fast tracepoint, use the "ftrace" command, with syntax identical to
411 the regular trace command.
413 ** Disconnected tracing
415 It is now possible to detach GDB from the target while it is running
416 a trace experiment, then reconnect later to see how the experiment
417 is going. In addition, a new variable disconnected-tracing lets you
418 tell the target agent whether to continue running a trace if the
419 connection is lost unexpectedly.
423 GDB now has the ability to save the trace buffer into a file, and
424 then use that file as a target, similarly to you can do with
425 corefiles. You can select trace frames, print data that was
426 collected in them, and use tstatus to display the state of the
427 tracing run at the moment that it was saved. To create a trace
428 file, use "tsave <filename>", and to use it, do "target tfile
431 ** Circular trace buffer
433 You can ask the target agent to handle the trace buffer as a
434 circular buffer, discarding the oldest trace frames to make room for
435 newer ones, by setting circular-trace-buffer to on. This feature may
436 not be available for all target agents.
441 The disassemble command, when invoked with two arguments, now requires
442 the arguments to be comma-separated.
445 The info variables command now displays variable definitions. Files
446 which only declare a variable are not shown.
449 The source command is now capable of sourcing Python scripts.
450 This feature is dependent on the debugger being build with Python
453 Related to this enhancement is also the introduction of a new command
454 "set script-extension" (see below).
456 * New commands (for set/show, see "New options" below)
458 record save [<FILENAME>]
459 Save a file (in core file format) containing the process record
460 execution log for replay debugging at a later time.
462 record restore <FILENAME>
463 Restore the process record execution log that was saved at an
464 earlier time, for replay debugging.
466 add-inferior [-copies <N>] [-exec <FILENAME>]
469 clone-inferior [-copies <N>] [ID]
470 Make a new inferior ready to execute the same program another
476 maint info program-spaces
477 List the program spaces loaded into GDB.
479 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
480 show remote interrupt-sequence
481 Allow the user to select one of ^C, a BREAK signal or BREAK-g
482 as the sequence to the remote target in order to interrupt the execution.
483 Ctrl-C is a default. Some system prefers BREAK which is high level of
484 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
485 Magic SysRq g. It is BREAK signal and character 'g'.
487 set remote interrupt-on-connect [on | off]
488 show remote interrupt-on-connect
489 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
490 remote target when gdb connects to it. This is needed when you debug
493 set remotebreak [on | off]
495 Deprecated. Use "set/show remote interrupt-sequence" instead.
497 tvariable $NAME [ = EXP ]
498 Create or modify a trace state variable.
501 List trace state variables and their values.
503 delete tvariable $NAME ...
504 Delete one or more trace state variables.
507 Evaluate the given expressions without collecting anything into the
508 trace buffer. (Valid in tracepoint actions only.)
510 ftrace FN / FILE:LINE / *ADDR
511 Define a fast tracepoint at the given function, line, or address.
513 * New expression syntax
515 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
516 GDB now parses 0b101010 identically with 42.
520 set follow-exec-mode new|same
521 show follow-exec-mode
522 Control whether GDB reuses the same inferior across an exec call or
523 creates a new one. This is useful to be able to restart the old
524 executable after the inferior having done an exec call.
526 set default-collect EXPR, ...
528 Define a list of expressions to be collected at each tracepoint.
529 This is a useful way to ensure essential items are not overlooked,
530 such as registers or a critical global variable.
532 set disconnected-tracing
533 show disconnected-tracing
534 If set to 1, the target is instructed to continue tracing if it
535 loses its connection to GDB. If 0, the target is to stop tracing
538 set circular-trace-buffer
539 show circular-trace-buffer
540 If set to on, the target is instructed to use a circular trace buffer
541 and discard the oldest trace frames instead of stopping the trace due
542 to a full trace buffer. If set to off, the trace stops when the buffer
543 fills up. Some targets may not support this.
545 set script-extension off|soft|strict
546 show script-extension
547 If set to "off", the debugger does not perform any script language
548 recognition, and all sourced files are assumed to be GDB scripts.
549 If set to "soft" (the default), files are sourced according to
550 filename extension, falling back to GDB scripts if the first
552 If set to "strict", files are sourced according to filename extension.
554 set ada trust-PAD-over-XVS on|off
555 show ada trust-PAD-over-XVS
556 If off, activate a workaround against a bug in the debugging information
557 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
558 the GCC sources for more information about the GNAT encoding and
559 PAD types in particular). It is always safe to set this option to
560 off, but this introduces a slight performance penalty. The default
563 * Python API Improvements
565 ** GDB provides the new class gdb.LazyString. This is useful in
566 some pretty-printing cases. The new method gdb.Value.lazy_string
567 provides a simple way to create objects of this type.
569 ** The fields returned by gdb.Type.fields now have an
570 `is_base_class' attribute.
572 ** The new method gdb.Type.range returns the range of an array type.
574 ** The new method gdb.parse_and_eval can be used to parse and
575 evaluate an expression.
580 Define a trace state variable.
583 Get the current value of a trace state variable.
586 Set desired tracing behavior upon disconnection.
589 Set the trace buffer to be linear or circular.
592 Get data about the tracepoints currently in use.
596 Process record now works correctly with hardware watchpoints.
598 Multiple bug fixes have been made to the mips-irix port, making it
599 much more reliable. In particular:
600 - Debugging threaded applications is now possible again. Previously,
601 GDB would hang while starting the program, or while waiting for
602 the program to stop at a breakpoint.
603 - Attaching to a running process no longer hangs.
604 - An error occurring while loading a core file has been fixed.
605 - Changing the value of the PC register now works again. This fixes
606 problems observed when using the "jump" command, or when calling
607 a function from GDB, or even when assigning a new value to $pc.
608 - With the "finish" and "return" commands, the return value for functions
609 returning a small array is now correctly printed.
610 - It is now possible to break on shared library code which gets executed
611 during a shared library init phase (code executed while executing
612 their .init section). Previously, the breakpoint would have no effect.
613 - GDB is now able to backtrace through the signal handler for
614 non-threaded programs.
616 PIE (Position Independent Executable) programs debugging is now supported.
617 This includes debugging execution of PIC (Position Independent Code) shared
618 libraries although for that, it should be possible to run such libraries as an
621 *** Changes in GDB 7.0
623 * GDB now has an interface for JIT compilation. Applications that
624 dynamically generate code can create symbol files in memory and register
625 them with GDB. For users, the feature should work transparently, and
626 for JIT developers, the interface is documented in the GDB manual in the
627 "JIT Compilation Interface" chapter.
629 * Tracepoints may now be conditional. The syntax is as for
630 breakpoints; either an "if" clause appended to the "trace" command,
631 or the "condition" command is available. GDB sends the condition to
632 the target for evaluation using the same bytecode format as is used
633 for tracepoint actions.
635 * The disassemble command now supports: an optional /r modifier, print the
636 raw instructions in hex as well as in symbolic form, and an optional /m
637 modifier to print mixed source+assembly.
639 * Process record and replay
641 In a architecture environment that supports ``process record and
642 replay'', ``process record and replay'' target can record a log of
643 the process execution, and replay it with both forward and reverse
646 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
647 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
648 set execution-direction {forward|reverse}, for targets that support
651 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
652 feature is available with a native GDB running on kernel version
655 * GDB now has support for multi-byte and wide character sets on the
656 target. Strings whose character type is wchar_t, char16_t, or
657 char32_t are now correctly printed. GDB supports wide- and unicode-
658 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
659 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
660 `printf'. This feature requires iconv to work properly; if your
661 system does not have a working iconv, GDB can use GNU libiconv. See
662 the installation instructions for more information.
664 * GDB now supports automatic retrieval of shared library files from
665 remote targets. To use this feature, specify a system root that begins
666 with the `remote:' prefix, either via the `set sysroot' command or via
667 the `--with-sysroot' configure-time option.
669 * "info sharedlibrary" now takes an optional regex of libraries to show,
670 and it now reports if a shared library has no debugging information.
672 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
673 now complete on file names.
675 * When completing in expressions, gdb will attempt to limit
676 completions to allowable structure or union fields, where appropriate.
677 For instance, consider:
679 # struct example { int f1; double f2; };
680 # struct example variable;
683 If the user types TAB at the end of this command line, the available
684 completions will be "f1" and "f2".
686 * Inlined functions are now supported. They show up in backtraces, and
687 the "step", "next", and "finish" commands handle them automatically.
689 * GDB now supports the token-splicing (##) and stringification (#)
690 operators when expanding macros. It also supports variable-arity
693 * GDB now supports inspecting extra signal information, exported by
694 the new $_siginfo convenience variable. The feature is currently
695 implemented on linux ARM, i386 and amd64.
697 * GDB can now display the VFP floating point registers and NEON vector
698 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
699 can provide these registers (requires Linux 2.6.30 or later). Remote
700 and simulator targets may also provide them.
705 Search memory for a sequence of bytes.
708 Turn off `+'/`-' protocol acknowledgments to permit more efficient
709 operation over reliable transport links. Use of this packet is
710 controlled by the `set remote noack-packet' command.
713 Kill the process with the specified process ID. Use this in preference
714 to `k' when multiprocess protocol extensions are supported.
717 Obtains additional operating system information
721 Read or write additional signal information.
723 * Removed remote protocol undocumented extension
725 An undocumented extension to the remote protocol's `S' stop reply
726 packet that permited the stub to pass a process id was removed.
727 Remote servers should use the `T' stop reply packet instead.
729 * GDB now supports multiple function calling conventions according to the
730 DWARF-2 DW_AT_calling_convention function attribute.
732 * The SH target utilizes the aforementioned change to distinguish between gcc
733 and Renesas calling convention. It also adds the new CLI commands
734 `set/show sh calling-convention'.
736 * GDB can now read compressed debug sections, as produced by GNU gold
737 with the --compress-debug-sections=zlib flag.
739 * 64-bit core files are now supported on AIX.
741 * Thread switching is now supported on Tru64.
743 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
744 which will be allocated using malloc later in program execution.
746 * The qXfer:libraries:read remote procotol packet now allows passing a
747 list of section offsets.
749 * On GNU/Linux, GDB can now attach to stopped processes. Several race
750 conditions handling signals delivered during attach or thread creation
751 have also been fixed.
753 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
754 From the user's standpoint, all unqualified instances of True and False
755 are treated as the standard definitions, regardless of context.
757 * GDB now parses C++ symbol and type names more flexibly. For
760 template<typename T> class C { };
763 GDB will now correctly handle all of:
765 ptype C<char const *>
767 ptype C<const char *>
770 * New features in the GDB remote stub, gdbserver
772 - The "--wrapper" command-line argument tells gdbserver to use a
773 wrapper program to launch programs for debugging.
775 - On PowerPC and S/390 targets, it is now possible to use a single
776 gdbserver executable to debug both 32-bit and 64-bit programs.
777 (This requires gdbserver itself to be built as a 64-bit executable.)
779 - gdbserver uses the new noack protocol mode for TCP connections to
780 reduce communications latency, if also supported and enabled in GDB.
782 - Support for the sparc64-linux-gnu target is now included in
785 - The amd64-linux build of gdbserver now supports debugging both
786 32-bit and 64-bit programs.
788 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
789 now support hardware watchpoints, and will use them automatically
794 GDB now has support for scripting using Python. Whether this is
795 available is determined at configure time.
797 New GDB commands can now be written in Python.
799 * Ada tasking support
801 Ada tasks can now be inspected in GDB. The following commands have
805 Print the list of Ada tasks.
807 Print detailed information about task number N.
809 Print the task number of the current task.
811 Switch the context of debugging to task number N.
813 * Support for user-defined prefixed commands. The "define" command can
814 add new commands to existing prefixes, e.g. "target".
816 * Multi-inferior, multi-process debugging.
818 GDB now has generalized support for multi-inferior debugging. See
819 "Debugging Multiple Inferiors" in the manual for more information.
820 Although availability still depends on target support, the command
821 set is more uniform now. The GNU/Linux specific multi-forks support
822 has been migrated to this new framework. This implied some user
823 visible changes; see "New commands" and also "Removed commands"
826 * Target descriptions can now describe the target OS ABI. See the
827 "Target Description Format" section in the user manual for more
830 * Target descriptions can now describe "compatible" architectures
831 to indicate that the target can execute applications for a different
832 architecture in addition to those for the main target architecture.
833 See the "Target Description Format" section in the user manual for
836 * Multi-architecture debugging.
838 GDB now includes general supports for debugging applications on
839 hybrid systems that use more than one single processor architecture
840 at the same time. Each such hybrid architecture still requires
841 specific support to be added. The only hybrid architecture supported
842 in this version of GDB is the Cell Broadband Engine.
844 * GDB now supports integrated debugging of Cell/B.E. applications that
845 use both the PPU and SPU architectures. To enable support for hybrid
846 Cell/B.E. debugging, you need to configure GDB to support both the
847 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
848 --enable-targets configure option.
850 * Non-stop mode debugging.
852 For some targets, GDB now supports an optional mode of operation in
853 which you can examine stopped threads while other threads continue
854 to execute freely. This is referred to as non-stop mode, with the
855 old mode referred to as all-stop mode. See the "Non-Stop Mode"
856 section in the user manual for more information.
858 To be able to support remote non-stop debugging, a remote stub needs
859 to implement the non-stop mode remote protocol extensions, as
860 described in the "Remote Non-Stop" section of the user manual. The
861 GDB remote stub, gdbserver, has been adjusted to support these
862 extensions on linux targets.
864 * New commands (for set/show, see "New options" below)
866 catch syscall [NAME(S) | NUMBER(S)]
867 Catch system calls. Arguments, which should be names of system
868 calls or their numbers, mean catch only those syscalls. Without
869 arguments, every syscall will be caught. When the inferior issues
870 any of the specified syscalls, GDB will stop and announce the system
871 call, both when it is called and when its call returns. This
872 feature is currently available with a native GDB running on the
873 Linux Kernel, under the following architectures: x86, x86_64,
874 PowerPC and PowerPC64.
876 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
878 Search memory for a sequence of bytes.
880 maint set python print-stack
881 maint show python print-stack
882 Show a stack trace when an error is encountered in a Python script.
885 Invoke CODE by passing it to the Python interpreter.
890 These allow macros to be defined, undefined, and listed
894 Show operating system information about processes.
897 List the inferiors currently under GDB's control.
900 Switch focus to inferior number NUM.
903 Detach from inferior number NUM.
906 Kill inferior number NUM.
911 show spu stop-on-load
912 Control whether to stop for new SPE threads during Cell/B.E. debugging.
914 set spu auto-flush-cache
915 show spu auto-flush-cache
916 Control whether to automatically flush the software-managed cache
917 during Cell/B.E. debugging.
919 set sh calling-convention
920 show sh calling-convention
921 Control the calling convention used when calling SH target functions.
925 Control display of timestamps with GDB debugging output.
927 set disassemble-next-line
928 show disassemble-next-line
929 Control display of disassembled source lines or instructions when
932 set remote noack-packet
933 show remote noack-packet
934 Set/show the use of remote protocol QStartNoAckMode packet. See above
935 under "New remote packets."
