1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.12
6 * GDB now supports access to the PKU register on GNU/Linux. The register is
7 added by the Memory Protection Keys for Userspace feature which will be
8 available in future Intel CPUs.
12 ** New functions to start, stop and access a running btrace recording.
14 * GDB now supports recording and replaying rdrand and rdseed Intel 64
17 * Building GDB and GDBserver now requires a C++11 compiler.
19 For example, GCC 4.8 or later.
21 It is no longer possible to build GDB or GDBserver with a C
22 compiler. The --disable-build-with-cxx configure option has been
25 * Building GDB and GDBserver now requires GNU make >= 3.81.
27 It is no longer supported to build GDB or GDBserver with another
28 implementation of the make program or an earlier version of GNU make.
30 * Native debugging on MS-Windows supports command-line redirection
32 Command-line arguments used for starting programs on MS-Windows can
33 now include redirection symbols supported by native Windows shells,
34 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
35 as "run", "start", and "set args", as well as the corresponding MI
38 * Support for thread names on MS-Windows.
40 GDB now catches and handles the special exception that programs
41 running on MS-Windows use to assign names to threads in the
44 * Support for Java programs compiled with gcj has been removed.
46 * User commands now accept an unlimited number of arguments.
47 Previously, only up to 10 was accepted.
49 * The "eval" command now expands user-defined command arguments.
51 This makes it easier to process a variable number of arguments:
56 eval "print $arg%d", $i
61 * Target descriptions can now describe registers for sparc32 and sparc64.
63 * GDB now supports DWARF version 5 (debug information format).
64 Its .debug_names index is not yet supported.
66 * New native configurations
68 FreeBSD/mips mips*-*-freebsd
73 Synopsys ARC arc*-*-elf32
74 FreeBSD/mips mips*-*-freebsd
79 Erases all the flash memory regions reported by the target.
84 Erases all the flash memory regions reported by the target. This is
85 equivalent to the CLI command flash-erase.
89 set disassembler-options
90 show disassembler-options
91 Controls the passing of target specific information to the disassembler.
92 If it is necessary to specify more than one disassembler option then
93 multiple options can be placed together into a comma separated list.
94 The default value is the empty string. Currently, the only supported
95 targets are ARM, PowerPC and S/390.
97 *** Changes in GDB 7.12
99 * GDB and GDBserver now build with a C++ compiler by default.
101 The --enable-build-with-cxx configure option is now enabled by
102 default. One must now explicitly configure with
103 --disable-build-with-cxx in order to build with a C compiler. This
104 option will be removed in a future release.
106 * GDBserver now supports recording btrace without maintaining an active
109 * GDB now supports a negative repeat count in the 'x' command to examine
110 memory backward from the given address. For example:
113 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
114 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
115 (gdb) x/-5i 0x0000000000400580
116 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
117 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
118 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
119 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
120 0x40057b <main(int, char**)+25>:
121 callq 0x400536 <Func1(int, char const*)>
123 * Fortran: Support structures with fields of dynamic types and
124 arrays of dynamic types.
126 * The symbol dumping maintenance commands have new syntax.
127 maint print symbols [-pc address] [--] [filename]
128 maint print symbols [-objfile objfile] [-source source] [--] [filename]
129 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
130 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
131 maint print msymbols [-objfile objfile] [--] [filename]
133 * GDB now supports multibit bitfields and enums in target register
136 * New Python-based convenience function $_as_string(val), which returns
137 the textual representation of a value. This function is especially
138 useful to obtain the text label of an enum value.
140 * Intel MPX bound violation handling.
142 Segmentation faults caused by a Intel MPX boundary violation
143 now display the kind of violation (upper or lower), the memory
144 address accessed and the memory bounds, along with the usual
145 signal received and code location.
149 Program received signal SIGSEGV, Segmentation fault
150 Upper bound violation while accessing address 0x7fffffffc3b3
151 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
152 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
154 * Rust language support.
155 GDB now supports debugging programs written in the Rust programming
156 language. See https://www.rust-lang.org/ for more information about
159 * Support for running interpreters on specified input/output devices
161 GDB now supports a new mechanism that allows frontends to provide
162 fully featured GDB console views, as a better alternative to
163 building such views on top of the "-interpreter-exec console"
164 command. See the new "new-ui" command below. With that command,
165 frontends can now start GDB in the traditional command-line mode
166 running in an embedded terminal emulator widget, and create a
167 separate MI interpreter running on a specified i/o device. In this
168 way, GDB handles line editing, history, tab completion, etc. in the
169 console all by itself, and the GUI uses the separate MI interpreter
170 for its own control and synchronization, invisible to the command
173 * The "catch syscall" command catches groups of related syscalls.
175 The "catch syscall" command now supports catching a group of related
176 syscalls using the 'group:' or 'g:' prefix.
181 skip -gfile file-glob-pattern
182 skip -function function
183 skip -rfunction regular-expression
184 A generalized form of the skip command, with new support for
185 glob-style file names and regular expressions for function names.
186 Additionally, a file spec and a function spec may now be combined.
188 maint info line-table REGEXP
189 Display the contents of GDB's internal line table data struture.
192 Run any GDB unit tests that were compiled in.
195 Start a new user interface instance running INTERP as interpreter,
196 using the TTY file for input/output.
200 ** gdb.Breakpoint objects have a new attribute "pending", which
201 indicates whether the breakpoint is pending.
202 ** Three new breakpoint-related events have been added:
203 gdb.breakpoint_created, gdb.breakpoint_modified, and
204 gdb.breakpoint_deleted.
207 Signal ("set") the given MS-Windows event object. This is used in
208 conjunction with the Windows JIT debugging (AeDebug) support, where
209 the OS suspends a crashing process until a debugger can attach to
210 it. Resuming the crashing process, in order to debug it, is done by
213 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
214 was added in GDBserver, including JIT compiling fast tracepoint's
215 conditional expression bytecode into native code.
217 * Support for various remote target protocols and ROM monitors has
220 target m32rsdi Remote M32R debugging over SDI
221 target mips MIPS remote debugging protocol
222 target pmon PMON ROM monitor
223 target ddb NEC's DDB variant of PMON for Vr4300
224 target rockhopper NEC RockHopper variant of PMON
225 target lsi LSI variant of PMO
227 * Support for tracepoints and fast tracepoints on powerpc-linux,
228 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
229 including JIT compiling fast tracepoint's conditional expression
230 bytecode into native code.
232 * MI async record =record-started now includes the method and format used for
233 recording. For example:
235 =record-started,thread-group="i1",method="btrace",format="bts"
237 * MI async record =thread-selected now includes the frame field. For example:
239 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
243 Andes NDS32 nds32*-*-elf
245 *** Changes in GDB 7.11
247 * GDB now supports debugging kernel-based threads on FreeBSD.
249 * Per-inferior thread numbers
251 Thread numbers are now per inferior instead of global. If you're
252 debugging multiple inferiors, GDB displays thread IDs using a
253 qualified INF_NUM.THR_NUM form. For example:
257 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
258 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
259 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
260 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
262 As consequence, thread numbers as visible in the $_thread
263 convenience variable and in Python's InferiorThread.num attribute
264 are no longer unique between inferiors.
266 GDB now maintains a second thread ID per thread, referred to as the
267 global thread ID, which is the new equivalent of thread numbers in
268 previous releases. See also $_gthread below.
270 For backwards compatibility, MI's thread IDs always refer to global
273 * Commands that accept thread IDs now accept the qualified
274 INF_NUM.THR_NUM form as well. For example:
277 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
280 * In commands that accept a list of thread IDs, you can now refer to
281 all threads of an inferior using a star wildcard. GDB accepts
282 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
283 refer to all threads of the current inferior. For example, "info
286 * You can use "info threads -gid" to display the global thread ID of
289 * The new convenience variable $_gthread holds the global number of
292 * The new convenience variable $_inferior holds the number of the
295 * GDB now displays the ID and name of the thread that hit a breakpoint
296 or received a signal, if your program is multi-threaded. For
299 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
300 Thread 1 "main" received signal SIGINT, Interrupt.
302 * Record btrace now supports non-stop mode.
304 * Support for tracepoints on aarch64-linux was added in GDBserver.
306 * The 'record instruction-history' command now indicates speculative execution
307 when using the Intel Processor Trace recording format.
309 * GDB now allows users to specify explicit locations, bypassing
310 the linespec parser. This feature is also available to GDB/MI
313 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
314 GDB now is able to debug both AArch64 applications and ARM applications
317 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
318 including JIT compiling fast tracepoint's conditional expression bytecode
321 * GDB now supports displaced stepping on AArch64 GNU/Linux.
323 * "info threads", "info inferiors", "info display", "info checkpoints"
324 and "maint info program-spaces" now list the corresponding items in
325 ascending ID order, for consistency with all other "info" commands.
327 * In Ada, the overloads selection menu has been enhanced to display the
328 parameter types and the return types for the matching overloaded subprograms.
332 maint set target-non-stop (on|off|auto)
333 maint show target-non-stop
334 Control whether GDB targets always operate in non-stop mode even if
335 "set non-stop" is "off". The default is "auto", meaning non-stop
336 mode is enabled if supported by the target.
338 maint set bfd-sharing
339 maint show bfd-sharing
340 Control the reuse of bfd objects.
344 Control display of debugging info regarding bfd caching.
348 Control display of debugging info regarding FreeBSD threads.
350 set remote multiprocess-extensions-packet
351 show remote multiprocess-extensions-packet
352 Set/show the use of the remote protocol multiprocess extensions.
354 set remote thread-events
355 show remote thread-events
356 Set/show the use of thread create/exit events.
358 set ada print-signatures on|off
359 show ada print-signatures"
360 Control whether parameter types and return types are displayed in overloads
361 selection menus. It is activaled (@code{on}) by default.
365 Controls the maximum size of memory, in bytes, that GDB will
366 allocate for value contents. Prevents incorrect programs from
367 causing GDB to allocate overly large buffers. Default is 64k.
369 * The "disassemble" command accepts a new modifier: /s.
370 It prints mixed source+disassembly like /m with two differences:
371 - disassembled instructions are now printed in program order, and
372 - and source for all relevant files is now printed.
373 The "/m" option is now considered deprecated: its "source-centric"
374 output hasn't proved useful in practice.
376 * The "record instruction-history" command accepts a new modifier: /s.
377 It behaves exactly like /m and prints mixed source+disassembly.
379 * The "set scheduler-locking" command supports a new mode "replay".
380 It behaves like "off" in record mode and like "on" in replay mode.
382 * Support for various ROM monitors has been removed:
384 target dbug dBUG ROM monitor for Motorola ColdFire
385 target picobug Motorola picobug monitor
386 target dink32 DINK32 ROM monitor for PowerPC
387 target m32r Renesas M32R/D ROM monitor
388 target mon2000 mon2000 ROM monitor
389 target ppcbug PPCBUG ROM monitor for PowerPC
391 * Support for reading/writing memory and extracting values on architectures
392 whose memory is addressable in units of any integral multiple of 8 bits.
397 Indicates that an exec system call was executed.
399 exec-events feature in qSupported
400 The qSupported packet allows GDB to request support for exec
401 events using the new 'gdbfeature' exec-event, and the qSupported
402 response can contain the corresponding 'stubfeature'. Set and
403 show commands can be used to display whether these features are enabled.
406 Equivalent to interrupting with the ^C character, but works in
409 thread created stop reason (T05 create:...)
410 Indicates that the thread was just created and is stopped at entry.
412 thread exit stop reply (w exitcode;tid)
413 Indicates that the thread has terminated.
416 Enables/disables thread create and exit event reporting. For
417 example, this is used in non-stop mode when GDB stops a set of
418 threads and synchronously waits for the their corresponding stop
419 replies. Without exit events, if one of the threads exits, GDB
420 would hang forever not knowing that it should no longer expect a
421 stop for that same thread.
424 Indicates that there are no resumed threads left in the target (all
425 threads are stopped). The remote stub reports support for this stop
426 reply to GDB's qSupported query.
429 Enables/disables catching syscalls from the inferior process.
430 The remote stub reports support for this packet to GDB's qSupported query.
432 syscall_entry stop reason
433 Indicates that a syscall was just called.
435 syscall_return stop reason
436 Indicates that a syscall just returned.
438 * Extended-remote exec events
440 ** GDB now has support for exec events on extended-remote Linux targets.
441 For such targets with Linux kernels 2.5.46 and later, this enables
442 follow-exec-mode and exec catchpoints.
444 set remote exec-event-feature-packet
445 show remote exec-event-feature-packet
446 Set/show the use of the remote exec event feature.
448 * Thread names in remote protocol
450 The reply to qXfer:threads:read may now include a name attribute for each
453 * Target remote mode fork and exec events
455 ** GDB now has support for fork and exec events on target remote mode
456 Linux targets. For such targets with Linux kernels 2.5.46 and later,
457 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
458 fork and exec catchpoints.
460 * Remote syscall events
462 ** GDB now has support for catch syscall on remote Linux targets,
463 currently enabled on x86/x86_64 architectures.
465 set remote catch-syscall-packet
466 show remote catch-syscall-packet
467 Set/show the use of the remote catch syscall feature.
471 ** The -var-set-format command now accepts the zero-hexadecimal
472 format. It outputs data in hexadecimal format with zero-padding on the
477 ** gdb.InferiorThread objects have a new attribute "global_num",
478 which refers to the thread's global thread ID. The existing
479 "num" attribute now refers to the thread's per-inferior number.
480 See "Per-inferior thread numbers" above.
481 ** gdb.InferiorThread objects have a new attribute "inferior", which
482 is the Inferior object the thread belongs to.
484 *** Changes in GDB 7.10
486 * Support for process record-replay and reverse debugging on aarch64*-linux*
487 targets has been added. GDB now supports recording of A64 instruction set
488 including advance SIMD instructions.
490 * Support for Sun's version of the "stabs" debug file format has been removed.
492 * GDB now honors the content of the file /proc/PID/coredump_filter
493 (PID is the process ID) on GNU/Linux systems. This file can be used
494 to specify the types of memory mappings that will be included in a
495 corefile. For more information, please refer to the manual page of
496 "core(5)". GDB also has a new command: "set use-coredump-filter
497 on|off". It allows to set whether GDB will read the content of the
498 /proc/PID/coredump_filter file when generating a corefile.
500 * The "info os" command on GNU/Linux can now display information on
502 "info os cpus" Listing of all cpus/cores on the system
504 * GDB has two new commands: "set serial parity odd|even|none" and
505 "show serial parity". These allows to set or show parity for the
508 * The "info source" command now displays the producer string if it was
509 present in the debug info. This typically includes the compiler version
510 and may include things like its command line arguments.
512 * The "info dll", an alias of the "info sharedlibrary" command,
513 is now available on all platforms.
515 * Directory names supplied to the "set sysroot" commands may be
516 prefixed with "target:" to tell GDB to access shared libraries from
517 the target system, be it local or remote. This replaces the prefix
518 "remote:". The default sysroot has been changed from "" to
519 "target:". "remote:" is automatically converted to "target:" for
520 backward compatibility.
522 * The system root specified by "set sysroot" will be prepended to the
523 filename of the main executable (if reported to GDB as absolute by
524 the operating system) when starting processes remotely, and when
525 attaching to already-running local or remote processes.
527 * GDB now supports automatic location and retrieval of executable
528 files from remote targets. Remote debugging can now be initiated
529 using only a "target remote" or "target extended-remote" command
530 (no "set sysroot" or "file" commands are required). See "New remote
533 * The "dump" command now supports verilog hex format.
535 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
537 * On GNU/Linux, GDB and gdbserver are now able to access executable
538 and shared library files without a "set sysroot" command when
539 attaching to processes running in different mount namespaces from
540 the debugger. This makes it possible to attach to processes in
541 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
542 See "New remote packets" below.
544 * The "tui reg" command now provides completion for all of the
545 available register groups, including target specific groups.
547 * The HISTSIZE environment variable is no longer read when determining
548 the size of GDB's command history. GDB now instead reads the dedicated
549 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
550 disables truncation of command history. Non-numeric values of GDBHISTSIZE
555 ** Memory ports can now be unbuffered.
559 ** gdb.Objfile objects have a new attribute "username",
560 which is the name of the objfile as specified by the user,
561 without, for example, resolving symlinks.
562 ** You can now write frame unwinders in Python.
563 ** gdb.Type objects have a new method "optimized_out",
564 returning optimized out gdb.Value instance of this type.
565 ** gdb.Value objects have new methods "reference_value" and
566 "const_value" which return a reference to the value and a
567 "const" version of the value respectively.
571 maint print symbol-cache
572 Print the contents of the symbol cache.
574 maint print symbol-cache-statistics
575 Print statistics of symbol cache usage.
577 maint flush-symbol-cache
578 Flush the contents of the symbol cache.
582 Start branch trace recording using Branch Trace Store (BTS) format.
585 Evaluate expression by using the compiler and print result.
589 Explicit commands for enabling and disabling tui mode.
592 set mpx bound on i386 and amd64
593 Support for bound table investigation on Intel MPX enabled applications.
597 Start branch trace recording using Intel Processor Trace format.
600 Print information about branch tracing internals.
602 maint btrace packet-history
603 Print the raw branch tracing data.
605 maint btrace clear-packet-history
606 Discard the stored raw branch tracing data.
609 Discard all branch tracing data. It will be fetched and processed
610 anew by the next "record" command.
615 Renamed from "set debug dwarf2-die".
617 Renamed from "show debug dwarf2-die".
620 Renamed from "set debug dwarf2-read".
621 show debug dwarf-read
622 Renamed from "show debug dwarf2-read".
624 maint set dwarf always-disassemble
625 Renamed from "maint set dwarf2 always-disassemble".
626 maint show dwarf always-disassemble
627 Renamed from "maint show dwarf2 always-disassemble".
629 maint set dwarf max-cache-age
630 Renamed from "maint set dwarf2 max-cache-age".
631 maint show dwarf max-cache-age
632 Renamed from "maint show dwarf2 max-cache-age".
635 show debug dwarf-line
636 Control display of debugging info regarding DWARF line processing.
640 Set the maximum number of candidates to be considered during
641 completion. The default value is 200. This limit allows GDB
642 to avoid generating large completion lists, the computation of
643 which can cause the debugger to become temporarily unresponsive.
645 set history remove-duplicates
646 show history remove-duplicates
647 Control the removal of duplicate history entries.
649 maint set symbol-cache-size
650 maint show symbol-cache-size
651 Control the size of the symbol cache.
653 set|show record btrace bts buffer-size
654 Set and show the size of the ring buffer used for branch tracing in
656 The obtained size may differ from the requested size. Use "info
657 record" to see the obtained buffer size.
659 set debug linux-namespaces
660 show debug linux-namespaces
661 Control display of debugging info regarding Linux namespaces.
663 set|show record btrace pt buffer-size
664 Set and show the size of the ring buffer used for branch tracing in
665 Intel Processor Trace format.
666 The obtained size may differ from the requested size. Use "info
667 record" to see the obtained buffer size.
669 maint set|show btrace pt skip-pad
670 Set and show whether PAD packets are skipped when computing the
673 * The command 'thread apply all' can now support new option '-ascending'
674 to call its specified command for all threads in ascending order.
676 * Python/Guile scripting
678 ** GDB now supports auto-loading of Python/Guile scripts contained in the
679 special section named `.debug_gdb_scripts'.
683 qXfer:btrace-conf:read
684 Return the branch trace configuration for the current thread.
686 Qbtrace-conf:bts:size
687 Set the requested ring buffer size for branch tracing in BTS format.
690 Enable Intel Procesor Trace-based branch tracing for the current
691 process. The remote stub reports support for this packet to GDB's
695 Set the requested ring buffer size for branch tracing in Intel Processor
699 Indicates a memory breakpoint instruction was executed, irrespective
700 of whether it was GDB that planted the breakpoint or the breakpoint
701 is hardcoded in the program. This is required for correct non-stop
705 Indicates the target stopped for a hardware breakpoint. This is
706 required for correct non-stop mode operation.
709 Return information about files on the remote system.
712 Return the full absolute name of the file that was executed to
713 create a process running on the remote system.
716 Select the filesystem on which vFile: operations with filename
717 arguments will operate. This is required for GDB to be able to
718 access files on remote targets where the remote stub does not
719 share a common filesystem with the inferior(s).
722 Indicates that a fork system call was executed.
725 Indicates that a vfork system call was executed.
727 vforkdone stop reason
728 Indicates that a vfork child of the specified process has executed
729 an exec or exit, allowing the vfork parent to resume execution.
731 fork-events and vfork-events features in qSupported
732 The qSupported packet allows GDB to request support for fork and
733 vfork events using new 'gdbfeatures' fork-events and vfork-events,
734 and the qSupported response can contain the corresponding
735 'stubfeatures'. Set and show commands can be used to display
736 whether these features are enabled.
738 * Extended-remote fork events
740 ** GDB now has support for fork events on extended-remote Linux
741 targets. For targets with Linux kernels 2.5.60 and later, this
742 enables follow-fork-mode and detach-on-fork for both fork and
743 vfork, as well as fork and vfork catchpoints.
745 * The info record command now shows the recording format and the
746 branch tracing configuration for the current thread when using
747 the btrace record target.
748 For the BTS format, it shows the ring buffer size.
750 * GDB now has support for DTrace USDT (Userland Static Defined
751 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
753 * GDB now supports access to vector registers on S/390 GNU/Linux
756 * Removed command line options
758 -xdb HP-UX XDB compatibility mode.
760 * Removed targets and native configurations
762 HP/PA running HP-UX hppa*-*-hpux*
763 Itanium running HP-UX ia64-*-hpux*
765 * New configure options
768 This configure option allows the user to build GDB with support for
769 Intel Processor Trace (default: auto). This requires libipt.
771 --with-libipt-prefix=PATH
772 Specify the path to the version of libipt that GDB should use.
773 $PATH/include should contain the intel-pt.h header and
774 $PATH/lib should contain the libipt.so library.
776 *** Changes in GDB 7.9.1
780 ** Xmethods can now specify a result type.
782 *** Changes in GDB 7.9
784 * GDB now supports hardware watchpoints on x86 GNU Hurd.
788 ** You can now access frame registers from Python scripts.
789 ** New attribute 'producer' for gdb.Symtab objects.
790 ** gdb.Objfile objects have a new attribute "progspace",
791 which is the gdb.Progspace object of the containing program space.
792 ** gdb.Objfile objects have a new attribute "owner".
793 ** gdb.Objfile objects have a new attribute "build_id",
794 which is the build ID generated when the file was built.
795 ** gdb.Objfile objects have a new method "add_separate_debug_file".
796 ** A new event "gdb.clear_objfiles" has been added, triggered when
797 selecting a new file to debug.
798 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
799 ** New function gdb.lookup_objfile.
801 New events which are triggered when GDB modifies the state of the
804 ** gdb.events.inferior_call_pre: Function call is about to be made.
805 ** gdb.events.inferior_call_post: Function call has just been made.
806 ** gdb.events.memory_changed: A memory location has been altered.
807 ** gdb.events.register_changed: A register has been altered.
809 * New Python-based convenience functions:
811 ** $_caller_is(name [, number_of_frames])
812 ** $_caller_matches(regexp [, number_of_frames])
813 ** $_any_caller_is(name [, number_of_frames])
814 ** $_any_caller_matches(regexp [, number_of_frames])
816 * GDB now supports the compilation and injection of source code into
817 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
818 to compile the source code to object code, and if successful, inject
819 and execute that code within the current context of the inferior.
820 Currently the C language is supported. The commands used to
821 interface with this new feature are:
823 compile code [-raw|-r] [--] [source code]
824 compile file [-raw|-r] filename
828 demangle [-l language] [--] name
829 Demangle "name" in the specified language, or the current language
830 if elided. This command is renamed from the "maint demangle" command.
831 The latter is kept as a no-op to avoid "maint demangle" being interpreted
832 as "maint demangler-warning".
834 queue-signal signal-name-or-number
835 Queue a signal to be delivered to the thread when it is resumed.
837 add-auto-load-scripts-directory directory
838 Add entries to the list of directories from which to load auto-loaded
841 maint print user-registers
842 List all currently available "user" registers.
844 compile code [-r|-raw] [--] [source code]
845 Compile, inject, and execute in the inferior the executable object
846 code produced by compiling the provided source code.
848 compile file [-r|-raw] filename
849 Compile and inject into the inferior the executable object code
850 produced by compiling the source code stored in the filename
853 * On resume, GDB now always passes the signal the program had stopped
854 for to the thread the signal was sent to, even if the user changed
855 threads before resuming. Previously GDB would often (but not
856 always) deliver the signal to the thread that happens to be current
859 * Conversely, the "signal" command now consistently delivers the
860 requested signal to the current thread. GDB now asks for
861 confirmation if the program had stopped for a signal and the user
862 switched threads meanwhile.
864 * "breakpoint always-inserted" modes "off" and "auto" merged.
866 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
867 won't remove breakpoints from the target until all threads stop,
868 even in non-stop mode. The "auto" mode has been removed, and "off"
869 is now the default mode.
