1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.12
8 ** New functions to start, stop and access a running btrace recording.
10 * GDB now supports recording and replaying rdrand and rdseed Intel 64
13 * Building GDB and GDBserver now requires a C++11 compiler.
15 For example, GCC 4.8 or later.
17 It is no longer possible to build GDB or GDBserver with a C
18 compiler. The --disable-build-with-cxx configure option has been
21 * Building GDB and GDBserver now requires GNU make >= 3.81.
23 It is no longer supported to build GDB or GDBserver with another
24 implementation of the make program or an earlier version of GNU make.
26 * Native debugging on MS-Windows supports command-line redirection
28 Command-line arguments used for starting programs on MS-Windows can
29 now include redirection symbols supported by native Windows shells,
30 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
31 as "run", "start", and "set args", as well as the corresponding MI
34 * Support for thread names on MS-Windows.
36 GDB now catches and handles the special exception that programs
37 running on MS-Windows use to assign names to threads in the
40 * Support for Java programs compiled with gcj has been removed.
42 * User commands now accept an unlimited number of arguments.
43 Previously, only up to 10 was accepted.
45 * The "eval" command now expands user-defined command arguments.
47 This makes it easier to process a variable number of arguments:
52 eval "print $arg%d", $i
57 * Target descriptions can now describe registers for sparc32 and sparc64.
59 * New native configurations
61 FreeBSD/mips mips*-*-freebsd
66 Synopsys ARC arc*-*-elf32
67 FreeBSD/mips mips*-*-freebsd
72 Erases all the flash memory regions reported by the target.
77 Erases all the flash memory regions reported by the target. This is
78 equivalent to the CLI command flash-erase.
80 *** Changes in GDB 7.12
82 * GDB and GDBserver now build with a C++ compiler by default.
84 The --enable-build-with-cxx configure option is now enabled by
85 default. One must now explicitly configure with
86 --disable-build-with-cxx in order to build with a C compiler. This
87 option will be removed in a future release.
89 * GDBserver now supports recording btrace without maintaining an active
92 * GDB now supports a negative repeat count in the 'x' command to examine
93 memory backward from the given address. For example:
96 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
97 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
98 (gdb) x/-5i 0x0000000000400580
99 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
100 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
101 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
102 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
103 0x40057b <main(int, char**)+25>:
104 callq 0x400536 <Func1(int, char const*)>
106 * Fortran: Support structures with fields of dynamic types and
107 arrays of dynamic types.
109 * The symbol dumping maintenance commands have new syntax.
110 maint print symbols [-pc address] [--] [filename]
111 maint print symbols [-objfile objfile] [-source source] [--] [filename]
112 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
113 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
114 maint print msymbols [-objfile objfile] [--] [filename]
116 * GDB now supports multibit bitfields and enums in target register
119 * New Python-based convenience function $_as_string(val), which returns
120 the textual representation of a value. This function is especially
121 useful to obtain the text label of an enum value.
123 * Intel MPX bound violation handling.
125 Segmentation faults caused by a Intel MPX boundary violation
126 now display the kind of violation (upper or lower), the memory
127 address accessed and the memory bounds, along with the usual
128 signal received and code location.
132 Program received signal SIGSEGV, Segmentation fault
133 Upper bound violation while accessing address 0x7fffffffc3b3
134 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
135 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
137 * Rust language support.
138 GDB now supports debugging programs written in the Rust programming
139 language. See https://www.rust-lang.org/ for more information about
142 * Support for running interpreters on specified input/output devices
144 GDB now supports a new mechanism that allows frontends to provide
145 fully featured GDB console views, as a better alternative to
146 building such views on top of the "-interpreter-exec console"
147 command. See the new "new-ui" command below. With that command,
148 frontends can now start GDB in the traditional command-line mode
149 running in an embedded terminal emulator widget, and create a
150 separate MI interpreter running on a specified i/o device. In this
151 way, GDB handles line editing, history, tab completion, etc. in the
152 console all by itself, and the GUI uses the separate MI interpreter
153 for its own control and synchronization, invisible to the command
156 * The "catch syscall" command catches groups of related syscalls.
158 The "catch syscall" command now supports catching a group of related
159 syscalls using the 'group:' or 'g:' prefix.
164 skip -gfile file-glob-pattern
165 skip -function function
166 skip -rfunction regular-expression
167 A generalized form of the skip command, with new support for
168 glob-style file names and regular expressions for function names.
169 Additionally, a file spec and a function spec may now be combined.
171 maint info line-table REGEXP
172 Display the contents of GDB's internal line table data struture.
175 Run any GDB unit tests that were compiled in.
178 Start a new user interface instance running INTERP as interpreter,
179 using the TTY file for input/output.
183 ** gdb.Breakpoint objects have a new attribute "pending", which
184 indicates whether the breakpoint is pending.
185 ** Three new breakpoint-related events have been added:
186 gdb.breakpoint_created, gdb.breakpoint_modified, and
187 gdb.breakpoint_deleted.
190 Signal ("set") the given MS-Windows event object. This is used in
191 conjunction with the Windows JIT debugging (AeDebug) support, where
192 the OS suspends a crashing process until a debugger can attach to
193 it. Resuming the crashing process, in order to debug it, is done by
196 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
197 was added in GDBserver, including JIT compiling fast tracepoint's
198 conditional expression bytecode into native code.
200 * Support for various remote target protocols and ROM monitors has
203 target m32rsdi Remote M32R debugging over SDI
204 target mips MIPS remote debugging protocol
205 target pmon PMON ROM monitor
206 target ddb NEC's DDB variant of PMON for Vr4300
207 target rockhopper NEC RockHopper variant of PMON
208 target lsi LSI variant of PMO
210 * Support for tracepoints and fast tracepoints on powerpc-linux,
211 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
212 including JIT compiling fast tracepoint's conditional expression
213 bytecode into native code.
215 * MI async record =record-started now includes the method and format used for
216 recording. For example:
218 =record-started,thread-group="i1",method="btrace",format="bts"
220 * MI async record =thread-selected now includes the frame field. For example:
222 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
226 Andes NDS32 nds32*-*-elf
228 *** Changes in GDB 7.11
230 * GDB now supports debugging kernel-based threads on FreeBSD.
232 * Per-inferior thread numbers
234 Thread numbers are now per inferior instead of global. If you're
235 debugging multiple inferiors, GDB displays thread IDs using a
236 qualified INF_NUM.THR_NUM form. For example:
240 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
241 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
242 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
243 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
245 As consequence, thread numbers as visible in the $_thread
246 convenience variable and in Python's InferiorThread.num attribute
247 are no longer unique between inferiors.
249 GDB now maintains a second thread ID per thread, referred to as the
250 global thread ID, which is the new equivalent of thread numbers in
251 previous releases. See also $_gthread below.
253 For backwards compatibility, MI's thread IDs always refer to global
256 * Commands that accept thread IDs now accept the qualified
257 INF_NUM.THR_NUM form as well. For example:
260 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
263 * In commands that accept a list of thread IDs, you can now refer to
264 all threads of an inferior using a star wildcard. GDB accepts
265 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
266 refer to all threads of the current inferior. For example, "info
269 * You can use "info threads -gid" to display the global thread ID of
272 * The new convenience variable $_gthread holds the global number of
275 * The new convenience variable $_inferior holds the number of the
278 * GDB now displays the ID and name of the thread that hit a breakpoint
279 or received a signal, if your program is multi-threaded. For
282 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
283 Thread 1 "main" received signal SIGINT, Interrupt.
285 * Record btrace now supports non-stop mode.
287 * Support for tracepoints on aarch64-linux was added in GDBserver.
289 * The 'record instruction-history' command now indicates speculative execution
290 when using the Intel Processor Trace recording format.
292 * GDB now allows users to specify explicit locations, bypassing
293 the linespec parser. This feature is also available to GDB/MI
296 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
297 GDB now is able to debug both AArch64 applications and ARM applications
300 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
301 including JIT compiling fast tracepoint's conditional expression bytecode
304 * GDB now supports displaced stepping on AArch64 GNU/Linux.
306 * "info threads", "info inferiors", "info display", "info checkpoints"
307 and "maint info program-spaces" now list the corresponding items in
308 ascending ID order, for consistency with all other "info" commands.
310 * In Ada, the overloads selection menu has been enhanced to display the
311 parameter types and the return types for the matching overloaded subprograms.
315 maint set target-non-stop (on|off|auto)
316 maint show target-non-stop
317 Control whether GDB targets always operate in non-stop mode even if
318 "set non-stop" is "off". The default is "auto", meaning non-stop
319 mode is enabled if supported by the target.
321 maint set bfd-sharing
322 maint show bfd-sharing
323 Control the reuse of bfd objects.
327 Control display of debugging info regarding bfd caching.
331 Control display of debugging info regarding FreeBSD threads.
333 set remote multiprocess-extensions-packet
334 show remote multiprocess-extensions-packet
335 Set/show the use of the remote protocol multiprocess extensions.
337 set remote thread-events
338 show remote thread-events
339 Set/show the use of thread create/exit events.
341 set ada print-signatures on|off
342 show ada print-signatures"
343 Control whether parameter types and return types are displayed in overloads
344 selection menus. It is activaled (@code{on}) by default.
348 Controls the maximum size of memory, in bytes, that GDB will
349 allocate for value contents. Prevents incorrect programs from
350 causing GDB to allocate overly large buffers. Default is 64k.
352 * The "disassemble" command accepts a new modifier: /s.
353 It prints mixed source+disassembly like /m with two differences:
354 - disassembled instructions are now printed in program order, and
355 - and source for all relevant files is now printed.
356 The "/m" option is now considered deprecated: its "source-centric"
357 output hasn't proved useful in practice.
359 * The "record instruction-history" command accepts a new modifier: /s.
360 It behaves exactly like /m and prints mixed source+disassembly.
362 * The "set scheduler-locking" command supports a new mode "replay".
363 It behaves like "off" in record mode and like "on" in replay mode.
365 * Support for various ROM monitors has been removed:
367 target dbug dBUG ROM monitor for Motorola ColdFire
368 target picobug Motorola picobug monitor
369 target dink32 DINK32 ROM monitor for PowerPC
370 target m32r Renesas M32R/D ROM monitor
371 target mon2000 mon2000 ROM monitor
372 target ppcbug PPCBUG ROM monitor for PowerPC
374 * Support for reading/writing memory and extracting values on architectures
375 whose memory is addressable in units of any integral multiple of 8 bits.
380 Indicates that an exec system call was executed.
382 exec-events feature in qSupported
383 The qSupported packet allows GDB to request support for exec
384 events using the new 'gdbfeature' exec-event, and the qSupported
385 response can contain the corresponding 'stubfeature'. Set and
386 show commands can be used to display whether these features are enabled.
389 Equivalent to interrupting with the ^C character, but works in
392 thread created stop reason (T05 create:...)
393 Indicates that the thread was just created and is stopped at entry.
395 thread exit stop reply (w exitcode;tid)
396 Indicates that the thread has terminated.
399 Enables/disables thread create and exit event reporting. For
400 example, this is used in non-stop mode when GDB stops a set of
401 threads and synchronously waits for the their corresponding stop
402 replies. Without exit events, if one of the threads exits, GDB
403 would hang forever not knowing that it should no longer expect a
404 stop for that same thread.
407 Indicates that there are no resumed threads left in the target (all
408 threads are stopped). The remote stub reports support for this stop
409 reply to GDB's qSupported query.
412 Enables/disables catching syscalls from the inferior process.
413 The remote stub reports support for this packet to GDB's qSupported query.
415 syscall_entry stop reason
416 Indicates that a syscall was just called.
418 syscall_return stop reason
419 Indicates that a syscall just returned.
421 * Extended-remote exec events
423 ** GDB now has support for exec events on extended-remote Linux targets.
424 For such targets with Linux kernels 2.5.46 and later, this enables
425 follow-exec-mode and exec catchpoints.
427 set remote exec-event-feature-packet
428 show remote exec-event-feature-packet
429 Set/show the use of the remote exec event feature.
431 * Thread names in remote protocol
433 The reply to qXfer:threads:read may now include a name attribute for each
436 * Target remote mode fork and exec events
438 ** GDB now has support for fork and exec events on target remote mode
439 Linux targets. For such targets with Linux kernels 2.5.46 and later,
440 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
441 fork and exec catchpoints.
443 * Remote syscall events
445 ** GDB now has support for catch syscall on remote Linux targets,
446 currently enabled on x86/x86_64 architectures.
448 set remote catch-syscall-packet
449 show remote catch-syscall-packet
450 Set/show the use of the remote catch syscall feature.
454 ** The -var-set-format command now accepts the zero-hexadecimal
455 format. It outputs data in hexadecimal format with zero-padding on the
460 ** gdb.InferiorThread objects have a new attribute "global_num",
461 which refers to the thread's global thread ID. The existing
462 "num" attribute now refers to the thread's per-inferior number.
463 See "Per-inferior thread numbers" above.
464 ** gdb.InferiorThread objects have a new attribute "inferior", which
465 is the Inferior object the thread belongs to.
467 *** Changes in GDB 7.10
469 * Support for process record-replay and reverse debugging on aarch64*-linux*
470 targets has been added. GDB now supports recording of A64 instruction set
471 including advance SIMD instructions.
473 * Support for Sun's version of the "stabs" debug file format has been removed.
475 * GDB now honors the content of the file /proc/PID/coredump_filter
476 (PID is the process ID) on GNU/Linux systems. This file can be used
477 to specify the types of memory mappings that will be included in a
478 corefile. For more information, please refer to the manual page of
479 "core(5)". GDB also has a new command: "set use-coredump-filter
480 on|off". It allows to set whether GDB will read the content of the
481 /proc/PID/coredump_filter file when generating a corefile.
483 * The "info os" command on GNU/Linux can now display information on
485 "info os cpus" Listing of all cpus/cores on the system
487 * GDB has two new commands: "set serial parity odd|even|none" and
488 "show serial parity". These allows to set or show parity for the
491 * The "info source" command now displays the producer string if it was
492 present in the debug info. This typically includes the compiler version
493 and may include things like its command line arguments.
495 * The "info dll", an alias of the "info sharedlibrary" command,
496 is now available on all platforms.
498 * Directory names supplied to the "set sysroot" commands may be
499 prefixed with "target:" to tell GDB to access shared libraries from
500 the target system, be it local or remote. This replaces the prefix
501 "remote:". The default sysroot has been changed from "" to
502 "target:". "remote:" is automatically converted to "target:" for
503 backward compatibility.
505 * The system root specified by "set sysroot" will be prepended to the
506 filename of the main executable (if reported to GDB as absolute by
507 the operating system) when starting processes remotely, and when
508 attaching to already-running local or remote processes.
510 * GDB now supports automatic location and retrieval of executable
511 files from remote targets. Remote debugging can now be initiated
512 using only a "target remote" or "target extended-remote" command
513 (no "set sysroot" or "file" commands are required). See "New remote
516 * The "dump" command now supports verilog hex format.
518 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
520 * On GNU/Linux, GDB and gdbserver are now able to access executable
521 and shared library files without a "set sysroot" command when
522 attaching to processes running in different mount namespaces from
523 the debugger. This makes it possible to attach to processes in
524 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
525 See "New remote packets" below.
527 * The "tui reg" command now provides completion for all of the
528 available register groups, including target specific groups.
530 * The HISTSIZE environment variable is no longer read when determining
531 the size of GDB's command history. GDB now instead reads the dedicated
532 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
533 disables truncation of command history. Non-numeric values of GDBHISTSIZE
538 ** Memory ports can now be unbuffered.
542 ** gdb.Objfile objects have a new attribute "username",
543 which is the name of the objfile as specified by the user,
544 without, for example, resolving symlinks.
545 ** You can now write frame unwinders in Python.
546 ** gdb.Type objects have a new method "optimized_out",
547 returning optimized out gdb.Value instance of this type.
548 ** gdb.Value objects have new methods "reference_value" and
549 "const_value" which return a reference to the value and a
550 "const" version of the value respectively.
554 maint print symbol-cache
555 Print the contents of the symbol cache.
557 maint print symbol-cache-statistics
558 Print statistics of symbol cache usage.
560 maint flush-symbol-cache
561 Flush the contents of the symbol cache.
565 Start branch trace recording using Branch Trace Store (BTS) format.
568 Evaluate expression by using the compiler and print result.
572 Explicit commands for enabling and disabling tui mode.
575 set mpx bound on i386 and amd64
576 Support for bound table investigation on Intel MPX enabled applications.
580 Start branch trace recording using Intel Processor Trace format.
583 Print information about branch tracing internals.
585 maint btrace packet-history
586 Print the raw branch tracing data.
588 maint btrace clear-packet-history
589 Discard the stored raw branch tracing data.
592 Discard all branch tracing data. It will be fetched and processed
593 anew by the next "record" command.
598 Renamed from "set debug dwarf2-die".
600 Renamed from "show debug dwarf2-die".
603 Renamed from "set debug dwarf2-read".
604 show debug dwarf-read
605 Renamed from "show debug dwarf2-read".
607 maint set dwarf always-disassemble
608 Renamed from "maint set dwarf2 always-disassemble".
609 maint show dwarf always-disassemble
610 Renamed from "maint show dwarf2 always-disassemble".
612 maint set dwarf max-cache-age
613 Renamed from "maint set dwarf2 max-cache-age".
614 maint show dwarf max-cache-age
615 Renamed from "maint show dwarf2 max-cache-age".
618 show debug dwarf-line
619 Control display of debugging info regarding DWARF line processing.
623 Set the maximum number of candidates to be considered during
624 completion. The default value is 200. This limit allows GDB
625 to avoid generating large completion lists, the computation of
626 which can cause the debugger to become temporarily unresponsive.
628 set history remove-duplicates
629 show history remove-duplicates
630 Control the removal of duplicate history entries.
632 maint set symbol-cache-size
633 maint show symbol-cache-size
634 Control the size of the symbol cache.
636 set|show record btrace bts buffer-size
637 Set and show the size of the ring buffer used for branch tracing in
639 The obtained size may differ from the requested size. Use "info
640 record" to see the obtained buffer size.
642 set debug linux-namespaces
643 show debug linux-namespaces
644 Control display of debugging info regarding Linux namespaces.
646 set|show record btrace pt buffer-size
647 Set and show the size of the ring buffer used for branch tracing in
648 Intel Processor Trace format.
649 The obtained size may differ from the requested size. Use "info
650 record" to see the obtained buffer size.
652 maint set|show btrace pt skip-pad
653 Set and show whether PAD packets are skipped when computing the
656 * The command 'thread apply all' can now support new option '-ascending'
657 to call its specified command for all threads in ascending order.
659 * Python/Guile scripting
661 ** GDB now supports auto-loading of Python/Guile scripts contained in the
662 special section named `.debug_gdb_scripts'.
666 qXfer:btrace-conf:read
667 Return the branch trace configuration for the current thread.
669 Qbtrace-conf:bts:size
670 Set the requested ring buffer size for branch tracing in BTS format.
673 Enable Intel Procesor Trace-based branch tracing for the current
674 process. The remote stub reports support for this packet to GDB's
678 Set the requested ring buffer size for branch tracing in Intel Processor
682 Indicates a memory breakpoint instruction was executed, irrespective
683 of whether it was GDB that planted the breakpoint or the breakpoint
684 is hardcoded in the program. This is required for correct non-stop
688 Indicates the target stopped for a hardware breakpoint. This is
689 required for correct non-stop mode operation.
692 Return information about files on the remote system.
695 Return the full absolute name of the file that was executed to
696 create a process running on the remote system.
699 Select the filesystem on which vFile: operations with filename
700 arguments will operate. This is required for GDB to be able to
701 access files on remote targets where the remote stub does not
702 share a common filesystem with the inferior(s).
705 Indicates that a fork system call was executed.
708 Indicates that a vfork system call was executed.
710 vforkdone stop reason
711 Indicates that a vfork child of the specified process has executed
712 an exec or exit, allowing the vfork parent to resume execution.
714 fork-events and vfork-events features in qSupported
715 The qSupported packet allows GDB to request support for fork and
716 vfork events using new 'gdbfeatures' fork-events and vfork-events,
717 and the qSupported response can contain the corresponding
718 'stubfeatures'. Set and show commands can be used to display
719 whether these features are enabled.
721 * Extended-remote fork events
723 ** GDB now has support for fork events on extended-remote Linux
724 targets. For targets with Linux kernels 2.5.60 and later, this
725 enables follow-fork-mode and detach-on-fork for both fork and
726 vfork, as well as fork and vfork catchpoints.
728 * The info record command now shows the recording format and the
729 branch tracing configuration for the current thread when using
730 the btrace record target.
731 For the BTS format, it shows the ring buffer size.
733 * GDB now has support for DTrace USDT (Userland Static Defined
734 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
736 * GDB now supports access to vector registers on S/390 GNU/Linux
739 * Removed command line options
741 -xdb HP-UX XDB compatibility mode.
743 * Removed targets and native configurations
745 HP/PA running HP-UX hppa*-*-hpux*
746 Itanium running HP-UX ia64-*-hpux*
748 * New configure options
751 This configure option allows the user to build GDB with support for
752 Intel Processor Trace (default: auto). This requires libipt.
754 --with-libipt-prefix=PATH
755 Specify the path to the version of libipt that GDB should use.
756 $PATH/include should contain the intel-pt.h header and
757 $PATH/lib should contain the libipt.so library.
759 *** Changes in GDB 7.9.1
763 ** Xmethods can now specify a result type.
765 *** Changes in GDB 7.9
767 * GDB now supports hardware watchpoints on x86 GNU Hurd.
771 ** You can now access frame registers from Python scripts.
772 ** New attribute 'producer' for gdb.Symtab objects.
773 ** gdb.Objfile objects have a new attribute "progspace",
774 which is the gdb.Progspace object of the containing program space.
775 ** gdb.Objfile objects have a new attribute "owner".
776 ** gdb.Objfile objects have a new attribute "build_id",
777 which is the build ID generated when the file was built.
778 ** gdb.Objfile objects have a new method "add_separate_debug_file".
779 ** A new event "gdb.clear_objfiles" has been added, triggered when
780 selecting a new file to debug.
781 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
782 ** New function gdb.lookup_objfile.
784 New events which are triggered when GDB modifies the state of the
787 ** gdb.events.inferior_call_pre: Function call is about to be made.
788 ** gdb.events.inferior_call_post: Function call has just been made.
789 ** gdb.events.memory_changed: A memory location has been altered.
790 ** gdb.events.register_changed: A register has been altered.
792 * New Python-based convenience functions:
794 ** $_caller_is(name [, number_of_frames])
795 ** $_caller_matches(regexp [, number_of_frames])
796 ** $_any_caller_is(name [, number_of_frames])
797 ** $_any_caller_matches(regexp [, number_of_frames])
799 * GDB now supports the compilation and injection of source code into
800 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
801 to compile the source code to object code, and if successful, inject
802 and execute that code within the current context of the inferior.
803 Currently the C language is supported. The commands used to
804 interface with this new feature are:
806 compile code [-raw|-r] [--] [source code]
807 compile file [-raw|-r] filename
811 demangle [-l language] [--] name
812 Demangle "name" in the specified language, or the current language
813 if elided. This command is renamed from the "maint demangle" command.
814 The latter is kept as a no-op to avoid "maint demangle" being interpreted
815 as "maint demangler-warning".
817 queue-signal signal-name-or-number
818 Queue a signal to be delivered to the thread when it is resumed.
820 add-auto-load-scripts-directory directory
821 Add entries to the list of directories from which to load auto-loaded
824 maint print user-registers
825 List all currently available "user" registers.
827 compile code [-r|-raw] [--] [source code]
828 Compile, inject, and execute in the inferior the executable object
829 code produced by compiling the provided source code.
831 compile file [-r|-raw] filename
832 Compile and inject into the inferior the executable object code
833 produced by compiling the source code stored in the filename
836 * On resume, GDB now always passes the signal the program had stopped
837 for to the thread the signal was sent to, even if the user changed
838 threads before resuming. Previously GDB would often (but not
839 always) deliver the signal to the thread that happens to be current
842 * Conversely, the "signal" command now consistently delivers the
843 requested signal to the current thread. GDB now asks for
844 confirmation if the program had stopped for a signal and the user
845 switched threads meanwhile.
847 * "breakpoint always-inserted" modes "off" and "auto" merged.
849 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
850 won't remove breakpoints from the target until all threads stop,
851 even in non-stop mode. The "auto" mode has been removed, and "off"
852 is now the default mode.
856 set debug symbol-lookup
857 show debug symbol-lookup
858 Control display of debugging info regarding symbol lookup.
862 ** The -list-thread-groups command outputs an exit-code field for
863 inferiors that have exited.
867 MIPS SDE mips*-sde*-elf*
871 Support for these obsolete configurations has been removed.
873 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
874 SGI Irix-5.x mips-*-irix5*
875 SGI Irix-6.x mips-*-irix6*
876 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
877 VAX running Ultrix vax-*-ultrix*
879 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
880 and "assf"), have been removed. Use the "sharedlibrary" command, or
881 its alias "share", instead.