937 set remote query-attached-packet
938 show remote query-attached-packet
939 Control use of remote protocol `qAttached' (query-attached) packet.
941 set remote read-siginfo-object
942 show remote read-siginfo-object
943 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
946 set remote write-siginfo-object
947 show remote write-siginfo-object
948 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
951 set remote reverse-continue
952 show remote reverse-continue
953 Control use of remote protocol 'bc' (reverse-continue) packet.
955 set remote reverse-step
956 show remote reverse-step
957 Control use of remote protocol 'bs' (reverse-step) packet.
959 set displaced-stepping
960 show displaced-stepping
961 Control displaced stepping mode. Displaced stepping is a way to
962 single-step over breakpoints without removing them from the debuggee.
963 Also known as "out-of-line single-stepping".
967 Control display of debugging info for displaced stepping.
969 maint set internal-error
970 maint show internal-error
971 Control what GDB does when an internal error is detected.
973 maint set internal-warning
974 maint show internal-warning
975 Control what GDB does when an internal warning is detected.
980 Use a wrapper program to launch programs for debugging.
982 set multiple-symbols (all|ask|cancel)
983 show multiple-symbols
984 The value of this variable can be changed to adjust the debugger behavior
985 when an expression or a breakpoint location contains an ambiguous symbol
986 name (an overloaded function name, for instance).
988 set breakpoint always-inserted
989 show breakpoint always-inserted
990 Keep breakpoints always inserted in the target, as opposed to inserting
991 them when resuming the target, and removing them when the target stops.
992 This option can improve debugger performance on slow remote targets.
994 set arm fallback-mode (arm|thumb|auto)
995 show arm fallback-mode
996 set arm force-mode (arm|thumb|auto)
998 These commands control how ARM GDB determines whether instructions
999 are ARM or Thumb. The default for both settings is auto, which uses
1000 the current CPSR value for instructions without symbols; previous
1001 versions of GDB behaved as if "set arm fallback-mode arm".
1003 set disable-randomization
1004 show disable-randomization
1005 Standalone programs run with the virtual address space randomization enabled
1006 by default on some platforms. This option keeps the addresses stable across
1007 multiple debugging sessions.
1011 Control whether other threads are stopped or not when some thread hits
1016 Requests that asynchronous execution is enabled in the target, if available.
1017 In this case, it's possible to resume target in the background, and interact
1018 with GDB while the target is running. "show target-async" displays the
1019 current state of asynchronous execution of the target.
1021 set target-wide-charset
1022 show target-wide-charset
1023 The target-wide-charset is the name of the character set that GDB
1024 uses when printing characters whose type is wchar_t.
1026 set tcp auto-retry (on|off)
1028 set tcp connect-timeout
1029 show tcp connect-timeout
1030 These commands allow GDB to retry failed TCP connections to a remote stub
1031 with a specified timeout period; this is useful if the stub is launched
1032 in parallel with GDB but may not be ready to accept connections immediately.
1034 set libthread-db-search-path
1035 show libthread-db-search-path
1036 Control list of directories which GDB will search for appropriate
1039 set schedule-multiple (on|off)
1040 show schedule-multiple
1041 Allow GDB to resume all threads of all processes or only threads of
1042 the current process.
1046 Use more aggressive caching for accesses to the stack. This improves
1047 performance of remote debugging (particularly backtraces) without
1048 affecting correctness.
1050 set interactive-mode (on|off|auto)
1051 show interactive-mode
1052 Control whether GDB runs in interactive mode (on) or not (off).
1053 When in interactive mode, GDB waits for the user to answer all
1054 queries. Otherwise, GDB does not wait and assumes the default
1055 answer. When set to auto (the default), GDB determines which
1056 mode to use based on the stdin settings.
1061 For program forks, this is replaced by the new more generic `info
1062 inferiors' command. To list checkpoints, you can still use the
1063 `info checkpoints' command, which was an alias for the `info forks'
1067 Replaced by the new `inferior' command. To switch between
1068 checkpoints, you can still use the `restart' command, which was an
1069 alias for the `fork' command.
1072 This is removed, since some targets don't have a notion of
1073 processes. To switch between processes, you can still use the
1074 `inferior' command using GDB's own inferior number.
1077 For program forks, this is replaced by the new more generic `kill
1078 inferior' command. To delete a checkpoint, you can still use the
1079 `delete checkpoint' command, which was an alias for the `delete
1083 For program forks, this is replaced by the new more generic `detach
1084 inferior' command. To detach a checkpoint, you can still use the
1085 `detach checkpoint' command, which was an alias for the `detach
1088 * New native configurations
1090 x86/x86_64 Darwin i[34567]86-*-darwin*
1092 x86_64 MinGW x86_64-*-mingw*
1096 Lattice Mico32 lm32-*
1097 x86 DICOS i[34567]86-*-dicos*
1098 x86_64 DICOS x86_64-*-dicos*
1101 * The GDB remote stub, gdbserver, now supports x86 Windows CE
1102 (mingw32ce) debugging.
1108 These commands were actually not implemented on any target.
1110 *** Changes in GDB 6.8
1112 * New native configurations
1114 NetBSD/hppa hppa*-*netbsd*
1115 Xtensa GNU/Linux xtensa*-*-linux*
1119 NetBSD/hppa hppa*-*-netbsd*
1120 Xtensa GNU/Lunux xtensa*-*-linux*
1122 * Change in command line behavior -- corefiles vs. process ids.
1124 When the '-p NUMBER' or '--pid NUMBER' options are used, and
1125 attaching to process NUMBER fails, GDB no longer attempts to open a
1126 core file named NUMBER. Attaching to a program using the -c option
1127 is no longer supported. Instead, use the '-p' or '--pid' options.
1129 * GDB can now be built as a native debugger for debugging Windows x86
1130 (mingw32) Portable Executable (PE) programs.
1132 * Pending breakpoints no longer change their number when their address
1135 * GDB now supports breakpoints with multiple locations,
1136 including breakpoints on C++ constructors, inside C++ templates,
1137 and in inlined functions.
1139 * GDB's ability to debug optimized code has been improved. GDB more
1140 accurately identifies function bodies and lexical blocks that occupy
1141 more than one contiguous range of addresses.
1143 * Target descriptions can now describe registers for PowerPC.
1145 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
1146 registers on PowerPC targets.
1148 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
1149 targets even when the libthread_db library is not available.
1151 * The GDB remote stub, gdbserver, now supports the new file transfer
1152 commands (remote put, remote get, and remote delete).
1154 * The GDB remote stub, gdbserver, now supports run and attach in
1155 extended-remote mode.
1157 * hppa*64*-*-hpux11* target broken
1158 The debugger is unable to start a program and fails with the following
1159 error: "Error trying to get information about dynamic linker".
1160 The gdb-6.7 release is also affected.
1162 * GDB now supports the --enable-targets= configure option to allow
1163 building a single GDB executable that supports multiple remote
1164 target architectures.
1166 * GDB now supports debugging C and C++ programs which use the
1167 Decimal Floating Point extension. In addition, the PowerPC target
1168 now has a set of pseudo-registers to inspect decimal float values
1169 stored in two consecutive float registers.
1171 * The -break-insert MI command can optionally create pending
1174 * Improved support for debugging Ada
1175 Many improvements to the Ada language support have been made. These
1177 - Better support for Ada2005 interface types
1178 - Improved handling of arrays and slices in general
1179 - Better support for Taft-amendment types
1180 - The '{type} ADDRESS' expression is now allowed on the left hand-side
1182 - Improved command completion in Ada
1185 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
1190 set print frame-arguments (all|scalars|none)
1191 show print frame-arguments
1192 The value of this variable can be changed to control which argument
1193 values should be printed by the debugger when displaying a frame.
1198 Transfer files to and from a remote target, and delete remote files.
1205 Transfer files to and from a remote target, and delete remote files.
1207 * New remote packets
1214 Open, close, read, write, and delete files on the remote system.
1217 Attach to an existing process on the remote system, in extended-remote
1221 Run a new process on the remote system, in extended-remote mode.
1223 *** Changes in GDB 6.7
1225 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
1226 bfd, libiberty and opcodes, as revealed by static analysis donated by
1227 Coverity, Inc. (http://scan.coverity.com).
1229 * When looking up multiply-defined global symbols, GDB will now prefer the
1230 symbol definition in the current shared library if it was built using the
1231 -Bsymbolic linker option.
1233 * When the Text User Interface (TUI) is not configured, GDB will now
1234 recognize the -tui command-line option and print a message that the TUI
1237 * The GDB remote stub, gdbserver, now has lower overhead for high
1238 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
1240 * GDB for MIPS targets now autodetects whether a remote target provides
1241 32-bit or 64-bit register values.
1243 * Support for C++ member pointers has been improved.
1245 * GDB now understands XML target descriptions, which specify the
1246 target's overall architecture. GDB can read a description from
1247 a local file or over the remote serial protocol.
1249 * Vectors of single-byte data use a new integer type which is not
1250 automatically displayed as character or string data.
1252 * The /s format now works with the print command. It displays
1253 arrays of single-byte integers and pointers to single-byte integers
1256 * Target descriptions can now describe target-specific registers,
1257 for architectures which have implemented the support (currently
1258 only ARM, M68K, and MIPS).
1260 * GDB and the GDB remote stub, gdbserver, now support the XScale
1263 * The GDB remote stub, gdbserver, has been updated to support
1264 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
1265 has been rewritten to use the standard GDB remote protocol.
1267 * GDB can now step into C++ functions which are called through thunks.
1269 * GDB for the Cell/B.E. SPU now supports overlay debugging.
1271 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
1272 layout. It also supports a TextSeg= and DataSeg= response when only
1273 segment base addresses (rather than offsets) are available.
1275 * The /i format now outputs any trailing branch delay slot instructions
1276 immediately following the last instruction within the count specified.
1278 * The GDB remote protocol "T" stop reply packet now supports a
1279 "library" response. Combined with the new "qXfer:libraries:read"
1280 packet, this response allows GDB to debug shared libraries on targets
1281 where the operating system manages the list of loaded libraries (e.g.
1282 Windows and SymbianOS).
1284 * The GDB remote stub, gdbserver, now supports dynamic link libraries
1285 (DLLs) on Windows and Windows CE targets.
1287 * GDB now supports a faster verification that a .debug file matches its binary
1288 according to its build-id signature, if the signature is present.
1294 Enable or disable hardware flow control (RTS/CTS) on the serial port
1295 when debugging using remote targets.
1297 set mem inaccessible-by-default
1298 show mem inaccessible-by-default
1299 If the target supplies a memory map, for instance via the remote
1300 protocol's "qXfer:memory-map:read" packet, setting this variable
1301 prevents GDB from accessing memory outside the memory map. This
1302 is useful for targets with memory mapped registers or which react
1303 badly to accesses of unmapped address space.
1305 set breakpoint auto-hw
1306 show breakpoint auto-hw
1307 If the target supplies a memory map, for instance via the remote
1308 protocol's "qXfer:memory-map:read" packet, setting this variable
1309 lets GDB use hardware breakpoints automatically for memory regions
1310 where it can not use software breakpoints. This covers both the
1311 "break" command and internal breakpoints used for other commands
1312 including "next" and "finish".
1315 catch exception unhandled
1316 Stop the program execution when Ada exceptions are raised.
1319 Stop the program execution when an Ada assertion failed.
1323 Set an alternate system root for target files. This is a more
1324 general version of "set solib-absolute-prefix", which is now
1325 an alias to "set sysroot".
1328 Provide extended SPU facility status information. This set of
1329 commands is available only when debugging the Cell/B.E. SPU
1332 * New native configurations
1334 OpenBSD/sh sh*-*openbsd*
1337 unset tdesc filename
1339 Use the specified local file as an XML target description, and do
1340 not query the target for its built-in description.
1344 OpenBSD/sh sh*-*-openbsd*
1345 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
1346 Toshiba Media Processor mep-elf
1348 * New remote packets
1351 Ignore the specified signals; pass them directly to the debugged program
1352 without stopping other threads or reporting them to GDB.
1354 qXfer:features:read:
1355 Read an XML target description from the target, which describes its
1360 Read or write contents of an spufs file on the target system. These
1361 packets are available only on the Cell/B.E. SPU architecture.
1363 qXfer:libraries:read:
1364 Report the loaded shared libraries. Combined with new "T" packet
1365 response, this packet allows GDB to debug shared libraries on
1366 targets where the operating system manages the list of loaded
1367 libraries (e.g. Windows and SymbianOS).
1371 Support for these obsolete configurations has been removed.
1379 i[34567]86-*-lynxos*
1380 i[34567]86-*-netware*
1381 i[34567]86-*-sco3.2v5*
1382 i[34567]86-*-sco3.2v4*
1384 i[34567]86-*-sysv4.2*
1387 i[34567]86-*-unixware2*
1388 i[34567]86-*-unixware*
1397 * Other removed features
1404 Various m68k-only ROM monitors.
1411 Various Renesas ROM monitors and debugging interfaces for SH and
1416 Support for a Macraigor serial interface to on-chip debugging.
1417 GDB does not directly support the newer parallel or USB
1422 A debug information format. The predecessor to DWARF 2 and
1423 DWARF 3, which are still supported.
1425 Support for the HP aCC compiler on HP-UX/PA-RISC
1427 SOM-encapsulated symbolic debugging information, automatic
1428 invocation of pxdb, and the aCC custom C++ ABI. This does not
1429 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
1430 with aCC can still be debugged on an assembly level.
1432 MIPS ".pdr" sections
1434 A MIPS-specific format used to describe stack frame layout
1435 in debugging information.
1439 GDB could work with an older version of Guile to debug
1440 the interpreter and Scheme programs running in it.
1442 set mips stack-arg-size
1443 set mips saved-gpreg-size
1445 Use "set mips abi" to control parameter passing for MIPS.
1447 *** Changes in GDB 6.6
1452 Cell Broadband Engine SPU spu-elf
1454 * GDB can now be configured as a cross-debugger targeting native Windows
1455 (mingw32) or Cygwin. It can communicate with a remote debugging stub
1456 running on a Windows system over TCP/IP to debug Windows programs.
1458 * The GDB remote stub, gdbserver, has been updated to support Windows and
1459 Cygwin debugging. Both single-threaded and multi-threaded programs are
1462 * The "set trust-readonly-sections" command works again. This command was
1463 broken in GDB 6.3, 6.4, and 6.5.
1465 * The "load" command now supports writing to flash memory, if the remote
1466 stub provides the required support.
1468 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
1469 longer requires symbolic debug information (e.g. DWARF-2).
1474 unset substitute-path
1475 show substitute-path
1476 Manage a list of substitution rules that GDB uses to rewrite the name
1477 of the directories where the sources are located. This can be useful
1478 for instance when the sources were moved to a different location
1479 between compilation and debugging.
1483 Print each CLI command as it is executed. Each command is prefixed with
1484 a number of `+' symbols representing the nesting depth.
1485 The source command now has a `-v' option to enable the same feature.
1489 The ARM Demon monitor support (RDP protocol, "target rdp").
1491 Kernel Object Display, an embedded debugging feature which only worked with
1492 an obsolete version of Cisco IOS.
