1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.12
6 * GDB and GDBserver now require building with a C++ compiler.
8 It is no longer possible to build GDB or GDBserver with a C
9 compiler. The --disable-build-with-cxx configure option has been
12 * Native debugging on MS-Windows supports command-line redirection
14 Command-line arguments used for starting programs on MS-Windows can
15 now include redirection symbols supported by native Windows shells,
16 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
17 as "run", "start", and "set args", as well as the corresponding MI
20 * Support for thread names on MS-Windows.
22 GDB now catches and handles the special exception that programs
23 running on MS-Windows use to assign names to threads in the
26 * Support for Java programs compiled with gcj has been removed.
30 Synopsys ARC arc*-*-elf32
32 *** Changes in GDB 7.12
34 * GDB and GDBserver now build with a C++ compiler by default.
36 The --enable-build-with-cxx configure option is now enabled by
37 default. One must now explicitly configure with
38 --disable-build-with-cxx in order to build with a C compiler. This
39 option will be removed in a future release.
41 * GDBserver now supports recording btrace without maintaining an active
44 * GDB now supports a negative repeat count in the 'x' command to examine
45 memory backward from the given address. For example:
48 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
49 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
50 (gdb) x/-5i 0x0000000000400580
51 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
52 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
53 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
54 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
55 0x40057b <main(int, char**)+25>:
56 callq 0x400536 <Func1(int, char const*)>
58 * Fortran: Support structures with fields of dynamic types and
59 arrays of dynamic types.
61 * GDB now supports multibit bitfields and enums in target register
64 * New Python-based convenience function $_as_string(val), which returns
65 the textual representation of a value. This function is especially
66 useful to obtain the text label of an enum value.
68 * Intel MPX bound violation handling.
70 Segmentation faults caused by a Intel MPX boundary violation
71 now display the kind of violation (upper or lower), the memory
72 address accessed and the memory bounds, along with the usual
73 signal received and code location.
77 Program received signal SIGSEGV, Segmentation fault
78 Upper bound violation while accessing address 0x7fffffffc3b3
79 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
80 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
82 * Rust language support.
83 GDB now supports debugging programs written in the Rust programming
84 language. See https://www.rust-lang.org/ for more information about
87 * Support for running interpreters on specified input/output devices
89 GDB now supports a new mechanism that allows frontends to provide
90 fully featured GDB console views, as a better alternative to
91 building such views on top of the "-interpreter-exec console"
92 command. See the new "new-ui" command below. With that command,
93 frontends can now start GDB in the traditional command-line mode
94 running in an embedded terminal emulator widget, and create a
95 separate MI interpreter running on a specified i/o device. In this
96 way, GDB handles line editing, history, tab completion, etc. in the
97 console all by itself, and the GUI uses the separate MI interpreter
98 for its own control and synchronization, invisible to the command
101 * The "catch syscall" command catches groups of related syscalls.
103 The "catch syscall" command now supports catching a group of related
104 syscalls using the 'group:' or 'g:' prefix.
109 skip -gfile file-glob-pattern
110 skip -function function
111 skip -rfunction regular-expression
112 A generalized form of the skip command, with new support for
113 glob-style file names and regular expressions for function names.
114 Additionally, a file spec and a function spec may now be combined.
116 maint info line-table REGEXP
117 Display the contents of GDB's internal line table data struture.
120 Run any GDB unit tests that were compiled in.
123 Start a new user interface instance running INTERP as interpreter,
124 using the TTY file for input/output.
128 ** gdb.Breakpoint objects have a new attribute "pending", which
129 indicates whether the breakpoint is pending.
130 ** Three new breakpoint-related events have been added:
131 gdb.breakpoint_created, gdb.breakpoint_modified, and
132 gdb.breakpoint_deleted.
135 Signal ("set") the given MS-Windows event object. This is used in
136 conjunction with the Windows JIT debugging (AeDebug) support, where
137 the OS suspends a crashing process until a debugger can attach to
138 it. Resuming the crashing process, in order to debug it, is done by
141 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
142 was added in GDBserver, including JIT compiling fast tracepoint's
143 conditional expression bytecode into native code.
145 * Support for various remote target protocols and ROM monitors has
148 target m32rsdi Remote M32R debugging over SDI
149 target mips MIPS remote debugging protocol
150 target pmon PMON ROM monitor
151 target ddb NEC's DDB variant of PMON for Vr4300
152 target rockhopper NEC RockHopper variant of PMON
153 target lsi LSI variant of PMO
155 * Support for tracepoints and fast tracepoints on powerpc-linux,
156 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
157 including JIT compiling fast tracepoint's conditional expression
158 bytecode into native code.
