1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.12
6 * Building GDB and GDBserver now requires a C++11 compiler.
8 For example, GCC 4.8 or later.
10 It is no longer possible to build GDB or GDBserver with a C
11 compiler. The --disable-build-with-cxx configure option has been
14 * Building GDB and GDBserver now requires GNU make >= 3.81.
16 It is no longer supported to build GDB or GDBserver with another
17 implementation of the make program or an earlier version of GNU make.
19 * Native debugging on MS-Windows supports command-line redirection
21 Command-line arguments used for starting programs on MS-Windows can
22 now include redirection symbols supported by native Windows shells,
23 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
24 as "run", "start", and "set args", as well as the corresponding MI
27 * Support for thread names on MS-Windows.
29 GDB now catches and handles the special exception that programs
30 running on MS-Windows use to assign names to threads in the
33 * Support for Java programs compiled with gcj has been removed.
35 * User commands now accept an unlimited number of arguments.
36 Previously, only up to 10 was accepted.
38 * The "eval" command now expands user-defined command arguments.
40 This makes it easier to process a variable number of arguments:
45 eval "print $arg%d", $i
52 Synopsys ARC arc*-*-elf32
54 *** Changes in GDB 7.12
56 * GDB and GDBserver now build with a C++ compiler by default.
58 The --enable-build-with-cxx configure option is now enabled by
59 default. One must now explicitly configure with
60 --disable-build-with-cxx in order to build with a C compiler. This
61 option will be removed in a future release.
63 * GDBserver now supports recording btrace without maintaining an active
66 * GDB now supports a negative repeat count in the 'x' command to examine
67 memory backward from the given address. For example:
70 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
71 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
72 (gdb) x/-5i 0x0000000000400580
73 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
74 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
75 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
76 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
77 0x40057b <main(int, char**)+25>:
78 callq 0x400536 <Func1(int, char const*)>
80 * Fortran: Support structures with fields of dynamic types and
81 arrays of dynamic types.
83 * GDB now supports multibit bitfields and enums in target register
86 * New Python-based convenience function $_as_string(val), which returns
87 the textual representation of a value. This function is especially
88 useful to obtain the text label of an enum value.
90 * Intel MPX bound violation handling.
92 Segmentation faults caused by a Intel MPX boundary violation
93 now display the kind of violation (upper or lower), the memory
94 address accessed and the memory bounds, along with the usual
95 signal received and code location.
99 Program received signal SIGSEGV, Segmentation fault
100 Upper bound violation while accessing address 0x7fffffffc3b3
101 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
102 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
104 * Rust language support.
105 GDB now supports debugging programs written in the Rust programming
106 language. See https://www.rust-lang.org/ for more information about
109 * Support for running interpreters on specified input/output devices
111 GDB now supports a new mechanism that allows frontends to provide
112 fully featured GDB console views, as a better alternative to
113 building such views on top of the "-interpreter-exec console"
114 command. See the new "new-ui" command below. With that command,
115 frontends can now start GDB in the traditional command-line mode
116 running in an embedded terminal emulator widget, and create a
117 separate MI interpreter running on a specified i/o device. In this
118 way, GDB handles line editing, history, tab completion, etc. in the
119 console all by itself, and the GUI uses the separate MI interpreter
120 for its own control and synchronization, invisible to the command
123 * The "catch syscall" command catches groups of related syscalls.
125 The "catch syscall" command now supports catching a group of related
126 syscalls using the 'group:' or 'g:' prefix.
131 skip -gfile file-glob-pattern
132 skip -function function
133 skip -rfunction regular-expression
134 A generalized form of the skip command, with new support for
135 glob-style file names and regular expressions for function names.
136 Additionally, a file spec and a function spec may now be combined.
138 maint info line-table REGEXP
139 Display the contents of GDB's internal line table data struture.
142 Run any GDB unit tests that were compiled in.
145 Start a new user interface instance running INTERP as interpreter,
146 using the TTY file for input/output.
150 ** gdb.Breakpoint objects have a new attribute "pending", which
151 indicates whether the breakpoint is pending.
152 ** Three new breakpoint-related events have been added:
153 gdb.breakpoint_created, gdb.breakpoint_modified, and
154 gdb.breakpoint_deleted.
157 Signal ("set") the given MS-Windows event object. This is used in
158 conjunction with the Windows JIT debugging (AeDebug) support, where
159 the OS suspends a crashing process until a debugger can attach to
160 it. Resuming the crashing process, in order to debug it, is done by
163 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
164 was added in GDBserver, including JIT compiling fast tracepoint's
165 conditional expression bytecode into native code.
167 * Support for various remote target protocols and ROM monitors has
170 target m32rsdi Remote M32R debugging over SDI
171 target mips MIPS remote debugging protocol
172 target pmon PMON ROM monitor
173 target ddb NEC's DDB variant of PMON for Vr4300
174 target rockhopper NEC RockHopper variant of PMON
175 target lsi LSI variant of PMO
177 * Support for tracepoints and fast tracepoints on powerpc-linux,
178 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
179 including JIT compiling fast tracepoint's conditional expression
180 bytecode into native code.
182 * MI async record =record-started now includes the method and format used for
183 recording. For example:
185 =record-started,thread-group="i1",method="btrace",format="bts"
187 * MI async record =thread-selected now includes the frame field. For example:
189 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
193 Andes NDS32 nds32*-*-elf
195 *** Changes in GDB 7.11
197 * GDB now supports debugging kernel-based threads on FreeBSD.
199 * Per-inferior thread numbers
201 Thread numbers are now per inferior instead of global. If you're
202 debugging multiple inferiors, GDB displays thread IDs using a
203 qualified INF_NUM.THR_NUM form. For example:
207 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
208 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
209 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
210 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
212 As consequence, thread numbers as visible in the $_thread
213 convenience variable and in Python's InferiorThread.num attribute
214 are no longer unique between inferiors.
216 GDB now maintains a second thread ID per thread, referred to as the
217 global thread ID, which is the new equivalent of thread numbers in
218 previous releases. See also $_gthread below.
220 For backwards compatibility, MI's thread IDs always refer to global
223 * Commands that accept thread IDs now accept the qualified
224 INF_NUM.THR_NUM form as well. For example:
227 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
230 * In commands that accept a list of thread IDs, you can now refer to
231 all threads of an inferior using a star wildcard. GDB accepts
232 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
233 refer to all threads of the current inferior. For example, "info
236 * You can use "info threads -gid" to display the global thread ID of
239 * The new convenience variable $_gthread holds the global number of
242 * The new convenience variable $_inferior holds the number of the
245 * GDB now displays the ID and name of the thread that hit a breakpoint
246 or received a signal, if your program is multi-threaded. For
249 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
250 Thread 1 "main" received signal SIGINT, Interrupt.
252 * Record btrace now supports non-stop mode.
254 * Support for tracepoints on aarch64-linux was added in GDBserver.
256 * The 'record instruction-history' command now indicates speculative execution
257 when using the Intel Processor Trace recording format.
259 * GDB now allows users to specify explicit locations, bypassing
260 the linespec parser. This feature is also available to GDB/MI
263 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
264 GDB now is able to debug both AArch64 applications and ARM applications
267 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
268 including JIT compiling fast tracepoint's conditional expression bytecode
271 * GDB now supports displaced stepping on AArch64 GNU/Linux.
273 * "info threads", "info inferiors", "info display", "info checkpoints"
274 and "maint info program-spaces" now list the corresponding items in
275 ascending ID order, for consistency with all other "info" commands.
277 * In Ada, the overloads selection menu has been enhanced to display the
278 parameter types and the return types for the matching overloaded subprograms.
282 maint set target-non-stop (on|off|auto)
283 maint show target-non-stop
284 Control whether GDB targets always operate in non-stop mode even if
285 "set non-stop" is "off". The default is "auto", meaning non-stop
286 mode is enabled if supported by the target.
288 maint set bfd-sharing
289 maint show bfd-sharing
290 Control the reuse of bfd objects.
294 Control display of debugging info regarding bfd caching.
298 Control display of debugging info regarding FreeBSD threads.
300 set remote multiprocess-extensions-packet
301 show remote multiprocess-extensions-packet
302 Set/show the use of the remote protocol multiprocess extensions.
304 set remote thread-events
305 show remote thread-events
306 Set/show the use of thread create/exit events.
308 set ada print-signatures on|off
309 show ada print-signatures"
310 Control whether parameter types and return types are displayed in overloads
311 selection menus. It is activaled (@code{on}) by default.
315 Controls the maximum size of memory, in bytes, that GDB will
316 allocate for value contents. Prevents incorrect programs from
317 causing GDB to allocate overly large buffers. Default is 64k.
319 * The "disassemble" command accepts a new modifier: /s.
320 It prints mixed source+disassembly like /m with two differences:
321 - disassembled instructions are now printed in program order, and
322 - and source for all relevant files is now printed.
323 The "/m" option is now considered deprecated: its "source-centric"
324 output hasn't proved useful in practice.
326 * The "record instruction-history" command accepts a new modifier: /s.
327 It behaves exactly like /m and prints mixed source+disassembly.
329 * The "set scheduler-locking" command supports a new mode "replay".
330 It behaves like "off" in record mode and like "on" in replay mode.
332 * Support for various ROM monitors has been removed:
334 target dbug dBUG ROM monitor for Motorola ColdFire
335 target picobug Motorola picobug monitor
336 target dink32 DINK32 ROM monitor for PowerPC
337 target m32r Renesas M32R/D ROM monitor
338 target mon2000 mon2000 ROM monitor
339 target ppcbug PPCBUG ROM monitor for PowerPC
341 * Support for reading/writing memory and extracting values on architectures
342 whose memory is addressable in units of any integral multiple of 8 bits.
347 Indicates that an exec system call was executed.
349 exec-events feature in qSupported
350 The qSupported packet allows GDB to request support for exec
351 events using the new 'gdbfeature' exec-event, and the qSupported
352 response can contain the corresponding 'stubfeature'. Set and
353 show commands can be used to display whether these features are enabled.
356 Equivalent to interrupting with the ^C character, but works in
359 thread created stop reason (T05 create:...)
360 Indicates that the thread was just created and is stopped at entry.
362 thread exit stop reply (w exitcode;tid)
363 Indicates that the thread has terminated.
366 Enables/disables thread create and exit event reporting. For
367 example, this is used in non-stop mode when GDB stops a set of
368 threads and synchronously waits for the their corresponding stop
369 replies. Without exit events, if one of the threads exits, GDB
370 would hang forever not knowing that it should no longer expect a
371 stop for that same thread.
374 Indicates that there are no resumed threads left in the target (all
375 threads are stopped). The remote stub reports support for this stop
376 reply to GDB's qSupported query.
379 Enables/disables catching syscalls from the inferior process.
380 The remote stub reports support for this packet to GDB's qSupported query.
382 syscall_entry stop reason
383 Indicates that a syscall was just called.
385 syscall_return stop reason
386 Indicates that a syscall just returned.
388 * Extended-remote exec events
390 ** GDB now has support for exec events on extended-remote Linux targets.
391 For such targets with Linux kernels 2.5.46 and later, this enables
392 follow-exec-mode and exec catchpoints.
394 set remote exec-event-feature-packet
395 show remote exec-event-feature-packet
396 Set/show the use of the remote exec event feature.
398 * Thread names in remote protocol
400 The reply to qXfer:threads:read may now include a name attribute for each
403 * Target remote mode fork and exec events
405 ** GDB now has support for fork and exec events on target remote mode
406 Linux targets. For such targets with Linux kernels 2.5.46 and later,
407 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
408 fork and exec catchpoints.
410 * Remote syscall events
412 ** GDB now has support for catch syscall on remote Linux targets,
413 currently enabled on x86/x86_64 architectures.
415 set remote catch-syscall-packet
416 show remote catch-syscall-packet
417 Set/show the use of the remote catch syscall feature.
421 ** The -var-set-format command now accepts the zero-hexadecimal
422 format. It outputs data in hexadecimal format with zero-padding on the
427 ** gdb.InferiorThread objects have a new attribute "global_num",
428 which refers to the thread's global thread ID. The existing
429 "num" attribute now refers to the thread's per-inferior number.
430 See "Per-inferior thread numbers" above.
431 ** gdb.InferiorThread objects have a new attribute "inferior", which
432 is the Inferior object the thread belongs to.
434 *** Changes in GDB 7.10
436 * Support for process record-replay and reverse debugging on aarch64*-linux*
437 targets has been added. GDB now supports recording of A64 instruction set
438 including advance SIMD instructions.
440 * Support for Sun's version of the "stabs" debug file format has been removed.
442 * GDB now honors the content of the file /proc/PID/coredump_filter
443 (PID is the process ID) on GNU/Linux systems. This file can be used
444 to specify the types of memory mappings that will be included in a
445 corefile. For more information, please refer to the manual page of
446 "core(5)". GDB also has a new command: "set use-coredump-filter
447 on|off". It allows to set whether GDB will read the content of the
448 /proc/PID/coredump_filter file when generating a corefile.
450 * The "info os" command on GNU/Linux can now display information on
452 "info os cpus" Listing of all cpus/cores on the system
454 * GDB has two new commands: "set serial parity odd|even|none" and
455 "show serial parity". These allows to set or show parity for the
458 * The "info source" command now displays the producer string if it was
459 present in the debug info. This typically includes the compiler version
460 and may include things like its command line arguments.
462 * The "info dll", an alias of the "info sharedlibrary" command,
463 is now available on all platforms.
465 * Directory names supplied to the "set sysroot" commands may be
466 prefixed with "target:" to tell GDB to access shared libraries from
467 the target system, be it local or remote. This replaces the prefix
468 "remote:". The default sysroot has been changed from "" to
469 "target:". "remote:" is automatically converted to "target:" for
470 backward compatibility.
472 * The system root specified by "set sysroot" will be prepended to the
473 filename of the main executable (if reported to GDB as absolute by
474 the operating system) when starting processes remotely, and when
475 attaching to already-running local or remote processes.
477 * GDB now supports automatic location and retrieval of executable
478 files from remote targets. Remote debugging can now be initiated
479 using only a "target remote" or "target extended-remote" command
480 (no "set sysroot" or "file" commands are required). See "New remote
483 * The "dump" command now supports verilog hex format.
485 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
487 * On GNU/Linux, GDB and gdbserver are now able to access executable
488 and shared library files without a "set sysroot" command when
489 attaching to processes running in different mount namespaces from
490 the debugger. This makes it possible to attach to processes in
491 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
492 See "New remote packets" below.
494 * The "tui reg" command now provides completion for all of the
495 available register groups, including target specific groups.
497 * The HISTSIZE environment variable is no longer read when determining
498 the size of GDB's command history. GDB now instead reads the dedicated
499 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
500 disables truncation of command history. Non-numeric values of GDBHISTSIZE
505 ** Memory ports can now be unbuffered.
509 ** gdb.Objfile objects have a new attribute "username",
510 which is the name of the objfile as specified by the user,
511 without, for example, resolving symlinks.
512 ** You can now write frame unwinders in Python.
513 ** gdb.Type objects have a new method "optimized_out",
514 returning optimized out gdb.Value instance of this type.
515 ** gdb.Value objects have new methods "reference_value" and
516 "const_value" which return a reference to the value and a
517 "const" version of the value respectively.
521 maint print symbol-cache
522 Print the contents of the symbol cache.
524 maint print symbol-cache-statistics
525 Print statistics of symbol cache usage.
527 maint flush-symbol-cache
528 Flush the contents of the symbol cache.
532 Start branch trace recording using Branch Trace Store (BTS) format.
535 Evaluate expression by using the compiler and print result.
539 Explicit commands for enabling and disabling tui mode.
542 set mpx bound on i386 and amd64
543 Support for bound table investigation on Intel MPX enabled applications.
547 Start branch trace recording using Intel Processor Trace format.
550 Print information about branch tracing internals.
552 maint btrace packet-history
553 Print the raw branch tracing data.
555 maint btrace clear-packet-history
556 Discard the stored raw branch tracing data.
559 Discard all branch tracing data. It will be fetched and processed
560 anew by the next "record" command.
565 Renamed from "set debug dwarf2-die".
567 Renamed from "show debug dwarf2-die".
570 Renamed from "set debug dwarf2-read".
571 show debug dwarf-read
572 Renamed from "show debug dwarf2-read".
574 maint set dwarf always-disassemble
575 Renamed from "maint set dwarf2 always-disassemble".
576 maint show dwarf always-disassemble
577 Renamed from "maint show dwarf2 always-disassemble".
579 maint set dwarf max-cache-age
580 Renamed from "maint set dwarf2 max-cache-age".
581 maint show dwarf max-cache-age
582 Renamed from "maint show dwarf2 max-cache-age".
585 show debug dwarf-line
586 Control display of debugging info regarding DWARF line processing.
590 Set the maximum number of candidates to be considered during
591 completion. The default value is 200. This limit allows GDB
592 to avoid generating large completion lists, the computation of
593 which can cause the debugger to become temporarily unresponsive.
595 set history remove-duplicates
596 show history remove-duplicates
597 Control the removal of duplicate history entries.
599 maint set symbol-cache-size
600 maint show symbol-cache-size
601 Control the size of the symbol cache.
603 set|show record btrace bts buffer-size
604 Set and show the size of the ring buffer used for branch tracing in
606 The obtained size may differ from the requested size. Use "info
607 record" to see the obtained buffer size.
609 set debug linux-namespaces
610 show debug linux-namespaces
611 Control display of debugging info regarding Linux namespaces.
613 set|show record btrace pt buffer-size
614 Set and show the size of the ring buffer used for branch tracing in
615 Intel Processor Trace format.
616 The obtained size may differ from the requested size. Use "info
617 record" to see the obtained buffer size.
619 maint set|show btrace pt skip-pad
620 Set and show whether PAD packets are skipped when computing the
623 * The command 'thread apply all' can now support new option '-ascending'
624 to call its specified command for all threads in ascending order.
626 * Python/Guile scripting
628 ** GDB now supports auto-loading of Python/Guile scripts contained in the
629 special section named `.debug_gdb_scripts'.
633 qXfer:btrace-conf:read
634 Return the branch trace configuration for the current thread.
636 Qbtrace-conf:bts:size
637 Set the requested ring buffer size for branch tracing in BTS format.
640 Enable Intel Procesor Trace-based branch tracing for the current
641 process. The remote stub reports support for this packet to GDB's
645 Set the requested ring buffer size for branch tracing in Intel Processor
649 Indicates a memory breakpoint instruction was executed, irrespective
650 of whether it was GDB that planted the breakpoint or the breakpoint
651 is hardcoded in the program. This is required for correct non-stop
655 Indicates the target stopped for a hardware breakpoint. This is
656 required for correct non-stop mode operation.
659 Return information about files on the remote system.
662 Return the full absolute name of the file that was executed to
663 create a process running on the remote system.
666 Select the filesystem on which vFile: operations with filename
667 arguments will operate. This is required for GDB to be able to
668 access files on remote targets where the remote stub does not
669 share a common filesystem with the inferior(s).
672 Indicates that a fork system call was executed.
675 Indicates that a vfork system call was executed.
677 vforkdone stop reason
678 Indicates that a vfork child of the specified process has executed
679 an exec or exit, allowing the vfork parent to resume execution.
681 fork-events and vfork-events features in qSupported
682 The qSupported packet allows GDB to request support for fork and
683 vfork events using new 'gdbfeatures' fork-events and vfork-events,
684 and the qSupported response can contain the corresponding
685 'stubfeatures'. Set and show commands can be used to display
686 whether these features are enabled.
688 * Extended-remote fork events
690 ** GDB now has support for fork events on extended-remote Linux
691 targets. For targets with Linux kernels 2.5.60 and later, this
692 enables follow-fork-mode and detach-on-fork for both fork and
693 vfork, as well as fork and vfork catchpoints.
695 * The info record command now shows the recording format and the
696 branch tracing configuration for the current thread when using
697 the btrace record target.
698 For the BTS format, it shows the ring buffer size.
700 * GDB now has support for DTrace USDT (Userland Static Defined
701 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
703 * GDB now supports access to vector registers on S/390 GNU/Linux
706 * Removed command line options
708 -xdb HP-UX XDB compatibility mode.
710 * Removed targets and native configurations
712 HP/PA running HP-UX hppa*-*-hpux*
713 Itanium running HP-UX ia64-*-hpux*
715 * New configure options
718 This configure option allows the user to build GDB with support for
719 Intel Processor Trace (default: auto). This requires libipt.
721 --with-libipt-prefix=PATH
722 Specify the path to the version of libipt that GDB should use.
723 $PATH/include should contain the intel-pt.h header and
724 $PATH/lib should contain the libipt.so library.
726 *** Changes in GDB 7.9.1
730 ** Xmethods can now specify a result type.
732 *** Changes in GDB 7.9
734 * GDB now supports hardware watchpoints on x86 GNU Hurd.
738 ** You can now access frame registers from Python scripts.
739 ** New attribute 'producer' for gdb.Symtab objects.
740 ** gdb.Objfile objects have a new attribute "progspace",
741 which is the gdb.Progspace object of the containing program space.
742 ** gdb.Objfile objects have a new attribute "owner".
743 ** gdb.Objfile objects have a new attribute "build_id",
744 which is the build ID generated when the file was built.
745 ** gdb.Objfile objects have a new method "add_separate_debug_file".
746 ** A new event "gdb.clear_objfiles" has been added, triggered when
747 selecting a new file to debug.
748 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
749 ** New function gdb.lookup_objfile.
751 New events which are triggered when GDB modifies the state of the
754 ** gdb.events.inferior_call_pre: Function call is about to be made.
755 ** gdb.events.inferior_call_post: Function call has just been made.
756 ** gdb.events.memory_changed: A memory location has been altered.
757 ** gdb.events.register_changed: A register has been altered.
759 * New Python-based convenience functions:
761 ** $_caller_is(name [, number_of_frames])
762 ** $_caller_matches(regexp [, number_of_frames])
763 ** $_any_caller_is(name [, number_of_frames])
764 ** $_any_caller_matches(regexp [, number_of_frames])
766 * GDB now supports the compilation and injection of source code into
767 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
768 to compile the source code to object code, and if successful, inject
769 and execute that code within the current context of the inferior.
770 Currently the C language is supported. The commands used to
771 interface with this new feature are:
773 compile code [-raw|-r] [--] [source code]
774 compile file [-raw|-r] filename
778 demangle [-l language] [--] name
779 Demangle "name" in the specified language, or the current language
780 if elided. This command is renamed from the "maint demangle" command.
781 The latter is kept as a no-op to avoid "maint demangle" being interpreted
782 as "maint demangler-warning".
784 queue-signal signal-name-or-number
785 Queue a signal to be delivered to the thread when it is resumed.
787 add-auto-load-scripts-directory directory
788 Add entries to the list of directories from which to load auto-loaded
791 maint print user-registers
792 List all currently available "user" registers.
794 compile code [-r|-raw] [--] [source code]
795 Compile, inject, and execute in the inferior the executable object
796 code produced by compiling the provided source code.
798 compile file [-r|-raw] filename
799 Compile and inject into the inferior the executable object code
800 produced by compiling the source code stored in the filename
803 * On resume, GDB now always passes the signal the program had stopped
804 for to the thread the signal was sent to, even if the user changed
805 threads before resuming. Previously GDB would often (but not
806 always) deliver the signal to the thread that happens to be current
809 * Conversely, the "signal" command now consistently delivers the
810 requested signal to the current thread. GDB now asks for
811 confirmation if the program had stopped for a signal and the user
812 switched threads meanwhile.
814 * "breakpoint always-inserted" modes "off" and "auto" merged.
816 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
817 won't remove breakpoints from the target until all threads stop,
818 even in non-stop mode. The "auto" mode has been removed, and "off"
819 is now the default mode.
823 set debug symbol-lookup
824 show debug symbol-lookup
825 Control display of debugging info regarding symbol lookup.
829 ** The -list-thread-groups command outputs an exit-code field for
830 inferiors that have exited.
834 MIPS SDE mips*-sde*-elf*
838 Support for these obsolete configurations has been removed.
840 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
841 SGI Irix-5.x mips-*-irix5*
842 SGI Irix-6.x mips-*-irix6*
843 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
844 VAX running Ultrix vax-*-ultrix*
846 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
847 and "assf"), have been removed. Use the "sharedlibrary" command, or
848 its alias "share", instead.
850 *** Changes in GDB 7.8
852 * New command line options
855 This is an alias for the --data-directory option.
857 * GDB supports printing and modifying of variable length automatic arrays
858 as specified in ISO C99.
860 * The ARM simulator now supports instruction level tracing
861 with or without disassembly.
865 GDB now has support for scripting using Guile. Whether this is
866 available is determined at configure time.
867 Guile version 2.0 or greater is required.
868 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
870 * New commands (for set/show, see "New options" below)
874 Invoke CODE by passing it to the Guile interpreter.
878 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
880 info auto-load guile-scripts [regexp]
881 Print the list of automatically loaded Guile scripts.
883 * The source command is now capable of sourcing Guile scripts.