873 set debug symbol-lookup
874 show debug symbol-lookup
875 Control display of debugging info regarding symbol lookup.
879 ** The -list-thread-groups command outputs an exit-code field for
880 inferiors that have exited.
884 MIPS SDE mips*-sde*-elf*
888 Support for these obsolete configurations has been removed.
890 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
891 SGI Irix-5.x mips-*-irix5*
892 SGI Irix-6.x mips-*-irix6*
893 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
894 VAX running Ultrix vax-*-ultrix*
896 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
897 and "assf"), have been removed. Use the "sharedlibrary" command, or
898 its alias "share", instead.
900 *** Changes in GDB 7.8
902 * New command line options
905 This is an alias for the --data-directory option.
907 * GDB supports printing and modifying of variable length automatic arrays
908 as specified in ISO C99.
910 * The ARM simulator now supports instruction level tracing
911 with or without disassembly.
915 GDB now has support for scripting using Guile. Whether this is
916 available is determined at configure time.
917 Guile version 2.0 or greater is required.
918 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
920 * New commands (for set/show, see "New options" below)
924 Invoke CODE by passing it to the Guile interpreter.
928 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
930 info auto-load guile-scripts [regexp]
931 Print the list of automatically loaded Guile scripts.
933 * The source command is now capable of sourcing Guile scripts.
934 This feature is dependent on the debugger being built with Guile support.
938 set print symbol-loading (off|brief|full)
939 show print symbol-loading
940 Control whether to print informational messages when loading symbol
941 information for a file. The default is "full", but when debugging
942 programs with large numbers of shared libraries the amount of output
945 set guile print-stack (none|message|full)
946 show guile print-stack
947 Show a stack trace when an error is encountered in a Guile script.
949 set auto-load guile-scripts (on|off)
950 show auto-load guile-scripts
951 Control auto-loading of Guile script files.
953 maint ada set ignore-descriptive-types (on|off)
954 maint ada show ignore-descriptive-types
955 Control whether the debugger should ignore descriptive types in Ada
956 programs. The default is not to ignore the descriptive types. See
957 the user manual for more details on descriptive types and the intended
958 usage of this option.
960 set auto-connect-native-target
962 Control whether GDB is allowed to automatically connect to the
963 native target for the run, attach, etc. commands when not connected
964 to any target yet. See also "target native" below.
966 set record btrace replay-memory-access (read-only|read-write)
967 show record btrace replay-memory-access
968 Control what memory accesses are allowed during replay.
970 maint set target-async (on|off)
971 maint show target-async
972 This controls whether GDB targets operate in synchronous or
973 asynchronous mode. Normally the default is asynchronous, if it is
974 available; but this can be changed to more easily debug problems
975 occurring only in synchronous mode.
977 set mi-async (on|off)
979 Control whether MI asynchronous mode is preferred. This supersedes
980 "set target-async" of previous GDB versions.
982 * "set target-async" is deprecated as a CLI option and is now an alias
983 for "set mi-async" (only puts MI into async mode).
985 * Background execution commands (e.g., "c&", "s&", etc.) are now
986 possible ``out of the box'' if the target supports them. Previously
987 the user would need to explicitly enable the possibility with the
988 "set target-async on" command.
990 * New features in the GDB remote stub, GDBserver
992 ** New option --debug-format=option1[,option2,...] allows one to add
993 additional text to each output. At present only timestamps
994 are supported: --debug-format=timestamps.
995 Timestamps can also be turned on with the
996 "monitor set debug-format timestamps" command from GDB.
998 * The 'record instruction-history' command now starts counting instructions
999 at one. This also affects the instruction ranges reported by the
1000 'record function-call-history' command when given the /i modifier.
1002 * The command 'record function-call-history' supports a new modifier '/c' to
1003 indent the function names based on their call stack depth.
1004 The fields for the '/i' and '/l' modifier have been reordered.
1005 The source line range is now prefixed with 'at'.
1006 The instruction range is now prefixed with 'inst'.
1007 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1008 "record instruction-history" and "list" commands.
1010 * The ranges given as arguments to the 'record function-call-history' and
1011 'record instruction-history' commands are now inclusive.
1013 * The btrace record target now supports the 'record goto' command.
1014 For locations inside the execution trace, the back trace is computed
1015 based on the information stored in the execution trace.
1017 * The btrace record target supports limited reverse execution and replay.
1018 The target does not record data and therefore does not allow reading
1019 memory or registers.
1021 * The "catch syscall" command now works on s390*-linux* targets.
1023 * The "compare-sections" command is no longer specific to target
1024 remote. It now works with all targets.
1026 * All native targets are now consistently called "native".
1027 Consequently, the "target child", "target GNU", "target djgpp",
1028 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1029 commands have been replaced with "target native". The QNX/NTO port
1030 leaves the "procfs" target in place and adds a "native" target for
1031 consistency with other ports. The impact on users should be minimal
1032 as these commands previously either throwed an error, or were
1033 no-ops. The target's name is visible in the output of the following
1034 commands: "help target", "info target", "info files", "maint print
1037 * The "target native" command now connects to the native target. This
1038 can be used to launch native programs even when "set
1039 auto-connect-native-target" is set to off.
1041 * GDB now supports access to Intel MPX registers on GNU/Linux.
1043 * Support for Intel AVX-512 registers on GNU/Linux.
1044 Support displaying and modifying Intel AVX-512 registers
1045 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1047 * New remote packets
1049 qXfer:btrace:read's annex
1050 The qXfer:btrace:read packet supports a new annex 'delta' to read
1051 branch trace incrementally.
1055 ** Valid Python operations on gdb.Value objects representing
1056 structs/classes invoke the corresponding overloaded operators if
1058 ** New `Xmethods' feature in the Python API. Xmethods are
1059 additional methods or replacements for existing methods of a C++
1060 class. This feature is useful for those cases where a method
1061 defined in C++ source code could be inlined or optimized out by
1062 the compiler, making it unavailable to GDB.
1065 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1067 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1068 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1069 its alias "share", instead.
1071 * The commands "set remotebaud" and "show remotebaud" are no longer
1072 supported. Use "set serial baud" and "show serial baud" (respectively)
1077 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1078 target-async". The latter is left as a deprecated alias of the
1079 former for backward compatibility. If the target supports it,
1080 CLI background execution commands are now always possible by
1081 default, independently of whether the frontend stated a
1082 preference for asynchronous execution with "-gdb-set mi-async".
1083 Previously "-gdb-set target-async off" affected both MI execution
1084 commands and CLI execution commands.
1086 *** Changes in GDB 7.7
1088 * Improved support for process record-replay and reverse debugging on
1089 arm*-linux* targets. Support for thumb32 and syscall instruction
1090 recording has been added.
1092 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1094 * GDB now supports Fission DWP file format version 2.
1095 http://gcc.gnu.org/wiki/DebugFission
1097 * New convenience function "$_isvoid", to check whether an expression
1098 is void. A void expression is an expression where the type of the
1099 result is "void". For example, some convenience variables may be
1100 "void" when evaluated (e.g., "$_exitcode" before the execution of
1101 the program being debugged; or an undefined convenience variable).
1102 Another example, when calling a function whose return type is
1105 * The "maintenance print objfiles" command now takes an optional regexp.
1107 * The "catch syscall" command now works on arm*-linux* targets.
1109 * GDB now consistently shows "<not saved>" when printing values of
1110 registers the debug info indicates have not been saved in the frame
1111 and there's nowhere to retrieve them from
1112 (callee-saved/call-clobbered registers):
1117 (gdb) info registers rax
1120 Before, the former would print "<optimized out>", and the latter
1121 "*value not available*".
1123 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1128 ** Frame filters and frame decorators have been added.
1129 ** Temporary breakpoints are now supported.
1130 ** Line tables representation has been added.
1131 ** New attribute 'parent_type' for gdb.Field objects.
1132 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1133 ** New attribute 'name' for gdb.Type objects.
1137 Nios II ELF nios2*-*-elf
1138 Nios II GNU/Linux nios2*-*-linux
1139 Texas Instruments MSP430 msp430*-*-elf
1141 * Removed native configurations
1143 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1144 been removed. ELF variants of these configurations are kept supported.
1146 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1147 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1148 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1149 i[34567]86-*-openbsd3.[0-3]
1150 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1151 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1152 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1156 Like "catch throw", but catches a re-thrown exception.
1157 maint check-psymtabs
1158 Renamed from old "maint check-symtabs".
1160 Perform consistency checks on symtabs.
1161 maint expand-symtabs
1162 Expand symtabs matching an optional regexp.
1165 Display the details of GDB configure-time options.
1167 maint set|show per-command
1168 maint set|show per-command space
1169 maint set|show per-command time
1170 maint set|show per-command symtab
1171 Enable display of per-command gdb resource usage.
1173 remove-symbol-file FILENAME
1174 remove-symbol-file -a ADDRESS
1175 Remove a symbol file added via add-symbol-file. The file to remove
1176 can be identified by its filename or by an address that lies within
1177 the boundaries of this symbol file in memory.
1180 info exceptions REGEXP
1181 Display the list of Ada exceptions defined in the program being
1182 debugged. If provided, only the exceptions whose names match REGEXP
1187 set debug symfile off|on
1189 Control display of debugging info regarding reading symbol files and
1190 symbol tables within those files
1192 set print raw frame-arguments
1193 show print raw frame-arguments
1194 Set/show whether to print frame arguments in raw mode,
1195 disregarding any defined pretty-printers.
1197 set remote trace-status-packet
1198 show remote trace-status-packet
1199 Set/show the use of remote protocol qTStatus packet.
1203 Control display of debugging messages related to Nios II targets.
1207 Control whether target-assisted range stepping is enabled.
1209 set startup-with-shell
1210 show startup-with-shell
1211 Specifies whether Unix child processes are started via a shell or
1216 Use the target memory cache for accesses to the code segment. This
1217 improves performance of remote debugging (particularly disassembly).
1219 * You can now use a literal value 'unlimited' for options that
1220 interpret 0 or -1 as meaning "unlimited". E.g., "set
1221 trace-buffer-size unlimited" is now an alias for "set
1222 trace-buffer-size -1" and "set height unlimited" is now an alias for
1225 * The "set debug symtab-create" debugging option of GDB has been changed to
1226 accept a verbosity level. 0 means "off", 1 provides basic debugging
1227 output, and values of 2 or greater provides more verbose output.
1229 * New command-line options
1231 Display the details of GDB configure-time options.
1233 * The command 'tsave' can now support new option '-ctf' to save trace
1234 buffer in Common Trace Format.
1236 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1239 * GDB now implements the the C++ 'typeid' operator.
1241 * The new convenience variable $_exception holds the exception being
1242 thrown or caught at an exception-related catchpoint.
1244 * The exception-related catchpoints, like "catch throw", now accept a
1245 regular expression which can be used to filter exceptions by type.
1247 * The new convenience variable $_exitsignal is automatically set to
1248 the terminating signal number when the program being debugged dies
1249 due to an uncaught signal.
1253 ** All MI commands now accept an optional "--language" option.
1254 Support for this feature can be verified by using the "-list-features"
1255 command, which should contain "language-option".
1257 ** The new command -info-gdb-mi-command allows the user to determine
1258 whether a GDB/MI command is supported or not.
1260 ** The "^error" result record returned when trying to execute an undefined
1261 GDB/MI command now provides a variable named "code" whose content is the
1262 "undefined-command" error code. Support for this feature can be verified
1263 by using the "-list-features" command, which should contain
1264 "undefined-command-error-code".
1266 ** The -trace-save MI command can optionally save trace buffer in Common
1269 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1271 ** The command -data-list-register-values now accepts an optional
1272 "--skip-unavailable" option. When used, only the available registers
1275 ** The new command -trace-frame-collected dumps collected variables,
1276 computed expressions, tvars, memory and registers in a traceframe.
1278 ** The commands -stack-list-locals, -stack-list-arguments and
1279 -stack-list-variables now accept an option "--skip-unavailable".
1280 When used, only the available locals or arguments are displayed.
1282 ** The -exec-run command now accepts an optional "--start" option.
1283 When used, the command follows the same semantics as the "start"
1284 command, stopping the program's execution at the start of its
1285 main subprogram. Support for this feature can be verified using
1286 the "-list-features" command, which should contain
1287 "exec-run-start-option".
1289 ** The new commands -catch-assert and -catch-exceptions insert
1290 catchpoints stopping the program when Ada exceptions are raised.
1292 ** The new command -info-ada-exceptions provides the equivalent of
1293 the new "info exceptions" command.
1295 * New system-wide configuration scripts
1296 A GDB installation now provides scripts suitable for use as system-wide
1297 configuration scripts for the following systems:
1301 * GDB now supports target-assigned range stepping with remote targets.
1302 This improves the performance of stepping source lines by reducing
1303 the number of control packets from/to GDB. See "New remote packets"
1306 * GDB now understands the element 'tvar' in the XML traceframe info.
1307 It has the id of the collected trace state variables.
1309 * On S/390 targets that provide the transactional-execution feature,
1310 the program interruption transaction diagnostic block (TDB) is now
1311 represented as a number of additional "registers" in GDB.
1313 * New remote packets
1317 The vCont packet supports a new 'r' action, that tells the remote
1318 stub to step through an address range itself, without GDB
1319 involvemement at each single-step.
1321 qXfer:libraries-svr4:read's annex
1322 The previously unused annex of the qXfer:libraries-svr4:read packet
1323 is now used to support passing an argument list. The remote stub
1324 reports support for this argument list to GDB's qSupported query.
1325 The defined arguments are "start" and "prev", used to reduce work
1326 necessary for library list updating, resulting in significant
1329 * New features in the GDB remote stub, GDBserver
1331 ** GDBserver now supports target-assisted range stepping. Currently
1332 enabled on x86/x86_64 GNU/Linux targets.
1334 ** GDBserver now adds element 'tvar' in the XML in the reply to
1335 'qXfer:traceframe-info:read'. It has the id of the collected
1336 trace state variables.
1338 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1341 * New 'z' formatter for printing and examining memory, this displays the
1342 value as hexadecimal zero padded on the left to the size of the type.
1344 * GDB can now use Windows x64 unwinding data.
1346 * The "set remotebaud" command has been replaced by "set serial baud".
1347 Similarly, "show remotebaud" has been replaced by "show serial baud".
1348 The "set remotebaud" and "show remotebaud" commands are still available
1349 to provide backward compatibility with older versions of GDB.
1351 *** Changes in GDB 7.6
1353 * Target record has been renamed to record-full.
1354 Record/replay is now enabled with the "record full" command.
1355 This also affects settings that are associated with full record/replay
1356 that have been moved from "set/show record" to "set/show record full":
1358 set|show record full insn-number-max
1359 set|show record full stop-at-limit
1360 set|show record full memory-query
1362 * A new record target "record-btrace" has been added. The new target
1363 uses hardware support to record the control-flow of a process. It
1364 does not support replaying the execution, but it implements the
1365 below new commands for investigating the recorded execution log.
1366 This new recording method can be enabled using:
1370 The "record-btrace" target is only available on Intel Atom processors
1371 and requires a Linux kernel 2.6.32 or later.
1373 * Two new commands have been added for record/replay to give information
1374 about the recorded execution without having to replay the execution.
1375 The commands are only supported by "record btrace".
1377 record instruction-history prints the execution history at
1378 instruction granularity
1380 record function-call-history prints the execution history at
1381 function granularity
1383 * New native configurations
1385 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1386 FreeBSD/powerpc powerpc*-*-freebsd
1387 x86_64/Cygwin x86_64-*-cygwin*
1388 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1392 ARM AArch64 aarch64*-*-elf
1393 ARM AArch64 GNU/Linux aarch64*-*-linux
1394 Lynx 178 PowerPC powerpc-*-lynx*178
1395 x86_64/Cygwin x86_64-*-cygwin*
1396 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1398 * If the configured location of system.gdbinit file (as given by the
1399 --with-system-gdbinit option at configure time) is in the
1400 data-directory (as specified by --with-gdb-datadir at configure
1401 time) or in one of its subdirectories, then GDB will look for the
1402 system-wide init file in the directory specified by the
1403 --data-directory command-line option.
1405 * New command line options:
1407 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1408 other initialization files, unlike -nx which disables all of them.
1410 * Removed command line options
1412 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1415 * The 'ptype' and 'whatis' commands now accept an argument to control
1418 * 'info proc' now works on some core files.
1422 ** Vectors can be created with gdb.Type.vector.
1424 ** Python's atexit.register now works in GDB.
1426 ** Types can be pretty-printed via a Python API.
1428 ** Python 3 is now supported (in addition to Python 2.4 or later)
1430 ** New class gdb.Architecture exposes GDB's internal representation
1431 of architecture in the Python API.
1433 ** New method Frame.architecture returns the gdb.Architecture object
1434 corresponding to the frame's architecture.
1436 * New Python-based convenience functions:
1438 ** $_memeq(buf1, buf2, length)
1439 ** $_streq(str1, str2)
1441 ** $_regex(str, regex)
1443 * The 'cd' command now defaults to using '~' (the home directory) if not
1446 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1447 default for GCC since November 2000.
1449 * The command 'forward-search' can now be abbreviated as 'fo'.
1451 * The command 'info tracepoints' can now display 'installed on target'
1452 or 'not installed on target' for each non-pending location of tracepoint.
1454 * New configure options
1456 --enable-libmcheck/--disable-libmcheck
1457 By default, development versions are built with -lmcheck on hosts
1458 that support it, in order to help track memory corruption issues.
1459 Release versions, on the other hand, are built without -lmcheck
1460 by default. The --enable-libmcheck/--disable-libmcheck configure
1461 options allow the user to override that default.
1462 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1463 This configure option allows the user to build GDB with
1464 libbabeltrace using which GDB can read Common Trace Format data.
1466 * New commands (for set/show, see "New options" below)
1469 Catch signals. This is similar to "handle", but allows commands and
1470 conditions to be attached.
1473 List the BFDs known to GDB.
1475 python-interactive [command]
1477 Start a Python interactive prompt, or evaluate the optional command
1478 and print the result of expressions.
1481 "py" is a new alias for "python".
1483 enable type-printer [name]...
1484 disable type-printer [name]...
1485 Enable or disable type printers.
1489 ** For the Renesas Super-H architecture, the "regs" command has been removed
1490 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1495 set print type methods (on|off)
1496 show print type methods
1497 Control whether method declarations are displayed by "ptype".
1498 The default is to show them.
1500 set print type typedefs (on|off)
1501 show print type typedefs
1502 Control whether typedef definitions are displayed by "ptype".
1503 The default is to show them.
1505 set filename-display basename|relative|absolute
1506 show filename-display
1507 Control the way in which filenames is displayed.
1508 The default is "relative", which preserves previous behavior.
1510 set trace-buffer-size
1511 show trace-buffer-size
1512 Request target to change the size of trace buffer.
1514 set remote trace-buffer-size-packet auto|on|off
1515 show remote trace-buffer-size-packet
1516 Control the use of the remote protocol `QTBuffer:size' packet.
1520 Control display of debugging messages related to ARM AArch64.
1523 set debug coff-pe-read
1524 show debug coff-pe-read
1525 Control display of debugging messages related to reading of COFF/PE
1530 Control display of debugging messages related to Mach-O symbols
1533 set debug notification
1534 show debug notification
1535 Control display of debugging info for async remote notification.
1539 ** Command parameter changes are now notified using new async record
1540 "=cmd-param-changed".
1541 ** Trace frame changes caused by command "tfind" are now notified using
1542 new async record "=traceframe-changed".
1543 ** The creation, deletion and modification of trace state variables
1544 are now notified using new async records "=tsv-created",
1545 "=tsv-deleted" and "=tsv-modified".
1546 ** The start and stop of process record are now notified using new
1547 async record "=record-started" and "=record-stopped".
1548 ** Memory changes are now notified using new async record
1550 ** The data-disassemble command response will include a "fullname" field
1551 containing the absolute file name when source has been requested.
1552 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1553 command, to allow pattern filling of memory areas.
1554 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1555 library load/unload events.
1556 ** The response to breakpoint commands and breakpoint async records
1557 includes an "installed" field containing a boolean state about each
1558 non-pending tracepoint location is whether installed on target or not.
1559 ** Output of the "-trace-status" command includes a "trace-file" field
1560 containing the name of the trace file being examined. This field is
1561 optional, and only present when examining a trace file.
1562 ** The "fullname" field is now always present along with the "file" field,
1563 even if the file cannot be found by GDB.
1565 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1566 You must have the LZMA library available when configuring GDB for this
1567 feature to be enabled. For more information, see:
1568 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1570 * New remote packets
1573 Set the size of trace buffer. The remote stub reports support for this
1574 packet to gdb's qSupported query.
1577 Enable Branch Trace Store (BTS)-based branch tracing for the current
1578 thread. The remote stub reports support for this packet to gdb's
1582 Disable branch tracing for the current thread. The remote stub reports
1583 support for this packet to gdb's qSupported query.
1586 Read the traced branches for the current thread. The remote stub
1587 reports support for this packet to gdb's qSupported query.
1589 *** Changes in GDB 7.5
1591 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1592 for more x32 ABI info.
1594 * GDB now supports access to MIPS DSP registers on Linux targets.
1596 * GDB now supports debugging microMIPS binaries.
1598 * The "info os" command on GNU/Linux can now display information on
1599 several new classes of objects managed by the operating system:
1600 "info os procgroups" lists process groups
1601 "info os files" lists file descriptors
1602 "info os sockets" lists internet-domain sockets
1603 "info os shm" lists shared-memory regions
1604 "info os semaphores" lists semaphores
1605 "info os msg" lists message queues
1606 "info os modules" lists loaded kernel modules
1608 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1609 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1610 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1611 options and inspect the probe arguments using the new $_probe_arg family
1612 of convenience variables. You can obtain more information about SystemTap
1613 in <http://sourceware.org/systemtap/>.
1615 * GDB now supports reversible debugging on ARM, it allows you to
1616 debug basic ARM and THUMB instructions, and provides
1617 record/replay support.
1619 * The option "symbol-reloading" has been deleted as it is no longer used.
1623 ** GDB commands implemented in Python can now be put in command class
1626 ** The "maint set python print-stack on|off" is now deleted.
1628 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1629 apply "flag enum"-style pretty-printing to any enum.
1631 ** gdb.lookup_symbol can now work when there is no current frame.
1633 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1634 the source at which the symbol was defined.
1636 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1637 method 'value'. The former indicates whether the symbol needs a
1638 frame in order to compute its value, and the latter computes the
1641 ** A new method 'referenced_value' on gdb.Value objects which can
1642 dereference pointer as well as C++ reference values.
1644 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1645 which return the global and static blocks (as gdb.Block objects),
1646 of the underlying symbol table, respectively.
1648 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1649 object associated with a PC value.
1651 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1652 of the address range occupied by code for the current source line.
1654 * Go language support.
1655 GDB now supports debugging programs written in the Go programming
1658 * GDBserver now supports stdio connections.
1659 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1661 * The binary "gdbtui" can no longer be built or installed.
1662 Use "gdb -tui" instead.
1664 * GDB will now print "flag" enums specially. A flag enum is one where
1665 all the enumerator values have no bits in common when pairwise
1666 "and"ed. When printing a value whose type is a flag enum, GDB will
1667 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1668 (gdb) print (enum E) 3
1671 * The filename part of a linespec will now match trailing components
1672 of a source file name. For example, "break gcc/expr.c:1000" will
1673 now set a breakpoint in build/gcc/expr.c, but not
1674 build/libcpp/expr.c.
1676 * The "info proc" and "generate-core-file" commands will now also
1677 work on remote targets connected to GDBserver on Linux.
1679 * The command "info catch" has been removed. It has been disabled
1680 since December 2007.
1682 * The "catch exception" and "catch assert" commands now accept
1683 a condition at the end of the command, much like the "break"
1684 command does. For instance:
1686 (gdb) catch exception Constraint_Error if Barrier = True
1688 Previously, it was possible to add a condition to such catchpoints,
1689 but it had to be done as a second step, after the catchpoint had been
1690 created, using the "condition" command.
1692 * The "info static-tracepoint-marker" command will now also work on
1693 native Linux targets with in-process agent.
1695 * GDB can now set breakpoints on inlined functions.
1697 * The .gdb_index section has been updated to include symbols for
1698 inlined functions. GDB will ignore older .gdb_index sections by
1699 default, which could cause symbol files to be loaded more slowly
1700 until their .gdb_index sections can be recreated. The new command
1701 "set use-deprecated-index-sections on" will cause GDB to use any older
1702 .gdb_index sections it finds. This will restore performance, but the
1703 ability to set breakpoints on inlined functions will be lost in symbol
1704 files with older .gdb_index sections.
1706 The .gdb_index section has also been updated to record more information
1707 about each symbol. This speeds up the "info variables", "info functions"
1708 and "info types" commands when used with programs having the .gdb_index
1709 section, as well as speeding up debugging with shared libraries using
1710 the .gdb_index section.
1712 * Ada support for GDB/MI Variable Objects has been added.
1714 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1719 ** New command -info-os is the MI equivalent of "info os".
