1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.2
10 ** Argument Dependent Lookup (ADL)
12 In C++ ADL lookup directs function search to the namespaces of its
13 arguments even if the namespace has not been imported.
23 Here the compiler will search for `foo' in the namespace of 'b'
24 and find A::foo. GDB now supports this. This construct is commonly
25 used in the Standard Template Library for operators.
27 ** Improved User Defined Operator Support
29 In addition to member operators, GDB now supports lookup of operators
30 defined in a namespace and imported with a `using' directive, operators
31 defined in the global scope, operators imported implicitly from an
32 anonymous namespace, and the ADL operators mentioned in the previous
34 GDB now also supports proper overload resolution for all the previously
35 mentioned flavors of operators.
37 ** static const class members
39 Printing of static const class members that are initialized in the
40 class definition has been fixed.
42 * Windows Thread Information Block access.
44 On Windows targets, GDB now supports displaying the Windows Thread
45 Information Block (TIB) structure. This structure is visible either
46 by using the new command `info w32 thread-information-block' or, by
47 dereferencing the new convenience variable named `$_tlb', a
48 thread-specific pointer to the TIB. This feature is also supported
49 when remote debugging using GDBserver.
53 Static tracepoints are calls in the user program into a tracing
54 library. One such library is a port of the LTTng kernel tracer to
55 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
56 When debugging with GDBserver, GDB now supports combining the GDB
57 tracepoint machinery with such libraries. For example: the user can
58 use GDB to probe a static tracepoint marker (a call from the user
59 program into the tracing library) with the new "strace" command (see
60 "New commands" below). This creates a "static tracepoint" in the
61 breakpoint list, that can be manipulated with the same feature set
62 as fast and regular tracepoints. E.g., collect registers, local and
63 global variables, collect trace state variables, and define
64 tracepoint conditions. In addition, the user can collect extra
65 static tracepoint marker specific data, by collecting the new
66 $_sdata internal variable. When analyzing the trace buffer, you can
67 inspect $_sdata like any other variable available to GDB. For more
68 information, see the "Tracepoints" chapter in GDB user manual. New
69 remote packets have been defined to support static tracepoints, see
70 the "New remote packets" section below.
76 Return the address of the Windows Thread Information Block of a given thread.
80 In response to several of the tracepoint packets, the target may now
81 also respond with a number of intermediate `qRelocInsn' request
82 packets before the final result packet, to have GDB handle
83 relocating an instruction to execute at a different address. This
84 is particularly useful for stubs that support fast tracepoints. GDB
85 reports support for this feature in the qSupported packet.
89 List static tracepoint markers in the target program.
93 List static tracepoint markers at a given address in the target
96 qXfer:statictrace:read
98 Read the static trace data collected (by a `collect $_sdata'
99 tracepoint action). The remote stub reports support for this packet
100 to gdb's qSupported query.
102 * The source command now accepts a -s option to force searching for the
103 script in the source search path even if the script name specifies
106 * New features in the GDB remote stub, GDBserver
108 - GDBserver now support tracepoints (including fast tracepoints, and
109 static tracepoints). The feature is currently supported by the
110 i386-linux and amd64-linux builds. See the "Tracepoints support
111 in gdbserver" section in the manual for more information.
113 GDBserver JIT compiles the tracepoint's conditional agent
114 expression bytecode into native code whenever possible for low
115 overhead dynamic tracepoints conditionals. For such tracepoints,
116 an expression that examines program state is evaluated when the
117 tracepoint is reached, in order to determine whether to capture
118 trace data. If the condition is simple and false, processing the
119 tracepoint finishes very quickly and no data is gathered.
121 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
122 for static tracepoints support.
124 - GDBserver now supports x86_64 Windows 64-bit debugging.
126 * GDB now sends xmlRegisters= in qSupported packet to indicate that
127 it understands register description.
129 * The --batch flag now disables pagination and queries.
131 * X86 general purpose registers
133 GDB now supports reading/writing byte, word and double-word x86
134 general purpose registers directly. This means you can use, say,
135 $ah or $ax to refer, respectively, to the byte register AH and
136 16-bit word register AX that are actually portions of the 32-bit
137 register EAX or 64-bit register RAX.
139 * The `commands' command now accepts a range of breakpoints to modify.
140 A plain `commands' following a command that creates multiple
141 breakpoints affects all the breakpoints set by that command. This
142 applies to breakpoints set by `rbreak', and also applies when a
143 single `break' command creates multiple breakpoints (e.g.,
144 breakpoints on overloaded c++ functions).
146 * The `rbreak' command now accepts a filename specification as part of
147 its argument, limiting the functions selected by the regex to those
148 in the specified file.
150 * Support for remote debugging Windows and SymbianOS shared libraries
151 from Unix hosts has been improved. Non Windows GDB builds now can
152 understand target reported file names that follow MS-DOS based file
153 system semantics, such as file names that include drive letters and
154 use the backslash character as directory separator. This makes it
155 possible to transparently use the "set sysroot" and "set
156 solib-search-path" on Unix hosts to point as host copies of the
157 target's shared libraries. See the new command "set
158 target-file-system-kind" described below, and the "Commands to
159 specify files" section in the user manual for more information.
163 eval template, expressions...
164 Convert the values of one or more expressions under the control
165 of the string template to a command line, and call it.
167 set target-file-system-kind unix|dos-based|auto
168 show target-file-system-kind
169 Set or show the assumed file system kind for target reported file
172 save breakpoints <filename>
173 Save all current breakpoint definitions to a file suitable for use
174 in a later debugging session. To read the saved breakpoint
175 definitions, use the `source' command.
177 `save tracepoints' is a new alias for `save-tracepoints'. The latter
180 info static-tracepoint-markers
181 Display information about static tracepoint markers in the target.
183 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
184 Define a static tracepoint by probing a marker at the given
185 function, line, address, or marker ID.
189 ** GDB now provides a new directory location, called the python directory,
190 where Python scripts written for GDB can be installed. The location
191 of that directory is <data-directory>/python, where <data-directory>
192 is the GDB data directory. For more details, see section `Scripting
193 GDB using Python' in the manual.
195 ** The GDB Python API now has access to breakpoints, symbols, symbol
196 tables, program spaces, inferiors, threads and frame's code blocks.
197 Additionally, GDB Parameters can now be created from the API, and
198 manipulated via set/show in the CLI.
200 ** New functions gdb.target_charset, gdb.target_wide_charset,
201 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
203 ** New exception gdb.GdbError.
205 ** Pretty-printers are now also looked up in the current program space.
207 ** Pretty-printers can now be individually enabled and disabled.
209 ** GDB now looks for names of Python scripts to auto-load in a
210 special section named `.debug_gdb_scripts', in addition to looking
211 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
213 * Tracepoint actions were unified with breakpoint commands. In particular,
214 there are no longer differences in "info break" output for breakpoints and
215 tracepoints and the "commands" command can be used for both tracepoints and
220 ARM Symbian arm*-*-symbianelf*
222 * D language support.
223 GDB now supports debugging programs written in the D programming
226 * GDB now supports the extended ptrace interface for PowerPC which is
227 available since Linux kernel version 2.6.34. This automatically enables
228 any hardware breakpoints and additional hardware watchpoints available in
229 the processor. The old ptrace interface exposes just one hardware
230 watchpoint and no hardware breakpoints.
232 * GDB is now able to use the Data Value Compare (DVC) register available on
233 embedded PowerPC processors to implement in hardware simple watchpoint
234 conditions of the form:
236 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
238 This works in native GDB running on Linux kernels with the extended ptrace
239 interface mentioned above.
241 *** Changes in GDB 7.1
247 GDB now supports importing of namespaces in C++. This enables the
248 user to inspect variables from imported namespaces. Support for
249 namepace aliasing has also been added. So, if a namespace is
250 aliased in the current scope (e.g. namepace C=A; ) the user can
251 print variables using the alias (e.g. (gdb) print C::x).
255 All known bugs relating to the printing of virtual base class were
256 fixed. It is now possible to call overloaded static methods using a
261 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
262 and reinterpret_cast<> are now handled by the C++ expression parser.
266 Xilinx MicroBlaze microblaze-*-*
271 Xilinx MicroBlaze microblaze
274 * Multi-program debugging.
276 GDB now has support for multi-program (a.k.a. multi-executable or
277 multi-exec) debugging. This allows for debugging multiple inferiors
278 simultaneously each running a different program under the same GDB
279 session. See "Debugging Multiple Inferiors and Programs" in the
280 manual for more information. This implied some user visible changes
281 in the multi-inferior support. For example, "info inferiors" now
282 lists inferiors that are not running yet or that have exited
283 already. See also "New commands" and "New options" below.
285 * New tracing features
287 GDB's tracepoint facility now includes several new features:
289 ** Trace state variables
291 GDB tracepoints now include support for trace state variables, which
292 are variables managed by the target agent during a tracing
293 experiment. They are useful for tracepoints that trigger each
294 other, so for instance one tracepoint can count hits in a variable,
295 and then a second tracepoint has a condition that is true when the
296 count reaches a particular value. Trace state variables share the
297 $-syntax of GDB convenience variables, and can appear in both
298 tracepoint actions and condition expressions. Use the "tvariable"
299 command to create, and "info tvariables" to view; see "Trace State
300 Variables" in the manual for more detail.
304 GDB now includes an option for defining fast tracepoints, which
305 targets may implement more efficiently, such as by installing a jump
306 into the target agent rather than a trap instruction. The resulting
307 speedup can be by two orders of magnitude or more, although the
308 tradeoff is that some program locations on some target architectures
309 might not allow fast tracepoint installation, for instance if the
310 instruction to be replaced is shorter than the jump. To request a
311 fast tracepoint, use the "ftrace" command, with syntax identical to
312 the regular trace command.
314 ** Disconnected tracing
316 It is now possible to detach GDB from the target while it is running
317 a trace experiment, then reconnect later to see how the experiment
318 is going. In addition, a new variable disconnected-tracing lets you
319 tell the target agent whether to continue running a trace if the
320 connection is lost unexpectedly.
324 GDB now has the ability to save the trace buffer into a file, and
325 then use that file as a target, similarly to you can do with
326 corefiles. You can select trace frames, print data that was
327 collected in them, and use tstatus to display the state of the
328 tracing run at the moment that it was saved. To create a trace
329 file, use "tsave <filename>", and to use it, do "target tfile
332 ** Circular trace buffer
334 You can ask the target agent to handle the trace buffer as a
335 circular buffer, discarding the oldest trace frames to make room for
336 newer ones, by setting circular-trace-buffer to on. This feature may
337 not be available for all target agents.
342 The disassemble command, when invoked with two arguments, now requires
343 the arguments to be comma-separated.
346 The info variables command now displays variable definitions. Files
347 which only declare a variable are not shown.
350 The source command is now capable of sourcing Python scripts.
351 This feature is dependent on the debugger being build with Python
354 Related to this enhancement is also the introduction of a new command
355 "set script-extension" (see below).
357 * New commands (for set/show, see "New options" below)
359 record save [<FILENAME>]
360 Save a file (in core file format) containing the process record
361 execution log for replay debugging at a later time.
363 record restore <FILENAME>
364 Restore the process record execution log that was saved at an
365 earlier time, for replay debugging.
367 add-inferior [-copies <N>] [-exec <FILENAME>]
370 clone-inferior [-copies <N>] [ID]
371 Make a new inferior ready to execute the same program another
377 maint info program-spaces
378 List the program spaces loaded into GDB.
380 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
381 show remote interrupt-sequence
382 Allow the user to select one of ^C, a BREAK signal or BREAK-g
383 as the sequence to the remote target in order to interrupt the execution.
384 Ctrl-C is a default. Some system prefers BREAK which is high level of
385 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
386 Magic SysRq g. It is BREAK signal and character 'g'.
388 set remote interrupt-on-connect [on | off]
389 show remote interrupt-on-connect
390 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
391 remote target when gdb connects to it. This is needed when you debug
394 set remotebreak [on | off]
396 Deprecated. Use "set/show remote interrupt-sequence" instead.
398 tvariable $NAME [ = EXP ]
399 Create or modify a trace state variable.
402 List trace state variables and their values.
404 delete tvariable $NAME ...
405 Delete one or more trace state variables.
408 Evaluate the given expressions without collecting anything into the
409 trace buffer. (Valid in tracepoint actions only.)
411 ftrace FN / FILE:LINE / *ADDR
412 Define a fast tracepoint at the given function, line, or address.
414 * New expression syntax
416 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
417 GDB now parses 0b101010 identically with 42.
421 set follow-exec-mode new|same
422 show follow-exec-mode
423 Control whether GDB reuses the same inferior across an exec call or
424 creates a new one. This is useful to be able to restart the old
425 executable after the inferior having done an exec call.
427 set default-collect EXPR, ...
429 Define a list of expressions to be collected at each tracepoint.
430 This is a useful way to ensure essential items are not overlooked,
431 such as registers or a critical global variable.
433 set disconnected-tracing
434 show disconnected-tracing
435 If set to 1, the target is instructed to continue tracing if it
436 loses its connection to GDB. If 0, the target is to stop tracing
439 set circular-trace-buffer
440 show circular-trace-buffer
441 If set to on, the target is instructed to use a circular trace buffer
442 and discard the oldest trace frames instead of stopping the trace due
443 to a full trace buffer. If set to off, the trace stops when the buffer
444 fills up. Some targets may not support this.
446 set script-extension off|soft|strict
447 show script-extension
448 If set to "off", the debugger does not perform any script language
449 recognition, and all sourced files are assumed to be GDB scripts.
450 If set to "soft" (the default), files are sourced according to
451 filename extension, falling back to GDB scripts if the first
453 If set to "strict", files are sourced according to filename extension.
455 set ada trust-PAD-over-XVS on|off
456 show ada trust-PAD-over-XVS
457 If off, activate a workaround against a bug in the debugging information
458 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
459 the GCC sources for more information about the GNAT encoding and
460 PAD types in particular). It is always safe to set this option to
461 off, but this introduces a slight performance penalty. The default
464 * Python API Improvements
466 ** GDB provides the new class gdb.LazyString. This is useful in
467 some pretty-printing cases. The new method gdb.Value.lazy_string
468 provides a simple way to create objects of this type.
470 ** The fields returned by gdb.Type.fields now have an
471 `is_base_class' attribute.
473 ** The new method gdb.Type.range returns the range of an array type.
475 ** The new method gdb.parse_and_eval can be used to parse and
476 evaluate an expression.
481 Define a trace state variable.
484 Get the current value of a trace state variable.
487 Set desired tracing behavior upon disconnection.
490 Set the trace buffer to be linear or circular.
493 Get data about the tracepoints currently in use.
497 Process record now works correctly with hardware watchpoints.
499 Multiple bug fixes have been made to the mips-irix port, making it
500 much more reliable. In particular:
501 - Debugging threaded applications is now possible again. Previously,
502 GDB would hang while starting the program, or while waiting for
503 the program to stop at a breakpoint.
504 - Attaching to a running process no longer hangs.
505 - An error occurring while loading a core file has been fixed.
506 - Changing the value of the PC register now works again. This fixes
507 problems observed when using the "jump" command, or when calling
508 a function from GDB, or even when assigning a new value to $pc.
509 - With the "finish" and "return" commands, the return value for functions
510 returning a small array is now correctly printed.
511 - It is now possible to break on shared library code which gets executed
512 during a shared library init phase (code executed while executing
513 their .init section). Previously, the breakpoint would have no effect.
514 - GDB is now able to backtrace through the signal handler for
515 non-threaded programs.
517 PIE (Position Independent Executable) programs debugging is now supported.
518 This includes debugging execution of PIC (Position Independent Code) shared
519 libraries although for that, it should be possible to run such libraries as an
522 *** Changes in GDB 7.0
524 * GDB now has an interface for JIT compilation. Applications that
525 dynamically generate code can create symbol files in memory and register
526 them with GDB. For users, the feature should work transparently, and
527 for JIT developers, the interface is documented in the GDB manual in the
528 "JIT Compilation Interface" chapter.
530 * Tracepoints may now be conditional. The syntax is as for
531 breakpoints; either an "if" clause appended to the "trace" command,
532 or the "condition" command is available. GDB sends the condition to
533 the target for evaluation using the same bytecode format as is used
534 for tracepoint actions.
536 * "disassemble" command with a /r modifier, print the raw instructions
537 in hex as well as in symbolic form.