884 This feature is dependent on the debugger being built with Guile support.
888 set print symbol-loading (off|brief|full)
889 show print symbol-loading
890 Control whether to print informational messages when loading symbol
891 information for a file. The default is "full", but when debugging
892 programs with large numbers of shared libraries the amount of output
895 set guile print-stack (none|message|full)
896 show guile print-stack
897 Show a stack trace when an error is encountered in a Guile script.
899 set auto-load guile-scripts (on|off)
900 show auto-load guile-scripts
901 Control auto-loading of Guile script files.
903 maint ada set ignore-descriptive-types (on|off)
904 maint ada show ignore-descriptive-types
905 Control whether the debugger should ignore descriptive types in Ada
906 programs. The default is not to ignore the descriptive types. See
907 the user manual for more details on descriptive types and the intended
908 usage of this option.
910 set auto-connect-native-target
912 Control whether GDB is allowed to automatically connect to the
913 native target for the run, attach, etc. commands when not connected
914 to any target yet. See also "target native" below.
916 set record btrace replay-memory-access (read-only|read-write)
917 show record btrace replay-memory-access
918 Control what memory accesses are allowed during replay.
920 maint set target-async (on|off)
921 maint show target-async
922 This controls whether GDB targets operate in synchronous or
923 asynchronous mode. Normally the default is asynchronous, if it is
924 available; but this can be changed to more easily debug problems
925 occurring only in synchronous mode.
927 set mi-async (on|off)
929 Control whether MI asynchronous mode is preferred. This supersedes
930 "set target-async" of previous GDB versions.
932 * "set target-async" is deprecated as a CLI option and is now an alias
933 for "set mi-async" (only puts MI into async mode).
935 * Background execution commands (e.g., "c&", "s&", etc.) are now
936 possible ``out of the box'' if the target supports them. Previously
937 the user would need to explicitly enable the possibility with the
938 "set target-async on" command.
940 * New features in the GDB remote stub, GDBserver
942 ** New option --debug-format=option1[,option2,...] allows one to add
943 additional text to each output. At present only timestamps
944 are supported: --debug-format=timestamps.
945 Timestamps can also be turned on with the
946 "monitor set debug-format timestamps" command from GDB.
948 * The 'record instruction-history' command now starts counting instructions
949 at one. This also affects the instruction ranges reported by the
950 'record function-call-history' command when given the /i modifier.
952 * The command 'record function-call-history' supports a new modifier '/c' to
953 indent the function names based on their call stack depth.
954 The fields for the '/i' and '/l' modifier have been reordered.
955 The source line range is now prefixed with 'at'.
956 The instruction range is now prefixed with 'inst'.
957 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
958 "record instruction-history" and "list" commands.
960 * The ranges given as arguments to the 'record function-call-history' and
961 'record instruction-history' commands are now inclusive.
963 * The btrace record target now supports the 'record goto' command.
964 For locations inside the execution trace, the back trace is computed
965 based on the information stored in the execution trace.
967 * The btrace record target supports limited reverse execution and replay.
968 The target does not record data and therefore does not allow reading
971 * The "catch syscall" command now works on s390*-linux* targets.
973 * The "compare-sections" command is no longer specific to target
974 remote. It now works with all targets.
976 * All native targets are now consistently called "native".
977 Consequently, the "target child", "target GNU", "target djgpp",
978 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
979 commands have been replaced with "target native". The QNX/NTO port
980 leaves the "procfs" target in place and adds a "native" target for
981 consistency with other ports. The impact on users should be minimal
982 as these commands previously either throwed an error, or were
983 no-ops. The target's name is visible in the output of the following
984 commands: "help target", "info target", "info files", "maint print
987 * The "target native" command now connects to the native target. This
988 can be used to launch native programs even when "set
989 auto-connect-native-target" is set to off.
991 * GDB now supports access to Intel MPX registers on GNU/Linux.
993 * Support for Intel AVX-512 registers on GNU/Linux.
994 Support displaying and modifying Intel AVX-512 registers
995 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
999 qXfer:btrace:read's annex
1000 The qXfer:btrace:read packet supports a new annex 'delta' to read
1001 branch trace incrementally.
1005 ** Valid Python operations on gdb.Value objects representing
1006 structs/classes invoke the corresponding overloaded operators if
1008 ** New `Xmethods' feature in the Python API. Xmethods are
1009 additional methods or replacements for existing methods of a C++
1010 class. This feature is useful for those cases where a method
1011 defined in C++ source code could be inlined or optimized out by
1012 the compiler, making it unavailable to GDB.
1015 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1017 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1018 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1019 its alias "share", instead.
1021 * The commands "set remotebaud" and "show remotebaud" are no longer
1022 supported. Use "set serial baud" and "show serial baud" (respectively)
1027 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1028 target-async". The latter is left as a deprecated alias of the
1029 former for backward compatibility. If the target supports it,
1030 CLI background execution commands are now always possible by
1031 default, independently of whether the frontend stated a
1032 preference for asynchronous execution with "-gdb-set mi-async".
1033 Previously "-gdb-set target-async off" affected both MI execution
1034 commands and CLI execution commands.
1036 *** Changes in GDB 7.7
1038 * Improved support for process record-replay and reverse debugging on
1039 arm*-linux* targets. Support for thumb32 and syscall instruction
1040 recording has been added.
1042 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1044 * GDB now supports Fission DWP file format version 2.
1045 http://gcc.gnu.org/wiki/DebugFission
1047 * New convenience function "$_isvoid", to check whether an expression
1048 is void. A void expression is an expression where the type of the
1049 result is "void". For example, some convenience variables may be
1050 "void" when evaluated (e.g., "$_exitcode" before the execution of
1051 the program being debugged; or an undefined convenience variable).
1052 Another example, when calling a function whose return type is
1055 * The "maintenance print objfiles" command now takes an optional regexp.
1057 * The "catch syscall" command now works on arm*-linux* targets.
1059 * GDB now consistently shows "<not saved>" when printing values of
1060 registers the debug info indicates have not been saved in the frame
1061 and there's nowhere to retrieve them from
1062 (callee-saved/call-clobbered registers):
1067 (gdb) info registers rax
1070 Before, the former would print "<optimized out>", and the latter
1071 "*value not available*".
1073 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1078 ** Frame filters and frame decorators have been added.
1079 ** Temporary breakpoints are now supported.
1080 ** Line tables representation has been added.
1081 ** New attribute 'parent_type' for gdb.Field objects.
1082 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1083 ** New attribute 'name' for gdb.Type objects.
1087 Nios II ELF nios2*-*-elf
1088 Nios II GNU/Linux nios2*-*-linux
1089 Texas Instruments MSP430 msp430*-*-elf
1091 * Removed native configurations
1093 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1094 been removed. ELF variants of these configurations are kept supported.
1096 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1097 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1098 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1099 i[34567]86-*-openbsd3.[0-3]
1100 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1101 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1102 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1106 Like "catch throw", but catches a re-thrown exception.
1107 maint check-psymtabs
1108 Renamed from old "maint check-symtabs".
1110 Perform consistency checks on symtabs.
1111 maint expand-symtabs
1112 Expand symtabs matching an optional regexp.
1115 Display the details of GDB configure-time options.
1117 maint set|show per-command
1118 maint set|show per-command space
1119 maint set|show per-command time
1120 maint set|show per-command symtab
1121 Enable display of per-command gdb resource usage.
1123 remove-symbol-file FILENAME
1124 remove-symbol-file -a ADDRESS
1125 Remove a symbol file added via add-symbol-file. The file to remove
1126 can be identified by its filename or by an address that lies within
1127 the boundaries of this symbol file in memory.
1130 info exceptions REGEXP
1131 Display the list of Ada exceptions defined in the program being
1132 debugged. If provided, only the exceptions whose names match REGEXP
1137 set debug symfile off|on
1139 Control display of debugging info regarding reading symbol files and
1140 symbol tables within those files
1142 set print raw frame-arguments
1143 show print raw frame-arguments
1144 Set/show whether to print frame arguments in raw mode,
1145 disregarding any defined pretty-printers.
1147 set remote trace-status-packet
1148 show remote trace-status-packet
1149 Set/show the use of remote protocol qTStatus packet.
1153 Control display of debugging messages related to Nios II targets.
1157 Control whether target-assisted range stepping is enabled.
1159 set startup-with-shell
1160 show startup-with-shell
1161 Specifies whether Unix child processes are started via a shell or
1166 Use the target memory cache for accesses to the code segment. This
1167 improves performance of remote debugging (particularly disassembly).
1169 * You can now use a literal value 'unlimited' for options that
1170 interpret 0 or -1 as meaning "unlimited". E.g., "set
1171 trace-buffer-size unlimited" is now an alias for "set
1172 trace-buffer-size -1" and "set height unlimited" is now an alias for
1175 * The "set debug symtab-create" debugging option of GDB has been changed to
1176 accept a verbosity level. 0 means "off", 1 provides basic debugging
1177 output, and values of 2 or greater provides more verbose output.
1179 * New command-line options
1181 Display the details of GDB configure-time options.
1183 * The command 'tsave' can now support new option '-ctf' to save trace
1184 buffer in Common Trace Format.
1186 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1189 * GDB now implements the the C++ 'typeid' operator.
1191 * The new convenience variable $_exception holds the exception being
1192 thrown or caught at an exception-related catchpoint.
1194 * The exception-related catchpoints, like "catch throw", now accept a
1195 regular expression which can be used to filter exceptions by type.
1197 * The new convenience variable $_exitsignal is automatically set to
1198 the terminating signal number when the program being debugged dies
1199 due to an uncaught signal.
1203 ** All MI commands now accept an optional "--language" option.
1204 Support for this feature can be verified by using the "-list-features"
1205 command, which should contain "language-option".
1207 ** The new command -info-gdb-mi-command allows the user to determine
1208 whether a GDB/MI command is supported or not.
1210 ** The "^error" result record returned when trying to execute an undefined
1211 GDB/MI command now provides a variable named "code" whose content is the
1212 "undefined-command" error code. Support for this feature can be verified
1213 by using the "-list-features" command, which should contain
1214 "undefined-command-error-code".
1216 ** The -trace-save MI command can optionally save trace buffer in Common
1219 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1221 ** The command -data-list-register-values now accepts an optional
1222 "--skip-unavailable" option. When used, only the available registers
1225 ** The new command -trace-frame-collected dumps collected variables,
1226 computed expressions, tvars, memory and registers in a traceframe.
1228 ** The commands -stack-list-locals, -stack-list-arguments and
1229 -stack-list-variables now accept an option "--skip-unavailable".
1230 When used, only the available locals or arguments are displayed.
1232 ** The -exec-run command now accepts an optional "--start" option.
1233 When used, the command follows the same semantics as the "start"
1234 command, stopping the program's execution at the start of its
1235 main subprogram. Support for this feature can be verified using
1236 the "-list-features" command, which should contain
1237 "exec-run-start-option".
1239 ** The new commands -catch-assert and -catch-exceptions insert
1240 catchpoints stopping the program when Ada exceptions are raised.
1242 ** The new command -info-ada-exceptions provides the equivalent of
1243 the new "info exceptions" command.
1245 * New system-wide configuration scripts
1246 A GDB installation now provides scripts suitable for use as system-wide
1247 configuration scripts for the following systems:
1251 * GDB now supports target-assigned range stepping with remote targets.
1252 This improves the performance of stepping source lines by reducing
1253 the number of control packets from/to GDB. See "New remote packets"
1256 * GDB now understands the element 'tvar' in the XML traceframe info.
1257 It has the id of the collected trace state variables.
1259 * On S/390 targets that provide the transactional-execution feature,
1260 the program interruption transaction diagnostic block (TDB) is now
1261 represented as a number of additional "registers" in GDB.
1263 * New remote packets
1267 The vCont packet supports a new 'r' action, that tells the remote
1268 stub to step through an address range itself, without GDB
1269 involvemement at each single-step.
1271 qXfer:libraries-svr4:read's annex
1272 The previously unused annex of the qXfer:libraries-svr4:read packet
1273 is now used to support passing an argument list. The remote stub
1274 reports support for this argument list to GDB's qSupported query.
1275 The defined arguments are "start" and "prev", used to reduce work
1276 necessary for library list updating, resulting in significant
1279 * New features in the GDB remote stub, GDBserver
1281 ** GDBserver now supports target-assisted range stepping. Currently
1282 enabled on x86/x86_64 GNU/Linux targets.
1284 ** GDBserver now adds element 'tvar' in the XML in the reply to
1285 'qXfer:traceframe-info:read'. It has the id of the collected
1286 trace state variables.
1288 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1291 * New 'z' formatter for printing and examining memory, this displays the
1292 value as hexadecimal zero padded on the left to the size of the type.
1294 * GDB can now use Windows x64 unwinding data.
1296 * The "set remotebaud" command has been replaced by "set serial baud".
1297 Similarly, "show remotebaud" has been replaced by "show serial baud".
1298 The "set remotebaud" and "show remotebaud" commands are still available
1299 to provide backward compatibility with older versions of GDB.
1301 *** Changes in GDB 7.6
1303 * Target record has been renamed to record-full.
1304 Record/replay is now enabled with the "record full" command.
1305 This also affects settings that are associated with full record/replay
1306 that have been moved from "set/show record" to "set/show record full":
1308 set|show record full insn-number-max
1309 set|show record full stop-at-limit
1310 set|show record full memory-query
1312 * A new record target "record-btrace" has been added. The new target
1313 uses hardware support to record the control-flow of a process. It
1314 does not support replaying the execution, but it implements the
1315 below new commands for investigating the recorded execution log.
1316 This new recording method can be enabled using:
1320 The "record-btrace" target is only available on Intel Atom processors
1321 and requires a Linux kernel 2.6.32 or later.
1323 * Two new commands have been added for record/replay to give information
1324 about the recorded execution without having to replay the execution.
1325 The commands are only supported by "record btrace".
1327 record instruction-history prints the execution history at
1328 instruction granularity
1330 record function-call-history prints the execution history at
1331 function granularity
1333 * New native configurations
1335 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1336 FreeBSD/powerpc powerpc*-*-freebsd
1337 x86_64/Cygwin x86_64-*-cygwin*
1338 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1342 ARM AArch64 aarch64*-*-elf
1343 ARM AArch64 GNU/Linux aarch64*-*-linux
1344 Lynx 178 PowerPC powerpc-*-lynx*178
1345 x86_64/Cygwin x86_64-*-cygwin*
1346 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1348 * If the configured location of system.gdbinit file (as given by the
1349 --with-system-gdbinit option at configure time) is in the
1350 data-directory (as specified by --with-gdb-datadir at configure
1351 time) or in one of its subdirectories, then GDB will look for the
1352 system-wide init file in the directory specified by the
1353 --data-directory command-line option.
1355 * New command line options:
1357 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1358 other initialization files, unlike -nx which disables all of them.
1360 * Removed command line options
1362 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1365 * The 'ptype' and 'whatis' commands now accept an argument to control
1368 * 'info proc' now works on some core files.
1372 ** Vectors can be created with gdb.Type.vector.
1374 ** Python's atexit.register now works in GDB.
1376 ** Types can be pretty-printed via a Python API.
1378 ** Python 3 is now supported (in addition to Python 2.4 or later)
1380 ** New class gdb.Architecture exposes GDB's internal representation
1381 of architecture in the Python API.
1383 ** New method Frame.architecture returns the gdb.Architecture object
1384 corresponding to the frame's architecture.
1386 * New Python-based convenience functions:
1388 ** $_memeq(buf1, buf2, length)
1389 ** $_streq(str1, str2)
1391 ** $_regex(str, regex)
1393 * The 'cd' command now defaults to using '~' (the home directory) if not
1396 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1397 default for GCC since November 2000.
1399 * The command 'forward-search' can now be abbreviated as 'fo'.
1401 * The command 'info tracepoints' can now display 'installed on target'
1402 or 'not installed on target' for each non-pending location of tracepoint.
1404 * New configure options
1406 --enable-libmcheck/--disable-libmcheck
1407 By default, development versions are built with -lmcheck on hosts
1408 that support it, in order to help track memory corruption issues.
1409 Release versions, on the other hand, are built without -lmcheck
1410 by default. The --enable-libmcheck/--disable-libmcheck configure
1411 options allow the user to override that default.
1412 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1413 This configure option allows the user to build GDB with
1414 libbabeltrace using which GDB can read Common Trace Format data.
1416 * New commands (for set/show, see "New options" below)
1419 Catch signals. This is similar to "handle", but allows commands and
1420 conditions to be attached.
1423 List the BFDs known to GDB.
1425 python-interactive [command]
1427 Start a Python interactive prompt, or evaluate the optional command
1428 and print the result of expressions.
1431 "py" is a new alias for "python".
1433 enable type-printer [name]...
1434 disable type-printer [name]...
1435 Enable or disable type printers.
1439 ** For the Renesas Super-H architecture, the "regs" command has been removed
1440 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1445 set print type methods (on|off)
1446 show print type methods
1447 Control whether method declarations are displayed by "ptype".
1448 The default is to show them.
1450 set print type typedefs (on|off)
1451 show print type typedefs
1452 Control whether typedef definitions are displayed by "ptype".
1453 The default is to show them.
1455 set filename-display basename|relative|absolute
1456 show filename-display
1457 Control the way in which filenames is displayed.
1458 The default is "relative", which preserves previous behavior.
1460 set trace-buffer-size
1461 show trace-buffer-size
1462 Request target to change the size of trace buffer.
1464 set remote trace-buffer-size-packet auto|on|off
1465 show remote trace-buffer-size-packet
1466 Control the use of the remote protocol `QTBuffer:size' packet.
1470 Control display of debugging messages related to ARM AArch64.
1473 set debug coff-pe-read
1474 show debug coff-pe-read
1475 Control display of debugging messages related to reading of COFF/PE
1480 Control display of debugging messages related to Mach-O symbols
1483 set debug notification
1484 show debug notification
1485 Control display of debugging info for async remote notification.
1489 ** Command parameter changes are now notified using new async record
1490 "=cmd-param-changed".
1491 ** Trace frame changes caused by command "tfind" are now notified using
1492 new async record "=traceframe-changed".
1493 ** The creation, deletion and modification of trace state variables
1494 are now notified using new async records "=tsv-created",
1495 "=tsv-deleted" and "=tsv-modified".
1496 ** The start and stop of process record are now notified using new
1497 async record "=record-started" and "=record-stopped".
1498 ** Memory changes are now notified using new async record
1500 ** The data-disassemble command response will include a "fullname" field
1501 containing the absolute file name when source has been requested.
1502 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1503 command, to allow pattern filling of memory areas.
1504 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1505 library load/unload events.
1506 ** The response to breakpoint commands and breakpoint async records
1507 includes an "installed" field containing a boolean state about each
1508 non-pending tracepoint location is whether installed on target or not.
1509 ** Output of the "-trace-status" command includes a "trace-file" field
1510 containing the name of the trace file being examined. This field is
1511 optional, and only present when examining a trace file.
1512 ** The "fullname" field is now always present along with the "file" field,
1513 even if the file cannot be found by GDB.
1515 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1516 You must have the LZMA library available when configuring GDB for this
1517 feature to be enabled. For more information, see:
1518 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1520 * New remote packets
1523 Set the size of trace buffer. The remote stub reports support for this
1524 packet to gdb's qSupported query.
1527 Enable Branch Trace Store (BTS)-based branch tracing for the current
1528 thread. The remote stub reports support for this packet to gdb's
1532 Disable branch tracing for the current thread. The remote stub reports
1533 support for this packet to gdb's qSupported query.
1536 Read the traced branches for the current thread. The remote stub
1537 reports support for this packet to gdb's qSupported query.
1539 *** Changes in GDB 7.5
1541 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1542 for more x32 ABI info.
1544 * GDB now supports access to MIPS DSP registers on Linux targets.
1546 * GDB now supports debugging microMIPS binaries.
1548 * The "info os" command on GNU/Linux can now display information on
1549 several new classes of objects managed by the operating system:
1550 "info os procgroups" lists process groups
1551 "info os files" lists file descriptors
1552 "info os sockets" lists internet-domain sockets
1553 "info os shm" lists shared-memory regions
1554 "info os semaphores" lists semaphores
1555 "info os msg" lists message queues
1556 "info os modules" lists loaded kernel modules
1558 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1559 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1560 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1561 options and inspect the probe arguments using the new $_probe_arg family
1562 of convenience variables. You can obtain more information about SystemTap
1563 in <http://sourceware.org/systemtap/>.
1565 * GDB now supports reversible debugging on ARM, it allows you to
1566 debug basic ARM and THUMB instructions, and provides
1567 record/replay support.
1569 * The option "symbol-reloading" has been deleted as it is no longer used.
1573 ** GDB commands implemented in Python can now be put in command class
1576 ** The "maint set python print-stack on|off" is now deleted.
1578 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1579 apply "flag enum"-style pretty-printing to any enum.
1581 ** gdb.lookup_symbol can now work when there is no current frame.
1583 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1584 the source at which the symbol was defined.
1586 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1587 method 'value'. The former indicates whether the symbol needs a
1588 frame in order to compute its value, and the latter computes the
1591 ** A new method 'referenced_value' on gdb.Value objects which can
1592 dereference pointer as well as C++ reference values.
1594 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1595 which return the global and static blocks (as gdb.Block objects),
1596 of the underlying symbol table, respectively.
1598 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1599 object associated with a PC value.
1601 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1602 of the address range occupied by code for the current source line.
1604 * Go language support.
1605 GDB now supports debugging programs written in the Go programming
1608 * GDBserver now supports stdio connections.
1609 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1611 * The binary "gdbtui" can no longer be built or installed.
1612 Use "gdb -tui" instead.
1614 * GDB will now print "flag" enums specially. A flag enum is one where
1615 all the enumerator values have no bits in common when pairwise
1616 "and"ed. When printing a value whose type is a flag enum, GDB will
1617 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1618 (gdb) print (enum E) 3
1621 * The filename part of a linespec will now match trailing components
1622 of a source file name. For example, "break gcc/expr.c:1000" will
1623 now set a breakpoint in build/gcc/expr.c, but not
1624 build/libcpp/expr.c.
1626 * The "info proc" and "generate-core-file" commands will now also
1627 work on remote targets connected to GDBserver on Linux.
1629 * The command "info catch" has been removed. It has been disabled
1630 since December 2007.
1632 * The "catch exception" and "catch assert" commands now accept
1633 a condition at the end of the command, much like the "break"
1634 command does. For instance:
1636 (gdb) catch exception Constraint_Error if Barrier = True
1638 Previously, it was possible to add a condition to such catchpoints,
1639 but it had to be done as a second step, after the catchpoint had been
1640 created, using the "condition" command.
1642 * The "info static-tracepoint-marker" command will now also work on
1643 native Linux targets with in-process agent.
1645 * GDB can now set breakpoints on inlined functions.
1647 * The .gdb_index section has been updated to include symbols for
1648 inlined functions. GDB will ignore older .gdb_index sections by
1649 default, which could cause symbol files to be loaded more slowly
1650 until their .gdb_index sections can be recreated. The new command
1651 "set use-deprecated-index-sections on" will cause GDB to use any older
1652 .gdb_index sections it finds. This will restore performance, but the
1653 ability to set breakpoints on inlined functions will be lost in symbol
1654 files with older .gdb_index sections.
1656 The .gdb_index section has also been updated to record more information
1657 about each symbol. This speeds up the "info variables", "info functions"
1658 and "info types" commands when used with programs having the .gdb_index
1659 section, as well as speeding up debugging with shared libraries using
1660 the .gdb_index section.
1662 * Ada support for GDB/MI Variable Objects has been added.
1664 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1669 ** New command -info-os is the MI equivalent of "info os".
1671 ** Output logs ("set logging" and related) now include MI output.
1675 ** "set use-deprecated-index-sections on|off"
1676 "show use-deprecated-index-sections on|off"
1677 Controls the use of deprecated .gdb_index sections.
1679 ** "catch load" and "catch unload" can be used to stop when a shared
1680 library is loaded or unloaded, respectively.
1682 ** "enable count" can be used to auto-disable a breakpoint after
1685 ** "info vtbl" can be used to show the virtual method tables for
1686 C++ and Java objects.
1688 ** "explore" and its sub commands "explore value" and "explore type"
1689 can be used to recursively explore values and types of
1690 expressions. These commands are available only if GDB is
1691 configured with '--with-python'.
1693 ** "info auto-load" shows status of all kinds of auto-loaded files,
1694 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1695 sequences of commands files, "info auto-load python-scripts"
1696 shows status of auto-loading Python script files,
1697 "info auto-load local-gdbinit" shows status of loading init file
1698 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1699 status of inferior specific thread debugging shared library loading.
1701 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1702 and "show auto-load-scripts" commands have been deprecated, use their
1703 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1704 and "show auto-load python-scripts" counterparts instead.