1494 The 'set download-write-size' and 'show download-write-size' commands.
1496 * New remote packets
1499 Tell a stub about GDB client features, and request remote target features.
1500 The first feature implemented is PacketSize, which allows the target to
1501 specify the size of packets it can handle - to minimize the number of
1502 packets required and improve performance when connected to a remote
1506 Fetch an OS auxilliary vector from the remote stub. This packet is a
1507 more efficient replacement for qPart:auxv:read.
1509 qXfer:memory-map:read:
1510 Fetch a memory map from the remote stub, including information about
1511 RAM, ROM, and flash memory devices.
1516 Erase and program a flash memory device.
1518 * Removed remote packets
1521 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
1522 used it, and only gdbserver implemented it.
1524 *** Changes in GDB 6.5
1528 Renesas M32C/M16C m32c-elf
1530 Morpho Technologies ms1 ms1-elf
1534 init-if-undefined Initialize a convenience variable, but
1535 only if it doesn't already have a value.
1537 The following commands are presently only implemented for native GNU/Linux:
1539 checkpoint Save a snapshot of the program state.
1541 restart <n> Return the program state to a
1542 previously saved state.
1544 info checkpoints List currently saved checkpoints.
1546 delete-checkpoint <n> Delete a previously saved checkpoint.
1548 set|show detach-on-fork Tell gdb whether to detach from a newly
1549 forked process, or to keep debugging it.
1551 info forks List forks of the user program that
1552 are available to be debugged.
1554 fork <n> Switch to debugging one of several
1555 forks of the user program that are
1556 available to be debugged.
1558 delete-fork <n> Delete a fork from the list of forks
1559 that are available to be debugged (and
1560 kill the forked process).
1562 detach-fork <n> Delete a fork from the list of forks
1563 that are available to be debugged (and
1564 allow the process to continue).
1568 Morpho Technologies ms2 ms1-elf
1570 * Improved Windows host support
1572 GDB now builds as a cross debugger hosted on i686-mingw32, including
1573 native console support, and remote communications using either
1574 network sockets or serial ports.
1576 * Improved Modula-2 language support
1578 GDB can now print most types in the Modula-2 syntax. This includes:
1579 basic types, set types, record types, enumerated types, range types,
1580 pointer types and ARRAY types. Procedure var parameters are correctly
1581 printed and hexadecimal addresses and character constants are also
1582 written in the Modula-2 syntax. Best results can be obtained by using
1583 GNU Modula-2 together with the -gdwarf-2 command line option.
1587 The ARM rdi-share module.
1589 The Netware NLM debug server.
1591 *** Changes in GDB 6.4
1593 * New native configurations
1595 OpenBSD/arm arm*-*-openbsd*
1596 OpenBSD/mips64 mips64-*-openbsd*
1600 Morpho Technologies ms1 ms1-elf
1602 * New command line options
1604 --batch-silent As for --batch, but totally silent.
1605 --return-child-result The debugger will exist with the same value
1606 the child (debugged) program exited with.
1607 --eval-command COMMAND, -ex COMMAND
1608 Execute a single GDB CLI command. This may be
1609 specified multiple times and in conjunction
1610 with the --command (-x) option.
1612 * Deprecated commands removed
1614 The following commands, that were deprecated in 2000, have been
1618 set|show arm disassembly-flavor set|show arm disassembler
1619 othernames set arm disassembler
1620 set|show remotedebug set|show debug remote
1621 set|show archdebug set|show debug arch
1622 set|show eventdebug set|show debug event
1625 * New BSD user-level threads support
1627 It is now possible to debug programs using the user-level threads
1628 library on OpenBSD and FreeBSD. Currently supported (target)
1631 FreeBSD/amd64 x86_64-*-freebsd*
1632 FreeBSD/i386 i386-*-freebsd*
1633 OpenBSD/i386 i386-*-openbsd*
1635 Note that the new kernel threads libraries introduced in FreeBSD 5.x
1636 are not yet supported.
1638 * New support for Matsushita MN10300 w/sim added
1639 (Work in progress). mn10300-elf.
1641 * REMOVED configurations and files
1643 VxWorks and the XDR protocol *-*-vxworks
1644 Motorola MCORE mcore-*-*
1645 National Semiconductor NS32000 ns32k-*-*
1647 * New "set print array-indexes" command
1649 After turning this setting "on", GDB prints the index of each element
1650 when displaying arrays. The default is "off" to preserve the previous
1653 * VAX floating point support
1655 GDB now supports the not-quite-ieee VAX F and D floating point formats.
1657 * User-defined command support
1659 In addition to using $arg0..$arg9 for argument passing, it is now possible
1660 to use $argc to determine now many arguments have been passed. See the
1661 section on user-defined commands in the user manual for more information.
1663 *** Changes in GDB 6.3:
1665 * New command line option
1667 GDB now accepts -l followed by a number to set the timeout for remote
1670 * GDB works with GCC -feliminate-dwarf2-dups
1672 GDB now supports a more compact representation of DWARF-2 debug
1673 information using DW_FORM_ref_addr references. These are produced
1674 by GCC with the option -feliminate-dwarf2-dups and also by some
1675 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
1676 to use -feliminate-dwarf2-dups.
1678 * Internationalization
1680 When supported by the host system, GDB will be built with
1681 internationalization (libintl). The task of marking up the sources is
1682 continued, we're looking forward to our first translation.
1686 Initial support for debugging programs compiled with the GNAT
1687 implementation of the Ada programming language has been integrated
1688 into GDB. In this release, support is limited to expression evaluation.
1690 * New native configurations
1692 GNU/Linux/m32r m32r-*-linux-gnu
1696 GDB's remote protocol now includes support for the 'p' packet. This
1697 packet is used to fetch individual registers from a remote inferior.
1699 * END-OF-LIFE registers[] compatibility module
1701 GDB's internal register infrastructure has been completely rewritten.
1702 The new infrastructure making possible the implementation of key new
1703 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
1706 GDB 6.3 will be the last release to include the the registers[]
1707 compatibility module that allowed out-of-date configurations to
1708 continue to work. This change directly impacts the following
1718 powerpc bdm protocol
1720 Unless there is activity to revive these configurations, they will be
1721 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
1723 * OBSOLETE configurations and files
1725 Configurations that have been declared obsolete in this release have
1726 been commented out. Unless there is activity to revive these
1727 configurations, the next release of GDB will have their sources
1728 permanently REMOVED.
1737 *** Changes in GDB 6.2.1:
1739 * MIPS `break main; run' gave an heuristic-fence-post warning
1741 When attempting to run even a simple program, a warning about
1742 heuristic-fence-post being hit would be reported. This problem has
1745 * MIPS IRIX 'long double' crashed GDB
1747 When examining a long double variable, GDB would get a segmentation
1748 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
1749 IRIX long double values).
1753 A bug in the VAX stack code was causing problems with the "next"
1754 command. This problem has been fixed.
1756 *** Changes in GDB 6.2:
1758 * Fix for ``many threads''
1760 On GNU/Linux systems that use the NPTL threads library, a program
1761 rapidly creating and deleting threads would confuse GDB leading to the
1764 ptrace: No such process.
1765 thread_db_get_info: cannot get thread info: generic error
1767 This problem has been fixed.
1769 * "-async" and "-noasync" options removed.
1771 Support for the broken "-noasync" option has been removed (it caused
1774 * New ``start'' command.
1776 This command runs the program until the begining of the main procedure.
1778 * New BSD Kernel Data Access Library (libkvm) interface
1780 Using ``target kvm'' it is now possible to debug kernel core dumps and
1781 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
1782 platforms. Currently supported (native-only) configurations are:
1784 FreeBSD/amd64 x86_64-*-freebsd*
1785 FreeBSD/i386 i?86-*-freebsd*
1786 NetBSD/i386 i?86-*-netbsd*
1787 NetBSD/m68k m68*-*-netbsd*
1788 NetBSD/sparc sparc-*-netbsd*
1789 OpenBSD/amd64 x86_64-*-openbsd*
1790 OpenBSD/i386 i?86-*-openbsd*
1791 OpenBSD/m68k m68*-openbsd*
1792 OpenBSD/sparc sparc-*-openbsd*
1794 * Signal trampoline code overhauled
1796 Many generic problems with GDB's signal handling code have been fixed.
1797 These include: backtraces through non-contiguous stacks; recognition
1798 of sa_sigaction signal trampolines; backtrace from a NULL pointer
1799 call; backtrace through a signal trampoline; step into and out of
1800 signal handlers; and single-stepping in the signal trampoline.
1802 Please note that kernel bugs are a limiting factor here. These
1803 features have been shown to work on an s390 GNU/Linux system that
1804 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
1806 * Cygwin support for DWARF 2 added.
1808 * New native configurations
1810 GNU/Linux/hppa hppa*-*-linux*
1811 OpenBSD/hppa hppa*-*-openbsd*
1812 OpenBSD/m68k m68*-*-openbsd*
1813 OpenBSD/m88k m88*-*-openbsd*
1814 OpenBSD/powerpc powerpc-*-openbsd*
1815 NetBSD/vax vax-*-netbsd*
1816 OpenBSD/vax vax-*-openbsd*
1818 * END-OF-LIFE frame compatibility module
1820 GDB's internal frame infrastructure has been completely rewritten.
1821 The new infrastructure making it possible to support key new features
1822 including DWARF 2 Call Frame Information. To aid in the task of
1823 migrating old configurations to this new infrastructure, a
1824 compatibility module, that allowed old configurations to continue to
1825 work, was also included.
1827 GDB 6.2 will be the last release to include this frame compatibility
1828 module. This change directly impacts the following configurations:
1838 Unless there is activity to revive these configurations, they will be
1839 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
1841 * REMOVED configurations and files
1843 Sun 3, running SunOS 3 m68*-*-sunos3*
1844 Sun 3, running SunOS 4 m68*-*-sunos4*
1845 Sun 2, running SunOS 3 m68000-*-sunos3*
1846 Sun 2, running SunOS 4 m68000-*-sunos4*
1847 Motorola 680x0 running LynxOS m68*-*-lynxos*
1848 AT&T 3b1/Unix pc m68*-att-*
1849 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
1850 decstation mips-dec-* mips-little-*
1851 riscos mips-*-riscos* mips-*-sysv*
1852 sonymips mips-sony-*
1853 sysv mips*-*-sysv4* (IRIX 5/6 not included)
1855 *** Changes in GDB 6.1.1:
1857 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
1859 The TUI (Text-mode User Interface) is now built as part of a default
1860 GDB configuration. It is enabled by either selecting the TUI with the
1861 command line option "-i=tui" or by running the separate "gdbtui"
1862 program. For more information on the TUI, see the manual "Debugging
1865 * Pending breakpoint support (also included in GDB 6.1)
1867 Support has been added to allow you to specify breakpoints in shared
1868 libraries that have not yet been loaded. If a breakpoint location
1869 cannot be found, and the "breakpoint pending" option is set to auto,
1870 GDB queries you if you wish to make the breakpoint pending on a future
1871 shared-library load. If and when GDB resolves the breakpoint symbol,
1872 the pending breakpoint is removed as one or more regular breakpoints
1875 Pending breakpoints are very useful for GCJ Java debugging.
1877 * Fixed ISO-C build problems
1879 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
1880 non ISO-C code that stopped them being built using a more strict ISO-C
1881 compiler (e.g., IBM's C compiler).
1883 * Fixed build problem on IRIX 5
1885 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
1886 wasn't able to compile compile on an IRIX 5 system.
1888 * Added execute permission to gdb/gdbserver/configure
1890 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
1891 permission. This bug would cause configure to fail on a number of
1892 systems (Solaris, IRIX). Ref: server/519.
1894 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
1896 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
1897 has been updated to use constant array sizes.
1899 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
1901 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
1902 its generated DWARF Call Frame Info. This encoding was causing GDB to
1903 panic, that panic has been fixed. Ref: gdb/1628.
1905 * Fixed a problem when examining parameters in shared library code.
1907 When examining parameters in optimized shared library code generated
1908 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
1909 not available''. GDB now correctly displays the variable's value.
1911 *** Changes in GDB 6.1:
1913 * Removed --with-mmalloc
1915 Support for the mmalloc memory manager has been removed, as it
1916 conflicted with the internal gdb byte cache.
1918 * Changes in AMD64 configurations
1920 The AMD64 target now includes the %cs and %ss registers. As a result
1921 the AMD64 remote protocol has changed; this affects the floating-point
1922 and SSE registers. If you rely on those registers for your debugging,
1923 you should upgrade gdbserver on the remote side.
1925 * Revised SPARC target
1927 The SPARC target has been completely revised, incorporating the
1928 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
1929 support for LynxOS and SunOS 4 has been dropped. Calling functions
1930 from within GDB on operating systems with a non-executable stack
1931 (Solaris, OpenBSD) now works.
1935 GDB has a new C++ demangler which does a better job on the mangled
1936 names generated by current versions of g++. It also runs faster, so
1937 with this and other changes gdb should now start faster on large C++
1940 * DWARF 2 Location Expressions
1942 GDB support for location expressions has been extended to support function
1943 arguments and frame bases. Older versions of GDB could crash when they
1946 * C++ nested types and namespaces
1948 GDB's support for nested types and namespaces in C++ has been
1949 improved, especially if you use the DWARF 2 debugging format. (This
1950 is the default for recent versions of GCC on most platforms.)
1951 Specifically, if you have a class "Inner" defined within a class or
1952 namespace "Outer", then GDB realizes that the class's name is
1953 "Outer::Inner", not simply "Inner". This should greatly reduce the
1954 frequency of complaints about not finding RTTI symbols. In addition,
1955 if you are stopped at inside of a function defined within a namespace,
1956 GDB modifies its name lookup accordingly.
1958 * New native configurations
1960 NetBSD/amd64 x86_64-*-netbsd*
1961 OpenBSD/amd64 x86_64-*-openbsd*
1962 OpenBSD/alpha alpha*-*-openbsd*
1963 OpenBSD/sparc sparc-*-openbsd*
1964 OpenBSD/sparc64 sparc64-*-openbsd*
1966 * New debugging protocols
1968 M32R with SDI protocol m32r-*-elf*
1970 * "set prompt-escape-char" command deleted.
1972 The command "set prompt-escape-char" has been deleted. This command,
1973 and its very obscure effet on GDB's prompt, was never documented,
1974 tested, nor mentioned in the NEWS file.
1976 * OBSOLETE configurations and files
1978 Configurations that have been declared obsolete in this release have
1979 been commented out. Unless there is activity to revive these
1980 configurations, the next release of GDB will have their sources
1981 permanently REMOVED.