539 * Process record and replay
541 In a architecture environment that supports ``process record and
542 replay'', ``process record and replay'' target can record a log of
543 the process execution, and replay it with both forward and reverse
546 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
547 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
548 set execution-direction {forward|reverse}, for targets that support
551 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
552 feature is available with a native GDB running on kernel version
555 * GDB now has support for multi-byte and wide character sets on the
556 target. Strings whose character type is wchar_t, char16_t, or
557 char32_t are now correctly printed. GDB supports wide- and unicode-
558 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
559 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
560 `printf'. This feature requires iconv to work properly; if your
561 system does not have a working iconv, GDB can use GNU libiconv. See
562 the installation instructions for more information.
564 * GDB now supports automatic retrieval of shared library files from
565 remote targets. To use this feature, specify a system root that begins
566 with the `remote:' prefix, either via the `set sysroot' command or via
567 the `--with-sysroot' configure-time option.
569 * "info sharedlibrary" now takes an optional regex of libraries to show,
570 and it now reports if a shared library has no debugging information.
572 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
573 now complete on file names.
575 * When completing in expressions, gdb will attempt to limit
576 completions to allowable structure or union fields, where appropriate.
577 For instance, consider:
579 # struct example { int f1; double f2; };
580 # struct example variable;
583 If the user types TAB at the end of this command line, the available
584 completions will be "f1" and "f2".
586 * Inlined functions are now supported. They show up in backtraces, and
587 the "step", "next", and "finish" commands handle them automatically.
589 * GDB now supports the token-splicing (##) and stringification (#)
590 operators when expanding macros. It also supports variable-arity
593 * GDB now supports inspecting extra signal information, exported by
594 the new $_siginfo convenience variable. The feature is currently
595 implemented on linux ARM, i386 and amd64.
597 * GDB can now display the VFP floating point registers and NEON vector
598 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
599 can provide these registers (requires Linux 2.6.30 or later). Remote
600 and simulator targets may also provide them.
605 Search memory for a sequence of bytes.
608 Turn off `+'/`-' protocol acknowledgments to permit more efficient
609 operation over reliable transport links. Use of this packet is
610 controlled by the `set remote noack-packet' command.
613 Kill the process with the specified process ID. Use this in preference
614 to `k' when multiprocess protocol extensions are supported.
617 Obtains additional operating system information
621 Read or write additional signal information.
623 * Removed remote protocol undocumented extension
625 An undocumented extension to the remote protocol's `S' stop reply
626 packet that permited the stub to pass a process id was removed.
627 Remote servers should use the `T' stop reply packet instead.
629 * The "disassemble" command now supports an optional /m modifier to print mixed
632 * GDB now supports multiple function calling conventions according to the
633 DWARF-2 DW_AT_calling_convention function attribute.
635 * The SH target utilizes the aforementioned change to distinguish between gcc
636 and Renesas calling convention. It also adds the new CLI commands
637 `set/show sh calling-convention'.
639 * GDB can now read compressed debug sections, as produced by GNU gold
640 with the --compress-debug-sections=zlib flag.
642 * 64-bit core files are now supported on AIX.
644 * Thread switching is now supported on Tru64.
646 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
647 which will be allocated using malloc later in program execution.
649 * The qXfer:libraries:read remote procotol packet now allows passing a
650 list of section offsets.
652 * On GNU/Linux, GDB can now attach to stopped processes. Several race
653 conditions handling signals delivered during attach or thread creation
654 have also been fixed.
656 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
657 From the user's standpoint, all unqualified instances of True and False
658 are treated as the standard definitions, regardless of context.
660 * GDB now parses C++ symbol and type names more flexibly. For
663 template<typename T> class C { };
666 GDB will now correctly handle all of:
668 ptype C<char const *>
670 ptype C<const char *>
673 * New features in the GDB remote stub, gdbserver
675 - The "--wrapper" command-line argument tells gdbserver to use a
676 wrapper program to launch programs for debugging.
678 - On PowerPC and S/390 targets, it is now possible to use a single
679 gdbserver executable to debug both 32-bit and 64-bit programs.
680 (This requires gdbserver itself to be built as a 64-bit executable.)
682 - gdbserver uses the new noack protocol mode for TCP connections to
683 reduce communications latency, if also supported and enabled in GDB.
685 - Support for the sparc64-linux-gnu target is now included in
688 - The amd64-linux build of gdbserver now supports debugging both
689 32-bit and 64-bit programs.
691 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
692 now support hardware watchpoints, and will use them automatically
697 GDB now has support for scripting using Python. Whether this is
698 available is determined at configure time.
700 New GDB commands can now be written in Python.
702 * Ada tasking support
704 Ada tasks can now be inspected in GDB. The following commands have
708 Print the list of Ada tasks.
710 Print detailed information about task number N.
712 Print the task number of the current task.
714 Switch the context of debugging to task number N.
716 * Support for user-defined prefixed commands. The "define" command can
717 add new commands to existing prefixes, e.g. "target".
719 * Multi-inferior, multi-process debugging.
721 GDB now has generalized support for multi-inferior debugging. See
722 "Debugging Multiple Inferiors" in the manual for more information.
723 Although availability still depends on target support, the command
724 set is more uniform now. The GNU/Linux specific multi-forks support
725 has been migrated to this new framework. This implied some user
726 visible changes; see "New commands" and also "Removed commands"
729 * Target descriptions can now describe the target OS ABI. See the
730 "Target Description Format" section in the user manual for more
733 * Target descriptions can now describe "compatible" architectures
734 to indicate that the target can execute applications for a different
735 architecture in addition to those for the main target architecture.
736 See the "Target Description Format" section in the user manual for
739 * Multi-architecture debugging.
741 GDB now includes general supports for debugging applications on
742 hybrid systems that use more than one single processor architecture
743 at the same time. Each such hybrid architecture still requires
744 specific support to be added. The only hybrid architecture supported
745 in this version of GDB is the Cell Broadband Engine.
747 * GDB now supports integrated debugging of Cell/B.E. applications that
748 use both the PPU and SPU architectures. To enable support for hybrid
749 Cell/B.E. debugging, you need to configure GDB to support both the
750 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
751 --enable-targets configure option.
753 * Non-stop mode debugging.
755 For some targets, GDB now supports an optional mode of operation in
756 which you can examine stopped threads while other threads continue
757 to execute freely. This is referred to as non-stop mode, with the
758 old mode referred to as all-stop mode. See the "Non-Stop Mode"
759 section in the user manual for more information.
761 To be able to support remote non-stop debugging, a remote stub needs
762 to implement the non-stop mode remote protocol extensions, as
763 described in the "Remote Non-Stop" section of the user manual. The
764 GDB remote stub, gdbserver, has been adjusted to support these
765 extensions on linux targets.
767 * New commands (for set/show, see "New options" below)
769 catch syscall [NAME(S) | NUMBER(S)]
770 Catch system calls. Arguments, which should be names of system
771 calls or their numbers, mean catch only those syscalls. Without
772 arguments, every syscall will be caught. When the inferior issues
773 any of the specified syscalls, GDB will stop and announce the system
774 call, both when it is called and when its call returns. This
775 feature is currently available with a native GDB running on the
776 Linux Kernel, under the following architectures: x86, x86_64,
777 PowerPC and PowerPC64.
779 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
781 Search memory for a sequence of bytes.
783 maint set python print-stack
784 maint show python print-stack
785 Show a stack trace when an error is encountered in a Python script.
788 Invoke CODE by passing it to the Python interpreter.
793 These allow macros to be defined, undefined, and listed
797 Show operating system information about processes.
800 List the inferiors currently under GDB's control.
803 Switch focus to inferior number NUM.
806 Detach from inferior number NUM.
809 Kill inferior number NUM.
814 show spu stop-on-load
815 Control whether to stop for new SPE threads during Cell/B.E. debugging.
817 set spu auto-flush-cache
818 show spu auto-flush-cache
819 Control whether to automatically flush the software-managed cache
820 during Cell/B.E. debugging.
822 set sh calling-convention
823 show sh calling-convention
824 Control the calling convention used when calling SH target functions.
828 Control display of timestamps with GDB debugging output.
830 set disassemble-next-line
831 show disassemble-next-line
832 Control display of disassembled source lines or instructions when
835 set remote noack-packet
836 show remote noack-packet
837 Set/show the use of remote protocol QStartNoAckMode packet. See above
838 under "New remote packets."
840 set remote query-attached-packet
841 show remote query-attached-packet
842 Control use of remote protocol `qAttached' (query-attached) packet.
844 set remote read-siginfo-object
845 show remote read-siginfo-object
846 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
849 set remote write-siginfo-object
850 show remote write-siginfo-object
851 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
854 set remote reverse-continue
855 show remote reverse-continue
856 Control use of remote protocol 'bc' (reverse-continue) packet.
858 set remote reverse-step
859 show remote reverse-step
860 Control use of remote protocol 'bs' (reverse-step) packet.
862 set displaced-stepping
863 show displaced-stepping
864 Control displaced stepping mode. Displaced stepping is a way to
865 single-step over breakpoints without removing them from the debuggee.
866 Also known as "out-of-line single-stepping".
870 Control display of debugging info for displaced stepping.
872 maint set internal-error
873 maint show internal-error
874 Control what GDB does when an internal error is detected.
876 maint set internal-warning
877 maint show internal-warning
878 Control what GDB does when an internal warning is detected.
883 Use a wrapper program to launch programs for debugging.
885 set multiple-symbols (all|ask|cancel)
886 show multiple-symbols
887 The value of this variable can be changed to adjust the debugger behavior
888 when an expression or a breakpoint location contains an ambiguous symbol
889 name (an overloaded function name, for instance).
891 set breakpoint always-inserted
892 show breakpoint always-inserted
893 Keep breakpoints always inserted in the target, as opposed to inserting
894 them when resuming the target, and removing them when the target stops.
895 This option can improve debugger performance on slow remote targets.
897 set arm fallback-mode (arm|thumb|auto)
898 show arm fallback-mode
899 set arm force-mode (arm|thumb|auto)
901 These commands control how ARM GDB determines whether instructions
902 are ARM or Thumb. The default for both settings is auto, which uses
903 the current CPSR value for instructions without symbols; previous
904 versions of GDB behaved as if "set arm fallback-mode arm".
906 set disable-randomization
907 show disable-randomization
908 Standalone programs run with the virtual address space randomization enabled
909 by default on some platforms. This option keeps the addresses stable across
910 multiple debugging sessions.
914 Control whether other threads are stopped or not when some thread hits
919 Requests that asynchronous execution is enabled in the target, if available.
920 In this case, it's possible to resume target in the background, and interact
921 with GDB while the target is running. "show target-async" displays the
922 current state of asynchronous execution of the target.
924 set target-wide-charset
925 show target-wide-charset
926 The target-wide-charset is the name of the character set that GDB
927 uses when printing characters whose type is wchar_t.
929 set tcp auto-retry (on|off)
931 set tcp connect-timeout
932 show tcp connect-timeout
933 These commands allow GDB to retry failed TCP connections to a remote stub
934 with a specified timeout period; this is useful if the stub is launched
935 in parallel with GDB but may not be ready to accept connections immediately.
937 set libthread-db-search-path
938 show libthread-db-search-path
939 Control list of directories which GDB will search for appropriate
942 set schedule-multiple (on|off)
943 show schedule-multiple
944 Allow GDB to resume all threads of all processes or only threads of
949 Use more aggressive caching for accesses to the stack. This improves
950 performance of remote debugging (particularly backtraces) without
951 affecting correctness.
953 set interactive-mode (on|off|auto)
954 show interactive-mode
955 Control whether GDB runs in interactive mode (on) or not (off).
956 When in interactive mode, GDB waits for the user to answer all
957 queries. Otherwise, GDB does not wait and assumes the default
958 answer. When set to auto (the default), GDB determines which
959 mode to use based on the stdin settings.
964 For program forks, this is replaced by the new more generic `info
965 inferiors' command. To list checkpoints, you can still use the
966 `info checkpoints' command, which was an alias for the `info forks'
970 Replaced by the new `inferior' command. To switch between
971 checkpoints, you can still use the `restart' command, which was an
972 alias for the `fork' command.
975 This is removed, since some targets don't have a notion of
976 processes. To switch between processes, you can still use the
977 `inferior' command using GDB's own inferior number.
980 For program forks, this is replaced by the new more generic `kill
981 inferior' command. To delete a checkpoint, you can still use the
982 `delete checkpoint' command, which was an alias for the `delete
986 For program forks, this is replaced by the new more generic `detach
987 inferior' command. To detach a checkpoint, you can still use the
988 `detach checkpoint' command, which was an alias for the `detach
991 * New native configurations
993 x86/x86_64 Darwin i[34567]86-*-darwin*
995 x86_64 MinGW x86_64-*-mingw*
999 Lattice Mico32 lm32-*
1000 x86 DICOS i[34567]86-*-dicos*
1001 x86_64 DICOS x86_64-*-dicos*
1004 * The GDB remote stub, gdbserver, now supports x86 Windows CE
1005 (mingw32ce) debugging.
1011 These commands were actually not implemented on any target.
1013 *** Changes in GDB 6.8
1015 * New native configurations
1017 NetBSD/hppa hppa*-*netbsd*
1018 Xtensa GNU/Linux xtensa*-*-linux*
1022 NetBSD/hppa hppa*-*-netbsd*
1023 Xtensa GNU/Lunux xtensa*-*-linux*
1025 * Change in command line behavior -- corefiles vs. process ids.
1027 When the '-p NUMBER' or '--pid NUMBER' options are used, and
1028 attaching to process NUMBER fails, GDB no longer attempts to open a
1029 core file named NUMBER. Attaching to a program using the -c option
1030 is no longer supported. Instead, use the '-p' or '--pid' options.
1032 * GDB can now be built as a native debugger for debugging Windows x86
1033 (mingw32) Portable Executable (PE) programs.
1035 * Pending breakpoints no longer change their number when their address
1038 * GDB now supports breakpoints with multiple locations,
1039 including breakpoints on C++ constructors, inside C++ templates,
1040 and in inlined functions.
1042 * GDB's ability to debug optimized code has been improved. GDB more
1043 accurately identifies function bodies and lexical blocks that occupy
1044 more than one contiguous range of addresses.
1046 * Target descriptions can now describe registers for PowerPC.
1048 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
1049 registers on PowerPC targets.
1051 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
1052 targets even when the libthread_db library is not available.
1054 * The GDB remote stub, gdbserver, now supports the new file transfer
1055 commands (remote put, remote get, and remote delete).
1057 * The GDB remote stub, gdbserver, now supports run and attach in
1058 extended-remote mode.
1060 * hppa*64*-*-hpux11* target broken
1061 The debugger is unable to start a program and fails with the following
1062 error: "Error trying to get information about dynamic linker".
1063 The gdb-6.7 release is also affected.
1065 * GDB now supports the --enable-targets= configure option to allow
1066 building a single GDB executable that supports multiple remote
1067 target architectures.
1069 * GDB now supports debugging C and C++ programs which use the
1070 Decimal Floating Point extension. In addition, the PowerPC target
1071 now has a set of pseudo-registers to inspect decimal float values
1072 stored in two consecutive float registers.
1074 * The -break-insert MI command can optionally create pending
1077 * Improved support for debugging Ada
1078 Many improvements to the Ada language support have been made. These
1080 - Better support for Ada2005 interface types
1081 - Improved handling of arrays and slices in general
1082 - Better support for Taft-amendment types
1083 - The '{type} ADDRESS' expression is now allowed on the left hand-side
1085 - Improved command completion in Ada
1088 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
1093 set print frame-arguments (all|scalars|none)
1094 show print frame-arguments
1095 The value of this variable can be changed to control which argument
1096 values should be printed by the debugger when displaying a frame.
1101 Transfer files to and from a remote target, and delete remote files.
1108 Transfer files to and from a remote target, and delete remote files.
1110 * New remote packets
1117 Open, close, read, write, and delete files on the remote system.
1120 Attach to an existing process on the remote system, in extended-remote
1124 Run a new process on the remote system, in extended-remote mode.
1126 *** Changes in GDB 6.7
1128 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
1129 bfd, libiberty and opcodes, as revealed by static analysis donated by
1130 Coverity, Inc. (http://scan.coverity.com).
1132 * When looking up multiply-defined global symbols, GDB will now prefer the
1133 symbol definition in the current shared library if it was built using the
1134 -Bsymbolic linker option.