1706 ** "dprintf location,format,args..." creates a dynamic printf, which
1707 is basically a breakpoint that does a printf and immediately
1708 resumes your program's execution, so it is like a printf that you
1709 can insert dynamically at runtime instead of at compiletime.
1711 ** "set print symbol"
1713 Controls whether GDB attempts to display the symbol, if any,
1714 corresponding to addresses it prints. This defaults to "on", but
1715 you can set it to "off" to restore GDB's previous behavior.
1717 * Deprecated commands
1719 ** For the Renesas Super-H architecture, the "regs" command has been
1720 deprecated, and "info all-registers" should be used instead.
1724 Renesas RL78 rl78-*-elf
1725 HP OpenVMS ia64 ia64-hp-openvms*
1727 * GDBserver supports evaluation of breakpoint conditions. When
1728 support is advertised by GDBserver, GDB may be told to send the
1729 breakpoint conditions in bytecode form to GDBserver. GDBserver
1730 will only report the breakpoint trigger to GDB when its condition
1735 set mips compression
1736 show mips compression
1737 Select the compressed ISA encoding used in functions that have no symbol
1738 information available. The encoding can be set to either of:
1741 and is updated automatically from ELF file flags if available.
1743 set breakpoint condition-evaluation
1744 show breakpoint condition-evaluation
1745 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1746 GDBserver ("target"). Default option "auto" chooses the most efficient
1748 This option can improve debugger efficiency depending on the speed of the
1752 Disable auto-loading globally.
1755 Show auto-loading setting of all kinds of auto-loaded files.
1757 set auto-load gdb-scripts on|off
1758 show auto-load gdb-scripts
1759 Control auto-loading of GDB canned sequences of commands files.
1761 set auto-load python-scripts on|off
1762 show auto-load python-scripts
1763 Control auto-loading of Python script files.
1765 set auto-load local-gdbinit on|off
1766 show auto-load local-gdbinit
1767 Control loading of init file (.gdbinit) from current directory.
1769 set auto-load libthread-db on|off
1770 show auto-load libthread-db
1771 Control auto-loading of inferior specific thread debugging shared library.
1773 set auto-load scripts-directory <dir1>[:<dir2>...]
1774 show auto-load scripts-directory
1775 Set a list of directories from which to load auto-loaded scripts.
1776 Automatically loaded Python scripts and GDB scripts are located in one
1777 of the directories listed by this option.
1778 The delimiter (':' above) may differ according to the host platform.
1780 set auto-load safe-path <dir1>[:<dir2>...]
1781 show auto-load safe-path
1782 Set a list of directories from which it is safe to auto-load files.
1783 The delimiter (':' above) may differ according to the host platform.
1785 set debug auto-load on|off
1786 show debug auto-load
1787 Control display of debugging info for auto-loading the files above.
1789 set dprintf-style gdb|call|agent
1791 Control the way in which a dynamic printf is performed; "gdb"
1792 requests a GDB printf command, while "call" causes dprintf to call a
1793 function in the inferior. "agent" requests that the target agent
1794 (such as GDBserver) do the printing.
1796 set dprintf-function <expr>
1797 show dprintf-function
1798 set dprintf-channel <expr>
1799 show dprintf-channel
1800 Set the function and optional first argument to the call when using
1801 the "call" style of dynamic printf.
1803 set disconnected-dprintf on|off
1804 show disconnected-dprintf
1805 Control whether agent-style dynamic printfs continue to be in effect
1806 after GDB disconnects.
1808 * New configure options
1810 --with-auto-load-dir
1811 Configure default value for the 'set auto-load scripts-directory'
1812 setting above. It defaults to '$debugdir:$datadir/auto-load',
1813 $debugdir representing global debugging info directories (available
1814 via 'show debug-file-directory') and $datadir representing GDB's data
1815 directory (available via 'show data-directory').
1817 --with-auto-load-safe-path
1818 Configure default value for the 'set auto-load safe-path' setting
1819 above. It defaults to the --with-auto-load-dir setting.
1821 --without-auto-load-safe-path
1822 Set 'set auto-load safe-path' to '/', effectively disabling this
1825 * New remote packets
1827 z0/z1 conditional breakpoints extension
1829 The z0/z1 breakpoint insertion packets have been extended to carry
1830 a list of conditional expressions over to the remote stub depending on the
1831 condition evaluation mode. The use of this extension can be controlled
1832 via the "set remote conditional-breakpoints-packet" command.
1836 Specify the signals which the remote stub may pass to the debugged
1837 program without GDB involvement.
1839 * New command line options
1841 --init-command=FILE, -ix Like --command, -x but execute it
1842 before loading inferior.
1843 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1844 execute it before loading inferior.
1846 *** Changes in GDB 7.4
1848 * GDB now handles ambiguous linespecs more consistently; the existing
1849 FILE:LINE support has been expanded to other types of linespecs. A
1850 breakpoint will now be set on all matching locations in all
1851 inferiors, and locations will be added or removed according to
1854 * GDB now allows you to skip uninteresting functions and files when
1855 stepping with the "skip function" and "skip file" commands.
1857 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1858 and "show remote hardware-watchpoint-length-limit". These allows to
1859 set or show the maximum length limit (in bytes) of a remote
1860 target hardware watchpoint.
1862 This allows e.g. to use "unlimited" hardware watchpoints with the
1863 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1864 watchpoints are slower than real hardware watchpoints but are
1865 significantly faster than gdb software watchpoints.
1869 ** The register_pretty_printer function in module gdb.printing now takes
1870 an optional `replace' argument. If True, the new printer replaces any
1873 ** The "maint set python print-stack on|off" command has been
1874 deprecated and will be deleted in GDB 7.5.
1875 A new command: "set python print-stack none|full|message" has
1876 replaced it. Additionally, the default for "print-stack" is
1877 now "message", which just prints the error message without
1880 ** A prompt substitution hook (prompt_hook) is now available to the
1883 ** A new Python module, gdb.prompt has been added to the GDB Python
1884 modules library. This module provides functionality for
1885 escape sequences in prompts (used by set/show
1886 extended-prompt). These escape sequences are replaced by their
1887 corresponding value.
1889 ** Python commands and convenience-functions located in
1890 'data-directory'/python/gdb/command and
1891 'data-directory'/python/gdb/function are now automatically loaded
1894 ** Blocks now provide four new attributes. global_block and
1895 static_block will return the global and static blocks
1896 respectively. is_static and is_global are boolean attributes
1897 that indicate if the block is one of those two types.
1899 ** Symbols now provide the "type" attribute, the type of the symbol.
1901 ** The "gdb.breakpoint" function has been deprecated in favor of
1904 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1905 of a function. This class is based on the "finish" command
1906 available in the CLI.
1908 ** Type objects for struct and union types now allow access to
1909 the fields using standard Python dictionary (mapping) methods.
1910 For example, "some_type['myfield']" now works, as does
1911 "some_type.items()".
1913 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1916 ** A new function, "deep_items" has been added to the gdb.types
1917 module in the GDB Python modules library. This function returns
1918 an iterator over the fields of a struct or union type. Unlike
1919 the standard Python "iteritems" method, it will recursively traverse
1920 any anonymous fields.
1924 ** "*stopped" events can report several new "reason"s, such as
1927 ** Breakpoint changes are now notified using new async records, like
1928 "=breakpoint-modified".
1930 ** New command -ada-task-info.
1932 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1933 $sdir specifies the default system locations of shared libraries.
1934 $pdir specifies the directory where the libpthread used by the application
1937 GDB no longer looks in $sdir and $pdir after it has searched the directories
1938 mentioned in libthread-db-search-path. If you want to search those
1939 directories, they must be specified in libthread-db-search-path.
1940 The default value of libthread-db-search-path on GNU/Linux and Solaris
1941 systems is now "$sdir:$pdir".
1943 $pdir is not supported by gdbserver, it is currently ignored.
1944 $sdir is supported by gdbserver.
1946 * New configure option --with-iconv-bin.
1947 When using the internationalization support like the one in the GNU C
1948 library, GDB will invoke the "iconv" program to get a list of supported
1949 character sets. If this program lives in a non-standard location, one can
1950 use this option to specify where to find it.
1952 * When natively debugging programs on PowerPC BookE processors running
1953 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1954 watchpoints, which specify a mask in addition to an address to watch.
1955 The mask specifies that some bits of an address (the bits which are
1956 reset in the mask) should be ignored when matching the address accessed
1957 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1958 section in the user manual for more details.
1960 * The new option --once causes GDBserver to stop listening for connections once
1961 the first connection is made. The listening port used by GDBserver will
1962 become available after that.
1964 * New commands "info macros" and "alias" have been added.
1966 * New function parameters suffix @entry specifies value of function parameter
1967 at the time the function got called. Entry values are available only since
1973 "!" is now an alias of the "shell" command.
1974 Note that no space is needed between "!" and SHELL COMMAND.
1978 watch EXPRESSION mask MASK_VALUE
1979 The watch command now supports the mask argument which allows creation
1980 of masked watchpoints, if the current architecture supports this feature.
1982 info auto-load-scripts [REGEXP]
1983 This command was formerly named "maintenance print section-scripts".
1984 It is now generally useful and is no longer a maintenance-only command.
1986 info macro [-all] [--] MACRO
1987 The info macro command has new options `-all' and `--'. The first for
1988 printing all definitions of a macro. The second for explicitly specifying
1989 the end of arguments and the beginning of the macro name in case the macro
1990 name starts with a hyphen.
1992 collect[/s] EXPRESSIONS
1993 The tracepoint collect command now takes an optional modifier "/s"
1994 that directs it to dereference pointer-to-character types and
1995 collect the bytes of memory up to a zero byte. The behavior is
1996 similar to what you see when you use the regular print command on a
1997 string. An optional integer following the "/s" sets a bound on the
1998 number of bytes that will be collected.
2001 The trace start command now interprets any supplied arguments as a
2002 note to be recorded with the trace run, with an effect similar to
2003 setting the variable trace-notes.
2006 The trace stop command now interprets any arguments as a note to be
2007 mentioned along with the tstatus report that the trace was stopped
2008 with a command. The effect is similar to setting the variable
2011 * Tracepoints can now be enabled and disabled at any time after a trace
2012 experiment has been started using the standard "enable" and "disable"
2013 commands. It is now possible to start a trace experiment with no enabled
2014 tracepoints; GDB will display a warning, but will allow the experiment to
2015 begin, assuming that tracepoints will be enabled as needed while the trace
2018 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2019 locations with 4-byte instructions, when they were previously
2020 limited to locations with instructions of 5 bytes or longer.
2024 set debug dwarf2-read
2025 show debug dwarf2-read
2026 Turns on or off display of debugging messages related to reading
2027 DWARF debug info. The default is off.
2029 set debug symtab-create
2030 show debug symtab-create
2031 Turns on or off display of debugging messages related to symbol table
2032 creation. The default is off.
2035 show extended-prompt
2036 Set the GDB prompt, and allow escape sequences to be inserted to
2037 display miscellaneous information (see 'help set extended-prompt'
2038 for the list of sequences). This prompt (and any information
2039 accessed through the escape sequences) is updated every time the
2040 prompt is displayed.
2042 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2043 show print entry-values
2044 Set printing of frame argument values at function entry. In some cases
2045 GDB can determine the value of function argument which was passed by the
2046 function caller, even if the value was modified inside the called function.
2048 set debug entry-values
2049 show debug entry-values
2050 Control display of debugging info for determining frame argument values at
2051 function entry and virtual tail call frames.
2053 set basenames-may-differ
2054 show basenames-may-differ
2055 Set whether a source file may have multiple base names.
2056 (A "base name" is the name of a file with the directory part removed.
2057 Example: The base name of "/home/user/hello.c" is "hello.c".)
2058 If set, GDB will canonicalize file names (e.g., expand symlinks)
2059 before comparing them. Canonicalization is an expensive operation,
2060 but it allows the same file be known by more than one base name.
2061 If not set (the default), all source files are assumed to have just
2062 one base name, and gdb will do file name comparisons more efficiently.
2068 Set a user name and notes for the current and any future trace runs.
2069 This is useful for long-running and/or disconnected traces, to
2070 inform others (or yourself) as to who is running the trace, supply
2071 contact information, or otherwise explain what is going on.
2073 set trace-stop-notes
2074 show trace-stop-notes
2075 Set a note attached to the trace run, that is displayed when the
2076 trace has been stopped by a tstop command. This is useful for
2077 instance as an explanation, if you are stopping a trace run that was
2078 started by someone else.
2080 * New remote packets
2084 Dynamically enable a tracepoint in a started trace experiment.
2088 Dynamically disable a tracepoint in a started trace experiment.
2092 Set the user and notes of the trace run.
2096 Query the current status of a tracepoint.
2100 Query the minimum length of instruction at which a fast tracepoint may
2103 * Dcache size (number of lines) and line-size are now runtime-configurable
2104 via "set dcache line" and "set dcache line-size" commands.
2108 Texas Instruments TMS320C6x tic6x-*-*
2112 Renesas RL78 rl78-*-elf
2114 *** Changes in GDB 7.3.1
2116 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2118 *** Changes in GDB 7.3
2120 * GDB has a new command: "thread find [REGEXP]".
2121 It finds the thread id whose name, target id, or thread extra info
2122 matches the given regular expression.
2124 * The "catch syscall" command now works on mips*-linux* targets.
2126 * The -data-disassemble MI command now supports modes 2 and 3 for
2127 dumping the instruction opcodes.
2129 * New command line options
2131 -data-directory DIR Specify DIR as the "data-directory".
2132 This is mostly for testing purposes.
2134 * The "maint set python auto-load on|off" command has been renamed to
2135 "set auto-load-scripts on|off".
2137 * GDB has a new command: "set directories".
2138 It is like the "dir" command except that it replaces the
2139 source path list instead of augmenting it.
2141 * GDB now understands thread names.
2143 On GNU/Linux, "info threads" will display the thread name as set by
2144 prctl or pthread_setname_np.
2146 There is also a new command, "thread name", which can be used to
2147 assign a name internally for GDB to display.
2150 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2151 has been integrated into GDB.
2155 ** The function gdb.Write now accepts an optional keyword 'stream'.
2156 This keyword, when provided, will direct the output to either
2157 stdout, stderr, or GDB's logging output.
2159 ** Parameters can now be be sub-classed in Python, and in particular
2160 you may implement the get_set_doc and get_show_doc functions.
2161 This improves how Parameter set/show documentation is processed
2162 and allows for more dynamic content.
2164 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2165 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2166 have an is_valid method.
2168 ** Breakpoints can now be sub-classed in Python, and in particular
2169 you may implement a 'stop' function that is executed each time
2170 the inferior reaches that breakpoint.
2172 ** New function gdb.lookup_global_symbol looks up a global symbol.
2174 ** GDB values in Python are now callable if the value represents a
2175 function. For example, if 'some_value' represents a function that
2176 takes two integer parameters and returns a value, you can call
2177 that function like so:
2179 result = some_value (10,20)
2181 ** Module gdb.types has been added.
2182 It contains a collection of utilities for working with gdb.Types objects:
2183 get_basic_type, has_field, make_enum_dict.
2185 ** Module gdb.printing has been added.
2186 It contains utilities for writing and registering pretty-printers.
2187 New classes: PrettyPrinter, SubPrettyPrinter,
2188 RegexpCollectionPrettyPrinter.
2189 New function: register_pretty_printer.
2191 ** New commands "info pretty-printers", "enable pretty-printer" and
2192 "disable pretty-printer" have been added.
2194 ** gdb.parameter("directories") is now available.
2196 ** New function gdb.newest_frame returns the newest frame in the
2199 ** The gdb.InferiorThread class has a new "name" attribute. This
2200 holds the thread's name.
2202 ** Python Support for Inferior events.
2203 Python scripts can add observers to be notified of events
2204 occurring in the process being debugged.
2205 The following events are currently supported:
2206 - gdb.events.cont Continue event.
2207 - gdb.events.exited Inferior exited event.
2208 - gdb.events.stop Signal received, and Breakpoint hit events.
2212 ** GDB now puts template parameters in scope when debugging in an
2213 instantiation. For example, if you have:
2215 template<int X> int func (void) { return X; }
2217 then if you step into func<5>, "print X" will show "5". This
2218 feature requires proper debuginfo support from the compiler; it
2219 was added to GCC 4.5.
2221 ** The motion commands "next", "finish", "until", and "advance" now
2222 work better when exceptions are thrown. In particular, GDB will
2223 no longer lose control of the inferior; instead, the GDB will
2224 stop the inferior at the point at which the exception is caught.
2225 This functionality requires a change in the exception handling
2226 code that was introduced in GCC 4.5.
2228 * GDB now follows GCC's rules on accessing volatile objects when
2229 reading or writing target state during expression evaluation.
2230 One notable difference to prior behavior is that "print x = 0"
2231 no longer generates a read of x; the value of the assignment is
2232 now always taken directly from the value being assigned.
2234 * GDB now has some support for using labels in the program's source in
2235 linespecs. For instance, you can use "advance label" to continue
2236 execution to a label.
2238 * GDB now has support for reading and writing a new .gdb_index
2239 section. This section holds a fast index of DWARF debugging
2240 information and can be used to greatly speed up GDB startup and
2241 operation. See the documentation for `save gdb-index' for details.
2243 * The "watch" command now accepts an optional "-location" argument.
2244 When used, this causes GDB to watch the memory referred to by the
2245 expression. Such a watchpoint is never deleted due to it going out
2248 * GDB now supports thread debugging of core dumps on GNU/Linux.
2250 GDB now activates thread debugging using the libthread_db library
2251 when debugging GNU/Linux core dumps, similarly to when debugging
2252 live processes. As a result, when debugging a core dump file, GDB
2253 is now able to display pthread_t ids of threads. For example, "info
2254 threads" shows the same output as when debugging the process when it
2255 was live. In earlier releases, you'd see something like this:
2258 * 1 LWP 6780 main () at main.c:10
2260 While now you see this:
2263 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2265 It is also now possible to inspect TLS variables when debugging core
2268 When debugging a core dump generated on a machine other than the one
2269 used to run GDB, you may need to point GDB at the correct
2270 libthread_db library with the "set libthread-db-search-path"
2271 command. See the user manual for more details on this command.
2273 * When natively debugging programs on PowerPC BookE processors running
2274 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2275 which stop execution of the inferior whenever it executes an instruction
2276 at any address within the specified range. See the "PowerPC Embedded"
2277 section in the user manual for more details.
2279 * New features in the GDB remote stub, GDBserver
2281 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2282 and i686 LynxOS (version 5.x).
2284 ** GDBserver is now supported on Blackfin Linux.
2286 * New native configurations
2288 ia64 HP-UX ia64-*-hpux*
2292 Analog Devices, Inc. Blackfin Processor bfin-*
2294 * Ada task switching is now supported on sparc-elf targets when
2295 debugging a program using the Ravenscar Profile. For more information,
2296 see the "Tasking Support when using the Ravenscar Profile" section
2297 in the GDB user manual.
2299 * Guile support was removed.
2301 * New features in the GNU simulator
2303 ** The --map-info flag lists all known core mappings.
2305 ** CFI flashes may be simulated via the "cfi" device.
2307 *** Changes in GDB 7.2
2309 * Shared library support for remote targets by default
2311 When GDB is configured for a generic, non-OS specific target, like
2312 for example, --target=arm-eabi or one of the many *-*-elf targets,
2313 GDB now queries remote stubs for loaded shared libraries using the
2314 `qXfer:libraries:read' packet. Previously, shared library support
2315 was always disabled for such configurations.
2319 ** Argument Dependent Lookup (ADL)
2321 In C++ ADL lookup directs function search to the namespaces of its
2322 arguments even if the namespace has not been imported.
2332 Here the compiler will search for `foo' in the namespace of 'b'
2333 and find A::foo. GDB now supports this. This construct is commonly
2334 used in the Standard Template Library for operators.
2336 ** Improved User Defined Operator Support
2338 In addition to member operators, GDB now supports lookup of operators
2339 defined in a namespace and imported with a `using' directive, operators
2340 defined in the global scope, operators imported implicitly from an
2341 anonymous namespace, and the ADL operators mentioned in the previous
2343 GDB now also supports proper overload resolution for all the previously
2344 mentioned flavors of operators.
2346 ** static const class members
2348 Printing of static const class members that are initialized in the
2349 class definition has been fixed.
2351 * Windows Thread Information Block access.
2353 On Windows targets, GDB now supports displaying the Windows Thread
2354 Information Block (TIB) structure. This structure is visible either
2355 by using the new command `info w32 thread-information-block' or, by
2356 dereferencing the new convenience variable named `$_tlb', a
2357 thread-specific pointer to the TIB. This feature is also supported
2358 when remote debugging using GDBserver.
2360 * Static tracepoints
2362 Static tracepoints are calls in the user program into a tracing
2363 library. One such library is a port of the LTTng kernel tracer to
2364 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2365 When debugging with GDBserver, GDB now supports combining the GDB
2366 tracepoint machinery with such libraries. For example: the user can
2367 use GDB to probe a static tracepoint marker (a call from the user
2368 program into the tracing library) with the new "strace" command (see
2369 "New commands" below). This creates a "static tracepoint" in the
2370 breakpoint list, that can be manipulated with the same feature set
2371 as fast and regular tracepoints. E.g., collect registers, local and
2372 global variables, collect trace state variables, and define
2373 tracepoint conditions. In addition, the user can collect extra
2374 static tracepoint marker specific data, by collecting the new
2375 $_sdata internal variable. When analyzing the trace buffer, you can
2376 inspect $_sdata like any other variable available to GDB. For more
2377 information, see the "Tracepoints" chapter in GDB user manual. New
2378 remote packets have been defined to support static tracepoints, see
2379 the "New remote packets" section below.
2381 * Better reconstruction of tracepoints after disconnected tracing
2383 GDB will attempt to download the original source form of tracepoint
2384 definitions when starting a trace run, and then will upload these
2385 upon reconnection to the target, resulting in a more accurate
2386 reconstruction of the tracepoints that are in use on the target.
2390 You can now exercise direct control over the ways that GDB can
2391 affect your program. For instance, you can disallow the setting of
2392 breakpoints, so that the program can run continuously (assuming
2393 non-stop mode). In addition, the "observer" variable is available
2394 to switch all of the different controls; in observer mode, GDB
2395 cannot affect the target's behavior at all, which is useful for
2396 tasks like diagnosing live systems in the field.
2398 * The new convenience variable $_thread holds the number of the
2401 * New remote packets
2405 Return the address of the Windows Thread Information Block of a given thread.
2409 In response to several of the tracepoint packets, the target may now
2410 also respond with a number of intermediate `qRelocInsn' request
2411 packets before the final result packet, to have GDB handle
2412 relocating an instruction to execute at a different address. This
2413 is particularly useful for stubs that support fast tracepoints. GDB
2414 reports support for this feature in the qSupported packet.
2418 List static tracepoint markers in the target program.
2422 List static tracepoint markers at a given address in the target
2425 qXfer:statictrace:read
2427 Read the static trace data collected (by a `collect $_sdata'
2428 tracepoint action). The remote stub reports support for this packet
2429 to gdb's qSupported query.
2433 Send the current settings of GDB's permission flags.
2437 Send part of the source (textual) form of a tracepoint definition,
2438 which includes location, conditional, and action list.
2440 * The source command now accepts a -s option to force searching for the
2441 script in the source search path even if the script name specifies
2444 * New features in the GDB remote stub, GDBserver
2446 - GDBserver now support tracepoints (including fast tracepoints, and
2447 static tracepoints). The feature is currently supported by the
2448 i386-linux and amd64-linux builds. See the "Tracepoints support
2449 in gdbserver" section in the manual for more information.
2451 GDBserver JIT compiles the tracepoint's conditional agent
2452 expression bytecode into native code whenever possible for low
2453 overhead dynamic tracepoints conditionals. For such tracepoints,
2454 an expression that examines program state is evaluated when the
2455 tracepoint is reached, in order to determine whether to capture
2456 trace data. If the condition is simple and false, processing the
2457 tracepoint finishes very quickly and no data is gathered.
2459 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2460 for static tracepoints support.
2462 - GDBserver now supports x86_64 Windows 64-bit debugging.
2464 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2465 it understands register description.
2467 * The --batch flag now disables pagination and queries.
2469 * X86 general purpose registers
2471 GDB now supports reading/writing byte, word and double-word x86
2472 general purpose registers directly. This means you can use, say,
2473 $ah or $ax to refer, respectively, to the byte register AH and
2474 16-bit word register AX that are actually portions of the 32-bit
2475 register EAX or 64-bit register RAX.
2477 * The `commands' command now accepts a range of breakpoints to modify.
2478 A plain `commands' following a command that creates multiple
2479 breakpoints affects all the breakpoints set by that command. This
2480 applies to breakpoints set by `rbreak', and also applies when a
2481 single `break' command creates multiple breakpoints (e.g.,
2482 breakpoints on overloaded c++ functions).
