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
53 FreeBSD/mips mips*-*-freebsd
55 *** Changes in GDB 7.12
57 * GDB and GDBserver now build with a C++ compiler by default.
59 The --enable-build-with-cxx configure option is now enabled by
60 default. One must now explicitly configure with
61 --disable-build-with-cxx in order to build with a C compiler. This
62 option will be removed in a future release.
64 * GDBserver now supports recording btrace without maintaining an active
67 * GDB now supports a negative repeat count in the 'x' command to examine
68 memory backward from the given address. For example:
71 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
72 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
73 (gdb) x/-5i 0x0000000000400580
74 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
75 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
76 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
77 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
78 0x40057b <main(int, char**)+25>:
79 callq 0x400536 <Func1(int, char const*)>
81 * Fortran: Support structures with fields of dynamic types and
82 arrays of dynamic types.
84 * The symbol dumping maintenance commands have new syntax.
85 maint print symbols [-pc address] [--] [filename]
86 maint print symbols [-objfile objfile] [-source source] [--] [filename]
87 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
88 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
89 maint print msymbols [-objfile objfile] [--] [filename]
91 * GDB now supports multibit bitfields and enums in target register
94 * New Python-based convenience function $_as_string(val), which returns
95 the textual representation of a value. This function is especially
96 useful to obtain the text label of an enum value.
98 * Intel MPX bound violation handling.
100 Segmentation faults caused by a Intel MPX boundary violation
101 now display the kind of violation (upper or lower), the memory
102 address accessed and the memory bounds, along with the usual
103 signal received and code location.
107 Program received signal SIGSEGV, Segmentation fault
108 Upper bound violation while accessing address 0x7fffffffc3b3
109 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
110 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
112 * Rust language support.
113 GDB now supports debugging programs written in the Rust programming
114 language. See https://www.rust-lang.org/ for more information about
117 * Support for running interpreters on specified input/output devices
119 GDB now supports a new mechanism that allows frontends to provide
120 fully featured GDB console views, as a better alternative to
121 building such views on top of the "-interpreter-exec console"
122 command. See the new "new-ui" command below. With that command,
123 frontends can now start GDB in the traditional command-line mode
124 running in an embedded terminal emulator widget, and create a
125 separate MI interpreter running on a specified i/o device. In this
126 way, GDB handles line editing, history, tab completion, etc. in the
127 console all by itself, and the GUI uses the separate MI interpreter
128 for its own control and synchronization, invisible to the command
131 * The "catch syscall" command catches groups of related syscalls.
133 The "catch syscall" command now supports catching a group of related
134 syscalls using the 'group:' or 'g:' prefix.
139 skip -gfile file-glob-pattern
140 skip -function function
141 skip -rfunction regular-expression
142 A generalized form of the skip command, with new support for
143 glob-style file names and regular expressions for function names.
144 Additionally, a file spec and a function spec may now be combined.
146 maint info line-table REGEXP
147 Display the contents of GDB's internal line table data struture.
150 Run any GDB unit tests that were compiled in.
153 Start a new user interface instance running INTERP as interpreter,
154 using the TTY file for input/output.
158 ** gdb.Breakpoint objects have a new attribute "pending", which
159 indicates whether the breakpoint is pending.
160 ** Three new breakpoint-related events have been added:
161 gdb.breakpoint_created, gdb.breakpoint_modified, and
162 gdb.breakpoint_deleted.
165 Signal ("set") the given MS-Windows event object. This is used in
166 conjunction with the Windows JIT debugging (AeDebug) support, where
167 the OS suspends a crashing process until a debugger can attach to
168 it. Resuming the crashing process, in order to debug it, is done by
171 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
172 was added in GDBserver, including JIT compiling fast tracepoint's
173 conditional expression bytecode into native code.
175 * Support for various remote target protocols and ROM monitors has
178 target m32rsdi Remote M32R debugging over SDI
179 target mips MIPS remote debugging protocol
180 target pmon PMON ROM monitor
181 target ddb NEC's DDB variant of PMON for Vr4300
182 target rockhopper NEC RockHopper variant of PMON
183 target lsi LSI variant of PMO
185 * Support for tracepoints and fast tracepoints on powerpc-linux,
186 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
187 including JIT compiling fast tracepoint's conditional expression
188 bytecode into native code.
190 * MI async record =record-started now includes the method and format used for
191 recording. For example:
193 =record-started,thread-group="i1",method="btrace",format="bts"
195 * MI async record =thread-selected now includes the frame field. For example:
197 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
201 Andes NDS32 nds32*-*-elf
203 *** Changes in GDB 7.11
205 * GDB now supports debugging kernel-based threads on FreeBSD.
207 * Per-inferior thread numbers
209 Thread numbers are now per inferior instead of global. If you're
210 debugging multiple inferiors, GDB displays thread IDs using a
211 qualified INF_NUM.THR_NUM form. For example:
215 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
216 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
217 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
218 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
220 As consequence, thread numbers as visible in the $_thread
221 convenience variable and in Python's InferiorThread.num attribute
222 are no longer unique between inferiors.
224 GDB now maintains a second thread ID per thread, referred to as the
225 global thread ID, which is the new equivalent of thread numbers in
226 previous releases. See also $_gthread below.
228 For backwards compatibility, MI's thread IDs always refer to global
231 * Commands that accept thread IDs now accept the qualified
232 INF_NUM.THR_NUM form as well. For example:
235 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
238 * In commands that accept a list of thread IDs, you can now refer to
239 all threads of an inferior using a star wildcard. GDB accepts
240 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
241 refer to all threads of the current inferior. For example, "info
244 * You can use "info threads -gid" to display the global thread ID of
247 * The new convenience variable $_gthread holds the global number of
250 * The new convenience variable $_inferior holds the number of the
253 * GDB now displays the ID and name of the thread that hit a breakpoint
254 or received a signal, if your program is multi-threaded. For
257 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
258 Thread 1 "main" received signal SIGINT, Interrupt.
260 * Record btrace now supports non-stop mode.
262 * Support for tracepoints on aarch64-linux was added in GDBserver.
264 * The 'record instruction-history' command now indicates speculative execution
265 when using the Intel Processor Trace recording format.
267 * GDB now allows users to specify explicit locations, bypassing
268 the linespec parser. This feature is also available to GDB/MI
271 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
272 GDB now is able to debug both AArch64 applications and ARM applications
275 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
276 including JIT compiling fast tracepoint's conditional expression bytecode
279 * GDB now supports displaced stepping on AArch64 GNU/Linux.
281 * "info threads", "info inferiors", "info display", "info checkpoints"
282 and "maint info program-spaces" now list the corresponding items in
283 ascending ID order, for consistency with all other "info" commands.
285 * In Ada, the overloads selection menu has been enhanced to display the
286 parameter types and the return types for the matching overloaded subprograms.
290 maint set target-non-stop (on|off|auto)
291 maint show target-non-stop
292 Control whether GDB targets always operate in non-stop mode even if
293 "set non-stop" is "off". The default is "auto", meaning non-stop
294 mode is enabled if supported by the target.
296 maint set bfd-sharing
297 maint show bfd-sharing
298 Control the reuse of bfd objects.
302 Control display of debugging info regarding bfd caching.
306 Control display of debugging info regarding FreeBSD threads.
308 set remote multiprocess-extensions-packet
309 show remote multiprocess-extensions-packet
310 Set/show the use of the remote protocol multiprocess extensions.
312 set remote thread-events
313 show remote thread-events
314 Set/show the use of thread create/exit events.
316 set ada print-signatures on|off
317 show ada print-signatures"
318 Control whether parameter types and return types are displayed in overloads
319 selection menus. It is activaled (@code{on}) by default.
323 Controls the maximum size of memory, in bytes, that GDB will
324 allocate for value contents. Prevents incorrect programs from
325 causing GDB to allocate overly large buffers. Default is 64k.
327 * The "disassemble" command accepts a new modifier: /s.
328 It prints mixed source+disassembly like /m with two differences:
329 - disassembled instructions are now printed in program order, and
330 - and source for all relevant files is now printed.
331 The "/m" option is now considered deprecated: its "source-centric"
332 output hasn't proved useful in practice.
334 * The "record instruction-history" command accepts a new modifier: /s.
335 It behaves exactly like /m and prints mixed source+disassembly.
337 * The "set scheduler-locking" command supports a new mode "replay".
338 It behaves like "off" in record mode and like "on" in replay mode.
340 * Support for various ROM monitors has been removed:
342 target dbug dBUG ROM monitor for Motorola ColdFire
343 target picobug Motorola picobug monitor
344 target dink32 DINK32 ROM monitor for PowerPC
345 target m32r Renesas M32R/D ROM monitor
346 target mon2000 mon2000 ROM monitor
347 target ppcbug PPCBUG ROM monitor for PowerPC
349 * Support for reading/writing memory and extracting values on architectures
350 whose memory is addressable in units of any integral multiple of 8 bits.
355 Indicates that an exec system call was executed.
357 exec-events feature in qSupported
358 The qSupported packet allows GDB to request support for exec
359 events using the new 'gdbfeature' exec-event, and the qSupported
360 response can contain the corresponding 'stubfeature'. Set and
361 show commands can be used to display whether these features are enabled.
364 Equivalent to interrupting with the ^C character, but works in
367 thread created stop reason (T05 create:...)
368 Indicates that the thread was just created and is stopped at entry.
370 thread exit stop reply (w exitcode;tid)
371 Indicates that the thread has terminated.
374 Enables/disables thread create and exit event reporting. For
375 example, this is used in non-stop mode when GDB stops a set of
376 threads and synchronously waits for the their corresponding stop
377 replies. Without exit events, if one of the threads exits, GDB
378 would hang forever not knowing that it should no longer expect a
379 stop for that same thread.
382 Indicates that there are no resumed threads left in the target (all
383 threads are stopped). The remote stub reports support for this stop
384 reply to GDB's qSupported query.
387 Enables/disables catching syscalls from the inferior process.
388 The remote stub reports support for this packet to GDB's qSupported query.
390 syscall_entry stop reason
391 Indicates that a syscall was just called.
393 syscall_return stop reason
394 Indicates that a syscall just returned.
396 * Extended-remote exec events
398 ** GDB now has support for exec events on extended-remote Linux targets.
399 For such targets with Linux kernels 2.5.46 and later, this enables
400 follow-exec-mode and exec catchpoints.
402 set remote exec-event-feature-packet
403 show remote exec-event-feature-packet
404 Set/show the use of the remote exec event feature.
406 * Thread names in remote protocol
408 The reply to qXfer:threads:read may now include a name attribute for each
411 * Target remote mode fork and exec events
413 ** GDB now has support for fork and exec events on target remote mode
414 Linux targets. For such targets with Linux kernels 2.5.46 and later,
415 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
416 fork and exec catchpoints.
418 * Remote syscall events
420 ** GDB now has support for catch syscall on remote Linux targets,
421 currently enabled on x86/x86_64 architectures.
423 set remote catch-syscall-packet
424 show remote catch-syscall-packet
425 Set/show the use of the remote catch syscall feature.
429 ** The -var-set-format command now accepts the zero-hexadecimal
430 format. It outputs data in hexadecimal format with zero-padding on the
435 ** gdb.InferiorThread objects have a new attribute "global_num",
436 which refers to the thread's global thread ID. The existing
437 "num" attribute now refers to the thread's per-inferior number.
438 See "Per-inferior thread numbers" above.
439 ** gdb.InferiorThread objects have a new attribute "inferior", which
440 is the Inferior object the thread belongs to.
442 *** Changes in GDB 7.10
444 * Support for process record-replay and reverse debugging on aarch64*-linux*
445 targets has been added. GDB now supports recording of A64 instruction set
446 including advance SIMD instructions.
448 * Support for Sun's version of the "stabs" debug file format has been removed.
450 * GDB now honors the content of the file /proc/PID/coredump_filter
451 (PID is the process ID) on GNU/Linux systems. This file can be used
452 to specify the types of memory mappings that will be included in a
453 corefile. For more information, please refer to the manual page of
454 "core(5)". GDB also has a new command: "set use-coredump-filter
455 on|off". It allows to set whether GDB will read the content of the
456 /proc/PID/coredump_filter file when generating a corefile.
458 * The "info os" command on GNU/Linux can now display information on
460 "info os cpus" Listing of all cpus/cores on the system
462 * GDB has two new commands: "set serial parity odd|even|none" and
463 "show serial parity". These allows to set or show parity for the
466 * The "info source" command now displays the producer string if it was
467 present in the debug info. This typically includes the compiler version
468 and may include things like its command line arguments.
470 * The "info dll", an alias of the "info sharedlibrary" command,
471 is now available on all platforms.
473 * Directory names supplied to the "set sysroot" commands may be
474 prefixed with "target:" to tell GDB to access shared libraries from
475 the target system, be it local or remote. This replaces the prefix
476 "remote:". The default sysroot has been changed from "" to
477 "target:". "remote:" is automatically converted to "target:" for
478 backward compatibility.
480 * The system root specified by "set sysroot" will be prepended to the
481 filename of the main executable (if reported to GDB as absolute by
482 the operating system) when starting processes remotely, and when
483 attaching to already-running local or remote processes.
485 * GDB now supports automatic location and retrieval of executable
486 files from remote targets. Remote debugging can now be initiated
487 using only a "target remote" or "target extended-remote" command
488 (no "set sysroot" or "file" commands are required). See "New remote
491 * The "dump" command now supports verilog hex format.
493 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
495 * On GNU/Linux, GDB and gdbserver are now able to access executable
496 and shared library files without a "set sysroot" command when
497 attaching to processes running in different mount namespaces from
498 the debugger. This makes it possible to attach to processes in
499 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
500 See "New remote packets" below.
502 * The "tui reg" command now provides completion for all of the
503 available register groups, including target specific groups.
505 * The HISTSIZE environment variable is no longer read when determining
506 the size of GDB's command history. GDB now instead reads the dedicated
507 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
508 disables truncation of command history. Non-numeric values of GDBHISTSIZE
513 ** Memory ports can now be unbuffered.
517 ** gdb.Objfile objects have a new attribute "username",
518 which is the name of the objfile as specified by the user,
519 without, for example, resolving symlinks.
520 ** You can now write frame unwinders in Python.
521 ** gdb.Type objects have a new method "optimized_out",
522 returning optimized out gdb.Value instance of this type.
523 ** gdb.Value objects have new methods "reference_value" and
524 "const_value" which return a reference to the value and a
525 "const" version of the value respectively.
529 maint print symbol-cache
530 Print the contents of the symbol cache.
532 maint print symbol-cache-statistics
533 Print statistics of symbol cache usage.
535 maint flush-symbol-cache
536 Flush the contents of the symbol cache.
540 Start branch trace recording using Branch Trace Store (BTS) format.
543 Evaluate expression by using the compiler and print result.
547 Explicit commands for enabling and disabling tui mode.
550 set mpx bound on i386 and amd64
551 Support for bound table investigation on Intel MPX enabled applications.
555 Start branch trace recording using Intel Processor Trace format.
558 Print information about branch tracing internals.
560 maint btrace packet-history
561 Print the raw branch tracing data.
563 maint btrace clear-packet-history
564 Discard the stored raw branch tracing data.
567 Discard all branch tracing data. It will be fetched and processed
568 anew by the next "record" command.
573 Renamed from "set debug dwarf2-die".
575 Renamed from "show debug dwarf2-die".
578 Renamed from "set debug dwarf2-read".
579 show debug dwarf-read
580 Renamed from "show debug dwarf2-read".
582 maint set dwarf always-disassemble
583 Renamed from "maint set dwarf2 always-disassemble".
584 maint show dwarf always-disassemble
585 Renamed from "maint show dwarf2 always-disassemble".
587 maint set dwarf max-cache-age
588 Renamed from "maint set dwarf2 max-cache-age".
589 maint show dwarf max-cache-age
590 Renamed from "maint show dwarf2 max-cache-age".
593 show debug dwarf-line
594 Control display of debugging info regarding DWARF line processing.
598 Set the maximum number of candidates to be considered during
599 completion. The default value is 200. This limit allows GDB
600 to avoid generating large completion lists, the computation of
601 which can cause the debugger to become temporarily unresponsive.
603 set history remove-duplicates
604 show history remove-duplicates
605 Control the removal of duplicate history entries.
607 maint set symbol-cache-size
608 maint show symbol-cache-size
609 Control the size of the symbol cache.
611 set|show record btrace bts buffer-size
612 Set and show the size of the ring buffer used for branch tracing in
614 The obtained size may differ from the requested size. Use "info
615 record" to see the obtained buffer size.
617 set debug linux-namespaces
618 show debug linux-namespaces
619 Control display of debugging info regarding Linux namespaces.
621 set|show record btrace pt buffer-size
622 Set and show the size of the ring buffer used for branch tracing in
623 Intel Processor Trace format.
624 The obtained size may differ from the requested size. Use "info
625 record" to see the obtained buffer size.
627 maint set|show btrace pt skip-pad
628 Set and show whether PAD packets are skipped when computing the
631 * The command 'thread apply all' can now support new option '-ascending'
632 to call its specified command for all threads in ascending order.
634 * Python/Guile scripting
636 ** GDB now supports auto-loading of Python/Guile scripts contained in the
637 special section named `.debug_gdb_scripts'.
641 qXfer:btrace-conf:read
642 Return the branch trace configuration for the current thread.
644 Qbtrace-conf:bts:size
645 Set the requested ring buffer size for branch tracing in BTS format.
648 Enable Intel Procesor Trace-based branch tracing for the current
649 process. The remote stub reports support for this packet to GDB's
653 Set the requested ring buffer size for branch tracing in Intel Processor
657 Indicates a memory breakpoint instruction was executed, irrespective
658 of whether it was GDB that planted the breakpoint or the breakpoint
659 is hardcoded in the program. This is required for correct non-stop
663 Indicates the target stopped for a hardware breakpoint. This is
664 required for correct non-stop mode operation.
667 Return information about files on the remote system.
670 Return the full absolute name of the file that was executed to
671 create a process running on the remote system.
674 Select the filesystem on which vFile: operations with filename
675 arguments will operate. This is required for GDB to be able to
676 access files on remote targets where the remote stub does not
677 share a common filesystem with the inferior(s).
680 Indicates that a fork system call was executed.
683 Indicates that a vfork system call was executed.
685 vforkdone stop reason
686 Indicates that a vfork child of the specified process has executed
687 an exec or exit, allowing the vfork parent to resume execution.
689 fork-events and vfork-events features in qSupported
690 The qSupported packet allows GDB to request support for fork and
691 vfork events using new 'gdbfeatures' fork-events and vfork-events,
692 and the qSupported response can contain the corresponding
693 'stubfeatures'. Set and show commands can be used to display
694 whether these features are enabled.
696 * Extended-remote fork events
698 ** GDB now has support for fork events on extended-remote Linux
699 targets. For targets with Linux kernels 2.5.60 and later, this
700 enables follow-fork-mode and detach-on-fork for both fork and
701 vfork, as well as fork and vfork catchpoints.
703 * The info record command now shows the recording format and the
704 branch tracing configuration for the current thread when using
705 the btrace record target.
706 For the BTS format, it shows the ring buffer size.
708 * GDB now has support for DTrace USDT (Userland Static Defined
709 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
711 * GDB now supports access to vector registers on S/390 GNU/Linux
714 * Removed command line options
716 -xdb HP-UX XDB compatibility mode.
718 * Removed targets and native configurations
720 HP/PA running HP-UX hppa*-*-hpux*
721 Itanium running HP-UX ia64-*-hpux*
723 * New configure options
726 This configure option allows the user to build GDB with support for
727 Intel Processor Trace (default: auto). This requires libipt.
729 --with-libipt-prefix=PATH
730 Specify the path to the version of libipt that GDB should use.
731 $PATH/include should contain the intel-pt.h header and
732 $PATH/lib should contain the libipt.so library.
734 *** Changes in GDB 7.9.1
738 ** Xmethods can now specify a result type.
740 *** Changes in GDB 7.9
742 * GDB now supports hardware watchpoints on x86 GNU Hurd.
746 ** You can now access frame registers from Python scripts.
747 ** New attribute 'producer' for gdb.Symtab objects.
748 ** gdb.Objfile objects have a new attribute "progspace",
749 which is the gdb.Progspace object of the containing program space.
750 ** gdb.Objfile objects have a new attribute "owner".
751 ** gdb.Objfile objects have a new attribute "build_id",
752 which is the build ID generated when the file was built.
753 ** gdb.Objfile objects have a new method "add_separate_debug_file".
754 ** A new event "gdb.clear_objfiles" has been added, triggered when
755 selecting a new file to debug.
756 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
757 ** New function gdb.lookup_objfile.
759 New events which are triggered when GDB modifies the state of the
762 ** gdb.events.inferior_call_pre: Function call is about to be made.
763 ** gdb.events.inferior_call_post: Function call has just been made.
764 ** gdb.events.memory_changed: A memory location has been altered.
765 ** gdb.events.register_changed: A register has been altered.
767 * New Python-based convenience functions:
769 ** $_caller_is(name [, number_of_frames])
770 ** $_caller_matches(regexp [, number_of_frames])
771 ** $_any_caller_is(name [, number_of_frames])
772 ** $_any_caller_matches(regexp [, number_of_frames])
774 * GDB now supports the compilation and injection of source code into
775 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
776 to compile the source code to object code, and if successful, inject
777 and execute that code within the current context of the inferior.
778 Currently the C language is supported. The commands used to
779 interface with this new feature are:
781 compile code [-raw|-r] [--] [source code]
782 compile file [-raw|-r] filename
786 demangle [-l language] [--] name
787 Demangle "name" in the specified language, or the current language
788 if elided. This command is renamed from the "maint demangle" command.
789 The latter is kept as a no-op to avoid "maint demangle" being interpreted
790 as "maint demangler-warning".
792 queue-signal signal-name-or-number
793 Queue a signal to be delivered to the thread when it is resumed.
795 add-auto-load-scripts-directory directory
796 Add entries to the list of directories from which to load auto-loaded
799 maint print user-registers
800 List all currently available "user" registers.
802 compile code [-r|-raw] [--] [source code]
803 Compile, inject, and execute in the inferior the executable object
804 code produced by compiling the provided source code.
806 compile file [-r|-raw] filename
807 Compile and inject into the inferior the executable object code
808 produced by compiling the source code stored in the filename
811 * On resume, GDB now always passes the signal the program had stopped
812 for to the thread the signal was sent to, even if the user changed
813 threads before resuming. Previously GDB would often (but not
814 always) deliver the signal to the thread that happens to be current
817 * Conversely, the "signal" command now consistently delivers the
818 requested signal to the current thread. GDB now asks for
819 confirmation if the program had stopped for a signal and the user
820 switched threads meanwhile.
822 * "breakpoint always-inserted" modes "off" and "auto" merged.
824 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
825 won't remove breakpoints from the target until all threads stop,
826 even in non-stop mode. The "auto" mode has been removed, and "off"
827 is now the default mode.
831 set debug symbol-lookup
832 show debug symbol-lookup
833 Control display of debugging info regarding symbol lookup.
837 ** The -list-thread-groups command outputs an exit-code field for
838 inferiors that have exited.
842 MIPS SDE mips*-sde*-elf*
846 Support for these obsolete configurations has been removed.
848 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
849 SGI Irix-5.x mips-*-irix5*
850 SGI Irix-6.x mips-*-irix6*
851 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
852 VAX running Ultrix vax-*-ultrix*
854 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
855 and "assf"), have been removed. Use the "sharedlibrary" command, or
856 its alias "share", instead.
858 *** Changes in GDB 7.8
860 * New command line options
863 This is an alias for the --data-directory option.
865 * GDB supports printing and modifying of variable length automatic arrays
866 as specified in ISO C99.
868 * The ARM simulator now supports instruction level tracing
869 with or without disassembly.
873 GDB now has support for scripting using Guile. Whether this is
874 available is determined at configure time.
875 Guile version 2.0 or greater is required.
876 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
878 * New commands (for set/show, see "New options" below)
882 Invoke CODE by passing it to the Guile interpreter.
886 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
888 info auto-load guile-scripts [regexp]
889 Print the list of automatically loaded Guile scripts.
891 * The source command is now capable of sourcing Guile scripts.
892 This feature is dependent on the debugger being built with Guile support.
896 set print symbol-loading (off|brief|full)
897 show print symbol-loading
898 Control whether to print informational messages when loading symbol
899 information for a file. The default is "full", but when debugging
900 programs with large numbers of shared libraries the amount of output
903 set guile print-stack (none|message|full)
904 show guile print-stack
905 Show a stack trace when an error is encountered in a Guile script.
907 set auto-load guile-scripts (on|off)
908 show auto-load guile-scripts
909 Control auto-loading of Guile script files.
911 maint ada set ignore-descriptive-types (on|off)
912 maint ada show ignore-descriptive-types
913 Control whether the debugger should ignore descriptive types in Ada
914 programs. The default is not to ignore the descriptive types. See
915 the user manual for more details on descriptive types and the intended
916 usage of this option.
