1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.2
6 * GDB now has some support for using labels in the program's source in
7 linespecs. For instance, you can use "advance label" to continue
10 * GDB now has support for reading and writing a new .gdb_index
11 section. This section holds a fast index of DWARF debugging
12 information and can be used to greatly speed up GDB startup and
13 operation. See the documentation for `save gdb-index' for details.
15 *** Changes in GDB 7.2
17 * Shared library support for remote targets by default
19 When GDB is configured for a generic, non-OS specific target, like
20 for example, --target=arm-eabi or one of the many *-*-elf targets,
21 GDB now queries remote stubs for loaded shared libraries using the
22 `qXfer:libraries:read' packet. Previously, shared library support
23 was always disabled for such configurations.
27 ** Argument Dependent Lookup (ADL)
29 In C++ ADL lookup directs function search to the namespaces of its
30 arguments even if the namespace has not been imported.
40 Here the compiler will search for `foo' in the namespace of 'b'
41 and find A::foo. GDB now supports this. This construct is commonly
42 used in the Standard Template Library for operators.
44 ** Improved User Defined Operator Support
46 In addition to member operators, GDB now supports lookup of operators
47 defined in a namespace and imported with a `using' directive, operators
48 defined in the global scope, operators imported implicitly from an
49 anonymous namespace, and the ADL operators mentioned in the previous
51 GDB now also supports proper overload resolution for all the previously
52 mentioned flavors of operators.
54 ** static const class members
56 Printing of static const class members that are initialized in the
57 class definition has been fixed.
59 * Windows Thread Information Block access.
61 On Windows targets, GDB now supports displaying the Windows Thread
62 Information Block (TIB) structure. This structure is visible either
63 by using the new command `info w32 thread-information-block' or, by
64 dereferencing the new convenience variable named `$_tlb', a
65 thread-specific pointer to the TIB. This feature is also supported
66 when remote debugging using GDBserver.
70 Static tracepoints are calls in the user program into a tracing
71 library. One such library is a port of the LTTng kernel tracer to
72 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
73 When debugging with GDBserver, GDB now supports combining the GDB
74 tracepoint machinery with such libraries. For example: the user can
75 use GDB to probe a static tracepoint marker (a call from the user
76 program into the tracing library) with the new "strace" command (see
77 "New commands" below). This creates a "static tracepoint" in the
78 breakpoint list, that can be manipulated with the same feature set
79 as fast and regular tracepoints. E.g., collect registers, local and
80 global variables, collect trace state variables, and define
81 tracepoint conditions. In addition, the user can collect extra
82 static tracepoint marker specific data, by collecting the new
83 $_sdata internal variable. When analyzing the trace buffer, you can
84 inspect $_sdata like any other variable available to GDB. For more
85 information, see the "Tracepoints" chapter in GDB user manual. New
86 remote packets have been defined to support static tracepoints, see
87 the "New remote packets" section below.
93 Return the address of the Windows Thread Information Block of a given thread.
97 In response to several of the tracepoint packets, the target may now
98 also respond with a number of intermediate `qRelocInsn' request
99 packets before the final result packet, to have GDB handle
100 relocating an instruction to execute at a different address. This
101 is particularly useful for stubs that support fast tracepoints. GDB
102 reports support for this feature in the qSupported packet.
106 List static tracepoint markers in the target program.
110 List static tracepoint markers at a given address in the target
113 qXfer:statictrace:read
115 Read the static trace data collected (by a `collect $_sdata'
116 tracepoint action). The remote stub reports support for this packet
117 to gdb's qSupported query.
119 * The source command now accepts a -s option to force searching for the
120 script in the source search path even if the script name specifies
123 * New features in the GDB remote stub, GDBserver
125 - GDBserver now support tracepoints (including fast tracepoints, and
126 static tracepoints). The feature is currently supported by the
127 i386-linux and amd64-linux builds. See the "Tracepoints support
128 in gdbserver" section in the manual for more information.
130 GDBserver JIT compiles the tracepoint's conditional agent
131 expression bytecode into native code whenever possible for low
132 overhead dynamic tracepoints conditionals. For such tracepoints,
133 an expression that examines program state is evaluated when the
134 tracepoint is reached, in order to determine whether to capture
135 trace data. If the condition is simple and false, processing the
136 tracepoint finishes very quickly and no data is gathered.
138 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
139 for static tracepoints support.
141 - GDBserver now supports x86_64 Windows 64-bit debugging.
143 * GDB now sends xmlRegisters= in qSupported packet to indicate that
144 it understands register description.
146 * The --batch flag now disables pagination and queries.
148 * X86 general purpose registers
150 GDB now supports reading/writing byte, word and double-word x86
151 general purpose registers directly. This means you can use, say,
152 $ah or $ax to refer, respectively, to the byte register AH and
153 16-bit word register AX that are actually portions of the 32-bit
154 register EAX or 64-bit register RAX.
156 * The `commands' command now accepts a range of breakpoints to modify.
157 A plain `commands' following a command that creates multiple
158 breakpoints affects all the breakpoints set by that command. This
159 applies to breakpoints set by `rbreak', and also applies when a
160 single `break' command creates multiple breakpoints (e.g.,
161 breakpoints on overloaded c++ functions).
163 * The `rbreak' command now accepts a filename specification as part of
164 its argument, limiting the functions selected by the regex to those
165 in the specified file.
167 * Support for remote debugging Windows and SymbianOS shared libraries
168 from Unix hosts has been improved. Non Windows GDB builds now can
169 understand target reported file names that follow MS-DOS based file
170 system semantics, such as file names that include drive letters and
171 use the backslash character as directory separator. This makes it
172 possible to transparently use the "set sysroot" and "set
173 solib-search-path" on Unix hosts to point as host copies of the
174 target's shared libraries. See the new command "set
175 target-file-system-kind" described below, and the "Commands to
176 specify files" section in the user manual for more information.
180 eval template, expressions...
181 Convert the values of one or more expressions under the control
182 of the string template to a command line, and call it.
184 set target-file-system-kind unix|dos-based|auto
185 show target-file-system-kind
186 Set or show the assumed file system kind for target reported file
189 save breakpoints <filename>
190 Save all current breakpoint definitions to a file suitable for use
191 in a later debugging session. To read the saved breakpoint
192 definitions, use the `source' command.
194 `save tracepoints' is a new alias for `save-tracepoints'. The latter
197 info static-tracepoint-markers
198 Display information about static tracepoint markers in the target.
200 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
201 Define a static tracepoint by probing a marker at the given
202 function, line, address, or marker ID.
207 The disassemble command now supports "start,+length" form of two arguments.
211 ** GDB now provides a new directory location, called the python directory,
212 where Python scripts written for GDB can be installed. The location
213 of that directory is <data-directory>/python, where <data-directory>
214 is the GDB data directory. For more details, see section `Scripting
215 GDB using Python' in the manual.
217 ** The GDB Python API now has access to breakpoints, symbols, symbol
218 tables, program spaces, inferiors, threads and frame's code blocks.
219 Additionally, GDB Parameters can now be created from the API, and
220 manipulated via set/show in the CLI.
222 ** New functions gdb.target_charset, gdb.target_wide_charset,
223 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
225 ** New exception gdb.GdbError.
227 ** Pretty-printers are now also looked up in the current program space.
229 ** Pretty-printers can now be individually enabled and disabled.
231 ** GDB now looks for names of Python scripts to auto-load in a
232 special section named `.debug_gdb_scripts', in addition to looking
233 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
235 * Tracepoint actions were unified with breakpoint commands. In particular,
236 there are no longer differences in "info break" output for breakpoints and
237 tracepoints and the "commands" command can be used for both tracepoints and
242 ARM Symbian arm*-*-symbianelf*
244 * D language support.
245 GDB now supports debugging programs written in the D programming
248 * GDB now supports the extended ptrace interface for PowerPC which is
249 available since Linux kernel version 2.6.34. This automatically enables
250 any hardware breakpoints and additional hardware watchpoints available in
251 the processor. The old ptrace interface exposes just one hardware
252 watchpoint and no hardware breakpoints.
254 * GDB is now able to use the Data Value Compare (DVC) register available on
255 embedded PowerPC processors to implement in hardware simple watchpoint
256 conditions of the form:
258 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
260 This works in native GDB running on Linux kernels with the extended ptrace
261 interface mentioned above.
263 *** Changes in GDB 7.1
269 GDB now supports importing of namespaces in C++. This enables the
270 user to inspect variables from imported namespaces. Support for
271 namepace aliasing has also been added. So, if a namespace is
272 aliased in the current scope (e.g. namepace C=A; ) the user can
273 print variables using the alias (e.g. (gdb) print C::x).
277 All known bugs relating to the printing of virtual base class were
278 fixed. It is now possible to call overloaded static methods using a
283 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
284 and reinterpret_cast<> are now handled by the C++ expression parser.
288 Xilinx MicroBlaze microblaze-*-*
293 Xilinx MicroBlaze microblaze
296 * Multi-program debugging.
298 GDB now has support for multi-program (a.k.a. multi-executable or
299 multi-exec) debugging. This allows for debugging multiple inferiors
300 simultaneously each running a different program under the same GDB
301 session. See "Debugging Multiple Inferiors and Programs" in the
302 manual for more information. This implied some user visible changes
303 in the multi-inferior support. For example, "info inferiors" now
304 lists inferiors that are not running yet or that have exited
305 already. See also "New commands" and "New options" below.
307 * New tracing features
309 GDB's tracepoint facility now includes several new features:
311 ** Trace state variables
313 GDB tracepoints now include support for trace state variables, which
314 are variables managed by the target agent during a tracing
315 experiment. They are useful for tracepoints that trigger each
316 other, so for instance one tracepoint can count hits in a variable,
317 and then a second tracepoint has a condition that is true when the
318 count reaches a particular value. Trace state variables share the
319 $-syntax of GDB convenience variables, and can appear in both
320 tracepoint actions and condition expressions. Use the "tvariable"
321 command to create, and "info tvariables" to view; see "Trace State
322 Variables" in the manual for more detail.
326 GDB now includes an option for defining fast tracepoints, which
327 targets may implement more efficiently, such as by installing a jump
328 into the target agent rather than a trap instruction. The resulting
329 speedup can be by two orders of magnitude or more, although the
330 tradeoff is that some program locations on some target architectures
331 might not allow fast tracepoint installation, for instance if the
332 instruction to be replaced is shorter than the jump. To request a
333 fast tracepoint, use the "ftrace" command, with syntax identical to
334 the regular trace command.
336 ** Disconnected tracing
338 It is now possible to detach GDB from the target while it is running
339 a trace experiment, then reconnect later to see how the experiment
340 is going. In addition, a new variable disconnected-tracing lets you
341 tell the target agent whether to continue running a trace if the
342 connection is lost unexpectedly.
346 GDB now has the ability to save the trace buffer into a file, and
347 then use that file as a target, similarly to you can do with
348 corefiles. You can select trace frames, print data that was
349 collected in them, and use tstatus to display the state of the
350 tracing run at the moment that it was saved. To create a trace
351 file, use "tsave <filename>", and to use it, do "target tfile
354 ** Circular trace buffer
356 You can ask the target agent to handle the trace buffer as a
357 circular buffer, discarding the oldest trace frames to make room for
358 newer ones, by setting circular-trace-buffer to on. This feature may
359 not be available for all target agents.
364 The disassemble command, when invoked with two arguments, now requires
365 the arguments to be comma-separated.
368 The info variables command now displays variable definitions. Files
369 which only declare a variable are not shown.
372 The source command is now capable of sourcing Python scripts.
373 This feature is dependent on the debugger being build with Python
376 Related to this enhancement is also the introduction of a new command
377 "set script-extension" (see below).
379 * New commands (for set/show, see "New options" below)
381 record save [<FILENAME>]
382 Save a file (in core file format) containing the process record
383 execution log for replay debugging at a later time.
385 record restore <FILENAME>
386 Restore the process record execution log that was saved at an
387 earlier time, for replay debugging.
389 add-inferior [-copies <N>] [-exec <FILENAME>]
392 clone-inferior [-copies <N>] [ID]
393 Make a new inferior ready to execute the same program another
399 maint info program-spaces
400 List the program spaces loaded into GDB.
402 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
403 show remote interrupt-sequence
404 Allow the user to select one of ^C, a BREAK signal or BREAK-g
405 as the sequence to the remote target in order to interrupt the execution.
406 Ctrl-C is a default. Some system prefers BREAK which is high level of
407 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
408 Magic SysRq g. It is BREAK signal and character 'g'.
410 set remote interrupt-on-connect [on | off]
411 show remote interrupt-on-connect
412 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
413 remote target when gdb connects to it. This is needed when you debug
416 set remotebreak [on | off]
418 Deprecated. Use "set/show remote interrupt-sequence" instead.
420 tvariable $NAME [ = EXP ]
421 Create or modify a trace state variable.
424 List trace state variables and their values.
426 delete tvariable $NAME ...
427 Delete one or more trace state variables.
430 Evaluate the given expressions without collecting anything into the
431 trace buffer. (Valid in tracepoint actions only.)
433 ftrace FN / FILE:LINE / *ADDR
434 Define a fast tracepoint at the given function, line, or address.
436 * New expression syntax
438 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
439 GDB now parses 0b101010 identically with 42.
443 set follow-exec-mode new|same
444 show follow-exec-mode
445 Control whether GDB reuses the same inferior across an exec call or
446 creates a new one. This is useful to be able to restart the old
447 executable after the inferior having done an exec call.
449 set default-collect EXPR, ...
451 Define a list of expressions to be collected at each tracepoint.
452 This is a useful way to ensure essential items are not overlooked,
453 such as registers or a critical global variable.
455 set disconnected-tracing
456 show disconnected-tracing
457 If set to 1, the target is instructed to continue tracing if it
458 loses its connection to GDB. If 0, the target is to stop tracing
461 set circular-trace-buffer
462 show circular-trace-buffer
463 If set to on, the target is instructed to use a circular trace buffer
464 and discard the oldest trace frames instead of stopping the trace due
465 to a full trace buffer. If set to off, the trace stops when the buffer
466 fills up. Some targets may not support this.
468 set script-extension off|soft|strict
469 show script-extension
470 If set to "off", the debugger does not perform any script language
471 recognition, and all sourced files are assumed to be GDB scripts.
472 If set to "soft" (the default), files are sourced according to
473 filename extension, falling back to GDB scripts if the first
475 If set to "strict", files are sourced according to filename extension.
477 set ada trust-PAD-over-XVS on|off
478 show ada trust-PAD-over-XVS
479 If off, activate a workaround against a bug in the debugging information
480 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
481 the GCC sources for more information about the GNAT encoding and
482 PAD types in particular). It is always safe to set this option to
483 off, but this introduces a slight performance penalty. The default
486 * Python API Improvements
488 ** GDB provides the new class gdb.LazyString. This is useful in
489 some pretty-printing cases. The new method gdb.Value.lazy_string
490 provides a simple way to create objects of this type.
492 ** The fields returned by gdb.Type.fields now have an
493 `is_base_class' attribute.
495 ** The new method gdb.Type.range returns the range of an array type.
497 ** The new method gdb.parse_and_eval can be used to parse and
498 evaluate an expression.
503 Define a trace state variable.
506 Get the current value of a trace state variable.
509 Set desired tracing behavior upon disconnection.
512 Set the trace buffer to be linear or circular.
515 Get data about the tracepoints currently in use.
519 Process record now works correctly with hardware watchpoints.
521 Multiple bug fixes have been made to the mips-irix port, making it
522 much more reliable. In particular:
523 - Debugging threaded applications is now possible again. Previously,
524 GDB would hang while starting the program, or while waiting for
525 the program to stop at a breakpoint.
526 - Attaching to a running process no longer hangs.
527 - An error occurring while loading a core file has been fixed.
528 - Changing the value of the PC register now works again. This fixes
529 problems observed when using the "jump" command, or when calling
530 a function from GDB, or even when assigning a new value to $pc.
531 - With the "finish" and "return" commands, the return value for functions
532 returning a small array is now correctly printed.
533 - It is now possible to break on shared library code which gets executed
534 during a shared library init phase (code executed while executing
535 their .init section). Previously, the breakpoint would have no effect.
536 - GDB is now able to backtrace through the signal handler for
537 non-threaded programs.