2484 * The `rbreak' command now accepts a filename specification as part of
2485 its argument, limiting the functions selected by the regex to those
2486 in the specified file.
2488 * Support for remote debugging Windows and SymbianOS shared libraries
2489 from Unix hosts has been improved. Non Windows GDB builds now can
2490 understand target reported file names that follow MS-DOS based file
2491 system semantics, such as file names that include drive letters and
2492 use the backslash character as directory separator. This makes it
2493 possible to transparently use the "set sysroot" and "set
2494 solib-search-path" on Unix hosts to point as host copies of the
2495 target's shared libraries. See the new command "set
2496 target-file-system-kind" described below, and the "Commands to
2497 specify files" section in the user manual for more information.
2501 eval template, expressions...
2502 Convert the values of one or more expressions under the control
2503 of the string template to a command line, and call it.
2505 set target-file-system-kind unix|dos-based|auto
2506 show target-file-system-kind
2507 Set or show the assumed file system kind for target reported file
2510 save breakpoints <filename>
2511 Save all current breakpoint definitions to a file suitable for use
2512 in a later debugging session. To read the saved breakpoint
2513 definitions, use the `source' command.
2515 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2518 info static-tracepoint-markers
2519 Display information about static tracepoint markers in the target.
2521 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2522 Define a static tracepoint by probing a marker at the given
2523 function, line, address, or marker ID.
2527 Enable and disable observer mode.
2529 set may-write-registers on|off
2530 set may-write-memory on|off
2531 set may-insert-breakpoints on|off
2532 set may-insert-tracepoints on|off
2533 set may-insert-fast-tracepoints on|off
2534 set may-interrupt on|off
2535 Set individual permissions for GDB effects on the target. Note that
2536 some of these settings can have undesirable or surprising
2537 consequences, particularly when changed in the middle of a session.
2538 For instance, disabling the writing of memory can prevent
2539 breakpoints from being inserted, cause single-stepping to fail, or
2540 even crash your program, if you disable after breakpoints have been
2541 inserted. However, GDB should not crash.
2543 set record memory-query on|off
2544 show record memory-query
2545 Control whether to stop the inferior if memory changes caused
2546 by an instruction cannot be recorded.
2551 The disassemble command now supports "start,+length" form of two arguments.
2555 ** GDB now provides a new directory location, called the python directory,
2556 where Python scripts written for GDB can be installed. The location
2557 of that directory is <data-directory>/python, where <data-directory>
2558 is the GDB data directory. For more details, see section `Scripting
2559 GDB using Python' in the manual.
2561 ** The GDB Python API now has access to breakpoints, symbols, symbol
2562 tables, program spaces, inferiors, threads and frame's code blocks.
2563 Additionally, GDB Parameters can now be created from the API, and
2564 manipulated via set/show in the CLI.
2566 ** New functions gdb.target_charset, gdb.target_wide_charset,
2567 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2569 ** New exception gdb.GdbError.
2571 ** Pretty-printers are now also looked up in the current program space.
2573 ** Pretty-printers can now be individually enabled and disabled.
2575 ** GDB now looks for names of Python scripts to auto-load in a
2576 special section named `.debug_gdb_scripts', in addition to looking
2577 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2579 * Tracepoint actions were unified with breakpoint commands. In particular,
2580 there are no longer differences in "info break" output for breakpoints and
2581 tracepoints and the "commands" command can be used for both tracepoints and
2582 regular breakpoints.
2586 ARM Symbian arm*-*-symbianelf*
2588 * D language support.
2589 GDB now supports debugging programs written in the D programming
2592 * GDB now supports the extended ptrace interface for PowerPC which is
2593 available since Linux kernel version 2.6.34. This automatically enables
2594 any hardware breakpoints and additional hardware watchpoints available in
2595 the processor. The old ptrace interface exposes just one hardware
2596 watchpoint and no hardware breakpoints.
2598 * GDB is now able to use the Data Value Compare (DVC) register available on
2599 embedded PowerPC processors to implement in hardware simple watchpoint
2600 conditions of the form:
2602 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2604 This works in native GDB running on Linux kernels with the extended ptrace
2605 interface mentioned above.
2607 *** Changes in GDB 7.1
2611 ** Namespace Support
2613 GDB now supports importing of namespaces in C++. This enables the
2614 user to inspect variables from imported namespaces. Support for
2615 namepace aliasing has also been added. So, if a namespace is
2616 aliased in the current scope (e.g. namepace C=A; ) the user can
2617 print variables using the alias (e.g. (gdb) print C::x).
2621 All known bugs relating to the printing of virtual base class were
2622 fixed. It is now possible to call overloaded static methods using a
2627 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2628 and reinterpret_cast<> are now handled by the C++ expression parser.
2632 Xilinx MicroBlaze microblaze-*-*
2637 Xilinx MicroBlaze microblaze
2640 * Multi-program debugging.
2642 GDB now has support for multi-program (a.k.a. multi-executable or
2643 multi-exec) debugging. This allows for debugging multiple inferiors
2644 simultaneously each running a different program under the same GDB
2645 session. See "Debugging Multiple Inferiors and Programs" in the
2646 manual for more information. This implied some user visible changes
2647 in the multi-inferior support. For example, "info inferiors" now
2648 lists inferiors that are not running yet or that have exited
2649 already. See also "New commands" and "New options" below.
2651 * New tracing features
2653 GDB's tracepoint facility now includes several new features:
2655 ** Trace state variables
2657 GDB tracepoints now include support for trace state variables, which
2658 are variables managed by the target agent during a tracing
2659 experiment. They are useful for tracepoints that trigger each
2660 other, so for instance one tracepoint can count hits in a variable,
2661 and then a second tracepoint has a condition that is true when the
2662 count reaches a particular value. Trace state variables share the
2663 $-syntax of GDB convenience variables, and can appear in both
2664 tracepoint actions and condition expressions. Use the "tvariable"
2665 command to create, and "info tvariables" to view; see "Trace State
2666 Variables" in the manual for more detail.
2670 GDB now includes an option for defining fast tracepoints, which
2671 targets may implement more efficiently, such as by installing a jump
2672 into the target agent rather than a trap instruction. The resulting
2673 speedup can be by two orders of magnitude or more, although the
2674 tradeoff is that some program locations on some target architectures
2675 might not allow fast tracepoint installation, for instance if the
2676 instruction to be replaced is shorter than the jump. To request a
2677 fast tracepoint, use the "ftrace" command, with syntax identical to
2678 the regular trace command.
2680 ** Disconnected tracing
2682 It is now possible to detach GDB from the target while it is running
2683 a trace experiment, then reconnect later to see how the experiment
2684 is going. In addition, a new variable disconnected-tracing lets you
2685 tell the target agent whether to continue running a trace if the
2686 connection is lost unexpectedly.
2690 GDB now has the ability to save the trace buffer into a file, and
2691 then use that file as a target, similarly to you can do with
2692 corefiles. You can select trace frames, print data that was
2693 collected in them, and use tstatus to display the state of the
2694 tracing run at the moment that it was saved. To create a trace
2695 file, use "tsave <filename>", and to use it, do "target tfile
2698 ** Circular trace buffer
2700 You can ask the target agent to handle the trace buffer as a
2701 circular buffer, discarding the oldest trace frames to make room for
2702 newer ones, by setting circular-trace-buffer to on. This feature may
2703 not be available for all target agents.
2708 The disassemble command, when invoked with two arguments, now requires
2709 the arguments to be comma-separated.
2712 The info variables command now displays variable definitions. Files
2713 which only declare a variable are not shown.
2716 The source command is now capable of sourcing Python scripts.
2717 This feature is dependent on the debugger being build with Python
2720 Related to this enhancement is also the introduction of a new command
2721 "set script-extension" (see below).
2723 * New commands (for set/show, see "New options" below)
2725 record save [<FILENAME>]
2726 Save a file (in core file format) containing the process record
2727 execution log for replay debugging at a later time.
2729 record restore <FILENAME>
2730 Restore the process record execution log that was saved at an
2731 earlier time, for replay debugging.
2733 add-inferior [-copies <N>] [-exec <FILENAME>]
2736 clone-inferior [-copies <N>] [ID]
2737 Make a new inferior ready to execute the same program another
2738 inferior has loaded.
2743 maint info program-spaces
2744 List the program spaces loaded into GDB.
2746 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2747 show remote interrupt-sequence
2748 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2749 as the sequence to the remote target in order to interrupt the execution.
2750 Ctrl-C is a default. Some system prefers BREAK which is high level of
2751 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2752 Magic SysRq g. It is BREAK signal and character 'g'.
2754 set remote interrupt-on-connect [on | off]
2755 show remote interrupt-on-connect
2756 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2757 remote target when gdb connects to it. This is needed when you debug
2760 set remotebreak [on | off]
2762 Deprecated. Use "set/show remote interrupt-sequence" instead.
2764 tvariable $NAME [ = EXP ]
2765 Create or modify a trace state variable.
2768 List trace state variables and their values.
2770 delete tvariable $NAME ...
2771 Delete one or more trace state variables.
2774 Evaluate the given expressions without collecting anything into the
2775 trace buffer. (Valid in tracepoint actions only.)
2777 ftrace FN / FILE:LINE / *ADDR
2778 Define a fast tracepoint at the given function, line, or address.
2780 * New expression syntax
2782 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2783 GDB now parses 0b101010 identically with 42.
2787 set follow-exec-mode new|same
2788 show follow-exec-mode
2789 Control whether GDB reuses the same inferior across an exec call or
2790 creates a new one. This is useful to be able to restart the old
2791 executable after the inferior having done an exec call.
2793 set default-collect EXPR, ...
2794 show default-collect
2795 Define a list of expressions to be collected at each tracepoint.
2796 This is a useful way to ensure essential items are not overlooked,
2797 such as registers or a critical global variable.
2799 set disconnected-tracing
2800 show disconnected-tracing
2801 If set to 1, the target is instructed to continue tracing if it
2802 loses its connection to GDB. If 0, the target is to stop tracing
2805 set circular-trace-buffer
2806 show circular-trace-buffer
2807 If set to on, the target is instructed to use a circular trace buffer
2808 and discard the oldest trace frames instead of stopping the trace due
2809 to a full trace buffer. If set to off, the trace stops when the buffer
2810 fills up. Some targets may not support this.
2812 set script-extension off|soft|strict
2813 show script-extension
2814 If set to "off", the debugger does not perform any script language
2815 recognition, and all sourced files are assumed to be GDB scripts.
2816 If set to "soft" (the default), files are sourced according to
2817 filename extension, falling back to GDB scripts if the first
2819 If set to "strict", files are sourced according to filename extension.
2821 set ada trust-PAD-over-XVS on|off
2822 show ada trust-PAD-over-XVS
2823 If off, activate a workaround against a bug in the debugging information
2824 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2825 the GCC sources for more information about the GNAT encoding and
2826 PAD types in particular). It is always safe to set this option to
2827 off, but this introduces a slight performance penalty. The default
2830 * Python API Improvements
2832 ** GDB provides the new class gdb.LazyString. This is useful in
2833 some pretty-printing cases. The new method gdb.Value.lazy_string
2834 provides a simple way to create objects of this type.
2836 ** The fields returned by gdb.Type.fields now have an
2837 `is_base_class' attribute.
2839 ** The new method gdb.Type.range returns the range of an array type.
2841 ** The new method gdb.parse_and_eval can be used to parse and
2842 evaluate an expression.
2844 * New remote packets
2847 Define a trace state variable.
2850 Get the current value of a trace state variable.
2853 Set desired tracing behavior upon disconnection.
2856 Set the trace buffer to be linear or circular.
2859 Get data about the tracepoints currently in use.
2863 Process record now works correctly with hardware watchpoints.
2865 Multiple bug fixes have been made to the mips-irix port, making it
2866 much more reliable. In particular:
2867 - Debugging threaded applications is now possible again. Previously,
2868 GDB would hang while starting the program, or while waiting for
2869 the program to stop at a breakpoint.
2870 - Attaching to a running process no longer hangs.
2871 - An error occurring while loading a core file has been fixed.
2872 - Changing the value of the PC register now works again. This fixes
2873 problems observed when using the "jump" command, or when calling
2874 a function from GDB, or even when assigning a new value to $pc.
2875 - With the "finish" and "return" commands, the return value for functions
2876 returning a small array is now correctly printed.
2877 - It is now possible to break on shared library code which gets executed
2878 during a shared library init phase (code executed while executing
2879 their .init section). Previously, the breakpoint would have no effect.
2880 - GDB is now able to backtrace through the signal handler for
2881 non-threaded programs.
2883 PIE (Position Independent Executable) programs debugging is now supported.
2884 This includes debugging execution of PIC (Position Independent Code) shared
2885 libraries although for that, it should be possible to run such libraries as an
2888 *** Changes in GDB 7.0
2890 * GDB now has an interface for JIT compilation. Applications that
2891 dynamically generate code can create symbol files in memory and register
2892 them with GDB. For users, the feature should work transparently, and
2893 for JIT developers, the interface is documented in the GDB manual in the
2894 "JIT Compilation Interface" chapter.
2896 * Tracepoints may now be conditional. The syntax is as for
2897 breakpoints; either an "if" clause appended to the "trace" command,
2898 or the "condition" command is available. GDB sends the condition to
2899 the target for evaluation using the same bytecode format as is used
2900 for tracepoint actions.
2902 * The disassemble command now supports: an optional /r modifier, print the
2903 raw instructions in hex as well as in symbolic form, and an optional /m
2904 modifier to print mixed source+assembly.
2906 * Process record and replay
2908 In a architecture environment that supports ``process record and
2909 replay'', ``process record and replay'' target can record a log of
2910 the process execution, and replay it with both forward and reverse
2913 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2914 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2915 set execution-direction {forward|reverse}, for targets that support
2918 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2919 feature is available with a native GDB running on kernel version
2922 * GDB now has support for multi-byte and wide character sets on the
2923 target. Strings whose character type is wchar_t, char16_t, or
2924 char32_t are now correctly printed. GDB supports wide- and unicode-
2925 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2926 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2927 `printf'. This feature requires iconv to work properly; if your
2928 system does not have a working iconv, GDB can use GNU libiconv. See
2929 the installation instructions for more information.
2931 * GDB now supports automatic retrieval of shared library files from
2932 remote targets. To use this feature, specify a system root that begins
2933 with the `remote:' prefix, either via the `set sysroot' command or via
2934 the `--with-sysroot' configure-time option.
2936 * "info sharedlibrary" now takes an optional regex of libraries to show,
2937 and it now reports if a shared library has no debugging information.
2939 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2940 now complete on file names.
2942 * When completing in expressions, gdb will attempt to limit
2943 completions to allowable structure or union fields, where appropriate.
2944 For instance, consider:
2946 # struct example { int f1; double f2; };
2947 # struct example variable;
2950 If the user types TAB at the end of this command line, the available
2951 completions will be "f1" and "f2".
2953 * Inlined functions are now supported. They show up in backtraces, and
2954 the "step", "next", and "finish" commands handle them automatically.
2956 * GDB now supports the token-splicing (##) and stringification (#)
2957 operators when expanding macros. It also supports variable-arity
2960 * GDB now supports inspecting extra signal information, exported by
2961 the new $_siginfo convenience variable. The feature is currently
2962 implemented on linux ARM, i386 and amd64.
2964 * GDB can now display the VFP floating point registers and NEON vector
2965 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2966 can provide these registers (requires Linux 2.6.30 or later). Remote
2967 and simulator targets may also provide them.
2969 * New remote packets
2972 Search memory for a sequence of bytes.
2975 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2976 operation over reliable transport links. Use of this packet is
2977 controlled by the `set remote noack-packet' command.
2980 Kill the process with the specified process ID. Use this in preference
2981 to `k' when multiprocess protocol extensions are supported.
2984 Obtains additional operating system information
2988 Read or write additional signal information.
2990 * Removed remote protocol undocumented extension
2992 An undocumented extension to the remote protocol's `S' stop reply
2993 packet that permited the stub to pass a process id was removed.
2994 Remote servers should use the `T' stop reply packet instead.
2996 * GDB now supports multiple function calling conventions according to the
2997 DWARF-2 DW_AT_calling_convention function attribute.
2999 * The SH target utilizes the aforementioned change to distinguish between gcc
3000 and Renesas calling convention. It also adds the new CLI commands
3001 `set/show sh calling-convention'.
3003 * GDB can now read compressed debug sections, as produced by GNU gold
3004 with the --compress-debug-sections=zlib flag.
3006 * 64-bit core files are now supported on AIX.
3008 * Thread switching is now supported on Tru64.
3010 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3011 which will be allocated using malloc later in program execution.
3013 * The qXfer:libraries:read remote procotol packet now allows passing a
3014 list of section offsets.
3016 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3017 conditions handling signals delivered during attach or thread creation
3018 have also been fixed.
3020 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3021 From the user's standpoint, all unqualified instances of True and False
3022 are treated as the standard definitions, regardless of context.
3024 * GDB now parses C++ symbol and type names more flexibly. For
3027 template<typename T> class C { };
3030 GDB will now correctly handle all of:
3032 ptype C<char const *>
3033 ptype C<char const*>
3034 ptype C<const char *>
3035 ptype C<const char*>
3037 * New features in the GDB remote stub, gdbserver
3039 - The "--wrapper" command-line argument tells gdbserver to use a
3040 wrapper program to launch programs for debugging.
3042 - On PowerPC and S/390 targets, it is now possible to use a single
3043 gdbserver executable to debug both 32-bit and 64-bit programs.
3044 (This requires gdbserver itself to be built as a 64-bit executable.)
3046 - gdbserver uses the new noack protocol mode for TCP connections to
3047 reduce communications latency, if also supported and enabled in GDB.
3049 - Support for the sparc64-linux-gnu target is now included in
3052 - The amd64-linux build of gdbserver now supports debugging both
3053 32-bit and 64-bit programs.
3055 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3056 now support hardware watchpoints, and will use them automatically
3061 GDB now has support for scripting using Python. Whether this is
3062 available is determined at configure time.
3064 New GDB commands can now be written in Python.
3066 * Ada tasking support
3068 Ada tasks can now be inspected in GDB. The following commands have
3072 Print the list of Ada tasks.
3074 Print detailed information about task number N.
3076 Print the task number of the current task.
3078 Switch the context of debugging to task number N.
3080 * Support for user-defined prefixed commands. The "define" command can
3081 add new commands to existing prefixes, e.g. "target".
3083 * Multi-inferior, multi-process debugging.
3085 GDB now has generalized support for multi-inferior debugging. See
3086 "Debugging Multiple Inferiors" in the manual for more information.
3087 Although availability still depends on target support, the command
3088 set is more uniform now. The GNU/Linux specific multi-forks support
3089 has been migrated to this new framework. This implied some user
3090 visible changes; see "New commands" and also "Removed commands"
3093 * Target descriptions can now describe the target OS ABI. See the
3094 "Target Description Format" section in the user manual for more
3097 * Target descriptions can now describe "compatible" architectures
3098 to indicate that the target can execute applications for a different
3099 architecture in addition to those for the main target architecture.
3100 See the "Target Description Format" section in the user manual for
3103 * Multi-architecture debugging.
3105 GDB now includes general supports for debugging applications on
3106 hybrid systems that use more than one single processor architecture
3107 at the same time. Each such hybrid architecture still requires
3108 specific support to be added. The only hybrid architecture supported
3109 in this version of GDB is the Cell Broadband Engine.
3111 * GDB now supports integrated debugging of Cell/B.E. applications that
3112 use both the PPU and SPU architectures. To enable support for hybrid
3113 Cell/B.E. debugging, you need to configure GDB to support both the
3114 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3115 --enable-targets configure option.
3117 * Non-stop mode debugging.
3119 For some targets, GDB now supports an optional mode of operation in
3120 which you can examine stopped threads while other threads continue
3121 to execute freely. This is referred to as non-stop mode, with the
3122 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3123 section in the user manual for more information.
3125 To be able to support remote non-stop debugging, a remote stub needs
3126 to implement the non-stop mode remote protocol extensions, as
3127 described in the "Remote Non-Stop" section of the user manual. The
3128 GDB remote stub, gdbserver, has been adjusted to support these
3129 extensions on linux targets.
3131 * New commands (for set/show, see "New options" below)
3133 catch syscall [NAME(S) | NUMBER(S)]
3134 Catch system calls. Arguments, which should be names of system
3135 calls or their numbers, mean catch only those syscalls. Without
3136 arguments, every syscall will be caught. When the inferior issues
3137 any of the specified syscalls, GDB will stop and announce the system
3138 call, both when it is called and when its call returns. This
3139 feature is currently available with a native GDB running on the
3140 Linux Kernel, under the following architectures: x86, x86_64,
3141 PowerPC and PowerPC64.
3143 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3145 Search memory for a sequence of bytes.
3147 maint set python print-stack
3148 maint show python print-stack
3149 Show a stack trace when an error is encountered in a Python script.
3152 Invoke CODE by passing it to the Python interpreter.
3157 These allow macros to be defined, undefined, and listed
3161 Show operating system information about processes.
3164 List the inferiors currently under GDB's control.
3167 Switch focus to inferior number NUM.
3170 Detach from inferior number NUM.
3173 Kill inferior number NUM.
3177 set spu stop-on-load
3178 show spu stop-on-load
3179 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3181 set spu auto-flush-cache
3182 show spu auto-flush-cache
3183 Control whether to automatically flush the software-managed cache
3184 during Cell/B.E. debugging.
3186 set sh calling-convention
3187 show sh calling-convention
3188 Control the calling convention used when calling SH target functions.
3191 show debug timestamp
3192 Control display of timestamps with GDB debugging output.
3194 set disassemble-next-line
3195 show disassemble-next-line
3196 Control display of disassembled source lines or instructions when
3199 set remote noack-packet
3200 show remote noack-packet
3201 Set/show the use of remote protocol QStartNoAckMode packet. See above
3202 under "New remote packets."
3204 set remote query-attached-packet
3205 show remote query-attached-packet
3206 Control use of remote protocol `qAttached' (query-attached) packet.
3208 set remote read-siginfo-object
3209 show remote read-siginfo-object
3210 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3213 set remote write-siginfo-object
3214 show remote write-siginfo-object
3215 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3218 set remote reverse-continue
3219 show remote reverse-continue
3220 Control use of remote protocol 'bc' (reverse-continue) packet.
3222 set remote reverse-step
3223 show remote reverse-step
3224 Control use of remote protocol 'bs' (reverse-step) packet.
3226 set displaced-stepping
3227 show displaced-stepping
3228 Control displaced stepping mode. Displaced stepping is a way to
3229 single-step over breakpoints without removing them from the debuggee.
3230 Also known as "out-of-line single-stepping".
3233 show debug displaced
3234 Control display of debugging info for displaced stepping.
3236 maint set internal-error
3237 maint show internal-error
3238 Control what GDB does when an internal error is detected.
3240 maint set internal-warning
3241 maint show internal-warning
3242 Control what GDB does when an internal warning is detected.
3247 Use a wrapper program to launch programs for debugging.
3249 set multiple-symbols (all|ask|cancel)
3250 show multiple-symbols
3251 The value of this variable can be changed to adjust the debugger behavior
3252 when an expression or a breakpoint location contains an ambiguous symbol
3253 name (an overloaded function name, for instance).
3255 set breakpoint always-inserted
3256 show breakpoint always-inserted
3257 Keep breakpoints always inserted in the target, as opposed to inserting
3258 them when resuming the target, and removing them when the target stops.
3259 This option can improve debugger performance on slow remote targets.
3261 set arm fallback-mode (arm|thumb|auto)
3262 show arm fallback-mode
3263 set arm force-mode (arm|thumb|auto)
3265 These commands control how ARM GDB determines whether instructions
3266 are ARM or Thumb. The default for both settings is auto, which uses
3267 the current CPSR value for instructions without symbols; previous
3268 versions of GDB behaved as if "set arm fallback-mode arm".
3270 set disable-randomization
3271 show disable-randomization
3272 Standalone programs run with the virtual address space randomization enabled
3273 by default on some platforms. This option keeps the addresses stable across
3274 multiple debugging sessions.
3278 Control whether other threads are stopped or not when some thread hits
3283 Requests that asynchronous execution is enabled in the target, if available.
3284 In this case, it's possible to resume target in the background, and interact
3285 with GDB while the target is running. "show target-async" displays the
3286 current state of asynchronous execution of the target.
3288 set target-wide-charset
3289 show target-wide-charset
3290 The target-wide-charset is the name of the character set that GDB
3291 uses when printing characters whose type is wchar_t.
3293 set tcp auto-retry (on|off)
3295 set tcp connect-timeout
3296 show tcp connect-timeout
3297 These commands allow GDB to retry failed TCP connections to a remote stub
3298 with a specified timeout period; this is useful if the stub is launched
3299 in parallel with GDB but may not be ready to accept connections immediately.