1136 * When the Text User Interface (TUI) is not configured, GDB will now
1137 recognize the -tui command-line option and print a message that the TUI
1140 * The GDB remote stub, gdbserver, now has lower overhead for high
1141 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
1143 * GDB for MIPS targets now autodetects whether a remote target provides
1144 32-bit or 64-bit register values.
1146 * Support for C++ member pointers has been improved.
1148 * GDB now understands XML target descriptions, which specify the
1149 target's overall architecture. GDB can read a description from
1150 a local file or over the remote serial protocol.
1152 * Vectors of single-byte data use a new integer type which is not
1153 automatically displayed as character or string data.
1155 * The /s format now works with the print command. It displays
1156 arrays of single-byte integers and pointers to single-byte integers
1159 * Target descriptions can now describe target-specific registers,
1160 for architectures which have implemented the support (currently
1161 only ARM, M68K, and MIPS).
1163 * GDB and the GDB remote stub, gdbserver, now support the XScale
1166 * The GDB remote stub, gdbserver, has been updated to support
1167 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
1168 has been rewritten to use the standard GDB remote protocol.
1170 * GDB can now step into C++ functions which are called through thunks.
1172 * GDB for the Cell/B.E. SPU now supports overlay debugging.
1174 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
1175 layout. It also supports a TextSeg= and DataSeg= response when only
1176 segment base addresses (rather than offsets) are available.
1178 * The /i format now outputs any trailing branch delay slot instructions
1179 immediately following the last instruction within the count specified.
1181 * The GDB remote protocol "T" stop reply packet now supports a
1182 "library" response. Combined with the new "qXfer:libraries:read"
1183 packet, this response allows GDB to debug shared libraries on targets
1184 where the operating system manages the list of loaded libraries (e.g.
1185 Windows and SymbianOS).
1187 * The GDB remote stub, gdbserver, now supports dynamic link libraries
1188 (DLLs) on Windows and Windows CE targets.
1190 * GDB now supports a faster verification that a .debug file matches its binary
1191 according to its build-id signature, if the signature is present.
1197 Enable or disable hardware flow control (RTS/CTS) on the serial port
1198 when debugging using remote targets.
1200 set mem inaccessible-by-default
1201 show mem inaccessible-by-default
1202 If the target supplies a memory map, for instance via the remote
1203 protocol's "qXfer:memory-map:read" packet, setting this variable
1204 prevents GDB from accessing memory outside the memory map. This
1205 is useful for targets with memory mapped registers or which react
1206 badly to accesses of unmapped address space.
1208 set breakpoint auto-hw
1209 show breakpoint auto-hw
1210 If the target supplies a memory map, for instance via the remote
1211 protocol's "qXfer:memory-map:read" packet, setting this variable
1212 lets GDB use hardware breakpoints automatically for memory regions
1213 where it can not use software breakpoints. This covers both the
1214 "break" command and internal breakpoints used for other commands
1215 including "next" and "finish".
1218 catch exception unhandled
1219 Stop the program execution when Ada exceptions are raised.
1222 Stop the program execution when an Ada assertion failed.
1226 Set an alternate system root for target files. This is a more
1227 general version of "set solib-absolute-prefix", which is now
1228 an alias to "set sysroot".
1231 Provide extended SPU facility status information. This set of
1232 commands is available only when debugging the Cell/B.E. SPU
1235 * New native configurations
1237 OpenBSD/sh sh*-*openbsd*
1240 unset tdesc filename
1242 Use the specified local file as an XML target description, and do
1243 not query the target for its built-in description.
1247 OpenBSD/sh sh*-*-openbsd*
1248 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
1249 Toshiba Media Processor mep-elf
1251 * New remote packets
1254 Ignore the specified signals; pass them directly to the debugged program
1255 without stopping other threads or reporting them to GDB.
1257 qXfer:features:read:
1258 Read an XML target description from the target, which describes its
1263 Read or write contents of an spufs file on the target system. These
1264 packets are available only on the Cell/B.E. SPU architecture.
1266 qXfer:libraries:read:
1267 Report the loaded shared libraries. Combined with new "T" packet
1268 response, this packet allows GDB to debug shared libraries on
1269 targets where the operating system manages the list of loaded
1270 libraries (e.g. Windows and SymbianOS).
1274 Support for these obsolete configurations has been removed.
1282 i[34567]86-*-lynxos*
1283 i[34567]86-*-netware*
1284 i[34567]86-*-sco3.2v5*
1285 i[34567]86-*-sco3.2v4*
1287 i[34567]86-*-sysv4.2*
1290 i[34567]86-*-unixware2*
1291 i[34567]86-*-unixware*
1300 * Other removed features
1307 Various m68k-only ROM monitors.
1314 Various Renesas ROM monitors and debugging interfaces for SH and
1319 Support for a Macraigor serial interface to on-chip debugging.
1320 GDB does not directly support the newer parallel or USB
1325 A debug information format. The predecessor to DWARF 2 and
1326 DWARF 3, which are still supported.
1328 Support for the HP aCC compiler on HP-UX/PA-RISC
1330 SOM-encapsulated symbolic debugging information, automatic
1331 invocation of pxdb, and the aCC custom C++ ABI. This does not
1332 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
1333 with aCC can still be debugged on an assembly level.
1335 MIPS ".pdr" sections
1337 A MIPS-specific format used to describe stack frame layout
1338 in debugging information.
1342 GDB could work with an older version of Guile to debug
1343 the interpreter and Scheme programs running in it.
1345 set mips stack-arg-size
1346 set mips saved-gpreg-size
1348 Use "set mips abi" to control parameter passing for MIPS.
1350 *** Changes in GDB 6.6
1355 Cell Broadband Engine SPU spu-elf
1357 * GDB can now be configured as a cross-debugger targeting native Windows
1358 (mingw32) or Cygwin. It can communicate with a remote debugging stub
1359 running on a Windows system over TCP/IP to debug Windows programs.
1361 * The GDB remote stub, gdbserver, has been updated to support Windows and
1362 Cygwin debugging. Both single-threaded and multi-threaded programs are
1365 * The "set trust-readonly-sections" command works again. This command was
1366 broken in GDB 6.3, 6.4, and 6.5.
1368 * The "load" command now supports writing to flash memory, if the remote
1369 stub provides the required support.
1371 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
1372 longer requires symbolic debug information (e.g. DWARF-2).
1377 unset substitute-path
1378 show substitute-path
1379 Manage a list of substitution rules that GDB uses to rewrite the name
1380 of the directories where the sources are located. This can be useful
1381 for instance when the sources were moved to a different location
1382 between compilation and debugging.
1386 Print each CLI command as it is executed. Each command is prefixed with
1387 a number of `+' symbols representing the nesting depth.
1388 The source command now has a `-v' option to enable the same feature.
1392 The ARM Demon monitor support (RDP protocol, "target rdp").
1394 Kernel Object Display, an embedded debugging feature which only worked with
1395 an obsolete version of Cisco IOS.
1397 The 'set download-write-size' and 'show download-write-size' commands.
1399 * New remote packets
1402 Tell a stub about GDB client features, and request remote target features.
1403 The first feature implemented is PacketSize, which allows the target to
1404 specify the size of packets it can handle - to minimize the number of
1405 packets required and improve performance when connected to a remote
1409 Fetch an OS auxilliary vector from the remote stub. This packet is a
1410 more efficient replacement for qPart:auxv:read.
1412 qXfer:memory-map:read:
1413 Fetch a memory map from the remote stub, including information about
1414 RAM, ROM, and flash memory devices.
1419 Erase and program a flash memory device.
1421 * Removed remote packets
1424 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
1425 used it, and only gdbserver implemented it.
1427 *** Changes in GDB 6.5
1431 Renesas M32C/M16C m32c-elf
1433 Morpho Technologies ms1 ms1-elf
1437 init-if-undefined Initialize a convenience variable, but
1438 only if it doesn't already have a value.
1440 The following commands are presently only implemented for native GNU/Linux:
1442 checkpoint Save a snapshot of the program state.
1444 restart <n> Return the program state to a
1445 previously saved state.
1447 info checkpoints List currently saved checkpoints.
1449 delete-checkpoint <n> Delete a previously saved checkpoint.
1451 set|show detach-on-fork Tell gdb whether to detach from a newly
1452 forked process, or to keep debugging it.
1454 info forks List forks of the user program that
1455 are available to be debugged.
1457 fork <n> Switch to debugging one of several
1458 forks of the user program that are
1459 available to be debugged.
1461 delete-fork <n> Delete a fork from the list of forks
1462 that are available to be debugged (and
1463 kill the forked process).
1465 detach-fork <n> Delete a fork from the list of forks
1466 that are available to be debugged (and
1467 allow the process to continue).
1471 Morpho Technologies ms2 ms1-elf
1473 * Improved Windows host support
1475 GDB now builds as a cross debugger hosted on i686-mingw32, including
1476 native console support, and remote communications using either
1477 network sockets or serial ports.
1479 * Improved Modula-2 language support
1481 GDB can now print most types in the Modula-2 syntax. This includes:
1482 basic types, set types, record types, enumerated types, range types,
1483 pointer types and ARRAY types. Procedure var parameters are correctly
1484 printed and hexadecimal addresses and character constants are also
1485 written in the Modula-2 syntax. Best results can be obtained by using
1486 GNU Modula-2 together with the -gdwarf-2 command line option.
1490 The ARM rdi-share module.
1492 The Netware NLM debug server.
1494 *** Changes in GDB 6.4
1496 * New native configurations
1498 OpenBSD/arm arm*-*-openbsd*
1499 OpenBSD/mips64 mips64-*-openbsd*
1503 Morpho Technologies ms1 ms1-elf
1505 * New command line options
1507 --batch-silent As for --batch, but totally silent.
1508 --return-child-result The debugger will exist with the same value
1509 the child (debugged) program exited with.
1510 --eval-command COMMAND, -ex COMMAND
1511 Execute a single GDB CLI command. This may be
1512 specified multiple times and in conjunction
1513 with the --command (-x) option.
1515 * Deprecated commands removed
1517 The following commands, that were deprecated in 2000, have been
1521 set|show arm disassembly-flavor set|show arm disassembler
1522 othernames set arm disassembler
1523 set|show remotedebug set|show debug remote
1524 set|show archdebug set|show debug arch
1525 set|show eventdebug set|show debug event
1528 * New BSD user-level threads support
1530 It is now possible to debug programs using the user-level threads
1531 library on OpenBSD and FreeBSD. Currently supported (target)
1534 FreeBSD/amd64 x86_64-*-freebsd*
1535 FreeBSD/i386 i386-*-freebsd*
1536 OpenBSD/i386 i386-*-openbsd*
1538 Note that the new kernel threads libraries introduced in FreeBSD 5.x
1539 are not yet supported.
1541 * New support for Matsushita MN10300 w/sim added
1542 (Work in progress). mn10300-elf.
1544 * REMOVED configurations and files
1546 VxWorks and the XDR protocol *-*-vxworks
1547 Motorola MCORE mcore-*-*
1548 National Semiconductor NS32000 ns32k-*-*
1550 * New "set print array-indexes" command
1552 After turning this setting "on", GDB prints the index of each element
1553 when displaying arrays. The default is "off" to preserve the previous
1556 * VAX floating point support
1558 GDB now supports the not-quite-ieee VAX F and D floating point formats.
1560 * User-defined command support
1562 In addition to using $arg0..$arg9 for argument passing, it is now possible
1563 to use $argc to determine now many arguments have been passed. See the
1564 section on user-defined commands in the user manual for more information.
1566 *** Changes in GDB 6.3:
1568 * New command line option
1570 GDB now accepts -l followed by a number to set the timeout for remote
1573 * GDB works with GCC -feliminate-dwarf2-dups
1575 GDB now supports a more compact representation of DWARF-2 debug
1576 information using DW_FORM_ref_addr references. These are produced
1577 by GCC with the option -feliminate-dwarf2-dups and also by some
1578 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
1579 to use -feliminate-dwarf2-dups.
1581 * Internationalization
1583 When supported by the host system, GDB will be built with
1584 internationalization (libintl). The task of marking up the sources is
1585 continued, we're looking forward to our first translation.
1589 Initial support for debugging programs compiled with the GNAT
1590 implementation of the Ada programming language has been integrated
1591 into GDB. In this release, support is limited to expression evaluation.
1593 * New native configurations
1595 GNU/Linux/m32r m32r-*-linux-gnu
1599 GDB's remote protocol now includes support for the 'p' packet. This
1600 packet is used to fetch individual registers from a remote inferior.
1602 * END-OF-LIFE registers[] compatibility module
1604 GDB's internal register infrastructure has been completely rewritten.
1605 The new infrastructure making possible the implementation of key new
1606 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
1609 GDB 6.3 will be the last release to include the the registers[]
1610 compatibility module that allowed out-of-date configurations to
1611 continue to work. This change directly impacts the following
1621 powerpc bdm protocol
1623 Unless there is activity to revive these configurations, they will be
1624 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
1626 * OBSOLETE configurations and files
1628 Configurations that have been declared obsolete in this release have
1629 been commented out. Unless there is activity to revive these
1630 configurations, the next release of GDB will have their sources
1631 permanently REMOVED.
1640 *** Changes in GDB 6.2.1:
1642 * MIPS `break main; run' gave an heuristic-fence-post warning
1644 When attempting to run even a simple program, a warning about
1645 heuristic-fence-post being hit would be reported. This problem has
1648 * MIPS IRIX 'long double' crashed GDB
1650 When examining a long double variable, GDB would get a segmentation
1651 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
1652 IRIX long double values).
1656 A bug in the VAX stack code was causing problems with the "next"
1657 command. This problem has been fixed.
1659 *** Changes in GDB 6.2:
1661 * Fix for ``many threads''
1663 On GNU/Linux systems that use the NPTL threads library, a program
1664 rapidly creating and deleting threads would confuse GDB leading to the
1667 ptrace: No such process.
1668 thread_db_get_info: cannot get thread info: generic error
1670 This problem has been fixed.
1672 * "-async" and "-noasync" options removed.
1674 Support for the broken "-noasync" option has been removed (it caused
1677 * New ``start'' command.
1679 This command runs the program until the begining of the main procedure.
1681 * New BSD Kernel Data Access Library (libkvm) interface
1683 Using ``target kvm'' it is now possible to debug kernel core dumps and
1684 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
1685 platforms. Currently supported (native-only) configurations are:
1687 FreeBSD/amd64 x86_64-*-freebsd*
1688 FreeBSD/i386 i?86-*-freebsd*
1689 NetBSD/i386 i?86-*-netbsd*
1690 NetBSD/m68k m68*-*-netbsd*
1691 NetBSD/sparc sparc-*-netbsd*
1692 OpenBSD/amd64 x86_64-*-openbsd*
1693 OpenBSD/i386 i?86-*-openbsd*
1694 OpenBSD/m68k m68*-openbsd*
1695 OpenBSD/sparc sparc-*-openbsd*
1697 * Signal trampoline code overhauled
1699 Many generic problems with GDB's signal handling code have been fixed.
1700 These include: backtraces through non-contiguous stacks; recognition
1701 of sa_sigaction signal trampolines; backtrace from a NULL pointer
1702 call; backtrace through a signal trampoline; step into and out of
1703 signal handlers; and single-stepping in the signal trampoline.
1705 Please note that kernel bugs are a limiting factor here. These
1706 features have been shown to work on an s390 GNU/Linux system that
1707 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
1709 * Cygwin support for DWARF 2 added.
1711 * New native configurations
1713 GNU/Linux/hppa hppa*-*-linux*
1714 OpenBSD/hppa hppa*-*-openbsd*
1715 OpenBSD/m68k m68*-*-openbsd*
1716 OpenBSD/m88k m88*-*-openbsd*
1717 OpenBSD/powerpc powerpc-*-openbsd*
1718 NetBSD/vax vax-*-netbsd*
1719 OpenBSD/vax vax-*-openbsd*
1721 * END-OF-LIFE frame compatibility module
1723 GDB's internal frame infrastructure has been completely rewritten.
1724 The new infrastructure making it possible to support key new features
1725 including DWARF 2 Call Frame Information. To aid in the task of
1726 migrating old configurations to this new infrastructure, a
1727 compatibility module, that allowed old configurations to continue to
1728 work, was also included.