160 * MI async record =record-started now includes the method and format used for
161 recording. For example:
163 =record-started,thread-group="i1",method="btrace",format="bts"
165 * MI async record =thread-selected now includes the frame field. For example:
167 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
171 Andes NDS32 nds32*-*-elf
173 *** Changes in GDB 7.11
175 * GDB now supports debugging kernel-based threads on FreeBSD.
177 * Per-inferior thread numbers
179 Thread numbers are now per inferior instead of global. If you're
180 debugging multiple inferiors, GDB displays thread IDs using a
181 qualified INF_NUM.THR_NUM form. For example:
185 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
186 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
187 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
188 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
190 As consequence, thread numbers as visible in the $_thread
191 convenience variable and in Python's InferiorThread.num attribute
192 are no longer unique between inferiors.
194 GDB now maintains a second thread ID per thread, referred to as the
195 global thread ID, which is the new equivalent of thread numbers in
196 previous releases. See also $_gthread below.
198 For backwards compatibility, MI's thread IDs always refer to global
201 * Commands that accept thread IDs now accept the qualified
202 INF_NUM.THR_NUM form as well. For example:
205 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
208 * In commands that accept a list of thread IDs, you can now refer to
209 all threads of an inferior using a star wildcard. GDB accepts
210 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
211 refer to all threads of the current inferior. For example, "info
214 * You can use "info threads -gid" to display the global thread ID of
217 * The new convenience variable $_gthread holds the global number of
220 * The new convenience variable $_inferior holds the number of the
223 * GDB now displays the ID and name of the thread that hit a breakpoint
224 or received a signal, if your program is multi-threaded. For
227 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
228 Thread 1 "main" received signal SIGINT, Interrupt.
230 * Record btrace now supports non-stop mode.
232 * Support for tracepoints on aarch64-linux was added in GDBserver.
234 * The 'record instruction-history' command now indicates speculative execution
235 when using the Intel Processor Trace recording format.
237 * GDB now allows users to specify explicit locations, bypassing
238 the linespec parser. This feature is also available to GDB/MI
241 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
242 GDB now is able to debug both AArch64 applications and ARM applications
245 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
246 including JIT compiling fast tracepoint's conditional expression bytecode
249 * GDB now supports displaced stepping on AArch64 GNU/Linux.
251 * "info threads", "info inferiors", "info display", "info checkpoints"
252 and "maint info program-spaces" now list the corresponding items in
253 ascending ID order, for consistency with all other "info" commands.
255 * In Ada, the overloads selection menu has been enhanced to display the
256 parameter types and the return types for the matching overloaded subprograms.
260 maint set target-non-stop (on|off|auto)
261 maint show target-non-stop
262 Control whether GDB targets always operate in non-stop mode even if
263 "set non-stop" is "off". The default is "auto", meaning non-stop
264 mode is enabled if supported by the target.
266 maint set bfd-sharing
267 maint show bfd-sharing
268 Control the reuse of bfd objects.
272 Control display of debugging info regarding bfd caching.
276 Control display of debugging info regarding FreeBSD threads.
278 set remote multiprocess-extensions-packet
279 show remote multiprocess-extensions-packet
280 Set/show the use of the remote protocol multiprocess extensions.
282 set remote thread-events
283 show remote thread-events
284 Set/show the use of thread create/exit events.
286 set ada print-signatures on|off
287 show ada print-signatures"
288 Control whether parameter types and return types are displayed in overloads
289 selection menus. It is activaled (@code{on}) by default.
293 Controls the maximum size of memory, in bytes, that GDB will
294 allocate for value contents. Prevents incorrect programs from
295 causing GDB to allocate overly large buffers. Default is 64k.
297 * The "disassemble" command accepts a new modifier: /s.
298 It prints mixed source+disassembly like /m with two differences:
299 - disassembled instructions are now printed in program order, and
300 - and source for all relevant files is now printed.
301 The "/m" option is now considered deprecated: its "source-centric"
302 output hasn't proved useful in practice.
304 * The "record instruction-history" command accepts a new modifier: /s.
305 It behaves exactly like /m and prints mixed source+disassembly.
307 * The "set scheduler-locking" command supports a new mode "replay".
308 It behaves like "off" in record mode and like "on" in replay mode.
310 * Support for various ROM monitors has been removed:
312 target dbug dBUG ROM monitor for Motorola ColdFire
313 target picobug Motorola picobug monitor
314 target dink32 DINK32 ROM monitor for PowerPC
315 target m32r Renesas M32R/D ROM monitor
316 target mon2000 mon2000 ROM monitor
317 target ppcbug PPCBUG ROM monitor for PowerPC
319 * Support for reading/writing memory and extracting values on architectures
320 whose memory is addressable in units of any integral multiple of 8 bits.