539 PIE (Position Independent Executable) programs debugging is now supported.
540 This includes debugging execution of PIC (Position Independent Code) shared
541 libraries although for that, it should be possible to run such libraries as an
544 *** Changes in GDB 7.0
546 * GDB now has an interface for JIT compilation. Applications that
547 dynamically generate code can create symbol files in memory and register
548 them with GDB. For users, the feature should work transparently, and
549 for JIT developers, the interface is documented in the GDB manual in the
550 "JIT Compilation Interface" chapter.
552 * Tracepoints may now be conditional. The syntax is as for
553 breakpoints; either an "if" clause appended to the "trace" command,
554 or the "condition" command is available. GDB sends the condition to
555 the target for evaluation using the same bytecode format as is used
556 for tracepoint actions.
558 * The disassemble command now supports: an optional /r modifier, print the
559 raw instructions in hex as well as in symbolic form, and an optional /m
560 modifier to print mixed source+assembly.
562 * Process record and replay
564 In a architecture environment that supports ``process record and
565 replay'', ``process record and replay'' target can record a log of
566 the process execution, and replay it with both forward and reverse
569 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
570 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
571 set execution-direction {forward|reverse}, for targets that support
574 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
575 feature is available with a native GDB running on kernel version
578 * GDB now has support for multi-byte and wide character sets on the
579 target. Strings whose character type is wchar_t, char16_t, or
580 char32_t are now correctly printed. GDB supports wide- and unicode-
581 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
582 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
583 `printf'. This feature requires iconv to work properly; if your
584 system does not have a working iconv, GDB can use GNU libiconv. See
585 the installation instructions for more information.
587 * GDB now supports automatic retrieval of shared library files from
588 remote targets. To use this feature, specify a system root that begins
589 with the `remote:' prefix, either via the `set sysroot' command or via
590 the `--with-sysroot' configure-time option.
592 * "info sharedlibrary" now takes an optional regex of libraries to show,
593 and it now reports if a shared library has no debugging information.
595 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
596 now complete on file names.
598 * When completing in expressions, gdb will attempt to limit
599 completions to allowable structure or union fields, where appropriate.
600 For instance, consider:
602 # struct example { int f1; double f2; };
603 # struct example variable;
606 If the user types TAB at the end of this command line, the available
607 completions will be "f1" and "f2".
609 * Inlined functions are now supported. They show up in backtraces, and
610 the "step", "next", and "finish" commands handle them automatically.
612 * GDB now supports the token-splicing (##) and stringification (#)
613 operators when expanding macros. It also supports variable-arity
616 * GDB now supports inspecting extra signal information, exported by
617 the new $_siginfo convenience variable. The feature is currently
618 implemented on linux ARM, i386 and amd64.
620 * GDB can now display the VFP floating point registers and NEON vector
621 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
622 can provide these registers (requires Linux 2.6.30 or later). Remote
623 and simulator targets may also provide them.
628 Search memory for a sequence of bytes.
631 Turn off `+'/`-' protocol acknowledgments to permit more efficient
632 operation over reliable transport links. Use of this packet is
633 controlled by the `set remote noack-packet' command.
636 Kill the process with the specified process ID. Use this in preference
637 to `k' when multiprocess protocol extensions are supported.
640 Obtains additional operating system information
644 Read or write additional signal information.
646 * Removed remote protocol undocumented extension
648 An undocumented extension to the remote protocol's `S' stop reply
649 packet that permited the stub to pass a process id was removed.
650 Remote servers should use the `T' stop reply packet instead.
652 * GDB now supports multiple function calling conventions according to the
653 DWARF-2 DW_AT_calling_convention function attribute.
655 * The SH target utilizes the aforementioned change to distinguish between gcc
656 and Renesas calling convention. It also adds the new CLI commands
657 `set/show sh calling-convention'.
659 * GDB can now read compressed debug sections, as produced by GNU gold
660 with the --compress-debug-sections=zlib flag.
662 * 64-bit core files are now supported on AIX.
664 * Thread switching is now supported on Tru64.
666 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
667 which will be allocated using malloc later in program execution.
669 * The qXfer:libraries:read remote procotol packet now allows passing a
670 list of section offsets.
672 * On GNU/Linux, GDB can now attach to stopped processes. Several race
673 conditions handling signals delivered during attach or thread creation
674 have also been fixed.
676 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
677 From the user's standpoint, all unqualified instances of True and False
678 are treated as the standard definitions, regardless of context.
680 * GDB now parses C++ symbol and type names more flexibly. For
683 template<typename T> class C { };
686 GDB will now correctly handle all of:
688 ptype C<char const *>
690 ptype C<const char *>
693 * New features in the GDB remote stub, gdbserver
695 - The "--wrapper" command-line argument tells gdbserver to use a
696 wrapper program to launch programs for debugging.
698 - On PowerPC and S/390 targets, it is now possible to use a single
699 gdbserver executable to debug both 32-bit and 64-bit programs.
700 (This requires gdbserver itself to be built as a 64-bit executable.)
702 - gdbserver uses the new noack protocol mode for TCP connections to
703 reduce communications latency, if also supported and enabled in GDB.
705 - Support for the sparc64-linux-gnu target is now included in
708 - The amd64-linux build of gdbserver now supports debugging both
709 32-bit and 64-bit programs.
711 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
712 now support hardware watchpoints, and will use them automatically
717 GDB now has support for scripting using Python. Whether this is
718 available is determined at configure time.
720 New GDB commands can now be written in Python.
722 * Ada tasking support
724 Ada tasks can now be inspected in GDB. The following commands have
728 Print the list of Ada tasks.
730 Print detailed information about task number N.
732 Print the task number of the current task.
734 Switch the context of debugging to task number N.
736 * Support for user-defined prefixed commands. The "define" command can
737 add new commands to existing prefixes, e.g. "target".
739 * Multi-inferior, multi-process debugging.
741 GDB now has generalized support for multi-inferior debugging. See
742 "Debugging Multiple Inferiors" in the manual for more information.
743 Although availability still depends on target support, the command
744 set is more uniform now. The GNU/Linux specific multi-forks support
745 has been migrated to this new framework. This implied some user
746 visible changes; see "New commands" and also "Removed commands"
749 * Target descriptions can now describe the target OS ABI. See the
750 "Target Description Format" section in the user manual for more
753 * Target descriptions can now describe "compatible" architectures
754 to indicate that the target can execute applications for a different
755 architecture in addition to those for the main target architecture.
756 See the "Target Description Format" section in the user manual for
759 * Multi-architecture debugging.
761 GDB now includes general supports for debugging applications on
762 hybrid systems that use more than one single processor architecture
763 at the same time. Each such hybrid architecture still requires
764 specific support to be added. The only hybrid architecture supported
765 in this version of GDB is the Cell Broadband Engine.
767 * GDB now supports integrated debugging of Cell/B.E. applications that
768 use both the PPU and SPU architectures. To enable support for hybrid
769 Cell/B.E. debugging, you need to configure GDB to support both the
770 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
771 --enable-targets configure option.
773 * Non-stop mode debugging.
775 For some targets, GDB now supports an optional mode of operation in
776 which you can examine stopped threads while other threads continue
777 to execute freely. This is referred to as non-stop mode, with the
778 old mode referred to as all-stop mode. See the "Non-Stop Mode"
779 section in the user manual for more information.
781 To be able to support remote non-stop debugging, a remote stub needs
782 to implement the non-stop mode remote protocol extensions, as
783 described in the "Remote Non-Stop" section of the user manual. The
784 GDB remote stub, gdbserver, has been adjusted to support these
785 extensions on linux targets.
787 * New commands (for set/show, see "New options" below)
789 catch syscall [NAME(S) | NUMBER(S)]
790 Catch system calls. Arguments, which should be names of system
791 calls or their numbers, mean catch only those syscalls. Without
792 arguments, every syscall will be caught. When the inferior issues
793 any of the specified syscalls, GDB will stop and announce the system
794 call, both when it is called and when its call returns. This
795 feature is currently available with a native GDB running on the
796 Linux Kernel, under the following architectures: x86, x86_64,
797 PowerPC and PowerPC64.
799 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
801 Search memory for a sequence of bytes.
803 maint set python print-stack
804 maint show python print-stack
805 Show a stack trace when an error is encountered in a Python script.
808 Invoke CODE by passing it to the Python interpreter.
813 These allow macros to be defined, undefined, and listed
817 Show operating system information about processes.
820 List the inferiors currently under GDB's control.
823 Switch focus to inferior number NUM.
826 Detach from inferior number NUM.
829 Kill inferior number NUM.
834 show spu stop-on-load
835 Control whether to stop for new SPE threads during Cell/B.E. debugging.
837 set spu auto-flush-cache
838 show spu auto-flush-cache
839 Control whether to automatically flush the software-managed cache
840 during Cell/B.E. debugging.
842 set sh calling-convention
843 show sh calling-convention
844 Control the calling convention used when calling SH target functions.
848 Control display of timestamps with GDB debugging output.
850 set disassemble-next-line
851 show disassemble-next-line
852 Control display of disassembled source lines or instructions when
855 set remote noack-packet
856 show remote noack-packet
857 Set/show the use of remote protocol QStartNoAckMode packet. See above
858 under "New remote packets."
860 set remote query-attached-packet
861 show remote query-attached-packet
862 Control use of remote protocol `qAttached' (query-attached) packet.
864 set remote read-siginfo-object
865 show remote read-siginfo-object
866 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
869 set remote write-siginfo-object
870 show remote write-siginfo-object
871 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
874 set remote reverse-continue
875 show remote reverse-continue
876 Control use of remote protocol 'bc' (reverse-continue) packet.
878 set remote reverse-step
879 show remote reverse-step
880 Control use of remote protocol 'bs' (reverse-step) packet.
882 set displaced-stepping
883 show displaced-stepping
884 Control displaced stepping mode. Displaced stepping is a way to
885 single-step over breakpoints without removing them from the debuggee.
886 Also known as "out-of-line single-stepping".
890 Control display of debugging info for displaced stepping.
892 maint set internal-error
893 maint show internal-error
894 Control what GDB does when an internal error is detected.
896 maint set internal-warning
897 maint show internal-warning
898 Control what GDB does when an internal warning is detected.
903 Use a wrapper program to launch programs for debugging.
905 set multiple-symbols (all|ask|cancel)
906 show multiple-symbols
907 The value of this variable can be changed to adjust the debugger behavior
908 when an expression or a breakpoint location contains an ambiguous symbol
909 name (an overloaded function name, for instance).
911 set breakpoint always-inserted
912 show breakpoint always-inserted
913 Keep breakpoints always inserted in the target, as opposed to inserting
914 them when resuming the target, and removing them when the target stops.
915 This option can improve debugger performance on slow remote targets.
917 set arm fallback-mode (arm|thumb|auto)
918 show arm fallback-mode
919 set arm force-mode (arm|thumb|auto)
921 These commands control how ARM GDB determines whether instructions
922 are ARM or Thumb. The default for both settings is auto, which uses
923 the current CPSR value for instructions without symbols; previous
924 versions of GDB behaved as if "set arm fallback-mode arm".
926 set disable-randomization
927 show disable-randomization
928 Standalone programs run with the virtual address space randomization enabled
929 by default on some platforms. This option keeps the addresses stable across
930 multiple debugging sessions.
934 Control whether other threads are stopped or not when some thread hits
939 Requests that asynchronous execution is enabled in the target, if available.
940 In this case, it's possible to resume target in the background, and interact
941 with GDB while the target is running. "show target-async" displays the
942 current state of asynchronous execution of the target.
944 set target-wide-charset
945 show target-wide-charset
946 The target-wide-charset is the name of the character set that GDB
947 uses when printing characters whose type is wchar_t.
949 set tcp auto-retry (on|off)
951 set tcp connect-timeout
952 show tcp connect-timeout
953 These commands allow GDB to retry failed TCP connections to a remote stub
954 with a specified timeout period; this is useful if the stub is launched
955 in parallel with GDB but may not be ready to accept connections immediately.
957 set libthread-db-search-path
958 show libthread-db-search-path
959 Control list of directories which GDB will search for appropriate
962 set schedule-multiple (on|off)
963 show schedule-multiple
964 Allow GDB to resume all threads of all processes or only threads of
969 Use more aggressive caching for accesses to the stack. This improves
970 performance of remote debugging (particularly backtraces) without
971 affecting correctness.
973 set interactive-mode (on|off|auto)
974 show interactive-mode
975 Control whether GDB runs in interactive mode (on) or not (off).
976 When in interactive mode, GDB waits for the user to answer all
977 queries. Otherwise, GDB does not wait and assumes the default
978 answer. When set to auto (the default), GDB determines which
979 mode to use based on the stdin settings.
984 For program forks, this is replaced by the new more generic `info
985 inferiors' command. To list checkpoints, you can still use the
986 `info checkpoints' command, which was an alias for the `info forks'
990 Replaced by the new `inferior' command. To switch between
991 checkpoints, you can still use the `restart' command, which was an
992 alias for the `fork' command.
995 This is removed, since some targets don't have a notion of
996 processes. To switch between processes, you can still use the
997 `inferior' command using GDB's own inferior number.
1000 For program forks, this is replaced by the new more generic `kill
1001 inferior' command. To delete a checkpoint, you can still use the
1002 `delete checkpoint' command, which was an alias for the `delete
1006 For program forks, this is replaced by the new more generic `detach
1007 inferior' command. To detach a checkpoint, you can still use the
1008 `detach checkpoint' command, which was an alias for the `detach
1011 * New native configurations
1013 x86/x86_64 Darwin i[34567]86-*-darwin*
1015 x86_64 MinGW x86_64-*-mingw*
1019 Lattice Mico32 lm32-*
1020 x86 DICOS i[34567]86-*-dicos*
1021 x86_64 DICOS x86_64-*-dicos*
1024 * The GDB remote stub, gdbserver, now supports x86 Windows CE
1025 (mingw32ce) debugging.
1031 These commands were actually not implemented on any target.
1033 *** Changes in GDB 6.8
1035 * New native configurations
1037 NetBSD/hppa hppa*-*netbsd*
1038 Xtensa GNU/Linux xtensa*-*-linux*
1042 NetBSD/hppa hppa*-*-netbsd*
1043 Xtensa GNU/Lunux xtensa*-*-linux*
1045 * Change in command line behavior -- corefiles vs. process ids.
1047 When the '-p NUMBER' or '--pid NUMBER' options are used, and
1048 attaching to process NUMBER fails, GDB no longer attempts to open a
1049 core file named NUMBER. Attaching to a program using the -c option
1050 is no longer supported. Instead, use the '-p' or '--pid' options.
1052 * GDB can now be built as a native debugger for debugging Windows x86
1053 (mingw32) Portable Executable (PE) programs.
1055 * Pending breakpoints no longer change their number when their address
1058 * GDB now supports breakpoints with multiple locations,
1059 including breakpoints on C++ constructors, inside C++ templates,
1060 and in inlined functions.
1062 * GDB's ability to debug optimized code has been improved. GDB more
1063 accurately identifies function bodies and lexical blocks that occupy
1064 more than one contiguous range of addresses.
1066 * Target descriptions can now describe registers for PowerPC.
1068 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
1069 registers on PowerPC targets.
1071 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
1072 targets even when the libthread_db library is not available.
1074 * The GDB remote stub, gdbserver, now supports the new file transfer
1075 commands (remote put, remote get, and remote delete).
1077 * The GDB remote stub, gdbserver, now supports run and attach in
1078 extended-remote mode.
1080 * hppa*64*-*-hpux11* target broken
1081 The debugger is unable to start a program and fails with the following
1082 error: "Error trying to get information about dynamic linker".
1083 The gdb-6.7 release is also affected.
1085 * GDB now supports the --enable-targets= configure option to allow
1086 building a single GDB executable that supports multiple remote
1087 target architectures.
1089 * GDB now supports debugging C and C++ programs which use the
1090 Decimal Floating Point extension. In addition, the PowerPC target
1091 now has a set of pseudo-registers to inspect decimal float values
1092 stored in two consecutive float registers.
1094 * The -break-insert MI command can optionally create pending
1097 * Improved support for debugging Ada
1098 Many improvements to the Ada language support have been made. These
1100 - Better support for Ada2005 interface types
1101 - Improved handling of arrays and slices in general
1102 - Better support for Taft-amendment types
1103 - The '{type} ADDRESS' expression is now allowed on the left hand-side
1105 - Improved command completion in Ada
1108 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
1113 set print frame-arguments (all|scalars|none)
1114 show print frame-arguments
1115 The value of this variable can be changed to control which argument
1116 values should be printed by the debugger when displaying a frame.
