1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.1
6 * Windows Thread Information Block access.
8 On Windows targets, GDB now supports displaying the Windows Thread
9 Information Block (TIB) structure. This structure is visible either
10 by using the new command `info w32 thread-information-block' or, by
11 dereferencing the new convenience variable named `$_tlb', a
12 thread-specific pointer to the TIB. This feature is also supported
13 when remote debugging using GDBserver.
19 Return the address of the Windows Thread Information Block of a given thread.
23 In response to several of the tracepoint packets, the target may now
24 also respond with a number of intermediate `qRelocInsn' request
25 packets before the final result packet, to have GDB handle
26 relocating an instruction to execute at a different address. This
27 is particularly useful for stubs that support fast tracepoints. GDB
28 reports support for this feature in the qSupported packet.
30 * The source command now accepts a -s option to force searching for the
31 script in the source search path even if the script name specifies
34 * New features in the GDB remote stub, GDBserver
36 - GDBserver now support tracepoints (including fast tracepoints).
37 The feature is currently supported by the i386-linux and
38 amd64-linux builds. See the "Tracepoints support in gdbserver"
39 section in the manual for more information.
41 - GDBserver now supports x86_64 Windows 64-bit debugging.
43 * GDB now sends xmlRegisters= in qSupported packet to indicate that
44 it understands register description.
46 * The --batch flag now disables pagination and queries.
48 * X86 general purpose registers
50 GDB now supports reading/writing byte, word and double-word x86
51 general purpose registers directly. This means you can use, say,
52 $ah or $ax to refer, respectively, to the byte register AH and
53 16-bit word register AX that are actually portions of the 32-bit
54 register EAX or 64-bit register RAX.
56 * The `commands' command now accepts a range of breakpoints to modify.
57 A plain `commands' following a command that creates multiple
58 breakpoints affects all the breakpoints set by that command. This
59 applies to breakpoints set by `rbreak', and also applies when a
60 single `break' command creates multiple breakpoints (e.g.,
61 breakpoints on overloaded c++ functions).
63 * The `rbreak' command now accepts a filename specification as part of
64 its argument, limiting the functions selected by the regex to those
65 in the specified file.
67 * Support for remote debugging Windows and SymbianOS shared libraries
68 from Unix hosts has been improved. Non Windows GDB builds now can
69 understand target reported file names that follow MS-DOS based file
70 system semantics, such as file names that include drive letters and
71 use the backslash character as directory separator. This makes it
72 possible to transparently use the "set sysroot" and "set
73 solib-search-path" on Unix hosts to point as host copies of the
74 target's shared libraries. See the new command "set
75 target-file-system-kind" described below, and the "Commands to
76 specify files" section in the user manual for more information.
80 set target-file-system-kind unix|dos-based|auto
81 show target-file-system-kind
82 Set or show the assumed file system kind for target reported file
85 save breakpoints <filename>
86 Save all current breakpoint definitions to a file suitable for use
87 in a later debugging session. To read the saved breakpoint
88 definitions, use the `source' command.
90 `save tracepoints' is a new alias for `save-tracepoints'. The latter
95 ** The GDB Python API now has access to breakpoints, symbols, symbol
96 tables, program spaces, and frame's code blocks. Additionally, GDB
97 Parameters can now be created from the API, and manipulated via
100 ** New functions gdb.target_charset, gdb.target_wide_charset,
101 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
103 ** New exception gdb.GdbError.
105 ** Pretty-printers are now also looked up in the current program space.
107 ** Pretty-printers can now be individually enabled and disabled.
109 ** GDB now looks for names of Python scripts to auto-load in a
110 special section named `.debug_gdb_scripts', in addition to looking
111 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
113 * Tracepoint actions were unified with breakpoint commands. In particular,
114 there are no longer differences in "info break" output for breakpoints and
115 tracepoints and the "commands" command can be used for both tracepoints and
120 ARM Symbian arm*-*-symbianelf*
122 * D language support.
123 GDB now supports debugging programs written in the D programming
126 *** Changes in GDB 7.1
132 GDB now supports importing of namespaces in C++. This enables the
133 user to inspect variables from imported namespaces. Support for
134 namepace aliasing has also been added. So, if a namespace is
135 aliased in the current scope (e.g. namepace C=A; ) the user can
136 print variables using the alias (e.g. (gdb) print C::x).
140 All known bugs relating to the printing of virtual base class were
141 fixed. It is now possible to call overloaded static methods using a
146 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
147 and reinterpret_cast<> are now handled by the C++ expression parser.
151 Xilinx MicroBlaze microblaze-*-*
156 Xilinx MicroBlaze microblaze
159 * Multi-program debugging.
161 GDB now has support for multi-program (a.k.a. multi-executable or
162 multi-exec) debugging. This allows for debugging multiple inferiors
163 simultaneously each running a different program under the same GDB
164 session. See "Debugging Multiple Inferiors and Programs" in the
165 manual for more information. This implied some user visible changes
166 in the multi-inferior support. For example, "info inferiors" now
167 lists inferiors that are not running yet or that have exited
168 already. See also "New commands" and "New options" below.
170 * New tracing features
172 GDB's tracepoint facility now includes several new features:
174 ** Trace state variables
176 GDB tracepoints now include support for trace state variables, which
177 are variables managed by the target agent during a tracing
178 experiment. They are useful for tracepoints that trigger each
179 other, so for instance one tracepoint can count hits in a variable,
180 and then a second tracepoint has a condition that is true when the
181 count reaches a particular value. Trace state variables share the
182 $-syntax of GDB convenience variables, and can appear in both
183 tracepoint actions and condition expressions. Use the "tvariable"
184 command to create, and "info tvariables" to view; see "Trace State
185 Variables" in the manual for more detail.
189 GDB now includes an option for defining fast tracepoints, which
190 targets may implement more efficiently, such as by installing a jump
191 into the target agent rather than a trap instruction. The resulting
192 speedup can be by two orders of magnitude or more, although the
193 tradeoff is that some program locations on some target architectures
194 might not allow fast tracepoint installation, for instance if the
195 instruction to be replaced is shorter than the jump. To request a
196 fast tracepoint, use the "ftrace" command, with syntax identical to
197 the regular trace command.
199 ** Disconnected tracing
201 It is now possible to detach GDB from the target while it is running
202 a trace experiment, then reconnect later to see how the experiment
203 is going. In addition, a new variable disconnected-tracing lets you
204 tell the target agent whether to continue running a trace if the
205 connection is lost unexpectedly.
209 GDB now has the ability to save the trace buffer into a file, and
210 then use that file as a target, similarly to you can do with
211 corefiles. You can select trace frames, print data that was
212 collected in them, and use tstatus to display the state of the
213 tracing run at the moment that it was saved. To create a trace
214 file, use "tsave <filename>", and to use it, do "target tfile
217 ** Circular trace buffer
219 You can ask the target agent to handle the trace buffer as a
220 circular buffer, discarding the oldest trace frames to make room for
221 newer ones, by setting circular-trace-buffer to on. This feature may
222 not be available for all target agents.
227 The disassemble command, when invoked with two arguments, now requires
228 the arguments to be comma-separated.
231 The info variables command now displays variable definitions. Files
232 which only declare a variable are not shown.
235 The source command is now capable of sourcing Python scripts.
236 This feature is dependent on the debugger being build with Python
239 Related to this enhancement is also the introduction of a new command
240 "set script-extension" (see below).
242 * New commands (for set/show, see "New options" below)
244 record save [<FILENAME>]
245 Save a file (in core file format) containing the process record
246 execution log for replay debugging at a later time.
248 record restore <FILENAME>
249 Restore the process record execution log that was saved at an
250 earlier time, for replay debugging.
252 add-inferior [-copies <N>] [-exec <FILENAME>]
255 clone-inferior [-copies <N>] [ID]
256 Make a new inferior ready to execute the same program another
262 maint info program-spaces
263 List the program spaces loaded into GDB.
265 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
266 show remote interrupt-sequence
267 Allow the user to select one of ^C, a BREAK signal or BREAK-g
268 as the sequence to the remote target in order to interrupt the execution.
269 Ctrl-C is a default. Some system prefers BREAK which is high level of
270 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
271 Magic SysRq g. It is BREAK signal and character 'g'.
273 set remote interrupt-on-connect [on | off]
274 show remote interrupt-on-connect
275 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
276 remote target when gdb connects to it. This is needed when you debug
279 set remotebreak [on | off]
281 Deprecated. Use "set/show remote interrupt-sequence" instead.
283 tvariable $NAME [ = EXP ]
284 Create or modify a trace state variable.
287 List trace state variables and their values.
289 delete tvariable $NAME ...
290 Delete one or more trace state variables.
293 Evaluate the given expressions without collecting anything into the
294 trace buffer. (Valid in tracepoint actions only.)
296 ftrace FN / FILE:LINE / *ADDR
297 Define a fast tracepoint at the given function, line, or address.
299 * New expression syntax
301 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
302 GDB now parses 0b101010 identically with 42.
306 set follow-exec-mode new|same
307 show follow-exec-mode
308 Control whether GDB reuses the same inferior across an exec call or
309 creates a new one. This is useful to be able to restart the old
310 executable after the inferior having done an exec call.
312 set default-collect EXPR, ...
314 Define a list of expressions to be collected at each tracepoint.
315 This is a useful way to ensure essential items are not overlooked,
316 such as registers or a critical global variable.
318 set disconnected-tracing
319 show disconnected-tracing
320 If set to 1, the target is instructed to continue tracing if it
321 loses its connection to GDB. If 0, the target is to stop tracing
324 set circular-trace-buffer
325 show circular-trace-buffer
326 If set to on, the target is instructed to use a circular trace buffer
327 and discard the oldest trace frames instead of stopping the trace due
328 to a full trace buffer. If set to off, the trace stops when the buffer
329 fills up. Some targets may not support this.
331 set script-extension off|soft|strict
332 show script-extension
333 If set to "off", the debugger does not perform any script language
334 recognition, and all sourced files are assumed to be GDB scripts.
335 If set to "soft" (the default), files are sourced according to
336 filename extension, falling back to GDB scripts if the first
338 If set to "strict", files are sourced according to filename extension.
340 set ada trust-PAD-over-XVS on|off
341 show ada trust-PAD-over-XVS
342 If off, activate a workaround against a bug in the debugging information
343 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
344 the GCC sources for more information about the GNAT encoding and
345 PAD types in particular). It is always safe to set this option to
346 off, but this introduces a slight performance penalty. The default
349 * Python API Improvements
351 ** GDB provides the new class gdb.LazyString. This is useful in
352 some pretty-printing cases. The new method gdb.Value.lazy_string
353 provides a simple way to create objects of this type.
355 ** The fields returned by gdb.Type.fields now have an
356 `is_base_class' attribute.
358 ** The new method gdb.Type.range returns the range of an array type.
360 ** The new method gdb.parse_and_eval can be used to parse and
361 evaluate an expression.
366 Define a trace state variable.
369 Get the current value of a trace state variable.
372 Set desired tracing behavior upon disconnection.
375 Set the trace buffer to be linear or circular.
378 Get data about the tracepoints currently in use.
382 Process record now works correctly with hardware watchpoints.
384 Multiple bug fixes have been made to the mips-irix port, making it
385 much more reliable. In particular:
386 - Debugging threaded applications is now possible again. Previously,
387 GDB would hang while starting the program, or while waiting for
388 the program to stop at a breakpoint.
389 - Attaching to a running process no longer hangs.
390 - An error occurring while loading a core file has been fixed.
391 - Changing the value of the PC register now works again. This fixes
392 problems observed when using the "jump" command, or when calling
393 a function from GDB, or even when assigning a new value to $pc.
394 - With the "finish" and "return" commands, the return value for functions
395 returning a small array is now correctly printed.
396 - It is now possible to break on shared library code which gets executed
397 during a shared library init phase (code executed while executing
398 their .init section). Previously, the breakpoint would have no effect.
399 - GDB is now able to backtrace through the signal handler for
400 non-threaded programs.
402 PIE (Position Independent Executable) programs debugging is now supported.
403 This includes debugging execution of PIC (Position Independent Code) shared
404 libraries although for that, it should be possible to run such libraries as an
407 *** Changes in GDB 7.0
409 * GDB now has an interface for JIT compilation. Applications that
410 dynamically generate code can create symbol files in memory and register
411 them with GDB. For users, the feature should work transparently, and
412 for JIT developers, the interface is documented in the GDB manual in the
413 "JIT Compilation Interface" chapter.
415 * Tracepoints may now be conditional. The syntax is as for
416 breakpoints; either an "if" clause appended to the "trace" command,
417 or the "condition" command is available. GDB sends the condition to
418 the target for evaluation using the same bytecode format as is used
419 for tracepoint actions.
421 * "disassemble" command with a /r modifier, print the raw instructions
422 in hex as well as in symbolic form.
424 * Process record and replay
426 In a architecture environment that supports ``process record and
427 replay'', ``process record and replay'' target can record a log of
428 the process execution, and replay it with both forward and reverse
431 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
432 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
433 set execution-direction {forward|reverse}, for targets that support
436 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
437 feature is available with a native GDB running on kernel version
440 * GDB now has support for multi-byte and wide character sets on the
441 target. Strings whose character type is wchar_t, char16_t, or
442 char32_t are now correctly printed. GDB supports wide- and unicode-
443 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
444 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
445 `printf'. This feature requires iconv to work properly; if your
446 system does not have a working iconv, GDB can use GNU libiconv. See
447 the installation instructions for more information.
449 * GDB now supports automatic retrieval of shared library files from
450 remote targets. To use this feature, specify a system root that begins
451 with the `remote:' prefix, either via the `set sysroot' command or via
452 the `--with-sysroot' configure-time option.
454 * "info sharedlibrary" now takes an optional regex of libraries to show,
455 and it now reports if a shared library has no debugging information.
457 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
458 now complete on file names.
460 * When completing in expressions, gdb will attempt to limit
461 completions to allowable structure or union fields, where appropriate.
462 For instance, consider:
464 # struct example { int f1; double f2; };
465 # struct example variable;
468 If the user types TAB at the end of this command line, the available
469 completions will be "f1" and "f2".
471 * Inlined functions are now supported. They show up in backtraces, and
472 the "step", "next", and "finish" commands handle them automatically.
474 * GDB now supports the token-splicing (##) and stringification (#)
475 operators when expanding macros. It also supports variable-arity
478 * GDB now supports inspecting extra signal information, exported by
479 the new $_siginfo convenience variable. The feature is currently
480 implemented on linux ARM, i386 and amd64.
482 * GDB can now display the VFP floating point registers and NEON vector
483 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
484 can provide these registers (requires Linux 2.6.30 or later). Remote
485 and simulator targets may also provide them.
490 Search memory for a sequence of bytes.
493 Turn off `+'/`-' protocol acknowledgments to permit more efficient
494 operation over reliable transport links. Use of this packet is
495 controlled by the `set remote noack-packet' command.
498 Kill the process with the specified process ID. Use this in preference
499 to `k' when multiprocess protocol extensions are supported.
502 Obtains additional operating system information
506 Read or write additional signal information.
508 * Removed remote protocol undocumented extension
510 An undocumented extension to the remote protocol's `S' stop reply
511 packet that permited the stub to pass a process id was removed.
512 Remote servers should use the `T' stop reply packet instead.
514 * The "disassemble" command now supports an optional /m modifier to print mixed
517 * GDB now supports multiple function calling conventions according to the
518 DWARF-2 DW_AT_calling_convention function attribute.
520 * The SH target utilizes the aforementioned change to distinguish between gcc
521 and Renesas calling convention. It also adds the new CLI commands
522 `set/show sh calling-convention'.
524 * GDB can now read compressed debug sections, as produced by GNU gold
525 with the --compress-debug-sections=zlib flag.
527 * 64-bit core files are now supported on AIX.
529 * Thread switching is now supported on Tru64.
531 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
532 which will be allocated using malloc later in program execution.