918 set auto-connect-native-target
920 Control whether GDB is allowed to automatically connect to the
921 native target for the run, attach, etc. commands when not connected
922 to any target yet. See also "target native" below.
924 set record btrace replay-memory-access (read-only|read-write)
925 show record btrace replay-memory-access
926 Control what memory accesses are allowed during replay.
928 maint set target-async (on|off)
929 maint show target-async
930 This controls whether GDB targets operate in synchronous or
931 asynchronous mode. Normally the default is asynchronous, if it is
932 available; but this can be changed to more easily debug problems
933 occurring only in synchronous mode.
935 set mi-async (on|off)
937 Control whether MI asynchronous mode is preferred. This supersedes
938 "set target-async" of previous GDB versions.
940 * "set target-async" is deprecated as a CLI option and is now an alias
941 for "set mi-async" (only puts MI into async mode).
943 * Background execution commands (e.g., "c&", "s&", etc.) are now
944 possible ``out of the box'' if the target supports them. Previously
945 the user would need to explicitly enable the possibility with the
946 "set target-async on" command.
948 * New features in the GDB remote stub, GDBserver
950 ** New option --debug-format=option1[,option2,...] allows one to add
951 additional text to each output. At present only timestamps
952 are supported: --debug-format=timestamps.
953 Timestamps can also be turned on with the
954 "monitor set debug-format timestamps" command from GDB.
956 * The 'record instruction-history' command now starts counting instructions
957 at one. This also affects the instruction ranges reported by the
958 'record function-call-history' command when given the /i modifier.
960 * The command 'record function-call-history' supports a new modifier '/c' to
961 indent the function names based on their call stack depth.
962 The fields for the '/i' and '/l' modifier have been reordered.
963 The source line range is now prefixed with 'at'.
964 The instruction range is now prefixed with 'inst'.
965 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
966 "record instruction-history" and "list" commands.
968 * The ranges given as arguments to the 'record function-call-history' and
969 'record instruction-history' commands are now inclusive.
971 * The btrace record target now supports the 'record goto' command.
972 For locations inside the execution trace, the back trace is computed
973 based on the information stored in the execution trace.
975 * The btrace record target supports limited reverse execution and replay.
976 The target does not record data and therefore does not allow reading
979 * The "catch syscall" command now works on s390*-linux* targets.
981 * The "compare-sections" command is no longer specific to target
982 remote. It now works with all targets.
984 * All native targets are now consistently called "native".
985 Consequently, the "target child", "target GNU", "target djgpp",
986 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
987 commands have been replaced with "target native". The QNX/NTO port
988 leaves the "procfs" target in place and adds a "native" target for
989 consistency with other ports. The impact on users should be minimal
990 as these commands previously either throwed an error, or were
991 no-ops. The target's name is visible in the output of the following
992 commands: "help target", "info target", "info files", "maint print
995 * The "target native" command now connects to the native target. This
996 can be used to launch native programs even when "set
997 auto-connect-native-target" is set to off.
999 * GDB now supports access to Intel MPX registers on GNU/Linux.
1001 * Support for Intel AVX-512 registers on GNU/Linux.
1002 Support displaying and modifying Intel AVX-512 registers
1003 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1005 * New remote packets
1007 qXfer:btrace:read's annex
1008 The qXfer:btrace:read packet supports a new annex 'delta' to read
1009 branch trace incrementally.
1013 ** Valid Python operations on gdb.Value objects representing
1014 structs/classes invoke the corresponding overloaded operators if
1016 ** New `Xmethods' feature in the Python API. Xmethods are
1017 additional methods or replacements for existing methods of a C++
1018 class. This feature is useful for those cases where a method
1019 defined in C++ source code could be inlined or optimized out by
1020 the compiler, making it unavailable to GDB.
1023 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1025 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1026 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1027 its alias "share", instead.
1029 * The commands "set remotebaud" and "show remotebaud" are no longer
1030 supported. Use "set serial baud" and "show serial baud" (respectively)
1035 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1036 target-async". The latter is left as a deprecated alias of the
1037 former for backward compatibility. If the target supports it,
1038 CLI background execution commands are now always possible by
1039 default, independently of whether the frontend stated a
1040 preference for asynchronous execution with "-gdb-set mi-async".
1041 Previously "-gdb-set target-async off" affected both MI execution
1042 commands and CLI execution commands.
1044 *** Changes in GDB 7.7
1046 * Improved support for process record-replay and reverse debugging on
1047 arm*-linux* targets. Support for thumb32 and syscall instruction
1048 recording has been added.
1050 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1052 * GDB now supports Fission DWP file format version 2.
1053 http://gcc.gnu.org/wiki/DebugFission
1055 * New convenience function "$_isvoid", to check whether an expression
1056 is void. A void expression is an expression where the type of the
1057 result is "void". For example, some convenience variables may be
1058 "void" when evaluated (e.g., "$_exitcode" before the execution of
1059 the program being debugged; or an undefined convenience variable).
1060 Another example, when calling a function whose return type is
1063 * The "maintenance print objfiles" command now takes an optional regexp.
1065 * The "catch syscall" command now works on arm*-linux* targets.
1067 * GDB now consistently shows "<not saved>" when printing values of
1068 registers the debug info indicates have not been saved in the frame
1069 and there's nowhere to retrieve them from
1070 (callee-saved/call-clobbered registers):
1075 (gdb) info registers rax
1078 Before, the former would print "<optimized out>", and the latter
1079 "*value not available*".
1081 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1086 ** Frame filters and frame decorators have been added.
1087 ** Temporary breakpoints are now supported.
1088 ** Line tables representation has been added.
1089 ** New attribute 'parent_type' for gdb.Field objects.
1090 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1091 ** New attribute 'name' for gdb.Type objects.
1095 Nios II ELF nios2*-*-elf
1096 Nios II GNU/Linux nios2*-*-linux
1097 Texas Instruments MSP430 msp430*-*-elf
1099 * Removed native configurations
1101 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1102 been removed. ELF variants of these configurations are kept supported.
1104 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1105 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1106 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1107 i[34567]86-*-openbsd3.[0-3]
1108 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1109 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1110 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1114 Like "catch throw", but catches a re-thrown exception.
1115 maint check-psymtabs
1116 Renamed from old "maint check-symtabs".
1118 Perform consistency checks on symtabs.
1119 maint expand-symtabs
1120 Expand symtabs matching an optional regexp.
1123 Display the details of GDB configure-time options.
1125 maint set|show per-command
1126 maint set|show per-command space
1127 maint set|show per-command time
1128 maint set|show per-command symtab
1129 Enable display of per-command gdb resource usage.
1131 remove-symbol-file FILENAME
1132 remove-symbol-file -a ADDRESS
1133 Remove a symbol file added via add-symbol-file. The file to remove
1134 can be identified by its filename or by an address that lies within
1135 the boundaries of this symbol file in memory.
1138 info exceptions REGEXP
1139 Display the list of Ada exceptions defined in the program being
1140 debugged. If provided, only the exceptions whose names match REGEXP
1145 set debug symfile off|on
1147 Control display of debugging info regarding reading symbol files and
1148 symbol tables within those files
1150 set print raw frame-arguments
1151 show print raw frame-arguments
1152 Set/show whether to print frame arguments in raw mode,
1153 disregarding any defined pretty-printers.
1155 set remote trace-status-packet
1156 show remote trace-status-packet
1157 Set/show the use of remote protocol qTStatus packet.
1161 Control display of debugging messages related to Nios II targets.
1165 Control whether target-assisted range stepping is enabled.
1167 set startup-with-shell
1168 show startup-with-shell
1169 Specifies whether Unix child processes are started via a shell or
1174 Use the target memory cache for accesses to the code segment. This
1175 improves performance of remote debugging (particularly disassembly).
1177 * You can now use a literal value 'unlimited' for options that
1178 interpret 0 or -1 as meaning "unlimited". E.g., "set
1179 trace-buffer-size unlimited" is now an alias for "set
1180 trace-buffer-size -1" and "set height unlimited" is now an alias for
1183 * The "set debug symtab-create" debugging option of GDB has been changed to
1184 accept a verbosity level. 0 means "off", 1 provides basic debugging
1185 output, and values of 2 or greater provides more verbose output.
1187 * New command-line options
1189 Display the details of GDB configure-time options.
1191 * The command 'tsave' can now support new option '-ctf' to save trace
1192 buffer in Common Trace Format.
1194 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1197 * GDB now implements the the C++ 'typeid' operator.
1199 * The new convenience variable $_exception holds the exception being
1200 thrown or caught at an exception-related catchpoint.
1202 * The exception-related catchpoints, like "catch throw", now accept a
1203 regular expression which can be used to filter exceptions by type.
1205 * The new convenience variable $_exitsignal is automatically set to
1206 the terminating signal number when the program being debugged dies
1207 due to an uncaught signal.
1211 ** All MI commands now accept an optional "--language" option.
1212 Support for this feature can be verified by using the "-list-features"
1213 command, which should contain "language-option".
1215 ** The new command -info-gdb-mi-command allows the user to determine
1216 whether a GDB/MI command is supported or not.
1218 ** The "^error" result record returned when trying to execute an undefined
1219 GDB/MI command now provides a variable named "code" whose content is the
1220 "undefined-command" error code. Support for this feature can be verified
1221 by using the "-list-features" command, which should contain
1222 "undefined-command-error-code".
1224 ** The -trace-save MI command can optionally save trace buffer in Common
1227 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1229 ** The command -data-list-register-values now accepts an optional
1230 "--skip-unavailable" option. When used, only the available registers
1233 ** The new command -trace-frame-collected dumps collected variables,
1234 computed expressions, tvars, memory and registers in a traceframe.
1236 ** The commands -stack-list-locals, -stack-list-arguments and
1237 -stack-list-variables now accept an option "--skip-unavailable".
1238 When used, only the available locals or arguments are displayed.
1240 ** The -exec-run command now accepts an optional "--start" option.
1241 When used, the command follows the same semantics as the "start"
1242 command, stopping the program's execution at the start of its
1243 main subprogram. Support for this feature can be verified using
1244 the "-list-features" command, which should contain
1245 "exec-run-start-option".
1247 ** The new commands -catch-assert and -catch-exceptions insert
1248 catchpoints stopping the program when Ada exceptions are raised.
1250 ** The new command -info-ada-exceptions provides the equivalent of
1251 the new "info exceptions" command.
1253 * New system-wide configuration scripts
1254 A GDB installation now provides scripts suitable for use as system-wide
1255 configuration scripts for the following systems:
1259 * GDB now supports target-assigned range stepping with remote targets.
1260 This improves the performance of stepping source lines by reducing
1261 the number of control packets from/to GDB. See "New remote packets"
1264 * GDB now understands the element 'tvar' in the XML traceframe info.
1265 It has the id of the collected trace state variables.
1267 * On S/390 targets that provide the transactional-execution feature,
1268 the program interruption transaction diagnostic block (TDB) is now
1269 represented as a number of additional "registers" in GDB.
1271 * New remote packets
1275 The vCont packet supports a new 'r' action, that tells the remote
1276 stub to step through an address range itself, without GDB
1277 involvemement at each single-step.
1279 qXfer:libraries-svr4:read's annex
1280 The previously unused annex of the qXfer:libraries-svr4:read packet
1281 is now used to support passing an argument list. The remote stub
1282 reports support for this argument list to GDB's qSupported query.
1283 The defined arguments are "start" and "prev", used to reduce work
1284 necessary for library list updating, resulting in significant
1287 * New features in the GDB remote stub, GDBserver
1289 ** GDBserver now supports target-assisted range stepping. Currently
1290 enabled on x86/x86_64 GNU/Linux targets.
1292 ** GDBserver now adds element 'tvar' in the XML in the reply to
1293 'qXfer:traceframe-info:read'. It has the id of the collected
1294 trace state variables.
1296 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1299 * New 'z' formatter for printing and examining memory, this displays the
1300 value as hexadecimal zero padded on the left to the size of the type.
1302 * GDB can now use Windows x64 unwinding data.
1304 * The "set remotebaud" command has been replaced by "set serial baud".
1305 Similarly, "show remotebaud" has been replaced by "show serial baud".
1306 The "set remotebaud" and "show remotebaud" commands are still available
1307 to provide backward compatibility with older versions of GDB.
1309 *** Changes in GDB 7.6
1311 * Target record has been renamed to record-full.
1312 Record/replay is now enabled with the "record full" command.
1313 This also affects settings that are associated with full record/replay
1314 that have been moved from "set/show record" to "set/show record full":
1316 set|show record full insn-number-max
1317 set|show record full stop-at-limit
1318 set|show record full memory-query
1320 * A new record target "record-btrace" has been added. The new target
1321 uses hardware support to record the control-flow of a process. It
1322 does not support replaying the execution, but it implements the
1323 below new commands for investigating the recorded execution log.
1324 This new recording method can be enabled using:
1328 The "record-btrace" target is only available on Intel Atom processors
1329 and requires a Linux kernel 2.6.32 or later.
1331 * Two new commands have been added for record/replay to give information
1332 about the recorded execution without having to replay the execution.
1333 The commands are only supported by "record btrace".
1335 record instruction-history prints the execution history at
1336 instruction granularity
1338 record function-call-history prints the execution history at
1339 function granularity
1341 * New native configurations
1343 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1344 FreeBSD/powerpc powerpc*-*-freebsd
1345 x86_64/Cygwin x86_64-*-cygwin*
1346 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1350 ARM AArch64 aarch64*-*-elf
1351 ARM AArch64 GNU/Linux aarch64*-*-linux
1352 Lynx 178 PowerPC powerpc-*-lynx*178
1353 x86_64/Cygwin x86_64-*-cygwin*
1354 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1356 * If the configured location of system.gdbinit file (as given by the
1357 --with-system-gdbinit option at configure time) is in the
1358 data-directory (as specified by --with-gdb-datadir at configure
1359 time) or in one of its subdirectories, then GDB will look for the
1360 system-wide init file in the directory specified by the
1361 --data-directory command-line option.
1363 * New command line options:
1365 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1366 other initialization files, unlike -nx which disables all of them.
1368 * Removed command line options
1370 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1373 * The 'ptype' and 'whatis' commands now accept an argument to control
1376 * 'info proc' now works on some core files.
1380 ** Vectors can be created with gdb.Type.vector.
1382 ** Python's atexit.register now works in GDB.
1384 ** Types can be pretty-printed via a Python API.
1386 ** Python 3 is now supported (in addition to Python 2.4 or later)
1388 ** New class gdb.Architecture exposes GDB's internal representation
1389 of architecture in the Python API.
1391 ** New method Frame.architecture returns the gdb.Architecture object
1392 corresponding to the frame's architecture.
1394 * New Python-based convenience functions:
1396 ** $_memeq(buf1, buf2, length)
1397 ** $_streq(str1, str2)
1399 ** $_regex(str, regex)
1401 * The 'cd' command now defaults to using '~' (the home directory) if not
1404 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1405 default for GCC since November 2000.
1407 * The command 'forward-search' can now be abbreviated as 'fo'.
1409 * The command 'info tracepoints' can now display 'installed on target'
1410 or 'not installed on target' for each non-pending location of tracepoint.
1412 * New configure options
1414 --enable-libmcheck/--disable-libmcheck
1415 By default, development versions are built with -lmcheck on hosts
1416 that support it, in order to help track memory corruption issues.
1417 Release versions, on the other hand, are built without -lmcheck
1418 by default. The --enable-libmcheck/--disable-libmcheck configure
1419 options allow the user to override that default.
1420 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1421 This configure option allows the user to build GDB with
1422 libbabeltrace using which GDB can read Common Trace Format data.
1424 * New commands (for set/show, see "New options" below)
1427 Catch signals. This is similar to "handle", but allows commands and
1428 conditions to be attached.
1431 List the BFDs known to GDB.
1433 python-interactive [command]
1435 Start a Python interactive prompt, or evaluate the optional command
1436 and print the result of expressions.
1439 "py" is a new alias for "python".
1441 enable type-printer [name]...
1442 disable type-printer [name]...
1443 Enable or disable type printers.
1447 ** For the Renesas Super-H architecture, the "regs" command has been removed
1448 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1453 set print type methods (on|off)
1454 show print type methods
1455 Control whether method declarations are displayed by "ptype".
1456 The default is to show them.
1458 set print type typedefs (on|off)
1459 show print type typedefs
1460 Control whether typedef definitions are displayed by "ptype".
1461 The default is to show them.
1463 set filename-display basename|relative|absolute
1464 show filename-display
1465 Control the way in which filenames is displayed.
1466 The default is "relative", which preserves previous behavior.
1468 set trace-buffer-size
1469 show trace-buffer-size
1470 Request target to change the size of trace buffer.
1472 set remote trace-buffer-size-packet auto|on|off
1473 show remote trace-buffer-size-packet
1474 Control the use of the remote protocol `QTBuffer:size' packet.
1478 Control display of debugging messages related to ARM AArch64.
1481 set debug coff-pe-read
1482 show debug coff-pe-read
1483 Control display of debugging messages related to reading of COFF/PE
1488 Control display of debugging messages related to Mach-O symbols
1491 set debug notification
1492 show debug notification
1493 Control display of debugging info for async remote notification.
1497 ** Command parameter changes are now notified using new async record
1498 "=cmd-param-changed".
1499 ** Trace frame changes caused by command "tfind" are now notified using
1500 new async record "=traceframe-changed".
1501 ** The creation, deletion and modification of trace state variables
1502 are now notified using new async records "=tsv-created",
1503 "=tsv-deleted" and "=tsv-modified".
1504 ** The start and stop of process record are now notified using new
1505 async record "=record-started" and "=record-stopped".
1506 ** Memory changes are now notified using new async record
1508 ** The data-disassemble command response will include a "fullname" field
1509 containing the absolute file name when source has been requested.
1510 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1511 command, to allow pattern filling of memory areas.
1512 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1513 library load/unload events.
1514 ** The response to breakpoint commands and breakpoint async records
1515 includes an "installed" field containing a boolean state about each
1516 non-pending tracepoint location is whether installed on target or not.
1517 ** Output of the "-trace-status" command includes a "trace-file" field
1518 containing the name of the trace file being examined. This field is
1519 optional, and only present when examining a trace file.
1520 ** The "fullname" field is now always present along with the "file" field,
1521 even if the file cannot be found by GDB.
1523 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1524 You must have the LZMA library available when configuring GDB for this
1525 feature to be enabled. For more information, see:
1526 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1528 * New remote packets
1531 Set the size of trace buffer. The remote stub reports support for this
1532 packet to gdb's qSupported query.
1535 Enable Branch Trace Store (BTS)-based branch tracing for the current
1536 thread. The remote stub reports support for this packet to gdb's
1540 Disable branch tracing for the current thread. The remote stub reports
1541 support for this packet to gdb's qSupported query.
1544 Read the traced branches for the current thread. The remote stub
1545 reports support for this packet to gdb's qSupported query.
1547 *** Changes in GDB 7.5
1549 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1550 for more x32 ABI info.
1552 * GDB now supports access to MIPS DSP registers on Linux targets.
1554 * GDB now supports debugging microMIPS binaries.
1556 * The "info os" command on GNU/Linux can now display information on
1557 several new classes of objects managed by the operating system:
1558 "info os procgroups" lists process groups
1559 "info os files" lists file descriptors
1560 "info os sockets" lists internet-domain sockets
1561 "info os shm" lists shared-memory regions
1562 "info os semaphores" lists semaphores
1563 "info os msg" lists message queues
1564 "info os modules" lists loaded kernel modules
1566 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1567 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1568 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1569 options and inspect the probe arguments using the new $_probe_arg family
1570 of convenience variables. You can obtain more information about SystemTap
1571 in <http://sourceware.org/systemtap/>.
1573 * GDB now supports reversible debugging on ARM, it allows you to
1574 debug basic ARM and THUMB instructions, and provides
1575 record/replay support.
1577 * The option "symbol-reloading" has been deleted as it is no longer used.
1581 ** GDB commands implemented in Python can now be put in command class
1584 ** The "maint set python print-stack on|off" is now deleted.
1586 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1587 apply "flag enum"-style pretty-printing to any enum.
1589 ** gdb.lookup_symbol can now work when there is no current frame.
1591 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1592 the source at which the symbol was defined.
1594 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1595 method 'value'. The former indicates whether the symbol needs a
1596 frame in order to compute its value, and the latter computes the
1599 ** A new method 'referenced_value' on gdb.Value objects which can
1600 dereference pointer as well as C++ reference values.
1602 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1603 which return the global and static blocks (as gdb.Block objects),
1604 of the underlying symbol table, respectively.
1606 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1607 object associated with a PC value.
1609 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1610 of the address range occupied by code for the current source line.
1612 * Go language support.
1613 GDB now supports debugging programs written in the Go programming
1616 * GDBserver now supports stdio connections.
1617 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1619 * The binary "gdbtui" can no longer be built or installed.
1620 Use "gdb -tui" instead.
1622 * GDB will now print "flag" enums specially. A flag enum is one where
1623 all the enumerator values have no bits in common when pairwise
1624 "and"ed. When printing a value whose type is a flag enum, GDB will
1625 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1626 (gdb) print (enum E) 3
1629 * The filename part of a linespec will now match trailing components
1630 of a source file name. For example, "break gcc/expr.c:1000" will
1631 now set a breakpoint in build/gcc/expr.c, but not
1632 build/libcpp/expr.c.
1634 * The "info proc" and "generate-core-file" commands will now also
1635 work on remote targets connected to GDBserver on Linux.
1637 * The command "info catch" has been removed. It has been disabled
1638 since December 2007.
1640 * The "catch exception" and "catch assert" commands now accept
1641 a condition at the end of the command, much like the "break"
1642 command does. For instance:
1644 (gdb) catch exception Constraint_Error if Barrier = True
1646 Previously, it was possible to add a condition to such catchpoints,
1647 but it had to be done as a second step, after the catchpoint had been
1648 created, using the "condition" command.
1650 * The "info static-tracepoint-marker" command will now also work on
1651 native Linux targets with in-process agent.
1653 * GDB can now set breakpoints on inlined functions.
1655 * The .gdb_index section has been updated to include symbols for
1656 inlined functions. GDB will ignore older .gdb_index sections by
1657 default, which could cause symbol files to be loaded more slowly
1658 until their .gdb_index sections can be recreated. The new command
1659 "set use-deprecated-index-sections on" will cause GDB to use any older
1660 .gdb_index sections it finds. This will restore performance, but the
1661 ability to set breakpoints on inlined functions will be lost in symbol
1662 files with older .gdb_index sections.
1664 The .gdb_index section has also been updated to record more information
1665 about each symbol. This speeds up the "info variables", "info functions"
1666 and "info types" commands when used with programs having the .gdb_index
1667 section, as well as speeding up debugging with shared libraries using
1668 the .gdb_index section.
1670 * Ada support for GDB/MI Variable Objects has been added.
1672 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1677 ** New command -info-os is the MI equivalent of "info os".
1679 ** Output logs ("set logging" and related) now include MI output.
1683 ** "set use-deprecated-index-sections on|off"
1684 "show use-deprecated-index-sections on|off"
1685 Controls the use of deprecated .gdb_index sections.
1687 ** "catch load" and "catch unload" can be used to stop when a shared
1688 library is loaded or unloaded, respectively.
1690 ** "enable count" can be used to auto-disable a breakpoint after
1693 ** "info vtbl" can be used to show the virtual method tables for
1694 C++ and Java objects.
1696 ** "explore" and its sub commands "explore value" and "explore type"
1697 can be used to recursively explore values and types of
1698 expressions. These commands are available only if GDB is
1699 configured with '--with-python'.
1701 ** "info auto-load" shows status of all kinds of auto-loaded files,
1702 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1703 sequences of commands files, "info auto-load python-scripts"
1704 shows status of auto-loading Python script files,
1705 "info auto-load local-gdbinit" shows status of loading init file
1706 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1707 status of inferior specific thread debugging shared library loading.
1709 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1710 and "show auto-load-scripts" commands have been deprecated, use their
1711 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1712 and "show auto-load python-scripts" counterparts instead.
1714 ** "dprintf location,format,args..." creates a dynamic printf, which
1715 is basically a breakpoint that does a printf and immediately
1716 resumes your program's execution, so it is like a printf that you
1717 can insert dynamically at runtime instead of at compiletime.
1719 ** "set print symbol"
1721 Controls whether GDB attempts to display the symbol, if any,
1722 corresponding to addresses it prints. This defaults to "on", but
1723 you can set it to "off" to restore GDB's previous behavior.