1721 ** Output logs ("set logging" and related) now include MI output.
1725 ** "set use-deprecated-index-sections on|off"
1726 "show use-deprecated-index-sections on|off"
1727 Controls the use of deprecated .gdb_index sections.
1729 ** "catch load" and "catch unload" can be used to stop when a shared
1730 library is loaded or unloaded, respectively.
1732 ** "enable count" can be used to auto-disable a breakpoint after
1735 ** "info vtbl" can be used to show the virtual method tables for
1736 C++ and Java objects.
1738 ** "explore" and its sub commands "explore value" and "explore type"
1739 can be used to recursively explore values and types of
1740 expressions. These commands are available only if GDB is
1741 configured with '--with-python'.
1743 ** "info auto-load" shows status of all kinds of auto-loaded files,
1744 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1745 sequences of commands files, "info auto-load python-scripts"
1746 shows status of auto-loading Python script files,
1747 "info auto-load local-gdbinit" shows status of loading init file
1748 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1749 status of inferior specific thread debugging shared library loading.
1751 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1752 and "show auto-load-scripts" commands have been deprecated, use their
1753 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1754 and "show auto-load python-scripts" counterparts instead.
1756 ** "dprintf location,format,args..." creates a dynamic printf, which
1757 is basically a breakpoint that does a printf and immediately
1758 resumes your program's execution, so it is like a printf that you
1759 can insert dynamically at runtime instead of at compiletime.
1761 ** "set print symbol"
1763 Controls whether GDB attempts to display the symbol, if any,
1764 corresponding to addresses it prints. This defaults to "on", but
1765 you can set it to "off" to restore GDB's previous behavior.
1767 * Deprecated commands
1769 ** For the Renesas Super-H architecture, the "regs" command has been
1770 deprecated, and "info all-registers" should be used instead.
1774 Renesas RL78 rl78-*-elf
1775 HP OpenVMS ia64 ia64-hp-openvms*
1777 * GDBserver supports evaluation of breakpoint conditions. When
1778 support is advertised by GDBserver, GDB may be told to send the
1779 breakpoint conditions in bytecode form to GDBserver. GDBserver
1780 will only report the breakpoint trigger to GDB when its condition
1785 set mips compression
1786 show mips compression
1787 Select the compressed ISA encoding used in functions that have no symbol
1788 information available. The encoding can be set to either of:
1791 and is updated automatically from ELF file flags if available.
1793 set breakpoint condition-evaluation
1794 show breakpoint condition-evaluation
1795 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1796 GDBserver ("target"). Default option "auto" chooses the most efficient
1798 This option can improve debugger efficiency depending on the speed of the
1802 Disable auto-loading globally.
1805 Show auto-loading setting of all kinds of auto-loaded files.
1807 set auto-load gdb-scripts on|off
1808 show auto-load gdb-scripts
1809 Control auto-loading of GDB canned sequences of commands files.
1811 set auto-load python-scripts on|off
1812 show auto-load python-scripts
1813 Control auto-loading of Python script files.
1815 set auto-load local-gdbinit on|off
1816 show auto-load local-gdbinit
1817 Control loading of init file (.gdbinit) from current directory.
1819 set auto-load libthread-db on|off
1820 show auto-load libthread-db
1821 Control auto-loading of inferior specific thread debugging shared library.
1823 set auto-load scripts-directory <dir1>[:<dir2>...]
1824 show auto-load scripts-directory
1825 Set a list of directories from which to load auto-loaded scripts.
1826 Automatically loaded Python scripts and GDB scripts are located in one
1827 of the directories listed by this option.
1828 The delimiter (':' above) may differ according to the host platform.
1830 set auto-load safe-path <dir1>[:<dir2>...]
1831 show auto-load safe-path
1832 Set a list of directories from which it is safe to auto-load files.
1833 The delimiter (':' above) may differ according to the host platform.
1835 set debug auto-load on|off
1836 show debug auto-load
1837 Control display of debugging info for auto-loading the files above.
1839 set dprintf-style gdb|call|agent
1841 Control the way in which a dynamic printf is performed; "gdb"
1842 requests a GDB printf command, while "call" causes dprintf to call a
1843 function in the inferior. "agent" requests that the target agent
1844 (such as GDBserver) do the printing.
1846 set dprintf-function <expr>
1847 show dprintf-function
1848 set dprintf-channel <expr>
1849 show dprintf-channel
1850 Set the function and optional first argument to the call when using
1851 the "call" style of dynamic printf.
1853 set disconnected-dprintf on|off
1854 show disconnected-dprintf
1855 Control whether agent-style dynamic printfs continue to be in effect
1856 after GDB disconnects.
1858 * New configure options
1860 --with-auto-load-dir
1861 Configure default value for the 'set auto-load scripts-directory'
1862 setting above. It defaults to '$debugdir:$datadir/auto-load',
1863 $debugdir representing global debugging info directories (available
1864 via 'show debug-file-directory') and $datadir representing GDB's data
1865 directory (available via 'show data-directory').
1867 --with-auto-load-safe-path
1868 Configure default value for the 'set auto-load safe-path' setting
1869 above. It defaults to the --with-auto-load-dir setting.
1871 --without-auto-load-safe-path
1872 Set 'set auto-load safe-path' to '/', effectively disabling this
1875 * New remote packets
1877 z0/z1 conditional breakpoints extension
1879 The z0/z1 breakpoint insertion packets have been extended to carry
1880 a list of conditional expressions over to the remote stub depending on the
1881 condition evaluation mode. The use of this extension can be controlled
1882 via the "set remote conditional-breakpoints-packet" command.
1886 Specify the signals which the remote stub may pass to the debugged
1887 program without GDB involvement.
1889 * New command line options
1891 --init-command=FILE, -ix Like --command, -x but execute it
1892 before loading inferior.
1893 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1894 execute it before loading inferior.
1896 *** Changes in GDB 7.4
1898 * GDB now handles ambiguous linespecs more consistently; the existing
1899 FILE:LINE support has been expanded to other types of linespecs. A
1900 breakpoint will now be set on all matching locations in all
1901 inferiors, and locations will be added or removed according to
1904 * GDB now allows you to skip uninteresting functions and files when
1905 stepping with the "skip function" and "skip file" commands.
1907 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1908 and "show remote hardware-watchpoint-length-limit". These allows to
1909 set or show the maximum length limit (in bytes) of a remote
1910 target hardware watchpoint.
1912 This allows e.g. to use "unlimited" hardware watchpoints with the
1913 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1914 watchpoints are slower than real hardware watchpoints but are
1915 significantly faster than gdb software watchpoints.
1919 ** The register_pretty_printer function in module gdb.printing now takes
1920 an optional `replace' argument. If True, the new printer replaces any
1923 ** The "maint set python print-stack on|off" command has been
1924 deprecated and will be deleted in GDB 7.5.
1925 A new command: "set python print-stack none|full|message" has
1926 replaced it. Additionally, the default for "print-stack" is
1927 now "message", which just prints the error message without
1930 ** A prompt substitution hook (prompt_hook) is now available to the
1933 ** A new Python module, gdb.prompt has been added to the GDB Python
1934 modules library. This module provides functionality for
1935 escape sequences in prompts (used by set/show
1936 extended-prompt). These escape sequences are replaced by their
1937 corresponding value.
1939 ** Python commands and convenience-functions located in
1940 'data-directory'/python/gdb/command and
1941 'data-directory'/python/gdb/function are now automatically loaded
1944 ** Blocks now provide four new attributes. global_block and
1945 static_block will return the global and static blocks
1946 respectively. is_static and is_global are boolean attributes
1947 that indicate if the block is one of those two types.
1949 ** Symbols now provide the "type" attribute, the type of the symbol.
1951 ** The "gdb.breakpoint" function has been deprecated in favor of
1954 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1955 of a function. This class is based on the "finish" command
1956 available in the CLI.
1958 ** Type objects for struct and union types now allow access to
1959 the fields using standard Python dictionary (mapping) methods.
1960 For example, "some_type['myfield']" now works, as does
1961 "some_type.items()".
1963 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1966 ** A new function, "deep_items" has been added to the gdb.types
1967 module in the GDB Python modules library. This function returns
1968 an iterator over the fields of a struct or union type. Unlike
1969 the standard Python "iteritems" method, it will recursively traverse
1970 any anonymous fields.
1974 ** "*stopped" events can report several new "reason"s, such as
1977 ** Breakpoint changes are now notified using new async records, like
1978 "=breakpoint-modified".
1980 ** New command -ada-task-info.
1982 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1983 $sdir specifies the default system locations of shared libraries.
1984 $pdir specifies the directory where the libpthread used by the application
1987 GDB no longer looks in $sdir and $pdir after it has searched the directories
1988 mentioned in libthread-db-search-path. If you want to search those
1989 directories, they must be specified in libthread-db-search-path.
1990 The default value of libthread-db-search-path on GNU/Linux and Solaris
1991 systems is now "$sdir:$pdir".
1993 $pdir is not supported by gdbserver, it is currently ignored.
1994 $sdir is supported by gdbserver.
1996 * New configure option --with-iconv-bin.
1997 When using the internationalization support like the one in the GNU C
1998 library, GDB will invoke the "iconv" program to get a list of supported
1999 character sets. If this program lives in a non-standard location, one can
2000 use this option to specify where to find it.
2002 * When natively debugging programs on PowerPC BookE processors running
2003 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2004 watchpoints, which specify a mask in addition to an address to watch.
2005 The mask specifies that some bits of an address (the bits which are
2006 reset in the mask) should be ignored when matching the address accessed
2007 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2008 section in the user manual for more details.
2010 * The new option --once causes GDBserver to stop listening for connections once
2011 the first connection is made. The listening port used by GDBserver will
2012 become available after that.
2014 * New commands "info macros" and "alias" have been added.
2016 * New function parameters suffix @entry specifies value of function parameter
2017 at the time the function got called. Entry values are available only since
2023 "!" is now an alias of the "shell" command.
2024 Note that no space is needed between "!" and SHELL COMMAND.
2028 watch EXPRESSION mask MASK_VALUE
2029 The watch command now supports the mask argument which allows creation
2030 of masked watchpoints, if the current architecture supports this feature.
2032 info auto-load-scripts [REGEXP]
2033 This command was formerly named "maintenance print section-scripts".
2034 It is now generally useful and is no longer a maintenance-only command.
2036 info macro [-all] [--] MACRO
2037 The info macro command has new options `-all' and `--'. The first for
2038 printing all definitions of a macro. The second for explicitly specifying
2039 the end of arguments and the beginning of the macro name in case the macro
2040 name starts with a hyphen.
2042 collect[/s] EXPRESSIONS
2043 The tracepoint collect command now takes an optional modifier "/s"
2044 that directs it to dereference pointer-to-character types and
2045 collect the bytes of memory up to a zero byte. The behavior is
2046 similar to what you see when you use the regular print command on a
2047 string. An optional integer following the "/s" sets a bound on the
2048 number of bytes that will be collected.
2051 The trace start command now interprets any supplied arguments as a
2052 note to be recorded with the trace run, with an effect similar to
2053 setting the variable trace-notes.
2056 The trace stop command now interprets any arguments as a note to be
2057 mentioned along with the tstatus report that the trace was stopped
2058 with a command. The effect is similar to setting the variable
2061 * Tracepoints can now be enabled and disabled at any time after a trace
2062 experiment has been started using the standard "enable" and "disable"
2063 commands. It is now possible to start a trace experiment with no enabled
2064 tracepoints; GDB will display a warning, but will allow the experiment to
2065 begin, assuming that tracepoints will be enabled as needed while the trace
2068 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2069 locations with 4-byte instructions, when they were previously
2070 limited to locations with instructions of 5 bytes or longer.
2074 set debug dwarf2-read
2075 show debug dwarf2-read
2076 Turns on or off display of debugging messages related to reading
2077 DWARF debug info. The default is off.
2079 set debug symtab-create
2080 show debug symtab-create
2081 Turns on or off display of debugging messages related to symbol table
2082 creation. The default is off.
2085 show extended-prompt
2086 Set the GDB prompt, and allow escape sequences to be inserted to
2087 display miscellaneous information (see 'help set extended-prompt'
2088 for the list of sequences). This prompt (and any information
2089 accessed through the escape sequences) is updated every time the
2090 prompt is displayed.
2092 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2093 show print entry-values
2094 Set printing of frame argument values at function entry. In some cases
2095 GDB can determine the value of function argument which was passed by the
2096 function caller, even if the value was modified inside the called function.
2098 set debug entry-values
2099 show debug entry-values
2100 Control display of debugging info for determining frame argument values at
2101 function entry and virtual tail call frames.
2103 set basenames-may-differ
2104 show basenames-may-differ
2105 Set whether a source file may have multiple base names.
2106 (A "base name" is the name of a file with the directory part removed.
2107 Example: The base name of "/home/user/hello.c" is "hello.c".)
2108 If set, GDB will canonicalize file names (e.g., expand symlinks)
2109 before comparing them. Canonicalization is an expensive operation,
2110 but it allows the same file be known by more than one base name.
2111 If not set (the default), all source files are assumed to have just
2112 one base name, and gdb will do file name comparisons more efficiently.
2118 Set a user name and notes for the current and any future trace runs.
2119 This is useful for long-running and/or disconnected traces, to
2120 inform others (or yourself) as to who is running the trace, supply
2121 contact information, or otherwise explain what is going on.
2123 set trace-stop-notes
2124 show trace-stop-notes
2125 Set a note attached to the trace run, that is displayed when the
2126 trace has been stopped by a tstop command. This is useful for
2127 instance as an explanation, if you are stopping a trace run that was
2128 started by someone else.
2130 * New remote packets
2134 Dynamically enable a tracepoint in a started trace experiment.
2138 Dynamically disable a tracepoint in a started trace experiment.
2142 Set the user and notes of the trace run.
2146 Query the current status of a tracepoint.
2150 Query the minimum length of instruction at which a fast tracepoint may
2153 * Dcache size (number of lines) and line-size are now runtime-configurable
2154 via "set dcache line" and "set dcache line-size" commands.
2158 Texas Instruments TMS320C6x tic6x-*-*
2162 Renesas RL78 rl78-*-elf
2164 *** Changes in GDB 7.3.1
2166 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2168 *** Changes in GDB 7.3
2170 * GDB has a new command: "thread find [REGEXP]".
2171 It finds the thread id whose name, target id, or thread extra info
2172 matches the given regular expression.
2174 * The "catch syscall" command now works on mips*-linux* targets.
2176 * The -data-disassemble MI command now supports modes 2 and 3 for
2177 dumping the instruction opcodes.
2179 * New command line options
2181 -data-directory DIR Specify DIR as the "data-directory".
2182 This is mostly for testing purposes.
2184 * The "maint set python auto-load on|off" command has been renamed to
2185 "set auto-load-scripts on|off".
2187 * GDB has a new command: "set directories".
2188 It is like the "dir" command except that it replaces the
2189 source path list instead of augmenting it.
2191 * GDB now understands thread names.
2193 On GNU/Linux, "info threads" will display the thread name as set by
2194 prctl or pthread_setname_np.
2196 There is also a new command, "thread name", which can be used to
2197 assign a name internally for GDB to display.
2200 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2201 has been integrated into GDB.
2205 ** The function gdb.Write now accepts an optional keyword 'stream'.
2206 This keyword, when provided, will direct the output to either
2207 stdout, stderr, or GDB's logging output.
2209 ** Parameters can now be be sub-classed in Python, and in particular
2210 you may implement the get_set_doc and get_show_doc functions.
2211 This improves how Parameter set/show documentation is processed
2212 and allows for more dynamic content.
2214 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2215 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2216 have an is_valid method.
2218 ** Breakpoints can now be sub-classed in Python, and in particular
2219 you may implement a 'stop' function that is executed each time
2220 the inferior reaches that breakpoint.
2222 ** New function gdb.lookup_global_symbol looks up a global symbol.
2224 ** GDB values in Python are now callable if the value represents a
2225 function. For example, if 'some_value' represents a function that
2226 takes two integer parameters and returns a value, you can call
2227 that function like so:
2229 result = some_value (10,20)
2231 ** Module gdb.types has been added.
2232 It contains a collection of utilities for working with gdb.Types objects:
2233 get_basic_type, has_field, make_enum_dict.
2235 ** Module gdb.printing has been added.
2236 It contains utilities for writing and registering pretty-printers.
2237 New classes: PrettyPrinter, SubPrettyPrinter,
2238 RegexpCollectionPrettyPrinter.
2239 New function: register_pretty_printer.
2241 ** New commands "info pretty-printers", "enable pretty-printer" and
2242 "disable pretty-printer" have been added.
2244 ** gdb.parameter("directories") is now available.
2246 ** New function gdb.newest_frame returns the newest frame in the
2249 ** The gdb.InferiorThread class has a new "name" attribute. This
2250 holds the thread's name.
2252 ** Python Support for Inferior events.
2253 Python scripts can add observers to be notified of events
2254 occurring in the process being debugged.
2255 The following events are currently supported:
2256 - gdb.events.cont Continue event.
2257 - gdb.events.exited Inferior exited event.
2258 - gdb.events.stop Signal received, and Breakpoint hit events.
2262 ** GDB now puts template parameters in scope when debugging in an
2263 instantiation. For example, if you have:
2265 template<int X> int func (void) { return X; }
2267 then if you step into func<5>, "print X" will show "5". This
2268 feature requires proper debuginfo support from the compiler; it
2269 was added to GCC 4.5.
2271 ** The motion commands "next", "finish", "until", and "advance" now
2272 work better when exceptions are thrown. In particular, GDB will
2273 no longer lose control of the inferior; instead, the GDB will
2274 stop the inferior at the point at which the exception is caught.
2275 This functionality requires a change in the exception handling
2276 code that was introduced in GCC 4.5.
2278 * GDB now follows GCC's rules on accessing volatile objects when
2279 reading or writing target state during expression evaluation.
2280 One notable difference to prior behavior is that "print x = 0"
2281 no longer generates a read of x; the value of the assignment is
2282 now always taken directly from the value being assigned.
2284 * GDB now has some support for using labels in the program's source in
2285 linespecs. For instance, you can use "advance label" to continue
2286 execution to a label.
2288 * GDB now has support for reading and writing a new .gdb_index
2289 section. This section holds a fast index of DWARF debugging
2290 information and can be used to greatly speed up GDB startup and
2291 operation. See the documentation for `save gdb-index' for details.
2293 * The "watch" command now accepts an optional "-location" argument.
2294 When used, this causes GDB to watch the memory referred to by the
2295 expression. Such a watchpoint is never deleted due to it going out
2298 * GDB now supports thread debugging of core dumps on GNU/Linux.
2300 GDB now activates thread debugging using the libthread_db library
2301 when debugging GNU/Linux core dumps, similarly to when debugging
2302 live processes. As a result, when debugging a core dump file, GDB
2303 is now able to display pthread_t ids of threads. For example, "info
2304 threads" shows the same output as when debugging the process when it
2305 was live. In earlier releases, you'd see something like this:
2308 * 1 LWP 6780 main () at main.c:10
2310 While now you see this:
2313 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2315 It is also now possible to inspect TLS variables when debugging core
2318 When debugging a core dump generated on a machine other than the one
2319 used to run GDB, you may need to point GDB at the correct
2320 libthread_db library with the "set libthread-db-search-path"
2321 command. See the user manual for more details on this command.
2323 * When natively debugging programs on PowerPC BookE processors running
2324 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2325 which stop execution of the inferior whenever it executes an instruction
2326 at any address within the specified range. See the "PowerPC Embedded"
2327 section in the user manual for more details.
2329 * New features in the GDB remote stub, GDBserver
2331 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2332 and i686 LynxOS (version 5.x).
2334 ** GDBserver is now supported on Blackfin Linux.
2336 * New native configurations
2338 ia64 HP-UX ia64-*-hpux*
2342 Analog Devices, Inc. Blackfin Processor bfin-*
2344 * Ada task switching is now supported on sparc-elf targets when
2345 debugging a program using the Ravenscar Profile. For more information,
2346 see the "Tasking Support when using the Ravenscar Profile" section
2347 in the GDB user manual.
2349 * Guile support was removed.
2351 * New features in the GNU simulator
2353 ** The --map-info flag lists all known core mappings.
2355 ** CFI flashes may be simulated via the "cfi" device.
2357 *** Changes in GDB 7.2
2359 * Shared library support for remote targets by default
2361 When GDB is configured for a generic, non-OS specific target, like
2362 for example, --target=arm-eabi or one of the many *-*-elf targets,
2363 GDB now queries remote stubs for loaded shared libraries using the
2364 `qXfer:libraries:read' packet. Previously, shared library support
2365 was always disabled for such configurations.
2369 ** Argument Dependent Lookup (ADL)
2371 In C++ ADL lookup directs function search to the namespaces of its
2372 arguments even if the namespace has not been imported.
2382 Here the compiler will search for `foo' in the namespace of 'b'
2383 and find A::foo. GDB now supports this. This construct is commonly
2384 used in the Standard Template Library for operators.
2386 ** Improved User Defined Operator Support
2388 In addition to member operators, GDB now supports lookup of operators
2389 defined in a namespace and imported with a `using' directive, operators
2390 defined in the global scope, operators imported implicitly from an
2391 anonymous namespace, and the ADL operators mentioned in the previous
2393 GDB now also supports proper overload resolution for all the previously
2394 mentioned flavors of operators.
2396 ** static const class members
2398 Printing of static const class members that are initialized in the
2399 class definition has been fixed.
2401 * Windows Thread Information Block access.
2403 On Windows targets, GDB now supports displaying the Windows Thread
2404 Information Block (TIB) structure. This structure is visible either
2405 by using the new command `info w32 thread-information-block' or, by
2406 dereferencing the new convenience variable named `$_tlb', a
2407 thread-specific pointer to the TIB. This feature is also supported
2408 when remote debugging using GDBserver.
2410 * Static tracepoints
2412 Static tracepoints are calls in the user program into a tracing
2413 library. One such library is a port of the LTTng kernel tracer to
2414 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2415 When debugging with GDBserver, GDB now supports combining the GDB
2416 tracepoint machinery with such libraries. For example: the user can
2417 use GDB to probe a static tracepoint marker (a call from the user
2418 program into the tracing library) with the new "strace" command (see
2419 "New commands" below). This creates a "static tracepoint" in the
2420 breakpoint list, that can be manipulated with the same feature set
2421 as fast and regular tracepoints. E.g., collect registers, local and
2422 global variables, collect trace state variables, and define
2423 tracepoint conditions. In addition, the user can collect extra
2424 static tracepoint marker specific data, by collecting the new
2425 $_sdata internal variable. When analyzing the trace buffer, you can
2426 inspect $_sdata like any other variable available to GDB. For more
2427 information, see the "Tracepoints" chapter in GDB user manual. New
2428 remote packets have been defined to support static tracepoints, see
2429 the "New remote packets" section below.
2431 * Better reconstruction of tracepoints after disconnected tracing
2433 GDB will attempt to download the original source form of tracepoint
2434 definitions when starting a trace run, and then will upload these
2435 upon reconnection to the target, resulting in a more accurate
2436 reconstruction of the tracepoints that are in use on the target.
2440 You can now exercise direct control over the ways that GDB can
2441 affect your program. For instance, you can disallow the setting of
2442 breakpoints, so that the program can run continuously (assuming
2443 non-stop mode). In addition, the "observer" variable is available
2444 to switch all of the different controls; in observer mode, GDB
2445 cannot affect the target's behavior at all, which is useful for
2446 tasks like diagnosing live systems in the field.
2448 * The new convenience variable $_thread holds the number of the
2451 * New remote packets
2455 Return the address of the Windows Thread Information Block of a given thread.
2459 In response to several of the tracepoint packets, the target may now
2460 also respond with a number of intermediate `qRelocInsn' request
2461 packets before the final result packet, to have GDB handle
2462 relocating an instruction to execute at a different address. This
2463 is particularly useful for stubs that support fast tracepoints. GDB
2464 reports support for this feature in the qSupported packet.
2468 List static tracepoint markers in the target program.
2472 List static tracepoint markers at a given address in the target
2475 qXfer:statictrace:read
2477 Read the static trace data collected (by a `collect $_sdata'
2478 tracepoint action). The remote stub reports support for this packet
2479 to gdb's qSupported query.
2483 Send the current settings of GDB's permission flags.
2487 Send part of the source (textual) form of a tracepoint definition,
2488 which includes location, conditional, and action list.
2490 * The source command now accepts a -s option to force searching for the
2491 script in the source search path even if the script name specifies
2494 * New features in the GDB remote stub, GDBserver
2496 - GDBserver now support tracepoints (including fast tracepoints, and
2497 static tracepoints). The feature is currently supported by the
2498 i386-linux and amd64-linux builds. See the "Tracepoints support
2499 in gdbserver" section in the manual for more information.
2501 GDBserver JIT compiles the tracepoint's conditional agent
2502 expression bytecode into native code whenever possible for low
2503 overhead dynamic tracepoints conditionals. For such tracepoints,
2504 an expression that examines program state is evaluated when the
2505 tracepoint is reached, in order to determine whether to capture
2506 trace data. If the condition is simple and false, processing the
2507 tracepoint finishes very quickly and no data is gathered.