534 * The qXfer:libraries:read remote procotol packet now allows passing a
535 list of section offsets.
537 * On GNU/Linux, GDB can now attach to stopped processes. Several race
538 conditions handling signals delivered during attach or thread creation
539 have also been fixed.
541 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
542 From the user's standpoint, all unqualified instances of True and False
543 are treated as the standard definitions, regardless of context.
545 * GDB now parses C++ symbol and type names more flexibly. For
548 template<typename T> class C { };
551 GDB will now correctly handle all of:
553 ptype C<char const *>
555 ptype C<const char *>
558 * New features in the GDB remote stub, gdbserver
560 - The "--wrapper" command-line argument tells gdbserver to use a
561 wrapper program to launch programs for debugging.
563 - On PowerPC and S/390 targets, it is now possible to use a single
564 gdbserver executable to debug both 32-bit and 64-bit programs.
565 (This requires gdbserver itself to be built as a 64-bit executable.)
567 - gdbserver uses the new noack protocol mode for TCP connections to
568 reduce communications latency, if also supported and enabled in GDB.
570 - Support for the sparc64-linux-gnu target is now included in
573 - The amd64-linux build of gdbserver now supports debugging both
574 32-bit and 64-bit programs.
576 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
577 now support hardware watchpoints, and will use them automatically
582 GDB now has support for scripting using Python. Whether this is
583 available is determined at configure time.
585 New GDB commands can now be written in Python.
587 * Ada tasking support
589 Ada tasks can now be inspected in GDB. The following commands have
593 Print the list of Ada tasks.
595 Print detailed information about task number N.
597 Print the task number of the current task.
599 Switch the context of debugging to task number N.
601 * Support for user-defined prefixed commands. The "define" command can
602 add new commands to existing prefixes, e.g. "target".
604 * Multi-inferior, multi-process debugging.
606 GDB now has generalized support for multi-inferior debugging. See
607 "Debugging Multiple Inferiors" in the manual for more information.
608 Although availability still depends on target support, the command
609 set is more uniform now. The GNU/Linux specific multi-forks support
610 has been migrated to this new framework. This implied some user
611 visible changes; see "New commands" and also "Removed commands"
614 * Target descriptions can now describe the target OS ABI. See the
615 "Target Description Format" section in the user manual for more
618 * Target descriptions can now describe "compatible" architectures
619 to indicate that the target can execute applications for a different
620 architecture in addition to those for the main target architecture.
621 See the "Target Description Format" section in the user manual for
624 * Multi-architecture debugging.
626 GDB now includes general supports for debugging applications on
627 hybrid systems that use more than one single processor architecture
628 at the same time. Each such hybrid architecture still requires
629 specific support to be added. The only hybrid architecture supported
630 in this version of GDB is the Cell Broadband Engine.
632 * GDB now supports integrated debugging of Cell/B.E. applications that
633 use both the PPU and SPU architectures. To enable support for hybrid
634 Cell/B.E. debugging, you need to configure GDB to support both the
635 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
636 --enable-targets configure option.
638 * Non-stop mode debugging.
640 For some targets, GDB now supports an optional mode of operation in
641 which you can examine stopped threads while other threads continue
642 to execute freely. This is referred to as non-stop mode, with the
643 old mode referred to as all-stop mode. See the "Non-Stop Mode"
644 section in the user manual for more information.
646 To be able to support remote non-stop debugging, a remote stub needs
647 to implement the non-stop mode remote protocol extensions, as
648 described in the "Remote Non-Stop" section of the user manual. The
649 GDB remote stub, gdbserver, has been adjusted to support these
650 extensions on linux targets.
652 * New commands (for set/show, see "New options" below)
654 catch syscall [NAME(S) | NUMBER(S)]
655 Catch system calls. Arguments, which should be names of system
656 calls or their numbers, mean catch only those syscalls. Without
657 arguments, every syscall will be caught. When the inferior issues
658 any of the specified syscalls, GDB will stop and announce the system
659 call, both when it is called and when its call returns. This
660 feature is currently available with a native GDB running on the
661 Linux Kernel, under the following architectures: x86, x86_64,
662 PowerPC and PowerPC64.
664 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
666 Search memory for a sequence of bytes.
668 maint set python print-stack
669 maint show python print-stack
670 Show a stack trace when an error is encountered in a Python script.
673 Invoke CODE by passing it to the Python interpreter.
678 These allow macros to be defined, undefined, and listed
682 Show operating system information about processes.
685 List the inferiors currently under GDB's control.
688 Switch focus to inferior number NUM.
691 Detach from inferior number NUM.
694 Kill inferior number NUM.
699 show spu stop-on-load
700 Control whether to stop for new SPE threads during Cell/B.E. debugging.
702 set spu auto-flush-cache
703 show spu auto-flush-cache
704 Control whether to automatically flush the software-managed cache
705 during Cell/B.E. debugging.
707 set sh calling-convention
708 show sh calling-convention
709 Control the calling convention used when calling SH target functions.
713 Control display of timestamps with GDB debugging output.
715 set disassemble-next-line
716 show disassemble-next-line
717 Control display of disassembled source lines or instructions when
720 set remote noack-packet
721 show remote noack-packet
722 Set/show the use of remote protocol QStartNoAckMode packet. See above
723 under "New remote packets."
725 set remote query-attached-packet
726 show remote query-attached-packet
727 Control use of remote protocol `qAttached' (query-attached) packet.
729 set remote read-siginfo-object
730 show remote read-siginfo-object
731 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
734 set remote write-siginfo-object
735 show remote write-siginfo-object
736 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
739 set remote reverse-continue
740 show remote reverse-continue
741 Control use of remote protocol 'bc' (reverse-continue) packet.
743 set remote reverse-step
744 show remote reverse-step
745 Control use of remote protocol 'bs' (reverse-step) packet.
747 set displaced-stepping
748 show displaced-stepping
749 Control displaced stepping mode. Displaced stepping is a way to
750 single-step over breakpoints without removing them from the debuggee.
751 Also known as "out-of-line single-stepping".
755 Control display of debugging info for displaced stepping.
757 maint set internal-error
758 maint show internal-error
759 Control what GDB does when an internal error is detected.
761 maint set internal-warning
762 maint show internal-warning
763 Control what GDB does when an internal warning is detected.
768 Use a wrapper program to launch programs for debugging.
770 set multiple-symbols (all|ask|cancel)
771 show multiple-symbols
772 The value of this variable can be changed to adjust the debugger behavior
773 when an expression or a breakpoint location contains an ambiguous symbol
774 name (an overloaded function name, for instance).
776 set breakpoint always-inserted
777 show breakpoint always-inserted
778 Keep breakpoints always inserted in the target, as opposed to inserting
779 them when resuming the target, and removing them when the target stops.
780 This option can improve debugger performance on slow remote targets.
782 set arm fallback-mode (arm|thumb|auto)
783 show arm fallback-mode
784 set arm force-mode (arm|thumb|auto)
786 These commands control how ARM GDB determines whether instructions
787 are ARM or Thumb. The default for both settings is auto, which uses
788 the current CPSR value for instructions without symbols; previous
789 versions of GDB behaved as if "set arm fallback-mode arm".
791 set disable-randomization
792 show disable-randomization
793 Standalone programs run with the virtual address space randomization enabled
794 by default on some platforms. This option keeps the addresses stable across
795 multiple debugging sessions.
799 Control whether other threads are stopped or not when some thread hits
804 Requests that asynchronous execution is enabled in the target, if available.
805 In this case, it's possible to resume target in the background, and interact
806 with GDB while the target is running. "show target-async" displays the
807 current state of asynchronous execution of the target.
809 set target-wide-charset
810 show target-wide-charset
811 The target-wide-charset is the name of the character set that GDB
812 uses when printing characters whose type is wchar_t.
814 set tcp auto-retry (on|off)
816 set tcp connect-timeout
817 show tcp connect-timeout
818 These commands allow GDB to retry failed TCP connections to a remote stub
819 with a specified timeout period; this is useful if the stub is launched
820 in parallel with GDB but may not be ready to accept connections immediately.
822 set libthread-db-search-path
823 show libthread-db-search-path
824 Control list of directories which GDB will search for appropriate
827 set schedule-multiple (on|off)
828 show schedule-multiple
829 Allow GDB to resume all threads of all processes or only threads of
834 Use more aggressive caching for accesses to the stack. This improves
835 performance of remote debugging (particularly backtraces) without
836 affecting correctness.
838 set interactive-mode (on|off|auto)
839 show interactive-mode
840 Control whether GDB runs in interactive mode (on) or not (off).
841 When in interactive mode, GDB waits for the user to answer all
842 queries. Otherwise, GDB does not wait and assumes the default
843 answer. When set to auto (the default), GDB determines which
844 mode to use based on the stdin settings.
849 For program forks, this is replaced by the new more generic `info
850 inferiors' command. To list checkpoints, you can still use the
851 `info checkpoints' command, which was an alias for the `info forks'
855 Replaced by the new `inferior' command. To switch between
856 checkpoints, you can still use the `restart' command, which was an
857 alias for the `fork' command.
860 This is removed, since some targets don't have a notion of
861 processes. To switch between processes, you can still use the
862 `inferior' command using GDB's own inferior number.
865 For program forks, this is replaced by the new more generic `kill
866 inferior' command. To delete a checkpoint, you can still use the
867 `delete checkpoint' command, which was an alias for the `delete
871 For program forks, this is replaced by the new more generic `detach
872 inferior' command. To detach a checkpoint, you can still use the
873 `detach checkpoint' command, which was an alias for the `detach
876 * New native configurations
878 x86/x86_64 Darwin i[34567]86-*-darwin*
880 x86_64 MinGW x86_64-*-mingw*
884 Lattice Mico32 lm32-*
885 x86 DICOS i[34567]86-*-dicos*
886 x86_64 DICOS x86_64-*-dicos*
889 * The GDB remote stub, gdbserver, now supports x86 Windows CE
890 (mingw32ce) debugging.
896 These commands were actually not implemented on any target.
898 *** Changes in GDB 6.8
900 * New native configurations
902 NetBSD/hppa hppa*-*netbsd*
903 Xtensa GNU/Linux xtensa*-*-linux*
907 NetBSD/hppa hppa*-*-netbsd*
908 Xtensa GNU/Lunux xtensa*-*-linux*
910 * Change in command line behavior -- corefiles vs. process ids.
912 When the '-p NUMBER' or '--pid NUMBER' options are used, and
913 attaching to process NUMBER fails, GDB no longer attempts to open a
914 core file named NUMBER. Attaching to a program using the -c option
915 is no longer supported. Instead, use the '-p' or '--pid' options.
917 * GDB can now be built as a native debugger for debugging Windows x86
918 (mingw32) Portable Executable (PE) programs.
920 * Pending breakpoints no longer change their number when their address
923 * GDB now supports breakpoints with multiple locations,
924 including breakpoints on C++ constructors, inside C++ templates,
925 and in inlined functions.
927 * GDB's ability to debug optimized code has been improved. GDB more
928 accurately identifies function bodies and lexical blocks that occupy
929 more than one contiguous range of addresses.
931 * Target descriptions can now describe registers for PowerPC.
933 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
934 registers on PowerPC targets.
936 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
937 targets even when the libthread_db library is not available.
939 * The GDB remote stub, gdbserver, now supports the new file transfer
940 commands (remote put, remote get, and remote delete).
942 * The GDB remote stub, gdbserver, now supports run and attach in
943 extended-remote mode.
945 * hppa*64*-*-hpux11* target broken
946 The debugger is unable to start a program and fails with the following
947 error: "Error trying to get information about dynamic linker".
948 The gdb-6.7 release is also affected.
950 * GDB now supports the --enable-targets= configure option to allow
951 building a single GDB executable that supports multiple remote
952 target architectures.
954 * GDB now supports debugging C and C++ programs which use the
955 Decimal Floating Point extension. In addition, the PowerPC target
956 now has a set of pseudo-registers to inspect decimal float values
957 stored in two consecutive float registers.
959 * The -break-insert MI command can optionally create pending
962 * Improved support for debugging Ada
963 Many improvements to the Ada language support have been made. These
965 - Better support for Ada2005 interface types
966 - Improved handling of arrays and slices in general
967 - Better support for Taft-amendment types
968 - The '{type} ADDRESS' expression is now allowed on the left hand-side
970 - Improved command completion in Ada
973 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
978 set print frame-arguments (all|scalars|none)
979 show print frame-arguments
980 The value of this variable can be changed to control which argument
981 values should be printed by the debugger when displaying a frame.
986 Transfer files to and from a remote target, and delete remote files.
993 Transfer files to and from a remote target, and delete remote files.
1002 Open, close, read, write, and delete files on the remote system.
1005 Attach to an existing process on the remote system, in extended-remote
1009 Run a new process on the remote system, in extended-remote mode.
1011 *** Changes in GDB 6.7
1013 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
1014 bfd, libiberty and opcodes, as revealed by static analysis donated by
1015 Coverity, Inc. (http://scan.coverity.com).
1017 * When looking up multiply-defined global symbols, GDB will now prefer the
1018 symbol definition in the current shared library if it was built using the
1019 -Bsymbolic linker option.
1021 * When the Text User Interface (TUI) is not configured, GDB will now
1022 recognize the -tui command-line option and print a message that the TUI
1025 * The GDB remote stub, gdbserver, now has lower overhead for high
1026 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
1028 * GDB for MIPS targets now autodetects whether a remote target provides
1029 32-bit or 64-bit register values.
1031 * Support for C++ member pointers has been improved.
1033 * GDB now understands XML target descriptions, which specify the
1034 target's overall architecture. GDB can read a description from
1035 a local file or over the remote serial protocol.
1037 * Vectors of single-byte data use a new integer type which is not
1038 automatically displayed as character or string data.
1040 * The /s format now works with the print command. It displays
1041 arrays of single-byte integers and pointers to single-byte integers
1044 * Target descriptions can now describe target-specific registers,
1045 for architectures which have implemented the support (currently
1046 only ARM, M68K, and MIPS).
1048 * GDB and the GDB remote stub, gdbserver, now support the XScale
1051 * The GDB remote stub, gdbserver, has been updated to support
1052 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
1053 has been rewritten to use the standard GDB remote protocol.
1055 * GDB can now step into C++ functions which are called through thunks.
1057 * GDB for the Cell/B.E. SPU now supports overlay debugging.
1059 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
1060 layout. It also supports a TextSeg= and DataSeg= response when only
1061 segment base addresses (rather than offsets) are available.
1063 * The /i format now outputs any trailing branch delay slot instructions
1064 immediately following the last instruction within the count specified.
1066 * The GDB remote protocol "T" stop reply packet now supports a
1067 "library" response. Combined with the new "qXfer:libraries:read"
1068 packet, this response allows GDB to debug shared libraries on targets
1069 where the operating system manages the list of loaded libraries (e.g.
1070 Windows and SymbianOS).
1072 * The GDB remote stub, gdbserver, now supports dynamic link libraries
1073 (DLLs) on Windows and Windows CE targets.
1075 * GDB now supports a faster verification that a .debug file matches its binary
1076 according to its build-id signature, if the signature is present.
1082 Enable or disable hardware flow control (RTS/CTS) on the serial port
1083 when debugging using remote targets.
1085 set mem inaccessible-by-default
1086 show mem inaccessible-by-default
1087 If the target supplies a memory map, for instance via the remote
1088 protocol's "qXfer:memory-map:read" packet, setting this variable
1089 prevents GDB from accessing memory outside the memory map. This
1090 is useful for targets with memory mapped registers or which react
1091 badly to accesses of unmapped address space.
1093 set breakpoint auto-hw
1094 show breakpoint auto-hw
1095 If the target supplies a memory map, for instance via the remote
1096 protocol's "qXfer:memory-map:read" packet, setting this variable
1097 lets GDB use hardware breakpoints automatically for memory regions
1098 where it can not use software breakpoints. This covers both the
1099 "break" command and internal breakpoints used for other commands
1100 including "next" and "finish".