325 Indicates that an exec system call was executed.
327 exec-events feature in qSupported
328 The qSupported packet allows GDB to request support for exec
329 events using the new 'gdbfeature' exec-event, and the qSupported
330 response can contain the corresponding 'stubfeature'. Set and
331 show commands can be used to display whether these features are enabled.
334 Equivalent to interrupting with the ^C character, but works in
337 thread created stop reason (T05 create:...)
338 Indicates that the thread was just created and is stopped at entry.
340 thread exit stop reply (w exitcode;tid)
341 Indicates that the thread has terminated.
344 Enables/disables thread create and exit event reporting. For
345 example, this is used in non-stop mode when GDB stops a set of
346 threads and synchronously waits for the their corresponding stop
347 replies. Without exit events, if one of the threads exits, GDB
348 would hang forever not knowing that it should no longer expect a
349 stop for that same thread.
352 Indicates that there are no resumed threads left in the target (all
353 threads are stopped). The remote stub reports support for this stop
354 reply to GDB's qSupported query.
357 Enables/disables catching syscalls from the inferior process.
358 The remote stub reports support for this packet to GDB's qSupported query.
360 syscall_entry stop reason
361 Indicates that a syscall was just called.
363 syscall_return stop reason
364 Indicates that a syscall just returned.
366 * Extended-remote exec events
368 ** GDB now has support for exec events on extended-remote Linux targets.
369 For such targets with Linux kernels 2.5.46 and later, this enables
370 follow-exec-mode and exec catchpoints.
372 set remote exec-event-feature-packet
373 show remote exec-event-feature-packet
374 Set/show the use of the remote exec event feature.
376 * Thread names in remote protocol
378 The reply to qXfer:threads:read may now include a name attribute for each
381 * Target remote mode fork and exec events
383 ** GDB now has support for fork and exec events on target remote mode
384 Linux targets. For such targets with Linux kernels 2.5.46 and later,
385 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
386 fork and exec catchpoints.
388 * Remote syscall events
390 ** GDB now has support for catch syscall on remote Linux targets,
391 currently enabled on x86/x86_64 architectures.
393 set remote catch-syscall-packet
394 show remote catch-syscall-packet
395 Set/show the use of the remote catch syscall feature.
399 ** The -var-set-format command now accepts the zero-hexadecimal
400 format. It outputs data in hexadecimal format with zero-padding on the
405 ** gdb.InferiorThread objects have a new attribute "global_num",
406 which refers to the thread's global thread ID. The existing
407 "num" attribute now refers to the thread's per-inferior number.
408 See "Per-inferior thread numbers" above.
409 ** gdb.InferiorThread objects have a new attribute "inferior", which
410 is the Inferior object the thread belongs to.
412 *** Changes in GDB 7.10
414 * Support for process record-replay and reverse debugging on aarch64*-linux*
415 targets has been added. GDB now supports recording of A64 instruction set
416 including advance SIMD instructions.
418 * Support for Sun's version of the "stabs" debug file format has been removed.
420 * GDB now honors the content of the file /proc/PID/coredump_filter
421 (PID is the process ID) on GNU/Linux systems. This file can be used
422 to specify the types of memory mappings that will be included in a
423 corefile. For more information, please refer to the manual page of
424 "core(5)". GDB also has a new command: "set use-coredump-filter
425 on|off". It allows to set whether GDB will read the content of the
426 /proc/PID/coredump_filter file when generating a corefile.
428 * The "info os" command on GNU/Linux can now display information on
430 "info os cpus" Listing of all cpus/cores on the system
432 * GDB has two new commands: "set serial parity odd|even|none" and
433 "show serial parity". These allows to set or show parity for the
436 * The "info source" command now displays the producer string if it was
437 present in the debug info. This typically includes the compiler version
438 and may include things like its command line arguments.
440 * The "info dll", an alias of the "info sharedlibrary" command,
441 is now available on all platforms.
443 * Directory names supplied to the "set sysroot" commands may be
444 prefixed with "target:" to tell GDB to access shared libraries from
445 the target system, be it local or remote. This replaces the prefix
446 "remote:". The default sysroot has been changed from "" to
447 "target:". "remote:" is automatically converted to "target:" for
448 backward compatibility.
450 * The system root specified by "set sysroot" will be prepended to the
451 filename of the main executable (if reported to GDB as absolute by
452 the operating system) when starting processes remotely, and when
453 attaching to already-running local or remote processes.