1121 Transfer files to and from a remote target, and delete remote files.
1128 Transfer files to and from a remote target, and delete remote files.
1130 * New remote packets
1137 Open, close, read, write, and delete files on the remote system.
1140 Attach to an existing process on the remote system, in extended-remote
1144 Run a new process on the remote system, in extended-remote mode.
1146 *** Changes in GDB 6.7
1148 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
1149 bfd, libiberty and opcodes, as revealed by static analysis donated by
1150 Coverity, Inc. (http://scan.coverity.com).
1152 * When looking up multiply-defined global symbols, GDB will now prefer the
1153 symbol definition in the current shared library if it was built using the
1154 -Bsymbolic linker option.
1156 * When the Text User Interface (TUI) is not configured, GDB will now
1157 recognize the -tui command-line option and print a message that the TUI
1160 * The GDB remote stub, gdbserver, now has lower overhead for high
1161 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
1163 * GDB for MIPS targets now autodetects whether a remote target provides
1164 32-bit or 64-bit register values.
1166 * Support for C++ member pointers has been improved.
1168 * GDB now understands XML target descriptions, which specify the
1169 target's overall architecture. GDB can read a description from
1170 a local file or over the remote serial protocol.
1172 * Vectors of single-byte data use a new integer type which is not
1173 automatically displayed as character or string data.
1175 * The /s format now works with the print command. It displays
1176 arrays of single-byte integers and pointers to single-byte integers
1179 * Target descriptions can now describe target-specific registers,
1180 for architectures which have implemented the support (currently
1181 only ARM, M68K, and MIPS).
1183 * GDB and the GDB remote stub, gdbserver, now support the XScale
1186 * The GDB remote stub, gdbserver, has been updated to support
1187 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
1188 has been rewritten to use the standard GDB remote protocol.
1190 * GDB can now step into C++ functions which are called through thunks.
1192 * GDB for the Cell/B.E. SPU now supports overlay debugging.
1194 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
1195 layout. It also supports a TextSeg= and DataSeg= response when only
1196 segment base addresses (rather than offsets) are available.
1198 * The /i format now outputs any trailing branch delay slot instructions
1199 immediately following the last instruction within the count specified.
1201 * The GDB remote protocol "T" stop reply packet now supports a
1202 "library" response. Combined with the new "qXfer:libraries:read"
1203 packet, this response allows GDB to debug shared libraries on targets
1204 where the operating system manages the list of loaded libraries (e.g.
1205 Windows and SymbianOS).
1207 * The GDB remote stub, gdbserver, now supports dynamic link libraries
1208 (DLLs) on Windows and Windows CE targets.
1210 * GDB now supports a faster verification that a .debug file matches its binary
1211 according to its build-id signature, if the signature is present.
1217 Enable or disable hardware flow control (RTS/CTS) on the serial port
1218 when debugging using remote targets.
1220 set mem inaccessible-by-default
1221 show mem inaccessible-by-default
1222 If the target supplies a memory map, for instance via the remote
1223 protocol's "qXfer:memory-map:read" packet, setting this variable
1224 prevents GDB from accessing memory outside the memory map. This
1225 is useful for targets with memory mapped registers or which react
1226 badly to accesses of unmapped address space.
1228 set breakpoint auto-hw
1229 show breakpoint auto-hw
1230 If the target supplies a memory map, for instance via the remote
1231 protocol's "qXfer:memory-map:read" packet, setting this variable
1232 lets GDB use hardware breakpoints automatically for memory regions
1233 where it can not use software breakpoints. This covers both the
1234 "break" command and internal breakpoints used for other commands
1235 including "next" and "finish".
1238 catch exception unhandled
1239 Stop the program execution when Ada exceptions are raised.
1242 Stop the program execution when an Ada assertion failed.
1246 Set an alternate system root for target files. This is a more
1247 general version of "set solib-absolute-prefix", which is now
1248 an alias to "set sysroot".
1251 Provide extended SPU facility status information. This set of
1252 commands is available only when debugging the Cell/B.E. SPU
1255 * New native configurations
1257 OpenBSD/sh sh*-*openbsd*
1260 unset tdesc filename
1262 Use the specified local file as an XML target description, and do
1263 not query the target for its built-in description.
1267 OpenBSD/sh sh*-*-openbsd*
1268 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
1269 Toshiba Media Processor mep-elf
1271 * New remote packets
1274 Ignore the specified signals; pass them directly to the debugged program
1275 without stopping other threads or reporting them to GDB.
1277 qXfer:features:read:
1278 Read an XML target description from the target, which describes its
1283 Read or write contents of an spufs file on the target system. These
1284 packets are available only on the Cell/B.E. SPU architecture.
1286 qXfer:libraries:read:
1287 Report the loaded shared libraries. Combined with new "T" packet
1288 response, this packet allows GDB to debug shared libraries on
1289 targets where the operating system manages the list of loaded
1290 libraries (e.g. Windows and SymbianOS).
1294 Support for these obsolete configurations has been removed.
1302 i[34567]86-*-lynxos*
1303 i[34567]86-*-netware*
1304 i[34567]86-*-sco3.2v5*
1305 i[34567]86-*-sco3.2v4*
1307 i[34567]86-*-sysv4.2*
1310 i[34567]86-*-unixware2*
1311 i[34567]86-*-unixware*
1320 * Other removed features
1327 Various m68k-only ROM monitors.
1334 Various Renesas ROM monitors and debugging interfaces for SH and
1339 Support for a Macraigor serial interface to on-chip debugging.
1340 GDB does not directly support the newer parallel or USB
1345 A debug information format. The predecessor to DWARF 2 and
1346 DWARF 3, which are still supported.
1348 Support for the HP aCC compiler on HP-UX/PA-RISC
1350 SOM-encapsulated symbolic debugging information, automatic
1351 invocation of pxdb, and the aCC custom C++ ABI. This does not
1352 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
1353 with aCC can still be debugged on an assembly level.
1355 MIPS ".pdr" sections
1357 A MIPS-specific format used to describe stack frame layout
1358 in debugging information.
1362 GDB could work with an older version of Guile to debug
1363 the interpreter and Scheme programs running in it.
1365 set mips stack-arg-size
1366 set mips saved-gpreg-size
1368 Use "set mips abi" to control parameter passing for MIPS.
1370 *** Changes in GDB 6.6
1375 Cell Broadband Engine SPU spu-elf
1377 * GDB can now be configured as a cross-debugger targeting native Windows
1378 (mingw32) or Cygwin. It can communicate with a remote debugging stub
1379 running on a Windows system over TCP/IP to debug Windows programs.
1381 * The GDB remote stub, gdbserver, has been updated to support Windows and
1382 Cygwin debugging. Both single-threaded and multi-threaded programs are
1385 * The "set trust-readonly-sections" command works again. This command was
1386 broken in GDB 6.3, 6.4, and 6.5.
1388 * The "load" command now supports writing to flash memory, if the remote
1389 stub provides the required support.
1391 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
1392 longer requires symbolic debug information (e.g. DWARF-2).
1397 unset substitute-path
1398 show substitute-path
1399 Manage a list of substitution rules that GDB uses to rewrite the name
1400 of the directories where the sources are located. This can be useful
1401 for instance when the sources were moved to a different location
1402 between compilation and debugging.
1406 Print each CLI command as it is executed. Each command is prefixed with
1407 a number of `+' symbols representing the nesting depth.
1408 The source command now has a `-v' option to enable the same feature.
1412 The ARM Demon monitor support (RDP protocol, "target rdp").
1414 Kernel Object Display, an embedded debugging feature which only worked with
1415 an obsolete version of Cisco IOS.
1417 The 'set download-write-size' and 'show download-write-size' commands.
1419 * New remote packets
1422 Tell a stub about GDB client features, and request remote target features.
1423 The first feature implemented is PacketSize, which allows the target to
1424 specify the size of packets it can handle - to minimize the number of
1425 packets required and improve performance when connected to a remote
1429 Fetch an OS auxilliary vector from the remote stub. This packet is a
1430 more efficient replacement for qPart:auxv:read.
1432 qXfer:memory-map:read:
1433 Fetch a memory map from the remote stub, including information about
1434 RAM, ROM, and flash memory devices.
1439 Erase and program a flash memory device.
1441 * Removed remote packets
1444 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
1445 used it, and only gdbserver implemented it.
1447 *** Changes in GDB 6.5
1451 Renesas M32C/M16C m32c-elf
1453 Morpho Technologies ms1 ms1-elf
1457 init-if-undefined Initialize a convenience variable, but
1458 only if it doesn't already have a value.
1460 The following commands are presently only implemented for native GNU/Linux:
1462 checkpoint Save a snapshot of the program state.
1464 restart <n> Return the program state to a
1465 previously saved state.
1467 info checkpoints List currently saved checkpoints.
1469 delete-checkpoint <n> Delete a previously saved checkpoint.
1471 set|show detach-on-fork Tell gdb whether to detach from a newly
1472 forked process, or to keep debugging it.
1474 info forks List forks of the user program that
1475 are available to be debugged.
1477 fork <n> Switch to debugging one of several
1478 forks of the user program that are
1479 available to be debugged.
1481 delete-fork <n> Delete a fork from the list of forks
1482 that are available to be debugged (and
1483 kill the forked process).
1485 detach-fork <n> Delete a fork from the list of forks
1486 that are available to be debugged (and
1487 allow the process to continue).
1491 Morpho Technologies ms2 ms1-elf
1493 * Improved Windows host support
1495 GDB now builds as a cross debugger hosted on i686-mingw32, including
1496 native console support, and remote communications using either
1497 network sockets or serial ports.
1499 * Improved Modula-2 language support
1501 GDB can now print most types in the Modula-2 syntax. This includes:
1502 basic types, set types, record types, enumerated types, range types,
1503 pointer types and ARRAY types. Procedure var parameters are correctly
1504 printed and hexadecimal addresses and character constants are also
1505 written in the Modula-2 syntax. Best results can be obtained by using
1506 GNU Modula-2 together with the -gdwarf-2 command line option.
1510 The ARM rdi-share module.
1512 The Netware NLM debug server.
1514 *** Changes in GDB 6.4
1516 * New native configurations
1518 OpenBSD/arm arm*-*-openbsd*
1519 OpenBSD/mips64 mips64-*-openbsd*
1523 Morpho Technologies ms1 ms1-elf
1525 * New command line options
1527 --batch-silent As for --batch, but totally silent.
1528 --return-child-result The debugger will exist with the same value
1529 the child (debugged) program exited with.
1530 --eval-command COMMAND, -ex COMMAND
1531 Execute a single GDB CLI command. This may be
1532 specified multiple times and in conjunction
1533 with the --command (-x) option.
1535 * Deprecated commands removed
1537 The following commands, that were deprecated in 2000, have been
1541 set|show arm disassembly-flavor set|show arm disassembler
1542 othernames set arm disassembler
1543 set|show remotedebug set|show debug remote
1544 set|show archdebug set|show debug arch
1545 set|show eventdebug set|show debug event
1548 * New BSD user-level threads support
1550 It is now possible to debug programs using the user-level threads
1551 library on OpenBSD and FreeBSD. Currently supported (target)
1554 FreeBSD/amd64 x86_64-*-freebsd*
1555 FreeBSD/i386 i386-*-freebsd*
1556 OpenBSD/i386 i386-*-openbsd*
1558 Note that the new kernel threads libraries introduced in FreeBSD 5.x
1559 are not yet supported.
1561 * New support for Matsushita MN10300 w/sim added
1562 (Work in progress). mn10300-elf.
1564 * REMOVED configurations and files
1566 VxWorks and the XDR protocol *-*-vxworks
1567 Motorola MCORE mcore-*-*
1568 National Semiconductor NS32000 ns32k-*-*
1570 * New "set print array-indexes" command
1572 After turning this setting "on", GDB prints the index of each element
1573 when displaying arrays. The default is "off" to preserve the previous
1576 * VAX floating point support
1578 GDB now supports the not-quite-ieee VAX F and D floating point formats.
1580 * User-defined command support
1582 In addition to using $arg0..$arg9 for argument passing, it is now possible
1583 to use $argc to determine now many arguments have been passed. See the
1584 section on user-defined commands in the user manual for more information.
1586 *** Changes in GDB 6.3:
1588 * New command line option
1590 GDB now accepts -l followed by a number to set the timeout for remote
1593 * GDB works with GCC -feliminate-dwarf2-dups
1595 GDB now supports a more compact representation of DWARF-2 debug
1596 information using DW_FORM_ref_addr references. These are produced
1597 by GCC with the option -feliminate-dwarf2-dups and also by some
1598 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
1599 to use -feliminate-dwarf2-dups.
1601 * Internationalization
1603 When supported by the host system, GDB will be built with
1604 internationalization (libintl). The task of marking up the sources is
1605 continued, we're looking forward to our first translation.
1609 Initial support for debugging programs compiled with the GNAT
1610 implementation of the Ada programming language has been integrated
1611 into GDB. In this release, support is limited to expression evaluation.
1613 * New native configurations
1615 GNU/Linux/m32r m32r-*-linux-gnu
1619 GDB's remote protocol now includes support for the 'p' packet. This
1620 packet is used to fetch individual registers from a remote inferior.
1622 * END-OF-LIFE registers[] compatibility module
1624 GDB's internal register infrastructure has been completely rewritten.
1625 The new infrastructure making possible the implementation of key new
1626 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
1629 GDB 6.3 will be the last release to include the the registers[]
1630 compatibility module that allowed out-of-date configurations to
1631 continue to work. This change directly impacts the following
1641 powerpc bdm protocol
1643 Unless there is activity to revive these configurations, they will be
1644 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
1646 * OBSOLETE configurations and files
1648 Configurations that have been declared obsolete in this release have
1649 been commented out. Unless there is activity to revive these
1650 configurations, the next release of GDB will have their sources
1651 permanently REMOVED.
1660 *** Changes in GDB 6.2.1:
1662 * MIPS `break main; run' gave an heuristic-fence-post warning
1664 When attempting to run even a simple program, a warning about
1665 heuristic-fence-post being hit would be reported. This problem has
1668 * MIPS IRIX 'long double' crashed GDB
1670 When examining a long double variable, GDB would get a segmentation
1671 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
1672 IRIX long double values).
1676 A bug in the VAX stack code was causing problems with the "next"
1677 command. This problem has been fixed.
1679 *** Changes in GDB 6.2:
1681 * Fix for ``many threads''
1683 On GNU/Linux systems that use the NPTL threads library, a program
1684 rapidly creating and deleting threads would confuse GDB leading to the
1687 ptrace: No such process.
1688 thread_db_get_info: cannot get thread info: generic error
1690 This problem has been fixed.
1692 * "-async" and "-noasync" options removed.
1694 Support for the broken "-noasync" option has been removed (it caused
1697 * New ``start'' command.
1699 This command runs the program until the begining of the main procedure.
1701 * New BSD Kernel Data Access Library (libkvm) interface
1703 Using ``target kvm'' it is now possible to debug kernel core dumps and
1704 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
1705 platforms. Currently supported (native-only) configurations are:
1707 FreeBSD/amd64 x86_64-*-freebsd*
1708 FreeBSD/i386 i?86-*-freebsd*
1709 NetBSD/i386 i?86-*-netbsd*
1710 NetBSD/m68k m68*-*-netbsd*
1711 NetBSD/sparc sparc-*-netbsd*
1712 OpenBSD/amd64 x86_64-*-openbsd*
1713 OpenBSD/i386 i?86-*-openbsd*
1714 OpenBSD/m68k m68*-openbsd*
1715 OpenBSD/sparc sparc-*-openbsd*
1717 * Signal trampoline code overhauled
1719 Many generic problems with GDB's signal handling code have been fixed.
1720 These include: backtraces through non-contiguous stacks; recognition
1721 of sa_sigaction signal trampolines; backtrace from a NULL pointer
1722 call; backtrace through a signal trampoline; step into and out of
1723 signal handlers; and single-stepping in the signal trampoline.
1725 Please note that kernel bugs are a limiting factor here. These
1726 features have been shown to work on an s390 GNU/Linux system that
1727 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
1729 * Cygwin support for DWARF 2 added.