1103 catch exception unhandled
1104 Stop the program execution when Ada exceptions are raised.
1107 Stop the program execution when an Ada assertion failed.
1111 Set an alternate system root for target files. This is a more
1112 general version of "set solib-absolute-prefix", which is now
1113 an alias to "set sysroot".
1116 Provide extended SPU facility status information. This set of
1117 commands is available only when debugging the Cell/B.E. SPU
1120 * New native configurations
1122 OpenBSD/sh sh*-*openbsd*
1125 unset tdesc filename
1127 Use the specified local file as an XML target description, and do
1128 not query the target for its built-in description.
1132 OpenBSD/sh sh*-*-openbsd*
1133 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
1134 Toshiba Media Processor mep-elf
1136 * New remote packets
1139 Ignore the specified signals; pass them directly to the debugged program
1140 without stopping other threads or reporting them to GDB.
1142 qXfer:features:read:
1143 Read an XML target description from the target, which describes its
1148 Read or write contents of an spufs file on the target system. These
1149 packets are available only on the Cell/B.E. SPU architecture.
1151 qXfer:libraries:read:
1152 Report the loaded shared libraries. Combined with new "T" packet
1153 response, this packet allows GDB to debug shared libraries on
1154 targets where the operating system manages the list of loaded
1155 libraries (e.g. Windows and SymbianOS).
1159 Support for these obsolete configurations has been removed.
1167 i[34567]86-*-lynxos*
1168 i[34567]86-*-netware*
1169 i[34567]86-*-sco3.2v5*
1170 i[34567]86-*-sco3.2v4*
1172 i[34567]86-*-sysv4.2*
1175 i[34567]86-*-unixware2*
1176 i[34567]86-*-unixware*
1185 * Other removed features
1192 Various m68k-only ROM monitors.
1199 Various Renesas ROM monitors and debugging interfaces for SH and
1204 Support for a Macraigor serial interface to on-chip debugging.
1205 GDB does not directly support the newer parallel or USB
1210 A debug information format. The predecessor to DWARF 2 and
1211 DWARF 3, which are still supported.
1213 Support for the HP aCC compiler on HP-UX/PA-RISC
1215 SOM-encapsulated symbolic debugging information, automatic
1216 invocation of pxdb, and the aCC custom C++ ABI. This does not
1217 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
1218 with aCC can still be debugged on an assembly level.
1220 MIPS ".pdr" sections
1222 A MIPS-specific format used to describe stack frame layout
1223 in debugging information.
1227 GDB could work with an older version of Guile to debug
1228 the interpreter and Scheme programs running in it.
1230 set mips stack-arg-size
1231 set mips saved-gpreg-size
1233 Use "set mips abi" to control parameter passing for MIPS.
1235 *** Changes in GDB 6.6
1240 Cell Broadband Engine SPU spu-elf
1242 * GDB can now be configured as a cross-debugger targeting native Windows
1243 (mingw32) or Cygwin. It can communicate with a remote debugging stub
1244 running on a Windows system over TCP/IP to debug Windows programs.
1246 * The GDB remote stub, gdbserver, has been updated to support Windows and
1247 Cygwin debugging. Both single-threaded and multi-threaded programs are
1250 * The "set trust-readonly-sections" command works again. This command was
1251 broken in GDB 6.3, 6.4, and 6.5.
1253 * The "load" command now supports writing to flash memory, if the remote
1254 stub provides the required support.
1256 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
1257 longer requires symbolic debug information (e.g. DWARF-2).
1262 unset substitute-path
1263 show substitute-path
1264 Manage a list of substitution rules that GDB uses to rewrite the name
1265 of the directories where the sources are located. This can be useful
1266 for instance when the sources were moved to a different location
1267 between compilation and debugging.
1271 Print each CLI command as it is executed. Each command is prefixed with
1272 a number of `+' symbols representing the nesting depth.
1273 The source command now has a `-v' option to enable the same feature.
1277 The ARM Demon monitor support (RDP protocol, "target rdp").
1279 Kernel Object Display, an embedded debugging feature which only worked with
1280 an obsolete version of Cisco IOS.
1282 The 'set download-write-size' and 'show download-write-size' commands.
1284 * New remote packets
1287 Tell a stub about GDB client features, and request remote target features.
1288 The first feature implemented is PacketSize, which allows the target to
1289 specify the size of packets it can handle - to minimize the number of
1290 packets required and improve performance when connected to a remote
1294 Fetch an OS auxilliary vector from the remote stub. This packet is a
1295 more efficient replacement for qPart:auxv:read.
1297 qXfer:memory-map:read:
1298 Fetch a memory map from the remote stub, including information about
1299 RAM, ROM, and flash memory devices.
1304 Erase and program a flash memory device.
1306 * Removed remote packets
1309 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
1310 used it, and only gdbserver implemented it.
1312 *** Changes in GDB 6.5
1316 Renesas M32C/M16C m32c-elf
1318 Morpho Technologies ms1 ms1-elf
1322 init-if-undefined Initialize a convenience variable, but
1323 only if it doesn't already have a value.
1325 The following commands are presently only implemented for native GNU/Linux:
1327 checkpoint Save a snapshot of the program state.
1329 restart <n> Return the program state to a
1330 previously saved state.
1332 info checkpoints List currently saved checkpoints.
1334 delete-checkpoint <n> Delete a previously saved checkpoint.
1336 set|show detach-on-fork Tell gdb whether to detach from a newly
1337 forked process, or to keep debugging it.
1339 info forks List forks of the user program that
1340 are available to be debugged.
1342 fork <n> Switch to debugging one of several
1343 forks of the user program that are
1344 available to be debugged.
1346 delete-fork <n> Delete a fork from the list of forks
1347 that are available to be debugged (and
1348 kill the forked process).
1350 detach-fork <n> Delete a fork from the list of forks
1351 that are available to be debugged (and
1352 allow the process to continue).
1356 Morpho Technologies ms2 ms1-elf
1358 * Improved Windows host support
1360 GDB now builds as a cross debugger hosted on i686-mingw32, including
1361 native console support, and remote communications using either
1362 network sockets or serial ports.
1364 * Improved Modula-2 language support
1366 GDB can now print most types in the Modula-2 syntax. This includes:
1367 basic types, set types, record types, enumerated types, range types,
1368 pointer types and ARRAY types. Procedure var parameters are correctly
1369 printed and hexadecimal addresses and character constants are also
1370 written in the Modula-2 syntax. Best results can be obtained by using
1371 GNU Modula-2 together with the -gdwarf-2 command line option.
1375 The ARM rdi-share module.
1377 The Netware NLM debug server.
1379 *** Changes in GDB 6.4
1381 * New native configurations
1383 OpenBSD/arm arm*-*-openbsd*
1384 OpenBSD/mips64 mips64-*-openbsd*
1388 Morpho Technologies ms1 ms1-elf
1390 * New command line options
1392 --batch-silent As for --batch, but totally silent.
1393 --return-child-result The debugger will exist with the same value
1394 the child (debugged) program exited with.
1395 --eval-command COMMAND, -ex COMMAND
1396 Execute a single GDB CLI command. This may be
1397 specified multiple times and in conjunction
1398 with the --command (-x) option.
1400 * Deprecated commands removed
1402 The following commands, that were deprecated in 2000, have been
1406 set|show arm disassembly-flavor set|show arm disassembler
1407 othernames set arm disassembler
1408 set|show remotedebug set|show debug remote
1409 set|show archdebug set|show debug arch
1410 set|show eventdebug set|show debug event
1413 * New BSD user-level threads support
1415 It is now possible to debug programs using the user-level threads
1416 library on OpenBSD and FreeBSD. Currently supported (target)
1419 FreeBSD/amd64 x86_64-*-freebsd*
1420 FreeBSD/i386 i386-*-freebsd*
1421 OpenBSD/i386 i386-*-openbsd*
1423 Note that the new kernel threads libraries introduced in FreeBSD 5.x
1424 are not yet supported.
1426 * New support for Matsushita MN10300 w/sim added
1427 (Work in progress). mn10300-elf.
1429 * REMOVED configurations and files
1431 VxWorks and the XDR protocol *-*-vxworks
1432 Motorola MCORE mcore-*-*
1433 National Semiconductor NS32000 ns32k-*-*
1435 * New "set print array-indexes" command
1437 After turning this setting "on", GDB prints the index of each element
1438 when displaying arrays. The default is "off" to preserve the previous
1441 * VAX floating point support
1443 GDB now supports the not-quite-ieee VAX F and D floating point formats.
1445 * User-defined command support
1447 In addition to using $arg0..$arg9 for argument passing, it is now possible
1448 to use $argc to determine now many arguments have been passed. See the
1449 section on user-defined commands in the user manual for more information.
1451 *** Changes in GDB 6.3:
1453 * New command line option
1455 GDB now accepts -l followed by a number to set the timeout for remote
1458 * GDB works with GCC -feliminate-dwarf2-dups
1460 GDB now supports a more compact representation of DWARF-2 debug
1461 information using DW_FORM_ref_addr references. These are produced
1462 by GCC with the option -feliminate-dwarf2-dups and also by some
1463 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
1464 to use -feliminate-dwarf2-dups.
1466 * Internationalization
1468 When supported by the host system, GDB will be built with
1469 internationalization (libintl). The task of marking up the sources is
1470 continued, we're looking forward to our first translation.
1474 Initial support for debugging programs compiled with the GNAT
1475 implementation of the Ada programming language has been integrated
1476 into GDB. In this release, support is limited to expression evaluation.
1478 * New native configurations
1480 GNU/Linux/m32r m32r-*-linux-gnu
1484 GDB's remote protocol now includes support for the 'p' packet. This
1485 packet is used to fetch individual registers from a remote inferior.
1487 * END-OF-LIFE registers[] compatibility module
1489 GDB's internal register infrastructure has been completely rewritten.
1490 The new infrastructure making possible the implementation of key new
1491 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
1494 GDB 6.3 will be the last release to include the the registers[]
1495 compatibility module that allowed out-of-date configurations to
1496 continue to work. This change directly impacts the following
1506 powerpc bdm protocol
1508 Unless there is activity to revive these configurations, they will be
1509 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
1511 * OBSOLETE configurations and files
1513 Configurations that have been declared obsolete in this release have
1514 been commented out. Unless there is activity to revive these
1515 configurations, the next release of GDB will have their sources
1516 permanently REMOVED.
1525 *** Changes in GDB 6.2.1:
1527 * MIPS `break main; run' gave an heuristic-fence-post warning
1529 When attempting to run even a simple program, a warning about
1530 heuristic-fence-post being hit would be reported. This problem has
1533 * MIPS IRIX 'long double' crashed GDB
1535 When examining a long double variable, GDB would get a segmentation
1536 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
1537 IRIX long double values).
1541 A bug in the VAX stack code was causing problems with the "next"
1542 command. This problem has been fixed.
1544 *** Changes in GDB 6.2:
1546 * Fix for ``many threads''
1548 On GNU/Linux systems that use the NPTL threads library, a program
1549 rapidly creating and deleting threads would confuse GDB leading to the
1552 ptrace: No such process.
1553 thread_db_get_info: cannot get thread info: generic error
1555 This problem has been fixed.
1557 * "-async" and "-noasync" options removed.
1559 Support for the broken "-noasync" option has been removed (it caused
1562 * New ``start'' command.
1564 This command runs the program until the begining of the main procedure.
1566 * New BSD Kernel Data Access Library (libkvm) interface
1568 Using ``target kvm'' it is now possible to debug kernel core dumps and
1569 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
1570 platforms. Currently supported (native-only) configurations are:
1572 FreeBSD/amd64 x86_64-*-freebsd*
1573 FreeBSD/i386 i?86-*-freebsd*
1574 NetBSD/i386 i?86-*-netbsd*
1575 NetBSD/m68k m68*-*-netbsd*
1576 NetBSD/sparc sparc-*-netbsd*
1577 OpenBSD/amd64 x86_64-*-openbsd*
1578 OpenBSD/i386 i?86-*-openbsd*
1579 OpenBSD/m68k m68*-openbsd*
1580 OpenBSD/sparc sparc-*-openbsd*
1582 * Signal trampoline code overhauled
1584 Many generic problems with GDB's signal handling code have been fixed.
1585 These include: backtraces through non-contiguous stacks; recognition
1586 of sa_sigaction signal trampolines; backtrace from a NULL pointer
1587 call; backtrace through a signal trampoline; step into and out of
1588 signal handlers; and single-stepping in the signal trampoline.
1590 Please note that kernel bugs are a limiting factor here. These
1591 features have been shown to work on an s390 GNU/Linux system that
1592 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
1594 * Cygwin support for DWARF 2 added.
1596 * New native configurations
1598 GNU/Linux/hppa hppa*-*-linux*
1599 OpenBSD/hppa hppa*-*-openbsd*
1600 OpenBSD/m68k m68*-*-openbsd*
1601 OpenBSD/m88k m88*-*-openbsd*
1602 OpenBSD/powerpc powerpc-*-openbsd*
1603 NetBSD/vax vax-*-netbsd*
1604 OpenBSD/vax vax-*-openbsd*
1606 * END-OF-LIFE frame compatibility module
1608 GDB's internal frame infrastructure has been completely rewritten.
1609 The new infrastructure making it possible to support key new features
1610 including DWARF 2 Call Frame Information. To aid in the task of
1611 migrating old configurations to this new infrastructure, a
1612 compatibility module, that allowed old configurations to continue to
1613 work, was also included.
1615 GDB 6.2 will be the last release to include this frame compatibility
1616 module. This change directly impacts the following configurations:
1626 Unless there is activity to revive these configurations, they will be
1627 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
1629 * REMOVED configurations and files
1631 Sun 3, running SunOS 3 m68*-*-sunos3*
1632 Sun 3, running SunOS 4 m68*-*-sunos4*
1633 Sun 2, running SunOS 3 m68000-*-sunos3*
1634 Sun 2, running SunOS 4 m68000-*-sunos4*
1635 Motorola 680x0 running LynxOS m68*-*-lynxos*
1636 AT&T 3b1/Unix pc m68*-att-*
1637 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
1638 decstation mips-dec-* mips-little-*
1639 riscos mips-*-riscos* mips-*-sysv*
1640 sonymips mips-sony-*
1641 sysv mips*-*-sysv4* (IRIX 5/6 not included)
1643 *** Changes in GDB 6.1.1:
1645 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
1647 The TUI (Text-mode User Interface) is now built as part of a default
1648 GDB configuration. It is enabled by either selecting the TUI with the
1649 command line option "-i=tui" or by running the separate "gdbtui"
1650 program. For more information on the TUI, see the manual "Debugging
1653 * Pending breakpoint support (also included in GDB 6.1)
1655 Support has been added to allow you to specify breakpoints in shared
1656 libraries that have not yet been loaded. If a breakpoint location
1657 cannot be found, and the "breakpoint pending" option is set to auto,
1658 GDB queries you if you wish to make the breakpoint pending on a future
1659 shared-library load. If and when GDB resolves the breakpoint symbol,
1660 the pending breakpoint is removed as one or more regular breakpoints
1663 Pending breakpoints are very useful for GCJ Java debugging.
1665 * Fixed ISO-C build problems
1667 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
1668 non ISO-C code that stopped them being built using a more strict ISO-C
1669 compiler (e.g., IBM's C compiler).
1671 * Fixed build problem on IRIX 5
1673 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
1674 wasn't able to compile compile on an IRIX 5 system.
1676 * Added execute permission to gdb/gdbserver/configure
1678 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
1679 permission. This bug would cause configure to fail on a number of
1680 systems (Solaris, IRIX). Ref: server/519.
1682 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
1684 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
1685 has been updated to use constant array sizes.
1687 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
1689 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
1690 its generated DWARF Call Frame Info. This encoding was causing GDB to
1691 panic, that panic has been fixed. Ref: gdb/1628.
