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
50 * Target descriptions can now describe registers for sparc32 and sparc64.
52 * New native configurations
54 FreeBSD/mips mips*-*-freebsd
59 Synopsys ARC arc*-*-elf32
60 FreeBSD/mips mips*-*-freebsd
65 Erases all the flash memory regions reported by the target.
70 Erases all the flash memory regions reported by the target. This is
71 equivalent to the CLI command flash-erase.
73 *** Changes in GDB 7.12
75 * GDB and GDBserver now build with a C++ compiler by default.
77 The --enable-build-with-cxx configure option is now enabled by
78 default. One must now explicitly configure with
79 --disable-build-with-cxx in order to build with a C compiler. This
80 option will be removed in a future release.
82 * GDBserver now supports recording btrace without maintaining an active
85 * GDB now supports a negative repeat count in the 'x' command to examine
86 memory backward from the given address. For example:
89 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
90 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
91 (gdb) x/-5i 0x0000000000400580
92 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
93 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
94 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
95 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
96 0x40057b <main(int, char**)+25>:
97 callq 0x400536 <Func1(int, char const*)>
99 * Fortran: Support structures with fields of dynamic types and
100 arrays of dynamic types.
102 * The symbol dumping maintenance commands have new syntax.
103 maint print symbols [-pc address] [--] [filename]
104 maint print symbols [-objfile objfile] [-source source] [--] [filename]
105 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
106 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
107 maint print msymbols [-objfile objfile] [--] [filename]
109 * GDB now supports multibit bitfields and enums in target register
112 * New Python-based convenience function $_as_string(val), which returns
113 the textual representation of a value. This function is especially
114 useful to obtain the text label of an enum value.
116 * Intel MPX bound violation handling.
118 Segmentation faults caused by a Intel MPX boundary violation
119 now display the kind of violation (upper or lower), the memory
120 address accessed and the memory bounds, along with the usual
121 signal received and code location.
125 Program received signal SIGSEGV, Segmentation fault
126 Upper bound violation while accessing address 0x7fffffffc3b3
127 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
128 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
130 * Rust language support.
131 GDB now supports debugging programs written in the Rust programming
132 language. See https://www.rust-lang.org/ for more information about
135 * Support for running interpreters on specified input/output devices
137 GDB now supports a new mechanism that allows frontends to provide
138 fully featured GDB console views, as a better alternative to
139 building such views on top of the "-interpreter-exec console"
140 command. See the new "new-ui" command below. With that command,
141 frontends can now start GDB in the traditional command-line mode
142 running in an embedded terminal emulator widget, and create a
143 separate MI interpreter running on a specified i/o device. In this
144 way, GDB handles line editing, history, tab completion, etc. in the
145 console all by itself, and the GUI uses the separate MI interpreter
146 for its own control and synchronization, invisible to the command
149 * The "catch syscall" command catches groups of related syscalls.
151 The "catch syscall" command now supports catching a group of related
152 syscalls using the 'group:' or 'g:' prefix.
157 skip -gfile file-glob-pattern
158 skip -function function
159 skip -rfunction regular-expression
160 A generalized form of the skip command, with new support for
161 glob-style file names and regular expressions for function names.
162 Additionally, a file spec and a function spec may now be combined.
164 maint info line-table REGEXP
165 Display the contents of GDB's internal line table data struture.
168 Run any GDB unit tests that were compiled in.
171 Start a new user interface instance running INTERP as interpreter,
172 using the TTY file for input/output.
176 ** gdb.Breakpoint objects have a new attribute "pending", which
177 indicates whether the breakpoint is pending.
178 ** Three new breakpoint-related events have been added:
179 gdb.breakpoint_created, gdb.breakpoint_modified, and
180 gdb.breakpoint_deleted.
183 Signal ("set") the given MS-Windows event object. This is used in
184 conjunction with the Windows JIT debugging (AeDebug) support, where
185 the OS suspends a crashing process until a debugger can attach to
186 it. Resuming the crashing process, in order to debug it, is done by
189 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
190 was added in GDBserver, including JIT compiling fast tracepoint's
191 conditional expression bytecode into native code.
193 * Support for various remote target protocols and ROM monitors has
196 target m32rsdi Remote M32R debugging over SDI
197 target mips MIPS remote debugging protocol
198 target pmon PMON ROM monitor
199 target ddb NEC's DDB variant of PMON for Vr4300
200 target rockhopper NEC RockHopper variant of PMON
201 target lsi LSI variant of PMO
203 * Support for tracepoints and fast tracepoints on powerpc-linux,
204 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
205 including JIT compiling fast tracepoint's conditional expression
206 bytecode into native code.
208 * MI async record =record-started now includes the method and format used for
209 recording. For example:
211 =record-started,thread-group="i1",method="btrace",format="bts"
213 * MI async record =thread-selected now includes the frame field. For example:
215 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
219 Andes NDS32 nds32*-*-elf
221 *** Changes in GDB 7.11
223 * GDB now supports debugging kernel-based threads on FreeBSD.
225 * Per-inferior thread numbers
227 Thread numbers are now per inferior instead of global. If you're
228 debugging multiple inferiors, GDB displays thread IDs using a
229 qualified INF_NUM.THR_NUM form. For example:
233 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
234 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
235 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
236 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
238 As consequence, thread numbers as visible in the $_thread
239 convenience variable and in Python's InferiorThread.num attribute
240 are no longer unique between inferiors.
242 GDB now maintains a second thread ID per thread, referred to as the
243 global thread ID, which is the new equivalent of thread numbers in
244 previous releases. See also $_gthread below.
246 For backwards compatibility, MI's thread IDs always refer to global
249 * Commands that accept thread IDs now accept the qualified
250 INF_NUM.THR_NUM form as well. For example:
253 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
256 * In commands that accept a list of thread IDs, you can now refer to
257 all threads of an inferior using a star wildcard. GDB accepts
258 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
259 refer to all threads of the current inferior. For example, "info
262 * You can use "info threads -gid" to display the global thread ID of
265 * The new convenience variable $_gthread holds the global number of
268 * The new convenience variable $_inferior holds the number of the
271 * GDB now displays the ID and name of the thread that hit a breakpoint
272 or received a signal, if your program is multi-threaded. For
275 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
276 Thread 1 "main" received signal SIGINT, Interrupt.
278 * Record btrace now supports non-stop mode.
280 * Support for tracepoints on aarch64-linux was added in GDBserver.
282 * The 'record instruction-history' command now indicates speculative execution
283 when using the Intel Processor Trace recording format.
285 * GDB now allows users to specify explicit locations, bypassing
286 the linespec parser. This feature is also available to GDB/MI
289 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
290 GDB now is able to debug both AArch64 applications and ARM applications
293 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
294 including JIT compiling fast tracepoint's conditional expression bytecode
297 * GDB now supports displaced stepping on AArch64 GNU/Linux.
299 * "info threads", "info inferiors", "info display", "info checkpoints"
300 and "maint info program-spaces" now list the corresponding items in
301 ascending ID order, for consistency with all other "info" commands.
303 * In Ada, the overloads selection menu has been enhanced to display the
304 parameter types and the return types for the matching overloaded subprograms.
308 maint set target-non-stop (on|off|auto)
309 maint show target-non-stop
310 Control whether GDB targets always operate in non-stop mode even if
311 "set non-stop" is "off". The default is "auto", meaning non-stop
312 mode is enabled if supported by the target.
314 maint set bfd-sharing
315 maint show bfd-sharing
316 Control the reuse of bfd objects.
320 Control display of debugging info regarding bfd caching.
324 Control display of debugging info regarding FreeBSD threads.
326 set remote multiprocess-extensions-packet
327 show remote multiprocess-extensions-packet
328 Set/show the use of the remote protocol multiprocess extensions.
330 set remote thread-events
331 show remote thread-events
332 Set/show the use of thread create/exit events.
334 set ada print-signatures on|off
335 show ada print-signatures"
336 Control whether parameter types and return types are displayed in overloads
337 selection menus. It is activaled (@code{on}) by default.
341 Controls the maximum size of memory, in bytes, that GDB will
342 allocate for value contents. Prevents incorrect programs from
343 causing GDB to allocate overly large buffers. Default is 64k.
345 * The "disassemble" command accepts a new modifier: /s.
346 It prints mixed source+disassembly like /m with two differences:
347 - disassembled instructions are now printed in program order, and
348 - and source for all relevant files is now printed.
349 The "/m" option is now considered deprecated: its "source-centric"
350 output hasn't proved useful in practice.
352 * The "record instruction-history" command accepts a new modifier: /s.
353 It behaves exactly like /m and prints mixed source+disassembly.
355 * The "set scheduler-locking" command supports a new mode "replay".
356 It behaves like "off" in record mode and like "on" in replay mode.
358 * Support for various ROM monitors has been removed:
360 target dbug dBUG ROM monitor for Motorola ColdFire
361 target picobug Motorola picobug monitor
362 target dink32 DINK32 ROM monitor for PowerPC
363 target m32r Renesas M32R/D ROM monitor
364 target mon2000 mon2000 ROM monitor
365 target ppcbug PPCBUG ROM monitor for PowerPC
367 * Support for reading/writing memory and extracting values on architectures
368 whose memory is addressable in units of any integral multiple of 8 bits.
373 Indicates that an exec system call was executed.
375 exec-events feature in qSupported
376 The qSupported packet allows GDB to request support for exec
377 events using the new 'gdbfeature' exec-event, and the qSupported
378 response can contain the corresponding 'stubfeature'. Set and
379 show commands can be used to display whether these features are enabled.
382 Equivalent to interrupting with the ^C character, but works in
385 thread created stop reason (T05 create:...)
386 Indicates that the thread was just created and is stopped at entry.
388 thread exit stop reply (w exitcode;tid)
389 Indicates that the thread has terminated.
392 Enables/disables thread create and exit event reporting. For
393 example, this is used in non-stop mode when GDB stops a set of
394 threads and synchronously waits for the their corresponding stop
395 replies. Without exit events, if one of the threads exits, GDB
396 would hang forever not knowing that it should no longer expect a
397 stop for that same thread.
400 Indicates that there are no resumed threads left in the target (all
401 threads are stopped). The remote stub reports support for this stop
402 reply to GDB's qSupported query.
405 Enables/disables catching syscalls from the inferior process.
406 The remote stub reports support for this packet to GDB's qSupported query.
408 syscall_entry stop reason
409 Indicates that a syscall was just called.
411 syscall_return stop reason
412 Indicates that a syscall just returned.
414 * Extended-remote exec events
416 ** GDB now has support for exec events on extended-remote Linux targets.
417 For such targets with Linux kernels 2.5.46 and later, this enables
418 follow-exec-mode and exec catchpoints.
420 set remote exec-event-feature-packet
421 show remote exec-event-feature-packet
422 Set/show the use of the remote exec event feature.
424 * Thread names in remote protocol
426 The reply to qXfer:threads:read may now include a name attribute for each
429 * Target remote mode fork and exec events
431 ** GDB now has support for fork and exec events on target remote mode
432 Linux targets. For such targets with Linux kernels 2.5.46 and later,
433 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
434 fork and exec catchpoints.
436 * Remote syscall events
438 ** GDB now has support for catch syscall on remote Linux targets,
439 currently enabled on x86/x86_64 architectures.
441 set remote catch-syscall-packet
442 show remote catch-syscall-packet
443 Set/show the use of the remote catch syscall feature.
447 ** The -var-set-format command now accepts the zero-hexadecimal
448 format. It outputs data in hexadecimal format with zero-padding on the
453 ** gdb.InferiorThread objects have a new attribute "global_num",
454 which refers to the thread's global thread ID. The existing
455 "num" attribute now refers to the thread's per-inferior number.
456 See "Per-inferior thread numbers" above.
457 ** gdb.InferiorThread objects have a new attribute "inferior", which
458 is the Inferior object the thread belongs to.
460 *** Changes in GDB 7.10
462 * Support for process record-replay and reverse debugging on aarch64*-linux*
463 targets has been added. GDB now supports recording of A64 instruction set
464 including advance SIMD instructions.
466 * Support for Sun's version of the "stabs" debug file format has been removed.
468 * GDB now honors the content of the file /proc/PID/coredump_filter
469 (PID is the process ID) on GNU/Linux systems. This file can be used
470 to specify the types of memory mappings that will be included in a
471 corefile. For more information, please refer to the manual page of
472 "core(5)". GDB also has a new command: "set use-coredump-filter
473 on|off". It allows to set whether GDB will read the content of the
474 /proc/PID/coredump_filter file when generating a corefile.
476 * The "info os" command on GNU/Linux can now display information on
478 "info os cpus" Listing of all cpus/cores on the system
480 * GDB has two new commands: "set serial parity odd|even|none" and
481 "show serial parity". These allows to set or show parity for the
484 * The "info source" command now displays the producer string if it was
485 present in the debug info. This typically includes the compiler version
486 and may include things like its command line arguments.
488 * The "info dll", an alias of the "info sharedlibrary" command,
489 is now available on all platforms.
491 * Directory names supplied to the "set sysroot" commands may be
492 prefixed with "target:" to tell GDB to access shared libraries from
493 the target system, be it local or remote. This replaces the prefix
494 "remote:". The default sysroot has been changed from "" to
495 "target:". "remote:" is automatically converted to "target:" for
496 backward compatibility.
498 * The system root specified by "set sysroot" will be prepended to the
499 filename of the main executable (if reported to GDB as absolute by
500 the operating system) when starting processes remotely, and when
501 attaching to already-running local or remote processes.
503 * GDB now supports automatic location and retrieval of executable
504 files from remote targets. Remote debugging can now be initiated
505 using only a "target remote" or "target extended-remote" command
506 (no "set sysroot" or "file" commands are required). See "New remote
509 * The "dump" command now supports verilog hex format.
511 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
513 * On GNU/Linux, GDB and gdbserver are now able to access executable
514 and shared library files without a "set sysroot" command when
515 attaching to processes running in different mount namespaces from
516 the debugger. This makes it possible to attach to processes in
517 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
518 See "New remote packets" below.
520 * The "tui reg" command now provides completion for all of the
521 available register groups, including target specific groups.
523 * The HISTSIZE environment variable is no longer read when determining
524 the size of GDB's command history. GDB now instead reads the dedicated
525 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
526 disables truncation of command history. Non-numeric values of GDBHISTSIZE
531 ** Memory ports can now be unbuffered.
535 ** gdb.Objfile objects have a new attribute "username",
536 which is the name of the objfile as specified by the user,
537 without, for example, resolving symlinks.
538 ** You can now write frame unwinders in Python.
539 ** gdb.Type objects have a new method "optimized_out",
540 returning optimized out gdb.Value instance of this type.
541 ** gdb.Value objects have new methods "reference_value" and
542 "const_value" which return a reference to the value and a
543 "const" version of the value respectively.
547 maint print symbol-cache
548 Print the contents of the symbol cache.
550 maint print symbol-cache-statistics
551 Print statistics of symbol cache usage.
553 maint flush-symbol-cache
554 Flush the contents of the symbol cache.
558 Start branch trace recording using Branch Trace Store (BTS) format.
561 Evaluate expression by using the compiler and print result.
565 Explicit commands for enabling and disabling tui mode.
568 set mpx bound on i386 and amd64
569 Support for bound table investigation on Intel MPX enabled applications.
573 Start branch trace recording using Intel Processor Trace format.
576 Print information about branch tracing internals.
578 maint btrace packet-history
579 Print the raw branch tracing data.
581 maint btrace clear-packet-history
582 Discard the stored raw branch tracing data.
585 Discard all branch tracing data. It will be fetched and processed
586 anew by the next "record" command.
591 Renamed from "set debug dwarf2-die".
593 Renamed from "show debug dwarf2-die".
596 Renamed from "set debug dwarf2-read".
597 show debug dwarf-read
598 Renamed from "show debug dwarf2-read".
600 maint set dwarf always-disassemble
601 Renamed from "maint set dwarf2 always-disassemble".
602 maint show dwarf always-disassemble
603 Renamed from "maint show dwarf2 always-disassemble".
605 maint set dwarf max-cache-age
606 Renamed from "maint set dwarf2 max-cache-age".
607 maint show dwarf max-cache-age
608 Renamed from "maint show dwarf2 max-cache-age".
611 show debug dwarf-line
612 Control display of debugging info regarding DWARF line processing.
616 Set the maximum number of candidates to be considered during
617 completion. The default value is 200. This limit allows GDB
618 to avoid generating large completion lists, the computation of
619 which can cause the debugger to become temporarily unresponsive.
621 set history remove-duplicates
622 show history remove-duplicates
623 Control the removal of duplicate history entries.
625 maint set symbol-cache-size
626 maint show symbol-cache-size
627 Control the size of the symbol cache.
629 set|show record btrace bts buffer-size
630 Set and show the size of the ring buffer used for branch tracing in
632 The obtained size may differ from the requested size. Use "info
633 record" to see the obtained buffer size.
635 set debug linux-namespaces
636 show debug linux-namespaces
637 Control display of debugging info regarding Linux namespaces.
639 set|show record btrace pt buffer-size
640 Set and show the size of the ring buffer used for branch tracing in
641 Intel Processor Trace format.
642 The obtained size may differ from the requested size. Use "info
643 record" to see the obtained buffer size.
645 maint set|show btrace pt skip-pad
646 Set and show whether PAD packets are skipped when computing the
649 * The command 'thread apply all' can now support new option '-ascending'
650 to call its specified command for all threads in ascending order.
652 * Python/Guile scripting
654 ** GDB now supports auto-loading of Python/Guile scripts contained in the
655 special section named `.debug_gdb_scripts'.
659 qXfer:btrace-conf:read
660 Return the branch trace configuration for the current thread.
662 Qbtrace-conf:bts:size
663 Set the requested ring buffer size for branch tracing in BTS format.
666 Enable Intel Procesor Trace-based branch tracing for the current
667 process. The remote stub reports support for this packet to GDB's
671 Set the requested ring buffer size for branch tracing in Intel Processor
675 Indicates a memory breakpoint instruction was executed, irrespective
676 of whether it was GDB that planted the breakpoint or the breakpoint
677 is hardcoded in the program. This is required for correct non-stop
681 Indicates the target stopped for a hardware breakpoint. This is
682 required for correct non-stop mode operation.
685 Return information about files on the remote system.
688 Return the full absolute name of the file that was executed to
689 create a process running on the remote system.
692 Select the filesystem on which vFile: operations with filename
693 arguments will operate. This is required for GDB to be able to
694 access files on remote targets where the remote stub does not
695 share a common filesystem with the inferior(s).
698 Indicates that a fork system call was executed.
701 Indicates that a vfork system call was executed.
703 vforkdone stop reason
704 Indicates that a vfork child of the specified process has executed
705 an exec or exit, allowing the vfork parent to resume execution.
707 fork-events and vfork-events features in qSupported
708 The qSupported packet allows GDB to request support for fork and
709 vfork events using new 'gdbfeatures' fork-events and vfork-events,
710 and the qSupported response can contain the corresponding
711 'stubfeatures'. Set and show commands can be used to display
712 whether these features are enabled.
714 * Extended-remote fork events
716 ** GDB now has support for fork events on extended-remote Linux
717 targets. For targets with Linux kernels 2.5.60 and later, this
718 enables follow-fork-mode and detach-on-fork for both fork and
719 vfork, as well as fork and vfork catchpoints.
721 * The info record command now shows the recording format and the
722 branch tracing configuration for the current thread when using
723 the btrace record target.
724 For the BTS format, it shows the ring buffer size.
726 * GDB now has support for DTrace USDT (Userland Static Defined
727 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
729 * GDB now supports access to vector registers on S/390 GNU/Linux
732 * Removed command line options
734 -xdb HP-UX XDB compatibility mode.
736 * Removed targets and native configurations
738 HP/PA running HP-UX hppa*-*-hpux*
739 Itanium running HP-UX ia64-*-hpux*
741 * New configure options
744 This configure option allows the user to build GDB with support for
745 Intel Processor Trace (default: auto). This requires libipt.
747 --with-libipt-prefix=PATH
748 Specify the path to the version of libipt that GDB should use.
749 $PATH/include should contain the intel-pt.h header and
750 $PATH/lib should contain the libipt.so library.
752 *** Changes in GDB 7.9.1
756 ** Xmethods can now specify a result type.
758 *** Changes in GDB 7.9
760 * GDB now supports hardware watchpoints on x86 GNU Hurd.
764 ** You can now access frame registers from Python scripts.
765 ** New attribute 'producer' for gdb.Symtab objects.
766 ** gdb.Objfile objects have a new attribute "progspace",
767 which is the gdb.Progspace object of the containing program space.
768 ** gdb.Objfile objects have a new attribute "owner".
769 ** gdb.Objfile objects have a new attribute "build_id",
770 which is the build ID generated when the file was built.
771 ** gdb.Objfile objects have a new method "add_separate_debug_file".
772 ** A new event "gdb.clear_objfiles" has been added, triggered when
773 selecting a new file to debug.
774 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
775 ** New function gdb.lookup_objfile.
777 New events which are triggered when GDB modifies the state of the
780 ** gdb.events.inferior_call_pre: Function call is about to be made.
781 ** gdb.events.inferior_call_post: Function call has just been made.
782 ** gdb.events.memory_changed: A memory location has been altered.
783 ** gdb.events.register_changed: A register has been altered.
785 * New Python-based convenience functions:
787 ** $_caller_is(name [, number_of_frames])
788 ** $_caller_matches(regexp [, number_of_frames])
789 ** $_any_caller_is(name [, number_of_frames])
790 ** $_any_caller_matches(regexp [, number_of_frames])
792 * GDB now supports the compilation and injection of source code into
793 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
794 to compile the source code to object code, and if successful, inject
795 and execute that code within the current context of the inferior.
796 Currently the C language is supported. The commands used to
797 interface with this new feature are:
799 compile code [-raw|-r] [--] [source code]
800 compile file [-raw|-r] filename
804 demangle [-l language] [--] name
805 Demangle "name" in the specified language, or the current language
806 if elided. This command is renamed from the "maint demangle" command.
807 The latter is kept as a no-op to avoid "maint demangle" being interpreted
808 as "maint demangler-warning".
810 queue-signal signal-name-or-number
811 Queue a signal to be delivered to the thread when it is resumed.
813 add-auto-load-scripts-directory directory
814 Add entries to the list of directories from which to load auto-loaded
817 maint print user-registers
818 List all currently available "user" registers.
820 compile code [-r|-raw] [--] [source code]
821 Compile, inject, and execute in the inferior the executable object
822 code produced by compiling the provided source code.
824 compile file [-r|-raw] filename
825 Compile and inject into the inferior the executable object code
826 produced by compiling the source code stored in the filename
829 * On resume, GDB now always passes the signal the program had stopped
830 for to the thread the signal was sent to, even if the user changed
831 threads before resuming. Previously GDB would often (but not
832 always) deliver the signal to the thread that happens to be current
835 * Conversely, the "signal" command now consistently delivers the
836 requested signal to the current thread. GDB now asks for
837 confirmation if the program had stopped for a signal and the user
838 switched threads meanwhile.
840 * "breakpoint always-inserted" modes "off" and "auto" merged.
842 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
843 won't remove breakpoints from the target until all threads stop,
844 even in non-stop mode. The "auto" mode has been removed, and "off"
845 is now the default mode.
849 set debug symbol-lookup
850 show debug symbol-lookup
851 Control display of debugging info regarding symbol lookup.
855 ** The -list-thread-groups command outputs an exit-code field for
856 inferiors that have exited.
860 MIPS SDE mips*-sde*-elf*
864 Support for these obsolete configurations has been removed.
866 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
867 SGI Irix-5.x mips-*-irix5*
868 SGI Irix-6.x mips-*-irix6*
869 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
870 VAX running Ultrix vax-*-ultrix*
872 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
873 and "assf"), have been removed. Use the "sharedlibrary" command, or
874 its alias "share", instead.
876 *** Changes in GDB 7.8
878 * New command line options
881 This is an alias for the --data-directory option.
883 * GDB supports printing and modifying of variable length automatic arrays
884 as specified in ISO C99.
886 * The ARM simulator now supports instruction level tracing
887 with or without disassembly.
891 GDB now has support for scripting using Guile. Whether this is
892 available is determined at configure time.
893 Guile version 2.0 or greater is required.
894 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
896 * New commands (for set/show, see "New options" below)
900 Invoke CODE by passing it to the Guile interpreter.
904 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
906 info auto-load guile-scripts [regexp]
907 Print the list of automatically loaded Guile scripts.
909 * The source command is now capable of sourcing Guile scripts.