3301 set libthread-db-search-path
3302 show libthread-db-search-path
3303 Control list of directories which GDB will search for appropriate
3306 set schedule-multiple (on|off)
3307 show schedule-multiple
3308 Allow GDB to resume all threads of all processes or only threads of
3309 the current process.
3313 Use more aggressive caching for accesses to the stack. This improves
3314 performance of remote debugging (particularly backtraces) without
3315 affecting correctness.
3317 set interactive-mode (on|off|auto)
3318 show interactive-mode
3319 Control whether GDB runs in interactive mode (on) or not (off).
3320 When in interactive mode, GDB waits for the user to answer all
3321 queries. Otherwise, GDB does not wait and assumes the default
3322 answer. When set to auto (the default), GDB determines which
3323 mode to use based on the stdin settings.
3328 For program forks, this is replaced by the new more generic `info
3329 inferiors' command. To list checkpoints, you can still use the
3330 `info checkpoints' command, which was an alias for the `info forks'
3334 Replaced by the new `inferior' command. To switch between
3335 checkpoints, you can still use the `restart' command, which was an
3336 alias for the `fork' command.
3339 This is removed, since some targets don't have a notion of
3340 processes. To switch between processes, you can still use the
3341 `inferior' command using GDB's own inferior number.
3344 For program forks, this is replaced by the new more generic `kill
3345 inferior' command. To delete a checkpoint, you can still use the
3346 `delete checkpoint' command, which was an alias for the `delete
3350 For program forks, this is replaced by the new more generic `detach
3351 inferior' command. To detach a checkpoint, you can still use the
3352 `detach checkpoint' command, which was an alias for the `detach
3355 * New native configurations
3357 x86/x86_64 Darwin i[34567]86-*-darwin*
3359 x86_64 MinGW x86_64-*-mingw*
3363 Lattice Mico32 lm32-*
3364 x86 DICOS i[34567]86-*-dicos*
3365 x86_64 DICOS x86_64-*-dicos*
3368 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3369 (mingw32ce) debugging.
3375 These commands were actually not implemented on any target.
3377 *** Changes in GDB 6.8
3379 * New native configurations
3381 NetBSD/hppa hppa*-*netbsd*
3382 Xtensa GNU/Linux xtensa*-*-linux*
3386 NetBSD/hppa hppa*-*-netbsd*
3387 Xtensa GNU/Lunux xtensa*-*-linux*
3389 * Change in command line behavior -- corefiles vs. process ids.
3391 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3392 attaching to process NUMBER fails, GDB no longer attempts to open a
3393 core file named NUMBER. Attaching to a program using the -c option
3394 is no longer supported. Instead, use the '-p' or '--pid' options.
3396 * GDB can now be built as a native debugger for debugging Windows x86
3397 (mingw32) Portable Executable (PE) programs.
3399 * Pending breakpoints no longer change their number when their address
3402 * GDB now supports breakpoints with multiple locations,
3403 including breakpoints on C++ constructors, inside C++ templates,
3404 and in inlined functions.
3406 * GDB's ability to debug optimized code has been improved. GDB more
3407 accurately identifies function bodies and lexical blocks that occupy
3408 more than one contiguous range of addresses.
3410 * Target descriptions can now describe registers for PowerPC.
3412 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3413 registers on PowerPC targets.
3415 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3416 targets even when the libthread_db library is not available.
3418 * The GDB remote stub, gdbserver, now supports the new file transfer
3419 commands (remote put, remote get, and remote delete).
3421 * The GDB remote stub, gdbserver, now supports run and attach in
3422 extended-remote mode.
3424 * hppa*64*-*-hpux11* target broken
3425 The debugger is unable to start a program and fails with the following
3426 error: "Error trying to get information about dynamic linker".
3427 The gdb-6.7 release is also affected.
3429 * GDB now supports the --enable-targets= configure option to allow
3430 building a single GDB executable that supports multiple remote
3431 target architectures.
3433 * GDB now supports debugging C and C++ programs which use the
3434 Decimal Floating Point extension. In addition, the PowerPC target
3435 now has a set of pseudo-registers to inspect decimal float values
3436 stored in two consecutive float registers.
3438 * The -break-insert MI command can optionally create pending
3441 * Improved support for debugging Ada
3442 Many improvements to the Ada language support have been made. These
3444 - Better support for Ada2005 interface types
3445 - Improved handling of arrays and slices in general
3446 - Better support for Taft-amendment types
3447 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3449 - Improved command completion in Ada
3452 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3457 set print frame-arguments (all|scalars|none)
3458 show print frame-arguments
3459 The value of this variable can be changed to control which argument
3460 values should be printed by the debugger when displaying a frame.
3465 Transfer files to and from a remote target, and delete remote files.
3472 Transfer files to and from a remote target, and delete remote files.
3474 * New remote packets
3481 Open, close, read, write, and delete files on the remote system.
3484 Attach to an existing process on the remote system, in extended-remote
3488 Run a new process on the remote system, in extended-remote mode.
3490 *** Changes in GDB 6.7
3492 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3493 bfd, libiberty and opcodes, as revealed by static analysis donated by
3494 Coverity, Inc. (http://scan.coverity.com).
3496 * When looking up multiply-defined global symbols, GDB will now prefer the
3497 symbol definition in the current shared library if it was built using the
3498 -Bsymbolic linker option.
3500 * When the Text User Interface (TUI) is not configured, GDB will now
3501 recognize the -tui command-line option and print a message that the TUI
3504 * The GDB remote stub, gdbserver, now has lower overhead for high
3505 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3507 * GDB for MIPS targets now autodetects whether a remote target provides
3508 32-bit or 64-bit register values.
3510 * Support for C++ member pointers has been improved.
3512 * GDB now understands XML target descriptions, which specify the
3513 target's overall architecture. GDB can read a description from
3514 a local file or over the remote serial protocol.
3516 * Vectors of single-byte data use a new integer type which is not
3517 automatically displayed as character or string data.
3519 * The /s format now works with the print command. It displays
3520 arrays of single-byte integers and pointers to single-byte integers
3523 * Target descriptions can now describe target-specific registers,
3524 for architectures which have implemented the support (currently
3525 only ARM, M68K, and MIPS).
3527 * GDB and the GDB remote stub, gdbserver, now support the XScale
3530 * The GDB remote stub, gdbserver, has been updated to support
3531 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3532 has been rewritten to use the standard GDB remote protocol.
3534 * GDB can now step into C++ functions which are called through thunks.
3536 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3538 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3539 layout. It also supports a TextSeg= and DataSeg= response when only
3540 segment base addresses (rather than offsets) are available.
3542 * The /i format now outputs any trailing branch delay slot instructions
3543 immediately following the last instruction within the count specified.
3545 * The GDB remote protocol "T" stop reply packet now supports a
3546 "library" response. Combined with the new "qXfer:libraries:read"
3547 packet, this response allows GDB to debug shared libraries on targets
3548 where the operating system manages the list of loaded libraries (e.g.
3549 Windows and SymbianOS).
3551 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3552 (DLLs) on Windows and Windows CE targets.
3554 * GDB now supports a faster verification that a .debug file matches its binary
3555 according to its build-id signature, if the signature is present.
3561 Enable or disable hardware flow control (RTS/CTS) on the serial port
3562 when debugging using remote targets.
3564 set mem inaccessible-by-default
3565 show mem inaccessible-by-default
3566 If the target supplies a memory map, for instance via the remote
3567 protocol's "qXfer:memory-map:read" packet, setting this variable
3568 prevents GDB from accessing memory outside the memory map. This
3569 is useful for targets with memory mapped registers or which react
3570 badly to accesses of unmapped address space.
3572 set breakpoint auto-hw
3573 show breakpoint auto-hw
3574 If the target supplies a memory map, for instance via the remote
3575 protocol's "qXfer:memory-map:read" packet, setting this variable
3576 lets GDB use hardware breakpoints automatically for memory regions
3577 where it can not use software breakpoints. This covers both the
3578 "break" command and internal breakpoints used for other commands
3579 including "next" and "finish".
3582 catch exception unhandled
3583 Stop the program execution when Ada exceptions are raised.
3586 Stop the program execution when an Ada assertion failed.
3590 Set an alternate system root for target files. This is a more
3591 general version of "set solib-absolute-prefix", which is now
3592 an alias to "set sysroot".
3595 Provide extended SPU facility status information. This set of
3596 commands is available only when debugging the Cell/B.E. SPU
3599 * New native configurations
3601 OpenBSD/sh sh*-*openbsd*
3604 unset tdesc filename
3606 Use the specified local file as an XML target description, and do
3607 not query the target for its built-in description.
3611 OpenBSD/sh sh*-*-openbsd*
3612 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3613 Toshiba Media Processor mep-elf
3615 * New remote packets
3618 Ignore the specified signals; pass them directly to the debugged program
3619 without stopping other threads or reporting them to GDB.
3621 qXfer:features:read:
3622 Read an XML target description from the target, which describes its
3627 Read or write contents of an spufs file on the target system. These
3628 packets are available only on the Cell/B.E. SPU architecture.
3630 qXfer:libraries:read:
3631 Report the loaded shared libraries. Combined with new "T" packet
3632 response, this packet allows GDB to debug shared libraries on
3633 targets where the operating system manages the list of loaded
3634 libraries (e.g. Windows and SymbianOS).
3638 Support for these obsolete configurations has been removed.
3646 i[34567]86-*-lynxos*
3647 i[34567]86-*-netware*
3648 i[34567]86-*-sco3.2v5*
3649 i[34567]86-*-sco3.2v4*
3651 i[34567]86-*-sysv4.2*
3654 i[34567]86-*-unixware2*
3655 i[34567]86-*-unixware*
3664 * Other removed features
3671 Various m68k-only ROM monitors.
3678 Various Renesas ROM monitors and debugging interfaces for SH and
3683 Support for a Macraigor serial interface to on-chip debugging.
3684 GDB does not directly support the newer parallel or USB
3689 A debug information format. The predecessor to DWARF 2 and
3690 DWARF 3, which are still supported.
3692 Support for the HP aCC compiler on HP-UX/PA-RISC
3694 SOM-encapsulated symbolic debugging information, automatic
3695 invocation of pxdb, and the aCC custom C++ ABI. This does not
3696 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3697 with aCC can still be debugged on an assembly level.
3699 MIPS ".pdr" sections
3701 A MIPS-specific format used to describe stack frame layout
3702 in debugging information.
3706 GDB could work with an older version of Guile to debug
3707 the interpreter and Scheme programs running in it.
3709 set mips stack-arg-size
3710 set mips saved-gpreg-size
3712 Use "set mips abi" to control parameter passing for MIPS.
3714 *** Changes in GDB 6.6
3719 Cell Broadband Engine SPU spu-elf
3721 * GDB can now be configured as a cross-debugger targeting native Windows
3722 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3723 running on a Windows system over TCP/IP to debug Windows programs.
3725 * The GDB remote stub, gdbserver, has been updated to support Windows and
3726 Cygwin debugging. Both single-threaded and multi-threaded programs are
3729 * The "set trust-readonly-sections" command works again. This command was
3730 broken in GDB 6.3, 6.4, and 6.5.
3732 * The "load" command now supports writing to flash memory, if the remote
3733 stub provides the required support.
3735 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3736 longer requires symbolic debug information (e.g. DWARF-2).
3741 unset substitute-path
3742 show substitute-path
3743 Manage a list of substitution rules that GDB uses to rewrite the name
3744 of the directories where the sources are located. This can be useful
3745 for instance when the sources were moved to a different location
3746 between compilation and debugging.
3750 Print each CLI command as it is executed. Each command is prefixed with
3751 a number of `+' symbols representing the nesting depth.
3752 The source command now has a `-v' option to enable the same feature.
3756 The ARM Demon monitor support (RDP protocol, "target rdp").
3758 Kernel Object Display, an embedded debugging feature which only worked with
3759 an obsolete version of Cisco IOS.
3761 The 'set download-write-size' and 'show download-write-size' commands.
3763 * New remote packets
3766 Tell a stub about GDB client features, and request remote target features.
3767 The first feature implemented is PacketSize, which allows the target to
3768 specify the size of packets it can handle - to minimize the number of
3769 packets required and improve performance when connected to a remote
3773 Fetch an OS auxilliary vector from the remote stub. This packet is a
3774 more efficient replacement for qPart:auxv:read.
3776 qXfer:memory-map:read:
3777 Fetch a memory map from the remote stub, including information about
3778 RAM, ROM, and flash memory devices.
3783 Erase and program a flash memory device.
3785 * Removed remote packets
3788 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3789 used it, and only gdbserver implemented it.
3791 *** Changes in GDB 6.5
3795 Renesas M32C/M16C m32c-elf
3797 Morpho Technologies ms1 ms1-elf
3801 init-if-undefined Initialize a convenience variable, but
3802 only if it doesn't already have a value.
3804 The following commands are presently only implemented for native GNU/Linux:
3806 checkpoint Save a snapshot of the program state.
3808 restart <n> Return the program state to a
3809 previously saved state.
3811 info checkpoints List currently saved checkpoints.
3813 delete-checkpoint <n> Delete a previously saved checkpoint.
3815 set|show detach-on-fork Tell gdb whether to detach from a newly
3816 forked process, or to keep debugging it.
3818 info forks List forks of the user program that
3819 are available to be debugged.
3821 fork <n> Switch to debugging one of several
3822 forks of the user program that are
3823 available to be debugged.
3825 delete-fork <n> Delete a fork from the list of forks
3826 that are available to be debugged (and
3827 kill the forked process).
3829 detach-fork <n> Delete a fork from the list of forks
3830 that are available to be debugged (and
3831 allow the process to continue).
3835 Morpho Technologies ms2 ms1-elf
3837 * Improved Windows host support
3839 GDB now builds as a cross debugger hosted on i686-mingw32, including
3840 native console support, and remote communications using either
3841 network sockets or serial ports.
3843 * Improved Modula-2 language support
3845 GDB can now print most types in the Modula-2 syntax. This includes:
3846 basic types, set types, record types, enumerated types, range types,
3847 pointer types and ARRAY types. Procedure var parameters are correctly
3848 printed and hexadecimal addresses and character constants are also
3849 written in the Modula-2 syntax. Best results can be obtained by using
3850 GNU Modula-2 together with the -gdwarf-2 command line option.
3854 The ARM rdi-share module.
3856 The Netware NLM debug server.
3858 *** Changes in GDB 6.4
3860 * New native configurations
3862 OpenBSD/arm arm*-*-openbsd*
3863 OpenBSD/mips64 mips64-*-openbsd*
3867 Morpho Technologies ms1 ms1-elf
3869 * New command line options
3871 --batch-silent As for --batch, but totally silent.
3872 --return-child-result The debugger will exist with the same value
3873 the child (debugged) program exited with.
3874 --eval-command COMMAND, -ex COMMAND
3875 Execute a single GDB CLI command. This may be
3876 specified multiple times and in conjunction
3877 with the --command (-x) option.
3879 * Deprecated commands removed
3881 The following commands, that were deprecated in 2000, have been
3885 set|show arm disassembly-flavor set|show arm disassembler
3886 othernames set arm disassembler
3887 set|show remotedebug set|show debug remote
3888 set|show archdebug set|show debug arch
3889 set|show eventdebug set|show debug event
3892 * New BSD user-level threads support
3894 It is now possible to debug programs using the user-level threads
3895 library on OpenBSD and FreeBSD. Currently supported (target)
3898 FreeBSD/amd64 x86_64-*-freebsd*
3899 FreeBSD/i386 i386-*-freebsd*
3900 OpenBSD/i386 i386-*-openbsd*
3902 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3903 are not yet supported.
3905 * New support for Matsushita MN10300 w/sim added
3906 (Work in progress). mn10300-elf.
3908 * REMOVED configurations and files
3910 VxWorks and the XDR protocol *-*-vxworks
3911 Motorola MCORE mcore-*-*
3912 National Semiconductor NS32000 ns32k-*-*
3914 * New "set print array-indexes" command
3916 After turning this setting "on", GDB prints the index of each element
3917 when displaying arrays. The default is "off" to preserve the previous
3920 * VAX floating point support
3922 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3924 * User-defined command support
3926 In addition to using $arg0..$arg9 for argument passing, it is now possible
3927 to use $argc to determine now many arguments have been passed. See the
3928 section on user-defined commands in the user manual for more information.
3930 *** Changes in GDB 6.3:
3932 * New command line option
3934 GDB now accepts -l followed by a number to set the timeout for remote
3937 * GDB works with GCC -feliminate-dwarf2-dups
3939 GDB now supports a more compact representation of DWARF-2 debug
3940 information using DW_FORM_ref_addr references. These are produced
3941 by GCC with the option -feliminate-dwarf2-dups and also by some
3942 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3943 to use -feliminate-dwarf2-dups.
3945 * Internationalization
3947 When supported by the host system, GDB will be built with
3948 internationalization (libintl). The task of marking up the sources is
3949 continued, we're looking forward to our first translation.
3953 Initial support for debugging programs compiled with the GNAT
3954 implementation of the Ada programming language has been integrated
3955 into GDB. In this release, support is limited to expression evaluation.
3957 * New native configurations
3959 GNU/Linux/m32r m32r-*-linux-gnu
3963 GDB's remote protocol now includes support for the 'p' packet. This
3964 packet is used to fetch individual registers from a remote inferior.
3966 * END-OF-LIFE registers[] compatibility module
3968 GDB's internal register infrastructure has been completely rewritten.
3969 The new infrastructure making possible the implementation of key new
3970 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3973 GDB 6.3 will be the last release to include the the registers[]
3974 compatibility module that allowed out-of-date configurations to
3975 continue to work. This change directly impacts the following
3985 powerpc bdm protocol
3987 Unless there is activity to revive these configurations, they will be
3988 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3990 * OBSOLETE configurations and files
3992 Configurations that have been declared obsolete in this release have
3993 been commented out. Unless there is activity to revive these
3994 configurations, the next release of GDB will have their sources
3995 permanently REMOVED.
4004 *** Changes in GDB 6.2.1:
4006 * MIPS `break main; run' gave an heuristic-fence-post warning
4008 When attempting to run even a simple program, a warning about
4009 heuristic-fence-post being hit would be reported. This problem has
4012 * MIPS IRIX 'long double' crashed GDB
4014 When examining a long double variable, GDB would get a segmentation
4015 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4016 IRIX long double values).
4020 A bug in the VAX stack code was causing problems with the "next"
4021 command. This problem has been fixed.
4023 *** Changes in GDB 6.2:
4025 * Fix for ``many threads''
4027 On GNU/Linux systems that use the NPTL threads library, a program
4028 rapidly creating and deleting threads would confuse GDB leading to the
4031 ptrace: No such process.
4032 thread_db_get_info: cannot get thread info: generic error
4034 This problem has been fixed.
4036 * "-async" and "-noasync" options removed.
4038 Support for the broken "-noasync" option has been removed (it caused
4041 * New ``start'' command.
4043 This command runs the program until the begining of the main procedure.
4045 * New BSD Kernel Data Access Library (libkvm) interface
4047 Using ``target kvm'' it is now possible to debug kernel core dumps and
4048 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4049 platforms. Currently supported (native-only) configurations are:
4051 FreeBSD/amd64 x86_64-*-freebsd*
4052 FreeBSD/i386 i?86-*-freebsd*
4053 NetBSD/i386 i?86-*-netbsd*
4054 NetBSD/m68k m68*-*-netbsd*
4055 NetBSD/sparc sparc-*-netbsd*
4056 OpenBSD/amd64 x86_64-*-openbsd*
4057 OpenBSD/i386 i?86-*-openbsd*
4058 OpenBSD/m68k m68*-openbsd*
4059 OpenBSD/sparc sparc-*-openbsd*
4061 * Signal trampoline code overhauled
4063 Many generic problems with GDB's signal handling code have been fixed.
4064 These include: backtraces through non-contiguous stacks; recognition
4065 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4066 call; backtrace through a signal trampoline; step into and out of
4067 signal handlers; and single-stepping in the signal trampoline.
4069 Please note that kernel bugs are a limiting factor here. These
4070 features have been shown to work on an s390 GNU/Linux system that
4071 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4073 * Cygwin support for DWARF 2 added.
4075 * New native configurations
4077 GNU/Linux/hppa hppa*-*-linux*
4078 OpenBSD/hppa hppa*-*-openbsd*
4079 OpenBSD/m68k m68*-*-openbsd*
4080 OpenBSD/m88k m88*-*-openbsd*
4081 OpenBSD/powerpc powerpc-*-openbsd*
4082 NetBSD/vax vax-*-netbsd*
4083 OpenBSD/vax vax-*-openbsd*
4085 * END-OF-LIFE frame compatibility module
4087 GDB's internal frame infrastructure has been completely rewritten.
4088 The new infrastructure making it possible to support key new features
4089 including DWARF 2 Call Frame Information. To aid in the task of
4090 migrating old configurations to this new infrastructure, a
4091 compatibility module, that allowed old configurations to continue to
4092 work, was also included.
4094 GDB 6.2 will be the last release to include this frame compatibility
4095 module. This change directly impacts the following configurations:
4105 Unless there is activity to revive these configurations, they will be
4106 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4108 * REMOVED configurations and files
4110 Sun 3, running SunOS 3 m68*-*-sunos3*
4111 Sun 3, running SunOS 4 m68*-*-sunos4*
4112 Sun 2, running SunOS 3 m68000-*-sunos3*
4113 Sun 2, running SunOS 4 m68000-*-sunos4*
4114 Motorola 680x0 running LynxOS m68*-*-lynxos*
4115 AT&T 3b1/Unix pc m68*-att-*
4116 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4117 decstation mips-dec-* mips-little-*
4118 riscos mips-*-riscos* mips-*-sysv*
4119 sonymips mips-sony-*
4120 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4122 *** Changes in GDB 6.1.1:
4124 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4126 The TUI (Text-mode User Interface) is now built as part of a default
4127 GDB configuration. It is enabled by either selecting the TUI with the
4128 command line option "-i=tui" or by running the separate "gdbtui"
4129 program. For more information on the TUI, see the manual "Debugging
4132 * Pending breakpoint support (also included in GDB 6.1)
4134 Support has been added to allow you to specify breakpoints in shared
4135 libraries that have not yet been loaded. If a breakpoint location
4136 cannot be found, and the "breakpoint pending" option is set to auto,
4137 GDB queries you if you wish to make the breakpoint pending on a future
4138 shared-library load. If and when GDB resolves the breakpoint symbol,
4139 the pending breakpoint is removed as one or more regular breakpoints
4142 Pending breakpoints are very useful for GCJ Java debugging.
4144 * Fixed ISO-C build problems
4146 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4147 non ISO-C code that stopped them being built using a more strict ISO-C
4148 compiler (e.g., IBM's C compiler).
4150 * Fixed build problem on IRIX 5
4152 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4153 wasn't able to compile compile on an IRIX 5 system.
4155 * Added execute permission to gdb/gdbserver/configure
4157 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4158 permission. This bug would cause configure to fail on a number of
4159 systems (Solaris, IRIX). Ref: server/519.
4161 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4163 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4164 has been updated to use constant array sizes.
4166 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4168 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4169 its generated DWARF Call Frame Info. This encoding was causing GDB to
4170 panic, that panic has been fixed. Ref: gdb/1628.
4172 * Fixed a problem when examining parameters in shared library code.
4174 When examining parameters in optimized shared library code generated
4175 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4176 not available''. GDB now correctly displays the variable's value.
4178 *** Changes in GDB 6.1:
4180 * Removed --with-mmalloc
4182 Support for the mmalloc memory manager has been removed, as it
4183 conflicted with the internal gdb byte cache.
4185 * Changes in AMD64 configurations
4187 The AMD64 target now includes the %cs and %ss registers. As a result
4188 the AMD64 remote protocol has changed; this affects the floating-point
4189 and SSE registers. If you rely on those registers for your debugging,
4190 you should upgrade gdbserver on the remote side.
4192 * Revised SPARC target
4194 The SPARC target has been completely revised, incorporating the
4195 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4196 support for LynxOS and SunOS 4 has been dropped. Calling functions
4197 from within GDB on operating systems with a non-executable stack
4198 (Solaris, OpenBSD) now works.
4202 GDB has a new C++ demangler which does a better job on the mangled
4203 names generated by current versions of g++. It also runs faster, so
4204 with this and other changes gdb should now start faster on large C++
4207 * DWARF 2 Location Expressions
4209 GDB support for location expressions has been extended to support function
4210 arguments and frame bases. Older versions of GDB could crash when they
4213 * C++ nested types and namespaces
4215 GDB's support for nested types and namespaces in C++ has been
4216 improved, especially if you use the DWARF 2 debugging format. (This
4217 is the default for recent versions of GCC on most platforms.)
