1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.12
6 * GDB now supports recording and replaying rdrand and rdseed Intel 64
9 * Building GDB and GDBserver now requires a C++11 compiler.
11 For example, GCC 4.8 or later.
13 It is no longer possible to build GDB or GDBserver with a C
14 compiler. The --disable-build-with-cxx configure option has been
17 * Building GDB and GDBserver now requires GNU make >= 3.81.
19 It is no longer supported to build GDB or GDBserver with another
20 implementation of the make program or an earlier version of GNU make.
22 * Native debugging on MS-Windows supports command-line redirection
24 Command-line arguments used for starting programs on MS-Windows can
25 now include redirection symbols supported by native Windows shells,
26 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
27 as "run", "start", and "set args", as well as the corresponding MI
30 * Support for thread names on MS-Windows.
32 GDB now catches and handles the special exception that programs
33 running on MS-Windows use to assign names to threads in the
36 * Support for Java programs compiled with gcj has been removed.
38 * User commands now accept an unlimited number of arguments.
39 Previously, only up to 10 was accepted.
41 * The "eval" command now expands user-defined command arguments.
43 This makes it easier to process a variable number of arguments:
48 eval "print $arg%d", $i
53 * Target descriptions can now describe registers for sparc32 and sparc64.
55 * New native configurations
57 FreeBSD/mips mips*-*-freebsd
62 Synopsys ARC arc*-*-elf32
63 FreeBSD/mips mips*-*-freebsd
68 Erases all the flash memory regions reported by the target.
73 Erases all the flash memory regions reported by the target. This is
74 equivalent to the CLI command flash-erase.
76 *** Changes in GDB 7.12
78 * GDB and GDBserver now build with a C++ compiler by default.
80 The --enable-build-with-cxx configure option is now enabled by
81 default. One must now explicitly configure with
82 --disable-build-with-cxx in order to build with a C compiler. This
83 option will be removed in a future release.
85 * GDBserver now supports recording btrace without maintaining an active
88 * GDB now supports a negative repeat count in the 'x' command to examine
89 memory backward from the given address. For example:
92 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
93 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
94 (gdb) x/-5i 0x0000000000400580
95 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
96 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
97 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
98 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
99 0x40057b <main(int, char**)+25>:
100 callq 0x400536 <Func1(int, char const*)>
102 * Fortran: Support structures with fields of dynamic types and
103 arrays of dynamic types.
105 * The symbol dumping maintenance commands have new syntax.
106 maint print symbols [-pc address] [--] [filename]
107 maint print symbols [-objfile objfile] [-source source] [--] [filename]
108 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
109 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
110 maint print msymbols [-objfile objfile] [--] [filename]
112 * GDB now supports multibit bitfields and enums in target register
115 * New Python-based convenience function $_as_string(val), which returns
116 the textual representation of a value. This function is especially
117 useful to obtain the text label of an enum value.
119 * Intel MPX bound violation handling.
121 Segmentation faults caused by a Intel MPX boundary violation
122 now display the kind of violation (upper or lower), the memory
123 address accessed and the memory bounds, along with the usual
124 signal received and code location.
128 Program received signal SIGSEGV, Segmentation fault
129 Upper bound violation while accessing address 0x7fffffffc3b3
130 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
131 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
133 * Rust language support.
134 GDB now supports debugging programs written in the Rust programming
135 language. See https://www.rust-lang.org/ for more information about
138 * Support for running interpreters on specified input/output devices
140 GDB now supports a new mechanism that allows frontends to provide
141 fully featured GDB console views, as a better alternative to
142 building such views on top of the "-interpreter-exec console"
143 command. See the new "new-ui" command below. With that command,
144 frontends can now start GDB in the traditional command-line mode
145 running in an embedded terminal emulator widget, and create a
146 separate MI interpreter running on a specified i/o device. In this
147 way, GDB handles line editing, history, tab completion, etc. in the
148 console all by itself, and the GUI uses the separate MI interpreter
149 for its own control and synchronization, invisible to the command
152 * The "catch syscall" command catches groups of related syscalls.
154 The "catch syscall" command now supports catching a group of related
155 syscalls using the 'group:' or 'g:' prefix.
160 skip -gfile file-glob-pattern
161 skip -function function
162 skip -rfunction regular-expression
163 A generalized form of the skip command, with new support for
164 glob-style file names and regular expressions for function names.
165 Additionally, a file spec and a function spec may now be combined.
167 maint info line-table REGEXP
168 Display the contents of GDB's internal line table data struture.
171 Run any GDB unit tests that were compiled in.
174 Start a new user interface instance running INTERP as interpreter,
175 using the TTY file for input/output.
179 ** gdb.Breakpoint objects have a new attribute "pending", which
180 indicates whether the breakpoint is pending.
181 ** Three new breakpoint-related events have been added:
182 gdb.breakpoint_created, gdb.breakpoint_modified, and
183 gdb.breakpoint_deleted.
186 Signal ("set") the given MS-Windows event object. This is used in
187 conjunction with the Windows JIT debugging (AeDebug) support, where
188 the OS suspends a crashing process until a debugger can attach to
189 it. Resuming the crashing process, in order to debug it, is done by
192 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
193 was added in GDBserver, including JIT compiling fast tracepoint's
194 conditional expression bytecode into native code.
196 * Support for various remote target protocols and ROM monitors has
199 target m32rsdi Remote M32R debugging over SDI
200 target mips MIPS remote debugging protocol
201 target pmon PMON ROM monitor
202 target ddb NEC's DDB variant of PMON for Vr4300
203 target rockhopper NEC RockHopper variant of PMON
204 target lsi LSI variant of PMO
206 * Support for tracepoints and fast tracepoints on powerpc-linux,
207 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
208 including JIT compiling fast tracepoint's conditional expression
209 bytecode into native code.
211 * MI async record =record-started now includes the method and format used for
212 recording. For example:
214 =record-started,thread-group="i1",method="btrace",format="bts"
216 * MI async record =thread-selected now includes the frame field. For example:
218 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
222 Andes NDS32 nds32*-*-elf
224 *** Changes in GDB 7.11
226 * GDB now supports debugging kernel-based threads on FreeBSD.
228 * Per-inferior thread numbers
230 Thread numbers are now per inferior instead of global. If you're
231 debugging multiple inferiors, GDB displays thread IDs using a
232 qualified INF_NUM.THR_NUM form. For example:
236 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
237 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
238 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
239 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
241 As consequence, thread numbers as visible in the $_thread
242 convenience variable and in Python's InferiorThread.num attribute
243 are no longer unique between inferiors.
245 GDB now maintains a second thread ID per thread, referred to as the
246 global thread ID, which is the new equivalent of thread numbers in
247 previous releases. See also $_gthread below.
249 For backwards compatibility, MI's thread IDs always refer to global
252 * Commands that accept thread IDs now accept the qualified
253 INF_NUM.THR_NUM form as well. For example:
256 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
259 * In commands that accept a list of thread IDs, you can now refer to
260 all threads of an inferior using a star wildcard. GDB accepts
261 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
262 refer to all threads of the current inferior. For example, "info
265 * You can use "info threads -gid" to display the global thread ID of
268 * The new convenience variable $_gthread holds the global number of
271 * The new convenience variable $_inferior holds the number of the
274 * GDB now displays the ID and name of the thread that hit a breakpoint
275 or received a signal, if your program is multi-threaded. For
278 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
279 Thread 1 "main" received signal SIGINT, Interrupt.
281 * Record btrace now supports non-stop mode.
283 * Support for tracepoints on aarch64-linux was added in GDBserver.
285 * The 'record instruction-history' command now indicates speculative execution
286 when using the Intel Processor Trace recording format.
288 * GDB now allows users to specify explicit locations, bypassing
289 the linespec parser. This feature is also available to GDB/MI
292 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
293 GDB now is able to debug both AArch64 applications and ARM applications
296 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
297 including JIT compiling fast tracepoint's conditional expression bytecode
300 * GDB now supports displaced stepping on AArch64 GNU/Linux.
302 * "info threads", "info inferiors", "info display", "info checkpoints"
303 and "maint info program-spaces" now list the corresponding items in
304 ascending ID order, for consistency with all other "info" commands.
306 * In Ada, the overloads selection menu has been enhanced to display the
307 parameter types and the return types for the matching overloaded subprograms.
311 maint set target-non-stop (on|off|auto)
312 maint show target-non-stop
313 Control whether GDB targets always operate in non-stop mode even if
314 "set non-stop" is "off". The default is "auto", meaning non-stop
315 mode is enabled if supported by the target.
317 maint set bfd-sharing
318 maint show bfd-sharing
319 Control the reuse of bfd objects.
323 Control display of debugging info regarding bfd caching.
327 Control display of debugging info regarding FreeBSD threads.
329 set remote multiprocess-extensions-packet
330 show remote multiprocess-extensions-packet
331 Set/show the use of the remote protocol multiprocess extensions.
333 set remote thread-events
334 show remote thread-events
335 Set/show the use of thread create/exit events.
337 set ada print-signatures on|off
338 show ada print-signatures"
339 Control whether parameter types and return types are displayed in overloads
340 selection menus. It is activaled (@code{on}) by default.
344 Controls the maximum size of memory, in bytes, that GDB will
345 allocate for value contents. Prevents incorrect programs from
346 causing GDB to allocate overly large buffers. Default is 64k.
348 * The "disassemble" command accepts a new modifier: /s.
349 It prints mixed source+disassembly like /m with two differences:
350 - disassembled instructions are now printed in program order, and
351 - and source for all relevant files is now printed.
352 The "/m" option is now considered deprecated: its "source-centric"
353 output hasn't proved useful in practice.
355 * The "record instruction-history" command accepts a new modifier: /s.
356 It behaves exactly like /m and prints mixed source+disassembly.
358 * The "set scheduler-locking" command supports a new mode "replay".
359 It behaves like "off" in record mode and like "on" in replay mode.
361 * Support for various ROM monitors has been removed:
363 target dbug dBUG ROM monitor for Motorola ColdFire
364 target picobug Motorola picobug monitor
365 target dink32 DINK32 ROM monitor for PowerPC
366 target m32r Renesas M32R/D ROM monitor
367 target mon2000 mon2000 ROM monitor
368 target ppcbug PPCBUG ROM monitor for PowerPC
370 * Support for reading/writing memory and extracting values on architectures
371 whose memory is addressable in units of any integral multiple of 8 bits.
376 Indicates that an exec system call was executed.
378 exec-events feature in qSupported
379 The qSupported packet allows GDB to request support for exec
380 events using the new 'gdbfeature' exec-event, and the qSupported
381 response can contain the corresponding 'stubfeature'. Set and
382 show commands can be used to display whether these features are enabled.
385 Equivalent to interrupting with the ^C character, but works in
388 thread created stop reason (T05 create:...)
389 Indicates that the thread was just created and is stopped at entry.
391 thread exit stop reply (w exitcode;tid)
392 Indicates that the thread has terminated.
395 Enables/disables thread create and exit event reporting. For
396 example, this is used in non-stop mode when GDB stops a set of
397 threads and synchronously waits for the their corresponding stop
398 replies. Without exit events, if one of the threads exits, GDB
399 would hang forever not knowing that it should no longer expect a
400 stop for that same thread.
403 Indicates that there are no resumed threads left in the target (all
404 threads are stopped). The remote stub reports support for this stop
405 reply to GDB's qSupported query.
408 Enables/disables catching syscalls from the inferior process.
409 The remote stub reports support for this packet to GDB's qSupported query.
411 syscall_entry stop reason
412 Indicates that a syscall was just called.
414 syscall_return stop reason
415 Indicates that a syscall just returned.
417 * Extended-remote exec events
419 ** GDB now has support for exec events on extended-remote Linux targets.
420 For such targets with Linux kernels 2.5.46 and later, this enables
421 follow-exec-mode and exec catchpoints.
423 set remote exec-event-feature-packet
424 show remote exec-event-feature-packet
425 Set/show the use of the remote exec event feature.
427 * Thread names in remote protocol
429 The reply to qXfer:threads:read may now include a name attribute for each
432 * Target remote mode fork and exec events
434 ** GDB now has support for fork and exec events on target remote mode
435 Linux targets. For such targets with Linux kernels 2.5.46 and later,
436 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
437 fork and exec catchpoints.
439 * Remote syscall events
441 ** GDB now has support for catch syscall on remote Linux targets,
442 currently enabled on x86/x86_64 architectures.
444 set remote catch-syscall-packet
445 show remote catch-syscall-packet
446 Set/show the use of the remote catch syscall feature.
450 ** The -var-set-format command now accepts the zero-hexadecimal
451 format. It outputs data in hexadecimal format with zero-padding on the
456 ** gdb.InferiorThread objects have a new attribute "global_num",
457 which refers to the thread's global thread ID. The existing
458 "num" attribute now refers to the thread's per-inferior number.
459 See "Per-inferior thread numbers" above.
460 ** gdb.InferiorThread objects have a new attribute "inferior", which
461 is the Inferior object the thread belongs to.
463 *** Changes in GDB 7.10
465 * Support for process record-replay and reverse debugging on aarch64*-linux*
466 targets has been added. GDB now supports recording of A64 instruction set
467 including advance SIMD instructions.
469 * Support for Sun's version of the "stabs" debug file format has been removed.
471 * GDB now honors the content of the file /proc/PID/coredump_filter
472 (PID is the process ID) on GNU/Linux systems. This file can be used
473 to specify the types of memory mappings that will be included in a
474 corefile. For more information, please refer to the manual page of
475 "core(5)". GDB also has a new command: "set use-coredump-filter
476 on|off". It allows to set whether GDB will read the content of the
477 /proc/PID/coredump_filter file when generating a corefile.
479 * The "info os" command on GNU/Linux can now display information on
481 "info os cpus" Listing of all cpus/cores on the system
483 * GDB has two new commands: "set serial parity odd|even|none" and
484 "show serial parity". These allows to set or show parity for the
487 * The "info source" command now displays the producer string if it was
488 present in the debug info. This typically includes the compiler version
489 and may include things like its command line arguments.
491 * The "info dll", an alias of the "info sharedlibrary" command,
492 is now available on all platforms.
494 * Directory names supplied to the "set sysroot" commands may be
495 prefixed with "target:" to tell GDB to access shared libraries from
496 the target system, be it local or remote. This replaces the prefix
497 "remote:". The default sysroot has been changed from "" to
498 "target:". "remote:" is automatically converted to "target:" for
499 backward compatibility.
501 * The system root specified by "set sysroot" will be prepended to the
502 filename of the main executable (if reported to GDB as absolute by
503 the operating system) when starting processes remotely, and when
504 attaching to already-running local or remote processes.
506 * GDB now supports automatic location and retrieval of executable
507 files from remote targets. Remote debugging can now be initiated
508 using only a "target remote" or "target extended-remote" command
509 (no "set sysroot" or "file" commands are required). See "New remote
512 * The "dump" command now supports verilog hex format.
514 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
516 * On GNU/Linux, GDB and gdbserver are now able to access executable
517 and shared library files without a "set sysroot" command when
518 attaching to processes running in different mount namespaces from
519 the debugger. This makes it possible to attach to processes in
520 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
521 See "New remote packets" below.
523 * The "tui reg" command now provides completion for all of the
524 available register groups, including target specific groups.
526 * The HISTSIZE environment variable is no longer read when determining
527 the size of GDB's command history. GDB now instead reads the dedicated
528 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
529 disables truncation of command history. Non-numeric values of GDBHISTSIZE
534 ** Memory ports can now be unbuffered.
538 ** gdb.Objfile objects have a new attribute "username",
539 which is the name of the objfile as specified by the user,
540 without, for example, resolving symlinks.
541 ** You can now write frame unwinders in Python.
542 ** gdb.Type objects have a new method "optimized_out",
543 returning optimized out gdb.Value instance of this type.
544 ** gdb.Value objects have new methods "reference_value" and
545 "const_value" which return a reference to the value and a
546 "const" version of the value respectively.
550 maint print symbol-cache
551 Print the contents of the symbol cache.
553 maint print symbol-cache-statistics
554 Print statistics of symbol cache usage.
556 maint flush-symbol-cache
557 Flush the contents of the symbol cache.
561 Start branch trace recording using Branch Trace Store (BTS) format.
564 Evaluate expression by using the compiler and print result.
568 Explicit commands for enabling and disabling tui mode.
571 set mpx bound on i386 and amd64
572 Support for bound table investigation on Intel MPX enabled applications.
576 Start branch trace recording using Intel Processor Trace format.
579 Print information about branch tracing internals.
581 maint btrace packet-history
582 Print the raw branch tracing data.
584 maint btrace clear-packet-history
585 Discard the stored raw branch tracing data.
588 Discard all branch tracing data. It will be fetched and processed
589 anew by the next "record" command.
594 Renamed from "set debug dwarf2-die".
596 Renamed from "show debug dwarf2-die".
599 Renamed from "set debug dwarf2-read".
600 show debug dwarf-read
601 Renamed from "show debug dwarf2-read".
603 maint set dwarf always-disassemble
604 Renamed from "maint set dwarf2 always-disassemble".
605 maint show dwarf always-disassemble
606 Renamed from "maint show dwarf2 always-disassemble".
608 maint set dwarf max-cache-age
609 Renamed from "maint set dwarf2 max-cache-age".
610 maint show dwarf max-cache-age
611 Renamed from "maint show dwarf2 max-cache-age".
614 show debug dwarf-line
615 Control display of debugging info regarding DWARF line processing.
619 Set the maximum number of candidates to be considered during
620 completion. The default value is 200. This limit allows GDB
621 to avoid generating large completion lists, the computation of
622 which can cause the debugger to become temporarily unresponsive.
624 set history remove-duplicates
625 show history remove-duplicates
626 Control the removal of duplicate history entries.
628 maint set symbol-cache-size
629 maint show symbol-cache-size
630 Control the size of the symbol cache.
632 set|show record btrace bts buffer-size
633 Set and show the size of the ring buffer used for branch tracing in
635 The obtained size may differ from the requested size. Use "info
636 record" to see the obtained buffer size.
638 set debug linux-namespaces
639 show debug linux-namespaces
640 Control display of debugging info regarding Linux namespaces.
642 set|show record btrace pt buffer-size
643 Set and show the size of the ring buffer used for branch tracing in
644 Intel Processor Trace format.
645 The obtained size may differ from the requested size. Use "info
646 record" to see the obtained buffer size.
648 maint set|show btrace pt skip-pad
649 Set and show whether PAD packets are skipped when computing the
652 * The command 'thread apply all' can now support new option '-ascending'
653 to call its specified command for all threads in ascending order.
655 * Python/Guile scripting
657 ** GDB now supports auto-loading of Python/Guile scripts contained in the
658 special section named `.debug_gdb_scripts'.
662 qXfer:btrace-conf:read
663 Return the branch trace configuration for the current thread.
665 Qbtrace-conf:bts:size
666 Set the requested ring buffer size for branch tracing in BTS format.
669 Enable Intel Procesor Trace-based branch tracing for the current
670 process. The remote stub reports support for this packet to GDB's
674 Set the requested ring buffer size for branch tracing in Intel Processor
678 Indicates a memory breakpoint instruction was executed, irrespective
679 of whether it was GDB that planted the breakpoint or the breakpoint
680 is hardcoded in the program. This is required for correct non-stop
684 Indicates the target stopped for a hardware breakpoint. This is
685 required for correct non-stop mode operation.
688 Return information about files on the remote system.
691 Return the full absolute name of the file that was executed to
692 create a process running on the remote system.
695 Select the filesystem on which vFile: operations with filename
696 arguments will operate. This is required for GDB to be able to
697 access files on remote targets where the remote stub does not
698 share a common filesystem with the inferior(s).
701 Indicates that a fork system call was executed.
704 Indicates that a vfork system call was executed.
706 vforkdone stop reason
707 Indicates that a vfork child of the specified process has executed
708 an exec or exit, allowing the vfork parent to resume execution.
710 fork-events and vfork-events features in qSupported
711 The qSupported packet allows GDB to request support for fork and
712 vfork events using new 'gdbfeatures' fork-events and vfork-events,
713 and the qSupported response can contain the corresponding
714 'stubfeatures'. Set and show commands can be used to display
715 whether these features are enabled.
717 * Extended-remote fork events
719 ** GDB now has support for fork events on extended-remote Linux
720 targets. For targets with Linux kernels 2.5.60 and later, this
721 enables follow-fork-mode and detach-on-fork for both fork and
722 vfork, as well as fork and vfork catchpoints.
724 * The info record command now shows the recording format and the
725 branch tracing configuration for the current thread when using
726 the btrace record target.
727 For the BTS format, it shows the ring buffer size.
729 * GDB now has support for DTrace USDT (Userland Static Defined
730 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
732 * GDB now supports access to vector registers on S/390 GNU/Linux
735 * Removed command line options
737 -xdb HP-UX XDB compatibility mode.
739 * Removed targets and native configurations
741 HP/PA running HP-UX hppa*-*-hpux*
742 Itanium running HP-UX ia64-*-hpux*
744 * New configure options
747 This configure option allows the user to build GDB with support for
748 Intel Processor Trace (default: auto). This requires libipt.
750 --with-libipt-prefix=PATH
751 Specify the path to the version of libipt that GDB should use.
752 $PATH/include should contain the intel-pt.h header and
753 $PATH/lib should contain the libipt.so library.
755 *** Changes in GDB 7.9.1
759 ** Xmethods can now specify a result type.
761 *** Changes in GDB 7.9
763 * GDB now supports hardware watchpoints on x86 GNU Hurd.
767 ** You can now access frame registers from Python scripts.
768 ** New attribute 'producer' for gdb.Symtab objects.
769 ** gdb.Objfile objects have a new attribute "progspace",
770 which is the gdb.Progspace object of the containing program space.
771 ** gdb.Objfile objects have a new attribute "owner".
772 ** gdb.Objfile objects have a new attribute "build_id",
773 which is the build ID generated when the file was built.
774 ** gdb.Objfile objects have a new method "add_separate_debug_file".
775 ** A new event "gdb.clear_objfiles" has been added, triggered when
776 selecting a new file to debug.
777 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
778 ** New function gdb.lookup_objfile.
780 New events which are triggered when GDB modifies the state of the
783 ** gdb.events.inferior_call_pre: Function call is about to be made.
784 ** gdb.events.inferior_call_post: Function call has just been made.
785 ** gdb.events.memory_changed: A memory location has been altered.
786 ** gdb.events.register_changed: A register has been altered.
788 * New Python-based convenience functions:
790 ** $_caller_is(name [, number_of_frames])
791 ** $_caller_matches(regexp [, number_of_frames])
792 ** $_any_caller_is(name [, number_of_frames])
793 ** $_any_caller_matches(regexp [, number_of_frames])
795 * GDB now supports the compilation and injection of source code into
796 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
797 to compile the source code to object code, and if successful, inject
798 and execute that code within the current context of the inferior.
799 Currently the C language is supported. The commands used to
800 interface with this new feature are:
802 compile code [-raw|-r] [--] [source code]
803 compile file [-raw|-r] filename
807 demangle [-l language] [--] name
808 Demangle "name" in the specified language, or the current language
809 if elided. This command is renamed from the "maint demangle" command.
810 The latter is kept as a no-op to avoid "maint demangle" being interpreted
811 as "maint demangler-warning".
813 queue-signal signal-name-or-number
814 Queue a signal to be delivered to the thread when it is resumed.
816 add-auto-load-scripts-directory directory
817 Add entries to the list of directories from which to load auto-loaded
820 maint print user-registers
821 List all currently available "user" registers.
823 compile code [-r|-raw] [--] [source code]
824 Compile, inject, and execute in the inferior the executable object
825 code produced by compiling the provided source code.
827 compile file [-r|-raw] filename
828 Compile and inject into the inferior the executable object code
829 produced by compiling the source code stored in the filename
832 * On resume, GDB now always passes the signal the program had stopped
833 for to the thread the signal was sent to, even if the user changed
834 threads before resuming. Previously GDB would often (but not
835 always) deliver the signal to the thread that happens to be current
838 * Conversely, the "signal" command now consistently delivers the
839 requested signal to the current thread. GDB now asks for
840 confirmation if the program had stopped for a signal and the user
841 switched threads meanwhile.
843 * "breakpoint always-inserted" modes "off" and "auto" merged.
845 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
846 won't remove breakpoints from the target until all threads stop,
847 even in non-stop mode. The "auto" mode has been removed, and "off"
848 is now the default mode.
852 set debug symbol-lookup
853 show debug symbol-lookup
854 Control display of debugging info regarding symbol lookup.
858 ** The -list-thread-groups command outputs an exit-code field for
859 inferiors that have exited.
863 MIPS SDE mips*-sde*-elf*
867 Support for these obsolete configurations has been removed.
869 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
870 SGI Irix-5.x mips-*-irix5*
871 SGI Irix-6.x mips-*-irix6*
872 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
873 VAX running Ultrix vax-*-ultrix*
875 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
876 and "assf"), have been removed. Use the "sharedlibrary" command, or
877 its alias "share", instead.