910 This feature is dependent on the debugger being built with Guile support.
914 set print symbol-loading (off|brief|full)
915 show print symbol-loading
916 Control whether to print informational messages when loading symbol
917 information for a file. The default is "full", but when debugging
918 programs with large numbers of shared libraries the amount of output
921 set guile print-stack (none|message|full)
922 show guile print-stack
923 Show a stack trace when an error is encountered in a Guile script.
925 set auto-load guile-scripts (on|off)
926 show auto-load guile-scripts
927 Control auto-loading of Guile script files.
929 maint ada set ignore-descriptive-types (on|off)
930 maint ada show ignore-descriptive-types
931 Control whether the debugger should ignore descriptive types in Ada
932 programs. The default is not to ignore the descriptive types. See
933 the user manual for more details on descriptive types and the intended
934 usage of this option.
936 set auto-connect-native-target
938 Control whether GDB is allowed to automatically connect to the
939 native target for the run, attach, etc. commands when not connected
940 to any target yet. See also "target native" below.
942 set record btrace replay-memory-access (read-only|read-write)
943 show record btrace replay-memory-access
944 Control what memory accesses are allowed during replay.
946 maint set target-async (on|off)
947 maint show target-async
948 This controls whether GDB targets operate in synchronous or
949 asynchronous mode. Normally the default is asynchronous, if it is
950 available; but this can be changed to more easily debug problems
951 occurring only in synchronous mode.
953 set mi-async (on|off)
955 Control whether MI asynchronous mode is preferred. This supersedes
956 "set target-async" of previous GDB versions.
958 * "set target-async" is deprecated as a CLI option and is now an alias
959 for "set mi-async" (only puts MI into async mode).
961 * Background execution commands (e.g., "c&", "s&", etc.) are now
962 possible ``out of the box'' if the target supports them. Previously
963 the user would need to explicitly enable the possibility with the
964 "set target-async on" command.
966 * New features in the GDB remote stub, GDBserver
968 ** New option --debug-format=option1[,option2,...] allows one to add
969 additional text to each output. At present only timestamps
970 are supported: --debug-format=timestamps.
971 Timestamps can also be turned on with the
972 "monitor set debug-format timestamps" command from GDB.
974 * The 'record instruction-history' command now starts counting instructions
975 at one. This also affects the instruction ranges reported by the
976 'record function-call-history' command when given the /i modifier.
978 * The command 'record function-call-history' supports a new modifier '/c' to
979 indent the function names based on their call stack depth.
980 The fields for the '/i' and '/l' modifier have been reordered.
981 The source line range is now prefixed with 'at'.
982 The instruction range is now prefixed with 'inst'.
983 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
984 "record instruction-history" and "list" commands.
986 * The ranges given as arguments to the 'record function-call-history' and
987 'record instruction-history' commands are now inclusive.
989 * The btrace record target now supports the 'record goto' command.
990 For locations inside the execution trace, the back trace is computed
991 based on the information stored in the execution trace.
993 * The btrace record target supports limited reverse execution and replay.
994 The target does not record data and therefore does not allow reading
997 * The "catch syscall" command now works on s390*-linux* targets.
999 * The "compare-sections" command is no longer specific to target
1000 remote. It now works with all targets.
1002 * All native targets are now consistently called "native".
1003 Consequently, the "target child", "target GNU", "target djgpp",
1004 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1005 commands have been replaced with "target native". The QNX/NTO port
1006 leaves the "procfs" target in place and adds a "native" target for
1007 consistency with other ports. The impact on users should be minimal
1008 as these commands previously either throwed an error, or were
1009 no-ops. The target's name is visible in the output of the following
1010 commands: "help target", "info target", "info files", "maint print
1013 * The "target native" command now connects to the native target. This
1014 can be used to launch native programs even when "set
1015 auto-connect-native-target" is set to off.
1017 * GDB now supports access to Intel MPX registers on GNU/Linux.
1019 * Support for Intel AVX-512 registers on GNU/Linux.
1020 Support displaying and modifying Intel AVX-512 registers
1021 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1023 * New remote packets
1025 qXfer:btrace:read's annex
1026 The qXfer:btrace:read packet supports a new annex 'delta' to read
1027 branch trace incrementally.
1031 ** Valid Python operations on gdb.Value objects representing
1032 structs/classes invoke the corresponding overloaded operators if
1034 ** New `Xmethods' feature in the Python API. Xmethods are
1035 additional methods or replacements for existing methods of a C++
1036 class. This feature is useful for those cases where a method
1037 defined in C++ source code could be inlined or optimized out by
1038 the compiler, making it unavailable to GDB.
1041 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1043 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1044 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1045 its alias "share", instead.
1047 * The commands "set remotebaud" and "show remotebaud" are no longer
1048 supported. Use "set serial baud" and "show serial baud" (respectively)
1053 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1054 target-async". The latter is left as a deprecated alias of the
1055 former for backward compatibility. If the target supports it,
1056 CLI background execution commands are now always possible by
1057 default, independently of whether the frontend stated a
1058 preference for asynchronous execution with "-gdb-set mi-async".
1059 Previously "-gdb-set target-async off" affected both MI execution
1060 commands and CLI execution commands.
1062 *** Changes in GDB 7.7
1064 * Improved support for process record-replay and reverse debugging on
1065 arm*-linux* targets. Support for thumb32 and syscall instruction
1066 recording has been added.
1068 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1070 * GDB now supports Fission DWP file format version 2.
1071 http://gcc.gnu.org/wiki/DebugFission
1073 * New convenience function "$_isvoid", to check whether an expression
1074 is void. A void expression is an expression where the type of the
1075 result is "void". For example, some convenience variables may be
1076 "void" when evaluated (e.g., "$_exitcode" before the execution of
1077 the program being debugged; or an undefined convenience variable).
1078 Another example, when calling a function whose return type is
1081 * The "maintenance print objfiles" command now takes an optional regexp.
1083 * The "catch syscall" command now works on arm*-linux* targets.
1085 * GDB now consistently shows "<not saved>" when printing values of
1086 registers the debug info indicates have not been saved in the frame
1087 and there's nowhere to retrieve them from
1088 (callee-saved/call-clobbered registers):
1093 (gdb) info registers rax
1096 Before, the former would print "<optimized out>", and the latter
1097 "*value not available*".
1099 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1104 ** Frame filters and frame decorators have been added.
1105 ** Temporary breakpoints are now supported.
1106 ** Line tables representation has been added.
1107 ** New attribute 'parent_type' for gdb.Field objects.
1108 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1109 ** New attribute 'name' for gdb.Type objects.
1113 Nios II ELF nios2*-*-elf
1114 Nios II GNU/Linux nios2*-*-linux
1115 Texas Instruments MSP430 msp430*-*-elf
1117 * Removed native configurations
1119 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1120 been removed. ELF variants of these configurations are kept supported.
1122 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1123 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1124 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1125 i[34567]86-*-openbsd3.[0-3]
1126 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1127 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1128 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1132 Like "catch throw", but catches a re-thrown exception.
1133 maint check-psymtabs
1134 Renamed from old "maint check-symtabs".
1136 Perform consistency checks on symtabs.
1137 maint expand-symtabs
1138 Expand symtabs matching an optional regexp.
1141 Display the details of GDB configure-time options.
1143 maint set|show per-command
1144 maint set|show per-command space
1145 maint set|show per-command time
1146 maint set|show per-command symtab
1147 Enable display of per-command gdb resource usage.
1149 remove-symbol-file FILENAME
1150 remove-symbol-file -a ADDRESS
1151 Remove a symbol file added via add-symbol-file. The file to remove
1152 can be identified by its filename or by an address that lies within
1153 the boundaries of this symbol file in memory.
1156 info exceptions REGEXP
1157 Display the list of Ada exceptions defined in the program being
1158 debugged. If provided, only the exceptions whose names match REGEXP
1163 set debug symfile off|on
1165 Control display of debugging info regarding reading symbol files and
1166 symbol tables within those files
1168 set print raw frame-arguments
1169 show print raw frame-arguments
1170 Set/show whether to print frame arguments in raw mode,
1171 disregarding any defined pretty-printers.
1173 set remote trace-status-packet
1174 show remote trace-status-packet
1175 Set/show the use of remote protocol qTStatus packet.
1179 Control display of debugging messages related to Nios II targets.
1183 Control whether target-assisted range stepping is enabled.
1185 set startup-with-shell
1186 show startup-with-shell
1187 Specifies whether Unix child processes are started via a shell or
1192 Use the target memory cache for accesses to the code segment. This
1193 improves performance of remote debugging (particularly disassembly).
1195 * You can now use a literal value 'unlimited' for options that
1196 interpret 0 or -1 as meaning "unlimited". E.g., "set
1197 trace-buffer-size unlimited" is now an alias for "set
1198 trace-buffer-size -1" and "set height unlimited" is now an alias for
1201 * The "set debug symtab-create" debugging option of GDB has been changed to
1202 accept a verbosity level. 0 means "off", 1 provides basic debugging
1203 output, and values of 2 or greater provides more verbose output.
1205 * New command-line options
1207 Display the details of GDB configure-time options.
1209 * The command 'tsave' can now support new option '-ctf' to save trace
1210 buffer in Common Trace Format.
1212 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1215 * GDB now implements the the C++ 'typeid' operator.
1217 * The new convenience variable $_exception holds the exception being
1218 thrown or caught at an exception-related catchpoint.
1220 * The exception-related catchpoints, like "catch throw", now accept a
1221 regular expression which can be used to filter exceptions by type.
1223 * The new convenience variable $_exitsignal is automatically set to
1224 the terminating signal number when the program being debugged dies
1225 due to an uncaught signal.
1229 ** All MI commands now accept an optional "--language" option.
1230 Support for this feature can be verified by using the "-list-features"
1231 command, which should contain "language-option".
1233 ** The new command -info-gdb-mi-command allows the user to determine
1234 whether a GDB/MI command is supported or not.
1236 ** The "^error" result record returned when trying to execute an undefined
1237 GDB/MI command now provides a variable named "code" whose content is the
1238 "undefined-command" error code. Support for this feature can be verified
1239 by using the "-list-features" command, which should contain
1240 "undefined-command-error-code".
1242 ** The -trace-save MI command can optionally save trace buffer in Common
1245 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1247 ** The command -data-list-register-values now accepts an optional
1248 "--skip-unavailable" option. When used, only the available registers
1251 ** The new command -trace-frame-collected dumps collected variables,
1252 computed expressions, tvars, memory and registers in a traceframe.
1254 ** The commands -stack-list-locals, -stack-list-arguments and
1255 -stack-list-variables now accept an option "--skip-unavailable".
1256 When used, only the available locals or arguments are displayed.
1258 ** The -exec-run command now accepts an optional "--start" option.
1259 When used, the command follows the same semantics as the "start"
1260 command, stopping the program's execution at the start of its
1261 main subprogram. Support for this feature can be verified using
1262 the "-list-features" command, which should contain
1263 "exec-run-start-option".
1265 ** The new commands -catch-assert and -catch-exceptions insert
1266 catchpoints stopping the program when Ada exceptions are raised.
1268 ** The new command -info-ada-exceptions provides the equivalent of
1269 the new "info exceptions" command.
1271 * New system-wide configuration scripts
1272 A GDB installation now provides scripts suitable for use as system-wide
1273 configuration scripts for the following systems:
1277 * GDB now supports target-assigned range stepping with remote targets.
1278 This improves the performance of stepping source lines by reducing
1279 the number of control packets from/to GDB. See "New remote packets"
1282 * GDB now understands the element 'tvar' in the XML traceframe info.
1283 It has the id of the collected trace state variables.
1285 * On S/390 targets that provide the transactional-execution feature,
1286 the program interruption transaction diagnostic block (TDB) is now
1287 represented as a number of additional "registers" in GDB.
1289 * New remote packets
1293 The vCont packet supports a new 'r' action, that tells the remote
1294 stub to step through an address range itself, without GDB
1295 involvemement at each single-step.
1297 qXfer:libraries-svr4:read's annex
1298 The previously unused annex of the qXfer:libraries-svr4:read packet
1299 is now used to support passing an argument list. The remote stub
1300 reports support for this argument list to GDB's qSupported query.
1301 The defined arguments are "start" and "prev", used to reduce work
1302 necessary for library list updating, resulting in significant
1305 * New features in the GDB remote stub, GDBserver
1307 ** GDBserver now supports target-assisted range stepping. Currently
1308 enabled on x86/x86_64 GNU/Linux targets.
1310 ** GDBserver now adds element 'tvar' in the XML in the reply to
1311 'qXfer:traceframe-info:read'. It has the id of the collected
1312 trace state variables.
1314 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1317 * New 'z' formatter for printing and examining memory, this displays the
1318 value as hexadecimal zero padded on the left to the size of the type.
1320 * GDB can now use Windows x64 unwinding data.
1322 * The "set remotebaud" command has been replaced by "set serial baud".
1323 Similarly, "show remotebaud" has been replaced by "show serial baud".
1324 The "set remotebaud" and "show remotebaud" commands are still available
1325 to provide backward compatibility with older versions of GDB.
1327 *** Changes in GDB 7.6
1329 * Target record has been renamed to record-full.
1330 Record/replay is now enabled with the "record full" command.
1331 This also affects settings that are associated with full record/replay
1332 that have been moved from "set/show record" to "set/show record full":
1334 set|show record full insn-number-max
1335 set|show record full stop-at-limit
1336 set|show record full memory-query
1338 * A new record target "record-btrace" has been added. The new target
1339 uses hardware support to record the control-flow of a process. It
1340 does not support replaying the execution, but it implements the
1341 below new commands for investigating the recorded execution log.
1342 This new recording method can be enabled using:
1346 The "record-btrace" target is only available on Intel Atom processors
1347 and requires a Linux kernel 2.6.32 or later.
1349 * Two new commands have been added for record/replay to give information
1350 about the recorded execution without having to replay the execution.
1351 The commands are only supported by "record btrace".
1353 record instruction-history prints the execution history at
1354 instruction granularity
1356 record function-call-history prints the execution history at
1357 function granularity
1359 * New native configurations
1361 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1362 FreeBSD/powerpc powerpc*-*-freebsd
1363 x86_64/Cygwin x86_64-*-cygwin*
1364 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1368 ARM AArch64 aarch64*-*-elf
1369 ARM AArch64 GNU/Linux aarch64*-*-linux
1370 Lynx 178 PowerPC powerpc-*-lynx*178
1371 x86_64/Cygwin x86_64-*-cygwin*
1372 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1374 * If the configured location of system.gdbinit file (as given by the
1375 --with-system-gdbinit option at configure time) is in the
1376 data-directory (as specified by --with-gdb-datadir at configure
1377 time) or in one of its subdirectories, then GDB will look for the
1378 system-wide init file in the directory specified by the
1379 --data-directory command-line option.
1381 * New command line options:
1383 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1384 other initialization files, unlike -nx which disables all of them.
1386 * Removed command line options
1388 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1391 * The 'ptype' and 'whatis' commands now accept an argument to control
1394 * 'info proc' now works on some core files.
1398 ** Vectors can be created with gdb.Type.vector.
1400 ** Python's atexit.register now works in GDB.
1402 ** Types can be pretty-printed via a Python API.
1404 ** Python 3 is now supported (in addition to Python 2.4 or later)
1406 ** New class gdb.Architecture exposes GDB's internal representation
1407 of architecture in the Python API.
1409 ** New method Frame.architecture returns the gdb.Architecture object
1410 corresponding to the frame's architecture.
1412 * New Python-based convenience functions:
1414 ** $_memeq(buf1, buf2, length)
1415 ** $_streq(str1, str2)
1417 ** $_regex(str, regex)
1419 * The 'cd' command now defaults to using '~' (the home directory) if not
1422 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1423 default for GCC since November 2000.
1425 * The command 'forward-search' can now be abbreviated as 'fo'.
1427 * The command 'info tracepoints' can now display 'installed on target'
1428 or 'not installed on target' for each non-pending location of tracepoint.
1430 * New configure options
1432 --enable-libmcheck/--disable-libmcheck
1433 By default, development versions are built with -lmcheck on hosts
1434 that support it, in order to help track memory corruption issues.
1435 Release versions, on the other hand, are built without -lmcheck
1436 by default. The --enable-libmcheck/--disable-libmcheck configure
1437 options allow the user to override that default.
1438 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1439 This configure option allows the user to build GDB with
1440 libbabeltrace using which GDB can read Common Trace Format data.
1442 * New commands (for set/show, see "New options" below)
1445 Catch signals. This is similar to "handle", but allows commands and
1446 conditions to be attached.
1449 List the BFDs known to GDB.
1451 python-interactive [command]
1453 Start a Python interactive prompt, or evaluate the optional command
1454 and print the result of expressions.
1457 "py" is a new alias for "python".
1459 enable type-printer [name]...
1460 disable type-printer [name]...
1461 Enable or disable type printers.
1465 ** For the Renesas Super-H architecture, the "regs" command has been removed
1466 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1471 set print type methods (on|off)
1472 show print type methods
1473 Control whether method declarations are displayed by "ptype".
1474 The default is to show them.
1476 set print type typedefs (on|off)
1477 show print type typedefs
1478 Control whether typedef definitions are displayed by "ptype".
1479 The default is to show them.
1481 set filename-display basename|relative|absolute
1482 show filename-display
1483 Control the way in which filenames is displayed.
1484 The default is "relative", which preserves previous behavior.
1486 set trace-buffer-size
1487 show trace-buffer-size
1488 Request target to change the size of trace buffer.
1490 set remote trace-buffer-size-packet auto|on|off
1491 show remote trace-buffer-size-packet
1492 Control the use of the remote protocol `QTBuffer:size' packet.
1496 Control display of debugging messages related to ARM AArch64.
1499 set debug coff-pe-read
1500 show debug coff-pe-read
1501 Control display of debugging messages related to reading of COFF/PE
1506 Control display of debugging messages related to Mach-O symbols
1509 set debug notification
1510 show debug notification
1511 Control display of debugging info for async remote notification.
1515 ** Command parameter changes are now notified using new async record
1516 "=cmd-param-changed".
1517 ** Trace frame changes caused by command "tfind" are now notified using
1518 new async record "=traceframe-changed".
1519 ** The creation, deletion and modification of trace state variables
1520 are now notified using new async records "=tsv-created",
1521 "=tsv-deleted" and "=tsv-modified".
1522 ** The start and stop of process record are now notified using new
1523 async record "=record-started" and "=record-stopped".
1524 ** Memory changes are now notified using new async record
1526 ** The data-disassemble command response will include a "fullname" field
1527 containing the absolute file name when source has been requested.
1528 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1529 command, to allow pattern filling of memory areas.
1530 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1531 library load/unload events.
1532 ** The response to breakpoint commands and breakpoint async records
1533 includes an "installed" field containing a boolean state about each
1534 non-pending tracepoint location is whether installed on target or not.
1535 ** Output of the "-trace-status" command includes a "trace-file" field
1536 containing the name of the trace file being examined. This field is
1537 optional, and only present when examining a trace file.
1538 ** The "fullname" field is now always present along with the "file" field,
1539 even if the file cannot be found by GDB.
1541 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1542 You must have the LZMA library available when configuring GDB for this
1543 feature to be enabled. For more information, see:
1544 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1546 * New remote packets
1549 Set the size of trace buffer. The remote stub reports support for this
1550 packet to gdb's qSupported query.
1553 Enable Branch Trace Store (BTS)-based branch tracing for the current
1554 thread. The remote stub reports support for this packet to gdb's
1558 Disable branch tracing for the current thread. The remote stub reports
1559 support for this packet to gdb's qSupported query.
1562 Read the traced branches for the current thread. The remote stub
1563 reports support for this packet to gdb's qSupported query.
1565 *** Changes in GDB 7.5
1567 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1568 for more x32 ABI info.
1570 * GDB now supports access to MIPS DSP registers on Linux targets.
1572 * GDB now supports debugging microMIPS binaries.
1574 * The "info os" command on GNU/Linux can now display information on
1575 several new classes of objects managed by the operating system:
1576 "info os procgroups" lists process groups
1577 "info os files" lists file descriptors
1578 "info os sockets" lists internet-domain sockets
1579 "info os shm" lists shared-memory regions
1580 "info os semaphores" lists semaphores
1581 "info os msg" lists message queues
1582 "info os modules" lists loaded kernel modules
1584 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1585 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1586 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1587 options and inspect the probe arguments using the new $_probe_arg family
1588 of convenience variables. You can obtain more information about SystemTap
1589 in <http://sourceware.org/systemtap/>.
1591 * GDB now supports reversible debugging on ARM, it allows you to
1592 debug basic ARM and THUMB instructions, and provides
1593 record/replay support.
1595 * The option "symbol-reloading" has been deleted as it is no longer used.
1599 ** GDB commands implemented in Python can now be put in command class
1602 ** The "maint set python print-stack on|off" is now deleted.
1604 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1605 apply "flag enum"-style pretty-printing to any enum.
1607 ** gdb.lookup_symbol can now work when there is no current frame.
1609 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1610 the source at which the symbol was defined.
1612 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1613 method 'value'. The former indicates whether the symbol needs a
1614 frame in order to compute its value, and the latter computes the
1617 ** A new method 'referenced_value' on gdb.Value objects which can
1618 dereference pointer as well as C++ reference values.
1620 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1621 which return the global and static blocks (as gdb.Block objects),
1622 of the underlying symbol table, respectively.
1624 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1625 object associated with a PC value.
1627 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1628 of the address range occupied by code for the current source line.
1630 * Go language support.
1631 GDB now supports debugging programs written in the Go programming
1634 * GDBserver now supports stdio connections.
1635 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1637 * The binary "gdbtui" can no longer be built or installed.
1638 Use "gdb -tui" instead.
1640 * GDB will now print "flag" enums specially. A flag enum is one where
1641 all the enumerator values have no bits in common when pairwise
1642 "and"ed. When printing a value whose type is a flag enum, GDB will
1643 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1644 (gdb) print (enum E) 3
1647 * The filename part of a linespec will now match trailing components
1648 of a source file name. For example, "break gcc/expr.c:1000" will
1649 now set a breakpoint in build/gcc/expr.c, but not
1650 build/libcpp/expr.c.
1652 * The "info proc" and "generate-core-file" commands will now also
1653 work on remote targets connected to GDBserver on Linux.
1655 * The command "info catch" has been removed. It has been disabled
1656 since December 2007.
1658 * The "catch exception" and "catch assert" commands now accept
1659 a condition at the end of the command, much like the "break"
1660 command does. For instance:
1662 (gdb) catch exception Constraint_Error if Barrier = True
1664 Previously, it was possible to add a condition to such catchpoints,
1665 but it had to be done as a second step, after the catchpoint had been
1666 created, using the "condition" command.
1668 * The "info static-tracepoint-marker" command will now also work on
1669 native Linux targets with in-process agent.
1671 * GDB can now set breakpoints on inlined functions.
1673 * The .gdb_index section has been updated to include symbols for
1674 inlined functions. GDB will ignore older .gdb_index sections by
1675 default, which could cause symbol files to be loaded more slowly
1676 until their .gdb_index sections can be recreated. The new command
1677 "set use-deprecated-index-sections on" will cause GDB to use any older
1678 .gdb_index sections it finds. This will restore performance, but the
1679 ability to set breakpoints on inlined functions will be lost in symbol
1680 files with older .gdb_index sections.
1682 The .gdb_index section has also been updated to record more information
1683 about each symbol. This speeds up the "info variables", "info functions"
1684 and "info types" commands when used with programs having the .gdb_index
1685 section, as well as speeding up debugging with shared libraries using
1686 the .gdb_index section.
1688 * Ada support for GDB/MI Variable Objects has been added.
1690 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1695 ** New command -info-os is the MI equivalent of "info os".
1697 ** Output logs ("set logging" and related) now include MI output.
1701 ** "set use-deprecated-index-sections on|off"
1702 "show use-deprecated-index-sections on|off"
1703 Controls the use of deprecated .gdb_index sections.
1705 ** "catch load" and "catch unload" can be used to stop when a shared
1706 library is loaded or unloaded, respectively.
1708 ** "enable count" can be used to auto-disable a breakpoint after
1711 ** "info vtbl" can be used to show the virtual method tables for
1712 C++ and Java objects.
1714 ** "explore" and its sub commands "explore value" and "explore type"
1715 can be used to recursively explore values and types of
1716 expressions. These commands are available only if GDB is
1717 configured with '--with-python'.
1719 ** "info auto-load" shows status of all kinds of auto-loaded files,
1720 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1721 sequences of commands files, "info auto-load python-scripts"
1722 shows status of auto-loading Python script files,
1723 "info auto-load local-gdbinit" shows status of loading init file
1724 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1725 status of inferior specific thread debugging shared library loading.
1727 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1728 and "show auto-load-scripts" commands have been deprecated, use their
1729 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1730 and "show auto-load python-scripts" counterparts instead.
1732 ** "dprintf location,format,args..." creates a dynamic printf, which
1733 is basically a breakpoint that does a printf and immediately
1734 resumes your program's execution, so it is like a printf that you
1735 can insert dynamically at runtime instead of at compiletime.