1730 GDB 6.2 will be the last release to include this frame compatibility
1731 module. This change directly impacts the following configurations:
1741 Unless there is activity to revive these configurations, they will be
1742 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
1744 * REMOVED configurations and files
1746 Sun 3, running SunOS 3 m68*-*-sunos3*
1747 Sun 3, running SunOS 4 m68*-*-sunos4*
1748 Sun 2, running SunOS 3 m68000-*-sunos3*
1749 Sun 2, running SunOS 4 m68000-*-sunos4*
1750 Motorola 680x0 running LynxOS m68*-*-lynxos*
1751 AT&T 3b1/Unix pc m68*-att-*
1752 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
1753 decstation mips-dec-* mips-little-*
1754 riscos mips-*-riscos* mips-*-sysv*
1755 sonymips mips-sony-*
1756 sysv mips*-*-sysv4* (IRIX 5/6 not included)
1758 *** Changes in GDB 6.1.1:
1760 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
1762 The TUI (Text-mode User Interface) is now built as part of a default
1763 GDB configuration. It is enabled by either selecting the TUI with the
1764 command line option "-i=tui" or by running the separate "gdbtui"
1765 program. For more information on the TUI, see the manual "Debugging
1768 * Pending breakpoint support (also included in GDB 6.1)
1770 Support has been added to allow you to specify breakpoints in shared
1771 libraries that have not yet been loaded. If a breakpoint location
1772 cannot be found, and the "breakpoint pending" option is set to auto,
1773 GDB queries you if you wish to make the breakpoint pending on a future
1774 shared-library load. If and when GDB resolves the breakpoint symbol,
1775 the pending breakpoint is removed as one or more regular breakpoints
1778 Pending breakpoints are very useful for GCJ Java debugging.
1780 * Fixed ISO-C build problems
1782 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
1783 non ISO-C code that stopped them being built using a more strict ISO-C
1784 compiler (e.g., IBM's C compiler).
1786 * Fixed build problem on IRIX 5
1788 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
1789 wasn't able to compile compile on an IRIX 5 system.
1791 * Added execute permission to gdb/gdbserver/configure
1793 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
1794 permission. This bug would cause configure to fail on a number of
1795 systems (Solaris, IRIX). Ref: server/519.
1797 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
1799 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
1800 has been updated to use constant array sizes.
1802 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
1804 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
1805 its generated DWARF Call Frame Info. This encoding was causing GDB to
1806 panic, that panic has been fixed. Ref: gdb/1628.
1808 * Fixed a problem when examining parameters in shared library code.
1810 When examining parameters in optimized shared library code generated
1811 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
1812 not available''. GDB now correctly displays the variable's value.
1814 *** Changes in GDB 6.1:
1816 * Removed --with-mmalloc
1818 Support for the mmalloc memory manager has been removed, as it
1819 conflicted with the internal gdb byte cache.
1821 * Changes in AMD64 configurations
1823 The AMD64 target now includes the %cs and %ss registers. As a result
1824 the AMD64 remote protocol has changed; this affects the floating-point
1825 and SSE registers. If you rely on those registers for your debugging,
1826 you should upgrade gdbserver on the remote side.
1828 * Revised SPARC target
1830 The SPARC target has been completely revised, incorporating the
1831 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
1832 support for LynxOS and SunOS 4 has been dropped. Calling functions
1833 from within GDB on operating systems with a non-executable stack
1834 (Solaris, OpenBSD) now works.
1838 GDB has a new C++ demangler which does a better job on the mangled
1839 names generated by current versions of g++. It also runs faster, so
1840 with this and other changes gdb should now start faster on large C++
1843 * DWARF 2 Location Expressions
1845 GDB support for location expressions has been extended to support function
1846 arguments and frame bases. Older versions of GDB could crash when they
1849 * C++ nested types and namespaces
1851 GDB's support for nested types and namespaces in C++ has been
1852 improved, especially if you use the DWARF 2 debugging format. (This
1853 is the default for recent versions of GCC on most platforms.)
1854 Specifically, if you have a class "Inner" defined within a class or
1855 namespace "Outer", then GDB realizes that the class's name is
1856 "Outer::Inner", not simply "Inner". This should greatly reduce the
1857 frequency of complaints about not finding RTTI symbols. In addition,
1858 if you are stopped at inside of a function defined within a namespace,
1859 GDB modifies its name lookup accordingly.
1861 * New native configurations
1863 NetBSD/amd64 x86_64-*-netbsd*
1864 OpenBSD/amd64 x86_64-*-openbsd*
1865 OpenBSD/alpha alpha*-*-openbsd*
1866 OpenBSD/sparc sparc-*-openbsd*
1867 OpenBSD/sparc64 sparc64-*-openbsd*
1869 * New debugging protocols
1871 M32R with SDI protocol m32r-*-elf*
1873 * "set prompt-escape-char" command deleted.
1875 The command "set prompt-escape-char" has been deleted. This command,
1876 and its very obscure effet on GDB's prompt, was never documented,
1877 tested, nor mentioned in the NEWS file.
1879 * OBSOLETE configurations and files
1881 Configurations that have been declared obsolete in this release have
1882 been commented out. Unless there is activity to revive these
1883 configurations, the next release of GDB will have their sources
1884 permanently REMOVED.
1886 Sun 3, running SunOS 3 m68*-*-sunos3*
1887 Sun 3, running SunOS 4 m68*-*-sunos4*
1888 Sun 2, running SunOS 3 m68000-*-sunos3*
1889 Sun 2, running SunOS 4 m68000-*-sunos4*
1890 Motorola 680x0 running LynxOS m68*-*-lynxos*
1891 AT&T 3b1/Unix pc m68*-att-*
1892 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
1893 decstation mips-dec-* mips-little-*
1894 riscos mips-*-riscos* mips-*-sysv*
1895 sonymips mips-sony-*
1896 sysv mips*-*-sysv4* (IRIX 5/6 not included)
1898 * REMOVED configurations and files
1900 SGI Irix-4.x mips-sgi-irix4 or iris4
1901 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
1902 Z8000 simulator z8k-zilog-none or z8ksim
1903 Matsushita MN10200 w/simulator mn10200-*-*
1904 H8/500 simulator h8500-hitachi-hms or h8500hms
1905 HP/PA running BSD hppa*-*-bsd*
1906 HP/PA running OSF/1 hppa*-*-osf*
1907 HP/PA Pro target hppa*-*-pro*
1908 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
1909 386BSD i[3456]86-*-bsd*
1910 Sequent family i[3456]86-sequent-sysv4*
1911 i[3456]86-sequent-sysv*
1912 i[3456]86-sequent-bsd*
1913 SPARC running LynxOS sparc-*-lynxos*
1914 SPARC running SunOS 4 sparc-*-sunos4*
1915 Tsqware Sparclet sparclet-*-*
1916 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
1918 *** Changes in GDB 6.0:
1922 Support for debugging the Objective-C programming language has been
1923 integrated into GDB.
1925 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
1927 DWARF 2's Call Frame Information makes available compiler generated
1928 information that more exactly describes the program's run-time stack.
1929 By using this information, GDB is able to provide more robust stack
1932 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
1933 have been updated to use a new backtrace mechanism which includes
1934 DWARF 2 CFI support.
1938 GDB's remote protocol has been extended to include support for hosted
1939 file I/O (where the remote target uses GDB's file system). See GDB's
1940 remote protocol documentation for details.
1942 * All targets using the new architecture framework.
1944 All of GDB's targets have been updated to use the new internal
1945 architecture framework. The way is now open for future GDB releases
1946 to include cross-architecture native debugging support (i386 on amd64,
1949 * GNU/Linux's Thread Local Storage (TLS)
1951 GDB now includes support for for the GNU/Linux implementation of
1952 per-thread variables.
1954 * GNU/Linux's Native POSIX Thread Library (NPTL)
1956 GDB's thread code has been updated to work with either the new
1957 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
1959 * Separate debug info.
1961 GDB, in conjunction with BINUTILS, now supports a mechanism for
1962 automatically loading debug information from a separate file. Instead
1963 of shipping full debug and non-debug versions of system libraries,
1964 system integrators can now instead ship just the stripped libraries
1965 and optional debug files.
1967 * DWARF 2 Location Expressions
1969 DWARF 2 Location Expressions allow the compiler to more completely
1970 describe the location of variables (even in optimized code) to the
1973 GDB now includes preliminary support for location expressions (support
1974 for DW_OP_piece is still missing).
1978 A number of long standing bugs that caused GDB to die while starting a
1979 Java application have been fixed. GDB's Java support is now
1980 considered "useable".
1982 * GNU/Linux support for fork, vfork, and exec.
1984 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
1985 commands are now implemented for GNU/Linux. They require a 2.5.x or later
1988 * GDB supports logging output to a file
1990 There are two new commands, "set logging" and "show logging", which can be
1991 used to capture GDB's output to a file.
1993 * The meaning of "detach" has changed for gdbserver
1995 The "detach" command will now resume the application, as documented. To
1996 disconnect from gdbserver and leave it stopped, use the new "disconnect"
1999 * d10v, m68hc11 `regs' command deprecated
2001 The `info registers' command has been updated so that it displays the
2002 registers using a format identical to the old `regs' command.
2006 A new command, "maint set profile on/off", has been added. This command can
2007 be used to enable or disable profiling while running GDB, to profile a
2008 session or a set of commands. In addition there is a new configure switch,
2009 "--enable-profiling", which will cause GDB to be compiled with profiling
2010 data, for more informative profiling results.
2012 * Default MI syntax changed to "mi2".
2014 The default MI (machine interface) syntax, enabled by the command line
2015 option "-i=mi", has been changed to "mi2". The previous MI syntax,
2016 "mi1", can be enabled by specifying the option "-i=mi1".
2018 Support for the original "mi0" syntax (included in GDB 5.0) has been
2021 Fix for gdb/192: removed extraneous space when displaying frame level.
2022 Fix for gdb/672: update changelist is now output in mi list format.
2023 Fix for gdb/702: a -var-assign that updates the value now shows up
2024 in a subsequent -var-update.
2026 * New native configurations.
2028 FreeBSD/amd64 x86_64-*-freebsd*
2030 * Multi-arched targets.
2032 HP/PA HPUX11 hppa*-*-hpux*
2033 Renesas M32R/D w/simulator m32r-*-elf*
2035 * OBSOLETE configurations and files
2037 Configurations that have been declared obsolete in this release have
2038 been commented out. Unless there is activity to revive these
2039 configurations, the next release of GDB will have their sources
2040 permanently REMOVED.
2042 Z8000 simulator z8k-zilog-none or z8ksim
2043 Matsushita MN10200 w/simulator mn10200-*-*
2044 H8/500 simulator h8500-hitachi-hms or h8500hms
2045 HP/PA running BSD hppa*-*-bsd*
2046 HP/PA running OSF/1 hppa*-*-osf*
2047 HP/PA Pro target hppa*-*-pro*
2048 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2049 Sequent family i[3456]86-sequent-sysv4*
2050 i[3456]86-sequent-sysv*
2051 i[3456]86-sequent-bsd*
2052 Tsqware Sparclet sparclet-*-*
2053 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2055 * REMOVED configurations and files
2058 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2059 IBM AIX PS/2 i[3456]86-*-aix
2060 i386 running Mach 3.0 i[3456]86-*-mach3*
2061 i386 running Mach i[3456]86-*-mach*
2062 i386 running OSF/1 i[3456]86-*osf1mk*
2063 HP/Apollo 68k Family m68*-apollo*-sysv*,
2065 m68*-hp-bsd*, m68*-hp-hpux*
2066 Argonaut Risc Chip (ARC) arc-*-*
2067 Mitsubishi D30V d30v-*-*
2068 Fujitsu FR30 fr30-*-elf*
2069 OS/9000 i[34]86-*-os9k
2070 I960 with MON960 i960-*-coff
2072 * MIPS $fp behavior changed
2074 The convenience variable $fp, for the MIPS, now consistently returns
2075 the address of the current frame's base. Previously, depending on the
2076 context, $fp could refer to either $sp or the current frame's base
2077 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
2078 The GNU Source-Level Debugger''.
2080 *** Changes in GDB 5.3:
2082 * GNU/Linux shared library multi-threaded performance improved.
2084 When debugging a multi-threaded application on GNU/Linux, GDB now uses
2085 `/proc', in preference to `ptrace' for memory reads. This may result
2086 in an improvement in the start-up time of multi-threaded, shared
2087 library applications when run under GDB. One GDB user writes: ``loads
2088 shared libs like mad''.
2090 * ``gdbserver'' now supports multi-threaded applications on some targets
2092 Support for debugging multi-threaded applications which use
2093 the GNU/Linux LinuxThreads package has been added for
2094 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
2095 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
2097 * GDB now supports C/C++ preprocessor macros.
2099 GDB now expands preprocessor macro invocations in C/C++ expressions,
2100 and provides various commands for showing macro definitions and how
2103 The new command `macro expand EXPRESSION' expands any macro
2104 invocations in expression, and shows the result.
2106 The new command `show macro MACRO-NAME' shows the definition of the
2107 macro named MACRO-NAME, and where it was defined.
2109 Most compilers don't include information about macros in the debugging
2110 information by default. In GCC 3.1, for example, you need to compile
2111 your program with the options `-gdwarf-2 -g3'. If the macro
2112 information is present in the executable, GDB will read it.
2114 * Multi-arched targets.
2116 DEC Alpha (partial) alpha*-*-*
2117 DEC VAX (partial) vax-*-*
2119 National Semiconductor NS32000 (partial) ns32k-*-*
2120 Motorola 68000 (partial) m68k-*-*
2121 Motorola MCORE mcore-*-*
2125 Fujitsu FRV architecture added by Red Hat frv*-*-*
2128 * New native configurations
2130 Alpha NetBSD alpha*-*-netbsd*
2131 SH NetBSD sh*-*-netbsdelf*
2132 MIPS NetBSD mips*-*-netbsd*
2133 UltraSPARC NetBSD sparc64-*-netbsd*
2135 * OBSOLETE configurations and files
2137 Configurations that have been declared obsolete in this release have
2138 been commented out. Unless there is activity to revive these
2139 configurations, the next release of GDB will have their sources
2140 permanently REMOVED.
2142 Mitsubishi D30V d30v-*-*
2143 OS/9000 i[34]86-*-os9k
2144 IBM AIX PS/2 i[3456]86-*-aix
2145 Fujitsu FR30 fr30-*-elf*
2146 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2147 Argonaut Risc Chip (ARC) arc-*-*
2148 i386 running Mach 3.0 i[3456]86-*-mach3*
2149 i386 running Mach i[3456]86-*-mach*
2150 i386 running OSF/1 i[3456]86-*osf1mk*
2151 HP/Apollo 68k Family m68*-apollo*-sysv*,
2153 m68*-hp-bsd*, m68*-hp-hpux*
2154 I960 with MON960 i960-*-coff
2156 * OBSOLETE languages
2158 CHILL, a Pascal like language used by telecommunications companies.
2160 * REMOVED configurations and files
2162 AMD 29k family via UDI a29k-amd-udi, udi29k
2163 A29K VxWorks a29k-*-vxworks
2164 AMD 29000 embedded, using EBMON a29k-none-none
2165 AMD 29000 embedded with COFF a29k-none-coff
2166 AMD 29000 embedded with a.out a29k-none-aout
2168 testsuite/gdb.hp/gdb.threads-hp/ directory
2170 * New command "set max-user-call-depth <nnn>"
2172 This command allows the user to limit the call depth of user-defined
2173 commands. The default is 1024.
2175 * Changes in FreeBSD/i386 native debugging.
2177 Support for the "generate-core-file" has been added.
2179 * New commands "dump", "append", and "restore".
2181 These commands allow data to be copied from target memory
2182 to a bfd-format or binary file (dump and append), and back
2183 from a file into memory (restore).
2185 * Improved "next/step" support on multi-processor Alpha Tru64.
2187 The previous single-step mechanism could cause unpredictable problems,
2188 including the random appearance of SIGSEGV or SIGTRAP signals. The use
2189 of a software single-step mechanism prevents this.
2191 *** Changes in GDB 5.2.1:
2199 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
2200 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
2201 Fix, by Joel Brobecker imported from mainline.
2203 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
2204 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
2205 Fix, by Fred Fish, imported from mainline.
2207 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
2208 Surprisingly enough, it works now.
2209 By Michal Ludvig, imported from mainline.
2211 i386 hardware watchpoint support:
2212 avoid misses on second run for some targets.