1693 * Fixed a problem when examining parameters in shared library code.
1695 When examining parameters in optimized shared library code generated
1696 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
1697 not available''. GDB now correctly displays the variable's value.
1699 *** Changes in GDB 6.1:
1701 * Removed --with-mmalloc
1703 Support for the mmalloc memory manager has been removed, as it
1704 conflicted with the internal gdb byte cache.
1706 * Changes in AMD64 configurations
1708 The AMD64 target now includes the %cs and %ss registers. As a result
1709 the AMD64 remote protocol has changed; this affects the floating-point
1710 and SSE registers. If you rely on those registers for your debugging,
1711 you should upgrade gdbserver on the remote side.
1713 * Revised SPARC target
1715 The SPARC target has been completely revised, incorporating the
1716 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
1717 support for LynxOS and SunOS 4 has been dropped. Calling functions
1718 from within GDB on operating systems with a non-executable stack
1719 (Solaris, OpenBSD) now works.
1723 GDB has a new C++ demangler which does a better job on the mangled
1724 names generated by current versions of g++. It also runs faster, so
1725 with this and other changes gdb should now start faster on large C++
1728 * DWARF 2 Location Expressions
1730 GDB support for location expressions has been extended to support function
1731 arguments and frame bases. Older versions of GDB could crash when they
1734 * C++ nested types and namespaces
1736 GDB's support for nested types and namespaces in C++ has been
1737 improved, especially if you use the DWARF 2 debugging format. (This
1738 is the default for recent versions of GCC on most platforms.)
1739 Specifically, if you have a class "Inner" defined within a class or
1740 namespace "Outer", then GDB realizes that the class's name is
1741 "Outer::Inner", not simply "Inner". This should greatly reduce the
1742 frequency of complaints about not finding RTTI symbols. In addition,
1743 if you are stopped at inside of a function defined within a namespace,
1744 GDB modifies its name lookup accordingly.
1746 * New native configurations
1748 NetBSD/amd64 x86_64-*-netbsd*
1749 OpenBSD/amd64 x86_64-*-openbsd*
1750 OpenBSD/alpha alpha*-*-openbsd*
1751 OpenBSD/sparc sparc-*-openbsd*
1752 OpenBSD/sparc64 sparc64-*-openbsd*
1754 * New debugging protocols
1756 M32R with SDI protocol m32r-*-elf*
1758 * "set prompt-escape-char" command deleted.
1760 The command "set prompt-escape-char" has been deleted. This command,
1761 and its very obscure effet on GDB's prompt, was never documented,
1762 tested, nor mentioned in the NEWS file.
1764 * OBSOLETE configurations and files
1766 Configurations that have been declared obsolete in this release have
1767 been commented out. Unless there is activity to revive these
1768 configurations, the next release of GDB will have their sources
1769 permanently REMOVED.
1771 Sun 3, running SunOS 3 m68*-*-sunos3*
1772 Sun 3, running SunOS 4 m68*-*-sunos4*
1773 Sun 2, running SunOS 3 m68000-*-sunos3*
1774 Sun 2, running SunOS 4 m68000-*-sunos4*
1775 Motorola 680x0 running LynxOS m68*-*-lynxos*
1776 AT&T 3b1/Unix pc m68*-att-*
1777 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
1778 decstation mips-dec-* mips-little-*
1779 riscos mips-*-riscos* mips-*-sysv*
1780 sonymips mips-sony-*
1781 sysv mips*-*-sysv4* (IRIX 5/6 not included)
1783 * REMOVED configurations and files
1785 SGI Irix-4.x mips-sgi-irix4 or iris4
1786 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
1787 Z8000 simulator z8k-zilog-none or z8ksim
1788 Matsushita MN10200 w/simulator mn10200-*-*
1789 H8/500 simulator h8500-hitachi-hms or h8500hms
1790 HP/PA running BSD hppa*-*-bsd*
1791 HP/PA running OSF/1 hppa*-*-osf*
1792 HP/PA Pro target hppa*-*-pro*
1793 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
1794 386BSD i[3456]86-*-bsd*
1795 Sequent family i[3456]86-sequent-sysv4*
1796 i[3456]86-sequent-sysv*
1797 i[3456]86-sequent-bsd*
1798 SPARC running LynxOS sparc-*-lynxos*
1799 SPARC running SunOS 4 sparc-*-sunos4*
1800 Tsqware Sparclet sparclet-*-*
1801 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
1803 *** Changes in GDB 6.0:
1807 Support for debugging the Objective-C programming language has been
1808 integrated into GDB.
1810 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
1812 DWARF 2's Call Frame Information makes available compiler generated
1813 information that more exactly describes the program's run-time stack.
1814 By using this information, GDB is able to provide more robust stack
1817 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
1818 have been updated to use a new backtrace mechanism which includes
1819 DWARF 2 CFI support.
1823 GDB's remote protocol has been extended to include support for hosted
1824 file I/O (where the remote target uses GDB's file system). See GDB's
1825 remote protocol documentation for details.
1827 * All targets using the new architecture framework.
1829 All of GDB's targets have been updated to use the new internal
1830 architecture framework. The way is now open for future GDB releases
1831 to include cross-architecture native debugging support (i386 on amd64,
1834 * GNU/Linux's Thread Local Storage (TLS)
1836 GDB now includes support for for the GNU/Linux implementation of
1837 per-thread variables.
1839 * GNU/Linux's Native POSIX Thread Library (NPTL)
1841 GDB's thread code has been updated to work with either the new
1842 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
1844 * Separate debug info.
1846 GDB, in conjunction with BINUTILS, now supports a mechanism for
1847 automatically loading debug information from a separate file. Instead
1848 of shipping full debug and non-debug versions of system libraries,
1849 system integrators can now instead ship just the stripped libraries
1850 and optional debug files.
1852 * DWARF 2 Location Expressions
1854 DWARF 2 Location Expressions allow the compiler to more completely
1855 describe the location of variables (even in optimized code) to the
1858 GDB now includes preliminary support for location expressions (support
1859 for DW_OP_piece is still missing).
1863 A number of long standing bugs that caused GDB to die while starting a
1864 Java application have been fixed. GDB's Java support is now
1865 considered "useable".
1867 * GNU/Linux support for fork, vfork, and exec.
1869 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
1870 commands are now implemented for GNU/Linux. They require a 2.5.x or later
1873 * GDB supports logging output to a file
1875 There are two new commands, "set logging" and "show logging", which can be
1876 used to capture GDB's output to a file.
1878 * The meaning of "detach" has changed for gdbserver
1880 The "detach" command will now resume the application, as documented. To
1881 disconnect from gdbserver and leave it stopped, use the new "disconnect"
1884 * d10v, m68hc11 `regs' command deprecated
1886 The `info registers' command has been updated so that it displays the
1887 registers using a format identical to the old `regs' command.
1891 A new command, "maint set profile on/off", has been added. This command can
1892 be used to enable or disable profiling while running GDB, to profile a
1893 session or a set of commands. In addition there is a new configure switch,
1894 "--enable-profiling", which will cause GDB to be compiled with profiling
1895 data, for more informative profiling results.
1897 * Default MI syntax changed to "mi2".
1899 The default MI (machine interface) syntax, enabled by the command line
1900 option "-i=mi", has been changed to "mi2". The previous MI syntax,
1901 "mi1", can be enabled by specifying the option "-i=mi1".
1903 Support for the original "mi0" syntax (included in GDB 5.0) has been
1906 Fix for gdb/192: removed extraneous space when displaying frame level.
1907 Fix for gdb/672: update changelist is now output in mi list format.
1908 Fix for gdb/702: a -var-assign that updates the value now shows up
1909 in a subsequent -var-update.
1911 * New native configurations.
1913 FreeBSD/amd64 x86_64-*-freebsd*
1915 * Multi-arched targets.
1917 HP/PA HPUX11 hppa*-*-hpux*
1918 Renesas M32R/D w/simulator m32r-*-elf*
1920 * OBSOLETE configurations and files
1922 Configurations that have been declared obsolete in this release have
1923 been commented out. Unless there is activity to revive these
1924 configurations, the next release of GDB will have their sources
1925 permanently REMOVED.
1927 Z8000 simulator z8k-zilog-none or z8ksim
1928 Matsushita MN10200 w/simulator mn10200-*-*
1929 H8/500 simulator h8500-hitachi-hms or h8500hms
1930 HP/PA running BSD hppa*-*-bsd*
1931 HP/PA running OSF/1 hppa*-*-osf*
1932 HP/PA Pro target hppa*-*-pro*
1933 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
1934 Sequent family i[3456]86-sequent-sysv4*
1935 i[3456]86-sequent-sysv*
1936 i[3456]86-sequent-bsd*
1937 Tsqware Sparclet sparclet-*-*
1938 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
1940 * REMOVED configurations and files
1943 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
1944 IBM AIX PS/2 i[3456]86-*-aix
1945 i386 running Mach 3.0 i[3456]86-*-mach3*
1946 i386 running Mach i[3456]86-*-mach*
1947 i386 running OSF/1 i[3456]86-*osf1mk*
1948 HP/Apollo 68k Family m68*-apollo*-sysv*,
1950 m68*-hp-bsd*, m68*-hp-hpux*
1951 Argonaut Risc Chip (ARC) arc-*-*
1952 Mitsubishi D30V d30v-*-*
1953 Fujitsu FR30 fr30-*-elf*
1954 OS/9000 i[34]86-*-os9k
1955 I960 with MON960 i960-*-coff
1957 * MIPS $fp behavior changed
1959 The convenience variable $fp, for the MIPS, now consistently returns
1960 the address of the current frame's base. Previously, depending on the
1961 context, $fp could refer to either $sp or the current frame's base
1962 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
1963 The GNU Source-Level Debugger''.
1965 *** Changes in GDB 5.3:
1967 * GNU/Linux shared library multi-threaded performance improved.
1969 When debugging a multi-threaded application on GNU/Linux, GDB now uses
1970 `/proc', in preference to `ptrace' for memory reads. This may result
1971 in an improvement in the start-up time of multi-threaded, shared
1972 library applications when run under GDB. One GDB user writes: ``loads
1973 shared libs like mad''.
1975 * ``gdbserver'' now supports multi-threaded applications on some targets
1977 Support for debugging multi-threaded applications which use
1978 the GNU/Linux LinuxThreads package has been added for
1979 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
1980 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
1982 * GDB now supports C/C++ preprocessor macros.
1984 GDB now expands preprocessor macro invocations in C/C++ expressions,
1985 and provides various commands for showing macro definitions and how
1988 The new command `macro expand EXPRESSION' expands any macro
1989 invocations in expression, and shows the result.
1991 The new command `show macro MACRO-NAME' shows the definition of the
1992 macro named MACRO-NAME, and where it was defined.
1994 Most compilers don't include information about macros in the debugging
1995 information by default. In GCC 3.1, for example, you need to compile
1996 your program with the options `-gdwarf-2 -g3'. If the macro
1997 information is present in the executable, GDB will read it.
1999 * Multi-arched targets.
2001 DEC Alpha (partial) alpha*-*-*
2002 DEC VAX (partial) vax-*-*
2004 National Semiconductor NS32000 (partial) ns32k-*-*
2005 Motorola 68000 (partial) m68k-*-*
2006 Motorola MCORE mcore-*-*
2010 Fujitsu FRV architecture added by Red Hat frv*-*-*
2013 * New native configurations
2015 Alpha NetBSD alpha*-*-netbsd*
2016 SH NetBSD sh*-*-netbsdelf*
2017 MIPS NetBSD mips*-*-netbsd*
2018 UltraSPARC NetBSD sparc64-*-netbsd*
2020 * OBSOLETE configurations and files
2022 Configurations that have been declared obsolete in this release have
2023 been commented out. Unless there is activity to revive these
2024 configurations, the next release of GDB will have their sources
2025 permanently REMOVED.
2027 Mitsubishi D30V d30v-*-*
2028 OS/9000 i[34]86-*-os9k
2029 IBM AIX PS/2 i[3456]86-*-aix
2030 Fujitsu FR30 fr30-*-elf*
2031 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2032 Argonaut Risc Chip (ARC) arc-*-*
2033 i386 running Mach 3.0 i[3456]86-*-mach3*
2034 i386 running Mach i[3456]86-*-mach*
2035 i386 running OSF/1 i[3456]86-*osf1mk*
2036 HP/Apollo 68k Family m68*-apollo*-sysv*,
2038 m68*-hp-bsd*, m68*-hp-hpux*
2039 I960 with MON960 i960-*-coff
2041 * OBSOLETE languages
2043 CHILL, a Pascal like language used by telecommunications companies.
2045 * REMOVED configurations and files
2047 AMD 29k family via UDI a29k-amd-udi, udi29k
2048 A29K VxWorks a29k-*-vxworks
2049 AMD 29000 embedded, using EBMON a29k-none-none
2050 AMD 29000 embedded with COFF a29k-none-coff
2051 AMD 29000 embedded with a.out a29k-none-aout
2053 testsuite/gdb.hp/gdb.threads-hp/ directory
2055 * New command "set max-user-call-depth <nnn>"
2057 This command allows the user to limit the call depth of user-defined
2058 commands. The default is 1024.
2060 * Changes in FreeBSD/i386 native debugging.
2062 Support for the "generate-core-file" has been added.
2064 * New commands "dump", "append", and "restore".
2066 These commands allow data to be copied from target memory
2067 to a bfd-format or binary file (dump and append), and back
2068 from a file into memory (restore).
2070 * Improved "next/step" support on multi-processor Alpha Tru64.
2072 The previous single-step mechanism could cause unpredictable problems,
2073 including the random appearance of SIGSEGV or SIGTRAP signals. The use
2074 of a software single-step mechanism prevents this.
2076 *** Changes in GDB 5.2.1:
2084 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
2085 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
2086 Fix, by Joel Brobecker imported from mainline.
2088 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
2089 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
2090 Fix, by Fred Fish, imported from mainline.
2092 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
2093 Surprisingly enough, it works now.
2094 By Michal Ludvig, imported from mainline.
2096 i386 hardware watchpoint support:
2097 avoid misses on second run for some targets.
2098 By Pierre Muller, imported from mainline.
2100 *** Changes in GDB 5.2:
2102 * New command "set trust-readonly-sections on[off]".
2104 This command is a hint that tells gdb that read-only sections
2105 really are read-only (ie. that their contents will not change).
2106 In this mode, gdb will go to the object file rather than the
2107 target to read memory from read-only sections (such as ".text").
2108 This can be a significant performance improvement on some
2109 (notably embedded) targets.
2111 * New command "generate-core-file" (or "gcore").
2113 This new gdb command allows the user to drop a core file of the child
2114 process state at any time. So far it's been implemented only for
2115 GNU/Linux and Solaris, but should be relatively easily ported to other
2116 hosts. Argument is core file name (defaults to core.<pid>).
2118 * New command line option
2120 GDB now accepts --pid or -p followed by a process id.
2122 * Change in command line behavior -- corefiles vs. process ids.
2124 There is a subtle behavior in the way in which GDB handles
2125 command line arguments. The first non-flag argument is always
2126 a program to debug, but the second non-flag argument may either
2127 be a corefile or a process id. Previously, GDB would attempt to
2128 open the second argument as a corefile, and if that failed, would
2129 issue a superfluous error message and then attempt to attach it as
2130 a process. Now, if the second argument begins with a non-digit,
2131 it will be treated as a corefile. If it begins with a digit,
2132 GDB will attempt to attach it as a process, and if no such process
2133 is found, will then attempt to open it as a corefile.
2135 * Changes in ARM configurations.
2137 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
2138 configuration is fully multi-arch.