1737 ** "set print symbol"
1739 Controls whether GDB attempts to display the symbol, if any,
1740 corresponding to addresses it prints. This defaults to "on", but
1741 you can set it to "off" to restore GDB's previous behavior.
1743 * Deprecated commands
1745 ** For the Renesas Super-H architecture, the "regs" command has been
1746 deprecated, and "info all-registers" should be used instead.
1750 Renesas RL78 rl78-*-elf
1751 HP OpenVMS ia64 ia64-hp-openvms*
1753 * GDBserver supports evaluation of breakpoint conditions. When
1754 support is advertised by GDBserver, GDB may be told to send the
1755 breakpoint conditions in bytecode form to GDBserver. GDBserver
1756 will only report the breakpoint trigger to GDB when its condition
1761 set mips compression
1762 show mips compression
1763 Select the compressed ISA encoding used in functions that have no symbol
1764 information available. The encoding can be set to either of:
1767 and is updated automatically from ELF file flags if available.
1769 set breakpoint condition-evaluation
1770 show breakpoint condition-evaluation
1771 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1772 GDBserver ("target"). Default option "auto" chooses the most efficient
1774 This option can improve debugger efficiency depending on the speed of the
1778 Disable auto-loading globally.
1781 Show auto-loading setting of all kinds of auto-loaded files.
1783 set auto-load gdb-scripts on|off
1784 show auto-load gdb-scripts
1785 Control auto-loading of GDB canned sequences of commands files.
1787 set auto-load python-scripts on|off
1788 show auto-load python-scripts
1789 Control auto-loading of Python script files.
1791 set auto-load local-gdbinit on|off
1792 show auto-load local-gdbinit
1793 Control loading of init file (.gdbinit) from current directory.
1795 set auto-load libthread-db on|off
1796 show auto-load libthread-db
1797 Control auto-loading of inferior specific thread debugging shared library.
1799 set auto-load scripts-directory <dir1>[:<dir2>...]
1800 show auto-load scripts-directory
1801 Set a list of directories from which to load auto-loaded scripts.
1802 Automatically loaded Python scripts and GDB scripts are located in one
1803 of the directories listed by this option.
1804 The delimiter (':' above) may differ according to the host platform.
1806 set auto-load safe-path <dir1>[:<dir2>...]
1807 show auto-load safe-path
1808 Set a list of directories from which it is safe to auto-load files.
1809 The delimiter (':' above) may differ according to the host platform.
1811 set debug auto-load on|off
1812 show debug auto-load
1813 Control display of debugging info for auto-loading the files above.
1815 set dprintf-style gdb|call|agent
1817 Control the way in which a dynamic printf is performed; "gdb"
1818 requests a GDB printf command, while "call" causes dprintf to call a
1819 function in the inferior. "agent" requests that the target agent
1820 (such as GDBserver) do the printing.
1822 set dprintf-function <expr>
1823 show dprintf-function
1824 set dprintf-channel <expr>
1825 show dprintf-channel
1826 Set the function and optional first argument to the call when using
1827 the "call" style of dynamic printf.
1829 set disconnected-dprintf on|off
1830 show disconnected-dprintf
1831 Control whether agent-style dynamic printfs continue to be in effect
1832 after GDB disconnects.
1834 * New configure options
1836 --with-auto-load-dir
1837 Configure default value for the 'set auto-load scripts-directory'
1838 setting above. It defaults to '$debugdir:$datadir/auto-load',
1839 $debugdir representing global debugging info directories (available
1840 via 'show debug-file-directory') and $datadir representing GDB's data
1841 directory (available via 'show data-directory').
1843 --with-auto-load-safe-path
1844 Configure default value for the 'set auto-load safe-path' setting
1845 above. It defaults to the --with-auto-load-dir setting.
1847 --without-auto-load-safe-path
1848 Set 'set auto-load safe-path' to '/', effectively disabling this
1851 * New remote packets
1853 z0/z1 conditional breakpoints extension
1855 The z0/z1 breakpoint insertion packets have been extended to carry
1856 a list of conditional expressions over to the remote stub depending on the
1857 condition evaluation mode. The use of this extension can be controlled
1858 via the "set remote conditional-breakpoints-packet" command.
1862 Specify the signals which the remote stub may pass to the debugged
1863 program without GDB involvement.
1865 * New command line options
1867 --init-command=FILE, -ix Like --command, -x but execute it
1868 before loading inferior.
1869 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1870 execute it before loading inferior.
1872 *** Changes in GDB 7.4
1874 * GDB now handles ambiguous linespecs more consistently; the existing
1875 FILE:LINE support has been expanded to other types of linespecs. A
1876 breakpoint will now be set on all matching locations in all
1877 inferiors, and locations will be added or removed according to
1880 * GDB now allows you to skip uninteresting functions and files when
1881 stepping with the "skip function" and "skip file" commands.
1883 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1884 and "show remote hardware-watchpoint-length-limit". These allows to
1885 set or show the maximum length limit (in bytes) of a remote
1886 target hardware watchpoint.
1888 This allows e.g. to use "unlimited" hardware watchpoints with the
1889 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1890 watchpoints are slower than real hardware watchpoints but are
1891 significantly faster than gdb software watchpoints.
1895 ** The register_pretty_printer function in module gdb.printing now takes
1896 an optional `replace' argument. If True, the new printer replaces any
1899 ** The "maint set python print-stack on|off" command has been
1900 deprecated and will be deleted in GDB 7.5.
1901 A new command: "set python print-stack none|full|message" has
1902 replaced it. Additionally, the default for "print-stack" is
1903 now "message", which just prints the error message without
1906 ** A prompt substitution hook (prompt_hook) is now available to the
1909 ** A new Python module, gdb.prompt has been added to the GDB Python
1910 modules library. This module provides functionality for
1911 escape sequences in prompts (used by set/show
1912 extended-prompt). These escape sequences are replaced by their
1913 corresponding value.
1915 ** Python commands and convenience-functions located in
1916 'data-directory'/python/gdb/command and
1917 'data-directory'/python/gdb/function are now automatically loaded
1920 ** Blocks now provide four new attributes. global_block and
1921 static_block will return the global and static blocks
1922 respectively. is_static and is_global are boolean attributes
1923 that indicate if the block is one of those two types.
1925 ** Symbols now provide the "type" attribute, the type of the symbol.
1927 ** The "gdb.breakpoint" function has been deprecated in favor of
1930 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1931 of a function. This class is based on the "finish" command
1932 available in the CLI.
1934 ** Type objects for struct and union types now allow access to
1935 the fields using standard Python dictionary (mapping) methods.
1936 For example, "some_type['myfield']" now works, as does
1937 "some_type.items()".
1939 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1942 ** A new function, "deep_items" has been added to the gdb.types
1943 module in the GDB Python modules library. This function returns
1944 an iterator over the fields of a struct or union type. Unlike
1945 the standard Python "iteritems" method, it will recursively traverse
1946 any anonymous fields.
1950 ** "*stopped" events can report several new "reason"s, such as
1953 ** Breakpoint changes are now notified using new async records, like
1954 "=breakpoint-modified".
1956 ** New command -ada-task-info.
1958 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1959 $sdir specifies the default system locations of shared libraries.
1960 $pdir specifies the directory where the libpthread used by the application
1963 GDB no longer looks in $sdir and $pdir after it has searched the directories
1964 mentioned in libthread-db-search-path. If you want to search those
1965 directories, they must be specified in libthread-db-search-path.
1966 The default value of libthread-db-search-path on GNU/Linux and Solaris
1967 systems is now "$sdir:$pdir".
1969 $pdir is not supported by gdbserver, it is currently ignored.
1970 $sdir is supported by gdbserver.
1972 * New configure option --with-iconv-bin.
1973 When using the internationalization support like the one in the GNU C
1974 library, GDB will invoke the "iconv" program to get a list of supported
1975 character sets. If this program lives in a non-standard location, one can
1976 use this option to specify where to find it.
1978 * When natively debugging programs on PowerPC BookE processors running
1979 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1980 watchpoints, which specify a mask in addition to an address to watch.
1981 The mask specifies that some bits of an address (the bits which are
1982 reset in the mask) should be ignored when matching the address accessed
1983 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1984 section in the user manual for more details.
1986 * The new option --once causes GDBserver to stop listening for connections once
1987 the first connection is made. The listening port used by GDBserver will
1988 become available after that.
1990 * New commands "info macros" and "alias" have been added.
1992 * New function parameters suffix @entry specifies value of function parameter
1993 at the time the function got called. Entry values are available only since
1999 "!" is now an alias of the "shell" command.
2000 Note that no space is needed between "!" and SHELL COMMAND.
2004 watch EXPRESSION mask MASK_VALUE
2005 The watch command now supports the mask argument which allows creation
2006 of masked watchpoints, if the current architecture supports this feature.
2008 info auto-load-scripts [REGEXP]
2009 This command was formerly named "maintenance print section-scripts".
2010 It is now generally useful and is no longer a maintenance-only command.
2012 info macro [-all] [--] MACRO
2013 The info macro command has new options `-all' and `--'. The first for
2014 printing all definitions of a macro. The second for explicitly specifying
2015 the end of arguments and the beginning of the macro name in case the macro
2016 name starts with a hyphen.
2018 collect[/s] EXPRESSIONS
2019 The tracepoint collect command now takes an optional modifier "/s"
2020 that directs it to dereference pointer-to-character types and
2021 collect the bytes of memory up to a zero byte. The behavior is
2022 similar to what you see when you use the regular print command on a
2023 string. An optional integer following the "/s" sets a bound on the
2024 number of bytes that will be collected.
2027 The trace start command now interprets any supplied arguments as a
2028 note to be recorded with the trace run, with an effect similar to
2029 setting the variable trace-notes.
2032 The trace stop command now interprets any arguments as a note to be
2033 mentioned along with the tstatus report that the trace was stopped
2034 with a command. The effect is similar to setting the variable
2037 * Tracepoints can now be enabled and disabled at any time after a trace
2038 experiment has been started using the standard "enable" and "disable"
2039 commands. It is now possible to start a trace experiment with no enabled
2040 tracepoints; GDB will display a warning, but will allow the experiment to
2041 begin, assuming that tracepoints will be enabled as needed while the trace
2044 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2045 locations with 4-byte instructions, when they were previously
2046 limited to locations with instructions of 5 bytes or longer.
2050 set debug dwarf2-read
2051 show debug dwarf2-read
2052 Turns on or off display of debugging messages related to reading
2053 DWARF debug info. The default is off.
2055 set debug symtab-create
2056 show debug symtab-create
2057 Turns on or off display of debugging messages related to symbol table
2058 creation. The default is off.
2061 show extended-prompt
2062 Set the GDB prompt, and allow escape sequences to be inserted to
2063 display miscellaneous information (see 'help set extended-prompt'
2064 for the list of sequences). This prompt (and any information
2065 accessed through the escape sequences) is updated every time the
2066 prompt is displayed.
2068 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2069 show print entry-values
2070 Set printing of frame argument values at function entry. In some cases
2071 GDB can determine the value of function argument which was passed by the
2072 function caller, even if the value was modified inside the called function.
2074 set debug entry-values
2075 show debug entry-values
2076 Control display of debugging info for determining frame argument values at
2077 function entry and virtual tail call frames.
2079 set basenames-may-differ
2080 show basenames-may-differ
2081 Set whether a source file may have multiple base names.
2082 (A "base name" is the name of a file with the directory part removed.
2083 Example: The base name of "/home/user/hello.c" is "hello.c".)
2084 If set, GDB will canonicalize file names (e.g., expand symlinks)
2085 before comparing them. Canonicalization is an expensive operation,
2086 but it allows the same file be known by more than one base name.
2087 If not set (the default), all source files are assumed to have just
2088 one base name, and gdb will do file name comparisons more efficiently.
2094 Set a user name and notes for the current and any future trace runs.
2095 This is useful for long-running and/or disconnected traces, to
2096 inform others (or yourself) as to who is running the trace, supply
2097 contact information, or otherwise explain what is going on.
2099 set trace-stop-notes
2100 show trace-stop-notes
2101 Set a note attached to the trace run, that is displayed when the
2102 trace has been stopped by a tstop command. This is useful for
2103 instance as an explanation, if you are stopping a trace run that was
2104 started by someone else.
2106 * New remote packets
2110 Dynamically enable a tracepoint in a started trace experiment.
2114 Dynamically disable a tracepoint in a started trace experiment.
2118 Set the user and notes of the trace run.
2122 Query the current status of a tracepoint.
2126 Query the minimum length of instruction at which a fast tracepoint may
2129 * Dcache size (number of lines) and line-size are now runtime-configurable
2130 via "set dcache line" and "set dcache line-size" commands.
2134 Texas Instruments TMS320C6x tic6x-*-*
2138 Renesas RL78 rl78-*-elf
2140 *** Changes in GDB 7.3.1
2142 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2144 *** Changes in GDB 7.3
2146 * GDB has a new command: "thread find [REGEXP]".
2147 It finds the thread id whose name, target id, or thread extra info
2148 matches the given regular expression.
2150 * The "catch syscall" command now works on mips*-linux* targets.
2152 * The -data-disassemble MI command now supports modes 2 and 3 for
2153 dumping the instruction opcodes.
2155 * New command line options
2157 -data-directory DIR Specify DIR as the "data-directory".
2158 This is mostly for testing purposes.
2160 * The "maint set python auto-load on|off" command has been renamed to
2161 "set auto-load-scripts on|off".
2163 * GDB has a new command: "set directories".
2164 It is like the "dir" command except that it replaces the
2165 source path list instead of augmenting it.
2167 * GDB now understands thread names.
2169 On GNU/Linux, "info threads" will display the thread name as set by
2170 prctl or pthread_setname_np.
2172 There is also a new command, "thread name", which can be used to
2173 assign a name internally for GDB to display.
2176 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2177 has been integrated into GDB.
2181 ** The function gdb.Write now accepts an optional keyword 'stream'.
2182 This keyword, when provided, will direct the output to either
2183 stdout, stderr, or GDB's logging output.
2185 ** Parameters can now be be sub-classed in Python, and in particular
2186 you may implement the get_set_doc and get_show_doc functions.
2187 This improves how Parameter set/show documentation is processed
2188 and allows for more dynamic content.
2190 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2191 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2192 have an is_valid method.
2194 ** Breakpoints can now be sub-classed in Python, and in particular
2195 you may implement a 'stop' function that is executed each time
2196 the inferior reaches that breakpoint.
2198 ** New function gdb.lookup_global_symbol looks up a global symbol.
2200 ** GDB values in Python are now callable if the value represents a
2201 function. For example, if 'some_value' represents a function that
2202 takes two integer parameters and returns a value, you can call
2203 that function like so:
2205 result = some_value (10,20)
2207 ** Module gdb.types has been added.
2208 It contains a collection of utilities for working with gdb.Types objects:
2209 get_basic_type, has_field, make_enum_dict.
2211 ** Module gdb.printing has been added.
2212 It contains utilities for writing and registering pretty-printers.
2213 New classes: PrettyPrinter, SubPrettyPrinter,
2214 RegexpCollectionPrettyPrinter.
2215 New function: register_pretty_printer.
2217 ** New commands "info pretty-printers", "enable pretty-printer" and
2218 "disable pretty-printer" have been added.
2220 ** gdb.parameter("directories") is now available.
2222 ** New function gdb.newest_frame returns the newest frame in the
2225 ** The gdb.InferiorThread class has a new "name" attribute. This
2226 holds the thread's name.
2228 ** Python Support for Inferior events.
2229 Python scripts can add observers to be notified of events
2230 occurring in the process being debugged.
2231 The following events are currently supported:
2232 - gdb.events.cont Continue event.
2233 - gdb.events.exited Inferior exited event.
2234 - gdb.events.stop Signal received, and Breakpoint hit events.
2238 ** GDB now puts template parameters in scope when debugging in an
2239 instantiation. For example, if you have:
2241 template<int X> int func (void) { return X; }
2243 then if you step into func<5>, "print X" will show "5". This
2244 feature requires proper debuginfo support from the compiler; it
2245 was added to GCC 4.5.
2247 ** The motion commands "next", "finish", "until", and "advance" now
2248 work better when exceptions are thrown. In particular, GDB will
2249 no longer lose control of the inferior; instead, the GDB will
2250 stop the inferior at the point at which the exception is caught.
2251 This functionality requires a change in the exception handling
2252 code that was introduced in GCC 4.5.
2254 * GDB now follows GCC's rules on accessing volatile objects when
2255 reading or writing target state during expression evaluation.
2256 One notable difference to prior behavior is that "print x = 0"
2257 no longer generates a read of x; the value of the assignment is
2258 now always taken directly from the value being assigned.
2260 * GDB now has some support for using labels in the program's source in
2261 linespecs. For instance, you can use "advance label" to continue
2262 execution to a label.
2264 * GDB now has support for reading and writing a new .gdb_index
2265 section. This section holds a fast index of DWARF debugging
2266 information and can be used to greatly speed up GDB startup and
2267 operation. See the documentation for `save gdb-index' for details.
2269 * The "watch" command now accepts an optional "-location" argument.
2270 When used, this causes GDB to watch the memory referred to by the
2271 expression. Such a watchpoint is never deleted due to it going out
2274 * GDB now supports thread debugging of core dumps on GNU/Linux.
2276 GDB now activates thread debugging using the libthread_db library
2277 when debugging GNU/Linux core dumps, similarly to when debugging
2278 live processes. As a result, when debugging a core dump file, GDB
2279 is now able to display pthread_t ids of threads. For example, "info
2280 threads" shows the same output as when debugging the process when it
2281 was live. In earlier releases, you'd see something like this:
2284 * 1 LWP 6780 main () at main.c:10
2286 While now you see this:
2289 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2291 It is also now possible to inspect TLS variables when debugging core
2294 When debugging a core dump generated on a machine other than the one
2295 used to run GDB, you may need to point GDB at the correct
2296 libthread_db library with the "set libthread-db-search-path"
2297 command. See the user manual for more details on this command.
2299 * When natively debugging programs on PowerPC BookE processors running
2300 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2301 which stop execution of the inferior whenever it executes an instruction
2302 at any address within the specified range. See the "PowerPC Embedded"
2303 section in the user manual for more details.
2305 * New features in the GDB remote stub, GDBserver
2307 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2308 and i686 LynxOS (version 5.x).
2310 ** GDBserver is now supported on Blackfin Linux.
2312 * New native configurations
2314 ia64 HP-UX ia64-*-hpux*
2318 Analog Devices, Inc. Blackfin Processor bfin-*
2320 * Ada task switching is now supported on sparc-elf targets when
2321 debugging a program using the Ravenscar Profile. For more information,
2322 see the "Tasking Support when using the Ravenscar Profile" section
2323 in the GDB user manual.
2325 * Guile support was removed.
2327 * New features in the GNU simulator
2329 ** The --map-info flag lists all known core mappings.
2331 ** CFI flashes may be simulated via the "cfi" device.
2333 *** Changes in GDB 7.2
2335 * Shared library support for remote targets by default
2337 When GDB is configured for a generic, non-OS specific target, like
2338 for example, --target=arm-eabi or one of the many *-*-elf targets,
2339 GDB now queries remote stubs for loaded shared libraries using the
2340 `qXfer:libraries:read' packet. Previously, shared library support
2341 was always disabled for such configurations.
2345 ** Argument Dependent Lookup (ADL)
2347 In C++ ADL lookup directs function search to the namespaces of its
2348 arguments even if the namespace has not been imported.
2358 Here the compiler will search for `foo' in the namespace of 'b'
2359 and find A::foo. GDB now supports this. This construct is commonly
2360 used in the Standard Template Library for operators.
2362 ** Improved User Defined Operator Support
2364 In addition to member operators, GDB now supports lookup of operators
2365 defined in a namespace and imported with a `using' directive, operators
2366 defined in the global scope, operators imported implicitly from an
2367 anonymous namespace, and the ADL operators mentioned in the previous
2369 GDB now also supports proper overload resolution for all the previously
2370 mentioned flavors of operators.
2372 ** static const class members
2374 Printing of static const class members that are initialized in the
2375 class definition has been fixed.
2377 * Windows Thread Information Block access.
2379 On Windows targets, GDB now supports displaying the Windows Thread
2380 Information Block (TIB) structure. This structure is visible either
2381 by using the new command `info w32 thread-information-block' or, by
2382 dereferencing the new convenience variable named `$_tlb', a
2383 thread-specific pointer to the TIB. This feature is also supported
2384 when remote debugging using GDBserver.
2386 * Static tracepoints
2388 Static tracepoints are calls in the user program into a tracing
2389 library. One such library is a port of the LTTng kernel tracer to
2390 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2391 When debugging with GDBserver, GDB now supports combining the GDB
2392 tracepoint machinery with such libraries. For example: the user can
2393 use GDB to probe a static tracepoint marker (a call from the user
2394 program into the tracing library) with the new "strace" command (see
2395 "New commands" below). This creates a "static tracepoint" in the
2396 breakpoint list, that can be manipulated with the same feature set
2397 as fast and regular tracepoints. E.g., collect registers, local and
2398 global variables, collect trace state variables, and define
2399 tracepoint conditions. In addition, the user can collect extra
2400 static tracepoint marker specific data, by collecting the new
2401 $_sdata internal variable. When analyzing the trace buffer, you can
2402 inspect $_sdata like any other variable available to GDB. For more
2403 information, see the "Tracepoints" chapter in GDB user manual. New
2404 remote packets have been defined to support static tracepoints, see
2405 the "New remote packets" section below.
2407 * Better reconstruction of tracepoints after disconnected tracing
2409 GDB will attempt to download the original source form of tracepoint
2410 definitions when starting a trace run, and then will upload these
2411 upon reconnection to the target, resulting in a more accurate
2412 reconstruction of the tracepoints that are in use on the target.
2416 You can now exercise direct control over the ways that GDB can
2417 affect your program. For instance, you can disallow the setting of
2418 breakpoints, so that the program can run continuously (assuming
2419 non-stop mode). In addition, the "observer" variable is available
2420 to switch all of the different controls; in observer mode, GDB
2421 cannot affect the target's behavior at all, which is useful for
2422 tasks like diagnosing live systems in the field.
2424 * The new convenience variable $_thread holds the number of the
2427 * New remote packets
2431 Return the address of the Windows Thread Information Block of a given thread.
2435 In response to several of the tracepoint packets, the target may now
2436 also respond with a number of intermediate `qRelocInsn' request
2437 packets before the final result packet, to have GDB handle
2438 relocating an instruction to execute at a different address. This
2439 is particularly useful for stubs that support fast tracepoints. GDB
2440 reports support for this feature in the qSupported packet.
2444 List static tracepoint markers in the target program.
2448 List static tracepoint markers at a given address in the target
2451 qXfer:statictrace:read
2453 Read the static trace data collected (by a `collect $_sdata'
2454 tracepoint action). The remote stub reports support for this packet
2455 to gdb's qSupported query.
2459 Send the current settings of GDB's permission flags.
2463 Send part of the source (textual) form of a tracepoint definition,
2464 which includes location, conditional, and action list.
2466 * The source command now accepts a -s option to force searching for the
2467 script in the source search path even if the script name specifies
2470 * New features in the GDB remote stub, GDBserver
2472 - GDBserver now support tracepoints (including fast tracepoints, and
2473 static tracepoints). The feature is currently supported by the
2474 i386-linux and amd64-linux builds. See the "Tracepoints support
2475 in gdbserver" section in the manual for more information.
2477 GDBserver JIT compiles the tracepoint's conditional agent
2478 expression bytecode into native code whenever possible for low
2479 overhead dynamic tracepoints conditionals. For such tracepoints,
2480 an expression that examines program state is evaluated when the
2481 tracepoint is reached, in order to determine whether to capture
2482 trace data. If the condition is simple and false, processing the
2483 tracepoint finishes very quickly and no data is gathered.
2485 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2486 for static tracepoints support.
2488 - GDBserver now supports x86_64 Windows 64-bit debugging.
2490 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2491 it understands register description.
2493 * The --batch flag now disables pagination and queries.
2495 * X86 general purpose registers
2497 GDB now supports reading/writing byte, word and double-word x86
2498 general purpose registers directly. This means you can use, say,
2499 $ah or $ax to refer, respectively, to the byte register AH and
2500 16-bit word register AX that are actually portions of the 32-bit
2501 register EAX or 64-bit register RAX.
2503 * The `commands' command now accepts a range of breakpoints to modify.
2504 A plain `commands' following a command that creates multiple
2505 breakpoints affects all the breakpoints set by that command. This
2506 applies to breakpoints set by `rbreak', and also applies when a
2507 single `break' command creates multiple breakpoints (e.g.,
2508 breakpoints on overloaded c++ functions).
2510 * The `rbreak' command now accepts a filename specification as part of
2511 its argument, limiting the functions selected by the regex to those
2512 in the specified file.