1983 Sun 3, running SunOS 3 m68*-*-sunos3*
1984 Sun 3, running SunOS 4 m68*-*-sunos4*
1985 Sun 2, running SunOS 3 m68000-*-sunos3*
1986 Sun 2, running SunOS 4 m68000-*-sunos4*
1987 Motorola 680x0 running LynxOS m68*-*-lynxos*
1988 AT&T 3b1/Unix pc m68*-att-*
1989 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
1990 decstation mips-dec-* mips-little-*
1991 riscos mips-*-riscos* mips-*-sysv*
1992 sonymips mips-sony-*
1993 sysv mips*-*-sysv4* (IRIX 5/6 not included)
1995 * REMOVED configurations and files
1997 SGI Irix-4.x mips-sgi-irix4 or iris4
1998 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
1999 Z8000 simulator z8k-zilog-none or z8ksim
2000 Matsushita MN10200 w/simulator mn10200-*-*
2001 H8/500 simulator h8500-hitachi-hms or h8500hms
2002 HP/PA running BSD hppa*-*-bsd*
2003 HP/PA running OSF/1 hppa*-*-osf*
2004 HP/PA Pro target hppa*-*-pro*
2005 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2006 386BSD i[3456]86-*-bsd*
2007 Sequent family i[3456]86-sequent-sysv4*
2008 i[3456]86-sequent-sysv*
2009 i[3456]86-sequent-bsd*
2010 SPARC running LynxOS sparc-*-lynxos*
2011 SPARC running SunOS 4 sparc-*-sunos4*
2012 Tsqware Sparclet sparclet-*-*
2013 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2015 *** Changes in GDB 6.0:
2019 Support for debugging the Objective-C programming language has been
2020 integrated into GDB.
2022 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
2024 DWARF 2's Call Frame Information makes available compiler generated
2025 information that more exactly describes the program's run-time stack.
2026 By using this information, GDB is able to provide more robust stack
2029 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
2030 have been updated to use a new backtrace mechanism which includes
2031 DWARF 2 CFI support.
2035 GDB's remote protocol has been extended to include support for hosted
2036 file I/O (where the remote target uses GDB's file system). See GDB's
2037 remote protocol documentation for details.
2039 * All targets using the new architecture framework.
2041 All of GDB's targets have been updated to use the new internal
2042 architecture framework. The way is now open for future GDB releases
2043 to include cross-architecture native debugging support (i386 on amd64,
2046 * GNU/Linux's Thread Local Storage (TLS)
2048 GDB now includes support for for the GNU/Linux implementation of
2049 per-thread variables.
2051 * GNU/Linux's Native POSIX Thread Library (NPTL)
2053 GDB's thread code has been updated to work with either the new
2054 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
2056 * Separate debug info.
2058 GDB, in conjunction with BINUTILS, now supports a mechanism for
2059 automatically loading debug information from a separate file. Instead
2060 of shipping full debug and non-debug versions of system libraries,
2061 system integrators can now instead ship just the stripped libraries
2062 and optional debug files.
2064 * DWARF 2 Location Expressions
2066 DWARF 2 Location Expressions allow the compiler to more completely
2067 describe the location of variables (even in optimized code) to the
2070 GDB now includes preliminary support for location expressions (support
2071 for DW_OP_piece is still missing).
2075 A number of long standing bugs that caused GDB to die while starting a
2076 Java application have been fixed. GDB's Java support is now
2077 considered "useable".
2079 * GNU/Linux support for fork, vfork, and exec.
2081 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
2082 commands are now implemented for GNU/Linux. They require a 2.5.x or later
2085 * GDB supports logging output to a file
2087 There are two new commands, "set logging" and "show logging", which can be
2088 used to capture GDB's output to a file.
2090 * The meaning of "detach" has changed for gdbserver
2092 The "detach" command will now resume the application, as documented. To
2093 disconnect from gdbserver and leave it stopped, use the new "disconnect"
2096 * d10v, m68hc11 `regs' command deprecated
2098 The `info registers' command has been updated so that it displays the
2099 registers using a format identical to the old `regs' command.
2103 A new command, "maint set profile on/off", has been added. This command can
2104 be used to enable or disable profiling while running GDB, to profile a
2105 session or a set of commands. In addition there is a new configure switch,
2106 "--enable-profiling", which will cause GDB to be compiled with profiling
2107 data, for more informative profiling results.
2109 * Default MI syntax changed to "mi2".
2111 The default MI (machine interface) syntax, enabled by the command line
2112 option "-i=mi", has been changed to "mi2". The previous MI syntax,
2113 "mi1", can be enabled by specifying the option "-i=mi1".
2115 Support for the original "mi0" syntax (included in GDB 5.0) has been
2118 Fix for gdb/192: removed extraneous space when displaying frame level.
2119 Fix for gdb/672: update changelist is now output in mi list format.
2120 Fix for gdb/702: a -var-assign that updates the value now shows up
2121 in a subsequent -var-update.
2123 * New native configurations.
2125 FreeBSD/amd64 x86_64-*-freebsd*
2127 * Multi-arched targets.
2129 HP/PA HPUX11 hppa*-*-hpux*
2130 Renesas M32R/D w/simulator m32r-*-elf*
2132 * OBSOLETE configurations and files
2134 Configurations that have been declared obsolete in this release have
2135 been commented out. Unless there is activity to revive these
2136 configurations, the next release of GDB will have their sources
2137 permanently REMOVED.
2139 Z8000 simulator z8k-zilog-none or z8ksim
2140 Matsushita MN10200 w/simulator mn10200-*-*
2141 H8/500 simulator h8500-hitachi-hms or h8500hms
2142 HP/PA running BSD hppa*-*-bsd*
2143 HP/PA running OSF/1 hppa*-*-osf*
2144 HP/PA Pro target hppa*-*-pro*
2145 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2146 Sequent family i[3456]86-sequent-sysv4*
2147 i[3456]86-sequent-sysv*
2148 i[3456]86-sequent-bsd*
2149 Tsqware Sparclet sparclet-*-*
2150 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2152 * REMOVED configurations and files
2155 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2156 IBM AIX PS/2 i[3456]86-*-aix
2157 i386 running Mach 3.0 i[3456]86-*-mach3*
2158 i386 running Mach i[3456]86-*-mach*
2159 i386 running OSF/1 i[3456]86-*osf1mk*
2160 HP/Apollo 68k Family m68*-apollo*-sysv*,
2162 m68*-hp-bsd*, m68*-hp-hpux*
2163 Argonaut Risc Chip (ARC) arc-*-*
2164 Mitsubishi D30V d30v-*-*
2165 Fujitsu FR30 fr30-*-elf*
2166 OS/9000 i[34]86-*-os9k
2167 I960 with MON960 i960-*-coff
2169 * MIPS $fp behavior changed
2171 The convenience variable $fp, for the MIPS, now consistently returns
2172 the address of the current frame's base. Previously, depending on the
2173 context, $fp could refer to either $sp or the current frame's base
2174 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
2175 The GNU Source-Level Debugger''.
2177 *** Changes in GDB 5.3:
2179 * GNU/Linux shared library multi-threaded performance improved.
2181 When debugging a multi-threaded application on GNU/Linux, GDB now uses
2182 `/proc', in preference to `ptrace' for memory reads. This may result
2183 in an improvement in the start-up time of multi-threaded, shared
2184 library applications when run under GDB. One GDB user writes: ``loads
2185 shared libs like mad''.
2187 * ``gdbserver'' now supports multi-threaded applications on some targets
2189 Support for debugging multi-threaded applications which use
2190 the GNU/Linux LinuxThreads package has been added for
2191 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
2192 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
2194 * GDB now supports C/C++ preprocessor macros.
2196 GDB now expands preprocessor macro invocations in C/C++ expressions,
2197 and provides various commands for showing macro definitions and how
2200 The new command `macro expand EXPRESSION' expands any macro
2201 invocations in expression, and shows the result.
2203 The new command `show macro MACRO-NAME' shows the definition of the
2204 macro named MACRO-NAME, and where it was defined.
2206 Most compilers don't include information about macros in the debugging
2207 information by default. In GCC 3.1, for example, you need to compile
2208 your program with the options `-gdwarf-2 -g3'. If the macro
2209 information is present in the executable, GDB will read it.
2211 * Multi-arched targets.
2213 DEC Alpha (partial) alpha*-*-*
2214 DEC VAX (partial) vax-*-*
2216 National Semiconductor NS32000 (partial) ns32k-*-*
2217 Motorola 68000 (partial) m68k-*-*
2218 Motorola MCORE mcore-*-*
2222 Fujitsu FRV architecture added by Red Hat frv*-*-*
2225 * New native configurations
2227 Alpha NetBSD alpha*-*-netbsd*
2228 SH NetBSD sh*-*-netbsdelf*
2229 MIPS NetBSD mips*-*-netbsd*
2230 UltraSPARC NetBSD sparc64-*-netbsd*
2232 * OBSOLETE configurations and files
2234 Configurations that have been declared obsolete in this release have
2235 been commented out. Unless there is activity to revive these
2236 configurations, the next release of GDB will have their sources
2237 permanently REMOVED.
2239 Mitsubishi D30V d30v-*-*
2240 OS/9000 i[34]86-*-os9k
2241 IBM AIX PS/2 i[3456]86-*-aix
2242 Fujitsu FR30 fr30-*-elf*
2243 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2244 Argonaut Risc Chip (ARC) arc-*-*
2245 i386 running Mach 3.0 i[3456]86-*-mach3*
2246 i386 running Mach i[3456]86-*-mach*
2247 i386 running OSF/1 i[3456]86-*osf1mk*
2248 HP/Apollo 68k Family m68*-apollo*-sysv*,
2250 m68*-hp-bsd*, m68*-hp-hpux*
2251 I960 with MON960 i960-*-coff
2253 * OBSOLETE languages
2255 CHILL, a Pascal like language used by telecommunications companies.
2257 * REMOVED configurations and files
2259 AMD 29k family via UDI a29k-amd-udi, udi29k
2260 A29K VxWorks a29k-*-vxworks
2261 AMD 29000 embedded, using EBMON a29k-none-none
2262 AMD 29000 embedded with COFF a29k-none-coff
2263 AMD 29000 embedded with a.out a29k-none-aout
2265 testsuite/gdb.hp/gdb.threads-hp/ directory
2267 * New command "set max-user-call-depth <nnn>"
2269 This command allows the user to limit the call depth of user-defined
2270 commands. The default is 1024.
2272 * Changes in FreeBSD/i386 native debugging.
2274 Support for the "generate-core-file" has been added.
2276 * New commands "dump", "append", and "restore".
2278 These commands allow data to be copied from target memory
2279 to a bfd-format or binary file (dump and append), and back
2280 from a file into memory (restore).
2282 * Improved "next/step" support on multi-processor Alpha Tru64.
2284 The previous single-step mechanism could cause unpredictable problems,
2285 including the random appearance of SIGSEGV or SIGTRAP signals. The use
2286 of a software single-step mechanism prevents this.
2288 *** Changes in GDB 5.2.1:
2296 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
2297 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
2298 Fix, by Joel Brobecker imported from mainline.
2300 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
2301 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
2302 Fix, by Fred Fish, imported from mainline.
2304 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
2305 Surprisingly enough, it works now.
2306 By Michal Ludvig, imported from mainline.
2308 i386 hardware watchpoint support:
2309 avoid misses on second run for some targets.
2310 By Pierre Muller, imported from mainline.
2312 *** Changes in GDB 5.2:
2314 * New command "set trust-readonly-sections on[off]".
2316 This command is a hint that tells gdb that read-only sections
2317 really are read-only (ie. that their contents will not change).
2318 In this mode, gdb will go to the object file rather than the
2319 target to read memory from read-only sections (such as ".text").
2320 This can be a significant performance improvement on some
2321 (notably embedded) targets.
2323 * New command "generate-core-file" (or "gcore").
2325 This new gdb command allows the user to drop a core file of the child
2326 process state at any time. So far it's been implemented only for
2327 GNU/Linux and Solaris, but should be relatively easily ported to other
2328 hosts. Argument is core file name (defaults to core.<pid>).
2330 * New command line option
2332 GDB now accepts --pid or -p followed by a process id.
2334 * Change in command line behavior -- corefiles vs. process ids.
2336 There is a subtle behavior in the way in which GDB handles
2337 command line arguments. The first non-flag argument is always
2338 a program to debug, but the second non-flag argument may either
2339 be a corefile or a process id. Previously, GDB would attempt to
2340 open the second argument as a corefile, and if that failed, would
2341 issue a superfluous error message and then attempt to attach it as
2342 a process. Now, if the second argument begins with a non-digit,
2343 it will be treated as a corefile. If it begins with a digit,
2344 GDB will attempt to attach it as a process, and if no such process
2345 is found, will then attempt to open it as a corefile.
2347 * Changes in ARM configurations.
2349 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
2350 configuration is fully multi-arch.
2352 * New native configurations
2354 ARM NetBSD arm*-*-netbsd*
2355 x86 OpenBSD i[3456]86-*-openbsd*
2356 AMD x86-64 running GNU/Linux x86_64-*-linux-*
2357 Sparc64 running FreeBSD sparc64-*-freebsd*
2361 Sanyo XStormy16 xstormy16-elf
2363 * OBSOLETE configurations and files
2365 Configurations that have been declared obsolete in this release have
2366 been commented out. Unless there is activity to revive these
2367 configurations, the next release of GDB will have their sources
2368 permanently REMOVED.
2370 AMD 29k family via UDI a29k-amd-udi, udi29k
2371 A29K VxWorks a29k-*-vxworks
2372 AMD 29000 embedded, using EBMON a29k-none-none
2373 AMD 29000 embedded with COFF a29k-none-coff
2374 AMD 29000 embedded with a.out a29k-none-aout
2376 testsuite/gdb.hp/gdb.threads-hp/ directory
2378 * REMOVED configurations and files
2380 TI TMS320C80 tic80-*-*
2382 PowerPC Solaris powerpcle-*-solaris*
2383 PowerPC Windows NT powerpcle-*-cygwin32
2384 PowerPC Netware powerpc-*-netware*
2385 Harris/CXUX m88k m88*-harris-cxux*
2386 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
2387 ns32k-utek-sysv* ns32k-utek-*
2388 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
2389 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
2390 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
2391 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
2392 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
2394 * Changes to command line processing
2396 The new `--args' feature can be used to specify command-line arguments
2397 for the inferior from gdb's command line.
2399 * Changes to key bindings
2401 There is a new `operate-and-get-next' function bound to `C-o'.
2403 *** Changes in GDB 5.1.1
2405 Fix compile problem on DJGPP.
2407 Fix a problem with floating-point registers on the i386 being
2410 Fix to stop GDB crashing on .debug_str debug info.
2412 Numerous documentation fixes.
2414 Numerous testsuite fixes.
2416 *** Changes in GDB 5.1:
2418 * New native configurations
2420 Alpha FreeBSD alpha*-*-freebsd*
2421 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
2422 MIPS GNU/Linux mips*-*-linux*
2423 MIPS SGI Irix 6.x mips*-sgi-irix6*
2424 ia64 AIX ia64-*-aix*
2425 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
2429 Motorola 68HC11 and 68HC12 m68hc11-elf
2431 UltraSparc running GNU/Linux sparc64-*-linux*
2433 * OBSOLETE configurations and files
2435 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
2436 Harris/CXUX m88k m88*-harris-cxux*
2437 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
2438 ns32k-utek-sysv* ns32k-utek-*
2439 TI TMS320C80 tic80-*-*
2441 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
2442 PowerPC Solaris powerpcle-*-solaris*
2443 PowerPC Windows NT powerpcle-*-cygwin32
2444 PowerPC Netware powerpc-*-netware*
2445 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
2446 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
2447 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
2448 Apple Macintosh (MPW) host N/A
2450 stuff.c (Program to stuff files into a specially prepared space in kdb)
2451 kdb-start.c (Main loop for the standalone kernel debugger)
2453 Configurations that have been declared obsolete in this release have
2454 been commented out. Unless there is activity to revive these
2455 configurations, the next release of GDB will have their sources
2456 permanently REMOVED.