1731 * New native configurations
1733 GNU/Linux/hppa hppa*-*-linux*
1734 OpenBSD/hppa hppa*-*-openbsd*
1735 OpenBSD/m68k m68*-*-openbsd*
1736 OpenBSD/m88k m88*-*-openbsd*
1737 OpenBSD/powerpc powerpc-*-openbsd*
1738 NetBSD/vax vax-*-netbsd*
1739 OpenBSD/vax vax-*-openbsd*
1741 * END-OF-LIFE frame compatibility module
1743 GDB's internal frame infrastructure has been completely rewritten.
1744 The new infrastructure making it possible to support key new features
1745 including DWARF 2 Call Frame Information. To aid in the task of
1746 migrating old configurations to this new infrastructure, a
1747 compatibility module, that allowed old configurations to continue to
1748 work, was also included.
1750 GDB 6.2 will be the last release to include this frame compatibility
1751 module. This change directly impacts the following configurations:
1761 Unless there is activity to revive these configurations, they will be
1762 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
1764 * REMOVED configurations and files
1766 Sun 3, running SunOS 3 m68*-*-sunos3*
1767 Sun 3, running SunOS 4 m68*-*-sunos4*
1768 Sun 2, running SunOS 3 m68000-*-sunos3*
1769 Sun 2, running SunOS 4 m68000-*-sunos4*
1770 Motorola 680x0 running LynxOS m68*-*-lynxos*
1771 AT&T 3b1/Unix pc m68*-att-*
1772 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
1773 decstation mips-dec-* mips-little-*
1774 riscos mips-*-riscos* mips-*-sysv*
1775 sonymips mips-sony-*
1776 sysv mips*-*-sysv4* (IRIX 5/6 not included)
1778 *** Changes in GDB 6.1.1:
1780 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
1782 The TUI (Text-mode User Interface) is now built as part of a default
1783 GDB configuration. It is enabled by either selecting the TUI with the
1784 command line option "-i=tui" or by running the separate "gdbtui"
1785 program. For more information on the TUI, see the manual "Debugging
1788 * Pending breakpoint support (also included in GDB 6.1)
1790 Support has been added to allow you to specify breakpoints in shared
1791 libraries that have not yet been loaded. If a breakpoint location
1792 cannot be found, and the "breakpoint pending" option is set to auto,
1793 GDB queries you if you wish to make the breakpoint pending on a future
1794 shared-library load. If and when GDB resolves the breakpoint symbol,
1795 the pending breakpoint is removed as one or more regular breakpoints
1798 Pending breakpoints are very useful for GCJ Java debugging.
1800 * Fixed ISO-C build problems
1802 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
1803 non ISO-C code that stopped them being built using a more strict ISO-C
1804 compiler (e.g., IBM's C compiler).
1806 * Fixed build problem on IRIX 5
1808 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
1809 wasn't able to compile compile on an IRIX 5 system.
1811 * Added execute permission to gdb/gdbserver/configure
1813 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
1814 permission. This bug would cause configure to fail on a number of
1815 systems (Solaris, IRIX). Ref: server/519.
1817 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
1819 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
1820 has been updated to use constant array sizes.
1822 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
1824 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
1825 its generated DWARF Call Frame Info. This encoding was causing GDB to
1826 panic, that panic has been fixed. Ref: gdb/1628.
1828 * Fixed a problem when examining parameters in shared library code.
1830 When examining parameters in optimized shared library code generated
1831 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
1832 not available''. GDB now correctly displays the variable's value.
1834 *** Changes in GDB 6.1:
1836 * Removed --with-mmalloc
1838 Support for the mmalloc memory manager has been removed, as it
1839 conflicted with the internal gdb byte cache.
1841 * Changes in AMD64 configurations
1843 The AMD64 target now includes the %cs and %ss registers. As a result
1844 the AMD64 remote protocol has changed; this affects the floating-point
1845 and SSE registers. If you rely on those registers for your debugging,
1846 you should upgrade gdbserver on the remote side.
1848 * Revised SPARC target
1850 The SPARC target has been completely revised, incorporating the
1851 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
1852 support for LynxOS and SunOS 4 has been dropped. Calling functions
1853 from within GDB on operating systems with a non-executable stack
1854 (Solaris, OpenBSD) now works.
1858 GDB has a new C++ demangler which does a better job on the mangled
1859 names generated by current versions of g++. It also runs faster, so
1860 with this and other changes gdb should now start faster on large C++
1863 * DWARF 2 Location Expressions
1865 GDB support for location expressions has been extended to support function
1866 arguments and frame bases. Older versions of GDB could crash when they
1869 * C++ nested types and namespaces
1871 GDB's support for nested types and namespaces in C++ has been
1872 improved, especially if you use the DWARF 2 debugging format. (This
1873 is the default for recent versions of GCC on most platforms.)
1874 Specifically, if you have a class "Inner" defined within a class or
1875 namespace "Outer", then GDB realizes that the class's name is
1876 "Outer::Inner", not simply "Inner". This should greatly reduce the
1877 frequency of complaints about not finding RTTI symbols. In addition,
1878 if you are stopped at inside of a function defined within a namespace,
1879 GDB modifies its name lookup accordingly.
1881 * New native configurations
1883 NetBSD/amd64 x86_64-*-netbsd*
1884 OpenBSD/amd64 x86_64-*-openbsd*
1885 OpenBSD/alpha alpha*-*-openbsd*
1886 OpenBSD/sparc sparc-*-openbsd*
1887 OpenBSD/sparc64 sparc64-*-openbsd*
1889 * New debugging protocols
1891 M32R with SDI protocol m32r-*-elf*
1893 * "set prompt-escape-char" command deleted.
1895 The command "set prompt-escape-char" has been deleted. This command,
1896 and its very obscure effet on GDB's prompt, was never documented,
1897 tested, nor mentioned in the NEWS file.
1899 * OBSOLETE configurations and files
1901 Configurations that have been declared obsolete in this release have
1902 been commented out. Unless there is activity to revive these
1903 configurations, the next release of GDB will have their sources
1904 permanently REMOVED.
1906 Sun 3, running SunOS 3 m68*-*-sunos3*
1907 Sun 3, running SunOS 4 m68*-*-sunos4*
1908 Sun 2, running SunOS 3 m68000-*-sunos3*
1909 Sun 2, running SunOS 4 m68000-*-sunos4*
1910 Motorola 680x0 running LynxOS m68*-*-lynxos*
1911 AT&T 3b1/Unix pc m68*-att-*
1912 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
1913 decstation mips-dec-* mips-little-*
1914 riscos mips-*-riscos* mips-*-sysv*
1915 sonymips mips-sony-*
1916 sysv mips*-*-sysv4* (IRIX 5/6 not included)
1918 * REMOVED configurations and files
1920 SGI Irix-4.x mips-sgi-irix4 or iris4
1921 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
1922 Z8000 simulator z8k-zilog-none or z8ksim
1923 Matsushita MN10200 w/simulator mn10200-*-*
1924 H8/500 simulator h8500-hitachi-hms or h8500hms
1925 HP/PA running BSD hppa*-*-bsd*
1926 HP/PA running OSF/1 hppa*-*-osf*
1927 HP/PA Pro target hppa*-*-pro*
1928 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
1929 386BSD i[3456]86-*-bsd*
1930 Sequent family i[3456]86-sequent-sysv4*
1931 i[3456]86-sequent-sysv*
1932 i[3456]86-sequent-bsd*
1933 SPARC running LynxOS sparc-*-lynxos*
1934 SPARC running SunOS 4 sparc-*-sunos4*
1935 Tsqware Sparclet sparclet-*-*
1936 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
1938 *** Changes in GDB 6.0:
1942 Support for debugging the Objective-C programming language has been
1943 integrated into GDB.
1945 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
1947 DWARF 2's Call Frame Information makes available compiler generated
1948 information that more exactly describes the program's run-time stack.
1949 By using this information, GDB is able to provide more robust stack
1952 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
1953 have been updated to use a new backtrace mechanism which includes
1954 DWARF 2 CFI support.
1958 GDB's remote protocol has been extended to include support for hosted
1959 file I/O (where the remote target uses GDB's file system). See GDB's
1960 remote protocol documentation for details.
1962 * All targets using the new architecture framework.
1964 All of GDB's targets have been updated to use the new internal
1965 architecture framework. The way is now open for future GDB releases
1966 to include cross-architecture native debugging support (i386 on amd64,
1969 * GNU/Linux's Thread Local Storage (TLS)
1971 GDB now includes support for for the GNU/Linux implementation of
1972 per-thread variables.
1974 * GNU/Linux's Native POSIX Thread Library (NPTL)
1976 GDB's thread code has been updated to work with either the new
1977 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
1979 * Separate debug info.
1981 GDB, in conjunction with BINUTILS, now supports a mechanism for
1982 automatically loading debug information from a separate file. Instead
1983 of shipping full debug and non-debug versions of system libraries,
1984 system integrators can now instead ship just the stripped libraries
1985 and optional debug files.
1987 * DWARF 2 Location Expressions
1989 DWARF 2 Location Expressions allow the compiler to more completely
1990 describe the location of variables (even in optimized code) to the
1993 GDB now includes preliminary support for location expressions (support
1994 for DW_OP_piece is still missing).
1998 A number of long standing bugs that caused GDB to die while starting a
1999 Java application have been fixed. GDB's Java support is now
2000 considered "useable".
2002 * GNU/Linux support for fork, vfork, and exec.
2004 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
2005 commands are now implemented for GNU/Linux. They require a 2.5.x or later
2008 * GDB supports logging output to a file
2010 There are two new commands, "set logging" and "show logging", which can be
2011 used to capture GDB's output to a file.
2013 * The meaning of "detach" has changed for gdbserver
2015 The "detach" command will now resume the application, as documented. To
2016 disconnect from gdbserver and leave it stopped, use the new "disconnect"
2019 * d10v, m68hc11 `regs' command deprecated
2021 The `info registers' command has been updated so that it displays the
2022 registers using a format identical to the old `regs' command.
2026 A new command, "maint set profile on/off", has been added. This command can
2027 be used to enable or disable profiling while running GDB, to profile a
2028 session or a set of commands. In addition there is a new configure switch,
2029 "--enable-profiling", which will cause GDB to be compiled with profiling
2030 data, for more informative profiling results.
2032 * Default MI syntax changed to "mi2".
2034 The default MI (machine interface) syntax, enabled by the command line
2035 option "-i=mi", has been changed to "mi2". The previous MI syntax,
2036 "mi1", can be enabled by specifying the option "-i=mi1".
2038 Support for the original "mi0" syntax (included in GDB 5.0) has been
2041 Fix for gdb/192: removed extraneous space when displaying frame level.
2042 Fix for gdb/672: update changelist is now output in mi list format.
2043 Fix for gdb/702: a -var-assign that updates the value now shows up
2044 in a subsequent -var-update.
2046 * New native configurations.
2048 FreeBSD/amd64 x86_64-*-freebsd*
2050 * Multi-arched targets.
2052 HP/PA HPUX11 hppa*-*-hpux*
2053 Renesas M32R/D w/simulator m32r-*-elf*
2055 * OBSOLETE configurations and files
2057 Configurations that have been declared obsolete in this release have
2058 been commented out. Unless there is activity to revive these
2059 configurations, the next release of GDB will have their sources
2060 permanently REMOVED.
2062 Z8000 simulator z8k-zilog-none or z8ksim
2063 Matsushita MN10200 w/simulator mn10200-*-*
2064 H8/500 simulator h8500-hitachi-hms or h8500hms
2065 HP/PA running BSD hppa*-*-bsd*
2066 HP/PA running OSF/1 hppa*-*-osf*
2067 HP/PA Pro target hppa*-*-pro*
2068 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2069 Sequent family i[3456]86-sequent-sysv4*
2070 i[3456]86-sequent-sysv*
2071 i[3456]86-sequent-bsd*
2072 Tsqware Sparclet sparclet-*-*
2073 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2075 * REMOVED configurations and files
2078 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2079 IBM AIX PS/2 i[3456]86-*-aix
2080 i386 running Mach 3.0 i[3456]86-*-mach3*
2081 i386 running Mach i[3456]86-*-mach*
2082 i386 running OSF/1 i[3456]86-*osf1mk*
2083 HP/Apollo 68k Family m68*-apollo*-sysv*,
2085 m68*-hp-bsd*, m68*-hp-hpux*
2086 Argonaut Risc Chip (ARC) arc-*-*
2087 Mitsubishi D30V d30v-*-*
2088 Fujitsu FR30 fr30-*-elf*
2089 OS/9000 i[34]86-*-os9k
2090 I960 with MON960 i960-*-coff
2092 * MIPS $fp behavior changed
2094 The convenience variable $fp, for the MIPS, now consistently returns
2095 the address of the current frame's base. Previously, depending on the
2096 context, $fp could refer to either $sp or the current frame's base
2097 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
2098 The GNU Source-Level Debugger''.
2100 *** Changes in GDB 5.3:
2102 * GNU/Linux shared library multi-threaded performance improved.
2104 When debugging a multi-threaded application on GNU/Linux, GDB now uses
2105 `/proc', in preference to `ptrace' for memory reads. This may result
2106 in an improvement in the start-up time of multi-threaded, shared
2107 library applications when run under GDB. One GDB user writes: ``loads
2108 shared libs like mad''.
2110 * ``gdbserver'' now supports multi-threaded applications on some targets
2112 Support for debugging multi-threaded applications which use
2113 the GNU/Linux LinuxThreads package has been added for
2114 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
2115 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
2117 * GDB now supports C/C++ preprocessor macros.
2119 GDB now expands preprocessor macro invocations in C/C++ expressions,
2120 and provides various commands for showing macro definitions and how
2123 The new command `macro expand EXPRESSION' expands any macro
2124 invocations in expression, and shows the result.
2126 The new command `show macro MACRO-NAME' shows the definition of the
2127 macro named MACRO-NAME, and where it was defined.
2129 Most compilers don't include information about macros in the debugging
2130 information by default. In GCC 3.1, for example, you need to compile
2131 your program with the options `-gdwarf-2 -g3'. If the macro
2132 information is present in the executable, GDB will read it.
2134 * Multi-arched targets.
2136 DEC Alpha (partial) alpha*-*-*
2137 DEC VAX (partial) vax-*-*
2139 National Semiconductor NS32000 (partial) ns32k-*-*
2140 Motorola 68000 (partial) m68k-*-*
2141 Motorola MCORE mcore-*-*
2145 Fujitsu FRV architecture added by Red Hat frv*-*-*
2148 * New native configurations
2150 Alpha NetBSD alpha*-*-netbsd*
2151 SH NetBSD sh*-*-netbsdelf*
2152 MIPS NetBSD mips*-*-netbsd*
2153 UltraSPARC NetBSD sparc64-*-netbsd*
2155 * OBSOLETE configurations and files
2157 Configurations that have been declared obsolete in this release have
2158 been commented out. Unless there is activity to revive these
2159 configurations, the next release of GDB will have their sources
2160 permanently REMOVED.
2162 Mitsubishi D30V d30v-*-*
2163 OS/9000 i[34]86-*-os9k
2164 IBM AIX PS/2 i[3456]86-*-aix
2165 Fujitsu FR30 fr30-*-elf*
2166 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2167 Argonaut Risc Chip (ARC) arc-*-*
2168 i386 running Mach 3.0 i[3456]86-*-mach3*
2169 i386 running Mach i[3456]86-*-mach*
2170 i386 running OSF/1 i[3456]86-*osf1mk*
2171 HP/Apollo 68k Family m68*-apollo*-sysv*,
2173 m68*-hp-bsd*, m68*-hp-hpux*
2174 I960 with MON960 i960-*-coff
2176 * OBSOLETE languages
2178 CHILL, a Pascal like language used by telecommunications companies.
2180 * REMOVED configurations and files
2182 AMD 29k family via UDI a29k-amd-udi, udi29k
2183 A29K VxWorks a29k-*-vxworks
2184 AMD 29000 embedded, using EBMON a29k-none-none
2185 AMD 29000 embedded with COFF a29k-none-coff
2186 AMD 29000 embedded with a.out a29k-none-aout
2188 testsuite/gdb.hp/gdb.threads-hp/ directory
2190 * New command "set max-user-call-depth <nnn>"
2192 This command allows the user to limit the call depth of user-defined
2193 commands. The default is 1024.
2195 * Changes in FreeBSD/i386 native debugging.
2197 Support for the "generate-core-file" has been added.
2199 * New commands "dump", "append", and "restore".
2201 These commands allow data to be copied from target memory
2202 to a bfd-format or binary file (dump and append), and back
2203 from a file into memory (restore).
2205 * Improved "next/step" support on multi-processor Alpha Tru64.
2207 The previous single-step mechanism could cause unpredictable problems,
2208 including the random appearance of SIGSEGV or SIGTRAP signals. The use
2209 of a software single-step mechanism prevents this.