2514 * Support for remote debugging Windows and SymbianOS shared libraries
2515 from Unix hosts has been improved. Non Windows GDB builds now can
2516 understand target reported file names that follow MS-DOS based file
2517 system semantics, such as file names that include drive letters and
2518 use the backslash character as directory separator. This makes it
2519 possible to transparently use the "set sysroot" and "set
2520 solib-search-path" on Unix hosts to point as host copies of the
2521 target's shared libraries. See the new command "set
2522 target-file-system-kind" described below, and the "Commands to
2523 specify files" section in the user manual for more information.
2527 eval template, expressions...
2528 Convert the values of one or more expressions under the control
2529 of the string template to a command line, and call it.
2531 set target-file-system-kind unix|dos-based|auto
2532 show target-file-system-kind
2533 Set or show the assumed file system kind for target reported file
2536 save breakpoints <filename>
2537 Save all current breakpoint definitions to a file suitable for use
2538 in a later debugging session. To read the saved breakpoint
2539 definitions, use the `source' command.
2541 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2544 info static-tracepoint-markers
2545 Display information about static tracepoint markers in the target.
2547 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2548 Define a static tracepoint by probing a marker at the given
2549 function, line, address, or marker ID.
2553 Enable and disable observer mode.
2555 set may-write-registers on|off
2556 set may-write-memory on|off
2557 set may-insert-breakpoints on|off
2558 set may-insert-tracepoints on|off
2559 set may-insert-fast-tracepoints on|off
2560 set may-interrupt on|off
2561 Set individual permissions for GDB effects on the target. Note that
2562 some of these settings can have undesirable or surprising
2563 consequences, particularly when changed in the middle of a session.
2564 For instance, disabling the writing of memory can prevent
2565 breakpoints from being inserted, cause single-stepping to fail, or
2566 even crash your program, if you disable after breakpoints have been
2567 inserted. However, GDB should not crash.
2569 set record memory-query on|off
2570 show record memory-query
2571 Control whether to stop the inferior if memory changes caused
2572 by an instruction cannot be recorded.
2577 The disassemble command now supports "start,+length" form of two arguments.
2581 ** GDB now provides a new directory location, called the python directory,
2582 where Python scripts written for GDB can be installed. The location
2583 of that directory is <data-directory>/python, where <data-directory>
2584 is the GDB data directory. For more details, see section `Scripting
2585 GDB using Python' in the manual.
2587 ** The GDB Python API now has access to breakpoints, symbols, symbol
2588 tables, program spaces, inferiors, threads and frame's code blocks.
2589 Additionally, GDB Parameters can now be created from the API, and
2590 manipulated via set/show in the CLI.
2592 ** New functions gdb.target_charset, gdb.target_wide_charset,
2593 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2595 ** New exception gdb.GdbError.
2597 ** Pretty-printers are now also looked up in the current program space.
2599 ** Pretty-printers can now be individually enabled and disabled.
2601 ** GDB now looks for names of Python scripts to auto-load in a
2602 special section named `.debug_gdb_scripts', in addition to looking
2603 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2605 * Tracepoint actions were unified with breakpoint commands. In particular,
2606 there are no longer differences in "info break" output for breakpoints and
2607 tracepoints and the "commands" command can be used for both tracepoints and
2608 regular breakpoints.
2612 ARM Symbian arm*-*-symbianelf*
2614 * D language support.
2615 GDB now supports debugging programs written in the D programming
2618 * GDB now supports the extended ptrace interface for PowerPC which is
2619 available since Linux kernel version 2.6.34. This automatically enables
2620 any hardware breakpoints and additional hardware watchpoints available in
2621 the processor. The old ptrace interface exposes just one hardware
2622 watchpoint and no hardware breakpoints.
2624 * GDB is now able to use the Data Value Compare (DVC) register available on
2625 embedded PowerPC processors to implement in hardware simple watchpoint
2626 conditions of the form:
2628 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2630 This works in native GDB running on Linux kernels with the extended ptrace
2631 interface mentioned above.
2633 *** Changes in GDB 7.1
2637 ** Namespace Support
2639 GDB now supports importing of namespaces in C++. This enables the
2640 user to inspect variables from imported namespaces. Support for
2641 namepace aliasing has also been added. So, if a namespace is
2642 aliased in the current scope (e.g. namepace C=A; ) the user can
2643 print variables using the alias (e.g. (gdb) print C::x).
2647 All known bugs relating to the printing of virtual base class were
2648 fixed. It is now possible to call overloaded static methods using a
2653 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2654 and reinterpret_cast<> are now handled by the C++ expression parser.
2658 Xilinx MicroBlaze microblaze-*-*
2663 Xilinx MicroBlaze microblaze
2666 * Multi-program debugging.
2668 GDB now has support for multi-program (a.k.a. multi-executable or
2669 multi-exec) debugging. This allows for debugging multiple inferiors
2670 simultaneously each running a different program under the same GDB
2671 session. See "Debugging Multiple Inferiors and Programs" in the
2672 manual for more information. This implied some user visible changes
2673 in the multi-inferior support. For example, "info inferiors" now
2674 lists inferiors that are not running yet or that have exited
2675 already. See also "New commands" and "New options" below.
2677 * New tracing features
2679 GDB's tracepoint facility now includes several new features:
2681 ** Trace state variables
2683 GDB tracepoints now include support for trace state variables, which
2684 are variables managed by the target agent during a tracing
2685 experiment. They are useful for tracepoints that trigger each
2686 other, so for instance one tracepoint can count hits in a variable,
2687 and then a second tracepoint has a condition that is true when the
2688 count reaches a particular value. Trace state variables share the
2689 $-syntax of GDB convenience variables, and can appear in both
2690 tracepoint actions and condition expressions. Use the "tvariable"
2691 command to create, and "info tvariables" to view; see "Trace State
2692 Variables" in the manual for more detail.
2696 GDB now includes an option for defining fast tracepoints, which
2697 targets may implement more efficiently, such as by installing a jump
2698 into the target agent rather than a trap instruction. The resulting
2699 speedup can be by two orders of magnitude or more, although the
2700 tradeoff is that some program locations on some target architectures
2701 might not allow fast tracepoint installation, for instance if the
2702 instruction to be replaced is shorter than the jump. To request a
2703 fast tracepoint, use the "ftrace" command, with syntax identical to
2704 the regular trace command.
2706 ** Disconnected tracing
2708 It is now possible to detach GDB from the target while it is running
2709 a trace experiment, then reconnect later to see how the experiment
2710 is going. In addition, a new variable disconnected-tracing lets you
2711 tell the target agent whether to continue running a trace if the
2712 connection is lost unexpectedly.
2716 GDB now has the ability to save the trace buffer into a file, and
2717 then use that file as a target, similarly to you can do with
2718 corefiles. You can select trace frames, print data that was
2719 collected in them, and use tstatus to display the state of the
2720 tracing run at the moment that it was saved. To create a trace
2721 file, use "tsave <filename>", and to use it, do "target tfile
2724 ** Circular trace buffer
2726 You can ask the target agent to handle the trace buffer as a
2727 circular buffer, discarding the oldest trace frames to make room for
2728 newer ones, by setting circular-trace-buffer to on. This feature may
2729 not be available for all target agents.
2734 The disassemble command, when invoked with two arguments, now requires
2735 the arguments to be comma-separated.
2738 The info variables command now displays variable definitions. Files
2739 which only declare a variable are not shown.
2742 The source command is now capable of sourcing Python scripts.
2743 This feature is dependent on the debugger being build with Python
2746 Related to this enhancement is also the introduction of a new command
2747 "set script-extension" (see below).
2749 * New commands (for set/show, see "New options" below)
2751 record save [<FILENAME>]
2752 Save a file (in core file format) containing the process record
2753 execution log for replay debugging at a later time.
2755 record restore <FILENAME>
2756 Restore the process record execution log that was saved at an
2757 earlier time, for replay debugging.
2759 add-inferior [-copies <N>] [-exec <FILENAME>]
2762 clone-inferior [-copies <N>] [ID]
2763 Make a new inferior ready to execute the same program another
2764 inferior has loaded.
2769 maint info program-spaces
2770 List the program spaces loaded into GDB.
2772 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2773 show remote interrupt-sequence
2774 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2775 as the sequence to the remote target in order to interrupt the execution.
2776 Ctrl-C is a default. Some system prefers BREAK which is high level of
2777 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2778 Magic SysRq g. It is BREAK signal and character 'g'.
2780 set remote interrupt-on-connect [on | off]
2781 show remote interrupt-on-connect
2782 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2783 remote target when gdb connects to it. This is needed when you debug
2786 set remotebreak [on | off]
2788 Deprecated. Use "set/show remote interrupt-sequence" instead.
2790 tvariable $NAME [ = EXP ]
2791 Create or modify a trace state variable.
2794 List trace state variables and their values.
2796 delete tvariable $NAME ...
2797 Delete one or more trace state variables.
2800 Evaluate the given expressions without collecting anything into the
2801 trace buffer. (Valid in tracepoint actions only.)
2803 ftrace FN / FILE:LINE / *ADDR
2804 Define a fast tracepoint at the given function, line, or address.
2806 * New expression syntax
2808 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2809 GDB now parses 0b101010 identically with 42.
2813 set follow-exec-mode new|same
2814 show follow-exec-mode
2815 Control whether GDB reuses the same inferior across an exec call or
2816 creates a new one. This is useful to be able to restart the old
2817 executable after the inferior having done an exec call.
2819 set default-collect EXPR, ...
2820 show default-collect
2821 Define a list of expressions to be collected at each tracepoint.
2822 This is a useful way to ensure essential items are not overlooked,
2823 such as registers or a critical global variable.
2825 set disconnected-tracing
2826 show disconnected-tracing
2827 If set to 1, the target is instructed to continue tracing if it
2828 loses its connection to GDB. If 0, the target is to stop tracing
2831 set circular-trace-buffer
2832 show circular-trace-buffer
2833 If set to on, the target is instructed to use a circular trace buffer
2834 and discard the oldest trace frames instead of stopping the trace due
2835 to a full trace buffer. If set to off, the trace stops when the buffer
2836 fills up. Some targets may not support this.
2838 set script-extension off|soft|strict
2839 show script-extension
2840 If set to "off", the debugger does not perform any script language
2841 recognition, and all sourced files are assumed to be GDB scripts.
2842 If set to "soft" (the default), files are sourced according to
2843 filename extension, falling back to GDB scripts if the first
2845 If set to "strict", files are sourced according to filename extension.
2847 set ada trust-PAD-over-XVS on|off
2848 show ada trust-PAD-over-XVS
2849 If off, activate a workaround against a bug in the debugging information
2850 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2851 the GCC sources for more information about the GNAT encoding and
2852 PAD types in particular). It is always safe to set this option to
2853 off, but this introduces a slight performance penalty. The default
2856 * Python API Improvements
2858 ** GDB provides the new class gdb.LazyString. This is useful in
2859 some pretty-printing cases. The new method gdb.Value.lazy_string
2860 provides a simple way to create objects of this type.
2862 ** The fields returned by gdb.Type.fields now have an
2863 `is_base_class' attribute.
2865 ** The new method gdb.Type.range returns the range of an array type.
2867 ** The new method gdb.parse_and_eval can be used to parse and
2868 evaluate an expression.
2870 * New remote packets
2873 Define a trace state variable.
2876 Get the current value of a trace state variable.
2879 Set desired tracing behavior upon disconnection.
2882 Set the trace buffer to be linear or circular.
2885 Get data about the tracepoints currently in use.
2889 Process record now works correctly with hardware watchpoints.
2891 Multiple bug fixes have been made to the mips-irix port, making it
2892 much more reliable. In particular:
2893 - Debugging threaded applications is now possible again. Previously,
2894 GDB would hang while starting the program, or while waiting for
2895 the program to stop at a breakpoint.
2896 - Attaching to a running process no longer hangs.
2897 - An error occurring while loading a core file has been fixed.
2898 - Changing the value of the PC register now works again. This fixes
2899 problems observed when using the "jump" command, or when calling
2900 a function from GDB, or even when assigning a new value to $pc.
2901 - With the "finish" and "return" commands, the return value for functions
2902 returning a small array is now correctly printed.
2903 - It is now possible to break on shared library code which gets executed
2904 during a shared library init phase (code executed while executing
2905 their .init section). Previously, the breakpoint would have no effect.
2906 - GDB is now able to backtrace through the signal handler for
2907 non-threaded programs.
2909 PIE (Position Independent Executable) programs debugging is now supported.
2910 This includes debugging execution of PIC (Position Independent Code) shared
2911 libraries although for that, it should be possible to run such libraries as an
2914 *** Changes in GDB 7.0
2916 * GDB now has an interface for JIT compilation. Applications that
2917 dynamically generate code can create symbol files in memory and register
2918 them with GDB. For users, the feature should work transparently, and
2919 for JIT developers, the interface is documented in the GDB manual in the
2920 "JIT Compilation Interface" chapter.
2922 * Tracepoints may now be conditional. The syntax is as for
2923 breakpoints; either an "if" clause appended to the "trace" command,
2924 or the "condition" command is available. GDB sends the condition to
2925 the target for evaluation using the same bytecode format as is used
2926 for tracepoint actions.
2928 * The disassemble command now supports: an optional /r modifier, print the
2929 raw instructions in hex as well as in symbolic form, and an optional /m
2930 modifier to print mixed source+assembly.
2932 * Process record and replay
2934 In a architecture environment that supports ``process record and
2935 replay'', ``process record and replay'' target can record a log of
2936 the process execution, and replay it with both forward and reverse
2939 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2940 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2941 set execution-direction {forward|reverse}, for targets that support
2944 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2945 feature is available with a native GDB running on kernel version
2948 * GDB now has support for multi-byte and wide character sets on the
2949 target. Strings whose character type is wchar_t, char16_t, or
2950 char32_t are now correctly printed. GDB supports wide- and unicode-
2951 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2952 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2953 `printf'. This feature requires iconv to work properly; if your
2954 system does not have a working iconv, GDB can use GNU libiconv. See
2955 the installation instructions for more information.
2957 * GDB now supports automatic retrieval of shared library files from
2958 remote targets. To use this feature, specify a system root that begins
2959 with the `remote:' prefix, either via the `set sysroot' command or via
2960 the `--with-sysroot' configure-time option.
2962 * "info sharedlibrary" now takes an optional regex of libraries to show,
2963 and it now reports if a shared library has no debugging information.
2965 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2966 now complete on file names.
2968 * When completing in expressions, gdb will attempt to limit
2969 completions to allowable structure or union fields, where appropriate.
2970 For instance, consider:
2972 # struct example { int f1; double f2; };
2973 # struct example variable;
2976 If the user types TAB at the end of this command line, the available
2977 completions will be "f1" and "f2".
2979 * Inlined functions are now supported. They show up in backtraces, and
2980 the "step", "next", and "finish" commands handle them automatically.
2982 * GDB now supports the token-splicing (##) and stringification (#)
2983 operators when expanding macros. It also supports variable-arity
2986 * GDB now supports inspecting extra signal information, exported by
2987 the new $_siginfo convenience variable. The feature is currently
2988 implemented on linux ARM, i386 and amd64.
2990 * GDB can now display the VFP floating point registers and NEON vector
2991 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2992 can provide these registers (requires Linux 2.6.30 or later). Remote
2993 and simulator targets may also provide them.
2995 * New remote packets
2998 Search memory for a sequence of bytes.
3001 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3002 operation over reliable transport links. Use of this packet is
3003 controlled by the `set remote noack-packet' command.
3006 Kill the process with the specified process ID. Use this in preference
3007 to `k' when multiprocess protocol extensions are supported.
3010 Obtains additional operating system information
3014 Read or write additional signal information.
3016 * Removed remote protocol undocumented extension
3018 An undocumented extension to the remote protocol's `S' stop reply
3019 packet that permited the stub to pass a process id was removed.
3020 Remote servers should use the `T' stop reply packet instead.
3022 * GDB now supports multiple function calling conventions according to the
3023 DWARF-2 DW_AT_calling_convention function attribute.
3025 * The SH target utilizes the aforementioned change to distinguish between gcc
3026 and Renesas calling convention. It also adds the new CLI commands
3027 `set/show sh calling-convention'.
3029 * GDB can now read compressed debug sections, as produced by GNU gold
3030 with the --compress-debug-sections=zlib flag.
3032 * 64-bit core files are now supported on AIX.
3034 * Thread switching is now supported on Tru64.
3036 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3037 which will be allocated using malloc later in program execution.
3039 * The qXfer:libraries:read remote procotol packet now allows passing a
3040 list of section offsets.
3042 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3043 conditions handling signals delivered during attach or thread creation
3044 have also been fixed.
3046 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3047 From the user's standpoint, all unqualified instances of True and False
3048 are treated as the standard definitions, regardless of context.
3050 * GDB now parses C++ symbol and type names more flexibly. For
3053 template<typename T> class C { };
3056 GDB will now correctly handle all of:
3058 ptype C<char const *>
3059 ptype C<char const*>
3060 ptype C<const char *>
3061 ptype C<const char*>
3063 * New features in the GDB remote stub, gdbserver
3065 - The "--wrapper" command-line argument tells gdbserver to use a
3066 wrapper program to launch programs for debugging.
3068 - On PowerPC and S/390 targets, it is now possible to use a single
3069 gdbserver executable to debug both 32-bit and 64-bit programs.
3070 (This requires gdbserver itself to be built as a 64-bit executable.)
3072 - gdbserver uses the new noack protocol mode for TCP connections to
3073 reduce communications latency, if also supported and enabled in GDB.
3075 - Support for the sparc64-linux-gnu target is now included in
3078 - The amd64-linux build of gdbserver now supports debugging both
3079 32-bit and 64-bit programs.
3081 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3082 now support hardware watchpoints, and will use them automatically
3087 GDB now has support for scripting using Python. Whether this is
3088 available is determined at configure time.
3090 New GDB commands can now be written in Python.
3092 * Ada tasking support
3094 Ada tasks can now be inspected in GDB. The following commands have
3098 Print the list of Ada tasks.
3100 Print detailed information about task number N.
3102 Print the task number of the current task.
3104 Switch the context of debugging to task number N.
3106 * Support for user-defined prefixed commands. The "define" command can
3107 add new commands to existing prefixes, e.g. "target".
3109 * Multi-inferior, multi-process debugging.
3111 GDB now has generalized support for multi-inferior debugging. See
3112 "Debugging Multiple Inferiors" in the manual for more information.
3113 Although availability still depends on target support, the command
3114 set is more uniform now. The GNU/Linux specific multi-forks support
3115 has been migrated to this new framework. This implied some user
3116 visible changes; see "New commands" and also "Removed commands"
3119 * Target descriptions can now describe the target OS ABI. See the
3120 "Target Description Format" section in the user manual for more
3123 * Target descriptions can now describe "compatible" architectures
3124 to indicate that the target can execute applications for a different
3125 architecture in addition to those for the main target architecture.
3126 See the "Target Description Format" section in the user manual for
3129 * Multi-architecture debugging.
3131 GDB now includes general supports for debugging applications on
3132 hybrid systems that use more than one single processor architecture
3133 at the same time. Each such hybrid architecture still requires
3134 specific support to be added. The only hybrid architecture supported
3135 in this version of GDB is the Cell Broadband Engine.
3137 * GDB now supports integrated debugging of Cell/B.E. applications that
3138 use both the PPU and SPU architectures. To enable support for hybrid
3139 Cell/B.E. debugging, you need to configure GDB to support both the
3140 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3141 --enable-targets configure option.
3143 * Non-stop mode debugging.
3145 For some targets, GDB now supports an optional mode of operation in
3146 which you can examine stopped threads while other threads continue
3147 to execute freely. This is referred to as non-stop mode, with the
3148 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3149 section in the user manual for more information.
3151 To be able to support remote non-stop debugging, a remote stub needs
3152 to implement the non-stop mode remote protocol extensions, as
3153 described in the "Remote Non-Stop" section of the user manual. The
3154 GDB remote stub, gdbserver, has been adjusted to support these
3155 extensions on linux targets.
3157 * New commands (for set/show, see "New options" below)
3159 catch syscall [NAME(S) | NUMBER(S)]
3160 Catch system calls. Arguments, which should be names of system
3161 calls or their numbers, mean catch only those syscalls. Without
3162 arguments, every syscall will be caught. When the inferior issues
3163 any of the specified syscalls, GDB will stop and announce the system
3164 call, both when it is called and when its call returns. This
3165 feature is currently available with a native GDB running on the
3166 Linux Kernel, under the following architectures: x86, x86_64,
3167 PowerPC and PowerPC64.
3169 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3171 Search memory for a sequence of bytes.
3173 maint set python print-stack
3174 maint show python print-stack
3175 Show a stack trace when an error is encountered in a Python script.
3178 Invoke CODE by passing it to the Python interpreter.
3183 These allow macros to be defined, undefined, and listed
3187 Show operating system information about processes.
3190 List the inferiors currently under GDB's control.
3193 Switch focus to inferior number NUM.
3196 Detach from inferior number NUM.
3199 Kill inferior number NUM.
3203 set spu stop-on-load
3204 show spu stop-on-load
3205 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3207 set spu auto-flush-cache
3208 show spu auto-flush-cache
3209 Control whether to automatically flush the software-managed cache
3210 during Cell/B.E. debugging.
3212 set sh calling-convention
3213 show sh calling-convention
3214 Control the calling convention used when calling SH target functions.
3217 show debug timestamp
3218 Control display of timestamps with GDB debugging output.
3220 set disassemble-next-line
3221 show disassemble-next-line
3222 Control display of disassembled source lines or instructions when
3225 set remote noack-packet
3226 show remote noack-packet
3227 Set/show the use of remote protocol QStartNoAckMode packet. See above
3228 under "New remote packets."
3230 set remote query-attached-packet
3231 show remote query-attached-packet
3232 Control use of remote protocol `qAttached' (query-attached) packet.
3234 set remote read-siginfo-object
3235 show remote read-siginfo-object
3236 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3239 set remote write-siginfo-object
3240 show remote write-siginfo-object
3241 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3244 set remote reverse-continue
3245 show remote reverse-continue
3246 Control use of remote protocol 'bc' (reverse-continue) packet.
3248 set remote reverse-step
3249 show remote reverse-step
3250 Control use of remote protocol 'bs' (reverse-step) packet.
3252 set displaced-stepping
3253 show displaced-stepping
3254 Control displaced stepping mode. Displaced stepping is a way to
3255 single-step over breakpoints without removing them from the debuggee.
3256 Also known as "out-of-line single-stepping".
3259 show debug displaced
3260 Control display of debugging info for displaced stepping.
3262 maint set internal-error
3263 maint show internal-error
3264 Control what GDB does when an internal error is detected.
3266 maint set internal-warning
3267 maint show internal-warning
3268 Control what GDB does when an internal warning is detected.
3273 Use a wrapper program to launch programs for debugging.
3275 set multiple-symbols (all|ask|cancel)
3276 show multiple-symbols
3277 The value of this variable can be changed to adjust the debugger behavior
3278 when an expression or a breakpoint location contains an ambiguous symbol
3279 name (an overloaded function name, for instance).
3281 set breakpoint always-inserted
3282 show breakpoint always-inserted
3283 Keep breakpoints always inserted in the target, as opposed to inserting
3284 them when resuming the target, and removing them when the target stops.
3285 This option can improve debugger performance on slow remote targets.
3287 set arm fallback-mode (arm|thumb|auto)
3288 show arm fallback-mode
3289 set arm force-mode (arm|thumb|auto)
3291 These commands control how ARM GDB determines whether instructions
3292 are ARM or Thumb. The default for both settings is auto, which uses
3293 the current CPSR value for instructions without symbols; previous
3294 versions of GDB behaved as if "set arm fallback-mode arm".
3296 set disable-randomization
3297 show disable-randomization
3298 Standalone programs run with the virtual address space randomization enabled
3299 by default on some platforms. This option keeps the addresses stable across
3300 multiple debugging sessions.
3304 Control whether other threads are stopped or not when some thread hits
3309 Requests that asynchronous execution is enabled in the target, if available.
3310 In this case, it's possible to resume target in the background, and interact
3311 with GDB while the target is running. "show target-async" displays the
3312 current state of asynchronous execution of the target.
3314 set target-wide-charset
3315 show target-wide-charset
3316 The target-wide-charset is the name of the character set that GDB
3317 uses when printing characters whose type is wchar_t.
3319 set tcp auto-retry (on|off)
3321 set tcp connect-timeout
3322 show tcp connect-timeout
3323 These commands allow GDB to retry failed TCP connections to a remote stub
3324 with a specified timeout period; this is useful if the stub is launched
3325 in parallel with GDB but may not be ready to accept connections immediately.
3327 set libthread-db-search-path
3328 show libthread-db-search-path
3329 Control list of directories which GDB will search for appropriate
3332 set schedule-multiple (on|off)
3333 show schedule-multiple
3334 Allow GDB to resume all threads of all processes or only threads of
3335 the current process.