1725 * Deprecated commands
1727 ** For the Renesas Super-H architecture, the "regs" command has been
1728 deprecated, and "info all-registers" should be used instead.
1732 Renesas RL78 rl78-*-elf
1733 HP OpenVMS ia64 ia64-hp-openvms*
1735 * GDBserver supports evaluation of breakpoint conditions. When
1736 support is advertised by GDBserver, GDB may be told to send the
1737 breakpoint conditions in bytecode form to GDBserver. GDBserver
1738 will only report the breakpoint trigger to GDB when its condition
1743 set mips compression
1744 show mips compression
1745 Select the compressed ISA encoding used in functions that have no symbol
1746 information available. The encoding can be set to either of:
1749 and is updated automatically from ELF file flags if available.
1751 set breakpoint condition-evaluation
1752 show breakpoint condition-evaluation
1753 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1754 GDBserver ("target"). Default option "auto" chooses the most efficient
1756 This option can improve debugger efficiency depending on the speed of the
1760 Disable auto-loading globally.
1763 Show auto-loading setting of all kinds of auto-loaded files.
1765 set auto-load gdb-scripts on|off
1766 show auto-load gdb-scripts
1767 Control auto-loading of GDB canned sequences of commands files.
1769 set auto-load python-scripts on|off
1770 show auto-load python-scripts
1771 Control auto-loading of Python script files.
1773 set auto-load local-gdbinit on|off
1774 show auto-load local-gdbinit
1775 Control loading of init file (.gdbinit) from current directory.
1777 set auto-load libthread-db on|off
1778 show auto-load libthread-db
1779 Control auto-loading of inferior specific thread debugging shared library.
1781 set auto-load scripts-directory <dir1>[:<dir2>...]
1782 show auto-load scripts-directory
1783 Set a list of directories from which to load auto-loaded scripts.
1784 Automatically loaded Python scripts and GDB scripts are located in one
1785 of the directories listed by this option.
1786 The delimiter (':' above) may differ according to the host platform.
1788 set auto-load safe-path <dir1>[:<dir2>...]
1789 show auto-load safe-path
1790 Set a list of directories from which it is safe to auto-load files.
1791 The delimiter (':' above) may differ according to the host platform.
1793 set debug auto-load on|off
1794 show debug auto-load
1795 Control display of debugging info for auto-loading the files above.
1797 set dprintf-style gdb|call|agent
1799 Control the way in which a dynamic printf is performed; "gdb"
1800 requests a GDB printf command, while "call" causes dprintf to call a
1801 function in the inferior. "agent" requests that the target agent
1802 (such as GDBserver) do the printing.
1804 set dprintf-function <expr>
1805 show dprintf-function
1806 set dprintf-channel <expr>
1807 show dprintf-channel
1808 Set the function and optional first argument to the call when using
1809 the "call" style of dynamic printf.
1811 set disconnected-dprintf on|off
1812 show disconnected-dprintf
1813 Control whether agent-style dynamic printfs continue to be in effect
1814 after GDB disconnects.
1816 * New configure options
1818 --with-auto-load-dir
1819 Configure default value for the 'set auto-load scripts-directory'
1820 setting above. It defaults to '$debugdir:$datadir/auto-load',
1821 $debugdir representing global debugging info directories (available
1822 via 'show debug-file-directory') and $datadir representing GDB's data
1823 directory (available via 'show data-directory').
1825 --with-auto-load-safe-path
1826 Configure default value for the 'set auto-load safe-path' setting
1827 above. It defaults to the --with-auto-load-dir setting.
1829 --without-auto-load-safe-path
1830 Set 'set auto-load safe-path' to '/', effectively disabling this
1833 * New remote packets
1835 z0/z1 conditional breakpoints extension
1837 The z0/z1 breakpoint insertion packets have been extended to carry
1838 a list of conditional expressions over to the remote stub depending on the
1839 condition evaluation mode. The use of this extension can be controlled
1840 via the "set remote conditional-breakpoints-packet" command.
1844 Specify the signals which the remote stub may pass to the debugged
1845 program without GDB involvement.
1847 * New command line options
1849 --init-command=FILE, -ix Like --command, -x but execute it
1850 before loading inferior.
1851 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1852 execute it before loading inferior.
1854 *** Changes in GDB 7.4
1856 * GDB now handles ambiguous linespecs more consistently; the existing
1857 FILE:LINE support has been expanded to other types of linespecs. A
1858 breakpoint will now be set on all matching locations in all
1859 inferiors, and locations will be added or removed according to
1862 * GDB now allows you to skip uninteresting functions and files when
1863 stepping with the "skip function" and "skip file" commands.
1865 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1866 and "show remote hardware-watchpoint-length-limit". These allows to
1867 set or show the maximum length limit (in bytes) of a remote
1868 target hardware watchpoint.
1870 This allows e.g. to use "unlimited" hardware watchpoints with the
1871 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1872 watchpoints are slower than real hardware watchpoints but are
1873 significantly faster than gdb software watchpoints.
1877 ** The register_pretty_printer function in module gdb.printing now takes
1878 an optional `replace' argument. If True, the new printer replaces any
1881 ** The "maint set python print-stack on|off" command has been
1882 deprecated and will be deleted in GDB 7.5.
1883 A new command: "set python print-stack none|full|message" has
1884 replaced it. Additionally, the default for "print-stack" is
1885 now "message", which just prints the error message without
1888 ** A prompt substitution hook (prompt_hook) is now available to the
1891 ** A new Python module, gdb.prompt has been added to the GDB Python
1892 modules library. This module provides functionality for
1893 escape sequences in prompts (used by set/show
1894 extended-prompt). These escape sequences are replaced by their
1895 corresponding value.
1897 ** Python commands and convenience-functions located in
1898 'data-directory'/python/gdb/command and
1899 'data-directory'/python/gdb/function are now automatically loaded
1902 ** Blocks now provide four new attributes. global_block and
1903 static_block will return the global and static blocks
1904 respectively. is_static and is_global are boolean attributes
1905 that indicate if the block is one of those two types.
1907 ** Symbols now provide the "type" attribute, the type of the symbol.
1909 ** The "gdb.breakpoint" function has been deprecated in favor of
1912 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1913 of a function. This class is based on the "finish" command
1914 available in the CLI.
1916 ** Type objects for struct and union types now allow access to
1917 the fields using standard Python dictionary (mapping) methods.
1918 For example, "some_type['myfield']" now works, as does
1919 "some_type.items()".
1921 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1924 ** A new function, "deep_items" has been added to the gdb.types
1925 module in the GDB Python modules library. This function returns
1926 an iterator over the fields of a struct or union type. Unlike
1927 the standard Python "iteritems" method, it will recursively traverse
1928 any anonymous fields.
1932 ** "*stopped" events can report several new "reason"s, such as
1935 ** Breakpoint changes are now notified using new async records, like
1936 "=breakpoint-modified".
1938 ** New command -ada-task-info.
1940 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1941 $sdir specifies the default system locations of shared libraries.
1942 $pdir specifies the directory where the libpthread used by the application
1945 GDB no longer looks in $sdir and $pdir after it has searched the directories
1946 mentioned in libthread-db-search-path. If you want to search those
1947 directories, they must be specified in libthread-db-search-path.
1948 The default value of libthread-db-search-path on GNU/Linux and Solaris
1949 systems is now "$sdir:$pdir".
1951 $pdir is not supported by gdbserver, it is currently ignored.
1952 $sdir is supported by gdbserver.
1954 * New configure option --with-iconv-bin.
1955 When using the internationalization support like the one in the GNU C
1956 library, GDB will invoke the "iconv" program to get a list of supported
1957 character sets. If this program lives in a non-standard location, one can
1958 use this option to specify where to find it.
1960 * When natively debugging programs on PowerPC BookE processors running
1961 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1962 watchpoints, which specify a mask in addition to an address to watch.
1963 The mask specifies that some bits of an address (the bits which are
1964 reset in the mask) should be ignored when matching the address accessed
1965 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1966 section in the user manual for more details.
1968 * The new option --once causes GDBserver to stop listening for connections once
1969 the first connection is made. The listening port used by GDBserver will
1970 become available after that.
1972 * New commands "info macros" and "alias" have been added.
1974 * New function parameters suffix @entry specifies value of function parameter
1975 at the time the function got called. Entry values are available only since
1981 "!" is now an alias of the "shell" command.
1982 Note that no space is needed between "!" and SHELL COMMAND.
1986 watch EXPRESSION mask MASK_VALUE
1987 The watch command now supports the mask argument which allows creation
1988 of masked watchpoints, if the current architecture supports this feature.
1990 info auto-load-scripts [REGEXP]
1991 This command was formerly named "maintenance print section-scripts".
1992 It is now generally useful and is no longer a maintenance-only command.
1994 info macro [-all] [--] MACRO
1995 The info macro command has new options `-all' and `--'. The first for
1996 printing all definitions of a macro. The second for explicitly specifying
1997 the end of arguments and the beginning of the macro name in case the macro
1998 name starts with a hyphen.
2000 collect[/s] EXPRESSIONS
2001 The tracepoint collect command now takes an optional modifier "/s"
2002 that directs it to dereference pointer-to-character types and
2003 collect the bytes of memory up to a zero byte. The behavior is
2004 similar to what you see when you use the regular print command on a
2005 string. An optional integer following the "/s" sets a bound on the
2006 number of bytes that will be collected.
2009 The trace start command now interprets any supplied arguments as a
2010 note to be recorded with the trace run, with an effect similar to
2011 setting the variable trace-notes.
2014 The trace stop command now interprets any arguments as a note to be
2015 mentioned along with the tstatus report that the trace was stopped
2016 with a command. The effect is similar to setting the variable
2019 * Tracepoints can now be enabled and disabled at any time after a trace
2020 experiment has been started using the standard "enable" and "disable"
2021 commands. It is now possible to start a trace experiment with no enabled
2022 tracepoints; GDB will display a warning, but will allow the experiment to
2023 begin, assuming that tracepoints will be enabled as needed while the trace
2026 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2027 locations with 4-byte instructions, when they were previously
2028 limited to locations with instructions of 5 bytes or longer.
2032 set debug dwarf2-read
2033 show debug dwarf2-read
2034 Turns on or off display of debugging messages related to reading
2035 DWARF debug info. The default is off.
2037 set debug symtab-create
2038 show debug symtab-create
2039 Turns on or off display of debugging messages related to symbol table
2040 creation. The default is off.
2043 show extended-prompt
2044 Set the GDB prompt, and allow escape sequences to be inserted to
2045 display miscellaneous information (see 'help set extended-prompt'
2046 for the list of sequences). This prompt (and any information
2047 accessed through the escape sequences) is updated every time the
2048 prompt is displayed.
2050 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2051 show print entry-values
2052 Set printing of frame argument values at function entry. In some cases
2053 GDB can determine the value of function argument which was passed by the
2054 function caller, even if the value was modified inside the called function.
2056 set debug entry-values
2057 show debug entry-values
2058 Control display of debugging info for determining frame argument values at
2059 function entry and virtual tail call frames.
2061 set basenames-may-differ
2062 show basenames-may-differ
2063 Set whether a source file may have multiple base names.
2064 (A "base name" is the name of a file with the directory part removed.
2065 Example: The base name of "/home/user/hello.c" is "hello.c".)
2066 If set, GDB will canonicalize file names (e.g., expand symlinks)
2067 before comparing them. Canonicalization is an expensive operation,
2068 but it allows the same file be known by more than one base name.
2069 If not set (the default), all source files are assumed to have just
2070 one base name, and gdb will do file name comparisons more efficiently.
2076 Set a user name and notes for the current and any future trace runs.
2077 This is useful for long-running and/or disconnected traces, to
2078 inform others (or yourself) as to who is running the trace, supply
2079 contact information, or otherwise explain what is going on.
2081 set trace-stop-notes
2082 show trace-stop-notes
2083 Set a note attached to the trace run, that is displayed when the
2084 trace has been stopped by a tstop command. This is useful for
2085 instance as an explanation, if you are stopping a trace run that was
2086 started by someone else.
2088 * New remote packets
2092 Dynamically enable a tracepoint in a started trace experiment.
2096 Dynamically disable a tracepoint in a started trace experiment.
2100 Set the user and notes of the trace run.
2104 Query the current status of a tracepoint.
2108 Query the minimum length of instruction at which a fast tracepoint may
2111 * Dcache size (number of lines) and line-size are now runtime-configurable
2112 via "set dcache line" and "set dcache line-size" commands.
2116 Texas Instruments TMS320C6x tic6x-*-*
2120 Renesas RL78 rl78-*-elf
2122 *** Changes in GDB 7.3.1
2124 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2126 *** Changes in GDB 7.3
2128 * GDB has a new command: "thread find [REGEXP]".
2129 It finds the thread id whose name, target id, or thread extra info
2130 matches the given regular expression.
2132 * The "catch syscall" command now works on mips*-linux* targets.
2134 * The -data-disassemble MI command now supports modes 2 and 3 for
2135 dumping the instruction opcodes.
2137 * New command line options
2139 -data-directory DIR Specify DIR as the "data-directory".
2140 This is mostly for testing purposes.
2142 * The "maint set python auto-load on|off" command has been renamed to
2143 "set auto-load-scripts on|off".
2145 * GDB has a new command: "set directories".
2146 It is like the "dir" command except that it replaces the
2147 source path list instead of augmenting it.
2149 * GDB now understands thread names.
2151 On GNU/Linux, "info threads" will display the thread name as set by
2152 prctl or pthread_setname_np.
2154 There is also a new command, "thread name", which can be used to
2155 assign a name internally for GDB to display.
2158 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2159 has been integrated into GDB.
2163 ** The function gdb.Write now accepts an optional keyword 'stream'.
2164 This keyword, when provided, will direct the output to either
2165 stdout, stderr, or GDB's logging output.
2167 ** Parameters can now be be sub-classed in Python, and in particular
2168 you may implement the get_set_doc and get_show_doc functions.
2169 This improves how Parameter set/show documentation is processed
2170 and allows for more dynamic content.
2172 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2173 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2174 have an is_valid method.
2176 ** Breakpoints can now be sub-classed in Python, and in particular
2177 you may implement a 'stop' function that is executed each time
2178 the inferior reaches that breakpoint.
2180 ** New function gdb.lookup_global_symbol looks up a global symbol.
2182 ** GDB values in Python are now callable if the value represents a
2183 function. For example, if 'some_value' represents a function that
2184 takes two integer parameters and returns a value, you can call
2185 that function like so:
2187 result = some_value (10,20)
2189 ** Module gdb.types has been added.
2190 It contains a collection of utilities for working with gdb.Types objects:
2191 get_basic_type, has_field, make_enum_dict.
2193 ** Module gdb.printing has been added.
2194 It contains utilities for writing and registering pretty-printers.
2195 New classes: PrettyPrinter, SubPrettyPrinter,
2196 RegexpCollectionPrettyPrinter.
2197 New function: register_pretty_printer.
2199 ** New commands "info pretty-printers", "enable pretty-printer" and
2200 "disable pretty-printer" have been added.
2202 ** gdb.parameter("directories") is now available.
2204 ** New function gdb.newest_frame returns the newest frame in the
2207 ** The gdb.InferiorThread class has a new "name" attribute. This
2208 holds the thread's name.
2210 ** Python Support for Inferior events.
2211 Python scripts can add observers to be notified of events
2212 occurring in the process being debugged.
2213 The following events are currently supported:
2214 - gdb.events.cont Continue event.
2215 - gdb.events.exited Inferior exited event.
2216 - gdb.events.stop Signal received, and Breakpoint hit events.
2220 ** GDB now puts template parameters in scope when debugging in an
2221 instantiation. For example, if you have:
2223 template<int X> int func (void) { return X; }
2225 then if you step into func<5>, "print X" will show "5". This
2226 feature requires proper debuginfo support from the compiler; it
2227 was added to GCC 4.5.
2229 ** The motion commands "next", "finish", "until", and "advance" now
2230 work better when exceptions are thrown. In particular, GDB will
2231 no longer lose control of the inferior; instead, the GDB will
2232 stop the inferior at the point at which the exception is caught.
2233 This functionality requires a change in the exception handling
2234 code that was introduced in GCC 4.5.
2236 * GDB now follows GCC's rules on accessing volatile objects when
2237 reading or writing target state during expression evaluation.
2238 One notable difference to prior behavior is that "print x = 0"
2239 no longer generates a read of x; the value of the assignment is
2240 now always taken directly from the value being assigned.
2242 * GDB now has some support for using labels in the program's source in
2243 linespecs. For instance, you can use "advance label" to continue
2244 execution to a label.
2246 * GDB now has support for reading and writing a new .gdb_index
2247 section. This section holds a fast index of DWARF debugging
2248 information and can be used to greatly speed up GDB startup and
2249 operation. See the documentation for `save gdb-index' for details.
2251 * The "watch" command now accepts an optional "-location" argument.
2252 When used, this causes GDB to watch the memory referred to by the
2253 expression. Such a watchpoint is never deleted due to it going out
2256 * GDB now supports thread debugging of core dumps on GNU/Linux.
2258 GDB now activates thread debugging using the libthread_db library
2259 when debugging GNU/Linux core dumps, similarly to when debugging
2260 live processes. As a result, when debugging a core dump file, GDB
2261 is now able to display pthread_t ids of threads. For example, "info
2262 threads" shows the same output as when debugging the process when it
2263 was live. In earlier releases, you'd see something like this:
2266 * 1 LWP 6780 main () at main.c:10
2268 While now you see this:
2271 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2273 It is also now possible to inspect TLS variables when debugging core
2276 When debugging a core dump generated on a machine other than the one
2277 used to run GDB, you may need to point GDB at the correct
2278 libthread_db library with the "set libthread-db-search-path"
2279 command. See the user manual for more details on this command.
2281 * When natively debugging programs on PowerPC BookE processors running
2282 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2283 which stop execution of the inferior whenever it executes an instruction
2284 at any address within the specified range. See the "PowerPC Embedded"
2285 section in the user manual for more details.
2287 * New features in the GDB remote stub, GDBserver
2289 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2290 and i686 LynxOS (version 5.x).
2292 ** GDBserver is now supported on Blackfin Linux.
2294 * New native configurations
2296 ia64 HP-UX ia64-*-hpux*
2300 Analog Devices, Inc. Blackfin Processor bfin-*
2302 * Ada task switching is now supported on sparc-elf targets when
2303 debugging a program using the Ravenscar Profile. For more information,
2304 see the "Tasking Support when using the Ravenscar Profile" section
2305 in the GDB user manual.
2307 * Guile support was removed.
2309 * New features in the GNU simulator
2311 ** The --map-info flag lists all known core mappings.
2313 ** CFI flashes may be simulated via the "cfi" device.
2315 *** Changes in GDB 7.2
2317 * Shared library support for remote targets by default
2319 When GDB is configured for a generic, non-OS specific target, like
2320 for example, --target=arm-eabi or one of the many *-*-elf targets,
2321 GDB now queries remote stubs for loaded shared libraries using the
2322 `qXfer:libraries:read' packet. Previously, shared library support
2323 was always disabled for such configurations.
2327 ** Argument Dependent Lookup (ADL)
2329 In C++ ADL lookup directs function search to the namespaces of its
2330 arguments even if the namespace has not been imported.
2340 Here the compiler will search for `foo' in the namespace of 'b'
2341 and find A::foo. GDB now supports this. This construct is commonly
2342 used in the Standard Template Library for operators.
2344 ** Improved User Defined Operator Support
2346 In addition to member operators, GDB now supports lookup of operators
2347 defined in a namespace and imported with a `using' directive, operators
2348 defined in the global scope, operators imported implicitly from an
2349 anonymous namespace, and the ADL operators mentioned in the previous
2351 GDB now also supports proper overload resolution for all the previously
2352 mentioned flavors of operators.
2354 ** static const class members
2356 Printing of static const class members that are initialized in the
2357 class definition has been fixed.
2359 * Windows Thread Information Block access.
2361 On Windows targets, GDB now supports displaying the Windows Thread
2362 Information Block (TIB) structure. This structure is visible either
2363 by using the new command `info w32 thread-information-block' or, by
2364 dereferencing the new convenience variable named `$_tlb', a
2365 thread-specific pointer to the TIB. This feature is also supported
2366 when remote debugging using GDBserver.
2368 * Static tracepoints
2370 Static tracepoints are calls in the user program into a tracing
2371 library. One such library is a port of the LTTng kernel tracer to
2372 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2373 When debugging with GDBserver, GDB now supports combining the GDB
2374 tracepoint machinery with such libraries. For example: the user can
2375 use GDB to probe a static tracepoint marker (a call from the user
2376 program into the tracing library) with the new "strace" command (see
2377 "New commands" below). This creates a "static tracepoint" in the
2378 breakpoint list, that can be manipulated with the same feature set
2379 as fast and regular tracepoints. E.g., collect registers, local and
2380 global variables, collect trace state variables, and define
2381 tracepoint conditions. In addition, the user can collect extra
2382 static tracepoint marker specific data, by collecting the new
2383 $_sdata internal variable. When analyzing the trace buffer, you can
2384 inspect $_sdata like any other variable available to GDB. For more
2385 information, see the "Tracepoints" chapter in GDB user manual. New
2386 remote packets have been defined to support static tracepoints, see
2387 the "New remote packets" section below.
2389 * Better reconstruction of tracepoints after disconnected tracing
2391 GDB will attempt to download the original source form of tracepoint
2392 definitions when starting a trace run, and then will upload these
2393 upon reconnection to the target, resulting in a more accurate
2394 reconstruction of the tracepoints that are in use on the target.
2398 You can now exercise direct control over the ways that GDB can
2399 affect your program. For instance, you can disallow the setting of
2400 breakpoints, so that the program can run continuously (assuming
2401 non-stop mode). In addition, the "observer" variable is available
2402 to switch all of the different controls; in observer mode, GDB
2403 cannot affect the target's behavior at all, which is useful for
2404 tasks like diagnosing live systems in the field.
2406 * The new convenience variable $_thread holds the number of the
2409 * New remote packets
2413 Return the address of the Windows Thread Information Block of a given thread.
2417 In response to several of the tracepoint packets, the target may now
2418 also respond with a number of intermediate `qRelocInsn' request
2419 packets before the final result packet, to have GDB handle
2420 relocating an instruction to execute at a different address. This
2421 is particularly useful for stubs that support fast tracepoints. GDB
2422 reports support for this feature in the qSupported packet.
2426 List static tracepoint markers in the target program.
2430 List static tracepoint markers at a given address in the target
2433 qXfer:statictrace:read
2435 Read the static trace data collected (by a `collect $_sdata'
2436 tracepoint action). The remote stub reports support for this packet
2437 to gdb's qSupported query.
2441 Send the current settings of GDB's permission flags.
2445 Send part of the source (textual) form of a tracepoint definition,
2446 which includes location, conditional, and action list.
2448 * The source command now accepts a -s option to force searching for the
2449 script in the source search path even if the script name specifies
2452 * New features in the GDB remote stub, GDBserver
2454 - GDBserver now support tracepoints (including fast tracepoints, and
2455 static tracepoints). The feature is currently supported by the
2456 i386-linux and amd64-linux builds. See the "Tracepoints support
2457 in gdbserver" section in the manual for more information.
2459 GDBserver JIT compiles the tracepoint's conditional agent
2460 expression bytecode into native code whenever possible for low
2461 overhead dynamic tracepoints conditionals. For such tracepoints,
2462 an expression that examines program state is evaluated when the
2463 tracepoint is reached, in order to determine whether to capture
2464 trace data. If the condition is simple and false, processing the
2465 tracepoint finishes very quickly and no data is gathered.
2467 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2468 for static tracepoints support.
2470 - GDBserver now supports x86_64 Windows 64-bit debugging.
2472 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2473 it understands register description.
2475 * The --batch flag now disables pagination and queries.
2477 * X86 general purpose registers
2479 GDB now supports reading/writing byte, word and double-word x86
2480 general purpose registers directly. This means you can use, say,
2481 $ah or $ax to refer, respectively, to the byte register AH and
2482 16-bit word register AX that are actually portions of the 32-bit
2483 register EAX or 64-bit register RAX.
2485 * The `commands' command now accepts a range of breakpoints to modify.
2486 A plain `commands' following a command that creates multiple
2487 breakpoints affects all the breakpoints set by that command. This
2488 applies to breakpoints set by `rbreak', and also applies when a
2489 single `break' command creates multiple breakpoints (e.g.,
2490 breakpoints on overloaded c++ functions).
2492 * The `rbreak' command now accepts a filename specification as part of
2493 its argument, limiting the functions selected by the regex to those
2494 in the specified file.