879 *** Changes in GDB 7.8
881 * New command line options
884 This is an alias for the --data-directory option.
886 * GDB supports printing and modifying of variable length automatic arrays
887 as specified in ISO C99.
889 * The ARM simulator now supports instruction level tracing
890 with or without disassembly.
894 GDB now has support for scripting using Guile. Whether this is
895 available is determined at configure time.
896 Guile version 2.0 or greater is required.
897 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
899 * New commands (for set/show, see "New options" below)
903 Invoke CODE by passing it to the Guile interpreter.
907 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
909 info auto-load guile-scripts [regexp]
910 Print the list of automatically loaded Guile scripts.
912 * The source command is now capable of sourcing Guile scripts.
913 This feature is dependent on the debugger being built with Guile support.
917 set print symbol-loading (off|brief|full)
918 show print symbol-loading
919 Control whether to print informational messages when loading symbol
920 information for a file. The default is "full", but when debugging
921 programs with large numbers of shared libraries the amount of output
924 set guile print-stack (none|message|full)
925 show guile print-stack
926 Show a stack trace when an error is encountered in a Guile script.
928 set auto-load guile-scripts (on|off)
929 show auto-load guile-scripts
930 Control auto-loading of Guile script files.
932 maint ada set ignore-descriptive-types (on|off)
933 maint ada show ignore-descriptive-types
934 Control whether the debugger should ignore descriptive types in Ada
935 programs. The default is not to ignore the descriptive types. See
936 the user manual for more details on descriptive types and the intended
937 usage of this option.
939 set auto-connect-native-target
941 Control whether GDB is allowed to automatically connect to the
942 native target for the run, attach, etc. commands when not connected
943 to any target yet. See also "target native" below.
945 set record btrace replay-memory-access (read-only|read-write)
946 show record btrace replay-memory-access
947 Control what memory accesses are allowed during replay.
949 maint set target-async (on|off)
950 maint show target-async
951 This controls whether GDB targets operate in synchronous or
952 asynchronous mode. Normally the default is asynchronous, if it is
953 available; but this can be changed to more easily debug problems
954 occurring only in synchronous mode.
956 set mi-async (on|off)
958 Control whether MI asynchronous mode is preferred. This supersedes
959 "set target-async" of previous GDB versions.
961 * "set target-async" is deprecated as a CLI option and is now an alias
962 for "set mi-async" (only puts MI into async mode).
964 * Background execution commands (e.g., "c&", "s&", etc.) are now
965 possible ``out of the box'' if the target supports them. Previously
966 the user would need to explicitly enable the possibility with the
967 "set target-async on" command.
969 * New features in the GDB remote stub, GDBserver
971 ** New option --debug-format=option1[,option2,...] allows one to add
972 additional text to each output. At present only timestamps
973 are supported: --debug-format=timestamps.
974 Timestamps can also be turned on with the
975 "monitor set debug-format timestamps" command from GDB.
977 * The 'record instruction-history' command now starts counting instructions
978 at one. This also affects the instruction ranges reported by the
979 'record function-call-history' command when given the /i modifier.
981 * The command 'record function-call-history' supports a new modifier '/c' to
982 indent the function names based on their call stack depth.
983 The fields for the '/i' and '/l' modifier have been reordered.
984 The source line range is now prefixed with 'at'.
985 The instruction range is now prefixed with 'inst'.
986 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
987 "record instruction-history" and "list" commands.
989 * The ranges given as arguments to the 'record function-call-history' and
990 'record instruction-history' commands are now inclusive.
992 * The btrace record target now supports the 'record goto' command.
993 For locations inside the execution trace, the back trace is computed
994 based on the information stored in the execution trace.
996 * The btrace record target supports limited reverse execution and replay.
997 The target does not record data and therefore does not allow reading
1000 * The "catch syscall" command now works on s390*-linux* targets.
1002 * The "compare-sections" command is no longer specific to target
1003 remote. It now works with all targets.
1005 * All native targets are now consistently called "native".
1006 Consequently, the "target child", "target GNU", "target djgpp",
1007 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1008 commands have been replaced with "target native". The QNX/NTO port
1009 leaves the "procfs" target in place and adds a "native" target for
1010 consistency with other ports. The impact on users should be minimal
1011 as these commands previously either throwed an error, or were
1012 no-ops. The target's name is visible in the output of the following
1013 commands: "help target", "info target", "info files", "maint print
1016 * The "target native" command now connects to the native target. This
1017 can be used to launch native programs even when "set
1018 auto-connect-native-target" is set to off.
1020 * GDB now supports access to Intel MPX registers on GNU/Linux.
1022 * Support for Intel AVX-512 registers on GNU/Linux.
1023 Support displaying and modifying Intel AVX-512 registers
1024 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1026 * New remote packets
1028 qXfer:btrace:read's annex
1029 The qXfer:btrace:read packet supports a new annex 'delta' to read
1030 branch trace incrementally.
1034 ** Valid Python operations on gdb.Value objects representing
1035 structs/classes invoke the corresponding overloaded operators if
1037 ** New `Xmethods' feature in the Python API. Xmethods are
1038 additional methods or replacements for existing methods of a C++
1039 class. This feature is useful for those cases where a method
1040 defined in C++ source code could be inlined or optimized out by
1041 the compiler, making it unavailable to GDB.
1044 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1046 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1047 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1048 its alias "share", instead.
1050 * The commands "set remotebaud" and "show remotebaud" are no longer
1051 supported. Use "set serial baud" and "show serial baud" (respectively)
1056 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1057 target-async". The latter is left as a deprecated alias of the
1058 former for backward compatibility. If the target supports it,
1059 CLI background execution commands are now always possible by
1060 default, independently of whether the frontend stated a
1061 preference for asynchronous execution with "-gdb-set mi-async".
1062 Previously "-gdb-set target-async off" affected both MI execution
1063 commands and CLI execution commands.
1065 *** Changes in GDB 7.7
1067 * Improved support for process record-replay and reverse debugging on
1068 arm*-linux* targets. Support for thumb32 and syscall instruction
1069 recording has been added.
1071 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1073 * GDB now supports Fission DWP file format version 2.
1074 http://gcc.gnu.org/wiki/DebugFission
1076 * New convenience function "$_isvoid", to check whether an expression
1077 is void. A void expression is an expression where the type of the
1078 result is "void". For example, some convenience variables may be
1079 "void" when evaluated (e.g., "$_exitcode" before the execution of
1080 the program being debugged; or an undefined convenience variable).
1081 Another example, when calling a function whose return type is
1084 * The "maintenance print objfiles" command now takes an optional regexp.
1086 * The "catch syscall" command now works on arm*-linux* targets.
1088 * GDB now consistently shows "<not saved>" when printing values of
1089 registers the debug info indicates have not been saved in the frame
1090 and there's nowhere to retrieve them from
1091 (callee-saved/call-clobbered registers):
1096 (gdb) info registers rax
1099 Before, the former would print "<optimized out>", and the latter
1100 "*value not available*".
1102 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1107 ** Frame filters and frame decorators have been added.
1108 ** Temporary breakpoints are now supported.
1109 ** Line tables representation has been added.
1110 ** New attribute 'parent_type' for gdb.Field objects.
1111 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1112 ** New attribute 'name' for gdb.Type objects.
1116 Nios II ELF nios2*-*-elf
1117 Nios II GNU/Linux nios2*-*-linux
1118 Texas Instruments MSP430 msp430*-*-elf
1120 * Removed native configurations
1122 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1123 been removed. ELF variants of these configurations are kept supported.
1125 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1126 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1127 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1128 i[34567]86-*-openbsd3.[0-3]
1129 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1130 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1131 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1135 Like "catch throw", but catches a re-thrown exception.
1136 maint check-psymtabs
1137 Renamed from old "maint check-symtabs".
1139 Perform consistency checks on symtabs.
1140 maint expand-symtabs
1141 Expand symtabs matching an optional regexp.
1144 Display the details of GDB configure-time options.
1146 maint set|show per-command
1147 maint set|show per-command space
1148 maint set|show per-command time
1149 maint set|show per-command symtab
1150 Enable display of per-command gdb resource usage.
1152 remove-symbol-file FILENAME
1153 remove-symbol-file -a ADDRESS
1154 Remove a symbol file added via add-symbol-file. The file to remove
1155 can be identified by its filename or by an address that lies within
1156 the boundaries of this symbol file in memory.
1159 info exceptions REGEXP
1160 Display the list of Ada exceptions defined in the program being
1161 debugged. If provided, only the exceptions whose names match REGEXP
1166 set debug symfile off|on
1168 Control display of debugging info regarding reading symbol files and
1169 symbol tables within those files
1171 set print raw frame-arguments
1172 show print raw frame-arguments
1173 Set/show whether to print frame arguments in raw mode,
1174 disregarding any defined pretty-printers.
1176 set remote trace-status-packet
1177 show remote trace-status-packet
1178 Set/show the use of remote protocol qTStatus packet.
1182 Control display of debugging messages related to Nios II targets.
1186 Control whether target-assisted range stepping is enabled.
1188 set startup-with-shell
1189 show startup-with-shell
1190 Specifies whether Unix child processes are started via a shell or
1195 Use the target memory cache for accesses to the code segment. This
1196 improves performance of remote debugging (particularly disassembly).
1198 * You can now use a literal value 'unlimited' for options that
1199 interpret 0 or -1 as meaning "unlimited". E.g., "set
1200 trace-buffer-size unlimited" is now an alias for "set
1201 trace-buffer-size -1" and "set height unlimited" is now an alias for
1204 * The "set debug symtab-create" debugging option of GDB has been changed to
1205 accept a verbosity level. 0 means "off", 1 provides basic debugging
1206 output, and values of 2 or greater provides more verbose output.
1208 * New command-line options
1210 Display the details of GDB configure-time options.
1212 * The command 'tsave' can now support new option '-ctf' to save trace
1213 buffer in Common Trace Format.
1215 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1218 * GDB now implements the the C++ 'typeid' operator.
1220 * The new convenience variable $_exception holds the exception being
1221 thrown or caught at an exception-related catchpoint.
1223 * The exception-related catchpoints, like "catch throw", now accept a
1224 regular expression which can be used to filter exceptions by type.
1226 * The new convenience variable $_exitsignal is automatically set to
1227 the terminating signal number when the program being debugged dies
1228 due to an uncaught signal.
1232 ** All MI commands now accept an optional "--language" option.
1233 Support for this feature can be verified by using the "-list-features"
1234 command, which should contain "language-option".
1236 ** The new command -info-gdb-mi-command allows the user to determine
1237 whether a GDB/MI command is supported or not.
1239 ** The "^error" result record returned when trying to execute an undefined
1240 GDB/MI command now provides a variable named "code" whose content is the
1241 "undefined-command" error code. Support for this feature can be verified
1242 by using the "-list-features" command, which should contain
1243 "undefined-command-error-code".
1245 ** The -trace-save MI command can optionally save trace buffer in Common
1248 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1250 ** The command -data-list-register-values now accepts an optional
1251 "--skip-unavailable" option. When used, only the available registers
1254 ** The new command -trace-frame-collected dumps collected variables,
1255 computed expressions, tvars, memory and registers in a traceframe.
1257 ** The commands -stack-list-locals, -stack-list-arguments and
1258 -stack-list-variables now accept an option "--skip-unavailable".
1259 When used, only the available locals or arguments are displayed.
1261 ** The -exec-run command now accepts an optional "--start" option.
1262 When used, the command follows the same semantics as the "start"
1263 command, stopping the program's execution at the start of its
1264 main subprogram. Support for this feature can be verified using
1265 the "-list-features" command, which should contain
1266 "exec-run-start-option".
1268 ** The new commands -catch-assert and -catch-exceptions insert
1269 catchpoints stopping the program when Ada exceptions are raised.
1271 ** The new command -info-ada-exceptions provides the equivalent of
1272 the new "info exceptions" command.
1274 * New system-wide configuration scripts
1275 A GDB installation now provides scripts suitable for use as system-wide
1276 configuration scripts for the following systems:
1280 * GDB now supports target-assigned range stepping with remote targets.
1281 This improves the performance of stepping source lines by reducing
1282 the number of control packets from/to GDB. See "New remote packets"
1285 * GDB now understands the element 'tvar' in the XML traceframe info.
1286 It has the id of the collected trace state variables.
1288 * On S/390 targets that provide the transactional-execution feature,
1289 the program interruption transaction diagnostic block (TDB) is now
1290 represented as a number of additional "registers" in GDB.
1292 * New remote packets
1296 The vCont packet supports a new 'r' action, that tells the remote
1297 stub to step through an address range itself, without GDB
1298 involvemement at each single-step.
1300 qXfer:libraries-svr4:read's annex
1301 The previously unused annex of the qXfer:libraries-svr4:read packet
1302 is now used to support passing an argument list. The remote stub
1303 reports support for this argument list to GDB's qSupported query.
1304 The defined arguments are "start" and "prev", used to reduce work
1305 necessary for library list updating, resulting in significant
1308 * New features in the GDB remote stub, GDBserver
1310 ** GDBserver now supports target-assisted range stepping. Currently
1311 enabled on x86/x86_64 GNU/Linux targets.
1313 ** GDBserver now adds element 'tvar' in the XML in the reply to
1314 'qXfer:traceframe-info:read'. It has the id of the collected
1315 trace state variables.
1317 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1320 * New 'z' formatter for printing and examining memory, this displays the
1321 value as hexadecimal zero padded on the left to the size of the type.
1323 * GDB can now use Windows x64 unwinding data.
1325 * The "set remotebaud" command has been replaced by "set serial baud".
1326 Similarly, "show remotebaud" has been replaced by "show serial baud".
1327 The "set remotebaud" and "show remotebaud" commands are still available
1328 to provide backward compatibility with older versions of GDB.
1330 *** Changes in GDB 7.6
1332 * Target record has been renamed to record-full.
1333 Record/replay is now enabled with the "record full" command.
1334 This also affects settings that are associated with full record/replay
1335 that have been moved from "set/show record" to "set/show record full":
1337 set|show record full insn-number-max
1338 set|show record full stop-at-limit
1339 set|show record full memory-query
1341 * A new record target "record-btrace" has been added. The new target
1342 uses hardware support to record the control-flow of a process. It
1343 does not support replaying the execution, but it implements the
1344 below new commands for investigating the recorded execution log.
1345 This new recording method can be enabled using:
1349 The "record-btrace" target is only available on Intel Atom processors
1350 and requires a Linux kernel 2.6.32 or later.
1352 * Two new commands have been added for record/replay to give information
1353 about the recorded execution without having to replay the execution.
1354 The commands are only supported by "record btrace".
1356 record instruction-history prints the execution history at
1357 instruction granularity
1359 record function-call-history prints the execution history at
1360 function granularity
1362 * New native configurations
1364 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1365 FreeBSD/powerpc powerpc*-*-freebsd
1366 x86_64/Cygwin x86_64-*-cygwin*
1367 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1371 ARM AArch64 aarch64*-*-elf
1372 ARM AArch64 GNU/Linux aarch64*-*-linux
1373 Lynx 178 PowerPC powerpc-*-lynx*178
1374 x86_64/Cygwin x86_64-*-cygwin*
1375 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1377 * If the configured location of system.gdbinit file (as given by the
1378 --with-system-gdbinit option at configure time) is in the
1379 data-directory (as specified by --with-gdb-datadir at configure
1380 time) or in one of its subdirectories, then GDB will look for the
1381 system-wide init file in the directory specified by the
1382 --data-directory command-line option.
1384 * New command line options:
1386 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1387 other initialization files, unlike -nx which disables all of them.
1389 * Removed command line options
1391 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1394 * The 'ptype' and 'whatis' commands now accept an argument to control
1397 * 'info proc' now works on some core files.
1401 ** Vectors can be created with gdb.Type.vector.
1403 ** Python's atexit.register now works in GDB.
1405 ** Types can be pretty-printed via a Python API.
1407 ** Python 3 is now supported (in addition to Python 2.4 or later)
1409 ** New class gdb.Architecture exposes GDB's internal representation
1410 of architecture in the Python API.
1412 ** New method Frame.architecture returns the gdb.Architecture object
1413 corresponding to the frame's architecture.
1415 * New Python-based convenience functions:
1417 ** $_memeq(buf1, buf2, length)
1418 ** $_streq(str1, str2)
1420 ** $_regex(str, regex)
1422 * The 'cd' command now defaults to using '~' (the home directory) if not
1425 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1426 default for GCC since November 2000.
1428 * The command 'forward-search' can now be abbreviated as 'fo'.
1430 * The command 'info tracepoints' can now display 'installed on target'
1431 or 'not installed on target' for each non-pending location of tracepoint.
1433 * New configure options
1435 --enable-libmcheck/--disable-libmcheck
1436 By default, development versions are built with -lmcheck on hosts
1437 that support it, in order to help track memory corruption issues.
1438 Release versions, on the other hand, are built without -lmcheck
1439 by default. The --enable-libmcheck/--disable-libmcheck configure
1440 options allow the user to override that default.
1441 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1442 This configure option allows the user to build GDB with
1443 libbabeltrace using which GDB can read Common Trace Format data.
1445 * New commands (for set/show, see "New options" below)
1448 Catch signals. This is similar to "handle", but allows commands and
1449 conditions to be attached.
1452 List the BFDs known to GDB.
1454 python-interactive [command]
1456 Start a Python interactive prompt, or evaluate the optional command
1457 and print the result of expressions.
1460 "py" is a new alias for "python".
1462 enable type-printer [name]...
1463 disable type-printer [name]...
1464 Enable or disable type printers.
1468 ** For the Renesas Super-H architecture, the "regs" command has been removed
1469 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1474 set print type methods (on|off)
1475 show print type methods
1476 Control whether method declarations are displayed by "ptype".
1477 The default is to show them.
1479 set print type typedefs (on|off)
1480 show print type typedefs
1481 Control whether typedef definitions are displayed by "ptype".
1482 The default is to show them.
1484 set filename-display basename|relative|absolute
1485 show filename-display
1486 Control the way in which filenames is displayed.
1487 The default is "relative", which preserves previous behavior.
1489 set trace-buffer-size
1490 show trace-buffer-size
1491 Request target to change the size of trace buffer.
1493 set remote trace-buffer-size-packet auto|on|off
1494 show remote trace-buffer-size-packet
1495 Control the use of the remote protocol `QTBuffer:size' packet.
1499 Control display of debugging messages related to ARM AArch64.
1502 set debug coff-pe-read
1503 show debug coff-pe-read
1504 Control display of debugging messages related to reading of COFF/PE
1509 Control display of debugging messages related to Mach-O symbols
1512 set debug notification
1513 show debug notification
1514 Control display of debugging info for async remote notification.
1518 ** Command parameter changes are now notified using new async record
1519 "=cmd-param-changed".
1520 ** Trace frame changes caused by command "tfind" are now notified using
1521 new async record "=traceframe-changed".
1522 ** The creation, deletion and modification of trace state variables
1523 are now notified using new async records "=tsv-created",
1524 "=tsv-deleted" and "=tsv-modified".
1525 ** The start and stop of process record are now notified using new
1526 async record "=record-started" and "=record-stopped".
1527 ** Memory changes are now notified using new async record
1529 ** The data-disassemble command response will include a "fullname" field
1530 containing the absolute file name when source has been requested.
1531 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1532 command, to allow pattern filling of memory areas.
1533 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1534 library load/unload events.
1535 ** The response to breakpoint commands and breakpoint async records
1536 includes an "installed" field containing a boolean state about each
1537 non-pending tracepoint location is whether installed on target or not.
1538 ** Output of the "-trace-status" command includes a "trace-file" field
1539 containing the name of the trace file being examined. This field is
1540 optional, and only present when examining a trace file.
1541 ** The "fullname" field is now always present along with the "file" field,
1542 even if the file cannot be found by GDB.
1544 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1545 You must have the LZMA library available when configuring GDB for this
1546 feature to be enabled. For more information, see:
1547 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1549 * New remote packets
1552 Set the size of trace buffer. The remote stub reports support for this
1553 packet to gdb's qSupported query.
1556 Enable Branch Trace Store (BTS)-based branch tracing for the current
1557 thread. The remote stub reports support for this packet to gdb's
1561 Disable branch tracing for the current thread. The remote stub reports
1562 support for this packet to gdb's qSupported query.
1565 Read the traced branches for the current thread. The remote stub
1566 reports support for this packet to gdb's qSupported query.
1568 *** Changes in GDB 7.5
1570 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1571 for more x32 ABI info.
1573 * GDB now supports access to MIPS DSP registers on Linux targets.
1575 * GDB now supports debugging microMIPS binaries.
1577 * The "info os" command on GNU/Linux can now display information on
1578 several new classes of objects managed by the operating system:
1579 "info os procgroups" lists process groups
1580 "info os files" lists file descriptors
1581 "info os sockets" lists internet-domain sockets
1582 "info os shm" lists shared-memory regions
1583 "info os semaphores" lists semaphores
1584 "info os msg" lists message queues
1585 "info os modules" lists loaded kernel modules
1587 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1588 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1589 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1590 options and inspect the probe arguments using the new $_probe_arg family
1591 of convenience variables. You can obtain more information about SystemTap
1592 in <http://sourceware.org/systemtap/>.
1594 * GDB now supports reversible debugging on ARM, it allows you to
1595 debug basic ARM and THUMB instructions, and provides
1596 record/replay support.
1598 * The option "symbol-reloading" has been deleted as it is no longer used.
1602 ** GDB commands implemented in Python can now be put in command class
1605 ** The "maint set python print-stack on|off" is now deleted.
1607 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1608 apply "flag enum"-style pretty-printing to any enum.
1610 ** gdb.lookup_symbol can now work when there is no current frame.
1612 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1613 the source at which the symbol was defined.
1615 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1616 method 'value'. The former indicates whether the symbol needs a
1617 frame in order to compute its value, and the latter computes the
1620 ** A new method 'referenced_value' on gdb.Value objects which can
1621 dereference pointer as well as C++ reference values.
1623 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1624 which return the global and static blocks (as gdb.Block objects),
1625 of the underlying symbol table, respectively.
1627 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1628 object associated with a PC value.
1630 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1631 of the address range occupied by code for the current source line.
1633 * Go language support.
1634 GDB now supports debugging programs written in the Go programming
1637 * GDBserver now supports stdio connections.
1638 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1640 * The binary "gdbtui" can no longer be built or installed.
1641 Use "gdb -tui" instead.
1643 * GDB will now print "flag" enums specially. A flag enum is one where
1644 all the enumerator values have no bits in common when pairwise
1645 "and"ed. When printing a value whose type is a flag enum, GDB will
1646 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1647 (gdb) print (enum E) 3
1650 * The filename part of a linespec will now match trailing components
1651 of a source file name. For example, "break gcc/expr.c:1000" will
1652 now set a breakpoint in build/gcc/expr.c, but not
1653 build/libcpp/expr.c.
1655 * The "info proc" and "generate-core-file" commands will now also
1656 work on remote targets connected to GDBserver on Linux.
1658 * The command "info catch" has been removed. It has been disabled
1659 since December 2007.
1661 * The "catch exception" and "catch assert" commands now accept
1662 a condition at the end of the command, much like the "break"
1663 command does. For instance:
1665 (gdb) catch exception Constraint_Error if Barrier = True
1667 Previously, it was possible to add a condition to such catchpoints,
1668 but it had to be done as a second step, after the catchpoint had been
1669 created, using the "condition" command.
1671 * The "info static-tracepoint-marker" command will now also work on
1672 native Linux targets with in-process agent.
1674 * GDB can now set breakpoints on inlined functions.
1676 * The .gdb_index section has been updated to include symbols for
1677 inlined functions. GDB will ignore older .gdb_index sections by
1678 default, which could cause symbol files to be loaded more slowly
1679 until their .gdb_index sections can be recreated. The new command
1680 "set use-deprecated-index-sections on" will cause GDB to use any older
1681 .gdb_index sections it finds. This will restore performance, but the
1682 ability to set breakpoints on inlined functions will be lost in symbol
1683 files with older .gdb_index sections.
1685 The .gdb_index section has also been updated to record more information
1686 about each symbol. This speeds up the "info variables", "info functions"
1687 and "info types" commands when used with programs having the .gdb_index
1688 section, as well as speeding up debugging with shared libraries using
1689 the .gdb_index section.
1691 * Ada support for GDB/MI Variable Objects has been added.
1693 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1698 ** New command -info-os is the MI equivalent of "info os".
1700 ** Output logs ("set logging" and related) now include MI output.
1704 ** "set use-deprecated-index-sections on|off"
1705 "show use-deprecated-index-sections on|off"
1706 Controls the use of deprecated .gdb_index sections.
1708 ** "catch load" and "catch unload" can be used to stop when a shared
1709 library is loaded or unloaded, respectively.
1711 ** "enable count" can be used to auto-disable a breakpoint after
1714 ** "info vtbl" can be used to show the virtual method tables for
1715 C++ and Java objects.
1717 ** "explore" and its sub commands "explore value" and "explore type"
1718 can be used to recursively explore values and types of
1719 expressions. These commands are available only if GDB is
1720 configured with '--with-python'.