883 *** Changes in GDB 7.8
885 * New command line options
888 This is an alias for the --data-directory option.
890 * GDB supports printing and modifying of variable length automatic arrays
891 as specified in ISO C99.
893 * The ARM simulator now supports instruction level tracing
894 with or without disassembly.
898 GDB now has support for scripting using Guile. Whether this is
899 available is determined at configure time.
900 Guile version 2.0 or greater is required.
901 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
903 * New commands (for set/show, see "New options" below)
907 Invoke CODE by passing it to the Guile interpreter.
911 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
913 info auto-load guile-scripts [regexp]
914 Print the list of automatically loaded Guile scripts.
916 * The source command is now capable of sourcing Guile scripts.
917 This feature is dependent on the debugger being built with Guile support.
921 set print symbol-loading (off|brief|full)
922 show print symbol-loading
923 Control whether to print informational messages when loading symbol
924 information for a file. The default is "full", but when debugging
925 programs with large numbers of shared libraries the amount of output
928 set guile print-stack (none|message|full)
929 show guile print-stack
930 Show a stack trace when an error is encountered in a Guile script.
932 set auto-load guile-scripts (on|off)
933 show auto-load guile-scripts
934 Control auto-loading of Guile script files.
936 maint ada set ignore-descriptive-types (on|off)
937 maint ada show ignore-descriptive-types
938 Control whether the debugger should ignore descriptive types in Ada
939 programs. The default is not to ignore the descriptive types. See
940 the user manual for more details on descriptive types and the intended
941 usage of this option.
943 set auto-connect-native-target
945 Control whether GDB is allowed to automatically connect to the
946 native target for the run, attach, etc. commands when not connected
947 to any target yet. See also "target native" below.
949 set record btrace replay-memory-access (read-only|read-write)
950 show record btrace replay-memory-access
951 Control what memory accesses are allowed during replay.
953 maint set target-async (on|off)
954 maint show target-async
955 This controls whether GDB targets operate in synchronous or
956 asynchronous mode. Normally the default is asynchronous, if it is
957 available; but this can be changed to more easily debug problems
958 occurring only in synchronous mode.
960 set mi-async (on|off)
962 Control whether MI asynchronous mode is preferred. This supersedes
963 "set target-async" of previous GDB versions.
965 * "set target-async" is deprecated as a CLI option and is now an alias
966 for "set mi-async" (only puts MI into async mode).
968 * Background execution commands (e.g., "c&", "s&", etc.) are now
969 possible ``out of the box'' if the target supports them. Previously
970 the user would need to explicitly enable the possibility with the
971 "set target-async on" command.
973 * New features in the GDB remote stub, GDBserver
975 ** New option --debug-format=option1[,option2,...] allows one to add
976 additional text to each output. At present only timestamps
977 are supported: --debug-format=timestamps.
978 Timestamps can also be turned on with the
979 "monitor set debug-format timestamps" command from GDB.
981 * The 'record instruction-history' command now starts counting instructions
982 at one. This also affects the instruction ranges reported by the
983 'record function-call-history' command when given the /i modifier.
985 * The command 'record function-call-history' supports a new modifier '/c' to
986 indent the function names based on their call stack depth.
987 The fields for the '/i' and '/l' modifier have been reordered.
988 The source line range is now prefixed with 'at'.
989 The instruction range is now prefixed with 'inst'.
990 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
991 "record instruction-history" and "list" commands.
993 * The ranges given as arguments to the 'record function-call-history' and
994 'record instruction-history' commands are now inclusive.
996 * The btrace record target now supports the 'record goto' command.
997 For locations inside the execution trace, the back trace is computed
998 based on the information stored in the execution trace.
1000 * The btrace record target supports limited reverse execution and replay.
1001 The target does not record data and therefore does not allow reading
1002 memory or registers.
1004 * The "catch syscall" command now works on s390*-linux* targets.
1006 * The "compare-sections" command is no longer specific to target
1007 remote. It now works with all targets.
1009 * All native targets are now consistently called "native".
1010 Consequently, the "target child", "target GNU", "target djgpp",
1011 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1012 commands have been replaced with "target native". The QNX/NTO port
1013 leaves the "procfs" target in place and adds a "native" target for
1014 consistency with other ports. The impact on users should be minimal
1015 as these commands previously either throwed an error, or were
1016 no-ops. The target's name is visible in the output of the following
1017 commands: "help target", "info target", "info files", "maint print
1020 * The "target native" command now connects to the native target. This
1021 can be used to launch native programs even when "set
1022 auto-connect-native-target" is set to off.
1024 * GDB now supports access to Intel MPX registers on GNU/Linux.
1026 * Support for Intel AVX-512 registers on GNU/Linux.
1027 Support displaying and modifying Intel AVX-512 registers
1028 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1030 * New remote packets
1032 qXfer:btrace:read's annex
1033 The qXfer:btrace:read packet supports a new annex 'delta' to read
1034 branch trace incrementally.
1038 ** Valid Python operations on gdb.Value objects representing
1039 structs/classes invoke the corresponding overloaded operators if
1041 ** New `Xmethods' feature in the Python API. Xmethods are
1042 additional methods or replacements for existing methods of a C++
1043 class. This feature is useful for those cases where a method
1044 defined in C++ source code could be inlined or optimized out by
1045 the compiler, making it unavailable to GDB.
1048 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1050 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1051 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1052 its alias "share", instead.
1054 * The commands "set remotebaud" and "show remotebaud" are no longer
1055 supported. Use "set serial baud" and "show serial baud" (respectively)
1060 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1061 target-async". The latter is left as a deprecated alias of the
1062 former for backward compatibility. If the target supports it,
1063 CLI background execution commands are now always possible by
1064 default, independently of whether the frontend stated a
1065 preference for asynchronous execution with "-gdb-set mi-async".
1066 Previously "-gdb-set target-async off" affected both MI execution
1067 commands and CLI execution commands.
1069 *** Changes in GDB 7.7
1071 * Improved support for process record-replay and reverse debugging on
1072 arm*-linux* targets. Support for thumb32 and syscall instruction
1073 recording has been added.
1075 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1077 * GDB now supports Fission DWP file format version 2.
1078 http://gcc.gnu.org/wiki/DebugFission
1080 * New convenience function "$_isvoid", to check whether an expression
1081 is void. A void expression is an expression where the type of the
1082 result is "void". For example, some convenience variables may be
1083 "void" when evaluated (e.g., "$_exitcode" before the execution of
1084 the program being debugged; or an undefined convenience variable).
1085 Another example, when calling a function whose return type is
1088 * The "maintenance print objfiles" command now takes an optional regexp.
1090 * The "catch syscall" command now works on arm*-linux* targets.
1092 * GDB now consistently shows "<not saved>" when printing values of
1093 registers the debug info indicates have not been saved in the frame
1094 and there's nowhere to retrieve them from
1095 (callee-saved/call-clobbered registers):
1100 (gdb) info registers rax
1103 Before, the former would print "<optimized out>", and the latter
1104 "*value not available*".
1106 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1111 ** Frame filters and frame decorators have been added.
1112 ** Temporary breakpoints are now supported.
1113 ** Line tables representation has been added.
1114 ** New attribute 'parent_type' for gdb.Field objects.
1115 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1116 ** New attribute 'name' for gdb.Type objects.
1120 Nios II ELF nios2*-*-elf
1121 Nios II GNU/Linux nios2*-*-linux
1122 Texas Instruments MSP430 msp430*-*-elf
1124 * Removed native configurations
1126 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1127 been removed. ELF variants of these configurations are kept supported.
1129 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1130 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1131 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1132 i[34567]86-*-openbsd3.[0-3]
1133 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1134 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1135 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1139 Like "catch throw", but catches a re-thrown exception.
1140 maint check-psymtabs
1141 Renamed from old "maint check-symtabs".
1143 Perform consistency checks on symtabs.
1144 maint expand-symtabs
1145 Expand symtabs matching an optional regexp.
1148 Display the details of GDB configure-time options.
1150 maint set|show per-command
1151 maint set|show per-command space
1152 maint set|show per-command time
1153 maint set|show per-command symtab
1154 Enable display of per-command gdb resource usage.
1156 remove-symbol-file FILENAME
1157 remove-symbol-file -a ADDRESS
1158 Remove a symbol file added via add-symbol-file. The file to remove
1159 can be identified by its filename or by an address that lies within
1160 the boundaries of this symbol file in memory.
1163 info exceptions REGEXP
1164 Display the list of Ada exceptions defined in the program being
1165 debugged. If provided, only the exceptions whose names match REGEXP
1170 set debug symfile off|on
1172 Control display of debugging info regarding reading symbol files and
1173 symbol tables within those files
1175 set print raw frame-arguments
1176 show print raw frame-arguments
1177 Set/show whether to print frame arguments in raw mode,
1178 disregarding any defined pretty-printers.
1180 set remote trace-status-packet
1181 show remote trace-status-packet
1182 Set/show the use of remote protocol qTStatus packet.
1186 Control display of debugging messages related to Nios II targets.
1190 Control whether target-assisted range stepping is enabled.
1192 set startup-with-shell
1193 show startup-with-shell
1194 Specifies whether Unix child processes are started via a shell or
1199 Use the target memory cache for accesses to the code segment. This
1200 improves performance of remote debugging (particularly disassembly).
1202 * You can now use a literal value 'unlimited' for options that
1203 interpret 0 or -1 as meaning "unlimited". E.g., "set
1204 trace-buffer-size unlimited" is now an alias for "set
1205 trace-buffer-size -1" and "set height unlimited" is now an alias for
1208 * The "set debug symtab-create" debugging option of GDB has been changed to
1209 accept a verbosity level. 0 means "off", 1 provides basic debugging
1210 output, and values of 2 or greater provides more verbose output.
1212 * New command-line options
1214 Display the details of GDB configure-time options.
1216 * The command 'tsave' can now support new option '-ctf' to save trace
1217 buffer in Common Trace Format.
1219 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1222 * GDB now implements the the C++ 'typeid' operator.
1224 * The new convenience variable $_exception holds the exception being
1225 thrown or caught at an exception-related catchpoint.
1227 * The exception-related catchpoints, like "catch throw", now accept a
1228 regular expression which can be used to filter exceptions by type.
1230 * The new convenience variable $_exitsignal is automatically set to
1231 the terminating signal number when the program being debugged dies
1232 due to an uncaught signal.
1236 ** All MI commands now accept an optional "--language" option.
1237 Support for this feature can be verified by using the "-list-features"
1238 command, which should contain "language-option".
1240 ** The new command -info-gdb-mi-command allows the user to determine
1241 whether a GDB/MI command is supported or not.
1243 ** The "^error" result record returned when trying to execute an undefined
1244 GDB/MI command now provides a variable named "code" whose content is the
1245 "undefined-command" error code. Support for this feature can be verified
1246 by using the "-list-features" command, which should contain
1247 "undefined-command-error-code".
1249 ** The -trace-save MI command can optionally save trace buffer in Common
1252 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1254 ** The command -data-list-register-values now accepts an optional
1255 "--skip-unavailable" option. When used, only the available registers
1258 ** The new command -trace-frame-collected dumps collected variables,
1259 computed expressions, tvars, memory and registers in a traceframe.
1261 ** The commands -stack-list-locals, -stack-list-arguments and
1262 -stack-list-variables now accept an option "--skip-unavailable".
1263 When used, only the available locals or arguments are displayed.
1265 ** The -exec-run command now accepts an optional "--start" option.
1266 When used, the command follows the same semantics as the "start"
1267 command, stopping the program's execution at the start of its
1268 main subprogram. Support for this feature can be verified using
1269 the "-list-features" command, which should contain
1270 "exec-run-start-option".
1272 ** The new commands -catch-assert and -catch-exceptions insert
1273 catchpoints stopping the program when Ada exceptions are raised.
1275 ** The new command -info-ada-exceptions provides the equivalent of
1276 the new "info exceptions" command.
1278 * New system-wide configuration scripts
1279 A GDB installation now provides scripts suitable for use as system-wide
1280 configuration scripts for the following systems:
1284 * GDB now supports target-assigned range stepping with remote targets.
1285 This improves the performance of stepping source lines by reducing
1286 the number of control packets from/to GDB. See "New remote packets"
1289 * GDB now understands the element 'tvar' in the XML traceframe info.
1290 It has the id of the collected trace state variables.
1292 * On S/390 targets that provide the transactional-execution feature,
1293 the program interruption transaction diagnostic block (TDB) is now
1294 represented as a number of additional "registers" in GDB.
1296 * New remote packets
1300 The vCont packet supports a new 'r' action, that tells the remote
1301 stub to step through an address range itself, without GDB
1302 involvemement at each single-step.
1304 qXfer:libraries-svr4:read's annex
1305 The previously unused annex of the qXfer:libraries-svr4:read packet
1306 is now used to support passing an argument list. The remote stub
1307 reports support for this argument list to GDB's qSupported query.
1308 The defined arguments are "start" and "prev", used to reduce work
1309 necessary for library list updating, resulting in significant
1312 * New features in the GDB remote stub, GDBserver
1314 ** GDBserver now supports target-assisted range stepping. Currently
1315 enabled on x86/x86_64 GNU/Linux targets.
1317 ** GDBserver now adds element 'tvar' in the XML in the reply to
1318 'qXfer:traceframe-info:read'. It has the id of the collected
1319 trace state variables.
1321 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1324 * New 'z' formatter for printing and examining memory, this displays the
1325 value as hexadecimal zero padded on the left to the size of the type.
1327 * GDB can now use Windows x64 unwinding data.
1329 * The "set remotebaud" command has been replaced by "set serial baud".
1330 Similarly, "show remotebaud" has been replaced by "show serial baud".
1331 The "set remotebaud" and "show remotebaud" commands are still available
1332 to provide backward compatibility with older versions of GDB.
1334 *** Changes in GDB 7.6
1336 * Target record has been renamed to record-full.
1337 Record/replay is now enabled with the "record full" command.
1338 This also affects settings that are associated with full record/replay
1339 that have been moved from "set/show record" to "set/show record full":
1341 set|show record full insn-number-max
1342 set|show record full stop-at-limit
1343 set|show record full memory-query
1345 * A new record target "record-btrace" has been added. The new target
1346 uses hardware support to record the control-flow of a process. It
1347 does not support replaying the execution, but it implements the
1348 below new commands for investigating the recorded execution log.
1349 This new recording method can be enabled using:
1353 The "record-btrace" target is only available on Intel Atom processors
1354 and requires a Linux kernel 2.6.32 or later.
1356 * Two new commands have been added for record/replay to give information
1357 about the recorded execution without having to replay the execution.
1358 The commands are only supported by "record btrace".
1360 record instruction-history prints the execution history at
1361 instruction granularity
1363 record function-call-history prints the execution history at
1364 function granularity
1366 * New native configurations
1368 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1369 FreeBSD/powerpc powerpc*-*-freebsd
1370 x86_64/Cygwin x86_64-*-cygwin*
1371 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1375 ARM AArch64 aarch64*-*-elf
1376 ARM AArch64 GNU/Linux aarch64*-*-linux
1377 Lynx 178 PowerPC powerpc-*-lynx*178
1378 x86_64/Cygwin x86_64-*-cygwin*
1379 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1381 * If the configured location of system.gdbinit file (as given by the
1382 --with-system-gdbinit option at configure time) is in the
1383 data-directory (as specified by --with-gdb-datadir at configure
1384 time) or in one of its subdirectories, then GDB will look for the
1385 system-wide init file in the directory specified by the
1386 --data-directory command-line option.
1388 * New command line options:
1390 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1391 other initialization files, unlike -nx which disables all of them.
1393 * Removed command line options
1395 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1398 * The 'ptype' and 'whatis' commands now accept an argument to control
1401 * 'info proc' now works on some core files.
1405 ** Vectors can be created with gdb.Type.vector.
1407 ** Python's atexit.register now works in GDB.
1409 ** Types can be pretty-printed via a Python API.
1411 ** Python 3 is now supported (in addition to Python 2.4 or later)
1413 ** New class gdb.Architecture exposes GDB's internal representation
1414 of architecture in the Python API.
1416 ** New method Frame.architecture returns the gdb.Architecture object
1417 corresponding to the frame's architecture.
1419 * New Python-based convenience functions:
1421 ** $_memeq(buf1, buf2, length)
1422 ** $_streq(str1, str2)
1424 ** $_regex(str, regex)
1426 * The 'cd' command now defaults to using '~' (the home directory) if not
1429 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1430 default for GCC since November 2000.
1432 * The command 'forward-search' can now be abbreviated as 'fo'.
1434 * The command 'info tracepoints' can now display 'installed on target'
1435 or 'not installed on target' for each non-pending location of tracepoint.
1437 * New configure options
1439 --enable-libmcheck/--disable-libmcheck
1440 By default, development versions are built with -lmcheck on hosts
1441 that support it, in order to help track memory corruption issues.
1442 Release versions, on the other hand, are built without -lmcheck
1443 by default. The --enable-libmcheck/--disable-libmcheck configure
1444 options allow the user to override that default.
1445 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1446 This configure option allows the user to build GDB with
1447 libbabeltrace using which GDB can read Common Trace Format data.
1449 * New commands (for set/show, see "New options" below)
1452 Catch signals. This is similar to "handle", but allows commands and
1453 conditions to be attached.
1456 List the BFDs known to GDB.
1458 python-interactive [command]
1460 Start a Python interactive prompt, or evaluate the optional command
1461 and print the result of expressions.
1464 "py" is a new alias for "python".
1466 enable type-printer [name]...
1467 disable type-printer [name]...
1468 Enable or disable type printers.
1472 ** For the Renesas Super-H architecture, the "regs" command has been removed
1473 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1478 set print type methods (on|off)
1479 show print type methods
1480 Control whether method declarations are displayed by "ptype".
1481 The default is to show them.
1483 set print type typedefs (on|off)
1484 show print type typedefs
1485 Control whether typedef definitions are displayed by "ptype".
1486 The default is to show them.
1488 set filename-display basename|relative|absolute
1489 show filename-display
1490 Control the way in which filenames is displayed.
1491 The default is "relative", which preserves previous behavior.
1493 set trace-buffer-size
1494 show trace-buffer-size
1495 Request target to change the size of trace buffer.
1497 set remote trace-buffer-size-packet auto|on|off
1498 show remote trace-buffer-size-packet
1499 Control the use of the remote protocol `QTBuffer:size' packet.
1503 Control display of debugging messages related to ARM AArch64.
1506 set debug coff-pe-read
1507 show debug coff-pe-read
1508 Control display of debugging messages related to reading of COFF/PE
1513 Control display of debugging messages related to Mach-O symbols
1516 set debug notification
1517 show debug notification
1518 Control display of debugging info for async remote notification.
1522 ** Command parameter changes are now notified using new async record
1523 "=cmd-param-changed".
1524 ** Trace frame changes caused by command "tfind" are now notified using
1525 new async record "=traceframe-changed".
1526 ** The creation, deletion and modification of trace state variables
1527 are now notified using new async records "=tsv-created",
1528 "=tsv-deleted" and "=tsv-modified".
1529 ** The start and stop of process record are now notified using new
1530 async record "=record-started" and "=record-stopped".
1531 ** Memory changes are now notified using new async record
1533 ** The data-disassemble command response will include a "fullname" field
1534 containing the absolute file name when source has been requested.
1535 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1536 command, to allow pattern filling of memory areas.
1537 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1538 library load/unload events.
1539 ** The response to breakpoint commands and breakpoint async records
1540 includes an "installed" field containing a boolean state about each
1541 non-pending tracepoint location is whether installed on target or not.
1542 ** Output of the "-trace-status" command includes a "trace-file" field
1543 containing the name of the trace file being examined. This field is
1544 optional, and only present when examining a trace file.
1545 ** The "fullname" field is now always present along with the "file" field,
1546 even if the file cannot be found by GDB.
1548 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1549 You must have the LZMA library available when configuring GDB for this
1550 feature to be enabled. For more information, see:
1551 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1553 * New remote packets
1556 Set the size of trace buffer. The remote stub reports support for this
1557 packet to gdb's qSupported query.
1560 Enable Branch Trace Store (BTS)-based branch tracing for the current
1561 thread. The remote stub reports support for this packet to gdb's
1565 Disable branch tracing for the current thread. The remote stub reports
1566 support for this packet to gdb's qSupported query.
1569 Read the traced branches for the current thread. The remote stub
1570 reports support for this packet to gdb's qSupported query.
1572 *** Changes in GDB 7.5
1574 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1575 for more x32 ABI info.
1577 * GDB now supports access to MIPS DSP registers on Linux targets.
1579 * GDB now supports debugging microMIPS binaries.
1581 * The "info os" command on GNU/Linux can now display information on
1582 several new classes of objects managed by the operating system:
1583 "info os procgroups" lists process groups
1584 "info os files" lists file descriptors
1585 "info os sockets" lists internet-domain sockets
1586 "info os shm" lists shared-memory regions
1587 "info os semaphores" lists semaphores
1588 "info os msg" lists message queues
1589 "info os modules" lists loaded kernel modules
1591 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1592 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1593 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1594 options and inspect the probe arguments using the new $_probe_arg family
1595 of convenience variables. You can obtain more information about SystemTap
1596 in <http://sourceware.org/systemtap/>.
1598 * GDB now supports reversible debugging on ARM, it allows you to
1599 debug basic ARM and THUMB instructions, and provides
1600 record/replay support.
1602 * The option "symbol-reloading" has been deleted as it is no longer used.
1606 ** GDB commands implemented in Python can now be put in command class
1609 ** The "maint set python print-stack on|off" is now deleted.
1611 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1612 apply "flag enum"-style pretty-printing to any enum.
1614 ** gdb.lookup_symbol can now work when there is no current frame.
1616 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1617 the source at which the symbol was defined.
1619 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1620 method 'value'. The former indicates whether the symbol needs a
1621 frame in order to compute its value, and the latter computes the
1624 ** A new method 'referenced_value' on gdb.Value objects which can
1625 dereference pointer as well as C++ reference values.
1627 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1628 which return the global and static blocks (as gdb.Block objects),
1629 of the underlying symbol table, respectively.
1631 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1632 object associated with a PC value.
1634 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1635 of the address range occupied by code for the current source line.
1637 * Go language support.
1638 GDB now supports debugging programs written in the Go programming
1641 * GDBserver now supports stdio connections.
1642 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1644 * The binary "gdbtui" can no longer be built or installed.
1645 Use "gdb -tui" instead.
1647 * GDB will now print "flag" enums specially. A flag enum is one where
1648 all the enumerator values have no bits in common when pairwise
1649 "and"ed. When printing a value whose type is a flag enum, GDB will
1650 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1651 (gdb) print (enum E) 3
1654 * The filename part of a linespec will now match trailing components
1655 of a source file name. For example, "break gcc/expr.c:1000" will
1656 now set a breakpoint in build/gcc/expr.c, but not
1657 build/libcpp/expr.c.
1659 * The "info proc" and "generate-core-file" commands will now also
1660 work on remote targets connected to GDBserver on Linux.
1662 * The command "info catch" has been removed. It has been disabled
1663 since December 2007.
1665 * The "catch exception" and "catch assert" commands now accept
1666 a condition at the end of the command, much like the "break"
1667 command does. For instance:
1669 (gdb) catch exception Constraint_Error if Barrier = True
1671 Previously, it was possible to add a condition to such catchpoints,
1672 but it had to be done as a second step, after the catchpoint had been
1673 created, using the "condition" command.
1675 * The "info static-tracepoint-marker" command will now also work on
1676 native Linux targets with in-process agent.
1678 * GDB can now set breakpoints on inlined functions.
1680 * The .gdb_index section has been updated to include symbols for
1681 inlined functions. GDB will ignore older .gdb_index sections by
1682 default, which could cause symbol files to be loaded more slowly
1683 until their .gdb_index sections can be recreated. The new command
1684 "set use-deprecated-index-sections on" will cause GDB to use any older
1685 .gdb_index sections it finds. This will restore performance, but the
1686 ability to set breakpoints on inlined functions will be lost in symbol
1687 files with older .gdb_index sections.
1689 The .gdb_index section has also been updated to record more information
1690 about each symbol. This speeds up the "info variables", "info functions"
1691 and "info types" commands when used with programs having the .gdb_index
1692 section, as well as speeding up debugging with shared libraries using
1693 the .gdb_index section.
1695 * Ada support for GDB/MI Variable Objects has been added.
1697 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1702 ** New command -info-os is the MI equivalent of "info os".
1704 ** Output logs ("set logging" and related) now include MI output.
1708 ** "set use-deprecated-index-sections on|off"
1709 "show use-deprecated-index-sections on|off"
1710 Controls the use of deprecated .gdb_index sections.
1712 ** "catch load" and "catch unload" can be used to stop when a shared
1713 library is loaded or unloaded, respectively.