2509 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2510 for static tracepoints support.
2512 - GDBserver now supports x86_64 Windows 64-bit debugging.
2514 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2515 it understands register description.
2517 * The --batch flag now disables pagination and queries.
2519 * X86 general purpose registers
2521 GDB now supports reading/writing byte, word and double-word x86
2522 general purpose registers directly. This means you can use, say,
2523 $ah or $ax to refer, respectively, to the byte register AH and
2524 16-bit word register AX that are actually portions of the 32-bit
2525 register EAX or 64-bit register RAX.
2527 * The `commands' command now accepts a range of breakpoints to modify.
2528 A plain `commands' following a command that creates multiple
2529 breakpoints affects all the breakpoints set by that command. This
2530 applies to breakpoints set by `rbreak', and also applies when a
2531 single `break' command creates multiple breakpoints (e.g.,
2532 breakpoints on overloaded c++ functions).
2534 * The `rbreak' command now accepts a filename specification as part of
2535 its argument, limiting the functions selected by the regex to those
2536 in the specified file.
2538 * Support for remote debugging Windows and SymbianOS shared libraries
2539 from Unix hosts has been improved. Non Windows GDB builds now can
2540 understand target reported file names that follow MS-DOS based file
2541 system semantics, such as file names that include drive letters and
2542 use the backslash character as directory separator. This makes it
2543 possible to transparently use the "set sysroot" and "set
2544 solib-search-path" on Unix hosts to point as host copies of the
2545 target's shared libraries. See the new command "set
2546 target-file-system-kind" described below, and the "Commands to
2547 specify files" section in the user manual for more information.
2551 eval template, expressions...
2552 Convert the values of one or more expressions under the control
2553 of the string template to a command line, and call it.
2555 set target-file-system-kind unix|dos-based|auto
2556 show target-file-system-kind
2557 Set or show the assumed file system kind for target reported file
2560 save breakpoints <filename>
2561 Save all current breakpoint definitions to a file suitable for use
2562 in a later debugging session. To read the saved breakpoint
2563 definitions, use the `source' command.
2565 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2568 info static-tracepoint-markers
2569 Display information about static tracepoint markers in the target.
2571 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2572 Define a static tracepoint by probing a marker at the given
2573 function, line, address, or marker ID.
2577 Enable and disable observer mode.
2579 set may-write-registers on|off
2580 set may-write-memory on|off
2581 set may-insert-breakpoints on|off
2582 set may-insert-tracepoints on|off
2583 set may-insert-fast-tracepoints on|off
2584 set may-interrupt on|off
2585 Set individual permissions for GDB effects on the target. Note that
2586 some of these settings can have undesirable or surprising
2587 consequences, particularly when changed in the middle of a session.
2588 For instance, disabling the writing of memory can prevent
2589 breakpoints from being inserted, cause single-stepping to fail, or
2590 even crash your program, if you disable after breakpoints have been
2591 inserted. However, GDB should not crash.
2593 set record memory-query on|off
2594 show record memory-query
2595 Control whether to stop the inferior if memory changes caused
2596 by an instruction cannot be recorded.
2601 The disassemble command now supports "start,+length" form of two arguments.
2605 ** GDB now provides a new directory location, called the python directory,
2606 where Python scripts written for GDB can be installed. The location
2607 of that directory is <data-directory>/python, where <data-directory>
2608 is the GDB data directory. For more details, see section `Scripting
2609 GDB using Python' in the manual.
2611 ** The GDB Python API now has access to breakpoints, symbols, symbol
2612 tables, program spaces, inferiors, threads and frame's code blocks.
2613 Additionally, GDB Parameters can now be created from the API, and
2614 manipulated via set/show in the CLI.
2616 ** New functions gdb.target_charset, gdb.target_wide_charset,
2617 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2619 ** New exception gdb.GdbError.
2621 ** Pretty-printers are now also looked up in the current program space.
2623 ** Pretty-printers can now be individually enabled and disabled.
2625 ** GDB now looks for names of Python scripts to auto-load in a
2626 special section named `.debug_gdb_scripts', in addition to looking
2627 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2629 * Tracepoint actions were unified with breakpoint commands. In particular,
2630 there are no longer differences in "info break" output for breakpoints and
2631 tracepoints and the "commands" command can be used for both tracepoints and
2632 regular breakpoints.
2636 ARM Symbian arm*-*-symbianelf*
2638 * D language support.
2639 GDB now supports debugging programs written in the D programming
2642 * GDB now supports the extended ptrace interface for PowerPC which is
2643 available since Linux kernel version 2.6.34. This automatically enables
2644 any hardware breakpoints and additional hardware watchpoints available in
2645 the processor. The old ptrace interface exposes just one hardware
2646 watchpoint and no hardware breakpoints.
2648 * GDB is now able to use the Data Value Compare (DVC) register available on
2649 embedded PowerPC processors to implement in hardware simple watchpoint
2650 conditions of the form:
2652 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2654 This works in native GDB running on Linux kernels with the extended ptrace
2655 interface mentioned above.
2657 *** Changes in GDB 7.1
2661 ** Namespace Support
2663 GDB now supports importing of namespaces in C++. This enables the
2664 user to inspect variables from imported namespaces. Support for
2665 namepace aliasing has also been added. So, if a namespace is
2666 aliased in the current scope (e.g. namepace C=A; ) the user can
2667 print variables using the alias (e.g. (gdb) print C::x).
2671 All known bugs relating to the printing of virtual base class were
2672 fixed. It is now possible to call overloaded static methods using a
2677 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2678 and reinterpret_cast<> are now handled by the C++ expression parser.
2682 Xilinx MicroBlaze microblaze-*-*
2687 Xilinx MicroBlaze microblaze
2690 * Multi-program debugging.
2692 GDB now has support for multi-program (a.k.a. multi-executable or
2693 multi-exec) debugging. This allows for debugging multiple inferiors
2694 simultaneously each running a different program under the same GDB
2695 session. See "Debugging Multiple Inferiors and Programs" in the
2696 manual for more information. This implied some user visible changes
2697 in the multi-inferior support. For example, "info inferiors" now
2698 lists inferiors that are not running yet or that have exited
2699 already. See also "New commands" and "New options" below.
2701 * New tracing features
2703 GDB's tracepoint facility now includes several new features:
2705 ** Trace state variables
2707 GDB tracepoints now include support for trace state variables, which
2708 are variables managed by the target agent during a tracing
2709 experiment. They are useful for tracepoints that trigger each
2710 other, so for instance one tracepoint can count hits in a variable,
2711 and then a second tracepoint has a condition that is true when the
2712 count reaches a particular value. Trace state variables share the
2713 $-syntax of GDB convenience variables, and can appear in both
2714 tracepoint actions and condition expressions. Use the "tvariable"
2715 command to create, and "info tvariables" to view; see "Trace State
2716 Variables" in the manual for more detail.
2720 GDB now includes an option for defining fast tracepoints, which
2721 targets may implement more efficiently, such as by installing a jump
2722 into the target agent rather than a trap instruction. The resulting
2723 speedup can be by two orders of magnitude or more, although the
2724 tradeoff is that some program locations on some target architectures
2725 might not allow fast tracepoint installation, for instance if the
2726 instruction to be replaced is shorter than the jump. To request a
2727 fast tracepoint, use the "ftrace" command, with syntax identical to
2728 the regular trace command.
2730 ** Disconnected tracing
2732 It is now possible to detach GDB from the target while it is running
2733 a trace experiment, then reconnect later to see how the experiment
2734 is going. In addition, a new variable disconnected-tracing lets you
2735 tell the target agent whether to continue running a trace if the
2736 connection is lost unexpectedly.
2740 GDB now has the ability to save the trace buffer into a file, and
2741 then use that file as a target, similarly to you can do with
2742 corefiles. You can select trace frames, print data that was
2743 collected in them, and use tstatus to display the state of the
2744 tracing run at the moment that it was saved. To create a trace
2745 file, use "tsave <filename>", and to use it, do "target tfile
2748 ** Circular trace buffer
2750 You can ask the target agent to handle the trace buffer as a
2751 circular buffer, discarding the oldest trace frames to make room for
2752 newer ones, by setting circular-trace-buffer to on. This feature may
2753 not be available for all target agents.
2758 The disassemble command, when invoked with two arguments, now requires
2759 the arguments to be comma-separated.
2762 The info variables command now displays variable definitions. Files
2763 which only declare a variable are not shown.
2766 The source command is now capable of sourcing Python scripts.
2767 This feature is dependent on the debugger being build with Python
2770 Related to this enhancement is also the introduction of a new command
2771 "set script-extension" (see below).
2773 * New commands (for set/show, see "New options" below)
2775 record save [<FILENAME>]
2776 Save a file (in core file format) containing the process record
2777 execution log for replay debugging at a later time.
2779 record restore <FILENAME>
2780 Restore the process record execution log that was saved at an
2781 earlier time, for replay debugging.
2783 add-inferior [-copies <N>] [-exec <FILENAME>]
2786 clone-inferior [-copies <N>] [ID]
2787 Make a new inferior ready to execute the same program another
2788 inferior has loaded.
2793 maint info program-spaces
2794 List the program spaces loaded into GDB.
2796 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2797 show remote interrupt-sequence
2798 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2799 as the sequence to the remote target in order to interrupt the execution.
2800 Ctrl-C is a default. Some system prefers BREAK which is high level of
2801 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2802 Magic SysRq g. It is BREAK signal and character 'g'.
2804 set remote interrupt-on-connect [on | off]
2805 show remote interrupt-on-connect
2806 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2807 remote target when gdb connects to it. This is needed when you debug
2810 set remotebreak [on | off]
2812 Deprecated. Use "set/show remote interrupt-sequence" instead.
2814 tvariable $NAME [ = EXP ]
2815 Create or modify a trace state variable.
2818 List trace state variables and their values.
2820 delete tvariable $NAME ...
2821 Delete one or more trace state variables.
2824 Evaluate the given expressions without collecting anything into the
2825 trace buffer. (Valid in tracepoint actions only.)
2827 ftrace FN / FILE:LINE / *ADDR
2828 Define a fast tracepoint at the given function, line, or address.
2830 * New expression syntax
2832 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2833 GDB now parses 0b101010 identically with 42.
2837 set follow-exec-mode new|same
2838 show follow-exec-mode
2839 Control whether GDB reuses the same inferior across an exec call or
2840 creates a new one. This is useful to be able to restart the old
2841 executable after the inferior having done an exec call.
2843 set default-collect EXPR, ...
2844 show default-collect
2845 Define a list of expressions to be collected at each tracepoint.
2846 This is a useful way to ensure essential items are not overlooked,
2847 such as registers or a critical global variable.
2849 set disconnected-tracing
2850 show disconnected-tracing
2851 If set to 1, the target is instructed to continue tracing if it
2852 loses its connection to GDB. If 0, the target is to stop tracing
2855 set circular-trace-buffer
2856 show circular-trace-buffer
2857 If set to on, the target is instructed to use a circular trace buffer
2858 and discard the oldest trace frames instead of stopping the trace due
2859 to a full trace buffer. If set to off, the trace stops when the buffer
2860 fills up. Some targets may not support this.
2862 set script-extension off|soft|strict
2863 show script-extension
2864 If set to "off", the debugger does not perform any script language
2865 recognition, and all sourced files are assumed to be GDB scripts.
2866 If set to "soft" (the default), files are sourced according to
2867 filename extension, falling back to GDB scripts if the first
2869 If set to "strict", files are sourced according to filename extension.
2871 set ada trust-PAD-over-XVS on|off
2872 show ada trust-PAD-over-XVS
2873 If off, activate a workaround against a bug in the debugging information
2874 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2875 the GCC sources for more information about the GNAT encoding and
2876 PAD types in particular). It is always safe to set this option to
2877 off, but this introduces a slight performance penalty. The default
2880 * Python API Improvements
2882 ** GDB provides the new class gdb.LazyString. This is useful in
2883 some pretty-printing cases. The new method gdb.Value.lazy_string
2884 provides a simple way to create objects of this type.
2886 ** The fields returned by gdb.Type.fields now have an
2887 `is_base_class' attribute.
2889 ** The new method gdb.Type.range returns the range of an array type.
2891 ** The new method gdb.parse_and_eval can be used to parse and
2892 evaluate an expression.
2894 * New remote packets
2897 Define a trace state variable.
2900 Get the current value of a trace state variable.
2903 Set desired tracing behavior upon disconnection.
2906 Set the trace buffer to be linear or circular.
2909 Get data about the tracepoints currently in use.
2913 Process record now works correctly with hardware watchpoints.
2915 Multiple bug fixes have been made to the mips-irix port, making it
2916 much more reliable. In particular:
2917 - Debugging threaded applications is now possible again. Previously,
2918 GDB would hang while starting the program, or while waiting for
2919 the program to stop at a breakpoint.
2920 - Attaching to a running process no longer hangs.
2921 - An error occurring while loading a core file has been fixed.
2922 - Changing the value of the PC register now works again. This fixes
2923 problems observed when using the "jump" command, or when calling
2924 a function from GDB, or even when assigning a new value to $pc.
2925 - With the "finish" and "return" commands, the return value for functions
2926 returning a small array is now correctly printed.
2927 - It is now possible to break on shared library code which gets executed
2928 during a shared library init phase (code executed while executing
2929 their .init section). Previously, the breakpoint would have no effect.
2930 - GDB is now able to backtrace through the signal handler for
2931 non-threaded programs.
2933 PIE (Position Independent Executable) programs debugging is now supported.
2934 This includes debugging execution of PIC (Position Independent Code) shared
2935 libraries although for that, it should be possible to run such libraries as an
2938 *** Changes in GDB 7.0
2940 * GDB now has an interface for JIT compilation. Applications that
2941 dynamically generate code can create symbol files in memory and register
2942 them with GDB. For users, the feature should work transparently, and
2943 for JIT developers, the interface is documented in the GDB manual in the
2944 "JIT Compilation Interface" chapter.
2946 * Tracepoints may now be conditional. The syntax is as for
2947 breakpoints; either an "if" clause appended to the "trace" command,
2948 or the "condition" command is available. GDB sends the condition to
2949 the target for evaluation using the same bytecode format as is used
2950 for tracepoint actions.
2952 * The disassemble command now supports: an optional /r modifier, print the
2953 raw instructions in hex as well as in symbolic form, and an optional /m
2954 modifier to print mixed source+assembly.
2956 * Process record and replay
2958 In a architecture environment that supports ``process record and
2959 replay'', ``process record and replay'' target can record a log of
2960 the process execution, and replay it with both forward and reverse
2963 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2964 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2965 set execution-direction {forward|reverse}, for targets that support
2968 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2969 feature is available with a native GDB running on kernel version
2972 * GDB now has support for multi-byte and wide character sets on the
2973 target. Strings whose character type is wchar_t, char16_t, or
2974 char32_t are now correctly printed. GDB supports wide- and unicode-
2975 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2976 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2977 `printf'. This feature requires iconv to work properly; if your
2978 system does not have a working iconv, GDB can use GNU libiconv. See
2979 the installation instructions for more information.
2981 * GDB now supports automatic retrieval of shared library files from
2982 remote targets. To use this feature, specify a system root that begins
2983 with the `remote:' prefix, either via the `set sysroot' command or via
2984 the `--with-sysroot' configure-time option.
2986 * "info sharedlibrary" now takes an optional regex of libraries to show,
2987 and it now reports if a shared library has no debugging information.
2989 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2990 now complete on file names.
2992 * When completing in expressions, gdb will attempt to limit
2993 completions to allowable structure or union fields, where appropriate.
2994 For instance, consider:
2996 # struct example { int f1; double f2; };
2997 # struct example variable;
3000 If the user types TAB at the end of this command line, the available
3001 completions will be "f1" and "f2".
3003 * Inlined functions are now supported. They show up in backtraces, and
3004 the "step", "next", and "finish" commands handle them automatically.
3006 * GDB now supports the token-splicing (##) and stringification (#)
3007 operators when expanding macros. It also supports variable-arity
3010 * GDB now supports inspecting extra signal information, exported by
3011 the new $_siginfo convenience variable. The feature is currently
3012 implemented on linux ARM, i386 and amd64.
3014 * GDB can now display the VFP floating point registers and NEON vector
3015 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3016 can provide these registers (requires Linux 2.6.30 or later). Remote
3017 and simulator targets may also provide them.
3019 * New remote packets
3022 Search memory for a sequence of bytes.
3025 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3026 operation over reliable transport links. Use of this packet is
3027 controlled by the `set remote noack-packet' command.
3030 Kill the process with the specified process ID. Use this in preference
3031 to `k' when multiprocess protocol extensions are supported.
3034 Obtains additional operating system information
3038 Read or write additional signal information.
3040 * Removed remote protocol undocumented extension
3042 An undocumented extension to the remote protocol's `S' stop reply
3043 packet that permited the stub to pass a process id was removed.
3044 Remote servers should use the `T' stop reply packet instead.
3046 * GDB now supports multiple function calling conventions according to the
3047 DWARF-2 DW_AT_calling_convention function attribute.
3049 * The SH target utilizes the aforementioned change to distinguish between gcc
3050 and Renesas calling convention. It also adds the new CLI commands
3051 `set/show sh calling-convention'.
3053 * GDB can now read compressed debug sections, as produced by GNU gold
3054 with the --compress-debug-sections=zlib flag.
3056 * 64-bit core files are now supported on AIX.
3058 * Thread switching is now supported on Tru64.
3060 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3061 which will be allocated using malloc later in program execution.
3063 * The qXfer:libraries:read remote procotol packet now allows passing a
3064 list of section offsets.
3066 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3067 conditions handling signals delivered during attach or thread creation
3068 have also been fixed.
3070 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3071 From the user's standpoint, all unqualified instances of True and False
3072 are treated as the standard definitions, regardless of context.
3074 * GDB now parses C++ symbol and type names more flexibly. For
3077 template<typename T> class C { };
3080 GDB will now correctly handle all of:
3082 ptype C<char const *>
3083 ptype C<char const*>
3084 ptype C<const char *>
3085 ptype C<const char*>
3087 * New features in the GDB remote stub, gdbserver
3089 - The "--wrapper" command-line argument tells gdbserver to use a
3090 wrapper program to launch programs for debugging.
3092 - On PowerPC and S/390 targets, it is now possible to use a single
3093 gdbserver executable to debug both 32-bit and 64-bit programs.
3094 (This requires gdbserver itself to be built as a 64-bit executable.)
3096 - gdbserver uses the new noack protocol mode for TCP connections to
3097 reduce communications latency, if also supported and enabled in GDB.
3099 - Support for the sparc64-linux-gnu target is now included in
3102 - The amd64-linux build of gdbserver now supports debugging both
3103 32-bit and 64-bit programs.
3105 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3106 now support hardware watchpoints, and will use them automatically
3111 GDB now has support for scripting using Python. Whether this is
3112 available is determined at configure time.
3114 New GDB commands can now be written in Python.
3116 * Ada tasking support
3118 Ada tasks can now be inspected in GDB. The following commands have
3122 Print the list of Ada tasks.
3124 Print detailed information about task number N.
3126 Print the task number of the current task.
3128 Switch the context of debugging to task number N.
3130 * Support for user-defined prefixed commands. The "define" command can
3131 add new commands to existing prefixes, e.g. "target".
3133 * Multi-inferior, multi-process debugging.
3135 GDB now has generalized support for multi-inferior debugging. See
3136 "Debugging Multiple Inferiors" in the manual for more information.
3137 Although availability still depends on target support, the command
3138 set is more uniform now. The GNU/Linux specific multi-forks support
3139 has been migrated to this new framework. This implied some user
3140 visible changes; see "New commands" and also "Removed commands"
3143 * Target descriptions can now describe the target OS ABI. See the
3144 "Target Description Format" section in the user manual for more
3147 * Target descriptions can now describe "compatible" architectures
3148 to indicate that the target can execute applications for a different
3149 architecture in addition to those for the main target architecture.
3150 See the "Target Description Format" section in the user manual for
3153 * Multi-architecture debugging.
3155 GDB now includes general supports for debugging applications on
3156 hybrid systems that use more than one single processor architecture
3157 at the same time. Each such hybrid architecture still requires
3158 specific support to be added. The only hybrid architecture supported
3159 in this version of GDB is the Cell Broadband Engine.
3161 * GDB now supports integrated debugging of Cell/B.E. applications that
3162 use both the PPU and SPU architectures. To enable support for hybrid
3163 Cell/B.E. debugging, you need to configure GDB to support both the
3164 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3165 --enable-targets configure option.
3167 * Non-stop mode debugging.
3169 For some targets, GDB now supports an optional mode of operation in
3170 which you can examine stopped threads while other threads continue
3171 to execute freely. This is referred to as non-stop mode, with the
3172 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3173 section in the user manual for more information.
3175 To be able to support remote non-stop debugging, a remote stub needs
3176 to implement the non-stop mode remote protocol extensions, as
3177 described in the "Remote Non-Stop" section of the user manual. The
3178 GDB remote stub, gdbserver, has been adjusted to support these
3179 extensions on linux targets.
3181 * New commands (for set/show, see "New options" below)
3183 catch syscall [NAME(S) | NUMBER(S)]
3184 Catch system calls. Arguments, which should be names of system
3185 calls or their numbers, mean catch only those syscalls. Without
3186 arguments, every syscall will be caught. When the inferior issues
3187 any of the specified syscalls, GDB will stop and announce the system
3188 call, both when it is called and when its call returns. This
3189 feature is currently available with a native GDB running on the
3190 Linux Kernel, under the following architectures: x86, x86_64,
3191 PowerPC and PowerPC64.
3193 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3195 Search memory for a sequence of bytes.
3197 maint set python print-stack
3198 maint show python print-stack
3199 Show a stack trace when an error is encountered in a Python script.
3202 Invoke CODE by passing it to the Python interpreter.
3207 These allow macros to be defined, undefined, and listed
3211 Show operating system information about processes.
3214 List the inferiors currently under GDB's control.
3217 Switch focus to inferior number NUM.
3220 Detach from inferior number NUM.
3223 Kill inferior number NUM.
3227 set spu stop-on-load
3228 show spu stop-on-load
3229 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3231 set spu auto-flush-cache
3232 show spu auto-flush-cache
3233 Control whether to automatically flush the software-managed cache
3234 during Cell/B.E. debugging.
3236 set sh calling-convention
3237 show sh calling-convention
3238 Control the calling convention used when calling SH target functions.
3241 show debug timestamp
3242 Control display of timestamps with GDB debugging output.
3244 set disassemble-next-line
3245 show disassemble-next-line
3246 Control display of disassembled source lines or instructions when
3249 set remote noack-packet
3250 show remote noack-packet
3251 Set/show the use of remote protocol QStartNoAckMode packet. See above
3252 under "New remote packets."
3254 set remote query-attached-packet
3255 show remote query-attached-packet
3256 Control use of remote protocol `qAttached' (query-attached) packet.
3258 set remote read-siginfo-object
3259 show remote read-siginfo-object
3260 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3263 set remote write-siginfo-object
3264 show remote write-siginfo-object
3265 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3268 set remote reverse-continue
3269 show remote reverse-continue
3270 Control use of remote protocol 'bc' (reverse-continue) packet.
3272 set remote reverse-step
3273 show remote reverse-step
3274 Control use of remote protocol 'bs' (reverse-step) packet.
3276 set displaced-stepping
3277 show displaced-stepping
3278 Control displaced stepping mode. Displaced stepping is a way to
3279 single-step over breakpoints without removing them from the debuggee.
3280 Also known as "out-of-line single-stepping".
3283 show debug displaced
3284 Control display of debugging info for displaced stepping.
3286 maint set internal-error
3287 maint show internal-error
3288 Control what GDB does when an internal error is detected.
3290 maint set internal-warning
3291 maint show internal-warning
3292 Control what GDB does when an internal warning is detected.
3297 Use a wrapper program to launch programs for debugging.
3299 set multiple-symbols (all|ask|cancel)
3300 show multiple-symbols
3301 The value of this variable can be changed to adjust the debugger behavior
3302 when an expression or a breakpoint location contains an ambiguous symbol
3303 name (an overloaded function name, for instance).
3305 set breakpoint always-inserted
3306 show breakpoint always-inserted
3307 Keep breakpoints always inserted in the target, as opposed to inserting
3308 them when resuming the target, and removing them when the target stops.
3309 This option can improve debugger performance on slow remote targets.
3311 set arm fallback-mode (arm|thumb|auto)
3312 show arm fallback-mode
3313 set arm force-mode (arm|thumb|auto)
3315 These commands control how ARM GDB determines whether instructions
3316 are ARM or Thumb. The default for both settings is auto, which uses
3317 the current CPSR value for instructions without symbols; previous
3318 versions of GDB behaved as if "set arm fallback-mode arm".
3320 set disable-randomization
3321 show disable-randomization
3322 Standalone programs run with the virtual address space randomization enabled
3323 by default on some platforms. This option keeps the addresses stable across
3324 multiple debugging sessions.