1722 ** "info auto-load" shows status of all kinds of auto-loaded files,
1723 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1724 sequences of commands files, "info auto-load python-scripts"
1725 shows status of auto-loading Python script files,
1726 "info auto-load local-gdbinit" shows status of loading init file
1727 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1728 status of inferior specific thread debugging shared library loading.
1730 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1731 and "show auto-load-scripts" commands have been deprecated, use their
1732 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1733 and "show auto-load python-scripts" counterparts instead.
1735 ** "dprintf location,format,args..." creates a dynamic printf, which
1736 is basically a breakpoint that does a printf and immediately
1737 resumes your program's execution, so it is like a printf that you
1738 can insert dynamically at runtime instead of at compiletime.
1740 ** "set print symbol"
1742 Controls whether GDB attempts to display the symbol, if any,
1743 corresponding to addresses it prints. This defaults to "on", but
1744 you can set it to "off" to restore GDB's previous behavior.
1746 * Deprecated commands
1748 ** For the Renesas Super-H architecture, the "regs" command has been
1749 deprecated, and "info all-registers" should be used instead.
1753 Renesas RL78 rl78-*-elf
1754 HP OpenVMS ia64 ia64-hp-openvms*
1756 * GDBserver supports evaluation of breakpoint conditions. When
1757 support is advertised by GDBserver, GDB may be told to send the
1758 breakpoint conditions in bytecode form to GDBserver. GDBserver
1759 will only report the breakpoint trigger to GDB when its condition
1764 set mips compression
1765 show mips compression
1766 Select the compressed ISA encoding used in functions that have no symbol
1767 information available. The encoding can be set to either of:
1770 and is updated automatically from ELF file flags if available.
1772 set breakpoint condition-evaluation
1773 show breakpoint condition-evaluation
1774 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1775 GDBserver ("target"). Default option "auto" chooses the most efficient
1777 This option can improve debugger efficiency depending on the speed of the
1781 Disable auto-loading globally.
1784 Show auto-loading setting of all kinds of auto-loaded files.
1786 set auto-load gdb-scripts on|off
1787 show auto-load gdb-scripts
1788 Control auto-loading of GDB canned sequences of commands files.
1790 set auto-load python-scripts on|off
1791 show auto-load python-scripts
1792 Control auto-loading of Python script files.
1794 set auto-load local-gdbinit on|off
1795 show auto-load local-gdbinit
1796 Control loading of init file (.gdbinit) from current directory.
1798 set auto-load libthread-db on|off
1799 show auto-load libthread-db
1800 Control auto-loading of inferior specific thread debugging shared library.
1802 set auto-load scripts-directory <dir1>[:<dir2>...]
1803 show auto-load scripts-directory
1804 Set a list of directories from which to load auto-loaded scripts.
1805 Automatically loaded Python scripts and GDB scripts are located in one
1806 of the directories listed by this option.
1807 The delimiter (':' above) may differ according to the host platform.
1809 set auto-load safe-path <dir1>[:<dir2>...]
1810 show auto-load safe-path
1811 Set a list of directories from which it is safe to auto-load files.
1812 The delimiter (':' above) may differ according to the host platform.
1814 set debug auto-load on|off
1815 show debug auto-load
1816 Control display of debugging info for auto-loading the files above.
1818 set dprintf-style gdb|call|agent
1820 Control the way in which a dynamic printf is performed; "gdb"
1821 requests a GDB printf command, while "call" causes dprintf to call a
1822 function in the inferior. "agent" requests that the target agent
1823 (such as GDBserver) do the printing.
1825 set dprintf-function <expr>
1826 show dprintf-function
1827 set dprintf-channel <expr>
1828 show dprintf-channel
1829 Set the function and optional first argument to the call when using
1830 the "call" style of dynamic printf.
1832 set disconnected-dprintf on|off
1833 show disconnected-dprintf
1834 Control whether agent-style dynamic printfs continue to be in effect
1835 after GDB disconnects.
1837 * New configure options
1839 --with-auto-load-dir
1840 Configure default value for the 'set auto-load scripts-directory'
1841 setting above. It defaults to '$debugdir:$datadir/auto-load',
1842 $debugdir representing global debugging info directories (available
1843 via 'show debug-file-directory') and $datadir representing GDB's data
1844 directory (available via 'show data-directory').
1846 --with-auto-load-safe-path
1847 Configure default value for the 'set auto-load safe-path' setting
1848 above. It defaults to the --with-auto-load-dir setting.
1850 --without-auto-load-safe-path
1851 Set 'set auto-load safe-path' to '/', effectively disabling this
1854 * New remote packets
1856 z0/z1 conditional breakpoints extension
1858 The z0/z1 breakpoint insertion packets have been extended to carry
1859 a list of conditional expressions over to the remote stub depending on the
1860 condition evaluation mode. The use of this extension can be controlled
1861 via the "set remote conditional-breakpoints-packet" command.
1865 Specify the signals which the remote stub may pass to the debugged
1866 program without GDB involvement.
1868 * New command line options
1870 --init-command=FILE, -ix Like --command, -x but execute it
1871 before loading inferior.
1872 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1873 execute it before loading inferior.
1875 *** Changes in GDB 7.4
1877 * GDB now handles ambiguous linespecs more consistently; the existing
1878 FILE:LINE support has been expanded to other types of linespecs. A
1879 breakpoint will now be set on all matching locations in all
1880 inferiors, and locations will be added or removed according to
1883 * GDB now allows you to skip uninteresting functions and files when
1884 stepping with the "skip function" and "skip file" commands.
1886 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1887 and "show remote hardware-watchpoint-length-limit". These allows to
1888 set or show the maximum length limit (in bytes) of a remote
1889 target hardware watchpoint.
1891 This allows e.g. to use "unlimited" hardware watchpoints with the
1892 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1893 watchpoints are slower than real hardware watchpoints but are
1894 significantly faster than gdb software watchpoints.
1898 ** The register_pretty_printer function in module gdb.printing now takes
1899 an optional `replace' argument. If True, the new printer replaces any
1902 ** The "maint set python print-stack on|off" command has been
1903 deprecated and will be deleted in GDB 7.5.
1904 A new command: "set python print-stack none|full|message" has
1905 replaced it. Additionally, the default for "print-stack" is
1906 now "message", which just prints the error message without
1909 ** A prompt substitution hook (prompt_hook) is now available to the
1912 ** A new Python module, gdb.prompt has been added to the GDB Python
1913 modules library. This module provides functionality for
1914 escape sequences in prompts (used by set/show
1915 extended-prompt). These escape sequences are replaced by their
1916 corresponding value.
1918 ** Python commands and convenience-functions located in
1919 'data-directory'/python/gdb/command and
1920 'data-directory'/python/gdb/function are now automatically loaded
1923 ** Blocks now provide four new attributes. global_block and
1924 static_block will return the global and static blocks
1925 respectively. is_static and is_global are boolean attributes
1926 that indicate if the block is one of those two types.
1928 ** Symbols now provide the "type" attribute, the type of the symbol.
1930 ** The "gdb.breakpoint" function has been deprecated in favor of
1933 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1934 of a function. This class is based on the "finish" command
1935 available in the CLI.
1937 ** Type objects for struct and union types now allow access to
1938 the fields using standard Python dictionary (mapping) methods.
1939 For example, "some_type['myfield']" now works, as does
1940 "some_type.items()".
1942 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1945 ** A new function, "deep_items" has been added to the gdb.types
1946 module in the GDB Python modules library. This function returns
1947 an iterator over the fields of a struct or union type. Unlike
1948 the standard Python "iteritems" method, it will recursively traverse
1949 any anonymous fields.
1953 ** "*stopped" events can report several new "reason"s, such as
1956 ** Breakpoint changes are now notified using new async records, like
1957 "=breakpoint-modified".
1959 ** New command -ada-task-info.
1961 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1962 $sdir specifies the default system locations of shared libraries.
1963 $pdir specifies the directory where the libpthread used by the application
1966 GDB no longer looks in $sdir and $pdir after it has searched the directories
1967 mentioned in libthread-db-search-path. If you want to search those
1968 directories, they must be specified in libthread-db-search-path.
1969 The default value of libthread-db-search-path on GNU/Linux and Solaris
1970 systems is now "$sdir:$pdir".
1972 $pdir is not supported by gdbserver, it is currently ignored.
1973 $sdir is supported by gdbserver.
1975 * New configure option --with-iconv-bin.
1976 When using the internationalization support like the one in the GNU C
1977 library, GDB will invoke the "iconv" program to get a list of supported
1978 character sets. If this program lives in a non-standard location, one can
1979 use this option to specify where to find it.
1981 * When natively debugging programs on PowerPC BookE processors running
1982 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1983 watchpoints, which specify a mask in addition to an address to watch.
1984 The mask specifies that some bits of an address (the bits which are
1985 reset in the mask) should be ignored when matching the address accessed
1986 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1987 section in the user manual for more details.
1989 * The new option --once causes GDBserver to stop listening for connections once
1990 the first connection is made. The listening port used by GDBserver will
1991 become available after that.
1993 * New commands "info macros" and "alias" have been added.
1995 * New function parameters suffix @entry specifies value of function parameter
1996 at the time the function got called. Entry values are available only since
2002 "!" is now an alias of the "shell" command.
2003 Note that no space is needed between "!" and SHELL COMMAND.
2007 watch EXPRESSION mask MASK_VALUE
2008 The watch command now supports the mask argument which allows creation
2009 of masked watchpoints, if the current architecture supports this feature.
2011 info auto-load-scripts [REGEXP]
2012 This command was formerly named "maintenance print section-scripts".
2013 It is now generally useful and is no longer a maintenance-only command.
2015 info macro [-all] [--] MACRO
2016 The info macro command has new options `-all' and `--'. The first for
2017 printing all definitions of a macro. The second for explicitly specifying
2018 the end of arguments and the beginning of the macro name in case the macro
2019 name starts with a hyphen.
2021 collect[/s] EXPRESSIONS
2022 The tracepoint collect command now takes an optional modifier "/s"
2023 that directs it to dereference pointer-to-character types and
2024 collect the bytes of memory up to a zero byte. The behavior is
2025 similar to what you see when you use the regular print command on a
2026 string. An optional integer following the "/s" sets a bound on the
2027 number of bytes that will be collected.
2030 The trace start command now interprets any supplied arguments as a
2031 note to be recorded with the trace run, with an effect similar to
2032 setting the variable trace-notes.
2035 The trace stop command now interprets any arguments as a note to be
2036 mentioned along with the tstatus report that the trace was stopped
2037 with a command. The effect is similar to setting the variable
2040 * Tracepoints can now be enabled and disabled at any time after a trace
2041 experiment has been started using the standard "enable" and "disable"
2042 commands. It is now possible to start a trace experiment with no enabled
2043 tracepoints; GDB will display a warning, but will allow the experiment to
2044 begin, assuming that tracepoints will be enabled as needed while the trace
2047 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2048 locations with 4-byte instructions, when they were previously
2049 limited to locations with instructions of 5 bytes or longer.
2053 set debug dwarf2-read
2054 show debug dwarf2-read
2055 Turns on or off display of debugging messages related to reading
2056 DWARF debug info. The default is off.
2058 set debug symtab-create
2059 show debug symtab-create
2060 Turns on or off display of debugging messages related to symbol table
2061 creation. The default is off.
2064 show extended-prompt
2065 Set the GDB prompt, and allow escape sequences to be inserted to
2066 display miscellaneous information (see 'help set extended-prompt'
2067 for the list of sequences). This prompt (and any information
2068 accessed through the escape sequences) is updated every time the
2069 prompt is displayed.
2071 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2072 show print entry-values
2073 Set printing of frame argument values at function entry. In some cases
2074 GDB can determine the value of function argument which was passed by the
2075 function caller, even if the value was modified inside the called function.
2077 set debug entry-values
2078 show debug entry-values
2079 Control display of debugging info for determining frame argument values at
2080 function entry and virtual tail call frames.
2082 set basenames-may-differ
2083 show basenames-may-differ
2084 Set whether a source file may have multiple base names.
2085 (A "base name" is the name of a file with the directory part removed.
2086 Example: The base name of "/home/user/hello.c" is "hello.c".)
2087 If set, GDB will canonicalize file names (e.g., expand symlinks)
2088 before comparing them. Canonicalization is an expensive operation,
2089 but it allows the same file be known by more than one base name.
2090 If not set (the default), all source files are assumed to have just
2091 one base name, and gdb will do file name comparisons more efficiently.
2097 Set a user name and notes for the current and any future trace runs.
2098 This is useful for long-running and/or disconnected traces, to
2099 inform others (or yourself) as to who is running the trace, supply
2100 contact information, or otherwise explain what is going on.
2102 set trace-stop-notes
2103 show trace-stop-notes
2104 Set a note attached to the trace run, that is displayed when the
2105 trace has been stopped by a tstop command. This is useful for
2106 instance as an explanation, if you are stopping a trace run that was
2107 started by someone else.
2109 * New remote packets
2113 Dynamically enable a tracepoint in a started trace experiment.
2117 Dynamically disable a tracepoint in a started trace experiment.
2121 Set the user and notes of the trace run.
2125 Query the current status of a tracepoint.
2129 Query the minimum length of instruction at which a fast tracepoint may
2132 * Dcache size (number of lines) and line-size are now runtime-configurable
2133 via "set dcache line" and "set dcache line-size" commands.
2137 Texas Instruments TMS320C6x tic6x-*-*
2141 Renesas RL78 rl78-*-elf
2143 *** Changes in GDB 7.3.1
2145 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2147 *** Changes in GDB 7.3
2149 * GDB has a new command: "thread find [REGEXP]".
2150 It finds the thread id whose name, target id, or thread extra info
2151 matches the given regular expression.
2153 * The "catch syscall" command now works on mips*-linux* targets.
2155 * The -data-disassemble MI command now supports modes 2 and 3 for
2156 dumping the instruction opcodes.
2158 * New command line options
2160 -data-directory DIR Specify DIR as the "data-directory".
2161 This is mostly for testing purposes.
2163 * The "maint set python auto-load on|off" command has been renamed to
2164 "set auto-load-scripts on|off".
2166 * GDB has a new command: "set directories".
2167 It is like the "dir" command except that it replaces the
2168 source path list instead of augmenting it.
2170 * GDB now understands thread names.
2172 On GNU/Linux, "info threads" will display the thread name as set by
2173 prctl or pthread_setname_np.
2175 There is also a new command, "thread name", which can be used to
2176 assign a name internally for GDB to display.
2179 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2180 has been integrated into GDB.
2184 ** The function gdb.Write now accepts an optional keyword 'stream'.
2185 This keyword, when provided, will direct the output to either
2186 stdout, stderr, or GDB's logging output.
2188 ** Parameters can now be be sub-classed in Python, and in particular
2189 you may implement the get_set_doc and get_show_doc functions.
2190 This improves how Parameter set/show documentation is processed
2191 and allows for more dynamic content.
2193 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2194 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2195 have an is_valid method.
2197 ** Breakpoints can now be sub-classed in Python, and in particular
2198 you may implement a 'stop' function that is executed each time
2199 the inferior reaches that breakpoint.
2201 ** New function gdb.lookup_global_symbol looks up a global symbol.
2203 ** GDB values in Python are now callable if the value represents a
2204 function. For example, if 'some_value' represents a function that
2205 takes two integer parameters and returns a value, you can call
2206 that function like so:
2208 result = some_value (10,20)
2210 ** Module gdb.types has been added.
2211 It contains a collection of utilities for working with gdb.Types objects:
2212 get_basic_type, has_field, make_enum_dict.
2214 ** Module gdb.printing has been added.
2215 It contains utilities for writing and registering pretty-printers.
2216 New classes: PrettyPrinter, SubPrettyPrinter,
2217 RegexpCollectionPrettyPrinter.
2218 New function: register_pretty_printer.
2220 ** New commands "info pretty-printers", "enable pretty-printer" and
2221 "disable pretty-printer" have been added.
2223 ** gdb.parameter("directories") is now available.
2225 ** New function gdb.newest_frame returns the newest frame in the
2228 ** The gdb.InferiorThread class has a new "name" attribute. This
2229 holds the thread's name.
2231 ** Python Support for Inferior events.
2232 Python scripts can add observers to be notified of events
2233 occurring in the process being debugged.
2234 The following events are currently supported:
2235 - gdb.events.cont Continue event.
2236 - gdb.events.exited Inferior exited event.
2237 - gdb.events.stop Signal received, and Breakpoint hit events.
2241 ** GDB now puts template parameters in scope when debugging in an
2242 instantiation. For example, if you have:
2244 template<int X> int func (void) { return X; }
2246 then if you step into func<5>, "print X" will show "5". This
2247 feature requires proper debuginfo support from the compiler; it
2248 was added to GCC 4.5.
2250 ** The motion commands "next", "finish", "until", and "advance" now
2251 work better when exceptions are thrown. In particular, GDB will
2252 no longer lose control of the inferior; instead, the GDB will
2253 stop the inferior at the point at which the exception is caught.
2254 This functionality requires a change in the exception handling
2255 code that was introduced in GCC 4.5.
2257 * GDB now follows GCC's rules on accessing volatile objects when
2258 reading or writing target state during expression evaluation.
2259 One notable difference to prior behavior is that "print x = 0"
2260 no longer generates a read of x; the value of the assignment is
2261 now always taken directly from the value being assigned.
2263 * GDB now has some support for using labels in the program's source in
2264 linespecs. For instance, you can use "advance label" to continue
2265 execution to a label.
2267 * GDB now has support for reading and writing a new .gdb_index
2268 section. This section holds a fast index of DWARF debugging
2269 information and can be used to greatly speed up GDB startup and
2270 operation. See the documentation for `save gdb-index' for details.
2272 * The "watch" command now accepts an optional "-location" argument.
2273 When used, this causes GDB to watch the memory referred to by the
2274 expression. Such a watchpoint is never deleted due to it going out
2277 * GDB now supports thread debugging of core dumps on GNU/Linux.
2279 GDB now activates thread debugging using the libthread_db library
2280 when debugging GNU/Linux core dumps, similarly to when debugging
2281 live processes. As a result, when debugging a core dump file, GDB
2282 is now able to display pthread_t ids of threads. For example, "info
2283 threads" shows the same output as when debugging the process when it
2284 was live. In earlier releases, you'd see something like this:
2287 * 1 LWP 6780 main () at main.c:10
2289 While now you see this:
2292 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2294 It is also now possible to inspect TLS variables when debugging core
2297 When debugging a core dump generated on a machine other than the one
2298 used to run GDB, you may need to point GDB at the correct
2299 libthread_db library with the "set libthread-db-search-path"
2300 command. See the user manual for more details on this command.
2302 * When natively debugging programs on PowerPC BookE processors running
2303 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2304 which stop execution of the inferior whenever it executes an instruction
2305 at any address within the specified range. See the "PowerPC Embedded"
2306 section in the user manual for more details.
2308 * New features in the GDB remote stub, GDBserver
2310 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2311 and i686 LynxOS (version 5.x).
2313 ** GDBserver is now supported on Blackfin Linux.
2315 * New native configurations
2317 ia64 HP-UX ia64-*-hpux*
2321 Analog Devices, Inc. Blackfin Processor bfin-*
2323 * Ada task switching is now supported on sparc-elf targets when
2324 debugging a program using the Ravenscar Profile. For more information,
2325 see the "Tasking Support when using the Ravenscar Profile" section
2326 in the GDB user manual.
2328 * Guile support was removed.
2330 * New features in the GNU simulator
2332 ** The --map-info flag lists all known core mappings.
2334 ** CFI flashes may be simulated via the "cfi" device.
2336 *** Changes in GDB 7.2
2338 * Shared library support for remote targets by default
2340 When GDB is configured for a generic, non-OS specific target, like
2341 for example, --target=arm-eabi or one of the many *-*-elf targets,
2342 GDB now queries remote stubs for loaded shared libraries using the
2343 `qXfer:libraries:read' packet. Previously, shared library support
2344 was always disabled for such configurations.
2348 ** Argument Dependent Lookup (ADL)
2350 In C++ ADL lookup directs function search to the namespaces of its
2351 arguments even if the namespace has not been imported.
2361 Here the compiler will search for `foo' in the namespace of 'b'
2362 and find A::foo. GDB now supports this. This construct is commonly
2363 used in the Standard Template Library for operators.
2365 ** Improved User Defined Operator Support
2367 In addition to member operators, GDB now supports lookup of operators
2368 defined in a namespace and imported with a `using' directive, operators
2369 defined in the global scope, operators imported implicitly from an
2370 anonymous namespace, and the ADL operators mentioned in the previous
2372 GDB now also supports proper overload resolution for all the previously
2373 mentioned flavors of operators.
2375 ** static const class members
2377 Printing of static const class members that are initialized in the
2378 class definition has been fixed.
2380 * Windows Thread Information Block access.
2382 On Windows targets, GDB now supports displaying the Windows Thread
2383 Information Block (TIB) structure. This structure is visible either
2384 by using the new command `info w32 thread-information-block' or, by
2385 dereferencing the new convenience variable named `$_tlb', a
2386 thread-specific pointer to the TIB. This feature is also supported
2387 when remote debugging using GDBserver.
2389 * Static tracepoints
2391 Static tracepoints are calls in the user program into a tracing
2392 library. One such library is a port of the LTTng kernel tracer to
2393 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2394 When debugging with GDBserver, GDB now supports combining the GDB
2395 tracepoint machinery with such libraries. For example: the user can
2396 use GDB to probe a static tracepoint marker (a call from the user
2397 program into the tracing library) with the new "strace" command (see
2398 "New commands" below). This creates a "static tracepoint" in the
2399 breakpoint list, that can be manipulated with the same feature set
2400 as fast and regular tracepoints. E.g., collect registers, local and
2401 global variables, collect trace state variables, and define
2402 tracepoint conditions. In addition, the user can collect extra
2403 static tracepoint marker specific data, by collecting the new
2404 $_sdata internal variable. When analyzing the trace buffer, you can
2405 inspect $_sdata like any other variable available to GDB. For more
2406 information, see the "Tracepoints" chapter in GDB user manual. New
2407 remote packets have been defined to support static tracepoints, see
2408 the "New remote packets" section below.
2410 * Better reconstruction of tracepoints after disconnected tracing
2412 GDB will attempt to download the original source form of tracepoint
2413 definitions when starting a trace run, and then will upload these
2414 upon reconnection to the target, resulting in a more accurate
2415 reconstruction of the tracepoints that are in use on the target.
2419 You can now exercise direct control over the ways that GDB can
2420 affect your program. For instance, you can disallow the setting of
2421 breakpoints, so that the program can run continuously (assuming
2422 non-stop mode). In addition, the "observer" variable is available
2423 to switch all of the different controls; in observer mode, GDB
2424 cannot affect the target's behavior at all, which is useful for
2425 tasks like diagnosing live systems in the field.
2427 * The new convenience variable $_thread holds the number of the
2430 * New remote packets
2434 Return the address of the Windows Thread Information Block of a given thread.
2438 In response to several of the tracepoint packets, the target may now
2439 also respond with a number of intermediate `qRelocInsn' request
2440 packets before the final result packet, to have GDB handle
2441 relocating an instruction to execute at a different address. This
2442 is particularly useful for stubs that support fast tracepoints. GDB
2443 reports support for this feature in the qSupported packet.
2447 List static tracepoint markers in the target program.
2451 List static tracepoint markers at a given address in the target
2454 qXfer:statictrace:read
2456 Read the static trace data collected (by a `collect $_sdata'
2457 tracepoint action). The remote stub reports support for this packet
2458 to gdb's qSupported query.
2462 Send the current settings of GDB's permission flags.
2466 Send part of the source (textual) form of a tracepoint definition,
2467 which includes location, conditional, and action list.
2469 * The source command now accepts a -s option to force searching for the
2470 script in the source search path even if the script name specifies
2473 * New features in the GDB remote stub, GDBserver
2475 - GDBserver now support tracepoints (including fast tracepoints, and
2476 static tracepoints). The feature is currently supported by the
2477 i386-linux and amd64-linux builds. See the "Tracepoints support
2478 in gdbserver" section in the manual for more information.
2480 GDBserver JIT compiles the tracepoint's conditional agent
2481 expression bytecode into native code whenever possible for low
2482 overhead dynamic tracepoints conditionals. For such tracepoints,
2483 an expression that examines program state is evaluated when the
2484 tracepoint is reached, in order to determine whether to capture
2485 trace data. If the condition is simple and false, processing the
2486 tracepoint finishes very quickly and no data is gathered.
2488 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2489 for static tracepoints support.
2491 - GDBserver now supports x86_64 Windows 64-bit debugging.
2493 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2494 it understands register description.
2496 * The --batch flag now disables pagination and queries.