2211 *** Changes in GDB 5.2.1:
2219 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
2220 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
2221 Fix, by Joel Brobecker imported from mainline.
2223 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
2224 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
2225 Fix, by Fred Fish, imported from mainline.
2227 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
2228 Surprisingly enough, it works now.
2229 By Michal Ludvig, imported from mainline.
2231 i386 hardware watchpoint support:
2232 avoid misses on second run for some targets.
2233 By Pierre Muller, imported from mainline.
2235 *** Changes in GDB 5.2:
2237 * New command "set trust-readonly-sections on[off]".
2239 This command is a hint that tells gdb that read-only sections
2240 really are read-only (ie. that their contents will not change).
2241 In this mode, gdb will go to the object file rather than the
2242 target to read memory from read-only sections (such as ".text").
2243 This can be a significant performance improvement on some
2244 (notably embedded) targets.
2246 * New command "generate-core-file" (or "gcore").
2248 This new gdb command allows the user to drop a core file of the child
2249 process state at any time. So far it's been implemented only for
2250 GNU/Linux and Solaris, but should be relatively easily ported to other
2251 hosts. Argument is core file name (defaults to core.<pid>).
2253 * New command line option
2255 GDB now accepts --pid or -p followed by a process id.
2257 * Change in command line behavior -- corefiles vs. process ids.
2259 There is a subtle behavior in the way in which GDB handles
2260 command line arguments. The first non-flag argument is always
2261 a program to debug, but the second non-flag argument may either
2262 be a corefile or a process id. Previously, GDB would attempt to
2263 open the second argument as a corefile, and if that failed, would
2264 issue a superfluous error message and then attempt to attach it as
2265 a process. Now, if the second argument begins with a non-digit,
2266 it will be treated as a corefile. If it begins with a digit,
2267 GDB will attempt to attach it as a process, and if no such process
2268 is found, will then attempt to open it as a corefile.
2270 * Changes in ARM configurations.
2272 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
2273 configuration is fully multi-arch.
2275 * New native configurations
2277 ARM NetBSD arm*-*-netbsd*
2278 x86 OpenBSD i[3456]86-*-openbsd*
2279 AMD x86-64 running GNU/Linux x86_64-*-linux-*
2280 Sparc64 running FreeBSD sparc64-*-freebsd*
2284 Sanyo XStormy16 xstormy16-elf
2286 * OBSOLETE configurations and files
2288 Configurations that have been declared obsolete in this release have
2289 been commented out. Unless there is activity to revive these
2290 configurations, the next release of GDB will have their sources
2291 permanently REMOVED.
2293 AMD 29k family via UDI a29k-amd-udi, udi29k
2294 A29K VxWorks a29k-*-vxworks
2295 AMD 29000 embedded, using EBMON a29k-none-none
2296 AMD 29000 embedded with COFF a29k-none-coff
2297 AMD 29000 embedded with a.out a29k-none-aout
2299 testsuite/gdb.hp/gdb.threads-hp/ directory
2301 * REMOVED configurations and files
2303 TI TMS320C80 tic80-*-*
2305 PowerPC Solaris powerpcle-*-solaris*
2306 PowerPC Windows NT powerpcle-*-cygwin32
2307 PowerPC Netware powerpc-*-netware*
2308 Harris/CXUX m88k m88*-harris-cxux*
2309 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
2310 ns32k-utek-sysv* ns32k-utek-*
2311 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
2312 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
2313 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
2314 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
2315 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
2317 * Changes to command line processing
2319 The new `--args' feature can be used to specify command-line arguments
2320 for the inferior from gdb's command line.
2322 * Changes to key bindings
2324 There is a new `operate-and-get-next' function bound to `C-o'.
2326 *** Changes in GDB 5.1.1
2328 Fix compile problem on DJGPP.
2330 Fix a problem with floating-point registers on the i386 being
2333 Fix to stop GDB crashing on .debug_str debug info.
2335 Numerous documentation fixes.
2337 Numerous testsuite fixes.
2339 *** Changes in GDB 5.1:
2341 * New native configurations
2343 Alpha FreeBSD alpha*-*-freebsd*
2344 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
2345 MIPS GNU/Linux mips*-*-linux*
2346 MIPS SGI Irix 6.x mips*-sgi-irix6*
2347 ia64 AIX ia64-*-aix*
2348 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
2352 Motorola 68HC11 and 68HC12 m68hc11-elf
2354 UltraSparc running GNU/Linux sparc64-*-linux*
2356 * OBSOLETE configurations and files
2358 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
2359 Harris/CXUX m88k m88*-harris-cxux*
2360 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
2361 ns32k-utek-sysv* ns32k-utek-*
2362 TI TMS320C80 tic80-*-*
2364 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
2365 PowerPC Solaris powerpcle-*-solaris*
2366 PowerPC Windows NT powerpcle-*-cygwin32
2367 PowerPC Netware powerpc-*-netware*
2368 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
2369 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
2370 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
2371 Apple Macintosh (MPW) host N/A
2373 stuff.c (Program to stuff files into a specially prepared space in kdb)
2374 kdb-start.c (Main loop for the standalone kernel debugger)
2376 Configurations that have been declared obsolete in this release have
2377 been commented out. Unless there is activity to revive these
2378 configurations, the next release of GDB will have their sources
2379 permanently REMOVED.
2381 * REMOVED configurations and files
2383 Altos 3068 m68*-altos-*
2384 Convex c1-*-*, c2-*-*
2386 ARM RISCix arm-*-* (as host)
2390 * GDB has been converted to ISO C.
2392 GDB's source code has been converted to ISO C. In particular, the
2393 sources are fully protoized, and rely on standard headers being
2398 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
2400 * The MI enabled by default.
2402 The new machine oriented interface (MI) introduced in GDB 5.0 has been
2403 revised and enabled by default. Packages which use GDB as a debugging
2404 engine behind a UI or another front end are encouraged to switch to
2405 using the GDB/MI interface, instead of the old annotations interface
2406 which is now deprecated.
2408 * Support for debugging Pascal programs.
2410 GDB now includes support for debugging Pascal programs. The following
2411 main features are supported:
2413 - Pascal-specific data types such as sets;
2415 - automatic recognition of Pascal sources based on file-name
2418 - Pascal-style display of data types, variables, and functions;
2420 - a Pascal expression parser.
2422 However, some important features are not yet supported.
2424 - Pascal string operations are not supported at all;
2426 - there are some problems with boolean types;
2428 - Pascal type hexadecimal constants are not supported
2429 because they conflict with the internal variables format;
2431 - support for Pascal objects and classes is not full yet;
2433 - unlike Pascal, GDB is case-sensitive for symbol names.
2435 * Changes in completion.
2437 Commands such as `shell', `run' and `set args', which pass arguments
2438 to inferior programs, now complete on file names, similar to what
2439 users expect at the shell prompt.
2441 Commands which accept locations, such as `disassemble', `print',
2442 `breakpoint', `until', etc. now complete on filenames as well as
2443 program symbols. Thus, if you type "break foob TAB", and the source
2444 files linked into the programs include `foobar.c', that file name will
2445 be one of the candidates for completion. However, file names are not
2446 considered for completion after you typed a colon that delimits a file
2447 name from a name of a function in that file, as in "break foo.c:bar".
2449 `set demangle-style' completes on available demangling styles.
2451 * New platform-independent commands:
2453 It is now possible to define a post-hook for a command as well as a
2454 hook that runs before the command. For more details, see the
2455 documentation of `hookpost' in the GDB manual.
2457 * Changes in GNU/Linux native debugging.
2459 Support for debugging multi-threaded programs has been completely
2460 revised for all platforms except m68k and sparc. You can now debug as
2461 many threads as your system allows you to have.
2463 Attach/detach is supported for multi-threaded programs.
2465 Support for SSE registers was added for x86. This doesn't work for
2466 multi-threaded programs though.
2468 * Changes in MIPS configurations.
2470 Multi-arch support is enabled for all MIPS configurations.
2472 GDB can now be built as native debugger on SGI Irix 6.x systems for
2473 debugging n32 executables. (Debugging 64-bit executables is not yet
2476 * Unified support for hardware watchpoints in all x86 configurations.
2478 Most (if not all) native x86 configurations support hardware-assisted
2479 breakpoints and watchpoints in a unified manner. This support
2480 implements debug register sharing between watchpoints, which allows to
2481 put a virtually infinite number of watchpoints on the same address,
2482 and also supports watching regions up to 16 bytes with several debug
2485 The new maintenance command `maintenance show-debug-regs' toggles
2486 debugging print-outs in functions that insert, remove, and test
2487 watchpoints and hardware breakpoints.
2489 * Changes in the DJGPP native configuration.
2491 New command ``info dos sysinfo'' displays assorted information about
2492 the CPU, OS, memory, and DPMI server.
2494 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
2495 display information about segment descriptors stored in GDT, LDT, and
2498 New commands ``info dos pde'' and ``info dos pte'' display entries
2499 from Page Directory and Page Tables (for now works with CWSDPMI only).
2500 New command ``info dos address-pte'' displays the Page Table entry for
2501 a given linear address.
2503 GDB can now pass command lines longer than 126 characters to the
2504 program being debugged (requires an update to the libdbg.a library
2505 which is part of the DJGPP development kit).
2507 DWARF2 debug info is now supported.
2509 It is now possible to `step' and `next' through calls to `longjmp'.
2511 * Changes in documentation.
2513 All GDB documentation was converted to GFDL, the GNU Free
2514 Documentation License.
2516 Tracepoints-related commands are now fully documented in the GDB
2519 TUI, the Text-mode User Interface, is now documented in the manual.
2521 Tracepoints-related commands are now fully documented in the GDB
2524 The "GDB Internals" manual now has an index. It also includes
2525 documentation of `ui_out' functions, GDB coding standards, x86
2526 hardware watchpoints, and memory region attributes.
2528 * GDB's version number moved to ``version.in''
2530 The Makefile variable VERSION has been replaced by the file
2531 ``version.in''. People creating GDB distributions should update the
2532 contents of this file.
2536 GUD support is now a standard part of the EMACS distribution.
2538 *** Changes in GDB 5.0:
2540 * Improved support for debugging FP programs on x86 targets
2542 Unified and much-improved support for debugging floating-point
2543 programs on all x86 targets. In particular, ``info float'' now
2544 displays the FP registers in the same format on all x86 targets, with
2545 greater level of detail.
2547 * Improvements and bugfixes in hardware-assisted watchpoints
2549 It is now possible to watch array elements, struct members, and
2550 bitfields with hardware-assisted watchpoints. Data-read watchpoints
2551 on x86 targets no longer erroneously trigger when the address is
2554 * Improvements in the native DJGPP version of GDB
2556 The distribution now includes all the scripts and auxiliary files
2557 necessary to build the native DJGPP version on MS-DOS/MS-Windows
2558 machines ``out of the box''.
2560 The DJGPP version can now debug programs that use signals. It is
2561 possible to catch signals that happened in the debuggee, deliver
2562 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
2563 would kill the program being debugged.) Programs that hook hardware
2564 interrupts (keyboard, timer, etc.) can also be debugged.
2566 It is now possible to debug DJGPP programs that redirect their
2567 standard handles or switch them to raw (as opposed to cooked) mode, or
2568 even close them. The command ``run < foo > bar'' works as expected,
2569 and ``info terminal'' reports useful information about the debuggee's
2570 terminal, including raw/cooked mode, redirection, etc.
2572 The DJGPP version now uses termios functions for console I/O, which
2573 enables debugging graphics programs. Interrupting GDB with Ctrl-C
2576 DOS-style file names with drive letters are now fully supported by
2579 It is now possible to debug DJGPP programs that switch their working
2580 directory. It is also possible to rerun the debuggee any number of
2581 times without restarting GDB; thus, you can use the same setup,
2582 breakpoints, etc. for many debugging sessions.
2584 * New native configurations
2586 ARM GNU/Linux arm*-*-linux*
2587 PowerPC GNU/Linux powerpc-*-linux*
2591 Motorola MCore mcore-*-*
2592 x86 VxWorks i[3456]86-*-vxworks*
2593 PowerPC VxWorks powerpc-*-vxworks*
2594 TI TMS320C80 tic80-*-*
2596 * OBSOLETE configurations
2598 Altos 3068 m68*-altos-*
2599 Convex c1-*-*, c2-*-*
2601 ARM RISCix arm-*-* (as host)
2604 Configurations that have been declared obsolete will be commented out,
2605 but the code will be left in place. If there is no activity to revive
2606 these configurations before the next release of GDB, the sources will
2607 be permanently REMOVED.
2609 * Gould support removed
2611 Support for the Gould PowerNode and NP1 has been removed.
2613 * New features for SVR4
2615 On SVR4 native platforms (such as Solaris), if you attach to a process
2616 without first loading a symbol file, GDB will now attempt to locate and
2617 load symbols from the running process's executable file.
2619 * Many C++ enhancements
2621 C++ support has been greatly improved. Overload resolution now works properly
2622 in almost all cases. RTTI support is on the way.
2624 * Remote targets can connect to a sub-program
2626 A popen(3) style serial-device has been added. This device starts a
2627 sub-process (such as a stand-alone simulator) and then communicates
2628 with that. The sub-program to run is specified using the syntax
2629 ``|<program> <args>'' vis:
2631 (gdb) set remotedebug 1
2632 (gdb) target extended-remote |mn10300-elf-sim program-args
2634 * MIPS 64 remote protocol
2636 A long standing bug in the mips64 remote protocol where by GDB
2637 expected certain 32 bit registers (ex SR) to be transfered as 32
2638 instead of 64 bits has been fixed.
2640 The command ``set remote-mips64-transfers-32bit-regs on'' has been
2641 added to provide backward compatibility with older versions of GDB.
2643 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
2645 The command ``set remotebinarydownload'' command has been replaced by
2646 ``set remote X-packet''. Other commands in ``set remote'' family
2647 include ``set remote P-packet''.
2649 * Breakpoint commands accept ranges.
2651 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
2652 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
2653 ``tracepoint passcount'' also accepts a range of tracepoints.
2655 * ``apropos'' command added.
2657 The ``apropos'' command searches through command names and
2658 documentation strings, printing out matches, making it much easier to
2659 try to find a command that does what you are looking for.
2663 A new machine oriented interface (MI) has been added to GDB. This
2664 interface is designed for debug environments running GDB as a separate
2665 process. This is part of the long term libGDB project. See the
2666 "GDB/MI" chapter of the GDB manual for further information. It can be
2667 enabled by configuring with:
2669 .../configure --enable-gdbmi
2671 *** Changes in GDB-4.18:
2673 * New native configurations
2675 HP-UX 10.20 hppa*-*-hpux10.20
2676 HP-UX 11.x hppa*-*-hpux11.0*
2677 M68K GNU/Linux m68*-*-linux*
2681 Fujitsu FR30 fr30-*-elf*
2682 Intel StrongARM strongarm-*-*
2683 Mitsubishi D30V d30v-*-*
2685 * OBSOLETE configurations
2687 Gould PowerNode, NP1 np1-*-*, pn-*-*
2689 Configurations that have been declared obsolete will be commented out,
2690 but the code will be left in place. If there is no activity to revive
2691 these configurations before the next release of GDB, the sources will
2692 be permanently REMOVED.
2696 As a compatibility experiment, GDB's source files buildsym.h and
2697 buildsym.c have been converted to pure standard C, no longer
2698 containing any K&R compatibility code. We believe that all systems in
2699 use today either come with a standard C compiler, or have a GCC port
2700 available. If this is not true, please report the affected
2701 configuration to bug-gdb@gnu.org immediately. See the README file for
2702 information about getting a standard C compiler if you don't have one
2707 GDB now uses readline 2.2.
2709 * set extension-language
2711 You can now control the mapping between filename extensions and source
2712 languages by using the `set extension-language' command. For instance,
2713 you can ask GDB to treat .c files as C++ by saying
2714 set extension-language .c c++
2715 The command `info extensions' lists all of the recognized extensions
2716 and their associated languages.