3328 Control whether other threads are stopped or not when some thread hits
3333 Requests that asynchronous execution is enabled in the target, if available.
3334 In this case, it's possible to resume target in the background, and interact
3335 with GDB while the target is running. "show target-async" displays the
3336 current state of asynchronous execution of the target.
3338 set target-wide-charset
3339 show target-wide-charset
3340 The target-wide-charset is the name of the character set that GDB
3341 uses when printing characters whose type is wchar_t.
3343 set tcp auto-retry (on|off)
3345 set tcp connect-timeout
3346 show tcp connect-timeout
3347 These commands allow GDB to retry failed TCP connections to a remote stub
3348 with a specified timeout period; this is useful if the stub is launched
3349 in parallel with GDB but may not be ready to accept connections immediately.
3351 set libthread-db-search-path
3352 show libthread-db-search-path
3353 Control list of directories which GDB will search for appropriate
3356 set schedule-multiple (on|off)
3357 show schedule-multiple
3358 Allow GDB to resume all threads of all processes or only threads of
3359 the current process.
3363 Use more aggressive caching for accesses to the stack. This improves
3364 performance of remote debugging (particularly backtraces) without
3365 affecting correctness.
3367 set interactive-mode (on|off|auto)
3368 show interactive-mode
3369 Control whether GDB runs in interactive mode (on) or not (off).
3370 When in interactive mode, GDB waits for the user to answer all
3371 queries. Otherwise, GDB does not wait and assumes the default
3372 answer. When set to auto (the default), GDB determines which
3373 mode to use based on the stdin settings.
3378 For program forks, this is replaced by the new more generic `info
3379 inferiors' command. To list checkpoints, you can still use the
3380 `info checkpoints' command, which was an alias for the `info forks'
3384 Replaced by the new `inferior' command. To switch between
3385 checkpoints, you can still use the `restart' command, which was an
3386 alias for the `fork' command.
3389 This is removed, since some targets don't have a notion of
3390 processes. To switch between processes, you can still use the
3391 `inferior' command using GDB's own inferior number.
3394 For program forks, this is replaced by the new more generic `kill
3395 inferior' command. To delete a checkpoint, you can still use the
3396 `delete checkpoint' command, which was an alias for the `delete
3400 For program forks, this is replaced by the new more generic `detach
3401 inferior' command. To detach a checkpoint, you can still use the
3402 `detach checkpoint' command, which was an alias for the `detach
3405 * New native configurations
3407 x86/x86_64 Darwin i[34567]86-*-darwin*
3409 x86_64 MinGW x86_64-*-mingw*
3413 Lattice Mico32 lm32-*
3414 x86 DICOS i[34567]86-*-dicos*
3415 x86_64 DICOS x86_64-*-dicos*
3418 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3419 (mingw32ce) debugging.
3425 These commands were actually not implemented on any target.
3427 *** Changes in GDB 6.8
3429 * New native configurations
3431 NetBSD/hppa hppa*-*netbsd*
3432 Xtensa GNU/Linux xtensa*-*-linux*
3436 NetBSD/hppa hppa*-*-netbsd*
3437 Xtensa GNU/Lunux xtensa*-*-linux*
3439 * Change in command line behavior -- corefiles vs. process ids.
3441 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3442 attaching to process NUMBER fails, GDB no longer attempts to open a
3443 core file named NUMBER. Attaching to a program using the -c option
3444 is no longer supported. Instead, use the '-p' or '--pid' options.
3446 * GDB can now be built as a native debugger for debugging Windows x86
3447 (mingw32) Portable Executable (PE) programs.
3449 * Pending breakpoints no longer change their number when their address
3452 * GDB now supports breakpoints with multiple locations,
3453 including breakpoints on C++ constructors, inside C++ templates,
3454 and in inlined functions.
3456 * GDB's ability to debug optimized code has been improved. GDB more
3457 accurately identifies function bodies and lexical blocks that occupy
3458 more than one contiguous range of addresses.
3460 * Target descriptions can now describe registers for PowerPC.
3462 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3463 registers on PowerPC targets.
3465 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3466 targets even when the libthread_db library is not available.
3468 * The GDB remote stub, gdbserver, now supports the new file transfer
3469 commands (remote put, remote get, and remote delete).
3471 * The GDB remote stub, gdbserver, now supports run and attach in
3472 extended-remote mode.
3474 * hppa*64*-*-hpux11* target broken
3475 The debugger is unable to start a program and fails with the following
3476 error: "Error trying to get information about dynamic linker".
3477 The gdb-6.7 release is also affected.
3479 * GDB now supports the --enable-targets= configure option to allow
3480 building a single GDB executable that supports multiple remote
3481 target architectures.
3483 * GDB now supports debugging C and C++ programs which use the
3484 Decimal Floating Point extension. In addition, the PowerPC target
3485 now has a set of pseudo-registers to inspect decimal float values
3486 stored in two consecutive float registers.
3488 * The -break-insert MI command can optionally create pending
3491 * Improved support for debugging Ada
3492 Many improvements to the Ada language support have been made. These
3494 - Better support for Ada2005 interface types
3495 - Improved handling of arrays and slices in general
3496 - Better support for Taft-amendment types
3497 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3499 - Improved command completion in Ada
3502 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3507 set print frame-arguments (all|scalars|none)
3508 show print frame-arguments
3509 The value of this variable can be changed to control which argument
3510 values should be printed by the debugger when displaying a frame.
3515 Transfer files to and from a remote target, and delete remote files.
3522 Transfer files to and from a remote target, and delete remote files.
3524 * New remote packets
3531 Open, close, read, write, and delete files on the remote system.
3534 Attach to an existing process on the remote system, in extended-remote
3538 Run a new process on the remote system, in extended-remote mode.
3540 *** Changes in GDB 6.7
3542 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3543 bfd, libiberty and opcodes, as revealed by static analysis donated by
3544 Coverity, Inc. (http://scan.coverity.com).
3546 * When looking up multiply-defined global symbols, GDB will now prefer the
3547 symbol definition in the current shared library if it was built using the
3548 -Bsymbolic linker option.
3550 * When the Text User Interface (TUI) is not configured, GDB will now
3551 recognize the -tui command-line option and print a message that the TUI
3554 * The GDB remote stub, gdbserver, now has lower overhead for high
3555 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3557 * GDB for MIPS targets now autodetects whether a remote target provides
3558 32-bit or 64-bit register values.
3560 * Support for C++ member pointers has been improved.
3562 * GDB now understands XML target descriptions, which specify the
3563 target's overall architecture. GDB can read a description from
3564 a local file or over the remote serial protocol.
3566 * Vectors of single-byte data use a new integer type which is not
3567 automatically displayed as character or string data.
3569 * The /s format now works with the print command. It displays
3570 arrays of single-byte integers and pointers to single-byte integers
3573 * Target descriptions can now describe target-specific registers,
3574 for architectures which have implemented the support (currently
3575 only ARM, M68K, and MIPS).
3577 * GDB and the GDB remote stub, gdbserver, now support the XScale
3580 * The GDB remote stub, gdbserver, has been updated to support
3581 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3582 has been rewritten to use the standard GDB remote protocol.
3584 * GDB can now step into C++ functions which are called through thunks.
3586 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3588 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3589 layout. It also supports a TextSeg= and DataSeg= response when only
3590 segment base addresses (rather than offsets) are available.
3592 * The /i format now outputs any trailing branch delay slot instructions
3593 immediately following the last instruction within the count specified.
3595 * The GDB remote protocol "T" stop reply packet now supports a
3596 "library" response. Combined with the new "qXfer:libraries:read"
3597 packet, this response allows GDB to debug shared libraries on targets
3598 where the operating system manages the list of loaded libraries (e.g.
3599 Windows and SymbianOS).
3601 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3602 (DLLs) on Windows and Windows CE targets.
3604 * GDB now supports a faster verification that a .debug file matches its binary
3605 according to its build-id signature, if the signature is present.
3611 Enable or disable hardware flow control (RTS/CTS) on the serial port
3612 when debugging using remote targets.
3614 set mem inaccessible-by-default
3615 show mem inaccessible-by-default
3616 If the target supplies a memory map, for instance via the remote
3617 protocol's "qXfer:memory-map:read" packet, setting this variable
3618 prevents GDB from accessing memory outside the memory map. This
3619 is useful for targets with memory mapped registers or which react
3620 badly to accesses of unmapped address space.
3622 set breakpoint auto-hw
3623 show breakpoint auto-hw
3624 If the target supplies a memory map, for instance via the remote
3625 protocol's "qXfer:memory-map:read" packet, setting this variable
3626 lets GDB use hardware breakpoints automatically for memory regions
3627 where it can not use software breakpoints. This covers both the
3628 "break" command and internal breakpoints used for other commands
3629 including "next" and "finish".
3632 catch exception unhandled
3633 Stop the program execution when Ada exceptions are raised.
3636 Stop the program execution when an Ada assertion failed.
3640 Set an alternate system root for target files. This is a more
3641 general version of "set solib-absolute-prefix", which is now
3642 an alias to "set sysroot".
3645 Provide extended SPU facility status information. This set of
3646 commands is available only when debugging the Cell/B.E. SPU
3649 * New native configurations
3651 OpenBSD/sh sh*-*openbsd*
3654 unset tdesc filename
3656 Use the specified local file as an XML target description, and do
3657 not query the target for its built-in description.
3661 OpenBSD/sh sh*-*-openbsd*
3662 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3663 Toshiba Media Processor mep-elf
3665 * New remote packets
3668 Ignore the specified signals; pass them directly to the debugged program
3669 without stopping other threads or reporting them to GDB.
3671 qXfer:features:read:
3672 Read an XML target description from the target, which describes its
3677 Read or write contents of an spufs file on the target system. These
3678 packets are available only on the Cell/B.E. SPU architecture.
3680 qXfer:libraries:read:
3681 Report the loaded shared libraries. Combined with new "T" packet
3682 response, this packet allows GDB to debug shared libraries on
3683 targets where the operating system manages the list of loaded
3684 libraries (e.g. Windows and SymbianOS).
3688 Support for these obsolete configurations has been removed.
3696 i[34567]86-*-lynxos*
3697 i[34567]86-*-netware*
3698 i[34567]86-*-sco3.2v5*
3699 i[34567]86-*-sco3.2v4*
3701 i[34567]86-*-sysv4.2*
3704 i[34567]86-*-unixware2*
3705 i[34567]86-*-unixware*
3714 * Other removed features
3721 Various m68k-only ROM monitors.
3728 Various Renesas ROM monitors and debugging interfaces for SH and
3733 Support for a Macraigor serial interface to on-chip debugging.
3734 GDB does not directly support the newer parallel or USB
3739 A debug information format. The predecessor to DWARF 2 and
3740 DWARF 3, which are still supported.
3742 Support for the HP aCC compiler on HP-UX/PA-RISC
3744 SOM-encapsulated symbolic debugging information, automatic
3745 invocation of pxdb, and the aCC custom C++ ABI. This does not
3746 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3747 with aCC can still be debugged on an assembly level.
3749 MIPS ".pdr" sections
3751 A MIPS-specific format used to describe stack frame layout
3752 in debugging information.
3756 GDB could work with an older version of Guile to debug
3757 the interpreter and Scheme programs running in it.
3759 set mips stack-arg-size
3760 set mips saved-gpreg-size
3762 Use "set mips abi" to control parameter passing for MIPS.
3764 *** Changes in GDB 6.6
3769 Cell Broadband Engine SPU spu-elf
3771 * GDB can now be configured as a cross-debugger targeting native Windows
3772 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3773 running on a Windows system over TCP/IP to debug Windows programs.
3775 * The GDB remote stub, gdbserver, has been updated to support Windows and
3776 Cygwin debugging. Both single-threaded and multi-threaded programs are
3779 * The "set trust-readonly-sections" command works again. This command was
3780 broken in GDB 6.3, 6.4, and 6.5.
3782 * The "load" command now supports writing to flash memory, if the remote
3783 stub provides the required support.
3785 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3786 longer requires symbolic debug information (e.g. DWARF-2).
3791 unset substitute-path
3792 show substitute-path
3793 Manage a list of substitution rules that GDB uses to rewrite the name
3794 of the directories where the sources are located. This can be useful
3795 for instance when the sources were moved to a different location
3796 between compilation and debugging.
3800 Print each CLI command as it is executed. Each command is prefixed with
3801 a number of `+' symbols representing the nesting depth.
3802 The source command now has a `-v' option to enable the same feature.
3806 The ARM Demon monitor support (RDP protocol, "target rdp").
3808 Kernel Object Display, an embedded debugging feature which only worked with
3809 an obsolete version of Cisco IOS.
3811 The 'set download-write-size' and 'show download-write-size' commands.
3813 * New remote packets
3816 Tell a stub about GDB client features, and request remote target features.
3817 The first feature implemented is PacketSize, which allows the target to
3818 specify the size of packets it can handle - to minimize the number of
3819 packets required and improve performance when connected to a remote
3823 Fetch an OS auxilliary vector from the remote stub. This packet is a
3824 more efficient replacement for qPart:auxv:read.
3826 qXfer:memory-map:read:
3827 Fetch a memory map from the remote stub, including information about
3828 RAM, ROM, and flash memory devices.
3833 Erase and program a flash memory device.
3835 * Removed remote packets
3838 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3839 used it, and only gdbserver implemented it.
3841 *** Changes in GDB 6.5
3845 Renesas M32C/M16C m32c-elf
3847 Morpho Technologies ms1 ms1-elf
3851 init-if-undefined Initialize a convenience variable, but
3852 only if it doesn't already have a value.
3854 The following commands are presently only implemented for native GNU/Linux:
3856 checkpoint Save a snapshot of the program state.
3858 restart <n> Return the program state to a
3859 previously saved state.
3861 info checkpoints List currently saved checkpoints.
3863 delete-checkpoint <n> Delete a previously saved checkpoint.
3865 set|show detach-on-fork Tell gdb whether to detach from a newly
3866 forked process, or to keep debugging it.
3868 info forks List forks of the user program that
3869 are available to be debugged.
3871 fork <n> Switch to debugging one of several
3872 forks of the user program that are
3873 available to be debugged.
3875 delete-fork <n> Delete a fork from the list of forks
3876 that are available to be debugged (and
3877 kill the forked process).
3879 detach-fork <n> Delete a fork from the list of forks
3880 that are available to be debugged (and
3881 allow the process to continue).
3885 Morpho Technologies ms2 ms1-elf
3887 * Improved Windows host support
3889 GDB now builds as a cross debugger hosted on i686-mingw32, including
3890 native console support, and remote communications using either
3891 network sockets or serial ports.
3893 * Improved Modula-2 language support
3895 GDB can now print most types in the Modula-2 syntax. This includes:
3896 basic types, set types, record types, enumerated types, range types,
3897 pointer types and ARRAY types. Procedure var parameters are correctly
3898 printed and hexadecimal addresses and character constants are also
3899 written in the Modula-2 syntax. Best results can be obtained by using
3900 GNU Modula-2 together with the -gdwarf-2 command line option.
3904 The ARM rdi-share module.
3906 The Netware NLM debug server.
3908 *** Changes in GDB 6.4
3910 * New native configurations
3912 OpenBSD/arm arm*-*-openbsd*
3913 OpenBSD/mips64 mips64-*-openbsd*
3917 Morpho Technologies ms1 ms1-elf
3919 * New command line options
3921 --batch-silent As for --batch, but totally silent.
3922 --return-child-result The debugger will exist with the same value
3923 the child (debugged) program exited with.
3924 --eval-command COMMAND, -ex COMMAND
3925 Execute a single GDB CLI command. This may be
3926 specified multiple times and in conjunction
3927 with the --command (-x) option.
3929 * Deprecated commands removed
3931 The following commands, that were deprecated in 2000, have been
3935 set|show arm disassembly-flavor set|show arm disassembler
3936 othernames set arm disassembler
3937 set|show remotedebug set|show debug remote
3938 set|show archdebug set|show debug arch
3939 set|show eventdebug set|show debug event
3942 * New BSD user-level threads support
3944 It is now possible to debug programs using the user-level threads
3945 library on OpenBSD and FreeBSD. Currently supported (target)
3948 FreeBSD/amd64 x86_64-*-freebsd*
3949 FreeBSD/i386 i386-*-freebsd*
3950 OpenBSD/i386 i386-*-openbsd*
3952 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3953 are not yet supported.
3955 * New support for Matsushita MN10300 w/sim added
3956 (Work in progress). mn10300-elf.
3958 * REMOVED configurations and files
3960 VxWorks and the XDR protocol *-*-vxworks
3961 Motorola MCORE mcore-*-*
3962 National Semiconductor NS32000 ns32k-*-*
3964 * New "set print array-indexes" command
3966 After turning this setting "on", GDB prints the index of each element
3967 when displaying arrays. The default is "off" to preserve the previous
3970 * VAX floating point support
3972 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3974 * User-defined command support
3976 In addition to using $arg0..$arg9 for argument passing, it is now possible
3977 to use $argc to determine now many arguments have been passed. See the
3978 section on user-defined commands in the user manual for more information.
3980 *** Changes in GDB 6.3:
3982 * New command line option
3984 GDB now accepts -l followed by a number to set the timeout for remote
3987 * GDB works with GCC -feliminate-dwarf2-dups
3989 GDB now supports a more compact representation of DWARF-2 debug
3990 information using DW_FORM_ref_addr references. These are produced
3991 by GCC with the option -feliminate-dwarf2-dups and also by some
3992 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3993 to use -feliminate-dwarf2-dups.
3995 * Internationalization
3997 When supported by the host system, GDB will be built with
3998 internationalization (libintl). The task of marking up the sources is
3999 continued, we're looking forward to our first translation.
4003 Initial support for debugging programs compiled with the GNAT
4004 implementation of the Ada programming language has been integrated
4005 into GDB. In this release, support is limited to expression evaluation.
4007 * New native configurations
4009 GNU/Linux/m32r m32r-*-linux-gnu
4013 GDB's remote protocol now includes support for the 'p' packet. This
4014 packet is used to fetch individual registers from a remote inferior.
4016 * END-OF-LIFE registers[] compatibility module
4018 GDB's internal register infrastructure has been completely rewritten.
4019 The new infrastructure making possible the implementation of key new
4020 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4023 GDB 6.3 will be the last release to include the the registers[]
4024 compatibility module that allowed out-of-date configurations to
4025 continue to work. This change directly impacts the following
4035 powerpc bdm protocol
4037 Unless there is activity to revive these configurations, they will be
4038 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4040 * OBSOLETE configurations and files
4042 Configurations that have been declared obsolete in this release have
4043 been commented out. Unless there is activity to revive these
4044 configurations, the next release of GDB will have their sources
4045 permanently REMOVED.
4054 *** Changes in GDB 6.2.1:
4056 * MIPS `break main; run' gave an heuristic-fence-post warning
4058 When attempting to run even a simple program, a warning about
4059 heuristic-fence-post being hit would be reported. This problem has
4062 * MIPS IRIX 'long double' crashed GDB
4064 When examining a long double variable, GDB would get a segmentation
4065 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4066 IRIX long double values).
4070 A bug in the VAX stack code was causing problems with the "next"
4071 command. This problem has been fixed.
4073 *** Changes in GDB 6.2:
4075 * Fix for ``many threads''
4077 On GNU/Linux systems that use the NPTL threads library, a program
4078 rapidly creating and deleting threads would confuse GDB leading to the
4081 ptrace: No such process.
4082 thread_db_get_info: cannot get thread info: generic error
4084 This problem has been fixed.
4086 * "-async" and "-noasync" options removed.
4088 Support for the broken "-noasync" option has been removed (it caused
4091 * New ``start'' command.
4093 This command runs the program until the begining of the main procedure.
4095 * New BSD Kernel Data Access Library (libkvm) interface
4097 Using ``target kvm'' it is now possible to debug kernel core dumps and
4098 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4099 platforms. Currently supported (native-only) configurations are:
4101 FreeBSD/amd64 x86_64-*-freebsd*
4102 FreeBSD/i386 i?86-*-freebsd*
4103 NetBSD/i386 i?86-*-netbsd*
4104 NetBSD/m68k m68*-*-netbsd*
4105 NetBSD/sparc sparc-*-netbsd*
4106 OpenBSD/amd64 x86_64-*-openbsd*
4107 OpenBSD/i386 i?86-*-openbsd*
4108 OpenBSD/m68k m68*-openbsd*
4109 OpenBSD/sparc sparc-*-openbsd*
4111 * Signal trampoline code overhauled
4113 Many generic problems with GDB's signal handling code have been fixed.
4114 These include: backtraces through non-contiguous stacks; recognition
4115 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4116 call; backtrace through a signal trampoline; step into and out of
4117 signal handlers; and single-stepping in the signal trampoline.
4119 Please note that kernel bugs are a limiting factor here. These
4120 features have been shown to work on an s390 GNU/Linux system that
4121 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4123 * Cygwin support for DWARF 2 added.
4125 * New native configurations
4127 GNU/Linux/hppa hppa*-*-linux*
4128 OpenBSD/hppa hppa*-*-openbsd*
4129 OpenBSD/m68k m68*-*-openbsd*
4130 OpenBSD/m88k m88*-*-openbsd*
4131 OpenBSD/powerpc powerpc-*-openbsd*
4132 NetBSD/vax vax-*-netbsd*
4133 OpenBSD/vax vax-*-openbsd*
4135 * END-OF-LIFE frame compatibility module
4137 GDB's internal frame infrastructure has been completely rewritten.
4138 The new infrastructure making it possible to support key new features
4139 including DWARF 2 Call Frame Information. To aid in the task of
4140 migrating old configurations to this new infrastructure, a
4141 compatibility module, that allowed old configurations to continue to
4142 work, was also included.
4144 GDB 6.2 will be the last release to include this frame compatibility
4145 module. This change directly impacts the following configurations:
4155 Unless there is activity to revive these configurations, they will be
4156 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4158 * REMOVED configurations and files
4160 Sun 3, running SunOS 3 m68*-*-sunos3*
4161 Sun 3, running SunOS 4 m68*-*-sunos4*
4162 Sun 2, running SunOS 3 m68000-*-sunos3*
4163 Sun 2, running SunOS 4 m68000-*-sunos4*
4164 Motorola 680x0 running LynxOS m68*-*-lynxos*
4165 AT&T 3b1/Unix pc m68*-att-*
4166 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4167 decstation mips-dec-* mips-little-*
4168 riscos mips-*-riscos* mips-*-sysv*
4169 sonymips mips-sony-*
4170 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4172 *** Changes in GDB 6.1.1:
4174 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4176 The TUI (Text-mode User Interface) is now built as part of a default
4177 GDB configuration. It is enabled by either selecting the TUI with the
4178 command line option "-i=tui" or by running the separate "gdbtui"
4179 program. For more information on the TUI, see the manual "Debugging
4182 * Pending breakpoint support (also included in GDB 6.1)
4184 Support has been added to allow you to specify breakpoints in shared
4185 libraries that have not yet been loaded. If a breakpoint location
4186 cannot be found, and the "breakpoint pending" option is set to auto,
4187 GDB queries you if you wish to make the breakpoint pending on a future
4188 shared-library load. If and when GDB resolves the breakpoint symbol,
4189 the pending breakpoint is removed as one or more regular breakpoints
4192 Pending breakpoints are very useful for GCJ Java debugging.
4194 * Fixed ISO-C build problems
4196 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4197 non ISO-C code that stopped them being built using a more strict ISO-C
4198 compiler (e.g., IBM's C compiler).
4200 * Fixed build problem on IRIX 5
4202 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4203 wasn't able to compile compile on an IRIX 5 system.
4205 * Added execute permission to gdb/gdbserver/configure
4207 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4208 permission. This bug would cause configure to fail on a number of
4209 systems (Solaris, IRIX). Ref: server/519.
4211 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4213 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4214 has been updated to use constant array sizes.
4216 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4218 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4219 its generated DWARF Call Frame Info. This encoding was causing GDB to
4220 panic, that panic has been fixed. Ref: gdb/1628.
4222 * Fixed a problem when examining parameters in shared library code.
4224 When examining parameters in optimized shared library code generated
4225 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4226 not available''. GDB now correctly displays the variable's value.
4228 *** Changes in GDB 6.1:
4230 * Removed --with-mmalloc
4232 Support for the mmalloc memory manager has been removed, as it
4233 conflicted with the internal gdb byte cache.
4235 * Changes in AMD64 configurations
4237 The AMD64 target now includes the %cs and %ss registers. As a result
4238 the AMD64 remote protocol has changed; this affects the floating-point
4239 and SSE registers. If you rely on those registers for your debugging,
4240 you should upgrade gdbserver on the remote side.
4242 * Revised SPARC target
4244 The SPARC target has been completely revised, incorporating the
4245 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4246 support for LynxOS and SunOS 4 has been dropped. Calling functions
4247 from within GDB on operating systems with a non-executable stack
4248 (Solaris, OpenBSD) now works.