1715 ** "enable count" can be used to auto-disable a breakpoint after
1718 ** "info vtbl" can be used to show the virtual method tables for
1719 C++ and Java objects.
1721 ** "explore" and its sub commands "explore value" and "explore type"
1722 can be used to recursively explore values and types of
1723 expressions. These commands are available only if GDB is
1724 configured with '--with-python'.
1726 ** "info auto-load" shows status of all kinds of auto-loaded files,
1727 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1728 sequences of commands files, "info auto-load python-scripts"
1729 shows status of auto-loading Python script files,
1730 "info auto-load local-gdbinit" shows status of loading init file
1731 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1732 status of inferior specific thread debugging shared library loading.
1734 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1735 and "show auto-load-scripts" commands have been deprecated, use their
1736 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1737 and "show auto-load python-scripts" counterparts instead.
1739 ** "dprintf location,format,args..." creates a dynamic printf, which
1740 is basically a breakpoint that does a printf and immediately
1741 resumes your program's execution, so it is like a printf that you
1742 can insert dynamically at runtime instead of at compiletime.
1744 ** "set print symbol"
1746 Controls whether GDB attempts to display the symbol, if any,
1747 corresponding to addresses it prints. This defaults to "on", but
1748 you can set it to "off" to restore GDB's previous behavior.
1750 * Deprecated commands
1752 ** For the Renesas Super-H architecture, the "regs" command has been
1753 deprecated, and "info all-registers" should be used instead.
1757 Renesas RL78 rl78-*-elf
1758 HP OpenVMS ia64 ia64-hp-openvms*
1760 * GDBserver supports evaluation of breakpoint conditions. When
1761 support is advertised by GDBserver, GDB may be told to send the
1762 breakpoint conditions in bytecode form to GDBserver. GDBserver
1763 will only report the breakpoint trigger to GDB when its condition
1768 set mips compression
1769 show mips compression
1770 Select the compressed ISA encoding used in functions that have no symbol
1771 information available. The encoding can be set to either of:
1774 and is updated automatically from ELF file flags if available.
1776 set breakpoint condition-evaluation
1777 show breakpoint condition-evaluation
1778 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1779 GDBserver ("target"). Default option "auto" chooses the most efficient
1781 This option can improve debugger efficiency depending on the speed of the
1785 Disable auto-loading globally.
1788 Show auto-loading setting of all kinds of auto-loaded files.
1790 set auto-load gdb-scripts on|off
1791 show auto-load gdb-scripts
1792 Control auto-loading of GDB canned sequences of commands files.
1794 set auto-load python-scripts on|off
1795 show auto-load python-scripts
1796 Control auto-loading of Python script files.
1798 set auto-load local-gdbinit on|off
1799 show auto-load local-gdbinit
1800 Control loading of init file (.gdbinit) from current directory.
1802 set auto-load libthread-db on|off
1803 show auto-load libthread-db
1804 Control auto-loading of inferior specific thread debugging shared library.
1806 set auto-load scripts-directory <dir1>[:<dir2>...]
1807 show auto-load scripts-directory
1808 Set a list of directories from which to load auto-loaded scripts.
1809 Automatically loaded Python scripts and GDB scripts are located in one
1810 of the directories listed by this option.
1811 The delimiter (':' above) may differ according to the host platform.
1813 set auto-load safe-path <dir1>[:<dir2>...]
1814 show auto-load safe-path
1815 Set a list of directories from which it is safe to auto-load files.
1816 The delimiter (':' above) may differ according to the host platform.
1818 set debug auto-load on|off
1819 show debug auto-load
1820 Control display of debugging info for auto-loading the files above.
1822 set dprintf-style gdb|call|agent
1824 Control the way in which a dynamic printf is performed; "gdb"
1825 requests a GDB printf command, while "call" causes dprintf to call a
1826 function in the inferior. "agent" requests that the target agent
1827 (such as GDBserver) do the printing.
1829 set dprintf-function <expr>
1830 show dprintf-function
1831 set dprintf-channel <expr>
1832 show dprintf-channel
1833 Set the function and optional first argument to the call when using
1834 the "call" style of dynamic printf.
1836 set disconnected-dprintf on|off
1837 show disconnected-dprintf
1838 Control whether agent-style dynamic printfs continue to be in effect
1839 after GDB disconnects.
1841 * New configure options
1843 --with-auto-load-dir
1844 Configure default value for the 'set auto-load scripts-directory'
1845 setting above. It defaults to '$debugdir:$datadir/auto-load',
1846 $debugdir representing global debugging info directories (available
1847 via 'show debug-file-directory') and $datadir representing GDB's data
1848 directory (available via 'show data-directory').
1850 --with-auto-load-safe-path
1851 Configure default value for the 'set auto-load safe-path' setting
1852 above. It defaults to the --with-auto-load-dir setting.
1854 --without-auto-load-safe-path
1855 Set 'set auto-load safe-path' to '/', effectively disabling this
1858 * New remote packets
1860 z0/z1 conditional breakpoints extension
1862 The z0/z1 breakpoint insertion packets have been extended to carry
1863 a list of conditional expressions over to the remote stub depending on the
1864 condition evaluation mode. The use of this extension can be controlled
1865 via the "set remote conditional-breakpoints-packet" command.
1869 Specify the signals which the remote stub may pass to the debugged
1870 program without GDB involvement.
1872 * New command line options
1874 --init-command=FILE, -ix Like --command, -x but execute it
1875 before loading inferior.
1876 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1877 execute it before loading inferior.
1879 *** Changes in GDB 7.4
1881 * GDB now handles ambiguous linespecs more consistently; the existing
1882 FILE:LINE support has been expanded to other types of linespecs. A
1883 breakpoint will now be set on all matching locations in all
1884 inferiors, and locations will be added or removed according to
1887 * GDB now allows you to skip uninteresting functions and files when
1888 stepping with the "skip function" and "skip file" commands.
1890 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1891 and "show remote hardware-watchpoint-length-limit". These allows to
1892 set or show the maximum length limit (in bytes) of a remote
1893 target hardware watchpoint.
1895 This allows e.g. to use "unlimited" hardware watchpoints with the
1896 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1897 watchpoints are slower than real hardware watchpoints but are
1898 significantly faster than gdb software watchpoints.
1902 ** The register_pretty_printer function in module gdb.printing now takes
1903 an optional `replace' argument. If True, the new printer replaces any
1906 ** The "maint set python print-stack on|off" command has been
1907 deprecated and will be deleted in GDB 7.5.
1908 A new command: "set python print-stack none|full|message" has
1909 replaced it. Additionally, the default for "print-stack" is
1910 now "message", which just prints the error message without
1913 ** A prompt substitution hook (prompt_hook) is now available to the
1916 ** A new Python module, gdb.prompt has been added to the GDB Python
1917 modules library. This module provides functionality for
1918 escape sequences in prompts (used by set/show
1919 extended-prompt). These escape sequences are replaced by their
1920 corresponding value.
1922 ** Python commands and convenience-functions located in
1923 'data-directory'/python/gdb/command and
1924 'data-directory'/python/gdb/function are now automatically loaded
1927 ** Blocks now provide four new attributes. global_block and
1928 static_block will return the global and static blocks
1929 respectively. is_static and is_global are boolean attributes
1930 that indicate if the block is one of those two types.
1932 ** Symbols now provide the "type" attribute, the type of the symbol.
1934 ** The "gdb.breakpoint" function has been deprecated in favor of
1937 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1938 of a function. This class is based on the "finish" command
1939 available in the CLI.
1941 ** Type objects for struct and union types now allow access to
1942 the fields using standard Python dictionary (mapping) methods.
1943 For example, "some_type['myfield']" now works, as does
1944 "some_type.items()".
1946 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1949 ** A new function, "deep_items" has been added to the gdb.types
1950 module in the GDB Python modules library. This function returns
1951 an iterator over the fields of a struct or union type. Unlike
1952 the standard Python "iteritems" method, it will recursively traverse
1953 any anonymous fields.
1957 ** "*stopped" events can report several new "reason"s, such as
1960 ** Breakpoint changes are now notified using new async records, like
1961 "=breakpoint-modified".
1963 ** New command -ada-task-info.
1965 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1966 $sdir specifies the default system locations of shared libraries.
1967 $pdir specifies the directory where the libpthread used by the application
1970 GDB no longer looks in $sdir and $pdir after it has searched the directories
1971 mentioned in libthread-db-search-path. If you want to search those
1972 directories, they must be specified in libthread-db-search-path.
1973 The default value of libthread-db-search-path on GNU/Linux and Solaris
1974 systems is now "$sdir:$pdir".
1976 $pdir is not supported by gdbserver, it is currently ignored.
1977 $sdir is supported by gdbserver.
1979 * New configure option --with-iconv-bin.
1980 When using the internationalization support like the one in the GNU C
1981 library, GDB will invoke the "iconv" program to get a list of supported
1982 character sets. If this program lives in a non-standard location, one can
1983 use this option to specify where to find it.
1985 * When natively debugging programs on PowerPC BookE processors running
1986 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1987 watchpoints, which specify a mask in addition to an address to watch.
1988 The mask specifies that some bits of an address (the bits which are
1989 reset in the mask) should be ignored when matching the address accessed
1990 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1991 section in the user manual for more details.
1993 * The new option --once causes GDBserver to stop listening for connections once
1994 the first connection is made. The listening port used by GDBserver will
1995 become available after that.
1997 * New commands "info macros" and "alias" have been added.
1999 * New function parameters suffix @entry specifies value of function parameter
2000 at the time the function got called. Entry values are available only since
2006 "!" is now an alias of the "shell" command.
2007 Note that no space is needed between "!" and SHELL COMMAND.
2011 watch EXPRESSION mask MASK_VALUE
2012 The watch command now supports the mask argument which allows creation
2013 of masked watchpoints, if the current architecture supports this feature.
2015 info auto-load-scripts [REGEXP]
2016 This command was formerly named "maintenance print section-scripts".
2017 It is now generally useful and is no longer a maintenance-only command.
2019 info macro [-all] [--] MACRO
2020 The info macro command has new options `-all' and `--'. The first for
2021 printing all definitions of a macro. The second for explicitly specifying
2022 the end of arguments and the beginning of the macro name in case the macro
2023 name starts with a hyphen.
2025 collect[/s] EXPRESSIONS
2026 The tracepoint collect command now takes an optional modifier "/s"
2027 that directs it to dereference pointer-to-character types and
2028 collect the bytes of memory up to a zero byte. The behavior is
2029 similar to what you see when you use the regular print command on a
2030 string. An optional integer following the "/s" sets a bound on the
2031 number of bytes that will be collected.
2034 The trace start command now interprets any supplied arguments as a
2035 note to be recorded with the trace run, with an effect similar to
2036 setting the variable trace-notes.
2039 The trace stop command now interprets any arguments as a note to be
2040 mentioned along with the tstatus report that the trace was stopped
2041 with a command. The effect is similar to setting the variable
2044 * Tracepoints can now be enabled and disabled at any time after a trace
2045 experiment has been started using the standard "enable" and "disable"
2046 commands. It is now possible to start a trace experiment with no enabled
2047 tracepoints; GDB will display a warning, but will allow the experiment to
2048 begin, assuming that tracepoints will be enabled as needed while the trace
2051 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2052 locations with 4-byte instructions, when they were previously
2053 limited to locations with instructions of 5 bytes or longer.
2057 set debug dwarf2-read
2058 show debug dwarf2-read
2059 Turns on or off display of debugging messages related to reading
2060 DWARF debug info. The default is off.
2062 set debug symtab-create
2063 show debug symtab-create
2064 Turns on or off display of debugging messages related to symbol table
2065 creation. The default is off.
2068 show extended-prompt
2069 Set the GDB prompt, and allow escape sequences to be inserted to
2070 display miscellaneous information (see 'help set extended-prompt'
2071 for the list of sequences). This prompt (and any information
2072 accessed through the escape sequences) is updated every time the
2073 prompt is displayed.
2075 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2076 show print entry-values
2077 Set printing of frame argument values at function entry. In some cases
2078 GDB can determine the value of function argument which was passed by the
2079 function caller, even if the value was modified inside the called function.
2081 set debug entry-values
2082 show debug entry-values
2083 Control display of debugging info for determining frame argument values at
2084 function entry and virtual tail call frames.
2086 set basenames-may-differ
2087 show basenames-may-differ
2088 Set whether a source file may have multiple base names.
2089 (A "base name" is the name of a file with the directory part removed.
2090 Example: The base name of "/home/user/hello.c" is "hello.c".)
2091 If set, GDB will canonicalize file names (e.g., expand symlinks)
2092 before comparing them. Canonicalization is an expensive operation,
2093 but it allows the same file be known by more than one base name.
2094 If not set (the default), all source files are assumed to have just
2095 one base name, and gdb will do file name comparisons more efficiently.
2101 Set a user name and notes for the current and any future trace runs.
2102 This is useful for long-running and/or disconnected traces, to
2103 inform others (or yourself) as to who is running the trace, supply
2104 contact information, or otherwise explain what is going on.
2106 set trace-stop-notes
2107 show trace-stop-notes
2108 Set a note attached to the trace run, that is displayed when the
2109 trace has been stopped by a tstop command. This is useful for
2110 instance as an explanation, if you are stopping a trace run that was
2111 started by someone else.
2113 * New remote packets
2117 Dynamically enable a tracepoint in a started trace experiment.
2121 Dynamically disable a tracepoint in a started trace experiment.
2125 Set the user and notes of the trace run.
2129 Query the current status of a tracepoint.
2133 Query the minimum length of instruction at which a fast tracepoint may
2136 * Dcache size (number of lines) and line-size are now runtime-configurable
2137 via "set dcache line" and "set dcache line-size" commands.
2141 Texas Instruments TMS320C6x tic6x-*-*
2145 Renesas RL78 rl78-*-elf
2147 *** Changes in GDB 7.3.1
2149 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2151 *** Changes in GDB 7.3
2153 * GDB has a new command: "thread find [REGEXP]".
2154 It finds the thread id whose name, target id, or thread extra info
2155 matches the given regular expression.
2157 * The "catch syscall" command now works on mips*-linux* targets.
2159 * The -data-disassemble MI command now supports modes 2 and 3 for
2160 dumping the instruction opcodes.
2162 * New command line options
2164 -data-directory DIR Specify DIR as the "data-directory".
2165 This is mostly for testing purposes.
2167 * The "maint set python auto-load on|off" command has been renamed to
2168 "set auto-load-scripts on|off".
2170 * GDB has a new command: "set directories".
2171 It is like the "dir" command except that it replaces the
2172 source path list instead of augmenting it.
2174 * GDB now understands thread names.
2176 On GNU/Linux, "info threads" will display the thread name as set by
2177 prctl or pthread_setname_np.
2179 There is also a new command, "thread name", which can be used to
2180 assign a name internally for GDB to display.
2183 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2184 has been integrated into GDB.
2188 ** The function gdb.Write now accepts an optional keyword 'stream'.
2189 This keyword, when provided, will direct the output to either
2190 stdout, stderr, or GDB's logging output.
2192 ** Parameters can now be be sub-classed in Python, and in particular
2193 you may implement the get_set_doc and get_show_doc functions.
2194 This improves how Parameter set/show documentation is processed
2195 and allows for more dynamic content.
2197 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2198 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2199 have an is_valid method.
2201 ** Breakpoints can now be sub-classed in Python, and in particular
2202 you may implement a 'stop' function that is executed each time
2203 the inferior reaches that breakpoint.
2205 ** New function gdb.lookup_global_symbol looks up a global symbol.
2207 ** GDB values in Python are now callable if the value represents a
2208 function. For example, if 'some_value' represents a function that
2209 takes two integer parameters and returns a value, you can call
2210 that function like so:
2212 result = some_value (10,20)
2214 ** Module gdb.types has been added.
2215 It contains a collection of utilities for working with gdb.Types objects:
2216 get_basic_type, has_field, make_enum_dict.
2218 ** Module gdb.printing has been added.
2219 It contains utilities for writing and registering pretty-printers.
2220 New classes: PrettyPrinter, SubPrettyPrinter,
2221 RegexpCollectionPrettyPrinter.
2222 New function: register_pretty_printer.
2224 ** New commands "info pretty-printers", "enable pretty-printer" and
2225 "disable pretty-printer" have been added.
2227 ** gdb.parameter("directories") is now available.
2229 ** New function gdb.newest_frame returns the newest frame in the
2232 ** The gdb.InferiorThread class has a new "name" attribute. This
2233 holds the thread's name.
2235 ** Python Support for Inferior events.
2236 Python scripts can add observers to be notified of events
2237 occurring in the process being debugged.
2238 The following events are currently supported:
2239 - gdb.events.cont Continue event.
2240 - gdb.events.exited Inferior exited event.
2241 - gdb.events.stop Signal received, and Breakpoint hit events.
2245 ** GDB now puts template parameters in scope when debugging in an
2246 instantiation. For example, if you have:
2248 template<int X> int func (void) { return X; }
2250 then if you step into func<5>, "print X" will show "5". This
2251 feature requires proper debuginfo support from the compiler; it
2252 was added to GCC 4.5.
2254 ** The motion commands "next", "finish", "until", and "advance" now
2255 work better when exceptions are thrown. In particular, GDB will
2256 no longer lose control of the inferior; instead, the GDB will
2257 stop the inferior at the point at which the exception is caught.
2258 This functionality requires a change in the exception handling
2259 code that was introduced in GCC 4.5.
2261 * GDB now follows GCC's rules on accessing volatile objects when
2262 reading or writing target state during expression evaluation.
2263 One notable difference to prior behavior is that "print x = 0"
2264 no longer generates a read of x; the value of the assignment is
2265 now always taken directly from the value being assigned.
2267 * GDB now has some support for using labels in the program's source in
2268 linespecs. For instance, you can use "advance label" to continue
2269 execution to a label.
2271 * GDB now has support for reading and writing a new .gdb_index
2272 section. This section holds a fast index of DWARF debugging
2273 information and can be used to greatly speed up GDB startup and
2274 operation. See the documentation for `save gdb-index' for details.
2276 * The "watch" command now accepts an optional "-location" argument.
2277 When used, this causes GDB to watch the memory referred to by the
2278 expression. Such a watchpoint is never deleted due to it going out
2281 * GDB now supports thread debugging of core dumps on GNU/Linux.
2283 GDB now activates thread debugging using the libthread_db library
2284 when debugging GNU/Linux core dumps, similarly to when debugging
2285 live processes. As a result, when debugging a core dump file, GDB
2286 is now able to display pthread_t ids of threads. For example, "info
2287 threads" shows the same output as when debugging the process when it
2288 was live. In earlier releases, you'd see something like this:
2291 * 1 LWP 6780 main () at main.c:10
2293 While now you see this:
2296 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2298 It is also now possible to inspect TLS variables when debugging core
2301 When debugging a core dump generated on a machine other than the one
2302 used to run GDB, you may need to point GDB at the correct
2303 libthread_db library with the "set libthread-db-search-path"
2304 command. See the user manual for more details on this command.
2306 * When natively debugging programs on PowerPC BookE processors running
2307 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2308 which stop execution of the inferior whenever it executes an instruction
2309 at any address within the specified range. See the "PowerPC Embedded"
2310 section in the user manual for more details.
2312 * New features in the GDB remote stub, GDBserver
2314 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2315 and i686 LynxOS (version 5.x).
2317 ** GDBserver is now supported on Blackfin Linux.
2319 * New native configurations
2321 ia64 HP-UX ia64-*-hpux*
2325 Analog Devices, Inc. Blackfin Processor bfin-*
2327 * Ada task switching is now supported on sparc-elf targets when
2328 debugging a program using the Ravenscar Profile. For more information,
2329 see the "Tasking Support when using the Ravenscar Profile" section
2330 in the GDB user manual.
2332 * Guile support was removed.
2334 * New features in the GNU simulator
2336 ** The --map-info flag lists all known core mappings.
2338 ** CFI flashes may be simulated via the "cfi" device.
2340 *** Changes in GDB 7.2
2342 * Shared library support for remote targets by default
2344 When GDB is configured for a generic, non-OS specific target, like
2345 for example, --target=arm-eabi or one of the many *-*-elf targets,
2346 GDB now queries remote stubs for loaded shared libraries using the
2347 `qXfer:libraries:read' packet. Previously, shared library support
2348 was always disabled for such configurations.
2352 ** Argument Dependent Lookup (ADL)
2354 In C++ ADL lookup directs function search to the namespaces of its
2355 arguments even if the namespace has not been imported.
2365 Here the compiler will search for `foo' in the namespace of 'b'
2366 and find A::foo. GDB now supports this. This construct is commonly
2367 used in the Standard Template Library for operators.
2369 ** Improved User Defined Operator Support
2371 In addition to member operators, GDB now supports lookup of operators
2372 defined in a namespace and imported with a `using' directive, operators
2373 defined in the global scope, operators imported implicitly from an
2374 anonymous namespace, and the ADL operators mentioned in the previous
2376 GDB now also supports proper overload resolution for all the previously
2377 mentioned flavors of operators.
2379 ** static const class members
2381 Printing of static const class members that are initialized in the
2382 class definition has been fixed.
2384 * Windows Thread Information Block access.
2386 On Windows targets, GDB now supports displaying the Windows Thread
2387 Information Block (TIB) structure. This structure is visible either
2388 by using the new command `info w32 thread-information-block' or, by
2389 dereferencing the new convenience variable named `$_tlb', a
2390 thread-specific pointer to the TIB. This feature is also supported
2391 when remote debugging using GDBserver.
2393 * Static tracepoints
2395 Static tracepoints are calls in the user program into a tracing
2396 library. One such library is a port of the LTTng kernel tracer to
2397 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2398 When debugging with GDBserver, GDB now supports combining the GDB
2399 tracepoint machinery with such libraries. For example: the user can
2400 use GDB to probe a static tracepoint marker (a call from the user
2401 program into the tracing library) with the new "strace" command (see
2402 "New commands" below). This creates a "static tracepoint" in the
2403 breakpoint list, that can be manipulated with the same feature set
2404 as fast and regular tracepoints. E.g., collect registers, local and
2405 global variables, collect trace state variables, and define
2406 tracepoint conditions. In addition, the user can collect extra
2407 static tracepoint marker specific data, by collecting the new
2408 $_sdata internal variable. When analyzing the trace buffer, you can
2409 inspect $_sdata like any other variable available to GDB. For more
2410 information, see the "Tracepoints" chapter in GDB user manual. New
2411 remote packets have been defined to support static tracepoints, see
2412 the "New remote packets" section below.
2414 * Better reconstruction of tracepoints after disconnected tracing
2416 GDB will attempt to download the original source form of tracepoint
2417 definitions when starting a trace run, and then will upload these
2418 upon reconnection to the target, resulting in a more accurate
2419 reconstruction of the tracepoints that are in use on the target.
2423 You can now exercise direct control over the ways that GDB can
2424 affect your program. For instance, you can disallow the setting of
2425 breakpoints, so that the program can run continuously (assuming
2426 non-stop mode). In addition, the "observer" variable is available
2427 to switch all of the different controls; in observer mode, GDB
2428 cannot affect the target's behavior at all, which is useful for
2429 tasks like diagnosing live systems in the field.
2431 * The new convenience variable $_thread holds the number of the
2434 * New remote packets
2438 Return the address of the Windows Thread Information Block of a given thread.
2442 In response to several of the tracepoint packets, the target may now
2443 also respond with a number of intermediate `qRelocInsn' request
2444 packets before the final result packet, to have GDB handle
2445 relocating an instruction to execute at a different address. This
2446 is particularly useful for stubs that support fast tracepoints. GDB
2447 reports support for this feature in the qSupported packet.
2451 List static tracepoint markers in the target program.
2455 List static tracepoint markers at a given address in the target
2458 qXfer:statictrace:read
2460 Read the static trace data collected (by a `collect $_sdata'
2461 tracepoint action). The remote stub reports support for this packet
2462 to gdb's qSupported query.
2466 Send the current settings of GDB's permission flags.
2470 Send part of the source (textual) form of a tracepoint definition,
2471 which includes location, conditional, and action list.
2473 * The source command now accepts a -s option to force searching for the
2474 script in the source search path even if the script name specifies
2477 * New features in the GDB remote stub, GDBserver
2479 - GDBserver now support tracepoints (including fast tracepoints, and
2480 static tracepoints). The feature is currently supported by the
2481 i386-linux and amd64-linux builds. See the "Tracepoints support
2482 in gdbserver" section in the manual for more information.
2484 GDBserver JIT compiles the tracepoint's conditional agent
2485 expression bytecode into native code whenever possible for low
2486 overhead dynamic tracepoints conditionals. For such tracepoints,
2487 an expression that examines program state is evaluated when the
2488 tracepoint is reached, in order to determine whether to capture
2489 trace data. If the condition is simple and false, processing the
2490 tracepoint finishes very quickly and no data is gathered.
2492 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2493 for static tracepoints support.
2495 - GDBserver now supports x86_64 Windows 64-bit debugging.
2497 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2498 it understands register description.
2500 * The --batch flag now disables pagination and queries.