2458 * REMOVED configurations and files
2460 Altos 3068 m68*-altos-*
2461 Convex c1-*-*, c2-*-*
2463 ARM RISCix arm-*-* (as host)
2467 * GDB has been converted to ISO C.
2469 GDB's source code has been converted to ISO C. In particular, the
2470 sources are fully protoized, and rely on standard headers being
2475 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
2477 * The MI enabled by default.
2479 The new machine oriented interface (MI) introduced in GDB 5.0 has been
2480 revised and enabled by default. Packages which use GDB as a debugging
2481 engine behind a UI or another front end are encouraged to switch to
2482 using the GDB/MI interface, instead of the old annotations interface
2483 which is now deprecated.
2485 * Support for debugging Pascal programs.
2487 GDB now includes support for debugging Pascal programs. The following
2488 main features are supported:
2490 - Pascal-specific data types such as sets;
2492 - automatic recognition of Pascal sources based on file-name
2495 - Pascal-style display of data types, variables, and functions;
2497 - a Pascal expression parser.
2499 However, some important features are not yet supported.
2501 - Pascal string operations are not supported at all;
2503 - there are some problems with boolean types;
2505 - Pascal type hexadecimal constants are not supported
2506 because they conflict with the internal variables format;
2508 - support for Pascal objects and classes is not full yet;
2510 - unlike Pascal, GDB is case-sensitive for symbol names.
2512 * Changes in completion.
2514 Commands such as `shell', `run' and `set args', which pass arguments
2515 to inferior programs, now complete on file names, similar to what
2516 users expect at the shell prompt.
2518 Commands which accept locations, such as `disassemble', `print',
2519 `breakpoint', `until', etc. now complete on filenames as well as
2520 program symbols. Thus, if you type "break foob TAB", and the source
2521 files linked into the programs include `foobar.c', that file name will
2522 be one of the candidates for completion. However, file names are not
2523 considered for completion after you typed a colon that delimits a file
2524 name from a name of a function in that file, as in "break foo.c:bar".
2526 `set demangle-style' completes on available demangling styles.
2528 * New platform-independent commands:
2530 It is now possible to define a post-hook for a command as well as a
2531 hook that runs before the command. For more details, see the
2532 documentation of `hookpost' in the GDB manual.
2534 * Changes in GNU/Linux native debugging.
2536 Support for debugging multi-threaded programs has been completely
2537 revised for all platforms except m68k and sparc. You can now debug as
2538 many threads as your system allows you to have.
2540 Attach/detach is supported for multi-threaded programs.
2542 Support for SSE registers was added for x86. This doesn't work for
2543 multi-threaded programs though.
2545 * Changes in MIPS configurations.
2547 Multi-arch support is enabled for all MIPS configurations.
2549 GDB can now be built as native debugger on SGI Irix 6.x systems for
2550 debugging n32 executables. (Debugging 64-bit executables is not yet
2553 * Unified support for hardware watchpoints in all x86 configurations.
2555 Most (if not all) native x86 configurations support hardware-assisted
2556 breakpoints and watchpoints in a unified manner. This support
2557 implements debug register sharing between watchpoints, which allows to
2558 put a virtually infinite number of watchpoints on the same address,
2559 and also supports watching regions up to 16 bytes with several debug
2562 The new maintenance command `maintenance show-debug-regs' toggles
2563 debugging print-outs in functions that insert, remove, and test
2564 watchpoints and hardware breakpoints.
2566 * Changes in the DJGPP native configuration.
2568 New command ``info dos sysinfo'' displays assorted information about
2569 the CPU, OS, memory, and DPMI server.
2571 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
2572 display information about segment descriptors stored in GDT, LDT, and
2575 New commands ``info dos pde'' and ``info dos pte'' display entries
2576 from Page Directory and Page Tables (for now works with CWSDPMI only).
2577 New command ``info dos address-pte'' displays the Page Table entry for
2578 a given linear address.
2580 GDB can now pass command lines longer than 126 characters to the
2581 program being debugged (requires an update to the libdbg.a library
2582 which is part of the DJGPP development kit).
2584 DWARF2 debug info is now supported.
2586 It is now possible to `step' and `next' through calls to `longjmp'.
2588 * Changes in documentation.
2590 All GDB documentation was converted to GFDL, the GNU Free
2591 Documentation License.
2593 Tracepoints-related commands are now fully documented in the GDB
2596 TUI, the Text-mode User Interface, is now documented in the manual.
2598 Tracepoints-related commands are now fully documented in the GDB
2601 The "GDB Internals" manual now has an index. It also includes
2602 documentation of `ui_out' functions, GDB coding standards, x86
2603 hardware watchpoints, and memory region attributes.
2605 * GDB's version number moved to ``version.in''
2607 The Makefile variable VERSION has been replaced by the file
2608 ``version.in''. People creating GDB distributions should update the
2609 contents of this file.
2613 GUD support is now a standard part of the EMACS distribution.
2615 *** Changes in GDB 5.0:
2617 * Improved support for debugging FP programs on x86 targets
2619 Unified and much-improved support for debugging floating-point
2620 programs on all x86 targets. In particular, ``info float'' now
2621 displays the FP registers in the same format on all x86 targets, with
2622 greater level of detail.
2624 * Improvements and bugfixes in hardware-assisted watchpoints
2626 It is now possible to watch array elements, struct members, and
2627 bitfields with hardware-assisted watchpoints. Data-read watchpoints
2628 on x86 targets no longer erroneously trigger when the address is
2631 * Improvements in the native DJGPP version of GDB
2633 The distribution now includes all the scripts and auxiliary files
2634 necessary to build the native DJGPP version on MS-DOS/MS-Windows
2635 machines ``out of the box''.
2637 The DJGPP version can now debug programs that use signals. It is
2638 possible to catch signals that happened in the debuggee, deliver
2639 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
2640 would kill the program being debugged.) Programs that hook hardware
2641 interrupts (keyboard, timer, etc.) can also be debugged.
2643 It is now possible to debug DJGPP programs that redirect their
2644 standard handles or switch them to raw (as opposed to cooked) mode, or
2645 even close them. The command ``run < foo > bar'' works as expected,
2646 and ``info terminal'' reports useful information about the debuggee's
2647 terminal, including raw/cooked mode, redirection, etc.
2649 The DJGPP version now uses termios functions for console I/O, which
2650 enables debugging graphics programs. Interrupting GDB with Ctrl-C
2653 DOS-style file names with drive letters are now fully supported by
2656 It is now possible to debug DJGPP programs that switch their working
2657 directory. It is also possible to rerun the debuggee any number of
2658 times without restarting GDB; thus, you can use the same setup,
2659 breakpoints, etc. for many debugging sessions.
2661 * New native configurations
2663 ARM GNU/Linux arm*-*-linux*
2664 PowerPC GNU/Linux powerpc-*-linux*
2668 Motorola MCore mcore-*-*
2669 x86 VxWorks i[3456]86-*-vxworks*
2670 PowerPC VxWorks powerpc-*-vxworks*
2671 TI TMS320C80 tic80-*-*
2673 * OBSOLETE configurations
2675 Altos 3068 m68*-altos-*
2676 Convex c1-*-*, c2-*-*
2678 ARM RISCix arm-*-* (as host)
2681 Configurations that have been declared obsolete will be commented out,
2682 but the code will be left in place. If there is no activity to revive
2683 these configurations before the next release of GDB, the sources will
2684 be permanently REMOVED.
2686 * Gould support removed
2688 Support for the Gould PowerNode and NP1 has been removed.
2690 * New features for SVR4
2692 On SVR4 native platforms (such as Solaris), if you attach to a process
2693 without first loading a symbol file, GDB will now attempt to locate and
2694 load symbols from the running process's executable file.
2696 * Many C++ enhancements
2698 C++ support has been greatly improved. Overload resolution now works properly
2699 in almost all cases. RTTI support is on the way.
2701 * Remote targets can connect to a sub-program
2703 A popen(3) style serial-device has been added. This device starts a
2704 sub-process (such as a stand-alone simulator) and then communicates
2705 with that. The sub-program to run is specified using the syntax
2706 ``|<program> <args>'' vis:
2708 (gdb) set remotedebug 1
2709 (gdb) target extended-remote |mn10300-elf-sim program-args
2711 * MIPS 64 remote protocol
2713 A long standing bug in the mips64 remote protocol where by GDB
2714 expected certain 32 bit registers (ex SR) to be transfered as 32
2715 instead of 64 bits has been fixed.
2717 The command ``set remote-mips64-transfers-32bit-regs on'' has been
2718 added to provide backward compatibility with older versions of GDB.
2720 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
2722 The command ``set remotebinarydownload'' command has been replaced by
2723 ``set remote X-packet''. Other commands in ``set remote'' family
2724 include ``set remote P-packet''.
2726 * Breakpoint commands accept ranges.
2728 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
2729 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
2730 ``tracepoint passcount'' also accepts a range of tracepoints.
2732 * ``apropos'' command added.
2734 The ``apropos'' command searches through command names and
2735 documentation strings, printing out matches, making it much easier to
2736 try to find a command that does what you are looking for.
2740 A new machine oriented interface (MI) has been added to GDB. This
2741 interface is designed for debug environments running GDB as a separate
2742 process. This is part of the long term libGDB project. See the
2743 "GDB/MI" chapter of the GDB manual for further information. It can be
2744 enabled by configuring with:
2746 .../configure --enable-gdbmi
2748 *** Changes in GDB-4.18:
2750 * New native configurations
2752 HP-UX 10.20 hppa*-*-hpux10.20
2753 HP-UX 11.x hppa*-*-hpux11.0*
2754 M68K GNU/Linux m68*-*-linux*
2758 Fujitsu FR30 fr30-*-elf*
2759 Intel StrongARM strongarm-*-*
2760 Mitsubishi D30V d30v-*-*
2762 * OBSOLETE configurations
2764 Gould PowerNode, NP1 np1-*-*, pn-*-*
2766 Configurations that have been declared obsolete will be commented out,
2767 but the code will be left in place. If there is no activity to revive
2768 these configurations before the next release of GDB, the sources will
2769 be permanently REMOVED.
2773 As a compatibility experiment, GDB's source files buildsym.h and
2774 buildsym.c have been converted to pure standard C, no longer
2775 containing any K&R compatibility code. We believe that all systems in
2776 use today either come with a standard C compiler, or have a GCC port
2777 available. If this is not true, please report the affected
2778 configuration to bug-gdb@gnu.org immediately. See the README file for
2779 information about getting a standard C compiler if you don't have one
2784 GDB now uses readline 2.2.
2786 * set extension-language
2788 You can now control the mapping between filename extensions and source
2789 languages by using the `set extension-language' command. For instance,
2790 you can ask GDB to treat .c files as C++ by saying
2791 set extension-language .c c++
2792 The command `info extensions' lists all of the recognized extensions
2793 and their associated languages.
2795 * Setting processor type for PowerPC and RS/6000
2797 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
2798 you can use the `set processor' command to specify what variant of the
2799 PowerPC family you are debugging. The command
2803 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
2804 following PowerPC and RS6000 variants:
2806 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
2807 rs6000 IBM RS6000 ("POWER") architecture, user-level view
2809 403GC IBM PowerPC 403GC
2810 505 Motorola PowerPC 505
2811 860 Motorola PowerPC 860 or 850
2812 601 Motorola PowerPC 601
2813 602 Motorola PowerPC 602
2814 603 Motorola/IBM PowerPC 603 or 603e
2815 604 Motorola PowerPC 604 or 604e
2816 750 Motorola/IBM PowerPC 750 or 750
2818 At the moment, this command just tells GDB what to name the
2819 special-purpose processor registers. Since almost all the affected
2820 registers are inaccessible to user-level programs, this command is
2821 only useful for remote debugging in its present form.
2825 Thanks to a major code donation from Hewlett-Packard, GDB now has much
2826 more extensive support for HP-UX. Added features include shared
2827 library support, kernel threads and hardware watchpoints for 11.00,
2828 support for HP's ANSI C and C++ compilers, and a compatibility mode
2829 for xdb and dbx commands.
2833 HP's donation includes the new concept of catchpoints, which is a
2834 generalization of the old catch command. On HP-UX, it is now possible
2835 to catch exec, fork, and vfork, as well as library loading.
2837 This means that the existing catch command has changed; its first
2838 argument now specifies the type of catch to be set up. See the
2839 output of "help catch" for a list of catchpoint types.
2841 * Debugging across forks
2843 On HP-UX, you can choose which process to debug when a fork() happens
2848 HP has donated a curses-based terminal user interface (TUI). To get
2849 it, build with --enable-tui. Although this can be enabled for any
2850 configuration, at present it only works for native HP debugging.
2852 * GDB remote protocol additions
2854 A new protocol packet 'X' that writes binary data is now available.
2855 Default behavior is to try 'X', then drop back to 'M' if the stub
2856 fails to respond. The settable variable `remotebinarydownload'
2857 allows explicit control over the use of 'X'.
2859 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
2860 full 64-bit address. The command
2862 set remoteaddresssize 32
2864 can be used to revert to the old behaviour. For existing remote stubs
2865 the change should not be noticed, as the additional address information
2868 In order to assist in debugging stubs, you may use the maintenance
2869 command `packet' to send any text string to the stub. For instance,
2871 maint packet heythere
2873 sends the packet "$heythere#<checksum>". Note that it is very easy to
2874 disrupt a debugging session by sending the wrong packet at the wrong
2877 The compare-sections command allows you to compare section data on the
2878 target to what is in the executable file without uploading or
2879 downloading, by comparing CRC checksums.
2881 * Tracing can collect general expressions
2883 You may now collect general expressions at tracepoints. This requires
2884 further additions to the target-side stub; see tracepoint.c and
2885 doc/agentexpr.texi for further details.
2887 * mask-address variable for Mips
2889 For Mips targets, you may control the zeroing of the upper 32 bits of
2890 a 64-bit address by entering `set mask-address on'. This is mainly
2891 of interest to users of embedded R4xxx and R5xxx processors.
2893 * Higher serial baud rates
2895 GDB's serial code now allows you to specify baud rates 57600, 115200,
2896 230400, and 460800 baud. (Note that your host system may not be able
2897 to achieve all of these rates.)
2901 The i960 configuration now includes an initial implementation of a
2902 builtin simulator, contributed by Jim Wilson.