2718 * Setting processor type for PowerPC and RS/6000
2720 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
2721 you can use the `set processor' command to specify what variant of the
2722 PowerPC family you are debugging. The command
2726 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
2727 following PowerPC and RS6000 variants:
2729 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
2730 rs6000 IBM RS6000 ("POWER") architecture, user-level view
2732 403GC IBM PowerPC 403GC
2733 505 Motorola PowerPC 505
2734 860 Motorola PowerPC 860 or 850
2735 601 Motorola PowerPC 601
2736 602 Motorola PowerPC 602
2737 603 Motorola/IBM PowerPC 603 or 603e
2738 604 Motorola PowerPC 604 or 604e
2739 750 Motorola/IBM PowerPC 750 or 750
2741 At the moment, this command just tells GDB what to name the
2742 special-purpose processor registers. Since almost all the affected
2743 registers are inaccessible to user-level programs, this command is
2744 only useful for remote debugging in its present form.
2748 Thanks to a major code donation from Hewlett-Packard, GDB now has much
2749 more extensive support for HP-UX. Added features include shared
2750 library support, kernel threads and hardware watchpoints for 11.00,
2751 support for HP's ANSI C and C++ compilers, and a compatibility mode
2752 for xdb and dbx commands.
2756 HP's donation includes the new concept of catchpoints, which is a
2757 generalization of the old catch command. On HP-UX, it is now possible
2758 to catch exec, fork, and vfork, as well as library loading.
2760 This means that the existing catch command has changed; its first
2761 argument now specifies the type of catch to be set up. See the
2762 output of "help catch" for a list of catchpoint types.
2764 * Debugging across forks
2766 On HP-UX, you can choose which process to debug when a fork() happens
2771 HP has donated a curses-based terminal user interface (TUI). To get
2772 it, build with --enable-tui. Although this can be enabled for any
2773 configuration, at present it only works for native HP debugging.
2775 * GDB remote protocol additions
2777 A new protocol packet 'X' that writes binary data is now available.
2778 Default behavior is to try 'X', then drop back to 'M' if the stub
2779 fails to respond. The settable variable `remotebinarydownload'
2780 allows explicit control over the use of 'X'.
2782 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
2783 full 64-bit address. The command
2785 set remoteaddresssize 32
2787 can be used to revert to the old behaviour. For existing remote stubs
2788 the change should not be noticed, as the additional address information
2791 In order to assist in debugging stubs, you may use the maintenance
2792 command `packet' to send any text string to the stub. For instance,
2794 maint packet heythere
2796 sends the packet "$heythere#<checksum>". Note that it is very easy to
2797 disrupt a debugging session by sending the wrong packet at the wrong
2800 The compare-sections command allows you to compare section data on the
2801 target to what is in the executable file without uploading or
2802 downloading, by comparing CRC checksums.
2804 * Tracing can collect general expressions
2806 You may now collect general expressions at tracepoints. This requires
2807 further additions to the target-side stub; see tracepoint.c and
2808 doc/agentexpr.texi for further details.
2810 * mask-address variable for Mips
2812 For Mips targets, you may control the zeroing of the upper 32 bits of
2813 a 64-bit address by entering `set mask-address on'. This is mainly
2814 of interest to users of embedded R4xxx and R5xxx processors.
2816 * Higher serial baud rates
2818 GDB's serial code now allows you to specify baud rates 57600, 115200,
2819 230400, and 460800 baud. (Note that your host system may not be able
2820 to achieve all of these rates.)
2824 The i960 configuration now includes an initial implementation of a
2825 builtin simulator, contributed by Jim Wilson.
2828 *** Changes in GDB-4.17:
2830 * New native configurations
2832 Alpha GNU/Linux alpha*-*-linux*
2833 Unixware 2.x i[3456]86-unixware2*
2834 Irix 6.x mips*-sgi-irix6*
2835 PowerPC GNU/Linux powerpc-*-linux*
2836 PowerPC Solaris powerpcle-*-solaris*
2837 Sparc GNU/Linux sparc-*-linux*
2838 Motorola sysV68 R3V7.1 m68k-motorola-sysv
2842 Argonaut Risc Chip (ARC) arc-*-*
2843 Hitachi H8/300S h8300*-*-*
2844 Matsushita MN10200 w/simulator mn10200-*-*
2845 Matsushita MN10300 w/simulator mn10300-*-*
2846 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
2847 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
2848 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
2849 Mitsubishi D10V w/simulator d10v-*-*
2850 Mitsubishi M32R/D w/simulator m32r-*-elf*
2851 Tsqware Sparclet sparclet-*-*
2852 NEC V850 w/simulator v850-*-*
2854 * New debugging protocols
2856 ARM with RDI protocol arm*-*-*
2857 M68K with dBUG monitor m68*-*-{aout,coff,elf}
2858 DDB and LSI variants of PMON protocol mips*-*-*
2859 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
2860 PowerPC with SDS protocol powerpc{,le}-*-eabi
2861 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
2865 All configurations can now understand and use the DWARF 2 debugging
2866 format. The choice is automatic, if the symbol file contains DWARF 2
2871 GDB now includes basic Java language support. This support is
2872 only useful with Java compilers that produce native machine code.
2874 * solib-absolute-prefix and solib-search-path
2876 For SunOS and SVR4 shared libraries, you may now set the prefix for
2877 loading absolute shared library symbol files, and the search path for
2878 locating non-absolute shared library symbol files.
2880 * Live range splitting
2882 GDB can now effectively debug code for which GCC has performed live
2883 range splitting as part of its optimization. See gdb/doc/LRS for
2884 more details on the expected format of the stabs information.
2888 GDB's support for the GNU Hurd, including thread debugging, has been
2889 updated to work with current versions of the Hurd.
2893 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
2894 instruction set. ARM GDB automatically detects when Thumb
2895 instructions are in use, and adjusts disassembly and backtracing
2900 GDB's MIPS target configurations now handle the MIP16 16-bit
2905 GDB now includes support for overlays; if an executable has been
2906 linked such that multiple sections are based at the same address, GDB
2907 will decide which section to use for symbolic info. You can choose to
2908 control the decision manually, using overlay commands, or implement
2909 additional target-side support and use "overlay load-target" to bring
2910 in the overlay mapping. Do "help overlay" for more detail.
2914 The command "info symbol <address>" displays information about
2915 the symbol at the specified address.
2919 The standard remote protocol now includes an extension that allows
2920 asynchronous collection and display of trace data. This requires
2921 extensive support in the target-side debugging stub. Tracing mode
2922 includes a new interaction mode in GDB and new commands: see the
2923 file tracepoint.c for more details.
2927 Configurations for embedded MIPS now include a simulator contributed
2928 by Cygnus Solutions. The simulator supports the instruction sets
2929 of most MIPS variants.
2933 Sparc configurations may now include the ERC32 simulator contributed
2934 by the European Space Agency. The simulator is not built into
2935 Sparc targets by default; configure with --enable-sim to include it.
2939 For target configurations that may include multiple variants of a
2940 basic architecture (such as MIPS and SH), you may now set the
2941 architecture explicitly. "set arch" sets, "info arch" lists
2942 the possible architectures.
2944 *** Changes in GDB-4.16:
2946 * New native configurations
2948 Windows 95, x86 Windows NT i[345]86-*-cygwin32
2949 M68K NetBSD m68k-*-netbsd*
2950 PowerPC AIX 4.x powerpc-*-aix*
2951 PowerPC MacOS powerpc-*-macos*
2952 PowerPC Windows NT powerpcle-*-cygwin32
2953 RS/6000 AIX 4.x rs6000-*-aix4*
2957 ARM with RDP protocol arm-*-*
2958 I960 with MON960 i960-*-coff
2959 MIPS VxWorks mips*-*-vxworks*
2960 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
2961 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
2963 Matra Sparclet sparclet-*-*
2967 The powerpc-eabi configuration now includes the PSIM simulator,
2968 contributed by Andrew Cagney, with assistance from Mike Meissner.
2969 PSIM is a very elaborate model of the PowerPC, including not only
2970 basic instruction set execution, but also details of execution unit
2971 performance and I/O hardware. See sim/ppc/README for more details.
2975 GDB now works with Solaris 2.5.
2977 * Windows 95/NT native
2979 GDB will now work as a native debugger on Windows 95 and Windows NT.
2980 To build it from source, you must use the "gnu-win32" environment,
2981 which uses a DLL to emulate enough of Unix to run the GNU tools.
2982 Further information, binaries, and sources are available at
2983 ftp.cygnus.com, under pub/gnu-win32.
2985 * dont-repeat command
2987 If a user-defined command includes the command `dont-repeat', then the
2988 command will not be repeated if the user just types return. This is
2989 useful if the command is time-consuming to run, so that accidental
2990 extra keystrokes don't run the same command many times.
2992 * Send break instead of ^C
2994 The standard remote protocol now includes an option to send a break
2995 rather than a ^C to the target in order to interrupt it. By default,
2996 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
2998 * Remote protocol timeout
3000 The standard remote protocol includes a new variable `remotetimeout'
3001 that allows you to set the number of seconds before GDB gives up trying
3002 to read from the target. The default value is 2.
3004 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
3006 By default GDB will automatically keep track of objects as they are
3007 loaded and unloaded by the dynamic linker. By using the command `set
3008 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
3009 when shared library events occur, thus allowing you to set breakpoints
3010 in shared libraries which are explicitly loaded by the inferior.
3012 Note this feature does not work on hpux8. On hpux9 you must link
3013 /usr/lib/end.o into your program. This feature should work
3014 automatically on hpux10.
3016 * Irix 5.x hardware watchpoint support
3018 Irix 5 configurations now support the use of hardware watchpoints.
3020 * Mips protocol "SYN garbage limit"
3022 When debugging a Mips target using the `target mips' protocol, you
3023 may set the number of characters that GDB will ignore by setting
3024 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
3025 every character. The default value is 1050.
3027 * Recording and replaying remote debug sessions
3029 If you set `remotelogfile' to the name of a file, gdb will write to it
3030 a recording of a remote debug session. This recording may then be
3031 replayed back to gdb using "gdbreplay". See gdbserver/README for
3032 details. This is useful when you have a problem with GDB while doing
3033 remote debugging; you can make a recording of the session and send it
3034 to someone else, who can then recreate the problem.
3036 * Speedups for remote debugging
3038 GDB includes speedups for downloading and stepping MIPS systems using
3039 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
3040 and more efficient S-record downloading.
3042 * Memory use reductions and statistics collection
3044 GDB now uses less memory and reports statistics about memory usage.
3045 Try the `maint print statistics' command, for example.
3047 *** Changes in GDB-4.15:
3049 * Psymtabs for XCOFF
3051 The symbol reader for AIX GDB now uses partial symbol tables. This
3052 can greatly improve startup time, especially for large executables.
3054 * Remote targets use caching
3056 Remote targets now use a data cache to speed up communication with the
3057 remote side. The data cache could lead to incorrect results because
3058 it doesn't know about volatile variables, thus making it impossible to
3059 debug targets which use memory mapped I/O devices. `set remotecache
3060 off' turns the the data cache off.
3062 * Remote targets may have threads
3064 The standard remote protocol now includes support for multiple threads
3065 in the target system, using new protocol commands 'H' and 'T'. See
3066 gdb/remote.c for details.
3070 If GDB is configured with `--enable-netrom', then it will include
3071 support for the NetROM ROM emulator from XLNT Designs. The NetROM
3072 acts as though it is a bank of ROM on the target board, but you can
3073 write into it over the network. GDB's support consists only of
3074 support for fast loading into the emulated ROM; to debug, you must use
3075 another protocol, such as standard remote protocol. The usual
3076 sequence is something like
3078 target nrom <netrom-hostname>
3080 target remote <netrom-hostname>:1235
3084 GDB now includes support for the Apple Macintosh, as a host only. It
3085 may be run as either an MPW tool or as a standalone application, and
3086 it can debug through the serial port. All the usual GDB commands are
3087 available, but to the target command, you must supply "serial" as the
3088 device type instead of "/dev/ttyXX". See mpw-README in the main
3089 directory for more information on how to build. The MPW configuration
3090 scripts */mpw-config.in support only a few targets, and only the
3091 mips-idt-ecoff target has been tested.
3095 GDB configuration now uses autoconf. This is not user-visible,
3096 but does simplify configuration and building.
3100 GDB now supports hpux10.
3102 *** Changes in GDB-4.14:
3104 * New native configurations
3106 x86 FreeBSD i[345]86-*-freebsd
3107 x86 NetBSD i[345]86-*-netbsd
3108 NS32k NetBSD ns32k-*-netbsd
3109 Sparc NetBSD sparc-*-netbsd
3113 A29K VxWorks a29k-*-vxworks
3114 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
3115 CPU32 EST-300 emulator m68*-*-est*
3116 PowerPC ELF powerpc-*-elf
3119 * Alpha OSF/1 support for procfs
3121 GDB now supports procfs under OSF/1-2.x and higher, which makes it
3122 possible to attach to running processes. As the mounting of the /proc
3123 filesystem is optional on the Alpha, GDB automatically determines
3124 the availability of /proc during startup. This can lead to problems
3125 if /proc is unmounted after GDB has been started.
3127 * Arguments to user-defined commands
3129 User commands may accept up to 10 arguments separated by whitespace.
3130 Arguments are accessed within the user command via $arg0..$arg9. A
3133 print $arg0 + $arg1 + $arg2
3135 To execute the command use:
3138 Defines the command "adder" which prints the sum of its three arguments.
3139 Note the arguments are text substitutions, so they may reference variables,
3140 use complex expressions, or even perform inferior function calls.
3142 * New `if' and `while' commands
3144 This makes it possible to write more sophisticated user-defined
3145 commands. Both commands take a single argument, which is the
3146 expression to evaluate, and must be followed by the commands to
3147 execute, one per line, if the expression is nonzero, the list being
3148 terminated by the word `end'. The `if' command list may include an
3149 `else' word, which causes the following commands to be executed only
3150 if the expression is zero.
3152 * Fortran source language mode
3154 GDB now includes partial support for Fortran 77. It will recognize
3155 Fortran programs and can evaluate a subset of Fortran expressions, but
3156 variables and functions may not be handled correctly. GDB will work
3157 with G77, but does not yet know much about symbols emitted by other
3160 * Better HPUX support
3162 Most debugging facilities now work on dynamic executables for HPPAs
3163 running hpux9 or later. You can attach to running dynamically linked
3164 processes, but by default the dynamic libraries will be read-only, so
3165 for instance you won't be able to put breakpoints in them. To change
3166 that behavior do the following before running the program:
3172 This will cause the libraries to be mapped private and read-write.
3173 To revert to the normal behavior, do this:
3179 You cannot set breakpoints or examine data in the library until after
3180 the library is loaded if the function/data symbols do not have
3183 GDB can now also read debug symbols produced by the HP C compiler on
3184 HPPAs (sorry, no C++, Fortran or 68k support).
3186 * Target byte order now dynamically selectable
3188 You can choose which byte order to use with a target system, via the
3189 commands "set endian big" and "set endian little", and you can see the
3190 current setting by using "show endian". You can also give the command
3191 "set endian auto", in which case GDB will use the byte order
3192 associated with the executable. Currently, only embedded MIPS
3193 configurations support dynamic selection of target byte order.
3195 * New DOS host serial code
3197 This version uses DPMI interrupts to handle buffered I/O, so you
3198 no longer need to run asynctsr when debugging boards connected to
3201 *** Changes in GDB-4.13:
3203 * New "complete" command
3205 This lists all the possible completions for the rest of the line, if it
3206 were to be given as a command itself. This is intended for use by emacs.
3208 * Trailing space optional in prompt
3210 "set prompt" no longer adds a space for you after the prompt you set. This
3211 allows you to set a prompt which ends in a space or one that does not.
3213 * Breakpoint hit counts
3215 "info break" now displays a count of the number of times the breakpoint
3216 has been hit. This is especially useful in conjunction with "ignore"; you
3217 can ignore a large number of breakpoint hits, look at the breakpoint info
3218 to see how many times the breakpoint was hit, then run again, ignoring one
3219 less than that number, and this will get you quickly to the last hit of
3222 * Ability to stop printing at NULL character
3224 "set print null-stop" will cause GDB to stop printing the characters of
3225 an array when the first NULL is encountered. This is useful when large
3226 arrays actually contain only short strings.
3228 * Shared library breakpoints
3230 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
3231 breakpoints in shared libraries before the executable is run.
3233 * Hardware watchpoints
3235 There is a new hardware breakpoint for the watch command for sparclite
3236 targets. See gdb/sparclite/hw_breakpoint.note.
3238 Hardware watchpoints are also now supported under GNU/Linux.
3242 Annotations have been added. These are for use with graphical interfaces,
3243 and are still experimental. Currently only gdba.el uses these.