2502 * X86 general purpose registers
2504 GDB now supports reading/writing byte, word and double-word x86
2505 general purpose registers directly. This means you can use, say,
2506 $ah or $ax to refer, respectively, to the byte register AH and
2507 16-bit word register AX that are actually portions of the 32-bit
2508 register EAX or 64-bit register RAX.
2510 * The `commands' command now accepts a range of breakpoints to modify.
2511 A plain `commands' following a command that creates multiple
2512 breakpoints affects all the breakpoints set by that command. This
2513 applies to breakpoints set by `rbreak', and also applies when a
2514 single `break' command creates multiple breakpoints (e.g.,
2515 breakpoints on overloaded c++ functions).
2517 * The `rbreak' command now accepts a filename specification as part of
2518 its argument, limiting the functions selected by the regex to those
2519 in the specified file.
2521 * Support for remote debugging Windows and SymbianOS shared libraries
2522 from Unix hosts has been improved. Non Windows GDB builds now can
2523 understand target reported file names that follow MS-DOS based file
2524 system semantics, such as file names that include drive letters and
2525 use the backslash character as directory separator. This makes it
2526 possible to transparently use the "set sysroot" and "set
2527 solib-search-path" on Unix hosts to point as host copies of the
2528 target's shared libraries. See the new command "set
2529 target-file-system-kind" described below, and the "Commands to
2530 specify files" section in the user manual for more information.
2534 eval template, expressions...
2535 Convert the values of one or more expressions under the control
2536 of the string template to a command line, and call it.
2538 set target-file-system-kind unix|dos-based|auto
2539 show target-file-system-kind
2540 Set or show the assumed file system kind for target reported file
2543 save breakpoints <filename>
2544 Save all current breakpoint definitions to a file suitable for use
2545 in a later debugging session. To read the saved breakpoint
2546 definitions, use the `source' command.
2548 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2551 info static-tracepoint-markers
2552 Display information about static tracepoint markers in the target.
2554 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2555 Define a static tracepoint by probing a marker at the given
2556 function, line, address, or marker ID.
2560 Enable and disable observer mode.
2562 set may-write-registers on|off
2563 set may-write-memory on|off
2564 set may-insert-breakpoints on|off
2565 set may-insert-tracepoints on|off
2566 set may-insert-fast-tracepoints on|off
2567 set may-interrupt on|off
2568 Set individual permissions for GDB effects on the target. Note that
2569 some of these settings can have undesirable or surprising
2570 consequences, particularly when changed in the middle of a session.
2571 For instance, disabling the writing of memory can prevent
2572 breakpoints from being inserted, cause single-stepping to fail, or
2573 even crash your program, if you disable after breakpoints have been
2574 inserted. However, GDB should not crash.
2576 set record memory-query on|off
2577 show record memory-query
2578 Control whether to stop the inferior if memory changes caused
2579 by an instruction cannot be recorded.
2584 The disassemble command now supports "start,+length" form of two arguments.
2588 ** GDB now provides a new directory location, called the python directory,
2589 where Python scripts written for GDB can be installed. The location
2590 of that directory is <data-directory>/python, where <data-directory>
2591 is the GDB data directory. For more details, see section `Scripting
2592 GDB using Python' in the manual.
2594 ** The GDB Python API now has access to breakpoints, symbols, symbol
2595 tables, program spaces, inferiors, threads and frame's code blocks.
2596 Additionally, GDB Parameters can now be created from the API, and
2597 manipulated via set/show in the CLI.
2599 ** New functions gdb.target_charset, gdb.target_wide_charset,
2600 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2602 ** New exception gdb.GdbError.
2604 ** Pretty-printers are now also looked up in the current program space.
2606 ** Pretty-printers can now be individually enabled and disabled.
2608 ** GDB now looks for names of Python scripts to auto-load in a
2609 special section named `.debug_gdb_scripts', in addition to looking
2610 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2612 * Tracepoint actions were unified with breakpoint commands. In particular,
2613 there are no longer differences in "info break" output for breakpoints and
2614 tracepoints and the "commands" command can be used for both tracepoints and
2615 regular breakpoints.
2619 ARM Symbian arm*-*-symbianelf*
2621 * D language support.
2622 GDB now supports debugging programs written in the D programming
2625 * GDB now supports the extended ptrace interface for PowerPC which is
2626 available since Linux kernel version 2.6.34. This automatically enables
2627 any hardware breakpoints and additional hardware watchpoints available in
2628 the processor. The old ptrace interface exposes just one hardware
2629 watchpoint and no hardware breakpoints.
2631 * GDB is now able to use the Data Value Compare (DVC) register available on
2632 embedded PowerPC processors to implement in hardware simple watchpoint
2633 conditions of the form:
2635 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2637 This works in native GDB running on Linux kernels with the extended ptrace
2638 interface mentioned above.
2640 *** Changes in GDB 7.1
2644 ** Namespace Support
2646 GDB now supports importing of namespaces in C++. This enables the
2647 user to inspect variables from imported namespaces. Support for
2648 namepace aliasing has also been added. So, if a namespace is
2649 aliased in the current scope (e.g. namepace C=A; ) the user can
2650 print variables using the alias (e.g. (gdb) print C::x).
2654 All known bugs relating to the printing of virtual base class were
2655 fixed. It is now possible to call overloaded static methods using a
2660 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2661 and reinterpret_cast<> are now handled by the C++ expression parser.
2665 Xilinx MicroBlaze microblaze-*-*
2670 Xilinx MicroBlaze microblaze
2673 * Multi-program debugging.
2675 GDB now has support for multi-program (a.k.a. multi-executable or
2676 multi-exec) debugging. This allows for debugging multiple inferiors
2677 simultaneously each running a different program under the same GDB
2678 session. See "Debugging Multiple Inferiors and Programs" in the
2679 manual for more information. This implied some user visible changes
2680 in the multi-inferior support. For example, "info inferiors" now
2681 lists inferiors that are not running yet or that have exited
2682 already. See also "New commands" and "New options" below.
2684 * New tracing features
2686 GDB's tracepoint facility now includes several new features:
2688 ** Trace state variables
2690 GDB tracepoints now include support for trace state variables, which
2691 are variables managed by the target agent during a tracing
2692 experiment. They are useful for tracepoints that trigger each
2693 other, so for instance one tracepoint can count hits in a variable,
2694 and then a second tracepoint has a condition that is true when the
2695 count reaches a particular value. Trace state variables share the
2696 $-syntax of GDB convenience variables, and can appear in both
2697 tracepoint actions and condition expressions. Use the "tvariable"
2698 command to create, and "info tvariables" to view; see "Trace State
2699 Variables" in the manual for more detail.
2703 GDB now includes an option for defining fast tracepoints, which
2704 targets may implement more efficiently, such as by installing a jump
2705 into the target agent rather than a trap instruction. The resulting
2706 speedup can be by two orders of magnitude or more, although the
2707 tradeoff is that some program locations on some target architectures
2708 might not allow fast tracepoint installation, for instance if the
2709 instruction to be replaced is shorter than the jump. To request a
2710 fast tracepoint, use the "ftrace" command, with syntax identical to
2711 the regular trace command.
2713 ** Disconnected tracing
2715 It is now possible to detach GDB from the target while it is running
2716 a trace experiment, then reconnect later to see how the experiment
2717 is going. In addition, a new variable disconnected-tracing lets you
2718 tell the target agent whether to continue running a trace if the
2719 connection is lost unexpectedly.
2723 GDB now has the ability to save the trace buffer into a file, and
2724 then use that file as a target, similarly to you can do with
2725 corefiles. You can select trace frames, print data that was
2726 collected in them, and use tstatus to display the state of the
2727 tracing run at the moment that it was saved. To create a trace
2728 file, use "tsave <filename>", and to use it, do "target tfile
2731 ** Circular trace buffer
2733 You can ask the target agent to handle the trace buffer as a
2734 circular buffer, discarding the oldest trace frames to make room for
2735 newer ones, by setting circular-trace-buffer to on. This feature may
2736 not be available for all target agents.
2741 The disassemble command, when invoked with two arguments, now requires
2742 the arguments to be comma-separated.
2745 The info variables command now displays variable definitions. Files
2746 which only declare a variable are not shown.
2749 The source command is now capable of sourcing Python scripts.
2750 This feature is dependent on the debugger being build with Python
2753 Related to this enhancement is also the introduction of a new command
2754 "set script-extension" (see below).
2756 * New commands (for set/show, see "New options" below)
2758 record save [<FILENAME>]
2759 Save a file (in core file format) containing the process record
2760 execution log for replay debugging at a later time.
2762 record restore <FILENAME>
2763 Restore the process record execution log that was saved at an
2764 earlier time, for replay debugging.
2766 add-inferior [-copies <N>] [-exec <FILENAME>]
2769 clone-inferior [-copies <N>] [ID]
2770 Make a new inferior ready to execute the same program another
2771 inferior has loaded.
2776 maint info program-spaces
2777 List the program spaces loaded into GDB.
2779 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2780 show remote interrupt-sequence
2781 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2782 as the sequence to the remote target in order to interrupt the execution.
2783 Ctrl-C is a default. Some system prefers BREAK which is high level of
2784 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2785 Magic SysRq g. It is BREAK signal and character 'g'.
2787 set remote interrupt-on-connect [on | off]
2788 show remote interrupt-on-connect
2789 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2790 remote target when gdb connects to it. This is needed when you debug
2793 set remotebreak [on | off]
2795 Deprecated. Use "set/show remote interrupt-sequence" instead.
2797 tvariable $NAME [ = EXP ]
2798 Create or modify a trace state variable.
2801 List trace state variables and their values.
2803 delete tvariable $NAME ...
2804 Delete one or more trace state variables.
2807 Evaluate the given expressions without collecting anything into the
2808 trace buffer. (Valid in tracepoint actions only.)
2810 ftrace FN / FILE:LINE / *ADDR
2811 Define a fast tracepoint at the given function, line, or address.
2813 * New expression syntax
2815 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2816 GDB now parses 0b101010 identically with 42.
2820 set follow-exec-mode new|same
2821 show follow-exec-mode
2822 Control whether GDB reuses the same inferior across an exec call or
2823 creates a new one. This is useful to be able to restart the old
2824 executable after the inferior having done an exec call.
2826 set default-collect EXPR, ...
2827 show default-collect
2828 Define a list of expressions to be collected at each tracepoint.
2829 This is a useful way to ensure essential items are not overlooked,
2830 such as registers or a critical global variable.
2832 set disconnected-tracing
2833 show disconnected-tracing
2834 If set to 1, the target is instructed to continue tracing if it
2835 loses its connection to GDB. If 0, the target is to stop tracing
2838 set circular-trace-buffer
2839 show circular-trace-buffer
2840 If set to on, the target is instructed to use a circular trace buffer
2841 and discard the oldest trace frames instead of stopping the trace due
2842 to a full trace buffer. If set to off, the trace stops when the buffer
2843 fills up. Some targets may not support this.
2845 set script-extension off|soft|strict
2846 show script-extension
2847 If set to "off", the debugger does not perform any script language
2848 recognition, and all sourced files are assumed to be GDB scripts.
2849 If set to "soft" (the default), files are sourced according to
2850 filename extension, falling back to GDB scripts if the first
2852 If set to "strict", files are sourced according to filename extension.
2854 set ada trust-PAD-over-XVS on|off
2855 show ada trust-PAD-over-XVS
2856 If off, activate a workaround against a bug in the debugging information
2857 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2858 the GCC sources for more information about the GNAT encoding and
2859 PAD types in particular). It is always safe to set this option to
2860 off, but this introduces a slight performance penalty. The default
2863 * Python API Improvements
2865 ** GDB provides the new class gdb.LazyString. This is useful in
2866 some pretty-printing cases. The new method gdb.Value.lazy_string
2867 provides a simple way to create objects of this type.
2869 ** The fields returned by gdb.Type.fields now have an
2870 `is_base_class' attribute.
2872 ** The new method gdb.Type.range returns the range of an array type.
2874 ** The new method gdb.parse_and_eval can be used to parse and
2875 evaluate an expression.
2877 * New remote packets
2880 Define a trace state variable.
2883 Get the current value of a trace state variable.
2886 Set desired tracing behavior upon disconnection.
2889 Set the trace buffer to be linear or circular.
2892 Get data about the tracepoints currently in use.
2896 Process record now works correctly with hardware watchpoints.
2898 Multiple bug fixes have been made to the mips-irix port, making it
2899 much more reliable. In particular:
2900 - Debugging threaded applications is now possible again. Previously,
2901 GDB would hang while starting the program, or while waiting for
2902 the program to stop at a breakpoint.
2903 - Attaching to a running process no longer hangs.
2904 - An error occurring while loading a core file has been fixed.
2905 - Changing the value of the PC register now works again. This fixes
2906 problems observed when using the "jump" command, or when calling
2907 a function from GDB, or even when assigning a new value to $pc.
2908 - With the "finish" and "return" commands, the return value for functions
2909 returning a small array is now correctly printed.
2910 - It is now possible to break on shared library code which gets executed
2911 during a shared library init phase (code executed while executing
2912 their .init section). Previously, the breakpoint would have no effect.
2913 - GDB is now able to backtrace through the signal handler for
2914 non-threaded programs.
2916 PIE (Position Independent Executable) programs debugging is now supported.
2917 This includes debugging execution of PIC (Position Independent Code) shared
2918 libraries although for that, it should be possible to run such libraries as an
2921 *** Changes in GDB 7.0
2923 * GDB now has an interface for JIT compilation. Applications that
2924 dynamically generate code can create symbol files in memory and register
2925 them with GDB. For users, the feature should work transparently, and
2926 for JIT developers, the interface is documented in the GDB manual in the
2927 "JIT Compilation Interface" chapter.
2929 * Tracepoints may now be conditional. The syntax is as for
2930 breakpoints; either an "if" clause appended to the "trace" command,
2931 or the "condition" command is available. GDB sends the condition to
2932 the target for evaluation using the same bytecode format as is used
2933 for tracepoint actions.
2935 * The disassemble command now supports: an optional /r modifier, print the
2936 raw instructions in hex as well as in symbolic form, and an optional /m
2937 modifier to print mixed source+assembly.
2939 * Process record and replay
2941 In a architecture environment that supports ``process record and
2942 replay'', ``process record and replay'' target can record a log of
2943 the process execution, and replay it with both forward and reverse
2946 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2947 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2948 set execution-direction {forward|reverse}, for targets that support
2951 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2952 feature is available with a native GDB running on kernel version
2955 * GDB now has support for multi-byte and wide character sets on the
2956 target. Strings whose character type is wchar_t, char16_t, or
2957 char32_t are now correctly printed. GDB supports wide- and unicode-
2958 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2959 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2960 `printf'. This feature requires iconv to work properly; if your
2961 system does not have a working iconv, GDB can use GNU libiconv. See
2962 the installation instructions for more information.
2964 * GDB now supports automatic retrieval of shared library files from
2965 remote targets. To use this feature, specify a system root that begins
2966 with the `remote:' prefix, either via the `set sysroot' command or via
2967 the `--with-sysroot' configure-time option.
2969 * "info sharedlibrary" now takes an optional regex of libraries to show,
2970 and it now reports if a shared library has no debugging information.
2972 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2973 now complete on file names.
2975 * When completing in expressions, gdb will attempt to limit
2976 completions to allowable structure or union fields, where appropriate.
2977 For instance, consider:
2979 # struct example { int f1; double f2; };
2980 # struct example variable;
2983 If the user types TAB at the end of this command line, the available
2984 completions will be "f1" and "f2".
2986 * Inlined functions are now supported. They show up in backtraces, and
2987 the "step", "next", and "finish" commands handle them automatically.
2989 * GDB now supports the token-splicing (##) and stringification (#)
2990 operators when expanding macros. It also supports variable-arity
2993 * GDB now supports inspecting extra signal information, exported by
2994 the new $_siginfo convenience variable. The feature is currently
2995 implemented on linux ARM, i386 and amd64.
2997 * GDB can now display the VFP floating point registers and NEON vector
2998 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2999 can provide these registers (requires Linux 2.6.30 or later). Remote
3000 and simulator targets may also provide them.
3002 * New remote packets
3005 Search memory for a sequence of bytes.
3008 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3009 operation over reliable transport links. Use of this packet is
3010 controlled by the `set remote noack-packet' command.
3013 Kill the process with the specified process ID. Use this in preference
3014 to `k' when multiprocess protocol extensions are supported.
3017 Obtains additional operating system information
3021 Read or write additional signal information.
3023 * Removed remote protocol undocumented extension
3025 An undocumented extension to the remote protocol's `S' stop reply
3026 packet that permited the stub to pass a process id was removed.
3027 Remote servers should use the `T' stop reply packet instead.
3029 * GDB now supports multiple function calling conventions according to the
3030 DWARF-2 DW_AT_calling_convention function attribute.
3032 * The SH target utilizes the aforementioned change to distinguish between gcc
3033 and Renesas calling convention. It also adds the new CLI commands
3034 `set/show sh calling-convention'.
3036 * GDB can now read compressed debug sections, as produced by GNU gold
3037 with the --compress-debug-sections=zlib flag.
3039 * 64-bit core files are now supported on AIX.
3041 * Thread switching is now supported on Tru64.
3043 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3044 which will be allocated using malloc later in program execution.
3046 * The qXfer:libraries:read remote procotol packet now allows passing a
3047 list of section offsets.
3049 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3050 conditions handling signals delivered during attach or thread creation
3051 have also been fixed.
3053 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3054 From the user's standpoint, all unqualified instances of True and False
3055 are treated as the standard definitions, regardless of context.
3057 * GDB now parses C++ symbol and type names more flexibly. For
3060 template<typename T> class C { };
3063 GDB will now correctly handle all of:
3065 ptype C<char const *>
3066 ptype C<char const*>
3067 ptype C<const char *>
3068 ptype C<const char*>
3070 * New features in the GDB remote stub, gdbserver
3072 - The "--wrapper" command-line argument tells gdbserver to use a
3073 wrapper program to launch programs for debugging.
3075 - On PowerPC and S/390 targets, it is now possible to use a single
3076 gdbserver executable to debug both 32-bit and 64-bit programs.
3077 (This requires gdbserver itself to be built as a 64-bit executable.)
3079 - gdbserver uses the new noack protocol mode for TCP connections to
3080 reduce communications latency, if also supported and enabled in GDB.
3082 - Support for the sparc64-linux-gnu target is now included in
3085 - The amd64-linux build of gdbserver now supports debugging both
3086 32-bit and 64-bit programs.
3088 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3089 now support hardware watchpoints, and will use them automatically
3094 GDB now has support for scripting using Python. Whether this is
3095 available is determined at configure time.
3097 New GDB commands can now be written in Python.
3099 * Ada tasking support
3101 Ada tasks can now be inspected in GDB. The following commands have
3105 Print the list of Ada tasks.
3107 Print detailed information about task number N.
3109 Print the task number of the current task.
3111 Switch the context of debugging to task number N.
3113 * Support for user-defined prefixed commands. The "define" command can
3114 add new commands to existing prefixes, e.g. "target".
3116 * Multi-inferior, multi-process debugging.
3118 GDB now has generalized support for multi-inferior debugging. See
3119 "Debugging Multiple Inferiors" in the manual for more information.
3120 Although availability still depends on target support, the command
3121 set is more uniform now. The GNU/Linux specific multi-forks support
3122 has been migrated to this new framework. This implied some user
3123 visible changes; see "New commands" and also "Removed commands"
3126 * Target descriptions can now describe the target OS ABI. See the
3127 "Target Description Format" section in the user manual for more
3130 * Target descriptions can now describe "compatible" architectures
3131 to indicate that the target can execute applications for a different
3132 architecture in addition to those for the main target architecture.
3133 See the "Target Description Format" section in the user manual for
3136 * Multi-architecture debugging.
3138 GDB now includes general supports for debugging applications on
3139 hybrid systems that use more than one single processor architecture
3140 at the same time. Each such hybrid architecture still requires
3141 specific support to be added. The only hybrid architecture supported
3142 in this version of GDB is the Cell Broadband Engine.
3144 * GDB now supports integrated debugging of Cell/B.E. applications that
3145 use both the PPU and SPU architectures. To enable support for hybrid
3146 Cell/B.E. debugging, you need to configure GDB to support both the
3147 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3148 --enable-targets configure option.
3150 * Non-stop mode debugging.
3152 For some targets, GDB now supports an optional mode of operation in
3153 which you can examine stopped threads while other threads continue
3154 to execute freely. This is referred to as non-stop mode, with the
3155 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3156 section in the user manual for more information.
3158 To be able to support remote non-stop debugging, a remote stub needs
3159 to implement the non-stop mode remote protocol extensions, as
3160 described in the "Remote Non-Stop" section of the user manual. The
3161 GDB remote stub, gdbserver, has been adjusted to support these
3162 extensions on linux targets.
3164 * New commands (for set/show, see "New options" below)
3166 catch syscall [NAME(S) | NUMBER(S)]
3167 Catch system calls. Arguments, which should be names of system
3168 calls or their numbers, mean catch only those syscalls. Without
3169 arguments, every syscall will be caught. When the inferior issues
3170 any of the specified syscalls, GDB will stop and announce the system
3171 call, both when it is called and when its call returns. This
3172 feature is currently available with a native GDB running on the
3173 Linux Kernel, under the following architectures: x86, x86_64,
3174 PowerPC and PowerPC64.
3176 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3178 Search memory for a sequence of bytes.
3180 maint set python print-stack
3181 maint show python print-stack
3182 Show a stack trace when an error is encountered in a Python script.
3185 Invoke CODE by passing it to the Python interpreter.
3190 These allow macros to be defined, undefined, and listed
3194 Show operating system information about processes.
3197 List the inferiors currently under GDB's control.
3200 Switch focus to inferior number NUM.
3203 Detach from inferior number NUM.
3206 Kill inferior number NUM.
3210 set spu stop-on-load
3211 show spu stop-on-load
3212 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3214 set spu auto-flush-cache
3215 show spu auto-flush-cache
3216 Control whether to automatically flush the software-managed cache
3217 during Cell/B.E. debugging.
3219 set sh calling-convention
3220 show sh calling-convention
3221 Control the calling convention used when calling SH target functions.
3224 show debug timestamp
3225 Control display of timestamps with GDB debugging output.
3227 set disassemble-next-line
3228 show disassemble-next-line
3229 Control display of disassembled source lines or instructions when
3232 set remote noack-packet
3233 show remote noack-packet
3234 Set/show the use of remote protocol QStartNoAckMode packet. See above
3235 under "New remote packets."
3237 set remote query-attached-packet
3238 show remote query-attached-packet
3239 Control use of remote protocol `qAttached' (query-attached) packet.
3241 set remote read-siginfo-object
3242 show remote read-siginfo-object
3243 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3246 set remote write-siginfo-object
3247 show remote write-siginfo-object
3248 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3251 set remote reverse-continue
3252 show remote reverse-continue
3253 Control use of remote protocol 'bc' (reverse-continue) packet.
3255 set remote reverse-step
3256 show remote reverse-step
3257 Control use of remote protocol 'bs' (reverse-step) packet.
3259 set displaced-stepping
3260 show displaced-stepping
3261 Control displaced stepping mode. Displaced stepping is a way to
3262 single-step over breakpoints without removing them from the debuggee.
3263 Also known as "out-of-line single-stepping".
3266 show debug displaced
3267 Control display of debugging info for displaced stepping.
3269 maint set internal-error
3270 maint show internal-error
3271 Control what GDB does when an internal error is detected.
3273 maint set internal-warning
3274 maint show internal-warning
3275 Control what GDB does when an internal warning is detected.
3280 Use a wrapper program to launch programs for debugging.
3282 set multiple-symbols (all|ask|cancel)
3283 show multiple-symbols
3284 The value of this variable can be changed to adjust the debugger behavior
3285 when an expression or a breakpoint location contains an ambiguous symbol
3286 name (an overloaded function name, for instance).
3288 set breakpoint always-inserted
3289 show breakpoint always-inserted
3290 Keep breakpoints always inserted in the target, as opposed to inserting
3291 them when resuming the target, and removing them when the target stops.
3292 This option can improve debugger performance on slow remote targets.
3294 set arm fallback-mode (arm|thumb|auto)
3295 show arm fallback-mode
3296 set arm force-mode (arm|thumb|auto)
3298 These commands control how ARM GDB determines whether instructions
3299 are ARM or Thumb. The default for both settings is auto, which uses
3300 the current CPSR value for instructions without symbols; previous
3301 versions of GDB behaved as if "set arm fallback-mode arm".
3303 set disable-randomization
3304 show disable-randomization
3305 Standalone programs run with the virtual address space randomization enabled
3306 by default on some platforms. This option keeps the addresses stable across
3307 multiple debugging sessions.
3311 Control whether other threads are stopped or not when some thread hits
3316 Requests that asynchronous execution is enabled in the target, if available.
3317 In this case, it's possible to resume target in the background, and interact
3318 with GDB while the target is running. "show target-async" displays the
3319 current state of asynchronous execution of the target.