2496 * Support for remote debugging Windows and SymbianOS shared libraries
2497 from Unix hosts has been improved. Non Windows GDB builds now can
2498 understand target reported file names that follow MS-DOS based file
2499 system semantics, such as file names that include drive letters and
2500 use the backslash character as directory separator. This makes it
2501 possible to transparently use the "set sysroot" and "set
2502 solib-search-path" on Unix hosts to point as host copies of the
2503 target's shared libraries. See the new command "set
2504 target-file-system-kind" described below, and the "Commands to
2505 specify files" section in the user manual for more information.
2509 eval template, expressions...
2510 Convert the values of one or more expressions under the control
2511 of the string template to a command line, and call it.
2513 set target-file-system-kind unix|dos-based|auto
2514 show target-file-system-kind
2515 Set or show the assumed file system kind for target reported file
2518 save breakpoints <filename>
2519 Save all current breakpoint definitions to a file suitable for use
2520 in a later debugging session. To read the saved breakpoint
2521 definitions, use the `source' command.
2523 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2526 info static-tracepoint-markers
2527 Display information about static tracepoint markers in the target.
2529 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2530 Define a static tracepoint by probing a marker at the given
2531 function, line, address, or marker ID.
2535 Enable and disable observer mode.
2537 set may-write-registers on|off
2538 set may-write-memory on|off
2539 set may-insert-breakpoints on|off
2540 set may-insert-tracepoints on|off
2541 set may-insert-fast-tracepoints on|off
2542 set may-interrupt on|off
2543 Set individual permissions for GDB effects on the target. Note that
2544 some of these settings can have undesirable or surprising
2545 consequences, particularly when changed in the middle of a session.
2546 For instance, disabling the writing of memory can prevent
2547 breakpoints from being inserted, cause single-stepping to fail, or
2548 even crash your program, if you disable after breakpoints have been
2549 inserted. However, GDB should not crash.
2551 set record memory-query on|off
2552 show record memory-query
2553 Control whether to stop the inferior if memory changes caused
2554 by an instruction cannot be recorded.
2559 The disassemble command now supports "start,+length" form of two arguments.
2563 ** GDB now provides a new directory location, called the python directory,
2564 where Python scripts written for GDB can be installed. The location
2565 of that directory is <data-directory>/python, where <data-directory>
2566 is the GDB data directory. For more details, see section `Scripting
2567 GDB using Python' in the manual.
2569 ** The GDB Python API now has access to breakpoints, symbols, symbol
2570 tables, program spaces, inferiors, threads and frame's code blocks.
2571 Additionally, GDB Parameters can now be created from the API, and
2572 manipulated via set/show in the CLI.
2574 ** New functions gdb.target_charset, gdb.target_wide_charset,
2575 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2577 ** New exception gdb.GdbError.
2579 ** Pretty-printers are now also looked up in the current program space.
2581 ** Pretty-printers can now be individually enabled and disabled.
2583 ** GDB now looks for names of Python scripts to auto-load in a
2584 special section named `.debug_gdb_scripts', in addition to looking
2585 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2587 * Tracepoint actions were unified with breakpoint commands. In particular,
2588 there are no longer differences in "info break" output for breakpoints and
2589 tracepoints and the "commands" command can be used for both tracepoints and
2590 regular breakpoints.
2594 ARM Symbian arm*-*-symbianelf*
2596 * D language support.
2597 GDB now supports debugging programs written in the D programming
2600 * GDB now supports the extended ptrace interface for PowerPC which is
2601 available since Linux kernel version 2.6.34. This automatically enables
2602 any hardware breakpoints and additional hardware watchpoints available in
2603 the processor. The old ptrace interface exposes just one hardware
2604 watchpoint and no hardware breakpoints.
2606 * GDB is now able to use the Data Value Compare (DVC) register available on
2607 embedded PowerPC processors to implement in hardware simple watchpoint
2608 conditions of the form:
2610 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2612 This works in native GDB running on Linux kernels with the extended ptrace
2613 interface mentioned above.
2615 *** Changes in GDB 7.1
2619 ** Namespace Support
2621 GDB now supports importing of namespaces in C++. This enables the
2622 user to inspect variables from imported namespaces. Support for
2623 namepace aliasing has also been added. So, if a namespace is
2624 aliased in the current scope (e.g. namepace C=A; ) the user can
2625 print variables using the alias (e.g. (gdb) print C::x).
2629 All known bugs relating to the printing of virtual base class were
2630 fixed. It is now possible to call overloaded static methods using a
2635 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2636 and reinterpret_cast<> are now handled by the C++ expression parser.
2640 Xilinx MicroBlaze microblaze-*-*
2645 Xilinx MicroBlaze microblaze
2648 * Multi-program debugging.
2650 GDB now has support for multi-program (a.k.a. multi-executable or
2651 multi-exec) debugging. This allows for debugging multiple inferiors
2652 simultaneously each running a different program under the same GDB
2653 session. See "Debugging Multiple Inferiors and Programs" in the
2654 manual for more information. This implied some user visible changes
2655 in the multi-inferior support. For example, "info inferiors" now
2656 lists inferiors that are not running yet or that have exited
2657 already. See also "New commands" and "New options" below.
2659 * New tracing features
2661 GDB's tracepoint facility now includes several new features:
2663 ** Trace state variables
2665 GDB tracepoints now include support for trace state variables, which
2666 are variables managed by the target agent during a tracing
2667 experiment. They are useful for tracepoints that trigger each
2668 other, so for instance one tracepoint can count hits in a variable,
2669 and then a second tracepoint has a condition that is true when the
2670 count reaches a particular value. Trace state variables share the
2671 $-syntax of GDB convenience variables, and can appear in both
2672 tracepoint actions and condition expressions. Use the "tvariable"
2673 command to create, and "info tvariables" to view; see "Trace State
2674 Variables" in the manual for more detail.
2678 GDB now includes an option for defining fast tracepoints, which
2679 targets may implement more efficiently, such as by installing a jump
2680 into the target agent rather than a trap instruction. The resulting
2681 speedup can be by two orders of magnitude or more, although the
2682 tradeoff is that some program locations on some target architectures
2683 might not allow fast tracepoint installation, for instance if the
2684 instruction to be replaced is shorter than the jump. To request a
2685 fast tracepoint, use the "ftrace" command, with syntax identical to
2686 the regular trace command.
2688 ** Disconnected tracing
2690 It is now possible to detach GDB from the target while it is running
2691 a trace experiment, then reconnect later to see how the experiment
2692 is going. In addition, a new variable disconnected-tracing lets you
2693 tell the target agent whether to continue running a trace if the
2694 connection is lost unexpectedly.
2698 GDB now has the ability to save the trace buffer into a file, and
2699 then use that file as a target, similarly to you can do with
2700 corefiles. You can select trace frames, print data that was
2701 collected in them, and use tstatus to display the state of the
2702 tracing run at the moment that it was saved. To create a trace
2703 file, use "tsave <filename>", and to use it, do "target tfile
2706 ** Circular trace buffer
2708 You can ask the target agent to handle the trace buffer as a
2709 circular buffer, discarding the oldest trace frames to make room for
2710 newer ones, by setting circular-trace-buffer to on. This feature may
2711 not be available for all target agents.
2716 The disassemble command, when invoked with two arguments, now requires
2717 the arguments to be comma-separated.
2720 The info variables command now displays variable definitions. Files
2721 which only declare a variable are not shown.
2724 The source command is now capable of sourcing Python scripts.
2725 This feature is dependent on the debugger being build with Python
2728 Related to this enhancement is also the introduction of a new command
2729 "set script-extension" (see below).
2731 * New commands (for set/show, see "New options" below)
2733 record save [<FILENAME>]
2734 Save a file (in core file format) containing the process record
2735 execution log for replay debugging at a later time.
2737 record restore <FILENAME>
2738 Restore the process record execution log that was saved at an
2739 earlier time, for replay debugging.
2741 add-inferior [-copies <N>] [-exec <FILENAME>]
2744 clone-inferior [-copies <N>] [ID]
2745 Make a new inferior ready to execute the same program another
2746 inferior has loaded.
2751 maint info program-spaces
2752 List the program spaces loaded into GDB.
2754 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2755 show remote interrupt-sequence
2756 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2757 as the sequence to the remote target in order to interrupt the execution.
2758 Ctrl-C is a default. Some system prefers BREAK which is high level of
2759 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2760 Magic SysRq g. It is BREAK signal and character 'g'.
2762 set remote interrupt-on-connect [on | off]
2763 show remote interrupt-on-connect
2764 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2765 remote target when gdb connects to it. This is needed when you debug
2768 set remotebreak [on | off]
2770 Deprecated. Use "set/show remote interrupt-sequence" instead.
2772 tvariable $NAME [ = EXP ]
2773 Create or modify a trace state variable.
2776 List trace state variables and their values.
2778 delete tvariable $NAME ...
2779 Delete one or more trace state variables.
2782 Evaluate the given expressions without collecting anything into the
2783 trace buffer. (Valid in tracepoint actions only.)
2785 ftrace FN / FILE:LINE / *ADDR
2786 Define a fast tracepoint at the given function, line, or address.
2788 * New expression syntax
2790 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2791 GDB now parses 0b101010 identically with 42.
2795 set follow-exec-mode new|same
2796 show follow-exec-mode
2797 Control whether GDB reuses the same inferior across an exec call or
2798 creates a new one. This is useful to be able to restart the old
2799 executable after the inferior having done an exec call.
2801 set default-collect EXPR, ...
2802 show default-collect
2803 Define a list of expressions to be collected at each tracepoint.
2804 This is a useful way to ensure essential items are not overlooked,
2805 such as registers or a critical global variable.
2807 set disconnected-tracing
2808 show disconnected-tracing
2809 If set to 1, the target is instructed to continue tracing if it
2810 loses its connection to GDB. If 0, the target is to stop tracing
2813 set circular-trace-buffer
2814 show circular-trace-buffer
2815 If set to on, the target is instructed to use a circular trace buffer
2816 and discard the oldest trace frames instead of stopping the trace due
2817 to a full trace buffer. If set to off, the trace stops when the buffer
2818 fills up. Some targets may not support this.
2820 set script-extension off|soft|strict
2821 show script-extension
2822 If set to "off", the debugger does not perform any script language
2823 recognition, and all sourced files are assumed to be GDB scripts.
2824 If set to "soft" (the default), files are sourced according to
2825 filename extension, falling back to GDB scripts if the first
2827 If set to "strict", files are sourced according to filename extension.
2829 set ada trust-PAD-over-XVS on|off
2830 show ada trust-PAD-over-XVS
2831 If off, activate a workaround against a bug in the debugging information
2832 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2833 the GCC sources for more information about the GNAT encoding and
2834 PAD types in particular). It is always safe to set this option to
2835 off, but this introduces a slight performance penalty. The default
2838 * Python API Improvements
2840 ** GDB provides the new class gdb.LazyString. This is useful in
2841 some pretty-printing cases. The new method gdb.Value.lazy_string
2842 provides a simple way to create objects of this type.
2844 ** The fields returned by gdb.Type.fields now have an
2845 `is_base_class' attribute.
2847 ** The new method gdb.Type.range returns the range of an array type.
2849 ** The new method gdb.parse_and_eval can be used to parse and
2850 evaluate an expression.
2852 * New remote packets
2855 Define a trace state variable.
2858 Get the current value of a trace state variable.
2861 Set desired tracing behavior upon disconnection.
2864 Set the trace buffer to be linear or circular.
2867 Get data about the tracepoints currently in use.
2871 Process record now works correctly with hardware watchpoints.
2873 Multiple bug fixes have been made to the mips-irix port, making it
2874 much more reliable. In particular:
2875 - Debugging threaded applications is now possible again. Previously,
2876 GDB would hang while starting the program, or while waiting for
2877 the program to stop at a breakpoint.
2878 - Attaching to a running process no longer hangs.
2879 - An error occurring while loading a core file has been fixed.
2880 - Changing the value of the PC register now works again. This fixes
2881 problems observed when using the "jump" command, or when calling
2882 a function from GDB, or even when assigning a new value to $pc.
2883 - With the "finish" and "return" commands, the return value for functions
2884 returning a small array is now correctly printed.
2885 - It is now possible to break on shared library code which gets executed
2886 during a shared library init phase (code executed while executing
2887 their .init section). Previously, the breakpoint would have no effect.
2888 - GDB is now able to backtrace through the signal handler for
2889 non-threaded programs.
2891 PIE (Position Independent Executable) programs debugging is now supported.
2892 This includes debugging execution of PIC (Position Independent Code) shared
2893 libraries although for that, it should be possible to run such libraries as an
2896 *** Changes in GDB 7.0
2898 * GDB now has an interface for JIT compilation. Applications that
2899 dynamically generate code can create symbol files in memory and register
2900 them with GDB. For users, the feature should work transparently, and
2901 for JIT developers, the interface is documented in the GDB manual in the
2902 "JIT Compilation Interface" chapter.
2904 * Tracepoints may now be conditional. The syntax is as for
2905 breakpoints; either an "if" clause appended to the "trace" command,
2906 or the "condition" command is available. GDB sends the condition to
2907 the target for evaluation using the same bytecode format as is used
2908 for tracepoint actions.
2910 * The disassemble command now supports: an optional /r modifier, print the
2911 raw instructions in hex as well as in symbolic form, and an optional /m
2912 modifier to print mixed source+assembly.
2914 * Process record and replay
2916 In a architecture environment that supports ``process record and
2917 replay'', ``process record and replay'' target can record a log of
2918 the process execution, and replay it with both forward and reverse
2921 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2922 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2923 set execution-direction {forward|reverse}, for targets that support
2926 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2927 feature is available with a native GDB running on kernel version
2930 * GDB now has support for multi-byte and wide character sets on the
2931 target. Strings whose character type is wchar_t, char16_t, or
2932 char32_t are now correctly printed. GDB supports wide- and unicode-
2933 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2934 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2935 `printf'. This feature requires iconv to work properly; if your
2936 system does not have a working iconv, GDB can use GNU libiconv. See
2937 the installation instructions for more information.
2939 * GDB now supports automatic retrieval of shared library files from
2940 remote targets. To use this feature, specify a system root that begins
2941 with the `remote:' prefix, either via the `set sysroot' command or via
2942 the `--with-sysroot' configure-time option.
2944 * "info sharedlibrary" now takes an optional regex of libraries to show,
2945 and it now reports if a shared library has no debugging information.
2947 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2948 now complete on file names.
2950 * When completing in expressions, gdb will attempt to limit
2951 completions to allowable structure or union fields, where appropriate.
2952 For instance, consider:
2954 # struct example { int f1; double f2; };
2955 # struct example variable;
2958 If the user types TAB at the end of this command line, the available
2959 completions will be "f1" and "f2".
2961 * Inlined functions are now supported. They show up in backtraces, and
2962 the "step", "next", and "finish" commands handle them automatically.
2964 * GDB now supports the token-splicing (##) and stringification (#)
2965 operators when expanding macros. It also supports variable-arity
2968 * GDB now supports inspecting extra signal information, exported by
2969 the new $_siginfo convenience variable. The feature is currently
2970 implemented on linux ARM, i386 and amd64.
2972 * GDB can now display the VFP floating point registers and NEON vector
2973 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2974 can provide these registers (requires Linux 2.6.30 or later). Remote
2975 and simulator targets may also provide them.
2977 * New remote packets
2980 Search memory for a sequence of bytes.
2983 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2984 operation over reliable transport links. Use of this packet is
2985 controlled by the `set remote noack-packet' command.
2988 Kill the process with the specified process ID. Use this in preference
2989 to `k' when multiprocess protocol extensions are supported.
2992 Obtains additional operating system information
2996 Read or write additional signal information.
2998 * Removed remote protocol undocumented extension
3000 An undocumented extension to the remote protocol's `S' stop reply
3001 packet that permited the stub to pass a process id was removed.
3002 Remote servers should use the `T' stop reply packet instead.
3004 * GDB now supports multiple function calling conventions according to the
3005 DWARF-2 DW_AT_calling_convention function attribute.
3007 * The SH target utilizes the aforementioned change to distinguish between gcc
3008 and Renesas calling convention. It also adds the new CLI commands
3009 `set/show sh calling-convention'.
3011 * GDB can now read compressed debug sections, as produced by GNU gold
3012 with the --compress-debug-sections=zlib flag.
3014 * 64-bit core files are now supported on AIX.
3016 * Thread switching is now supported on Tru64.
3018 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3019 which will be allocated using malloc later in program execution.
3021 * The qXfer:libraries:read remote procotol packet now allows passing a
3022 list of section offsets.
3024 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3025 conditions handling signals delivered during attach or thread creation
3026 have also been fixed.
3028 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3029 From the user's standpoint, all unqualified instances of True and False
3030 are treated as the standard definitions, regardless of context.
3032 * GDB now parses C++ symbol and type names more flexibly. For
3035 template<typename T> class C { };
3038 GDB will now correctly handle all of:
3040 ptype C<char const *>
3041 ptype C<char const*>
3042 ptype C<const char *>
3043 ptype C<const char*>
3045 * New features in the GDB remote stub, gdbserver
3047 - The "--wrapper" command-line argument tells gdbserver to use a
3048 wrapper program to launch programs for debugging.
3050 - On PowerPC and S/390 targets, it is now possible to use a single
3051 gdbserver executable to debug both 32-bit and 64-bit programs.
3052 (This requires gdbserver itself to be built as a 64-bit executable.)
3054 - gdbserver uses the new noack protocol mode for TCP connections to
3055 reduce communications latency, if also supported and enabled in GDB.
3057 - Support for the sparc64-linux-gnu target is now included in
3060 - The amd64-linux build of gdbserver now supports debugging both
3061 32-bit and 64-bit programs.
3063 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3064 now support hardware watchpoints, and will use them automatically
3069 GDB now has support for scripting using Python. Whether this is
3070 available is determined at configure time.
3072 New GDB commands can now be written in Python.
3074 * Ada tasking support
3076 Ada tasks can now be inspected in GDB. The following commands have
3080 Print the list of Ada tasks.
3082 Print detailed information about task number N.
3084 Print the task number of the current task.
3086 Switch the context of debugging to task number N.
3088 * Support for user-defined prefixed commands. The "define" command can
3089 add new commands to existing prefixes, e.g. "target".
3091 * Multi-inferior, multi-process debugging.
3093 GDB now has generalized support for multi-inferior debugging. See
3094 "Debugging Multiple Inferiors" in the manual for more information.
3095 Although availability still depends on target support, the command
3096 set is more uniform now. The GNU/Linux specific multi-forks support
3097 has been migrated to this new framework. This implied some user
3098 visible changes; see "New commands" and also "Removed commands"
3101 * Target descriptions can now describe the target OS ABI. See the
3102 "Target Description Format" section in the user manual for more
3105 * Target descriptions can now describe "compatible" architectures
3106 to indicate that the target can execute applications for a different
3107 architecture in addition to those for the main target architecture.
3108 See the "Target Description Format" section in the user manual for
3111 * Multi-architecture debugging.
3113 GDB now includes general supports for debugging applications on
3114 hybrid systems that use more than one single processor architecture
3115 at the same time. Each such hybrid architecture still requires
3116 specific support to be added. The only hybrid architecture supported
3117 in this version of GDB is the Cell Broadband Engine.
3119 * GDB now supports integrated debugging of Cell/B.E. applications that
3120 use both the PPU and SPU architectures. To enable support for hybrid
3121 Cell/B.E. debugging, you need to configure GDB to support both the
3122 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3123 --enable-targets configure option.
3125 * Non-stop mode debugging.
3127 For some targets, GDB now supports an optional mode of operation in
3128 which you can examine stopped threads while other threads continue
3129 to execute freely. This is referred to as non-stop mode, with the
3130 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3131 section in the user manual for more information.
3133 To be able to support remote non-stop debugging, a remote stub needs
3134 to implement the non-stop mode remote protocol extensions, as
3135 described in the "Remote Non-Stop" section of the user manual. The
3136 GDB remote stub, gdbserver, has been adjusted to support these
3137 extensions on linux targets.
3139 * New commands (for set/show, see "New options" below)
3141 catch syscall [NAME(S) | NUMBER(S)]
3142 Catch system calls. Arguments, which should be names of system
3143 calls or their numbers, mean catch only those syscalls. Without
3144 arguments, every syscall will be caught. When the inferior issues
3145 any of the specified syscalls, GDB will stop and announce the system
3146 call, both when it is called and when its call returns. This
3147 feature is currently available with a native GDB running on the
3148 Linux Kernel, under the following architectures: x86, x86_64,
3149 PowerPC and PowerPC64.
3151 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3153 Search memory for a sequence of bytes.
3155 maint set python print-stack
3156 maint show python print-stack
3157 Show a stack trace when an error is encountered in a Python script.
3160 Invoke CODE by passing it to the Python interpreter.
3165 These allow macros to be defined, undefined, and listed
3169 Show operating system information about processes.
3172 List the inferiors currently under GDB's control.
3175 Switch focus to inferior number NUM.
3178 Detach from inferior number NUM.
3181 Kill inferior number NUM.
3185 set spu stop-on-load
3186 show spu stop-on-load
3187 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3189 set spu auto-flush-cache
3190 show spu auto-flush-cache
3191 Control whether to automatically flush the software-managed cache
3192 during Cell/B.E. debugging.
3194 set sh calling-convention
3195 show sh calling-convention
3196 Control the calling convention used when calling SH target functions.
3199 show debug timestamp
3200 Control display of timestamps with GDB debugging output.
3202 set disassemble-next-line
3203 show disassemble-next-line
3204 Control display of disassembled source lines or instructions when
3207 set remote noack-packet
3208 show remote noack-packet
3209 Set/show the use of remote protocol QStartNoAckMode packet. See above
3210 under "New remote packets."
3212 set remote query-attached-packet
3213 show remote query-attached-packet
3214 Control use of remote protocol `qAttached' (query-attached) packet.
3216 set remote read-siginfo-object
3217 show remote read-siginfo-object
3218 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3221 set remote write-siginfo-object
3222 show remote write-siginfo-object
3223 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3226 set remote reverse-continue
3227 show remote reverse-continue
3228 Control use of remote protocol 'bc' (reverse-continue) packet.
3230 set remote reverse-step
3231 show remote reverse-step
3232 Control use of remote protocol 'bs' (reverse-step) packet.
3234 set displaced-stepping
3235 show displaced-stepping
3236 Control displaced stepping mode. Displaced stepping is a way to
3237 single-step over breakpoints without removing them from the debuggee.
3238 Also known as "out-of-line single-stepping".
3241 show debug displaced
3242 Control display of debugging info for displaced stepping.
3244 maint set internal-error
3245 maint show internal-error
3246 Control what GDB does when an internal error is detected.
3248 maint set internal-warning
3249 maint show internal-warning
3250 Control what GDB does when an internal warning is detected.
3255 Use a wrapper program to launch programs for debugging.
3257 set multiple-symbols (all|ask|cancel)
3258 show multiple-symbols
3259 The value of this variable can be changed to adjust the debugger behavior
3260 when an expression or a breakpoint location contains an ambiguous symbol
3261 name (an overloaded function name, for instance).
3263 set breakpoint always-inserted
3264 show breakpoint always-inserted
3265 Keep breakpoints always inserted in the target, as opposed to inserting
3266 them when resuming the target, and removing them when the target stops.
3267 This option can improve debugger performance on slow remote targets.
3269 set arm fallback-mode (arm|thumb|auto)
3270 show arm fallback-mode
3271 set arm force-mode (arm|thumb|auto)
3273 These commands control how ARM GDB determines whether instructions
3274 are ARM or Thumb. The default for both settings is auto, which uses
3275 the current CPSR value for instructions without symbols; previous
3276 versions of GDB behaved as if "set arm fallback-mode arm".
3278 set disable-randomization
3279 show disable-randomization
3280 Standalone programs run with the virtual address space randomization enabled
3281 by default on some platforms. This option keeps the addresses stable across
3282 multiple debugging sessions.
3286 Control whether other threads are stopped or not when some thread hits
3291 Requests that asynchronous execution is enabled in the target, if available.
3292 In this case, it's possible to resume target in the background, and interact
3293 with GDB while the target is running. "show target-async" displays the
3294 current state of asynchronous execution of the target.
3296 set target-wide-charset
3297 show target-wide-charset
3298 The target-wide-charset is the name of the character set that GDB
3299 uses when printing characters whose type is wchar_t.
3301 set tcp auto-retry (on|off)
3303 set tcp connect-timeout
3304 show tcp connect-timeout
3305 These commands allow GDB to retry failed TCP connections to a remote stub
3306 with a specified timeout period; this is useful if the stub is launched
3307 in parallel with GDB but may not be ready to accept connections immediately.
3309 set libthread-db-search-path
3310 show libthread-db-search-path
3311 Control list of directories which GDB will search for appropriate
3314 set schedule-multiple (on|off)
3315 show schedule-multiple
3316 Allow GDB to resume all threads of all processes or only threads of
3317 the current process.