2498 * X86 general purpose registers
2500 GDB now supports reading/writing byte, word and double-word x86
2501 general purpose registers directly. This means you can use, say,
2502 $ah or $ax to refer, respectively, to the byte register AH and
2503 16-bit word register AX that are actually portions of the 32-bit
2504 register EAX or 64-bit register RAX.
2506 * The `commands' command now accepts a range of breakpoints to modify.
2507 A plain `commands' following a command that creates multiple
2508 breakpoints affects all the breakpoints set by that command. This
2509 applies to breakpoints set by `rbreak', and also applies when a
2510 single `break' command creates multiple breakpoints (e.g.,
2511 breakpoints on overloaded c++ functions).
2513 * The `rbreak' command now accepts a filename specification as part of
2514 its argument, limiting the functions selected by the regex to those
2515 in the specified file.
2517 * Support for remote debugging Windows and SymbianOS shared libraries
2518 from Unix hosts has been improved. Non Windows GDB builds now can
2519 understand target reported file names that follow MS-DOS based file
2520 system semantics, such as file names that include drive letters and
2521 use the backslash character as directory separator. This makes it
2522 possible to transparently use the "set sysroot" and "set
2523 solib-search-path" on Unix hosts to point as host copies of the
2524 target's shared libraries. See the new command "set
2525 target-file-system-kind" described below, and the "Commands to
2526 specify files" section in the user manual for more information.
2530 eval template, expressions...
2531 Convert the values of one or more expressions under the control
2532 of the string template to a command line, and call it.
2534 set target-file-system-kind unix|dos-based|auto
2535 show target-file-system-kind
2536 Set or show the assumed file system kind for target reported file
2539 save breakpoints <filename>
2540 Save all current breakpoint definitions to a file suitable for use
2541 in a later debugging session. To read the saved breakpoint
2542 definitions, use the `source' command.
2544 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2547 info static-tracepoint-markers
2548 Display information about static tracepoint markers in the target.
2550 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2551 Define a static tracepoint by probing a marker at the given
2552 function, line, address, or marker ID.
2556 Enable and disable observer mode.
2558 set may-write-registers on|off
2559 set may-write-memory on|off
2560 set may-insert-breakpoints on|off
2561 set may-insert-tracepoints on|off
2562 set may-insert-fast-tracepoints on|off
2563 set may-interrupt on|off
2564 Set individual permissions for GDB effects on the target. Note that
2565 some of these settings can have undesirable or surprising
2566 consequences, particularly when changed in the middle of a session.
2567 For instance, disabling the writing of memory can prevent
2568 breakpoints from being inserted, cause single-stepping to fail, or
2569 even crash your program, if you disable after breakpoints have been
2570 inserted. However, GDB should not crash.
2572 set record memory-query on|off
2573 show record memory-query
2574 Control whether to stop the inferior if memory changes caused
2575 by an instruction cannot be recorded.
2580 The disassemble command now supports "start,+length" form of two arguments.
2584 ** GDB now provides a new directory location, called the python directory,
2585 where Python scripts written for GDB can be installed. The location
2586 of that directory is <data-directory>/python, where <data-directory>
2587 is the GDB data directory. For more details, see section `Scripting
2588 GDB using Python' in the manual.
2590 ** The GDB Python API now has access to breakpoints, symbols, symbol
2591 tables, program spaces, inferiors, threads and frame's code blocks.
2592 Additionally, GDB Parameters can now be created from the API, and
2593 manipulated via set/show in the CLI.
2595 ** New functions gdb.target_charset, gdb.target_wide_charset,
2596 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2598 ** New exception gdb.GdbError.
2600 ** Pretty-printers are now also looked up in the current program space.
2602 ** Pretty-printers can now be individually enabled and disabled.
2604 ** GDB now looks for names of Python scripts to auto-load in a
2605 special section named `.debug_gdb_scripts', in addition to looking
2606 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2608 * Tracepoint actions were unified with breakpoint commands. In particular,
2609 there are no longer differences in "info break" output for breakpoints and
2610 tracepoints and the "commands" command can be used for both tracepoints and
2611 regular breakpoints.
2615 ARM Symbian arm*-*-symbianelf*
2617 * D language support.
2618 GDB now supports debugging programs written in the D programming
2621 * GDB now supports the extended ptrace interface for PowerPC which is
2622 available since Linux kernel version 2.6.34. This automatically enables
2623 any hardware breakpoints and additional hardware watchpoints available in
2624 the processor. The old ptrace interface exposes just one hardware
2625 watchpoint and no hardware breakpoints.
2627 * GDB is now able to use the Data Value Compare (DVC) register available on
2628 embedded PowerPC processors to implement in hardware simple watchpoint
2629 conditions of the form:
2631 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2633 This works in native GDB running on Linux kernels with the extended ptrace
2634 interface mentioned above.
2636 *** Changes in GDB 7.1
2640 ** Namespace Support
2642 GDB now supports importing of namespaces in C++. This enables the
2643 user to inspect variables from imported namespaces. Support for
2644 namepace aliasing has also been added. So, if a namespace is
2645 aliased in the current scope (e.g. namepace C=A; ) the user can
2646 print variables using the alias (e.g. (gdb) print C::x).
2650 All known bugs relating to the printing of virtual base class were
2651 fixed. It is now possible to call overloaded static methods using a
2656 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2657 and reinterpret_cast<> are now handled by the C++ expression parser.
2661 Xilinx MicroBlaze microblaze-*-*
2666 Xilinx MicroBlaze microblaze
2669 * Multi-program debugging.
2671 GDB now has support for multi-program (a.k.a. multi-executable or
2672 multi-exec) debugging. This allows for debugging multiple inferiors
2673 simultaneously each running a different program under the same GDB
2674 session. See "Debugging Multiple Inferiors and Programs" in the
2675 manual for more information. This implied some user visible changes
2676 in the multi-inferior support. For example, "info inferiors" now
2677 lists inferiors that are not running yet or that have exited
2678 already. See also "New commands" and "New options" below.
2680 * New tracing features
2682 GDB's tracepoint facility now includes several new features:
2684 ** Trace state variables
2686 GDB tracepoints now include support for trace state variables, which
2687 are variables managed by the target agent during a tracing
2688 experiment. They are useful for tracepoints that trigger each
2689 other, so for instance one tracepoint can count hits in a variable,
2690 and then a second tracepoint has a condition that is true when the
2691 count reaches a particular value. Trace state variables share the
2692 $-syntax of GDB convenience variables, and can appear in both
2693 tracepoint actions and condition expressions. Use the "tvariable"
2694 command to create, and "info tvariables" to view; see "Trace State
2695 Variables" in the manual for more detail.
2699 GDB now includes an option for defining fast tracepoints, which
2700 targets may implement more efficiently, such as by installing a jump
2701 into the target agent rather than a trap instruction. The resulting
2702 speedup can be by two orders of magnitude or more, although the
2703 tradeoff is that some program locations on some target architectures
2704 might not allow fast tracepoint installation, for instance if the
2705 instruction to be replaced is shorter than the jump. To request a
2706 fast tracepoint, use the "ftrace" command, with syntax identical to
2707 the regular trace command.
2709 ** Disconnected tracing
2711 It is now possible to detach GDB from the target while it is running
2712 a trace experiment, then reconnect later to see how the experiment
2713 is going. In addition, a new variable disconnected-tracing lets you
2714 tell the target agent whether to continue running a trace if the
2715 connection is lost unexpectedly.
2719 GDB now has the ability to save the trace buffer into a file, and
2720 then use that file as a target, similarly to you can do with
2721 corefiles. You can select trace frames, print data that was
2722 collected in them, and use tstatus to display the state of the
2723 tracing run at the moment that it was saved. To create a trace
2724 file, use "tsave <filename>", and to use it, do "target tfile
2727 ** Circular trace buffer
2729 You can ask the target agent to handle the trace buffer as a
2730 circular buffer, discarding the oldest trace frames to make room for
2731 newer ones, by setting circular-trace-buffer to on. This feature may
2732 not be available for all target agents.
2737 The disassemble command, when invoked with two arguments, now requires
2738 the arguments to be comma-separated.
2741 The info variables command now displays variable definitions. Files
2742 which only declare a variable are not shown.
2745 The source command is now capable of sourcing Python scripts.
2746 This feature is dependent on the debugger being build with Python
2749 Related to this enhancement is also the introduction of a new command
2750 "set script-extension" (see below).
2752 * New commands (for set/show, see "New options" below)
2754 record save [<FILENAME>]
2755 Save a file (in core file format) containing the process record
2756 execution log for replay debugging at a later time.
2758 record restore <FILENAME>
2759 Restore the process record execution log that was saved at an
2760 earlier time, for replay debugging.
2762 add-inferior [-copies <N>] [-exec <FILENAME>]
2765 clone-inferior [-copies <N>] [ID]
2766 Make a new inferior ready to execute the same program another
2767 inferior has loaded.
2772 maint info program-spaces
2773 List the program spaces loaded into GDB.
2775 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2776 show remote interrupt-sequence
2777 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2778 as the sequence to the remote target in order to interrupt the execution.
2779 Ctrl-C is a default. Some system prefers BREAK which is high level of
2780 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2781 Magic SysRq g. It is BREAK signal and character 'g'.
2783 set remote interrupt-on-connect [on | off]
2784 show remote interrupt-on-connect
2785 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2786 remote target when gdb connects to it. This is needed when you debug
2789 set remotebreak [on | off]
2791 Deprecated. Use "set/show remote interrupt-sequence" instead.
2793 tvariable $NAME [ = EXP ]
2794 Create or modify a trace state variable.
2797 List trace state variables and their values.
2799 delete tvariable $NAME ...
2800 Delete one or more trace state variables.
2803 Evaluate the given expressions without collecting anything into the
2804 trace buffer. (Valid in tracepoint actions only.)
2806 ftrace FN / FILE:LINE / *ADDR
2807 Define a fast tracepoint at the given function, line, or address.
2809 * New expression syntax
2811 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2812 GDB now parses 0b101010 identically with 42.
2816 set follow-exec-mode new|same
2817 show follow-exec-mode
2818 Control whether GDB reuses the same inferior across an exec call or
2819 creates a new one. This is useful to be able to restart the old
2820 executable after the inferior having done an exec call.
2822 set default-collect EXPR, ...
2823 show default-collect
2824 Define a list of expressions to be collected at each tracepoint.
2825 This is a useful way to ensure essential items are not overlooked,
2826 such as registers or a critical global variable.
2828 set disconnected-tracing
2829 show disconnected-tracing
2830 If set to 1, the target is instructed to continue tracing if it
2831 loses its connection to GDB. If 0, the target is to stop tracing
2834 set circular-trace-buffer
2835 show circular-trace-buffer
2836 If set to on, the target is instructed to use a circular trace buffer
2837 and discard the oldest trace frames instead of stopping the trace due
2838 to a full trace buffer. If set to off, the trace stops when the buffer
2839 fills up. Some targets may not support this.
2841 set script-extension off|soft|strict
2842 show script-extension
2843 If set to "off", the debugger does not perform any script language
2844 recognition, and all sourced files are assumed to be GDB scripts.
2845 If set to "soft" (the default), files are sourced according to
2846 filename extension, falling back to GDB scripts if the first
2848 If set to "strict", files are sourced according to filename extension.
2850 set ada trust-PAD-over-XVS on|off
2851 show ada trust-PAD-over-XVS
2852 If off, activate a workaround against a bug in the debugging information
2853 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2854 the GCC sources for more information about the GNAT encoding and
2855 PAD types in particular). It is always safe to set this option to
2856 off, but this introduces a slight performance penalty. The default
2859 * Python API Improvements
2861 ** GDB provides the new class gdb.LazyString. This is useful in
2862 some pretty-printing cases. The new method gdb.Value.lazy_string
2863 provides a simple way to create objects of this type.
2865 ** The fields returned by gdb.Type.fields now have an
2866 `is_base_class' attribute.
2868 ** The new method gdb.Type.range returns the range of an array type.
2870 ** The new method gdb.parse_and_eval can be used to parse and
2871 evaluate an expression.
2873 * New remote packets
2876 Define a trace state variable.
2879 Get the current value of a trace state variable.
2882 Set desired tracing behavior upon disconnection.
2885 Set the trace buffer to be linear or circular.
2888 Get data about the tracepoints currently in use.
2892 Process record now works correctly with hardware watchpoints.
2894 Multiple bug fixes have been made to the mips-irix port, making it
2895 much more reliable. In particular:
2896 - Debugging threaded applications is now possible again. Previously,
2897 GDB would hang while starting the program, or while waiting for
2898 the program to stop at a breakpoint.
2899 - Attaching to a running process no longer hangs.
2900 - An error occurring while loading a core file has been fixed.
2901 - Changing the value of the PC register now works again. This fixes
2902 problems observed when using the "jump" command, or when calling
2903 a function from GDB, or even when assigning a new value to $pc.
2904 - With the "finish" and "return" commands, the return value for functions
2905 returning a small array is now correctly printed.
2906 - It is now possible to break on shared library code which gets executed
2907 during a shared library init phase (code executed while executing
2908 their .init section). Previously, the breakpoint would have no effect.
2909 - GDB is now able to backtrace through the signal handler for
2910 non-threaded programs.
2912 PIE (Position Independent Executable) programs debugging is now supported.
2913 This includes debugging execution of PIC (Position Independent Code) shared
2914 libraries although for that, it should be possible to run such libraries as an
2917 *** Changes in GDB 7.0
2919 * GDB now has an interface for JIT compilation. Applications that
2920 dynamically generate code can create symbol files in memory and register
2921 them with GDB. For users, the feature should work transparently, and
2922 for JIT developers, the interface is documented in the GDB manual in the
2923 "JIT Compilation Interface" chapter.
2925 * Tracepoints may now be conditional. The syntax is as for
2926 breakpoints; either an "if" clause appended to the "trace" command,
2927 or the "condition" command is available. GDB sends the condition to
2928 the target for evaluation using the same bytecode format as is used
2929 for tracepoint actions.
2931 * The disassemble command now supports: an optional /r modifier, print the
2932 raw instructions in hex as well as in symbolic form, and an optional /m
2933 modifier to print mixed source+assembly.
2935 * Process record and replay
2937 In a architecture environment that supports ``process record and
2938 replay'', ``process record and replay'' target can record a log of
2939 the process execution, and replay it with both forward and reverse
2942 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2943 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2944 set execution-direction {forward|reverse}, for targets that support
2947 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2948 feature is available with a native GDB running on kernel version
2951 * GDB now has support for multi-byte and wide character sets on the
2952 target. Strings whose character type is wchar_t, char16_t, or
2953 char32_t are now correctly printed. GDB supports wide- and unicode-
2954 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2955 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2956 `printf'. This feature requires iconv to work properly; if your
2957 system does not have a working iconv, GDB can use GNU libiconv. See
2958 the installation instructions for more information.
2960 * GDB now supports automatic retrieval of shared library files from
2961 remote targets. To use this feature, specify a system root that begins
2962 with the `remote:' prefix, either via the `set sysroot' command or via
2963 the `--with-sysroot' configure-time option.
2965 * "info sharedlibrary" now takes an optional regex of libraries to show,
2966 and it now reports if a shared library has no debugging information.
2968 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2969 now complete on file names.
2971 * When completing in expressions, gdb will attempt to limit
2972 completions to allowable structure or union fields, where appropriate.
2973 For instance, consider:
2975 # struct example { int f1; double f2; };
2976 # struct example variable;
2979 If the user types TAB at the end of this command line, the available
2980 completions will be "f1" and "f2".
2982 * Inlined functions are now supported. They show up in backtraces, and
2983 the "step", "next", and "finish" commands handle them automatically.
2985 * GDB now supports the token-splicing (##) and stringification (#)
2986 operators when expanding macros. It also supports variable-arity
2989 * GDB now supports inspecting extra signal information, exported by
2990 the new $_siginfo convenience variable. The feature is currently
2991 implemented on linux ARM, i386 and amd64.
2993 * GDB can now display the VFP floating point registers and NEON vector
2994 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2995 can provide these registers (requires Linux 2.6.30 or later). Remote
2996 and simulator targets may also provide them.
2998 * New remote packets
3001 Search memory for a sequence of bytes.
3004 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3005 operation over reliable transport links. Use of this packet is
3006 controlled by the `set remote noack-packet' command.
3009 Kill the process with the specified process ID. Use this in preference
3010 to `k' when multiprocess protocol extensions are supported.
3013 Obtains additional operating system information
3017 Read or write additional signal information.
3019 * Removed remote protocol undocumented extension
3021 An undocumented extension to the remote protocol's `S' stop reply
3022 packet that permited the stub to pass a process id was removed.
3023 Remote servers should use the `T' stop reply packet instead.
3025 * GDB now supports multiple function calling conventions according to the
3026 DWARF-2 DW_AT_calling_convention function attribute.
3028 * The SH target utilizes the aforementioned change to distinguish between gcc
3029 and Renesas calling convention. It also adds the new CLI commands
3030 `set/show sh calling-convention'.
3032 * GDB can now read compressed debug sections, as produced by GNU gold
3033 with the --compress-debug-sections=zlib flag.
3035 * 64-bit core files are now supported on AIX.
3037 * Thread switching is now supported on Tru64.
3039 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3040 which will be allocated using malloc later in program execution.
3042 * The qXfer:libraries:read remote procotol packet now allows passing a
3043 list of section offsets.
3045 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3046 conditions handling signals delivered during attach or thread creation
3047 have also been fixed.
3049 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3050 From the user's standpoint, all unqualified instances of True and False
3051 are treated as the standard definitions, regardless of context.
3053 * GDB now parses C++ symbol and type names more flexibly. For
3056 template<typename T> class C { };
3059 GDB will now correctly handle all of:
3061 ptype C<char const *>
3062 ptype C<char const*>
3063 ptype C<const char *>
3064 ptype C<const char*>
3066 * New features in the GDB remote stub, gdbserver
3068 - The "--wrapper" command-line argument tells gdbserver to use a
3069 wrapper program to launch programs for debugging.
3071 - On PowerPC and S/390 targets, it is now possible to use a single
3072 gdbserver executable to debug both 32-bit and 64-bit programs.
3073 (This requires gdbserver itself to be built as a 64-bit executable.)
3075 - gdbserver uses the new noack protocol mode for TCP connections to
3076 reduce communications latency, if also supported and enabled in GDB.
3078 - Support for the sparc64-linux-gnu target is now included in
3081 - The amd64-linux build of gdbserver now supports debugging both
3082 32-bit and 64-bit programs.
3084 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3085 now support hardware watchpoints, and will use them automatically
3090 GDB now has support for scripting using Python. Whether this is
3091 available is determined at configure time.
3093 New GDB commands can now be written in Python.
3095 * Ada tasking support
3097 Ada tasks can now be inspected in GDB. The following commands have
3101 Print the list of Ada tasks.
3103 Print detailed information about task number N.
3105 Print the task number of the current task.
3107 Switch the context of debugging to task number N.
3109 * Support for user-defined prefixed commands. The "define" command can
3110 add new commands to existing prefixes, e.g. "target".
3112 * Multi-inferior, multi-process debugging.
3114 GDB now has generalized support for multi-inferior debugging. See
3115 "Debugging Multiple Inferiors" in the manual for more information.
3116 Although availability still depends on target support, the command
3117 set is more uniform now. The GNU/Linux specific multi-forks support
3118 has been migrated to this new framework. This implied some user
3119 visible changes; see "New commands" and also "Removed commands"
3122 * Target descriptions can now describe the target OS ABI. See the
3123 "Target Description Format" section in the user manual for more
3126 * Target descriptions can now describe "compatible" architectures
3127 to indicate that the target can execute applications for a different
3128 architecture in addition to those for the main target architecture.
3129 See the "Target Description Format" section in the user manual for
3132 * Multi-architecture debugging.
3134 GDB now includes general supports for debugging applications on
3135 hybrid systems that use more than one single processor architecture
3136 at the same time. Each such hybrid architecture still requires
3137 specific support to be added. The only hybrid architecture supported
3138 in this version of GDB is the Cell Broadband Engine.
3140 * GDB now supports integrated debugging of Cell/B.E. applications that
3141 use both the PPU and SPU architectures. To enable support for hybrid
3142 Cell/B.E. debugging, you need to configure GDB to support both the
3143 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3144 --enable-targets configure option.
3146 * Non-stop mode debugging.
3148 For some targets, GDB now supports an optional mode of operation in
3149 which you can examine stopped threads while other threads continue
3150 to execute freely. This is referred to as non-stop mode, with the
3151 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3152 section in the user manual for more information.
3154 To be able to support remote non-stop debugging, a remote stub needs
3155 to implement the non-stop mode remote protocol extensions, as
3156 described in the "Remote Non-Stop" section of the user manual. The
3157 GDB remote stub, gdbserver, has been adjusted to support these
3158 extensions on linux targets.
3160 * New commands (for set/show, see "New options" below)
3162 catch syscall [NAME(S) | NUMBER(S)]
3163 Catch system calls. Arguments, which should be names of system
3164 calls or their numbers, mean catch only those syscalls. Without
3165 arguments, every syscall will be caught. When the inferior issues
3166 any of the specified syscalls, GDB will stop and announce the system
3167 call, both when it is called and when its call returns. This
3168 feature is currently available with a native GDB running on the
3169 Linux Kernel, under the following architectures: x86, x86_64,
3170 PowerPC and PowerPC64.
3172 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3174 Search memory for a sequence of bytes.
3176 maint set python print-stack
3177 maint show python print-stack
3178 Show a stack trace when an error is encountered in a Python script.
3181 Invoke CODE by passing it to the Python interpreter.
3186 These allow macros to be defined, undefined, and listed
3190 Show operating system information about processes.
3193 List the inferiors currently under GDB's control.
3196 Switch focus to inferior number NUM.
3199 Detach from inferior number NUM.
3202 Kill inferior number NUM.
3206 set spu stop-on-load
3207 show spu stop-on-load
3208 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3210 set spu auto-flush-cache
3211 show spu auto-flush-cache
3212 Control whether to automatically flush the software-managed cache
3213 during Cell/B.E. debugging.
3215 set sh calling-convention
3216 show sh calling-convention
3217 Control the calling convention used when calling SH target functions.
3220 show debug timestamp
3221 Control display of timestamps with GDB debugging output.
3223 set disassemble-next-line
3224 show disassemble-next-line
3225 Control display of disassembled source lines or instructions when
3228 set remote noack-packet
3229 show remote noack-packet
3230 Set/show the use of remote protocol QStartNoAckMode packet. See above
3231 under "New remote packets."
3233 set remote query-attached-packet
3234 show remote query-attached-packet
3235 Control use of remote protocol `qAttached' (query-attached) packet.
3237 set remote read-siginfo-object
3238 show remote read-siginfo-object
3239 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3242 set remote write-siginfo-object
3243 show remote write-siginfo-object
3244 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3247 set remote reverse-continue
3248 show remote reverse-continue
3249 Control use of remote protocol 'bc' (reverse-continue) packet.
3251 set remote reverse-step
3252 show remote reverse-step
3253 Control use of remote protocol 'bs' (reverse-step) packet.
3255 set displaced-stepping
3256 show displaced-stepping
3257 Control displaced stepping mode. Displaced stepping is a way to
3258 single-step over breakpoints without removing them from the debuggee.
3259 Also known as "out-of-line single-stepping".
3262 show debug displaced
3263 Control display of debugging info for displaced stepping.
3265 maint set internal-error
3266 maint show internal-error
3267 Control what GDB does when an internal error is detected.
3269 maint set internal-warning
3270 maint show internal-warning
3271 Control what GDB does when an internal warning is detected.
3276 Use a wrapper program to launch programs for debugging.
3278 set multiple-symbols (all|ask|cancel)
3279 show multiple-symbols
3280 The value of this variable can be changed to adjust the debugger behavior
3281 when an expression or a breakpoint location contains an ambiguous symbol
3282 name (an overloaded function name, for instance).
3284 set breakpoint always-inserted
3285 show breakpoint always-inserted
3286 Keep breakpoints always inserted in the target, as opposed to inserting
3287 them when resuming the target, and removing them when the target stops.
3288 This option can improve debugger performance on slow remote targets.
3290 set arm fallback-mode (arm|thumb|auto)
3291 show arm fallback-mode
3292 set arm force-mode (arm|thumb|auto)
3294 These commands control how ARM GDB determines whether instructions
3295 are ARM or Thumb. The default for both settings is auto, which uses
3296 the current CPSR value for instructions without symbols; previous
3297 versions of GDB behaved as if "set arm fallback-mode arm".
3299 set disable-randomization
3300 show disable-randomization
3301 Standalone programs run with the virtual address space randomization enabled
3302 by default on some platforms. This option keeps the addresses stable across
3303 multiple debugging sessions.
3307 Control whether other threads are stopped or not when some thread hits
3312 Requests that asynchronous execution is enabled in the target, if available.
3313 In this case, it's possible to resume target in the background, and interact
3314 with GDB while the target is running. "show target-async" displays the
3315 current state of asynchronous execution of the target.