2213 By Pierre Muller, imported from mainline.
2215 *** Changes in GDB 5.2:
2217 * New command "set trust-readonly-sections on[off]".
2219 This command is a hint that tells gdb that read-only sections
2220 really are read-only (ie. that their contents will not change).
2221 In this mode, gdb will go to the object file rather than the
2222 target to read memory from read-only sections (such as ".text").
2223 This can be a significant performance improvement on some
2224 (notably embedded) targets.
2226 * New command "generate-core-file" (or "gcore").
2228 This new gdb command allows the user to drop a core file of the child
2229 process state at any time. So far it's been implemented only for
2230 GNU/Linux and Solaris, but should be relatively easily ported to other
2231 hosts. Argument is core file name (defaults to core.<pid>).
2233 * New command line option
2235 GDB now accepts --pid or -p followed by a process id.
2237 * Change in command line behavior -- corefiles vs. process ids.
2239 There is a subtle behavior in the way in which GDB handles
2240 command line arguments. The first non-flag argument is always
2241 a program to debug, but the second non-flag argument may either
2242 be a corefile or a process id. Previously, GDB would attempt to
2243 open the second argument as a corefile, and if that failed, would
2244 issue a superfluous error message and then attempt to attach it as
2245 a process. Now, if the second argument begins with a non-digit,
2246 it will be treated as a corefile. If it begins with a digit,
2247 GDB will attempt to attach it as a process, and if no such process
2248 is found, will then attempt to open it as a corefile.
2250 * Changes in ARM configurations.
2252 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
2253 configuration is fully multi-arch.
2255 * New native configurations
2257 ARM NetBSD arm*-*-netbsd*
2258 x86 OpenBSD i[3456]86-*-openbsd*
2259 AMD x86-64 running GNU/Linux x86_64-*-linux-*
2260 Sparc64 running FreeBSD sparc64-*-freebsd*
2264 Sanyo XStormy16 xstormy16-elf
2266 * OBSOLETE configurations and files
2268 Configurations that have been declared obsolete in this release have
2269 been commented out. Unless there is activity to revive these
2270 configurations, the next release of GDB will have their sources
2271 permanently REMOVED.
2273 AMD 29k family via UDI a29k-amd-udi, udi29k
2274 A29K VxWorks a29k-*-vxworks
2275 AMD 29000 embedded, using EBMON a29k-none-none
2276 AMD 29000 embedded with COFF a29k-none-coff
2277 AMD 29000 embedded with a.out a29k-none-aout
2279 testsuite/gdb.hp/gdb.threads-hp/ directory
2281 * REMOVED configurations and files
2283 TI TMS320C80 tic80-*-*
2285 PowerPC Solaris powerpcle-*-solaris*
2286 PowerPC Windows NT powerpcle-*-cygwin32
2287 PowerPC Netware powerpc-*-netware*
2288 Harris/CXUX m88k m88*-harris-cxux*
2289 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
2290 ns32k-utek-sysv* ns32k-utek-*
2291 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
2292 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
2293 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
2294 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
2295 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
2297 * Changes to command line processing
2299 The new `--args' feature can be used to specify command-line arguments
2300 for the inferior from gdb's command line.
2302 * Changes to key bindings
2304 There is a new `operate-and-get-next' function bound to `C-o'.
2306 *** Changes in GDB 5.1.1
2308 Fix compile problem on DJGPP.
2310 Fix a problem with floating-point registers on the i386 being
2313 Fix to stop GDB crashing on .debug_str debug info.
2315 Numerous documentation fixes.
2317 Numerous testsuite fixes.
2319 *** Changes in GDB 5.1:
2321 * New native configurations
2323 Alpha FreeBSD alpha*-*-freebsd*
2324 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
2325 MIPS GNU/Linux mips*-*-linux*
2326 MIPS SGI Irix 6.x mips*-sgi-irix6*
2327 ia64 AIX ia64-*-aix*
2328 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
2332 Motorola 68HC11 and 68HC12 m68hc11-elf
2334 UltraSparc running GNU/Linux sparc64-*-linux*
2336 * OBSOLETE configurations and files
2338 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
2339 Harris/CXUX m88k m88*-harris-cxux*
2340 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
2341 ns32k-utek-sysv* ns32k-utek-*
2342 TI TMS320C80 tic80-*-*
2344 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
2345 PowerPC Solaris powerpcle-*-solaris*
2346 PowerPC Windows NT powerpcle-*-cygwin32
2347 PowerPC Netware powerpc-*-netware*
2348 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
2349 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
2350 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
2351 Apple Macintosh (MPW) host N/A
2353 stuff.c (Program to stuff files into a specially prepared space in kdb)
2354 kdb-start.c (Main loop for the standalone kernel debugger)
2356 Configurations that have been declared obsolete in this release have
2357 been commented out. Unless there is activity to revive these
2358 configurations, the next release of GDB will have their sources
2359 permanently REMOVED.
2361 * REMOVED configurations and files
2363 Altos 3068 m68*-altos-*
2364 Convex c1-*-*, c2-*-*
2366 ARM RISCix arm-*-* (as host)
2370 * GDB has been converted to ISO C.
2372 GDB's source code has been converted to ISO C. In particular, the
2373 sources are fully protoized, and rely on standard headers being
2378 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
2380 * The MI enabled by default.
2382 The new machine oriented interface (MI) introduced in GDB 5.0 has been
2383 revised and enabled by default. Packages which use GDB as a debugging
2384 engine behind a UI or another front end are encouraged to switch to
2385 using the GDB/MI interface, instead of the old annotations interface
2386 which is now deprecated.
2388 * Support for debugging Pascal programs.
2390 GDB now includes support for debugging Pascal programs. The following
2391 main features are supported:
2393 - Pascal-specific data types such as sets;
2395 - automatic recognition of Pascal sources based on file-name
2398 - Pascal-style display of data types, variables, and functions;
2400 - a Pascal expression parser.
2402 However, some important features are not yet supported.
2404 - Pascal string operations are not supported at all;
2406 - there are some problems with boolean types;
2408 - Pascal type hexadecimal constants are not supported
2409 because they conflict with the internal variables format;
2411 - support for Pascal objects and classes is not full yet;
2413 - unlike Pascal, GDB is case-sensitive for symbol names.
2415 * Changes in completion.
2417 Commands such as `shell', `run' and `set args', which pass arguments
2418 to inferior programs, now complete on file names, similar to what
2419 users expect at the shell prompt.
2421 Commands which accept locations, such as `disassemble', `print',
2422 `breakpoint', `until', etc. now complete on filenames as well as
2423 program symbols. Thus, if you type "break foob TAB", and the source
2424 files linked into the programs include `foobar.c', that file name will
2425 be one of the candidates for completion. However, file names are not
2426 considered for completion after you typed a colon that delimits a file
2427 name from a name of a function in that file, as in "break foo.c:bar".
2429 `set demangle-style' completes on available demangling styles.
2431 * New platform-independent commands:
2433 It is now possible to define a post-hook for a command as well as a
2434 hook that runs before the command. For more details, see the
2435 documentation of `hookpost' in the GDB manual.
2437 * Changes in GNU/Linux native debugging.
2439 Support for debugging multi-threaded programs has been completely
2440 revised for all platforms except m68k and sparc. You can now debug as
2441 many threads as your system allows you to have.
2443 Attach/detach is supported for multi-threaded programs.
2445 Support for SSE registers was added for x86. This doesn't work for
2446 multi-threaded programs though.
2448 * Changes in MIPS configurations.
2450 Multi-arch support is enabled for all MIPS configurations.
2452 GDB can now be built as native debugger on SGI Irix 6.x systems for
2453 debugging n32 executables. (Debugging 64-bit executables is not yet
2456 * Unified support for hardware watchpoints in all x86 configurations.
2458 Most (if not all) native x86 configurations support hardware-assisted
2459 breakpoints and watchpoints in a unified manner. This support
2460 implements debug register sharing between watchpoints, which allows to
2461 put a virtually infinite number of watchpoints on the same address,
2462 and also supports watching regions up to 16 bytes with several debug
2465 The new maintenance command `maintenance show-debug-regs' toggles
2466 debugging print-outs in functions that insert, remove, and test
2467 watchpoints and hardware breakpoints.
2469 * Changes in the DJGPP native configuration.
2471 New command ``info dos sysinfo'' displays assorted information about
2472 the CPU, OS, memory, and DPMI server.
2474 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
2475 display information about segment descriptors stored in GDT, LDT, and
2478 New commands ``info dos pde'' and ``info dos pte'' display entries
2479 from Page Directory and Page Tables (for now works with CWSDPMI only).
2480 New command ``info dos address-pte'' displays the Page Table entry for
2481 a given linear address.
2483 GDB can now pass command lines longer than 126 characters to the
2484 program being debugged (requires an update to the libdbg.a library
2485 which is part of the DJGPP development kit).
2487 DWARF2 debug info is now supported.
2489 It is now possible to `step' and `next' through calls to `longjmp'.
2491 * Changes in documentation.
2493 All GDB documentation was converted to GFDL, the GNU Free
2494 Documentation License.
2496 Tracepoints-related commands are now fully documented in the GDB
2499 TUI, the Text-mode User Interface, is now documented in the manual.
2501 Tracepoints-related commands are now fully documented in the GDB
2504 The "GDB Internals" manual now has an index. It also includes
2505 documentation of `ui_out' functions, GDB coding standards, x86
2506 hardware watchpoints, and memory region attributes.
2508 * GDB's version number moved to ``version.in''
2510 The Makefile variable VERSION has been replaced by the file
2511 ``version.in''. People creating GDB distributions should update the
2512 contents of this file.
2516 GUD support is now a standard part of the EMACS distribution.
2518 *** Changes in GDB 5.0:
2520 * Improved support for debugging FP programs on x86 targets
2522 Unified and much-improved support for debugging floating-point
2523 programs on all x86 targets. In particular, ``info float'' now
2524 displays the FP registers in the same format on all x86 targets, with
2525 greater level of detail.
2527 * Improvements and bugfixes in hardware-assisted watchpoints
2529 It is now possible to watch array elements, struct members, and
2530 bitfields with hardware-assisted watchpoints. Data-read watchpoints
2531 on x86 targets no longer erroneously trigger when the address is
2534 * Improvements in the native DJGPP version of GDB
2536 The distribution now includes all the scripts and auxiliary files
2537 necessary to build the native DJGPP version on MS-DOS/MS-Windows
2538 machines ``out of the box''.
2540 The DJGPP version can now debug programs that use signals. It is
2541 possible to catch signals that happened in the debuggee, deliver
2542 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
2543 would kill the program being debugged.) Programs that hook hardware
2544 interrupts (keyboard, timer, etc.) can also be debugged.
2546 It is now possible to debug DJGPP programs that redirect their
2547 standard handles or switch them to raw (as opposed to cooked) mode, or
2548 even close them. The command ``run < foo > bar'' works as expected,
2549 and ``info terminal'' reports useful information about the debuggee's
2550 terminal, including raw/cooked mode, redirection, etc.
2552 The DJGPP version now uses termios functions for console I/O, which
2553 enables debugging graphics programs. Interrupting GDB with Ctrl-C
2556 DOS-style file names with drive letters are now fully supported by
2559 It is now possible to debug DJGPP programs that switch their working
2560 directory. It is also possible to rerun the debuggee any number of
2561 times without restarting GDB; thus, you can use the same setup,
2562 breakpoints, etc. for many debugging sessions.
2564 * New native configurations
2566 ARM GNU/Linux arm*-*-linux*
2567 PowerPC GNU/Linux powerpc-*-linux*
2571 Motorola MCore mcore-*-*
2572 x86 VxWorks i[3456]86-*-vxworks*
2573 PowerPC VxWorks powerpc-*-vxworks*
2574 TI TMS320C80 tic80-*-*
2576 * OBSOLETE configurations
2578 Altos 3068 m68*-altos-*
2579 Convex c1-*-*, c2-*-*
2581 ARM RISCix arm-*-* (as host)
2584 Configurations that have been declared obsolete will be commented out,
2585 but the code will be left in place. If there is no activity to revive
2586 these configurations before the next release of GDB, the sources will
2587 be permanently REMOVED.
2589 * Gould support removed
2591 Support for the Gould PowerNode and NP1 has been removed.
2593 * New features for SVR4
2595 On SVR4 native platforms (such as Solaris), if you attach to a process
2596 without first loading a symbol file, GDB will now attempt to locate and
2597 load symbols from the running process's executable file.
2599 * Many C++ enhancements
2601 C++ support has been greatly improved. Overload resolution now works properly
2602 in almost all cases. RTTI support is on the way.
2604 * Remote targets can connect to a sub-program
2606 A popen(3) style serial-device has been added. This device starts a
2607 sub-process (such as a stand-alone simulator) and then communicates
2608 with that. The sub-program to run is specified using the syntax
2609 ``|<program> <args>'' vis:
2611 (gdb) set remotedebug 1
2612 (gdb) target extended-remote |mn10300-elf-sim program-args
2614 * MIPS 64 remote protocol
2616 A long standing bug in the mips64 remote protocol where by GDB
2617 expected certain 32 bit registers (ex SR) to be transfered as 32
2618 instead of 64 bits has been fixed.
2620 The command ``set remote-mips64-transfers-32bit-regs on'' has been
2621 added to provide backward compatibility with older versions of GDB.
2623 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
2625 The command ``set remotebinarydownload'' command has been replaced by
2626 ``set remote X-packet''. Other commands in ``set remote'' family
2627 include ``set remote P-packet''.
2629 * Breakpoint commands accept ranges.
2631 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
2632 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
2633 ``tracepoint passcount'' also accepts a range of tracepoints.
2635 * ``apropos'' command added.
2637 The ``apropos'' command searches through command names and
2638 documentation strings, printing out matches, making it much easier to
2639 try to find a command that does what you are looking for.
2643 A new machine oriented interface (MI) has been added to GDB. This
2644 interface is designed for debug environments running GDB as a separate
2645 process. This is part of the long term libGDB project. See the
2646 "GDB/MI" chapter of the GDB manual for further information. It can be
2647 enabled by configuring with:
2649 .../configure --enable-gdbmi
2651 *** Changes in GDB-4.18:
2653 * New native configurations
2655 HP-UX 10.20 hppa*-*-hpux10.20
2656 HP-UX 11.x hppa*-*-hpux11.0*
2657 M68K GNU/Linux m68*-*-linux*
2661 Fujitsu FR30 fr30-*-elf*
2662 Intel StrongARM strongarm-*-*
2663 Mitsubishi D30V d30v-*-*
2665 * OBSOLETE configurations
2667 Gould PowerNode, NP1 np1-*-*, pn-*-*
2669 Configurations that have been declared obsolete will be commented out,
2670 but the code will be left in place. If there is no activity to revive
2671 these configurations before the next release of GDB, the sources will
2672 be permanently REMOVED.
2676 As a compatibility experiment, GDB's source files buildsym.h and
2677 buildsym.c have been converted to pure standard C, no longer
2678 containing any K&R compatibility code. We believe that all systems in
2679 use today either come with a standard C compiler, or have a GCC port
2680 available. If this is not true, please report the affected
2681 configuration to bug-gdb@gnu.org immediately. See the README file for
2682 information about getting a standard C compiler if you don't have one
2687 GDB now uses readline 2.2.
2689 * set extension-language
2691 You can now control the mapping between filename extensions and source
2692 languages by using the `set extension-language' command. For instance,
2693 you can ask GDB to treat .c files as C++ by saying
2694 set extension-language .c c++
2695 The command `info extensions' lists all of the recognized extensions
2696 and their associated languages.
2698 * Setting processor type for PowerPC and RS/6000
2700 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
2701 you can use the `set processor' command to specify what variant of the
2702 PowerPC family you are debugging. The command
2706 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
2707 following PowerPC and RS6000 variants:
2709 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
2710 rs6000 IBM RS6000 ("POWER") architecture, user-level view
2712 403GC IBM PowerPC 403GC
2713 505 Motorola PowerPC 505
2714 860 Motorola PowerPC 860 or 850
2715 601 Motorola PowerPC 601
2716 602 Motorola PowerPC 602
2717 603 Motorola/IBM PowerPC 603 or 603e
2718 604 Motorola PowerPC 604 or 604e
2719 750 Motorola/IBM PowerPC 750 or 750
2721 At the moment, this command just tells GDB what to name the
2722 special-purpose processor registers. Since almost all the affected
2723 registers are inaccessible to user-level programs, this command is
2724 only useful for remote debugging in its present form.