2140 * New native configurations
2142 ARM NetBSD arm*-*-netbsd*
2143 x86 OpenBSD i[3456]86-*-openbsd*
2144 AMD x86-64 running GNU/Linux x86_64-*-linux-*
2145 Sparc64 running FreeBSD sparc64-*-freebsd*
2149 Sanyo XStormy16 xstormy16-elf
2151 * OBSOLETE configurations and files
2153 Configurations that have been declared obsolete in this release have
2154 been commented out. Unless there is activity to revive these
2155 configurations, the next release of GDB will have their sources
2156 permanently REMOVED.
2158 AMD 29k family via UDI a29k-amd-udi, udi29k
2159 A29K VxWorks a29k-*-vxworks
2160 AMD 29000 embedded, using EBMON a29k-none-none
2161 AMD 29000 embedded with COFF a29k-none-coff
2162 AMD 29000 embedded with a.out a29k-none-aout
2164 testsuite/gdb.hp/gdb.threads-hp/ directory
2166 * REMOVED configurations and files
2168 TI TMS320C80 tic80-*-*
2170 PowerPC Solaris powerpcle-*-solaris*
2171 PowerPC Windows NT powerpcle-*-cygwin32
2172 PowerPC Netware powerpc-*-netware*
2173 Harris/CXUX m88k m88*-harris-cxux*
2174 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
2175 ns32k-utek-sysv* ns32k-utek-*
2176 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
2177 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
2178 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
2179 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
2180 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
2182 * Changes to command line processing
2184 The new `--args' feature can be used to specify command-line arguments
2185 for the inferior from gdb's command line.
2187 * Changes to key bindings
2189 There is a new `operate-and-get-next' function bound to `C-o'.
2191 *** Changes in GDB 5.1.1
2193 Fix compile problem on DJGPP.
2195 Fix a problem with floating-point registers on the i386 being
2198 Fix to stop GDB crashing on .debug_str debug info.
2200 Numerous documentation fixes.
2202 Numerous testsuite fixes.
2204 *** Changes in GDB 5.1:
2206 * New native configurations
2208 Alpha FreeBSD alpha*-*-freebsd*
2209 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
2210 MIPS GNU/Linux mips*-*-linux*
2211 MIPS SGI Irix 6.x mips*-sgi-irix6*
2212 ia64 AIX ia64-*-aix*
2213 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
2217 Motorola 68HC11 and 68HC12 m68hc11-elf
2219 UltraSparc running GNU/Linux sparc64-*-linux*
2221 * OBSOLETE configurations and files
2223 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
2224 Harris/CXUX m88k m88*-harris-cxux*
2225 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
2226 ns32k-utek-sysv* ns32k-utek-*
2227 TI TMS320C80 tic80-*-*
2229 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
2230 PowerPC Solaris powerpcle-*-solaris*
2231 PowerPC Windows NT powerpcle-*-cygwin32
2232 PowerPC Netware powerpc-*-netware*
2233 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
2234 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
2235 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
2236 Apple Macintosh (MPW) host N/A
2238 stuff.c (Program to stuff files into a specially prepared space in kdb)
2239 kdb-start.c (Main loop for the standalone kernel debugger)
2241 Configurations that have been declared obsolete in this release have
2242 been commented out. Unless there is activity to revive these
2243 configurations, the next release of GDB will have their sources
2244 permanently REMOVED.
2246 * REMOVED configurations and files
2248 Altos 3068 m68*-altos-*
2249 Convex c1-*-*, c2-*-*
2251 ARM RISCix arm-*-* (as host)
2255 * GDB has been converted to ISO C.
2257 GDB's source code has been converted to ISO C. In particular, the
2258 sources are fully protoized, and rely on standard headers being
2263 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
2265 * The MI enabled by default.
2267 The new machine oriented interface (MI) introduced in GDB 5.0 has been
2268 revised and enabled by default. Packages which use GDB as a debugging
2269 engine behind a UI or another front end are encouraged to switch to
2270 using the GDB/MI interface, instead of the old annotations interface
2271 which is now deprecated.
2273 * Support for debugging Pascal programs.
2275 GDB now includes support for debugging Pascal programs. The following
2276 main features are supported:
2278 - Pascal-specific data types such as sets;
2280 - automatic recognition of Pascal sources based on file-name
2283 - Pascal-style display of data types, variables, and functions;
2285 - a Pascal expression parser.
2287 However, some important features are not yet supported.
2289 - Pascal string operations are not supported at all;
2291 - there are some problems with boolean types;
2293 - Pascal type hexadecimal constants are not supported
2294 because they conflict with the internal variables format;
2296 - support for Pascal objects and classes is not full yet;
2298 - unlike Pascal, GDB is case-sensitive for symbol names.
2300 * Changes in completion.
2302 Commands such as `shell', `run' and `set args', which pass arguments
2303 to inferior programs, now complete on file names, similar to what
2304 users expect at the shell prompt.
2306 Commands which accept locations, such as `disassemble', `print',
2307 `breakpoint', `until', etc. now complete on filenames as well as
2308 program symbols. Thus, if you type "break foob TAB", and the source
2309 files linked into the programs include `foobar.c', that file name will
2310 be one of the candidates for completion. However, file names are not
2311 considered for completion after you typed a colon that delimits a file
2312 name from a name of a function in that file, as in "break foo.c:bar".
2314 `set demangle-style' completes on available demangling styles.
2316 * New platform-independent commands:
2318 It is now possible to define a post-hook for a command as well as a
2319 hook that runs before the command. For more details, see the
2320 documentation of `hookpost' in the GDB manual.
2322 * Changes in GNU/Linux native debugging.
2324 Support for debugging multi-threaded programs has been completely
2325 revised for all platforms except m68k and sparc. You can now debug as
2326 many threads as your system allows you to have.
2328 Attach/detach is supported for multi-threaded programs.
2330 Support for SSE registers was added for x86. This doesn't work for
2331 multi-threaded programs though.
2333 * Changes in MIPS configurations.
2335 Multi-arch support is enabled for all MIPS configurations.
2337 GDB can now be built as native debugger on SGI Irix 6.x systems for
2338 debugging n32 executables. (Debugging 64-bit executables is not yet
2341 * Unified support for hardware watchpoints in all x86 configurations.
2343 Most (if not all) native x86 configurations support hardware-assisted
2344 breakpoints and watchpoints in a unified manner. This support
2345 implements debug register sharing between watchpoints, which allows to
2346 put a virtually infinite number of watchpoints on the same address,
2347 and also supports watching regions up to 16 bytes with several debug
2350 The new maintenance command `maintenance show-debug-regs' toggles
2351 debugging print-outs in functions that insert, remove, and test
2352 watchpoints and hardware breakpoints.
2354 * Changes in the DJGPP native configuration.
2356 New command ``info dos sysinfo'' displays assorted information about
2357 the CPU, OS, memory, and DPMI server.
2359 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
2360 display information about segment descriptors stored in GDT, LDT, and
2363 New commands ``info dos pde'' and ``info dos pte'' display entries
2364 from Page Directory and Page Tables (for now works with CWSDPMI only).
2365 New command ``info dos address-pte'' displays the Page Table entry for
2366 a given linear address.
2368 GDB can now pass command lines longer than 126 characters to the
2369 program being debugged (requires an update to the libdbg.a library
2370 which is part of the DJGPP development kit).
2372 DWARF2 debug info is now supported.
2374 It is now possible to `step' and `next' through calls to `longjmp'.
2376 * Changes in documentation.
2378 All GDB documentation was converted to GFDL, the GNU Free
2379 Documentation License.
2381 Tracepoints-related commands are now fully documented in the GDB
2384 TUI, the Text-mode User Interface, is now documented in the manual.
2386 Tracepoints-related commands are now fully documented in the GDB
2389 The "GDB Internals" manual now has an index. It also includes
2390 documentation of `ui_out' functions, GDB coding standards, x86
2391 hardware watchpoints, and memory region attributes.
2393 * GDB's version number moved to ``version.in''
2395 The Makefile variable VERSION has been replaced by the file
2396 ``version.in''. People creating GDB distributions should update the
2397 contents of this file.
2401 GUD support is now a standard part of the EMACS distribution.
2403 *** Changes in GDB 5.0:
2405 * Improved support for debugging FP programs on x86 targets
2407 Unified and much-improved support for debugging floating-point
2408 programs on all x86 targets. In particular, ``info float'' now
2409 displays the FP registers in the same format on all x86 targets, with
2410 greater level of detail.
2412 * Improvements and bugfixes in hardware-assisted watchpoints
2414 It is now possible to watch array elements, struct members, and
2415 bitfields with hardware-assisted watchpoints. Data-read watchpoints
2416 on x86 targets no longer erroneously trigger when the address is
2419 * Improvements in the native DJGPP version of GDB
2421 The distribution now includes all the scripts and auxiliary files
2422 necessary to build the native DJGPP version on MS-DOS/MS-Windows
2423 machines ``out of the box''.
2425 The DJGPP version can now debug programs that use signals. It is
2426 possible to catch signals that happened in the debuggee, deliver
2427 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
2428 would kill the program being debugged.) Programs that hook hardware
2429 interrupts (keyboard, timer, etc.) can also be debugged.
2431 It is now possible to debug DJGPP programs that redirect their
2432 standard handles or switch them to raw (as opposed to cooked) mode, or
2433 even close them. The command ``run < foo > bar'' works as expected,
2434 and ``info terminal'' reports useful information about the debuggee's
2435 terminal, including raw/cooked mode, redirection, etc.
2437 The DJGPP version now uses termios functions for console I/O, which
2438 enables debugging graphics programs. Interrupting GDB with Ctrl-C
2441 DOS-style file names with drive letters are now fully supported by
2444 It is now possible to debug DJGPP programs that switch their working
2445 directory. It is also possible to rerun the debuggee any number of
2446 times without restarting GDB; thus, you can use the same setup,
2447 breakpoints, etc. for many debugging sessions.
2449 * New native configurations
2451 ARM GNU/Linux arm*-*-linux*
2452 PowerPC GNU/Linux powerpc-*-linux*
2456 Motorola MCore mcore-*-*
2457 x86 VxWorks i[3456]86-*-vxworks*
2458 PowerPC VxWorks powerpc-*-vxworks*
2459 TI TMS320C80 tic80-*-*
2461 * OBSOLETE configurations
2463 Altos 3068 m68*-altos-*
2464 Convex c1-*-*, c2-*-*
2466 ARM RISCix arm-*-* (as host)
2469 Configurations that have been declared obsolete will be commented out,
2470 but the code will be left in place. If there is no activity to revive
2471 these configurations before the next release of GDB, the sources will
2472 be permanently REMOVED.
2474 * Gould support removed
2476 Support for the Gould PowerNode and NP1 has been removed.
2478 * New features for SVR4
2480 On SVR4 native platforms (such as Solaris), if you attach to a process
2481 without first loading a symbol file, GDB will now attempt to locate and
2482 load symbols from the running process's executable file.
2484 * Many C++ enhancements
2486 C++ support has been greatly improved. Overload resolution now works properly
2487 in almost all cases. RTTI support is on the way.
2489 * Remote targets can connect to a sub-program
2491 A popen(3) style serial-device has been added. This device starts a
2492 sub-process (such as a stand-alone simulator) and then communicates
2493 with that. The sub-program to run is specified using the syntax
2494 ``|<program> <args>'' vis:
2496 (gdb) set remotedebug 1
2497 (gdb) target extended-remote |mn10300-elf-sim program-args
2499 * MIPS 64 remote protocol
2501 A long standing bug in the mips64 remote protocol where by GDB
2502 expected certain 32 bit registers (ex SR) to be transfered as 32
2503 instead of 64 bits has been fixed.
2505 The command ``set remote-mips64-transfers-32bit-regs on'' has been
2506 added to provide backward compatibility with older versions of GDB.
2508 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
2510 The command ``set remotebinarydownload'' command has been replaced by
2511 ``set remote X-packet''. Other commands in ``set remote'' family
2512 include ``set remote P-packet''.
2514 * Breakpoint commands accept ranges.
2516 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
2517 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
2518 ``tracepoint passcount'' also accepts a range of tracepoints.
2520 * ``apropos'' command added.
2522 The ``apropos'' command searches through command names and
2523 documentation strings, printing out matches, making it much easier to
2524 try to find a command that does what you are looking for.
2528 A new machine oriented interface (MI) has been added to GDB. This
2529 interface is designed for debug environments running GDB as a separate
2530 process. This is part of the long term libGDB project. See the
2531 "GDB/MI" chapter of the GDB manual for further information. It can be
2532 enabled by configuring with:
2534 .../configure --enable-gdbmi
2536 *** Changes in GDB-4.18:
2538 * New native configurations
2540 HP-UX 10.20 hppa*-*-hpux10.20
2541 HP-UX 11.x hppa*-*-hpux11.0*
2542 M68K GNU/Linux m68*-*-linux*
2546 Fujitsu FR30 fr30-*-elf*
2547 Intel StrongARM strongarm-*-*
2548 Mitsubishi D30V d30v-*-*
2550 * OBSOLETE configurations
2552 Gould PowerNode, NP1 np1-*-*, pn-*-*
2554 Configurations that have been declared obsolete will be commented out,
2555 but the code will be left in place. If there is no activity to revive
2556 these configurations before the next release of GDB, the sources will
2557 be permanently REMOVED.
2561 As a compatibility experiment, GDB's source files buildsym.h and
2562 buildsym.c have been converted to pure standard C, no longer
2563 containing any K&R compatibility code. We believe that all systems in
2564 use today either come with a standard C compiler, or have a GCC port
2565 available. If this is not true, please report the affected
2566 configuration to bug-gdb@gnu.org immediately. See the README file for
2567 information about getting a standard C compiler if you don't have one
2572 GDB now uses readline 2.2.
2574 * set extension-language
2576 You can now control the mapping between filename extensions and source
2577 languages by using the `set extension-language' command. For instance,
2578 you can ask GDB to treat .c files as C++ by saying
2579 set extension-language .c c++
2580 The command `info extensions' lists all of the recognized extensions
2581 and their associated languages.
2583 * Setting processor type for PowerPC and RS/6000
2585 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
2586 you can use the `set processor' command to specify what variant of the
2587 PowerPC family you are debugging. The command
2591 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
2592 following PowerPC and RS6000 variants:
2594 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
2595 rs6000 IBM RS6000 ("POWER") architecture, user-level view
2597 403GC IBM PowerPC 403GC
2598 505 Motorola PowerPC 505
2599 860 Motorola PowerPC 860 or 850
2600 601 Motorola PowerPC 601
2601 602 Motorola PowerPC 602
2602 603 Motorola/IBM PowerPC 603 or 603e
2603 604 Motorola PowerPC 604 or 604e
2604 750 Motorola/IBM PowerPC 750 or 750
2606 At the moment, this command just tells GDB what to name the
2607 special-purpose processor registers. Since almost all the affected
2608 registers are inaccessible to user-level programs, this command is
2609 only useful for remote debugging in its present form.
2613 Thanks to a major code donation from Hewlett-Packard, GDB now has much
2614 more extensive support for HP-UX. Added features include shared
2615 library support, kernel threads and hardware watchpoints for 11.00,
2616 support for HP's ANSI C and C++ compilers, and a compatibility mode
2617 for xdb and dbx commands.
2621 HP's donation includes the new concept of catchpoints, which is a
2622 generalization of the old catch command. On HP-UX, it is now possible
2623 to catch exec, fork, and vfork, as well as library loading.
2625 This means that the existing catch command has changed; its first
2626 argument now specifies the type of catch to be set up. See the
2627 output of "help catch" for a list of catchpoint types.
2629 * Debugging across forks
2631 On HP-UX, you can choose which process to debug when a fork() happens
2636 HP has donated a curses-based terminal user interface (TUI). To get
2637 it, build with --enable-tui. Although this can be enabled for any
2638 configuration, at present it only works for native HP debugging.
2640 * GDB remote protocol additions
2642 A new protocol packet 'X' that writes binary data is now available.
2643 Default behavior is to try 'X', then drop back to 'M' if the stub
2644 fails to respond. The settable variable `remotebinarydownload'
2645 allows explicit control over the use of 'X'.