3339 Use more aggressive caching for accesses to the stack. This improves
3340 performance of remote debugging (particularly backtraces) without
3341 affecting correctness.
3343 set interactive-mode (on|off|auto)
3344 show interactive-mode
3345 Control whether GDB runs in interactive mode (on) or not (off).
3346 When in interactive mode, GDB waits for the user to answer all
3347 queries. Otherwise, GDB does not wait and assumes the default
3348 answer. When set to auto (the default), GDB determines which
3349 mode to use based on the stdin settings.
3354 For program forks, this is replaced by the new more generic `info
3355 inferiors' command. To list checkpoints, you can still use the
3356 `info checkpoints' command, which was an alias for the `info forks'
3360 Replaced by the new `inferior' command. To switch between
3361 checkpoints, you can still use the `restart' command, which was an
3362 alias for the `fork' command.
3365 This is removed, since some targets don't have a notion of
3366 processes. To switch between processes, you can still use the
3367 `inferior' command using GDB's own inferior number.
3370 For program forks, this is replaced by the new more generic `kill
3371 inferior' command. To delete a checkpoint, you can still use the
3372 `delete checkpoint' command, which was an alias for the `delete
3376 For program forks, this is replaced by the new more generic `detach
3377 inferior' command. To detach a checkpoint, you can still use the
3378 `detach checkpoint' command, which was an alias for the `detach
3381 * New native configurations
3383 x86/x86_64 Darwin i[34567]86-*-darwin*
3385 x86_64 MinGW x86_64-*-mingw*
3389 Lattice Mico32 lm32-*
3390 x86 DICOS i[34567]86-*-dicos*
3391 x86_64 DICOS x86_64-*-dicos*
3394 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3395 (mingw32ce) debugging.
3401 These commands were actually not implemented on any target.
3403 *** Changes in GDB 6.8
3405 * New native configurations
3407 NetBSD/hppa hppa*-*netbsd*
3408 Xtensa GNU/Linux xtensa*-*-linux*
3412 NetBSD/hppa hppa*-*-netbsd*
3413 Xtensa GNU/Lunux xtensa*-*-linux*
3415 * Change in command line behavior -- corefiles vs. process ids.
3417 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3418 attaching to process NUMBER fails, GDB no longer attempts to open a
3419 core file named NUMBER. Attaching to a program using the -c option
3420 is no longer supported. Instead, use the '-p' or '--pid' options.
3422 * GDB can now be built as a native debugger for debugging Windows x86
3423 (mingw32) Portable Executable (PE) programs.
3425 * Pending breakpoints no longer change their number when their address
3428 * GDB now supports breakpoints with multiple locations,
3429 including breakpoints on C++ constructors, inside C++ templates,
3430 and in inlined functions.
3432 * GDB's ability to debug optimized code has been improved. GDB more
3433 accurately identifies function bodies and lexical blocks that occupy
3434 more than one contiguous range of addresses.
3436 * Target descriptions can now describe registers for PowerPC.
3438 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3439 registers on PowerPC targets.
3441 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3442 targets even when the libthread_db library is not available.
3444 * The GDB remote stub, gdbserver, now supports the new file transfer
3445 commands (remote put, remote get, and remote delete).
3447 * The GDB remote stub, gdbserver, now supports run and attach in
3448 extended-remote mode.
3450 * hppa*64*-*-hpux11* target broken
3451 The debugger is unable to start a program and fails with the following
3452 error: "Error trying to get information about dynamic linker".
3453 The gdb-6.7 release is also affected.
3455 * GDB now supports the --enable-targets= configure option to allow
3456 building a single GDB executable that supports multiple remote
3457 target architectures.
3459 * GDB now supports debugging C and C++ programs which use the
3460 Decimal Floating Point extension. In addition, the PowerPC target
3461 now has a set of pseudo-registers to inspect decimal float values
3462 stored in two consecutive float registers.
3464 * The -break-insert MI command can optionally create pending
3467 * Improved support for debugging Ada
3468 Many improvements to the Ada language support have been made. These
3470 - Better support for Ada2005 interface types
3471 - Improved handling of arrays and slices in general
3472 - Better support for Taft-amendment types
3473 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3475 - Improved command completion in Ada
3478 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3483 set print frame-arguments (all|scalars|none)
3484 show print frame-arguments
3485 The value of this variable can be changed to control which argument
3486 values should be printed by the debugger when displaying a frame.
3491 Transfer files to and from a remote target, and delete remote files.
3498 Transfer files to and from a remote target, and delete remote files.
3500 * New remote packets
3507 Open, close, read, write, and delete files on the remote system.
3510 Attach to an existing process on the remote system, in extended-remote
3514 Run a new process on the remote system, in extended-remote mode.
3516 *** Changes in GDB 6.7
3518 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3519 bfd, libiberty and opcodes, as revealed by static analysis donated by
3520 Coverity, Inc. (http://scan.coverity.com).
3522 * When looking up multiply-defined global symbols, GDB will now prefer the
3523 symbol definition in the current shared library if it was built using the
3524 -Bsymbolic linker option.
3526 * When the Text User Interface (TUI) is not configured, GDB will now
3527 recognize the -tui command-line option and print a message that the TUI
3530 * The GDB remote stub, gdbserver, now has lower overhead for high
3531 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3533 * GDB for MIPS targets now autodetects whether a remote target provides
3534 32-bit or 64-bit register values.
3536 * Support for C++ member pointers has been improved.
3538 * GDB now understands XML target descriptions, which specify the
3539 target's overall architecture. GDB can read a description from
3540 a local file or over the remote serial protocol.
3542 * Vectors of single-byte data use a new integer type which is not
3543 automatically displayed as character or string data.
3545 * The /s format now works with the print command. It displays
3546 arrays of single-byte integers and pointers to single-byte integers
3549 * Target descriptions can now describe target-specific registers,
3550 for architectures which have implemented the support (currently
3551 only ARM, M68K, and MIPS).
3553 * GDB and the GDB remote stub, gdbserver, now support the XScale
3556 * The GDB remote stub, gdbserver, has been updated to support
3557 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3558 has been rewritten to use the standard GDB remote protocol.
3560 * GDB can now step into C++ functions which are called through thunks.
3562 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3564 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3565 layout. It also supports a TextSeg= and DataSeg= response when only
3566 segment base addresses (rather than offsets) are available.
3568 * The /i format now outputs any trailing branch delay slot instructions
3569 immediately following the last instruction within the count specified.
3571 * The GDB remote protocol "T" stop reply packet now supports a
3572 "library" response. Combined with the new "qXfer:libraries:read"
3573 packet, this response allows GDB to debug shared libraries on targets
3574 where the operating system manages the list of loaded libraries (e.g.
3575 Windows and SymbianOS).
3577 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3578 (DLLs) on Windows and Windows CE targets.
3580 * GDB now supports a faster verification that a .debug file matches its binary
3581 according to its build-id signature, if the signature is present.
3587 Enable or disable hardware flow control (RTS/CTS) on the serial port
3588 when debugging using remote targets.
3590 set mem inaccessible-by-default
3591 show mem inaccessible-by-default
3592 If the target supplies a memory map, for instance via the remote
3593 protocol's "qXfer:memory-map:read" packet, setting this variable
3594 prevents GDB from accessing memory outside the memory map. This
3595 is useful for targets with memory mapped registers or which react
3596 badly to accesses of unmapped address space.
3598 set breakpoint auto-hw
3599 show breakpoint auto-hw
3600 If the target supplies a memory map, for instance via the remote
3601 protocol's "qXfer:memory-map:read" packet, setting this variable
3602 lets GDB use hardware breakpoints automatically for memory regions
3603 where it can not use software breakpoints. This covers both the
3604 "break" command and internal breakpoints used for other commands
3605 including "next" and "finish".
3608 catch exception unhandled
3609 Stop the program execution when Ada exceptions are raised.
3612 Stop the program execution when an Ada assertion failed.
3616 Set an alternate system root for target files. This is a more
3617 general version of "set solib-absolute-prefix", which is now
3618 an alias to "set sysroot".
3621 Provide extended SPU facility status information. This set of
3622 commands is available only when debugging the Cell/B.E. SPU
3625 * New native configurations
3627 OpenBSD/sh sh*-*openbsd*
3630 unset tdesc filename
3632 Use the specified local file as an XML target description, and do
3633 not query the target for its built-in description.
3637 OpenBSD/sh sh*-*-openbsd*
3638 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3639 Toshiba Media Processor mep-elf
3641 * New remote packets
3644 Ignore the specified signals; pass them directly to the debugged program
3645 without stopping other threads or reporting them to GDB.
3647 qXfer:features:read:
3648 Read an XML target description from the target, which describes its
3653 Read or write contents of an spufs file on the target system. These
3654 packets are available only on the Cell/B.E. SPU architecture.
3656 qXfer:libraries:read:
3657 Report the loaded shared libraries. Combined with new "T" packet
3658 response, this packet allows GDB to debug shared libraries on
3659 targets where the operating system manages the list of loaded
3660 libraries (e.g. Windows and SymbianOS).
3664 Support for these obsolete configurations has been removed.
3672 i[34567]86-*-lynxos*
3673 i[34567]86-*-netware*
3674 i[34567]86-*-sco3.2v5*
3675 i[34567]86-*-sco3.2v4*
3677 i[34567]86-*-sysv4.2*
3680 i[34567]86-*-unixware2*
3681 i[34567]86-*-unixware*
3690 * Other removed features
3697 Various m68k-only ROM monitors.
3704 Various Renesas ROM monitors and debugging interfaces for SH and
3709 Support for a Macraigor serial interface to on-chip debugging.
3710 GDB does not directly support the newer parallel or USB
3715 A debug information format. The predecessor to DWARF 2 and
3716 DWARF 3, which are still supported.
3718 Support for the HP aCC compiler on HP-UX/PA-RISC
3720 SOM-encapsulated symbolic debugging information, automatic
3721 invocation of pxdb, and the aCC custom C++ ABI. This does not
3722 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3723 with aCC can still be debugged on an assembly level.
3725 MIPS ".pdr" sections
3727 A MIPS-specific format used to describe stack frame layout
3728 in debugging information.
3732 GDB could work with an older version of Guile to debug
3733 the interpreter and Scheme programs running in it.
3735 set mips stack-arg-size
3736 set mips saved-gpreg-size
3738 Use "set mips abi" to control parameter passing for MIPS.
3740 *** Changes in GDB 6.6
3745 Cell Broadband Engine SPU spu-elf
3747 * GDB can now be configured as a cross-debugger targeting native Windows
3748 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3749 running on a Windows system over TCP/IP to debug Windows programs.
3751 * The GDB remote stub, gdbserver, has been updated to support Windows and
3752 Cygwin debugging. Both single-threaded and multi-threaded programs are
3755 * The "set trust-readonly-sections" command works again. This command was
3756 broken in GDB 6.3, 6.4, and 6.5.
3758 * The "load" command now supports writing to flash memory, if the remote
3759 stub provides the required support.
3761 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3762 longer requires symbolic debug information (e.g. DWARF-2).
3767 unset substitute-path
3768 show substitute-path
3769 Manage a list of substitution rules that GDB uses to rewrite the name
3770 of the directories where the sources are located. This can be useful
3771 for instance when the sources were moved to a different location
3772 between compilation and debugging.
3776 Print each CLI command as it is executed. Each command is prefixed with
3777 a number of `+' symbols representing the nesting depth.
3778 The source command now has a `-v' option to enable the same feature.
3782 The ARM Demon monitor support (RDP protocol, "target rdp").
3784 Kernel Object Display, an embedded debugging feature which only worked with
3785 an obsolete version of Cisco IOS.
3787 The 'set download-write-size' and 'show download-write-size' commands.
3789 * New remote packets
3792 Tell a stub about GDB client features, and request remote target features.
3793 The first feature implemented is PacketSize, which allows the target to
3794 specify the size of packets it can handle - to minimize the number of
3795 packets required and improve performance when connected to a remote
3799 Fetch an OS auxilliary vector from the remote stub. This packet is a
3800 more efficient replacement for qPart:auxv:read.
3802 qXfer:memory-map:read:
3803 Fetch a memory map from the remote stub, including information about
3804 RAM, ROM, and flash memory devices.
3809 Erase and program a flash memory device.
3811 * Removed remote packets
3814 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3815 used it, and only gdbserver implemented it.
3817 *** Changes in GDB 6.5
3821 Renesas M32C/M16C m32c-elf
3823 Morpho Technologies ms1 ms1-elf
3827 init-if-undefined Initialize a convenience variable, but
3828 only if it doesn't already have a value.
3830 The following commands are presently only implemented for native GNU/Linux:
3832 checkpoint Save a snapshot of the program state.
3834 restart <n> Return the program state to a
3835 previously saved state.
3837 info checkpoints List currently saved checkpoints.
3839 delete-checkpoint <n> Delete a previously saved checkpoint.
3841 set|show detach-on-fork Tell gdb whether to detach from a newly
3842 forked process, or to keep debugging it.
3844 info forks List forks of the user program that
3845 are available to be debugged.
3847 fork <n> Switch to debugging one of several
3848 forks of the user program that are
3849 available to be debugged.
3851 delete-fork <n> Delete a fork from the list of forks
3852 that are available to be debugged (and
3853 kill the forked process).
3855 detach-fork <n> Delete a fork from the list of forks
3856 that are available to be debugged (and
3857 allow the process to continue).
3861 Morpho Technologies ms2 ms1-elf
3863 * Improved Windows host support
3865 GDB now builds as a cross debugger hosted on i686-mingw32, including
3866 native console support, and remote communications using either
3867 network sockets or serial ports.
3869 * Improved Modula-2 language support
3871 GDB can now print most types in the Modula-2 syntax. This includes:
3872 basic types, set types, record types, enumerated types, range types,
3873 pointer types and ARRAY types. Procedure var parameters are correctly
3874 printed and hexadecimal addresses and character constants are also
3875 written in the Modula-2 syntax. Best results can be obtained by using
3876 GNU Modula-2 together with the -gdwarf-2 command line option.
3880 The ARM rdi-share module.
3882 The Netware NLM debug server.
3884 *** Changes in GDB 6.4
3886 * New native configurations
3888 OpenBSD/arm arm*-*-openbsd*
3889 OpenBSD/mips64 mips64-*-openbsd*
3893 Morpho Technologies ms1 ms1-elf
3895 * New command line options
3897 --batch-silent As for --batch, but totally silent.
3898 --return-child-result The debugger will exist with the same value
3899 the child (debugged) program exited with.
3900 --eval-command COMMAND, -ex COMMAND
3901 Execute a single GDB CLI command. This may be
3902 specified multiple times and in conjunction
3903 with the --command (-x) option.
3905 * Deprecated commands removed
3907 The following commands, that were deprecated in 2000, have been
3911 set|show arm disassembly-flavor set|show arm disassembler
3912 othernames set arm disassembler
3913 set|show remotedebug set|show debug remote
3914 set|show archdebug set|show debug arch
3915 set|show eventdebug set|show debug event
3918 * New BSD user-level threads support
3920 It is now possible to debug programs using the user-level threads
3921 library on OpenBSD and FreeBSD. Currently supported (target)
3924 FreeBSD/amd64 x86_64-*-freebsd*
3925 FreeBSD/i386 i386-*-freebsd*
3926 OpenBSD/i386 i386-*-openbsd*
3928 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3929 are not yet supported.
3931 * New support for Matsushita MN10300 w/sim added
3932 (Work in progress). mn10300-elf.
3934 * REMOVED configurations and files
3936 VxWorks and the XDR protocol *-*-vxworks
3937 Motorola MCORE mcore-*-*
3938 National Semiconductor NS32000 ns32k-*-*
3940 * New "set print array-indexes" command
3942 After turning this setting "on", GDB prints the index of each element
3943 when displaying arrays. The default is "off" to preserve the previous
3946 * VAX floating point support
3948 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3950 * User-defined command support
3952 In addition to using $arg0..$arg9 for argument passing, it is now possible
3953 to use $argc to determine now many arguments have been passed. See the
3954 section on user-defined commands in the user manual for more information.
3956 *** Changes in GDB 6.3:
3958 * New command line option
3960 GDB now accepts -l followed by a number to set the timeout for remote
3963 * GDB works with GCC -feliminate-dwarf2-dups
3965 GDB now supports a more compact representation of DWARF-2 debug
3966 information using DW_FORM_ref_addr references. These are produced
3967 by GCC with the option -feliminate-dwarf2-dups and also by some
3968 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3969 to use -feliminate-dwarf2-dups.
3971 * Internationalization
3973 When supported by the host system, GDB will be built with
3974 internationalization (libintl). The task of marking up the sources is
3975 continued, we're looking forward to our first translation.
3979 Initial support for debugging programs compiled with the GNAT
3980 implementation of the Ada programming language has been integrated
3981 into GDB. In this release, support is limited to expression evaluation.
3983 * New native configurations
3985 GNU/Linux/m32r m32r-*-linux-gnu
3989 GDB's remote protocol now includes support for the 'p' packet. This
3990 packet is used to fetch individual registers from a remote inferior.
3992 * END-OF-LIFE registers[] compatibility module
3994 GDB's internal register infrastructure has been completely rewritten.
3995 The new infrastructure making possible the implementation of key new
3996 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3999 GDB 6.3 will be the last release to include the the registers[]
4000 compatibility module that allowed out-of-date configurations to
4001 continue to work. This change directly impacts the following
4011 powerpc bdm protocol
4013 Unless there is activity to revive these configurations, they will be
4014 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4016 * OBSOLETE configurations and files
4018 Configurations that have been declared obsolete in this release have
4019 been commented out. Unless there is activity to revive these
4020 configurations, the next release of GDB will have their sources
4021 permanently REMOVED.
4030 *** Changes in GDB 6.2.1:
4032 * MIPS `break main; run' gave an heuristic-fence-post warning
4034 When attempting to run even a simple program, a warning about
4035 heuristic-fence-post being hit would be reported. This problem has
4038 * MIPS IRIX 'long double' crashed GDB
4040 When examining a long double variable, GDB would get a segmentation
4041 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4042 IRIX long double values).
4046 A bug in the VAX stack code was causing problems with the "next"
4047 command. This problem has been fixed.
4049 *** Changes in GDB 6.2:
4051 * Fix for ``many threads''
4053 On GNU/Linux systems that use the NPTL threads library, a program
4054 rapidly creating and deleting threads would confuse GDB leading to the
4057 ptrace: No such process.
4058 thread_db_get_info: cannot get thread info: generic error
4060 This problem has been fixed.
4062 * "-async" and "-noasync" options removed.
4064 Support for the broken "-noasync" option has been removed (it caused
4067 * New ``start'' command.
4069 This command runs the program until the begining of the main procedure.
4071 * New BSD Kernel Data Access Library (libkvm) interface
4073 Using ``target kvm'' it is now possible to debug kernel core dumps and
4074 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4075 platforms. Currently supported (native-only) configurations are:
4077 FreeBSD/amd64 x86_64-*-freebsd*
4078 FreeBSD/i386 i?86-*-freebsd*
4079 NetBSD/i386 i?86-*-netbsd*
4080 NetBSD/m68k m68*-*-netbsd*
4081 NetBSD/sparc sparc-*-netbsd*
4082 OpenBSD/amd64 x86_64-*-openbsd*
4083 OpenBSD/i386 i?86-*-openbsd*
4084 OpenBSD/m68k m68*-openbsd*
4085 OpenBSD/sparc sparc-*-openbsd*
4087 * Signal trampoline code overhauled
4089 Many generic problems with GDB's signal handling code have been fixed.
4090 These include: backtraces through non-contiguous stacks; recognition
4091 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4092 call; backtrace through a signal trampoline; step into and out of
4093 signal handlers; and single-stepping in the signal trampoline.
4095 Please note that kernel bugs are a limiting factor here. These
4096 features have been shown to work on an s390 GNU/Linux system that
4097 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4099 * Cygwin support for DWARF 2 added.
4101 * New native configurations
4103 GNU/Linux/hppa hppa*-*-linux*
4104 OpenBSD/hppa hppa*-*-openbsd*
4105 OpenBSD/m68k m68*-*-openbsd*
4106 OpenBSD/m88k m88*-*-openbsd*
4107 OpenBSD/powerpc powerpc-*-openbsd*
4108 NetBSD/vax vax-*-netbsd*
4109 OpenBSD/vax vax-*-openbsd*
4111 * END-OF-LIFE frame compatibility module
4113 GDB's internal frame infrastructure has been completely rewritten.
4114 The new infrastructure making it possible to support key new features
4115 including DWARF 2 Call Frame Information. To aid in the task of
4116 migrating old configurations to this new infrastructure, a
4117 compatibility module, that allowed old configurations to continue to
4118 work, was also included.
4120 GDB 6.2 will be the last release to include this frame compatibility
4121 module. This change directly impacts the following configurations:
4131 Unless there is activity to revive these configurations, they will be
4132 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4134 * REMOVED configurations and files
4136 Sun 3, running SunOS 3 m68*-*-sunos3*
4137 Sun 3, running SunOS 4 m68*-*-sunos4*
4138 Sun 2, running SunOS 3 m68000-*-sunos3*
4139 Sun 2, running SunOS 4 m68000-*-sunos4*
4140 Motorola 680x0 running LynxOS m68*-*-lynxos*
4141 AT&T 3b1/Unix pc m68*-att-*
4142 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4143 decstation mips-dec-* mips-little-*
4144 riscos mips-*-riscos* mips-*-sysv*
4145 sonymips mips-sony-*
4146 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4148 *** Changes in GDB 6.1.1:
4150 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4152 The TUI (Text-mode User Interface) is now built as part of a default
4153 GDB configuration. It is enabled by either selecting the TUI with the
4154 command line option "-i=tui" or by running the separate "gdbtui"
4155 program. For more information on the TUI, see the manual "Debugging
4158 * Pending breakpoint support (also included in GDB 6.1)
4160 Support has been added to allow you to specify breakpoints in shared
4161 libraries that have not yet been loaded. If a breakpoint location
4162 cannot be found, and the "breakpoint pending" option is set to auto,
4163 GDB queries you if you wish to make the breakpoint pending on a future
4164 shared-library load. If and when GDB resolves the breakpoint symbol,
4165 the pending breakpoint is removed as one or more regular breakpoints
4168 Pending breakpoints are very useful for GCJ Java debugging.
4170 * Fixed ISO-C build problems
4172 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4173 non ISO-C code that stopped them being built using a more strict ISO-C
4174 compiler (e.g., IBM's C compiler).
4176 * Fixed build problem on IRIX 5
4178 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4179 wasn't able to compile compile on an IRIX 5 system.
4181 * Added execute permission to gdb/gdbserver/configure
4183 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4184 permission. This bug would cause configure to fail on a number of
4185 systems (Solaris, IRIX). Ref: server/519.
4187 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4189 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4190 has been updated to use constant array sizes.
4192 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4194 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4195 its generated DWARF Call Frame Info. This encoding was causing GDB to
4196 panic, that panic has been fixed. Ref: gdb/1628.
4198 * Fixed a problem when examining parameters in shared library code.
4200 When examining parameters in optimized shared library code generated
4201 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4202 not available''. GDB now correctly displays the variable's value.
4204 *** Changes in GDB 6.1:
4206 * Removed --with-mmalloc
4208 Support for the mmalloc memory manager has been removed, as it
4209 conflicted with the internal gdb byte cache.
4211 * Changes in AMD64 configurations
4213 The AMD64 target now includes the %cs and %ss registers. As a result
4214 the AMD64 remote protocol has changed; this affects the floating-point
4215 and SSE registers. If you rely on those registers for your debugging,
4216 you should upgrade gdbserver on the remote side.
4218 * Revised SPARC target
4220 The SPARC target has been completely revised, incorporating the
4221 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4222 support for LynxOS and SunOS 4 has been dropped. Calling functions
4223 from within GDB on operating systems with a non-executable stack
4224 (Solaris, OpenBSD) now works.
4228 GDB has a new C++ demangler which does a better job on the mangled
4229 names generated by current versions of g++. It also runs faster, so
4230 with this and other changes gdb should now start faster on large C++
4233 * DWARF 2 Location Expressions
4235 GDB support for location expressions has been extended to support function
4236 arguments and frame bases. Older versions of GDB could crash when they
4239 * C++ nested types and namespaces
4241 GDB's support for nested types and namespaces in C++ has been
4242 improved, especially if you use the DWARF 2 debugging format. (This
4243 is the default for recent versions of GCC on most platforms.)