4252 GDB has a new C++ demangler which does a better job on the mangled
4253 names generated by current versions of g++. It also runs faster, so
4254 with this and other changes gdb should now start faster on large C++
4257 * DWARF 2 Location Expressions
4259 GDB support for location expressions has been extended to support function
4260 arguments and frame bases. Older versions of GDB could crash when they
4263 * C++ nested types and namespaces
4265 GDB's support for nested types and namespaces in C++ has been
4266 improved, especially if you use the DWARF 2 debugging format. (This
4267 is the default for recent versions of GCC on most platforms.)
4268 Specifically, if you have a class "Inner" defined within a class or
4269 namespace "Outer", then GDB realizes that the class's name is
4270 "Outer::Inner", not simply "Inner". This should greatly reduce the
4271 frequency of complaints about not finding RTTI symbols. In addition,
4272 if you are stopped at inside of a function defined within a namespace,
4273 GDB modifies its name lookup accordingly.
4275 * New native configurations
4277 NetBSD/amd64 x86_64-*-netbsd*
4278 OpenBSD/amd64 x86_64-*-openbsd*
4279 OpenBSD/alpha alpha*-*-openbsd*
4280 OpenBSD/sparc sparc-*-openbsd*
4281 OpenBSD/sparc64 sparc64-*-openbsd*
4283 * New debugging protocols
4285 M32R with SDI protocol m32r-*-elf*
4287 * "set prompt-escape-char" command deleted.
4289 The command "set prompt-escape-char" has been deleted. This command,
4290 and its very obscure effet on GDB's prompt, was never documented,
4291 tested, nor mentioned in the NEWS file.
4293 * OBSOLETE configurations and files
4295 Configurations that have been declared obsolete in this release have
4296 been commented out. Unless there is activity to revive these
4297 configurations, the next release of GDB will have their sources
4298 permanently REMOVED.
4300 Sun 3, running SunOS 3 m68*-*-sunos3*
4301 Sun 3, running SunOS 4 m68*-*-sunos4*
4302 Sun 2, running SunOS 3 m68000-*-sunos3*
4303 Sun 2, running SunOS 4 m68000-*-sunos4*
4304 Motorola 680x0 running LynxOS m68*-*-lynxos*
4305 AT&T 3b1/Unix pc m68*-att-*
4306 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4307 decstation mips-dec-* mips-little-*
4308 riscos mips-*-riscos* mips-*-sysv*
4309 sonymips mips-sony-*
4310 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4312 * REMOVED configurations and files
4314 SGI Irix-4.x mips-sgi-irix4 or iris4
4315 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4316 Z8000 simulator z8k-zilog-none or z8ksim
4317 Matsushita MN10200 w/simulator mn10200-*-*
4318 H8/500 simulator h8500-hitachi-hms or h8500hms
4319 HP/PA running BSD hppa*-*-bsd*
4320 HP/PA running OSF/1 hppa*-*-osf*
4321 HP/PA Pro target hppa*-*-pro*
4322 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4323 386BSD i[3456]86-*-bsd*
4324 Sequent family i[3456]86-sequent-sysv4*
4325 i[3456]86-sequent-sysv*
4326 i[3456]86-sequent-bsd*
4327 SPARC running LynxOS sparc-*-lynxos*
4328 SPARC running SunOS 4 sparc-*-sunos4*
4329 Tsqware Sparclet sparclet-*-*
4330 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4332 *** Changes in GDB 6.0:
4336 Support for debugging the Objective-C programming language has been
4337 integrated into GDB.
4339 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4341 DWARF 2's Call Frame Information makes available compiler generated
4342 information that more exactly describes the program's run-time stack.
4343 By using this information, GDB is able to provide more robust stack
4346 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4347 have been updated to use a new backtrace mechanism which includes
4348 DWARF 2 CFI support.
4352 GDB's remote protocol has been extended to include support for hosted
4353 file I/O (where the remote target uses GDB's file system). See GDB's
4354 remote protocol documentation for details.
4356 * All targets using the new architecture framework.
4358 All of GDB's targets have been updated to use the new internal
4359 architecture framework. The way is now open for future GDB releases
4360 to include cross-architecture native debugging support (i386 on amd64,
4363 * GNU/Linux's Thread Local Storage (TLS)
4365 GDB now includes support for for the GNU/Linux implementation of
4366 per-thread variables.
4368 * GNU/Linux's Native POSIX Thread Library (NPTL)
4370 GDB's thread code has been updated to work with either the new
4371 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4373 * Separate debug info.
4375 GDB, in conjunction with BINUTILS, now supports a mechanism for
4376 automatically loading debug information from a separate file. Instead
4377 of shipping full debug and non-debug versions of system libraries,
4378 system integrators can now instead ship just the stripped libraries
4379 and optional debug files.
4381 * DWARF 2 Location Expressions
4383 DWARF 2 Location Expressions allow the compiler to more completely
4384 describe the location of variables (even in optimized code) to the
4387 GDB now includes preliminary support for location expressions (support
4388 for DW_OP_piece is still missing).
4392 A number of long standing bugs that caused GDB to die while starting a
4393 Java application have been fixed. GDB's Java support is now
4394 considered "useable".
4396 * GNU/Linux support for fork, vfork, and exec.
4398 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4399 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4402 * GDB supports logging output to a file
4404 There are two new commands, "set logging" and "show logging", which can be
4405 used to capture GDB's output to a file.
4407 * The meaning of "detach" has changed for gdbserver
4409 The "detach" command will now resume the application, as documented. To
4410 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4413 * d10v, m68hc11 `regs' command deprecated
4415 The `info registers' command has been updated so that it displays the
4416 registers using a format identical to the old `regs' command.
4420 A new command, "maint set profile on/off", has been added. This command can
4421 be used to enable or disable profiling while running GDB, to profile a
4422 session or a set of commands. In addition there is a new configure switch,
4423 "--enable-profiling", which will cause GDB to be compiled with profiling
4424 data, for more informative profiling results.
4426 * Default MI syntax changed to "mi2".
4428 The default MI (machine interface) syntax, enabled by the command line
4429 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4430 "mi1", can be enabled by specifying the option "-i=mi1".
4432 Support for the original "mi0" syntax (included in GDB 5.0) has been
4435 Fix for gdb/192: removed extraneous space when displaying frame level.
4436 Fix for gdb/672: update changelist is now output in mi list format.
4437 Fix for gdb/702: a -var-assign that updates the value now shows up
4438 in a subsequent -var-update.
4440 * New native configurations.
4442 FreeBSD/amd64 x86_64-*-freebsd*
4444 * Multi-arched targets.
4446 HP/PA HPUX11 hppa*-*-hpux*
4447 Renesas M32R/D w/simulator m32r-*-elf*
4449 * OBSOLETE configurations and files
4451 Configurations that have been declared obsolete in this release have
4452 been commented out. Unless there is activity to revive these
4453 configurations, the next release of GDB will have their sources
4454 permanently REMOVED.
4456 Z8000 simulator z8k-zilog-none or z8ksim
4457 Matsushita MN10200 w/simulator mn10200-*-*
4458 H8/500 simulator h8500-hitachi-hms or h8500hms
4459 HP/PA running BSD hppa*-*-bsd*
4460 HP/PA running OSF/1 hppa*-*-osf*
4461 HP/PA Pro target hppa*-*-pro*
4462 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4463 Sequent family i[3456]86-sequent-sysv4*
4464 i[3456]86-sequent-sysv*
4465 i[3456]86-sequent-bsd*
4466 Tsqware Sparclet sparclet-*-*
4467 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4469 * REMOVED configurations and files
4472 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4473 IBM AIX PS/2 i[3456]86-*-aix
4474 i386 running Mach 3.0 i[3456]86-*-mach3*
4475 i386 running Mach i[3456]86-*-mach*
4476 i386 running OSF/1 i[3456]86-*osf1mk*
4477 HP/Apollo 68k Family m68*-apollo*-sysv*,
4479 m68*-hp-bsd*, m68*-hp-hpux*
4480 Argonaut Risc Chip (ARC) arc-*-*
4481 Mitsubishi D30V d30v-*-*
4482 Fujitsu FR30 fr30-*-elf*
4483 OS/9000 i[34]86-*-os9k
4484 I960 with MON960 i960-*-coff
4486 * MIPS $fp behavior changed
4488 The convenience variable $fp, for the MIPS, now consistently returns
4489 the address of the current frame's base. Previously, depending on the
4490 context, $fp could refer to either $sp or the current frame's base
4491 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4492 The GNU Source-Level Debugger''.
4494 *** Changes in GDB 5.3:
4496 * GNU/Linux shared library multi-threaded performance improved.
4498 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4499 `/proc', in preference to `ptrace' for memory reads. This may result
4500 in an improvement in the start-up time of multi-threaded, shared
4501 library applications when run under GDB. One GDB user writes: ``loads
4502 shared libs like mad''.
4504 * ``gdbserver'' now supports multi-threaded applications on some targets
4506 Support for debugging multi-threaded applications which use
4507 the GNU/Linux LinuxThreads package has been added for
4508 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4509 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4511 * GDB now supports C/C++ preprocessor macros.
4513 GDB now expands preprocessor macro invocations in C/C++ expressions,
4514 and provides various commands for showing macro definitions and how
4517 The new command `macro expand EXPRESSION' expands any macro
4518 invocations in expression, and shows the result.
4520 The new command `show macro MACRO-NAME' shows the definition of the
4521 macro named MACRO-NAME, and where it was defined.
4523 Most compilers don't include information about macros in the debugging
4524 information by default. In GCC 3.1, for example, you need to compile
4525 your program with the options `-gdwarf-2 -g3'. If the macro
4526 information is present in the executable, GDB will read it.
4528 * Multi-arched targets.
4530 DEC Alpha (partial) alpha*-*-*
4531 DEC VAX (partial) vax-*-*
4533 National Semiconductor NS32000 (partial) ns32k-*-*
4534 Motorola 68000 (partial) m68k-*-*
4535 Motorola MCORE mcore-*-*
4539 Fujitsu FRV architecture added by Red Hat frv*-*-*
4542 * New native configurations
4544 Alpha NetBSD alpha*-*-netbsd*
4545 SH NetBSD sh*-*-netbsdelf*
4546 MIPS NetBSD mips*-*-netbsd*
4547 UltraSPARC NetBSD sparc64-*-netbsd*
4549 * OBSOLETE configurations and files
4551 Configurations that have been declared obsolete in this release have
4552 been commented out. Unless there is activity to revive these
4553 configurations, the next release of GDB will have their sources
4554 permanently REMOVED.
4556 Mitsubishi D30V d30v-*-*
4557 OS/9000 i[34]86-*-os9k
4558 IBM AIX PS/2 i[3456]86-*-aix
4559 Fujitsu FR30 fr30-*-elf*
4560 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4561 Argonaut Risc Chip (ARC) arc-*-*
4562 i386 running Mach 3.0 i[3456]86-*-mach3*
4563 i386 running Mach i[3456]86-*-mach*
4564 i386 running OSF/1 i[3456]86-*osf1mk*
4565 HP/Apollo 68k Family m68*-apollo*-sysv*,
4567 m68*-hp-bsd*, m68*-hp-hpux*
4568 I960 with MON960 i960-*-coff
4570 * OBSOLETE languages
4572 CHILL, a Pascal like language used by telecommunications companies.
4574 * REMOVED configurations and files
4576 AMD 29k family via UDI a29k-amd-udi, udi29k
4577 A29K VxWorks a29k-*-vxworks
4578 AMD 29000 embedded, using EBMON a29k-none-none
4579 AMD 29000 embedded with COFF a29k-none-coff
4580 AMD 29000 embedded with a.out a29k-none-aout
4582 testsuite/gdb.hp/gdb.threads-hp/ directory
4584 * New command "set max-user-call-depth <nnn>"
4586 This command allows the user to limit the call depth of user-defined
4587 commands. The default is 1024.
4589 * Changes in FreeBSD/i386 native debugging.
4591 Support for the "generate-core-file" has been added.
4593 * New commands "dump", "append", and "restore".
4595 These commands allow data to be copied from target memory
4596 to a bfd-format or binary file (dump and append), and back
4597 from a file into memory (restore).
4599 * Improved "next/step" support on multi-processor Alpha Tru64.
4601 The previous single-step mechanism could cause unpredictable problems,
4602 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4603 of a software single-step mechanism prevents this.
4605 *** Changes in GDB 5.2.1:
4613 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4614 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4615 Fix, by Joel Brobecker imported from mainline.
4617 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4618 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4619 Fix, by Fred Fish, imported from mainline.
4621 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4622 Surprisingly enough, it works now.
4623 By Michal Ludvig, imported from mainline.
4625 i386 hardware watchpoint support:
4626 avoid misses on second run for some targets.
4627 By Pierre Muller, imported from mainline.
4629 *** Changes in GDB 5.2:
4631 * New command "set trust-readonly-sections on[off]".
4633 This command is a hint that tells gdb that read-only sections
4634 really are read-only (ie. that their contents will not change).
4635 In this mode, gdb will go to the object file rather than the
4636 target to read memory from read-only sections (such as ".text").
4637 This can be a significant performance improvement on some
4638 (notably embedded) targets.
4640 * New command "generate-core-file" (or "gcore").
4642 This new gdb command allows the user to drop a core file of the child
4643 process state at any time. So far it's been implemented only for
4644 GNU/Linux and Solaris, but should be relatively easily ported to other
4645 hosts. Argument is core file name (defaults to core.<pid>).
4647 * New command line option
4649 GDB now accepts --pid or -p followed by a process id.
4651 * Change in command line behavior -- corefiles vs. process ids.
4653 There is a subtle behavior in the way in which GDB handles
4654 command line arguments. The first non-flag argument is always
4655 a program to debug, but the second non-flag argument may either
4656 be a corefile or a process id. Previously, GDB would attempt to
4657 open the second argument as a corefile, and if that failed, would
4658 issue a superfluous error message and then attempt to attach it as
4659 a process. Now, if the second argument begins with a non-digit,
4660 it will be treated as a corefile. If it begins with a digit,
4661 GDB will attempt to attach it as a process, and if no such process
4662 is found, will then attempt to open it as a corefile.
4664 * Changes in ARM configurations.
4666 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4667 configuration is fully multi-arch.
4669 * New native configurations
4671 ARM NetBSD arm*-*-netbsd*
4672 x86 OpenBSD i[3456]86-*-openbsd*
4673 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4674 Sparc64 running FreeBSD sparc64-*-freebsd*
4678 Sanyo XStormy16 xstormy16-elf
4680 * OBSOLETE configurations and files
4682 Configurations that have been declared obsolete in this release have
4683 been commented out. Unless there is activity to revive these
4684 configurations, the next release of GDB will have their sources
4685 permanently REMOVED.
4687 AMD 29k family via UDI a29k-amd-udi, udi29k
4688 A29K VxWorks a29k-*-vxworks
4689 AMD 29000 embedded, using EBMON a29k-none-none
4690 AMD 29000 embedded with COFF a29k-none-coff
4691 AMD 29000 embedded with a.out a29k-none-aout
4693 testsuite/gdb.hp/gdb.threads-hp/ directory
4695 * REMOVED configurations and files
4697 TI TMS320C80 tic80-*-*
4699 PowerPC Solaris powerpcle-*-solaris*
4700 PowerPC Windows NT powerpcle-*-cygwin32
4701 PowerPC Netware powerpc-*-netware*
4702 Harris/CXUX m88k m88*-harris-cxux*
4703 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4704 ns32k-utek-sysv* ns32k-utek-*
4705 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4706 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4707 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4708 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4709 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4711 * Changes to command line processing
4713 The new `--args' feature can be used to specify command-line arguments
4714 for the inferior from gdb's command line.
4716 * Changes to key bindings
4718 There is a new `operate-and-get-next' function bound to `C-o'.
4720 *** Changes in GDB 5.1.1
4722 Fix compile problem on DJGPP.
4724 Fix a problem with floating-point registers on the i386 being
4727 Fix to stop GDB crashing on .debug_str debug info.
4729 Numerous documentation fixes.
4731 Numerous testsuite fixes.
4733 *** Changes in GDB 5.1:
4735 * New native configurations
4737 Alpha FreeBSD alpha*-*-freebsd*
4738 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4739 MIPS GNU/Linux mips*-*-linux*
4740 MIPS SGI Irix 6.x mips*-sgi-irix6*
4741 ia64 AIX ia64-*-aix*
4742 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4746 Motorola 68HC11 and 68HC12 m68hc11-elf
4748 UltraSparc running GNU/Linux sparc64-*-linux*
4750 * OBSOLETE configurations and files
4752 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4753 Harris/CXUX m88k m88*-harris-cxux*
4754 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4755 ns32k-utek-sysv* ns32k-utek-*
4756 TI TMS320C80 tic80-*-*
4758 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4759 PowerPC Solaris powerpcle-*-solaris*
4760 PowerPC Windows NT powerpcle-*-cygwin32
4761 PowerPC Netware powerpc-*-netware*
4762 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4763 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4764 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4765 Apple Macintosh (MPW) host N/A
4767 stuff.c (Program to stuff files into a specially prepared space in kdb)
4768 kdb-start.c (Main loop for the standalone kernel debugger)
4770 Configurations that have been declared obsolete in this release have
4771 been commented out. Unless there is activity to revive these
4772 configurations, the next release of GDB will have their sources
4773 permanently REMOVED.
4775 * REMOVED configurations and files
4777 Altos 3068 m68*-altos-*
4778 Convex c1-*-*, c2-*-*
4780 ARM RISCix arm-*-* (as host)
4784 * GDB has been converted to ISO C.
4786 GDB's source code has been converted to ISO C. In particular, the
4787 sources are fully protoized, and rely on standard headers being
4792 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4794 * The MI enabled by default.
4796 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4797 revised and enabled by default. Packages which use GDB as a debugging
4798 engine behind a UI or another front end are encouraged to switch to
4799 using the GDB/MI interface, instead of the old annotations interface
4800 which is now deprecated.
4802 * Support for debugging Pascal programs.
4804 GDB now includes support for debugging Pascal programs. The following
4805 main features are supported:
4807 - Pascal-specific data types such as sets;
4809 - automatic recognition of Pascal sources based on file-name
4812 - Pascal-style display of data types, variables, and functions;
4814 - a Pascal expression parser.
4816 However, some important features are not yet supported.
4818 - Pascal string operations are not supported at all;
4820 - there are some problems with boolean types;
4822 - Pascal type hexadecimal constants are not supported
4823 because they conflict with the internal variables format;
4825 - support for Pascal objects and classes is not full yet;
4827 - unlike Pascal, GDB is case-sensitive for symbol names.
4829 * Changes in completion.
4831 Commands such as `shell', `run' and `set args', which pass arguments
4832 to inferior programs, now complete on file names, similar to what
4833 users expect at the shell prompt.
4835 Commands which accept locations, such as `disassemble', `print',
4836 `breakpoint', `until', etc. now complete on filenames as well as
4837 program symbols. Thus, if you type "break foob TAB", and the source
4838 files linked into the programs include `foobar.c', that file name will
4839 be one of the candidates for completion. However, file names are not
4840 considered for completion after you typed a colon that delimits a file
4841 name from a name of a function in that file, as in "break foo.c:bar".
4843 `set demangle-style' completes on available demangling styles.
4845 * New platform-independent commands:
4847 It is now possible to define a post-hook for a command as well as a
4848 hook that runs before the command. For more details, see the
4849 documentation of `hookpost' in the GDB manual.
4851 * Changes in GNU/Linux native debugging.
4853 Support for debugging multi-threaded programs has been completely
4854 revised for all platforms except m68k and sparc. You can now debug as
4855 many threads as your system allows you to have.
4857 Attach/detach is supported for multi-threaded programs.
4859 Support for SSE registers was added for x86. This doesn't work for
4860 multi-threaded programs though.
4862 * Changes in MIPS configurations.
4864 Multi-arch support is enabled for all MIPS configurations.
4866 GDB can now be built as native debugger on SGI Irix 6.x systems for
4867 debugging n32 executables. (Debugging 64-bit executables is not yet
4870 * Unified support for hardware watchpoints in all x86 configurations.
4872 Most (if not all) native x86 configurations support hardware-assisted
4873 breakpoints and watchpoints in a unified manner. This support
4874 implements debug register sharing between watchpoints, which allows to
4875 put a virtually infinite number of watchpoints on the same address,
4876 and also supports watching regions up to 16 bytes with several debug
4879 The new maintenance command `maintenance show-debug-regs' toggles
4880 debugging print-outs in functions that insert, remove, and test
4881 watchpoints and hardware breakpoints.
4883 * Changes in the DJGPP native configuration.
4885 New command ``info dos sysinfo'' displays assorted information about
4886 the CPU, OS, memory, and DPMI server.
4888 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4889 display information about segment descriptors stored in GDT, LDT, and
4892 New commands ``info dos pde'' and ``info dos pte'' display entries
4893 from Page Directory and Page Tables (for now works with CWSDPMI only).
4894 New command ``info dos address-pte'' displays the Page Table entry for
4895 a given linear address.
4897 GDB can now pass command lines longer than 126 characters to the
4898 program being debugged (requires an update to the libdbg.a library
4899 which is part of the DJGPP development kit).
4901 DWARF2 debug info is now supported.
4903 It is now possible to `step' and `next' through calls to `longjmp'.
4905 * Changes in documentation.
4907 All GDB documentation was converted to GFDL, the GNU Free
4908 Documentation License.
4910 Tracepoints-related commands are now fully documented in the GDB
4913 TUI, the Text-mode User Interface, is now documented in the manual.
4915 Tracepoints-related commands are now fully documented in the GDB
4918 The "GDB Internals" manual now has an index. It also includes
4919 documentation of `ui_out' functions, GDB coding standards, x86
4920 hardware watchpoints, and memory region attributes.
4922 * GDB's version number moved to ``version.in''
4924 The Makefile variable VERSION has been replaced by the file
4925 ``version.in''. People creating GDB distributions should update the
4926 contents of this file.
4930 GUD support is now a standard part of the EMACS distribution.
4932 *** Changes in GDB 5.0:
4934 * Improved support for debugging FP programs on x86 targets
4936 Unified and much-improved support for debugging floating-point
4937 programs on all x86 targets. In particular, ``info float'' now
4938 displays the FP registers in the same format on all x86 targets, with
4939 greater level of detail.
4941 * Improvements and bugfixes in hardware-assisted watchpoints
4943 It is now possible to watch array elements, struct members, and
4944 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4945 on x86 targets no longer erroneously trigger when the address is
4948 * Improvements in the native DJGPP version of GDB
4950 The distribution now includes all the scripts and auxiliary files
4951 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4952 machines ``out of the box''.
4954 The DJGPP version can now debug programs that use signals. It is
4955 possible to catch signals that happened in the debuggee, deliver
4956 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4957 would kill the program being debugged.) Programs that hook hardware
4958 interrupts (keyboard, timer, etc.) can also be debugged.
4960 It is now possible to debug DJGPP programs that redirect their
4961 standard handles or switch them to raw (as opposed to cooked) mode, or
4962 even close them. The command ``run < foo > bar'' works as expected,
4963 and ``info terminal'' reports useful information about the debuggee's
4964 terminal, including raw/cooked mode, redirection, etc.
4966 The DJGPP version now uses termios functions for console I/O, which
4967 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4970 DOS-style file names with drive letters are now fully supported by
4973 It is now possible to debug DJGPP programs that switch their working
4974 directory. It is also possible to rerun the debuggee any number of
4975 times without restarting GDB; thus, you can use the same setup,
4976 breakpoints, etc. for many debugging sessions.
4978 * New native configurations
4980 ARM GNU/Linux arm*-*-linux*
4981 PowerPC GNU/Linux powerpc-*-linux*
4985 Motorola MCore mcore-*-*
4986 x86 VxWorks i[3456]86-*-vxworks*
4987 PowerPC VxWorks powerpc-*-vxworks*
4988 TI TMS320C80 tic80-*-*
4990 * OBSOLETE configurations
4992 Altos 3068 m68*-altos-*
4993 Convex c1-*-*, c2-*-*
4995 ARM RISCix arm-*-* (as host)
4998 Configurations that have been declared obsolete will be commented out,
4999 but the code will be left in place. If there is no activity to revive
5000 these configurations before the next release of GDB, the sources will
5001 be permanently REMOVED.
5003 * Gould support removed
5005 Support for the Gould PowerNode and NP1 has been removed.
5007 * New features for SVR4
5009 On SVR4 native platforms (such as Solaris), if you attach to a process
5010 without first loading a symbol file, GDB will now attempt to locate and
5011 load symbols from the running process's executable file.
5013 * Many C++ enhancements
5015 C++ support has been greatly improved. Overload resolution now works properly
5016 in almost all cases. RTTI support is on the way.
5018 * Remote targets can connect to a sub-program
5020 A popen(3) style serial-device has been added. This device starts a
5021 sub-process (such as a stand-alone simulator) and then communicates
5022 with that. The sub-program to run is specified using the syntax
5023 ``|<program> <args>'' vis:
5025 (gdb) set remotedebug 1
5026 (gdb) target extended-remote |mn10300-elf-sim program-args
5028 * MIPS 64 remote protocol
5030 A long standing bug in the mips64 remote protocol where by GDB
5031 expected certain 32 bit registers (ex SR) to be transfered as 32
5032 instead of 64 bits has been fixed.