2647 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
2648 full 64-bit address. The command
2650 set remoteaddresssize 32
2652 can be used to revert to the old behaviour. For existing remote stubs
2653 the change should not be noticed, as the additional address information
2656 In order to assist in debugging stubs, you may use the maintenance
2657 command `packet' to send any text string to the stub. For instance,
2659 maint packet heythere
2661 sends the packet "$heythere#<checksum>". Note that it is very easy to
2662 disrupt a debugging session by sending the wrong packet at the wrong
2665 The compare-sections command allows you to compare section data on the
2666 target to what is in the executable file without uploading or
2667 downloading, by comparing CRC checksums.
2669 * Tracing can collect general expressions
2671 You may now collect general expressions at tracepoints. This requires
2672 further additions to the target-side stub; see tracepoint.c and
2673 doc/agentexpr.texi for further details.
2675 * mask-address variable for Mips
2677 For Mips targets, you may control the zeroing of the upper 32 bits of
2678 a 64-bit address by entering `set mask-address on'. This is mainly
2679 of interest to users of embedded R4xxx and R5xxx processors.
2681 * Higher serial baud rates
2683 GDB's serial code now allows you to specify baud rates 57600, 115200,
2684 230400, and 460800 baud. (Note that your host system may not be able
2685 to achieve all of these rates.)
2689 The i960 configuration now includes an initial implementation of a
2690 builtin simulator, contributed by Jim Wilson.
2693 *** Changes in GDB-4.17:
2695 * New native configurations
2697 Alpha GNU/Linux alpha*-*-linux*
2698 Unixware 2.x i[3456]86-unixware2*
2699 Irix 6.x mips*-sgi-irix6*
2700 PowerPC GNU/Linux powerpc-*-linux*
2701 PowerPC Solaris powerpcle-*-solaris*
2702 Sparc GNU/Linux sparc-*-linux*
2703 Motorola sysV68 R3V7.1 m68k-motorola-sysv
2707 Argonaut Risc Chip (ARC) arc-*-*
2708 Hitachi H8/300S h8300*-*-*
2709 Matsushita MN10200 w/simulator mn10200-*-*
2710 Matsushita MN10300 w/simulator mn10300-*-*
2711 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
2712 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
2713 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
2714 Mitsubishi D10V w/simulator d10v-*-*
2715 Mitsubishi M32R/D w/simulator m32r-*-elf*
2716 Tsqware Sparclet sparclet-*-*
2717 NEC V850 w/simulator v850-*-*
2719 * New debugging protocols
2721 ARM with RDI protocol arm*-*-*
2722 M68K with dBUG monitor m68*-*-{aout,coff,elf}
2723 DDB and LSI variants of PMON protocol mips*-*-*
2724 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
2725 PowerPC with SDS protocol powerpc{,le}-*-eabi
2726 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
2730 All configurations can now understand and use the DWARF 2 debugging
2731 format. The choice is automatic, if the symbol file contains DWARF 2
2736 GDB now includes basic Java language support. This support is
2737 only useful with Java compilers that produce native machine code.
2739 * solib-absolute-prefix and solib-search-path
2741 For SunOS and SVR4 shared libraries, you may now set the prefix for
2742 loading absolute shared library symbol files, and the search path for
2743 locating non-absolute shared library symbol files.
2745 * Live range splitting
2747 GDB can now effectively debug code for which GCC has performed live
2748 range splitting as part of its optimization. See gdb/doc/LRS for
2749 more details on the expected format of the stabs information.
2753 GDB's support for the GNU Hurd, including thread debugging, has been
2754 updated to work with current versions of the Hurd.
2758 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
2759 instruction set. ARM GDB automatically detects when Thumb
2760 instructions are in use, and adjusts disassembly and backtracing
2765 GDB's MIPS target configurations now handle the MIP16 16-bit
2770 GDB now includes support for overlays; if an executable has been
2771 linked such that multiple sections are based at the same address, GDB
2772 will decide which section to use for symbolic info. You can choose to
2773 control the decision manually, using overlay commands, or implement
2774 additional target-side support and use "overlay load-target" to bring
2775 in the overlay mapping. Do "help overlay" for more detail.
2779 The command "info symbol <address>" displays information about
2780 the symbol at the specified address.
2784 The standard remote protocol now includes an extension that allows
2785 asynchronous collection and display of trace data. This requires
2786 extensive support in the target-side debugging stub. Tracing mode
2787 includes a new interaction mode in GDB and new commands: see the
2788 file tracepoint.c for more details.
2792 Configurations for embedded MIPS now include a simulator contributed
2793 by Cygnus Solutions. The simulator supports the instruction sets
2794 of most MIPS variants.
2798 Sparc configurations may now include the ERC32 simulator contributed
2799 by the European Space Agency. The simulator is not built into
2800 Sparc targets by default; configure with --enable-sim to include it.
2804 For target configurations that may include multiple variants of a
2805 basic architecture (such as MIPS and SH), you may now set the
2806 architecture explicitly. "set arch" sets, "info arch" lists
2807 the possible architectures.
2809 *** Changes in GDB-4.16:
2811 * New native configurations
2813 Windows 95, x86 Windows NT i[345]86-*-cygwin32
2814 M68K NetBSD m68k-*-netbsd*
2815 PowerPC AIX 4.x powerpc-*-aix*
2816 PowerPC MacOS powerpc-*-macos*
2817 PowerPC Windows NT powerpcle-*-cygwin32
2818 RS/6000 AIX 4.x rs6000-*-aix4*
2822 ARM with RDP protocol arm-*-*
2823 I960 with MON960 i960-*-coff
2824 MIPS VxWorks mips*-*-vxworks*
2825 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
2826 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
2828 Matra Sparclet sparclet-*-*
2832 The powerpc-eabi configuration now includes the PSIM simulator,
2833 contributed by Andrew Cagney, with assistance from Mike Meissner.
2834 PSIM is a very elaborate model of the PowerPC, including not only
2835 basic instruction set execution, but also details of execution unit
2836 performance and I/O hardware. See sim/ppc/README for more details.
2840 GDB now works with Solaris 2.5.
2842 * Windows 95/NT native
2844 GDB will now work as a native debugger on Windows 95 and Windows NT.
2845 To build it from source, you must use the "gnu-win32" environment,
2846 which uses a DLL to emulate enough of Unix to run the GNU tools.
2847 Further information, binaries, and sources are available at
2848 ftp.cygnus.com, under pub/gnu-win32.
2850 * dont-repeat command
2852 If a user-defined command includes the command `dont-repeat', then the
2853 command will not be repeated if the user just types return. This is
2854 useful if the command is time-consuming to run, so that accidental
2855 extra keystrokes don't run the same command many times.
2857 * Send break instead of ^C
2859 The standard remote protocol now includes an option to send a break
2860 rather than a ^C to the target in order to interrupt it. By default,
2861 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
2863 * Remote protocol timeout
2865 The standard remote protocol includes a new variable `remotetimeout'
2866 that allows you to set the number of seconds before GDB gives up trying
2867 to read from the target. The default value is 2.
2869 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
2871 By default GDB will automatically keep track of objects as they are
2872 loaded and unloaded by the dynamic linker. By using the command `set
2873 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
2874 when shared library events occur, thus allowing you to set breakpoints
2875 in shared libraries which are explicitly loaded by the inferior.
2877 Note this feature does not work on hpux8. On hpux9 you must link
2878 /usr/lib/end.o into your program. This feature should work
2879 automatically on hpux10.
2881 * Irix 5.x hardware watchpoint support
2883 Irix 5 configurations now support the use of hardware watchpoints.
2885 * Mips protocol "SYN garbage limit"
2887 When debugging a Mips target using the `target mips' protocol, you
2888 may set the number of characters that GDB will ignore by setting
2889 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
2890 every character. The default value is 1050.
2892 * Recording and replaying remote debug sessions
2894 If you set `remotelogfile' to the name of a file, gdb will write to it
2895 a recording of a remote debug session. This recording may then be
2896 replayed back to gdb using "gdbreplay". See gdbserver/README for
2897 details. This is useful when you have a problem with GDB while doing
2898 remote debugging; you can make a recording of the session and send it
2899 to someone else, who can then recreate the problem.
2901 * Speedups for remote debugging
2903 GDB includes speedups for downloading and stepping MIPS systems using
2904 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
2905 and more efficient S-record downloading.
2907 * Memory use reductions and statistics collection
2909 GDB now uses less memory and reports statistics about memory usage.
2910 Try the `maint print statistics' command, for example.
2912 *** Changes in GDB-4.15:
2914 * Psymtabs for XCOFF
2916 The symbol reader for AIX GDB now uses partial symbol tables. This
2917 can greatly improve startup time, especially for large executables.
2919 * Remote targets use caching
2921 Remote targets now use a data cache to speed up communication with the
2922 remote side. The data cache could lead to incorrect results because
2923 it doesn't know about volatile variables, thus making it impossible to
2924 debug targets which use memory mapped I/O devices. `set remotecache
2925 off' turns the the data cache off.
2927 * Remote targets may have threads
2929 The standard remote protocol now includes support for multiple threads
2930 in the target system, using new protocol commands 'H' and 'T'. See
2931 gdb/remote.c for details.
2935 If GDB is configured with `--enable-netrom', then it will include
2936 support for the NetROM ROM emulator from XLNT Designs. The NetROM
2937 acts as though it is a bank of ROM on the target board, but you can
2938 write into it over the network. GDB's support consists only of
2939 support for fast loading into the emulated ROM; to debug, you must use
2940 another protocol, such as standard remote protocol. The usual
2941 sequence is something like
2943 target nrom <netrom-hostname>
2945 target remote <netrom-hostname>:1235
2949 GDB now includes support for the Apple Macintosh, as a host only. It
2950 may be run as either an MPW tool or as a standalone application, and
2951 it can debug through the serial port. All the usual GDB commands are
2952 available, but to the target command, you must supply "serial" as the
2953 device type instead of "/dev/ttyXX". See mpw-README in the main
2954 directory for more information on how to build. The MPW configuration
2955 scripts */mpw-config.in support only a few targets, and only the
2956 mips-idt-ecoff target has been tested.
2960 GDB configuration now uses autoconf. This is not user-visible,
2961 but does simplify configuration and building.
2965 GDB now supports hpux10.
2967 *** Changes in GDB-4.14:
2969 * New native configurations
2971 x86 FreeBSD i[345]86-*-freebsd
2972 x86 NetBSD i[345]86-*-netbsd
2973 NS32k NetBSD ns32k-*-netbsd
2974 Sparc NetBSD sparc-*-netbsd
2978 A29K VxWorks a29k-*-vxworks
2979 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
2980 CPU32 EST-300 emulator m68*-*-est*
2981 PowerPC ELF powerpc-*-elf
2984 * Alpha OSF/1 support for procfs
2986 GDB now supports procfs under OSF/1-2.x and higher, which makes it
2987 possible to attach to running processes. As the mounting of the /proc
2988 filesystem is optional on the Alpha, GDB automatically determines
2989 the availability of /proc during startup. This can lead to problems
2990 if /proc is unmounted after GDB has been started.
2992 * Arguments to user-defined commands
2994 User commands may accept up to 10 arguments separated by whitespace.
2995 Arguments are accessed within the user command via $arg0..$arg9. A
2998 print $arg0 + $arg1 + $arg2
3000 To execute the command use:
3003 Defines the command "adder" which prints the sum of its three arguments.
3004 Note the arguments are text substitutions, so they may reference variables,
3005 use complex expressions, or even perform inferior function calls.
3007 * New `if' and `while' commands
3009 This makes it possible to write more sophisticated user-defined
3010 commands. Both commands take a single argument, which is the
3011 expression to evaluate, and must be followed by the commands to
3012 execute, one per line, if the expression is nonzero, the list being
3013 terminated by the word `end'. The `if' command list may include an
3014 `else' word, which causes the following commands to be executed only
3015 if the expression is zero.
3017 * Fortran source language mode
3019 GDB now includes partial support for Fortran 77. It will recognize
3020 Fortran programs and can evaluate a subset of Fortran expressions, but
3021 variables and functions may not be handled correctly. GDB will work
3022 with G77, but does not yet know much about symbols emitted by other
3025 * Better HPUX support
3027 Most debugging facilities now work on dynamic executables for HPPAs
3028 running hpux9 or later. You can attach to running dynamically linked
3029 processes, but by default the dynamic libraries will be read-only, so
3030 for instance you won't be able to put breakpoints in them. To change
3031 that behavior do the following before running the program:
3037 This will cause the libraries to be mapped private and read-write.
3038 To revert to the normal behavior, do this:
3044 You cannot set breakpoints or examine data in the library until after
3045 the library is loaded if the function/data symbols do not have
3048 GDB can now also read debug symbols produced by the HP C compiler on
3049 HPPAs (sorry, no C++, Fortran or 68k support).
3051 * Target byte order now dynamically selectable
3053 You can choose which byte order to use with a target system, via the
3054 commands "set endian big" and "set endian little", and you can see the
3055 current setting by using "show endian". You can also give the command
3056 "set endian auto", in which case GDB will use the byte order
3057 associated with the executable. Currently, only embedded MIPS
3058 configurations support dynamic selection of target byte order.
3060 * New DOS host serial code
3062 This version uses DPMI interrupts to handle buffered I/O, so you
3063 no longer need to run asynctsr when debugging boards connected to
3066 *** Changes in GDB-4.13:
3068 * New "complete" command
3070 This lists all the possible completions for the rest of the line, if it
3071 were to be given as a command itself. This is intended for use by emacs.
3073 * Trailing space optional in prompt
3075 "set prompt" no longer adds a space for you after the prompt you set. This
3076 allows you to set a prompt which ends in a space or one that does not.
3078 * Breakpoint hit counts
3080 "info break" now displays a count of the number of times the breakpoint
3081 has been hit. This is especially useful in conjunction with "ignore"; you
3082 can ignore a large number of breakpoint hits, look at the breakpoint info
3083 to see how many times the breakpoint was hit, then run again, ignoring one
3084 less than that number, and this will get you quickly to the last hit of
3087 * Ability to stop printing at NULL character
3089 "set print null-stop" will cause GDB to stop printing the characters of
3090 an array when the first NULL is encountered. This is useful when large
3091 arrays actually contain only short strings.
3093 * Shared library breakpoints
3095 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
3096 breakpoints in shared libraries before the executable is run.
3098 * Hardware watchpoints
3100 There is a new hardware breakpoint for the watch command for sparclite
3101 targets. See gdb/sparclite/hw_breakpoint.note.
3103 Hardware watchpoints are also now supported under GNU/Linux.
3107 Annotations have been added. These are for use with graphical interfaces,
3108 and are still experimental. Currently only gdba.el uses these.
3110 * Improved Irix 5 support
3112 GDB now works properly with Irix 5.2.
3114 * Improved HPPA support
3116 GDB now works properly with the latest GCC and GAS.
3118 * New native configurations
3120 Sequent PTX4 i[34]86-sequent-ptx4
3121 HPPA running OSF/1 hppa*-*-osf*
3122 Atari TT running SVR4 m68*-*-sysv4*
3123 RS/6000 LynxOS rs6000-*-lynxos*
3127 OS/9000 i[34]86-*-os9k
3128 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
3131 * Hitachi SH7000 and E7000-PC ICE support
3133 There is now support for communicating with the Hitachi E7000-PC ICE.
3134 This is available automatically when GDB is configured for the SH.
3138 As usual, a variety of small fixes and improvements, both generic
3139 and configuration-specific. See the ChangeLog for more detail.
3141 *** Changes in GDB-4.12:
3143 * Irix 5 is now supported
3147 GDB-4.12 on the HPPA has a number of changes which make it unable
3148 to debug the output from the currently released versions of GCC and
3149 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
3150 of GCC and GAS, versions of these tools designed to work with GDB-4.12
3151 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
3154 *** Changes in GDB-4.11:
3156 * User visible changes:
3160 The "set remotedebug" option is now consistent between the mips remote
3161 target, remote targets using the gdb-specific protocol, UDI (AMD's
3162 debug protocol for the 29k) and the 88k bug monitor. It is now an
3163 integer specifying a debug level (normally 0 or 1, but 2 means more
3164 debugging info for the mips target).