3321 set target-wide-charset
3322 show target-wide-charset
3323 The target-wide-charset is the name of the character set that GDB
3324 uses when printing characters whose type is wchar_t.
3326 set tcp auto-retry (on|off)
3328 set tcp connect-timeout
3329 show tcp connect-timeout
3330 These commands allow GDB to retry failed TCP connections to a remote stub
3331 with a specified timeout period; this is useful if the stub is launched
3332 in parallel with GDB but may not be ready to accept connections immediately.
3334 set libthread-db-search-path
3335 show libthread-db-search-path
3336 Control list of directories which GDB will search for appropriate
3339 set schedule-multiple (on|off)
3340 show schedule-multiple
3341 Allow GDB to resume all threads of all processes or only threads of
3342 the current process.
3346 Use more aggressive caching for accesses to the stack. This improves
3347 performance of remote debugging (particularly backtraces) without
3348 affecting correctness.
3350 set interactive-mode (on|off|auto)
3351 show interactive-mode
3352 Control whether GDB runs in interactive mode (on) or not (off).
3353 When in interactive mode, GDB waits for the user to answer all
3354 queries. Otherwise, GDB does not wait and assumes the default
3355 answer. When set to auto (the default), GDB determines which
3356 mode to use based on the stdin settings.
3361 For program forks, this is replaced by the new more generic `info
3362 inferiors' command. To list checkpoints, you can still use the
3363 `info checkpoints' command, which was an alias for the `info forks'
3367 Replaced by the new `inferior' command. To switch between
3368 checkpoints, you can still use the `restart' command, which was an
3369 alias for the `fork' command.
3372 This is removed, since some targets don't have a notion of
3373 processes. To switch between processes, you can still use the
3374 `inferior' command using GDB's own inferior number.
3377 For program forks, this is replaced by the new more generic `kill
3378 inferior' command. To delete a checkpoint, you can still use the
3379 `delete checkpoint' command, which was an alias for the `delete
3383 For program forks, this is replaced by the new more generic `detach
3384 inferior' command. To detach a checkpoint, you can still use the
3385 `detach checkpoint' command, which was an alias for the `detach
3388 * New native configurations
3390 x86/x86_64 Darwin i[34567]86-*-darwin*
3392 x86_64 MinGW x86_64-*-mingw*
3396 Lattice Mico32 lm32-*
3397 x86 DICOS i[34567]86-*-dicos*
3398 x86_64 DICOS x86_64-*-dicos*
3401 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3402 (mingw32ce) debugging.
3408 These commands were actually not implemented on any target.
3410 *** Changes in GDB 6.8
3412 * New native configurations
3414 NetBSD/hppa hppa*-*netbsd*
3415 Xtensa GNU/Linux xtensa*-*-linux*
3419 NetBSD/hppa hppa*-*-netbsd*
3420 Xtensa GNU/Lunux xtensa*-*-linux*
3422 * Change in command line behavior -- corefiles vs. process ids.
3424 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3425 attaching to process NUMBER fails, GDB no longer attempts to open a
3426 core file named NUMBER. Attaching to a program using the -c option
3427 is no longer supported. Instead, use the '-p' or '--pid' options.
3429 * GDB can now be built as a native debugger for debugging Windows x86
3430 (mingw32) Portable Executable (PE) programs.
3432 * Pending breakpoints no longer change their number when their address
3435 * GDB now supports breakpoints with multiple locations,
3436 including breakpoints on C++ constructors, inside C++ templates,
3437 and in inlined functions.
3439 * GDB's ability to debug optimized code has been improved. GDB more
3440 accurately identifies function bodies and lexical blocks that occupy
3441 more than one contiguous range of addresses.
3443 * Target descriptions can now describe registers for PowerPC.
3445 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3446 registers on PowerPC targets.
3448 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3449 targets even when the libthread_db library is not available.
3451 * The GDB remote stub, gdbserver, now supports the new file transfer
3452 commands (remote put, remote get, and remote delete).
3454 * The GDB remote stub, gdbserver, now supports run and attach in
3455 extended-remote mode.
3457 * hppa*64*-*-hpux11* target broken
3458 The debugger is unable to start a program and fails with the following
3459 error: "Error trying to get information about dynamic linker".
3460 The gdb-6.7 release is also affected.
3462 * GDB now supports the --enable-targets= configure option to allow
3463 building a single GDB executable that supports multiple remote
3464 target architectures.
3466 * GDB now supports debugging C and C++ programs which use the
3467 Decimal Floating Point extension. In addition, the PowerPC target
3468 now has a set of pseudo-registers to inspect decimal float values
3469 stored in two consecutive float registers.
3471 * The -break-insert MI command can optionally create pending
3474 * Improved support for debugging Ada
3475 Many improvements to the Ada language support have been made. These
3477 - Better support for Ada2005 interface types
3478 - Improved handling of arrays and slices in general
3479 - Better support for Taft-amendment types
3480 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3482 - Improved command completion in Ada
3485 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3490 set print frame-arguments (all|scalars|none)
3491 show print frame-arguments
3492 The value of this variable can be changed to control which argument
3493 values should be printed by the debugger when displaying a frame.
3498 Transfer files to and from a remote target, and delete remote files.
3505 Transfer files to and from a remote target, and delete remote files.
3507 * New remote packets
3514 Open, close, read, write, and delete files on the remote system.
3517 Attach to an existing process on the remote system, in extended-remote
3521 Run a new process on the remote system, in extended-remote mode.
3523 *** Changes in GDB 6.7
3525 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3526 bfd, libiberty and opcodes, as revealed by static analysis donated by
3527 Coverity, Inc. (http://scan.coverity.com).
3529 * When looking up multiply-defined global symbols, GDB will now prefer the
3530 symbol definition in the current shared library if it was built using the
3531 -Bsymbolic linker option.
3533 * When the Text User Interface (TUI) is not configured, GDB will now
3534 recognize the -tui command-line option and print a message that the TUI
3537 * The GDB remote stub, gdbserver, now has lower overhead for high
3538 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3540 * GDB for MIPS targets now autodetects whether a remote target provides
3541 32-bit or 64-bit register values.
3543 * Support for C++ member pointers has been improved.
3545 * GDB now understands XML target descriptions, which specify the
3546 target's overall architecture. GDB can read a description from
3547 a local file or over the remote serial protocol.
3549 * Vectors of single-byte data use a new integer type which is not
3550 automatically displayed as character or string data.
3552 * The /s format now works with the print command. It displays
3553 arrays of single-byte integers and pointers to single-byte integers
3556 * Target descriptions can now describe target-specific registers,
3557 for architectures which have implemented the support (currently
3558 only ARM, M68K, and MIPS).
3560 * GDB and the GDB remote stub, gdbserver, now support the XScale
3563 * The GDB remote stub, gdbserver, has been updated to support
3564 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3565 has been rewritten to use the standard GDB remote protocol.
3567 * GDB can now step into C++ functions which are called through thunks.
3569 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3571 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3572 layout. It also supports a TextSeg= and DataSeg= response when only
3573 segment base addresses (rather than offsets) are available.
3575 * The /i format now outputs any trailing branch delay slot instructions
3576 immediately following the last instruction within the count specified.
3578 * The GDB remote protocol "T" stop reply packet now supports a
3579 "library" response. Combined with the new "qXfer:libraries:read"
3580 packet, this response allows GDB to debug shared libraries on targets
3581 where the operating system manages the list of loaded libraries (e.g.
3582 Windows and SymbianOS).
3584 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3585 (DLLs) on Windows and Windows CE targets.
3587 * GDB now supports a faster verification that a .debug file matches its binary
3588 according to its build-id signature, if the signature is present.
3594 Enable or disable hardware flow control (RTS/CTS) on the serial port
3595 when debugging using remote targets.
3597 set mem inaccessible-by-default
3598 show mem inaccessible-by-default
3599 If the target supplies a memory map, for instance via the remote
3600 protocol's "qXfer:memory-map:read" packet, setting this variable
3601 prevents GDB from accessing memory outside the memory map. This
3602 is useful for targets with memory mapped registers or which react
3603 badly to accesses of unmapped address space.
3605 set breakpoint auto-hw
3606 show breakpoint auto-hw
3607 If the target supplies a memory map, for instance via the remote
3608 protocol's "qXfer:memory-map:read" packet, setting this variable
3609 lets GDB use hardware breakpoints automatically for memory regions
3610 where it can not use software breakpoints. This covers both the
3611 "break" command and internal breakpoints used for other commands
3612 including "next" and "finish".
3615 catch exception unhandled
3616 Stop the program execution when Ada exceptions are raised.
3619 Stop the program execution when an Ada assertion failed.
3623 Set an alternate system root for target files. This is a more
3624 general version of "set solib-absolute-prefix", which is now
3625 an alias to "set sysroot".
3628 Provide extended SPU facility status information. This set of
3629 commands is available only when debugging the Cell/B.E. SPU
3632 * New native configurations
3634 OpenBSD/sh sh*-*openbsd*
3637 unset tdesc filename
3639 Use the specified local file as an XML target description, and do
3640 not query the target for its built-in description.
3644 OpenBSD/sh sh*-*-openbsd*
3645 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3646 Toshiba Media Processor mep-elf
3648 * New remote packets
3651 Ignore the specified signals; pass them directly to the debugged program
3652 without stopping other threads or reporting them to GDB.
3654 qXfer:features:read:
3655 Read an XML target description from the target, which describes its
3660 Read or write contents of an spufs file on the target system. These
3661 packets are available only on the Cell/B.E. SPU architecture.
3663 qXfer:libraries:read:
3664 Report the loaded shared libraries. Combined with new "T" packet
3665 response, this packet allows GDB to debug shared libraries on
3666 targets where the operating system manages the list of loaded
3667 libraries (e.g. Windows and SymbianOS).
3671 Support for these obsolete configurations has been removed.
3679 i[34567]86-*-lynxos*
3680 i[34567]86-*-netware*
3681 i[34567]86-*-sco3.2v5*
3682 i[34567]86-*-sco3.2v4*
3684 i[34567]86-*-sysv4.2*
3687 i[34567]86-*-unixware2*
3688 i[34567]86-*-unixware*
3697 * Other removed features
3704 Various m68k-only ROM monitors.
3711 Various Renesas ROM monitors and debugging interfaces for SH and
3716 Support for a Macraigor serial interface to on-chip debugging.
3717 GDB does not directly support the newer parallel or USB
3722 A debug information format. The predecessor to DWARF 2 and
3723 DWARF 3, which are still supported.
3725 Support for the HP aCC compiler on HP-UX/PA-RISC
3727 SOM-encapsulated symbolic debugging information, automatic
3728 invocation of pxdb, and the aCC custom C++ ABI. This does not
3729 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3730 with aCC can still be debugged on an assembly level.
3732 MIPS ".pdr" sections
3734 A MIPS-specific format used to describe stack frame layout
3735 in debugging information.
3739 GDB could work with an older version of Guile to debug
3740 the interpreter and Scheme programs running in it.
3742 set mips stack-arg-size
3743 set mips saved-gpreg-size
3745 Use "set mips abi" to control parameter passing for MIPS.
3747 *** Changes in GDB 6.6
3752 Cell Broadband Engine SPU spu-elf
3754 * GDB can now be configured as a cross-debugger targeting native Windows
3755 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3756 running on a Windows system over TCP/IP to debug Windows programs.
3758 * The GDB remote stub, gdbserver, has been updated to support Windows and
3759 Cygwin debugging. Both single-threaded and multi-threaded programs are
3762 * The "set trust-readonly-sections" command works again. This command was
3763 broken in GDB 6.3, 6.4, and 6.5.
3765 * The "load" command now supports writing to flash memory, if the remote
3766 stub provides the required support.
3768 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3769 longer requires symbolic debug information (e.g. DWARF-2).
3774 unset substitute-path
3775 show substitute-path
3776 Manage a list of substitution rules that GDB uses to rewrite the name
3777 of the directories where the sources are located. This can be useful
3778 for instance when the sources were moved to a different location
3779 between compilation and debugging.
3783 Print each CLI command as it is executed. Each command is prefixed with
3784 a number of `+' symbols representing the nesting depth.
3785 The source command now has a `-v' option to enable the same feature.
3789 The ARM Demon monitor support (RDP protocol, "target rdp").
3791 Kernel Object Display, an embedded debugging feature which only worked with
3792 an obsolete version of Cisco IOS.
3794 The 'set download-write-size' and 'show download-write-size' commands.
3796 * New remote packets
3799 Tell a stub about GDB client features, and request remote target features.
3800 The first feature implemented is PacketSize, which allows the target to
3801 specify the size of packets it can handle - to minimize the number of
3802 packets required and improve performance when connected to a remote
3806 Fetch an OS auxilliary vector from the remote stub. This packet is a
3807 more efficient replacement for qPart:auxv:read.
3809 qXfer:memory-map:read:
3810 Fetch a memory map from the remote stub, including information about
3811 RAM, ROM, and flash memory devices.
3816 Erase and program a flash memory device.
3818 * Removed remote packets
3821 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3822 used it, and only gdbserver implemented it.
3824 *** Changes in GDB 6.5
3828 Renesas M32C/M16C m32c-elf
3830 Morpho Technologies ms1 ms1-elf
3834 init-if-undefined Initialize a convenience variable, but
3835 only if it doesn't already have a value.
3837 The following commands are presently only implemented for native GNU/Linux:
3839 checkpoint Save a snapshot of the program state.
3841 restart <n> Return the program state to a
3842 previously saved state.
3844 info checkpoints List currently saved checkpoints.
3846 delete-checkpoint <n> Delete a previously saved checkpoint.
3848 set|show detach-on-fork Tell gdb whether to detach from a newly
3849 forked process, or to keep debugging it.
3851 info forks List forks of the user program that
3852 are available to be debugged.
3854 fork <n> Switch to debugging one of several
3855 forks of the user program that are
3856 available to be debugged.
3858 delete-fork <n> Delete a fork from the list of forks
3859 that are available to be debugged (and
3860 kill the forked process).
3862 detach-fork <n> Delete a fork from the list of forks
3863 that are available to be debugged (and
3864 allow the process to continue).
3868 Morpho Technologies ms2 ms1-elf
3870 * Improved Windows host support
3872 GDB now builds as a cross debugger hosted on i686-mingw32, including
3873 native console support, and remote communications using either
3874 network sockets or serial ports.
3876 * Improved Modula-2 language support
3878 GDB can now print most types in the Modula-2 syntax. This includes:
3879 basic types, set types, record types, enumerated types, range types,
3880 pointer types and ARRAY types. Procedure var parameters are correctly
3881 printed and hexadecimal addresses and character constants are also
3882 written in the Modula-2 syntax. Best results can be obtained by using
3883 GNU Modula-2 together with the -gdwarf-2 command line option.
3887 The ARM rdi-share module.
3889 The Netware NLM debug server.
3891 *** Changes in GDB 6.4
3893 * New native configurations
3895 OpenBSD/arm arm*-*-openbsd*
3896 OpenBSD/mips64 mips64-*-openbsd*
3900 Morpho Technologies ms1 ms1-elf
3902 * New command line options
3904 --batch-silent As for --batch, but totally silent.
3905 --return-child-result The debugger will exist with the same value
3906 the child (debugged) program exited with.
3907 --eval-command COMMAND, -ex COMMAND
3908 Execute a single GDB CLI command. This may be
3909 specified multiple times and in conjunction
3910 with the --command (-x) option.
3912 * Deprecated commands removed
3914 The following commands, that were deprecated in 2000, have been
3918 set|show arm disassembly-flavor set|show arm disassembler
3919 othernames set arm disassembler
3920 set|show remotedebug set|show debug remote
3921 set|show archdebug set|show debug arch
3922 set|show eventdebug set|show debug event
3925 * New BSD user-level threads support
3927 It is now possible to debug programs using the user-level threads
3928 library on OpenBSD and FreeBSD. Currently supported (target)
3931 FreeBSD/amd64 x86_64-*-freebsd*
3932 FreeBSD/i386 i386-*-freebsd*
3933 OpenBSD/i386 i386-*-openbsd*
3935 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3936 are not yet supported.
3938 * New support for Matsushita MN10300 w/sim added
3939 (Work in progress). mn10300-elf.
3941 * REMOVED configurations and files
3943 VxWorks and the XDR protocol *-*-vxworks
3944 Motorola MCORE mcore-*-*
3945 National Semiconductor NS32000 ns32k-*-*
3947 * New "set print array-indexes" command
3949 After turning this setting "on", GDB prints the index of each element
3950 when displaying arrays. The default is "off" to preserve the previous
3953 * VAX floating point support
3955 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3957 * User-defined command support
3959 In addition to using $arg0..$arg9 for argument passing, it is now possible
3960 to use $argc to determine now many arguments have been passed. See the
3961 section on user-defined commands in the user manual for more information.
3963 *** Changes in GDB 6.3:
3965 * New command line option
3967 GDB now accepts -l followed by a number to set the timeout for remote
3970 * GDB works with GCC -feliminate-dwarf2-dups
3972 GDB now supports a more compact representation of DWARF-2 debug
3973 information using DW_FORM_ref_addr references. These are produced
3974 by GCC with the option -feliminate-dwarf2-dups and also by some
3975 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3976 to use -feliminate-dwarf2-dups.
3978 * Internationalization
3980 When supported by the host system, GDB will be built with
3981 internationalization (libintl). The task of marking up the sources is
3982 continued, we're looking forward to our first translation.
3986 Initial support for debugging programs compiled with the GNAT
3987 implementation of the Ada programming language has been integrated
3988 into GDB. In this release, support is limited to expression evaluation.
3990 * New native configurations
3992 GNU/Linux/m32r m32r-*-linux-gnu
3996 GDB's remote protocol now includes support for the 'p' packet. This
3997 packet is used to fetch individual registers from a remote inferior.
3999 * END-OF-LIFE registers[] compatibility module
4001 GDB's internal register infrastructure has been completely rewritten.
4002 The new infrastructure making possible the implementation of key new
4003 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4006 GDB 6.3 will be the last release to include the the registers[]
4007 compatibility module that allowed out-of-date configurations to
4008 continue to work. This change directly impacts the following
4018 powerpc bdm protocol
4020 Unless there is activity to revive these configurations, they will be
4021 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4023 * OBSOLETE configurations and files
4025 Configurations that have been declared obsolete in this release have
4026 been commented out. Unless there is activity to revive these
4027 configurations, the next release of GDB will have their sources
4028 permanently REMOVED.
4037 *** Changes in GDB 6.2.1:
4039 * MIPS `break main; run' gave an heuristic-fence-post warning
4041 When attempting to run even a simple program, a warning about
4042 heuristic-fence-post being hit would be reported. This problem has
4045 * MIPS IRIX 'long double' crashed GDB
4047 When examining a long double variable, GDB would get a segmentation
4048 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4049 IRIX long double values).
4053 A bug in the VAX stack code was causing problems with the "next"
4054 command. This problem has been fixed.
4056 *** Changes in GDB 6.2:
4058 * Fix for ``many threads''
4060 On GNU/Linux systems that use the NPTL threads library, a program
4061 rapidly creating and deleting threads would confuse GDB leading to the
4064 ptrace: No such process.
4065 thread_db_get_info: cannot get thread info: generic error
4067 This problem has been fixed.
4069 * "-async" and "-noasync" options removed.
4071 Support for the broken "-noasync" option has been removed (it caused
4074 * New ``start'' command.
4076 This command runs the program until the begining of the main procedure.
4078 * New BSD Kernel Data Access Library (libkvm) interface
4080 Using ``target kvm'' it is now possible to debug kernel core dumps and
4081 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4082 platforms. Currently supported (native-only) configurations are:
4084 FreeBSD/amd64 x86_64-*-freebsd*
4085 FreeBSD/i386 i?86-*-freebsd*
4086 NetBSD/i386 i?86-*-netbsd*
4087 NetBSD/m68k m68*-*-netbsd*
4088 NetBSD/sparc sparc-*-netbsd*
4089 OpenBSD/amd64 x86_64-*-openbsd*
4090 OpenBSD/i386 i?86-*-openbsd*
4091 OpenBSD/m68k m68*-openbsd*
4092 OpenBSD/sparc sparc-*-openbsd*
4094 * Signal trampoline code overhauled
4096 Many generic problems with GDB's signal handling code have been fixed.
4097 These include: backtraces through non-contiguous stacks; recognition
4098 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4099 call; backtrace through a signal trampoline; step into and out of
4100 signal handlers; and single-stepping in the signal trampoline.
4102 Please note that kernel bugs are a limiting factor here. These
4103 features have been shown to work on an s390 GNU/Linux system that
4104 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4106 * Cygwin support for DWARF 2 added.
4108 * New native configurations
4110 GNU/Linux/hppa hppa*-*-linux*
4111 OpenBSD/hppa hppa*-*-openbsd*
4112 OpenBSD/m68k m68*-*-openbsd*
4113 OpenBSD/m88k m88*-*-openbsd*
4114 OpenBSD/powerpc powerpc-*-openbsd*
4115 NetBSD/vax vax-*-netbsd*
4116 OpenBSD/vax vax-*-openbsd*
4118 * END-OF-LIFE frame compatibility module
4120 GDB's internal frame infrastructure has been completely rewritten.
4121 The new infrastructure making it possible to support key new features
4122 including DWARF 2 Call Frame Information. To aid in the task of
4123 migrating old configurations to this new infrastructure, a
4124 compatibility module, that allowed old configurations to continue to
4125 work, was also included.
4127 GDB 6.2 will be the last release to include this frame compatibility
4128 module. This change directly impacts the following configurations:
4138 Unless there is activity to revive these configurations, they will be
4139 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4141 * REMOVED configurations and files
4143 Sun 3, running SunOS 3 m68*-*-sunos3*
4144 Sun 3, running SunOS 4 m68*-*-sunos4*
4145 Sun 2, running SunOS 3 m68000-*-sunos3*
4146 Sun 2, running SunOS 4 m68000-*-sunos4*
4147 Motorola 680x0 running LynxOS m68*-*-lynxos*
4148 AT&T 3b1/Unix pc m68*-att-*
4149 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4150 decstation mips-dec-* mips-little-*
4151 riscos mips-*-riscos* mips-*-sysv*
4152 sonymips mips-sony-*
4153 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4155 *** Changes in GDB 6.1.1:
4157 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4159 The TUI (Text-mode User Interface) is now built as part of a default
4160 GDB configuration. It is enabled by either selecting the TUI with the
4161 command line option "-i=tui" or by running the separate "gdbtui"
4162 program. For more information on the TUI, see the manual "Debugging
4165 * Pending breakpoint support (also included in GDB 6.1)
4167 Support has been added to allow you to specify breakpoints in shared
4168 libraries that have not yet been loaded. If a breakpoint location
4169 cannot be found, and the "breakpoint pending" option is set to auto,
4170 GDB queries you if you wish to make the breakpoint pending on a future
4171 shared-library load. If and when GDB resolves the breakpoint symbol,
4172 the pending breakpoint is removed as one or more regular breakpoints
4175 Pending breakpoints are very useful for GCJ Java debugging.
4177 * Fixed ISO-C build problems
4179 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4180 non ISO-C code that stopped them being built using a more strict ISO-C
4181 compiler (e.g., IBM's C compiler).
4183 * Fixed build problem on IRIX 5
4185 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4186 wasn't able to compile compile on an IRIX 5 system.
4188 * Added execute permission to gdb/gdbserver/configure
4190 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4191 permission. This bug would cause configure to fail on a number of
4192 systems (Solaris, IRIX). Ref: server/519.
4194 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4196 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4197 has been updated to use constant array sizes.
4199 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4201 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4202 its generated DWARF Call Frame Info. This encoding was causing GDB to
4203 panic, that panic has been fixed. Ref: gdb/1628.
4205 * Fixed a problem when examining parameters in shared library code.
4207 When examining parameters in optimized shared library code generated
4208 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4209 not available''. GDB now correctly displays the variable's value.
4211 *** Changes in GDB 6.1:
4213 * Removed --with-mmalloc
4215 Support for the mmalloc memory manager has been removed, as it
4216 conflicted with the internal gdb byte cache.
4218 * Changes in AMD64 configurations
4220 The AMD64 target now includes the %cs and %ss registers. As a result
4221 the AMD64 remote protocol has changed; this affects the floating-point
4222 and SSE registers. If you rely on those registers for your debugging,
4223 you should upgrade gdbserver on the remote side.
4225 * Revised SPARC target
4227 The SPARC target has been completely revised, incorporating the
4228 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4229 support for LynxOS and SunOS 4 has been dropped. Calling functions
4230 from within GDB on operating systems with a non-executable stack
4231 (Solaris, OpenBSD) now works.
4235 GDB has a new C++ demangler which does a better job on the mangled
4236 names generated by current versions of g++. It also runs faster, so
4237 with this and other changes gdb should now start faster on large C++
4240 * DWARF 2 Location Expressions
4242 GDB support for location expressions has been extended to support function
4243 arguments and frame bases. Older versions of GDB could crash when they
4246 * C++ nested types and namespaces
4248 GDB's support for nested types and namespaces in C++ has been
4249 improved, especially if you use the DWARF 2 debugging format. (This
4250 is the default for recent versions of GCC on most platforms.)