3321 Use more aggressive caching for accesses to the stack. This improves
3322 performance of remote debugging (particularly backtraces) without
3323 affecting correctness.
3325 set interactive-mode (on|off|auto)
3326 show interactive-mode
3327 Control whether GDB runs in interactive mode (on) or not (off).
3328 When in interactive mode, GDB waits for the user to answer all
3329 queries. Otherwise, GDB does not wait and assumes the default
3330 answer. When set to auto (the default), GDB determines which
3331 mode to use based on the stdin settings.
3336 For program forks, this is replaced by the new more generic `info
3337 inferiors' command. To list checkpoints, you can still use the
3338 `info checkpoints' command, which was an alias for the `info forks'
3342 Replaced by the new `inferior' command. To switch between
3343 checkpoints, you can still use the `restart' command, which was an
3344 alias for the `fork' command.
3347 This is removed, since some targets don't have a notion of
3348 processes. To switch between processes, you can still use the
3349 `inferior' command using GDB's own inferior number.
3352 For program forks, this is replaced by the new more generic `kill
3353 inferior' command. To delete a checkpoint, you can still use the
3354 `delete checkpoint' command, which was an alias for the `delete
3358 For program forks, this is replaced by the new more generic `detach
3359 inferior' command. To detach a checkpoint, you can still use the
3360 `detach checkpoint' command, which was an alias for the `detach
3363 * New native configurations
3365 x86/x86_64 Darwin i[34567]86-*-darwin*
3367 x86_64 MinGW x86_64-*-mingw*
3371 Lattice Mico32 lm32-*
3372 x86 DICOS i[34567]86-*-dicos*
3373 x86_64 DICOS x86_64-*-dicos*
3376 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3377 (mingw32ce) debugging.
3383 These commands were actually not implemented on any target.
3385 *** Changes in GDB 6.8
3387 * New native configurations
3389 NetBSD/hppa hppa*-*netbsd*
3390 Xtensa GNU/Linux xtensa*-*-linux*
3394 NetBSD/hppa hppa*-*-netbsd*
3395 Xtensa GNU/Lunux xtensa*-*-linux*
3397 * Change in command line behavior -- corefiles vs. process ids.
3399 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3400 attaching to process NUMBER fails, GDB no longer attempts to open a
3401 core file named NUMBER. Attaching to a program using the -c option
3402 is no longer supported. Instead, use the '-p' or '--pid' options.
3404 * GDB can now be built as a native debugger for debugging Windows x86
3405 (mingw32) Portable Executable (PE) programs.
3407 * Pending breakpoints no longer change their number when their address
3410 * GDB now supports breakpoints with multiple locations,
3411 including breakpoints on C++ constructors, inside C++ templates,
3412 and in inlined functions.
3414 * GDB's ability to debug optimized code has been improved. GDB more
3415 accurately identifies function bodies and lexical blocks that occupy
3416 more than one contiguous range of addresses.
3418 * Target descriptions can now describe registers for PowerPC.
3420 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3421 registers on PowerPC targets.
3423 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3424 targets even when the libthread_db library is not available.
3426 * The GDB remote stub, gdbserver, now supports the new file transfer
3427 commands (remote put, remote get, and remote delete).
3429 * The GDB remote stub, gdbserver, now supports run and attach in
3430 extended-remote mode.
3432 * hppa*64*-*-hpux11* target broken
3433 The debugger is unable to start a program and fails with the following
3434 error: "Error trying to get information about dynamic linker".
3435 The gdb-6.7 release is also affected.
3437 * GDB now supports the --enable-targets= configure option to allow
3438 building a single GDB executable that supports multiple remote
3439 target architectures.
3441 * GDB now supports debugging C and C++ programs which use the
3442 Decimal Floating Point extension. In addition, the PowerPC target
3443 now has a set of pseudo-registers to inspect decimal float values
3444 stored in two consecutive float registers.
3446 * The -break-insert MI command can optionally create pending
3449 * Improved support for debugging Ada
3450 Many improvements to the Ada language support have been made. These
3452 - Better support for Ada2005 interface types
3453 - Improved handling of arrays and slices in general
3454 - Better support for Taft-amendment types
3455 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3457 - Improved command completion in Ada
3460 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3465 set print frame-arguments (all|scalars|none)
3466 show print frame-arguments
3467 The value of this variable can be changed to control which argument
3468 values should be printed by the debugger when displaying a frame.
3473 Transfer files to and from a remote target, and delete remote files.
3480 Transfer files to and from a remote target, and delete remote files.
3482 * New remote packets
3489 Open, close, read, write, and delete files on the remote system.
3492 Attach to an existing process on the remote system, in extended-remote
3496 Run a new process on the remote system, in extended-remote mode.
3498 *** Changes in GDB 6.7
3500 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3501 bfd, libiberty and opcodes, as revealed by static analysis donated by
3502 Coverity, Inc. (http://scan.coverity.com).
3504 * When looking up multiply-defined global symbols, GDB will now prefer the
3505 symbol definition in the current shared library if it was built using the
3506 -Bsymbolic linker option.
3508 * When the Text User Interface (TUI) is not configured, GDB will now
3509 recognize the -tui command-line option and print a message that the TUI
3512 * The GDB remote stub, gdbserver, now has lower overhead for high
3513 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3515 * GDB for MIPS targets now autodetects whether a remote target provides
3516 32-bit or 64-bit register values.
3518 * Support for C++ member pointers has been improved.
3520 * GDB now understands XML target descriptions, which specify the
3521 target's overall architecture. GDB can read a description from
3522 a local file or over the remote serial protocol.
3524 * Vectors of single-byte data use a new integer type which is not
3525 automatically displayed as character or string data.
3527 * The /s format now works with the print command. It displays
3528 arrays of single-byte integers and pointers to single-byte integers
3531 * Target descriptions can now describe target-specific registers,
3532 for architectures which have implemented the support (currently
3533 only ARM, M68K, and MIPS).
3535 * GDB and the GDB remote stub, gdbserver, now support the XScale
3538 * The GDB remote stub, gdbserver, has been updated to support
3539 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3540 has been rewritten to use the standard GDB remote protocol.
3542 * GDB can now step into C++ functions which are called through thunks.
3544 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3546 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3547 layout. It also supports a TextSeg= and DataSeg= response when only
3548 segment base addresses (rather than offsets) are available.
3550 * The /i format now outputs any trailing branch delay slot instructions
3551 immediately following the last instruction within the count specified.
3553 * The GDB remote protocol "T" stop reply packet now supports a
3554 "library" response. Combined with the new "qXfer:libraries:read"
3555 packet, this response allows GDB to debug shared libraries on targets
3556 where the operating system manages the list of loaded libraries (e.g.
3557 Windows and SymbianOS).
3559 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3560 (DLLs) on Windows and Windows CE targets.
3562 * GDB now supports a faster verification that a .debug file matches its binary
3563 according to its build-id signature, if the signature is present.
3569 Enable or disable hardware flow control (RTS/CTS) on the serial port
3570 when debugging using remote targets.
3572 set mem inaccessible-by-default
3573 show mem inaccessible-by-default
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 prevents GDB from accessing memory outside the memory map. This
3577 is useful for targets with memory mapped registers or which react
3578 badly to accesses of unmapped address space.
3580 set breakpoint auto-hw
3581 show breakpoint auto-hw
3582 If the target supplies a memory map, for instance via the remote
3583 protocol's "qXfer:memory-map:read" packet, setting this variable
3584 lets GDB use hardware breakpoints automatically for memory regions
3585 where it can not use software breakpoints. This covers both the
3586 "break" command and internal breakpoints used for other commands
3587 including "next" and "finish".
3590 catch exception unhandled
3591 Stop the program execution when Ada exceptions are raised.
3594 Stop the program execution when an Ada assertion failed.
3598 Set an alternate system root for target files. This is a more
3599 general version of "set solib-absolute-prefix", which is now
3600 an alias to "set sysroot".
3603 Provide extended SPU facility status information. This set of
3604 commands is available only when debugging the Cell/B.E. SPU
3607 * New native configurations
3609 OpenBSD/sh sh*-*openbsd*
3612 unset tdesc filename
3614 Use the specified local file as an XML target description, and do
3615 not query the target for its built-in description.
3619 OpenBSD/sh sh*-*-openbsd*
3620 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3621 Toshiba Media Processor mep-elf
3623 * New remote packets
3626 Ignore the specified signals; pass them directly to the debugged program
3627 without stopping other threads or reporting them to GDB.
3629 qXfer:features:read:
3630 Read an XML target description from the target, which describes its
3635 Read or write contents of an spufs file on the target system. These
3636 packets are available only on the Cell/B.E. SPU architecture.
3638 qXfer:libraries:read:
3639 Report the loaded shared libraries. Combined with new "T" packet
3640 response, this packet allows GDB to debug shared libraries on
3641 targets where the operating system manages the list of loaded
3642 libraries (e.g. Windows and SymbianOS).
3646 Support for these obsolete configurations has been removed.
3654 i[34567]86-*-lynxos*
3655 i[34567]86-*-netware*
3656 i[34567]86-*-sco3.2v5*
3657 i[34567]86-*-sco3.2v4*
3659 i[34567]86-*-sysv4.2*
3662 i[34567]86-*-unixware2*
3663 i[34567]86-*-unixware*
3672 * Other removed features
3679 Various m68k-only ROM monitors.
3686 Various Renesas ROM monitors and debugging interfaces for SH and
3691 Support for a Macraigor serial interface to on-chip debugging.
3692 GDB does not directly support the newer parallel or USB
3697 A debug information format. The predecessor to DWARF 2 and
3698 DWARF 3, which are still supported.
3700 Support for the HP aCC compiler on HP-UX/PA-RISC
3702 SOM-encapsulated symbolic debugging information, automatic
3703 invocation of pxdb, and the aCC custom C++ ABI. This does not
3704 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3705 with aCC can still be debugged on an assembly level.
3707 MIPS ".pdr" sections
3709 A MIPS-specific format used to describe stack frame layout
3710 in debugging information.
3714 GDB could work with an older version of Guile to debug
3715 the interpreter and Scheme programs running in it.
3717 set mips stack-arg-size
3718 set mips saved-gpreg-size
3720 Use "set mips abi" to control parameter passing for MIPS.
3722 *** Changes in GDB 6.6
3727 Cell Broadband Engine SPU spu-elf
3729 * GDB can now be configured as a cross-debugger targeting native Windows
3730 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3731 running on a Windows system over TCP/IP to debug Windows programs.
3733 * The GDB remote stub, gdbserver, has been updated to support Windows and
3734 Cygwin debugging. Both single-threaded and multi-threaded programs are
3737 * The "set trust-readonly-sections" command works again. This command was
3738 broken in GDB 6.3, 6.4, and 6.5.
3740 * The "load" command now supports writing to flash memory, if the remote
3741 stub provides the required support.
3743 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3744 longer requires symbolic debug information (e.g. DWARF-2).
3749 unset substitute-path
3750 show substitute-path
3751 Manage a list of substitution rules that GDB uses to rewrite the name
3752 of the directories where the sources are located. This can be useful
3753 for instance when the sources were moved to a different location
3754 between compilation and debugging.
3758 Print each CLI command as it is executed. Each command is prefixed with
3759 a number of `+' symbols representing the nesting depth.
3760 The source command now has a `-v' option to enable the same feature.
3764 The ARM Demon monitor support (RDP protocol, "target rdp").
3766 Kernel Object Display, an embedded debugging feature which only worked with
3767 an obsolete version of Cisco IOS.
3769 The 'set download-write-size' and 'show download-write-size' commands.
3771 * New remote packets
3774 Tell a stub about GDB client features, and request remote target features.
3775 The first feature implemented is PacketSize, which allows the target to
3776 specify the size of packets it can handle - to minimize the number of
3777 packets required and improve performance when connected to a remote
3781 Fetch an OS auxilliary vector from the remote stub. This packet is a
3782 more efficient replacement for qPart:auxv:read.
3784 qXfer:memory-map:read:
3785 Fetch a memory map from the remote stub, including information about
3786 RAM, ROM, and flash memory devices.
3791 Erase and program a flash memory device.
3793 * Removed remote packets
3796 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3797 used it, and only gdbserver implemented it.
3799 *** Changes in GDB 6.5
3803 Renesas M32C/M16C m32c-elf
3805 Morpho Technologies ms1 ms1-elf
3809 init-if-undefined Initialize a convenience variable, but
3810 only if it doesn't already have a value.
3812 The following commands are presently only implemented for native GNU/Linux:
3814 checkpoint Save a snapshot of the program state.
3816 restart <n> Return the program state to a
3817 previously saved state.
3819 info checkpoints List currently saved checkpoints.
3821 delete-checkpoint <n> Delete a previously saved checkpoint.
3823 set|show detach-on-fork Tell gdb whether to detach from a newly
3824 forked process, or to keep debugging it.
3826 info forks List forks of the user program that
3827 are available to be debugged.
3829 fork <n> Switch to debugging one of several
3830 forks of the user program that are
3831 available to be debugged.
3833 delete-fork <n> Delete a fork from the list of forks
3834 that are available to be debugged (and
3835 kill the forked process).
3837 detach-fork <n> Delete a fork from the list of forks
3838 that are available to be debugged (and
3839 allow the process to continue).
3843 Morpho Technologies ms2 ms1-elf
3845 * Improved Windows host support
3847 GDB now builds as a cross debugger hosted on i686-mingw32, including
3848 native console support, and remote communications using either
3849 network sockets or serial ports.
3851 * Improved Modula-2 language support
3853 GDB can now print most types in the Modula-2 syntax. This includes:
3854 basic types, set types, record types, enumerated types, range types,
3855 pointer types and ARRAY types. Procedure var parameters are correctly
3856 printed and hexadecimal addresses and character constants are also
3857 written in the Modula-2 syntax. Best results can be obtained by using
3858 GNU Modula-2 together with the -gdwarf-2 command line option.
3862 The ARM rdi-share module.
3864 The Netware NLM debug server.
3866 *** Changes in GDB 6.4
3868 * New native configurations
3870 OpenBSD/arm arm*-*-openbsd*
3871 OpenBSD/mips64 mips64-*-openbsd*
3875 Morpho Technologies ms1 ms1-elf
3877 * New command line options
3879 --batch-silent As for --batch, but totally silent.
3880 --return-child-result The debugger will exist with the same value
3881 the child (debugged) program exited with.
3882 --eval-command COMMAND, -ex COMMAND
3883 Execute a single GDB CLI command. This may be
3884 specified multiple times and in conjunction
3885 with the --command (-x) option.
3887 * Deprecated commands removed
3889 The following commands, that were deprecated in 2000, have been
3893 set|show arm disassembly-flavor set|show arm disassembler
3894 othernames set arm disassembler
3895 set|show remotedebug set|show debug remote
3896 set|show archdebug set|show debug arch
3897 set|show eventdebug set|show debug event
3900 * New BSD user-level threads support
3902 It is now possible to debug programs using the user-level threads
3903 library on OpenBSD and FreeBSD. Currently supported (target)
3906 FreeBSD/amd64 x86_64-*-freebsd*
3907 FreeBSD/i386 i386-*-freebsd*
3908 OpenBSD/i386 i386-*-openbsd*
3910 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3911 are not yet supported.
3913 * New support for Matsushita MN10300 w/sim added
3914 (Work in progress). mn10300-elf.
3916 * REMOVED configurations and files
3918 VxWorks and the XDR protocol *-*-vxworks
3919 Motorola MCORE mcore-*-*
3920 National Semiconductor NS32000 ns32k-*-*
3922 * New "set print array-indexes" command
3924 After turning this setting "on", GDB prints the index of each element
3925 when displaying arrays. The default is "off" to preserve the previous
3928 * VAX floating point support
3930 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3932 * User-defined command support
3934 In addition to using $arg0..$arg9 for argument passing, it is now possible
3935 to use $argc to determine now many arguments have been passed. See the
3936 section on user-defined commands in the user manual for more information.
3938 *** Changes in GDB 6.3:
3940 * New command line option
3942 GDB now accepts -l followed by a number to set the timeout for remote
3945 * GDB works with GCC -feliminate-dwarf2-dups
3947 GDB now supports a more compact representation of DWARF-2 debug
3948 information using DW_FORM_ref_addr references. These are produced
3949 by GCC with the option -feliminate-dwarf2-dups and also by some
3950 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3951 to use -feliminate-dwarf2-dups.
3953 * Internationalization
3955 When supported by the host system, GDB will be built with
3956 internationalization (libintl). The task of marking up the sources is
3957 continued, we're looking forward to our first translation.
3961 Initial support for debugging programs compiled with the GNAT
3962 implementation of the Ada programming language has been integrated
3963 into GDB. In this release, support is limited to expression evaluation.
3965 * New native configurations
3967 GNU/Linux/m32r m32r-*-linux-gnu
3971 GDB's remote protocol now includes support for the 'p' packet. This
3972 packet is used to fetch individual registers from a remote inferior.
3974 * END-OF-LIFE registers[] compatibility module
3976 GDB's internal register infrastructure has been completely rewritten.
3977 The new infrastructure making possible the implementation of key new
3978 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3981 GDB 6.3 will be the last release to include the the registers[]
3982 compatibility module that allowed out-of-date configurations to
3983 continue to work. This change directly impacts the following
3993 powerpc bdm protocol
3995 Unless there is activity to revive these configurations, they will be
3996 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3998 * OBSOLETE configurations and files
4000 Configurations that have been declared obsolete in this release have
4001 been commented out. Unless there is activity to revive these
4002 configurations, the next release of GDB will have their sources
4003 permanently REMOVED.
4012 *** Changes in GDB 6.2.1:
4014 * MIPS `break main; run' gave an heuristic-fence-post warning
4016 When attempting to run even a simple program, a warning about
4017 heuristic-fence-post being hit would be reported. This problem has
4020 * MIPS IRIX 'long double' crashed GDB
4022 When examining a long double variable, GDB would get a segmentation
4023 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4024 IRIX long double values).
4028 A bug in the VAX stack code was causing problems with the "next"
4029 command. This problem has been fixed.
4031 *** Changes in GDB 6.2:
4033 * Fix for ``many threads''
4035 On GNU/Linux systems that use the NPTL threads library, a program
4036 rapidly creating and deleting threads would confuse GDB leading to the
4039 ptrace: No such process.
4040 thread_db_get_info: cannot get thread info: generic error
4042 This problem has been fixed.
4044 * "-async" and "-noasync" options removed.
4046 Support for the broken "-noasync" option has been removed (it caused
4049 * New ``start'' command.
4051 This command runs the program until the begining of the main procedure.
4053 * New BSD Kernel Data Access Library (libkvm) interface
4055 Using ``target kvm'' it is now possible to debug kernel core dumps and
4056 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4057 platforms. Currently supported (native-only) configurations are:
4059 FreeBSD/amd64 x86_64-*-freebsd*
4060 FreeBSD/i386 i?86-*-freebsd*
4061 NetBSD/i386 i?86-*-netbsd*
4062 NetBSD/m68k m68*-*-netbsd*
4063 NetBSD/sparc sparc-*-netbsd*
4064 OpenBSD/amd64 x86_64-*-openbsd*
4065 OpenBSD/i386 i?86-*-openbsd*
4066 OpenBSD/m68k m68*-openbsd*
4067 OpenBSD/sparc sparc-*-openbsd*
4069 * Signal trampoline code overhauled
4071 Many generic problems with GDB's signal handling code have been fixed.
4072 These include: backtraces through non-contiguous stacks; recognition
4073 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4074 call; backtrace through a signal trampoline; step into and out of
4075 signal handlers; and single-stepping in the signal trampoline.
4077 Please note that kernel bugs are a limiting factor here. These
4078 features have been shown to work on an s390 GNU/Linux system that
4079 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4081 * Cygwin support for DWARF 2 added.
4083 * New native configurations
4085 GNU/Linux/hppa hppa*-*-linux*
4086 OpenBSD/hppa hppa*-*-openbsd*
4087 OpenBSD/m68k m68*-*-openbsd*
4088 OpenBSD/m88k m88*-*-openbsd*
4089 OpenBSD/powerpc powerpc-*-openbsd*
4090 NetBSD/vax vax-*-netbsd*
4091 OpenBSD/vax vax-*-openbsd*
4093 * END-OF-LIFE frame compatibility module
4095 GDB's internal frame infrastructure has been completely rewritten.
4096 The new infrastructure making it possible to support key new features
4097 including DWARF 2 Call Frame Information. To aid in the task of
4098 migrating old configurations to this new infrastructure, a
4099 compatibility module, that allowed old configurations to continue to
4100 work, was also included.
4102 GDB 6.2 will be the last release to include this frame compatibility
4103 module. This change directly impacts the following configurations:
4113 Unless there is activity to revive these configurations, they will be
4114 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4116 * REMOVED configurations and files
4118 Sun 3, running SunOS 3 m68*-*-sunos3*
4119 Sun 3, running SunOS 4 m68*-*-sunos4*
4120 Sun 2, running SunOS 3 m68000-*-sunos3*
4121 Sun 2, running SunOS 4 m68000-*-sunos4*
4122 Motorola 680x0 running LynxOS m68*-*-lynxos*
4123 AT&T 3b1/Unix pc m68*-att-*
4124 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4125 decstation mips-dec-* mips-little-*
4126 riscos mips-*-riscos* mips-*-sysv*
4127 sonymips mips-sony-*
4128 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4130 *** Changes in GDB 6.1.1:
4132 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4134 The TUI (Text-mode User Interface) is now built as part of a default
4135 GDB configuration. It is enabled by either selecting the TUI with the
4136 command line option "-i=tui" or by running the separate "gdbtui"
4137 program. For more information on the TUI, see the manual "Debugging
4140 * Pending breakpoint support (also included in GDB 6.1)
4142 Support has been added to allow you to specify breakpoints in shared
4143 libraries that have not yet been loaded. If a breakpoint location
4144 cannot be found, and the "breakpoint pending" option is set to auto,
4145 GDB queries you if you wish to make the breakpoint pending on a future
4146 shared-library load. If and when GDB resolves the breakpoint symbol,
4147 the pending breakpoint is removed as one or more regular breakpoints
4150 Pending breakpoints are very useful for GCJ Java debugging.
4152 * Fixed ISO-C build problems
4154 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4155 non ISO-C code that stopped them being built using a more strict ISO-C
4156 compiler (e.g., IBM's C compiler).
4158 * Fixed build problem on IRIX 5
4160 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4161 wasn't able to compile compile on an IRIX 5 system.
4163 * Added execute permission to gdb/gdbserver/configure
4165 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4166 permission. This bug would cause configure to fail on a number of
4167 systems (Solaris, IRIX). Ref: server/519.
4169 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4171 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4172 has been updated to use constant array sizes.
4174 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4176 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4177 its generated DWARF Call Frame Info. This encoding was causing GDB to
4178 panic, that panic has been fixed. Ref: gdb/1628.
4180 * Fixed a problem when examining parameters in shared library code.
4182 When examining parameters in optimized shared library code generated
4183 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4184 not available''. GDB now correctly displays the variable's value.
4186 *** Changes in GDB 6.1:
4188 * Removed --with-mmalloc
4190 Support for the mmalloc memory manager has been removed, as it
4191 conflicted with the internal gdb byte cache.
4193 * Changes in AMD64 configurations
4195 The AMD64 target now includes the %cs and %ss registers. As a result
4196 the AMD64 remote protocol has changed; this affects the floating-point
4197 and SSE registers. If you rely on those registers for your debugging,
4198 you should upgrade gdbserver on the remote side.
4200 * Revised SPARC target
4202 The SPARC target has been completely revised, incorporating the
4203 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4204 support for LynxOS and SunOS 4 has been dropped. Calling functions
4205 from within GDB on operating systems with a non-executable stack
4206 (Solaris, OpenBSD) now works.
4210 GDB has a new C++ demangler which does a better job on the mangled
4211 names generated by current versions of g++. It also runs faster, so
4212 with this and other changes gdb should now start faster on large C++
4215 * DWARF 2 Location Expressions
4217 GDB support for location expressions has been extended to support function
4218 arguments and frame bases. Older versions of GDB could crash when they
4221 * C++ nested types and namespaces
4223 GDB's support for nested types and namespaces in C++ has been
4224 improved, especially if you use the DWARF 2 debugging format. (This
4225 is the default for recent versions of GCC on most platforms.)
4226 Specifically, if you have a class "Inner" defined within a class or
4227 namespace "Outer", then GDB realizes that the class's name is
4228 "Outer::Inner", not simply "Inner". This should greatly reduce the
4229 frequency of complaints about not finding RTTI symbols. In addition,
4230 if you are stopped at inside of a function defined within a namespace,
4231 GDB modifies its name lookup accordingly.
4233 * New native configurations
4235 NetBSD/amd64 x86_64-*-netbsd*
4236 OpenBSD/amd64 x86_64-*-openbsd*
4237 OpenBSD/alpha alpha*-*-openbsd*
4238 OpenBSD/sparc sparc-*-openbsd*
4239 OpenBSD/sparc64 sparc64-*-openbsd*
4241 * New debugging protocols
4243 M32R with SDI protocol m32r-*-elf*
4245 * "set prompt-escape-char" command deleted.