3166 * DEC Alpha native support
3168 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
3169 debug info, but GDB works fairly well with the DEC compiler and should
3170 work with a future GCC release. See the README file for a few
3171 Alpha-specific notes.
3173 * Preliminary thread implementation
3175 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
3177 * LynxOS native and target support for 386
3179 This release has been hosted on LynxOS 2.2, and also can be configured
3180 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
3183 * Improvements in C++ mangling/demangling.
3185 This release has much better g++ debugging, specifically in name
3186 mangling/demangling, virtual function calls, print virtual table,
3187 call methods, ...etc.
3189 *** Changes in GDB-4.10:
3191 * User visible changes:
3193 Remote debugging using the GDB-specific (`target remote') protocol now
3194 supports the `load' command. This is only useful if you have some
3195 other way of getting the stub to the target system, and you can put it
3196 somewhere in memory where it won't get clobbered by the download.
3198 Filename completion now works.
3200 When run under emacs mode, the "info line" command now causes the
3201 arrow to point to the line specified. Also, "info line" prints
3202 addresses in symbolic form (as well as hex).
3204 All vxworks based targets now support a user settable option, called
3205 vxworks-timeout. This option represents the number of seconds gdb
3206 should wait for responses to rpc's. You might want to use this if
3207 your vxworks target is, perhaps, a slow software simulator or happens
3208 to be on the far side of a thin network line.
3212 This release contains support for using a DEC alpha as a GDB host for
3213 cross debugging. Native alpha debugging is not supported yet.
3216 *** Changes in GDB-4.9:
3220 This is the first GDB release which is accompanied by a matching testsuite.
3221 The testsuite requires installation of dejagnu, which should be available
3222 via ftp from most sites that carry GNU software.
3226 'Cfront' style demangling has had its name changed to 'ARM' style, to
3227 emphasize that it was written from the specifications in the C++ Annotated
3228 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
3229 disclaimers, it still generated too much confusion with users attempting to
3230 use gdb with AT&T cfront.
3234 GDB now uses a standard remote interface to a simulator library.
3235 So far, the library contains simulators for the Zilog Z8001/2, the
3236 Hitachi H8/300, H8/500 and Super-H.
3238 * New targets supported
3240 H8/300 simulator h8300-hitachi-hms or h8300hms
3241 H8/500 simulator h8500-hitachi-hms or h8500hms
3242 SH simulator sh-hitachi-hms or sh
3243 Z8000 simulator z8k-zilog-none or z8ksim
3244 IDT MIPS board over serial line mips-idt-ecoff
3246 Cross-debugging to GO32 targets is supported. It requires a custom
3247 version of the i386-stub.c module which is integrated with the
3248 GO32 memory extender.
3250 * New remote protocols
3252 MIPS remote debugging protocol.
3254 * New source languages supported
3256 This version includes preliminary support for Chill, a Pascal like language
3257 used by telecommunications companies. Chill support is also being integrated
3258 into the GNU compiler, but we don't know when it will be publically available.
3261 *** Changes in GDB-4.8:
3263 * HP Precision Architecture supported
3265 GDB now supports HP PA-RISC machines running HPUX. A preliminary
3266 version of this support was available as a set of patches from the
3267 University of Utah. GDB does not support debugging of programs
3268 compiled with the HP compiler, because HP will not document their file
3269 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
3270 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
3272 Many problems in the preliminary version have been fixed.
3274 * Faster and better demangling
3276 We have improved template demangling and fixed numerous bugs in the GNU style
3277 demangler. It can now handle type modifiers such as `static' or `const'. Wide
3278 character types (wchar_t) are now supported. Demangling of each symbol is now
3279 only done once, and is cached when the symbol table for a file is read in.
3280 This results in a small increase in memory usage for C programs, a moderate
3281 increase in memory usage for C++ programs, and a fantastic speedup in
3284 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
3285 from the specifications in the Annotated Reference Manual, which AT&T's
3286 compiler does not actually implement.
3288 * G++ multiple inheritance compiler problem
3290 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
3291 inheritance lattices was reworked to properly discover ambiguities. We
3292 recently found an example which causes this new algorithm to fail in a
3293 very subtle way, producing bad debug information for those classes.
3294 The file 'gcc.patch' (in this directory) can be applied to gcc to
3295 circumvent the problem. A future GCC release will contain a complete
3298 The previous G++ debug info problem (mentioned below for the gdb-4.7
3299 release) is fixed in gcc version 2.3.2.
3301 * Improved configure script
3303 The `configure' script will now attempt to guess your system type if
3304 you don't supply a host system type. The old scheme of supplying a
3305 host system triplet is preferable over using this. All the magic is
3306 done in the new `config.guess' script. Examine it for details.
3308 We have also brought our configure script much more in line with the FSF's
3309 version. It now supports the --with-xxx options. In particular,
3310 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
3311 The resulting GDB will not be able to read arbitrary object file formats --
3312 only the format ``expected'' to be used on the configured target system.
3313 We hope to make this the default in a future release.
3315 * Documentation improvements
3317 There's new internal documentation on how to modify GDB, and how to
3318 produce clean changes to the code. We implore people to read it
3319 before submitting changes.
3321 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
3322 M4 macros. The new texinfo.tex is provided in this release. Pre-built
3323 `info' files are also provided. To build `info' files from scratch,
3324 you will need the latest `makeinfo' release, which will be available in
3325 a future texinfo-X.Y release.
3327 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
3328 We're not sure exactly which versions have this problem, but it has
3329 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
3330 or better. If that isn't possible, there is a patch in
3331 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
3332 around this problem.
3336 GDB now supports array constants that can be used in expressions typed in by
3337 the user. The syntax is `{element, element, ...}'. Ie: you can now type
3338 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
3341 The new directory `gdb/sparclite' contains a program that demonstrates
3342 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
3344 * New native hosts supported
3346 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
3347 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
3349 * New targets supported
3351 AMD 29k family via UDI a29k-amd-udi or udi29k
3353 * New file formats supported
3355 BFD now supports reading HP/PA-RISC executables (SOM file format?),
3356 HPUX core files, and SCO 3.2v2 core files.
3360 Attaching to processes now works again; thanks for the many bug reports.
3362 We have also stomped on a bunch of core dumps caused by
3363 printf_filtered("%s") problems.
3365 We eliminated a copyright problem on the rpc and ptrace header files
3366 for VxWorks, which was discovered at the last minute during the 4.7
3367 release. You should now be able to build a VxWorks GDB.
3369 You can now interrupt gdb while an attached process is running. This
3370 will cause the attached process to stop, and give control back to GDB.
3372 We fixed problems caused by using too many file descriptors
3373 for reading symbols from object files and libraries. This was
3374 especially a problem for programs that used many (~100) shared
3377 The `step' command now only enters a subroutine if there is line number
3378 information for the subroutine. Otherwise it acts like the `next'
3379 command. Previously, `step' would enter subroutines if there was
3380 any debugging information about the routine. This avoids problems
3381 when using `cc -g1' on MIPS machines.
3383 * Internal improvements
3385 GDB's internal interfaces have been improved to make it easier to support
3386 debugging of multiple languages in the future.
3388 GDB now uses a common structure for symbol information internally.
3389 Minimal symbols (derived from linkage symbols in object files), partial
3390 symbols (from a quick scan of debug information), and full symbols
3391 contain a common subset of information, making it easier to write
3392 shared code that handles any of them.
3394 * New command line options
3396 We now accept --silent as an alias for --quiet.
3400 The memory-mapped-malloc library is now licensed under the GNU Library
3401 General Public License.
3403 *** Changes in GDB-4.7:
3405 * Host/native/target split
3407 GDB has had some major internal surgery to untangle the support for
3408 hosts and remote targets. Now, when you configure GDB for a remote
3409 target, it will no longer load in all of the support for debugging
3410 local programs on the host. When fully completed and tested, this will
3411 ensure that arbitrary host/target combinations are possible.
3413 The primary conceptual shift is to separate the non-portable code in
3414 GDB into three categories. Host specific code is required any time GDB
3415 is compiled on that host, regardless of the target. Target specific
3416 code relates to the peculiarities of the target, but can be compiled on
3417 any host. Native specific code is everything else: it can only be
3418 built when the host and target are the same system. Child process
3419 handling and core file support are two common `native' examples.
3421 GDB's use of /proc for controlling Unix child processes is now cleaner.
3422 It has been split out into a single module under the `target_ops' vector,
3423 plus two native-dependent functions for each system that uses /proc.
3425 * New hosts supported
3427 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
3428 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
3429 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
3431 * New targets supported
3433 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3434 68030 and CPU32 m68030-*-*, m68332-*-*
3436 * New native hosts supported
3438 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
3439 (386bsd is not well tested yet)
3440 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
3442 * New file formats supported
3444 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
3445 supports reading of `a.out.adobe' object files, which are an a.out
3446 format extended with minimal information about multiple sections.
3450 `show copying' is the same as the old `info copying'.
3451 `show warranty' is the same as `info warrantee'.
3452 These were renamed for consistency. The old commands continue to work.
3454 `info handle' is a new alias for `info signals'.
3456 You can now define pre-command hooks, which attach arbitrary command
3457 scripts to any command. The commands in the hook will be executed
3458 prior to the user's command. You can also create a hook which will be
3459 executed whenever the program stops. See gdb.texinfo.
3463 We now deal with Cfront style name mangling, and can even extract type
3464 info from mangled symbols. GDB can automatically figure out which
3465 symbol mangling style your C++ compiler uses.
3467 Calling of methods and virtual functions has been improved as well.
3471 The crash that occured when debugging Sun Ansi-C compiled binaries is
3472 fixed. This was due to mishandling of the extra N_SO stabs output
3475 We also finally got Ultrix 4.2 running in house, and fixed core file
3476 support, with help from a dozen people on the net.
3478 John M. Farrell discovered that the reason that single-stepping was so
3479 slow on all of the Mips based platforms (primarily SGI and DEC) was
3480 that we were trying to demangle and lookup a symbol used for internal
3481 purposes on every instruction that was being stepped through. Changing
3482 the name of that symbol so that it couldn't be mistaken for a C++
3483 mangled symbol sped things up a great deal.
3485 Rich Pixley sped up symbol lookups in general by getting much smarter
3486 about when C++ symbol mangling is necessary. This should make symbol
3487 completion (TAB on the command line) much faster. It's not as fast as
3488 we'd like, but it's significantly faster than gdb-4.6.
3492 A new user controllable variable 'call_scratch_address' can
3493 specify the location of a scratch area to be used when GDB
3494 calls a function in the target. This is necessary because the
3495 usual method of putting the scratch area on the stack does not work
3496 in systems that have separate instruction and data spaces.
3498 We integrated changes to support the 29k UDI (Universal Debugger
3499 Interface), but discovered at the last minute that we didn't have all
3500 of the appropriate copyright paperwork. We are working with AMD to
3501 resolve this, and hope to have it available soon.
3505 We have sped up the remote serial line protocol, especially for targets
3506 with lots of registers. It now supports a new `expedited status' ('T')
3507 message which can be used in place of the existing 'S' status message.
3508 This allows the remote stub to send only the registers that GDB
3509 needs to make a quick decision about single-stepping or conditional
3510 breakpoints, eliminating the need to fetch the entire register set for
3511 each instruction being stepped through.
3513 The GDB remote serial protocol now implements a write-through cache for
3514 registers, only re-reading the registers if the target has run.
3516 There is also a new remote serial stub for SPARC processors. You can
3517 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
3518 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
3519 processor with a serial port.
3523 Configure.in files have become much easier to read and modify. A new
3524 `table driven' format makes it more obvious what configurations are
3525 supported, and what files each one uses.
3529 There is a new opcodes library which will eventually contain all of the
3530 disassembly routines and opcode tables. At present, it only contains
3531 Sparc and Z8000 routines. This will allow the assembler, debugger, and
3532 disassembler (binutils/objdump) to share these routines.
3534 The libiberty library is now copylefted under the GNU Library General
3535 Public License. This allows more liberal use, and was done so libg++
3536 can use it. This makes no difference to GDB, since the Library License
3537 grants all the rights from the General Public License.
3541 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
3542 reference to the stabs symbol info used by the debugger. It is (as far
3543 as we know) the only published document on this fascinating topic. We
3544 encourage you to read it, compare it to the stabs information on your
3545 system, and send improvements on the document in general (to
3546 bug-gdb@prep.ai.mit.edu).
3548 And, of course, many bugs have been fixed.
3551 *** Changes in GDB-4.6:
3553 * Better support for C++ function names
3555 GDB now accepts as input the "demangled form" of C++ overloaded function
3556 names and member function names, and can do command completion on such names
3557 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
3558 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
3559 Make use of command completion, it is your friend.
3561 GDB also now accepts a variety of C++ mangled symbol formats. They are
3562 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
3563 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
3564 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
3565 for the list of formats.
3567 * G++ symbol mangling problem
3569 Recent versions of gcc have a bug in how they emit debugging information for
3570 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
3571 directory) can be applied to gcc to fix the problem. Alternatively, if you
3572 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
3573 usual symptom is difficulty with setting breakpoints on methods. GDB complains
3574 about the method being non-existent. (We believe that version 2.2.2 of GCC has
3577 * New 'maintenance' command
3579 All of the commands related to hacking GDB internals have been moved out of
3580 the main command set, and now live behind the 'maintenance' command. This
3581 can also be abbreviated as 'mt'. The following changes were made:
3583 dump-me -> maintenance dump-me
3584 info all-breakpoints -> maintenance info breakpoints
3585 printmsyms -> maintenance print msyms
3586 printobjfiles -> maintenance print objfiles
3587 printpsyms -> maintenance print psymbols
3588 printsyms -> maintenance print symbols
3590 The following commands are new:
3592 maintenance demangle Call internal GDB demangler routine to
3593 demangle a C++ link name and prints the result.
3594 maintenance print type Print a type chain for a given symbol
3596 * Change to .gdbinit file processing
3598 We now read the $HOME/.gdbinit file before processing the argv arguments
3599 (e.g. reading symbol files or core files). This allows global parameters to
3600 be set, which will apply during the symbol reading. The ./.gdbinit is still
3601 read after argv processing.
3603 * New hosts supported
3605 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
3607 GNU/Linux support i386-unknown-linux or linux
3609 We are also including code to support the HP/PA running BSD and HPUX. This
3610 is almost guaranteed not to work, as we didn't have time to test or build it
3611 for this release. We are including it so that the more adventurous (or
3612 masochistic) of you can play with it. We also had major problems with the
3613 fact that the compiler that we got from HP doesn't support the -g option.
3616 * New targets supported
3618 Hitachi H8/300 h8300-hitachi-hms or h8300hms
3620 * More smarts about finding #include files
3622 GDB now remembers the compilation directory for all include files, and for
3623 all files from which C is generated (like yacc and lex sources). This
3624 greatly improves GDB's ability to find yacc/lex sources, and include files,
3625 especially if you are debugging your program from a directory different from
3626 the one that contains your sources.
3628 We also fixed a bug which caused difficulty with listing and setting
3629 breakpoints in include files which contain C code. (In the past, you had to
3630 try twice in order to list an include file that you hadn't looked at before.)
3632 * Interesting infernals change
3634 GDB now deals with arbitrary numbers of sections, where the symbols for each
3635 section must be relocated relative to that section's landing place in the
3636 target's address space. This work was needed to support ELF with embedded
3637 stabs used by Solaris-2.0.
3639 * Bug fixes (of course!)
3641 There have been loads of fixes for the following things:
3642 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
3643 i960, stabs, DOS(GO32), procfs, etc...