2728 Thanks to a major code donation from Hewlett-Packard, GDB now has much
2729 more extensive support for HP-UX. Added features include shared
2730 library support, kernel threads and hardware watchpoints for 11.00,
2731 support for HP's ANSI C and C++ compilers, and a compatibility mode
2732 for xdb and dbx commands.
2736 HP's donation includes the new concept of catchpoints, which is a
2737 generalization of the old catch command. On HP-UX, it is now possible
2738 to catch exec, fork, and vfork, as well as library loading.
2740 This means that the existing catch command has changed; its first
2741 argument now specifies the type of catch to be set up. See the
2742 output of "help catch" for a list of catchpoint types.
2744 * Debugging across forks
2746 On HP-UX, you can choose which process to debug when a fork() happens
2751 HP has donated a curses-based terminal user interface (TUI). To get
2752 it, build with --enable-tui. Although this can be enabled for any
2753 configuration, at present it only works for native HP debugging.
2755 * GDB remote protocol additions
2757 A new protocol packet 'X' that writes binary data is now available.
2758 Default behavior is to try 'X', then drop back to 'M' if the stub
2759 fails to respond. The settable variable `remotebinarydownload'
2760 allows explicit control over the use of 'X'.
2762 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
2763 full 64-bit address. The command
2765 set remoteaddresssize 32
2767 can be used to revert to the old behaviour. For existing remote stubs
2768 the change should not be noticed, as the additional address information
2771 In order to assist in debugging stubs, you may use the maintenance
2772 command `packet' to send any text string to the stub. For instance,
2774 maint packet heythere
2776 sends the packet "$heythere#<checksum>". Note that it is very easy to
2777 disrupt a debugging session by sending the wrong packet at the wrong
2780 The compare-sections command allows you to compare section data on the
2781 target to what is in the executable file without uploading or
2782 downloading, by comparing CRC checksums.
2784 * Tracing can collect general expressions
2786 You may now collect general expressions at tracepoints. This requires
2787 further additions to the target-side stub; see tracepoint.c and
2788 doc/agentexpr.texi for further details.
2790 * mask-address variable for Mips
2792 For Mips targets, you may control the zeroing of the upper 32 bits of
2793 a 64-bit address by entering `set mask-address on'. This is mainly
2794 of interest to users of embedded R4xxx and R5xxx processors.
2796 * Higher serial baud rates
2798 GDB's serial code now allows you to specify baud rates 57600, 115200,
2799 230400, and 460800 baud. (Note that your host system may not be able
2800 to achieve all of these rates.)
2804 The i960 configuration now includes an initial implementation of a
2805 builtin simulator, contributed by Jim Wilson.
2808 *** Changes in GDB-4.17:
2810 * New native configurations
2812 Alpha GNU/Linux alpha*-*-linux*
2813 Unixware 2.x i[3456]86-unixware2*
2814 Irix 6.x mips*-sgi-irix6*
2815 PowerPC GNU/Linux powerpc-*-linux*
2816 PowerPC Solaris powerpcle-*-solaris*
2817 Sparc GNU/Linux sparc-*-linux*
2818 Motorola sysV68 R3V7.1 m68k-motorola-sysv
2822 Argonaut Risc Chip (ARC) arc-*-*
2823 Hitachi H8/300S h8300*-*-*
2824 Matsushita MN10200 w/simulator mn10200-*-*
2825 Matsushita MN10300 w/simulator mn10300-*-*
2826 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
2827 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
2828 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
2829 Mitsubishi D10V w/simulator d10v-*-*
2830 Mitsubishi M32R/D w/simulator m32r-*-elf*
2831 Tsqware Sparclet sparclet-*-*
2832 NEC V850 w/simulator v850-*-*
2834 * New debugging protocols
2836 ARM with RDI protocol arm*-*-*
2837 M68K with dBUG monitor m68*-*-{aout,coff,elf}
2838 DDB and LSI variants of PMON protocol mips*-*-*
2839 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
2840 PowerPC with SDS protocol powerpc{,le}-*-eabi
2841 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
2845 All configurations can now understand and use the DWARF 2 debugging
2846 format. The choice is automatic, if the symbol file contains DWARF 2
2851 GDB now includes basic Java language support. This support is
2852 only useful with Java compilers that produce native machine code.
2854 * solib-absolute-prefix and solib-search-path
2856 For SunOS and SVR4 shared libraries, you may now set the prefix for
2857 loading absolute shared library symbol files, and the search path for
2858 locating non-absolute shared library symbol files.
2860 * Live range splitting
2862 GDB can now effectively debug code for which GCC has performed live
2863 range splitting as part of its optimization. See gdb/doc/LRS for
2864 more details on the expected format of the stabs information.
2868 GDB's support for the GNU Hurd, including thread debugging, has been
2869 updated to work with current versions of the Hurd.
2873 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
2874 instruction set. ARM GDB automatically detects when Thumb
2875 instructions are in use, and adjusts disassembly and backtracing
2880 GDB's MIPS target configurations now handle the MIP16 16-bit
2885 GDB now includes support for overlays; if an executable has been
2886 linked such that multiple sections are based at the same address, GDB
2887 will decide which section to use for symbolic info. You can choose to
2888 control the decision manually, using overlay commands, or implement
2889 additional target-side support and use "overlay load-target" to bring
2890 in the overlay mapping. Do "help overlay" for more detail.
2894 The command "info symbol <address>" displays information about
2895 the symbol at the specified address.
2899 The standard remote protocol now includes an extension that allows
2900 asynchronous collection and display of trace data. This requires
2901 extensive support in the target-side debugging stub. Tracing mode
2902 includes a new interaction mode in GDB and new commands: see the
2903 file tracepoint.c for more details.
2907 Configurations for embedded MIPS now include a simulator contributed
2908 by Cygnus Solutions. The simulator supports the instruction sets
2909 of most MIPS variants.
2913 Sparc configurations may now include the ERC32 simulator contributed
2914 by the European Space Agency. The simulator is not built into
2915 Sparc targets by default; configure with --enable-sim to include it.
2919 For target configurations that may include multiple variants of a
2920 basic architecture (such as MIPS and SH), you may now set the
2921 architecture explicitly. "set arch" sets, "info arch" lists
2922 the possible architectures.
2924 *** Changes in GDB-4.16:
2926 * New native configurations
2928 Windows 95, x86 Windows NT i[345]86-*-cygwin32
2929 M68K NetBSD m68k-*-netbsd*
2930 PowerPC AIX 4.x powerpc-*-aix*
2931 PowerPC MacOS powerpc-*-macos*
2932 PowerPC Windows NT powerpcle-*-cygwin32
2933 RS/6000 AIX 4.x rs6000-*-aix4*
2937 ARM with RDP protocol arm-*-*
2938 I960 with MON960 i960-*-coff
2939 MIPS VxWorks mips*-*-vxworks*
2940 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
2941 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
2943 Matra Sparclet sparclet-*-*
2947 The powerpc-eabi configuration now includes the PSIM simulator,
2948 contributed by Andrew Cagney, with assistance from Mike Meissner.
2949 PSIM is a very elaborate model of the PowerPC, including not only
2950 basic instruction set execution, but also details of execution unit
2951 performance and I/O hardware. See sim/ppc/README for more details.
2955 GDB now works with Solaris 2.5.
2957 * Windows 95/NT native
2959 GDB will now work as a native debugger on Windows 95 and Windows NT.
2960 To build it from source, you must use the "gnu-win32" environment,
2961 which uses a DLL to emulate enough of Unix to run the GNU tools.
2962 Further information, binaries, and sources are available at
2963 ftp.cygnus.com, under pub/gnu-win32.
2965 * dont-repeat command
2967 If a user-defined command includes the command `dont-repeat', then the
2968 command will not be repeated if the user just types return. This is
2969 useful if the command is time-consuming to run, so that accidental
2970 extra keystrokes don't run the same command many times.
2972 * Send break instead of ^C
2974 The standard remote protocol now includes an option to send a break
2975 rather than a ^C to the target in order to interrupt it. By default,
2976 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
2978 * Remote protocol timeout
2980 The standard remote protocol includes a new variable `remotetimeout'
2981 that allows you to set the number of seconds before GDB gives up trying
2982 to read from the target. The default value is 2.
2984 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
2986 By default GDB will automatically keep track of objects as they are
2987 loaded and unloaded by the dynamic linker. By using the command `set
2988 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
2989 when shared library events occur, thus allowing you to set breakpoints
2990 in shared libraries which are explicitly loaded by the inferior.
2992 Note this feature does not work on hpux8. On hpux9 you must link
2993 /usr/lib/end.o into your program. This feature should work
2994 automatically on hpux10.
2996 * Irix 5.x hardware watchpoint support
2998 Irix 5 configurations now support the use of hardware watchpoints.
3000 * Mips protocol "SYN garbage limit"
3002 When debugging a Mips target using the `target mips' protocol, you
3003 may set the number of characters that GDB will ignore by setting
3004 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
3005 every character. The default value is 1050.
3007 * Recording and replaying remote debug sessions
3009 If you set `remotelogfile' to the name of a file, gdb will write to it
3010 a recording of a remote debug session. This recording may then be
3011 replayed back to gdb using "gdbreplay". See gdbserver/README for
3012 details. This is useful when you have a problem with GDB while doing
3013 remote debugging; you can make a recording of the session and send it
3014 to someone else, who can then recreate the problem.
3016 * Speedups for remote debugging
3018 GDB includes speedups for downloading and stepping MIPS systems using
3019 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
3020 and more efficient S-record downloading.
3022 * Memory use reductions and statistics collection
3024 GDB now uses less memory and reports statistics about memory usage.
3025 Try the `maint print statistics' command, for example.
3027 *** Changes in GDB-4.15:
3029 * Psymtabs for XCOFF
3031 The symbol reader for AIX GDB now uses partial symbol tables. This
3032 can greatly improve startup time, especially for large executables.
3034 * Remote targets use caching
3036 Remote targets now use a data cache to speed up communication with the
3037 remote side. The data cache could lead to incorrect results because
3038 it doesn't know about volatile variables, thus making it impossible to
3039 debug targets which use memory mapped I/O devices. `set remotecache
3040 off' turns the the data cache off.
3042 * Remote targets may have threads
3044 The standard remote protocol now includes support for multiple threads
3045 in the target system, using new protocol commands 'H' and 'T'. See
3046 gdb/remote.c for details.
3050 If GDB is configured with `--enable-netrom', then it will include
3051 support for the NetROM ROM emulator from XLNT Designs. The NetROM
3052 acts as though it is a bank of ROM on the target board, but you can
3053 write into it over the network. GDB's support consists only of
3054 support for fast loading into the emulated ROM; to debug, you must use
3055 another protocol, such as standard remote protocol. The usual
3056 sequence is something like
3058 target nrom <netrom-hostname>
3060 target remote <netrom-hostname>:1235
3064 GDB now includes support for the Apple Macintosh, as a host only. It
3065 may be run as either an MPW tool or as a standalone application, and
3066 it can debug through the serial port. All the usual GDB commands are
3067 available, but to the target command, you must supply "serial" as the
3068 device type instead of "/dev/ttyXX". See mpw-README in the main
3069 directory for more information on how to build. The MPW configuration
3070 scripts */mpw-config.in support only a few targets, and only the
3071 mips-idt-ecoff target has been tested.
3075 GDB configuration now uses autoconf. This is not user-visible,
3076 but does simplify configuration and building.
3080 GDB now supports hpux10.
3082 *** Changes in GDB-4.14:
3084 * New native configurations
3086 x86 FreeBSD i[345]86-*-freebsd
3087 x86 NetBSD i[345]86-*-netbsd
3088 NS32k NetBSD ns32k-*-netbsd
3089 Sparc NetBSD sparc-*-netbsd
3093 A29K VxWorks a29k-*-vxworks
3094 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
3095 CPU32 EST-300 emulator m68*-*-est*
3096 PowerPC ELF powerpc-*-elf
3099 * Alpha OSF/1 support for procfs
3101 GDB now supports procfs under OSF/1-2.x and higher, which makes it
3102 possible to attach to running processes. As the mounting of the /proc
3103 filesystem is optional on the Alpha, GDB automatically determines
3104 the availability of /proc during startup. This can lead to problems
3105 if /proc is unmounted after GDB has been started.
3107 * Arguments to user-defined commands
3109 User commands may accept up to 10 arguments separated by whitespace.
3110 Arguments are accessed within the user command via $arg0..$arg9. A
3113 print $arg0 + $arg1 + $arg2
3115 To execute the command use:
3118 Defines the command "adder" which prints the sum of its three arguments.
3119 Note the arguments are text substitutions, so they may reference variables,
3120 use complex expressions, or even perform inferior function calls.
3122 * New `if' and `while' commands
3124 This makes it possible to write more sophisticated user-defined
3125 commands. Both commands take a single argument, which is the
3126 expression to evaluate, and must be followed by the commands to
3127 execute, one per line, if the expression is nonzero, the list being
3128 terminated by the word `end'. The `if' command list may include an
3129 `else' word, which causes the following commands to be executed only
3130 if the expression is zero.
3132 * Fortran source language mode
3134 GDB now includes partial support for Fortran 77. It will recognize
3135 Fortran programs and can evaluate a subset of Fortran expressions, but
3136 variables and functions may not be handled correctly. GDB will work
3137 with G77, but does not yet know much about symbols emitted by other
3140 * Better HPUX support
3142 Most debugging facilities now work on dynamic executables for HPPAs
3143 running hpux9 or later. You can attach to running dynamically linked
3144 processes, but by default the dynamic libraries will be read-only, so
3145 for instance you won't be able to put breakpoints in them. To change
3146 that behavior do the following before running the program:
3152 This will cause the libraries to be mapped private and read-write.
3153 To revert to the normal behavior, do this:
3159 You cannot set breakpoints or examine data in the library until after
3160 the library is loaded if the function/data symbols do not have
3163 GDB can now also read debug symbols produced by the HP C compiler on
3164 HPPAs (sorry, no C++, Fortran or 68k support).
3166 * Target byte order now dynamically selectable
3168 You can choose which byte order to use with a target system, via the
3169 commands "set endian big" and "set endian little", and you can see the
3170 current setting by using "show endian". You can also give the command
3171 "set endian auto", in which case GDB will use the byte order
3172 associated with the executable. Currently, only embedded MIPS
3173 configurations support dynamic selection of target byte order.
3175 * New DOS host serial code
3177 This version uses DPMI interrupts to handle buffered I/O, so you
3178 no longer need to run asynctsr when debugging boards connected to
3181 *** Changes in GDB-4.13:
3183 * New "complete" command
3185 This lists all the possible completions for the rest of the line, if it
3186 were to be given as a command itself. This is intended for use by emacs.
3188 * Trailing space optional in prompt
3190 "set prompt" no longer adds a space for you after the prompt you set. This
3191 allows you to set a prompt which ends in a space or one that does not.
3193 * Breakpoint hit counts
3195 "info break" now displays a count of the number of times the breakpoint
3196 has been hit. This is especially useful in conjunction with "ignore"; you
3197 can ignore a large number of breakpoint hits, look at the breakpoint info
3198 to see how many times the breakpoint was hit, then run again, ignoring one
3199 less than that number, and this will get you quickly to the last hit of
3202 * Ability to stop printing at NULL character
3204 "set print null-stop" will cause GDB to stop printing the characters of
3205 an array when the first NULL is encountered. This is useful when large
3206 arrays actually contain only short strings.
3208 * Shared library breakpoints
3210 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
3211 breakpoints in shared libraries before the executable is run.
3213 * Hardware watchpoints
3215 There is a new hardware breakpoint for the watch command for sparclite
3216 targets. See gdb/sparclite/hw_breakpoint.note.
3218 Hardware watchpoints are also now supported under GNU/Linux.
3222 Annotations have been added. These are for use with graphical interfaces,
3223 and are still experimental. Currently only gdba.el uses these.