4251 Specifically, if you have a class "Inner" defined within a class or
4252 namespace "Outer", then GDB realizes that the class's name is
4253 "Outer::Inner", not simply "Inner". This should greatly reduce the
4254 frequency of complaints about not finding RTTI symbols. In addition,
4255 if you are stopped at inside of a function defined within a namespace,
4256 GDB modifies its name lookup accordingly.
4258 * New native configurations
4260 NetBSD/amd64 x86_64-*-netbsd*
4261 OpenBSD/amd64 x86_64-*-openbsd*
4262 OpenBSD/alpha alpha*-*-openbsd*
4263 OpenBSD/sparc sparc-*-openbsd*
4264 OpenBSD/sparc64 sparc64-*-openbsd*
4266 * New debugging protocols
4268 M32R with SDI protocol m32r-*-elf*
4270 * "set prompt-escape-char" command deleted.
4272 The command "set prompt-escape-char" has been deleted. This command,
4273 and its very obscure effet on GDB's prompt, was never documented,
4274 tested, nor mentioned in the NEWS file.
4276 * OBSOLETE configurations and files
4278 Configurations that have been declared obsolete in this release have
4279 been commented out. Unless there is activity to revive these
4280 configurations, the next release of GDB will have their sources
4281 permanently REMOVED.
4283 Sun 3, running SunOS 3 m68*-*-sunos3*
4284 Sun 3, running SunOS 4 m68*-*-sunos4*
4285 Sun 2, running SunOS 3 m68000-*-sunos3*
4286 Sun 2, running SunOS 4 m68000-*-sunos4*
4287 Motorola 680x0 running LynxOS m68*-*-lynxos*
4288 AT&T 3b1/Unix pc m68*-att-*
4289 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4290 decstation mips-dec-* mips-little-*
4291 riscos mips-*-riscos* mips-*-sysv*
4292 sonymips mips-sony-*
4293 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4295 * REMOVED configurations and files
4297 SGI Irix-4.x mips-sgi-irix4 or iris4
4298 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4299 Z8000 simulator z8k-zilog-none or z8ksim
4300 Matsushita MN10200 w/simulator mn10200-*-*
4301 H8/500 simulator h8500-hitachi-hms or h8500hms
4302 HP/PA running BSD hppa*-*-bsd*
4303 HP/PA running OSF/1 hppa*-*-osf*
4304 HP/PA Pro target hppa*-*-pro*
4305 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4306 386BSD i[3456]86-*-bsd*
4307 Sequent family i[3456]86-sequent-sysv4*
4308 i[3456]86-sequent-sysv*
4309 i[3456]86-sequent-bsd*
4310 SPARC running LynxOS sparc-*-lynxos*
4311 SPARC running SunOS 4 sparc-*-sunos4*
4312 Tsqware Sparclet sparclet-*-*
4313 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4315 *** Changes in GDB 6.0:
4319 Support for debugging the Objective-C programming language has been
4320 integrated into GDB.
4322 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4324 DWARF 2's Call Frame Information makes available compiler generated
4325 information that more exactly describes the program's run-time stack.
4326 By using this information, GDB is able to provide more robust stack
4329 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4330 have been updated to use a new backtrace mechanism which includes
4331 DWARF 2 CFI support.
4335 GDB's remote protocol has been extended to include support for hosted
4336 file I/O (where the remote target uses GDB's file system). See GDB's
4337 remote protocol documentation for details.
4339 * All targets using the new architecture framework.
4341 All of GDB's targets have been updated to use the new internal
4342 architecture framework. The way is now open for future GDB releases
4343 to include cross-architecture native debugging support (i386 on amd64,
4346 * GNU/Linux's Thread Local Storage (TLS)
4348 GDB now includes support for for the GNU/Linux implementation of
4349 per-thread variables.
4351 * GNU/Linux's Native POSIX Thread Library (NPTL)
4353 GDB's thread code has been updated to work with either the new
4354 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4356 * Separate debug info.
4358 GDB, in conjunction with BINUTILS, now supports a mechanism for
4359 automatically loading debug information from a separate file. Instead
4360 of shipping full debug and non-debug versions of system libraries,
4361 system integrators can now instead ship just the stripped libraries
4362 and optional debug files.
4364 * DWARF 2 Location Expressions
4366 DWARF 2 Location Expressions allow the compiler to more completely
4367 describe the location of variables (even in optimized code) to the
4370 GDB now includes preliminary support for location expressions (support
4371 for DW_OP_piece is still missing).
4375 A number of long standing bugs that caused GDB to die while starting a
4376 Java application have been fixed. GDB's Java support is now
4377 considered "useable".
4379 * GNU/Linux support for fork, vfork, and exec.
4381 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4382 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4385 * GDB supports logging output to a file
4387 There are two new commands, "set logging" and "show logging", which can be
4388 used to capture GDB's output to a file.
4390 * The meaning of "detach" has changed for gdbserver
4392 The "detach" command will now resume the application, as documented. To
4393 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4396 * d10v, m68hc11 `regs' command deprecated
4398 The `info registers' command has been updated so that it displays the
4399 registers using a format identical to the old `regs' command.
4403 A new command, "maint set profile on/off", has been added. This command can
4404 be used to enable or disable profiling while running GDB, to profile a
4405 session or a set of commands. In addition there is a new configure switch,
4406 "--enable-profiling", which will cause GDB to be compiled with profiling
4407 data, for more informative profiling results.
4409 * Default MI syntax changed to "mi2".
4411 The default MI (machine interface) syntax, enabled by the command line
4412 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4413 "mi1", can be enabled by specifying the option "-i=mi1".
4415 Support for the original "mi0" syntax (included in GDB 5.0) has been
4418 Fix for gdb/192: removed extraneous space when displaying frame level.
4419 Fix for gdb/672: update changelist is now output in mi list format.
4420 Fix for gdb/702: a -var-assign that updates the value now shows up
4421 in a subsequent -var-update.
4423 * New native configurations.
4425 FreeBSD/amd64 x86_64-*-freebsd*
4427 * Multi-arched targets.
4429 HP/PA HPUX11 hppa*-*-hpux*
4430 Renesas M32R/D w/simulator m32r-*-elf*
4432 * OBSOLETE configurations and files
4434 Configurations that have been declared obsolete in this release have
4435 been commented out. Unless there is activity to revive these
4436 configurations, the next release of GDB will have their sources
4437 permanently REMOVED.
4439 Z8000 simulator z8k-zilog-none or z8ksim
4440 Matsushita MN10200 w/simulator mn10200-*-*
4441 H8/500 simulator h8500-hitachi-hms or h8500hms
4442 HP/PA running BSD hppa*-*-bsd*
4443 HP/PA running OSF/1 hppa*-*-osf*
4444 HP/PA Pro target hppa*-*-pro*
4445 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4446 Sequent family i[3456]86-sequent-sysv4*
4447 i[3456]86-sequent-sysv*
4448 i[3456]86-sequent-bsd*
4449 Tsqware Sparclet sparclet-*-*
4450 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4452 * REMOVED configurations and files
4455 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4456 IBM AIX PS/2 i[3456]86-*-aix
4457 i386 running Mach 3.0 i[3456]86-*-mach3*
4458 i386 running Mach i[3456]86-*-mach*
4459 i386 running OSF/1 i[3456]86-*osf1mk*
4460 HP/Apollo 68k Family m68*-apollo*-sysv*,
4462 m68*-hp-bsd*, m68*-hp-hpux*
4463 Argonaut Risc Chip (ARC) arc-*-*
4464 Mitsubishi D30V d30v-*-*
4465 Fujitsu FR30 fr30-*-elf*
4466 OS/9000 i[34]86-*-os9k
4467 I960 with MON960 i960-*-coff
4469 * MIPS $fp behavior changed
4471 The convenience variable $fp, for the MIPS, now consistently returns
4472 the address of the current frame's base. Previously, depending on the
4473 context, $fp could refer to either $sp or the current frame's base
4474 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4475 The GNU Source-Level Debugger''.
4477 *** Changes in GDB 5.3:
4479 * GNU/Linux shared library multi-threaded performance improved.
4481 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4482 `/proc', in preference to `ptrace' for memory reads. This may result
4483 in an improvement in the start-up time of multi-threaded, shared
4484 library applications when run under GDB. One GDB user writes: ``loads
4485 shared libs like mad''.
4487 * ``gdbserver'' now supports multi-threaded applications on some targets
4489 Support for debugging multi-threaded applications which use
4490 the GNU/Linux LinuxThreads package has been added for
4491 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4492 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4494 * GDB now supports C/C++ preprocessor macros.
4496 GDB now expands preprocessor macro invocations in C/C++ expressions,
4497 and provides various commands for showing macro definitions and how
4500 The new command `macro expand EXPRESSION' expands any macro
4501 invocations in expression, and shows the result.
4503 The new command `show macro MACRO-NAME' shows the definition of the
4504 macro named MACRO-NAME, and where it was defined.
4506 Most compilers don't include information about macros in the debugging
4507 information by default. In GCC 3.1, for example, you need to compile
4508 your program with the options `-gdwarf-2 -g3'. If the macro
4509 information is present in the executable, GDB will read it.
4511 * Multi-arched targets.
4513 DEC Alpha (partial) alpha*-*-*
4514 DEC VAX (partial) vax-*-*
4516 National Semiconductor NS32000 (partial) ns32k-*-*
4517 Motorola 68000 (partial) m68k-*-*
4518 Motorola MCORE mcore-*-*
4522 Fujitsu FRV architecture added by Red Hat frv*-*-*
4525 * New native configurations
4527 Alpha NetBSD alpha*-*-netbsd*
4528 SH NetBSD sh*-*-netbsdelf*
4529 MIPS NetBSD mips*-*-netbsd*
4530 UltraSPARC NetBSD sparc64-*-netbsd*
4532 * OBSOLETE configurations and files
4534 Configurations that have been declared obsolete in this release have
4535 been commented out. Unless there is activity to revive these
4536 configurations, the next release of GDB will have their sources
4537 permanently REMOVED.
4539 Mitsubishi D30V d30v-*-*
4540 OS/9000 i[34]86-*-os9k
4541 IBM AIX PS/2 i[3456]86-*-aix
4542 Fujitsu FR30 fr30-*-elf*
4543 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4544 Argonaut Risc Chip (ARC) arc-*-*
4545 i386 running Mach 3.0 i[3456]86-*-mach3*
4546 i386 running Mach i[3456]86-*-mach*
4547 i386 running OSF/1 i[3456]86-*osf1mk*
4548 HP/Apollo 68k Family m68*-apollo*-sysv*,
4550 m68*-hp-bsd*, m68*-hp-hpux*
4551 I960 with MON960 i960-*-coff
4553 * OBSOLETE languages
4555 CHILL, a Pascal like language used by telecommunications companies.
4557 * REMOVED configurations and files
4559 AMD 29k family via UDI a29k-amd-udi, udi29k
4560 A29K VxWorks a29k-*-vxworks
4561 AMD 29000 embedded, using EBMON a29k-none-none
4562 AMD 29000 embedded with COFF a29k-none-coff
4563 AMD 29000 embedded with a.out a29k-none-aout
4565 testsuite/gdb.hp/gdb.threads-hp/ directory
4567 * New command "set max-user-call-depth <nnn>"
4569 This command allows the user to limit the call depth of user-defined
4570 commands. The default is 1024.
4572 * Changes in FreeBSD/i386 native debugging.
4574 Support for the "generate-core-file" has been added.
4576 * New commands "dump", "append", and "restore".
4578 These commands allow data to be copied from target memory
4579 to a bfd-format or binary file (dump and append), and back
4580 from a file into memory (restore).
4582 * Improved "next/step" support on multi-processor Alpha Tru64.
4584 The previous single-step mechanism could cause unpredictable problems,
4585 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4586 of a software single-step mechanism prevents this.
4588 *** Changes in GDB 5.2.1:
4596 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4597 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4598 Fix, by Joel Brobecker imported from mainline.
4600 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4601 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4602 Fix, by Fred Fish, imported from mainline.
4604 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4605 Surprisingly enough, it works now.
4606 By Michal Ludvig, imported from mainline.
4608 i386 hardware watchpoint support:
4609 avoid misses on second run for some targets.
4610 By Pierre Muller, imported from mainline.
4612 *** Changes in GDB 5.2:
4614 * New command "set trust-readonly-sections on[off]".
4616 This command is a hint that tells gdb that read-only sections
4617 really are read-only (ie. that their contents will not change).
4618 In this mode, gdb will go to the object file rather than the
4619 target to read memory from read-only sections (such as ".text").
4620 This can be a significant performance improvement on some
4621 (notably embedded) targets.
4623 * New command "generate-core-file" (or "gcore").
4625 This new gdb command allows the user to drop a core file of the child
4626 process state at any time. So far it's been implemented only for
4627 GNU/Linux and Solaris, but should be relatively easily ported to other
4628 hosts. Argument is core file name (defaults to core.<pid>).
4630 * New command line option
4632 GDB now accepts --pid or -p followed by a process id.
4634 * Change in command line behavior -- corefiles vs. process ids.
4636 There is a subtle behavior in the way in which GDB handles
4637 command line arguments. The first non-flag argument is always
4638 a program to debug, but the second non-flag argument may either
4639 be a corefile or a process id. Previously, GDB would attempt to
4640 open the second argument as a corefile, and if that failed, would
4641 issue a superfluous error message and then attempt to attach it as
4642 a process. Now, if the second argument begins with a non-digit,
4643 it will be treated as a corefile. If it begins with a digit,
4644 GDB will attempt to attach it as a process, and if no such process
4645 is found, will then attempt to open it as a corefile.
4647 * Changes in ARM configurations.
4649 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4650 configuration is fully multi-arch.
4652 * New native configurations
4654 ARM NetBSD arm*-*-netbsd*
4655 x86 OpenBSD i[3456]86-*-openbsd*
4656 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4657 Sparc64 running FreeBSD sparc64-*-freebsd*
4661 Sanyo XStormy16 xstormy16-elf
4663 * OBSOLETE configurations and files
4665 Configurations that have been declared obsolete in this release have
4666 been commented out. Unless there is activity to revive these
4667 configurations, the next release of GDB will have their sources
4668 permanently REMOVED.
4670 AMD 29k family via UDI a29k-amd-udi, udi29k
4671 A29K VxWorks a29k-*-vxworks
4672 AMD 29000 embedded, using EBMON a29k-none-none
4673 AMD 29000 embedded with COFF a29k-none-coff
4674 AMD 29000 embedded with a.out a29k-none-aout
4676 testsuite/gdb.hp/gdb.threads-hp/ directory
4678 * REMOVED configurations and files
4680 TI TMS320C80 tic80-*-*
4682 PowerPC Solaris powerpcle-*-solaris*
4683 PowerPC Windows NT powerpcle-*-cygwin32
4684 PowerPC Netware powerpc-*-netware*
4685 Harris/CXUX m88k m88*-harris-cxux*
4686 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4687 ns32k-utek-sysv* ns32k-utek-*
4688 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4689 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4690 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4691 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4692 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4694 * Changes to command line processing
4696 The new `--args' feature can be used to specify command-line arguments
4697 for the inferior from gdb's command line.
4699 * Changes to key bindings
4701 There is a new `operate-and-get-next' function bound to `C-o'.
4703 *** Changes in GDB 5.1.1
4705 Fix compile problem on DJGPP.
4707 Fix a problem with floating-point registers on the i386 being
4710 Fix to stop GDB crashing on .debug_str debug info.
4712 Numerous documentation fixes.
4714 Numerous testsuite fixes.
4716 *** Changes in GDB 5.1:
4718 * New native configurations
4720 Alpha FreeBSD alpha*-*-freebsd*
4721 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4722 MIPS GNU/Linux mips*-*-linux*
4723 MIPS SGI Irix 6.x mips*-sgi-irix6*
4724 ia64 AIX ia64-*-aix*
4725 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4729 Motorola 68HC11 and 68HC12 m68hc11-elf
4731 UltraSparc running GNU/Linux sparc64-*-linux*
4733 * OBSOLETE configurations and files
4735 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4736 Harris/CXUX m88k m88*-harris-cxux*
4737 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4738 ns32k-utek-sysv* ns32k-utek-*
4739 TI TMS320C80 tic80-*-*
4741 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4742 PowerPC Solaris powerpcle-*-solaris*
4743 PowerPC Windows NT powerpcle-*-cygwin32
4744 PowerPC Netware powerpc-*-netware*
4745 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4746 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4747 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4748 Apple Macintosh (MPW) host N/A
4750 stuff.c (Program to stuff files into a specially prepared space in kdb)
4751 kdb-start.c (Main loop for the standalone kernel debugger)
4753 Configurations that have been declared obsolete in this release have
4754 been commented out. Unless there is activity to revive these
4755 configurations, the next release of GDB will have their sources
4756 permanently REMOVED.
4758 * REMOVED configurations and files
4760 Altos 3068 m68*-altos-*
4761 Convex c1-*-*, c2-*-*
4763 ARM RISCix arm-*-* (as host)
4767 * GDB has been converted to ISO C.
4769 GDB's source code has been converted to ISO C. In particular, the
4770 sources are fully protoized, and rely on standard headers being
4775 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4777 * The MI enabled by default.
4779 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4780 revised and enabled by default. Packages which use GDB as a debugging
4781 engine behind a UI or another front end are encouraged to switch to
4782 using the GDB/MI interface, instead of the old annotations interface
4783 which is now deprecated.
4785 * Support for debugging Pascal programs.
4787 GDB now includes support for debugging Pascal programs. The following
4788 main features are supported:
4790 - Pascal-specific data types such as sets;
4792 - automatic recognition of Pascal sources based on file-name
4795 - Pascal-style display of data types, variables, and functions;
4797 - a Pascal expression parser.
4799 However, some important features are not yet supported.
4801 - Pascal string operations are not supported at all;
4803 - there are some problems with boolean types;
4805 - Pascal type hexadecimal constants are not supported
4806 because they conflict with the internal variables format;
4808 - support for Pascal objects and classes is not full yet;
4810 - unlike Pascal, GDB is case-sensitive for symbol names.
4812 * Changes in completion.
4814 Commands such as `shell', `run' and `set args', which pass arguments
4815 to inferior programs, now complete on file names, similar to what
4816 users expect at the shell prompt.
4818 Commands which accept locations, such as `disassemble', `print',
4819 `breakpoint', `until', etc. now complete on filenames as well as
4820 program symbols. Thus, if you type "break foob TAB", and the source
4821 files linked into the programs include `foobar.c', that file name will
4822 be one of the candidates for completion. However, file names are not
4823 considered for completion after you typed a colon that delimits a file
4824 name from a name of a function in that file, as in "break foo.c:bar".
4826 `set demangle-style' completes on available demangling styles.
4828 * New platform-independent commands:
4830 It is now possible to define a post-hook for a command as well as a
4831 hook that runs before the command. For more details, see the
4832 documentation of `hookpost' in the GDB manual.
4834 * Changes in GNU/Linux native debugging.
4836 Support for debugging multi-threaded programs has been completely
4837 revised for all platforms except m68k and sparc. You can now debug as
4838 many threads as your system allows you to have.
4840 Attach/detach is supported for multi-threaded programs.
4842 Support for SSE registers was added for x86. This doesn't work for
4843 multi-threaded programs though.
4845 * Changes in MIPS configurations.
4847 Multi-arch support is enabled for all MIPS configurations.
4849 GDB can now be built as native debugger on SGI Irix 6.x systems for
4850 debugging n32 executables. (Debugging 64-bit executables is not yet
4853 * Unified support for hardware watchpoints in all x86 configurations.
4855 Most (if not all) native x86 configurations support hardware-assisted
4856 breakpoints and watchpoints in a unified manner. This support
4857 implements debug register sharing between watchpoints, which allows to
4858 put a virtually infinite number of watchpoints on the same address,
4859 and also supports watching regions up to 16 bytes with several debug
4862 The new maintenance command `maintenance show-debug-regs' toggles
4863 debugging print-outs in functions that insert, remove, and test
4864 watchpoints and hardware breakpoints.
4866 * Changes in the DJGPP native configuration.
4868 New command ``info dos sysinfo'' displays assorted information about
4869 the CPU, OS, memory, and DPMI server.
4871 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4872 display information about segment descriptors stored in GDT, LDT, and
4875 New commands ``info dos pde'' and ``info dos pte'' display entries
4876 from Page Directory and Page Tables (for now works with CWSDPMI only).
4877 New command ``info dos address-pte'' displays the Page Table entry for
4878 a given linear address.
4880 GDB can now pass command lines longer than 126 characters to the
4881 program being debugged (requires an update to the libdbg.a library
4882 which is part of the DJGPP development kit).
4884 DWARF2 debug info is now supported.
4886 It is now possible to `step' and `next' through calls to `longjmp'.
4888 * Changes in documentation.
4890 All GDB documentation was converted to GFDL, the GNU Free
4891 Documentation License.
4893 Tracepoints-related commands are now fully documented in the GDB
4896 TUI, the Text-mode User Interface, is now documented in the manual.
4898 Tracepoints-related commands are now fully documented in the GDB
4901 The "GDB Internals" manual now has an index. It also includes
4902 documentation of `ui_out' functions, GDB coding standards, x86
4903 hardware watchpoints, and memory region attributes.
4905 * GDB's version number moved to ``version.in''
4907 The Makefile variable VERSION has been replaced by the file
4908 ``version.in''. People creating GDB distributions should update the
4909 contents of this file.
4913 GUD support is now a standard part of the EMACS distribution.
4915 *** Changes in GDB 5.0:
4917 * Improved support for debugging FP programs on x86 targets
4919 Unified and much-improved support for debugging floating-point
4920 programs on all x86 targets. In particular, ``info float'' now
4921 displays the FP registers in the same format on all x86 targets, with
4922 greater level of detail.
4924 * Improvements and bugfixes in hardware-assisted watchpoints
4926 It is now possible to watch array elements, struct members, and
4927 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4928 on x86 targets no longer erroneously trigger when the address is
4931 * Improvements in the native DJGPP version of GDB
4933 The distribution now includes all the scripts and auxiliary files
4934 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4935 machines ``out of the box''.
4937 The DJGPP version can now debug programs that use signals. It is
4938 possible to catch signals that happened in the debuggee, deliver
4939 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4940 would kill the program being debugged.) Programs that hook hardware
4941 interrupts (keyboard, timer, etc.) can also be debugged.
4943 It is now possible to debug DJGPP programs that redirect their
4944 standard handles or switch them to raw (as opposed to cooked) mode, or
4945 even close them. The command ``run < foo > bar'' works as expected,
4946 and ``info terminal'' reports useful information about the debuggee's
4947 terminal, including raw/cooked mode, redirection, etc.
4949 The DJGPP version now uses termios functions for console I/O, which
4950 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4953 DOS-style file names with drive letters are now fully supported by
4956 It is now possible to debug DJGPP programs that switch their working
4957 directory. It is also possible to rerun the debuggee any number of
4958 times without restarting GDB; thus, you can use the same setup,
4959 breakpoints, etc. for many debugging sessions.
4961 * New native configurations
4963 ARM GNU/Linux arm*-*-linux*
4964 PowerPC GNU/Linux powerpc-*-linux*
4968 Motorola MCore mcore-*-*
4969 x86 VxWorks i[3456]86-*-vxworks*
4970 PowerPC VxWorks powerpc-*-vxworks*
4971 TI TMS320C80 tic80-*-*
4973 * OBSOLETE configurations
4975 Altos 3068 m68*-altos-*
4976 Convex c1-*-*, c2-*-*
4978 ARM RISCix arm-*-* (as host)
4981 Configurations that have been declared obsolete will be commented out,
4982 but the code will be left in place. If there is no activity to revive
4983 these configurations before the next release of GDB, the sources will
4984 be permanently REMOVED.
4986 * Gould support removed
4988 Support for the Gould PowerNode and NP1 has been removed.
4990 * New features for SVR4
4992 On SVR4 native platforms (such as Solaris), if you attach to a process
4993 without first loading a symbol file, GDB will now attempt to locate and
4994 load symbols from the running process's executable file.
4996 * Many C++ enhancements
4998 C++ support has been greatly improved. Overload resolution now works properly
4999 in almost all cases. RTTI support is on the way.
5001 * Remote targets can connect to a sub-program
5003 A popen(3) style serial-device has been added. This device starts a
5004 sub-process (such as a stand-alone simulator) and then communicates
5005 with that. The sub-program to run is specified using the syntax
5006 ``|<program> <args>'' vis:
5008 (gdb) set remotedebug 1
5009 (gdb) target extended-remote |mn10300-elf-sim program-args
5011 * MIPS 64 remote protocol
5013 A long standing bug in the mips64 remote protocol where by GDB
5014 expected certain 32 bit registers (ex SR) to be transfered as 32
5015 instead of 64 bits has been fixed.