4244 Specifically, if you have a class "Inner" defined within a class or
4245 namespace "Outer", then GDB realizes that the class's name is
4246 "Outer::Inner", not simply "Inner". This should greatly reduce the
4247 frequency of complaints about not finding RTTI symbols. In addition,
4248 if you are stopped at inside of a function defined within a namespace,
4249 GDB modifies its name lookup accordingly.
4251 * New native configurations
4253 NetBSD/amd64 x86_64-*-netbsd*
4254 OpenBSD/amd64 x86_64-*-openbsd*
4255 OpenBSD/alpha alpha*-*-openbsd*
4256 OpenBSD/sparc sparc-*-openbsd*
4257 OpenBSD/sparc64 sparc64-*-openbsd*
4259 * New debugging protocols
4261 M32R with SDI protocol m32r-*-elf*
4263 * "set prompt-escape-char" command deleted.
4265 The command "set prompt-escape-char" has been deleted. This command,
4266 and its very obscure effet on GDB's prompt, was never documented,
4267 tested, nor mentioned in the NEWS file.
4269 * OBSOLETE configurations and files
4271 Configurations that have been declared obsolete in this release have
4272 been commented out. Unless there is activity to revive these
4273 configurations, the next release of GDB will have their sources
4274 permanently REMOVED.
4276 Sun 3, running SunOS 3 m68*-*-sunos3*
4277 Sun 3, running SunOS 4 m68*-*-sunos4*
4278 Sun 2, running SunOS 3 m68000-*-sunos3*
4279 Sun 2, running SunOS 4 m68000-*-sunos4*
4280 Motorola 680x0 running LynxOS m68*-*-lynxos*
4281 AT&T 3b1/Unix pc m68*-att-*
4282 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4283 decstation mips-dec-* mips-little-*
4284 riscos mips-*-riscos* mips-*-sysv*
4285 sonymips mips-sony-*
4286 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4288 * REMOVED configurations and files
4290 SGI Irix-4.x mips-sgi-irix4 or iris4
4291 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4292 Z8000 simulator z8k-zilog-none or z8ksim
4293 Matsushita MN10200 w/simulator mn10200-*-*
4294 H8/500 simulator h8500-hitachi-hms or h8500hms
4295 HP/PA running BSD hppa*-*-bsd*
4296 HP/PA running OSF/1 hppa*-*-osf*
4297 HP/PA Pro target hppa*-*-pro*
4298 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4299 386BSD i[3456]86-*-bsd*
4300 Sequent family i[3456]86-sequent-sysv4*
4301 i[3456]86-sequent-sysv*
4302 i[3456]86-sequent-bsd*
4303 SPARC running LynxOS sparc-*-lynxos*
4304 SPARC running SunOS 4 sparc-*-sunos4*
4305 Tsqware Sparclet sparclet-*-*
4306 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4308 *** Changes in GDB 6.0:
4312 Support for debugging the Objective-C programming language has been
4313 integrated into GDB.
4315 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4317 DWARF 2's Call Frame Information makes available compiler generated
4318 information that more exactly describes the program's run-time stack.
4319 By using this information, GDB is able to provide more robust stack
4322 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4323 have been updated to use a new backtrace mechanism which includes
4324 DWARF 2 CFI support.
4328 GDB's remote protocol has been extended to include support for hosted
4329 file I/O (where the remote target uses GDB's file system). See GDB's
4330 remote protocol documentation for details.
4332 * All targets using the new architecture framework.
4334 All of GDB's targets have been updated to use the new internal
4335 architecture framework. The way is now open for future GDB releases
4336 to include cross-architecture native debugging support (i386 on amd64,
4339 * GNU/Linux's Thread Local Storage (TLS)
4341 GDB now includes support for for the GNU/Linux implementation of
4342 per-thread variables.
4344 * GNU/Linux's Native POSIX Thread Library (NPTL)
4346 GDB's thread code has been updated to work with either the new
4347 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4349 * Separate debug info.
4351 GDB, in conjunction with BINUTILS, now supports a mechanism for
4352 automatically loading debug information from a separate file. Instead
4353 of shipping full debug and non-debug versions of system libraries,
4354 system integrators can now instead ship just the stripped libraries
4355 and optional debug files.
4357 * DWARF 2 Location Expressions
4359 DWARF 2 Location Expressions allow the compiler to more completely
4360 describe the location of variables (even in optimized code) to the
4363 GDB now includes preliminary support for location expressions (support
4364 for DW_OP_piece is still missing).
4368 A number of long standing bugs that caused GDB to die while starting a
4369 Java application have been fixed. GDB's Java support is now
4370 considered "useable".
4372 * GNU/Linux support for fork, vfork, and exec.
4374 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4375 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4378 * GDB supports logging output to a file
4380 There are two new commands, "set logging" and "show logging", which can be
4381 used to capture GDB's output to a file.
4383 * The meaning of "detach" has changed for gdbserver
4385 The "detach" command will now resume the application, as documented. To
4386 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4389 * d10v, m68hc11 `regs' command deprecated
4391 The `info registers' command has been updated so that it displays the
4392 registers using a format identical to the old `regs' command.
4396 A new command, "maint set profile on/off", has been added. This command can
4397 be used to enable or disable profiling while running GDB, to profile a
4398 session or a set of commands. In addition there is a new configure switch,
4399 "--enable-profiling", which will cause GDB to be compiled with profiling
4400 data, for more informative profiling results.
4402 * Default MI syntax changed to "mi2".
4404 The default MI (machine interface) syntax, enabled by the command line
4405 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4406 "mi1", can be enabled by specifying the option "-i=mi1".
4408 Support for the original "mi0" syntax (included in GDB 5.0) has been
4411 Fix for gdb/192: removed extraneous space when displaying frame level.
4412 Fix for gdb/672: update changelist is now output in mi list format.
4413 Fix for gdb/702: a -var-assign that updates the value now shows up
4414 in a subsequent -var-update.
4416 * New native configurations.
4418 FreeBSD/amd64 x86_64-*-freebsd*
4420 * Multi-arched targets.
4422 HP/PA HPUX11 hppa*-*-hpux*
4423 Renesas M32R/D w/simulator m32r-*-elf*
4425 * OBSOLETE configurations and files
4427 Configurations that have been declared obsolete in this release have
4428 been commented out. Unless there is activity to revive these
4429 configurations, the next release of GDB will have their sources
4430 permanently REMOVED.
4432 Z8000 simulator z8k-zilog-none or z8ksim
4433 Matsushita MN10200 w/simulator mn10200-*-*
4434 H8/500 simulator h8500-hitachi-hms or h8500hms
4435 HP/PA running BSD hppa*-*-bsd*
4436 HP/PA running OSF/1 hppa*-*-osf*
4437 HP/PA Pro target hppa*-*-pro*
4438 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4439 Sequent family i[3456]86-sequent-sysv4*
4440 i[3456]86-sequent-sysv*
4441 i[3456]86-sequent-bsd*
4442 Tsqware Sparclet sparclet-*-*
4443 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4445 * REMOVED configurations and files
4448 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4449 IBM AIX PS/2 i[3456]86-*-aix
4450 i386 running Mach 3.0 i[3456]86-*-mach3*
4451 i386 running Mach i[3456]86-*-mach*
4452 i386 running OSF/1 i[3456]86-*osf1mk*
4453 HP/Apollo 68k Family m68*-apollo*-sysv*,
4455 m68*-hp-bsd*, m68*-hp-hpux*
4456 Argonaut Risc Chip (ARC) arc-*-*
4457 Mitsubishi D30V d30v-*-*
4458 Fujitsu FR30 fr30-*-elf*
4459 OS/9000 i[34]86-*-os9k
4460 I960 with MON960 i960-*-coff
4462 * MIPS $fp behavior changed
4464 The convenience variable $fp, for the MIPS, now consistently returns
4465 the address of the current frame's base. Previously, depending on the
4466 context, $fp could refer to either $sp or the current frame's base
4467 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4468 The GNU Source-Level Debugger''.
4470 *** Changes in GDB 5.3:
4472 * GNU/Linux shared library multi-threaded performance improved.
4474 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4475 `/proc', in preference to `ptrace' for memory reads. This may result
4476 in an improvement in the start-up time of multi-threaded, shared
4477 library applications when run under GDB. One GDB user writes: ``loads
4478 shared libs like mad''.
4480 * ``gdbserver'' now supports multi-threaded applications on some targets
4482 Support for debugging multi-threaded applications which use
4483 the GNU/Linux LinuxThreads package has been added for
4484 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4485 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4487 * GDB now supports C/C++ preprocessor macros.
4489 GDB now expands preprocessor macro invocations in C/C++ expressions,
4490 and provides various commands for showing macro definitions and how
4493 The new command `macro expand EXPRESSION' expands any macro
4494 invocations in expression, and shows the result.
4496 The new command `show macro MACRO-NAME' shows the definition of the
4497 macro named MACRO-NAME, and where it was defined.
4499 Most compilers don't include information about macros in the debugging
4500 information by default. In GCC 3.1, for example, you need to compile
4501 your program with the options `-gdwarf-2 -g3'. If the macro
4502 information is present in the executable, GDB will read it.
4504 * Multi-arched targets.
4506 DEC Alpha (partial) alpha*-*-*
4507 DEC VAX (partial) vax-*-*
4509 National Semiconductor NS32000 (partial) ns32k-*-*
4510 Motorola 68000 (partial) m68k-*-*
4511 Motorola MCORE mcore-*-*
4515 Fujitsu FRV architecture added by Red Hat frv*-*-*
4518 * New native configurations
4520 Alpha NetBSD alpha*-*-netbsd*
4521 SH NetBSD sh*-*-netbsdelf*
4522 MIPS NetBSD mips*-*-netbsd*
4523 UltraSPARC NetBSD sparc64-*-netbsd*
4525 * OBSOLETE configurations and files
4527 Configurations that have been declared obsolete in this release have
4528 been commented out. Unless there is activity to revive these
4529 configurations, the next release of GDB will have their sources
4530 permanently REMOVED.
4532 Mitsubishi D30V d30v-*-*
4533 OS/9000 i[34]86-*-os9k
4534 IBM AIX PS/2 i[3456]86-*-aix
4535 Fujitsu FR30 fr30-*-elf*
4536 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4537 Argonaut Risc Chip (ARC) arc-*-*
4538 i386 running Mach 3.0 i[3456]86-*-mach3*
4539 i386 running Mach i[3456]86-*-mach*
4540 i386 running OSF/1 i[3456]86-*osf1mk*
4541 HP/Apollo 68k Family m68*-apollo*-sysv*,
4543 m68*-hp-bsd*, m68*-hp-hpux*
4544 I960 with MON960 i960-*-coff
4546 * OBSOLETE languages
4548 CHILL, a Pascal like language used by telecommunications companies.
4550 * REMOVED configurations and files
4552 AMD 29k family via UDI a29k-amd-udi, udi29k
4553 A29K VxWorks a29k-*-vxworks
4554 AMD 29000 embedded, using EBMON a29k-none-none
4555 AMD 29000 embedded with COFF a29k-none-coff
4556 AMD 29000 embedded with a.out a29k-none-aout
4558 testsuite/gdb.hp/gdb.threads-hp/ directory
4560 * New command "set max-user-call-depth <nnn>"
4562 This command allows the user to limit the call depth of user-defined
4563 commands. The default is 1024.
4565 * Changes in FreeBSD/i386 native debugging.
4567 Support for the "generate-core-file" has been added.
4569 * New commands "dump", "append", and "restore".
4571 These commands allow data to be copied from target memory
4572 to a bfd-format or binary file (dump and append), and back
4573 from a file into memory (restore).
4575 * Improved "next/step" support on multi-processor Alpha Tru64.
4577 The previous single-step mechanism could cause unpredictable problems,
4578 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4579 of a software single-step mechanism prevents this.
4581 *** Changes in GDB 5.2.1:
4589 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4590 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4591 Fix, by Joel Brobecker imported from mainline.
4593 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4594 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4595 Fix, by Fred Fish, imported from mainline.
4597 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4598 Surprisingly enough, it works now.
4599 By Michal Ludvig, imported from mainline.
4601 i386 hardware watchpoint support:
4602 avoid misses on second run for some targets.
4603 By Pierre Muller, imported from mainline.
4605 *** Changes in GDB 5.2:
4607 * New command "set trust-readonly-sections on[off]".
4609 This command is a hint that tells gdb that read-only sections
4610 really are read-only (ie. that their contents will not change).
4611 In this mode, gdb will go to the object file rather than the
4612 target to read memory from read-only sections (such as ".text").
4613 This can be a significant performance improvement on some
4614 (notably embedded) targets.
4616 * New command "generate-core-file" (or "gcore").
4618 This new gdb command allows the user to drop a core file of the child
4619 process state at any time. So far it's been implemented only for
4620 GNU/Linux and Solaris, but should be relatively easily ported to other
4621 hosts. Argument is core file name (defaults to core.<pid>).
4623 * New command line option
4625 GDB now accepts --pid or -p followed by a process id.
4627 * Change in command line behavior -- corefiles vs. process ids.
4629 There is a subtle behavior in the way in which GDB handles
4630 command line arguments. The first non-flag argument is always
4631 a program to debug, but the second non-flag argument may either
4632 be a corefile or a process id. Previously, GDB would attempt to
4633 open the second argument as a corefile, and if that failed, would
4634 issue a superfluous error message and then attempt to attach it as
4635 a process. Now, if the second argument begins with a non-digit,
4636 it will be treated as a corefile. If it begins with a digit,
4637 GDB will attempt to attach it as a process, and if no such process
4638 is found, will then attempt to open it as a corefile.
4640 * Changes in ARM configurations.
4642 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4643 configuration is fully multi-arch.
4645 * New native configurations
4647 ARM NetBSD arm*-*-netbsd*
4648 x86 OpenBSD i[3456]86-*-openbsd*
4649 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4650 Sparc64 running FreeBSD sparc64-*-freebsd*
4654 Sanyo XStormy16 xstormy16-elf
4656 * OBSOLETE configurations and files
4658 Configurations that have been declared obsolete in this release have
4659 been commented out. Unless there is activity to revive these
4660 configurations, the next release of GDB will have their sources
4661 permanently REMOVED.
4663 AMD 29k family via UDI a29k-amd-udi, udi29k
4664 A29K VxWorks a29k-*-vxworks
4665 AMD 29000 embedded, using EBMON a29k-none-none
4666 AMD 29000 embedded with COFF a29k-none-coff
4667 AMD 29000 embedded with a.out a29k-none-aout
4669 testsuite/gdb.hp/gdb.threads-hp/ directory
4671 * REMOVED configurations and files
4673 TI TMS320C80 tic80-*-*
4675 PowerPC Solaris powerpcle-*-solaris*
4676 PowerPC Windows NT powerpcle-*-cygwin32
4677 PowerPC Netware powerpc-*-netware*
4678 Harris/CXUX m88k m88*-harris-cxux*
4679 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4680 ns32k-utek-sysv* ns32k-utek-*
4681 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4682 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4683 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4684 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4685 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4687 * Changes to command line processing
4689 The new `--args' feature can be used to specify command-line arguments
4690 for the inferior from gdb's command line.
4692 * Changes to key bindings
4694 There is a new `operate-and-get-next' function bound to `C-o'.
4696 *** Changes in GDB 5.1.1
4698 Fix compile problem on DJGPP.
4700 Fix a problem with floating-point registers on the i386 being
4703 Fix to stop GDB crashing on .debug_str debug info.
4705 Numerous documentation fixes.
4707 Numerous testsuite fixes.
4709 *** Changes in GDB 5.1:
4711 * New native configurations
4713 Alpha FreeBSD alpha*-*-freebsd*
4714 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4715 MIPS GNU/Linux mips*-*-linux*
4716 MIPS SGI Irix 6.x mips*-sgi-irix6*
4717 ia64 AIX ia64-*-aix*
4718 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4722 Motorola 68HC11 and 68HC12 m68hc11-elf
4724 UltraSparc running GNU/Linux sparc64-*-linux*
4726 * OBSOLETE configurations and files
4728 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4729 Harris/CXUX m88k m88*-harris-cxux*
4730 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4731 ns32k-utek-sysv* ns32k-utek-*
4732 TI TMS320C80 tic80-*-*
4734 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4735 PowerPC Solaris powerpcle-*-solaris*
4736 PowerPC Windows NT powerpcle-*-cygwin32
4737 PowerPC Netware powerpc-*-netware*
4738 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4739 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4740 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4741 Apple Macintosh (MPW) host N/A
4743 stuff.c (Program to stuff files into a specially prepared space in kdb)
4744 kdb-start.c (Main loop for the standalone kernel debugger)
4746 Configurations that have been declared obsolete in this release have
4747 been commented out. Unless there is activity to revive these
4748 configurations, the next release of GDB will have their sources
4749 permanently REMOVED.
4751 * REMOVED configurations and files
4753 Altos 3068 m68*-altos-*
4754 Convex c1-*-*, c2-*-*
4756 ARM RISCix arm-*-* (as host)
4760 * GDB has been converted to ISO C.
4762 GDB's source code has been converted to ISO C. In particular, the
4763 sources are fully protoized, and rely on standard headers being
4768 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4770 * The MI enabled by default.
4772 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4773 revised and enabled by default. Packages which use GDB as a debugging
4774 engine behind a UI or another front end are encouraged to switch to
4775 using the GDB/MI interface, instead of the old annotations interface
4776 which is now deprecated.
4778 * Support for debugging Pascal programs.
4780 GDB now includes support for debugging Pascal programs. The following
4781 main features are supported:
4783 - Pascal-specific data types such as sets;
4785 - automatic recognition of Pascal sources based on file-name
4788 - Pascal-style display of data types, variables, and functions;
4790 - a Pascal expression parser.
4792 However, some important features are not yet supported.
4794 - Pascal string operations are not supported at all;
4796 - there are some problems with boolean types;
4798 - Pascal type hexadecimal constants are not supported
4799 because they conflict with the internal variables format;
4801 - support for Pascal objects and classes is not full yet;
4803 - unlike Pascal, GDB is case-sensitive for symbol names.
4805 * Changes in completion.
4807 Commands such as `shell', `run' and `set args', which pass arguments
4808 to inferior programs, now complete on file names, similar to what
4809 users expect at the shell prompt.
4811 Commands which accept locations, such as `disassemble', `print',
4812 `breakpoint', `until', etc. now complete on filenames as well as
4813 program symbols. Thus, if you type "break foob TAB", and the source
4814 files linked into the programs include `foobar.c', that file name will
4815 be one of the candidates for completion. However, file names are not
4816 considered for completion after you typed a colon that delimits a file
4817 name from a name of a function in that file, as in "break foo.c:bar".
4819 `set demangle-style' completes on available demangling styles.
4821 * New platform-independent commands:
4823 It is now possible to define a post-hook for a command as well as a
4824 hook that runs before the command. For more details, see the
4825 documentation of `hookpost' in the GDB manual.
4827 * Changes in GNU/Linux native debugging.
4829 Support for debugging multi-threaded programs has been completely
4830 revised for all platforms except m68k and sparc. You can now debug as
4831 many threads as your system allows you to have.
4833 Attach/detach is supported for multi-threaded programs.
4835 Support for SSE registers was added for x86. This doesn't work for
4836 multi-threaded programs though.
4838 * Changes in MIPS configurations.
4840 Multi-arch support is enabled for all MIPS configurations.
4842 GDB can now be built as native debugger on SGI Irix 6.x systems for
4843 debugging n32 executables. (Debugging 64-bit executables is not yet
4846 * Unified support for hardware watchpoints in all x86 configurations.
4848 Most (if not all) native x86 configurations support hardware-assisted
4849 breakpoints and watchpoints in a unified manner. This support
4850 implements debug register sharing between watchpoints, which allows to
4851 put a virtually infinite number of watchpoints on the same address,
4852 and also supports watching regions up to 16 bytes with several debug
4855 The new maintenance command `maintenance show-debug-regs' toggles
4856 debugging print-outs in functions that insert, remove, and test
4857 watchpoints and hardware breakpoints.
4859 * Changes in the DJGPP native configuration.
4861 New command ``info dos sysinfo'' displays assorted information about
4862 the CPU, OS, memory, and DPMI server.
4864 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4865 display information about segment descriptors stored in GDT, LDT, and
4868 New commands ``info dos pde'' and ``info dos pte'' display entries
4869 from Page Directory and Page Tables (for now works with CWSDPMI only).
4870 New command ``info dos address-pte'' displays the Page Table entry for
4871 a given linear address.
4873 GDB can now pass command lines longer than 126 characters to the
4874 program being debugged (requires an update to the libdbg.a library
4875 which is part of the DJGPP development kit).
4877 DWARF2 debug info is now supported.
4879 It is now possible to `step' and `next' through calls to `longjmp'.
4881 * Changes in documentation.
4883 All GDB documentation was converted to GFDL, the GNU Free
4884 Documentation License.
4886 Tracepoints-related commands are now fully documented in the GDB
4889 TUI, the Text-mode User Interface, is now documented in the manual.
4891 Tracepoints-related commands are now fully documented in the GDB
4894 The "GDB Internals" manual now has an index. It also includes
4895 documentation of `ui_out' functions, GDB coding standards, x86
4896 hardware watchpoints, and memory region attributes.
4898 * GDB's version number moved to ``version.in''
4900 The Makefile variable VERSION has been replaced by the file
4901 ``version.in''. People creating GDB distributions should update the
4902 contents of this file.
4906 GUD support is now a standard part of the EMACS distribution.
4908 *** Changes in GDB 5.0:
4910 * Improved support for debugging FP programs on x86 targets
4912 Unified and much-improved support for debugging floating-point
4913 programs on all x86 targets. In particular, ``info float'' now
4914 displays the FP registers in the same format on all x86 targets, with
4915 greater level of detail.
4917 * Improvements and bugfixes in hardware-assisted watchpoints
4919 It is now possible to watch array elements, struct members, and
4920 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4921 on x86 targets no longer erroneously trigger when the address is
4924 * Improvements in the native DJGPP version of GDB
4926 The distribution now includes all the scripts and auxiliary files
4927 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4928 machines ``out of the box''.
4930 The DJGPP version can now debug programs that use signals. It is
4931 possible to catch signals that happened in the debuggee, deliver
4932 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4933 would kill the program being debugged.) Programs that hook hardware
4934 interrupts (keyboard, timer, etc.) can also be debugged.
4936 It is now possible to debug DJGPP programs that redirect their
4937 standard handles or switch them to raw (as opposed to cooked) mode, or
4938 even close them. The command ``run < foo > bar'' works as expected,
4939 and ``info terminal'' reports useful information about the debuggee's
4940 terminal, including raw/cooked mode, redirection, etc.
4942 The DJGPP version now uses termios functions for console I/O, which
4943 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4946 DOS-style file names with drive letters are now fully supported by
4949 It is now possible to debug DJGPP programs that switch their working
4950 directory. It is also possible to rerun the debuggee any number of
4951 times without restarting GDB; thus, you can use the same setup,
4952 breakpoints, etc. for many debugging sessions.
4954 * New native configurations
4956 ARM GNU/Linux arm*-*-linux*
4957 PowerPC GNU/Linux powerpc-*-linux*
4961 Motorola MCore mcore-*-*
4962 x86 VxWorks i[3456]86-*-vxworks*
4963 PowerPC VxWorks powerpc-*-vxworks*
4964 TI TMS320C80 tic80-*-*
4966 * OBSOLETE configurations
4968 Altos 3068 m68*-altos-*
4969 Convex c1-*-*, c2-*-*
4971 ARM RISCix arm-*-* (as host)
4974 Configurations that have been declared obsolete will be commented out,
4975 but the code will be left in place. If there is no activity to revive
4976 these configurations before the next release of GDB, the sources will
4977 be permanently REMOVED.
4979 * Gould support removed
4981 Support for the Gould PowerNode and NP1 has been removed.
4983 * New features for SVR4
4985 On SVR4 native platforms (such as Solaris), if you attach to a process
4986 without first loading a symbol file, GDB will now attempt to locate and
4987 load symbols from the running process's executable file.
4989 * Many C++ enhancements
4991 C++ support has been greatly improved. Overload resolution now works properly
4992 in almost all cases. RTTI support is on the way.
4994 * Remote targets can connect to a sub-program
4996 A popen(3) style serial-device has been added. This device starts a
4997 sub-process (such as a stand-alone simulator) and then communicates
4998 with that. The sub-program to run is specified using the syntax
4999 ``|<program> <args>'' vis:
5001 (gdb) set remotedebug 1
5002 (gdb) target extended-remote |mn10300-elf-sim program-args
5004 * MIPS 64 remote protocol
5006 A long standing bug in the mips64 remote protocol where by GDB
5007 expected certain 32 bit registers (ex SR) to be transfered as 32
5008 instead of 64 bits has been fixed.
5010 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5011 added to provide backward compatibility with older versions of GDB.
5013 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5015 The command ``set remotebinarydownload'' command has been replaced by
5016 ``set remote X-packet''. Other commands in ``set remote'' family
5017 include ``set remote P-packet''.
5019 * Breakpoint commands accept ranges.