3225 * Improved Irix 5 support
3227 GDB now works properly with Irix 5.2.
3229 * Improved HPPA support
3231 GDB now works properly with the latest GCC and GAS.
3233 * New native configurations
3235 Sequent PTX4 i[34]86-sequent-ptx4
3236 HPPA running OSF/1 hppa*-*-osf*
3237 Atari TT running SVR4 m68*-*-sysv4*
3238 RS/6000 LynxOS rs6000-*-lynxos*
3242 OS/9000 i[34]86-*-os9k
3243 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
3246 * Hitachi SH7000 and E7000-PC ICE support
3248 There is now support for communicating with the Hitachi E7000-PC ICE.
3249 This is available automatically when GDB is configured for the SH.
3253 As usual, a variety of small fixes and improvements, both generic
3254 and configuration-specific. See the ChangeLog for more detail.
3256 *** Changes in GDB-4.12:
3258 * Irix 5 is now supported
3262 GDB-4.12 on the HPPA has a number of changes which make it unable
3263 to debug the output from the currently released versions of GCC and
3264 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
3265 of GCC and GAS, versions of these tools designed to work with GDB-4.12
3266 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
3269 *** Changes in GDB-4.11:
3271 * User visible changes:
3275 The "set remotedebug" option is now consistent between the mips remote
3276 target, remote targets using the gdb-specific protocol, UDI (AMD's
3277 debug protocol for the 29k) and the 88k bug monitor. It is now an
3278 integer specifying a debug level (normally 0 or 1, but 2 means more
3279 debugging info for the mips target).
3281 * DEC Alpha native support
3283 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
3284 debug info, but GDB works fairly well with the DEC compiler and should
3285 work with a future GCC release. See the README file for a few
3286 Alpha-specific notes.
3288 * Preliminary thread implementation
3290 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
3292 * LynxOS native and target support for 386
3294 This release has been hosted on LynxOS 2.2, and also can be configured
3295 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
3298 * Improvements in C++ mangling/demangling.
3300 This release has much better g++ debugging, specifically in name
3301 mangling/demangling, virtual function calls, print virtual table,
3302 call methods, ...etc.
3304 *** Changes in GDB-4.10:
3306 * User visible changes:
3308 Remote debugging using the GDB-specific (`target remote') protocol now
3309 supports the `load' command. This is only useful if you have some
3310 other way of getting the stub to the target system, and you can put it
3311 somewhere in memory where it won't get clobbered by the download.
3313 Filename completion now works.
3315 When run under emacs mode, the "info line" command now causes the
3316 arrow to point to the line specified. Also, "info line" prints
3317 addresses in symbolic form (as well as hex).
3319 All vxworks based targets now support a user settable option, called
3320 vxworks-timeout. This option represents the number of seconds gdb
3321 should wait for responses to rpc's. You might want to use this if
3322 your vxworks target is, perhaps, a slow software simulator or happens
3323 to be on the far side of a thin network line.
3327 This release contains support for using a DEC alpha as a GDB host for
3328 cross debugging. Native alpha debugging is not supported yet.
3331 *** Changes in GDB-4.9:
3335 This is the first GDB release which is accompanied by a matching testsuite.
3336 The testsuite requires installation of dejagnu, which should be available
3337 via ftp from most sites that carry GNU software.
3341 'Cfront' style demangling has had its name changed to 'ARM' style, to
3342 emphasize that it was written from the specifications in the C++ Annotated
3343 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
3344 disclaimers, it still generated too much confusion with users attempting to
3345 use gdb with AT&T cfront.
3349 GDB now uses a standard remote interface to a simulator library.
3350 So far, the library contains simulators for the Zilog Z8001/2, the
3351 Hitachi H8/300, H8/500 and Super-H.
3353 * New targets supported
3355 H8/300 simulator h8300-hitachi-hms or h8300hms
3356 H8/500 simulator h8500-hitachi-hms or h8500hms
3357 SH simulator sh-hitachi-hms or sh
3358 Z8000 simulator z8k-zilog-none or z8ksim
3359 IDT MIPS board over serial line mips-idt-ecoff
3361 Cross-debugging to GO32 targets is supported. It requires a custom
3362 version of the i386-stub.c module which is integrated with the
3363 GO32 memory extender.
3365 * New remote protocols
3367 MIPS remote debugging protocol.
3369 * New source languages supported
3371 This version includes preliminary support for Chill, a Pascal like language
3372 used by telecommunications companies. Chill support is also being integrated
3373 into the GNU compiler, but we don't know when it will be publically available.
3376 *** Changes in GDB-4.8:
3378 * HP Precision Architecture supported
3380 GDB now supports HP PA-RISC machines running HPUX. A preliminary
3381 version of this support was available as a set of patches from the
3382 University of Utah. GDB does not support debugging of programs
3383 compiled with the HP compiler, because HP will not document their file
3384 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
3385 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
3387 Many problems in the preliminary version have been fixed.
3389 * Faster and better demangling
3391 We have improved template demangling and fixed numerous bugs in the GNU style
3392 demangler. It can now handle type modifiers such as `static' or `const'. Wide
3393 character types (wchar_t) are now supported. Demangling of each symbol is now
3394 only done once, and is cached when the symbol table for a file is read in.
3395 This results in a small increase in memory usage for C programs, a moderate
3396 increase in memory usage for C++ programs, and a fantastic speedup in
3399 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
3400 from the specifications in the Annotated Reference Manual, which AT&T's
3401 compiler does not actually implement.
3403 * G++ multiple inheritance compiler problem
3405 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
3406 inheritance lattices was reworked to properly discover ambiguities. We
3407 recently found an example which causes this new algorithm to fail in a
3408 very subtle way, producing bad debug information for those classes.
3409 The file 'gcc.patch' (in this directory) can be applied to gcc to
3410 circumvent the problem. A future GCC release will contain a complete
3413 The previous G++ debug info problem (mentioned below for the gdb-4.7
3414 release) is fixed in gcc version 2.3.2.
3416 * Improved configure script
3418 The `configure' script will now attempt to guess your system type if
3419 you don't supply a host system type. The old scheme of supplying a
3420 host system triplet is preferable over using this. All the magic is
3421 done in the new `config.guess' script. Examine it for details.
3423 We have also brought our configure script much more in line with the FSF's
3424 version. It now supports the --with-xxx options. In particular,
3425 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
3426 The resulting GDB will not be able to read arbitrary object file formats --
3427 only the format ``expected'' to be used on the configured target system.
3428 We hope to make this the default in a future release.
3430 * Documentation improvements
3432 There's new internal documentation on how to modify GDB, and how to
3433 produce clean changes to the code. We implore people to read it
3434 before submitting changes.
3436 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
3437 M4 macros. The new texinfo.tex is provided in this release. Pre-built
3438 `info' files are also provided. To build `info' files from scratch,
3439 you will need the latest `makeinfo' release, which will be available in
3440 a future texinfo-X.Y release.
3442 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
3443 We're not sure exactly which versions have this problem, but it has
3444 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
3445 or better. If that isn't possible, there is a patch in
3446 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
3447 around this problem.
3451 GDB now supports array constants that can be used in expressions typed in by
3452 the user. The syntax is `{element, element, ...}'. Ie: you can now type
3453 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
3456 The new directory `gdb/sparclite' contains a program that demonstrates
3457 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
3459 * New native hosts supported
3461 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
3462 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
3464 * New targets supported
3466 AMD 29k family via UDI a29k-amd-udi or udi29k
3468 * New file formats supported
3470 BFD now supports reading HP/PA-RISC executables (SOM file format?),
3471 HPUX core files, and SCO 3.2v2 core files.
3475 Attaching to processes now works again; thanks for the many bug reports.
3477 We have also stomped on a bunch of core dumps caused by
3478 printf_filtered("%s") problems.
3480 We eliminated a copyright problem on the rpc and ptrace header files
3481 for VxWorks, which was discovered at the last minute during the 4.7
3482 release. You should now be able to build a VxWorks GDB.
3484 You can now interrupt gdb while an attached process is running. This
3485 will cause the attached process to stop, and give control back to GDB.
3487 We fixed problems caused by using too many file descriptors
3488 for reading symbols from object files and libraries. This was
3489 especially a problem for programs that used many (~100) shared
3492 The `step' command now only enters a subroutine if there is line number
3493 information for the subroutine. Otherwise it acts like the `next'
3494 command. Previously, `step' would enter subroutines if there was
3495 any debugging information about the routine. This avoids problems
3496 when using `cc -g1' on MIPS machines.
3498 * Internal improvements
3500 GDB's internal interfaces have been improved to make it easier to support
3501 debugging of multiple languages in the future.
3503 GDB now uses a common structure for symbol information internally.
3504 Minimal symbols (derived from linkage symbols in object files), partial
3505 symbols (from a quick scan of debug information), and full symbols
3506 contain a common subset of information, making it easier to write
3507 shared code that handles any of them.
3509 * New command line options
3511 We now accept --silent as an alias for --quiet.
3515 The memory-mapped-malloc library is now licensed under the GNU Library
3516 General Public License.
3518 *** Changes in GDB-4.7:
3520 * Host/native/target split
3522 GDB has had some major internal surgery to untangle the support for
3523 hosts and remote targets. Now, when you configure GDB for a remote
3524 target, it will no longer load in all of the support for debugging
3525 local programs on the host. When fully completed and tested, this will
3526 ensure that arbitrary host/target combinations are possible.
3528 The primary conceptual shift is to separate the non-portable code in
3529 GDB into three categories. Host specific code is required any time GDB
3530 is compiled on that host, regardless of the target. Target specific
3531 code relates to the peculiarities of the target, but can be compiled on
3532 any host. Native specific code is everything else: it can only be
3533 built when the host and target are the same system. Child process
3534 handling and core file support are two common `native' examples.
3536 GDB's use of /proc for controlling Unix child processes is now cleaner.
3537 It has been split out into a single module under the `target_ops' vector,
3538 plus two native-dependent functions for each system that uses /proc.
3540 * New hosts supported
3542 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
3543 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
3544 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
3546 * New targets supported
3548 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3549 68030 and CPU32 m68030-*-*, m68332-*-*
3551 * New native hosts supported
3553 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
3554 (386bsd is not well tested yet)
3555 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
3557 * New file formats supported
3559 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
3560 supports reading of `a.out.adobe' object files, which are an a.out
3561 format extended with minimal information about multiple sections.
3565 `show copying' is the same as the old `info copying'.
3566 `show warranty' is the same as `info warrantee'.
3567 These were renamed for consistency. The old commands continue to work.
3569 `info handle' is a new alias for `info signals'.
3571 You can now define pre-command hooks, which attach arbitrary command
3572 scripts to any command. The commands in the hook will be executed
3573 prior to the user's command. You can also create a hook which will be
3574 executed whenever the program stops. See gdb.texinfo.
3578 We now deal with Cfront style name mangling, and can even extract type
3579 info from mangled symbols. GDB can automatically figure out which
3580 symbol mangling style your C++ compiler uses.
3582 Calling of methods and virtual functions has been improved as well.
3586 The crash that occured when debugging Sun Ansi-C compiled binaries is
3587 fixed. This was due to mishandling of the extra N_SO stabs output
3590 We also finally got Ultrix 4.2 running in house, and fixed core file
3591 support, with help from a dozen people on the net.
3593 John M. Farrell discovered that the reason that single-stepping was so
3594 slow on all of the Mips based platforms (primarily SGI and DEC) was
3595 that we were trying to demangle and lookup a symbol used for internal
3596 purposes on every instruction that was being stepped through. Changing
3597 the name of that symbol so that it couldn't be mistaken for a C++
3598 mangled symbol sped things up a great deal.
3600 Rich Pixley sped up symbol lookups in general by getting much smarter
3601 about when C++ symbol mangling is necessary. This should make symbol
3602 completion (TAB on the command line) much faster. It's not as fast as
3603 we'd like, but it's significantly faster than gdb-4.6.
3607 A new user controllable variable 'call_scratch_address' can
3608 specify the location of a scratch area to be used when GDB
3609 calls a function in the target. This is necessary because the
3610 usual method of putting the scratch area on the stack does not work
3611 in systems that have separate instruction and data spaces.
3613 We integrated changes to support the 29k UDI (Universal Debugger
3614 Interface), but discovered at the last minute that we didn't have all
3615 of the appropriate copyright paperwork. We are working with AMD to
3616 resolve this, and hope to have it available soon.
3620 We have sped up the remote serial line protocol, especially for targets
3621 with lots of registers. It now supports a new `expedited status' ('T')
3622 message which can be used in place of the existing 'S' status message.
3623 This allows the remote stub to send only the registers that GDB
3624 needs to make a quick decision about single-stepping or conditional
3625 breakpoints, eliminating the need to fetch the entire register set for
3626 each instruction being stepped through.
3628 The GDB remote serial protocol now implements a write-through cache for
3629 registers, only re-reading the registers if the target has run.
3631 There is also a new remote serial stub for SPARC processors. You can
3632 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
3633 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
3634 processor with a serial port.
3638 Configure.in files have become much easier to read and modify. A new
3639 `table driven' format makes it more obvious what configurations are
3640 supported, and what files each one uses.
3644 There is a new opcodes library which will eventually contain all of the
3645 disassembly routines and opcode tables. At present, it only contains
3646 Sparc and Z8000 routines. This will allow the assembler, debugger, and
3647 disassembler (binutils/objdump) to share these routines.
3649 The libiberty library is now copylefted under the GNU Library General
3650 Public License. This allows more liberal use, and was done so libg++
3651 can use it. This makes no difference to GDB, since the Library License
3652 grants all the rights from the General Public License.
3656 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
3657 reference to the stabs symbol info used by the debugger. It is (as far
3658 as we know) the only published document on this fascinating topic. We
3659 encourage you to read it, compare it to the stabs information on your
3660 system, and send improvements on the document in general (to
3661 bug-gdb@prep.ai.mit.edu).
3663 And, of course, many bugs have been fixed.
3666 *** Changes in GDB-4.6:
3668 * Better support for C++ function names
3670 GDB now accepts as input the "demangled form" of C++ overloaded function
3671 names and member function names, and can do command completion on such names
3672 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
3673 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
3674 Make use of command completion, it is your friend.
3676 GDB also now accepts a variety of C++ mangled symbol formats. They are
3677 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
3678 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
3679 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
3680 for the list of formats.
3682 * G++ symbol mangling problem
3684 Recent versions of gcc have a bug in how they emit debugging information for
3685 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
3686 directory) can be applied to gcc to fix the problem. Alternatively, if you
3687 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
3688 usual symptom is difficulty with setting breakpoints on methods. GDB complains
3689 about the method being non-existent. (We believe that version 2.2.2 of GCC has
3692 * New 'maintenance' command
3694 All of the commands related to hacking GDB internals have been moved out of
3695 the main command set, and now live behind the 'maintenance' command. This
3696 can also be abbreviated as 'mt'. The following changes were made:
3698 dump-me -> maintenance dump-me
3699 info all-breakpoints -> maintenance info breakpoints
3700 printmsyms -> maintenance print msyms
3701 printobjfiles -> maintenance print objfiles
3702 printpsyms -> maintenance print psymbols
3703 printsyms -> maintenance print symbols
3705 The following commands are new:
3707 maintenance demangle Call internal GDB demangler routine to
3708 demangle a C++ link name and prints the result.
3709 maintenance print type Print a type chain for a given symbol
3711 * Change to .gdbinit file processing
3713 We now read the $HOME/.gdbinit file before processing the argv arguments
3714 (e.g. reading symbol files or core files). This allows global parameters to
3715 be set, which will apply during the symbol reading. The ./.gdbinit is still
3716 read after argv processing.
3718 * New hosts supported
3720 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
3722 GNU/Linux support i386-unknown-linux or linux
3724 We are also including code to support the HP/PA running BSD and HPUX. This
3725 is almost guaranteed not to work, as we didn't have time to test or build it
3726 for this release. We are including it so that the more adventurous (or
3727 masochistic) of you can play with it. We also had major problems with the
3728 fact that the compiler that we got from HP doesn't support the -g option.
3731 * New targets supported
3733 Hitachi H8/300 h8300-hitachi-hms or h8300hms
3735 * More smarts about finding #include files
3737 GDB now remembers the compilation directory for all include files, and for
3738 all files from which C is generated (like yacc and lex sources). This
3739 greatly improves GDB's ability to find yacc/lex sources, and include files,
3740 especially if you are debugging your program from a directory different from
3741 the one that contains your sources.
3743 We also fixed a bug which caused difficulty with listing and setting
3744 breakpoints in include files which contain C code. (In the past, you had to
3745 try twice in order to list an include file that you hadn't looked at before.)