3317 set target-wide-charset
3318 show target-wide-charset
3319 The target-wide-charset is the name of the character set that GDB
3320 uses when printing characters whose type is wchar_t.
3322 set tcp auto-retry (on|off)
3324 set tcp connect-timeout
3325 show tcp connect-timeout
3326 These commands allow GDB to retry failed TCP connections to a remote stub
3327 with a specified timeout period; this is useful if the stub is launched
3328 in parallel with GDB but may not be ready to accept connections immediately.
3330 set libthread-db-search-path
3331 show libthread-db-search-path
3332 Control list of directories which GDB will search for appropriate
3335 set schedule-multiple (on|off)
3336 show schedule-multiple
3337 Allow GDB to resume all threads of all processes or only threads of
3338 the current process.
3342 Use more aggressive caching for accesses to the stack. This improves
3343 performance of remote debugging (particularly backtraces) without
3344 affecting correctness.
3346 set interactive-mode (on|off|auto)
3347 show interactive-mode
3348 Control whether GDB runs in interactive mode (on) or not (off).
3349 When in interactive mode, GDB waits for the user to answer all
3350 queries. Otherwise, GDB does not wait and assumes the default
3351 answer. When set to auto (the default), GDB determines which
3352 mode to use based on the stdin settings.
3357 For program forks, this is replaced by the new more generic `info
3358 inferiors' command. To list checkpoints, you can still use the
3359 `info checkpoints' command, which was an alias for the `info forks'
3363 Replaced by the new `inferior' command. To switch between
3364 checkpoints, you can still use the `restart' command, which was an
3365 alias for the `fork' command.
3368 This is removed, since some targets don't have a notion of
3369 processes. To switch between processes, you can still use the
3370 `inferior' command using GDB's own inferior number.
3373 For program forks, this is replaced by the new more generic `kill
3374 inferior' command. To delete a checkpoint, you can still use the
3375 `delete checkpoint' command, which was an alias for the `delete
3379 For program forks, this is replaced by the new more generic `detach
3380 inferior' command. To detach a checkpoint, you can still use the
3381 `detach checkpoint' command, which was an alias for the `detach
3384 * New native configurations
3386 x86/x86_64 Darwin i[34567]86-*-darwin*
3388 x86_64 MinGW x86_64-*-mingw*
3392 Lattice Mico32 lm32-*
3393 x86 DICOS i[34567]86-*-dicos*
3394 x86_64 DICOS x86_64-*-dicos*
3397 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3398 (mingw32ce) debugging.
3404 These commands were actually not implemented on any target.
3406 *** Changes in GDB 6.8
3408 * New native configurations
3410 NetBSD/hppa hppa*-*netbsd*
3411 Xtensa GNU/Linux xtensa*-*-linux*
3415 NetBSD/hppa hppa*-*-netbsd*
3416 Xtensa GNU/Lunux xtensa*-*-linux*
3418 * Change in command line behavior -- corefiles vs. process ids.
3420 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3421 attaching to process NUMBER fails, GDB no longer attempts to open a
3422 core file named NUMBER. Attaching to a program using the -c option
3423 is no longer supported. Instead, use the '-p' or '--pid' options.
3425 * GDB can now be built as a native debugger for debugging Windows x86
3426 (mingw32) Portable Executable (PE) programs.
3428 * Pending breakpoints no longer change their number when their address
3431 * GDB now supports breakpoints with multiple locations,
3432 including breakpoints on C++ constructors, inside C++ templates,
3433 and in inlined functions.
3435 * GDB's ability to debug optimized code has been improved. GDB more
3436 accurately identifies function bodies and lexical blocks that occupy
3437 more than one contiguous range of addresses.
3439 * Target descriptions can now describe registers for PowerPC.
3441 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3442 registers on PowerPC targets.
3444 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3445 targets even when the libthread_db library is not available.
3447 * The GDB remote stub, gdbserver, now supports the new file transfer
3448 commands (remote put, remote get, and remote delete).
3450 * The GDB remote stub, gdbserver, now supports run and attach in
3451 extended-remote mode.
3453 * hppa*64*-*-hpux11* target broken
3454 The debugger is unable to start a program and fails with the following
3455 error: "Error trying to get information about dynamic linker".
3456 The gdb-6.7 release is also affected.
3458 * GDB now supports the --enable-targets= configure option to allow
3459 building a single GDB executable that supports multiple remote
3460 target architectures.
3462 * GDB now supports debugging C and C++ programs which use the
3463 Decimal Floating Point extension. In addition, the PowerPC target
3464 now has a set of pseudo-registers to inspect decimal float values
3465 stored in two consecutive float registers.
3467 * The -break-insert MI command can optionally create pending
3470 * Improved support for debugging Ada
3471 Many improvements to the Ada language support have been made. These
3473 - Better support for Ada2005 interface types
3474 - Improved handling of arrays and slices in general
3475 - Better support for Taft-amendment types
3476 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3478 - Improved command completion in Ada
3481 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3486 set print frame-arguments (all|scalars|none)
3487 show print frame-arguments
3488 The value of this variable can be changed to control which argument
3489 values should be printed by the debugger when displaying a frame.
3494 Transfer files to and from a remote target, and delete remote files.
3501 Transfer files to and from a remote target, and delete remote files.
3503 * New remote packets
3510 Open, close, read, write, and delete files on the remote system.
3513 Attach to an existing process on the remote system, in extended-remote
3517 Run a new process on the remote system, in extended-remote mode.
3519 *** Changes in GDB 6.7
3521 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3522 bfd, libiberty and opcodes, as revealed by static analysis donated by
3523 Coverity, Inc. (http://scan.coverity.com).
3525 * When looking up multiply-defined global symbols, GDB will now prefer the
3526 symbol definition in the current shared library if it was built using the
3527 -Bsymbolic linker option.
3529 * When the Text User Interface (TUI) is not configured, GDB will now
3530 recognize the -tui command-line option and print a message that the TUI
3533 * The GDB remote stub, gdbserver, now has lower overhead for high
3534 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3536 * GDB for MIPS targets now autodetects whether a remote target provides
3537 32-bit or 64-bit register values.
3539 * Support for C++ member pointers has been improved.
3541 * GDB now understands XML target descriptions, which specify the
3542 target's overall architecture. GDB can read a description from
3543 a local file or over the remote serial protocol.
3545 * Vectors of single-byte data use a new integer type which is not
3546 automatically displayed as character or string data.
3548 * The /s format now works with the print command. It displays
3549 arrays of single-byte integers and pointers to single-byte integers
3552 * Target descriptions can now describe target-specific registers,
3553 for architectures which have implemented the support (currently
3554 only ARM, M68K, and MIPS).
3556 * GDB and the GDB remote stub, gdbserver, now support the XScale
3559 * The GDB remote stub, gdbserver, has been updated to support
3560 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3561 has been rewritten to use the standard GDB remote protocol.
3563 * GDB can now step into C++ functions which are called through thunks.
3565 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3567 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3568 layout. It also supports a TextSeg= and DataSeg= response when only
3569 segment base addresses (rather than offsets) are available.
3571 * The /i format now outputs any trailing branch delay slot instructions
3572 immediately following the last instruction within the count specified.
3574 * The GDB remote protocol "T" stop reply packet now supports a
3575 "library" response. Combined with the new "qXfer:libraries:read"
3576 packet, this response allows GDB to debug shared libraries on targets
3577 where the operating system manages the list of loaded libraries (e.g.
3578 Windows and SymbianOS).
3580 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3581 (DLLs) on Windows and Windows CE targets.
3583 * GDB now supports a faster verification that a .debug file matches its binary
3584 according to its build-id signature, if the signature is present.
3590 Enable or disable hardware flow control (RTS/CTS) on the serial port
3591 when debugging using remote targets.
3593 set mem inaccessible-by-default
3594 show mem inaccessible-by-default
3595 If the target supplies a memory map, for instance via the remote
3596 protocol's "qXfer:memory-map:read" packet, setting this variable
3597 prevents GDB from accessing memory outside the memory map. This
3598 is useful for targets with memory mapped registers or which react
3599 badly to accesses of unmapped address space.
3601 set breakpoint auto-hw
3602 show breakpoint auto-hw
3603 If the target supplies a memory map, for instance via the remote
3604 protocol's "qXfer:memory-map:read" packet, setting this variable
3605 lets GDB use hardware breakpoints automatically for memory regions
3606 where it can not use software breakpoints. This covers both the
3607 "break" command and internal breakpoints used for other commands
3608 including "next" and "finish".
3611 catch exception unhandled
3612 Stop the program execution when Ada exceptions are raised.
3615 Stop the program execution when an Ada assertion failed.
3619 Set an alternate system root for target files. This is a more
3620 general version of "set solib-absolute-prefix", which is now
3621 an alias to "set sysroot".
3624 Provide extended SPU facility status information. This set of
3625 commands is available only when debugging the Cell/B.E. SPU
3628 * New native configurations
3630 OpenBSD/sh sh*-*openbsd*
3633 unset tdesc filename
3635 Use the specified local file as an XML target description, and do
3636 not query the target for its built-in description.
3640 OpenBSD/sh sh*-*-openbsd*
3641 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3642 Toshiba Media Processor mep-elf
3644 * New remote packets
3647 Ignore the specified signals; pass them directly to the debugged program
3648 without stopping other threads or reporting them to GDB.
3650 qXfer:features:read:
3651 Read an XML target description from the target, which describes its
3656 Read or write contents of an spufs file on the target system. These
3657 packets are available only on the Cell/B.E. SPU architecture.
3659 qXfer:libraries:read:
3660 Report the loaded shared libraries. Combined with new "T" packet
3661 response, this packet allows GDB to debug shared libraries on
3662 targets where the operating system manages the list of loaded
3663 libraries (e.g. Windows and SymbianOS).
3667 Support for these obsolete configurations has been removed.
3675 i[34567]86-*-lynxos*
3676 i[34567]86-*-netware*
3677 i[34567]86-*-sco3.2v5*
3678 i[34567]86-*-sco3.2v4*
3680 i[34567]86-*-sysv4.2*
3683 i[34567]86-*-unixware2*
3684 i[34567]86-*-unixware*
3693 * Other removed features
3700 Various m68k-only ROM monitors.
3707 Various Renesas ROM monitors and debugging interfaces for SH and
3712 Support for a Macraigor serial interface to on-chip debugging.
3713 GDB does not directly support the newer parallel or USB
3718 A debug information format. The predecessor to DWARF 2 and
3719 DWARF 3, which are still supported.
3721 Support for the HP aCC compiler on HP-UX/PA-RISC
3723 SOM-encapsulated symbolic debugging information, automatic
3724 invocation of pxdb, and the aCC custom C++ ABI. This does not
3725 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3726 with aCC can still be debugged on an assembly level.
3728 MIPS ".pdr" sections
3730 A MIPS-specific format used to describe stack frame layout
3731 in debugging information.
3735 GDB could work with an older version of Guile to debug
3736 the interpreter and Scheme programs running in it.
3738 set mips stack-arg-size
3739 set mips saved-gpreg-size
3741 Use "set mips abi" to control parameter passing for MIPS.
3743 *** Changes in GDB 6.6
3748 Cell Broadband Engine SPU spu-elf
3750 * GDB can now be configured as a cross-debugger targeting native Windows
3751 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3752 running on a Windows system over TCP/IP to debug Windows programs.
3754 * The GDB remote stub, gdbserver, has been updated to support Windows and
3755 Cygwin debugging. Both single-threaded and multi-threaded programs are
3758 * The "set trust-readonly-sections" command works again. This command was
3759 broken in GDB 6.3, 6.4, and 6.5.
3761 * The "load" command now supports writing to flash memory, if the remote
3762 stub provides the required support.
3764 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3765 longer requires symbolic debug information (e.g. DWARF-2).
3770 unset substitute-path
3771 show substitute-path
3772 Manage a list of substitution rules that GDB uses to rewrite the name
3773 of the directories where the sources are located. This can be useful
3774 for instance when the sources were moved to a different location
3775 between compilation and debugging.
3779 Print each CLI command as it is executed. Each command is prefixed with
3780 a number of `+' symbols representing the nesting depth.
3781 The source command now has a `-v' option to enable the same feature.
3785 The ARM Demon monitor support (RDP protocol, "target rdp").
3787 Kernel Object Display, an embedded debugging feature which only worked with
3788 an obsolete version of Cisco IOS.
3790 The 'set download-write-size' and 'show download-write-size' commands.
3792 * New remote packets
3795 Tell a stub about GDB client features, and request remote target features.
3796 The first feature implemented is PacketSize, which allows the target to
3797 specify the size of packets it can handle - to minimize the number of
3798 packets required and improve performance when connected to a remote
3802 Fetch an OS auxilliary vector from the remote stub. This packet is a
3803 more efficient replacement for qPart:auxv:read.
3805 qXfer:memory-map:read:
3806 Fetch a memory map from the remote stub, including information about
3807 RAM, ROM, and flash memory devices.
3812 Erase and program a flash memory device.
3814 * Removed remote packets
3817 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3818 used it, and only gdbserver implemented it.
3820 *** Changes in GDB 6.5
3824 Renesas M32C/M16C m32c-elf
3826 Morpho Technologies ms1 ms1-elf
3830 init-if-undefined Initialize a convenience variable, but
3831 only if it doesn't already have a value.
3833 The following commands are presently only implemented for native GNU/Linux:
3835 checkpoint Save a snapshot of the program state.
3837 restart <n> Return the program state to a
3838 previously saved state.
3840 info checkpoints List currently saved checkpoints.
3842 delete-checkpoint <n> Delete a previously saved checkpoint.
3844 set|show detach-on-fork Tell gdb whether to detach from a newly
3845 forked process, or to keep debugging it.
3847 info forks List forks of the user program that
3848 are available to be debugged.
3850 fork <n> Switch to debugging one of several
3851 forks of the user program that are
3852 available to be debugged.
3854 delete-fork <n> Delete a fork from the list of forks
3855 that are available to be debugged (and
3856 kill the forked process).
3858 detach-fork <n> Delete a fork from the list of forks
3859 that are available to be debugged (and
3860 allow the process to continue).
3864 Morpho Technologies ms2 ms1-elf
3866 * Improved Windows host support
3868 GDB now builds as a cross debugger hosted on i686-mingw32, including
3869 native console support, and remote communications using either
3870 network sockets or serial ports.
3872 * Improved Modula-2 language support
3874 GDB can now print most types in the Modula-2 syntax. This includes:
3875 basic types, set types, record types, enumerated types, range types,
3876 pointer types and ARRAY types. Procedure var parameters are correctly
3877 printed and hexadecimal addresses and character constants are also
3878 written in the Modula-2 syntax. Best results can be obtained by using
3879 GNU Modula-2 together with the -gdwarf-2 command line option.
3883 The ARM rdi-share module.
3885 The Netware NLM debug server.
3887 *** Changes in GDB 6.4
3889 * New native configurations
3891 OpenBSD/arm arm*-*-openbsd*
3892 OpenBSD/mips64 mips64-*-openbsd*
3896 Morpho Technologies ms1 ms1-elf
3898 * New command line options
3900 --batch-silent As for --batch, but totally silent.
3901 --return-child-result The debugger will exist with the same value
3902 the child (debugged) program exited with.
3903 --eval-command COMMAND, -ex COMMAND
3904 Execute a single GDB CLI command. This may be
3905 specified multiple times and in conjunction
3906 with the --command (-x) option.
3908 * Deprecated commands removed
3910 The following commands, that were deprecated in 2000, have been
3914 set|show arm disassembly-flavor set|show arm disassembler
3915 othernames set arm disassembler
3916 set|show remotedebug set|show debug remote
3917 set|show archdebug set|show debug arch
3918 set|show eventdebug set|show debug event
3921 * New BSD user-level threads support
3923 It is now possible to debug programs using the user-level threads
3924 library on OpenBSD and FreeBSD. Currently supported (target)
3927 FreeBSD/amd64 x86_64-*-freebsd*
3928 FreeBSD/i386 i386-*-freebsd*
3929 OpenBSD/i386 i386-*-openbsd*
3931 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3932 are not yet supported.
3934 * New support for Matsushita MN10300 w/sim added
3935 (Work in progress). mn10300-elf.
3937 * REMOVED configurations and files
3939 VxWorks and the XDR protocol *-*-vxworks
3940 Motorola MCORE mcore-*-*
3941 National Semiconductor NS32000 ns32k-*-*
3943 * New "set print array-indexes" command
3945 After turning this setting "on", GDB prints the index of each element
3946 when displaying arrays. The default is "off" to preserve the previous
3949 * VAX floating point support
3951 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3953 * User-defined command support
3955 In addition to using $arg0..$arg9 for argument passing, it is now possible
3956 to use $argc to determine now many arguments have been passed. See the
3957 section on user-defined commands in the user manual for more information.
3959 *** Changes in GDB 6.3:
3961 * New command line option
3963 GDB now accepts -l followed by a number to set the timeout for remote
3966 * GDB works with GCC -feliminate-dwarf2-dups
3968 GDB now supports a more compact representation of DWARF-2 debug
3969 information using DW_FORM_ref_addr references. These are produced
3970 by GCC with the option -feliminate-dwarf2-dups and also by some
3971 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3972 to use -feliminate-dwarf2-dups.
3974 * Internationalization
3976 When supported by the host system, GDB will be built with
3977 internationalization (libintl). The task of marking up the sources is
3978 continued, we're looking forward to our first translation.
3982 Initial support for debugging programs compiled with the GNAT
3983 implementation of the Ada programming language has been integrated
3984 into GDB. In this release, support is limited to expression evaluation.
3986 * New native configurations
3988 GNU/Linux/m32r m32r-*-linux-gnu
3992 GDB's remote protocol now includes support for the 'p' packet. This
3993 packet is used to fetch individual registers from a remote inferior.
3995 * END-OF-LIFE registers[] compatibility module
3997 GDB's internal register infrastructure has been completely rewritten.
3998 The new infrastructure making possible the implementation of key new
3999 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4002 GDB 6.3 will be the last release to include the the registers[]
4003 compatibility module that allowed out-of-date configurations to
4004 continue to work. This change directly impacts the following
4014 powerpc bdm protocol
4016 Unless there is activity to revive these configurations, they will be
4017 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4019 * OBSOLETE configurations and files
4021 Configurations that have been declared obsolete in this release have
4022 been commented out. Unless there is activity to revive these
4023 configurations, the next release of GDB will have their sources
4024 permanently REMOVED.
4033 *** Changes in GDB 6.2.1:
4035 * MIPS `break main; run' gave an heuristic-fence-post warning
4037 When attempting to run even a simple program, a warning about
4038 heuristic-fence-post being hit would be reported. This problem has
4041 * MIPS IRIX 'long double' crashed GDB
4043 When examining a long double variable, GDB would get a segmentation
4044 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4045 IRIX long double values).
4049 A bug in the VAX stack code was causing problems with the "next"
4050 command. This problem has been fixed.
4052 *** Changes in GDB 6.2:
4054 * Fix for ``many threads''
4056 On GNU/Linux systems that use the NPTL threads library, a program
4057 rapidly creating and deleting threads would confuse GDB leading to the
4060 ptrace: No such process.
4061 thread_db_get_info: cannot get thread info: generic error
4063 This problem has been fixed.
4065 * "-async" and "-noasync" options removed.
4067 Support for the broken "-noasync" option has been removed (it caused
4070 * New ``start'' command.
4072 This command runs the program until the begining of the main procedure.
4074 * New BSD Kernel Data Access Library (libkvm) interface
4076 Using ``target kvm'' it is now possible to debug kernel core dumps and
4077 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4078 platforms. Currently supported (native-only) configurations are:
4080 FreeBSD/amd64 x86_64-*-freebsd*
4081 FreeBSD/i386 i?86-*-freebsd*
4082 NetBSD/i386 i?86-*-netbsd*
4083 NetBSD/m68k m68*-*-netbsd*
4084 NetBSD/sparc sparc-*-netbsd*
4085 OpenBSD/amd64 x86_64-*-openbsd*
4086 OpenBSD/i386 i?86-*-openbsd*
4087 OpenBSD/m68k m68*-openbsd*
4088 OpenBSD/sparc sparc-*-openbsd*
4090 * Signal trampoline code overhauled
4092 Many generic problems with GDB's signal handling code have been fixed.
4093 These include: backtraces through non-contiguous stacks; recognition
4094 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4095 call; backtrace through a signal trampoline; step into and out of
4096 signal handlers; and single-stepping in the signal trampoline.
4098 Please note that kernel bugs are a limiting factor here. These
4099 features have been shown to work on an s390 GNU/Linux system that
4100 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4102 * Cygwin support for DWARF 2 added.
4104 * New native configurations
4106 GNU/Linux/hppa hppa*-*-linux*
4107 OpenBSD/hppa hppa*-*-openbsd*
4108 OpenBSD/m68k m68*-*-openbsd*
4109 OpenBSD/m88k m88*-*-openbsd*
4110 OpenBSD/powerpc powerpc-*-openbsd*
4111 NetBSD/vax vax-*-netbsd*
4112 OpenBSD/vax vax-*-openbsd*
4114 * END-OF-LIFE frame compatibility module
4116 GDB's internal frame infrastructure has been completely rewritten.
4117 The new infrastructure making it possible to support key new features
4118 including DWARF 2 Call Frame Information. To aid in the task of
4119 migrating old configurations to this new infrastructure, a
4120 compatibility module, that allowed old configurations to continue to
4121 work, was also included.
4123 GDB 6.2 will be the last release to include this frame compatibility
4124 module. This change directly impacts the following configurations:
4134 Unless there is activity to revive these configurations, they will be
4135 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4137 * REMOVED configurations and files
4139 Sun 3, running SunOS 3 m68*-*-sunos3*
4140 Sun 3, running SunOS 4 m68*-*-sunos4*
4141 Sun 2, running SunOS 3 m68000-*-sunos3*
4142 Sun 2, running SunOS 4 m68000-*-sunos4*
4143 Motorola 680x0 running LynxOS m68*-*-lynxos*
4144 AT&T 3b1/Unix pc m68*-att-*
4145 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4146 decstation mips-dec-* mips-little-*
4147 riscos mips-*-riscos* mips-*-sysv*
4148 sonymips mips-sony-*
4149 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4151 *** Changes in GDB 6.1.1:
4153 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4155 The TUI (Text-mode User Interface) is now built as part of a default
4156 GDB configuration. It is enabled by either selecting the TUI with the
4157 command line option "-i=tui" or by running the separate "gdbtui"
4158 program. For more information on the TUI, see the manual "Debugging
4161 * Pending breakpoint support (also included in GDB 6.1)
4163 Support has been added to allow you to specify breakpoints in shared
4164 libraries that have not yet been loaded. If a breakpoint location
4165 cannot be found, and the "breakpoint pending" option is set to auto,
4166 GDB queries you if you wish to make the breakpoint pending on a future
4167 shared-library load. If and when GDB resolves the breakpoint symbol,
4168 the pending breakpoint is removed as one or more regular breakpoints
4171 Pending breakpoints are very useful for GCJ Java debugging.
4173 * Fixed ISO-C build problems
4175 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4176 non ISO-C code that stopped them being built using a more strict ISO-C
4177 compiler (e.g., IBM's C compiler).
4179 * Fixed build problem on IRIX 5
4181 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4182 wasn't able to compile compile on an IRIX 5 system.
4184 * Added execute permission to gdb/gdbserver/configure
4186 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4187 permission. This bug would cause configure to fail on a number of
4188 systems (Solaris, IRIX). Ref: server/519.
4190 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4192 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4193 has been updated to use constant array sizes.
4195 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4197 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4198 its generated DWARF Call Frame Info. This encoding was causing GDB to
4199 panic, that panic has been fixed. Ref: gdb/1628.
4201 * Fixed a problem when examining parameters in shared library code.
4203 When examining parameters in optimized shared library code generated
4204 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4205 not available''. GDB now correctly displays the variable's value.
4207 *** Changes in GDB 6.1:
4209 * Removed --with-mmalloc
4211 Support for the mmalloc memory manager has been removed, as it
4212 conflicted with the internal gdb byte cache.
4214 * Changes in AMD64 configurations
4216 The AMD64 target now includes the %cs and %ss registers. As a result
4217 the AMD64 remote protocol has changed; this affects the floating-point
4218 and SSE registers. If you rely on those registers for your debugging,
4219 you should upgrade gdbserver on the remote side.
4221 * Revised SPARC target
4223 The SPARC target has been completely revised, incorporating the
4224 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4225 support for LynxOS and SunOS 4 has been dropped. Calling functions
4226 from within GDB on operating systems with a non-executable stack
4227 (Solaris, OpenBSD) now works.
4231 GDB has a new C++ demangler which does a better job on the mangled
4232 names generated by current versions of g++. It also runs faster, so
4233 with this and other changes gdb should now start faster on large C++
4236 * DWARF 2 Location Expressions
4238 GDB support for location expressions has been extended to support function
4239 arguments and frame bases. Older versions of GDB could crash when they
4242 * C++ nested types and namespaces
4244 GDB's support for nested types and namespaces in C++ has been
4245 improved, especially if you use the DWARF 2 debugging format. (This
4246 is the default for recent versions of GCC on most platforms.)