5017 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5018 added to provide backward compatibility with older versions of GDB.
5020 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5022 The command ``set remotebinarydownload'' command has been replaced by
5023 ``set remote X-packet''. Other commands in ``set remote'' family
5024 include ``set remote P-packet''.
5026 * Breakpoint commands accept ranges.
5028 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5029 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5030 ``tracepoint passcount'' also accepts a range of tracepoints.
5032 * ``apropos'' command added.
5034 The ``apropos'' command searches through command names and
5035 documentation strings, printing out matches, making it much easier to
5036 try to find a command that does what you are looking for.
5040 A new machine oriented interface (MI) has been added to GDB. This
5041 interface is designed for debug environments running GDB as a separate
5042 process. This is part of the long term libGDB project. See the
5043 "GDB/MI" chapter of the GDB manual for further information. It can be
5044 enabled by configuring with:
5046 .../configure --enable-gdbmi
5048 *** Changes in GDB-4.18:
5050 * New native configurations
5052 HP-UX 10.20 hppa*-*-hpux10.20
5053 HP-UX 11.x hppa*-*-hpux11.0*
5054 M68K GNU/Linux m68*-*-linux*
5058 Fujitsu FR30 fr30-*-elf*
5059 Intel StrongARM strongarm-*-*
5060 Mitsubishi D30V d30v-*-*
5062 * OBSOLETE configurations
5064 Gould PowerNode, NP1 np1-*-*, pn-*-*
5066 Configurations that have been declared obsolete will be commented out,
5067 but the code will be left in place. If there is no activity to revive
5068 these configurations before the next release of GDB, the sources will
5069 be permanently REMOVED.
5073 As a compatibility experiment, GDB's source files buildsym.h and
5074 buildsym.c have been converted to pure standard C, no longer
5075 containing any K&R compatibility code. We believe that all systems in
5076 use today either come with a standard C compiler, or have a GCC port
5077 available. If this is not true, please report the affected
5078 configuration to bug-gdb@gnu.org immediately. See the README file for
5079 information about getting a standard C compiler if you don't have one
5084 GDB now uses readline 2.2.
5086 * set extension-language
5088 You can now control the mapping between filename extensions and source
5089 languages by using the `set extension-language' command. For instance,
5090 you can ask GDB to treat .c files as C++ by saying
5091 set extension-language .c c++
5092 The command `info extensions' lists all of the recognized extensions
5093 and their associated languages.
5095 * Setting processor type for PowerPC and RS/6000
5097 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5098 you can use the `set processor' command to specify what variant of the
5099 PowerPC family you are debugging. The command
5103 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5104 following PowerPC and RS6000 variants:
5106 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5107 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5109 403GC IBM PowerPC 403GC
5110 505 Motorola PowerPC 505
5111 860 Motorola PowerPC 860 or 850
5112 601 Motorola PowerPC 601
5113 602 Motorola PowerPC 602
5114 603 Motorola/IBM PowerPC 603 or 603e
5115 604 Motorola PowerPC 604 or 604e
5116 750 Motorola/IBM PowerPC 750 or 750
5118 At the moment, this command just tells GDB what to name the
5119 special-purpose processor registers. Since almost all the affected
5120 registers are inaccessible to user-level programs, this command is
5121 only useful for remote debugging in its present form.
5125 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5126 more extensive support for HP-UX. Added features include shared
5127 library support, kernel threads and hardware watchpoints for 11.00,
5128 support for HP's ANSI C and C++ compilers, and a compatibility mode
5129 for xdb and dbx commands.
5133 HP's donation includes the new concept of catchpoints, which is a
5134 generalization of the old catch command. On HP-UX, it is now possible
5135 to catch exec, fork, and vfork, as well as library loading.
5137 This means that the existing catch command has changed; its first
5138 argument now specifies the type of catch to be set up. See the
5139 output of "help catch" for a list of catchpoint types.
5141 * Debugging across forks
5143 On HP-UX, you can choose which process to debug when a fork() happens
5148 HP has donated a curses-based terminal user interface (TUI). To get
5149 it, build with --enable-tui. Although this can be enabled for any
5150 configuration, at present it only works for native HP debugging.
5152 * GDB remote protocol additions
5154 A new protocol packet 'X' that writes binary data is now available.
5155 Default behavior is to try 'X', then drop back to 'M' if the stub
5156 fails to respond. The settable variable `remotebinarydownload'
5157 allows explicit control over the use of 'X'.
5159 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5160 full 64-bit address. The command
5162 set remoteaddresssize 32
5164 can be used to revert to the old behaviour. For existing remote stubs
5165 the change should not be noticed, as the additional address information
5168 In order to assist in debugging stubs, you may use the maintenance
5169 command `packet' to send any text string to the stub. For instance,
5171 maint packet heythere
5173 sends the packet "$heythere#<checksum>". Note that it is very easy to
5174 disrupt a debugging session by sending the wrong packet at the wrong
5177 The compare-sections command allows you to compare section data on the
5178 target to what is in the executable file without uploading or
5179 downloading, by comparing CRC checksums.
5181 * Tracing can collect general expressions
5183 You may now collect general expressions at tracepoints. This requires
5184 further additions to the target-side stub; see tracepoint.c and
5185 doc/agentexpr.texi for further details.
5187 * mask-address variable for Mips
5189 For Mips targets, you may control the zeroing of the upper 32 bits of
5190 a 64-bit address by entering `set mask-address on'. This is mainly
5191 of interest to users of embedded R4xxx and R5xxx processors.
5193 * Higher serial baud rates
5195 GDB's serial code now allows you to specify baud rates 57600, 115200,
5196 230400, and 460800 baud. (Note that your host system may not be able
5197 to achieve all of these rates.)
5201 The i960 configuration now includes an initial implementation of a
5202 builtin simulator, contributed by Jim Wilson.
5205 *** Changes in GDB-4.17:
5207 * New native configurations
5209 Alpha GNU/Linux alpha*-*-linux*
5210 Unixware 2.x i[3456]86-unixware2*
5211 Irix 6.x mips*-sgi-irix6*
5212 PowerPC GNU/Linux powerpc-*-linux*
5213 PowerPC Solaris powerpcle-*-solaris*
5214 Sparc GNU/Linux sparc-*-linux*
5215 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5219 Argonaut Risc Chip (ARC) arc-*-*
5220 Hitachi H8/300S h8300*-*-*
5221 Matsushita MN10200 w/simulator mn10200-*-*
5222 Matsushita MN10300 w/simulator mn10300-*-*
5223 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5224 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5225 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5226 Mitsubishi D10V w/simulator d10v-*-*
5227 Mitsubishi M32R/D w/simulator m32r-*-elf*
5228 Tsqware Sparclet sparclet-*-*
5229 NEC V850 w/simulator v850-*-*
5231 * New debugging protocols
5233 ARM with RDI protocol arm*-*-*
5234 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5235 DDB and LSI variants of PMON protocol mips*-*-*
5236 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5237 PowerPC with SDS protocol powerpc{,le}-*-eabi
5238 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5242 All configurations can now understand and use the DWARF 2 debugging
5243 format. The choice is automatic, if the symbol file contains DWARF 2
5248 GDB now includes basic Java language support. This support is
5249 only useful with Java compilers that produce native machine code.
5251 * solib-absolute-prefix and solib-search-path
5253 For SunOS and SVR4 shared libraries, you may now set the prefix for
5254 loading absolute shared library symbol files, and the search path for
5255 locating non-absolute shared library symbol files.
5257 * Live range splitting
5259 GDB can now effectively debug code for which GCC has performed live
5260 range splitting as part of its optimization. See gdb/doc/LRS for
5261 more details on the expected format of the stabs information.
5265 GDB's support for the GNU Hurd, including thread debugging, has been
5266 updated to work with current versions of the Hurd.
5270 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5271 instruction set. ARM GDB automatically detects when Thumb
5272 instructions are in use, and adjusts disassembly and backtracing
5277 GDB's MIPS target configurations now handle the MIP16 16-bit
5282 GDB now includes support for overlays; if an executable has been
5283 linked such that multiple sections are based at the same address, GDB
5284 will decide which section to use for symbolic info. You can choose to
5285 control the decision manually, using overlay commands, or implement
5286 additional target-side support and use "overlay load-target" to bring
5287 in the overlay mapping. Do "help overlay" for more detail.
5291 The command "info symbol <address>" displays information about
5292 the symbol at the specified address.
5296 The standard remote protocol now includes an extension that allows
5297 asynchronous collection and display of trace data. This requires
5298 extensive support in the target-side debugging stub. Tracing mode
5299 includes a new interaction mode in GDB and new commands: see the
5300 file tracepoint.c for more details.
5304 Configurations for embedded MIPS now include a simulator contributed
5305 by Cygnus Solutions. The simulator supports the instruction sets
5306 of most MIPS variants.
5310 Sparc configurations may now include the ERC32 simulator contributed
5311 by the European Space Agency. The simulator is not built into
5312 Sparc targets by default; configure with --enable-sim to include it.
5316 For target configurations that may include multiple variants of a
5317 basic architecture (such as MIPS and SH), you may now set the
5318 architecture explicitly. "set arch" sets, "info arch" lists
5319 the possible architectures.
5321 *** Changes in GDB-4.16:
5323 * New native configurations
5325 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5326 M68K NetBSD m68k-*-netbsd*
5327 PowerPC AIX 4.x powerpc-*-aix*
5328 PowerPC MacOS powerpc-*-macos*
5329 PowerPC Windows NT powerpcle-*-cygwin32
5330 RS/6000 AIX 4.x rs6000-*-aix4*
5334 ARM with RDP protocol arm-*-*
5335 I960 with MON960 i960-*-coff
5336 MIPS VxWorks mips*-*-vxworks*
5337 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5338 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5340 Matra Sparclet sparclet-*-*
5344 The powerpc-eabi configuration now includes the PSIM simulator,
5345 contributed by Andrew Cagney, with assistance from Mike Meissner.
5346 PSIM is a very elaborate model of the PowerPC, including not only
5347 basic instruction set execution, but also details of execution unit
5348 performance and I/O hardware. See sim/ppc/README for more details.
5352 GDB now works with Solaris 2.5.
5354 * Windows 95/NT native
5356 GDB will now work as a native debugger on Windows 95 and Windows NT.
5357 To build it from source, you must use the "gnu-win32" environment,
5358 which uses a DLL to emulate enough of Unix to run the GNU tools.
5359 Further information, binaries, and sources are available at
5360 ftp.cygnus.com, under pub/gnu-win32.
5362 * dont-repeat command
5364 If a user-defined command includes the command `dont-repeat', then the
5365 command will not be repeated if the user just types return. This is
5366 useful if the command is time-consuming to run, so that accidental
5367 extra keystrokes don't run the same command many times.
5369 * Send break instead of ^C
5371 The standard remote protocol now includes an option to send a break
5372 rather than a ^C to the target in order to interrupt it. By default,
5373 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5375 * Remote protocol timeout
5377 The standard remote protocol includes a new variable `remotetimeout'
5378 that allows you to set the number of seconds before GDB gives up trying
5379 to read from the target. The default value is 2.
5381 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5383 By default GDB will automatically keep track of objects as they are
5384 loaded and unloaded by the dynamic linker. By using the command `set
5385 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5386 when shared library events occur, thus allowing you to set breakpoints
5387 in shared libraries which are explicitly loaded by the inferior.
5389 Note this feature does not work on hpux8. On hpux9 you must link
5390 /usr/lib/end.o into your program. This feature should work
5391 automatically on hpux10.
5393 * Irix 5.x hardware watchpoint support
5395 Irix 5 configurations now support the use of hardware watchpoints.
5397 * Mips protocol "SYN garbage limit"
5399 When debugging a Mips target using the `target mips' protocol, you
5400 may set the number of characters that GDB will ignore by setting
5401 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5402 every character. The default value is 1050.
5404 * Recording and replaying remote debug sessions
5406 If you set `remotelogfile' to the name of a file, gdb will write to it
5407 a recording of a remote debug session. This recording may then be
5408 replayed back to gdb using "gdbreplay". See gdbserver/README for
5409 details. This is useful when you have a problem with GDB while doing
5410 remote debugging; you can make a recording of the session and send it
5411 to someone else, who can then recreate the problem.
5413 * Speedups for remote debugging
5415 GDB includes speedups for downloading and stepping MIPS systems using
5416 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5417 and more efficient S-record downloading.
5419 * Memory use reductions and statistics collection
5421 GDB now uses less memory and reports statistics about memory usage.
5422 Try the `maint print statistics' command, for example.
5424 *** Changes in GDB-4.15:
5426 * Psymtabs for XCOFF
5428 The symbol reader for AIX GDB now uses partial symbol tables. This
5429 can greatly improve startup time, especially for large executables.
5431 * Remote targets use caching
5433 Remote targets now use a data cache to speed up communication with the
5434 remote side. The data cache could lead to incorrect results because
5435 it doesn't know about volatile variables, thus making it impossible to
5436 debug targets which use memory mapped I/O devices. `set remotecache
5437 off' turns the the data cache off.
5439 * Remote targets may have threads
5441 The standard remote protocol now includes support for multiple threads
5442 in the target system, using new protocol commands 'H' and 'T'. See
5443 gdb/remote.c for details.
5447 If GDB is configured with `--enable-netrom', then it will include
5448 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5449 acts as though it is a bank of ROM on the target board, but you can
5450 write into it over the network. GDB's support consists only of
5451 support for fast loading into the emulated ROM; to debug, you must use
5452 another protocol, such as standard remote protocol. The usual
5453 sequence is something like
5455 target nrom <netrom-hostname>
5457 target remote <netrom-hostname>:1235
5461 GDB now includes support for the Apple Macintosh, as a host only. It
5462 may be run as either an MPW tool or as a standalone application, and
5463 it can debug through the serial port. All the usual GDB commands are
5464 available, but to the target command, you must supply "serial" as the
5465 device type instead of "/dev/ttyXX". See mpw-README in the main
5466 directory for more information on how to build. The MPW configuration
5467 scripts */mpw-config.in support only a few targets, and only the
5468 mips-idt-ecoff target has been tested.
5472 GDB configuration now uses autoconf. This is not user-visible,
5473 but does simplify configuration and building.
5477 GDB now supports hpux10.
5479 *** Changes in GDB-4.14:
5481 * New native configurations
5483 x86 FreeBSD i[345]86-*-freebsd
5484 x86 NetBSD i[345]86-*-netbsd
5485 NS32k NetBSD ns32k-*-netbsd
5486 Sparc NetBSD sparc-*-netbsd
5490 A29K VxWorks a29k-*-vxworks
5491 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5492 CPU32 EST-300 emulator m68*-*-est*
5493 PowerPC ELF powerpc-*-elf
5496 * Alpha OSF/1 support for procfs
5498 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5499 possible to attach to running processes. As the mounting of the /proc
5500 filesystem is optional on the Alpha, GDB automatically determines
5501 the availability of /proc during startup. This can lead to problems
5502 if /proc is unmounted after GDB has been started.
5504 * Arguments to user-defined commands
5506 User commands may accept up to 10 arguments separated by whitespace.
5507 Arguments are accessed within the user command via $arg0..$arg9. A
5510 print $arg0 + $arg1 + $arg2
5512 To execute the command use:
5515 Defines the command "adder" which prints the sum of its three arguments.
5516 Note the arguments are text substitutions, so they may reference variables,
5517 use complex expressions, or even perform inferior function calls.
5519 * New `if' and `while' commands
5521 This makes it possible to write more sophisticated user-defined
5522 commands. Both commands take a single argument, which is the
5523 expression to evaluate, and must be followed by the commands to
5524 execute, one per line, if the expression is nonzero, the list being
5525 terminated by the word `end'. The `if' command list may include an
5526 `else' word, which causes the following commands to be executed only
5527 if the expression is zero.
5529 * Fortran source language mode
5531 GDB now includes partial support for Fortran 77. It will recognize
5532 Fortran programs and can evaluate a subset of Fortran expressions, but
5533 variables and functions may not be handled correctly. GDB will work
5534 with G77, but does not yet know much about symbols emitted by other
5537 * Better HPUX support
5539 Most debugging facilities now work on dynamic executables for HPPAs
5540 running hpux9 or later. You can attach to running dynamically linked
5541 processes, but by default the dynamic libraries will be read-only, so
5542 for instance you won't be able to put breakpoints in them. To change
5543 that behavior do the following before running the program:
5549 This will cause the libraries to be mapped private and read-write.
5550 To revert to the normal behavior, do this:
5556 You cannot set breakpoints or examine data in the library until after
5557 the library is loaded if the function/data symbols do not have
5560 GDB can now also read debug symbols produced by the HP C compiler on
5561 HPPAs (sorry, no C++, Fortran or 68k support).
5563 * Target byte order now dynamically selectable
5565 You can choose which byte order to use with a target system, via the
5566 commands "set endian big" and "set endian little", and you can see the
5567 current setting by using "show endian". You can also give the command
5568 "set endian auto", in which case GDB will use the byte order
5569 associated with the executable. Currently, only embedded MIPS
5570 configurations support dynamic selection of target byte order.
5572 * New DOS host serial code
5574 This version uses DPMI interrupts to handle buffered I/O, so you
5575 no longer need to run asynctsr when debugging boards connected to
5578 *** Changes in GDB-4.13:
5580 * New "complete" command
5582 This lists all the possible completions for the rest of the line, if it
5583 were to be given as a command itself. This is intended for use by emacs.
5585 * Trailing space optional in prompt
5587 "set prompt" no longer adds a space for you after the prompt you set. This
5588 allows you to set a prompt which ends in a space or one that does not.
5590 * Breakpoint hit counts
5592 "info break" now displays a count of the number of times the breakpoint
5593 has been hit. This is especially useful in conjunction with "ignore"; you
5594 can ignore a large number of breakpoint hits, look at the breakpoint info
5595 to see how many times the breakpoint was hit, then run again, ignoring one
5596 less than that number, and this will get you quickly to the last hit of
5599 * Ability to stop printing at NULL character
5601 "set print null-stop" will cause GDB to stop printing the characters of
5602 an array when the first NULL is encountered. This is useful when large
5603 arrays actually contain only short strings.
5605 * Shared library breakpoints
5607 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5608 breakpoints in shared libraries before the executable is run.
5610 * Hardware watchpoints
5612 There is a new hardware breakpoint for the watch command for sparclite
5613 targets. See gdb/sparclite/hw_breakpoint.note.
5615 Hardware watchpoints are also now supported under GNU/Linux.
5619 Annotations have been added. These are for use with graphical interfaces,
5620 and are still experimental. Currently only gdba.el uses these.
5622 * Improved Irix 5 support
5624 GDB now works properly with Irix 5.2.
5626 * Improved HPPA support
5628 GDB now works properly with the latest GCC and GAS.
5630 * New native configurations
5632 Sequent PTX4 i[34]86-sequent-ptx4
5633 HPPA running OSF/1 hppa*-*-osf*
5634 Atari TT running SVR4 m68*-*-sysv4*
5635 RS/6000 LynxOS rs6000-*-lynxos*
5639 OS/9000 i[34]86-*-os9k
5640 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5643 * Hitachi SH7000 and E7000-PC ICE support
5645 There is now support for communicating with the Hitachi E7000-PC ICE.
5646 This is available automatically when GDB is configured for the SH.
5650 As usual, a variety of small fixes and improvements, both generic
5651 and configuration-specific. See the ChangeLog for more detail.
5653 *** Changes in GDB-4.12:
5655 * Irix 5 is now supported
5659 GDB-4.12 on the HPPA has a number of changes which make it unable
5660 to debug the output from the currently released versions of GCC and
5661 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5662 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5663 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5666 *** Changes in GDB-4.11:
5668 * User visible changes:
5672 The "set remotedebug" option is now consistent between the mips remote
5673 target, remote targets using the gdb-specific protocol, UDI (AMD's
5674 debug protocol for the 29k) and the 88k bug monitor. It is now an
5675 integer specifying a debug level (normally 0 or 1, but 2 means more
5676 debugging info for the mips target).
5678 * DEC Alpha native support
5680 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5681 debug info, but GDB works fairly well with the DEC compiler and should
5682 work with a future GCC release. See the README file for a few
5683 Alpha-specific notes.
5685 * Preliminary thread implementation
5687 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5689 * LynxOS native and target support for 386
5691 This release has been hosted on LynxOS 2.2, and also can be configured
5692 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5695 * Improvements in C++ mangling/demangling.
5697 This release has much better g++ debugging, specifically in name
5698 mangling/demangling, virtual function calls, print virtual table,
5699 call methods, ...etc.
5701 *** Changes in GDB-4.10:
5703 * User visible changes:
5705 Remote debugging using the GDB-specific (`target remote') protocol now
5706 supports the `load' command. This is only useful if you have some
5707 other way of getting the stub to the target system, and you can put it
5708 somewhere in memory where it won't get clobbered by the download.
5710 Filename completion now works.
5712 When run under emacs mode, the "info line" command now causes the
5713 arrow to point to the line specified. Also, "info line" prints
5714 addresses in symbolic form (as well as hex).
5716 All vxworks based targets now support a user settable option, called
5717 vxworks-timeout. This option represents the number of seconds gdb
5718 should wait for responses to rpc's. You might want to use this if
5719 your vxworks target is, perhaps, a slow software simulator or happens
5720 to be on the far side of a thin network line.
5724 This release contains support for using a DEC alpha as a GDB host for
5725 cross debugging. Native alpha debugging is not supported yet.
5728 *** Changes in GDB-4.9:
5732 This is the first GDB release which is accompanied by a matching testsuite.
5733 The testsuite requires installation of dejagnu, which should be available
5734 via ftp from most sites that carry GNU software.
5738 'Cfront' style demangling has had its name changed to 'ARM' style, to
5739 emphasize that it was written from the specifications in the C++ Annotated
5740 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5741 disclaimers, it still generated too much confusion with users attempting to
5742 use gdb with AT&T cfront.
5746 GDB now uses a standard remote interface to a simulator library.
5747 So far, the library contains simulators for the Zilog Z8001/2, the
5748 Hitachi H8/300, H8/500 and Super-H.
5750 * New targets supported
5752 H8/300 simulator h8300-hitachi-hms or h8300hms
5753 H8/500 simulator h8500-hitachi-hms or h8500hms
5754 SH simulator sh-hitachi-hms or sh
5755 Z8000 simulator z8k-zilog-none or z8ksim
5756 IDT MIPS board over serial line mips-idt-ecoff
5758 Cross-debugging to GO32 targets is supported. It requires a custom
5759 version of the i386-stub.c module which is integrated with the
5760 GO32 memory extender.
5762 * New remote protocols
5764 MIPS remote debugging protocol.
5766 * New source languages supported
5768 This version includes preliminary support for Chill, a Pascal like language
5769 used by telecommunications companies. Chill support is also being integrated
5770 into the GNU compiler, but we don't know when it will be publically available.
5773 *** Changes in GDB-4.8:
5775 * HP Precision Architecture supported
5777 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5778 version of this support was available as a set of patches from the
5779 University of Utah. GDB does not support debugging of programs
5780 compiled with the HP compiler, because HP will not document their file
5781 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5782 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5784 Many problems in the preliminary version have been fixed.
5786 * Faster and better demangling
5788 We have improved template demangling and fixed numerous bugs in the GNU style
5789 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5790 character types (wchar_t) are now supported. Demangling of each symbol is now
5791 only done once, and is cached when the symbol table for a file is read in.
5792 This results in a small increase in memory usage for C programs, a moderate
5793 increase in memory usage for C++ programs, and a fantastic speedup in
5796 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5797 from the specifications in the Annotated Reference Manual, which AT&T's
5798 compiler does not actually implement.
5800 * G++ multiple inheritance compiler problem
5802 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5803 inheritance lattices was reworked to properly discover ambiguities. We
5804 recently found an example which causes this new algorithm to fail in a
5805 very subtle way, producing bad debug information for those classes.
5806 The file 'gcc.patch' (in this directory) can be applied to gcc to
5807 circumvent the problem. A future GCC release will contain a complete
5810 The previous G++ debug info problem (mentioned below for the gdb-4.7
5811 release) is fixed in gcc version 2.3.2.
5813 * Improved configure script
5815 The `configure' script will now attempt to guess your system type if
5816 you don't supply a host system type. The old scheme of supplying a
5817 host system triplet is preferable over using this. All the magic is
5818 done in the new `config.guess' script. Examine it for details.
5820 We have also brought our configure script much more in line with the FSF's
5821 version. It now supports the --with-xxx options. In particular,
5822 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5823 The resulting GDB will not be able to read arbitrary object file formats --
5824 only the format ``expected'' to be used on the configured target system.
5825 We hope to make this the default in a future release.
5827 * Documentation improvements
5829 There's new internal documentation on how to modify GDB, and how to
5830 produce clean changes to the code. We implore people to read it
5831 before submitting changes.
5833 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5834 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5835 `info' files are also provided. To build `info' files from scratch,
5836 you will need the latest `makeinfo' release, which will be available in
5837 a future texinfo-X.Y release.