455 * GDB now supports automatic location and retrieval of executable
456 files from remote targets. Remote debugging can now be initiated
457 using only a "target remote" or "target extended-remote" command
458 (no "set sysroot" or "file" commands are required). See "New remote
461 * The "dump" command now supports verilog hex format.
463 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
465 * On GNU/Linux, GDB and gdbserver are now able to access executable
466 and shared library files without a "set sysroot" command when
467 attaching to processes running in different mount namespaces from
468 the debugger. This makes it possible to attach to processes in
469 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
470 See "New remote packets" below.
472 * The "tui reg" command now provides completion for all of the
473 available register groups, including target specific groups.
475 * The HISTSIZE environment variable is no longer read when determining
476 the size of GDB's command history. GDB now instead reads the dedicated
477 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
478 disables truncation of command history. Non-numeric values of GDBHISTSIZE
483 ** Memory ports can now be unbuffered.
487 ** gdb.Objfile objects have a new attribute "username",
488 which is the name of the objfile as specified by the user,
489 without, for example, resolving symlinks.
490 ** You can now write frame unwinders in Python.
491 ** gdb.Type objects have a new method "optimized_out",
492 returning optimized out gdb.Value instance of this type.
493 ** gdb.Value objects have new methods "reference_value" and
494 "const_value" which return a reference to the value and a
495 "const" version of the value respectively.
499 maint print symbol-cache
500 Print the contents of the symbol cache.
502 maint print symbol-cache-statistics
503 Print statistics of symbol cache usage.
505 maint flush-symbol-cache
506 Flush the contents of the symbol cache.
510 Start branch trace recording using Branch Trace Store (BTS) format.
513 Evaluate expression by using the compiler and print result.
517 Explicit commands for enabling and disabling tui mode.
520 set mpx bound on i386 and amd64
521 Support for bound table investigation on Intel MPX enabled applications.
525 Start branch trace recording using Intel Processor Trace format.
528 Print information about branch tracing internals.
530 maint btrace packet-history
531 Print the raw branch tracing data.
533 maint btrace clear-packet-history
534 Discard the stored raw branch tracing data.
537 Discard all branch tracing data. It will be fetched and processed
538 anew by the next "record" command.
543 Renamed from "set debug dwarf2-die".
545 Renamed from "show debug dwarf2-die".
548 Renamed from "set debug dwarf2-read".
549 show debug dwarf-read
550 Renamed from "show debug dwarf2-read".
552 maint set dwarf always-disassemble
553 Renamed from "maint set dwarf2 always-disassemble".
554 maint show dwarf always-disassemble
555 Renamed from "maint show dwarf2 always-disassemble".
557 maint set dwarf max-cache-age
558 Renamed from "maint set dwarf2 max-cache-age".
559 maint show dwarf max-cache-age
560 Renamed from "maint show dwarf2 max-cache-age".
563 show debug dwarf-line
564 Control display of debugging info regarding DWARF line processing.
568 Set the maximum number of candidates to be considered during
569 completion. The default value is 200. This limit allows GDB
570 to avoid generating large completion lists, the computation of
571 which can cause the debugger to become temporarily unresponsive.
573 set history remove-duplicates
574 show history remove-duplicates
575 Control the removal of duplicate history entries.
577 maint set symbol-cache-size
578 maint show symbol-cache-size
579 Control the size of the symbol cache.
581 set|show record btrace bts buffer-size
582 Set and show the size of the ring buffer used for branch tracing in
584 The obtained size may differ from the requested size. Use "info
585 record" to see the obtained buffer size.
587 set debug linux-namespaces
588 show debug linux-namespaces
589 Control display of debugging info regarding Linux namespaces.
591 set|show record btrace pt buffer-size
592 Set and show the size of the ring buffer used for branch tracing in
593 Intel Processor Trace format.
594 The obtained size may differ from the requested size. Use "info
595 record" to see the obtained buffer size.
597 maint set|show btrace pt skip-pad
598 Set and show whether PAD packets are skipped when computing the
601 * The command 'thread apply all' can now support new option '-ascending'
602 to call its specified command for all threads in ascending order.
604 * Python/Guile scripting
606 ** GDB now supports auto-loading of Python/Guile scripts contained in the
607 special section named `.debug_gdb_scripts'.