4247 The command "set prompt-escape-char" has been deleted. This command,
4248 and its very obscure effet on GDB's prompt, was never documented,
4249 tested, nor mentioned in the NEWS file.
4251 * OBSOLETE configurations and files
4253 Configurations that have been declared obsolete in this release have
4254 been commented out. Unless there is activity to revive these
4255 configurations, the next release of GDB will have their sources
4256 permanently REMOVED.
4258 Sun 3, running SunOS 3 m68*-*-sunos3*
4259 Sun 3, running SunOS 4 m68*-*-sunos4*
4260 Sun 2, running SunOS 3 m68000-*-sunos3*
4261 Sun 2, running SunOS 4 m68000-*-sunos4*
4262 Motorola 680x0 running LynxOS m68*-*-lynxos*
4263 AT&T 3b1/Unix pc m68*-att-*
4264 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4265 decstation mips-dec-* mips-little-*
4266 riscos mips-*-riscos* mips-*-sysv*
4267 sonymips mips-sony-*
4268 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4270 * REMOVED configurations and files
4272 SGI Irix-4.x mips-sgi-irix4 or iris4
4273 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4274 Z8000 simulator z8k-zilog-none or z8ksim
4275 Matsushita MN10200 w/simulator mn10200-*-*
4276 H8/500 simulator h8500-hitachi-hms or h8500hms
4277 HP/PA running BSD hppa*-*-bsd*
4278 HP/PA running OSF/1 hppa*-*-osf*
4279 HP/PA Pro target hppa*-*-pro*
4280 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4281 386BSD i[3456]86-*-bsd*
4282 Sequent family i[3456]86-sequent-sysv4*
4283 i[3456]86-sequent-sysv*
4284 i[3456]86-sequent-bsd*
4285 SPARC running LynxOS sparc-*-lynxos*
4286 SPARC running SunOS 4 sparc-*-sunos4*
4287 Tsqware Sparclet sparclet-*-*
4288 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4290 *** Changes in GDB 6.0:
4294 Support for debugging the Objective-C programming language has been
4295 integrated into GDB.
4297 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4299 DWARF 2's Call Frame Information makes available compiler generated
4300 information that more exactly describes the program's run-time stack.
4301 By using this information, GDB is able to provide more robust stack
4304 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4305 have been updated to use a new backtrace mechanism which includes
4306 DWARF 2 CFI support.
4310 GDB's remote protocol has been extended to include support for hosted
4311 file I/O (where the remote target uses GDB's file system). See GDB's
4312 remote protocol documentation for details.
4314 * All targets using the new architecture framework.
4316 All of GDB's targets have been updated to use the new internal
4317 architecture framework. The way is now open for future GDB releases
4318 to include cross-architecture native debugging support (i386 on amd64,
4321 * GNU/Linux's Thread Local Storage (TLS)
4323 GDB now includes support for for the GNU/Linux implementation of
4324 per-thread variables.
4326 * GNU/Linux's Native POSIX Thread Library (NPTL)
4328 GDB's thread code has been updated to work with either the new
4329 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4331 * Separate debug info.
4333 GDB, in conjunction with BINUTILS, now supports a mechanism for
4334 automatically loading debug information from a separate file. Instead
4335 of shipping full debug and non-debug versions of system libraries,
4336 system integrators can now instead ship just the stripped libraries
4337 and optional debug files.
4339 * DWARF 2 Location Expressions
4341 DWARF 2 Location Expressions allow the compiler to more completely
4342 describe the location of variables (even in optimized code) to the
4345 GDB now includes preliminary support for location expressions (support
4346 for DW_OP_piece is still missing).
4350 A number of long standing bugs that caused GDB to die while starting a
4351 Java application have been fixed. GDB's Java support is now
4352 considered "useable".
4354 * GNU/Linux support for fork, vfork, and exec.
4356 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4357 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4360 * GDB supports logging output to a file
4362 There are two new commands, "set logging" and "show logging", which can be
4363 used to capture GDB's output to a file.
4365 * The meaning of "detach" has changed for gdbserver
4367 The "detach" command will now resume the application, as documented. To
4368 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4371 * d10v, m68hc11 `regs' command deprecated
4373 The `info registers' command has been updated so that it displays the
4374 registers using a format identical to the old `regs' command.
4378 A new command, "maint set profile on/off", has been added. This command can
4379 be used to enable or disable profiling while running GDB, to profile a
4380 session or a set of commands. In addition there is a new configure switch,
4381 "--enable-profiling", which will cause GDB to be compiled with profiling
4382 data, for more informative profiling results.
4384 * Default MI syntax changed to "mi2".
4386 The default MI (machine interface) syntax, enabled by the command line
4387 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4388 "mi1", can be enabled by specifying the option "-i=mi1".
4390 Support for the original "mi0" syntax (included in GDB 5.0) has been
4393 Fix for gdb/192: removed extraneous space when displaying frame level.
4394 Fix for gdb/672: update changelist is now output in mi list format.
4395 Fix for gdb/702: a -var-assign that updates the value now shows up
4396 in a subsequent -var-update.
4398 * New native configurations.
4400 FreeBSD/amd64 x86_64-*-freebsd*
4402 * Multi-arched targets.
4404 HP/PA HPUX11 hppa*-*-hpux*
4405 Renesas M32R/D w/simulator m32r-*-elf*
4407 * OBSOLETE configurations and files
4409 Configurations that have been declared obsolete in this release have
4410 been commented out. Unless there is activity to revive these
4411 configurations, the next release of GDB will have their sources
4412 permanently REMOVED.
4414 Z8000 simulator z8k-zilog-none or z8ksim
4415 Matsushita MN10200 w/simulator mn10200-*-*
4416 H8/500 simulator h8500-hitachi-hms or h8500hms
4417 HP/PA running BSD hppa*-*-bsd*
4418 HP/PA running OSF/1 hppa*-*-osf*
4419 HP/PA Pro target hppa*-*-pro*
4420 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4421 Sequent family i[3456]86-sequent-sysv4*
4422 i[3456]86-sequent-sysv*
4423 i[3456]86-sequent-bsd*
4424 Tsqware Sparclet sparclet-*-*
4425 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4427 * REMOVED configurations and files
4430 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4431 IBM AIX PS/2 i[3456]86-*-aix
4432 i386 running Mach 3.0 i[3456]86-*-mach3*
4433 i386 running Mach i[3456]86-*-mach*
4434 i386 running OSF/1 i[3456]86-*osf1mk*
4435 HP/Apollo 68k Family m68*-apollo*-sysv*,
4437 m68*-hp-bsd*, m68*-hp-hpux*
4438 Argonaut Risc Chip (ARC) arc-*-*
4439 Mitsubishi D30V d30v-*-*
4440 Fujitsu FR30 fr30-*-elf*
4441 OS/9000 i[34]86-*-os9k
4442 I960 with MON960 i960-*-coff
4444 * MIPS $fp behavior changed
4446 The convenience variable $fp, for the MIPS, now consistently returns
4447 the address of the current frame's base. Previously, depending on the
4448 context, $fp could refer to either $sp or the current frame's base
4449 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4450 The GNU Source-Level Debugger''.
4452 *** Changes in GDB 5.3:
4454 * GNU/Linux shared library multi-threaded performance improved.
4456 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4457 `/proc', in preference to `ptrace' for memory reads. This may result
4458 in an improvement in the start-up time of multi-threaded, shared
4459 library applications when run under GDB. One GDB user writes: ``loads
4460 shared libs like mad''.
4462 * ``gdbserver'' now supports multi-threaded applications on some targets
4464 Support for debugging multi-threaded applications which use
4465 the GNU/Linux LinuxThreads package has been added for
4466 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4467 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4469 * GDB now supports C/C++ preprocessor macros.
4471 GDB now expands preprocessor macro invocations in C/C++ expressions,
4472 and provides various commands for showing macro definitions and how
4475 The new command `macro expand EXPRESSION' expands any macro
4476 invocations in expression, and shows the result.
4478 The new command `show macro MACRO-NAME' shows the definition of the
4479 macro named MACRO-NAME, and where it was defined.
4481 Most compilers don't include information about macros in the debugging
4482 information by default. In GCC 3.1, for example, you need to compile
4483 your program with the options `-gdwarf-2 -g3'. If the macro
4484 information is present in the executable, GDB will read it.
4486 * Multi-arched targets.
4488 DEC Alpha (partial) alpha*-*-*
4489 DEC VAX (partial) vax-*-*
4491 National Semiconductor NS32000 (partial) ns32k-*-*
4492 Motorola 68000 (partial) m68k-*-*
4493 Motorola MCORE mcore-*-*
4497 Fujitsu FRV architecture added by Red Hat frv*-*-*
4500 * New native configurations
4502 Alpha NetBSD alpha*-*-netbsd*
4503 SH NetBSD sh*-*-netbsdelf*
4504 MIPS NetBSD mips*-*-netbsd*
4505 UltraSPARC NetBSD sparc64-*-netbsd*
4507 * OBSOLETE configurations and files
4509 Configurations that have been declared obsolete in this release have
4510 been commented out. Unless there is activity to revive these
4511 configurations, the next release of GDB will have their sources
4512 permanently REMOVED.
4514 Mitsubishi D30V d30v-*-*
4515 OS/9000 i[34]86-*-os9k
4516 IBM AIX PS/2 i[3456]86-*-aix
4517 Fujitsu FR30 fr30-*-elf*
4518 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4519 Argonaut Risc Chip (ARC) arc-*-*
4520 i386 running Mach 3.0 i[3456]86-*-mach3*
4521 i386 running Mach i[3456]86-*-mach*
4522 i386 running OSF/1 i[3456]86-*osf1mk*
4523 HP/Apollo 68k Family m68*-apollo*-sysv*,
4525 m68*-hp-bsd*, m68*-hp-hpux*
4526 I960 with MON960 i960-*-coff
4528 * OBSOLETE languages
4530 CHILL, a Pascal like language used by telecommunications companies.
4532 * REMOVED configurations and files
4534 AMD 29k family via UDI a29k-amd-udi, udi29k
4535 A29K VxWorks a29k-*-vxworks
4536 AMD 29000 embedded, using EBMON a29k-none-none
4537 AMD 29000 embedded with COFF a29k-none-coff
4538 AMD 29000 embedded with a.out a29k-none-aout
4540 testsuite/gdb.hp/gdb.threads-hp/ directory
4542 * New command "set max-user-call-depth <nnn>"
4544 This command allows the user to limit the call depth of user-defined
4545 commands. The default is 1024.
4547 * Changes in FreeBSD/i386 native debugging.
4549 Support for the "generate-core-file" has been added.
4551 * New commands "dump", "append", and "restore".
4553 These commands allow data to be copied from target memory
4554 to a bfd-format or binary file (dump and append), and back
4555 from a file into memory (restore).
4557 * Improved "next/step" support on multi-processor Alpha Tru64.
4559 The previous single-step mechanism could cause unpredictable problems,
4560 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4561 of a software single-step mechanism prevents this.
4563 *** Changes in GDB 5.2.1:
4571 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4572 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4573 Fix, by Joel Brobecker imported from mainline.
4575 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4576 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4577 Fix, by Fred Fish, imported from mainline.
4579 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4580 Surprisingly enough, it works now.
4581 By Michal Ludvig, imported from mainline.
4583 i386 hardware watchpoint support:
4584 avoid misses on second run for some targets.
4585 By Pierre Muller, imported from mainline.
4587 *** Changes in GDB 5.2:
4589 * New command "set trust-readonly-sections on[off]".
4591 This command is a hint that tells gdb that read-only sections
4592 really are read-only (ie. that their contents will not change).
4593 In this mode, gdb will go to the object file rather than the
4594 target to read memory from read-only sections (such as ".text").
4595 This can be a significant performance improvement on some
4596 (notably embedded) targets.
4598 * New command "generate-core-file" (or "gcore").
4600 This new gdb command allows the user to drop a core file of the child
4601 process state at any time. So far it's been implemented only for
4602 GNU/Linux and Solaris, but should be relatively easily ported to other
4603 hosts. Argument is core file name (defaults to core.<pid>).
4605 * New command line option
4607 GDB now accepts --pid or -p followed by a process id.
4609 * Change in command line behavior -- corefiles vs. process ids.
4611 There is a subtle behavior in the way in which GDB handles
4612 command line arguments. The first non-flag argument is always
4613 a program to debug, but the second non-flag argument may either
4614 be a corefile or a process id. Previously, GDB would attempt to
4615 open the second argument as a corefile, and if that failed, would
4616 issue a superfluous error message and then attempt to attach it as
4617 a process. Now, if the second argument begins with a non-digit,
4618 it will be treated as a corefile. If it begins with a digit,
4619 GDB will attempt to attach it as a process, and if no such process
4620 is found, will then attempt to open it as a corefile.
4622 * Changes in ARM configurations.
4624 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4625 configuration is fully multi-arch.
4627 * New native configurations
4629 ARM NetBSD arm*-*-netbsd*
4630 x86 OpenBSD i[3456]86-*-openbsd*
4631 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4632 Sparc64 running FreeBSD sparc64-*-freebsd*
4636 Sanyo XStormy16 xstormy16-elf
4638 * OBSOLETE configurations and files
4640 Configurations that have been declared obsolete in this release have
4641 been commented out. Unless there is activity to revive these
4642 configurations, the next release of GDB will have their sources
4643 permanently REMOVED.
4645 AMD 29k family via UDI a29k-amd-udi, udi29k
4646 A29K VxWorks a29k-*-vxworks
4647 AMD 29000 embedded, using EBMON a29k-none-none
4648 AMD 29000 embedded with COFF a29k-none-coff
4649 AMD 29000 embedded with a.out a29k-none-aout
4651 testsuite/gdb.hp/gdb.threads-hp/ directory
4653 * REMOVED configurations and files
4655 TI TMS320C80 tic80-*-*
4657 PowerPC Solaris powerpcle-*-solaris*
4658 PowerPC Windows NT powerpcle-*-cygwin32
4659 PowerPC Netware powerpc-*-netware*
4660 Harris/CXUX m88k m88*-harris-cxux*
4661 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4662 ns32k-utek-sysv* ns32k-utek-*
4663 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4664 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4665 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4666 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4667 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4669 * Changes to command line processing
4671 The new `--args' feature can be used to specify command-line arguments
4672 for the inferior from gdb's command line.
4674 * Changes to key bindings
4676 There is a new `operate-and-get-next' function bound to `C-o'.
4678 *** Changes in GDB 5.1.1
4680 Fix compile problem on DJGPP.
4682 Fix a problem with floating-point registers on the i386 being
4685 Fix to stop GDB crashing on .debug_str debug info.
4687 Numerous documentation fixes.
4689 Numerous testsuite fixes.
4691 *** Changes in GDB 5.1:
4693 * New native configurations
4695 Alpha FreeBSD alpha*-*-freebsd*
4696 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4697 MIPS GNU/Linux mips*-*-linux*
4698 MIPS SGI Irix 6.x mips*-sgi-irix6*
4699 ia64 AIX ia64-*-aix*
4700 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4704 Motorola 68HC11 and 68HC12 m68hc11-elf
4706 UltraSparc running GNU/Linux sparc64-*-linux*
4708 * OBSOLETE configurations and files
4710 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4711 Harris/CXUX m88k m88*-harris-cxux*
4712 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4713 ns32k-utek-sysv* ns32k-utek-*
4714 TI TMS320C80 tic80-*-*
4716 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4717 PowerPC Solaris powerpcle-*-solaris*
4718 PowerPC Windows NT powerpcle-*-cygwin32
4719 PowerPC Netware powerpc-*-netware*
4720 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4721 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4722 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4723 Apple Macintosh (MPW) host N/A
4725 stuff.c (Program to stuff files into a specially prepared space in kdb)
4726 kdb-start.c (Main loop for the standalone kernel debugger)
4728 Configurations that have been declared obsolete in this release have
4729 been commented out. Unless there is activity to revive these
4730 configurations, the next release of GDB will have their sources
4731 permanently REMOVED.
4733 * REMOVED configurations and files
4735 Altos 3068 m68*-altos-*
4736 Convex c1-*-*, c2-*-*
4738 ARM RISCix arm-*-* (as host)
4742 * GDB has been converted to ISO C.
4744 GDB's source code has been converted to ISO C. In particular, the
4745 sources are fully protoized, and rely on standard headers being
4750 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4752 * The MI enabled by default.
4754 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4755 revised and enabled by default. Packages which use GDB as a debugging
4756 engine behind a UI or another front end are encouraged to switch to
4757 using the GDB/MI interface, instead of the old annotations interface
4758 which is now deprecated.
4760 * Support for debugging Pascal programs.
4762 GDB now includes support for debugging Pascal programs. The following
4763 main features are supported:
4765 - Pascal-specific data types such as sets;
4767 - automatic recognition of Pascal sources based on file-name
4770 - Pascal-style display of data types, variables, and functions;
4772 - a Pascal expression parser.
4774 However, some important features are not yet supported.
4776 - Pascal string operations are not supported at all;
4778 - there are some problems with boolean types;
4780 - Pascal type hexadecimal constants are not supported
4781 because they conflict with the internal variables format;
4783 - support for Pascal objects and classes is not full yet;
4785 - unlike Pascal, GDB is case-sensitive for symbol names.
4787 * Changes in completion.
4789 Commands such as `shell', `run' and `set args', which pass arguments
4790 to inferior programs, now complete on file names, similar to what
4791 users expect at the shell prompt.
4793 Commands which accept locations, such as `disassemble', `print',
4794 `breakpoint', `until', etc. now complete on filenames as well as
4795 program symbols. Thus, if you type "break foob TAB", and the source
4796 files linked into the programs include `foobar.c', that file name will
4797 be one of the candidates for completion. However, file names are not
4798 considered for completion after you typed a colon that delimits a file
4799 name from a name of a function in that file, as in "break foo.c:bar".
4801 `set demangle-style' completes on available demangling styles.
4803 * New platform-independent commands:
4805 It is now possible to define a post-hook for a command as well as a
4806 hook that runs before the command. For more details, see the
4807 documentation of `hookpost' in the GDB manual.
4809 * Changes in GNU/Linux native debugging.
4811 Support for debugging multi-threaded programs has been completely
4812 revised for all platforms except m68k and sparc. You can now debug as
4813 many threads as your system allows you to have.
4815 Attach/detach is supported for multi-threaded programs.
4817 Support for SSE registers was added for x86. This doesn't work for
4818 multi-threaded programs though.
4820 * Changes in MIPS configurations.
4822 Multi-arch support is enabled for all MIPS configurations.
4824 GDB can now be built as native debugger on SGI Irix 6.x systems for
4825 debugging n32 executables. (Debugging 64-bit executables is not yet
4828 * Unified support for hardware watchpoints in all x86 configurations.
4830 Most (if not all) native x86 configurations support hardware-assisted
4831 breakpoints and watchpoints in a unified manner. This support
4832 implements debug register sharing between watchpoints, which allows to
4833 put a virtually infinite number of watchpoints on the same address,
4834 and also supports watching regions up to 16 bytes with several debug
4837 The new maintenance command `maintenance show-debug-regs' toggles
4838 debugging print-outs in functions that insert, remove, and test
4839 watchpoints and hardware breakpoints.
4841 * Changes in the DJGPP native configuration.
4843 New command ``info dos sysinfo'' displays assorted information about
4844 the CPU, OS, memory, and DPMI server.
4846 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4847 display information about segment descriptors stored in GDT, LDT, and
4850 New commands ``info dos pde'' and ``info dos pte'' display entries
4851 from Page Directory and Page Tables (for now works with CWSDPMI only).
4852 New command ``info dos address-pte'' displays the Page Table entry for
4853 a given linear address.
4855 GDB can now pass command lines longer than 126 characters to the
4856 program being debugged (requires an update to the libdbg.a library
4857 which is part of the DJGPP development kit).
4859 DWARF2 debug info is now supported.
4861 It is now possible to `step' and `next' through calls to `longjmp'.
4863 * Changes in documentation.
4865 All GDB documentation was converted to GFDL, the GNU Free
4866 Documentation License.
4868 Tracepoints-related commands are now fully documented in the GDB
4871 TUI, the Text-mode User Interface, is now documented in the manual.
4873 Tracepoints-related commands are now fully documented in the GDB
4876 The "GDB Internals" manual now has an index. It also includes
4877 documentation of `ui_out' functions, GDB coding standards, x86
4878 hardware watchpoints, and memory region attributes.
4880 * GDB's version number moved to ``version.in''
4882 The Makefile variable VERSION has been replaced by the file
4883 ``version.in''. People creating GDB distributions should update the
4884 contents of this file.
4888 GUD support is now a standard part of the EMACS distribution.
4890 *** Changes in GDB 5.0:
4892 * Improved support for debugging FP programs on x86 targets
4894 Unified and much-improved support for debugging floating-point
4895 programs on all x86 targets. In particular, ``info float'' now
4896 displays the FP registers in the same format on all x86 targets, with
4897 greater level of detail.
4899 * Improvements and bugfixes in hardware-assisted watchpoints
4901 It is now possible to watch array elements, struct members, and
4902 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4903 on x86 targets no longer erroneously trigger when the address is
4906 * Improvements in the native DJGPP version of GDB
4908 The distribution now includes all the scripts and auxiliary files
4909 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4910 machines ``out of the box''.
4912 The DJGPP version can now debug programs that use signals. It is
4913 possible to catch signals that happened in the debuggee, deliver
4914 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4915 would kill the program being debugged.) Programs that hook hardware
4916 interrupts (keyboard, timer, etc.) can also be debugged.
4918 It is now possible to debug DJGPP programs that redirect their
4919 standard handles or switch them to raw (as opposed to cooked) mode, or
4920 even close them. The command ``run < foo > bar'' works as expected,
4921 and ``info terminal'' reports useful information about the debuggee's
4922 terminal, including raw/cooked mode, redirection, etc.
4924 The DJGPP version now uses termios functions for console I/O, which
4925 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4928 DOS-style file names with drive letters are now fully supported by
4931 It is now possible to debug DJGPP programs that switch their working
4932 directory. It is also possible to rerun the debuggee any number of
4933 times without restarting GDB; thus, you can use the same setup,
4934 breakpoints, etc. for many debugging sessions.
4936 * New native configurations
4938 ARM GNU/Linux arm*-*-linux*
4939 PowerPC GNU/Linux powerpc-*-linux*
4943 Motorola MCore mcore-*-*
4944 x86 VxWorks i[3456]86-*-vxworks*
4945 PowerPC VxWorks powerpc-*-vxworks*
4946 TI TMS320C80 tic80-*-*
4948 * OBSOLETE configurations
4950 Altos 3068 m68*-altos-*
4951 Convex c1-*-*, c2-*-*
4953 ARM RISCix arm-*-* (as host)
4956 Configurations that have been declared obsolete will be commented out,
4957 but the code will be left in place. If there is no activity to revive
4958 these configurations before the next release of GDB, the sources will
4959 be permanently REMOVED.
4961 * Gould support removed
4963 Support for the Gould PowerNode and NP1 has been removed.
4965 * New features for SVR4
4967 On SVR4 native platforms (such as Solaris), if you attach to a process
4968 without first loading a symbol file, GDB will now attempt to locate and
4969 load symbols from the running process's executable file.
4971 * Many C++ enhancements
4973 C++ support has been greatly improved. Overload resolution now works properly
4974 in almost all cases. RTTI support is on the way.
4976 * Remote targets can connect to a sub-program
4978 A popen(3) style serial-device has been added. This device starts a
4979 sub-process (such as a stand-alone simulator) and then communicates
4980 with that. The sub-program to run is specified using the syntax
4981 ``|<program> <args>'' vis:
4983 (gdb) set remotedebug 1
4984 (gdb) target extended-remote |mn10300-elf-sim program-args
4986 * MIPS 64 remote protocol
4988 A long standing bug in the mips64 remote protocol where by GDB
4989 expected certain 32 bit registers (ex SR) to be transfered as 32
4990 instead of 64 bits has been fixed.
4992 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4993 added to provide backward compatibility with older versions of GDB.
4995 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4997 The command ``set remotebinarydownload'' command has been replaced by
4998 ``set remote X-packet''. Other commands in ``set remote'' family
4999 include ``set remote P-packet''.
5001 * Breakpoint commands accept ranges.
5003 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5004 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5005 ``tracepoint passcount'' also accepts a range of tracepoints.
5007 * ``apropos'' command added.