5839 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5840 We're not sure exactly which versions have this problem, but it has
5841 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5842 or better. If that isn't possible, there is a patch in
5843 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5844 around this problem.
5848 GDB now supports array constants that can be used in expressions typed in by
5849 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5850 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5853 The new directory `gdb/sparclite' contains a program that demonstrates
5854 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5856 * New native hosts supported
5858 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5859 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5861 * New targets supported
5863 AMD 29k family via UDI a29k-amd-udi or udi29k
5865 * New file formats supported
5867 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5868 HPUX core files, and SCO 3.2v2 core files.
5872 Attaching to processes now works again; thanks for the many bug reports.
5874 We have also stomped on a bunch of core dumps caused by
5875 printf_filtered("%s") problems.
5877 We eliminated a copyright problem on the rpc and ptrace header files
5878 for VxWorks, which was discovered at the last minute during the 4.7
5879 release. You should now be able to build a VxWorks GDB.
5881 You can now interrupt gdb while an attached process is running. This
5882 will cause the attached process to stop, and give control back to GDB.
5884 We fixed problems caused by using too many file descriptors
5885 for reading symbols from object files and libraries. This was
5886 especially a problem for programs that used many (~100) shared
5889 The `step' command now only enters a subroutine if there is line number
5890 information for the subroutine. Otherwise it acts like the `next'
5891 command. Previously, `step' would enter subroutines if there was
5892 any debugging information about the routine. This avoids problems
5893 when using `cc -g1' on MIPS machines.
5895 * Internal improvements
5897 GDB's internal interfaces have been improved to make it easier to support
5898 debugging of multiple languages in the future.
5900 GDB now uses a common structure for symbol information internally.
5901 Minimal symbols (derived from linkage symbols in object files), partial
5902 symbols (from a quick scan of debug information), and full symbols
5903 contain a common subset of information, making it easier to write
5904 shared code that handles any of them.
5906 * New command line options
5908 We now accept --silent as an alias for --quiet.
5912 The memory-mapped-malloc library is now licensed under the GNU Library
5913 General Public License.
5915 *** Changes in GDB-4.7:
5917 * Host/native/target split
5919 GDB has had some major internal surgery to untangle the support for
5920 hosts and remote targets. Now, when you configure GDB for a remote
5921 target, it will no longer load in all of the support for debugging
5922 local programs on the host. When fully completed and tested, this will
5923 ensure that arbitrary host/target combinations are possible.
5925 The primary conceptual shift is to separate the non-portable code in
5926 GDB into three categories. Host specific code is required any time GDB
5927 is compiled on that host, regardless of the target. Target specific
5928 code relates to the peculiarities of the target, but can be compiled on
5929 any host. Native specific code is everything else: it can only be
5930 built when the host and target are the same system. Child process
5931 handling and core file support are two common `native' examples.
5933 GDB's use of /proc for controlling Unix child processes is now cleaner.
5934 It has been split out into a single module under the `target_ops' vector,
5935 plus two native-dependent functions for each system that uses /proc.
5937 * New hosts supported
5939 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5940 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5941 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5943 * New targets supported
5945 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5946 68030 and CPU32 m68030-*-*, m68332-*-*
5948 * New native hosts supported
5950 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5951 (386bsd is not well tested yet)
5952 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5954 * New file formats supported
5956 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5957 supports reading of `a.out.adobe' object files, which are an a.out
5958 format extended with minimal information about multiple sections.
5962 `show copying' is the same as the old `info copying'.
5963 `show warranty' is the same as `info warrantee'.
5964 These were renamed for consistency. The old commands continue to work.
5966 `info handle' is a new alias for `info signals'.
5968 You can now define pre-command hooks, which attach arbitrary command
5969 scripts to any command. The commands in the hook will be executed
5970 prior to the user's command. You can also create a hook which will be
5971 executed whenever the program stops. See gdb.texinfo.
5975 We now deal with Cfront style name mangling, and can even extract type
5976 info from mangled symbols. GDB can automatically figure out which
5977 symbol mangling style your C++ compiler uses.
5979 Calling of methods and virtual functions has been improved as well.
5983 The crash that occured when debugging Sun Ansi-C compiled binaries is
5984 fixed. This was due to mishandling of the extra N_SO stabs output
5987 We also finally got Ultrix 4.2 running in house, and fixed core file
5988 support, with help from a dozen people on the net.
5990 John M. Farrell discovered that the reason that single-stepping was so
5991 slow on all of the Mips based platforms (primarily SGI and DEC) was
5992 that we were trying to demangle and lookup a symbol used for internal
5993 purposes on every instruction that was being stepped through. Changing
5994 the name of that symbol so that it couldn't be mistaken for a C++
5995 mangled symbol sped things up a great deal.
5997 Rich Pixley sped up symbol lookups in general by getting much smarter
5998 about when C++ symbol mangling is necessary. This should make symbol
5999 completion (TAB on the command line) much faster. It's not as fast as
6000 we'd like, but it's significantly faster than gdb-4.6.
6004 A new user controllable variable 'call_scratch_address' can
6005 specify the location of a scratch area to be used when GDB
6006 calls a function in the target. This is necessary because the
6007 usual method of putting the scratch area on the stack does not work
6008 in systems that have separate instruction and data spaces.
6010 We integrated changes to support the 29k UDI (Universal Debugger
6011 Interface), but discovered at the last minute that we didn't have all
6012 of the appropriate copyright paperwork. We are working with AMD to
6013 resolve this, and hope to have it available soon.
6017 We have sped up the remote serial line protocol, especially for targets
6018 with lots of registers. It now supports a new `expedited status' ('T')
6019 message which can be used in place of the existing 'S' status message.
6020 This allows the remote stub to send only the registers that GDB
6021 needs to make a quick decision about single-stepping or conditional
6022 breakpoints, eliminating the need to fetch the entire register set for
6023 each instruction being stepped through.
6025 The GDB remote serial protocol now implements a write-through cache for
6026 registers, only re-reading the registers if the target has run.
6028 There is also a new remote serial stub for SPARC processors. You can
6029 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6030 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6031 processor with a serial port.
6035 Configure.in files have become much easier to read and modify. A new
6036 `table driven' format makes it more obvious what configurations are
6037 supported, and what files each one uses.
6041 There is a new opcodes library which will eventually contain all of the
6042 disassembly routines and opcode tables. At present, it only contains
6043 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6044 disassembler (binutils/objdump) to share these routines.
6046 The libiberty library is now copylefted under the GNU Library General
6047 Public License. This allows more liberal use, and was done so libg++
6048 can use it. This makes no difference to GDB, since the Library License
6049 grants all the rights from the General Public License.
6053 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6054 reference to the stabs symbol info used by the debugger. It is (as far
6055 as we know) the only published document on this fascinating topic. We
6056 encourage you to read it, compare it to the stabs information on your
6057 system, and send improvements on the document in general (to
6058 bug-gdb@prep.ai.mit.edu).
6060 And, of course, many bugs have been fixed.
6063 *** Changes in GDB-4.6:
6065 * Better support for C++ function names
6067 GDB now accepts as input the "demangled form" of C++ overloaded function
6068 names and member function names, and can do command completion on such names
6069 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6070 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6071 Make use of command completion, it is your friend.
6073 GDB also now accepts a variety of C++ mangled symbol formats. They are
6074 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6075 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6076 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6077 for the list of formats.
6079 * G++ symbol mangling problem
6081 Recent versions of gcc have a bug in how they emit debugging information for
6082 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6083 directory) can be applied to gcc to fix the problem. Alternatively, if you
6084 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6085 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6086 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6089 * New 'maintenance' command
6091 All of the commands related to hacking GDB internals have been moved out of
6092 the main command set, and now live behind the 'maintenance' command. This
6093 can also be abbreviated as 'mt'. The following changes were made:
6095 dump-me -> maintenance dump-me
6096 info all-breakpoints -> maintenance info breakpoints
6097 printmsyms -> maintenance print msyms
6098 printobjfiles -> maintenance print objfiles
6099 printpsyms -> maintenance print psymbols
6100 printsyms -> maintenance print symbols
6102 The following commands are new:
6104 maintenance demangle Call internal GDB demangler routine to
6105 demangle a C++ link name and prints the result.
6106 maintenance print type Print a type chain for a given symbol
6108 * Change to .gdbinit file processing
6110 We now read the $HOME/.gdbinit file before processing the argv arguments
6111 (e.g. reading symbol files or core files). This allows global parameters to
6112 be set, which will apply during the symbol reading. The ./.gdbinit is still
6113 read after argv processing.
6115 * New hosts supported
6117 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6119 GNU/Linux support i386-unknown-linux or linux
6121 We are also including code to support the HP/PA running BSD and HPUX. This
6122 is almost guaranteed not to work, as we didn't have time to test or build it
6123 for this release. We are including it so that the more adventurous (or
6124 masochistic) of you can play with it. We also had major problems with the
6125 fact that the compiler that we got from HP doesn't support the -g option.
6128 * New targets supported
6130 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6132 * More smarts about finding #include files
6134 GDB now remembers the compilation directory for all include files, and for
6135 all files from which C is generated (like yacc and lex sources). This
6136 greatly improves GDB's ability to find yacc/lex sources, and include files,
6137 especially if you are debugging your program from a directory different from
6138 the one that contains your sources.
6140 We also fixed a bug which caused difficulty with listing and setting
6141 breakpoints in include files which contain C code. (In the past, you had to
6142 try twice in order to list an include file that you hadn't looked at before.)
6144 * Interesting infernals change
6146 GDB now deals with arbitrary numbers of sections, where the symbols for each
6147 section must be relocated relative to that section's landing place in the
6148 target's address space. This work was needed to support ELF with embedded
6149 stabs used by Solaris-2.0.
6151 * Bug fixes (of course!)
6153 There have been loads of fixes for the following things:
6154 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6155 i960, stabs, DOS(GO32), procfs, etc...
6157 See the ChangeLog for details.
6159 *** Changes in GDB-4.5:
6161 * New machines supported (host and target)
6163 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6165 SGI Irix-4.x mips-sgi-irix4 or iris4
6167 * New malloc package
6169 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6170 Mmalloc is capable of handling mutiple heaps of memory. It is also
6171 capable of saving a heap to a file, and then mapping it back in later.
6172 This can be used to greatly speedup the startup of GDB by using a
6173 pre-parsed symbol table which lives in a mmalloc managed heap. For
6174 more details, please read mmalloc/mmalloc.texi.
6178 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6179 'help info proc' for details.
6181 * MIPS ecoff symbol table format
6183 The code that reads MIPS symbol table format is now supported on all hosts.
6184 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6187 * File name changes for MS-DOS
6189 Many files in the config directories have been renamed to make it easier to
6190 support GDB on MS-DOSe systems (which have very restrictive file name
6191 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6192 environment) is close to working but has some remaining problems. Note
6193 that debugging of DOS programs is not supported, due to limitations
6194 in the ``operating system'', but it can be used to host cross-debugging.
6196 * Cross byte order fixes
6198 Many fixes have been made to support cross debugging of Sparc and MIPS
6199 targets from hosts whose byte order differs.
6201 * New -mapped and -readnow options
6203 If memory-mapped files are available on your system through the 'mmap'
6204 system call, you can use the -mapped option on the `file' or
6205 `symbol-file' commands to cause GDB to write the symbols from your
6206 program into a reusable file. If the program you are debugging is
6207 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6208 Future GDB debugging sessions will notice the presence of this file,
6209 and will quickly map in symbol information from it, rather than reading
6210 the symbol table from the executable program. Using the '-mapped'
6211 option in a GDB `file' or `symbol-file' command has the same effect as
6212 starting GDB with the '-mapped' command-line option.
6214 You can cause GDB to read the entire symbol table immediately by using
6215 the '-readnow' option with any of the commands that load symbol table
6216 information (or on the GDB command line). This makes the command
6217 slower, but makes future operations faster.
6219 The -mapped and -readnow options are typically combined in order to
6220 build a `fred.syms' file that contains complete symbol information.
6221 A simple GDB invocation to do nothing but build a `.syms' file for future
6224 gdb -batch -nx -mapped -readnow programname
6226 The `.syms' file is specific to the host machine on which GDB is run.
6227 It holds an exact image of GDB's internal symbol table. It cannot be
6228 shared across multiple host platforms.
6230 * longjmp() handling
6232 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6233 siglongjmp() without losing control. This feature has not yet been ported to
6234 all systems. It currently works on many 386 platforms, all MIPS-based
6235 platforms (SGI, DECstation, etc), and Sun3/4.
6239 Preliminary work has been put in to support the new Solaris OS from Sun. At
6240 this time, it can control and debug processes, but it is not capable of
6245 As always, many many bug fixes. The major areas were with g++, and mipsread.
6246 People using the MIPS-based platforms should experience fewer mysterious
6247 crashes and trashed symbol tables.
6249 *** Changes in GDB-4.4:
6251 * New machines supported (host and target)
6253 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6255 BSD Reno on Vax vax-dec-bsd
6256 Ultrix on Vax vax-dec-ultrix
6258 * New machines supported (target)
6260 AMD 29000 embedded, using EBMON a29k-none-none
6264 GDB continues to improve its handling of C++. `References' work better.
6265 The demangler has also been improved, and now deals with symbols mangled as
6266 per the Annotated C++ Reference Guide.
6268 GDB also now handles `stabs' symbol information embedded in MIPS
6269 `ecoff' symbol tables. Since the ecoff format was not easily
6270 extensible to handle new languages such as C++, this appeared to be a
6271 good way to put C++ debugging info into MIPS binaries. This option
6272 will be supported in the GNU C compiler, version 2, when it is
6275 * New features for SVR4
6277 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6278 shared libraries. Debugging dynamically linked programs should present
6279 only minor differences from debugging statically linked programs.
6281 The `info proc' command will print out information about any process
6282 on an SVR4 system (including the one you are debugging). At the moment,
6283 it prints the address mappings of the process.
6285 If you bring up GDB on another SVR4 system, please send mail to
6286 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6288 * Better dynamic linking support in SunOS
6290 Reading symbols from shared libraries which contain debugging symbols
6291 now works properly. However, there remain issues such as automatic
6292 skipping of `transfer vector' code during function calls, which
6293 make it harder to debug code in a shared library, than to debug the
6294 same code linked statically.
6298 GDB is now using the latest `getopt' routines from the FSF. This
6299 version accepts the -- prefix for options with long names. GDB will
6300 continue to accept the old forms (-option and +option) as well.
6301 Various single letter abbreviations for options have been explicity
6302 added to the option table so that they won't get overshadowed in the
6303 future by other options that begin with the same letter.
6307 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6308 Many assorted bugs have been handled. Many more remain to be handled.
6309 See the various ChangeLog files (primarily in gdb and bfd) for details.
6312 *** Changes in GDB-4.3:
6314 * New machines supported (host and target)
6316 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6317 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6318 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6320 * Almost SCO Unix support
6322 We had hoped to support:
6323 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6324 (except for core file support), but we discovered very late in the release
6325 that it has problems with process groups that render gdb unusable. Sorry
6326 about that. I encourage people to fix it and post the fixes.
6328 * Preliminary ELF and DWARF support
6330 GDB can read ELF object files on System V Release 4, and can handle
6331 debugging records for C, in DWARF format, in ELF files. This support
6332 is preliminary. If you bring up GDB on another SVR4 system, please
6333 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6338 GDB now uses the latest `readline' library. One user-visible change
6339 is that two tabs will list possible command completions, which previously
6340 required typing M-? (meta-question mark, or ESC ?).
6344 The `stepi' bug that many of you noticed has been squashed.
6345 Many bugs in C++ have been handled. Many more remain to be handled.
6346 See the various ChangeLog files (primarily in gdb and bfd) for details.
6348 * State of the MIPS world (in case you wondered):
6350 GDB can understand the symbol tables emitted by the compilers
6351 supplied by most vendors of MIPS-based machines, including DEC. These
6352 symbol tables are in a format that essentially nobody else uses.
6354 Some versions of gcc come with an assembler post-processor called
6355 mips-tfile. This program is required if you want to do source-level
6356 debugging of gcc-compiled programs. I believe FSF does not ship
6357 mips-tfile with gcc version 1, but it will eventually come with gcc
6360 Debugging of g++ output remains a problem. g++ version 1.xx does not
6361 really support it at all. (If you're lucky, you should be able to get
6362 line numbers and stack traces to work, but no parameters or local
6363 variables.) With some work it should be possible to improve the
6366 When gcc version 2 is released, you will have somewhat better luck.
6367 However, even then you will get confusing results for inheritance and
6370 We will eventually provide full debugging of g++ output on
6371 DECstations. This will probably involve some kind of stabs-in-ecoff
6372 encapulation, but the details have not been worked out yet.
6375 *** Changes in GDB-4.2:
6377 * Improved configuration
6379 Only one copy of `configure' exists now, and it is not self-modifying.
6380 Porting BFD is simpler.
6384 The `step' and `next' commands now only stop at the first instruction
6385 of a source line. This prevents the multiple stops that used to occur
6386 in switch statements, for-loops, etc. `Step' continues to stop if a
6387 function that has debugging information is called within the line.
6391 Lots of small bugs fixed. More remain.
6393 * New host supported (not target)
6395 Intel 386 PC clone running Mach i386-none-mach
6398 *** Changes in GDB-4.1:
6400 * Multiple source language support
6402 GDB now has internal scaffolding to handle several source languages.
6403 It determines the type of each source file from its filename extension,
6404 and will switch expression parsing and number formatting to match the
6405 language of the function in the currently selected stack frame.
6406 You can also specifically set the language to be used, with
6407 `set language c' or `set language modula-2'.
6411 GDB now has preliminary support for the GNU Modula-2 compiler,
6412 currently under development at the State University of New York at
6413 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6414 continue through the fall of 1991 and into 1992.
6416 Other Modula-2 compilers are currently not supported, and attempting to
6417 debug programs compiled with them will likely result in an error as the
6418 symbol table is read. Feel free to work on it, though!
6420 There are hooks in GDB for strict type checking and range checking,
6421 in the `Modula-2 philosophy', but they do not currently work.
6425 GDB can now write to executable and core files (e.g. patch
6426 a variable's value). You must turn this switch on, specify
6427 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6428 by assigning a new value to a variable. Modifications take
6431 * Automatic SunOS shared library reading
6433 When you run your program, GDB automatically determines where its
6434 shared libraries (if any) have been loaded, and reads their symbols.
6435 The `share' command is no longer needed. This also works when
6436 examining core files.
6440 You can specify the number of lines that the `list' command shows.
6443 * New machines supported (host and target)
6445 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6446 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6447 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6449 * New hosts supported (not targets)
6451 IBM RT/PC: romp-ibm-aix or rtpc
6453 * New targets supported (not hosts)
6455 AMD 29000 embedded with COFF a29k-none-coff
6456 AMD 29000 embedded with a.out a29k-none-aout
6457 Ultracomputer remote kernel debug a29k-nyu-kern
6459 * New remote interfaces
6465 *** Changes in GDB-4.0:
6469 Wide output is wrapped at good places to make the output more readable.
6471 Gdb now supports cross-debugging from a host machine of one type to a
6472 target machine of another type. Communication with the target system
6473 is over serial lines. The ``target'' command handles connecting to the
6474 remote system; the ``load'' command will download a program into the
6475 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6476 also supports debugging of realtime processes running under VxWorks,
6477 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6478 stub on the target system.
6480 New CPUs supported include the AMD 29000 and Intel 960.
6482 GDB now reads object files and symbol tables via a ``binary file''
6483 library, which allows a single copy of GDB to debug programs of multiple
6484 object file types such as a.out and coff.
6486 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6487 refcard.dvi and refcard.ps are available to format it).
6490 * Control-Variable user interface simplified
6492 All variables that control the operation of the debugger can be set
6493 by the ``set'' command, and displayed by the ``show'' command.
6495 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6496 ``Show prompt'' produces the response:
6497 Gdb's prompt is new-gdb=>.
6499 What follows are the NEW set commands. The command ``help set'' will
6500 print a complete list of old and new set commands. ``help set FOO''
6501 will give a longer description of the variable FOO. ``show'' will show
6502 all of the variable descriptions and their current settings.
6504 confirm on/off: Enables warning questions for operations that are
6505 hard to recover from, e.g. rerunning the program while
6506 it is already running. Default is ON.
6508 editing on/off: Enables EMACS style command line editing
6509 of input. Previous lines can be recalled with
6510 control-P, the current line can be edited with control-B,
6511 you can search for commands with control-R, etc.
6514 history filename NAME: NAME is where the gdb command history
6515 will be stored. The default is .gdb_history,
6516 or the value of the environment variable
6519 history size N: The size, in commands, of the command history. The
6520 default is 256, or the value of the environment variable
6523 history save on/off: If this value is set to ON, the history file will
6524 be saved after exiting gdb. If set to OFF, the
6525 file will not be saved. The default is OFF.
6527 history expansion on/off: If this value is set to ON, then csh-like
6528 history expansion will be performed on
6529 command line input. The default is OFF.
6531 radix N: Sets the default radix for input and output. It can be set
6532 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6533 in the current radix, so "set radix 10" is always a no-op.
6535 height N: This integer value is the number of lines on a page. Default
6536 is 24, the current `stty rows'' setting, or the ``li#''
6537 setting from the termcap entry matching the environment
6540 width N: This integer value is the number of characters on a line.
6541 Default is 80, the current `stty cols'' setting, or the ``co#''
6542 setting from the termcap entry matching the environment
6545 Note: ``set screensize'' is obsolete. Use ``set height'' and
6546 ``set width'' instead.
6548 print address on/off: Print memory addresses in various command displays,
6549 such as stack traces and structure values. Gdb looks
6550 more ``symbolic'' if you turn this off; it looks more
6551 ``machine level'' with it on. Default is ON.
6553 print array on/off: Prettyprint arrays. New convenient format! Default
6556 print demangle on/off: Print C++ symbols in "source" form if on,
6559 print asm-demangle on/off: Same, for assembler level printouts
6562 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6565 * Support for Epoch Environment.
6567 The epoch environment is a version of Emacs v18 with windowing. One
6568 new command, ``inspect'', is identical to ``print'', except that if you
6569 are running in the epoch environment, the value is printed in its own
6573 * Support for Shared Libraries
6575 GDB can now debug programs and core files that use SunOS shared libraries.
6576 Symbols from a shared library cannot be referenced
6577 before the shared library has been linked with the program (this
6578 happens after you type ``run'' and before the function main() is entered).
6579 At any time after this linking (including when examining core files
6580 from dynamically linked programs), gdb reads the symbols from each
6581 shared library when you type the ``sharedlibrary'' command.
6582 It can be abbreviated ``share''.
6584 sharedlibrary REGEXP: Load shared object library symbols for files
6585 matching a unix regular expression. No argument
6586 indicates to load symbols for all shared libraries.
6588 info sharedlibrary: Status of loaded shared libraries.
6593 A watchpoint stops execution of a program whenever the value of an
6594 expression changes. Checking for this slows down execution
6595 tremendously whenever you are in the scope of the expression, but is
6596 quite useful for catching tough ``bit-spreader'' or pointer misuse
6597 problems. Some machines such as the 386 have hardware for doing this
6598 more quickly, and future versions of gdb will use this hardware.
6600 watch EXP: Set a watchpoint (breakpoint) for an expression.
6602 info watchpoints: Information about your watchpoints.
6604 delete N: Deletes watchpoint number N (same as breakpoints).
6605 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6606 enable N: Re-enables watchpoint number N (same as breakpoints).
6609 * C++ multiple inheritance
6611 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6614 * C++ exception handling
6616 Gdb now supports limited C++ exception handling. Besides the existing
6617 ability to breakpoint on an exception handler, gdb can breakpoint on
6618 the raising of an exception (before the stack is peeled back to the
6621 catch FOO: If there is a FOO exception handler in the dynamic scope,
6622 set a breakpoint to catch exceptions which may be raised there.
6623 Multiple exceptions (``catch foo bar baz'') may be caught.
6625 info catch: Lists all exceptions which may be caught in the
6626 current stack frame.
6629 * Minor command changes
6631 The command ``call func (arg, arg, ...)'' now acts like the print
6632 command, except it does not print or save a value if the function's result
6633 is void. This is similar to dbx usage.
6635 The ``up'' and ``down'' commands now always print the frame they end up
6636 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6637 frames without printing.
6639 * New directory command
6641 'dir' now adds directories to the FRONT of the source search path.
6642 The path starts off empty. Source files that contain debug information
6643 about the directory in which they were compiled can be found even
6644 with an empty path; Sun CC and GCC include this information. If GDB can't
6645 find your source file in the current directory, type "dir .".
6647 * Configuring GDB for compilation
6649 For normal use, type ``./configure host''. See README or gdb.texinfo
6652 GDB now handles cross debugging. If you are remotely debugging between
6653 two different machines, type ``./configure host -target=targ''.
6654 Host is the machine where GDB will run; targ is the machine
6655 where the program that you are debugging will run.