5021 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5022 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5023 ``tracepoint passcount'' also accepts a range of tracepoints.
5025 * ``apropos'' command added.
5027 The ``apropos'' command searches through command names and
5028 documentation strings, printing out matches, making it much easier to
5029 try to find a command that does what you are looking for.
5033 A new machine oriented interface (MI) has been added to GDB. This
5034 interface is designed for debug environments running GDB as a separate
5035 process. This is part of the long term libGDB project. See the
5036 "GDB/MI" chapter of the GDB manual for further information. It can be
5037 enabled by configuring with:
5039 .../configure --enable-gdbmi
5041 *** Changes in GDB-4.18:
5043 * New native configurations
5045 HP-UX 10.20 hppa*-*-hpux10.20
5046 HP-UX 11.x hppa*-*-hpux11.0*
5047 M68K GNU/Linux m68*-*-linux*
5051 Fujitsu FR30 fr30-*-elf*
5052 Intel StrongARM strongarm-*-*
5053 Mitsubishi D30V d30v-*-*
5055 * OBSOLETE configurations
5057 Gould PowerNode, NP1 np1-*-*, pn-*-*
5059 Configurations that have been declared obsolete will be commented out,
5060 but the code will be left in place. If there is no activity to revive
5061 these configurations before the next release of GDB, the sources will
5062 be permanently REMOVED.
5066 As a compatibility experiment, GDB's source files buildsym.h and
5067 buildsym.c have been converted to pure standard C, no longer
5068 containing any K&R compatibility code. We believe that all systems in
5069 use today either come with a standard C compiler, or have a GCC port
5070 available. If this is not true, please report the affected
5071 configuration to bug-gdb@gnu.org immediately. See the README file for
5072 information about getting a standard C compiler if you don't have one
5077 GDB now uses readline 2.2.
5079 * set extension-language
5081 You can now control the mapping between filename extensions and source
5082 languages by using the `set extension-language' command. For instance,
5083 you can ask GDB to treat .c files as C++ by saying
5084 set extension-language .c c++
5085 The command `info extensions' lists all of the recognized extensions
5086 and their associated languages.
5088 * Setting processor type for PowerPC and RS/6000
5090 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5091 you can use the `set processor' command to specify what variant of the
5092 PowerPC family you are debugging. The command
5096 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5097 following PowerPC and RS6000 variants:
5099 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5100 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5102 403GC IBM PowerPC 403GC
5103 505 Motorola PowerPC 505
5104 860 Motorola PowerPC 860 or 850
5105 601 Motorola PowerPC 601
5106 602 Motorola PowerPC 602
5107 603 Motorola/IBM PowerPC 603 or 603e
5108 604 Motorola PowerPC 604 or 604e
5109 750 Motorola/IBM PowerPC 750 or 750
5111 At the moment, this command just tells GDB what to name the
5112 special-purpose processor registers. Since almost all the affected
5113 registers are inaccessible to user-level programs, this command is
5114 only useful for remote debugging in its present form.
5118 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5119 more extensive support for HP-UX. Added features include shared
5120 library support, kernel threads and hardware watchpoints for 11.00,
5121 support for HP's ANSI C and C++ compilers, and a compatibility mode
5122 for xdb and dbx commands.
5126 HP's donation includes the new concept of catchpoints, which is a
5127 generalization of the old catch command. On HP-UX, it is now possible
5128 to catch exec, fork, and vfork, as well as library loading.
5130 This means that the existing catch command has changed; its first
5131 argument now specifies the type of catch to be set up. See the
5132 output of "help catch" for a list of catchpoint types.
5134 * Debugging across forks
5136 On HP-UX, you can choose which process to debug when a fork() happens
5141 HP has donated a curses-based terminal user interface (TUI). To get
5142 it, build with --enable-tui. Although this can be enabled for any
5143 configuration, at present it only works for native HP debugging.
5145 * GDB remote protocol additions
5147 A new protocol packet 'X' that writes binary data is now available.
5148 Default behavior is to try 'X', then drop back to 'M' if the stub
5149 fails to respond. The settable variable `remotebinarydownload'
5150 allows explicit control over the use of 'X'.
5152 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5153 full 64-bit address. The command
5155 set remoteaddresssize 32
5157 can be used to revert to the old behaviour. For existing remote stubs
5158 the change should not be noticed, as the additional address information
5161 In order to assist in debugging stubs, you may use the maintenance
5162 command `packet' to send any text string to the stub. For instance,
5164 maint packet heythere
5166 sends the packet "$heythere#<checksum>". Note that it is very easy to
5167 disrupt a debugging session by sending the wrong packet at the wrong
5170 The compare-sections command allows you to compare section data on the
5171 target to what is in the executable file without uploading or
5172 downloading, by comparing CRC checksums.
5174 * Tracing can collect general expressions
5176 You may now collect general expressions at tracepoints. This requires
5177 further additions to the target-side stub; see tracepoint.c and
5178 doc/agentexpr.texi for further details.
5180 * mask-address variable for Mips
5182 For Mips targets, you may control the zeroing of the upper 32 bits of
5183 a 64-bit address by entering `set mask-address on'. This is mainly
5184 of interest to users of embedded R4xxx and R5xxx processors.
5186 * Higher serial baud rates
5188 GDB's serial code now allows you to specify baud rates 57600, 115200,
5189 230400, and 460800 baud. (Note that your host system may not be able
5190 to achieve all of these rates.)
5194 The i960 configuration now includes an initial implementation of a
5195 builtin simulator, contributed by Jim Wilson.
5198 *** Changes in GDB-4.17:
5200 * New native configurations
5202 Alpha GNU/Linux alpha*-*-linux*
5203 Unixware 2.x i[3456]86-unixware2*
5204 Irix 6.x mips*-sgi-irix6*
5205 PowerPC GNU/Linux powerpc-*-linux*
5206 PowerPC Solaris powerpcle-*-solaris*
5207 Sparc GNU/Linux sparc-*-linux*
5208 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5212 Argonaut Risc Chip (ARC) arc-*-*
5213 Hitachi H8/300S h8300*-*-*
5214 Matsushita MN10200 w/simulator mn10200-*-*
5215 Matsushita MN10300 w/simulator mn10300-*-*
5216 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5217 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5218 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5219 Mitsubishi D10V w/simulator d10v-*-*
5220 Mitsubishi M32R/D w/simulator m32r-*-elf*
5221 Tsqware Sparclet sparclet-*-*
5222 NEC V850 w/simulator v850-*-*
5224 * New debugging protocols
5226 ARM with RDI protocol arm*-*-*
5227 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5228 DDB and LSI variants of PMON protocol mips*-*-*
5229 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5230 PowerPC with SDS protocol powerpc{,le}-*-eabi
5231 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5235 All configurations can now understand and use the DWARF 2 debugging
5236 format. The choice is automatic, if the symbol file contains DWARF 2
5241 GDB now includes basic Java language support. This support is
5242 only useful with Java compilers that produce native machine code.
5244 * solib-absolute-prefix and solib-search-path
5246 For SunOS and SVR4 shared libraries, you may now set the prefix for
5247 loading absolute shared library symbol files, and the search path for
5248 locating non-absolute shared library symbol files.
5250 * Live range splitting
5252 GDB can now effectively debug code for which GCC has performed live
5253 range splitting as part of its optimization. See gdb/doc/LRS for
5254 more details on the expected format of the stabs information.
5258 GDB's support for the GNU Hurd, including thread debugging, has been
5259 updated to work with current versions of the Hurd.
5263 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5264 instruction set. ARM GDB automatically detects when Thumb
5265 instructions are in use, and adjusts disassembly and backtracing
5270 GDB's MIPS target configurations now handle the MIP16 16-bit
5275 GDB now includes support for overlays; if an executable has been
5276 linked such that multiple sections are based at the same address, GDB
5277 will decide which section to use for symbolic info. You can choose to
5278 control the decision manually, using overlay commands, or implement
5279 additional target-side support and use "overlay load-target" to bring
5280 in the overlay mapping. Do "help overlay" for more detail.
5284 The command "info symbol <address>" displays information about
5285 the symbol at the specified address.
5289 The standard remote protocol now includes an extension that allows
5290 asynchronous collection and display of trace data. This requires
5291 extensive support in the target-side debugging stub. Tracing mode
5292 includes a new interaction mode in GDB and new commands: see the
5293 file tracepoint.c for more details.
5297 Configurations for embedded MIPS now include a simulator contributed
5298 by Cygnus Solutions. The simulator supports the instruction sets
5299 of most MIPS variants.
5303 Sparc configurations may now include the ERC32 simulator contributed
5304 by the European Space Agency. The simulator is not built into
5305 Sparc targets by default; configure with --enable-sim to include it.
5309 For target configurations that may include multiple variants of a
5310 basic architecture (such as MIPS and SH), you may now set the
5311 architecture explicitly. "set arch" sets, "info arch" lists
5312 the possible architectures.
5314 *** Changes in GDB-4.16:
5316 * New native configurations
5318 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5319 M68K NetBSD m68k-*-netbsd*
5320 PowerPC AIX 4.x powerpc-*-aix*
5321 PowerPC MacOS powerpc-*-macos*
5322 PowerPC Windows NT powerpcle-*-cygwin32
5323 RS/6000 AIX 4.x rs6000-*-aix4*
5327 ARM with RDP protocol arm-*-*
5328 I960 with MON960 i960-*-coff
5329 MIPS VxWorks mips*-*-vxworks*
5330 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5331 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5333 Matra Sparclet sparclet-*-*
5337 The powerpc-eabi configuration now includes the PSIM simulator,
5338 contributed by Andrew Cagney, with assistance from Mike Meissner.
5339 PSIM is a very elaborate model of the PowerPC, including not only
5340 basic instruction set execution, but also details of execution unit
5341 performance and I/O hardware. See sim/ppc/README for more details.
5345 GDB now works with Solaris 2.5.
5347 * Windows 95/NT native
5349 GDB will now work as a native debugger on Windows 95 and Windows NT.
5350 To build it from source, you must use the "gnu-win32" environment,
5351 which uses a DLL to emulate enough of Unix to run the GNU tools.
5352 Further information, binaries, and sources are available at
5353 ftp.cygnus.com, under pub/gnu-win32.
5355 * dont-repeat command
5357 If a user-defined command includes the command `dont-repeat', then the
5358 command will not be repeated if the user just types return. This is
5359 useful if the command is time-consuming to run, so that accidental
5360 extra keystrokes don't run the same command many times.
5362 * Send break instead of ^C
5364 The standard remote protocol now includes an option to send a break
5365 rather than a ^C to the target in order to interrupt it. By default,
5366 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5368 * Remote protocol timeout
5370 The standard remote protocol includes a new variable `remotetimeout'
5371 that allows you to set the number of seconds before GDB gives up trying
5372 to read from the target. The default value is 2.
5374 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5376 By default GDB will automatically keep track of objects as they are
5377 loaded and unloaded by the dynamic linker. By using the command `set
5378 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5379 when shared library events occur, thus allowing you to set breakpoints
5380 in shared libraries which are explicitly loaded by the inferior.
5382 Note this feature does not work on hpux8. On hpux9 you must link
5383 /usr/lib/end.o into your program. This feature should work
5384 automatically on hpux10.
5386 * Irix 5.x hardware watchpoint support
5388 Irix 5 configurations now support the use of hardware watchpoints.
5390 * Mips protocol "SYN garbage limit"
5392 When debugging a Mips target using the `target mips' protocol, you
5393 may set the number of characters that GDB will ignore by setting
5394 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5395 every character. The default value is 1050.
5397 * Recording and replaying remote debug sessions
5399 If you set `remotelogfile' to the name of a file, gdb will write to it
5400 a recording of a remote debug session. This recording may then be
5401 replayed back to gdb using "gdbreplay". See gdbserver/README for
5402 details. This is useful when you have a problem with GDB while doing
5403 remote debugging; you can make a recording of the session and send it
5404 to someone else, who can then recreate the problem.
5406 * Speedups for remote debugging
5408 GDB includes speedups for downloading and stepping MIPS systems using
5409 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5410 and more efficient S-record downloading.
5412 * Memory use reductions and statistics collection
5414 GDB now uses less memory and reports statistics about memory usage.
5415 Try the `maint print statistics' command, for example.
5417 *** Changes in GDB-4.15:
5419 * Psymtabs for XCOFF
5421 The symbol reader for AIX GDB now uses partial symbol tables. This
5422 can greatly improve startup time, especially for large executables.
5424 * Remote targets use caching
5426 Remote targets now use a data cache to speed up communication with the
5427 remote side. The data cache could lead to incorrect results because
5428 it doesn't know about volatile variables, thus making it impossible to
5429 debug targets which use memory mapped I/O devices. `set remotecache
5430 off' turns the the data cache off.
5432 * Remote targets may have threads
5434 The standard remote protocol now includes support for multiple threads
5435 in the target system, using new protocol commands 'H' and 'T'. See
5436 gdb/remote.c for details.
5440 If GDB is configured with `--enable-netrom', then it will include
5441 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5442 acts as though it is a bank of ROM on the target board, but you can
5443 write into it over the network. GDB's support consists only of
5444 support for fast loading into the emulated ROM; to debug, you must use
5445 another protocol, such as standard remote protocol. The usual
5446 sequence is something like
5448 target nrom <netrom-hostname>
5450 target remote <netrom-hostname>:1235
5454 GDB now includes support for the Apple Macintosh, as a host only. It
5455 may be run as either an MPW tool or as a standalone application, and
5456 it can debug through the serial port. All the usual GDB commands are
5457 available, but to the target command, you must supply "serial" as the
5458 device type instead of "/dev/ttyXX". See mpw-README in the main
5459 directory for more information on how to build. The MPW configuration
5460 scripts */mpw-config.in support only a few targets, and only the
5461 mips-idt-ecoff target has been tested.
5465 GDB configuration now uses autoconf. This is not user-visible,
5466 but does simplify configuration and building.
5470 GDB now supports hpux10.
5472 *** Changes in GDB-4.14:
5474 * New native configurations
5476 x86 FreeBSD i[345]86-*-freebsd
5477 x86 NetBSD i[345]86-*-netbsd
5478 NS32k NetBSD ns32k-*-netbsd
5479 Sparc NetBSD sparc-*-netbsd
5483 A29K VxWorks a29k-*-vxworks
5484 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5485 CPU32 EST-300 emulator m68*-*-est*
5486 PowerPC ELF powerpc-*-elf
5489 * Alpha OSF/1 support for procfs
5491 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5492 possible to attach to running processes. As the mounting of the /proc
5493 filesystem is optional on the Alpha, GDB automatically determines
5494 the availability of /proc during startup. This can lead to problems
5495 if /proc is unmounted after GDB has been started.
5497 * Arguments to user-defined commands
5499 User commands may accept up to 10 arguments separated by whitespace.
5500 Arguments are accessed within the user command via $arg0..$arg9. A
5503 print $arg0 + $arg1 + $arg2
5505 To execute the command use:
5508 Defines the command "adder" which prints the sum of its three arguments.
5509 Note the arguments are text substitutions, so they may reference variables,
5510 use complex expressions, or even perform inferior function calls.
5512 * New `if' and `while' commands
5514 This makes it possible to write more sophisticated user-defined
5515 commands. Both commands take a single argument, which is the
5516 expression to evaluate, and must be followed by the commands to
5517 execute, one per line, if the expression is nonzero, the list being
5518 terminated by the word `end'. The `if' command list may include an
5519 `else' word, which causes the following commands to be executed only
5520 if the expression is zero.
5522 * Fortran source language mode
5524 GDB now includes partial support for Fortran 77. It will recognize
5525 Fortran programs and can evaluate a subset of Fortran expressions, but
5526 variables and functions may not be handled correctly. GDB will work
5527 with G77, but does not yet know much about symbols emitted by other
5530 * Better HPUX support
5532 Most debugging facilities now work on dynamic executables for HPPAs
5533 running hpux9 or later. You can attach to running dynamically linked
5534 processes, but by default the dynamic libraries will be read-only, so
5535 for instance you won't be able to put breakpoints in them. To change
5536 that behavior do the following before running the program:
5542 This will cause the libraries to be mapped private and read-write.
5543 To revert to the normal behavior, do this:
5549 You cannot set breakpoints or examine data in the library until after
5550 the library is loaded if the function/data symbols do not have
5553 GDB can now also read debug symbols produced by the HP C compiler on
5554 HPPAs (sorry, no C++, Fortran or 68k support).
5556 * Target byte order now dynamically selectable
5558 You can choose which byte order to use with a target system, via the
5559 commands "set endian big" and "set endian little", and you can see the
5560 current setting by using "show endian". You can also give the command
5561 "set endian auto", in which case GDB will use the byte order
5562 associated with the executable. Currently, only embedded MIPS
5563 configurations support dynamic selection of target byte order.
5565 * New DOS host serial code
5567 This version uses DPMI interrupts to handle buffered I/O, so you
5568 no longer need to run asynctsr when debugging boards connected to
5571 *** Changes in GDB-4.13:
5573 * New "complete" command
5575 This lists all the possible completions for the rest of the line, if it
5576 were to be given as a command itself. This is intended for use by emacs.
5578 * Trailing space optional in prompt
5580 "set prompt" no longer adds a space for you after the prompt you set. This
5581 allows you to set a prompt which ends in a space or one that does not.
5583 * Breakpoint hit counts
5585 "info break" now displays a count of the number of times the breakpoint
5586 has been hit. This is especially useful in conjunction with "ignore"; you
5587 can ignore a large number of breakpoint hits, look at the breakpoint info
5588 to see how many times the breakpoint was hit, then run again, ignoring one
5589 less than that number, and this will get you quickly to the last hit of
5592 * Ability to stop printing at NULL character
5594 "set print null-stop" will cause GDB to stop printing the characters of
5595 an array when the first NULL is encountered. This is useful when large
5596 arrays actually contain only short strings.
5598 * Shared library breakpoints
5600 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5601 breakpoints in shared libraries before the executable is run.
5603 * Hardware watchpoints
5605 There is a new hardware breakpoint for the watch command for sparclite
5606 targets. See gdb/sparclite/hw_breakpoint.note.
5608 Hardware watchpoints are also now supported under GNU/Linux.
5612 Annotations have been added. These are for use with graphical interfaces,
5613 and are still experimental. Currently only gdba.el uses these.
5615 * Improved Irix 5 support
5617 GDB now works properly with Irix 5.2.
5619 * Improved HPPA support
5621 GDB now works properly with the latest GCC and GAS.
5623 * New native configurations
5625 Sequent PTX4 i[34]86-sequent-ptx4
5626 HPPA running OSF/1 hppa*-*-osf*
5627 Atari TT running SVR4 m68*-*-sysv4*
5628 RS/6000 LynxOS rs6000-*-lynxos*
5632 OS/9000 i[34]86-*-os9k
5633 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5636 * Hitachi SH7000 and E7000-PC ICE support
5638 There is now support for communicating with the Hitachi E7000-PC ICE.
5639 This is available automatically when GDB is configured for the SH.
5643 As usual, a variety of small fixes and improvements, both generic
5644 and configuration-specific. See the ChangeLog for more detail.
5646 *** Changes in GDB-4.12:
5648 * Irix 5 is now supported
5652 GDB-4.12 on the HPPA has a number of changes which make it unable
5653 to debug the output from the currently released versions of GCC and
5654 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5655 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5656 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5659 *** Changes in GDB-4.11:
5661 * User visible changes:
5665 The "set remotedebug" option is now consistent between the mips remote
5666 target, remote targets using the gdb-specific protocol, UDI (AMD's
5667 debug protocol for the 29k) and the 88k bug monitor. It is now an
5668 integer specifying a debug level (normally 0 or 1, but 2 means more
5669 debugging info for the mips target).
5671 * DEC Alpha native support
5673 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5674 debug info, but GDB works fairly well with the DEC compiler and should
5675 work with a future GCC release. See the README file for a few
5676 Alpha-specific notes.
5678 * Preliminary thread implementation
5680 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5682 * LynxOS native and target support for 386
5684 This release has been hosted on LynxOS 2.2, and also can be configured
5685 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5688 * Improvements in C++ mangling/demangling.
5690 This release has much better g++ debugging, specifically in name
5691 mangling/demangling, virtual function calls, print virtual table,
5692 call methods, ...etc.
5694 *** Changes in GDB-4.10:
5696 * User visible changes:
5698 Remote debugging using the GDB-specific (`target remote') protocol now
5699 supports the `load' command. This is only useful if you have some
5700 other way of getting the stub to the target system, and you can put it
5701 somewhere in memory where it won't get clobbered by the download.
5703 Filename completion now works.
5705 When run under emacs mode, the "info line" command now causes the
5706 arrow to point to the line specified. Also, "info line" prints
5707 addresses in symbolic form (as well as hex).
5709 All vxworks based targets now support a user settable option, called
5710 vxworks-timeout. This option represents the number of seconds gdb
5711 should wait for responses to rpc's. You might want to use this if
5712 your vxworks target is, perhaps, a slow software simulator or happens
5713 to be on the far side of a thin network line.
5717 This release contains support for using a DEC alpha as a GDB host for
5718 cross debugging. Native alpha debugging is not supported yet.
5721 *** Changes in GDB-4.9:
5725 This is the first GDB release which is accompanied by a matching testsuite.
5726 The testsuite requires installation of dejagnu, which should be available
5727 via ftp from most sites that carry GNU software.
5731 'Cfront' style demangling has had its name changed to 'ARM' style, to
5732 emphasize that it was written from the specifications in the C++ Annotated
5733 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5734 disclaimers, it still generated too much confusion with users attempting to
5735 use gdb with AT&T cfront.
5739 GDB now uses a standard remote interface to a simulator library.
5740 So far, the library contains simulators for the Zilog Z8001/2, the
5741 Hitachi H8/300, H8/500 and Super-H.
5743 * New targets supported
5745 H8/300 simulator h8300-hitachi-hms or h8300hms
5746 H8/500 simulator h8500-hitachi-hms or h8500hms
5747 SH simulator sh-hitachi-hms or sh
5748 Z8000 simulator z8k-zilog-none or z8ksim
5749 IDT MIPS board over serial line mips-idt-ecoff
5751 Cross-debugging to GO32 targets is supported. It requires a custom
5752 version of the i386-stub.c module which is integrated with the
5753 GO32 memory extender.
5755 * New remote protocols
5757 MIPS remote debugging protocol.
5759 * New source languages supported
5761 This version includes preliminary support for Chill, a Pascal like language
5762 used by telecommunications companies. Chill support is also being integrated
5763 into the GNU compiler, but we don't know when it will be publically available.
5766 *** Changes in GDB-4.8:
5768 * HP Precision Architecture supported
5770 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5771 version of this support was available as a set of patches from the
5772 University of Utah. GDB does not support debugging of programs
5773 compiled with the HP compiler, because HP will not document their file
5774 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5775 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5777 Many problems in the preliminary version have been fixed.
5779 * Faster and better demangling
5781 We have improved template demangling and fixed numerous bugs in the GNU style
5782 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5783 character types (wchar_t) are now supported. Demangling of each symbol is now
5784 only done once, and is cached when the symbol table for a file is read in.
5785 This results in a small increase in memory usage for C programs, a moderate
5786 increase in memory usage for C++ programs, and a fantastic speedup in
5789 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5790 from the specifications in the Annotated Reference Manual, which AT&T's
5791 compiler does not actually implement.
5793 * G++ multiple inheritance compiler problem
5795 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5796 inheritance lattices was reworked to properly discover ambiguities. We
5797 recently found an example which causes this new algorithm to fail in a
5798 very subtle way, producing bad debug information for those classes.
5799 The file 'gcc.patch' (in this directory) can be applied to gcc to
5800 circumvent the problem. A future GCC release will contain a complete
5803 The previous G++ debug info problem (mentioned below for the gdb-4.7
5804 release) is fixed in gcc version 2.3.2.
5806 * Improved configure script
5808 The `configure' script will now attempt to guess your system type if
5809 you don't supply a host system type. The old scheme of supplying a
5810 host system triplet is preferable over using this. All the magic is
5811 done in the new `config.guess' script. Examine it for details.
5813 We have also brought our configure script much more in line with the FSF's
5814 version. It now supports the --with-xxx options. In particular,
5815 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5816 The resulting GDB will not be able to read arbitrary object file formats --
5817 only the format ``expected'' to be used on the configured target system.
5818 We hope to make this the default in a future release.
5820 * Documentation improvements
5822 There's new internal documentation on how to modify GDB, and how to
5823 produce clean changes to the code. We implore people to read it
5824 before submitting changes.
5826 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5827 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5828 `info' files are also provided. To build `info' files from scratch,
5829 you will need the latest `makeinfo' release, which will be available in
5830 a future texinfo-X.Y release.
5832 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5833 We're not sure exactly which versions have this problem, but it has
5834 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5835 or better. If that isn't possible, there is a patch in
5836 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5837 around this problem.