5034 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5035 added to provide backward compatibility with older versions of GDB.
5037 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5039 The command ``set remotebinarydownload'' command has been replaced by
5040 ``set remote X-packet''. Other commands in ``set remote'' family
5041 include ``set remote P-packet''.
5043 * Breakpoint commands accept ranges.
5045 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5046 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5047 ``tracepoint passcount'' also accepts a range of tracepoints.
5049 * ``apropos'' command added.
5051 The ``apropos'' command searches through command names and
5052 documentation strings, printing out matches, making it much easier to
5053 try to find a command that does what you are looking for.
5057 A new machine oriented interface (MI) has been added to GDB. This
5058 interface is designed for debug environments running GDB as a separate
5059 process. This is part of the long term libGDB project. See the
5060 "GDB/MI" chapter of the GDB manual for further information. It can be
5061 enabled by configuring with:
5063 .../configure --enable-gdbmi
5065 *** Changes in GDB-4.18:
5067 * New native configurations
5069 HP-UX 10.20 hppa*-*-hpux10.20
5070 HP-UX 11.x hppa*-*-hpux11.0*
5071 M68K GNU/Linux m68*-*-linux*
5075 Fujitsu FR30 fr30-*-elf*
5076 Intel StrongARM strongarm-*-*
5077 Mitsubishi D30V d30v-*-*
5079 * OBSOLETE configurations
5081 Gould PowerNode, NP1 np1-*-*, pn-*-*
5083 Configurations that have been declared obsolete will be commented out,
5084 but the code will be left in place. If there is no activity to revive
5085 these configurations before the next release of GDB, the sources will
5086 be permanently REMOVED.
5090 As a compatibility experiment, GDB's source files buildsym.h and
5091 buildsym.c have been converted to pure standard C, no longer
5092 containing any K&R compatibility code. We believe that all systems in
5093 use today either come with a standard C compiler, or have a GCC port
5094 available. If this is not true, please report the affected
5095 configuration to bug-gdb@gnu.org immediately. See the README file for
5096 information about getting a standard C compiler if you don't have one
5101 GDB now uses readline 2.2.
5103 * set extension-language
5105 You can now control the mapping between filename extensions and source
5106 languages by using the `set extension-language' command. For instance,
5107 you can ask GDB to treat .c files as C++ by saying
5108 set extension-language .c c++
5109 The command `info extensions' lists all of the recognized extensions
5110 and their associated languages.
5112 * Setting processor type for PowerPC and RS/6000
5114 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5115 you can use the `set processor' command to specify what variant of the
5116 PowerPC family you are debugging. The command
5120 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5121 following PowerPC and RS6000 variants:
5123 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5124 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5126 403GC IBM PowerPC 403GC
5127 505 Motorola PowerPC 505
5128 860 Motorola PowerPC 860 or 850
5129 601 Motorola PowerPC 601
5130 602 Motorola PowerPC 602
5131 603 Motorola/IBM PowerPC 603 or 603e
5132 604 Motorola PowerPC 604 or 604e
5133 750 Motorola/IBM PowerPC 750 or 750
5135 At the moment, this command just tells GDB what to name the
5136 special-purpose processor registers. Since almost all the affected
5137 registers are inaccessible to user-level programs, this command is
5138 only useful for remote debugging in its present form.
5142 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5143 more extensive support for HP-UX. Added features include shared
5144 library support, kernel threads and hardware watchpoints for 11.00,
5145 support for HP's ANSI C and C++ compilers, and a compatibility mode
5146 for xdb and dbx commands.
5150 HP's donation includes the new concept of catchpoints, which is a
5151 generalization of the old catch command. On HP-UX, it is now possible
5152 to catch exec, fork, and vfork, as well as library loading.
5154 This means that the existing catch command has changed; its first
5155 argument now specifies the type of catch to be set up. See the
5156 output of "help catch" for a list of catchpoint types.
5158 * Debugging across forks
5160 On HP-UX, you can choose which process to debug when a fork() happens
5165 HP has donated a curses-based terminal user interface (TUI). To get
5166 it, build with --enable-tui. Although this can be enabled for any
5167 configuration, at present it only works for native HP debugging.
5169 * GDB remote protocol additions
5171 A new protocol packet 'X' that writes binary data is now available.
5172 Default behavior is to try 'X', then drop back to 'M' if the stub
5173 fails to respond. The settable variable `remotebinarydownload'
5174 allows explicit control over the use of 'X'.
5176 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5177 full 64-bit address. The command
5179 set remoteaddresssize 32
5181 can be used to revert to the old behaviour. For existing remote stubs
5182 the change should not be noticed, as the additional address information
5185 In order to assist in debugging stubs, you may use the maintenance
5186 command `packet' to send any text string to the stub. For instance,
5188 maint packet heythere
5190 sends the packet "$heythere#<checksum>". Note that it is very easy to
5191 disrupt a debugging session by sending the wrong packet at the wrong
5194 The compare-sections command allows you to compare section data on the
5195 target to what is in the executable file without uploading or
5196 downloading, by comparing CRC checksums.
5198 * Tracing can collect general expressions
5200 You may now collect general expressions at tracepoints. This requires
5201 further additions to the target-side stub; see tracepoint.c and
5202 doc/agentexpr.texi for further details.
5204 * mask-address variable for Mips
5206 For Mips targets, you may control the zeroing of the upper 32 bits of
5207 a 64-bit address by entering `set mask-address on'. This is mainly
5208 of interest to users of embedded R4xxx and R5xxx processors.
5210 * Higher serial baud rates
5212 GDB's serial code now allows you to specify baud rates 57600, 115200,
5213 230400, and 460800 baud. (Note that your host system may not be able
5214 to achieve all of these rates.)
5218 The i960 configuration now includes an initial implementation of a
5219 builtin simulator, contributed by Jim Wilson.
5222 *** Changes in GDB-4.17:
5224 * New native configurations
5226 Alpha GNU/Linux alpha*-*-linux*
5227 Unixware 2.x i[3456]86-unixware2*
5228 Irix 6.x mips*-sgi-irix6*
5229 PowerPC GNU/Linux powerpc-*-linux*
5230 PowerPC Solaris powerpcle-*-solaris*
5231 Sparc GNU/Linux sparc-*-linux*
5232 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5236 Argonaut Risc Chip (ARC) arc-*-*
5237 Hitachi H8/300S h8300*-*-*
5238 Matsushita MN10200 w/simulator mn10200-*-*
5239 Matsushita MN10300 w/simulator mn10300-*-*
5240 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5241 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5242 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5243 Mitsubishi D10V w/simulator d10v-*-*
5244 Mitsubishi M32R/D w/simulator m32r-*-elf*
5245 Tsqware Sparclet sparclet-*-*
5246 NEC V850 w/simulator v850-*-*
5248 * New debugging protocols
5250 ARM with RDI protocol arm*-*-*
5251 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5252 DDB and LSI variants of PMON protocol mips*-*-*
5253 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5254 PowerPC with SDS protocol powerpc{,le}-*-eabi
5255 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5259 All configurations can now understand and use the DWARF 2 debugging
5260 format. The choice is automatic, if the symbol file contains DWARF 2
5265 GDB now includes basic Java language support. This support is
5266 only useful with Java compilers that produce native machine code.
5268 * solib-absolute-prefix and solib-search-path
5270 For SunOS and SVR4 shared libraries, you may now set the prefix for
5271 loading absolute shared library symbol files, and the search path for
5272 locating non-absolute shared library symbol files.
5274 * Live range splitting
5276 GDB can now effectively debug code for which GCC has performed live
5277 range splitting as part of its optimization. See gdb/doc/LRS for
5278 more details on the expected format of the stabs information.
5282 GDB's support for the GNU Hurd, including thread debugging, has been
5283 updated to work with current versions of the Hurd.
5287 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5288 instruction set. ARM GDB automatically detects when Thumb
5289 instructions are in use, and adjusts disassembly and backtracing
5294 GDB's MIPS target configurations now handle the MIP16 16-bit
5299 GDB now includes support for overlays; if an executable has been
5300 linked such that multiple sections are based at the same address, GDB
5301 will decide which section to use for symbolic info. You can choose to
5302 control the decision manually, using overlay commands, or implement
5303 additional target-side support and use "overlay load-target" to bring
5304 in the overlay mapping. Do "help overlay" for more detail.
5308 The command "info symbol <address>" displays information about
5309 the symbol at the specified address.
5313 The standard remote protocol now includes an extension that allows
5314 asynchronous collection and display of trace data. This requires
5315 extensive support in the target-side debugging stub. Tracing mode
5316 includes a new interaction mode in GDB and new commands: see the
5317 file tracepoint.c for more details.
5321 Configurations for embedded MIPS now include a simulator contributed
5322 by Cygnus Solutions. The simulator supports the instruction sets
5323 of most MIPS variants.
5327 Sparc configurations may now include the ERC32 simulator contributed
5328 by the European Space Agency. The simulator is not built into
5329 Sparc targets by default; configure with --enable-sim to include it.
5333 For target configurations that may include multiple variants of a
5334 basic architecture (such as MIPS and SH), you may now set the
5335 architecture explicitly. "set arch" sets, "info arch" lists
5336 the possible architectures.
5338 *** Changes in GDB-4.16:
5340 * New native configurations
5342 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5343 M68K NetBSD m68k-*-netbsd*
5344 PowerPC AIX 4.x powerpc-*-aix*
5345 PowerPC MacOS powerpc-*-macos*
5346 PowerPC Windows NT powerpcle-*-cygwin32
5347 RS/6000 AIX 4.x rs6000-*-aix4*
5351 ARM with RDP protocol arm-*-*
5352 I960 with MON960 i960-*-coff
5353 MIPS VxWorks mips*-*-vxworks*
5354 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5355 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5357 Matra Sparclet sparclet-*-*
5361 The powerpc-eabi configuration now includes the PSIM simulator,
5362 contributed by Andrew Cagney, with assistance from Mike Meissner.
5363 PSIM is a very elaborate model of the PowerPC, including not only
5364 basic instruction set execution, but also details of execution unit
5365 performance and I/O hardware. See sim/ppc/README for more details.
5369 GDB now works with Solaris 2.5.
5371 * Windows 95/NT native
5373 GDB will now work as a native debugger on Windows 95 and Windows NT.
5374 To build it from source, you must use the "gnu-win32" environment,
5375 which uses a DLL to emulate enough of Unix to run the GNU tools.
5376 Further information, binaries, and sources are available at
5377 ftp.cygnus.com, under pub/gnu-win32.
5379 * dont-repeat command
5381 If a user-defined command includes the command `dont-repeat', then the
5382 command will not be repeated if the user just types return. This is
5383 useful if the command is time-consuming to run, so that accidental
5384 extra keystrokes don't run the same command many times.
5386 * Send break instead of ^C
5388 The standard remote protocol now includes an option to send a break
5389 rather than a ^C to the target in order to interrupt it. By default,
5390 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5392 * Remote protocol timeout
5394 The standard remote protocol includes a new variable `remotetimeout'
5395 that allows you to set the number of seconds before GDB gives up trying
5396 to read from the target. The default value is 2.
5398 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5400 By default GDB will automatically keep track of objects as they are
5401 loaded and unloaded by the dynamic linker. By using the command `set
5402 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5403 when shared library events occur, thus allowing you to set breakpoints
5404 in shared libraries which are explicitly loaded by the inferior.
5406 Note this feature does not work on hpux8. On hpux9 you must link
5407 /usr/lib/end.o into your program. This feature should work
5408 automatically on hpux10.
5410 * Irix 5.x hardware watchpoint support
5412 Irix 5 configurations now support the use of hardware watchpoints.
5414 * Mips protocol "SYN garbage limit"
5416 When debugging a Mips target using the `target mips' protocol, you
5417 may set the number of characters that GDB will ignore by setting
5418 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5419 every character. The default value is 1050.
5421 * Recording and replaying remote debug sessions
5423 If you set `remotelogfile' to the name of a file, gdb will write to it
5424 a recording of a remote debug session. This recording may then be
5425 replayed back to gdb using "gdbreplay". See gdbserver/README for
5426 details. This is useful when you have a problem with GDB while doing
5427 remote debugging; you can make a recording of the session and send it
5428 to someone else, who can then recreate the problem.
5430 * Speedups for remote debugging
5432 GDB includes speedups for downloading and stepping MIPS systems using
5433 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5434 and more efficient S-record downloading.
5436 * Memory use reductions and statistics collection
5438 GDB now uses less memory and reports statistics about memory usage.
5439 Try the `maint print statistics' command, for example.
5441 *** Changes in GDB-4.15:
5443 * Psymtabs for XCOFF
5445 The symbol reader for AIX GDB now uses partial symbol tables. This
5446 can greatly improve startup time, especially for large executables.
5448 * Remote targets use caching
5450 Remote targets now use a data cache to speed up communication with the
5451 remote side. The data cache could lead to incorrect results because
5452 it doesn't know about volatile variables, thus making it impossible to
5453 debug targets which use memory mapped I/O devices. `set remotecache
5454 off' turns the the data cache off.
5456 * Remote targets may have threads
5458 The standard remote protocol now includes support for multiple threads
5459 in the target system, using new protocol commands 'H' and 'T'. See
5460 gdb/remote.c for details.
5464 If GDB is configured with `--enable-netrom', then it will include
5465 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5466 acts as though it is a bank of ROM on the target board, but you can
5467 write into it over the network. GDB's support consists only of
5468 support for fast loading into the emulated ROM; to debug, you must use
5469 another protocol, such as standard remote protocol. The usual
5470 sequence is something like
5472 target nrom <netrom-hostname>
5474 target remote <netrom-hostname>:1235
5478 GDB now includes support for the Apple Macintosh, as a host only. It
5479 may be run as either an MPW tool or as a standalone application, and
5480 it can debug through the serial port. All the usual GDB commands are
5481 available, but to the target command, you must supply "serial" as the
5482 device type instead of "/dev/ttyXX". See mpw-README in the main
5483 directory for more information on how to build. The MPW configuration
5484 scripts */mpw-config.in support only a few targets, and only the
5485 mips-idt-ecoff target has been tested.
5489 GDB configuration now uses autoconf. This is not user-visible,
5490 but does simplify configuration and building.
5494 GDB now supports hpux10.
5496 *** Changes in GDB-4.14:
5498 * New native configurations
5500 x86 FreeBSD i[345]86-*-freebsd
5501 x86 NetBSD i[345]86-*-netbsd
5502 NS32k NetBSD ns32k-*-netbsd
5503 Sparc NetBSD sparc-*-netbsd
5507 A29K VxWorks a29k-*-vxworks
5508 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5509 CPU32 EST-300 emulator m68*-*-est*
5510 PowerPC ELF powerpc-*-elf
5513 * Alpha OSF/1 support for procfs
5515 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5516 possible to attach to running processes. As the mounting of the /proc
5517 filesystem is optional on the Alpha, GDB automatically determines
5518 the availability of /proc during startup. This can lead to problems
5519 if /proc is unmounted after GDB has been started.
5521 * Arguments to user-defined commands
5523 User commands may accept up to 10 arguments separated by whitespace.
5524 Arguments are accessed within the user command via $arg0..$arg9. A
5527 print $arg0 + $arg1 + $arg2
5529 To execute the command use:
5532 Defines the command "adder" which prints the sum of its three arguments.
5533 Note the arguments are text substitutions, so they may reference variables,
5534 use complex expressions, or even perform inferior function calls.
5536 * New `if' and `while' commands
5538 This makes it possible to write more sophisticated user-defined
5539 commands. Both commands take a single argument, which is the
5540 expression to evaluate, and must be followed by the commands to
5541 execute, one per line, if the expression is nonzero, the list being
5542 terminated by the word `end'. The `if' command list may include an
5543 `else' word, which causes the following commands to be executed only
5544 if the expression is zero.
5546 * Fortran source language mode
5548 GDB now includes partial support for Fortran 77. It will recognize
5549 Fortran programs and can evaluate a subset of Fortran expressions, but
5550 variables and functions may not be handled correctly. GDB will work
5551 with G77, but does not yet know much about symbols emitted by other
5554 * Better HPUX support
5556 Most debugging facilities now work on dynamic executables for HPPAs
5557 running hpux9 or later. You can attach to running dynamically linked
5558 processes, but by default the dynamic libraries will be read-only, so
5559 for instance you won't be able to put breakpoints in them. To change
5560 that behavior do the following before running the program:
5566 This will cause the libraries to be mapped private and read-write.
5567 To revert to the normal behavior, do this:
5573 You cannot set breakpoints or examine data in the library until after
5574 the library is loaded if the function/data symbols do not have
5577 GDB can now also read debug symbols produced by the HP C compiler on
5578 HPPAs (sorry, no C++, Fortran or 68k support).
5580 * Target byte order now dynamically selectable
5582 You can choose which byte order to use with a target system, via the
5583 commands "set endian big" and "set endian little", and you can see the
5584 current setting by using "show endian". You can also give the command
5585 "set endian auto", in which case GDB will use the byte order
5586 associated with the executable. Currently, only embedded MIPS
5587 configurations support dynamic selection of target byte order.
5589 * New DOS host serial code
5591 This version uses DPMI interrupts to handle buffered I/O, so you
5592 no longer need to run asynctsr when debugging boards connected to
5595 *** Changes in GDB-4.13:
5597 * New "complete" command
5599 This lists all the possible completions for the rest of the line, if it
5600 were to be given as a command itself. This is intended for use by emacs.
5602 * Trailing space optional in prompt
5604 "set prompt" no longer adds a space for you after the prompt you set. This
5605 allows you to set a prompt which ends in a space or one that does not.
5607 * Breakpoint hit counts
5609 "info break" now displays a count of the number of times the breakpoint
5610 has been hit. This is especially useful in conjunction with "ignore"; you
5611 can ignore a large number of breakpoint hits, look at the breakpoint info
5612 to see how many times the breakpoint was hit, then run again, ignoring one
5613 less than that number, and this will get you quickly to the last hit of
5616 * Ability to stop printing at NULL character
5618 "set print null-stop" will cause GDB to stop printing the characters of
5619 an array when the first NULL is encountered. This is useful when large
5620 arrays actually contain only short strings.
5622 * Shared library breakpoints
5624 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5625 breakpoints in shared libraries before the executable is run.
5627 * Hardware watchpoints
5629 There is a new hardware breakpoint for the watch command for sparclite
5630 targets. See gdb/sparclite/hw_breakpoint.note.
5632 Hardware watchpoints are also now supported under GNU/Linux.
5636 Annotations have been added. These are for use with graphical interfaces,
5637 and are still experimental. Currently only gdba.el uses these.
5639 * Improved Irix 5 support
5641 GDB now works properly with Irix 5.2.
5643 * Improved HPPA support
5645 GDB now works properly with the latest GCC and GAS.
5647 * New native configurations
5649 Sequent PTX4 i[34]86-sequent-ptx4
5650 HPPA running OSF/1 hppa*-*-osf*
5651 Atari TT running SVR4 m68*-*-sysv4*
5652 RS/6000 LynxOS rs6000-*-lynxos*
5656 OS/9000 i[34]86-*-os9k
5657 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5660 * Hitachi SH7000 and E7000-PC ICE support
5662 There is now support for communicating with the Hitachi E7000-PC ICE.
5663 This is available automatically when GDB is configured for the SH.
5667 As usual, a variety of small fixes and improvements, both generic
5668 and configuration-specific. See the ChangeLog for more detail.
5670 *** Changes in GDB-4.12:
5672 * Irix 5 is now supported
5676 GDB-4.12 on the HPPA has a number of changes which make it unable
5677 to debug the output from the currently released versions of GCC and
5678 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5679 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5680 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5683 *** Changes in GDB-4.11:
5685 * User visible changes:
5689 The "set remotedebug" option is now consistent between the mips remote
5690 target, remote targets using the gdb-specific protocol, UDI (AMD's
5691 debug protocol for the 29k) and the 88k bug monitor. It is now an
5692 integer specifying a debug level (normally 0 or 1, but 2 means more
5693 debugging info for the mips target).
5695 * DEC Alpha native support
5697 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5698 debug info, but GDB works fairly well with the DEC compiler and should
5699 work with a future GCC release. See the README file for a few
5700 Alpha-specific notes.
5702 * Preliminary thread implementation
5704 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5706 * LynxOS native and target support for 386
5708 This release has been hosted on LynxOS 2.2, and also can be configured
5709 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5712 * Improvements in C++ mangling/demangling.
5714 This release has much better g++ debugging, specifically in name
5715 mangling/demangling, virtual function calls, print virtual table,
5716 call methods, ...etc.
5718 *** Changes in GDB-4.10:
5720 * User visible changes:
5722 Remote debugging using the GDB-specific (`target remote') protocol now
5723 supports the `load' command. This is only useful if you have some
5724 other way of getting the stub to the target system, and you can put it
5725 somewhere in memory where it won't get clobbered by the download.
5727 Filename completion now works.
5729 When run under emacs mode, the "info line" command now causes the
5730 arrow to point to the line specified. Also, "info line" prints
5731 addresses in symbolic form (as well as hex).
5733 All vxworks based targets now support a user settable option, called
5734 vxworks-timeout. This option represents the number of seconds gdb
5735 should wait for responses to rpc's. You might want to use this if
5736 your vxworks target is, perhaps, a slow software simulator or happens
5737 to be on the far side of a thin network line.
5741 This release contains support for using a DEC alpha as a GDB host for
5742 cross debugging. Native alpha debugging is not supported yet.
5745 *** Changes in GDB-4.9:
5749 This is the first GDB release which is accompanied by a matching testsuite.
5750 The testsuite requires installation of dejagnu, which should be available
5751 via ftp from most sites that carry GNU software.
5755 'Cfront' style demangling has had its name changed to 'ARM' style, to
5756 emphasize that it was written from the specifications in the C++ Annotated
5757 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5758 disclaimers, it still generated too much confusion with users attempting to
5759 use gdb with AT&T cfront.
5763 GDB now uses a standard remote interface to a simulator library.
5764 So far, the library contains simulators for the Zilog Z8001/2, the
5765 Hitachi H8/300, H8/500 and Super-H.
5767 * New targets supported
5769 H8/300 simulator h8300-hitachi-hms or h8300hms
5770 H8/500 simulator h8500-hitachi-hms or h8500hms
5771 SH simulator sh-hitachi-hms or sh
5772 Z8000 simulator z8k-zilog-none or z8ksim
5773 IDT MIPS board over serial line mips-idt-ecoff
5775 Cross-debugging to GO32 targets is supported. It requires a custom
5776 version of the i386-stub.c module which is integrated with the
5777 GO32 memory extender.
5779 * New remote protocols
5781 MIPS remote debugging protocol.
5783 * New source languages supported
5785 This version includes preliminary support for Chill, a Pascal like language
5786 used by telecommunications companies. Chill support is also being integrated
5787 into the GNU compiler, but we don't know when it will be publically available.
5790 *** Changes in GDB-4.8:
5792 * HP Precision Architecture supported
5794 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5795 version of this support was available as a set of patches from the
5796 University of Utah. GDB does not support debugging of programs
5797 compiled with the HP compiler, because HP will not document their file
5798 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5799 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5801 Many problems in the preliminary version have been fixed.
5803 * Faster and better demangling
5805 We have improved template demangling and fixed numerous bugs in the GNU style
5806 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5807 character types (wchar_t) are now supported. Demangling of each symbol is now
5808 only done once, and is cached when the symbol table for a file is read in.
5809 This results in a small increase in memory usage for C programs, a moderate
5810 increase in memory usage for C++ programs, and a fantastic speedup in
5813 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5814 from the specifications in the Annotated Reference Manual, which AT&T's
5815 compiler does not actually implement.
5817 * G++ multiple inheritance compiler problem
5819 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5820 inheritance lattices was reworked to properly discover ambiguities. We
5821 recently found an example which causes this new algorithm to fail in a
5822 very subtle way, producing bad debug information for those classes.
5823 The file 'gcc.patch' (in this directory) can be applied to gcc to
5824 circumvent the problem. A future GCC release will contain a complete
5827 The previous G++ debug info problem (mentioned below for the gdb-4.7
5828 release) is fixed in gcc version 2.3.2.
5830 * Improved configure script
5832 The `configure' script will now attempt to guess your system type if
5833 you don't supply a host system type. The old scheme of supplying a
5834 host system triplet is preferable over using this. All the magic is
5835 done in the new `config.guess' script. Examine it for details.
5837 We have also brought our configure script much more in line with the FSF's
5838 version. It now supports the --with-xxx options. In particular,
5839 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5840 The resulting GDB will not be able to read arbitrary object file formats --
5841 only the format ``expected'' to be used on the configured target system.
5842 We hope to make this the default in a future release.
5844 * Documentation improvements
5846 There's new internal documentation on how to modify GDB, and how to
5847 produce clean changes to the code. We implore people to read it
5848 before submitting changes.