5009 The ``apropos'' command searches through command names and
5010 documentation strings, printing out matches, making it much easier to
5011 try to find a command that does what you are looking for.
5015 A new machine oriented interface (MI) has been added to GDB. This
5016 interface is designed for debug environments running GDB as a separate
5017 process. This is part of the long term libGDB project. See the
5018 "GDB/MI" chapter of the GDB manual for further information. It can be
5019 enabled by configuring with:
5021 .../configure --enable-gdbmi
5023 *** Changes in GDB-4.18:
5025 * New native configurations
5027 HP-UX 10.20 hppa*-*-hpux10.20
5028 HP-UX 11.x hppa*-*-hpux11.0*
5029 M68K GNU/Linux m68*-*-linux*
5033 Fujitsu FR30 fr30-*-elf*
5034 Intel StrongARM strongarm-*-*
5035 Mitsubishi D30V d30v-*-*
5037 * OBSOLETE configurations
5039 Gould PowerNode, NP1 np1-*-*, pn-*-*
5041 Configurations that have been declared obsolete will be commented out,
5042 but the code will be left in place. If there is no activity to revive
5043 these configurations before the next release of GDB, the sources will
5044 be permanently REMOVED.
5048 As a compatibility experiment, GDB's source files buildsym.h and
5049 buildsym.c have been converted to pure standard C, no longer
5050 containing any K&R compatibility code. We believe that all systems in
5051 use today either come with a standard C compiler, or have a GCC port
5052 available. If this is not true, please report the affected
5053 configuration to bug-gdb@gnu.org immediately. See the README file for
5054 information about getting a standard C compiler if you don't have one
5059 GDB now uses readline 2.2.
5061 * set extension-language
5063 You can now control the mapping between filename extensions and source
5064 languages by using the `set extension-language' command. For instance,
5065 you can ask GDB to treat .c files as C++ by saying
5066 set extension-language .c c++
5067 The command `info extensions' lists all of the recognized extensions
5068 and their associated languages.
5070 * Setting processor type for PowerPC and RS/6000
5072 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5073 you can use the `set processor' command to specify what variant of the
5074 PowerPC family you are debugging. The command
5078 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5079 following PowerPC and RS6000 variants:
5081 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5082 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5084 403GC IBM PowerPC 403GC
5085 505 Motorola PowerPC 505
5086 860 Motorola PowerPC 860 or 850
5087 601 Motorola PowerPC 601
5088 602 Motorola PowerPC 602
5089 603 Motorola/IBM PowerPC 603 or 603e
5090 604 Motorola PowerPC 604 or 604e
5091 750 Motorola/IBM PowerPC 750 or 750
5093 At the moment, this command just tells GDB what to name the
5094 special-purpose processor registers. Since almost all the affected
5095 registers are inaccessible to user-level programs, this command is
5096 only useful for remote debugging in its present form.
5100 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5101 more extensive support for HP-UX. Added features include shared
5102 library support, kernel threads and hardware watchpoints for 11.00,
5103 support for HP's ANSI C and C++ compilers, and a compatibility mode
5104 for xdb and dbx commands.
5108 HP's donation includes the new concept of catchpoints, which is a
5109 generalization of the old catch command. On HP-UX, it is now possible
5110 to catch exec, fork, and vfork, as well as library loading.
5112 This means that the existing catch command has changed; its first
5113 argument now specifies the type of catch to be set up. See the
5114 output of "help catch" for a list of catchpoint types.
5116 * Debugging across forks
5118 On HP-UX, you can choose which process to debug when a fork() happens
5123 HP has donated a curses-based terminal user interface (TUI). To get
5124 it, build with --enable-tui. Although this can be enabled for any
5125 configuration, at present it only works for native HP debugging.
5127 * GDB remote protocol additions
5129 A new protocol packet 'X' that writes binary data is now available.
5130 Default behavior is to try 'X', then drop back to 'M' if the stub
5131 fails to respond. The settable variable `remotebinarydownload'
5132 allows explicit control over the use of 'X'.
5134 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5135 full 64-bit address. The command
5137 set remoteaddresssize 32
5139 can be used to revert to the old behaviour. For existing remote stubs
5140 the change should not be noticed, as the additional address information
5143 In order to assist in debugging stubs, you may use the maintenance
5144 command `packet' to send any text string to the stub. For instance,
5146 maint packet heythere
5148 sends the packet "$heythere#<checksum>". Note that it is very easy to
5149 disrupt a debugging session by sending the wrong packet at the wrong
5152 The compare-sections command allows you to compare section data on the
5153 target to what is in the executable file without uploading or
5154 downloading, by comparing CRC checksums.
5156 * Tracing can collect general expressions
5158 You may now collect general expressions at tracepoints. This requires
5159 further additions to the target-side stub; see tracepoint.c and
5160 doc/agentexpr.texi for further details.
5162 * mask-address variable for Mips
5164 For Mips targets, you may control the zeroing of the upper 32 bits of
5165 a 64-bit address by entering `set mask-address on'. This is mainly
5166 of interest to users of embedded R4xxx and R5xxx processors.
5168 * Higher serial baud rates
5170 GDB's serial code now allows you to specify baud rates 57600, 115200,
5171 230400, and 460800 baud. (Note that your host system may not be able
5172 to achieve all of these rates.)
5176 The i960 configuration now includes an initial implementation of a
5177 builtin simulator, contributed by Jim Wilson.
5180 *** Changes in GDB-4.17:
5182 * New native configurations
5184 Alpha GNU/Linux alpha*-*-linux*
5185 Unixware 2.x i[3456]86-unixware2*
5186 Irix 6.x mips*-sgi-irix6*
5187 PowerPC GNU/Linux powerpc-*-linux*
5188 PowerPC Solaris powerpcle-*-solaris*
5189 Sparc GNU/Linux sparc-*-linux*
5190 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5194 Argonaut Risc Chip (ARC) arc-*-*
5195 Hitachi H8/300S h8300*-*-*
5196 Matsushita MN10200 w/simulator mn10200-*-*
5197 Matsushita MN10300 w/simulator mn10300-*-*
5198 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5199 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5200 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5201 Mitsubishi D10V w/simulator d10v-*-*
5202 Mitsubishi M32R/D w/simulator m32r-*-elf*
5203 Tsqware Sparclet sparclet-*-*
5204 NEC V850 w/simulator v850-*-*
5206 * New debugging protocols
5208 ARM with RDI protocol arm*-*-*
5209 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5210 DDB and LSI variants of PMON protocol mips*-*-*
5211 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5212 PowerPC with SDS protocol powerpc{,le}-*-eabi
5213 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5217 All configurations can now understand and use the DWARF 2 debugging
5218 format. The choice is automatic, if the symbol file contains DWARF 2
5223 GDB now includes basic Java language support. This support is
5224 only useful with Java compilers that produce native machine code.
5226 * solib-absolute-prefix and solib-search-path
5228 For SunOS and SVR4 shared libraries, you may now set the prefix for
5229 loading absolute shared library symbol files, and the search path for
5230 locating non-absolute shared library symbol files.
5232 * Live range splitting
5234 GDB can now effectively debug code for which GCC has performed live
5235 range splitting as part of its optimization. See gdb/doc/LRS for
5236 more details on the expected format of the stabs information.
5240 GDB's support for the GNU Hurd, including thread debugging, has been
5241 updated to work with current versions of the Hurd.
5245 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5246 instruction set. ARM GDB automatically detects when Thumb
5247 instructions are in use, and adjusts disassembly and backtracing
5252 GDB's MIPS target configurations now handle the MIP16 16-bit
5257 GDB now includes support for overlays; if an executable has been
5258 linked such that multiple sections are based at the same address, GDB
5259 will decide which section to use for symbolic info. You can choose to
5260 control the decision manually, using overlay commands, or implement
5261 additional target-side support and use "overlay load-target" to bring
5262 in the overlay mapping. Do "help overlay" for more detail.
5266 The command "info symbol <address>" displays information about
5267 the symbol at the specified address.
5271 The standard remote protocol now includes an extension that allows
5272 asynchronous collection and display of trace data. This requires
5273 extensive support in the target-side debugging stub. Tracing mode
5274 includes a new interaction mode in GDB and new commands: see the
5275 file tracepoint.c for more details.
5279 Configurations for embedded MIPS now include a simulator contributed
5280 by Cygnus Solutions. The simulator supports the instruction sets
5281 of most MIPS variants.
5285 Sparc configurations may now include the ERC32 simulator contributed
5286 by the European Space Agency. The simulator is not built into
5287 Sparc targets by default; configure with --enable-sim to include it.
5291 For target configurations that may include multiple variants of a
5292 basic architecture (such as MIPS and SH), you may now set the
5293 architecture explicitly. "set arch" sets, "info arch" lists
5294 the possible architectures.
5296 *** Changes in GDB-4.16:
5298 * New native configurations
5300 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5301 M68K NetBSD m68k-*-netbsd*
5302 PowerPC AIX 4.x powerpc-*-aix*
5303 PowerPC MacOS powerpc-*-macos*
5304 PowerPC Windows NT powerpcle-*-cygwin32
5305 RS/6000 AIX 4.x rs6000-*-aix4*
5309 ARM with RDP protocol arm-*-*
5310 I960 with MON960 i960-*-coff
5311 MIPS VxWorks mips*-*-vxworks*
5312 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5313 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5315 Matra Sparclet sparclet-*-*
5319 The powerpc-eabi configuration now includes the PSIM simulator,
5320 contributed by Andrew Cagney, with assistance from Mike Meissner.
5321 PSIM is a very elaborate model of the PowerPC, including not only
5322 basic instruction set execution, but also details of execution unit
5323 performance and I/O hardware. See sim/ppc/README for more details.
5327 GDB now works with Solaris 2.5.
5329 * Windows 95/NT native
5331 GDB will now work as a native debugger on Windows 95 and Windows NT.
5332 To build it from source, you must use the "gnu-win32" environment,
5333 which uses a DLL to emulate enough of Unix to run the GNU tools.
5334 Further information, binaries, and sources are available at
5335 ftp.cygnus.com, under pub/gnu-win32.
5337 * dont-repeat command
5339 If a user-defined command includes the command `dont-repeat', then the
5340 command will not be repeated if the user just types return. This is
5341 useful if the command is time-consuming to run, so that accidental
5342 extra keystrokes don't run the same command many times.
5344 * Send break instead of ^C
5346 The standard remote protocol now includes an option to send a break
5347 rather than a ^C to the target in order to interrupt it. By default,
5348 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5350 * Remote protocol timeout
5352 The standard remote protocol includes a new variable `remotetimeout'
5353 that allows you to set the number of seconds before GDB gives up trying
5354 to read from the target. The default value is 2.
5356 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5358 By default GDB will automatically keep track of objects as they are
5359 loaded and unloaded by the dynamic linker. By using the command `set
5360 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5361 when shared library events occur, thus allowing you to set breakpoints
5362 in shared libraries which are explicitly loaded by the inferior.
5364 Note this feature does not work on hpux8. On hpux9 you must link
5365 /usr/lib/end.o into your program. This feature should work
5366 automatically on hpux10.
5368 * Irix 5.x hardware watchpoint support
5370 Irix 5 configurations now support the use of hardware watchpoints.
5372 * Mips protocol "SYN garbage limit"
5374 When debugging a Mips target using the `target mips' protocol, you
5375 may set the number of characters that GDB will ignore by setting
5376 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5377 every character. The default value is 1050.
5379 * Recording and replaying remote debug sessions
5381 If you set `remotelogfile' to the name of a file, gdb will write to it
5382 a recording of a remote debug session. This recording may then be
5383 replayed back to gdb using "gdbreplay". See gdbserver/README for
5384 details. This is useful when you have a problem with GDB while doing
5385 remote debugging; you can make a recording of the session and send it
5386 to someone else, who can then recreate the problem.
5388 * Speedups for remote debugging
5390 GDB includes speedups for downloading and stepping MIPS systems using
5391 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5392 and more efficient S-record downloading.
5394 * Memory use reductions and statistics collection
5396 GDB now uses less memory and reports statistics about memory usage.
5397 Try the `maint print statistics' command, for example.
5399 *** Changes in GDB-4.15:
5401 * Psymtabs for XCOFF
5403 The symbol reader for AIX GDB now uses partial symbol tables. This
5404 can greatly improve startup time, especially for large executables.
5406 * Remote targets use caching
5408 Remote targets now use a data cache to speed up communication with the
5409 remote side. The data cache could lead to incorrect results because
5410 it doesn't know about volatile variables, thus making it impossible to
5411 debug targets which use memory mapped I/O devices. `set remotecache
5412 off' turns the the data cache off.
5414 * Remote targets may have threads
5416 The standard remote protocol now includes support for multiple threads
5417 in the target system, using new protocol commands 'H' and 'T'. See
5418 gdb/remote.c for details.
5422 If GDB is configured with `--enable-netrom', then it will include
5423 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5424 acts as though it is a bank of ROM on the target board, but you can
5425 write into it over the network. GDB's support consists only of
5426 support for fast loading into the emulated ROM; to debug, you must use
5427 another protocol, such as standard remote protocol. The usual
5428 sequence is something like
5430 target nrom <netrom-hostname>
5432 target remote <netrom-hostname>:1235
5436 GDB now includes support for the Apple Macintosh, as a host only. It
5437 may be run as either an MPW tool or as a standalone application, and
5438 it can debug through the serial port. All the usual GDB commands are
5439 available, but to the target command, you must supply "serial" as the
5440 device type instead of "/dev/ttyXX". See mpw-README in the main
5441 directory for more information on how to build. The MPW configuration
5442 scripts */mpw-config.in support only a few targets, and only the
5443 mips-idt-ecoff target has been tested.
5447 GDB configuration now uses autoconf. This is not user-visible,
5448 but does simplify configuration and building.
5452 GDB now supports hpux10.
5454 *** Changes in GDB-4.14:
5456 * New native configurations
5458 x86 FreeBSD i[345]86-*-freebsd
5459 x86 NetBSD i[345]86-*-netbsd
5460 NS32k NetBSD ns32k-*-netbsd
5461 Sparc NetBSD sparc-*-netbsd
5465 A29K VxWorks a29k-*-vxworks
5466 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5467 CPU32 EST-300 emulator m68*-*-est*
5468 PowerPC ELF powerpc-*-elf
5471 * Alpha OSF/1 support for procfs
5473 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5474 possible to attach to running processes. As the mounting of the /proc
5475 filesystem is optional on the Alpha, GDB automatically determines
5476 the availability of /proc during startup. This can lead to problems
5477 if /proc is unmounted after GDB has been started.
5479 * Arguments to user-defined commands
5481 User commands may accept up to 10 arguments separated by whitespace.
5482 Arguments are accessed within the user command via $arg0..$arg9. A
5485 print $arg0 + $arg1 + $arg2
5487 To execute the command use:
5490 Defines the command "adder" which prints the sum of its three arguments.
5491 Note the arguments are text substitutions, so they may reference variables,
5492 use complex expressions, or even perform inferior function calls.
5494 * New `if' and `while' commands
5496 This makes it possible to write more sophisticated user-defined
5497 commands. Both commands take a single argument, which is the
5498 expression to evaluate, and must be followed by the commands to
5499 execute, one per line, if the expression is nonzero, the list being
5500 terminated by the word `end'. The `if' command list may include an
5501 `else' word, which causes the following commands to be executed only
5502 if the expression is zero.
5504 * Fortran source language mode
5506 GDB now includes partial support for Fortran 77. It will recognize
5507 Fortran programs and can evaluate a subset of Fortran expressions, but
5508 variables and functions may not be handled correctly. GDB will work
5509 with G77, but does not yet know much about symbols emitted by other
5512 * Better HPUX support
5514 Most debugging facilities now work on dynamic executables for HPPAs
5515 running hpux9 or later. You can attach to running dynamically linked
5516 processes, but by default the dynamic libraries will be read-only, so
5517 for instance you won't be able to put breakpoints in them. To change
5518 that behavior do the following before running the program:
5524 This will cause the libraries to be mapped private and read-write.
5525 To revert to the normal behavior, do this:
5531 You cannot set breakpoints or examine data in the library until after
5532 the library is loaded if the function/data symbols do not have
5535 GDB can now also read debug symbols produced by the HP C compiler on
5536 HPPAs (sorry, no C++, Fortran or 68k support).
5538 * Target byte order now dynamically selectable
5540 You can choose which byte order to use with a target system, via the
5541 commands "set endian big" and "set endian little", and you can see the
5542 current setting by using "show endian". You can also give the command
5543 "set endian auto", in which case GDB will use the byte order
5544 associated with the executable. Currently, only embedded MIPS
5545 configurations support dynamic selection of target byte order.
5547 * New DOS host serial code
5549 This version uses DPMI interrupts to handle buffered I/O, so you
5550 no longer need to run asynctsr when debugging boards connected to
5553 *** Changes in GDB-4.13:
5555 * New "complete" command
5557 This lists all the possible completions for the rest of the line, if it
5558 were to be given as a command itself. This is intended for use by emacs.
5560 * Trailing space optional in prompt
5562 "set prompt" no longer adds a space for you after the prompt you set. This
5563 allows you to set a prompt which ends in a space or one that does not.
5565 * Breakpoint hit counts
5567 "info break" now displays a count of the number of times the breakpoint
5568 has been hit. This is especially useful in conjunction with "ignore"; you
5569 can ignore a large number of breakpoint hits, look at the breakpoint info
5570 to see how many times the breakpoint was hit, then run again, ignoring one
5571 less than that number, and this will get you quickly to the last hit of
5574 * Ability to stop printing at NULL character
5576 "set print null-stop" will cause GDB to stop printing the characters of
5577 an array when the first NULL is encountered. This is useful when large
5578 arrays actually contain only short strings.
5580 * Shared library breakpoints
5582 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5583 breakpoints in shared libraries before the executable is run.
5585 * Hardware watchpoints
5587 There is a new hardware breakpoint for the watch command for sparclite
5588 targets. See gdb/sparclite/hw_breakpoint.note.
5590 Hardware watchpoints are also now supported under GNU/Linux.
5594 Annotations have been added. These are for use with graphical interfaces,
5595 and are still experimental. Currently only gdba.el uses these.
5597 * Improved Irix 5 support
5599 GDB now works properly with Irix 5.2.
5601 * Improved HPPA support
5603 GDB now works properly with the latest GCC and GAS.
5605 * New native configurations
5607 Sequent PTX4 i[34]86-sequent-ptx4
5608 HPPA running OSF/1 hppa*-*-osf*
5609 Atari TT running SVR4 m68*-*-sysv4*
5610 RS/6000 LynxOS rs6000-*-lynxos*
5614 OS/9000 i[34]86-*-os9k
5615 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5618 * Hitachi SH7000 and E7000-PC ICE support
5620 There is now support for communicating with the Hitachi E7000-PC ICE.
5621 This is available automatically when GDB is configured for the SH.
5625 As usual, a variety of small fixes and improvements, both generic
5626 and configuration-specific. See the ChangeLog for more detail.
5628 *** Changes in GDB-4.12:
5630 * Irix 5 is now supported
5634 GDB-4.12 on the HPPA has a number of changes which make it unable
5635 to debug the output from the currently released versions of GCC and
5636 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5637 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5638 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5641 *** Changes in GDB-4.11:
5643 * User visible changes:
5647 The "set remotedebug" option is now consistent between the mips remote
5648 target, remote targets using the gdb-specific protocol, UDI (AMD's
5649 debug protocol for the 29k) and the 88k bug monitor. It is now an
5650 integer specifying a debug level (normally 0 or 1, but 2 means more
5651 debugging info for the mips target).
5653 * DEC Alpha native support
5655 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5656 debug info, but GDB works fairly well with the DEC compiler and should
5657 work with a future GCC release. See the README file for a few
5658 Alpha-specific notes.
5660 * Preliminary thread implementation
5662 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5664 * LynxOS native and target support for 386
5666 This release has been hosted on LynxOS 2.2, and also can be configured
5667 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5670 * Improvements in C++ mangling/demangling.
5672 This release has much better g++ debugging, specifically in name
5673 mangling/demangling, virtual function calls, print virtual table,
5674 call methods, ...etc.
5676 *** Changes in GDB-4.10:
5678 * User visible changes:
5680 Remote debugging using the GDB-specific (`target remote') protocol now
5681 supports the `load' command. This is only useful if you have some
5682 other way of getting the stub to the target system, and you can put it
5683 somewhere in memory where it won't get clobbered by the download.
5685 Filename completion now works.
5687 When run under emacs mode, the "info line" command now causes the
5688 arrow to point to the line specified. Also, "info line" prints
5689 addresses in symbolic form (as well as hex).
5691 All vxworks based targets now support a user settable option, called
5692 vxworks-timeout. This option represents the number of seconds gdb
5693 should wait for responses to rpc's. You might want to use this if
5694 your vxworks target is, perhaps, a slow software simulator or happens
5695 to be on the far side of a thin network line.
5699 This release contains support for using a DEC alpha as a GDB host for
5700 cross debugging. Native alpha debugging is not supported yet.
5703 *** Changes in GDB-4.9:
5707 This is the first GDB release which is accompanied by a matching testsuite.
5708 The testsuite requires installation of dejagnu, which should be available
5709 via ftp from most sites that carry GNU software.
5713 'Cfront' style demangling has had its name changed to 'ARM' style, to
5714 emphasize that it was written from the specifications in the C++ Annotated
5715 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5716 disclaimers, it still generated too much confusion with users attempting to
5717 use gdb with AT&T cfront.
5721 GDB now uses a standard remote interface to a simulator library.
5722 So far, the library contains simulators for the Zilog Z8001/2, the
5723 Hitachi H8/300, H8/500 and Super-H.
5725 * New targets supported
5727 H8/300 simulator h8300-hitachi-hms or h8300hms
5728 H8/500 simulator h8500-hitachi-hms or h8500hms
5729 SH simulator sh-hitachi-hms or sh
5730 Z8000 simulator z8k-zilog-none or z8ksim
5731 IDT MIPS board over serial line mips-idt-ecoff
5733 Cross-debugging to GO32 targets is supported. It requires a custom
5734 version of the i386-stub.c module which is integrated with the
5735 GO32 memory extender.
5737 * New remote protocols
5739 MIPS remote debugging protocol.
5741 * New source languages supported
5743 This version includes preliminary support for Chill, a Pascal like language
5744 used by telecommunications companies. Chill support is also being integrated
5745 into the GNU compiler, but we don't know when it will be publically available.
5748 *** Changes in GDB-4.8:
5750 * HP Precision Architecture supported
5752 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5753 version of this support was available as a set of patches from the
5754 University of Utah. GDB does not support debugging of programs
5755 compiled with the HP compiler, because HP will not document their file
5756 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5757 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5759 Many problems in the preliminary version have been fixed.
5761 * Faster and better demangling
5763 We have improved template demangling and fixed numerous bugs in the GNU style
5764 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5765 character types (wchar_t) are now supported. Demangling of each symbol is now
5766 only done once, and is cached when the symbol table for a file is read in.
5767 This results in a small increase in memory usage for C programs, a moderate
5768 increase in memory usage for C++ programs, and a fantastic speedup in
5771 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5772 from the specifications in the Annotated Reference Manual, which AT&T's
5773 compiler does not actually implement.
5775 * G++ multiple inheritance compiler problem
5777 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5778 inheritance lattices was reworked to properly discover ambiguities. We
5779 recently found an example which causes this new algorithm to fail in a
5780 very subtle way, producing bad debug information for those classes.
5781 The file 'gcc.patch' (in this directory) can be applied to gcc to
5782 circumvent the problem. A future GCC release will contain a complete
5785 The previous G++ debug info problem (mentioned below for the gdb-4.7
5786 release) is fixed in gcc version 2.3.2.
5788 * Improved configure script
5790 The `configure' script will now attempt to guess your system type if
5791 you don't supply a host system type. The old scheme of supplying a
5792 host system triplet is preferable over using this. All the magic is
5793 done in the new `config.guess' script. Examine it for details.
5795 We have also brought our configure script much more in line with the FSF's
5796 version. It now supports the --with-xxx options. In particular,
5797 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5798 The resulting GDB will not be able to read arbitrary object file formats --
5799 only the format ``expected'' to be used on the configured target system.
5800 We hope to make this the default in a future release.
5802 * Documentation improvements
5804 There's new internal documentation on how to modify GDB, and how to
5805 produce clean changes to the code. We implore people to read it
5806 before submitting changes.
5808 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5809 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5810 `info' files are also provided. To build `info' files from scratch,
5811 you will need the latest `makeinfo' release, which will be available in
5812 a future texinfo-X.Y release.
5814 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5815 We're not sure exactly which versions have this problem, but it has
5816 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5817 or better. If that isn't possible, there is a patch in
5818 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5819 around this problem.