2905 *** Changes in GDB-4.17:
2907 * New native configurations
2909 Alpha GNU/Linux alpha*-*-linux*
2910 Unixware 2.x i[3456]86-unixware2*
2911 Irix 6.x mips*-sgi-irix6*
2912 PowerPC GNU/Linux powerpc-*-linux*
2913 PowerPC Solaris powerpcle-*-solaris*
2914 Sparc GNU/Linux sparc-*-linux*
2915 Motorola sysV68 R3V7.1 m68k-motorola-sysv
2919 Argonaut Risc Chip (ARC) arc-*-*
2920 Hitachi H8/300S h8300*-*-*
2921 Matsushita MN10200 w/simulator mn10200-*-*
2922 Matsushita MN10300 w/simulator mn10300-*-*
2923 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
2924 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
2925 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
2926 Mitsubishi D10V w/simulator d10v-*-*
2927 Mitsubishi M32R/D w/simulator m32r-*-elf*
2928 Tsqware Sparclet sparclet-*-*
2929 NEC V850 w/simulator v850-*-*
2931 * New debugging protocols
2933 ARM with RDI protocol arm*-*-*
2934 M68K with dBUG monitor m68*-*-{aout,coff,elf}
2935 DDB and LSI variants of PMON protocol mips*-*-*
2936 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
2937 PowerPC with SDS protocol powerpc{,le}-*-eabi
2938 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
2942 All configurations can now understand and use the DWARF 2 debugging
2943 format. The choice is automatic, if the symbol file contains DWARF 2
2948 GDB now includes basic Java language support. This support is
2949 only useful with Java compilers that produce native machine code.
2951 * solib-absolute-prefix and solib-search-path
2953 For SunOS and SVR4 shared libraries, you may now set the prefix for
2954 loading absolute shared library symbol files, and the search path for
2955 locating non-absolute shared library symbol files.
2957 * Live range splitting
2959 GDB can now effectively debug code for which GCC has performed live
2960 range splitting as part of its optimization. See gdb/doc/LRS for
2961 more details on the expected format of the stabs information.
2965 GDB's support for the GNU Hurd, including thread debugging, has been
2966 updated to work with current versions of the Hurd.
2970 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
2971 instruction set. ARM GDB automatically detects when Thumb
2972 instructions are in use, and adjusts disassembly and backtracing
2977 GDB's MIPS target configurations now handle the MIP16 16-bit
2982 GDB now includes support for overlays; if an executable has been
2983 linked such that multiple sections are based at the same address, GDB
2984 will decide which section to use for symbolic info. You can choose to
2985 control the decision manually, using overlay commands, or implement
2986 additional target-side support and use "overlay load-target" to bring
2987 in the overlay mapping. Do "help overlay" for more detail.
2991 The command "info symbol <address>" displays information about
2992 the symbol at the specified address.
2996 The standard remote protocol now includes an extension that allows
2997 asynchronous collection and display of trace data. This requires
2998 extensive support in the target-side debugging stub. Tracing mode
2999 includes a new interaction mode in GDB and new commands: see the
3000 file tracepoint.c for more details.
3004 Configurations for embedded MIPS now include a simulator contributed
3005 by Cygnus Solutions. The simulator supports the instruction sets
3006 of most MIPS variants.
3010 Sparc configurations may now include the ERC32 simulator contributed
3011 by the European Space Agency. The simulator is not built into
3012 Sparc targets by default; configure with --enable-sim to include it.
3016 For target configurations that may include multiple variants of a
3017 basic architecture (such as MIPS and SH), you may now set the
3018 architecture explicitly. "set arch" sets, "info arch" lists
3019 the possible architectures.
3021 *** Changes in GDB-4.16:
3023 * New native configurations
3025 Windows 95, x86 Windows NT i[345]86-*-cygwin32
3026 M68K NetBSD m68k-*-netbsd*
3027 PowerPC AIX 4.x powerpc-*-aix*
3028 PowerPC MacOS powerpc-*-macos*
3029 PowerPC Windows NT powerpcle-*-cygwin32
3030 RS/6000 AIX 4.x rs6000-*-aix4*
3034 ARM with RDP protocol arm-*-*
3035 I960 with MON960 i960-*-coff
3036 MIPS VxWorks mips*-*-vxworks*
3037 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
3038 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
3040 Matra Sparclet sparclet-*-*
3044 The powerpc-eabi configuration now includes the PSIM simulator,
3045 contributed by Andrew Cagney, with assistance from Mike Meissner.
3046 PSIM is a very elaborate model of the PowerPC, including not only
3047 basic instruction set execution, but also details of execution unit
3048 performance and I/O hardware. See sim/ppc/README for more details.
3052 GDB now works with Solaris 2.5.
3054 * Windows 95/NT native
3056 GDB will now work as a native debugger on Windows 95 and Windows NT.
3057 To build it from source, you must use the "gnu-win32" environment,
3058 which uses a DLL to emulate enough of Unix to run the GNU tools.
3059 Further information, binaries, and sources are available at
3060 ftp.cygnus.com, under pub/gnu-win32.
3062 * dont-repeat command
3064 If a user-defined command includes the command `dont-repeat', then the
3065 command will not be repeated if the user just types return. This is
3066 useful if the command is time-consuming to run, so that accidental
3067 extra keystrokes don't run the same command many times.
3069 * Send break instead of ^C
3071 The standard remote protocol now includes an option to send a break
3072 rather than a ^C to the target in order to interrupt it. By default,
3073 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
3075 * Remote protocol timeout
3077 The standard remote protocol includes a new variable `remotetimeout'
3078 that allows you to set the number of seconds before GDB gives up trying
3079 to read from the target. The default value is 2.
3081 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
3083 By default GDB will automatically keep track of objects as they are
3084 loaded and unloaded by the dynamic linker. By using the command `set
3085 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
3086 when shared library events occur, thus allowing you to set breakpoints
3087 in shared libraries which are explicitly loaded by the inferior.
3089 Note this feature does not work on hpux8. On hpux9 you must link
3090 /usr/lib/end.o into your program. This feature should work
3091 automatically on hpux10.
3093 * Irix 5.x hardware watchpoint support
3095 Irix 5 configurations now support the use of hardware watchpoints.
3097 * Mips protocol "SYN garbage limit"
3099 When debugging a Mips target using the `target mips' protocol, you
3100 may set the number of characters that GDB will ignore by setting
3101 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
3102 every character. The default value is 1050.
3104 * Recording and replaying remote debug sessions
3106 If you set `remotelogfile' to the name of a file, gdb will write to it
3107 a recording of a remote debug session. This recording may then be
3108 replayed back to gdb using "gdbreplay". See gdbserver/README for
3109 details. This is useful when you have a problem with GDB while doing
3110 remote debugging; you can make a recording of the session and send it
3111 to someone else, who can then recreate the problem.
3113 * Speedups for remote debugging
3115 GDB includes speedups for downloading and stepping MIPS systems using
3116 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
3117 and more efficient S-record downloading.
3119 * Memory use reductions and statistics collection
3121 GDB now uses less memory and reports statistics about memory usage.
3122 Try the `maint print statistics' command, for example.
3124 *** Changes in GDB-4.15:
3126 * Psymtabs for XCOFF
3128 The symbol reader for AIX GDB now uses partial symbol tables. This
3129 can greatly improve startup time, especially for large executables.
3131 * Remote targets use caching
3133 Remote targets now use a data cache to speed up communication with the
3134 remote side. The data cache could lead to incorrect results because
3135 it doesn't know about volatile variables, thus making it impossible to
3136 debug targets which use memory mapped I/O devices. `set remotecache
3137 off' turns the the data cache off.
3139 * Remote targets may have threads
3141 The standard remote protocol now includes support for multiple threads
3142 in the target system, using new protocol commands 'H' and 'T'. See
3143 gdb/remote.c for details.
3147 If GDB is configured with `--enable-netrom', then it will include
3148 support for the NetROM ROM emulator from XLNT Designs. The NetROM
3149 acts as though it is a bank of ROM on the target board, but you can
3150 write into it over the network. GDB's support consists only of
3151 support for fast loading into the emulated ROM; to debug, you must use
3152 another protocol, such as standard remote protocol. The usual
3153 sequence is something like
3155 target nrom <netrom-hostname>
3157 target remote <netrom-hostname>:1235
3161 GDB now includes support for the Apple Macintosh, as a host only. It
3162 may be run as either an MPW tool or as a standalone application, and
3163 it can debug through the serial port. All the usual GDB commands are
3164 available, but to the target command, you must supply "serial" as the
3165 device type instead of "/dev/ttyXX". See mpw-README in the main
3166 directory for more information on how to build. The MPW configuration
3167 scripts */mpw-config.in support only a few targets, and only the
3168 mips-idt-ecoff target has been tested.
3172 GDB configuration now uses autoconf. This is not user-visible,
3173 but does simplify configuration and building.
3177 GDB now supports hpux10.
3179 *** Changes in GDB-4.14:
3181 * New native configurations
3183 x86 FreeBSD i[345]86-*-freebsd
3184 x86 NetBSD i[345]86-*-netbsd
3185 NS32k NetBSD ns32k-*-netbsd
3186 Sparc NetBSD sparc-*-netbsd
3190 A29K VxWorks a29k-*-vxworks
3191 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
3192 CPU32 EST-300 emulator m68*-*-est*
3193 PowerPC ELF powerpc-*-elf
3196 * Alpha OSF/1 support for procfs
3198 GDB now supports procfs under OSF/1-2.x and higher, which makes it
3199 possible to attach to running processes. As the mounting of the /proc
3200 filesystem is optional on the Alpha, GDB automatically determines
3201 the availability of /proc during startup. This can lead to problems
3202 if /proc is unmounted after GDB has been started.
3204 * Arguments to user-defined commands
3206 User commands may accept up to 10 arguments separated by whitespace.
3207 Arguments are accessed within the user command via $arg0..$arg9. A
3210 print $arg0 + $arg1 + $arg2
3212 To execute the command use:
3215 Defines the command "adder" which prints the sum of its three arguments.
3216 Note the arguments are text substitutions, so they may reference variables,
3217 use complex expressions, or even perform inferior function calls.
3219 * New `if' and `while' commands
3221 This makes it possible to write more sophisticated user-defined
3222 commands. Both commands take a single argument, which is the
3223 expression to evaluate, and must be followed by the commands to
3224 execute, one per line, if the expression is nonzero, the list being
3225 terminated by the word `end'. The `if' command list may include an
3226 `else' word, which causes the following commands to be executed only
3227 if the expression is zero.
3229 * Fortran source language mode
3231 GDB now includes partial support for Fortran 77. It will recognize
3232 Fortran programs and can evaluate a subset of Fortran expressions, but
3233 variables and functions may not be handled correctly. GDB will work
3234 with G77, but does not yet know much about symbols emitted by other
3237 * Better HPUX support
3239 Most debugging facilities now work on dynamic executables for HPPAs
3240 running hpux9 or later. You can attach to running dynamically linked
3241 processes, but by default the dynamic libraries will be read-only, so
3242 for instance you won't be able to put breakpoints in them. To change
3243 that behavior do the following before running the program:
3249 This will cause the libraries to be mapped private and read-write.
3250 To revert to the normal behavior, do this:
3256 You cannot set breakpoints or examine data in the library until after
3257 the library is loaded if the function/data symbols do not have
3260 GDB can now also read debug symbols produced by the HP C compiler on
3261 HPPAs (sorry, no C++, Fortran or 68k support).
3263 * Target byte order now dynamically selectable
3265 You can choose which byte order to use with a target system, via the
3266 commands "set endian big" and "set endian little", and you can see the
3267 current setting by using "show endian". You can also give the command
3268 "set endian auto", in which case GDB will use the byte order
3269 associated with the executable. Currently, only embedded MIPS
3270 configurations support dynamic selection of target byte order.
3272 * New DOS host serial code
3274 This version uses DPMI interrupts to handle buffered I/O, so you
3275 no longer need to run asynctsr when debugging boards connected to
3278 *** Changes in GDB-4.13:
3280 * New "complete" command
3282 This lists all the possible completions for the rest of the line, if it
3283 were to be given as a command itself. This is intended for use by emacs.
3285 * Trailing space optional in prompt
3287 "set prompt" no longer adds a space for you after the prompt you set. This
3288 allows you to set a prompt which ends in a space or one that does not.
3290 * Breakpoint hit counts
3292 "info break" now displays a count of the number of times the breakpoint
3293 has been hit. This is especially useful in conjunction with "ignore"; you
3294 can ignore a large number of breakpoint hits, look at the breakpoint info
3295 to see how many times the breakpoint was hit, then run again, ignoring one
3296 less than that number, and this will get you quickly to the last hit of
3299 * Ability to stop printing at NULL character
3301 "set print null-stop" will cause GDB to stop printing the characters of
3302 an array when the first NULL is encountered. This is useful when large
3303 arrays actually contain only short strings.
3305 * Shared library breakpoints
3307 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
3308 breakpoints in shared libraries before the executable is run.
3310 * Hardware watchpoints
3312 There is a new hardware breakpoint for the watch command for sparclite
3313 targets. See gdb/sparclite/hw_breakpoint.note.
3315 Hardware watchpoints are also now supported under GNU/Linux.
3319 Annotations have been added. These are for use with graphical interfaces,
3320 and are still experimental. Currently only gdba.el uses these.
3322 * Improved Irix 5 support
3324 GDB now works properly with Irix 5.2.
3326 * Improved HPPA support
3328 GDB now works properly with the latest GCC and GAS.
3330 * New native configurations
3332 Sequent PTX4 i[34]86-sequent-ptx4
3333 HPPA running OSF/1 hppa*-*-osf*
3334 Atari TT running SVR4 m68*-*-sysv4*
3335 RS/6000 LynxOS rs6000-*-lynxos*
3339 OS/9000 i[34]86-*-os9k
3340 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
3343 * Hitachi SH7000 and E7000-PC ICE support
3345 There is now support for communicating with the Hitachi E7000-PC ICE.
3346 This is available automatically when GDB is configured for the SH.
3350 As usual, a variety of small fixes and improvements, both generic
3351 and configuration-specific. See the ChangeLog for more detail.
3353 *** Changes in GDB-4.12:
3355 * Irix 5 is now supported
3359 GDB-4.12 on the HPPA has a number of changes which make it unable
3360 to debug the output from the currently released versions of GCC and
3361 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
3362 of GCC and GAS, versions of these tools designed to work with GDB-4.12
3363 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
3366 *** Changes in GDB-4.11:
3368 * User visible changes:
3372 The "set remotedebug" option is now consistent between the mips remote
3373 target, remote targets using the gdb-specific protocol, UDI (AMD's
3374 debug protocol for the 29k) and the 88k bug monitor. It is now an
3375 integer specifying a debug level (normally 0 or 1, but 2 means more
3376 debugging info for the mips target).
3378 * DEC Alpha native support
3380 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
3381 debug info, but GDB works fairly well with the DEC compiler and should
3382 work with a future GCC release. See the README file for a few
3383 Alpha-specific notes.
3385 * Preliminary thread implementation
3387 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
3389 * LynxOS native and target support for 386
3391 This release has been hosted on LynxOS 2.2, and also can be configured
3392 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
3395 * Improvements in C++ mangling/demangling.
3397 This release has much better g++ debugging, specifically in name
3398 mangling/demangling, virtual function calls, print virtual table,
3399 call methods, ...etc.
3401 *** Changes in GDB-4.10:
3403 * User visible changes:
3405 Remote debugging using the GDB-specific (`target remote') protocol now
3406 supports the `load' command. This is only useful if you have some
3407 other way of getting the stub to the target system, and you can put it
3408 somewhere in memory where it won't get clobbered by the download.
3410 Filename completion now works.
3412 When run under emacs mode, the "info line" command now causes the
3413 arrow to point to the line specified. Also, "info line" prints
3414 addresses in symbolic form (as well as hex).