3747 * Interesting infernals change
3749 GDB now deals with arbitrary numbers of sections, where the symbols for each
3750 section must be relocated relative to that section's landing place in the
3751 target's address space. This work was needed to support ELF with embedded
3752 stabs used by Solaris-2.0.
3754 * Bug fixes (of course!)
3756 There have been loads of fixes for the following things:
3757 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
3758 i960, stabs, DOS(GO32), procfs, etc...
3760 See the ChangeLog for details.
3762 *** Changes in GDB-4.5:
3764 * New machines supported (host and target)
3766 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
3768 SGI Irix-4.x mips-sgi-irix4 or iris4
3770 * New malloc package
3772 GDB now uses a new memory manager called mmalloc, based on gmalloc.
3773 Mmalloc is capable of handling mutiple heaps of memory. It is also
3774 capable of saving a heap to a file, and then mapping it back in later.
3775 This can be used to greatly speedup the startup of GDB by using a
3776 pre-parsed symbol table which lives in a mmalloc managed heap. For
3777 more details, please read mmalloc/mmalloc.texi.
3781 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
3782 'help info proc' for details.
3784 * MIPS ecoff symbol table format
3786 The code that reads MIPS symbol table format is now supported on all hosts.
3787 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
3790 * File name changes for MS-DOS
3792 Many files in the config directories have been renamed to make it easier to
3793 support GDB on MS-DOSe systems (which have very restrictive file name
3794 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
3795 environment) is close to working but has some remaining problems. Note
3796 that debugging of DOS programs is not supported, due to limitations
3797 in the ``operating system'', but it can be used to host cross-debugging.
3799 * Cross byte order fixes
3801 Many fixes have been made to support cross debugging of Sparc and MIPS
3802 targets from hosts whose byte order differs.
3804 * New -mapped and -readnow options
3806 If memory-mapped files are available on your system through the 'mmap'
3807 system call, you can use the -mapped option on the `file' or
3808 `symbol-file' commands to cause GDB to write the symbols from your
3809 program into a reusable file. If the program you are debugging is
3810 called `/path/fred', the mapped symbol file will be `./fred.syms'.
3811 Future GDB debugging sessions will notice the presence of this file,
3812 and will quickly map in symbol information from it, rather than reading
3813 the symbol table from the executable program. Using the '-mapped'
3814 option in a GDB `file' or `symbol-file' command has the same effect as
3815 starting GDB with the '-mapped' command-line option.
3817 You can cause GDB to read the entire symbol table immediately by using
3818 the '-readnow' option with any of the commands that load symbol table
3819 information (or on the GDB command line). This makes the command
3820 slower, but makes future operations faster.
3822 The -mapped and -readnow options are typically combined in order to
3823 build a `fred.syms' file that contains complete symbol information.
3824 A simple GDB invocation to do nothing but build a `.syms' file for future
3827 gdb -batch -nx -mapped -readnow programname
3829 The `.syms' file is specific to the host machine on which GDB is run.
3830 It holds an exact image of GDB's internal symbol table. It cannot be
3831 shared across multiple host platforms.
3833 * longjmp() handling
3835 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
3836 siglongjmp() without losing control. This feature has not yet been ported to
3837 all systems. It currently works on many 386 platforms, all MIPS-based
3838 platforms (SGI, DECstation, etc), and Sun3/4.
3842 Preliminary work has been put in to support the new Solaris OS from Sun. At
3843 this time, it can control and debug processes, but it is not capable of
3848 As always, many many bug fixes. The major areas were with g++, and mipsread.
3849 People using the MIPS-based platforms should experience fewer mysterious
3850 crashes and trashed symbol tables.
3852 *** Changes in GDB-4.4:
3854 * New machines supported (host and target)
3856 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
3858 BSD Reno on Vax vax-dec-bsd
3859 Ultrix on Vax vax-dec-ultrix
3861 * New machines supported (target)
3863 AMD 29000 embedded, using EBMON a29k-none-none
3867 GDB continues to improve its handling of C++. `References' work better.
3868 The demangler has also been improved, and now deals with symbols mangled as
3869 per the Annotated C++ Reference Guide.
3871 GDB also now handles `stabs' symbol information embedded in MIPS
3872 `ecoff' symbol tables. Since the ecoff format was not easily
3873 extensible to handle new languages such as C++, this appeared to be a
3874 good way to put C++ debugging info into MIPS binaries. This option
3875 will be supported in the GNU C compiler, version 2, when it is
3878 * New features for SVR4
3880 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
3881 shared libraries. Debugging dynamically linked programs should present
3882 only minor differences from debugging statically linked programs.
3884 The `info proc' command will print out information about any process
3885 on an SVR4 system (including the one you are debugging). At the moment,
3886 it prints the address mappings of the process.
3888 If you bring up GDB on another SVR4 system, please send mail to
3889 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
3891 * Better dynamic linking support in SunOS
3893 Reading symbols from shared libraries which contain debugging symbols
3894 now works properly. However, there remain issues such as automatic
3895 skipping of `transfer vector' code during function calls, which
3896 make it harder to debug code in a shared library, than to debug the
3897 same code linked statically.
3901 GDB is now using the latest `getopt' routines from the FSF. This
3902 version accepts the -- prefix for options with long names. GDB will
3903 continue to accept the old forms (-option and +option) as well.
3904 Various single letter abbreviations for options have been explicity
3905 added to the option table so that they won't get overshadowed in the
3906 future by other options that begin with the same letter.
3910 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
3911 Many assorted bugs have been handled. Many more remain to be handled.
3912 See the various ChangeLog files (primarily in gdb and bfd) for details.
3915 *** Changes in GDB-4.3:
3917 * New machines supported (host and target)
3919 Amiga 3000 running Amix m68k-cbm-svr4 or amix
3920 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
3921 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3923 * Almost SCO Unix support
3925 We had hoped to support:
3926 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
3927 (except for core file support), but we discovered very late in the release
3928 that it has problems with process groups that render gdb unusable. Sorry
3929 about that. I encourage people to fix it and post the fixes.
3931 * Preliminary ELF and DWARF support
3933 GDB can read ELF object files on System V Release 4, and can handle
3934 debugging records for C, in DWARF format, in ELF files. This support
3935 is preliminary. If you bring up GDB on another SVR4 system, please
3936 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
3941 GDB now uses the latest `readline' library. One user-visible change
3942 is that two tabs will list possible command completions, which previously
3943 required typing M-? (meta-question mark, or ESC ?).
3947 The `stepi' bug that many of you noticed has been squashed.
3948 Many bugs in C++ have been handled. Many more remain to be handled.
3949 See the various ChangeLog files (primarily in gdb and bfd) for details.
3951 * State of the MIPS world (in case you wondered):
3953 GDB can understand the symbol tables emitted by the compilers
3954 supplied by most vendors of MIPS-based machines, including DEC. These
3955 symbol tables are in a format that essentially nobody else uses.
3957 Some versions of gcc come with an assembler post-processor called
3958 mips-tfile. This program is required if you want to do source-level
3959 debugging of gcc-compiled programs. I believe FSF does not ship
3960 mips-tfile with gcc version 1, but it will eventually come with gcc
3963 Debugging of g++ output remains a problem. g++ version 1.xx does not
3964 really support it at all. (If you're lucky, you should be able to get
3965 line numbers and stack traces to work, but no parameters or local
3966 variables.) With some work it should be possible to improve the
3969 When gcc version 2 is released, you will have somewhat better luck.
3970 However, even then you will get confusing results for inheritance and
3973 We will eventually provide full debugging of g++ output on
3974 DECstations. This will probably involve some kind of stabs-in-ecoff
3975 encapulation, but the details have not been worked out yet.
3978 *** Changes in GDB-4.2:
3980 * Improved configuration
3982 Only one copy of `configure' exists now, and it is not self-modifying.
3983 Porting BFD is simpler.
3987 The `step' and `next' commands now only stop at the first instruction
3988 of a source line. This prevents the multiple stops that used to occur
3989 in switch statements, for-loops, etc. `Step' continues to stop if a
3990 function that has debugging information is called within the line.
3994 Lots of small bugs fixed. More remain.
3996 * New host supported (not target)
3998 Intel 386 PC clone running Mach i386-none-mach
4001 *** Changes in GDB-4.1:
4003 * Multiple source language support
4005 GDB now has internal scaffolding to handle several source languages.
4006 It determines the type of each source file from its filename extension,
4007 and will switch expression parsing and number formatting to match the
4008 language of the function in the currently selected stack frame.
4009 You can also specifically set the language to be used, with
4010 `set language c' or `set language modula-2'.
4014 GDB now has preliminary support for the GNU Modula-2 compiler,
4015 currently under development at the State University of New York at
4016 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
4017 continue through the fall of 1991 and into 1992.
4019 Other Modula-2 compilers are currently not supported, and attempting to
4020 debug programs compiled with them will likely result in an error as the
4021 symbol table is read. Feel free to work on it, though!
4023 There are hooks in GDB for strict type checking and range checking,
4024 in the `Modula-2 philosophy', but they do not currently work.
4028 GDB can now write to executable and core files (e.g. patch
4029 a variable's value). You must turn this switch on, specify
4030 the file ("exec foo" or "core foo"), *then* modify it, e.g.
4031 by assigning a new value to a variable. Modifications take
4034 * Automatic SunOS shared library reading
4036 When you run your program, GDB automatically determines where its
4037 shared libraries (if any) have been loaded, and reads their symbols.
4038 The `share' command is no longer needed. This also works when
4039 examining core files.
4043 You can specify the number of lines that the `list' command shows.
4046 * New machines supported (host and target)
4048 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4049 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
4050 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
4052 * New hosts supported (not targets)
4054 IBM RT/PC: romp-ibm-aix or rtpc
4056 * New targets supported (not hosts)
4058 AMD 29000 embedded with COFF a29k-none-coff
4059 AMD 29000 embedded with a.out a29k-none-aout
4060 Ultracomputer remote kernel debug a29k-nyu-kern
4062 * New remote interfaces
4068 *** Changes in GDB-4.0:
4072 Wide output is wrapped at good places to make the output more readable.
4074 Gdb now supports cross-debugging from a host machine of one type to a
4075 target machine of another type. Communication with the target system
4076 is over serial lines. The ``target'' command handles connecting to the
4077 remote system; the ``load'' command will download a program into the
4078 remote system. Serial stubs for the m68k and i386 are provided. Gdb
4079 also supports debugging of realtime processes running under VxWorks,
4080 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
4081 stub on the target system.
4083 New CPUs supported include the AMD 29000 and Intel 960.
4085 GDB now reads object files and symbol tables via a ``binary file''
4086 library, which allows a single copy of GDB to debug programs of multiple
4087 object file types such as a.out and coff.
4089 There is now a GDB reference card in "doc/refcard.tex". (Make targets
4090 refcard.dvi and refcard.ps are available to format it).
4093 * Control-Variable user interface simplified
4095 All variables that control the operation of the debugger can be set
4096 by the ``set'' command, and displayed by the ``show'' command.
4098 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
4099 ``Show prompt'' produces the response:
4100 Gdb's prompt is new-gdb=>.
4102 What follows are the NEW set commands. The command ``help set'' will
4103 print a complete list of old and new set commands. ``help set FOO''
4104 will give a longer description of the variable FOO. ``show'' will show
4105 all of the variable descriptions and their current settings.
4107 confirm on/off: Enables warning questions for operations that are
4108 hard to recover from, e.g. rerunning the program while
4109 it is already running. Default is ON.
4111 editing on/off: Enables EMACS style command line editing
4112 of input. Previous lines can be recalled with
4113 control-P, the current line can be edited with control-B,
4114 you can search for commands with control-R, etc.
4117 history filename NAME: NAME is where the gdb command history
4118 will be stored. The default is .gdb_history,
4119 or the value of the environment variable
4122 history size N: The size, in commands, of the command history. The
4123 default is 256, or the value of the environment variable
4126 history save on/off: If this value is set to ON, the history file will
4127 be saved after exiting gdb. If set to OFF, the
4128 file will not be saved. The default is OFF.
4130 history expansion on/off: If this value is set to ON, then csh-like
4131 history expansion will be performed on
4132 command line input. The default is OFF.
4134 radix N: Sets the default radix for input and output. It can be set
4135 to 8, 10, or 16. Note that the argument to "radix" is interpreted
4136 in the current radix, so "set radix 10" is always a no-op.
4138 height N: This integer value is the number of lines on a page. Default
4139 is 24, the current `stty rows'' setting, or the ``li#''
4140 setting from the termcap entry matching the environment
4143 width N: This integer value is the number of characters on a line.
4144 Default is 80, the current `stty cols'' setting, or the ``co#''
4145 setting from the termcap entry matching the environment
4148 Note: ``set screensize'' is obsolete. Use ``set height'' and
4149 ``set width'' instead.
4151 print address on/off: Print memory addresses in various command displays,
4152 such as stack traces and structure values. Gdb looks
4153 more ``symbolic'' if you turn this off; it looks more
4154 ``machine level'' with it on. Default is ON.
4156 print array on/off: Prettyprint arrays. New convenient format! Default
4159 print demangle on/off: Print C++ symbols in "source" form if on,
4162 print asm-demangle on/off: Same, for assembler level printouts
4165 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
4168 * Support for Epoch Environment.
4170 The epoch environment is a version of Emacs v18 with windowing. One
4171 new command, ``inspect'', is identical to ``print'', except that if you
4172 are running in the epoch environment, the value is printed in its own
4176 * Support for Shared Libraries
4178 GDB can now debug programs and core files that use SunOS shared libraries.
4179 Symbols from a shared library cannot be referenced
4180 before the shared library has been linked with the program (this
4181 happens after you type ``run'' and before the function main() is entered).
4182 At any time after this linking (including when examining core files
4183 from dynamically linked programs), gdb reads the symbols from each
4184 shared library when you type the ``sharedlibrary'' command.
4185 It can be abbreviated ``share''.
4187 sharedlibrary REGEXP: Load shared object library symbols for files
4188 matching a unix regular expression. No argument
4189 indicates to load symbols for all shared libraries.
4191 info sharedlibrary: Status of loaded shared libraries.
4196 A watchpoint stops execution of a program whenever the value of an
4197 expression changes. Checking for this slows down execution
4198 tremendously whenever you are in the scope of the expression, but is
4199 quite useful for catching tough ``bit-spreader'' or pointer misuse
4200 problems. Some machines such as the 386 have hardware for doing this
4201 more quickly, and future versions of gdb will use this hardware.
4203 watch EXP: Set a watchpoint (breakpoint) for an expression.
4205 info watchpoints: Information about your watchpoints.
4207 delete N: Deletes watchpoint number N (same as breakpoints).
4208 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
4209 enable N: Re-enables watchpoint number N (same as breakpoints).
4212 * C++ multiple inheritance
4214 When used with a GCC version 2 compiler, GDB supports multiple inheritance
4217 * C++ exception handling
4219 Gdb now supports limited C++ exception handling. Besides the existing
4220 ability to breakpoint on an exception handler, gdb can breakpoint on
4221 the raising of an exception (before the stack is peeled back to the
4224 catch FOO: If there is a FOO exception handler in the dynamic scope,
4225 set a breakpoint to catch exceptions which may be raised there.
4226 Multiple exceptions (``catch foo bar baz'') may be caught.
4228 info catch: Lists all exceptions which may be caught in the
4229 current stack frame.
4232 * Minor command changes
4234 The command ``call func (arg, arg, ...)'' now acts like the print
4235 command, except it does not print or save a value if the function's result
4236 is void. This is similar to dbx usage.
4238 The ``up'' and ``down'' commands now always print the frame they end up
4239 at; ``up-silently'' and `down-silently'' can be used in scripts to change
4240 frames without printing.
4242 * New directory command
4244 'dir' now adds directories to the FRONT of the source search path.
4245 The path starts off empty. Source files that contain debug information
4246 about the directory in which they were compiled can be found even
4247 with an empty path; Sun CC and GCC include this information. If GDB can't
4248 find your source file in the current directory, type "dir .".
4250 * Configuring GDB for compilation
4252 For normal use, type ``./configure host''. See README or gdb.texinfo
4255 GDB now handles cross debugging. If you are remotely debugging between
4256 two different machines, type ``./configure host -target=targ''.
4257 Host is the machine where GDB will run; targ is the machine
4258 where the program that you are debugging will run.