4218 Specifically, if you have a class "Inner" defined within a class or
4219 namespace "Outer", then GDB realizes that the class's name is
4220 "Outer::Inner", not simply "Inner". This should greatly reduce the
4221 frequency of complaints about not finding RTTI symbols. In addition,
4222 if you are stopped at inside of a function defined within a namespace,
4223 GDB modifies its name lookup accordingly.
4225 * New native configurations
4227 NetBSD/amd64 x86_64-*-netbsd*
4228 OpenBSD/amd64 x86_64-*-openbsd*
4229 OpenBSD/alpha alpha*-*-openbsd*
4230 OpenBSD/sparc sparc-*-openbsd*
4231 OpenBSD/sparc64 sparc64-*-openbsd*
4233 * New debugging protocols
4235 M32R with SDI protocol m32r-*-elf*
4237 * "set prompt-escape-char" command deleted.
4239 The command "set prompt-escape-char" has been deleted. This command,
4240 and its very obscure effet on GDB's prompt, was never documented,
4241 tested, nor mentioned in the NEWS file.
4243 * OBSOLETE configurations and files
4245 Configurations that have been declared obsolete in this release have
4246 been commented out. Unless there is activity to revive these
4247 configurations, the next release of GDB will have their sources
4248 permanently REMOVED.
4250 Sun 3, running SunOS 3 m68*-*-sunos3*
4251 Sun 3, running SunOS 4 m68*-*-sunos4*
4252 Sun 2, running SunOS 3 m68000-*-sunos3*
4253 Sun 2, running SunOS 4 m68000-*-sunos4*
4254 Motorola 680x0 running LynxOS m68*-*-lynxos*
4255 AT&T 3b1/Unix pc m68*-att-*
4256 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4257 decstation mips-dec-* mips-little-*
4258 riscos mips-*-riscos* mips-*-sysv*
4259 sonymips mips-sony-*
4260 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4262 * REMOVED configurations and files
4264 SGI Irix-4.x mips-sgi-irix4 or iris4
4265 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4266 Z8000 simulator z8k-zilog-none or z8ksim
4267 Matsushita MN10200 w/simulator mn10200-*-*
4268 H8/500 simulator h8500-hitachi-hms or h8500hms
4269 HP/PA running BSD hppa*-*-bsd*
4270 HP/PA running OSF/1 hppa*-*-osf*
4271 HP/PA Pro target hppa*-*-pro*
4272 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4273 386BSD i[3456]86-*-bsd*
4274 Sequent family i[3456]86-sequent-sysv4*
4275 i[3456]86-sequent-sysv*
4276 i[3456]86-sequent-bsd*
4277 SPARC running LynxOS sparc-*-lynxos*
4278 SPARC running SunOS 4 sparc-*-sunos4*
4279 Tsqware Sparclet sparclet-*-*
4280 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4282 *** Changes in GDB 6.0:
4286 Support for debugging the Objective-C programming language has been
4287 integrated into GDB.
4289 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4291 DWARF 2's Call Frame Information makes available compiler generated
4292 information that more exactly describes the program's run-time stack.
4293 By using this information, GDB is able to provide more robust stack
4296 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4297 have been updated to use a new backtrace mechanism which includes
4298 DWARF 2 CFI support.
4302 GDB's remote protocol has been extended to include support for hosted
4303 file I/O (where the remote target uses GDB's file system). See GDB's
4304 remote protocol documentation for details.
4306 * All targets using the new architecture framework.
4308 All of GDB's targets have been updated to use the new internal
4309 architecture framework. The way is now open for future GDB releases
4310 to include cross-architecture native debugging support (i386 on amd64,
4313 * GNU/Linux's Thread Local Storage (TLS)
4315 GDB now includes support for for the GNU/Linux implementation of
4316 per-thread variables.
4318 * GNU/Linux's Native POSIX Thread Library (NPTL)
4320 GDB's thread code has been updated to work with either the new
4321 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4323 * Separate debug info.
4325 GDB, in conjunction with BINUTILS, now supports a mechanism for
4326 automatically loading debug information from a separate file. Instead
4327 of shipping full debug and non-debug versions of system libraries,
4328 system integrators can now instead ship just the stripped libraries
4329 and optional debug files.
4331 * DWARF 2 Location Expressions
4333 DWARF 2 Location Expressions allow the compiler to more completely
4334 describe the location of variables (even in optimized code) to the
4337 GDB now includes preliminary support for location expressions (support
4338 for DW_OP_piece is still missing).
4342 A number of long standing bugs that caused GDB to die while starting a
4343 Java application have been fixed. GDB's Java support is now
4344 considered "useable".
4346 * GNU/Linux support for fork, vfork, and exec.
4348 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4349 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4352 * GDB supports logging output to a file
4354 There are two new commands, "set logging" and "show logging", which can be
4355 used to capture GDB's output to a file.
4357 * The meaning of "detach" has changed for gdbserver
4359 The "detach" command will now resume the application, as documented. To
4360 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4363 * d10v, m68hc11 `regs' command deprecated
4365 The `info registers' command has been updated so that it displays the
4366 registers using a format identical to the old `regs' command.
4370 A new command, "maint set profile on/off", has been added. This command can
4371 be used to enable or disable profiling while running GDB, to profile a
4372 session or a set of commands. In addition there is a new configure switch,
4373 "--enable-profiling", which will cause GDB to be compiled with profiling
4374 data, for more informative profiling results.
4376 * Default MI syntax changed to "mi2".
4378 The default MI (machine interface) syntax, enabled by the command line
4379 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4380 "mi1", can be enabled by specifying the option "-i=mi1".
4382 Support for the original "mi0" syntax (included in GDB 5.0) has been
4385 Fix for gdb/192: removed extraneous space when displaying frame level.
4386 Fix for gdb/672: update changelist is now output in mi list format.
4387 Fix for gdb/702: a -var-assign that updates the value now shows up
4388 in a subsequent -var-update.
4390 * New native configurations.
4392 FreeBSD/amd64 x86_64-*-freebsd*
4394 * Multi-arched targets.
4396 HP/PA HPUX11 hppa*-*-hpux*
4397 Renesas M32R/D w/simulator m32r-*-elf*
4399 * OBSOLETE configurations and files
4401 Configurations that have been declared obsolete in this release have
4402 been commented out. Unless there is activity to revive these
4403 configurations, the next release of GDB will have their sources
4404 permanently REMOVED.
4406 Z8000 simulator z8k-zilog-none or z8ksim
4407 Matsushita MN10200 w/simulator mn10200-*-*
4408 H8/500 simulator h8500-hitachi-hms or h8500hms
4409 HP/PA running BSD hppa*-*-bsd*
4410 HP/PA running OSF/1 hppa*-*-osf*
4411 HP/PA Pro target hppa*-*-pro*
4412 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4413 Sequent family i[3456]86-sequent-sysv4*
4414 i[3456]86-sequent-sysv*
4415 i[3456]86-sequent-bsd*
4416 Tsqware Sparclet sparclet-*-*
4417 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4419 * REMOVED configurations and files
4422 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4423 IBM AIX PS/2 i[3456]86-*-aix
4424 i386 running Mach 3.0 i[3456]86-*-mach3*
4425 i386 running Mach i[3456]86-*-mach*
4426 i386 running OSF/1 i[3456]86-*osf1mk*
4427 HP/Apollo 68k Family m68*-apollo*-sysv*,
4429 m68*-hp-bsd*, m68*-hp-hpux*
4430 Argonaut Risc Chip (ARC) arc-*-*
4431 Mitsubishi D30V d30v-*-*
4432 Fujitsu FR30 fr30-*-elf*
4433 OS/9000 i[34]86-*-os9k
4434 I960 with MON960 i960-*-coff
4436 * MIPS $fp behavior changed
4438 The convenience variable $fp, for the MIPS, now consistently returns
4439 the address of the current frame's base. Previously, depending on the
4440 context, $fp could refer to either $sp or the current frame's base
4441 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4442 The GNU Source-Level Debugger''.
4444 *** Changes in GDB 5.3:
4446 * GNU/Linux shared library multi-threaded performance improved.
4448 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4449 `/proc', in preference to `ptrace' for memory reads. This may result
4450 in an improvement in the start-up time of multi-threaded, shared
4451 library applications when run under GDB. One GDB user writes: ``loads
4452 shared libs like mad''.
4454 * ``gdbserver'' now supports multi-threaded applications on some targets
4456 Support for debugging multi-threaded applications which use
4457 the GNU/Linux LinuxThreads package has been added for
4458 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4459 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4461 * GDB now supports C/C++ preprocessor macros.
4463 GDB now expands preprocessor macro invocations in C/C++ expressions,
4464 and provides various commands for showing macro definitions and how
4467 The new command `macro expand EXPRESSION' expands any macro
4468 invocations in expression, and shows the result.
4470 The new command `show macro MACRO-NAME' shows the definition of the
4471 macro named MACRO-NAME, and where it was defined.
4473 Most compilers don't include information about macros in the debugging
4474 information by default. In GCC 3.1, for example, you need to compile
4475 your program with the options `-gdwarf-2 -g3'. If the macro
4476 information is present in the executable, GDB will read it.
4478 * Multi-arched targets.
4480 DEC Alpha (partial) alpha*-*-*
4481 DEC VAX (partial) vax-*-*
4483 National Semiconductor NS32000 (partial) ns32k-*-*
4484 Motorola 68000 (partial) m68k-*-*
4485 Motorola MCORE mcore-*-*
4489 Fujitsu FRV architecture added by Red Hat frv*-*-*
4492 * New native configurations
4494 Alpha NetBSD alpha*-*-netbsd*
4495 SH NetBSD sh*-*-netbsdelf*
4496 MIPS NetBSD mips*-*-netbsd*
4497 UltraSPARC NetBSD sparc64-*-netbsd*
4499 * OBSOLETE configurations and files
4501 Configurations that have been declared obsolete in this release have
4502 been commented out. Unless there is activity to revive these
4503 configurations, the next release of GDB will have their sources
4504 permanently REMOVED.
4506 Mitsubishi D30V d30v-*-*
4507 OS/9000 i[34]86-*-os9k
4508 IBM AIX PS/2 i[3456]86-*-aix
4509 Fujitsu FR30 fr30-*-elf*
4510 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4511 Argonaut Risc Chip (ARC) arc-*-*
4512 i386 running Mach 3.0 i[3456]86-*-mach3*
4513 i386 running Mach i[3456]86-*-mach*
4514 i386 running OSF/1 i[3456]86-*osf1mk*
4515 HP/Apollo 68k Family m68*-apollo*-sysv*,
4517 m68*-hp-bsd*, m68*-hp-hpux*
4518 I960 with MON960 i960-*-coff
4520 * OBSOLETE languages
4522 CHILL, a Pascal like language used by telecommunications companies.
4524 * REMOVED configurations and files
4526 AMD 29k family via UDI a29k-amd-udi, udi29k
4527 A29K VxWorks a29k-*-vxworks
4528 AMD 29000 embedded, using EBMON a29k-none-none
4529 AMD 29000 embedded with COFF a29k-none-coff
4530 AMD 29000 embedded with a.out a29k-none-aout
4532 testsuite/gdb.hp/gdb.threads-hp/ directory
4534 * New command "set max-user-call-depth <nnn>"
4536 This command allows the user to limit the call depth of user-defined
4537 commands. The default is 1024.
4539 * Changes in FreeBSD/i386 native debugging.
4541 Support for the "generate-core-file" has been added.
4543 * New commands "dump", "append", and "restore".
4545 These commands allow data to be copied from target memory
4546 to a bfd-format or binary file (dump and append), and back
4547 from a file into memory (restore).
4549 * Improved "next/step" support on multi-processor Alpha Tru64.
4551 The previous single-step mechanism could cause unpredictable problems,
4552 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4553 of a software single-step mechanism prevents this.
4555 *** Changes in GDB 5.2.1:
4563 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4564 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4565 Fix, by Joel Brobecker imported from mainline.
4567 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4568 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4569 Fix, by Fred Fish, imported from mainline.
4571 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4572 Surprisingly enough, it works now.
4573 By Michal Ludvig, imported from mainline.
4575 i386 hardware watchpoint support:
4576 avoid misses on second run for some targets.
4577 By Pierre Muller, imported from mainline.
4579 *** Changes in GDB 5.2:
4581 * New command "set trust-readonly-sections on[off]".
4583 This command is a hint that tells gdb that read-only sections
4584 really are read-only (ie. that their contents will not change).
4585 In this mode, gdb will go to the object file rather than the
4586 target to read memory from read-only sections (such as ".text").
4587 This can be a significant performance improvement on some
4588 (notably embedded) targets.
4590 * New command "generate-core-file" (or "gcore").
4592 This new gdb command allows the user to drop a core file of the child
4593 process state at any time. So far it's been implemented only for
4594 GNU/Linux and Solaris, but should be relatively easily ported to other
4595 hosts. Argument is core file name (defaults to core.<pid>).
4597 * New command line option
4599 GDB now accepts --pid or -p followed by a process id.
4601 * Change in command line behavior -- corefiles vs. process ids.
4603 There is a subtle behavior in the way in which GDB handles
4604 command line arguments. The first non-flag argument is always
4605 a program to debug, but the second non-flag argument may either
4606 be a corefile or a process id. Previously, GDB would attempt to
4607 open the second argument as a corefile, and if that failed, would
4608 issue a superfluous error message and then attempt to attach it as
4609 a process. Now, if the second argument begins with a non-digit,
4610 it will be treated as a corefile. If it begins with a digit,
4611 GDB will attempt to attach it as a process, and if no such process
4612 is found, will then attempt to open it as a corefile.
4614 * Changes in ARM configurations.
4616 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4617 configuration is fully multi-arch.
4619 * New native configurations
4621 ARM NetBSD arm*-*-netbsd*
4622 x86 OpenBSD i[3456]86-*-openbsd*
4623 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4624 Sparc64 running FreeBSD sparc64-*-freebsd*
4628 Sanyo XStormy16 xstormy16-elf
4630 * OBSOLETE configurations and files
4632 Configurations that have been declared obsolete in this release have
4633 been commented out. Unless there is activity to revive these
4634 configurations, the next release of GDB will have their sources
4635 permanently REMOVED.
4637 AMD 29k family via UDI a29k-amd-udi, udi29k
4638 A29K VxWorks a29k-*-vxworks
4639 AMD 29000 embedded, using EBMON a29k-none-none
4640 AMD 29000 embedded with COFF a29k-none-coff
4641 AMD 29000 embedded with a.out a29k-none-aout
4643 testsuite/gdb.hp/gdb.threads-hp/ directory
4645 * REMOVED configurations and files
4647 TI TMS320C80 tic80-*-*
4649 PowerPC Solaris powerpcle-*-solaris*
4650 PowerPC Windows NT powerpcle-*-cygwin32
4651 PowerPC Netware powerpc-*-netware*
4652 Harris/CXUX m88k m88*-harris-cxux*
4653 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4654 ns32k-utek-sysv* ns32k-utek-*
4655 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4656 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4657 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4658 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4659 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4661 * Changes to command line processing
4663 The new `--args' feature can be used to specify command-line arguments
4664 for the inferior from gdb's command line.
4666 * Changes to key bindings
4668 There is a new `operate-and-get-next' function bound to `C-o'.
4670 *** Changes in GDB 5.1.1
4672 Fix compile problem on DJGPP.
4674 Fix a problem with floating-point registers on the i386 being
4677 Fix to stop GDB crashing on .debug_str debug info.
4679 Numerous documentation fixes.
4681 Numerous testsuite fixes.
4683 *** Changes in GDB 5.1:
4685 * New native configurations
4687 Alpha FreeBSD alpha*-*-freebsd*
4688 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4689 MIPS GNU/Linux mips*-*-linux*
4690 MIPS SGI Irix 6.x mips*-sgi-irix6*
4691 ia64 AIX ia64-*-aix*
4692 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4696 Motorola 68HC11 and 68HC12 m68hc11-elf
4698 UltraSparc running GNU/Linux sparc64-*-linux*
4700 * OBSOLETE configurations and files
4702 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4703 Harris/CXUX m88k m88*-harris-cxux*
4704 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4705 ns32k-utek-sysv* ns32k-utek-*
4706 TI TMS320C80 tic80-*-*
4708 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4709 PowerPC Solaris powerpcle-*-solaris*
4710 PowerPC Windows NT powerpcle-*-cygwin32
4711 PowerPC Netware powerpc-*-netware*
4712 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4713 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4714 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4715 Apple Macintosh (MPW) host N/A
4717 stuff.c (Program to stuff files into a specially prepared space in kdb)
4718 kdb-start.c (Main loop for the standalone kernel debugger)
4720 Configurations that have been declared obsolete in this release have
4721 been commented out. Unless there is activity to revive these
4722 configurations, the next release of GDB will have their sources
4723 permanently REMOVED.
4725 * REMOVED configurations and files
4727 Altos 3068 m68*-altos-*
4728 Convex c1-*-*, c2-*-*
4730 ARM RISCix arm-*-* (as host)
4734 * GDB has been converted to ISO C.
4736 GDB's source code has been converted to ISO C. In particular, the
4737 sources are fully protoized, and rely on standard headers being
4742 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4744 * The MI enabled by default.
4746 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4747 revised and enabled by default. Packages which use GDB as a debugging
4748 engine behind a UI or another front end are encouraged to switch to
4749 using the GDB/MI interface, instead of the old annotations interface
4750 which is now deprecated.
4752 * Support for debugging Pascal programs.
4754 GDB now includes support for debugging Pascal programs. The following
4755 main features are supported:
4757 - Pascal-specific data types such as sets;
4759 - automatic recognition of Pascal sources based on file-name
4762 - Pascal-style display of data types, variables, and functions;
4764 - a Pascal expression parser.
4766 However, some important features are not yet supported.
4768 - Pascal string operations are not supported at all;
4770 - there are some problems with boolean types;
4772 - Pascal type hexadecimal constants are not supported
4773 because they conflict with the internal variables format;
4775 - support for Pascal objects and classes is not full yet;
4777 - unlike Pascal, GDB is case-sensitive for symbol names.
4779 * Changes in completion.
4781 Commands such as `shell', `run' and `set args', which pass arguments
4782 to inferior programs, now complete on file names, similar to what
4783 users expect at the shell prompt.
4785 Commands which accept locations, such as `disassemble', `print',
4786 `breakpoint', `until', etc. now complete on filenames as well as
4787 program symbols. Thus, if you type "break foob TAB", and the source
4788 files linked into the programs include `foobar.c', that file name will
4789 be one of the candidates for completion. However, file names are not
4790 considered for completion after you typed a colon that delimits a file
4791 name from a name of a function in that file, as in "break foo.c:bar".
4793 `set demangle-style' completes on available demangling styles.
4795 * New platform-independent commands:
4797 It is now possible to define a post-hook for a command as well as a
4798 hook that runs before the command. For more details, see the
4799 documentation of `hookpost' in the GDB manual.
4801 * Changes in GNU/Linux native debugging.
4803 Support for debugging multi-threaded programs has been completely
4804 revised for all platforms except m68k and sparc. You can now debug as
4805 many threads as your system allows you to have.
4807 Attach/detach is supported for multi-threaded programs.
4809 Support for SSE registers was added for x86. This doesn't work for
4810 multi-threaded programs though.
4812 * Changes in MIPS configurations.
4814 Multi-arch support is enabled for all MIPS configurations.
4816 GDB can now be built as native debugger on SGI Irix 6.x systems for
4817 debugging n32 executables. (Debugging 64-bit executables is not yet
4820 * Unified support for hardware watchpoints in all x86 configurations.
4822 Most (if not all) native x86 configurations support hardware-assisted
4823 breakpoints and watchpoints in a unified manner. This support
4824 implements debug register sharing between watchpoints, which allows to
4825 put a virtually infinite number of watchpoints on the same address,
4826 and also supports watching regions up to 16 bytes with several debug
4829 The new maintenance command `maintenance show-debug-regs' toggles
4830 debugging print-outs in functions that insert, remove, and test
4831 watchpoints and hardware breakpoints.
4833 * Changes in the DJGPP native configuration.
4835 New command ``info dos sysinfo'' displays assorted information about
4836 the CPU, OS, memory, and DPMI server.
4838 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4839 display information about segment descriptors stored in GDT, LDT, and
4842 New commands ``info dos pde'' and ``info dos pte'' display entries
4843 from Page Directory and Page Tables (for now works with CWSDPMI only).
4844 New command ``info dos address-pte'' displays the Page Table entry for
4845 a given linear address.
4847 GDB can now pass command lines longer than 126 characters to the
4848 program being debugged (requires an update to the libdbg.a library
4849 which is part of the DJGPP development kit).
4851 DWARF2 debug info is now supported.
4853 It is now possible to `step' and `next' through calls to `longjmp'.
4855 * Changes in documentation.
4857 All GDB documentation was converted to GFDL, the GNU Free
4858 Documentation License.
4860 Tracepoints-related commands are now fully documented in the GDB
4863 TUI, the Text-mode User Interface, is now documented in the manual.
4865 Tracepoints-related commands are now fully documented in the GDB
4868 The "GDB Internals" manual now has an index. It also includes
4869 documentation of `ui_out' functions, GDB coding standards, x86
4870 hardware watchpoints, and memory region attributes.
4872 * GDB's version number moved to ``version.in''
4874 The Makefile variable VERSION has been replaced by the file
4875 ``version.in''. People creating GDB distributions should update the
4876 contents of this file.
4880 GUD support is now a standard part of the EMACS distribution.
4882 *** Changes in GDB 5.0:
4884 * Improved support for debugging FP programs on x86 targets
4886 Unified and much-improved support for debugging floating-point
4887 programs on all x86 targets. In particular, ``info float'' now
4888 displays the FP registers in the same format on all x86 targets, with
4889 greater level of detail.
4891 * Improvements and bugfixes in hardware-assisted watchpoints
4893 It is now possible to watch array elements, struct members, and
4894 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4895 on x86 targets no longer erroneously trigger when the address is
4898 * Improvements in the native DJGPP version of GDB
4900 The distribution now includes all the scripts and auxiliary files
4901 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4902 machines ``out of the box''.
4904 The DJGPP version can now debug programs that use signals. It is
4905 possible to catch signals that happened in the debuggee, deliver
4906 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4907 would kill the program being debugged.) Programs that hook hardware
4908 interrupts (keyboard, timer, etc.) can also be debugged.
4910 It is now possible to debug DJGPP programs that redirect their
4911 standard handles or switch them to raw (as opposed to cooked) mode, or
4912 even close them. The command ``run < foo > bar'' works as expected,
4913 and ``info terminal'' reports useful information about the debuggee's
4914 terminal, including raw/cooked mode, redirection, etc.
4916 The DJGPP version now uses termios functions for console I/O, which
4917 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4920 DOS-style file names with drive letters are now fully supported by
4923 It is now possible to debug DJGPP programs that switch their working
4924 directory. It is also possible to rerun the debuggee any number of
4925 times without restarting GDB; thus, you can use the same setup,
4926 breakpoints, etc. for many debugging sessions.
4928 * New native configurations
4930 ARM GNU/Linux arm*-*-linux*
4931 PowerPC GNU/Linux powerpc-*-linux*
4935 Motorola MCore mcore-*-*
4936 x86 VxWorks i[3456]86-*-vxworks*
4937 PowerPC VxWorks powerpc-*-vxworks*
4938 TI TMS320C80 tic80-*-*
4940 * OBSOLETE configurations
4942 Altos 3068 m68*-altos-*
4943 Convex c1-*-*, c2-*-*
4945 ARM RISCix arm-*-* (as host)
4948 Configurations that have been declared obsolete will be commented out,
4949 but the code will be left in place. If there is no activity to revive
4950 these configurations before the next release of GDB, the sources will
4951 be permanently REMOVED.
4953 * Gould support removed
4955 Support for the Gould PowerNode and NP1 has been removed.
4957 * New features for SVR4
4959 On SVR4 native platforms (such as Solaris), if you attach to a process
4960 without first loading a symbol file, GDB will now attempt to locate and
4961 load symbols from the running process's executable file.
4963 * Many C++ enhancements
4965 C++ support has been greatly improved. Overload resolution now works properly
4966 in almost all cases. RTTI support is on the way.
4968 * Remote targets can connect to a sub-program
4970 A popen(3) style serial-device has been added. This device starts a
4971 sub-process (such as a stand-alone simulator) and then communicates
4972 with that. The sub-program to run is specified using the syntax
4973 ``|<program> <args>'' vis:
4975 (gdb) set remotedebug 1
4976 (gdb) target extended-remote |mn10300-elf-sim program-args
4978 * MIPS 64 remote protocol
4980 A long standing bug in the mips64 remote protocol where by GDB
4981 expected certain 32 bit registers (ex SR) to be transfered as 32
4982 instead of 64 bits has been fixed.
4984 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4985 added to provide backward compatibility with older versions of GDB.
4987 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4989 The command ``set remotebinarydownload'' command has been replaced by
4990 ``set remote X-packet''. Other commands in ``set remote'' family
4991 include ``set remote P-packet''.