3645 See the ChangeLog for details.
3647 *** Changes in GDB-4.5:
3649 * New machines supported (host and target)
3651 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
3653 SGI Irix-4.x mips-sgi-irix4 or iris4
3655 * New malloc package
3657 GDB now uses a new memory manager called mmalloc, based on gmalloc.
3658 Mmalloc is capable of handling mutiple heaps of memory. It is also
3659 capable of saving a heap to a file, and then mapping it back in later.
3660 This can be used to greatly speedup the startup of GDB by using a
3661 pre-parsed symbol table which lives in a mmalloc managed heap. For
3662 more details, please read mmalloc/mmalloc.texi.
3666 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
3667 'help info proc' for details.
3669 * MIPS ecoff symbol table format
3671 The code that reads MIPS symbol table format is now supported on all hosts.
3672 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
3675 * File name changes for MS-DOS
3677 Many files in the config directories have been renamed to make it easier to
3678 support GDB on MS-DOSe systems (which have very restrictive file name
3679 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
3680 environment) is close to working but has some remaining problems. Note
3681 that debugging of DOS programs is not supported, due to limitations
3682 in the ``operating system'', but it can be used to host cross-debugging.
3684 * Cross byte order fixes
3686 Many fixes have been made to support cross debugging of Sparc and MIPS
3687 targets from hosts whose byte order differs.
3689 * New -mapped and -readnow options
3691 If memory-mapped files are available on your system through the 'mmap'
3692 system call, you can use the -mapped option on the `file' or
3693 `symbol-file' commands to cause GDB to write the symbols from your
3694 program into a reusable file. If the program you are debugging is
3695 called `/path/fred', the mapped symbol file will be `./fred.syms'.
3696 Future GDB debugging sessions will notice the presence of this file,
3697 and will quickly map in symbol information from it, rather than reading
3698 the symbol table from the executable program. Using the '-mapped'
3699 option in a GDB `file' or `symbol-file' command has the same effect as
3700 starting GDB with the '-mapped' command-line option.
3702 You can cause GDB to read the entire symbol table immediately by using
3703 the '-readnow' option with any of the commands that load symbol table
3704 information (or on the GDB command line). This makes the command
3705 slower, but makes future operations faster.
3707 The -mapped and -readnow options are typically combined in order to
3708 build a `fred.syms' file that contains complete symbol information.
3709 A simple GDB invocation to do nothing but build a `.syms' file for future
3712 gdb -batch -nx -mapped -readnow programname
3714 The `.syms' file is specific to the host machine on which GDB is run.
3715 It holds an exact image of GDB's internal symbol table. It cannot be
3716 shared across multiple host platforms.
3718 * longjmp() handling
3720 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
3721 siglongjmp() without losing control. This feature has not yet been ported to
3722 all systems. It currently works on many 386 platforms, all MIPS-based
3723 platforms (SGI, DECstation, etc), and Sun3/4.
3727 Preliminary work has been put in to support the new Solaris OS from Sun. At
3728 this time, it can control and debug processes, but it is not capable of
3733 As always, many many bug fixes. The major areas were with g++, and mipsread.
3734 People using the MIPS-based platforms should experience fewer mysterious
3735 crashes and trashed symbol tables.
3737 *** Changes in GDB-4.4:
3739 * New machines supported (host and target)
3741 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
3743 BSD Reno on Vax vax-dec-bsd
3744 Ultrix on Vax vax-dec-ultrix
3746 * New machines supported (target)
3748 AMD 29000 embedded, using EBMON a29k-none-none
3752 GDB continues to improve its handling of C++. `References' work better.
3753 The demangler has also been improved, and now deals with symbols mangled as
3754 per the Annotated C++ Reference Guide.
3756 GDB also now handles `stabs' symbol information embedded in MIPS
3757 `ecoff' symbol tables. Since the ecoff format was not easily
3758 extensible to handle new languages such as C++, this appeared to be a
3759 good way to put C++ debugging info into MIPS binaries. This option
3760 will be supported in the GNU C compiler, version 2, when it is
3763 * New features for SVR4
3765 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
3766 shared libraries. Debugging dynamically linked programs should present
3767 only minor differences from debugging statically linked programs.
3769 The `info proc' command will print out information about any process
3770 on an SVR4 system (including the one you are debugging). At the moment,
3771 it prints the address mappings of the process.
3773 If you bring up GDB on another SVR4 system, please send mail to
3774 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
3776 * Better dynamic linking support in SunOS
3778 Reading symbols from shared libraries which contain debugging symbols
3779 now works properly. However, there remain issues such as automatic
3780 skipping of `transfer vector' code during function calls, which
3781 make it harder to debug code in a shared library, than to debug the
3782 same code linked statically.
3786 GDB is now using the latest `getopt' routines from the FSF. This
3787 version accepts the -- prefix for options with long names. GDB will
3788 continue to accept the old forms (-option and +option) as well.
3789 Various single letter abbreviations for options have been explicity
3790 added to the option table so that they won't get overshadowed in the
3791 future by other options that begin with the same letter.
3795 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
3796 Many assorted bugs have been handled. Many more remain to be handled.
3797 See the various ChangeLog files (primarily in gdb and bfd) for details.
3800 *** Changes in GDB-4.3:
3802 * New machines supported (host and target)
3804 Amiga 3000 running Amix m68k-cbm-svr4 or amix
3805 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
3806 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3808 * Almost SCO Unix support
3810 We had hoped to support:
3811 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
3812 (except for core file support), but we discovered very late in the release
3813 that it has problems with process groups that render gdb unusable. Sorry
3814 about that. I encourage people to fix it and post the fixes.
3816 * Preliminary ELF and DWARF support
3818 GDB can read ELF object files on System V Release 4, and can handle
3819 debugging records for C, in DWARF format, in ELF files. This support
3820 is preliminary. If you bring up GDB on another SVR4 system, please
3821 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
3826 GDB now uses the latest `readline' library. One user-visible change
3827 is that two tabs will list possible command completions, which previously
3828 required typing M-? (meta-question mark, or ESC ?).
3832 The `stepi' bug that many of you noticed has been squashed.
3833 Many bugs in C++ have been handled. Many more remain to be handled.
3834 See the various ChangeLog files (primarily in gdb and bfd) for details.
3836 * State of the MIPS world (in case you wondered):
3838 GDB can understand the symbol tables emitted by the compilers
3839 supplied by most vendors of MIPS-based machines, including DEC. These
3840 symbol tables are in a format that essentially nobody else uses.
3842 Some versions of gcc come with an assembler post-processor called
3843 mips-tfile. This program is required if you want to do source-level
3844 debugging of gcc-compiled programs. I believe FSF does not ship
3845 mips-tfile with gcc version 1, but it will eventually come with gcc
3848 Debugging of g++ output remains a problem. g++ version 1.xx does not
3849 really support it at all. (If you're lucky, you should be able to get
3850 line numbers and stack traces to work, but no parameters or local
3851 variables.) With some work it should be possible to improve the
3854 When gcc version 2 is released, you will have somewhat better luck.
3855 However, even then you will get confusing results for inheritance and
3858 We will eventually provide full debugging of g++ output on
3859 DECstations. This will probably involve some kind of stabs-in-ecoff
3860 encapulation, but the details have not been worked out yet.
3863 *** Changes in GDB-4.2:
3865 * Improved configuration
3867 Only one copy of `configure' exists now, and it is not self-modifying.
3868 Porting BFD is simpler.
3872 The `step' and `next' commands now only stop at the first instruction
3873 of a source line. This prevents the multiple stops that used to occur
3874 in switch statements, for-loops, etc. `Step' continues to stop if a
3875 function that has debugging information is called within the line.
3879 Lots of small bugs fixed. More remain.
3881 * New host supported (not target)
3883 Intel 386 PC clone running Mach i386-none-mach
3886 *** Changes in GDB-4.1:
3888 * Multiple source language support
3890 GDB now has internal scaffolding to handle several source languages.
3891 It determines the type of each source file from its filename extension,
3892 and will switch expression parsing and number formatting to match the
3893 language of the function in the currently selected stack frame.
3894 You can also specifically set the language to be used, with
3895 `set language c' or `set language modula-2'.
3899 GDB now has preliminary support for the GNU Modula-2 compiler,
3900 currently under development at the State University of New York at
3901 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
3902 continue through the fall of 1991 and into 1992.
3904 Other Modula-2 compilers are currently not supported, and attempting to
3905 debug programs compiled with them will likely result in an error as the
3906 symbol table is read. Feel free to work on it, though!
3908 There are hooks in GDB for strict type checking and range checking,
3909 in the `Modula-2 philosophy', but they do not currently work.
3913 GDB can now write to executable and core files (e.g. patch
3914 a variable's value). You must turn this switch on, specify
3915 the file ("exec foo" or "core foo"), *then* modify it, e.g.
3916 by assigning a new value to a variable. Modifications take
3919 * Automatic SunOS shared library reading
3921 When you run your program, GDB automatically determines where its
3922 shared libraries (if any) have been loaded, and reads their symbols.
3923 The `share' command is no longer needed. This also works when
3924 examining core files.
3928 You can specify the number of lines that the `list' command shows.
3931 * New machines supported (host and target)
3933 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3934 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
3935 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
3937 * New hosts supported (not targets)
3939 IBM RT/PC: romp-ibm-aix or rtpc
3941 * New targets supported (not hosts)
3943 AMD 29000 embedded with COFF a29k-none-coff
3944 AMD 29000 embedded with a.out a29k-none-aout
3945 Ultracomputer remote kernel debug a29k-nyu-kern
3947 * New remote interfaces
3953 *** Changes in GDB-4.0:
3957 Wide output is wrapped at good places to make the output more readable.
3959 Gdb now supports cross-debugging from a host machine of one type to a
3960 target machine of another type. Communication with the target system
3961 is over serial lines. The ``target'' command handles connecting to the
3962 remote system; the ``load'' command will download a program into the
3963 remote system. Serial stubs for the m68k and i386 are provided. Gdb
3964 also supports debugging of realtime processes running under VxWorks,
3965 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
3966 stub on the target system.
3968 New CPUs supported include the AMD 29000 and Intel 960.
3970 GDB now reads object files and symbol tables via a ``binary file''
3971 library, which allows a single copy of GDB to debug programs of multiple
3972 object file types such as a.out and coff.
3974 There is now a GDB reference card in "doc/refcard.tex". (Make targets
3975 refcard.dvi and refcard.ps are available to format it).
3978 * Control-Variable user interface simplified
3980 All variables that control the operation of the debugger can be set
3981 by the ``set'' command, and displayed by the ``show'' command.
3983 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
3984 ``Show prompt'' produces the response:
3985 Gdb's prompt is new-gdb=>.
3987 What follows are the NEW set commands. The command ``help set'' will
3988 print a complete list of old and new set commands. ``help set FOO''
3989 will give a longer description of the variable FOO. ``show'' will show
3990 all of the variable descriptions and their current settings.
3992 confirm on/off: Enables warning questions for operations that are
3993 hard to recover from, e.g. rerunning the program while
3994 it is already running. Default is ON.
3996 editing on/off: Enables EMACS style command line editing
3997 of input. Previous lines can be recalled with
3998 control-P, the current line can be edited with control-B,
3999 you can search for commands with control-R, etc.
4002 history filename NAME: NAME is where the gdb command history
4003 will be stored. The default is .gdb_history,
4004 or the value of the environment variable
4007 history size N: The size, in commands, of the command history. The
4008 default is 256, or the value of the environment variable
4011 history save on/off: If this value is set to ON, the history file will
4012 be saved after exiting gdb. If set to OFF, the
4013 file will not be saved. The default is OFF.
4015 history expansion on/off: If this value is set to ON, then csh-like
4016 history expansion will be performed on
4017 command line input. The default is OFF.
4019 radix N: Sets the default radix for input and output. It can be set
4020 to 8, 10, or 16. Note that the argument to "radix" is interpreted
4021 in the current radix, so "set radix 10" is always a no-op.
4023 height N: This integer value is the number of lines on a page. Default
4024 is 24, the current `stty rows'' setting, or the ``li#''
4025 setting from the termcap entry matching the environment
4028 width N: This integer value is the number of characters on a line.
4029 Default is 80, the current `stty cols'' setting, or the ``co#''
4030 setting from the termcap entry matching the environment
4033 Note: ``set screensize'' is obsolete. Use ``set height'' and
4034 ``set width'' instead.
4036 print address on/off: Print memory addresses in various command displays,
4037 such as stack traces and structure values. Gdb looks
4038 more ``symbolic'' if you turn this off; it looks more
4039 ``machine level'' with it on. Default is ON.
4041 print array on/off: Prettyprint arrays. New convenient format! Default
4044 print demangle on/off: Print C++ symbols in "source" form if on,
4047 print asm-demangle on/off: Same, for assembler level printouts
4050 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
4053 * Support for Epoch Environment.
4055 The epoch environment is a version of Emacs v18 with windowing. One
4056 new command, ``inspect'', is identical to ``print'', except that if you
4057 are running in the epoch environment, the value is printed in its own
4061 * Support for Shared Libraries
4063 GDB can now debug programs and core files that use SunOS shared libraries.
4064 Symbols from a shared library cannot be referenced
4065 before the shared library has been linked with the program (this
4066 happens after you type ``run'' and before the function main() is entered).
4067 At any time after this linking (including when examining core files
4068 from dynamically linked programs), gdb reads the symbols from each
4069 shared library when you type the ``sharedlibrary'' command.
4070 It can be abbreviated ``share''.
4072 sharedlibrary REGEXP: Load shared object library symbols for files
4073 matching a unix regular expression. No argument
4074 indicates to load symbols for all shared libraries.
4076 info sharedlibrary: Status of loaded shared libraries.
4081 A watchpoint stops execution of a program whenever the value of an
4082 expression changes. Checking for this slows down execution
4083 tremendously whenever you are in the scope of the expression, but is
4084 quite useful for catching tough ``bit-spreader'' or pointer misuse
4085 problems. Some machines such as the 386 have hardware for doing this
4086 more quickly, and future versions of gdb will use this hardware.
4088 watch EXP: Set a watchpoint (breakpoint) for an expression.
4090 info watchpoints: Information about your watchpoints.
4092 delete N: Deletes watchpoint number N (same as breakpoints).
4093 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
4094 enable N: Re-enables watchpoint number N (same as breakpoints).
4097 * C++ multiple inheritance
4099 When used with a GCC version 2 compiler, GDB supports multiple inheritance
4102 * C++ exception handling
4104 Gdb now supports limited C++ exception handling. Besides the existing
4105 ability to breakpoint on an exception handler, gdb can breakpoint on
4106 the raising of an exception (before the stack is peeled back to the
4109 catch FOO: If there is a FOO exception handler in the dynamic scope,
4110 set a breakpoint to catch exceptions which may be raised there.
4111 Multiple exceptions (``catch foo bar baz'') may be caught.
4113 info catch: Lists all exceptions which may be caught in the
4114 current stack frame.
4117 * Minor command changes
4119 The command ``call func (arg, arg, ...)'' now acts like the print
4120 command, except it does not print or save a value if the function's result
4121 is void. This is similar to dbx usage.
4123 The ``up'' and ``down'' commands now always print the frame they end up
4124 at; ``up-silently'' and `down-silently'' can be used in scripts to change
4125 frames without printing.
4127 * New directory command
4129 'dir' now adds directories to the FRONT of the source search path.
4130 The path starts off empty. Source files that contain debug information
4131 about the directory in which they were compiled can be found even
4132 with an empty path; Sun CC and GCC include this information. If GDB can't
4133 find your source file in the current directory, type "dir .".
4135 * Configuring GDB for compilation
4137 For normal use, type ``./configure host''. See README or gdb.texinfo
4140 GDB now handles cross debugging. If you are remotely debugging between
4141 two different machines, type ``./configure host -target=targ''.
4142 Host is the machine where GDB will run; targ is the machine
4143 where the program that you are debugging will run.