5850 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5851 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5852 `info' files are also provided. To build `info' files from scratch,
5853 you will need the latest `makeinfo' release, which will be available in
5854 a future texinfo-X.Y release.
5856 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5857 We're not sure exactly which versions have this problem, but it has
5858 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5859 or better. If that isn't possible, there is a patch in
5860 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5861 around this problem.
5865 GDB now supports array constants that can be used in expressions typed in by
5866 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5867 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5870 The new directory `gdb/sparclite' contains a program that demonstrates
5871 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5873 * New native hosts supported
5875 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5876 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5878 * New targets supported
5880 AMD 29k family via UDI a29k-amd-udi or udi29k
5882 * New file formats supported
5884 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5885 HPUX core files, and SCO 3.2v2 core files.
5889 Attaching to processes now works again; thanks for the many bug reports.
5891 We have also stomped on a bunch of core dumps caused by
5892 printf_filtered("%s") problems.
5894 We eliminated a copyright problem on the rpc and ptrace header files
5895 for VxWorks, which was discovered at the last minute during the 4.7
5896 release. You should now be able to build a VxWorks GDB.
5898 You can now interrupt gdb while an attached process is running. This
5899 will cause the attached process to stop, and give control back to GDB.
5901 We fixed problems caused by using too many file descriptors
5902 for reading symbols from object files and libraries. This was
5903 especially a problem for programs that used many (~100) shared
5906 The `step' command now only enters a subroutine if there is line number
5907 information for the subroutine. Otherwise it acts like the `next'
5908 command. Previously, `step' would enter subroutines if there was
5909 any debugging information about the routine. This avoids problems
5910 when using `cc -g1' on MIPS machines.
5912 * Internal improvements
5914 GDB's internal interfaces have been improved to make it easier to support
5915 debugging of multiple languages in the future.
5917 GDB now uses a common structure for symbol information internally.
5918 Minimal symbols (derived from linkage symbols in object files), partial
5919 symbols (from a quick scan of debug information), and full symbols
5920 contain a common subset of information, making it easier to write
5921 shared code that handles any of them.
5923 * New command line options
5925 We now accept --silent as an alias for --quiet.
5929 The memory-mapped-malloc library is now licensed under the GNU Library
5930 General Public License.
5932 *** Changes in GDB-4.7:
5934 * Host/native/target split
5936 GDB has had some major internal surgery to untangle the support for
5937 hosts and remote targets. Now, when you configure GDB for a remote
5938 target, it will no longer load in all of the support for debugging
5939 local programs on the host. When fully completed and tested, this will
5940 ensure that arbitrary host/target combinations are possible.
5942 The primary conceptual shift is to separate the non-portable code in
5943 GDB into three categories. Host specific code is required any time GDB
5944 is compiled on that host, regardless of the target. Target specific
5945 code relates to the peculiarities of the target, but can be compiled on
5946 any host. Native specific code is everything else: it can only be
5947 built when the host and target are the same system. Child process
5948 handling and core file support are two common `native' examples.
5950 GDB's use of /proc for controlling Unix child processes is now cleaner.
5951 It has been split out into a single module under the `target_ops' vector,
5952 plus two native-dependent functions for each system that uses /proc.
5954 * New hosts supported
5956 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5957 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5958 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5960 * New targets supported
5962 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5963 68030 and CPU32 m68030-*-*, m68332-*-*
5965 * New native hosts supported
5967 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5968 (386bsd is not well tested yet)
5969 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5971 * New file formats supported
5973 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5974 supports reading of `a.out.adobe' object files, which are an a.out
5975 format extended with minimal information about multiple sections.
5979 `show copying' is the same as the old `info copying'.
5980 `show warranty' is the same as `info warrantee'.
5981 These were renamed for consistency. The old commands continue to work.
5983 `info handle' is a new alias for `info signals'.
5985 You can now define pre-command hooks, which attach arbitrary command
5986 scripts to any command. The commands in the hook will be executed
5987 prior to the user's command. You can also create a hook which will be
5988 executed whenever the program stops. See gdb.texinfo.
5992 We now deal with Cfront style name mangling, and can even extract type
5993 info from mangled symbols. GDB can automatically figure out which
5994 symbol mangling style your C++ compiler uses.
5996 Calling of methods and virtual functions has been improved as well.
6000 The crash that occured when debugging Sun Ansi-C compiled binaries is
6001 fixed. This was due to mishandling of the extra N_SO stabs output
6004 We also finally got Ultrix 4.2 running in house, and fixed core file
6005 support, with help from a dozen people on the net.
6007 John M. Farrell discovered that the reason that single-stepping was so
6008 slow on all of the Mips based platforms (primarily SGI and DEC) was
6009 that we were trying to demangle and lookup a symbol used for internal
6010 purposes on every instruction that was being stepped through. Changing
6011 the name of that symbol so that it couldn't be mistaken for a C++
6012 mangled symbol sped things up a great deal.
6014 Rich Pixley sped up symbol lookups in general by getting much smarter
6015 about when C++ symbol mangling is necessary. This should make symbol
6016 completion (TAB on the command line) much faster. It's not as fast as
6017 we'd like, but it's significantly faster than gdb-4.6.
6021 A new user controllable variable 'call_scratch_address' can
6022 specify the location of a scratch area to be used when GDB
6023 calls a function in the target. This is necessary because the
6024 usual method of putting the scratch area on the stack does not work
6025 in systems that have separate instruction and data spaces.
6027 We integrated changes to support the 29k UDI (Universal Debugger
6028 Interface), but discovered at the last minute that we didn't have all
6029 of the appropriate copyright paperwork. We are working with AMD to
6030 resolve this, and hope to have it available soon.
6034 We have sped up the remote serial line protocol, especially for targets
6035 with lots of registers. It now supports a new `expedited status' ('T')
6036 message which can be used in place of the existing 'S' status message.
6037 This allows the remote stub to send only the registers that GDB
6038 needs to make a quick decision about single-stepping or conditional
6039 breakpoints, eliminating the need to fetch the entire register set for
6040 each instruction being stepped through.
6042 The GDB remote serial protocol now implements a write-through cache for
6043 registers, only re-reading the registers if the target has run.
6045 There is also a new remote serial stub for SPARC processors. You can
6046 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6047 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6048 processor with a serial port.
6052 Configure.in files have become much easier to read and modify. A new
6053 `table driven' format makes it more obvious what configurations are
6054 supported, and what files each one uses.
6058 There is a new opcodes library which will eventually contain all of the
6059 disassembly routines and opcode tables. At present, it only contains
6060 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6061 disassembler (binutils/objdump) to share these routines.
6063 The libiberty library is now copylefted under the GNU Library General
6064 Public License. This allows more liberal use, and was done so libg++
6065 can use it. This makes no difference to GDB, since the Library License
6066 grants all the rights from the General Public License.
6070 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6071 reference to the stabs symbol info used by the debugger. It is (as far
6072 as we know) the only published document on this fascinating topic. We
6073 encourage you to read it, compare it to the stabs information on your
6074 system, and send improvements on the document in general (to
6075 bug-gdb@prep.ai.mit.edu).
6077 And, of course, many bugs have been fixed.
6080 *** Changes in GDB-4.6:
6082 * Better support for C++ function names
6084 GDB now accepts as input the "demangled form" of C++ overloaded function
6085 names and member function names, and can do command completion on such names
6086 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6087 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6088 Make use of command completion, it is your friend.
6090 GDB also now accepts a variety of C++ mangled symbol formats. They are
6091 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6092 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6093 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6094 for the list of formats.
6096 * G++ symbol mangling problem
6098 Recent versions of gcc have a bug in how they emit debugging information for
6099 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6100 directory) can be applied to gcc to fix the problem. Alternatively, if you
6101 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6102 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6103 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6106 * New 'maintenance' command
6108 All of the commands related to hacking GDB internals have been moved out of
6109 the main command set, and now live behind the 'maintenance' command. This
6110 can also be abbreviated as 'mt'. The following changes were made:
6112 dump-me -> maintenance dump-me
6113 info all-breakpoints -> maintenance info breakpoints
6114 printmsyms -> maintenance print msyms
6115 printobjfiles -> maintenance print objfiles
6116 printpsyms -> maintenance print psymbols
6117 printsyms -> maintenance print symbols
6119 The following commands are new:
6121 maintenance demangle Call internal GDB demangler routine to
6122 demangle a C++ link name and prints the result.
6123 maintenance print type Print a type chain for a given symbol
6125 * Change to .gdbinit file processing
6127 We now read the $HOME/.gdbinit file before processing the argv arguments
6128 (e.g. reading symbol files or core files). This allows global parameters to
6129 be set, which will apply during the symbol reading. The ./.gdbinit is still
6130 read after argv processing.
6132 * New hosts supported
6134 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6136 GNU/Linux support i386-unknown-linux or linux
6138 We are also including code to support the HP/PA running BSD and HPUX. This
6139 is almost guaranteed not to work, as we didn't have time to test or build it
6140 for this release. We are including it so that the more adventurous (or
6141 masochistic) of you can play with it. We also had major problems with the
6142 fact that the compiler that we got from HP doesn't support the -g option.
6145 * New targets supported
6147 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6149 * More smarts about finding #include files
6151 GDB now remembers the compilation directory for all include files, and for
6152 all files from which C is generated (like yacc and lex sources). This
6153 greatly improves GDB's ability to find yacc/lex sources, and include files,
6154 especially if you are debugging your program from a directory different from
6155 the one that contains your sources.
6157 We also fixed a bug which caused difficulty with listing and setting
6158 breakpoints in include files which contain C code. (In the past, you had to
6159 try twice in order to list an include file that you hadn't looked at before.)
6161 * Interesting infernals change
6163 GDB now deals with arbitrary numbers of sections, where the symbols for each
6164 section must be relocated relative to that section's landing place in the
6165 target's address space. This work was needed to support ELF with embedded
6166 stabs used by Solaris-2.0.
6168 * Bug fixes (of course!)
6170 There have been loads of fixes for the following things:
6171 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6172 i960, stabs, DOS(GO32), procfs, etc...
6174 See the ChangeLog for details.
6176 *** Changes in GDB-4.5:
6178 * New machines supported (host and target)
6180 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6182 SGI Irix-4.x mips-sgi-irix4 or iris4
6184 * New malloc package
6186 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6187 Mmalloc is capable of handling mutiple heaps of memory. It is also
6188 capable of saving a heap to a file, and then mapping it back in later.
6189 This can be used to greatly speedup the startup of GDB by using a
6190 pre-parsed symbol table which lives in a mmalloc managed heap. For
6191 more details, please read mmalloc/mmalloc.texi.
6195 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6196 'help info proc' for details.
6198 * MIPS ecoff symbol table format
6200 The code that reads MIPS symbol table format is now supported on all hosts.
6201 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6204 * File name changes for MS-DOS
6206 Many files in the config directories have been renamed to make it easier to
6207 support GDB on MS-DOSe systems (which have very restrictive file name
6208 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6209 environment) is close to working but has some remaining problems. Note
6210 that debugging of DOS programs is not supported, due to limitations
6211 in the ``operating system'', but it can be used to host cross-debugging.
6213 * Cross byte order fixes
6215 Many fixes have been made to support cross debugging of Sparc and MIPS
6216 targets from hosts whose byte order differs.
6218 * New -mapped and -readnow options
6220 If memory-mapped files are available on your system through the 'mmap'
6221 system call, you can use the -mapped option on the `file' or
6222 `symbol-file' commands to cause GDB to write the symbols from your
6223 program into a reusable file. If the program you are debugging is
6224 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6225 Future GDB debugging sessions will notice the presence of this file,
6226 and will quickly map in symbol information from it, rather than reading
6227 the symbol table from the executable program. Using the '-mapped'
6228 option in a GDB `file' or `symbol-file' command has the same effect as
6229 starting GDB with the '-mapped' command-line option.
6231 You can cause GDB to read the entire symbol table immediately by using
6232 the '-readnow' option with any of the commands that load symbol table
6233 information (or on the GDB command line). This makes the command
6234 slower, but makes future operations faster.
6236 The -mapped and -readnow options are typically combined in order to
6237 build a `fred.syms' file that contains complete symbol information.
6238 A simple GDB invocation to do nothing but build a `.syms' file for future
6241 gdb -batch -nx -mapped -readnow programname
6243 The `.syms' file is specific to the host machine on which GDB is run.
6244 It holds an exact image of GDB's internal symbol table. It cannot be
6245 shared across multiple host platforms.
6247 * longjmp() handling
6249 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6250 siglongjmp() without losing control. This feature has not yet been ported to
6251 all systems. It currently works on many 386 platforms, all MIPS-based
6252 platforms (SGI, DECstation, etc), and Sun3/4.
6256 Preliminary work has been put in to support the new Solaris OS from Sun. At
6257 this time, it can control and debug processes, but it is not capable of
6262 As always, many many bug fixes. The major areas were with g++, and mipsread.
6263 People using the MIPS-based platforms should experience fewer mysterious
6264 crashes and trashed symbol tables.
6266 *** Changes in GDB-4.4:
6268 * New machines supported (host and target)
6270 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6272 BSD Reno on Vax vax-dec-bsd
6273 Ultrix on Vax vax-dec-ultrix
6275 * New machines supported (target)
6277 AMD 29000 embedded, using EBMON a29k-none-none
6281 GDB continues to improve its handling of C++. `References' work better.
6282 The demangler has also been improved, and now deals with symbols mangled as
6283 per the Annotated C++ Reference Guide.
6285 GDB also now handles `stabs' symbol information embedded in MIPS
6286 `ecoff' symbol tables. Since the ecoff format was not easily
6287 extensible to handle new languages such as C++, this appeared to be a
6288 good way to put C++ debugging info into MIPS binaries. This option
6289 will be supported in the GNU C compiler, version 2, when it is
6292 * New features for SVR4
6294 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6295 shared libraries. Debugging dynamically linked programs should present
6296 only minor differences from debugging statically linked programs.
6298 The `info proc' command will print out information about any process
6299 on an SVR4 system (including the one you are debugging). At the moment,
6300 it prints the address mappings of the process.
6302 If you bring up GDB on another SVR4 system, please send mail to
6303 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6305 * Better dynamic linking support in SunOS
6307 Reading symbols from shared libraries which contain debugging symbols
6308 now works properly. However, there remain issues such as automatic
6309 skipping of `transfer vector' code during function calls, which
6310 make it harder to debug code in a shared library, than to debug the
6311 same code linked statically.
6315 GDB is now using the latest `getopt' routines from the FSF. This
6316 version accepts the -- prefix for options with long names. GDB will
6317 continue to accept the old forms (-option and +option) as well.
6318 Various single letter abbreviations for options have been explicity
6319 added to the option table so that they won't get overshadowed in the
6320 future by other options that begin with the same letter.
6324 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6325 Many assorted bugs have been handled. Many more remain to be handled.
6326 See the various ChangeLog files (primarily in gdb and bfd) for details.
6329 *** Changes in GDB-4.3:
6331 * New machines supported (host and target)
6333 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6334 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6335 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6337 * Almost SCO Unix support
6339 We had hoped to support:
6340 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6341 (except for core file support), but we discovered very late in the release
6342 that it has problems with process groups that render gdb unusable. Sorry
6343 about that. I encourage people to fix it and post the fixes.
6345 * Preliminary ELF and DWARF support
6347 GDB can read ELF object files on System V Release 4, and can handle
6348 debugging records for C, in DWARF format, in ELF files. This support
6349 is preliminary. If you bring up GDB on another SVR4 system, please
6350 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6355 GDB now uses the latest `readline' library. One user-visible change
6356 is that two tabs will list possible command completions, which previously
6357 required typing M-? (meta-question mark, or ESC ?).
6361 The `stepi' bug that many of you noticed has been squashed.
6362 Many bugs in C++ have been handled. Many more remain to be handled.
6363 See the various ChangeLog files (primarily in gdb and bfd) for details.
6365 * State of the MIPS world (in case you wondered):
6367 GDB can understand the symbol tables emitted by the compilers
6368 supplied by most vendors of MIPS-based machines, including DEC. These
6369 symbol tables are in a format that essentially nobody else uses.
6371 Some versions of gcc come with an assembler post-processor called
6372 mips-tfile. This program is required if you want to do source-level
6373 debugging of gcc-compiled programs. I believe FSF does not ship
6374 mips-tfile with gcc version 1, but it will eventually come with gcc
6377 Debugging of g++ output remains a problem. g++ version 1.xx does not
6378 really support it at all. (If you're lucky, you should be able to get
6379 line numbers and stack traces to work, but no parameters or local
6380 variables.) With some work it should be possible to improve the
6383 When gcc version 2 is released, you will have somewhat better luck.
6384 However, even then you will get confusing results for inheritance and
6387 We will eventually provide full debugging of g++ output on
6388 DECstations. This will probably involve some kind of stabs-in-ecoff
6389 encapulation, but the details have not been worked out yet.
6392 *** Changes in GDB-4.2:
6394 * Improved configuration
6396 Only one copy of `configure' exists now, and it is not self-modifying.
6397 Porting BFD is simpler.
6401 The `step' and `next' commands now only stop at the first instruction
6402 of a source line. This prevents the multiple stops that used to occur
6403 in switch statements, for-loops, etc. `Step' continues to stop if a
6404 function that has debugging information is called within the line.
6408 Lots of small bugs fixed. More remain.
6410 * New host supported (not target)
6412 Intel 386 PC clone running Mach i386-none-mach
6415 *** Changes in GDB-4.1:
6417 * Multiple source language support
6419 GDB now has internal scaffolding to handle several source languages.
6420 It determines the type of each source file from its filename extension,
6421 and will switch expression parsing and number formatting to match the
6422 language of the function in the currently selected stack frame.
6423 You can also specifically set the language to be used, with
6424 `set language c' or `set language modula-2'.
6428 GDB now has preliminary support for the GNU Modula-2 compiler,
6429 currently under development at the State University of New York at
6430 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6431 continue through the fall of 1991 and into 1992.
6433 Other Modula-2 compilers are currently not supported, and attempting to
6434 debug programs compiled with them will likely result in an error as the
6435 symbol table is read. Feel free to work on it, though!
6437 There are hooks in GDB for strict type checking and range checking,
6438 in the `Modula-2 philosophy', but they do not currently work.
6442 GDB can now write to executable and core files (e.g. patch
6443 a variable's value). You must turn this switch on, specify
6444 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6445 by assigning a new value to a variable. Modifications take
6448 * Automatic SunOS shared library reading
6450 When you run your program, GDB automatically determines where its
6451 shared libraries (if any) have been loaded, and reads their symbols.
6452 The `share' command is no longer needed. This also works when
6453 examining core files.
6457 You can specify the number of lines that the `list' command shows.
6460 * New machines supported (host and target)
6462 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6463 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6464 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6466 * New hosts supported (not targets)
6468 IBM RT/PC: romp-ibm-aix or rtpc
6470 * New targets supported (not hosts)
6472 AMD 29000 embedded with COFF a29k-none-coff
6473 AMD 29000 embedded with a.out a29k-none-aout
6474 Ultracomputer remote kernel debug a29k-nyu-kern
6476 * New remote interfaces
6482 *** Changes in GDB-4.0:
6486 Wide output is wrapped at good places to make the output more readable.
6488 Gdb now supports cross-debugging from a host machine of one type to a
6489 target machine of another type. Communication with the target system
6490 is over serial lines. The ``target'' command handles connecting to the
6491 remote system; the ``load'' command will download a program into the
6492 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6493 also supports debugging of realtime processes running under VxWorks,
6494 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6495 stub on the target system.
6497 New CPUs supported include the AMD 29000 and Intel 960.
6499 GDB now reads object files and symbol tables via a ``binary file''
6500 library, which allows a single copy of GDB to debug programs of multiple
6501 object file types such as a.out and coff.
6503 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6504 refcard.dvi and refcard.ps are available to format it).
6507 * Control-Variable user interface simplified
6509 All variables that control the operation of the debugger can be set
6510 by the ``set'' command, and displayed by the ``show'' command.
6512 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6513 ``Show prompt'' produces the response:
6514 Gdb's prompt is new-gdb=>.
6516 What follows are the NEW set commands. The command ``help set'' will
6517 print a complete list of old and new set commands. ``help set FOO''
6518 will give a longer description of the variable FOO. ``show'' will show
6519 all of the variable descriptions and their current settings.
6521 confirm on/off: Enables warning questions for operations that are
6522 hard to recover from, e.g. rerunning the program while
6523 it is already running. Default is ON.
6525 editing on/off: Enables EMACS style command line editing
6526 of input. Previous lines can be recalled with
6527 control-P, the current line can be edited with control-B,
6528 you can search for commands with control-R, etc.
6531 history filename NAME: NAME is where the gdb command history
6532 will be stored. The default is .gdb_history,
6533 or the value of the environment variable
6536 history size N: The size, in commands, of the command history. The
6537 default is 256, or the value of the environment variable
6540 history save on/off: If this value is set to ON, the history file will
6541 be saved after exiting gdb. If set to OFF, the
6542 file will not be saved. The default is OFF.
6544 history expansion on/off: If this value is set to ON, then csh-like
6545 history expansion will be performed on
6546 command line input. The default is OFF.
6548 radix N: Sets the default radix for input and output. It can be set
6549 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6550 in the current radix, so "set radix 10" is always a no-op.
6552 height N: This integer value is the number of lines on a page. Default
6553 is 24, the current `stty rows'' setting, or the ``li#''
6554 setting from the termcap entry matching the environment
6557 width N: This integer value is the number of characters on a line.
6558 Default is 80, the current `stty cols'' setting, or the ``co#''
6559 setting from the termcap entry matching the environment
6562 Note: ``set screensize'' is obsolete. Use ``set height'' and
6563 ``set width'' instead.
6565 print address on/off: Print memory addresses in various command displays,
6566 such as stack traces and structure values. Gdb looks
6567 more ``symbolic'' if you turn this off; it looks more
6568 ``machine level'' with it on. Default is ON.
6570 print array on/off: Prettyprint arrays. New convenient format! Default
6573 print demangle on/off: Print C++ symbols in "source" form if on,
6576 print asm-demangle on/off: Same, for assembler level printouts
6579 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6582 * Support for Epoch Environment.
6584 The epoch environment is a version of Emacs v18 with windowing. One
6585 new command, ``inspect'', is identical to ``print'', except that if you
6586 are running in the epoch environment, the value is printed in its own
6590 * Support for Shared Libraries
6592 GDB can now debug programs and core files that use SunOS shared libraries.
6593 Symbols from a shared library cannot be referenced
6594 before the shared library has been linked with the program (this
6595 happens after you type ``run'' and before the function main() is entered).
6596 At any time after this linking (including when examining core files
6597 from dynamically linked programs), gdb reads the symbols from each
6598 shared library when you type the ``sharedlibrary'' command.
6599 It can be abbreviated ``share''.
6601 sharedlibrary REGEXP: Load shared object library symbols for files
6602 matching a unix regular expression. No argument
6603 indicates to load symbols for all shared libraries.
6605 info sharedlibrary: Status of loaded shared libraries.
6610 A watchpoint stops execution of a program whenever the value of an
6611 expression changes. Checking for this slows down execution
6612 tremendously whenever you are in the scope of the expression, but is
6613 quite useful for catching tough ``bit-spreader'' or pointer misuse
6614 problems. Some machines such as the 386 have hardware for doing this
6615 more quickly, and future versions of gdb will use this hardware.
6617 watch EXP: Set a watchpoint (breakpoint) for an expression.
6619 info watchpoints: Information about your watchpoints.
6621 delete N: Deletes watchpoint number N (same as breakpoints).
6622 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6623 enable N: Re-enables watchpoint number N (same as breakpoints).
6626 * C++ multiple inheritance
6628 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6631 * C++ exception handling
6633 Gdb now supports limited C++ exception handling. Besides the existing
6634 ability to breakpoint on an exception handler, gdb can breakpoint on
6635 the raising of an exception (before the stack is peeled back to the
6638 catch FOO: If there is a FOO exception handler in the dynamic scope,
6639 set a breakpoint to catch exceptions which may be raised there.
6640 Multiple exceptions (``catch foo bar baz'') may be caught.
6642 info catch: Lists all exceptions which may be caught in the
6643 current stack frame.
6646 * Minor command changes
6648 The command ``call func (arg, arg, ...)'' now acts like the print
6649 command, except it does not print or save a value if the function's result
6650 is void. This is similar to dbx usage.
6652 The ``up'' and ``down'' commands now always print the frame they end up
6653 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6654 frames without printing.
6656 * New directory command
6658 'dir' now adds directories to the FRONT of the source search path.
6659 The path starts off empty. Source files that contain debug information
6660 about the directory in which they were compiled can be found even
6661 with an empty path; Sun CC and GCC include this information. If GDB can't
6662 find your source file in the current directory, type "dir .".
6664 * Configuring GDB for compilation
6666 For normal use, type ``./configure host''. See README or gdb.texinfo
6669 GDB now handles cross debugging. If you are remotely debugging between
6670 two different machines, type ``./configure host -target=targ''.
6671 Host is the machine where GDB will run; targ is the machine
6672 where the program that you are debugging will run.