5841 GDB now supports array constants that can be used in expressions typed in by
5842 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5843 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5846 The new directory `gdb/sparclite' contains a program that demonstrates
5847 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5849 * New native hosts supported
5851 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5852 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5854 * New targets supported
5856 AMD 29k family via UDI a29k-amd-udi or udi29k
5858 * New file formats supported
5860 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5861 HPUX core files, and SCO 3.2v2 core files.
5865 Attaching to processes now works again; thanks for the many bug reports.
5867 We have also stomped on a bunch of core dumps caused by
5868 printf_filtered("%s") problems.
5870 We eliminated a copyright problem on the rpc and ptrace header files
5871 for VxWorks, which was discovered at the last minute during the 4.7
5872 release. You should now be able to build a VxWorks GDB.
5874 You can now interrupt gdb while an attached process is running. This
5875 will cause the attached process to stop, and give control back to GDB.
5877 We fixed problems caused by using too many file descriptors
5878 for reading symbols from object files and libraries. This was
5879 especially a problem for programs that used many (~100) shared
5882 The `step' command now only enters a subroutine if there is line number
5883 information for the subroutine. Otherwise it acts like the `next'
5884 command. Previously, `step' would enter subroutines if there was
5885 any debugging information about the routine. This avoids problems
5886 when using `cc -g1' on MIPS machines.
5888 * Internal improvements
5890 GDB's internal interfaces have been improved to make it easier to support
5891 debugging of multiple languages in the future.
5893 GDB now uses a common structure for symbol information internally.
5894 Minimal symbols (derived from linkage symbols in object files), partial
5895 symbols (from a quick scan of debug information), and full symbols
5896 contain a common subset of information, making it easier to write
5897 shared code that handles any of them.
5899 * New command line options
5901 We now accept --silent as an alias for --quiet.
5905 The memory-mapped-malloc library is now licensed under the GNU Library
5906 General Public License.
5908 *** Changes in GDB-4.7:
5910 * Host/native/target split
5912 GDB has had some major internal surgery to untangle the support for
5913 hosts and remote targets. Now, when you configure GDB for a remote
5914 target, it will no longer load in all of the support for debugging
5915 local programs on the host. When fully completed and tested, this will
5916 ensure that arbitrary host/target combinations are possible.
5918 The primary conceptual shift is to separate the non-portable code in
5919 GDB into three categories. Host specific code is required any time GDB
5920 is compiled on that host, regardless of the target. Target specific
5921 code relates to the peculiarities of the target, but can be compiled on
5922 any host. Native specific code is everything else: it can only be
5923 built when the host and target are the same system. Child process
5924 handling and core file support are two common `native' examples.
5926 GDB's use of /proc for controlling Unix child processes is now cleaner.
5927 It has been split out into a single module under the `target_ops' vector,
5928 plus two native-dependent functions for each system that uses /proc.
5930 * New hosts supported
5932 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5933 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5934 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5936 * New targets supported
5938 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5939 68030 and CPU32 m68030-*-*, m68332-*-*
5941 * New native hosts supported
5943 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5944 (386bsd is not well tested yet)
5945 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5947 * New file formats supported
5949 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5950 supports reading of `a.out.adobe' object files, which are an a.out
5951 format extended with minimal information about multiple sections.
5955 `show copying' is the same as the old `info copying'.
5956 `show warranty' is the same as `info warrantee'.
5957 These were renamed for consistency. The old commands continue to work.
5959 `info handle' is a new alias for `info signals'.
5961 You can now define pre-command hooks, which attach arbitrary command
5962 scripts to any command. The commands in the hook will be executed
5963 prior to the user's command. You can also create a hook which will be
5964 executed whenever the program stops. See gdb.texinfo.
5968 We now deal with Cfront style name mangling, and can even extract type
5969 info from mangled symbols. GDB can automatically figure out which
5970 symbol mangling style your C++ compiler uses.
5972 Calling of methods and virtual functions has been improved as well.
5976 The crash that occured when debugging Sun Ansi-C compiled binaries is
5977 fixed. This was due to mishandling of the extra N_SO stabs output
5980 We also finally got Ultrix 4.2 running in house, and fixed core file
5981 support, with help from a dozen people on the net.
5983 John M. Farrell discovered that the reason that single-stepping was so
5984 slow on all of the Mips based platforms (primarily SGI and DEC) was
5985 that we were trying to demangle and lookup a symbol used for internal
5986 purposes on every instruction that was being stepped through. Changing
5987 the name of that symbol so that it couldn't be mistaken for a C++
5988 mangled symbol sped things up a great deal.
5990 Rich Pixley sped up symbol lookups in general by getting much smarter
5991 about when C++ symbol mangling is necessary. This should make symbol
5992 completion (TAB on the command line) much faster. It's not as fast as
5993 we'd like, but it's significantly faster than gdb-4.6.
5997 A new user controllable variable 'call_scratch_address' can
5998 specify the location of a scratch area to be used when GDB
5999 calls a function in the target. This is necessary because the
6000 usual method of putting the scratch area on the stack does not work
6001 in systems that have separate instruction and data spaces.
6003 We integrated changes to support the 29k UDI (Universal Debugger
6004 Interface), but discovered at the last minute that we didn't have all
6005 of the appropriate copyright paperwork. We are working with AMD to
6006 resolve this, and hope to have it available soon.
6010 We have sped up the remote serial line protocol, especially for targets
6011 with lots of registers. It now supports a new `expedited status' ('T')
6012 message which can be used in place of the existing 'S' status message.
6013 This allows the remote stub to send only the registers that GDB
6014 needs to make a quick decision about single-stepping or conditional
6015 breakpoints, eliminating the need to fetch the entire register set for
6016 each instruction being stepped through.
6018 The GDB remote serial protocol now implements a write-through cache for
6019 registers, only re-reading the registers if the target has run.
6021 There is also a new remote serial stub for SPARC processors. You can
6022 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6023 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6024 processor with a serial port.
6028 Configure.in files have become much easier to read and modify. A new
6029 `table driven' format makes it more obvious what configurations are
6030 supported, and what files each one uses.
6034 There is a new opcodes library which will eventually contain all of the
6035 disassembly routines and opcode tables. At present, it only contains
6036 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6037 disassembler (binutils/objdump) to share these routines.
6039 The libiberty library is now copylefted under the GNU Library General
6040 Public License. This allows more liberal use, and was done so libg++
6041 can use it. This makes no difference to GDB, since the Library License
6042 grants all the rights from the General Public License.
6046 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6047 reference to the stabs symbol info used by the debugger. It is (as far
6048 as we know) the only published document on this fascinating topic. We
6049 encourage you to read it, compare it to the stabs information on your
6050 system, and send improvements on the document in general (to
6051 bug-gdb@prep.ai.mit.edu).
6053 And, of course, many bugs have been fixed.
6056 *** Changes in GDB-4.6:
6058 * Better support for C++ function names
6060 GDB now accepts as input the "demangled form" of C++ overloaded function
6061 names and member function names, and can do command completion on such names
6062 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6063 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6064 Make use of command completion, it is your friend.
6066 GDB also now accepts a variety of C++ mangled symbol formats. They are
6067 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6068 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6069 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6070 for the list of formats.
6072 * G++ symbol mangling problem
6074 Recent versions of gcc have a bug in how they emit debugging information for
6075 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6076 directory) can be applied to gcc to fix the problem. Alternatively, if you
6077 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6078 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6079 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6082 * New 'maintenance' command
6084 All of the commands related to hacking GDB internals have been moved out of
6085 the main command set, and now live behind the 'maintenance' command. This
6086 can also be abbreviated as 'mt'. The following changes were made:
6088 dump-me -> maintenance dump-me
6089 info all-breakpoints -> maintenance info breakpoints
6090 printmsyms -> maintenance print msyms
6091 printobjfiles -> maintenance print objfiles
6092 printpsyms -> maintenance print psymbols
6093 printsyms -> maintenance print symbols
6095 The following commands are new:
6097 maintenance demangle Call internal GDB demangler routine to
6098 demangle a C++ link name and prints the result.
6099 maintenance print type Print a type chain for a given symbol
6101 * Change to .gdbinit file processing
6103 We now read the $HOME/.gdbinit file before processing the argv arguments
6104 (e.g. reading symbol files or core files). This allows global parameters to
6105 be set, which will apply during the symbol reading. The ./.gdbinit is still
6106 read after argv processing.
6108 * New hosts supported
6110 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6112 GNU/Linux support i386-unknown-linux or linux
6114 We are also including code to support the HP/PA running BSD and HPUX. This
6115 is almost guaranteed not to work, as we didn't have time to test or build it
6116 for this release. We are including it so that the more adventurous (or
6117 masochistic) of you can play with it. We also had major problems with the
6118 fact that the compiler that we got from HP doesn't support the -g option.
6121 * New targets supported
6123 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6125 * More smarts about finding #include files
6127 GDB now remembers the compilation directory for all include files, and for
6128 all files from which C is generated (like yacc and lex sources). This
6129 greatly improves GDB's ability to find yacc/lex sources, and include files,
6130 especially if you are debugging your program from a directory different from
6131 the one that contains your sources.
6133 We also fixed a bug which caused difficulty with listing and setting
6134 breakpoints in include files which contain C code. (In the past, you had to
6135 try twice in order to list an include file that you hadn't looked at before.)
6137 * Interesting infernals change
6139 GDB now deals with arbitrary numbers of sections, where the symbols for each
6140 section must be relocated relative to that section's landing place in the
6141 target's address space. This work was needed to support ELF with embedded
6142 stabs used by Solaris-2.0.
6144 * Bug fixes (of course!)
6146 There have been loads of fixes for the following things:
6147 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6148 i960, stabs, DOS(GO32), procfs, etc...
6150 See the ChangeLog for details.
6152 *** Changes in GDB-4.5:
6154 * New machines supported (host and target)
6156 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6158 SGI Irix-4.x mips-sgi-irix4 or iris4
6160 * New malloc package
6162 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6163 Mmalloc is capable of handling mutiple heaps of memory. It is also
6164 capable of saving a heap to a file, and then mapping it back in later.
6165 This can be used to greatly speedup the startup of GDB by using a
6166 pre-parsed symbol table which lives in a mmalloc managed heap. For
6167 more details, please read mmalloc/mmalloc.texi.
6171 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6172 'help info proc' for details.
6174 * MIPS ecoff symbol table format
6176 The code that reads MIPS symbol table format is now supported on all hosts.
6177 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6180 * File name changes for MS-DOS
6182 Many files in the config directories have been renamed to make it easier to
6183 support GDB on MS-DOSe systems (which have very restrictive file name
6184 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6185 environment) is close to working but has some remaining problems. Note
6186 that debugging of DOS programs is not supported, due to limitations
6187 in the ``operating system'', but it can be used to host cross-debugging.
6189 * Cross byte order fixes
6191 Many fixes have been made to support cross debugging of Sparc and MIPS
6192 targets from hosts whose byte order differs.
6194 * New -mapped and -readnow options
6196 If memory-mapped files are available on your system through the 'mmap'
6197 system call, you can use the -mapped option on the `file' or
6198 `symbol-file' commands to cause GDB to write the symbols from your
6199 program into a reusable file. If the program you are debugging is
6200 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6201 Future GDB debugging sessions will notice the presence of this file,
6202 and will quickly map in symbol information from it, rather than reading
6203 the symbol table from the executable program. Using the '-mapped'
6204 option in a GDB `file' or `symbol-file' command has the same effect as
6205 starting GDB with the '-mapped' command-line option.
6207 You can cause GDB to read the entire symbol table immediately by using
6208 the '-readnow' option with any of the commands that load symbol table
6209 information (or on the GDB command line). This makes the command
6210 slower, but makes future operations faster.
6212 The -mapped and -readnow options are typically combined in order to
6213 build a `fred.syms' file that contains complete symbol information.
6214 A simple GDB invocation to do nothing but build a `.syms' file for future
6217 gdb -batch -nx -mapped -readnow programname
6219 The `.syms' file is specific to the host machine on which GDB is run.
6220 It holds an exact image of GDB's internal symbol table. It cannot be
6221 shared across multiple host platforms.
6223 * longjmp() handling
6225 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6226 siglongjmp() without losing control. This feature has not yet been ported to
6227 all systems. It currently works on many 386 platforms, all MIPS-based
6228 platforms (SGI, DECstation, etc), and Sun3/4.
6232 Preliminary work has been put in to support the new Solaris OS from Sun. At
6233 this time, it can control and debug processes, but it is not capable of
6238 As always, many many bug fixes. The major areas were with g++, and mipsread.
6239 People using the MIPS-based platforms should experience fewer mysterious
6240 crashes and trashed symbol tables.
6242 *** Changes in GDB-4.4:
6244 * New machines supported (host and target)
6246 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6248 BSD Reno on Vax vax-dec-bsd
6249 Ultrix on Vax vax-dec-ultrix
6251 * New machines supported (target)
6253 AMD 29000 embedded, using EBMON a29k-none-none
6257 GDB continues to improve its handling of C++. `References' work better.
6258 The demangler has also been improved, and now deals with symbols mangled as
6259 per the Annotated C++ Reference Guide.
6261 GDB also now handles `stabs' symbol information embedded in MIPS
6262 `ecoff' symbol tables. Since the ecoff format was not easily
6263 extensible to handle new languages such as C++, this appeared to be a
6264 good way to put C++ debugging info into MIPS binaries. This option
6265 will be supported in the GNU C compiler, version 2, when it is
6268 * New features for SVR4
6270 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6271 shared libraries. Debugging dynamically linked programs should present
6272 only minor differences from debugging statically linked programs.
6274 The `info proc' command will print out information about any process
6275 on an SVR4 system (including the one you are debugging). At the moment,
6276 it prints the address mappings of the process.
6278 If you bring up GDB on another SVR4 system, please send mail to
6279 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6281 * Better dynamic linking support in SunOS
6283 Reading symbols from shared libraries which contain debugging symbols
6284 now works properly. However, there remain issues such as automatic
6285 skipping of `transfer vector' code during function calls, which
6286 make it harder to debug code in a shared library, than to debug the
6287 same code linked statically.
6291 GDB is now using the latest `getopt' routines from the FSF. This
6292 version accepts the -- prefix for options with long names. GDB will
6293 continue to accept the old forms (-option and +option) as well.
6294 Various single letter abbreviations for options have been explicity
6295 added to the option table so that they won't get overshadowed in the
6296 future by other options that begin with the same letter.
6300 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6301 Many assorted bugs have been handled. Many more remain to be handled.
6302 See the various ChangeLog files (primarily in gdb and bfd) for details.
6305 *** Changes in GDB-4.3:
6307 * New machines supported (host and target)
6309 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6310 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6311 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6313 * Almost SCO Unix support
6315 We had hoped to support:
6316 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6317 (except for core file support), but we discovered very late in the release
6318 that it has problems with process groups that render gdb unusable. Sorry
6319 about that. I encourage people to fix it and post the fixes.
6321 * Preliminary ELF and DWARF support
6323 GDB can read ELF object files on System V Release 4, and can handle
6324 debugging records for C, in DWARF format, in ELF files. This support
6325 is preliminary. If you bring up GDB on another SVR4 system, please
6326 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6331 GDB now uses the latest `readline' library. One user-visible change
6332 is that two tabs will list possible command completions, which previously
6333 required typing M-? (meta-question mark, or ESC ?).
6337 The `stepi' bug that many of you noticed has been squashed.
6338 Many bugs in C++ have been handled. Many more remain to be handled.
6339 See the various ChangeLog files (primarily in gdb and bfd) for details.
6341 * State of the MIPS world (in case you wondered):
6343 GDB can understand the symbol tables emitted by the compilers
6344 supplied by most vendors of MIPS-based machines, including DEC. These
6345 symbol tables are in a format that essentially nobody else uses.
6347 Some versions of gcc come with an assembler post-processor called
6348 mips-tfile. This program is required if you want to do source-level
6349 debugging of gcc-compiled programs. I believe FSF does not ship
6350 mips-tfile with gcc version 1, but it will eventually come with gcc
6353 Debugging of g++ output remains a problem. g++ version 1.xx does not
6354 really support it at all. (If you're lucky, you should be able to get
6355 line numbers and stack traces to work, but no parameters or local
6356 variables.) With some work it should be possible to improve the
6359 When gcc version 2 is released, you will have somewhat better luck.
6360 However, even then you will get confusing results for inheritance and
6363 We will eventually provide full debugging of g++ output on
6364 DECstations. This will probably involve some kind of stabs-in-ecoff
6365 encapulation, but the details have not been worked out yet.
6368 *** Changes in GDB-4.2:
6370 * Improved configuration
6372 Only one copy of `configure' exists now, and it is not self-modifying.
6373 Porting BFD is simpler.
6377 The `step' and `next' commands now only stop at the first instruction
6378 of a source line. This prevents the multiple stops that used to occur
6379 in switch statements, for-loops, etc. `Step' continues to stop if a
6380 function that has debugging information is called within the line.
6384 Lots of small bugs fixed. More remain.
6386 * New host supported (not target)
6388 Intel 386 PC clone running Mach i386-none-mach
6391 *** Changes in GDB-4.1:
6393 * Multiple source language support
6395 GDB now has internal scaffolding to handle several source languages.
6396 It determines the type of each source file from its filename extension,
6397 and will switch expression parsing and number formatting to match the
6398 language of the function in the currently selected stack frame.
6399 You can also specifically set the language to be used, with
6400 `set language c' or `set language modula-2'.
6404 GDB now has preliminary support for the GNU Modula-2 compiler,
6405 currently under development at the State University of New York at
6406 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6407 continue through the fall of 1991 and into 1992.
6409 Other Modula-2 compilers are currently not supported, and attempting to
6410 debug programs compiled with them will likely result in an error as the
6411 symbol table is read. Feel free to work on it, though!
6413 There are hooks in GDB for strict type checking and range checking,
6414 in the `Modula-2 philosophy', but they do not currently work.
6418 GDB can now write to executable and core files (e.g. patch
6419 a variable's value). You must turn this switch on, specify
6420 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6421 by assigning a new value to a variable. Modifications take
6424 * Automatic SunOS shared library reading
6426 When you run your program, GDB automatically determines where its
6427 shared libraries (if any) have been loaded, and reads their symbols.
6428 The `share' command is no longer needed. This also works when
6429 examining core files.
6433 You can specify the number of lines that the `list' command shows.
6436 * New machines supported (host and target)
6438 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6439 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6440 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6442 * New hosts supported (not targets)
6444 IBM RT/PC: romp-ibm-aix or rtpc
6446 * New targets supported (not hosts)
6448 AMD 29000 embedded with COFF a29k-none-coff
6449 AMD 29000 embedded with a.out a29k-none-aout
6450 Ultracomputer remote kernel debug a29k-nyu-kern
6452 * New remote interfaces
6458 *** Changes in GDB-4.0:
6462 Wide output is wrapped at good places to make the output more readable.
6464 Gdb now supports cross-debugging from a host machine of one type to a
6465 target machine of another type. Communication with the target system
6466 is over serial lines. The ``target'' command handles connecting to the
6467 remote system; the ``load'' command will download a program into the
6468 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6469 also supports debugging of realtime processes running under VxWorks,
6470 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6471 stub on the target system.
6473 New CPUs supported include the AMD 29000 and Intel 960.
6475 GDB now reads object files and symbol tables via a ``binary file''
6476 library, which allows a single copy of GDB to debug programs of multiple
6477 object file types such as a.out and coff.
6479 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6480 refcard.dvi and refcard.ps are available to format it).
6483 * Control-Variable user interface simplified
6485 All variables that control the operation of the debugger can be set
6486 by the ``set'' command, and displayed by the ``show'' command.
6488 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6489 ``Show prompt'' produces the response:
6490 Gdb's prompt is new-gdb=>.
6492 What follows are the NEW set commands. The command ``help set'' will
6493 print a complete list of old and new set commands. ``help set FOO''
6494 will give a longer description of the variable FOO. ``show'' will show
6495 all of the variable descriptions and their current settings.
6497 confirm on/off: Enables warning questions for operations that are
6498 hard to recover from, e.g. rerunning the program while
6499 it is already running. Default is ON.
6501 editing on/off: Enables EMACS style command line editing
6502 of input. Previous lines can be recalled with
6503 control-P, the current line can be edited with control-B,
6504 you can search for commands with control-R, etc.
6507 history filename NAME: NAME is where the gdb command history
6508 will be stored. The default is .gdb_history,
6509 or the value of the environment variable
6512 history size N: The size, in commands, of the command history. The
6513 default is 256, or the value of the environment variable
6516 history save on/off: If this value is set to ON, the history file will
6517 be saved after exiting gdb. If set to OFF, the
6518 file will not be saved. The default is OFF.
6520 history expansion on/off: If this value is set to ON, then csh-like
6521 history expansion will be performed on
6522 command line input. The default is OFF.
6524 radix N: Sets the default radix for input and output. It can be set
6525 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6526 in the current radix, so "set radix 10" is always a no-op.
6528 height N: This integer value is the number of lines on a page. Default
6529 is 24, the current `stty rows'' setting, or the ``li#''
6530 setting from the termcap entry matching the environment
6533 width N: This integer value is the number of characters on a line.
6534 Default is 80, the current `stty cols'' setting, or the ``co#''
6535 setting from the termcap entry matching the environment
6538 Note: ``set screensize'' is obsolete. Use ``set height'' and
6539 ``set width'' instead.
6541 print address on/off: Print memory addresses in various command displays,
6542 such as stack traces and structure values. Gdb looks
6543 more ``symbolic'' if you turn this off; it looks more
6544 ``machine level'' with it on. Default is ON.
6546 print array on/off: Prettyprint arrays. New convenient format! Default
6549 print demangle on/off: Print C++ symbols in "source" form if on,
6552 print asm-demangle on/off: Same, for assembler level printouts
6555 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6558 * Support for Epoch Environment.
6560 The epoch environment is a version of Emacs v18 with windowing. One
6561 new command, ``inspect'', is identical to ``print'', except that if you
6562 are running in the epoch environment, the value is printed in its own
6566 * Support for Shared Libraries
6568 GDB can now debug programs and core files that use SunOS shared libraries.
6569 Symbols from a shared library cannot be referenced
6570 before the shared library has been linked with the program (this
6571 happens after you type ``run'' and before the function main() is entered).
6572 At any time after this linking (including when examining core files
6573 from dynamically linked programs), gdb reads the symbols from each
6574 shared library when you type the ``sharedlibrary'' command.
6575 It can be abbreviated ``share''.
6577 sharedlibrary REGEXP: Load shared object library symbols for files
6578 matching a unix regular expression. No argument
6579 indicates to load symbols for all shared libraries.
6581 info sharedlibrary: Status of loaded shared libraries.
6586 A watchpoint stops execution of a program whenever the value of an
6587 expression changes. Checking for this slows down execution
6588 tremendously whenever you are in the scope of the expression, but is
6589 quite useful for catching tough ``bit-spreader'' or pointer misuse
6590 problems. Some machines such as the 386 have hardware for doing this
6591 more quickly, and future versions of gdb will use this hardware.
6593 watch EXP: Set a watchpoint (breakpoint) for an expression.
6595 info watchpoints: Information about your watchpoints.
6597 delete N: Deletes watchpoint number N (same as breakpoints).
6598 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6599 enable N: Re-enables watchpoint number N (same as breakpoints).
6602 * C++ multiple inheritance
6604 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6607 * C++ exception handling
6609 Gdb now supports limited C++ exception handling. Besides the existing
6610 ability to breakpoint on an exception handler, gdb can breakpoint on
6611 the raising of an exception (before the stack is peeled back to the
6614 catch FOO: If there is a FOO exception handler in the dynamic scope,
6615 set a breakpoint to catch exceptions which may be raised there.
6616 Multiple exceptions (``catch foo bar baz'') may be caught.
6618 info catch: Lists all exceptions which may be caught in the
6619 current stack frame.
6622 * Minor command changes
6624 The command ``call func (arg, arg, ...)'' now acts like the print
6625 command, except it does not print or save a value if the function's result
6626 is void. This is similar to dbx usage.
6628 The ``up'' and ``down'' commands now always print the frame they end up
6629 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6630 frames without printing.
6632 * New directory command
6634 'dir' now adds directories to the FRONT of the source search path.
6635 The path starts off empty. Source files that contain debug information
6636 about the directory in which they were compiled can be found even
6637 with an empty path; Sun CC and GCC include this information. If GDB can't
6638 find your source file in the current directory, type "dir .".
6640 * Configuring GDB for compilation
6642 For normal use, type ``./configure host''. See README or gdb.texinfo
6645 GDB now handles cross debugging. If you are remotely debugging between
6646 two different machines, type ``./configure host -target=targ''.
6647 Host is the machine where GDB will run; targ is the machine
6648 where the program that you are debugging will run.
projects / deliverable / binutils-gdb.git / blob