3416 All vxworks based targets now support a user settable option, called
3417 vxworks-timeout. This option represents the number of seconds gdb
3418 should wait for responses to rpc's. You might want to use this if
3419 your vxworks target is, perhaps, a slow software simulator or happens
3420 to be on the far side of a thin network line.
3424 This release contains support for using a DEC alpha as a GDB host for
3425 cross debugging. Native alpha debugging is not supported yet.
3428 *** Changes in GDB-4.9:
3432 This is the first GDB release which is accompanied by a matching testsuite.
3433 The testsuite requires installation of dejagnu, which should be available
3434 via ftp from most sites that carry GNU software.
3438 'Cfront' style demangling has had its name changed to 'ARM' style, to
3439 emphasize that it was written from the specifications in the C++ Annotated
3440 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
3441 disclaimers, it still generated too much confusion with users attempting to
3442 use gdb with AT&T cfront.
3446 GDB now uses a standard remote interface to a simulator library.
3447 So far, the library contains simulators for the Zilog Z8001/2, the
3448 Hitachi H8/300, H8/500 and Super-H.
3450 * New targets supported
3452 H8/300 simulator h8300-hitachi-hms or h8300hms
3453 H8/500 simulator h8500-hitachi-hms or h8500hms
3454 SH simulator sh-hitachi-hms or sh
3455 Z8000 simulator z8k-zilog-none or z8ksim
3456 IDT MIPS board over serial line mips-idt-ecoff
3458 Cross-debugging to GO32 targets is supported. It requires a custom
3459 version of the i386-stub.c module which is integrated with the
3460 GO32 memory extender.
3462 * New remote protocols
3464 MIPS remote debugging protocol.
3466 * New source languages supported
3468 This version includes preliminary support for Chill, a Pascal like language
3469 used by telecommunications companies. Chill support is also being integrated
3470 into the GNU compiler, but we don't know when it will be publically available.
3473 *** Changes in GDB-4.8:
3475 * HP Precision Architecture supported
3477 GDB now supports HP PA-RISC machines running HPUX. A preliminary
3478 version of this support was available as a set of patches from the
3479 University of Utah. GDB does not support debugging of programs
3480 compiled with the HP compiler, because HP will not document their file
3481 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
3482 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
3484 Many problems in the preliminary version have been fixed.
3486 * Faster and better demangling
3488 We have improved template demangling and fixed numerous bugs in the GNU style
3489 demangler. It can now handle type modifiers such as `static' or `const'. Wide
3490 character types (wchar_t) are now supported. Demangling of each symbol is now
3491 only done once, and is cached when the symbol table for a file is read in.
3492 This results in a small increase in memory usage for C programs, a moderate
3493 increase in memory usage for C++ programs, and a fantastic speedup in
3496 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
3497 from the specifications in the Annotated Reference Manual, which AT&T's
3498 compiler does not actually implement.
3500 * G++ multiple inheritance compiler problem
3502 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
3503 inheritance lattices was reworked to properly discover ambiguities. We
3504 recently found an example which causes this new algorithm to fail in a
3505 very subtle way, producing bad debug information for those classes.
3506 The file 'gcc.patch' (in this directory) can be applied to gcc to
3507 circumvent the problem. A future GCC release will contain a complete
3510 The previous G++ debug info problem (mentioned below for the gdb-4.7
3511 release) is fixed in gcc version 2.3.2.
3513 * Improved configure script
3515 The `configure' script will now attempt to guess your system type if
3516 you don't supply a host system type. The old scheme of supplying a
3517 host system triplet is preferable over using this. All the magic is
3518 done in the new `config.guess' script. Examine it for details.
3520 We have also brought our configure script much more in line with the FSF's
3521 version. It now supports the --with-xxx options. In particular,
3522 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
3523 The resulting GDB will not be able to read arbitrary object file formats --
3524 only the format ``expected'' to be used on the configured target system.
3525 We hope to make this the default in a future release.
3527 * Documentation improvements
3529 There's new internal documentation on how to modify GDB, and how to
3530 produce clean changes to the code. We implore people to read it
3531 before submitting changes.
3533 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
3534 M4 macros. The new texinfo.tex is provided in this release. Pre-built
3535 `info' files are also provided. To build `info' files from scratch,
3536 you will need the latest `makeinfo' release, which will be available in
3537 a future texinfo-X.Y release.
3539 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
3540 We're not sure exactly which versions have this problem, but it has
3541 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
3542 or better. If that isn't possible, there is a patch in
3543 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
3544 around this problem.
3548 GDB now supports array constants that can be used in expressions typed in by
3549 the user. The syntax is `{element, element, ...}'. Ie: you can now type
3550 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
3553 The new directory `gdb/sparclite' contains a program that demonstrates
3554 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
3556 * New native hosts supported
3558 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
3559 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
3561 * New targets supported
3563 AMD 29k family via UDI a29k-amd-udi or udi29k
3565 * New file formats supported
3567 BFD now supports reading HP/PA-RISC executables (SOM file format?),
3568 HPUX core files, and SCO 3.2v2 core files.
3572 Attaching to processes now works again; thanks for the many bug reports.
3574 We have also stomped on a bunch of core dumps caused by
3575 printf_filtered("%s") problems.
3577 We eliminated a copyright problem on the rpc and ptrace header files
3578 for VxWorks, which was discovered at the last minute during the 4.7
3579 release. You should now be able to build a VxWorks GDB.
3581 You can now interrupt gdb while an attached process is running. This
3582 will cause the attached process to stop, and give control back to GDB.
3584 We fixed problems caused by using too many file descriptors
3585 for reading symbols from object files and libraries. This was
3586 especially a problem for programs that used many (~100) shared
3589 The `step' command now only enters a subroutine if there is line number
3590 information for the subroutine. Otherwise it acts like the `next'
3591 command. Previously, `step' would enter subroutines if there was
3592 any debugging information about the routine. This avoids problems
3593 when using `cc -g1' on MIPS machines.
3595 * Internal improvements
3597 GDB's internal interfaces have been improved to make it easier to support
3598 debugging of multiple languages in the future.
3600 GDB now uses a common structure for symbol information internally.
3601 Minimal symbols (derived from linkage symbols in object files), partial
3602 symbols (from a quick scan of debug information), and full symbols
3603 contain a common subset of information, making it easier to write
3604 shared code that handles any of them.
3606 * New command line options
3608 We now accept --silent as an alias for --quiet.
3612 The memory-mapped-malloc library is now licensed under the GNU Library
3613 General Public License.
3615 *** Changes in GDB-4.7:
3617 * Host/native/target split
3619 GDB has had some major internal surgery to untangle the support for
3620 hosts and remote targets. Now, when you configure GDB for a remote
3621 target, it will no longer load in all of the support for debugging
3622 local programs on the host. When fully completed and tested, this will
3623 ensure that arbitrary host/target combinations are possible.
3625 The primary conceptual shift is to separate the non-portable code in
3626 GDB into three categories. Host specific code is required any time GDB
3627 is compiled on that host, regardless of the target. Target specific
3628 code relates to the peculiarities of the target, but can be compiled on
3629 any host. Native specific code is everything else: it can only be
3630 built when the host and target are the same system. Child process
3631 handling and core file support are two common `native' examples.
3633 GDB's use of /proc for controlling Unix child processes is now cleaner.
3634 It has been split out into a single module under the `target_ops' vector,
3635 plus two native-dependent functions for each system that uses /proc.
3637 * New hosts supported
3639 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
3640 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
3641 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
3643 * New targets supported
3645 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3646 68030 and CPU32 m68030-*-*, m68332-*-*
3648 * New native hosts supported
3650 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
3651 (386bsd is not well tested yet)
3652 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
3654 * New file formats supported
3656 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
3657 supports reading of `a.out.adobe' object files, which are an a.out
3658 format extended with minimal information about multiple sections.
3662 `show copying' is the same as the old `info copying'.
3663 `show warranty' is the same as `info warrantee'.
3664 These were renamed for consistency. The old commands continue to work.
3666 `info handle' is a new alias for `info signals'.
3668 You can now define pre-command hooks, which attach arbitrary command
3669 scripts to any command. The commands in the hook will be executed
3670 prior to the user's command. You can also create a hook which will be
3671 executed whenever the program stops. See gdb.texinfo.
3675 We now deal with Cfront style name mangling, and can even extract type
3676 info from mangled symbols. GDB can automatically figure out which
3677 symbol mangling style your C++ compiler uses.
3679 Calling of methods and virtual functions has been improved as well.
3683 The crash that occured when debugging Sun Ansi-C compiled binaries is
3684 fixed. This was due to mishandling of the extra N_SO stabs output
3687 We also finally got Ultrix 4.2 running in house, and fixed core file
3688 support, with help from a dozen people on the net.
3690 John M. Farrell discovered that the reason that single-stepping was so
3691 slow on all of the Mips based platforms (primarily SGI and DEC) was
3692 that we were trying to demangle and lookup a symbol used for internal
3693 purposes on every instruction that was being stepped through. Changing
3694 the name of that symbol so that it couldn't be mistaken for a C++
3695 mangled symbol sped things up a great deal.
3697 Rich Pixley sped up symbol lookups in general by getting much smarter
3698 about when C++ symbol mangling is necessary. This should make symbol
3699 completion (TAB on the command line) much faster. It's not as fast as
3700 we'd like, but it's significantly faster than gdb-4.6.
3704 A new user controllable variable 'call_scratch_address' can
3705 specify the location of a scratch area to be used when GDB
3706 calls a function in the target. This is necessary because the
3707 usual method of putting the scratch area on the stack does not work
3708 in systems that have separate instruction and data spaces.
3710 We integrated changes to support the 29k UDI (Universal Debugger
3711 Interface), but discovered at the last minute that we didn't have all
3712 of the appropriate copyright paperwork. We are working with AMD to
3713 resolve this, and hope to have it available soon.
3717 We have sped up the remote serial line protocol, especially for targets
3718 with lots of registers. It now supports a new `expedited status' ('T')
3719 message which can be used in place of the existing 'S' status message.
3720 This allows the remote stub to send only the registers that GDB
3721 needs to make a quick decision about single-stepping or conditional
3722 breakpoints, eliminating the need to fetch the entire register set for
3723 each instruction being stepped through.
3725 The GDB remote serial protocol now implements a write-through cache for
3726 registers, only re-reading the registers if the target has run.
3728 There is also a new remote serial stub for SPARC processors. You can
3729 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
3730 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
3731 processor with a serial port.
3735 Configure.in files have become much easier to read and modify. A new
3736 `table driven' format makes it more obvious what configurations are
3737 supported, and what files each one uses.
3741 There is a new opcodes library which will eventually contain all of the
3742 disassembly routines and opcode tables. At present, it only contains
3743 Sparc and Z8000 routines. This will allow the assembler, debugger, and
3744 disassembler (binutils/objdump) to share these routines.
3746 The libiberty library is now copylefted under the GNU Library General
3747 Public License. This allows more liberal use, and was done so libg++
3748 can use it. This makes no difference to GDB, since the Library License
3749 grants all the rights from the General Public License.
3753 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
3754 reference to the stabs symbol info used by the debugger. It is (as far
3755 as we know) the only published document on this fascinating topic. We
3756 encourage you to read it, compare it to the stabs information on your
3757 system, and send improvements on the document in general (to
3758 bug-gdb@prep.ai.mit.edu).
3760 And, of course, many bugs have been fixed.
3763 *** Changes in GDB-4.6:
3765 * Better support for C++ function names
3767 GDB now accepts as input the "demangled form" of C++ overloaded function
3768 names and member function names, and can do command completion on such names
3769 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
3770 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
3771 Make use of command completion, it is your friend.
3773 GDB also now accepts a variety of C++ mangled symbol formats. They are
3774 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
3775 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
3776 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
3777 for the list of formats.
3779 * G++ symbol mangling problem
3781 Recent versions of gcc have a bug in how they emit debugging information for
3782 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
3783 directory) can be applied to gcc to fix the problem. Alternatively, if you
3784 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
3785 usual symptom is difficulty with setting breakpoints on methods. GDB complains
3786 about the method being non-existent. (We believe that version 2.2.2 of GCC has
3789 * New 'maintenance' command
3791 All of the commands related to hacking GDB internals have been moved out of
3792 the main command set, and now live behind the 'maintenance' command. This
3793 can also be abbreviated as 'mt'. The following changes were made:
3795 dump-me -> maintenance dump-me
3796 info all-breakpoints -> maintenance info breakpoints
3797 printmsyms -> maintenance print msyms
3798 printobjfiles -> maintenance print objfiles
3799 printpsyms -> maintenance print psymbols
3800 printsyms -> maintenance print symbols
3802 The following commands are new:
3804 maintenance demangle Call internal GDB demangler routine to
3805 demangle a C++ link name and prints the result.
3806 maintenance print type Print a type chain for a given symbol
3808 * Change to .gdbinit file processing
3810 We now read the $HOME/.gdbinit file before processing the argv arguments
3811 (e.g. reading symbol files or core files). This allows global parameters to
3812 be set, which will apply during the symbol reading. The ./.gdbinit is still
3813 read after argv processing.
3815 * New hosts supported
3817 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
3819 GNU/Linux support i386-unknown-linux or linux
3821 We are also including code to support the HP/PA running BSD and HPUX. This
3822 is almost guaranteed not to work, as we didn't have time to test or build it
3823 for this release. We are including it so that the more adventurous (or
3824 masochistic) of you can play with it. We also had major problems with the
3825 fact that the compiler that we got from HP doesn't support the -g option.
3828 * New targets supported
3830 Hitachi H8/300 h8300-hitachi-hms or h8300hms
3832 * More smarts about finding #include files
3834 GDB now remembers the compilation directory for all include files, and for
3835 all files from which C is generated (like yacc and lex sources). This
3836 greatly improves GDB's ability to find yacc/lex sources, and include files,
3837 especially if you are debugging your program from a directory different from
3838 the one that contains your sources.
3840 We also fixed a bug which caused difficulty with listing and setting
3841 breakpoints in include files which contain C code. (In the past, you had to
3842 try twice in order to list an include file that you hadn't looked at before.)
3844 * Interesting infernals change
3846 GDB now deals with arbitrary numbers of sections, where the symbols for each
3847 section must be relocated relative to that section's landing place in the
3848 target's address space. This work was needed to support ELF with embedded
3849 stabs used by Solaris-2.0.
3851 * Bug fixes (of course!)
3853 There have been loads of fixes for the following things:
3854 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
3855 i960, stabs, DOS(GO32), procfs, etc...
3857 See the ChangeLog for details.
3859 *** Changes in GDB-4.5:
3861 * New machines supported (host and target)
3863 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
3865 SGI Irix-4.x mips-sgi-irix4 or iris4
3867 * New malloc package
3869 GDB now uses a new memory manager called mmalloc, based on gmalloc.
3870 Mmalloc is capable of handling mutiple heaps of memory. It is also
3871 capable of saving a heap to a file, and then mapping it back in later.
3872 This can be used to greatly speedup the startup of GDB by using a
3873 pre-parsed symbol table which lives in a mmalloc managed heap. For
3874 more details, please read mmalloc/mmalloc.texi.
3878 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
3879 'help info proc' for details.