3245 * Improved Irix 5 support
3247 GDB now works properly with Irix 5.2.
3249 * Improved HPPA support
3251 GDB now works properly with the latest GCC and GAS.
3253 * New native configurations
3255 Sequent PTX4 i[34]86-sequent-ptx4
3256 HPPA running OSF/1 hppa*-*-osf*
3257 Atari TT running SVR4 m68*-*-sysv4*
3258 RS/6000 LynxOS rs6000-*-lynxos*
3262 OS/9000 i[34]86-*-os9k
3263 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
3266 * Hitachi SH7000 and E7000-PC ICE support
3268 There is now support for communicating with the Hitachi E7000-PC ICE.
3269 This is available automatically when GDB is configured for the SH.
3273 As usual, a variety of small fixes and improvements, both generic
3274 and configuration-specific. See the ChangeLog for more detail.
3276 *** Changes in GDB-4.12:
3278 * Irix 5 is now supported
3282 GDB-4.12 on the HPPA has a number of changes which make it unable
3283 to debug the output from the currently released versions of GCC and
3284 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
3285 of GCC and GAS, versions of these tools designed to work with GDB-4.12
3286 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
3289 *** Changes in GDB-4.11:
3291 * User visible changes:
3295 The "set remotedebug" option is now consistent between the mips remote
3296 target, remote targets using the gdb-specific protocol, UDI (AMD's
3297 debug protocol for the 29k) and the 88k bug monitor. It is now an
3298 integer specifying a debug level (normally 0 or 1, but 2 means more
3299 debugging info for the mips target).
3301 * DEC Alpha native support
3303 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
3304 debug info, but GDB works fairly well with the DEC compiler and should
3305 work with a future GCC release. See the README file for a few
3306 Alpha-specific notes.
3308 * Preliminary thread implementation
3310 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
3312 * LynxOS native and target support for 386
3314 This release has been hosted on LynxOS 2.2, and also can be configured
3315 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
3318 * Improvements in C++ mangling/demangling.
3320 This release has much better g++ debugging, specifically in name
3321 mangling/demangling, virtual function calls, print virtual table,
3322 call methods, ...etc.
3324 *** Changes in GDB-4.10:
3326 * User visible changes:
3328 Remote debugging using the GDB-specific (`target remote') protocol now
3329 supports the `load' command. This is only useful if you have some
3330 other way of getting the stub to the target system, and you can put it
3331 somewhere in memory where it won't get clobbered by the download.
3333 Filename completion now works.
3335 When run under emacs mode, the "info line" command now causes the
3336 arrow to point to the line specified. Also, "info line" prints
3337 addresses in symbolic form (as well as hex).
3339 All vxworks based targets now support a user settable option, called
3340 vxworks-timeout. This option represents the number of seconds gdb
3341 should wait for responses to rpc's. You might want to use this if
3342 your vxworks target is, perhaps, a slow software simulator or happens
3343 to be on the far side of a thin network line.
3347 This release contains support for using a DEC alpha as a GDB host for
3348 cross debugging. Native alpha debugging is not supported yet.
3351 *** Changes in GDB-4.9:
3355 This is the first GDB release which is accompanied by a matching testsuite.
3356 The testsuite requires installation of dejagnu, which should be available
3357 via ftp from most sites that carry GNU software.
3361 'Cfront' style demangling has had its name changed to 'ARM' style, to
3362 emphasize that it was written from the specifications in the C++ Annotated
3363 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
3364 disclaimers, it still generated too much confusion with users attempting to
3365 use gdb with AT&T cfront.
3369 GDB now uses a standard remote interface to a simulator library.
3370 So far, the library contains simulators for the Zilog Z8001/2, the
3371 Hitachi H8/300, H8/500 and Super-H.
3373 * New targets supported
3375 H8/300 simulator h8300-hitachi-hms or h8300hms
3376 H8/500 simulator h8500-hitachi-hms or h8500hms
3377 SH simulator sh-hitachi-hms or sh
3378 Z8000 simulator z8k-zilog-none or z8ksim
3379 IDT MIPS board over serial line mips-idt-ecoff
3381 Cross-debugging to GO32 targets is supported. It requires a custom
3382 version of the i386-stub.c module which is integrated with the
3383 GO32 memory extender.
3385 * New remote protocols
3387 MIPS remote debugging protocol.
3389 * New source languages supported
3391 This version includes preliminary support for Chill, a Pascal like language
3392 used by telecommunications companies. Chill support is also being integrated
3393 into the GNU compiler, but we don't know when it will be publically available.
3396 *** Changes in GDB-4.8:
3398 * HP Precision Architecture supported
3400 GDB now supports HP PA-RISC machines running HPUX. A preliminary
3401 version of this support was available as a set of patches from the
3402 University of Utah. GDB does not support debugging of programs
3403 compiled with the HP compiler, because HP will not document their file
3404 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
3405 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
3407 Many problems in the preliminary version have been fixed.
3409 * Faster and better demangling
3411 We have improved template demangling and fixed numerous bugs in the GNU style
3412 demangler. It can now handle type modifiers such as `static' or `const'. Wide
3413 character types (wchar_t) are now supported. Demangling of each symbol is now
3414 only done once, and is cached when the symbol table for a file is read in.
3415 This results in a small increase in memory usage for C programs, a moderate
3416 increase in memory usage for C++ programs, and a fantastic speedup in
3419 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
3420 from the specifications in the Annotated Reference Manual, which AT&T's
3421 compiler does not actually implement.
3423 * G++ multiple inheritance compiler problem
3425 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
3426 inheritance lattices was reworked to properly discover ambiguities. We
3427 recently found an example which causes this new algorithm to fail in a
3428 very subtle way, producing bad debug information for those classes.
3429 The file 'gcc.patch' (in this directory) can be applied to gcc to
3430 circumvent the problem. A future GCC release will contain a complete
3433 The previous G++ debug info problem (mentioned below for the gdb-4.7
3434 release) is fixed in gcc version 2.3.2.
3436 * Improved configure script
3438 The `configure' script will now attempt to guess your system type if
3439 you don't supply a host system type. The old scheme of supplying a
3440 host system triplet is preferable over using this. All the magic is
3441 done in the new `config.guess' script. Examine it for details.
3443 We have also brought our configure script much more in line with the FSF's
3444 version. It now supports the --with-xxx options. In particular,
3445 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
3446 The resulting GDB will not be able to read arbitrary object file formats --
3447 only the format ``expected'' to be used on the configured target system.
3448 We hope to make this the default in a future release.
3450 * Documentation improvements
3452 There's new internal documentation on how to modify GDB, and how to
3453 produce clean changes to the code. We implore people to read it
3454 before submitting changes.
3456 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
3457 M4 macros. The new texinfo.tex is provided in this release. Pre-built
3458 `info' files are also provided. To build `info' files from scratch,
3459 you will need the latest `makeinfo' release, which will be available in
3460 a future texinfo-X.Y release.
3462 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
3463 We're not sure exactly which versions have this problem, but it has
3464 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
3465 or better. If that isn't possible, there is a patch in
3466 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
3467 around this problem.
3471 GDB now supports array constants that can be used in expressions typed in by
3472 the user. The syntax is `{element, element, ...}'. Ie: you can now type
3473 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
3476 The new directory `gdb/sparclite' contains a program that demonstrates
3477 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
3479 * New native hosts supported
3481 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
3482 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
3484 * New targets supported
3486 AMD 29k family via UDI a29k-amd-udi or udi29k
3488 * New file formats supported
3490 BFD now supports reading HP/PA-RISC executables (SOM file format?),
3491 HPUX core files, and SCO 3.2v2 core files.
3495 Attaching to processes now works again; thanks for the many bug reports.
3497 We have also stomped on a bunch of core dumps caused by
3498 printf_filtered("%s") problems.
3500 We eliminated a copyright problem on the rpc and ptrace header files
3501 for VxWorks, which was discovered at the last minute during the 4.7
3502 release. You should now be able to build a VxWorks GDB.
3504 You can now interrupt gdb while an attached process is running. This
3505 will cause the attached process to stop, and give control back to GDB.
3507 We fixed problems caused by using too many file descriptors
3508 for reading symbols from object files and libraries. This was
3509 especially a problem for programs that used many (~100) shared
3512 The `step' command now only enters a subroutine if there is line number
3513 information for the subroutine. Otherwise it acts like the `next'
3514 command. Previously, `step' would enter subroutines if there was
3515 any debugging information about the routine. This avoids problems
3516 when using `cc -g1' on MIPS machines.
3518 * Internal improvements
3520 GDB's internal interfaces have been improved to make it easier to support
3521 debugging of multiple languages in the future.
3523 GDB now uses a common structure for symbol information internally.
3524 Minimal symbols (derived from linkage symbols in object files), partial
3525 symbols (from a quick scan of debug information), and full symbols
3526 contain a common subset of information, making it easier to write
3527 shared code that handles any of them.
3529 * New command line options
3531 We now accept --silent as an alias for --quiet.
3535 The memory-mapped-malloc library is now licensed under the GNU Library
3536 General Public License.
3538 *** Changes in GDB-4.7:
3540 * Host/native/target split
3542 GDB has had some major internal surgery to untangle the support for
3543 hosts and remote targets. Now, when you configure GDB for a remote
3544 target, it will no longer load in all of the support for debugging
3545 local programs on the host. When fully completed and tested, this will
3546 ensure that arbitrary host/target combinations are possible.
3548 The primary conceptual shift is to separate the non-portable code in
3549 GDB into three categories. Host specific code is required any time GDB
3550 is compiled on that host, regardless of the target. Target specific
3551 code relates to the peculiarities of the target, but can be compiled on
3552 any host. Native specific code is everything else: it can only be
3553 built when the host and target are the same system. Child process
3554 handling and core file support are two common `native' examples.
3556 GDB's use of /proc for controlling Unix child processes is now cleaner.
3557 It has been split out into a single module under the `target_ops' vector,
3558 plus two native-dependent functions for each system that uses /proc.
3560 * New hosts supported
3562 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
3563 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
3564 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
3566 * New targets supported
3568 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3569 68030 and CPU32 m68030-*-*, m68332-*-*
3571 * New native hosts supported
3573 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
3574 (386bsd is not well tested yet)
3575 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
3577 * New file formats supported
3579 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
3580 supports reading of `a.out.adobe' object files, which are an a.out
3581 format extended with minimal information about multiple sections.
3585 `show copying' is the same as the old `info copying'.
3586 `show warranty' is the same as `info warrantee'.
3587 These were renamed for consistency. The old commands continue to work.
3589 `info handle' is a new alias for `info signals'.
3591 You can now define pre-command hooks, which attach arbitrary command
3592 scripts to any command. The commands in the hook will be executed
3593 prior to the user's command. You can also create a hook which will be
3594 executed whenever the program stops. See gdb.texinfo.
3598 We now deal with Cfront style name mangling, and can even extract type
3599 info from mangled symbols. GDB can automatically figure out which
3600 symbol mangling style your C++ compiler uses.
3602 Calling of methods and virtual functions has been improved as well.
3606 The crash that occured when debugging Sun Ansi-C compiled binaries is
3607 fixed. This was due to mishandling of the extra N_SO stabs output
3610 We also finally got Ultrix 4.2 running in house, and fixed core file
3611 support, with help from a dozen people on the net.
3613 John M. Farrell discovered that the reason that single-stepping was so
3614 slow on all of the Mips based platforms (primarily SGI and DEC) was
3615 that we were trying to demangle and lookup a symbol used for internal
3616 purposes on every instruction that was being stepped through. Changing
3617 the name of that symbol so that it couldn't be mistaken for a C++
3618 mangled symbol sped things up a great deal.
3620 Rich Pixley sped up symbol lookups in general by getting much smarter
3621 about when C++ symbol mangling is necessary. This should make symbol
3622 completion (TAB on the command line) much faster. It's not as fast as
3623 we'd like, but it's significantly faster than gdb-4.6.
3627 A new user controllable variable 'call_scratch_address' can
3628 specify the location of a scratch area to be used when GDB
3629 calls a function in the target. This is necessary because the
3630 usual method of putting the scratch area on the stack does not work
3631 in systems that have separate instruction and data spaces.
3633 We integrated changes to support the 29k UDI (Universal Debugger
3634 Interface), but discovered at the last minute that we didn't have all
3635 of the appropriate copyright paperwork. We are working with AMD to
3636 resolve this, and hope to have it available soon.
3640 We have sped up the remote serial line protocol, especially for targets
3641 with lots of registers. It now supports a new `expedited status' ('T')
3642 message which can be used in place of the existing 'S' status message.
3643 This allows the remote stub to send only the registers that GDB
3644 needs to make a quick decision about single-stepping or conditional
3645 breakpoints, eliminating the need to fetch the entire register set for
3646 each instruction being stepped through.
3648 The GDB remote serial protocol now implements a write-through cache for
3649 registers, only re-reading the registers if the target has run.
3651 There is also a new remote serial stub for SPARC processors. You can
3652 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
3653 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
3654 processor with a serial port.
3658 Configure.in files have become much easier to read and modify. A new
3659 `table driven' format makes it more obvious what configurations are
3660 supported, and what files each one uses.
3664 There is a new opcodes library which will eventually contain all of the
3665 disassembly routines and opcode tables. At present, it only contains
3666 Sparc and Z8000 routines. This will allow the assembler, debugger, and
3667 disassembler (binutils/objdump) to share these routines.
3669 The libiberty library is now copylefted under the GNU Library General
3670 Public License. This allows more liberal use, and was done so libg++
3671 can use it. This makes no difference to GDB, since the Library License
3672 grants all the rights from the General Public License.
3676 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
3677 reference to the stabs symbol info used by the debugger. It is (as far
3678 as we know) the only published document on this fascinating topic. We
3679 encourage you to read it, compare it to the stabs information on your
3680 system, and send improvements on the document in general (to
3681 bug-gdb@prep.ai.mit.edu).
3683 And, of course, many bugs have been fixed.
3686 *** Changes in GDB-4.6:
3688 * Better support for C++ function names
3690 GDB now accepts as input the "demangled form" of C++ overloaded function
3691 names and member function names, and can do command completion on such names
3692 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
3693 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
3694 Make use of command completion, it is your friend.
3696 GDB also now accepts a variety of C++ mangled symbol formats. They are
3697 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
3698 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
3699 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
3700 for the list of formats.
3702 * G++ symbol mangling problem
3704 Recent versions of gcc have a bug in how they emit debugging information for
3705 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
3706 directory) can be applied to gcc to fix the problem. Alternatively, if you
3707 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
3708 usual symptom is difficulty with setting breakpoints on methods. GDB complains
3709 about the method being non-existent. (We believe that version 2.2.2 of GCC has
3712 * New 'maintenance' command
3714 All of the commands related to hacking GDB internals have been moved out of
3715 the main command set, and now live behind the 'maintenance' command. This
3716 can also be abbreviated as 'mt'. The following changes were made:
3718 dump-me -> maintenance dump-me
3719 info all-breakpoints -> maintenance info breakpoints
3720 printmsyms -> maintenance print msyms
3721 printobjfiles -> maintenance print objfiles
3722 printpsyms -> maintenance print psymbols
3723 printsyms -> maintenance print symbols
3725 The following commands are new:
3727 maintenance demangle Call internal GDB demangler routine to
3728 demangle a C++ link name and prints the result.
3729 maintenance print type Print a type chain for a given symbol
3731 * Change to .gdbinit file processing
3733 We now read the $HOME/.gdbinit file before processing the argv arguments
3734 (e.g. reading symbol files or core files). This allows global parameters to
3735 be set, which will apply during the symbol reading. The ./.gdbinit is still
3736 read after argv processing.
3738 * New hosts supported
3740 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
3742 GNU/Linux support i386-unknown-linux or linux
3744 We are also including code to support the HP/PA running BSD and HPUX. This
3745 is almost guaranteed not to work, as we didn't have time to test or build it
3746 for this release. We are including it so that the more adventurous (or
3747 masochistic) of you can play with it. We also had major problems with the
3748 fact that the compiler that we got from HP doesn't support the -g option.
3751 * New targets supported
3753 Hitachi H8/300 h8300-hitachi-hms or h8300hms
3755 * More smarts about finding #include files
3757 GDB now remembers the compilation directory for all include files, and for
3758 all files from which C is generated (like yacc and lex sources). This
3759 greatly improves GDB's ability to find yacc/lex sources, and include files,
3760 especially if you are debugging your program from a directory different from
3761 the one that contains your sources.