611 qXfer:btrace-conf:read
612 Return the branch trace configuration for the current thread.
614 Qbtrace-conf:bts:size
615 Set the requested ring buffer size for branch tracing in BTS format.
618 Enable Intel Procesor Trace-based branch tracing for the current
619 process. The remote stub reports support for this packet to GDB's
623 Set the requested ring buffer size for branch tracing in Intel Processor
627 Indicates a memory breakpoint instruction was executed, irrespective
628 of whether it was GDB that planted the breakpoint or the breakpoint
629 is hardcoded in the program. This is required for correct non-stop
633 Indicates the target stopped for a hardware breakpoint. This is
634 required for correct non-stop mode operation.
637 Return information about files on the remote system.
640 Return the full absolute name of the file that was executed to
641 create a process running on the remote system.
644 Select the filesystem on which vFile: operations with filename
645 arguments will operate. This is required for GDB to be able to
646 access files on remote targets where the remote stub does not
647 share a common filesystem with the inferior(s).
650 Indicates that a fork system call was executed.
653 Indicates that a vfork system call was executed.
655 vforkdone stop reason
656 Indicates that a vfork child of the specified process has executed
657 an exec or exit, allowing the vfork parent to resume execution.
659 fork-events and vfork-events features in qSupported
660 The qSupported packet allows GDB to request support for fork and
661 vfork events using new 'gdbfeatures' fork-events and vfork-events,
662 and the qSupported response can contain the corresponding
663 'stubfeatures'. Set and show commands can be used to display
664 whether these features are enabled.
666 * Extended-remote fork events
668 ** GDB now has support for fork events on extended-remote Linux
669 targets. For targets with Linux kernels 2.5.60 and later, this
670 enables follow-fork-mode and detach-on-fork for both fork and
671 vfork, as well as fork and vfork catchpoints.
673 * The info record command now shows the recording format and the
674 branch tracing configuration for the current thread when using
675 the btrace record target.
676 For the BTS format, it shows the ring buffer size.
678 * GDB now has support for DTrace USDT (Userland Static Defined
679 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
681 * GDB now supports access to vector registers on S/390 GNU/Linux
684 * Removed command line options
686 -xdb HP-UX XDB compatibility mode.
688 * Removed targets and native configurations
690 HP/PA running HP-UX hppa*-*-hpux*
691 Itanium running HP-UX ia64-*-hpux*
693 * New configure options
696 This configure option allows the user to build GDB with support for
697 Intel Processor Trace (default: auto). This requires libipt.
699 --with-libipt-prefix=PATH
700 Specify the path to the version of libipt that GDB should use.
701 $PATH/include should contain the intel-pt.h header and
702 $PATH/lib should contain the libipt.so library.
704 *** Changes in GDB 7.9.1
708 ** Xmethods can now specify a result type.
710 *** Changes in GDB 7.9
712 * GDB now supports hardware watchpoints on x86 GNU Hurd.
716 ** You can now access frame registers from Python scripts.
717 ** New attribute 'producer' for gdb.Symtab objects.
718 ** gdb.Objfile objects have a new attribute "progspace",
719 which is the gdb.Progspace object of the containing program space.
720 ** gdb.Objfile objects have a new attribute "owner".
721 ** gdb.Objfile objects have a new attribute "build_id",
722 which is the build ID generated when the file was built.
723 ** gdb.Objfile objects have a new method "add_separate_debug_file".
724 ** A new event "gdb.clear_objfiles" has been added, triggered when
725 selecting a new file to debug.
726 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
727 ** New function gdb.lookup_objfile.
729 New events which are triggered when GDB modifies the state of the
732 ** gdb.events.inferior_call_pre: Function call is about to be made.
733 ** gdb.events.inferior_call_post: Function call has just been made.
734 ** gdb.events.memory_changed: A memory location has been altered.
735 ** gdb.events.register_changed: A register has been altered.
737 * New Python-based convenience functions:
739 ** $_caller_is(name [, number_of_frames])
740 ** $_caller_matches(regexp [, number_of_frames])
741 ** $_any_caller_is(name [, number_of_frames])
742 ** $_any_caller_matches(regexp [, number_of_frames])
744 * GDB now supports the compilation and injection of source code into
745 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
746 to compile the source code to object code, and if successful, inject
747 and execute that code within the current context of the inferior.
748 Currently the C language is supported. The commands used to
749 interface with this new feature are:
751 compile code [-raw|-r] [--] [source code]
752 compile file [-raw|-r] filename
756 demangle [-l language] [--] name
757 Demangle "name" in the specified language, or the current language
758 if elided. This command is renamed from the "maint demangle" command.
759 The latter is kept as a no-op to avoid "maint demangle" being interpreted
760 as "maint demangler-warning".