5823 GDB now supports array constants that can be used in expressions typed in by
5824 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5825 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5828 The new directory `gdb/sparclite' contains a program that demonstrates
5829 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5831 * New native hosts supported
5833 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5834 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5836 * New targets supported
5838 AMD 29k family via UDI a29k-amd-udi or udi29k
5840 * New file formats supported
5842 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5843 HPUX core files, and SCO 3.2v2 core files.
5847 Attaching to processes now works again; thanks for the many bug reports.
5849 We have also stomped on a bunch of core dumps caused by
5850 printf_filtered("%s") problems.
5852 We eliminated a copyright problem on the rpc and ptrace header files
5853 for VxWorks, which was discovered at the last minute during the 4.7
5854 release. You should now be able to build a VxWorks GDB.
5856 You can now interrupt gdb while an attached process is running. This
5857 will cause the attached process to stop, and give control back to GDB.
5859 We fixed problems caused by using too many file descriptors
5860 for reading symbols from object files and libraries. This was
5861 especially a problem for programs that used many (~100) shared
5864 The `step' command now only enters a subroutine if there is line number
5865 information for the subroutine. Otherwise it acts like the `next'
5866 command. Previously, `step' would enter subroutines if there was
5867 any debugging information about the routine. This avoids problems
5868 when using `cc -g1' on MIPS machines.
5870 * Internal improvements
5872 GDB's internal interfaces have been improved to make it easier to support
5873 debugging of multiple languages in the future.
5875 GDB now uses a common structure for symbol information internally.
5876 Minimal symbols (derived from linkage symbols in object files), partial
5877 symbols (from a quick scan of debug information), and full symbols
5878 contain a common subset of information, making it easier to write
5879 shared code that handles any of them.
5881 * New command line options
5883 We now accept --silent as an alias for --quiet.
5887 The memory-mapped-malloc library is now licensed under the GNU Library
5888 General Public License.
5890 *** Changes in GDB-4.7:
5892 * Host/native/target split
5894 GDB has had some major internal surgery to untangle the support for
5895 hosts and remote targets. Now, when you configure GDB for a remote
5896 target, it will no longer load in all of the support for debugging
5897 local programs on the host. When fully completed and tested, this will
5898 ensure that arbitrary host/target combinations are possible.
5900 The primary conceptual shift is to separate the non-portable code in
5901 GDB into three categories. Host specific code is required any time GDB
5902 is compiled on that host, regardless of the target. Target specific
5903 code relates to the peculiarities of the target, but can be compiled on
5904 any host. Native specific code is everything else: it can only be
5905 built when the host and target are the same system. Child process
5906 handling and core file support are two common `native' examples.
5908 GDB's use of /proc for controlling Unix child processes is now cleaner.
5909 It has been split out into a single module under the `target_ops' vector,
5910 plus two native-dependent functions for each system that uses /proc.
5912 * New hosts supported
5914 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5915 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5916 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5918 * New targets supported
5920 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5921 68030 and CPU32 m68030-*-*, m68332-*-*
5923 * New native hosts supported
5925 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5926 (386bsd is not well tested yet)
5927 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5929 * New file formats supported
5931 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5932 supports reading of `a.out.adobe' object files, which are an a.out
5933 format extended with minimal information about multiple sections.
5937 `show copying' is the same as the old `info copying'.
5938 `show warranty' is the same as `info warrantee'.
5939 These were renamed for consistency. The old commands continue to work.
5941 `info handle' is a new alias for `info signals'.
5943 You can now define pre-command hooks, which attach arbitrary command
5944 scripts to any command. The commands in the hook will be executed
5945 prior to the user's command. You can also create a hook which will be
5946 executed whenever the program stops. See gdb.texinfo.
5950 We now deal with Cfront style name mangling, and can even extract type
5951 info from mangled symbols. GDB can automatically figure out which
5952 symbol mangling style your C++ compiler uses.
5954 Calling of methods and virtual functions has been improved as well.
5958 The crash that occured when debugging Sun Ansi-C compiled binaries is
5959 fixed. This was due to mishandling of the extra N_SO stabs output
5962 We also finally got Ultrix 4.2 running in house, and fixed core file
5963 support, with help from a dozen people on the net.
5965 John M. Farrell discovered that the reason that single-stepping was so
5966 slow on all of the Mips based platforms (primarily SGI and DEC) was
5967 that we were trying to demangle and lookup a symbol used for internal
5968 purposes on every instruction that was being stepped through. Changing
5969 the name of that symbol so that it couldn't be mistaken for a C++
5970 mangled symbol sped things up a great deal.
5972 Rich Pixley sped up symbol lookups in general by getting much smarter
5973 about when C++ symbol mangling is necessary. This should make symbol
5974 completion (TAB on the command line) much faster. It's not as fast as
5975 we'd like, but it's significantly faster than gdb-4.6.
5979 A new user controllable variable 'call_scratch_address' can
5980 specify the location of a scratch area to be used when GDB
5981 calls a function in the target. This is necessary because the
5982 usual method of putting the scratch area on the stack does not work
5983 in systems that have separate instruction and data spaces.
5985 We integrated changes to support the 29k UDI (Universal Debugger
5986 Interface), but discovered at the last minute that we didn't have all
5987 of the appropriate copyright paperwork. We are working with AMD to
5988 resolve this, and hope to have it available soon.
5992 We have sped up the remote serial line protocol, especially for targets
5993 with lots of registers. It now supports a new `expedited status' ('T')
5994 message which can be used in place of the existing 'S' status message.
5995 This allows the remote stub to send only the registers that GDB
5996 needs to make a quick decision about single-stepping or conditional
5997 breakpoints, eliminating the need to fetch the entire register set for
5998 each instruction being stepped through.
6000 The GDB remote serial protocol now implements a write-through cache for
6001 registers, only re-reading the registers if the target has run.
6003 There is also a new remote serial stub for SPARC processors. You can
6004 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6005 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6006 processor with a serial port.
6010 Configure.in files have become much easier to read and modify. A new
6011 `table driven' format makes it more obvious what configurations are
6012 supported, and what files each one uses.
6016 There is a new opcodes library which will eventually contain all of the
6017 disassembly routines and opcode tables. At present, it only contains
6018 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6019 disassembler (binutils/objdump) to share these routines.
6021 The libiberty library is now copylefted under the GNU Library General
6022 Public License. This allows more liberal use, and was done so libg++
6023 can use it. This makes no difference to GDB, since the Library License
6024 grants all the rights from the General Public License.
6028 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6029 reference to the stabs symbol info used by the debugger. It is (as far
6030 as we know) the only published document on this fascinating topic. We
6031 encourage you to read it, compare it to the stabs information on your
6032 system, and send improvements on the document in general (to
6033 bug-gdb@prep.ai.mit.edu).
6035 And, of course, many bugs have been fixed.
6038 *** Changes in GDB-4.6:
6040 * Better support for C++ function names
6042 GDB now accepts as input the "demangled form" of C++ overloaded function
6043 names and member function names, and can do command completion on such names
6044 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6045 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6046 Make use of command completion, it is your friend.
6048 GDB also now accepts a variety of C++ mangled symbol formats. They are
6049 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6050 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6051 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6052 for the list of formats.
6054 * G++ symbol mangling problem
6056 Recent versions of gcc have a bug in how they emit debugging information for
6057 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6058 directory) can be applied to gcc to fix the problem. Alternatively, if you
6059 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6060 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6061 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6064 * New 'maintenance' command
6066 All of the commands related to hacking GDB internals have been moved out of
6067 the main command set, and now live behind the 'maintenance' command. This
6068 can also be abbreviated as 'mt'. The following changes were made:
6070 dump-me -> maintenance dump-me
6071 info all-breakpoints -> maintenance info breakpoints
6072 printmsyms -> maintenance print msyms
6073 printobjfiles -> maintenance print objfiles
6074 printpsyms -> maintenance print psymbols
6075 printsyms -> maintenance print symbols
6077 The following commands are new:
6079 maintenance demangle Call internal GDB demangler routine to
6080 demangle a C++ link name and prints the result.
6081 maintenance print type Print a type chain for a given symbol
6083 * Change to .gdbinit file processing
6085 We now read the $HOME/.gdbinit file before processing the argv arguments
6086 (e.g. reading symbol files or core files). This allows global parameters to
6087 be set, which will apply during the symbol reading. The ./.gdbinit is still
6088 read after argv processing.
6090 * New hosts supported
6092 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6094 GNU/Linux support i386-unknown-linux or linux
6096 We are also including code to support the HP/PA running BSD and HPUX. This
6097 is almost guaranteed not to work, as we didn't have time to test or build it
6098 for this release. We are including it so that the more adventurous (or
6099 masochistic) of you can play with it. We also had major problems with the
6100 fact that the compiler that we got from HP doesn't support the -g option.
6103 * New targets supported
6105 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6107 * More smarts about finding #include files
6109 GDB now remembers the compilation directory for all include files, and for
6110 all files from which C is generated (like yacc and lex sources). This
6111 greatly improves GDB's ability to find yacc/lex sources, and include files,
6112 especially if you are debugging your program from a directory different from
6113 the one that contains your sources.
6115 We also fixed a bug which caused difficulty with listing and setting
6116 breakpoints in include files which contain C code. (In the past, you had to
6117 try twice in order to list an include file that you hadn't looked at before.)
6119 * Interesting infernals change
6121 GDB now deals with arbitrary numbers of sections, where the symbols for each
6122 section must be relocated relative to that section's landing place in the
6123 target's address space. This work was needed to support ELF with embedded
6124 stabs used by Solaris-2.0.
6126 * Bug fixes (of course!)
6128 There have been loads of fixes for the following things:
6129 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6130 i960, stabs, DOS(GO32), procfs, etc...
6132 See the ChangeLog for details.
6134 *** Changes in GDB-4.5:
6136 * New machines supported (host and target)
6138 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6140 SGI Irix-4.x mips-sgi-irix4 or iris4
6142 * New malloc package
6144 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6145 Mmalloc is capable of handling mutiple heaps of memory. It is also
6146 capable of saving a heap to a file, and then mapping it back in later.
6147 This can be used to greatly speedup the startup of GDB by using a
6148 pre-parsed symbol table which lives in a mmalloc managed heap. For
6149 more details, please read mmalloc/mmalloc.texi.
6153 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6154 'help info proc' for details.
6156 * MIPS ecoff symbol table format
6158 The code that reads MIPS symbol table format is now supported on all hosts.
6159 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6162 * File name changes for MS-DOS
6164 Many files in the config directories have been renamed to make it easier to
6165 support GDB on MS-DOSe systems (which have very restrictive file name
6166 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6167 environment) is close to working but has some remaining problems. Note
6168 that debugging of DOS programs is not supported, due to limitations
6169 in the ``operating system'', but it can be used to host cross-debugging.
6171 * Cross byte order fixes
6173 Many fixes have been made to support cross debugging of Sparc and MIPS
6174 targets from hosts whose byte order differs.
6176 * New -mapped and -readnow options
6178 If memory-mapped files are available on your system through the 'mmap'
6179 system call, you can use the -mapped option on the `file' or
6180 `symbol-file' commands to cause GDB to write the symbols from your
6181 program into a reusable file. If the program you are debugging is
6182 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6183 Future GDB debugging sessions will notice the presence of this file,
6184 and will quickly map in symbol information from it, rather than reading
6185 the symbol table from the executable program. Using the '-mapped'
6186 option in a GDB `file' or `symbol-file' command has the same effect as
6187 starting GDB with the '-mapped' command-line option.
6189 You can cause GDB to read the entire symbol table immediately by using
6190 the '-readnow' option with any of the commands that load symbol table
6191 information (or on the GDB command line). This makes the command
6192 slower, but makes future operations faster.
6194 The -mapped and -readnow options are typically combined in order to
6195 build a `fred.syms' file that contains complete symbol information.
6196 A simple GDB invocation to do nothing but build a `.syms' file for future
6199 gdb -batch -nx -mapped -readnow programname
6201 The `.syms' file is specific to the host machine on which GDB is run.
6202 It holds an exact image of GDB's internal symbol table. It cannot be
6203 shared across multiple host platforms.
6205 * longjmp() handling
6207 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6208 siglongjmp() without losing control. This feature has not yet been ported to
6209 all systems. It currently works on many 386 platforms, all MIPS-based
6210 platforms (SGI, DECstation, etc), and Sun3/4.
6214 Preliminary work has been put in to support the new Solaris OS from Sun. At
6215 this time, it can control and debug processes, but it is not capable of
6220 As always, many many bug fixes. The major areas were with g++, and mipsread.
6221 People using the MIPS-based platforms should experience fewer mysterious
6222 crashes and trashed symbol tables.
6224 *** Changes in GDB-4.4:
6226 * New machines supported (host and target)
6228 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6230 BSD Reno on Vax vax-dec-bsd
6231 Ultrix on Vax vax-dec-ultrix
6233 * New machines supported (target)
6235 AMD 29000 embedded, using EBMON a29k-none-none
6239 GDB continues to improve its handling of C++. `References' work better.
6240 The demangler has also been improved, and now deals with symbols mangled as
6241 per the Annotated C++ Reference Guide.
6243 GDB also now handles `stabs' symbol information embedded in MIPS
6244 `ecoff' symbol tables. Since the ecoff format was not easily
6245 extensible to handle new languages such as C++, this appeared to be a
6246 good way to put C++ debugging info into MIPS binaries. This option
6247 will be supported in the GNU C compiler, version 2, when it is
6250 * New features for SVR4
6252 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6253 shared libraries. Debugging dynamically linked programs should present
6254 only minor differences from debugging statically linked programs.
6256 The `info proc' command will print out information about any process
6257 on an SVR4 system (including the one you are debugging). At the moment,
6258 it prints the address mappings of the process.
6260 If you bring up GDB on another SVR4 system, please send mail to
6261 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6263 * Better dynamic linking support in SunOS
6265 Reading symbols from shared libraries which contain debugging symbols
6266 now works properly. However, there remain issues such as automatic
6267 skipping of `transfer vector' code during function calls, which
6268 make it harder to debug code in a shared library, than to debug the
6269 same code linked statically.
6273 GDB is now using the latest `getopt' routines from the FSF. This
6274 version accepts the -- prefix for options with long names. GDB will
6275 continue to accept the old forms (-option and +option) as well.
6276 Various single letter abbreviations for options have been explicity
6277 added to the option table so that they won't get overshadowed in the
6278 future by other options that begin with the same letter.
6282 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6283 Many assorted bugs have been handled. Many more remain to be handled.
6284 See the various ChangeLog files (primarily in gdb and bfd) for details.
6287 *** Changes in GDB-4.3:
6289 * New machines supported (host and target)
6291 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6292 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6293 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6295 * Almost SCO Unix support
6297 We had hoped to support:
6298 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6299 (except for core file support), but we discovered very late in the release
6300 that it has problems with process groups that render gdb unusable. Sorry
6301 about that. I encourage people to fix it and post the fixes.
6303 * Preliminary ELF and DWARF support
6305 GDB can read ELF object files on System V Release 4, and can handle
6306 debugging records for C, in DWARF format, in ELF files. This support
6307 is preliminary. If you bring up GDB on another SVR4 system, please
6308 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6313 GDB now uses the latest `readline' library. One user-visible change
6314 is that two tabs will list possible command completions, which previously
6315 required typing M-? (meta-question mark, or ESC ?).
6319 The `stepi' bug that many of you noticed has been squashed.
6320 Many bugs in C++ have been handled. Many more remain to be handled.
6321 See the various ChangeLog files (primarily in gdb and bfd) for details.
6323 * State of the MIPS world (in case you wondered):
6325 GDB can understand the symbol tables emitted by the compilers
6326 supplied by most vendors of MIPS-based machines, including DEC. These
6327 symbol tables are in a format that essentially nobody else uses.
6329 Some versions of gcc come with an assembler post-processor called
6330 mips-tfile. This program is required if you want to do source-level
6331 debugging of gcc-compiled programs. I believe FSF does not ship
6332 mips-tfile with gcc version 1, but it will eventually come with gcc
6335 Debugging of g++ output remains a problem. g++ version 1.xx does not
6336 really support it at all. (If you're lucky, you should be able to get
6337 line numbers and stack traces to work, but no parameters or local
6338 variables.) With some work it should be possible to improve the
6341 When gcc version 2 is released, you will have somewhat better luck.
6342 However, even then you will get confusing results for inheritance and
6345 We will eventually provide full debugging of g++ output on
6346 DECstations. This will probably involve some kind of stabs-in-ecoff
6347 encapulation, but the details have not been worked out yet.
6350 *** Changes in GDB-4.2:
6352 * Improved configuration
6354 Only one copy of `configure' exists now, and it is not self-modifying.
6355 Porting BFD is simpler.
6359 The `step' and `next' commands now only stop at the first instruction
6360 of a source line. This prevents the multiple stops that used to occur
6361 in switch statements, for-loops, etc. `Step' continues to stop if a
6362 function that has debugging information is called within the line.
6366 Lots of small bugs fixed. More remain.
6368 * New host supported (not target)
6370 Intel 386 PC clone running Mach i386-none-mach
6373 *** Changes in GDB-4.1:
6375 * Multiple source language support
6377 GDB now has internal scaffolding to handle several source languages.
6378 It determines the type of each source file from its filename extension,
6379 and will switch expression parsing and number formatting to match the
6380 language of the function in the currently selected stack frame.
6381 You can also specifically set the language to be used, with
6382 `set language c' or `set language modula-2'.
6386 GDB now has preliminary support for the GNU Modula-2 compiler,
6387 currently under development at the State University of New York at
6388 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6389 continue through the fall of 1991 and into 1992.
6391 Other Modula-2 compilers are currently not supported, and attempting to
6392 debug programs compiled with them will likely result in an error as the
6393 symbol table is read. Feel free to work on it, though!
6395 There are hooks in GDB for strict type checking and range checking,
6396 in the `Modula-2 philosophy', but they do not currently work.
6400 GDB can now write to executable and core files (e.g. patch
6401 a variable's value). You must turn this switch on, specify
6402 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6403 by assigning a new value to a variable. Modifications take
6406 * Automatic SunOS shared library reading
6408 When you run your program, GDB automatically determines where its
6409 shared libraries (if any) have been loaded, and reads their symbols.
6410 The `share' command is no longer needed. This also works when
6411 examining core files.
6415 You can specify the number of lines that the `list' command shows.
6418 * New machines supported (host and target)
6420 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6421 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6422 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6424 * New hosts supported (not targets)
6426 IBM RT/PC: romp-ibm-aix or rtpc
6428 * New targets supported (not hosts)
6430 AMD 29000 embedded with COFF a29k-none-coff
6431 AMD 29000 embedded with a.out a29k-none-aout
6432 Ultracomputer remote kernel debug a29k-nyu-kern
6434 * New remote interfaces
6440 *** Changes in GDB-4.0:
6444 Wide output is wrapped at good places to make the output more readable.
6446 Gdb now supports cross-debugging from a host machine of one type to a
6447 target machine of another type. Communication with the target system
6448 is over serial lines. The ``target'' command handles connecting to the
6449 remote system; the ``load'' command will download a program into the
6450 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6451 also supports debugging of realtime processes running under VxWorks,
6452 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6453 stub on the target system.
6455 New CPUs supported include the AMD 29000 and Intel 960.
6457 GDB now reads object files and symbol tables via a ``binary file''
6458 library, which allows a single copy of GDB to debug programs of multiple
6459 object file types such as a.out and coff.
6461 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6462 refcard.dvi and refcard.ps are available to format it).
6465 * Control-Variable user interface simplified
6467 All variables that control the operation of the debugger can be set
6468 by the ``set'' command, and displayed by the ``show'' command.
6470 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6471 ``Show prompt'' produces the response:
6472 Gdb's prompt is new-gdb=>.
6474 What follows are the NEW set commands. The command ``help set'' will
6475 print a complete list of old and new set commands. ``help set FOO''
6476 will give a longer description of the variable FOO. ``show'' will show
6477 all of the variable descriptions and their current settings.
6479 confirm on/off: Enables warning questions for operations that are
6480 hard to recover from, e.g. rerunning the program while
6481 it is already running. Default is ON.
6483 editing on/off: Enables EMACS style command line editing
6484 of input. Previous lines can be recalled with
6485 control-P, the current line can be edited with control-B,
6486 you can search for commands with control-R, etc.
6489 history filename NAME: NAME is where the gdb command history
6490 will be stored. The default is .gdb_history,
6491 or the value of the environment variable
6494 history size N: The size, in commands, of the command history. The
6495 default is 256, or the value of the environment variable
6498 history save on/off: If this value is set to ON, the history file will
6499 be saved after exiting gdb. If set to OFF, the
6500 file will not be saved. The default is OFF.
6502 history expansion on/off: If this value is set to ON, then csh-like
6503 history expansion will be performed on
6504 command line input. The default is OFF.
6506 radix N: Sets the default radix for input and output. It can be set
6507 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6508 in the current radix, so "set radix 10" is always a no-op.
6510 height N: This integer value is the number of lines on a page. Default
6511 is 24, the current `stty rows'' setting, or the ``li#''
6512 setting from the termcap entry matching the environment
6515 width N: This integer value is the number of characters on a line.
6516 Default is 80, the current `stty cols'' setting, or the ``co#''
6517 setting from the termcap entry matching the environment
6520 Note: ``set screensize'' is obsolete. Use ``set height'' and
6521 ``set width'' instead.
6523 print address on/off: Print memory addresses in various command displays,
6524 such as stack traces and structure values. Gdb looks
6525 more ``symbolic'' if you turn this off; it looks more
6526 ``machine level'' with it on. Default is ON.
6528 print array on/off: Prettyprint arrays. New convenient format! Default
6531 print demangle on/off: Print C++ symbols in "source" form if on,
6534 print asm-demangle on/off: Same, for assembler level printouts
6537 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6540 * Support for Epoch Environment.
6542 The epoch environment is a version of Emacs v18 with windowing. One
6543 new command, ``inspect'', is identical to ``print'', except that if you
6544 are running in the epoch environment, the value is printed in its own
6548 * Support for Shared Libraries
6550 GDB can now debug programs and core files that use SunOS shared libraries.
6551 Symbols from a shared library cannot be referenced
6552 before the shared library has been linked with the program (this
6553 happens after you type ``run'' and before the function main() is entered).
6554 At any time after this linking (including when examining core files
6555 from dynamically linked programs), gdb reads the symbols from each
6556 shared library when you type the ``sharedlibrary'' command.
6557 It can be abbreviated ``share''.
6559 sharedlibrary REGEXP: Load shared object library symbols for files
6560 matching a unix regular expression. No argument
6561 indicates to load symbols for all shared libraries.
6563 info sharedlibrary: Status of loaded shared libraries.
6568 A watchpoint stops execution of a program whenever the value of an
6569 expression changes. Checking for this slows down execution
6570 tremendously whenever you are in the scope of the expression, but is
6571 quite useful for catching tough ``bit-spreader'' or pointer misuse
6572 problems. Some machines such as the 386 have hardware for doing this
6573 more quickly, and future versions of gdb will use this hardware.
6575 watch EXP: Set a watchpoint (breakpoint) for an expression.
6577 info watchpoints: Information about your watchpoints.
6579 delete N: Deletes watchpoint number N (same as breakpoints).
6580 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6581 enable N: Re-enables watchpoint number N (same as breakpoints).
6584 * C++ multiple inheritance
6586 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6589 * C++ exception handling
6591 Gdb now supports limited C++ exception handling. Besides the existing
6592 ability to breakpoint on an exception handler, gdb can breakpoint on
6593 the raising of an exception (before the stack is peeled back to the
6596 catch FOO: If there is a FOO exception handler in the dynamic scope,
6597 set a breakpoint to catch exceptions which may be raised there.
6598 Multiple exceptions (``catch foo bar baz'') may be caught.
6600 info catch: Lists all exceptions which may be caught in the
6601 current stack frame.
6604 * Minor command changes
6606 The command ``call func (arg, arg, ...)'' now acts like the print
6607 command, except it does not print or save a value if the function's result
6608 is void. This is similar to dbx usage.
6610 The ``up'' and ``down'' commands now always print the frame they end up
6611 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6612 frames without printing.
6614 * New directory command
6616 'dir' now adds directories to the FRONT of the source search path.
6617 The path starts off empty. Source files that contain debug information
6618 about the directory in which they were compiled can be found even
6619 with an empty path; Sun CC and GCC include this information. If GDB can't
6620 find your source file in the current directory, type "dir .".
6622 * Configuring GDB for compilation
6624 For normal use, type ``./configure host''. See README or gdb.texinfo
6627 GDB now handles cross debugging. If you are remotely debugging between
6628 two different machines, type ``./configure host -target=targ''.
6629 Host is the machine where GDB will run; targ is the machine
6630 where the program that you are debugging will run.