4247 Specifically, if you have a class "Inner" defined within a class or
4248 namespace "Outer", then GDB realizes that the class's name is
4249 "Outer::Inner", not simply "Inner". This should greatly reduce the
4250 frequency of complaints about not finding RTTI symbols. In addition,
4251 if you are stopped at inside of a function defined within a namespace,
4252 GDB modifies its name lookup accordingly.
4254 * New native configurations
4256 NetBSD/amd64 x86_64-*-netbsd*
4257 OpenBSD/amd64 x86_64-*-openbsd*
4258 OpenBSD/alpha alpha*-*-openbsd*
4259 OpenBSD/sparc sparc-*-openbsd*
4260 OpenBSD/sparc64 sparc64-*-openbsd*
4262 * New debugging protocols
4264 M32R with SDI protocol m32r-*-elf*
4266 * "set prompt-escape-char" command deleted.
4268 The command "set prompt-escape-char" has been deleted. This command,
4269 and its very obscure effet on GDB's prompt, was never documented,
4270 tested, nor mentioned in the NEWS file.
4272 * OBSOLETE configurations and files
4274 Configurations that have been declared obsolete in this release have
4275 been commented out. Unless there is activity to revive these
4276 configurations, the next release of GDB will have their sources
4277 permanently REMOVED.
4279 Sun 3, running SunOS 3 m68*-*-sunos3*
4280 Sun 3, running SunOS 4 m68*-*-sunos4*
4281 Sun 2, running SunOS 3 m68000-*-sunos3*
4282 Sun 2, running SunOS 4 m68000-*-sunos4*
4283 Motorola 680x0 running LynxOS m68*-*-lynxos*
4284 AT&T 3b1/Unix pc m68*-att-*
4285 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4286 decstation mips-dec-* mips-little-*
4287 riscos mips-*-riscos* mips-*-sysv*
4288 sonymips mips-sony-*
4289 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4291 * REMOVED configurations and files
4293 SGI Irix-4.x mips-sgi-irix4 or iris4
4294 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4295 Z8000 simulator z8k-zilog-none or z8ksim
4296 Matsushita MN10200 w/simulator mn10200-*-*
4297 H8/500 simulator h8500-hitachi-hms or h8500hms
4298 HP/PA running BSD hppa*-*-bsd*
4299 HP/PA running OSF/1 hppa*-*-osf*
4300 HP/PA Pro target hppa*-*-pro*
4301 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4302 386BSD i[3456]86-*-bsd*
4303 Sequent family i[3456]86-sequent-sysv4*
4304 i[3456]86-sequent-sysv*
4305 i[3456]86-sequent-bsd*
4306 SPARC running LynxOS sparc-*-lynxos*
4307 SPARC running SunOS 4 sparc-*-sunos4*
4308 Tsqware Sparclet sparclet-*-*
4309 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4311 *** Changes in GDB 6.0:
4315 Support for debugging the Objective-C programming language has been
4316 integrated into GDB.
4318 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4320 DWARF 2's Call Frame Information makes available compiler generated
4321 information that more exactly describes the program's run-time stack.
4322 By using this information, GDB is able to provide more robust stack
4325 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4326 have been updated to use a new backtrace mechanism which includes
4327 DWARF 2 CFI support.
4331 GDB's remote protocol has been extended to include support for hosted
4332 file I/O (where the remote target uses GDB's file system). See GDB's
4333 remote protocol documentation for details.
4335 * All targets using the new architecture framework.
4337 All of GDB's targets have been updated to use the new internal
4338 architecture framework. The way is now open for future GDB releases
4339 to include cross-architecture native debugging support (i386 on amd64,
4342 * GNU/Linux's Thread Local Storage (TLS)
4344 GDB now includes support for for the GNU/Linux implementation of
4345 per-thread variables.
4347 * GNU/Linux's Native POSIX Thread Library (NPTL)
4349 GDB's thread code has been updated to work with either the new
4350 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4352 * Separate debug info.
4354 GDB, in conjunction with BINUTILS, now supports a mechanism for
4355 automatically loading debug information from a separate file. Instead
4356 of shipping full debug and non-debug versions of system libraries,
4357 system integrators can now instead ship just the stripped libraries
4358 and optional debug files.
4360 * DWARF 2 Location Expressions
4362 DWARF 2 Location Expressions allow the compiler to more completely
4363 describe the location of variables (even in optimized code) to the
4366 GDB now includes preliminary support for location expressions (support
4367 for DW_OP_piece is still missing).
4371 A number of long standing bugs that caused GDB to die while starting a
4372 Java application have been fixed. GDB's Java support is now
4373 considered "useable".
4375 * GNU/Linux support for fork, vfork, and exec.
4377 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4378 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4381 * GDB supports logging output to a file
4383 There are two new commands, "set logging" and "show logging", which can be
4384 used to capture GDB's output to a file.
4386 * The meaning of "detach" has changed for gdbserver
4388 The "detach" command will now resume the application, as documented. To
4389 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4392 * d10v, m68hc11 `regs' command deprecated
4394 The `info registers' command has been updated so that it displays the
4395 registers using a format identical to the old `regs' command.
4399 A new command, "maint set profile on/off", has been added. This command can
4400 be used to enable or disable profiling while running GDB, to profile a
4401 session or a set of commands. In addition there is a new configure switch,
4402 "--enable-profiling", which will cause GDB to be compiled with profiling
4403 data, for more informative profiling results.
4405 * Default MI syntax changed to "mi2".
4407 The default MI (machine interface) syntax, enabled by the command line
4408 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4409 "mi1", can be enabled by specifying the option "-i=mi1".
4411 Support for the original "mi0" syntax (included in GDB 5.0) has been
4414 Fix for gdb/192: removed extraneous space when displaying frame level.
4415 Fix for gdb/672: update changelist is now output in mi list format.
4416 Fix for gdb/702: a -var-assign that updates the value now shows up
4417 in a subsequent -var-update.
4419 * New native configurations.
4421 FreeBSD/amd64 x86_64-*-freebsd*
4423 * Multi-arched targets.
4425 HP/PA HPUX11 hppa*-*-hpux*
4426 Renesas M32R/D w/simulator m32r-*-elf*
4428 * OBSOLETE configurations and files
4430 Configurations that have been declared obsolete in this release have
4431 been commented out. Unless there is activity to revive these
4432 configurations, the next release of GDB will have their sources
4433 permanently REMOVED.
4435 Z8000 simulator z8k-zilog-none or z8ksim
4436 Matsushita MN10200 w/simulator mn10200-*-*
4437 H8/500 simulator h8500-hitachi-hms or h8500hms
4438 HP/PA running BSD hppa*-*-bsd*
4439 HP/PA running OSF/1 hppa*-*-osf*
4440 HP/PA Pro target hppa*-*-pro*
4441 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4442 Sequent family i[3456]86-sequent-sysv4*
4443 i[3456]86-sequent-sysv*
4444 i[3456]86-sequent-bsd*
4445 Tsqware Sparclet sparclet-*-*
4446 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4448 * REMOVED configurations and files
4451 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4452 IBM AIX PS/2 i[3456]86-*-aix
4453 i386 running Mach 3.0 i[3456]86-*-mach3*
4454 i386 running Mach i[3456]86-*-mach*
4455 i386 running OSF/1 i[3456]86-*osf1mk*
4456 HP/Apollo 68k Family m68*-apollo*-sysv*,
4458 m68*-hp-bsd*, m68*-hp-hpux*
4459 Argonaut Risc Chip (ARC) arc-*-*
4460 Mitsubishi D30V d30v-*-*
4461 Fujitsu FR30 fr30-*-elf*
4462 OS/9000 i[34]86-*-os9k
4463 I960 with MON960 i960-*-coff
4465 * MIPS $fp behavior changed
4467 The convenience variable $fp, for the MIPS, now consistently returns
4468 the address of the current frame's base. Previously, depending on the
4469 context, $fp could refer to either $sp or the current frame's base
4470 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4471 The GNU Source-Level Debugger''.
4473 *** Changes in GDB 5.3:
4475 * GNU/Linux shared library multi-threaded performance improved.
4477 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4478 `/proc', in preference to `ptrace' for memory reads. This may result
4479 in an improvement in the start-up time of multi-threaded, shared
4480 library applications when run under GDB. One GDB user writes: ``loads
4481 shared libs like mad''.
4483 * ``gdbserver'' now supports multi-threaded applications on some targets
4485 Support for debugging multi-threaded applications which use
4486 the GNU/Linux LinuxThreads package has been added for
4487 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4488 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4490 * GDB now supports C/C++ preprocessor macros.
4492 GDB now expands preprocessor macro invocations in C/C++ expressions,
4493 and provides various commands for showing macro definitions and how
4496 The new command `macro expand EXPRESSION' expands any macro
4497 invocations in expression, and shows the result.
4499 The new command `show macro MACRO-NAME' shows the definition of the
4500 macro named MACRO-NAME, and where it was defined.
4502 Most compilers don't include information about macros in the debugging
4503 information by default. In GCC 3.1, for example, you need to compile
4504 your program with the options `-gdwarf-2 -g3'. If the macro
4505 information is present in the executable, GDB will read it.
4507 * Multi-arched targets.
4509 DEC Alpha (partial) alpha*-*-*
4510 DEC VAX (partial) vax-*-*
4512 National Semiconductor NS32000 (partial) ns32k-*-*
4513 Motorola 68000 (partial) m68k-*-*
4514 Motorola MCORE mcore-*-*
4518 Fujitsu FRV architecture added by Red Hat frv*-*-*
4521 * New native configurations
4523 Alpha NetBSD alpha*-*-netbsd*
4524 SH NetBSD sh*-*-netbsdelf*
4525 MIPS NetBSD mips*-*-netbsd*
4526 UltraSPARC NetBSD sparc64-*-netbsd*
4528 * OBSOLETE configurations and files
4530 Configurations that have been declared obsolete in this release have
4531 been commented out. Unless there is activity to revive these
4532 configurations, the next release of GDB will have their sources
4533 permanently REMOVED.
4535 Mitsubishi D30V d30v-*-*
4536 OS/9000 i[34]86-*-os9k
4537 IBM AIX PS/2 i[3456]86-*-aix
4538 Fujitsu FR30 fr30-*-elf*
4539 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4540 Argonaut Risc Chip (ARC) arc-*-*
4541 i386 running Mach 3.0 i[3456]86-*-mach3*
4542 i386 running Mach i[3456]86-*-mach*
4543 i386 running OSF/1 i[3456]86-*osf1mk*
4544 HP/Apollo 68k Family m68*-apollo*-sysv*,
4546 m68*-hp-bsd*, m68*-hp-hpux*
4547 I960 with MON960 i960-*-coff
4549 * OBSOLETE languages
4551 CHILL, a Pascal like language used by telecommunications companies.
4553 * REMOVED configurations and files
4555 AMD 29k family via UDI a29k-amd-udi, udi29k
4556 A29K VxWorks a29k-*-vxworks
4557 AMD 29000 embedded, using EBMON a29k-none-none
4558 AMD 29000 embedded with COFF a29k-none-coff
4559 AMD 29000 embedded with a.out a29k-none-aout
4561 testsuite/gdb.hp/gdb.threads-hp/ directory
4563 * New command "set max-user-call-depth <nnn>"
4565 This command allows the user to limit the call depth of user-defined
4566 commands. The default is 1024.
4568 * Changes in FreeBSD/i386 native debugging.
4570 Support for the "generate-core-file" has been added.
4572 * New commands "dump", "append", and "restore".
4574 These commands allow data to be copied from target memory
4575 to a bfd-format or binary file (dump and append), and back
4576 from a file into memory (restore).
4578 * Improved "next/step" support on multi-processor Alpha Tru64.
4580 The previous single-step mechanism could cause unpredictable problems,
4581 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4582 of a software single-step mechanism prevents this.
4584 *** Changes in GDB 5.2.1:
4592 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4593 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4594 Fix, by Joel Brobecker imported from mainline.
4596 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4597 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4598 Fix, by Fred Fish, imported from mainline.
4600 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4601 Surprisingly enough, it works now.
4602 By Michal Ludvig, imported from mainline.
4604 i386 hardware watchpoint support:
4605 avoid misses on second run for some targets.
4606 By Pierre Muller, imported from mainline.
4608 *** Changes in GDB 5.2:
4610 * New command "set trust-readonly-sections on[off]".
4612 This command is a hint that tells gdb that read-only sections
4613 really are read-only (ie. that their contents will not change).
4614 In this mode, gdb will go to the object file rather than the
4615 target to read memory from read-only sections (such as ".text").
4616 This can be a significant performance improvement on some
4617 (notably embedded) targets.
4619 * New command "generate-core-file" (or "gcore").
4621 This new gdb command allows the user to drop a core file of the child
4622 process state at any time. So far it's been implemented only for
4623 GNU/Linux and Solaris, but should be relatively easily ported to other
4624 hosts. Argument is core file name (defaults to core.<pid>).
4626 * New command line option
4628 GDB now accepts --pid or -p followed by a process id.
4630 * Change in command line behavior -- corefiles vs. process ids.
4632 There is a subtle behavior in the way in which GDB handles
4633 command line arguments. The first non-flag argument is always
4634 a program to debug, but the second non-flag argument may either
4635 be a corefile or a process id. Previously, GDB would attempt to
4636 open the second argument as a corefile, and if that failed, would
4637 issue a superfluous error message and then attempt to attach it as
4638 a process. Now, if the second argument begins with a non-digit,
4639 it will be treated as a corefile. If it begins with a digit,
4640 GDB will attempt to attach it as a process, and if no such process
4641 is found, will then attempt to open it as a corefile.
4643 * Changes in ARM configurations.
4645 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4646 configuration is fully multi-arch.
4648 * New native configurations
4650 ARM NetBSD arm*-*-netbsd*
4651 x86 OpenBSD i[3456]86-*-openbsd*
4652 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4653 Sparc64 running FreeBSD sparc64-*-freebsd*
4657 Sanyo XStormy16 xstormy16-elf
4659 * OBSOLETE configurations and files
4661 Configurations that have been declared obsolete in this release have
4662 been commented out. Unless there is activity to revive these
4663 configurations, the next release of GDB will have their sources
4664 permanently REMOVED.
4666 AMD 29k family via UDI a29k-amd-udi, udi29k
4667 A29K VxWorks a29k-*-vxworks
4668 AMD 29000 embedded, using EBMON a29k-none-none
4669 AMD 29000 embedded with COFF a29k-none-coff
4670 AMD 29000 embedded with a.out a29k-none-aout
4672 testsuite/gdb.hp/gdb.threads-hp/ directory
4674 * REMOVED configurations and files
4676 TI TMS320C80 tic80-*-*
4678 PowerPC Solaris powerpcle-*-solaris*
4679 PowerPC Windows NT powerpcle-*-cygwin32
4680 PowerPC Netware powerpc-*-netware*
4681 Harris/CXUX m88k m88*-harris-cxux*
4682 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4683 ns32k-utek-sysv* ns32k-utek-*
4684 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4685 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4686 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4687 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4688 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4690 * Changes to command line processing
4692 The new `--args' feature can be used to specify command-line arguments
4693 for the inferior from gdb's command line.
4695 * Changes to key bindings
4697 There is a new `operate-and-get-next' function bound to `C-o'.
4699 *** Changes in GDB 5.1.1
4701 Fix compile problem on DJGPP.
4703 Fix a problem with floating-point registers on the i386 being
4706 Fix to stop GDB crashing on .debug_str debug info.
4708 Numerous documentation fixes.
4710 Numerous testsuite fixes.
4712 *** Changes in GDB 5.1:
4714 * New native configurations
4716 Alpha FreeBSD alpha*-*-freebsd*
4717 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4718 MIPS GNU/Linux mips*-*-linux*
4719 MIPS SGI Irix 6.x mips*-sgi-irix6*
4720 ia64 AIX ia64-*-aix*
4721 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4725 Motorola 68HC11 and 68HC12 m68hc11-elf
4727 UltraSparc running GNU/Linux sparc64-*-linux*
4729 * OBSOLETE configurations and files
4731 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4732 Harris/CXUX m88k m88*-harris-cxux*
4733 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4734 ns32k-utek-sysv* ns32k-utek-*
4735 TI TMS320C80 tic80-*-*
4737 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4738 PowerPC Solaris powerpcle-*-solaris*
4739 PowerPC Windows NT powerpcle-*-cygwin32
4740 PowerPC Netware powerpc-*-netware*
4741 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4742 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4743 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4744 Apple Macintosh (MPW) host N/A
4746 stuff.c (Program to stuff files into a specially prepared space in kdb)
4747 kdb-start.c (Main loop for the standalone kernel debugger)
4749 Configurations that have been declared obsolete in this release have
4750 been commented out. Unless there is activity to revive these
4751 configurations, the next release of GDB will have their sources
4752 permanently REMOVED.
4754 * REMOVED configurations and files
4756 Altos 3068 m68*-altos-*
4757 Convex c1-*-*, c2-*-*
4759 ARM RISCix arm-*-* (as host)
4763 * GDB has been converted to ISO C.
4765 GDB's source code has been converted to ISO C. In particular, the
4766 sources are fully protoized, and rely on standard headers being
4771 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4773 * The MI enabled by default.
4775 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4776 revised and enabled by default. Packages which use GDB as a debugging
4777 engine behind a UI or another front end are encouraged to switch to
4778 using the GDB/MI interface, instead of the old annotations interface
4779 which is now deprecated.
4781 * Support for debugging Pascal programs.
4783 GDB now includes support for debugging Pascal programs. The following
4784 main features are supported:
4786 - Pascal-specific data types such as sets;
4788 - automatic recognition of Pascal sources based on file-name
4791 - Pascal-style display of data types, variables, and functions;
4793 - a Pascal expression parser.
4795 However, some important features are not yet supported.
4797 - Pascal string operations are not supported at all;
4799 - there are some problems with boolean types;
4801 - Pascal type hexadecimal constants are not supported
4802 because they conflict with the internal variables format;
4804 - support for Pascal objects and classes is not full yet;
4806 - unlike Pascal, GDB is case-sensitive for symbol names.
4808 * Changes in completion.
4810 Commands such as `shell', `run' and `set args', which pass arguments
4811 to inferior programs, now complete on file names, similar to what
4812 users expect at the shell prompt.
4814 Commands which accept locations, such as `disassemble', `print',
4815 `breakpoint', `until', etc. now complete on filenames as well as
4816 program symbols. Thus, if you type "break foob TAB", and the source
4817 files linked into the programs include `foobar.c', that file name will
4818 be one of the candidates for completion. However, file names are not
4819 considered for completion after you typed a colon that delimits a file
4820 name from a name of a function in that file, as in "break foo.c:bar".
4822 `set demangle-style' completes on available demangling styles.
4824 * New platform-independent commands:
4826 It is now possible to define a post-hook for a command as well as a
4827 hook that runs before the command. For more details, see the
4828 documentation of `hookpost' in the GDB manual.
4830 * Changes in GNU/Linux native debugging.
4832 Support for debugging multi-threaded programs has been completely
4833 revised for all platforms except m68k and sparc. You can now debug as
4834 many threads as your system allows you to have.
4836 Attach/detach is supported for multi-threaded programs.
4838 Support for SSE registers was added for x86. This doesn't work for
4839 multi-threaded programs though.
4841 * Changes in MIPS configurations.
4843 Multi-arch support is enabled for all MIPS configurations.
4845 GDB can now be built as native debugger on SGI Irix 6.x systems for
4846 debugging n32 executables. (Debugging 64-bit executables is not yet
4849 * Unified support for hardware watchpoints in all x86 configurations.
4851 Most (if not all) native x86 configurations support hardware-assisted
4852 breakpoints and watchpoints in a unified manner. This support
4853 implements debug register sharing between watchpoints, which allows to
4854 put a virtually infinite number of watchpoints on the same address,
4855 and also supports watching regions up to 16 bytes with several debug
4858 The new maintenance command `maintenance show-debug-regs' toggles
4859 debugging print-outs in functions that insert, remove, and test
4860 watchpoints and hardware breakpoints.
4862 * Changes in the DJGPP native configuration.
4864 New command ``info dos sysinfo'' displays assorted information about
4865 the CPU, OS, memory, and DPMI server.
4867 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4868 display information about segment descriptors stored in GDT, LDT, and
4871 New commands ``info dos pde'' and ``info dos pte'' display entries
4872 from Page Directory and Page Tables (for now works with CWSDPMI only).
4873 New command ``info dos address-pte'' displays the Page Table entry for
4874 a given linear address.
4876 GDB can now pass command lines longer than 126 characters to the
4877 program being debugged (requires an update to the libdbg.a library
4878 which is part of the DJGPP development kit).
4880 DWARF2 debug info is now supported.
4882 It is now possible to `step' and `next' through calls to `longjmp'.
4884 * Changes in documentation.
4886 All GDB documentation was converted to GFDL, the GNU Free
4887 Documentation License.
4889 Tracepoints-related commands are now fully documented in the GDB
4892 TUI, the Text-mode User Interface, is now documented in the manual.
4894 Tracepoints-related commands are now fully documented in the GDB
4897 The "GDB Internals" manual now has an index. It also includes
4898 documentation of `ui_out' functions, GDB coding standards, x86
4899 hardware watchpoints, and memory region attributes.
4901 * GDB's version number moved to ``version.in''
4903 The Makefile variable VERSION has been replaced by the file
4904 ``version.in''. People creating GDB distributions should update the
4905 contents of this file.
4909 GUD support is now a standard part of the EMACS distribution.
4911 *** Changes in GDB 5.0:
4913 * Improved support for debugging FP programs on x86 targets
4915 Unified and much-improved support for debugging floating-point
4916 programs on all x86 targets. In particular, ``info float'' now
4917 displays the FP registers in the same format on all x86 targets, with
4918 greater level of detail.
4920 * Improvements and bugfixes in hardware-assisted watchpoints
4922 It is now possible to watch array elements, struct members, and
4923 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4924 on x86 targets no longer erroneously trigger when the address is
4927 * Improvements in the native DJGPP version of GDB
4929 The distribution now includes all the scripts and auxiliary files
4930 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4931 machines ``out of the box''.
4933 The DJGPP version can now debug programs that use signals. It is
4934 possible to catch signals that happened in the debuggee, deliver
4935 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4936 would kill the program being debugged.) Programs that hook hardware
4937 interrupts (keyboard, timer, etc.) can also be debugged.
4939 It is now possible to debug DJGPP programs that redirect their
4940 standard handles or switch them to raw (as opposed to cooked) mode, or
4941 even close them. The command ``run < foo > bar'' works as expected,
4942 and ``info terminal'' reports useful information about the debuggee's
4943 terminal, including raw/cooked mode, redirection, etc.
4945 The DJGPP version now uses termios functions for console I/O, which
4946 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4949 DOS-style file names with drive letters are now fully supported by
4952 It is now possible to debug DJGPP programs that switch their working
4953 directory. It is also possible to rerun the debuggee any number of
4954 times without restarting GDB; thus, you can use the same setup,
4955 breakpoints, etc. for many debugging sessions.
4957 * New native configurations
4959 ARM GNU/Linux arm*-*-linux*
4960 PowerPC GNU/Linux powerpc-*-linux*
4964 Motorola MCore mcore-*-*
4965 x86 VxWorks i[3456]86-*-vxworks*
4966 PowerPC VxWorks powerpc-*-vxworks*
4967 TI TMS320C80 tic80-*-*
4969 * OBSOLETE configurations
4971 Altos 3068 m68*-altos-*
4972 Convex c1-*-*, c2-*-*
4974 ARM RISCix arm-*-* (as host)
4977 Configurations that have been declared obsolete will be commented out,
4978 but the code will be left in place. If there is no activity to revive
4979 these configurations before the next release of GDB, the sources will
4980 be permanently REMOVED.
4982 * Gould support removed
4984 Support for the Gould PowerNode and NP1 has been removed.
4986 * New features for SVR4
4988 On SVR4 native platforms (such as Solaris), if you attach to a process
4989 without first loading a symbol file, GDB will now attempt to locate and
4990 load symbols from the running process's executable file.
4992 * Many C++ enhancements
4994 C++ support has been greatly improved. Overload resolution now works properly
4995 in almost all cases. RTTI support is on the way.
4997 * Remote targets can connect to a sub-program
4999 A popen(3) style serial-device has been added. This device starts a
5000 sub-process (such as a stand-alone simulator) and then communicates
5001 with that. The sub-program to run is specified using the syntax
5002 ``|<program> <args>'' vis:
5004 (gdb) set remotedebug 1
5005 (gdb) target extended-remote |mn10300-elf-sim program-args
5007 * MIPS 64 remote protocol
5009 A long standing bug in the mips64 remote protocol where by GDB
5010 expected certain 32 bit registers (ex SR) to be transfered as 32
5011 instead of 64 bits has been fixed.