4993 * Breakpoint commands accept ranges.
4995 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4996 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4997 ``tracepoint passcount'' also accepts a range of tracepoints.
4999 * ``apropos'' command added.
5001 The ``apropos'' command searches through command names and
5002 documentation strings, printing out matches, making it much easier to
5003 try to find a command that does what you are looking for.
5007 A new machine oriented interface (MI) has been added to GDB. This
5008 interface is designed for debug environments running GDB as a separate
5009 process. This is part of the long term libGDB project. See the
5010 "GDB/MI" chapter of the GDB manual for further information. It can be
5011 enabled by configuring with:
5013 .../configure --enable-gdbmi
5015 *** Changes in GDB-4.18:
5017 * New native configurations
5019 HP-UX 10.20 hppa*-*-hpux10.20
5020 HP-UX 11.x hppa*-*-hpux11.0*
5021 M68K GNU/Linux m68*-*-linux*
5025 Fujitsu FR30 fr30-*-elf*
5026 Intel StrongARM strongarm-*-*
5027 Mitsubishi D30V d30v-*-*
5029 * OBSOLETE configurations
5031 Gould PowerNode, NP1 np1-*-*, pn-*-*
5033 Configurations that have been declared obsolete will be commented out,
5034 but the code will be left in place. If there is no activity to revive
5035 these configurations before the next release of GDB, the sources will
5036 be permanently REMOVED.
5040 As a compatibility experiment, GDB's source files buildsym.h and
5041 buildsym.c have been converted to pure standard C, no longer
5042 containing any K&R compatibility code. We believe that all systems in
5043 use today either come with a standard C compiler, or have a GCC port
5044 available. If this is not true, please report the affected
5045 configuration to bug-gdb@gnu.org immediately. See the README file for
5046 information about getting a standard C compiler if you don't have one
5051 GDB now uses readline 2.2.
5053 * set extension-language
5055 You can now control the mapping between filename extensions and source
5056 languages by using the `set extension-language' command. For instance,
5057 you can ask GDB to treat .c files as C++ by saying
5058 set extension-language .c c++
5059 The command `info extensions' lists all of the recognized extensions
5060 and their associated languages.
5062 * Setting processor type for PowerPC and RS/6000
5064 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5065 you can use the `set processor' command to specify what variant of the
5066 PowerPC family you are debugging. The command
5070 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5071 following PowerPC and RS6000 variants:
5073 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5074 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5076 403GC IBM PowerPC 403GC
5077 505 Motorola PowerPC 505
5078 860 Motorola PowerPC 860 or 850
5079 601 Motorola PowerPC 601
5080 602 Motorola PowerPC 602
5081 603 Motorola/IBM PowerPC 603 or 603e
5082 604 Motorola PowerPC 604 or 604e
5083 750 Motorola/IBM PowerPC 750 or 750
5085 At the moment, this command just tells GDB what to name the
5086 special-purpose processor registers. Since almost all the affected
5087 registers are inaccessible to user-level programs, this command is
5088 only useful for remote debugging in its present form.
5092 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5093 more extensive support for HP-UX. Added features include shared
5094 library support, kernel threads and hardware watchpoints for 11.00,
5095 support for HP's ANSI C and C++ compilers, and a compatibility mode
5096 for xdb and dbx commands.
5100 HP's donation includes the new concept of catchpoints, which is a
5101 generalization of the old catch command. On HP-UX, it is now possible
5102 to catch exec, fork, and vfork, as well as library loading.
5104 This means that the existing catch command has changed; its first
5105 argument now specifies the type of catch to be set up. See the
5106 output of "help catch" for a list of catchpoint types.
5108 * Debugging across forks
5110 On HP-UX, you can choose which process to debug when a fork() happens
5115 HP has donated a curses-based terminal user interface (TUI). To get
5116 it, build with --enable-tui. Although this can be enabled for any
5117 configuration, at present it only works for native HP debugging.
5119 * GDB remote protocol additions
5121 A new protocol packet 'X' that writes binary data is now available.
5122 Default behavior is to try 'X', then drop back to 'M' if the stub
5123 fails to respond. The settable variable `remotebinarydownload'
5124 allows explicit control over the use of 'X'.
5126 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5127 full 64-bit address. The command
5129 set remoteaddresssize 32
5131 can be used to revert to the old behaviour. For existing remote stubs
5132 the change should not be noticed, as the additional address information
5135 In order to assist in debugging stubs, you may use the maintenance
5136 command `packet' to send any text string to the stub. For instance,
5138 maint packet heythere
5140 sends the packet "$heythere#<checksum>". Note that it is very easy to
5141 disrupt a debugging session by sending the wrong packet at the wrong
5144 The compare-sections command allows you to compare section data on the
5145 target to what is in the executable file without uploading or
5146 downloading, by comparing CRC checksums.
5148 * Tracing can collect general expressions
5150 You may now collect general expressions at tracepoints. This requires
5151 further additions to the target-side stub; see tracepoint.c and
5152 doc/agentexpr.texi for further details.
5154 * mask-address variable for Mips
5156 For Mips targets, you may control the zeroing of the upper 32 bits of
5157 a 64-bit address by entering `set mask-address on'. This is mainly
5158 of interest to users of embedded R4xxx and R5xxx processors.
5160 * Higher serial baud rates
5162 GDB's serial code now allows you to specify baud rates 57600, 115200,
5163 230400, and 460800 baud. (Note that your host system may not be able
5164 to achieve all of these rates.)
5168 The i960 configuration now includes an initial implementation of a
5169 builtin simulator, contributed by Jim Wilson.
5172 *** Changes in GDB-4.17:
5174 * New native configurations
5176 Alpha GNU/Linux alpha*-*-linux*
5177 Unixware 2.x i[3456]86-unixware2*
5178 Irix 6.x mips*-sgi-irix6*
5179 PowerPC GNU/Linux powerpc-*-linux*
5180 PowerPC Solaris powerpcle-*-solaris*
5181 Sparc GNU/Linux sparc-*-linux*
5182 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5186 Argonaut Risc Chip (ARC) arc-*-*
5187 Hitachi H8/300S h8300*-*-*
5188 Matsushita MN10200 w/simulator mn10200-*-*
5189 Matsushita MN10300 w/simulator mn10300-*-*
5190 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5191 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5192 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5193 Mitsubishi D10V w/simulator d10v-*-*
5194 Mitsubishi M32R/D w/simulator m32r-*-elf*
5195 Tsqware Sparclet sparclet-*-*
5196 NEC V850 w/simulator v850-*-*
5198 * New debugging protocols
5200 ARM with RDI protocol arm*-*-*
5201 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5202 DDB and LSI variants of PMON protocol mips*-*-*
5203 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5204 PowerPC with SDS protocol powerpc{,le}-*-eabi
5205 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5209 All configurations can now understand and use the DWARF 2 debugging
5210 format. The choice is automatic, if the symbol file contains DWARF 2
5215 GDB now includes basic Java language support. This support is
5216 only useful with Java compilers that produce native machine code.
5218 * solib-absolute-prefix and solib-search-path
5220 For SunOS and SVR4 shared libraries, you may now set the prefix for
5221 loading absolute shared library symbol files, and the search path for
5222 locating non-absolute shared library symbol files.
5224 * Live range splitting
5226 GDB can now effectively debug code for which GCC has performed live
5227 range splitting as part of its optimization. See gdb/doc/LRS for
5228 more details on the expected format of the stabs information.
5232 GDB's support for the GNU Hurd, including thread debugging, has been
5233 updated to work with current versions of the Hurd.
5237 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5238 instruction set. ARM GDB automatically detects when Thumb
5239 instructions are in use, and adjusts disassembly and backtracing
5244 GDB's MIPS target configurations now handle the MIP16 16-bit
5249 GDB now includes support for overlays; if an executable has been
5250 linked such that multiple sections are based at the same address, GDB
5251 will decide which section to use for symbolic info. You can choose to
5252 control the decision manually, using overlay commands, or implement
5253 additional target-side support and use "overlay load-target" to bring
5254 in the overlay mapping. Do "help overlay" for more detail.
5258 The command "info symbol <address>" displays information about
5259 the symbol at the specified address.
5263 The standard remote protocol now includes an extension that allows
5264 asynchronous collection and display of trace data. This requires
5265 extensive support in the target-side debugging stub. Tracing mode
5266 includes a new interaction mode in GDB and new commands: see the
5267 file tracepoint.c for more details.
5271 Configurations for embedded MIPS now include a simulator contributed
5272 by Cygnus Solutions. The simulator supports the instruction sets
5273 of most MIPS variants.
5277 Sparc configurations may now include the ERC32 simulator contributed
5278 by the European Space Agency. The simulator is not built into
5279 Sparc targets by default; configure with --enable-sim to include it.
5283 For target configurations that may include multiple variants of a
5284 basic architecture (such as MIPS and SH), you may now set the
5285 architecture explicitly. "set arch" sets, "info arch" lists
5286 the possible architectures.
5288 *** Changes in GDB-4.16:
5290 * New native configurations
5292 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5293 M68K NetBSD m68k-*-netbsd*
5294 PowerPC AIX 4.x powerpc-*-aix*
5295 PowerPC MacOS powerpc-*-macos*
5296 PowerPC Windows NT powerpcle-*-cygwin32
5297 RS/6000 AIX 4.x rs6000-*-aix4*
5301 ARM with RDP protocol arm-*-*
5302 I960 with MON960 i960-*-coff
5303 MIPS VxWorks mips*-*-vxworks*
5304 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5305 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5307 Matra Sparclet sparclet-*-*
5311 The powerpc-eabi configuration now includes the PSIM simulator,
5312 contributed by Andrew Cagney, with assistance from Mike Meissner.
5313 PSIM is a very elaborate model of the PowerPC, including not only
5314 basic instruction set execution, but also details of execution unit
5315 performance and I/O hardware. See sim/ppc/README for more details.
5319 GDB now works with Solaris 2.5.
5321 * Windows 95/NT native
5323 GDB will now work as a native debugger on Windows 95 and Windows NT.
5324 To build it from source, you must use the "gnu-win32" environment,
5325 which uses a DLL to emulate enough of Unix to run the GNU tools.
5326 Further information, binaries, and sources are available at
5327 ftp.cygnus.com, under pub/gnu-win32.
5329 * dont-repeat command
5331 If a user-defined command includes the command `dont-repeat', then the
5332 command will not be repeated if the user just types return. This is
5333 useful if the command is time-consuming to run, so that accidental
5334 extra keystrokes don't run the same command many times.
5336 * Send break instead of ^C
5338 The standard remote protocol now includes an option to send a break
5339 rather than a ^C to the target in order to interrupt it. By default,
5340 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5342 * Remote protocol timeout
5344 The standard remote protocol includes a new variable `remotetimeout'
5345 that allows you to set the number of seconds before GDB gives up trying
5346 to read from the target. The default value is 2.
5348 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5350 By default GDB will automatically keep track of objects as they are
5351 loaded and unloaded by the dynamic linker. By using the command `set
5352 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5353 when shared library events occur, thus allowing you to set breakpoints
5354 in shared libraries which are explicitly loaded by the inferior.
5356 Note this feature does not work on hpux8. On hpux9 you must link
5357 /usr/lib/end.o into your program. This feature should work
5358 automatically on hpux10.
5360 * Irix 5.x hardware watchpoint support
5362 Irix 5 configurations now support the use of hardware watchpoints.
5364 * Mips protocol "SYN garbage limit"
5366 When debugging a Mips target using the `target mips' protocol, you
5367 may set the number of characters that GDB will ignore by setting
5368 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5369 every character. The default value is 1050.
5371 * Recording and replaying remote debug sessions
5373 If you set `remotelogfile' to the name of a file, gdb will write to it
5374 a recording of a remote debug session. This recording may then be
5375 replayed back to gdb using "gdbreplay". See gdbserver/README for
5376 details. This is useful when you have a problem with GDB while doing
5377 remote debugging; you can make a recording of the session and send it
5378 to someone else, who can then recreate the problem.
5380 * Speedups for remote debugging
5382 GDB includes speedups for downloading and stepping MIPS systems using
5383 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5384 and more efficient S-record downloading.
5386 * Memory use reductions and statistics collection
5388 GDB now uses less memory and reports statistics about memory usage.
5389 Try the `maint print statistics' command, for example.
5391 *** Changes in GDB-4.15:
5393 * Psymtabs for XCOFF
5395 The symbol reader for AIX GDB now uses partial symbol tables. This
5396 can greatly improve startup time, especially for large executables.
5398 * Remote targets use caching
5400 Remote targets now use a data cache to speed up communication with the
5401 remote side. The data cache could lead to incorrect results because
5402 it doesn't know about volatile variables, thus making it impossible to
5403 debug targets which use memory mapped I/O devices. `set remotecache
5404 off' turns the the data cache off.
5406 * Remote targets may have threads
5408 The standard remote protocol now includes support for multiple threads
5409 in the target system, using new protocol commands 'H' and 'T'. See
5410 gdb/remote.c for details.
5414 If GDB is configured with `--enable-netrom', then it will include
5415 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5416 acts as though it is a bank of ROM on the target board, but you can
5417 write into it over the network. GDB's support consists only of
5418 support for fast loading into the emulated ROM; to debug, you must use
5419 another protocol, such as standard remote protocol. The usual
5420 sequence is something like
5422 target nrom <netrom-hostname>
5424 target remote <netrom-hostname>:1235
5428 GDB now includes support for the Apple Macintosh, as a host only. It
5429 may be run as either an MPW tool or as a standalone application, and
5430 it can debug through the serial port. All the usual GDB commands are
5431 available, but to the target command, you must supply "serial" as the
5432 device type instead of "/dev/ttyXX". See mpw-README in the main
5433 directory for more information on how to build. The MPW configuration
5434 scripts */mpw-config.in support only a few targets, and only the
5435 mips-idt-ecoff target has been tested.
5439 GDB configuration now uses autoconf. This is not user-visible,
5440 but does simplify configuration and building.
5444 GDB now supports hpux10.
5446 *** Changes in GDB-4.14:
5448 * New native configurations
5450 x86 FreeBSD i[345]86-*-freebsd
5451 x86 NetBSD i[345]86-*-netbsd
5452 NS32k NetBSD ns32k-*-netbsd
5453 Sparc NetBSD sparc-*-netbsd
5457 A29K VxWorks a29k-*-vxworks
5458 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5459 CPU32 EST-300 emulator m68*-*-est*
5460 PowerPC ELF powerpc-*-elf
5463 * Alpha OSF/1 support for procfs
5465 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5466 possible to attach to running processes. As the mounting of the /proc
5467 filesystem is optional on the Alpha, GDB automatically determines
5468 the availability of /proc during startup. This can lead to problems
5469 if /proc is unmounted after GDB has been started.
5471 * Arguments to user-defined commands
5473 User commands may accept up to 10 arguments separated by whitespace.
5474 Arguments are accessed within the user command via $arg0..$arg9. A
5477 print $arg0 + $arg1 + $arg2
5479 To execute the command use:
5482 Defines the command "adder" which prints the sum of its three arguments.
5483 Note the arguments are text substitutions, so they may reference variables,
5484 use complex expressions, or even perform inferior function calls.
5486 * New `if' and `while' commands
5488 This makes it possible to write more sophisticated user-defined
5489 commands. Both commands take a single argument, which is the
5490 expression to evaluate, and must be followed by the commands to
5491 execute, one per line, if the expression is nonzero, the list being
5492 terminated by the word `end'. The `if' command list may include an
5493 `else' word, which causes the following commands to be executed only
5494 if the expression is zero.
5496 * Fortran source language mode
5498 GDB now includes partial support for Fortran 77. It will recognize
5499 Fortran programs and can evaluate a subset of Fortran expressions, but
5500 variables and functions may not be handled correctly. GDB will work
5501 with G77, but does not yet know much about symbols emitted by other
5504 * Better HPUX support
5506 Most debugging facilities now work on dynamic executables for HPPAs
5507 running hpux9 or later. You can attach to running dynamically linked
5508 processes, but by default the dynamic libraries will be read-only, so
5509 for instance you won't be able to put breakpoints in them. To change
5510 that behavior do the following before running the program:
5516 This will cause the libraries to be mapped private and read-write.
5517 To revert to the normal behavior, do this:
5523 You cannot set breakpoints or examine data in the library until after
5524 the library is loaded if the function/data symbols do not have
5527 GDB can now also read debug symbols produced by the HP C compiler on
5528 HPPAs (sorry, no C++, Fortran or 68k support).
5530 * Target byte order now dynamically selectable
5532 You can choose which byte order to use with a target system, via the
5533 commands "set endian big" and "set endian little", and you can see the
5534 current setting by using "show endian". You can also give the command
5535 "set endian auto", in which case GDB will use the byte order
5536 associated with the executable. Currently, only embedded MIPS
5537 configurations support dynamic selection of target byte order.
5539 * New DOS host serial code
5541 This version uses DPMI interrupts to handle buffered I/O, so you
5542 no longer need to run asynctsr when debugging boards connected to
5545 *** Changes in GDB-4.13:
5547 * New "complete" command
5549 This lists all the possible completions for the rest of the line, if it
5550 were to be given as a command itself. This is intended for use by emacs.
5552 * Trailing space optional in prompt
5554 "set prompt" no longer adds a space for you after the prompt you set. This
5555 allows you to set a prompt which ends in a space or one that does not.
5557 * Breakpoint hit counts
5559 "info break" now displays a count of the number of times the breakpoint
5560 has been hit. This is especially useful in conjunction with "ignore"; you
5561 can ignore a large number of breakpoint hits, look at the breakpoint info
5562 to see how many times the breakpoint was hit, then run again, ignoring one
5563 less than that number, and this will get you quickly to the last hit of
5566 * Ability to stop printing at NULL character
5568 "set print null-stop" will cause GDB to stop printing the characters of
5569 an array when the first NULL is encountered. This is useful when large
5570 arrays actually contain only short strings.
5572 * Shared library breakpoints
5574 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5575 breakpoints in shared libraries before the executable is run.
5577 * Hardware watchpoints
5579 There is a new hardware breakpoint for the watch command for sparclite
5580 targets. See gdb/sparclite/hw_breakpoint.note.
5582 Hardware watchpoints are also now supported under GNU/Linux.
5586 Annotations have been added. These are for use with graphical interfaces,
5587 and are still experimental. Currently only gdba.el uses these.
5589 * Improved Irix 5 support
5591 GDB now works properly with Irix 5.2.
5593 * Improved HPPA support
5595 GDB now works properly with the latest GCC and GAS.
5597 * New native configurations
5599 Sequent PTX4 i[34]86-sequent-ptx4
5600 HPPA running OSF/1 hppa*-*-osf*
5601 Atari TT running SVR4 m68*-*-sysv4*
5602 RS/6000 LynxOS rs6000-*-lynxos*
5606 OS/9000 i[34]86-*-os9k
5607 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5610 * Hitachi SH7000 and E7000-PC ICE support
5612 There is now support for communicating with the Hitachi E7000-PC ICE.
5613 This is available automatically when GDB is configured for the SH.
5617 As usual, a variety of small fixes and improvements, both generic
5618 and configuration-specific. See the ChangeLog for more detail.
5620 *** Changes in GDB-4.12:
5622 * Irix 5 is now supported
5626 GDB-4.12 on the HPPA has a number of changes which make it unable
5627 to debug the output from the currently released versions of GCC and
5628 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5629 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5630 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5633 *** Changes in GDB-4.11:
5635 * User visible changes:
5639 The "set remotedebug" option is now consistent between the mips remote
5640 target, remote targets using the gdb-specific protocol, UDI (AMD's
5641 debug protocol for the 29k) and the 88k bug monitor. It is now an
5642 integer specifying a debug level (normally 0 or 1, but 2 means more
5643 debugging info for the mips target).
5645 * DEC Alpha native support
5647 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5648 debug info, but GDB works fairly well with the DEC compiler and should
5649 work with a future GCC release. See the README file for a few
5650 Alpha-specific notes.
5652 * Preliminary thread implementation
5654 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5656 * LynxOS native and target support for 386
5658 This release has been hosted on LynxOS 2.2, and also can be configured
5659 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5662 * Improvements in C++ mangling/demangling.
5664 This release has much better g++ debugging, specifically in name
5665 mangling/demangling, virtual function calls, print virtual table,
5666 call methods, ...etc.
5668 *** Changes in GDB-4.10:
5670 * User visible changes:
5672 Remote debugging using the GDB-specific (`target remote') protocol now
5673 supports the `load' command. This is only useful if you have some
5674 other way of getting the stub to the target system, and you can put it
5675 somewhere in memory where it won't get clobbered by the download.
5677 Filename completion now works.
5679 When run under emacs mode, the "info line" command now causes the
5680 arrow to point to the line specified. Also, "info line" prints
5681 addresses in symbolic form (as well as hex).
5683 All vxworks based targets now support a user settable option, called
5684 vxworks-timeout. This option represents the number of seconds gdb
5685 should wait for responses to rpc's. You might want to use this if
5686 your vxworks target is, perhaps, a slow software simulator or happens
5687 to be on the far side of a thin network line.
5691 This release contains support for using a DEC alpha as a GDB host for
5692 cross debugging. Native alpha debugging is not supported yet.
5695 *** Changes in GDB-4.9:
5699 This is the first GDB release which is accompanied by a matching testsuite.
5700 The testsuite requires installation of dejagnu, which should be available
5701 via ftp from most sites that carry GNU software.
5705 'Cfront' style demangling has had its name changed to 'ARM' style, to
5706 emphasize that it was written from the specifications in the C++ Annotated
5707 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5708 disclaimers, it still generated too much confusion with users attempting to
5709 use gdb with AT&T cfront.
5713 GDB now uses a standard remote interface to a simulator library.
5714 So far, the library contains simulators for the Zilog Z8001/2, the
5715 Hitachi H8/300, H8/500 and Super-H.
5717 * New targets supported
5719 H8/300 simulator h8300-hitachi-hms or h8300hms
5720 H8/500 simulator h8500-hitachi-hms or h8500hms
5721 SH simulator sh-hitachi-hms or sh
5722 Z8000 simulator z8k-zilog-none or z8ksim
5723 IDT MIPS board over serial line mips-idt-ecoff
5725 Cross-debugging to GO32 targets is supported. It requires a custom
5726 version of the i386-stub.c module which is integrated with the
5727 GO32 memory extender.
5729 * New remote protocols
5731 MIPS remote debugging protocol.
5733 * New source languages supported
5735 This version includes preliminary support for Chill, a Pascal like language
5736 used by telecommunications companies. Chill support is also being integrated
5737 into the GNU compiler, but we don't know when it will be publically available.
5740 *** Changes in GDB-4.8:
5742 * HP Precision Architecture supported
5744 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5745 version of this support was available as a set of patches from the
5746 University of Utah. GDB does not support debugging of programs
5747 compiled with the HP compiler, because HP will not document their file
5748 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5749 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5751 Many problems in the preliminary version have been fixed.
5753 * Faster and better demangling
5755 We have improved template demangling and fixed numerous bugs in the GNU style
5756 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5757 character types (wchar_t) are now supported. Demangling of each symbol is now
5758 only done once, and is cached when the symbol table for a file is read in.
5759 This results in a small increase in memory usage for C programs, a moderate
5760 increase in memory usage for C++ programs, and a fantastic speedup in
5763 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5764 from the specifications in the Annotated Reference Manual, which AT&T's
5765 compiler does not actually implement.
5767 * G++ multiple inheritance compiler problem
5769 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5770 inheritance lattices was reworked to properly discover ambiguities. We
5771 recently found an example which causes this new algorithm to fail in a
5772 very subtle way, producing bad debug information for those classes.
5773 The file 'gcc.patch' (in this directory) can be applied to gcc to
5774 circumvent the problem. A future GCC release will contain a complete
5777 The previous G++ debug info problem (mentioned below for the gdb-4.7
5778 release) is fixed in gcc version 2.3.2.
5780 * Improved configure script
5782 The `configure' script will now attempt to guess your system type if
5783 you don't supply a host system type. The old scheme of supplying a
5784 host system triplet is preferable over using this. All the magic is
5785 done in the new `config.guess' script. Examine it for details.
5787 We have also brought our configure script much more in line with the FSF's
5788 version. It now supports the --with-xxx options. In particular,
5789 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5790 The resulting GDB will not be able to read arbitrary object file formats --
5791 only the format ``expected'' to be used on the configured target system.
5792 We hope to make this the default in a future release.
5794 * Documentation improvements
5796 There's new internal documentation on how to modify GDB, and how to
5797 produce clean changes to the code. We implore people to read it
5798 before submitting changes.
5800 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5801 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5802 `info' files are also provided. To build `info' files from scratch,
5803 you will need the latest `makeinfo' release, which will be available in
5804 a future texinfo-X.Y release.
5806 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5807 We're not sure exactly which versions have this problem, but it has
5808 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5809 or better. If that isn't possible, there is a patch in
5810 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5811 around this problem.