3881 * MIPS ecoff symbol table format
3883 The code that reads MIPS symbol table format is now supported on all hosts.
3884 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
3887 * File name changes for MS-DOS
3889 Many files in the config directories have been renamed to make it easier to
3890 support GDB on MS-DOSe systems (which have very restrictive file name
3891 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
3892 environment) is close to working but has some remaining problems. Note
3893 that debugging of DOS programs is not supported, due to limitations
3894 in the ``operating system'', but it can be used to host cross-debugging.
3896 * Cross byte order fixes
3898 Many fixes have been made to support cross debugging of Sparc and MIPS
3899 targets from hosts whose byte order differs.
3901 * New -mapped and -readnow options
3903 If memory-mapped files are available on your system through the 'mmap'
3904 system call, you can use the -mapped option on the `file' or
3905 `symbol-file' commands to cause GDB to write the symbols from your
3906 program into a reusable file. If the program you are debugging is
3907 called `/path/fred', the mapped symbol file will be `./fred.syms'.
3908 Future GDB debugging sessions will notice the presence of this file,
3909 and will quickly map in symbol information from it, rather than reading
3910 the symbol table from the executable program. Using the '-mapped'
3911 option in a GDB `file' or `symbol-file' command has the same effect as
3912 starting GDB with the '-mapped' command-line option.
3914 You can cause GDB to read the entire symbol table immediately by using
3915 the '-readnow' option with any of the commands that load symbol table
3916 information (or on the GDB command line). This makes the command
3917 slower, but makes future operations faster.
3919 The -mapped and -readnow options are typically combined in order to
3920 build a `fred.syms' file that contains complete symbol information.
3921 A simple GDB invocation to do nothing but build a `.syms' file for future
3924 gdb -batch -nx -mapped -readnow programname
3926 The `.syms' file is specific to the host machine on which GDB is run.
3927 It holds an exact image of GDB's internal symbol table. It cannot be
3928 shared across multiple host platforms.
3930 * longjmp() handling
3932 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
3933 siglongjmp() without losing control. This feature has not yet been ported to
3934 all systems. It currently works on many 386 platforms, all MIPS-based
3935 platforms (SGI, DECstation, etc), and Sun3/4.
3939 Preliminary work has been put in to support the new Solaris OS from Sun. At
3940 this time, it can control and debug processes, but it is not capable of
3945 As always, many many bug fixes. The major areas were with g++, and mipsread.
3946 People using the MIPS-based platforms should experience fewer mysterious
3947 crashes and trashed symbol tables.
3949 *** Changes in GDB-4.4:
3951 * New machines supported (host and target)
3953 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
3955 BSD Reno on Vax vax-dec-bsd
3956 Ultrix on Vax vax-dec-ultrix
3958 * New machines supported (target)
3960 AMD 29000 embedded, using EBMON a29k-none-none
3964 GDB continues to improve its handling of C++. `References' work better.
3965 The demangler has also been improved, and now deals with symbols mangled as
3966 per the Annotated C++ Reference Guide.
3968 GDB also now handles `stabs' symbol information embedded in MIPS
3969 `ecoff' symbol tables. Since the ecoff format was not easily
3970 extensible to handle new languages such as C++, this appeared to be a
3971 good way to put C++ debugging info into MIPS binaries. This option
3972 will be supported in the GNU C compiler, version 2, when it is
3975 * New features for SVR4
3977 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
3978 shared libraries. Debugging dynamically linked programs should present
3979 only minor differences from debugging statically linked programs.
3981 The `info proc' command will print out information about any process
3982 on an SVR4 system (including the one you are debugging). At the moment,
3983 it prints the address mappings of the process.
3985 If you bring up GDB on another SVR4 system, please send mail to
3986 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
3988 * Better dynamic linking support in SunOS
3990 Reading symbols from shared libraries which contain debugging symbols
3991 now works properly. However, there remain issues such as automatic
3992 skipping of `transfer vector' code during function calls, which
3993 make it harder to debug code in a shared library, than to debug the
3994 same code linked statically.
3998 GDB is now using the latest `getopt' routines from the FSF. This
3999 version accepts the -- prefix for options with long names. GDB will
4000 continue to accept the old forms (-option and +option) as well.
4001 Various single letter abbreviations for options have been explicity
4002 added to the option table so that they won't get overshadowed in the
4003 future by other options that begin with the same letter.
4007 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
4008 Many assorted bugs have been handled. Many more remain to be handled.
4009 See the various ChangeLog files (primarily in gdb and bfd) for details.
4012 *** Changes in GDB-4.3:
4014 * New machines supported (host and target)
4016 Amiga 3000 running Amix m68k-cbm-svr4 or amix
4017 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
4018 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4020 * Almost SCO Unix support
4022 We had hoped to support:
4023 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4024 (except for core file support), but we discovered very late in the release
4025 that it has problems with process groups that render gdb unusable. Sorry
4026 about that. I encourage people to fix it and post the fixes.
4028 * Preliminary ELF and DWARF support
4030 GDB can read ELF object files on System V Release 4, and can handle
4031 debugging records for C, in DWARF format, in ELF files. This support
4032 is preliminary. If you bring up GDB on another SVR4 system, please
4033 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
4038 GDB now uses the latest `readline' library. One user-visible change
4039 is that two tabs will list possible command completions, which previously
4040 required typing M-? (meta-question mark, or ESC ?).
4044 The `stepi' bug that many of you noticed has been squashed.
4045 Many bugs in C++ have been handled. Many more remain to be handled.
4046 See the various ChangeLog files (primarily in gdb and bfd) for details.
4048 * State of the MIPS world (in case you wondered):
4050 GDB can understand the symbol tables emitted by the compilers
4051 supplied by most vendors of MIPS-based machines, including DEC. These
4052 symbol tables are in a format that essentially nobody else uses.
4054 Some versions of gcc come with an assembler post-processor called
4055 mips-tfile. This program is required if you want to do source-level
4056 debugging of gcc-compiled programs. I believe FSF does not ship
4057 mips-tfile with gcc version 1, but it will eventually come with gcc
4060 Debugging of g++ output remains a problem. g++ version 1.xx does not
4061 really support it at all. (If you're lucky, you should be able to get
4062 line numbers and stack traces to work, but no parameters or local
4063 variables.) With some work it should be possible to improve the
4066 When gcc version 2 is released, you will have somewhat better luck.
4067 However, even then you will get confusing results for inheritance and
4070 We will eventually provide full debugging of g++ output on
4071 DECstations. This will probably involve some kind of stabs-in-ecoff
4072 encapulation, but the details have not been worked out yet.
4075 *** Changes in GDB-4.2:
4077 * Improved configuration
4079 Only one copy of `configure' exists now, and it is not self-modifying.
4080 Porting BFD is simpler.
4084 The `step' and `next' commands now only stop at the first instruction
4085 of a source line. This prevents the multiple stops that used to occur
4086 in switch statements, for-loops, etc. `Step' continues to stop if a
4087 function that has debugging information is called within the line.
4091 Lots of small bugs fixed. More remain.
4093 * New host supported (not target)
4095 Intel 386 PC clone running Mach i386-none-mach
4098 *** Changes in GDB-4.1:
4100 * Multiple source language support
4102 GDB now has internal scaffolding to handle several source languages.
4103 It determines the type of each source file from its filename extension,
4104 and will switch expression parsing and number formatting to match the
4105 language of the function in the currently selected stack frame.
4106 You can also specifically set the language to be used, with
4107 `set language c' or `set language modula-2'.
4111 GDB now has preliminary support for the GNU Modula-2 compiler,
4112 currently under development at the State University of New York at
4113 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
4114 continue through the fall of 1991 and into 1992.
4116 Other Modula-2 compilers are currently not supported, and attempting to
4117 debug programs compiled with them will likely result in an error as the
4118 symbol table is read. Feel free to work on it, though!
4120 There are hooks in GDB for strict type checking and range checking,
4121 in the `Modula-2 philosophy', but they do not currently work.
4125 GDB can now write to executable and core files (e.g. patch
4126 a variable's value). You must turn this switch on, specify
4127 the file ("exec foo" or "core foo"), *then* modify it, e.g.
4128 by assigning a new value to a variable. Modifications take
4131 * Automatic SunOS shared library reading
4133 When you run your program, GDB automatically determines where its
4134 shared libraries (if any) have been loaded, and reads their symbols.
4135 The `share' command is no longer needed. This also works when
4136 examining core files.
4140 You can specify the number of lines that the `list' command shows.
4143 * New machines supported (host and target)
4145 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4146 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
4147 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
4149 * New hosts supported (not targets)
4151 IBM RT/PC: romp-ibm-aix or rtpc
4153 * New targets supported (not hosts)
4155 AMD 29000 embedded with COFF a29k-none-coff
4156 AMD 29000 embedded with a.out a29k-none-aout
4157 Ultracomputer remote kernel debug a29k-nyu-kern
4159 * New remote interfaces
4165 *** Changes in GDB-4.0:
4169 Wide output is wrapped at good places to make the output more readable.
4171 Gdb now supports cross-debugging from a host machine of one type to a
4172 target machine of another type. Communication with the target system
4173 is over serial lines. The ``target'' command handles connecting to the
4174 remote system; the ``load'' command will download a program into the
4175 remote system. Serial stubs for the m68k and i386 are provided. Gdb
4176 also supports debugging of realtime processes running under VxWorks,
4177 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
4178 stub on the target system.
4180 New CPUs supported include the AMD 29000 and Intel 960.
4182 GDB now reads object files and symbol tables via a ``binary file''
4183 library, which allows a single copy of GDB to debug programs of multiple
4184 object file types such as a.out and coff.
4186 There is now a GDB reference card in "doc/refcard.tex". (Make targets
4187 refcard.dvi and refcard.ps are available to format it).
4190 * Control-Variable user interface simplified
4192 All variables that control the operation of the debugger can be set
4193 by the ``set'' command, and displayed by the ``show'' command.
4195 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
4196 ``Show prompt'' produces the response:
4197 Gdb's prompt is new-gdb=>.
4199 What follows are the NEW set commands. The command ``help set'' will
4200 print a complete list of old and new set commands. ``help set FOO''
4201 will give a longer description of the variable FOO. ``show'' will show
4202 all of the variable descriptions and their current settings.
4204 confirm on/off: Enables warning questions for operations that are
4205 hard to recover from, e.g. rerunning the program while
4206 it is already running. Default is ON.
4208 editing on/off: Enables EMACS style command line editing
4209 of input. Previous lines can be recalled with
4210 control-P, the current line can be edited with control-B,
4211 you can search for commands with control-R, etc.
4214 history filename NAME: NAME is where the gdb command history
4215 will be stored. The default is .gdb_history,
4216 or the value of the environment variable
4219 history size N: The size, in commands, of the command history. The
4220 default is 256, or the value of the environment variable
4223 history save on/off: If this value is set to ON, the history file will
4224 be saved after exiting gdb. If set to OFF, the
4225 file will not be saved. The default is OFF.
4227 history expansion on/off: If this value is set to ON, then csh-like
4228 history expansion will be performed on
4229 command line input. The default is OFF.
4231 radix N: Sets the default radix for input and output. It can be set
4232 to 8, 10, or 16. Note that the argument to "radix" is interpreted
4233 in the current radix, so "set radix 10" is always a no-op.
4235 height N: This integer value is the number of lines on a page. Default
4236 is 24, the current `stty rows'' setting, or the ``li#''
4237 setting from the termcap entry matching the environment
4240 width N: This integer value is the number of characters on a line.
4241 Default is 80, the current `stty cols'' setting, or the ``co#''
4242 setting from the termcap entry matching the environment
4245 Note: ``set screensize'' is obsolete. Use ``set height'' and
4246 ``set width'' instead.
4248 print address on/off: Print memory addresses in various command displays,
4249 such as stack traces and structure values. Gdb looks
4250 more ``symbolic'' if you turn this off; it looks more
4251 ``machine level'' with it on. Default is ON.
4253 print array on/off: Prettyprint arrays. New convenient format! Default
4256 print demangle on/off: Print C++ symbols in "source" form if on,
4259 print asm-demangle on/off: Same, for assembler level printouts
4262 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
4265 * Support for Epoch Environment.
4267 The epoch environment is a version of Emacs v18 with windowing. One
4268 new command, ``inspect'', is identical to ``print'', except that if you
4269 are running in the epoch environment, the value is printed in its own
4273 * Support for Shared Libraries
4275 GDB can now debug programs and core files that use SunOS shared libraries.
4276 Symbols from a shared library cannot be referenced
4277 before the shared library has been linked with the program (this
4278 happens after you type ``run'' and before the function main() is entered).
4279 At any time after this linking (including when examining core files
4280 from dynamically linked programs), gdb reads the symbols from each
4281 shared library when you type the ``sharedlibrary'' command.
4282 It can be abbreviated ``share''.
4284 sharedlibrary REGEXP: Load shared object library symbols for files
4285 matching a unix regular expression. No argument
4286 indicates to load symbols for all shared libraries.
4288 info sharedlibrary: Status of loaded shared libraries.
4293 A watchpoint stops execution of a program whenever the value of an
4294 expression changes. Checking for this slows down execution
4295 tremendously whenever you are in the scope of the expression, but is
4296 quite useful for catching tough ``bit-spreader'' or pointer misuse
4297 problems. Some machines such as the 386 have hardware for doing this
4298 more quickly, and future versions of gdb will use this hardware.
4300 watch EXP: Set a watchpoint (breakpoint) for an expression.
4302 info watchpoints: Information about your watchpoints.
4304 delete N: Deletes watchpoint number N (same as breakpoints).
4305 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
4306 enable N: Re-enables watchpoint number N (same as breakpoints).
4309 * C++ multiple inheritance
4311 When used with a GCC version 2 compiler, GDB supports multiple inheritance
4314 * C++ exception handling
4316 Gdb now supports limited C++ exception handling. Besides the existing
4317 ability to breakpoint on an exception handler, gdb can breakpoint on
4318 the raising of an exception (before the stack is peeled back to the
4321 catch FOO: If there is a FOO exception handler in the dynamic scope,
4322 set a breakpoint to catch exceptions which may be raised there.
4323 Multiple exceptions (``catch foo bar baz'') may be caught.
4325 info catch: Lists all exceptions which may be caught in the
4326 current stack frame.
4329 * Minor command changes
4331 The command ``call func (arg, arg, ...)'' now acts like the print
4332 command, except it does not print or save a value if the function's result
4333 is void. This is similar to dbx usage.
4335 The ``up'' and ``down'' commands now always print the frame they end up
4336 at; ``up-silently'' and `down-silently'' can be used in scripts to change
4337 frames without printing.
4339 * New directory command
4341 'dir' now adds directories to the FRONT of the source search path.
4342 The path starts off empty. Source files that contain debug information
4343 about the directory in which they were compiled can be found even
4344 with an empty path; Sun CC and GCC include this information. If GDB can't
4345 find your source file in the current directory, type "dir .".
4347 * Configuring GDB for compilation
4349 For normal use, type ``./configure host''. See README or gdb.texinfo
4352 GDB now handles cross debugging. If you are remotely debugging between
4353 two different machines, type ``./configure host -target=targ''.
4354 Host is the machine where GDB will run; targ is the machine
4355 where the program that you are debugging will run.