5013 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5014 added to provide backward compatibility with older versions of GDB.
5016 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5018 The command ``set remotebinarydownload'' command has been replaced by
5019 ``set remote X-packet''. Other commands in ``set remote'' family
5020 include ``set remote P-packet''.
5022 * Breakpoint commands accept ranges.
5024 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5025 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5026 ``tracepoint passcount'' also accepts a range of tracepoints.
5028 * ``apropos'' command added.
5030 The ``apropos'' command searches through command names and
5031 documentation strings, printing out matches, making it much easier to
5032 try to find a command that does what you are looking for.
5036 A new machine oriented interface (MI) has been added to GDB. This
5037 interface is designed for debug environments running GDB as a separate
5038 process. This is part of the long term libGDB project. See the
5039 "GDB/MI" chapter of the GDB manual for further information. It can be
5040 enabled by configuring with:
5042 .../configure --enable-gdbmi
5044 *** Changes in GDB-4.18:
5046 * New native configurations
5048 HP-UX 10.20 hppa*-*-hpux10.20
5049 HP-UX 11.x hppa*-*-hpux11.0*
5050 M68K GNU/Linux m68*-*-linux*
5054 Fujitsu FR30 fr30-*-elf*
5055 Intel StrongARM strongarm-*-*
5056 Mitsubishi D30V d30v-*-*
5058 * OBSOLETE configurations
5060 Gould PowerNode, NP1 np1-*-*, pn-*-*
5062 Configurations that have been declared obsolete will be commented out,
5063 but the code will be left in place. If there is no activity to revive
5064 these configurations before the next release of GDB, the sources will
5065 be permanently REMOVED.
5069 As a compatibility experiment, GDB's source files buildsym.h and
5070 buildsym.c have been converted to pure standard C, no longer
5071 containing any K&R compatibility code. We believe that all systems in
5072 use today either come with a standard C compiler, or have a GCC port
5073 available. If this is not true, please report the affected
5074 configuration to bug-gdb@gnu.org immediately. See the README file for
5075 information about getting a standard C compiler if you don't have one
5080 GDB now uses readline 2.2.
5082 * set extension-language
5084 You can now control the mapping between filename extensions and source
5085 languages by using the `set extension-language' command. For instance,
5086 you can ask GDB to treat .c files as C++ by saying
5087 set extension-language .c c++
5088 The command `info extensions' lists all of the recognized extensions
5089 and their associated languages.
5091 * Setting processor type for PowerPC and RS/6000
5093 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5094 you can use the `set processor' command to specify what variant of the
5095 PowerPC family you are debugging. The command
5099 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5100 following PowerPC and RS6000 variants:
5102 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5103 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5105 403GC IBM PowerPC 403GC
5106 505 Motorola PowerPC 505
5107 860 Motorola PowerPC 860 or 850
5108 601 Motorola PowerPC 601
5109 602 Motorola PowerPC 602
5110 603 Motorola/IBM PowerPC 603 or 603e
5111 604 Motorola PowerPC 604 or 604e
5112 750 Motorola/IBM PowerPC 750 or 750
5114 At the moment, this command just tells GDB what to name the
5115 special-purpose processor registers. Since almost all the affected
5116 registers are inaccessible to user-level programs, this command is
5117 only useful for remote debugging in its present form.
5121 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5122 more extensive support for HP-UX. Added features include shared
5123 library support, kernel threads and hardware watchpoints for 11.00,
5124 support for HP's ANSI C and C++ compilers, and a compatibility mode
5125 for xdb and dbx commands.
5129 HP's donation includes the new concept of catchpoints, which is a
5130 generalization of the old catch command. On HP-UX, it is now possible
5131 to catch exec, fork, and vfork, as well as library loading.
5133 This means that the existing catch command has changed; its first
5134 argument now specifies the type of catch to be set up. See the
5135 output of "help catch" for a list of catchpoint types.
5137 * Debugging across forks
5139 On HP-UX, you can choose which process to debug when a fork() happens
5144 HP has donated a curses-based terminal user interface (TUI). To get
5145 it, build with --enable-tui. Although this can be enabled for any
5146 configuration, at present it only works for native HP debugging.
5148 * GDB remote protocol additions
5150 A new protocol packet 'X' that writes binary data is now available.
5151 Default behavior is to try 'X', then drop back to 'M' if the stub
5152 fails to respond. The settable variable `remotebinarydownload'
5153 allows explicit control over the use of 'X'.
5155 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5156 full 64-bit address. The command
5158 set remoteaddresssize 32
5160 can be used to revert to the old behaviour. For existing remote stubs
5161 the change should not be noticed, as the additional address information
5164 In order to assist in debugging stubs, you may use the maintenance
5165 command `packet' to send any text string to the stub. For instance,
5167 maint packet heythere
5169 sends the packet "$heythere#<checksum>". Note that it is very easy to
5170 disrupt a debugging session by sending the wrong packet at the wrong
5173 The compare-sections command allows you to compare section data on the
5174 target to what is in the executable file without uploading or
5175 downloading, by comparing CRC checksums.
5177 * Tracing can collect general expressions
5179 You may now collect general expressions at tracepoints. This requires
5180 further additions to the target-side stub; see tracepoint.c and
5181 doc/agentexpr.texi for further details.
5183 * mask-address variable for Mips
5185 For Mips targets, you may control the zeroing of the upper 32 bits of
5186 a 64-bit address by entering `set mask-address on'. This is mainly
5187 of interest to users of embedded R4xxx and R5xxx processors.
5189 * Higher serial baud rates
5191 GDB's serial code now allows you to specify baud rates 57600, 115200,
5192 230400, and 460800 baud. (Note that your host system may not be able
5193 to achieve all of these rates.)
5197 The i960 configuration now includes an initial implementation of a
5198 builtin simulator, contributed by Jim Wilson.
5201 *** Changes in GDB-4.17:
5203 * New native configurations
5205 Alpha GNU/Linux alpha*-*-linux*
5206 Unixware 2.x i[3456]86-unixware2*
5207 Irix 6.x mips*-sgi-irix6*
5208 PowerPC GNU/Linux powerpc-*-linux*
5209 PowerPC Solaris powerpcle-*-solaris*
5210 Sparc GNU/Linux sparc-*-linux*
5211 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5215 Argonaut Risc Chip (ARC) arc-*-*
5216 Hitachi H8/300S h8300*-*-*
5217 Matsushita MN10200 w/simulator mn10200-*-*
5218 Matsushita MN10300 w/simulator mn10300-*-*
5219 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5220 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5221 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5222 Mitsubishi D10V w/simulator d10v-*-*
5223 Mitsubishi M32R/D w/simulator m32r-*-elf*
5224 Tsqware Sparclet sparclet-*-*
5225 NEC V850 w/simulator v850-*-*
5227 * New debugging protocols
5229 ARM with RDI protocol arm*-*-*
5230 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5231 DDB and LSI variants of PMON protocol mips*-*-*
5232 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5233 PowerPC with SDS protocol powerpc{,le}-*-eabi
5234 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5238 All configurations can now understand and use the DWARF 2 debugging
5239 format. The choice is automatic, if the symbol file contains DWARF 2
5244 GDB now includes basic Java language support. This support is
5245 only useful with Java compilers that produce native machine code.
5247 * solib-absolute-prefix and solib-search-path
5249 For SunOS and SVR4 shared libraries, you may now set the prefix for
5250 loading absolute shared library symbol files, and the search path for
5251 locating non-absolute shared library symbol files.
5253 * Live range splitting
5255 GDB can now effectively debug code for which GCC has performed live
5256 range splitting as part of its optimization. See gdb/doc/LRS for
5257 more details on the expected format of the stabs information.
5261 GDB's support for the GNU Hurd, including thread debugging, has been
5262 updated to work with current versions of the Hurd.
5266 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5267 instruction set. ARM GDB automatically detects when Thumb
5268 instructions are in use, and adjusts disassembly and backtracing
5273 GDB's MIPS target configurations now handle the MIP16 16-bit
5278 GDB now includes support for overlays; if an executable has been
5279 linked such that multiple sections are based at the same address, GDB
5280 will decide which section to use for symbolic info. You can choose to
5281 control the decision manually, using overlay commands, or implement
5282 additional target-side support and use "overlay load-target" to bring
5283 in the overlay mapping. Do "help overlay" for more detail.
5287 The command "info symbol <address>" displays information about
5288 the symbol at the specified address.
5292 The standard remote protocol now includes an extension that allows
5293 asynchronous collection and display of trace data. This requires
5294 extensive support in the target-side debugging stub. Tracing mode
5295 includes a new interaction mode in GDB and new commands: see the
5296 file tracepoint.c for more details.
5300 Configurations for embedded MIPS now include a simulator contributed
5301 by Cygnus Solutions. The simulator supports the instruction sets
5302 of most MIPS variants.
5306 Sparc configurations may now include the ERC32 simulator contributed
5307 by the European Space Agency. The simulator is not built into
5308 Sparc targets by default; configure with --enable-sim to include it.
5312 For target configurations that may include multiple variants of a
5313 basic architecture (such as MIPS and SH), you may now set the
5314 architecture explicitly. "set arch" sets, "info arch" lists
5315 the possible architectures.
5317 *** Changes in GDB-4.16:
5319 * New native configurations
5321 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5322 M68K NetBSD m68k-*-netbsd*
5323 PowerPC AIX 4.x powerpc-*-aix*
5324 PowerPC MacOS powerpc-*-macos*
5325 PowerPC Windows NT powerpcle-*-cygwin32
5326 RS/6000 AIX 4.x rs6000-*-aix4*
5330 ARM with RDP protocol arm-*-*
5331 I960 with MON960 i960-*-coff
5332 MIPS VxWorks mips*-*-vxworks*
5333 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5334 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5336 Matra Sparclet sparclet-*-*
5340 The powerpc-eabi configuration now includes the PSIM simulator,
5341 contributed by Andrew Cagney, with assistance from Mike Meissner.
5342 PSIM is a very elaborate model of the PowerPC, including not only
5343 basic instruction set execution, but also details of execution unit
5344 performance and I/O hardware. See sim/ppc/README for more details.
5348 GDB now works with Solaris 2.5.
5350 * Windows 95/NT native
5352 GDB will now work as a native debugger on Windows 95 and Windows NT.
5353 To build it from source, you must use the "gnu-win32" environment,
5354 which uses a DLL to emulate enough of Unix to run the GNU tools.
5355 Further information, binaries, and sources are available at
5356 ftp.cygnus.com, under pub/gnu-win32.
5358 * dont-repeat command
5360 If a user-defined command includes the command `dont-repeat', then the
5361 command will not be repeated if the user just types return. This is
5362 useful if the command is time-consuming to run, so that accidental
5363 extra keystrokes don't run the same command many times.
5365 * Send break instead of ^C
5367 The standard remote protocol now includes an option to send a break
5368 rather than a ^C to the target in order to interrupt it. By default,
5369 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5371 * Remote protocol timeout
5373 The standard remote protocol includes a new variable `remotetimeout'
5374 that allows you to set the number of seconds before GDB gives up trying
5375 to read from the target. The default value is 2.
5377 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5379 By default GDB will automatically keep track of objects as they are
5380 loaded and unloaded by the dynamic linker. By using the command `set
5381 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5382 when shared library events occur, thus allowing you to set breakpoints
5383 in shared libraries which are explicitly loaded by the inferior.
5385 Note this feature does not work on hpux8. On hpux9 you must link
5386 /usr/lib/end.o into your program. This feature should work
5387 automatically on hpux10.
5389 * Irix 5.x hardware watchpoint support
5391 Irix 5 configurations now support the use of hardware watchpoints.
5393 * Mips protocol "SYN garbage limit"
5395 When debugging a Mips target using the `target mips' protocol, you
5396 may set the number of characters that GDB will ignore by setting
5397 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5398 every character. The default value is 1050.
5400 * Recording and replaying remote debug sessions
5402 If you set `remotelogfile' to the name of a file, gdb will write to it
5403 a recording of a remote debug session. This recording may then be
5404 replayed back to gdb using "gdbreplay". See gdbserver/README for
5405 details. This is useful when you have a problem with GDB while doing
5406 remote debugging; you can make a recording of the session and send it
5407 to someone else, who can then recreate the problem.
5409 * Speedups for remote debugging
5411 GDB includes speedups for downloading and stepping MIPS systems using
5412 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5413 and more efficient S-record downloading.
5415 * Memory use reductions and statistics collection
5417 GDB now uses less memory and reports statistics about memory usage.
5418 Try the `maint print statistics' command, for example.
5420 *** Changes in GDB-4.15:
5422 * Psymtabs for XCOFF
5424 The symbol reader for AIX GDB now uses partial symbol tables. This
5425 can greatly improve startup time, especially for large executables.
5427 * Remote targets use caching
5429 Remote targets now use a data cache to speed up communication with the
5430 remote side. The data cache could lead to incorrect results because
5431 it doesn't know about volatile variables, thus making it impossible to
5432 debug targets which use memory mapped I/O devices. `set remotecache
5433 off' turns the the data cache off.
5435 * Remote targets may have threads
5437 The standard remote protocol now includes support for multiple threads
5438 in the target system, using new protocol commands 'H' and 'T'. See
5439 gdb/remote.c for details.
5443 If GDB is configured with `--enable-netrom', then it will include
5444 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5445 acts as though it is a bank of ROM on the target board, but you can
5446 write into it over the network. GDB's support consists only of
5447 support for fast loading into the emulated ROM; to debug, you must use
5448 another protocol, such as standard remote protocol. The usual
5449 sequence is something like
5451 target nrom <netrom-hostname>
5453 target remote <netrom-hostname>:1235
5457 GDB now includes support for the Apple Macintosh, as a host only. It
5458 may be run as either an MPW tool or as a standalone application, and
5459 it can debug through the serial port. All the usual GDB commands are
5460 available, but to the target command, you must supply "serial" as the
5461 device type instead of "/dev/ttyXX". See mpw-README in the main
5462 directory for more information on how to build. The MPW configuration
5463 scripts */mpw-config.in support only a few targets, and only the
5464 mips-idt-ecoff target has been tested.
5468 GDB configuration now uses autoconf. This is not user-visible,
5469 but does simplify configuration and building.
5473 GDB now supports hpux10.
5475 *** Changes in GDB-4.14:
5477 * New native configurations
5479 x86 FreeBSD i[345]86-*-freebsd
5480 x86 NetBSD i[345]86-*-netbsd
5481 NS32k NetBSD ns32k-*-netbsd
5482 Sparc NetBSD sparc-*-netbsd
5486 A29K VxWorks a29k-*-vxworks
5487 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5488 CPU32 EST-300 emulator m68*-*-est*
5489 PowerPC ELF powerpc-*-elf
5492 * Alpha OSF/1 support for procfs
5494 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5495 possible to attach to running processes. As the mounting of the /proc
5496 filesystem is optional on the Alpha, GDB automatically determines
5497 the availability of /proc during startup. This can lead to problems
5498 if /proc is unmounted after GDB has been started.
5500 * Arguments to user-defined commands
5502 User commands may accept up to 10 arguments separated by whitespace.
5503 Arguments are accessed within the user command via $arg0..$arg9. A
5506 print $arg0 + $arg1 + $arg2
5508 To execute the command use:
5511 Defines the command "adder" which prints the sum of its three arguments.
5512 Note the arguments are text substitutions, so they may reference variables,
5513 use complex expressions, or even perform inferior function calls.
5515 * New `if' and `while' commands
5517 This makes it possible to write more sophisticated user-defined
5518 commands. Both commands take a single argument, which is the
5519 expression to evaluate, and must be followed by the commands to
5520 execute, one per line, if the expression is nonzero, the list being
5521 terminated by the word `end'. The `if' command list may include an
5522 `else' word, which causes the following commands to be executed only
5523 if the expression is zero.
5525 * Fortran source language mode
5527 GDB now includes partial support for Fortran 77. It will recognize
5528 Fortran programs and can evaluate a subset of Fortran expressions, but
5529 variables and functions may not be handled correctly. GDB will work
5530 with G77, but does not yet know much about symbols emitted by other
5533 * Better HPUX support
5535 Most debugging facilities now work on dynamic executables for HPPAs
5536 running hpux9 or later. You can attach to running dynamically linked
5537 processes, but by default the dynamic libraries will be read-only, so
5538 for instance you won't be able to put breakpoints in them. To change
5539 that behavior do the following before running the program:
5545 This will cause the libraries to be mapped private and read-write.
5546 To revert to the normal behavior, do this:
5552 You cannot set breakpoints or examine data in the library until after
5553 the library is loaded if the function/data symbols do not have
5556 GDB can now also read debug symbols produced by the HP C compiler on
5557 HPPAs (sorry, no C++, Fortran or 68k support).
5559 * Target byte order now dynamically selectable
5561 You can choose which byte order to use with a target system, via the
5562 commands "set endian big" and "set endian little", and you can see the
5563 current setting by using "show endian". You can also give the command
5564 "set endian auto", in which case GDB will use the byte order
5565 associated with the executable. Currently, only embedded MIPS
5566 configurations support dynamic selection of target byte order.
5568 * New DOS host serial code
5570 This version uses DPMI interrupts to handle buffered I/O, so you
5571 no longer need to run asynctsr when debugging boards connected to
5574 *** Changes in GDB-4.13:
5576 * New "complete" command
5578 This lists all the possible completions for the rest of the line, if it
5579 were to be given as a command itself. This is intended for use by emacs.
5581 * Trailing space optional in prompt
5583 "set prompt" no longer adds a space for you after the prompt you set. This
5584 allows you to set a prompt which ends in a space or one that does not.
5586 * Breakpoint hit counts
5588 "info break" now displays a count of the number of times the breakpoint
5589 has been hit. This is especially useful in conjunction with "ignore"; you
5590 can ignore a large number of breakpoint hits, look at the breakpoint info
5591 to see how many times the breakpoint was hit, then run again, ignoring one
5592 less than that number, and this will get you quickly to the last hit of
5595 * Ability to stop printing at NULL character
5597 "set print null-stop" will cause GDB to stop printing the characters of
5598 an array when the first NULL is encountered. This is useful when large
5599 arrays actually contain only short strings.
5601 * Shared library breakpoints
5603 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5604 breakpoints in shared libraries before the executable is run.
5606 * Hardware watchpoints
5608 There is a new hardware breakpoint for the watch command for sparclite
5609 targets. See gdb/sparclite/hw_breakpoint.note.
5611 Hardware watchpoints are also now supported under GNU/Linux.
5615 Annotations have been added. These are for use with graphical interfaces,
5616 and are still experimental. Currently only gdba.el uses these.
5618 * Improved Irix 5 support
5620 GDB now works properly with Irix 5.2.
5622 * Improved HPPA support
5624 GDB now works properly with the latest GCC and GAS.
5626 * New native configurations
5628 Sequent PTX4 i[34]86-sequent-ptx4
5629 HPPA running OSF/1 hppa*-*-osf*
5630 Atari TT running SVR4 m68*-*-sysv4*
5631 RS/6000 LynxOS rs6000-*-lynxos*
5635 OS/9000 i[34]86-*-os9k
5636 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5639 * Hitachi SH7000 and E7000-PC ICE support
5641 There is now support for communicating with the Hitachi E7000-PC ICE.
5642 This is available automatically when GDB is configured for the SH.
5646 As usual, a variety of small fixes and improvements, both generic
5647 and configuration-specific. See the ChangeLog for more detail.
5649 *** Changes in GDB-4.12:
5651 * Irix 5 is now supported
5655 GDB-4.12 on the HPPA has a number of changes which make it unable
5656 to debug the output from the currently released versions of GCC and
5657 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5658 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5659 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5662 *** Changes in GDB-4.11:
5664 * User visible changes:
5668 The "set remotedebug" option is now consistent between the mips remote
5669 target, remote targets using the gdb-specific protocol, UDI (AMD's
5670 debug protocol for the 29k) and the 88k bug monitor. It is now an
5671 integer specifying a debug level (normally 0 or 1, but 2 means more
5672 debugging info for the mips target).
5674 * DEC Alpha native support
5676 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5677 debug info, but GDB works fairly well with the DEC compiler and should
5678 work with a future GCC release. See the README file for a few
5679 Alpha-specific notes.
5681 * Preliminary thread implementation
5683 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5685 * LynxOS native and target support for 386
5687 This release has been hosted on LynxOS 2.2, and also can be configured
5688 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5691 * Improvements in C++ mangling/demangling.
5693 This release has much better g++ debugging, specifically in name
5694 mangling/demangling, virtual function calls, print virtual table,
5695 call methods, ...etc.
5697 *** Changes in GDB-4.10:
5699 * User visible changes:
5701 Remote debugging using the GDB-specific (`target remote') protocol now
5702 supports the `load' command. This is only useful if you have some
5703 other way of getting the stub to the target system, and you can put it
5704 somewhere in memory where it won't get clobbered by the download.
5706 Filename completion now works.
5708 When run under emacs mode, the "info line" command now causes the
5709 arrow to point to the line specified. Also, "info line" prints
5710 addresses in symbolic form (as well as hex).
5712 All vxworks based targets now support a user settable option, called
5713 vxworks-timeout. This option represents the number of seconds gdb
5714 should wait for responses to rpc's. You might want to use this if
5715 your vxworks target is, perhaps, a slow software simulator or happens
5716 to be on the far side of a thin network line.
5720 This release contains support for using a DEC alpha as a GDB host for
5721 cross debugging. Native alpha debugging is not supported yet.
5724 *** Changes in GDB-4.9:
5728 This is the first GDB release which is accompanied by a matching testsuite.
5729 The testsuite requires installation of dejagnu, which should be available
5730 via ftp from most sites that carry GNU software.
5734 'Cfront' style demangling has had its name changed to 'ARM' style, to
5735 emphasize that it was written from the specifications in the C++ Annotated
5736 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5737 disclaimers, it still generated too much confusion with users attempting to
5738 use gdb with AT&T cfront.
5742 GDB now uses a standard remote interface to a simulator library.
5743 So far, the library contains simulators for the Zilog Z8001/2, the
5744 Hitachi H8/300, H8/500 and Super-H.
5746 * New targets supported
5748 H8/300 simulator h8300-hitachi-hms or h8300hms
5749 H8/500 simulator h8500-hitachi-hms or h8500hms
5750 SH simulator sh-hitachi-hms or sh
5751 Z8000 simulator z8k-zilog-none or z8ksim
5752 IDT MIPS board over serial line mips-idt-ecoff
5754 Cross-debugging to GO32 targets is supported. It requires a custom
5755 version of the i386-stub.c module which is integrated with the
5756 GO32 memory extender.
5758 * New remote protocols
5760 MIPS remote debugging protocol.
5762 * New source languages supported
5764 This version includes preliminary support for Chill, a Pascal like language
5765 used by telecommunications companies. Chill support is also being integrated
5766 into the GNU compiler, but we don't know when it will be publically available.
5769 *** Changes in GDB-4.8:
5771 * HP Precision Architecture supported
5773 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5774 version of this support was available as a set of patches from the
5775 University of Utah. GDB does not support debugging of programs
5776 compiled with the HP compiler, because HP will not document their file
5777 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5778 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5780 Many problems in the preliminary version have been fixed.
5782 * Faster and better demangling
5784 We have improved template demangling and fixed numerous bugs in the GNU style
5785 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5786 character types (wchar_t) are now supported. Demangling of each symbol is now
5787 only done once, and is cached when the symbol table for a file is read in.
5788 This results in a small increase in memory usage for C programs, a moderate
5789 increase in memory usage for C++ programs, and a fantastic speedup in
5792 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5793 from the specifications in the Annotated Reference Manual, which AT&T's
5794 compiler does not actually implement.
5796 * G++ multiple inheritance compiler problem
5798 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5799 inheritance lattices was reworked to properly discover ambiguities. We
5800 recently found an example which causes this new algorithm to fail in a
5801 very subtle way, producing bad debug information for those classes.
5802 The file 'gcc.patch' (in this directory) can be applied to gcc to
5803 circumvent the problem. A future GCC release will contain a complete
5806 The previous G++ debug info problem (mentioned below for the gdb-4.7
5807 release) is fixed in gcc version 2.3.2.
5809 * Improved configure script
5811 The `configure' script will now attempt to guess your system type if
5812 you don't supply a host system type. The old scheme of supplying a
5813 host system triplet is preferable over using this. All the magic is
5814 done in the new `config.guess' script. Examine it for details.
5816 We have also brought our configure script much more in line with the FSF's
5817 version. It now supports the --with-xxx options. In particular,
5818 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5819 The resulting GDB will not be able to read arbitrary object file formats --
5820 only the format ``expected'' to be used on the configured target system.
5821 We hope to make this the default in a future release.
5823 * Documentation improvements
5825 There's new internal documentation on how to modify GDB, and how to
5826 produce clean changes to the code. We implore people to read it
5827 before submitting changes.
5829 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5830 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5831 `info' files are also provided. To build `info' files from scratch,
5832 you will need the latest `makeinfo' release, which will be available in
5833 a future texinfo-X.Y release.