5815 GDB now supports array constants that can be used in expressions typed in by
5816 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5817 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5820 The new directory `gdb/sparclite' contains a program that demonstrates
5821 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5823 * New native hosts supported
5825 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5826 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5828 * New targets supported
5830 AMD 29k family via UDI a29k-amd-udi or udi29k
5832 * New file formats supported
5834 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5835 HPUX core files, and SCO 3.2v2 core files.
5839 Attaching to processes now works again; thanks for the many bug reports.
5841 We have also stomped on a bunch of core dumps caused by
5842 printf_filtered("%s") problems.
5844 We eliminated a copyright problem on the rpc and ptrace header files
5845 for VxWorks, which was discovered at the last minute during the 4.7
5846 release. You should now be able to build a VxWorks GDB.
5848 You can now interrupt gdb while an attached process is running. This
5849 will cause the attached process to stop, and give control back to GDB.
5851 We fixed problems caused by using too many file descriptors
5852 for reading symbols from object files and libraries. This was
5853 especially a problem for programs that used many (~100) shared
5856 The `step' command now only enters a subroutine if there is line number
5857 information for the subroutine. Otherwise it acts like the `next'
5858 command. Previously, `step' would enter subroutines if there was
5859 any debugging information about the routine. This avoids problems
5860 when using `cc -g1' on MIPS machines.
5862 * Internal improvements
5864 GDB's internal interfaces have been improved to make it easier to support
5865 debugging of multiple languages in the future.
5867 GDB now uses a common structure for symbol information internally.
5868 Minimal symbols (derived from linkage symbols in object files), partial
5869 symbols (from a quick scan of debug information), and full symbols
5870 contain a common subset of information, making it easier to write
5871 shared code that handles any of them.
5873 * New command line options
5875 We now accept --silent as an alias for --quiet.
5879 The memory-mapped-malloc library is now licensed under the GNU Library
5880 General Public License.
5882 *** Changes in GDB-4.7:
5884 * Host/native/target split
5886 GDB has had some major internal surgery to untangle the support for
5887 hosts and remote targets. Now, when you configure GDB for a remote
5888 target, it will no longer load in all of the support for debugging
5889 local programs on the host. When fully completed and tested, this will
5890 ensure that arbitrary host/target combinations are possible.
5892 The primary conceptual shift is to separate the non-portable code in
5893 GDB into three categories. Host specific code is required any time GDB
5894 is compiled on that host, regardless of the target. Target specific
5895 code relates to the peculiarities of the target, but can be compiled on
5896 any host. Native specific code is everything else: it can only be
5897 built when the host and target are the same system. Child process
5898 handling and core file support are two common `native' examples.
5900 GDB's use of /proc for controlling Unix child processes is now cleaner.
5901 It has been split out into a single module under the `target_ops' vector,
5902 plus two native-dependent functions for each system that uses /proc.
5904 * New hosts supported
5906 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5907 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5908 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5910 * New targets supported
5912 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5913 68030 and CPU32 m68030-*-*, m68332-*-*
5915 * New native hosts supported
5917 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5918 (386bsd is not well tested yet)
5919 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5921 * New file formats supported
5923 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5924 supports reading of `a.out.adobe' object files, which are an a.out
5925 format extended with minimal information about multiple sections.
5929 `show copying' is the same as the old `info copying'.
5930 `show warranty' is the same as `info warrantee'.
5931 These were renamed for consistency. The old commands continue to work.
5933 `info handle' is a new alias for `info signals'.
5935 You can now define pre-command hooks, which attach arbitrary command
5936 scripts to any command. The commands in the hook will be executed
5937 prior to the user's command. You can also create a hook which will be
5938 executed whenever the program stops. See gdb.texinfo.
5942 We now deal with Cfront style name mangling, and can even extract type
5943 info from mangled symbols. GDB can automatically figure out which
5944 symbol mangling style your C++ compiler uses.
5946 Calling of methods and virtual functions has been improved as well.
5950 The crash that occured when debugging Sun Ansi-C compiled binaries is
5951 fixed. This was due to mishandling of the extra N_SO stabs output
5954 We also finally got Ultrix 4.2 running in house, and fixed core file
5955 support, with help from a dozen people on the net.
5957 John M. Farrell discovered that the reason that single-stepping was so
5958 slow on all of the Mips based platforms (primarily SGI and DEC) was
5959 that we were trying to demangle and lookup a symbol used for internal
5960 purposes on every instruction that was being stepped through. Changing
5961 the name of that symbol so that it couldn't be mistaken for a C++
5962 mangled symbol sped things up a great deal.
5964 Rich Pixley sped up symbol lookups in general by getting much smarter
5965 about when C++ symbol mangling is necessary. This should make symbol
5966 completion (TAB on the command line) much faster. It's not as fast as
5967 we'd like, but it's significantly faster than gdb-4.6.
5971 A new user controllable variable 'call_scratch_address' can
5972 specify the location of a scratch area to be used when GDB
5973 calls a function in the target. This is necessary because the
5974 usual method of putting the scratch area on the stack does not work
5975 in systems that have separate instruction and data spaces.
5977 We integrated changes to support the 29k UDI (Universal Debugger
5978 Interface), but discovered at the last minute that we didn't have all
5979 of the appropriate copyright paperwork. We are working with AMD to
5980 resolve this, and hope to have it available soon.
5984 We have sped up the remote serial line protocol, especially for targets
5985 with lots of registers. It now supports a new `expedited status' ('T')
5986 message which can be used in place of the existing 'S' status message.
5987 This allows the remote stub to send only the registers that GDB
5988 needs to make a quick decision about single-stepping or conditional
5989 breakpoints, eliminating the need to fetch the entire register set for
5990 each instruction being stepped through.
5992 The GDB remote serial protocol now implements a write-through cache for
5993 registers, only re-reading the registers if the target has run.
5995 There is also a new remote serial stub for SPARC processors. You can
5996 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5997 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5998 processor with a serial port.
6002 Configure.in files have become much easier to read and modify. A new
6003 `table driven' format makes it more obvious what configurations are
6004 supported, and what files each one uses.
6008 There is a new opcodes library which will eventually contain all of the
6009 disassembly routines and opcode tables. At present, it only contains
6010 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6011 disassembler (binutils/objdump) to share these routines.
6013 The libiberty library is now copylefted under the GNU Library General
6014 Public License. This allows more liberal use, and was done so libg++
6015 can use it. This makes no difference to GDB, since the Library License
6016 grants all the rights from the General Public License.
6020 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6021 reference to the stabs symbol info used by the debugger. It is (as far
6022 as we know) the only published document on this fascinating topic. We
6023 encourage you to read it, compare it to the stabs information on your
6024 system, and send improvements on the document in general (to
6025 bug-gdb@prep.ai.mit.edu).
6027 And, of course, many bugs have been fixed.
6030 *** Changes in GDB-4.6:
6032 * Better support for C++ function names
6034 GDB now accepts as input the "demangled form" of C++ overloaded function
6035 names and member function names, and can do command completion on such names
6036 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6037 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6038 Make use of command completion, it is your friend.
6040 GDB also now accepts a variety of C++ mangled symbol formats. They are
6041 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6042 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6043 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6044 for the list of formats.
6046 * G++ symbol mangling problem
6048 Recent versions of gcc have a bug in how they emit debugging information for
6049 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6050 directory) can be applied to gcc to fix the problem. Alternatively, if you
6051 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6052 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6053 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6056 * New 'maintenance' command
6058 All of the commands related to hacking GDB internals have been moved out of
6059 the main command set, and now live behind the 'maintenance' command. This
6060 can also be abbreviated as 'mt'. The following changes were made:
6062 dump-me -> maintenance dump-me
6063 info all-breakpoints -> maintenance info breakpoints
6064 printmsyms -> maintenance print msyms
6065 printobjfiles -> maintenance print objfiles
6066 printpsyms -> maintenance print psymbols
6067 printsyms -> maintenance print symbols
6069 The following commands are new:
6071 maintenance demangle Call internal GDB demangler routine to
6072 demangle a C++ link name and prints the result.
6073 maintenance print type Print a type chain for a given symbol
6075 * Change to .gdbinit file processing
6077 We now read the $HOME/.gdbinit file before processing the argv arguments
6078 (e.g. reading symbol files or core files). This allows global parameters to
6079 be set, which will apply during the symbol reading. The ./.gdbinit is still
6080 read after argv processing.
6082 * New hosts supported
6084 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6086 GNU/Linux support i386-unknown-linux or linux
6088 We are also including code to support the HP/PA running BSD and HPUX. This
6089 is almost guaranteed not to work, as we didn't have time to test or build it
6090 for this release. We are including it so that the more adventurous (or
6091 masochistic) of you can play with it. We also had major problems with the
6092 fact that the compiler that we got from HP doesn't support the -g option.
6095 * New targets supported
6097 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6099 * More smarts about finding #include files
6101 GDB now remembers the compilation directory for all include files, and for
6102 all files from which C is generated (like yacc and lex sources). This
6103 greatly improves GDB's ability to find yacc/lex sources, and include files,
6104 especially if you are debugging your program from a directory different from
6105 the one that contains your sources.
6107 We also fixed a bug which caused difficulty with listing and setting
6108 breakpoints in include files which contain C code. (In the past, you had to
6109 try twice in order to list an include file that you hadn't looked at before.)
6111 * Interesting infernals change
6113 GDB now deals with arbitrary numbers of sections, where the symbols for each
6114 section must be relocated relative to that section's landing place in the
6115 target's address space. This work was needed to support ELF with embedded
6116 stabs used by Solaris-2.0.
6118 * Bug fixes (of course!)
6120 There have been loads of fixes for the following things:
6121 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6122 i960, stabs, DOS(GO32), procfs, etc...
6124 See the ChangeLog for details.
6126 *** Changes in GDB-4.5:
6128 * New machines supported (host and target)
6130 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6132 SGI Irix-4.x mips-sgi-irix4 or iris4
6134 * New malloc package
6136 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6137 Mmalloc is capable of handling mutiple heaps of memory. It is also
6138 capable of saving a heap to a file, and then mapping it back in later.
6139 This can be used to greatly speedup the startup of GDB by using a
6140 pre-parsed symbol table which lives in a mmalloc managed heap. For
6141 more details, please read mmalloc/mmalloc.texi.
6145 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6146 'help info proc' for details.
6148 * MIPS ecoff symbol table format
6150 The code that reads MIPS symbol table format is now supported on all hosts.
6151 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6154 * File name changes for MS-DOS
6156 Many files in the config directories have been renamed to make it easier to
6157 support GDB on MS-DOSe systems (which have very restrictive file name
6158 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6159 environment) is close to working but has some remaining problems. Note
6160 that debugging of DOS programs is not supported, due to limitations
6161 in the ``operating system'', but it can be used to host cross-debugging.
6163 * Cross byte order fixes
6165 Many fixes have been made to support cross debugging of Sparc and MIPS
6166 targets from hosts whose byte order differs.
6168 * New -mapped and -readnow options
6170 If memory-mapped files are available on your system through the 'mmap'
6171 system call, you can use the -mapped option on the `file' or
6172 `symbol-file' commands to cause GDB to write the symbols from your
6173 program into a reusable file. If the program you are debugging is
6174 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6175 Future GDB debugging sessions will notice the presence of this file,
6176 and will quickly map in symbol information from it, rather than reading
6177 the symbol table from the executable program. Using the '-mapped'
6178 option in a GDB `file' or `symbol-file' command has the same effect as
6179 starting GDB with the '-mapped' command-line option.
6181 You can cause GDB to read the entire symbol table immediately by using
6182 the '-readnow' option with any of the commands that load symbol table
6183 information (or on the GDB command line). This makes the command
6184 slower, but makes future operations faster.
6186 The -mapped and -readnow options are typically combined in order to
6187 build a `fred.syms' file that contains complete symbol information.
6188 A simple GDB invocation to do nothing but build a `.syms' file for future
6191 gdb -batch -nx -mapped -readnow programname
6193 The `.syms' file is specific to the host machine on which GDB is run.
6194 It holds an exact image of GDB's internal symbol table. It cannot be
6195 shared across multiple host platforms.
6197 * longjmp() handling
6199 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6200 siglongjmp() without losing control. This feature has not yet been ported to
6201 all systems. It currently works on many 386 platforms, all MIPS-based
6202 platforms (SGI, DECstation, etc), and Sun3/4.
6206 Preliminary work has been put in to support the new Solaris OS from Sun. At
6207 this time, it can control and debug processes, but it is not capable of
6212 As always, many many bug fixes. The major areas were with g++, and mipsread.
6213 People using the MIPS-based platforms should experience fewer mysterious
6214 crashes and trashed symbol tables.
6216 *** Changes in GDB-4.4:
6218 * New machines supported (host and target)
6220 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6222 BSD Reno on Vax vax-dec-bsd
6223 Ultrix on Vax vax-dec-ultrix
6225 * New machines supported (target)
6227 AMD 29000 embedded, using EBMON a29k-none-none
6231 GDB continues to improve its handling of C++. `References' work better.
6232 The demangler has also been improved, and now deals with symbols mangled as
6233 per the Annotated C++ Reference Guide.
6235 GDB also now handles `stabs' symbol information embedded in MIPS
6236 `ecoff' symbol tables. Since the ecoff format was not easily
6237 extensible to handle new languages such as C++, this appeared to be a
6238 good way to put C++ debugging info into MIPS binaries. This option
6239 will be supported in the GNU C compiler, version 2, when it is
6242 * New features for SVR4
6244 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6245 shared libraries. Debugging dynamically linked programs should present
6246 only minor differences from debugging statically linked programs.
6248 The `info proc' command will print out information about any process
6249 on an SVR4 system (including the one you are debugging). At the moment,
6250 it prints the address mappings of the process.
6252 If you bring up GDB on another SVR4 system, please send mail to
6253 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6255 * Better dynamic linking support in SunOS
6257 Reading symbols from shared libraries which contain debugging symbols
6258 now works properly. However, there remain issues such as automatic
6259 skipping of `transfer vector' code during function calls, which
6260 make it harder to debug code in a shared library, than to debug the
6261 same code linked statically.
6265 GDB is now using the latest `getopt' routines from the FSF. This
6266 version accepts the -- prefix for options with long names. GDB will
6267 continue to accept the old forms (-option and +option) as well.
6268 Various single letter abbreviations for options have been explicity
6269 added to the option table so that they won't get overshadowed in the
6270 future by other options that begin with the same letter.
6274 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6275 Many assorted bugs have been handled. Many more remain to be handled.
6276 See the various ChangeLog files (primarily in gdb and bfd) for details.
6279 *** Changes in GDB-4.3:
6281 * New machines supported (host and target)
6283 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6284 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6285 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6287 * Almost SCO Unix support
6289 We had hoped to support:
6290 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6291 (except for core file support), but we discovered very late in the release
6292 that it has problems with process groups that render gdb unusable. Sorry
6293 about that. I encourage people to fix it and post the fixes.
6295 * Preliminary ELF and DWARF support
6297 GDB can read ELF object files on System V Release 4, and can handle
6298 debugging records for C, in DWARF format, in ELF files. This support
6299 is preliminary. If you bring up GDB on another SVR4 system, please
6300 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6305 GDB now uses the latest `readline' library. One user-visible change
6306 is that two tabs will list possible command completions, which previously
6307 required typing M-? (meta-question mark, or ESC ?).
6311 The `stepi' bug that many of you noticed has been squashed.
6312 Many bugs in C++ have been handled. Many more remain to be handled.
6313 See the various ChangeLog files (primarily in gdb and bfd) for details.
6315 * State of the MIPS world (in case you wondered):
6317 GDB can understand the symbol tables emitted by the compilers
6318 supplied by most vendors of MIPS-based machines, including DEC. These
6319 symbol tables are in a format that essentially nobody else uses.
6321 Some versions of gcc come with an assembler post-processor called
6322 mips-tfile. This program is required if you want to do source-level
6323 debugging of gcc-compiled programs. I believe FSF does not ship
6324 mips-tfile with gcc version 1, but it will eventually come with gcc
6327 Debugging of g++ output remains a problem. g++ version 1.xx does not
6328 really support it at all. (If you're lucky, you should be able to get
6329 line numbers and stack traces to work, but no parameters or local
6330 variables.) With some work it should be possible to improve the
6333 When gcc version 2 is released, you will have somewhat better luck.
6334 However, even then you will get confusing results for inheritance and
6337 We will eventually provide full debugging of g++ output on
6338 DECstations. This will probably involve some kind of stabs-in-ecoff
6339 encapulation, but the details have not been worked out yet.
6342 *** Changes in GDB-4.2:
6344 * Improved configuration
6346 Only one copy of `configure' exists now, and it is not self-modifying.
6347 Porting BFD is simpler.
6351 The `step' and `next' commands now only stop at the first instruction
6352 of a source line. This prevents the multiple stops that used to occur
6353 in switch statements, for-loops, etc. `Step' continues to stop if a
6354 function that has debugging information is called within the line.
6358 Lots of small bugs fixed. More remain.
6360 * New host supported (not target)
6362 Intel 386 PC clone running Mach i386-none-mach
6365 *** Changes in GDB-4.1:
6367 * Multiple source language support
6369 GDB now has internal scaffolding to handle several source languages.
6370 It determines the type of each source file from its filename extension,
6371 and will switch expression parsing and number formatting to match the
6372 language of the function in the currently selected stack frame.
6373 You can also specifically set the language to be used, with
6374 `set language c' or `set language modula-2'.
6378 GDB now has preliminary support for the GNU Modula-2 compiler,
6379 currently under development at the State University of New York at
6380 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6381 continue through the fall of 1991 and into 1992.
6383 Other Modula-2 compilers are currently not supported, and attempting to
6384 debug programs compiled with them will likely result in an error as the
6385 symbol table is read. Feel free to work on it, though!
6387 There are hooks in GDB for strict type checking and range checking,
6388 in the `Modula-2 philosophy', but they do not currently work.
6392 GDB can now write to executable and core files (e.g. patch
6393 a variable's value). You must turn this switch on, specify
6394 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6395 by assigning a new value to a variable. Modifications take
6398 * Automatic SunOS shared library reading
6400 When you run your program, GDB automatically determines where its
6401 shared libraries (if any) have been loaded, and reads their symbols.
6402 The `share' command is no longer needed. This also works when
6403 examining core files.
6407 You can specify the number of lines that the `list' command shows.
6410 * New machines supported (host and target)
6412 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6413 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6414 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6416 * New hosts supported (not targets)
6418 IBM RT/PC: romp-ibm-aix or rtpc
6420 * New targets supported (not hosts)
6422 AMD 29000 embedded with COFF a29k-none-coff
6423 AMD 29000 embedded with a.out a29k-none-aout
6424 Ultracomputer remote kernel debug a29k-nyu-kern
6426 * New remote interfaces
6432 *** Changes in GDB-4.0:
6436 Wide output is wrapped at good places to make the output more readable.
6438 Gdb now supports cross-debugging from a host machine of one type to a
6439 target machine of another type. Communication with the target system
6440 is over serial lines. The ``target'' command handles connecting to the
6441 remote system; the ``load'' command will download a program into the
6442 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6443 also supports debugging of realtime processes running under VxWorks,
6444 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6445 stub on the target system.
6447 New CPUs supported include the AMD 29000 and Intel 960.
6449 GDB now reads object files and symbol tables via a ``binary file''
6450 library, which allows a single copy of GDB to debug programs of multiple
6451 object file types such as a.out and coff.
6453 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6454 refcard.dvi and refcard.ps are available to format it).
6457 * Control-Variable user interface simplified
6459 All variables that control the operation of the debugger can be set
6460 by the ``set'' command, and displayed by the ``show'' command.
6462 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6463 ``Show prompt'' produces the response:
6464 Gdb's prompt is new-gdb=>.
6466 What follows are the NEW set commands. The command ``help set'' will
6467 print a complete list of old and new set commands. ``help set FOO''
6468 will give a longer description of the variable FOO. ``show'' will show
6469 all of the variable descriptions and their current settings.
6471 confirm on/off: Enables warning questions for operations that are
6472 hard to recover from, e.g. rerunning the program while
6473 it is already running. Default is ON.
6475 editing on/off: Enables EMACS style command line editing
6476 of input. Previous lines can be recalled with
6477 control-P, the current line can be edited with control-B,
6478 you can search for commands with control-R, etc.
6481 history filename NAME: NAME is where the gdb command history
6482 will be stored. The default is .gdb_history,
6483 or the value of the environment variable
6486 history size N: The size, in commands, of the command history. The
6487 default is 256, or the value of the environment variable
6490 history save on/off: If this value is set to ON, the history file will
6491 be saved after exiting gdb. If set to OFF, the
6492 file will not be saved. The default is OFF.
6494 history expansion on/off: If this value is set to ON, then csh-like
6495 history expansion will be performed on
6496 command line input. The default is OFF.
6498 radix N: Sets the default radix for input and output. It can be set
6499 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6500 in the current radix, so "set radix 10" is always a no-op.
6502 height N: This integer value is the number of lines on a page. Default
6503 is 24, the current `stty rows'' setting, or the ``li#''
6504 setting from the termcap entry matching the environment
6507 width N: This integer value is the number of characters on a line.
6508 Default is 80, the current `stty cols'' setting, or the ``co#''
6509 setting from the termcap entry matching the environment
6512 Note: ``set screensize'' is obsolete. Use ``set height'' and
6513 ``set width'' instead.
6515 print address on/off: Print memory addresses in various command displays,
6516 such as stack traces and structure values. Gdb looks
6517 more ``symbolic'' if you turn this off; it looks more
6518 ``machine level'' with it on. Default is ON.
6520 print array on/off: Prettyprint arrays. New convenient format! Default
6523 print demangle on/off: Print C++ symbols in "source" form if on,
6526 print asm-demangle on/off: Same, for assembler level printouts
6529 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6532 * Support for Epoch Environment.
6534 The epoch environment is a version of Emacs v18 with windowing. One
6535 new command, ``inspect'', is identical to ``print'', except that if you
6536 are running in the epoch environment, the value is printed in its own
6540 * Support for Shared Libraries
6542 GDB can now debug programs and core files that use SunOS shared libraries.
6543 Symbols from a shared library cannot be referenced
6544 before the shared library has been linked with the program (this
6545 happens after you type ``run'' and before the function main() is entered).
6546 At any time after this linking (including when examining core files
6547 from dynamically linked programs), gdb reads the symbols from each
6548 shared library when you type the ``sharedlibrary'' command.
6549 It can be abbreviated ``share''.
6551 sharedlibrary REGEXP: Load shared object library symbols for files
6552 matching a unix regular expression. No argument
6553 indicates to load symbols for all shared libraries.
6555 info sharedlibrary: Status of loaded shared libraries.
6560 A watchpoint stops execution of a program whenever the value of an
6561 expression changes. Checking for this slows down execution
6562 tremendously whenever you are in the scope of the expression, but is
6563 quite useful for catching tough ``bit-spreader'' or pointer misuse
6564 problems. Some machines such as the 386 have hardware for doing this
6565 more quickly, and future versions of gdb will use this hardware.
6567 watch EXP: Set a watchpoint (breakpoint) for an expression.
6569 info watchpoints: Information about your watchpoints.
6571 delete N: Deletes watchpoint number N (same as breakpoints).
6572 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6573 enable N: Re-enables watchpoint number N (same as breakpoints).
6576 * C++ multiple inheritance
6578 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6581 * C++ exception handling
6583 Gdb now supports limited C++ exception handling. Besides the existing
6584 ability to breakpoint on an exception handler, gdb can breakpoint on
6585 the raising of an exception (before the stack is peeled back to the
6588 catch FOO: If there is a FOO exception handler in the dynamic scope,
6589 set a breakpoint to catch exceptions which may be raised there.
6590 Multiple exceptions (``catch foo bar baz'') may be caught.
6592 info catch: Lists all exceptions which may be caught in the
6593 current stack frame.
6596 * Minor command changes
6598 The command ``call func (arg, arg, ...)'' now acts like the print
6599 command, except it does not print or save a value if the function's result
6600 is void. This is similar to dbx usage.
6602 The ``up'' and ``down'' commands now always print the frame they end up
6603 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6604 frames without printing.
6606 * New directory command
6608 'dir' now adds directories to the FRONT of the source search path.
6609 The path starts off empty. Source files that contain debug information
6610 about the directory in which they were compiled can be found even
6611 with an empty path; Sun CC and GCC include this information. If GDB can't
6612 find your source file in the current directory, type "dir .".
6614 * Configuring GDB for compilation
6616 For normal use, type ``./configure host''. See README or gdb.texinfo
6619 GDB now handles cross debugging. If you are remotely debugging between
6620 two different machines, type ``./configure host -target=targ''.
6621 Host is the machine where GDB will run; targ is the machine
6622 where the program that you are debugging will run.
projects / external / binutils.git / blob