762 queue-signal signal-name-or-number
763 Queue a signal to be delivered to the thread when it is resumed.
765 add-auto-load-scripts-directory directory
766 Add entries to the list of directories from which to load auto-loaded
769 maint print user-registers
770 List all currently available "user" registers.
772 compile code [-r|-raw] [--] [source code]
773 Compile, inject, and execute in the inferior the executable object
774 code produced by compiling the provided source code.
776 compile file [-r|-raw] filename
777 Compile and inject into the inferior the executable object code
778 produced by compiling the source code stored in the filename
781 * On resume, GDB now always passes the signal the program had stopped
782 for to the thread the signal was sent to, even if the user changed
783 threads before resuming. Previously GDB would often (but not
784 always) deliver the signal to the thread that happens to be current
787 * Conversely, the "signal" command now consistently delivers the
788 requested signal to the current thread. GDB now asks for
789 confirmation if the program had stopped for a signal and the user
790 switched threads meanwhile.
792 * "breakpoint always-inserted" modes "off" and "auto" merged.
794 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
795 won't remove breakpoints from the target until all threads stop,
796 even in non-stop mode. The "auto" mode has been removed, and "off"
797 is now the default mode.
801 set debug symbol-lookup
802 show debug symbol-lookup
803 Control display of debugging info regarding symbol lookup.
807 ** The -list-thread-groups command outputs an exit-code field for
808 inferiors that have exited.
812 MIPS SDE mips*-sde*-elf*
816 Support for these obsolete configurations has been removed.
818 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
819 SGI Irix-5.x mips-*-irix5*
820 SGI Irix-6.x mips-*-irix6*
821 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
822 VAX running Ultrix vax-*-ultrix*
824 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
825 and "assf"), have been removed. Use the "sharedlibrary" command, or
826 its alias "share", instead.
828 *** Changes in GDB 7.8
830 * New command line options
833 This is an alias for the --data-directory option.
835 * GDB supports printing and modifying of variable length automatic arrays
836 as specified in ISO C99.
838 * The ARM simulator now supports instruction level tracing
839 with or without disassembly.
843 GDB now has support for scripting using Guile. Whether this is
844 available is determined at configure time.
845 Guile version 2.0 or greater is required.
846 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
848 * New commands (for set/show, see "New options" below)
852 Invoke CODE by passing it to the Guile interpreter.
856 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
858 info auto-load guile-scripts [regexp]
859 Print the list of automatically loaded Guile scripts.
861 * The source command is now capable of sourcing Guile scripts.
862 This feature is dependent on the debugger being built with Guile support.
866 set print symbol-loading (off|brief|full)
867 show print symbol-loading
868 Control whether to print informational messages when loading symbol
869 information for a file. The default is "full", but when debugging
870 programs with large numbers of shared libraries the amount of output
873 set guile print-stack (none|message|full)
874 show guile print-stack
875 Show a stack trace when an error is encountered in a Guile script.
877 set auto-load guile-scripts (on|off)
878 show auto-load guile-scripts
879 Control auto-loading of Guile script files.
881 maint ada set ignore-descriptive-types (on|off)
882 maint ada show ignore-descriptive-types
883 Control whether the debugger should ignore descriptive types in Ada
884 programs. The default is not to ignore the descriptive types. See
885 the user manual for more details on descriptive types and the intended
886 usage of this option.
888 set auto-connect-native-target
890 Control whether GDB is allowed to automatically connect to the
891 native target for the run, attach, etc. commands when not connected
892 to any target yet. See also "target native" below.
894 set record btrace replay-memory-access (read-only|read-write)
895 show record btrace replay-memory-access
896 Control what memory accesses are allowed during replay.
898 maint set target-async (on|off)
899 maint show target-async
900 This controls whether GDB targets operate in synchronous or
901 asynchronous mode. Normally the default is asynchronous, if it is
902 available; but this can be changed to more easily debug problems
903 occurring only in synchronous mode.
905 set mi-async (on|off)
907 Control whether MI asynchronous mode is preferred. This supersedes
908 "set target-async" of previous GDB versions.
910 * "set target-async" is deprecated as a CLI option and is now an alias
911 for "set mi-async" (only puts MI into async mode).
913 * Background execution commands (e.g., "c&", "s&", etc.) are now
914 possible ``out of the box'' if the target supports them. Previously
915 the user would need to explicitly enable the possibility with the
916 "set target-async on" command.
918 * New features in the GDB remote stub, GDBserver
920 ** New option --debug-format=option1[,option2,...] allows one to add
921 additional text to each output. At present only timestamps
922 are supported: --debug-format=timestamps.
923 Timestamps can also be turned on with the
924 "monitor set debug-format timestamps" command from GDB.