5835 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5836 We're not sure exactly which versions have this problem, but it has
5837 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5838 or better. If that isn't possible, there is a patch in
5839 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5840 around this problem.
5844 GDB now supports array constants that can be used in expressions typed in by
5845 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5846 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5849 The new directory `gdb/sparclite' contains a program that demonstrates
5850 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5852 * New native hosts supported
5854 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5855 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5857 * New targets supported
5859 AMD 29k family via UDI a29k-amd-udi or udi29k
5861 * New file formats supported
5863 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5864 HPUX core files, and SCO 3.2v2 core files.
5868 Attaching to processes now works again; thanks for the many bug reports.
5870 We have also stomped on a bunch of core dumps caused by
5871 printf_filtered("%s") problems.
5873 We eliminated a copyright problem on the rpc and ptrace header files
5874 for VxWorks, which was discovered at the last minute during the 4.7
5875 release. You should now be able to build a VxWorks GDB.
5877 You can now interrupt gdb while an attached process is running. This
5878 will cause the attached process to stop, and give control back to GDB.
5880 We fixed problems caused by using too many file descriptors
5881 for reading symbols from object files and libraries. This was
5882 especially a problem for programs that used many (~100) shared
5885 The `step' command now only enters a subroutine if there is line number
5886 information for the subroutine. Otherwise it acts like the `next'
5887 command. Previously, `step' would enter subroutines if there was
5888 any debugging information about the routine. This avoids problems
5889 when using `cc -g1' on MIPS machines.
5891 * Internal improvements
5893 GDB's internal interfaces have been improved to make it easier to support
5894 debugging of multiple languages in the future.
5896 GDB now uses a common structure for symbol information internally.
5897 Minimal symbols (derived from linkage symbols in object files), partial
5898 symbols (from a quick scan of debug information), and full symbols
5899 contain a common subset of information, making it easier to write
5900 shared code that handles any of them.
5902 * New command line options
5904 We now accept --silent as an alias for --quiet.
5908 The memory-mapped-malloc library is now licensed under the GNU Library
5909 General Public License.
5911 *** Changes in GDB-4.7:
5913 * Host/native/target split
5915 GDB has had some major internal surgery to untangle the support for
5916 hosts and remote targets. Now, when you configure GDB for a remote
5917 target, it will no longer load in all of the support for debugging
5918 local programs on the host. When fully completed and tested, this will
5919 ensure that arbitrary host/target combinations are possible.
5921 The primary conceptual shift is to separate the non-portable code in
5922 GDB into three categories. Host specific code is required any time GDB
5923 is compiled on that host, regardless of the target. Target specific
5924 code relates to the peculiarities of the target, but can be compiled on
5925 any host. Native specific code is everything else: it can only be
5926 built when the host and target are the same system. Child process
5927 handling and core file support are two common `native' examples.
5929 GDB's use of /proc for controlling Unix child processes is now cleaner.
5930 It has been split out into a single module under the `target_ops' vector,
5931 plus two native-dependent functions for each system that uses /proc.
5933 * New hosts supported
5935 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5936 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5937 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5939 * New targets supported
5941 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5942 68030 and CPU32 m68030-*-*, m68332-*-*
5944 * New native hosts supported
5946 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5947 (386bsd is not well tested yet)
5948 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5950 * New file formats supported
5952 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5953 supports reading of `a.out.adobe' object files, which are an a.out
5954 format extended with minimal information about multiple sections.
5958 `show copying' is the same as the old `info copying'.
5959 `show warranty' is the same as `info warrantee'.
5960 These were renamed for consistency. The old commands continue to work.
5962 `info handle' is a new alias for `info signals'.
5964 You can now define pre-command hooks, which attach arbitrary command
5965 scripts to any command. The commands in the hook will be executed
5966 prior to the user's command. You can also create a hook which will be
5967 executed whenever the program stops. See gdb.texinfo.
5971 We now deal with Cfront style name mangling, and can even extract type
5972 info from mangled symbols. GDB can automatically figure out which
5973 symbol mangling style your C++ compiler uses.
5975 Calling of methods and virtual functions has been improved as well.
5979 The crash that occured when debugging Sun Ansi-C compiled binaries is
5980 fixed. This was due to mishandling of the extra N_SO stabs output
5983 We also finally got Ultrix 4.2 running in house, and fixed core file
5984 support, with help from a dozen people on the net.
5986 John M. Farrell discovered that the reason that single-stepping was so
5987 slow on all of the Mips based platforms (primarily SGI and DEC) was
5988 that we were trying to demangle and lookup a symbol used for internal
5989 purposes on every instruction that was being stepped through. Changing
5990 the name of that symbol so that it couldn't be mistaken for a C++
5991 mangled symbol sped things up a great deal.
5993 Rich Pixley sped up symbol lookups in general by getting much smarter
5994 about when C++ symbol mangling is necessary. This should make symbol
5995 completion (TAB on the command line) much faster. It's not as fast as
5996 we'd like, but it's significantly faster than gdb-4.6.
6000 A new user controllable variable 'call_scratch_address' can
6001 specify the location of a scratch area to be used when GDB
6002 calls a function in the target. This is necessary because the
6003 usual method of putting the scratch area on the stack does not work
6004 in systems that have separate instruction and data spaces.
6006 We integrated changes to support the 29k UDI (Universal Debugger
6007 Interface), but discovered at the last minute that we didn't have all
6008 of the appropriate copyright paperwork. We are working with AMD to
6009 resolve this, and hope to have it available soon.
6013 We have sped up the remote serial line protocol, especially for targets
6014 with lots of registers. It now supports a new `expedited status' ('T')
6015 message which can be used in place of the existing 'S' status message.
6016 This allows the remote stub to send only the registers that GDB
6017 needs to make a quick decision about single-stepping or conditional
6018 breakpoints, eliminating the need to fetch the entire register set for
6019 each instruction being stepped through.
6021 The GDB remote serial protocol now implements a write-through cache for
6022 registers, only re-reading the registers if the target has run.
6024 There is also a new remote serial stub for SPARC processors. You can
6025 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6026 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6027 processor with a serial port.
6031 Configure.in files have become much easier to read and modify. A new
6032 `table driven' format makes it more obvious what configurations are
6033 supported, and what files each one uses.
6037 There is a new opcodes library which will eventually contain all of the
6038 disassembly routines and opcode tables. At present, it only contains
6039 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6040 disassembler (binutils/objdump) to share these routines.
6042 The libiberty library is now copylefted under the GNU Library General
6043 Public License. This allows more liberal use, and was done so libg++
6044 can use it. This makes no difference to GDB, since the Library License
6045 grants all the rights from the General Public License.
6049 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6050 reference to the stabs symbol info used by the debugger. It is (as far
6051 as we know) the only published document on this fascinating topic. We
6052 encourage you to read it, compare it to the stabs information on your
6053 system, and send improvements on the document in general (to
6054 bug-gdb@prep.ai.mit.edu).
6056 And, of course, many bugs have been fixed.
6059 *** Changes in GDB-4.6:
6061 * Better support for C++ function names
6063 GDB now accepts as input the "demangled form" of C++ overloaded function
6064 names and member function names, and can do command completion on such names
6065 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6066 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6067 Make use of command completion, it is your friend.
6069 GDB also now accepts a variety of C++ mangled symbol formats. They are
6070 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6071 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6072 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6073 for the list of formats.
6075 * G++ symbol mangling problem
6077 Recent versions of gcc have a bug in how they emit debugging information for
6078 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6079 directory) can be applied to gcc to fix the problem. Alternatively, if you
6080 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6081 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6082 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6085 * New 'maintenance' command
6087 All of the commands related to hacking GDB internals have been moved out of
6088 the main command set, and now live behind the 'maintenance' command. This
6089 can also be abbreviated as 'mt'. The following changes were made:
6091 dump-me -> maintenance dump-me
6092 info all-breakpoints -> maintenance info breakpoints
6093 printmsyms -> maintenance print msyms
6094 printobjfiles -> maintenance print objfiles
6095 printpsyms -> maintenance print psymbols
6096 printsyms -> maintenance print symbols
6098 The following commands are new:
6100 maintenance demangle Call internal GDB demangler routine to
6101 demangle a C++ link name and prints the result.
6102 maintenance print type Print a type chain for a given symbol
6104 * Change to .gdbinit file processing
6106 We now read the $HOME/.gdbinit file before processing the argv arguments
6107 (e.g. reading symbol files or core files). This allows global parameters to
6108 be set, which will apply during the symbol reading. The ./.gdbinit is still
6109 read after argv processing.
6111 * New hosts supported
6113 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6115 GNU/Linux support i386-unknown-linux or linux
6117 We are also including code to support the HP/PA running BSD and HPUX. This
6118 is almost guaranteed not to work, as we didn't have time to test or build it
6119 for this release. We are including it so that the more adventurous (or
6120 masochistic) of you can play with it. We also had major problems with the
6121 fact that the compiler that we got from HP doesn't support the -g option.
6124 * New targets supported
6126 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6128 * More smarts about finding #include files
6130 GDB now remembers the compilation directory for all include files, and for
6131 all files from which C is generated (like yacc and lex sources). This
6132 greatly improves GDB's ability to find yacc/lex sources, and include files,
6133 especially if you are debugging your program from a directory different from
6134 the one that contains your sources.
6136 We also fixed a bug which caused difficulty with listing and setting
6137 breakpoints in include files which contain C code. (In the past, you had to
6138 try twice in order to list an include file that you hadn't looked at before.)
6140 * Interesting infernals change
6142 GDB now deals with arbitrary numbers of sections, where the symbols for each
6143 section must be relocated relative to that section's landing place in the
6144 target's address space. This work was needed to support ELF with embedded
6145 stabs used by Solaris-2.0.
6147 * Bug fixes (of course!)
6149 There have been loads of fixes for the following things:
6150 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6151 i960, stabs, DOS(GO32), procfs, etc...
6153 See the ChangeLog for details.
6155 *** Changes in GDB-4.5:
6157 * New machines supported (host and target)
6159 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6161 SGI Irix-4.x mips-sgi-irix4 or iris4
6163 * New malloc package
6165 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6166 Mmalloc is capable of handling mutiple heaps of memory. It is also
6167 capable of saving a heap to a file, and then mapping it back in later.
6168 This can be used to greatly speedup the startup of GDB by using a
6169 pre-parsed symbol table which lives in a mmalloc managed heap. For
6170 more details, please read mmalloc/mmalloc.texi.
6174 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6175 'help info proc' for details.
6177 * MIPS ecoff symbol table format
6179 The code that reads MIPS symbol table format is now supported on all hosts.
6180 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6183 * File name changes for MS-DOS
6185 Many files in the config directories have been renamed to make it easier to
6186 support GDB on MS-DOSe systems (which have very restrictive file name
6187 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6188 environment) is close to working but has some remaining problems. Note
6189 that debugging of DOS programs is not supported, due to limitations
6190 in the ``operating system'', but it can be used to host cross-debugging.
6192 * Cross byte order fixes
6194 Many fixes have been made to support cross debugging of Sparc and MIPS
6195 targets from hosts whose byte order differs.
6197 * New -mapped and -readnow options
6199 If memory-mapped files are available on your system through the 'mmap'
6200 system call, you can use the -mapped option on the `file' or
6201 `symbol-file' commands to cause GDB to write the symbols from your
6202 program into a reusable file. If the program you are debugging is
6203 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6204 Future GDB debugging sessions will notice the presence of this file,
6205 and will quickly map in symbol information from it, rather than reading
6206 the symbol table from the executable program. Using the '-mapped'
6207 option in a GDB `file' or `symbol-file' command has the same effect as
6208 starting GDB with the '-mapped' command-line option.
6210 You can cause GDB to read the entire symbol table immediately by using
6211 the '-readnow' option with any of the commands that load symbol table
6212 information (or on the GDB command line). This makes the command
6213 slower, but makes future operations faster.
6215 The -mapped and -readnow options are typically combined in order to
6216 build a `fred.syms' file that contains complete symbol information.
6217 A simple GDB invocation to do nothing but build a `.syms' file for future
6220 gdb -batch -nx -mapped -readnow programname
6222 The `.syms' file is specific to the host machine on which GDB is run.
6223 It holds an exact image of GDB's internal symbol table. It cannot be
6224 shared across multiple host platforms.
6226 * longjmp() handling
6228 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6229 siglongjmp() without losing control. This feature has not yet been ported to
6230 all systems. It currently works on many 386 platforms, all MIPS-based
6231 platforms (SGI, DECstation, etc), and Sun3/4.
6235 Preliminary work has been put in to support the new Solaris OS from Sun. At
6236 this time, it can control and debug processes, but it is not capable of
6241 As always, many many bug fixes. The major areas were with g++, and mipsread.
6242 People using the MIPS-based platforms should experience fewer mysterious
6243 crashes and trashed symbol tables.
6245 *** Changes in GDB-4.4:
6247 * New machines supported (host and target)
6249 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6251 BSD Reno on Vax vax-dec-bsd
6252 Ultrix on Vax vax-dec-ultrix
6254 * New machines supported (target)
6256 AMD 29000 embedded, using EBMON a29k-none-none
6260 GDB continues to improve its handling of C++. `References' work better.
6261 The demangler has also been improved, and now deals with symbols mangled as
6262 per the Annotated C++ Reference Guide.
6264 GDB also now handles `stabs' symbol information embedded in MIPS
6265 `ecoff' symbol tables. Since the ecoff format was not easily
6266 extensible to handle new languages such as C++, this appeared to be a
6267 good way to put C++ debugging info into MIPS binaries. This option
6268 will be supported in the GNU C compiler, version 2, when it is
6271 * New features for SVR4
6273 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6274 shared libraries. Debugging dynamically linked programs should present
6275 only minor differences from debugging statically linked programs.
6277 The `info proc' command will print out information about any process
6278 on an SVR4 system (including the one you are debugging). At the moment,
6279 it prints the address mappings of the process.
6281 If you bring up GDB on another SVR4 system, please send mail to
6282 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6284 * Better dynamic linking support in SunOS
6286 Reading symbols from shared libraries which contain debugging symbols
6287 now works properly. However, there remain issues such as automatic
6288 skipping of `transfer vector' code during function calls, which
6289 make it harder to debug code in a shared library, than to debug the
6290 same code linked statically.
6294 GDB is now using the latest `getopt' routines from the FSF. This
6295 version accepts the -- prefix for options with long names. GDB will
6296 continue to accept the old forms (-option and +option) as well.
6297 Various single letter abbreviations for options have been explicity
6298 added to the option table so that they won't get overshadowed in the
6299 future by other options that begin with the same letter.
6303 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6304 Many assorted bugs have been handled. Many more remain to be handled.
6305 See the various ChangeLog files (primarily in gdb and bfd) for details.
6308 *** Changes in GDB-4.3:
6310 * New machines supported (host and target)
6312 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6313 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6314 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6316 * Almost SCO Unix support
6318 We had hoped to support:
6319 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6320 (except for core file support), but we discovered very late in the release
6321 that it has problems with process groups that render gdb unusable. Sorry
6322 about that. I encourage people to fix it and post the fixes.
6324 * Preliminary ELF and DWARF support
6326 GDB can read ELF object files on System V Release 4, and can handle
6327 debugging records for C, in DWARF format, in ELF files. This support
6328 is preliminary. If you bring up GDB on another SVR4 system, please
6329 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6334 GDB now uses the latest `readline' library. One user-visible change
6335 is that two tabs will list possible command completions, which previously
6336 required typing M-? (meta-question mark, or ESC ?).
6340 The `stepi' bug that many of you noticed has been squashed.
6341 Many bugs in C++ have been handled. Many more remain to be handled.
6342 See the various ChangeLog files (primarily in gdb and bfd) for details.
6344 * State of the MIPS world (in case you wondered):
6346 GDB can understand the symbol tables emitted by the compilers
6347 supplied by most vendors of MIPS-based machines, including DEC. These
6348 symbol tables are in a format that essentially nobody else uses.
6350 Some versions of gcc come with an assembler post-processor called
6351 mips-tfile. This program is required if you want to do source-level
6352 debugging of gcc-compiled programs. I believe FSF does not ship
6353 mips-tfile with gcc version 1, but it will eventually come with gcc
6356 Debugging of g++ output remains a problem. g++ version 1.xx does not
6357 really support it at all. (If you're lucky, you should be able to get
6358 line numbers and stack traces to work, but no parameters or local
6359 variables.) With some work it should be possible to improve the
6362 When gcc version 2 is released, you will have somewhat better luck.
6363 However, even then you will get confusing results for inheritance and
6366 We will eventually provide full debugging of g++ output on
6367 DECstations. This will probably involve some kind of stabs-in-ecoff
6368 encapulation, but the details have not been worked out yet.
6371 *** Changes in GDB-4.2:
6373 * Improved configuration
6375 Only one copy of `configure' exists now, and it is not self-modifying.
6376 Porting BFD is simpler.
6380 The `step' and `next' commands now only stop at the first instruction
6381 of a source line. This prevents the multiple stops that used to occur
6382 in switch statements, for-loops, etc. `Step' continues to stop if a
6383 function that has debugging information is called within the line.
6387 Lots of small bugs fixed. More remain.
6389 * New host supported (not target)
6391 Intel 386 PC clone running Mach i386-none-mach
6394 *** Changes in GDB-4.1:
6396 * Multiple source language support
6398 GDB now has internal scaffolding to handle several source languages.
6399 It determines the type of each source file from its filename extension,
6400 and will switch expression parsing and number formatting to match the
6401 language of the function in the currently selected stack frame.
6402 You can also specifically set the language to be used, with
6403 `set language c' or `set language modula-2'.
6407 GDB now has preliminary support for the GNU Modula-2 compiler,
6408 currently under development at the State University of New York at
6409 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6410 continue through the fall of 1991 and into 1992.
6412 Other Modula-2 compilers are currently not supported, and attempting to
6413 debug programs compiled with them will likely result in an error as the
6414 symbol table is read. Feel free to work on it, though!
6416 There are hooks in GDB for strict type checking and range checking,
6417 in the `Modula-2 philosophy', but they do not currently work.
6421 GDB can now write to executable and core files (e.g. patch
6422 a variable's value). You must turn this switch on, specify
6423 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6424 by assigning a new value to a variable. Modifications take
6427 * Automatic SunOS shared library reading
6429 When you run your program, GDB automatically determines where its
6430 shared libraries (if any) have been loaded, and reads their symbols.
6431 The `share' command is no longer needed. This also works when
6432 examining core files.
6436 You can specify the number of lines that the `list' command shows.
6439 * New machines supported (host and target)
6441 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6442 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6443 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6445 * New hosts supported (not targets)
6447 IBM RT/PC: romp-ibm-aix or rtpc
6449 * New targets supported (not hosts)
6451 AMD 29000 embedded with COFF a29k-none-coff
6452 AMD 29000 embedded with a.out a29k-none-aout
6453 Ultracomputer remote kernel debug a29k-nyu-kern
6455 * New remote interfaces
6461 *** Changes in GDB-4.0:
6465 Wide output is wrapped at good places to make the output more readable.
6467 Gdb now supports cross-debugging from a host machine of one type to a
6468 target machine of another type. Communication with the target system
6469 is over serial lines. The ``target'' command handles connecting to the
6470 remote system; the ``load'' command will download a program into the
6471 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6472 also supports debugging of realtime processes running under VxWorks,
6473 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6474 stub on the target system.
6476 New CPUs supported include the AMD 29000 and Intel 960.
6478 GDB now reads object files and symbol tables via a ``binary file''
6479 library, which allows a single copy of GDB to debug programs of multiple
6480 object file types such as a.out and coff.
6482 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6483 refcard.dvi and refcard.ps are available to format it).
6486 * Control-Variable user interface simplified
6488 All variables that control the operation of the debugger can be set
6489 by the ``set'' command, and displayed by the ``show'' command.
6491 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6492 ``Show prompt'' produces the response:
6493 Gdb's prompt is new-gdb=>.
6495 What follows are the NEW set commands. The command ``help set'' will
6496 print a complete list of old and new set commands. ``help set FOO''
6497 will give a longer description of the variable FOO. ``show'' will show
6498 all of the variable descriptions and their current settings.
6500 confirm on/off: Enables warning questions for operations that are
6501 hard to recover from, e.g. rerunning the program while
6502 it is already running. Default is ON.
6504 editing on/off: Enables EMACS style command line editing
6505 of input. Previous lines can be recalled with
6506 control-P, the current line can be edited with control-B,
6507 you can search for commands with control-R, etc.
6510 history filename NAME: NAME is where the gdb command history
6511 will be stored. The default is .gdb_history,
6512 or the value of the environment variable
6515 history size N: The size, in commands, of the command history. The
6516 default is 256, or the value of the environment variable
6519 history save on/off: If this value is set to ON, the history file will
6520 be saved after exiting gdb. If set to OFF, the
6521 file will not be saved. The default is OFF.
6523 history expansion on/off: If this value is set to ON, then csh-like
6524 history expansion will be performed on
6525 command line input. The default is OFF.
6527 radix N: Sets the default radix for input and output. It can be set
6528 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6529 in the current radix, so "set radix 10" is always a no-op.
6531 height N: This integer value is the number of lines on a page. Default
6532 is 24, the current `stty rows'' setting, or the ``li#''
6533 setting from the termcap entry matching the environment
6536 width N: This integer value is the number of characters on a line.
6537 Default is 80, the current `stty cols'' setting, or the ``co#''
6538 setting from the termcap entry matching the environment
6541 Note: ``set screensize'' is obsolete. Use ``set height'' and
6542 ``set width'' instead.
6544 print address on/off: Print memory addresses in various command displays,
6545 such as stack traces and structure values. Gdb looks
6546 more ``symbolic'' if you turn this off; it looks more
6547 ``machine level'' with it on. Default is ON.
6549 print array on/off: Prettyprint arrays. New convenient format! Default
6552 print demangle on/off: Print C++ symbols in "source" form if on,
6555 print asm-demangle on/off: Same, for assembler level printouts
6558 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6561 * Support for Epoch Environment.
6563 The epoch environment is a version of Emacs v18 with windowing. One
6564 new command, ``inspect'', is identical to ``print'', except that if you
6565 are running in the epoch environment, the value is printed in its own
6569 * Support for Shared Libraries
6571 GDB can now debug programs and core files that use SunOS shared libraries.
6572 Symbols from a shared library cannot be referenced
6573 before the shared library has been linked with the program (this
6574 happens after you type ``run'' and before the function main() is entered).
6575 At any time after this linking (including when examining core files
6576 from dynamically linked programs), gdb reads the symbols from each
6577 shared library when you type the ``sharedlibrary'' command.
6578 It can be abbreviated ``share''.
6580 sharedlibrary REGEXP: Load shared object library symbols for files
6581 matching a unix regular expression. No argument
6582 indicates to load symbols for all shared libraries.
6584 info sharedlibrary: Status of loaded shared libraries.
6589 A watchpoint stops execution of a program whenever the value of an
6590 expression changes. Checking for this slows down execution
6591 tremendously whenever you are in the scope of the expression, but is
6592 quite useful for catching tough ``bit-spreader'' or pointer misuse
6593 problems. Some machines such as the 386 have hardware for doing this
6594 more quickly, and future versions of gdb will use this hardware.
6596 watch EXP: Set a watchpoint (breakpoint) for an expression.
6598 info watchpoints: Information about your watchpoints.
6600 delete N: Deletes watchpoint number N (same as breakpoints).
6601 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6602 enable N: Re-enables watchpoint number N (same as breakpoints).
6605 * C++ multiple inheritance
6607 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6610 * C++ exception handling
6612 Gdb now supports limited C++ exception handling. Besides the existing
6613 ability to breakpoint on an exception handler, gdb can breakpoint on
6614 the raising of an exception (before the stack is peeled back to the
6617 catch FOO: If there is a FOO exception handler in the dynamic scope,
6618 set a breakpoint to catch exceptions which may be raised there.
6619 Multiple exceptions (``catch foo bar baz'') may be caught.
6621 info catch: Lists all exceptions which may be caught in the
6622 current stack frame.
6625 * Minor command changes
6627 The command ``call func (arg, arg, ...)'' now acts like the print
6628 command, except it does not print or save a value if the function's result
6629 is void. This is similar to dbx usage.
6631 The ``up'' and ``down'' commands now always print the frame they end up
6632 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6633 frames without printing.
6635 * New directory command
6637 'dir' now adds directories to the FRONT of the source search path.
6638 The path starts off empty. Source files that contain debug information
6639 about the directory in which they were compiled can be found even
6640 with an empty path; Sun CC and GCC include this information. If GDB can't
6641 find your source file in the current directory, type "dir .".
6643 * Configuring GDB for compilation
6645 For normal use, type ``./configure host''. See README or gdb.texinfo
6648 GDB now handles cross debugging. If you are remotely debugging between
6649 two different machines, type ``./configure host -target=targ''.
6650 Host is the machine where GDB will run; targ is the machine
6651 where the program that you are debugging will run.