3763 We also fixed a bug which caused difficulty with listing and setting
3764 breakpoints in include files which contain C code. (In the past, you had to
3765 try twice in order to list an include file that you hadn't looked at before.)
3767 * Interesting infernals change
3769 GDB now deals with arbitrary numbers of sections, where the symbols for each
3770 section must be relocated relative to that section's landing place in the
3771 target's address space. This work was needed to support ELF with embedded
3772 stabs used by Solaris-2.0.
3774 * Bug fixes (of course!)
3776 There have been loads of fixes for the following things:
3777 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
3778 i960, stabs, DOS(GO32), procfs, etc...
3780 See the ChangeLog for details.
3782 *** Changes in GDB-4.5:
3784 * New machines supported (host and target)
3786 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
3788 SGI Irix-4.x mips-sgi-irix4 or iris4
3790 * New malloc package
3792 GDB now uses a new memory manager called mmalloc, based on gmalloc.
3793 Mmalloc is capable of handling mutiple heaps of memory. It is also
3794 capable of saving a heap to a file, and then mapping it back in later.
3795 This can be used to greatly speedup the startup of GDB by using a
3796 pre-parsed symbol table which lives in a mmalloc managed heap. For
3797 more details, please read mmalloc/mmalloc.texi.
3801 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
3802 'help info proc' for details.
3804 * MIPS ecoff symbol table format
3806 The code that reads MIPS symbol table format is now supported on all hosts.
3807 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
3810 * File name changes for MS-DOS
3812 Many files in the config directories have been renamed to make it easier to
3813 support GDB on MS-DOSe systems (which have very restrictive file name
3814 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
3815 environment) is close to working but has some remaining problems. Note
3816 that debugging of DOS programs is not supported, due to limitations
3817 in the ``operating system'', but it can be used to host cross-debugging.
3819 * Cross byte order fixes
3821 Many fixes have been made to support cross debugging of Sparc and MIPS
3822 targets from hosts whose byte order differs.
3824 * New -mapped and -readnow options
3826 If memory-mapped files are available on your system through the 'mmap'
3827 system call, you can use the -mapped option on the `file' or
3828 `symbol-file' commands to cause GDB to write the symbols from your
3829 program into a reusable file. If the program you are debugging is
3830 called `/path/fred', the mapped symbol file will be `./fred.syms'.
3831 Future GDB debugging sessions will notice the presence of this file,
3832 and will quickly map in symbol information from it, rather than reading
3833 the symbol table from the executable program. Using the '-mapped'
3834 option in a GDB `file' or `symbol-file' command has the same effect as
3835 starting GDB with the '-mapped' command-line option.
3837 You can cause GDB to read the entire symbol table immediately by using
3838 the '-readnow' option with any of the commands that load symbol table
3839 information (or on the GDB command line). This makes the command
3840 slower, but makes future operations faster.
3842 The -mapped and -readnow options are typically combined in order to
3843 build a `fred.syms' file that contains complete symbol information.
3844 A simple GDB invocation to do nothing but build a `.syms' file for future
3847 gdb -batch -nx -mapped -readnow programname
3849 The `.syms' file is specific to the host machine on which GDB is run.
3850 It holds an exact image of GDB's internal symbol table. It cannot be
3851 shared across multiple host platforms.
3853 * longjmp() handling
3855 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
3856 siglongjmp() without losing control. This feature has not yet been ported to
3857 all systems. It currently works on many 386 platforms, all MIPS-based
3858 platforms (SGI, DECstation, etc), and Sun3/4.
3862 Preliminary work has been put in to support the new Solaris OS from Sun. At
3863 this time, it can control and debug processes, but it is not capable of
3868 As always, many many bug fixes. The major areas were with g++, and mipsread.
3869 People using the MIPS-based platforms should experience fewer mysterious
3870 crashes and trashed symbol tables.
3872 *** Changes in GDB-4.4:
3874 * New machines supported (host and target)
3876 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
3878 BSD Reno on Vax vax-dec-bsd
3879 Ultrix on Vax vax-dec-ultrix
3881 * New machines supported (target)
3883 AMD 29000 embedded, using EBMON a29k-none-none
3887 GDB continues to improve its handling of C++. `References' work better.
3888 The demangler has also been improved, and now deals with symbols mangled as
3889 per the Annotated C++ Reference Guide.
3891 GDB also now handles `stabs' symbol information embedded in MIPS
3892 `ecoff' symbol tables. Since the ecoff format was not easily
3893 extensible to handle new languages such as C++, this appeared to be a
3894 good way to put C++ debugging info into MIPS binaries. This option
3895 will be supported in the GNU C compiler, version 2, when it is
3898 * New features for SVR4
3900 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
3901 shared libraries. Debugging dynamically linked programs should present
3902 only minor differences from debugging statically linked programs.
3904 The `info proc' command will print out information about any process
3905 on an SVR4 system (including the one you are debugging). At the moment,
3906 it prints the address mappings of the process.
3908 If you bring up GDB on another SVR4 system, please send mail to
3909 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
3911 * Better dynamic linking support in SunOS
3913 Reading symbols from shared libraries which contain debugging symbols
3914 now works properly. However, there remain issues such as automatic
3915 skipping of `transfer vector' code during function calls, which
3916 make it harder to debug code in a shared library, than to debug the
3917 same code linked statically.
3921 GDB is now using the latest `getopt' routines from the FSF. This
3922 version accepts the -- prefix for options with long names. GDB will
3923 continue to accept the old forms (-option and +option) as well.
3924 Various single letter abbreviations for options have been explicity
3925 added to the option table so that they won't get overshadowed in the
3926 future by other options that begin with the same letter.
3930 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
3931 Many assorted bugs have been handled. Many more remain to be handled.
3932 See the various ChangeLog files (primarily in gdb and bfd) for details.
3935 *** Changes in GDB-4.3:
3937 * New machines supported (host and target)
3939 Amiga 3000 running Amix m68k-cbm-svr4 or amix
3940 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
3941 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3943 * Almost SCO Unix support
3945 We had hoped to support:
3946 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
3947 (except for core file support), but we discovered very late in the release
3948 that it has problems with process groups that render gdb unusable. Sorry
3949 about that. I encourage people to fix it and post the fixes.
3951 * Preliminary ELF and DWARF support
3953 GDB can read ELF object files on System V Release 4, and can handle
3954 debugging records for C, in DWARF format, in ELF files. This support
3955 is preliminary. If you bring up GDB on another SVR4 system, please
3956 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
3961 GDB now uses the latest `readline' library. One user-visible change
3962 is that two tabs will list possible command completions, which previously
3963 required typing M-? (meta-question mark, or ESC ?).
3967 The `stepi' bug that many of you noticed has been squashed.
3968 Many bugs in C++ have been handled. Many more remain to be handled.
3969 See the various ChangeLog files (primarily in gdb and bfd) for details.
3971 * State of the MIPS world (in case you wondered):
3973 GDB can understand the symbol tables emitted by the compilers
3974 supplied by most vendors of MIPS-based machines, including DEC. These
3975 symbol tables are in a format that essentially nobody else uses.
3977 Some versions of gcc come with an assembler post-processor called
3978 mips-tfile. This program is required if you want to do source-level
3979 debugging of gcc-compiled programs. I believe FSF does not ship
3980 mips-tfile with gcc version 1, but it will eventually come with gcc
3983 Debugging of g++ output remains a problem. g++ version 1.xx does not
3984 really support it at all. (If you're lucky, you should be able to get
3985 line numbers and stack traces to work, but no parameters or local
3986 variables.) With some work it should be possible to improve the
3989 When gcc version 2 is released, you will have somewhat better luck.
3990 However, even then you will get confusing results for inheritance and
3993 We will eventually provide full debugging of g++ output on
3994 DECstations. This will probably involve some kind of stabs-in-ecoff
3995 encapulation, but the details have not been worked out yet.
3998 *** Changes in GDB-4.2:
4000 * Improved configuration
4002 Only one copy of `configure' exists now, and it is not self-modifying.
4003 Porting BFD is simpler.
4007 The `step' and `next' commands now only stop at the first instruction
4008 of a source line. This prevents the multiple stops that used to occur
4009 in switch statements, for-loops, etc. `Step' continues to stop if a
4010 function that has debugging information is called within the line.
4014 Lots of small bugs fixed. More remain.
4016 * New host supported (not target)
4018 Intel 386 PC clone running Mach i386-none-mach
4021 *** Changes in GDB-4.1:
4023 * Multiple source language support
4025 GDB now has internal scaffolding to handle several source languages.
4026 It determines the type of each source file from its filename extension,
4027 and will switch expression parsing and number formatting to match the
4028 language of the function in the currently selected stack frame.
4029 You can also specifically set the language to be used, with
4030 `set language c' or `set language modula-2'.
4034 GDB now has preliminary support for the GNU Modula-2 compiler,
4035 currently under development at the State University of New York at
4036 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
4037 continue through the fall of 1991 and into 1992.
4039 Other Modula-2 compilers are currently not supported, and attempting to
4040 debug programs compiled with them will likely result in an error as the
4041 symbol table is read. Feel free to work on it, though!
4043 There are hooks in GDB for strict type checking and range checking,
4044 in the `Modula-2 philosophy', but they do not currently work.
4048 GDB can now write to executable and core files (e.g. patch
4049 a variable's value). You must turn this switch on, specify
4050 the file ("exec foo" or "core foo"), *then* modify it, e.g.
4051 by assigning a new value to a variable. Modifications take
4054 * Automatic SunOS shared library reading
4056 When you run your program, GDB automatically determines where its
4057 shared libraries (if any) have been loaded, and reads their symbols.
4058 The `share' command is no longer needed. This also works when
4059 examining core files.
4063 You can specify the number of lines that the `list' command shows.
4066 * New machines supported (host and target)
4068 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4069 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
4070 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
4072 * New hosts supported (not targets)
4074 IBM RT/PC: romp-ibm-aix or rtpc
4076 * New targets supported (not hosts)
4078 AMD 29000 embedded with COFF a29k-none-coff
4079 AMD 29000 embedded with a.out a29k-none-aout
4080 Ultracomputer remote kernel debug a29k-nyu-kern
4082 * New remote interfaces
4088 *** Changes in GDB-4.0:
4092 Wide output is wrapped at good places to make the output more readable.
4094 Gdb now supports cross-debugging from a host machine of one type to a
4095 target machine of another type. Communication with the target system
4096 is over serial lines. The ``target'' command handles connecting to the
4097 remote system; the ``load'' command will download a program into the
4098 remote system. Serial stubs for the m68k and i386 are provided. Gdb
4099 also supports debugging of realtime processes running under VxWorks,
4100 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
4101 stub on the target system.
4103 New CPUs supported include the AMD 29000 and Intel 960.
4105 GDB now reads object files and symbol tables via a ``binary file''
4106 library, which allows a single copy of GDB to debug programs of multiple
4107 object file types such as a.out and coff.
4109 There is now a GDB reference card in "doc/refcard.tex". (Make targets
4110 refcard.dvi and refcard.ps are available to format it).
4113 * Control-Variable user interface simplified
4115 All variables that control the operation of the debugger can be set
4116 by the ``set'' command, and displayed by the ``show'' command.
4118 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
4119 ``Show prompt'' produces the response:
4120 Gdb's prompt is new-gdb=>.
4122 What follows are the NEW set commands. The command ``help set'' will
4123 print a complete list of old and new set commands. ``help set FOO''
4124 will give a longer description of the variable FOO. ``show'' will show
4125 all of the variable descriptions and their current settings.
4127 confirm on/off: Enables warning questions for operations that are
4128 hard to recover from, e.g. rerunning the program while
4129 it is already running. Default is ON.
4131 editing on/off: Enables EMACS style command line editing
4132 of input. Previous lines can be recalled with
4133 control-P, the current line can be edited with control-B,
4134 you can search for commands with control-R, etc.
4137 history filename NAME: NAME is where the gdb command history
4138 will be stored. The default is .gdb_history,
4139 or the value of the environment variable
4142 history size N: The size, in commands, of the command history. The
4143 default is 256, or the value of the environment variable
4146 history save on/off: If this value is set to ON, the history file will
4147 be saved after exiting gdb. If set to OFF, the
4148 file will not be saved. The default is OFF.
4150 history expansion on/off: If this value is set to ON, then csh-like
4151 history expansion will be performed on
4152 command line input. The default is OFF.
4154 radix N: Sets the default radix for input and output. It can be set
4155 to 8, 10, or 16. Note that the argument to "radix" is interpreted
4156 in the current radix, so "set radix 10" is always a no-op.
4158 height N: This integer value is the number of lines on a page. Default
4159 is 24, the current `stty rows'' setting, or the ``li#''
4160 setting from the termcap entry matching the environment
4163 width N: This integer value is the number of characters on a line.
4164 Default is 80, the current `stty cols'' setting, or the ``co#''
4165 setting from the termcap entry matching the environment
4168 Note: ``set screensize'' is obsolete. Use ``set height'' and
4169 ``set width'' instead.
4171 print address on/off: Print memory addresses in various command displays,
4172 such as stack traces and structure values. Gdb looks
4173 more ``symbolic'' if you turn this off; it looks more
4174 ``machine level'' with it on. Default is ON.
4176 print array on/off: Prettyprint arrays. New convenient format! Default
4179 print demangle on/off: Print C++ symbols in "source" form if on,
4182 print asm-demangle on/off: Same, for assembler level printouts
4185 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
4188 * Support for Epoch Environment.
4190 The epoch environment is a version of Emacs v18 with windowing. One
4191 new command, ``inspect'', is identical to ``print'', except that if you
4192 are running in the epoch environment, the value is printed in its own
4196 * Support for Shared Libraries
4198 GDB can now debug programs and core files that use SunOS shared libraries.
4199 Symbols from a shared library cannot be referenced
4200 before the shared library has been linked with the program (this
4201 happens after you type ``run'' and before the function main() is entered).
4202 At any time after this linking (including when examining core files
4203 from dynamically linked programs), gdb reads the symbols from each
4204 shared library when you type the ``sharedlibrary'' command.
4205 It can be abbreviated ``share''.
4207 sharedlibrary REGEXP: Load shared object library symbols for files
4208 matching a unix regular expression. No argument
4209 indicates to load symbols for all shared libraries.
4211 info sharedlibrary: Status of loaded shared libraries.
4216 A watchpoint stops execution of a program whenever the value of an
4217 expression changes. Checking for this slows down execution
4218 tremendously whenever you are in the scope of the expression, but is
4219 quite useful for catching tough ``bit-spreader'' or pointer misuse
4220 problems. Some machines such as the 386 have hardware for doing this
4221 more quickly, and future versions of gdb will use this hardware.
4223 watch EXP: Set a watchpoint (breakpoint) for an expression.
4225 info watchpoints: Information about your watchpoints.
4227 delete N: Deletes watchpoint number N (same as breakpoints).
4228 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
4229 enable N: Re-enables watchpoint number N (same as breakpoints).
4232 * C++ multiple inheritance
4234 When used with a GCC version 2 compiler, GDB supports multiple inheritance
4237 * C++ exception handling
4239 Gdb now supports limited C++ exception handling. Besides the existing
4240 ability to breakpoint on an exception handler, gdb can breakpoint on
4241 the raising of an exception (before the stack is peeled back to the
4244 catch FOO: If there is a FOO exception handler in the dynamic scope,
4245 set a breakpoint to catch exceptions which may be raised there.
4246 Multiple exceptions (``catch foo bar baz'') may be caught.
4248 info catch: Lists all exceptions which may be caught in the
4249 current stack frame.
4252 * Minor command changes
4254 The command ``call func (arg, arg, ...)'' now acts like the print
4255 command, except it does not print or save a value if the function's result
4256 is void. This is similar to dbx usage.
4258 The ``up'' and ``down'' commands now always print the frame they end up
4259 at; ``up-silently'' and `down-silently'' can be used in scripts to change
4260 frames without printing.
4262 * New directory command
4264 'dir' now adds directories to the FRONT of the source search path.
4265 The path starts off empty. Source files that contain debug information
4266 about the directory in which they were compiled can be found even
4267 with an empty path; Sun CC and GCC include this information. If GDB can't
4268 find your source file in the current directory, type "dir .".
4270 * Configuring GDB for compilation
4272 For normal use, type ``./configure host''. See README or gdb.texinfo
4275 GDB now handles cross debugging. If you are remotely debugging between
4276 two different machines, type ``./configure host -target=targ''.
4277 Host is the machine where GDB will run; targ is the machine
4278 where the program that you are debugging will run.