926 * The 'record instruction-history' command now starts counting instructions
927 at one. This also affects the instruction ranges reported by the
928 'record function-call-history' command when given the /i modifier.
930 * The command 'record function-call-history' supports a new modifier '/c' to
931 indent the function names based on their call stack depth.
932 The fields for the '/i' and '/l' modifier have been reordered.
933 The source line range is now prefixed with 'at'.
934 The instruction range is now prefixed with 'inst'.
935 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
936 "record instruction-history" and "list" commands.
938 * The ranges given as arguments to the 'record function-call-history' and
939 'record instruction-history' commands are now inclusive.
941 * The btrace record target now supports the 'record goto' command.
942 For locations inside the execution trace, the back trace is computed
943 based on the information stored in the execution trace.
945 * The btrace record target supports limited reverse execution and replay.
946 The target does not record data and therefore does not allow reading
949 * The "catch syscall" command now works on s390*-linux* targets.
951 * The "compare-sections" command is no longer specific to target
952 remote. It now works with all targets.
954 * All native targets are now consistently called "native".
955 Consequently, the "target child", "target GNU", "target djgpp",
956 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
957 commands have been replaced with "target native". The QNX/NTO port
958 leaves the "procfs" target in place and adds a "native" target for
959 consistency with other ports. The impact on users should be minimal
960 as these commands previously either throwed an error, or were
961 no-ops. The target's name is visible in the output of the following
962 commands: "help target", "info target", "info files", "maint print
965 * The "target native" command now connects to the native target. This
966 can be used to launch native programs even when "set
967 auto-connect-native-target" is set to off.
969 * GDB now supports access to Intel MPX registers on GNU/Linux.
971 * Support for Intel AVX-512 registers on GNU/Linux.
972 Support displaying and modifying Intel AVX-512 registers
973 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
977 qXfer:btrace:read's annex
978 The qXfer:btrace:read packet supports a new annex 'delta' to read
979 branch trace incrementally.
983 ** Valid Python operations on gdb.Value objects representing
984 structs/classes invoke the corresponding overloaded operators if
986 ** New `Xmethods' feature in the Python API. Xmethods are
987 additional methods or replacements for existing methods of a C++
988 class. This feature is useful for those cases where a method
989 defined in C++ source code could be inlined or optimized out by
990 the compiler, making it unavailable to GDB.
993 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
995 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
996 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
997 its alias "share", instead.
999 * The commands "set remotebaud" and "show remotebaud" are no longer
1000 supported. Use "set serial baud" and "show serial baud" (respectively)
1005 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1006 target-async". The latter is left as a deprecated alias of the
1007 former for backward compatibility. If the target supports it,
1008 CLI background execution commands are now always possible by
1009 default, independently of whether the frontend stated a
1010 preference for asynchronous execution with "-gdb-set mi-async".
1011 Previously "-gdb-set target-async off" affected both MI execution
1012 commands and CLI execution commands.
1014 *** Changes in GDB 7.7
1016 * Improved support for process record-replay and reverse debugging on
1017 arm*-linux* targets. Support for thumb32 and syscall instruction
1018 recording has been added.
1020 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1022 * GDB now supports Fission DWP file format version 2.
1023 http://gcc.gnu.org/wiki/DebugFission
1025 * New convenience function "$_isvoid", to check whether an expression
1026 is void. A void expression is an expression where the type of the
1027 result is "void". For example, some convenience variables may be
1028 "void" when evaluated (e.g., "$_exitcode" before the execution of
1029 the program being debugged; or an undefined convenience variable).
1030 Another example, when calling a function whose return type is
1033 * The "maintenance print objfiles" command now takes an optional regexp.
1035 * The "catch syscall" command now works on arm*-linux* targets.
1037 * GDB now consistently shows "<not saved>" when printing values of
1038 registers the debug info indicates have not been saved in the frame
1039 and there's nowhere to retrieve them from
1040 (callee-saved/call-clobbered registers):
1045 (gdb) info registers rax
1048 Before, the former would print "<optimized out>", and the latter
1049 "*value not available*".
1051 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1056 ** Frame filters and frame decorators have been added.
1057 ** Temporary breakpoints are now supported.
1058 ** Line tables representation has been added.
1059 ** New attribute 'parent_type' for gdb.Field objects.
1060 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1061 ** New attribute 'name' for gdb.Type objects.
1065 Nios II ELF nios2*-*-elf
1066 Nios II GNU/Linux nios2*-*-linux
1067 Texas Instruments MSP430 msp430*-*-elf
1069 * Removed native configurations
1071 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1072 been removed. ELF variants of these configurations are kept supported.
1074 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1075 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1076 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1077 i[34567]86-*-openbsd3.[0-3]
1078 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1079 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1080 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1084 Like "catch throw", but catches a re-thrown exception.
1085 maint check-psymtabs
1086 Renamed from old "maint check-symtabs".
1088 Perform consistency checks on symtabs.
1089 maint expand-symtabs
1090 Expand symtabs matching an optional regexp.
1093 Display the details of GDB configure-time options.
1095 maint set|show per-command
1096 maint set|show per-command space
1097 maint set|show per-command time
1098 maint set|show per-command symtab
1099 Enable display of per-command gdb resource usage.
1101 remove-symbol-file FILENAME
1102 remove-symbol-file -a ADDRESS
1103 Remove a symbol file added via add-symbol-file. The file to remove
1104 can be identified by its filename or by an address that lies within
1105 the boundaries of this symbol file in memory.
1108 info exceptions REGEXP
1109 Display the list of Ada exceptions defined in the program being
1110 debugged. If provided, only the exceptions whose names match REGEXP
1115 set debug symfile off|on
1117 Control display of debugging info regarding reading symbol files and
1118 symbol tables within those files
1120 set print raw frame-arguments
1121 show print raw frame-arguments
1122 Set/show whether to print frame arguments in raw mode,
1123 disregarding any defined pretty-printers.
1125 set remote trace-status-packet
1126 show remote trace-status-packet
1127 Set/show the use of remote protocol qTStatus packet.
1131 Control display of debugging messages related to Nios II targets.
1135 Control whether target-assisted range stepping is enabled.
1137 set startup-with-shell
1138 show startup-with-shell
1139 Specifies whether Unix child processes are started via a shell or
1144 Use the target memory cache for accesses to the code segment. This
1145 improves performance of remote debugging (particularly disassembly).
1147 * You can now use a literal value 'unlimited' for options that
1148 interpret 0 or -1 as meaning "unlimited". E.g., "set
1149 trace-buffer-size unlimited" is now an alias for "set
1150 trace-buffer-size -1" and "set height unlimited" is now an alias for
1153 * The "set debug symtab-create" debugging option of GDB has been changed to
1154 accept a verbosity level. 0 means "off", 1 provides basic debugging
1155 output, and values of 2 or greater provides more verbose output.
1157 * New command-line options
1159 Display the details of GDB configure-time options.
1161 * The command 'tsave' can now support new option '-ctf' to save trace
1162 buffer in Common Trace Format.
1164 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1167 * GDB now implements the the C++ 'typeid' operator.
1169 * The new convenience variable $_exception holds the exception being
1170 thrown or caught at an exception-related catchpoint.
1172 * The exception-related catchpoints, like "catch throw", now accept a
1173 regular expression which can be used to filter exceptions by type.
1175 * The new convenience variable $_exitsignal is automatically set to
1176 the terminating signal number when the program being debugged dies
1177 due to an uncaught signal.
1181 ** All MI commands now accept an optional "--language" option.
1182 Support for this feature can be verified by using the "-list-features"
1183 command, which should contain "language-option".
1185 ** The new command -info-gdb-mi-command allows the user to determine
1186 whether a GDB/MI command is supported or not.
1188 ** The "^error" result record returned when trying to execute an undefined
1189 GDB/MI command now provides a variable named "code" whose content is the
1190 "undefined-command" error code. Support for this feature can be verified
1191 by using the "-list-features" command, which should contain
1192 "undefined-command-error-code".
1194 ** The -trace-save MI command can optionally save trace buffer in Common
1197 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1199 ** The command -data-list-register-values now accepts an optional
1200 "--skip-unavailable" option. When used, only the available registers
1203 ** The new command -trace-frame-collected dumps collected variables,
1204 computed expressions, tvars, memory and registers in a traceframe.
1206 ** The commands -stack-list-locals, -stack-list-arguments and
1207 -stack-list-variables now accept an option "--skip-unavailable".
1208 When used, only the available locals or arguments are displayed.
1210 ** The -exec-run command now accepts an optional "--start" option.
1211 When used, the command follows the same semantics as the "start"
1212 command, stopping the program's execution at the start of its
1213 main subprogram. Support for this feature can be verified using
1214 the "-list-features" command, which should contain
1215 "exec-run-start-option".
1217 ** The new commands -catch-assert and -catch-exceptions insert
1218 catchpoints stopping the program when Ada exceptions are raised.
1220 ** The new command -info-ada-exceptions provides the equivalent of
1221 the new "info exceptions" command.
1223 * New system-wide configuration scripts
1224 A GDB installation now provides scripts suitable for use as system-wide
1225 configuration scripts for the following systems:
1229 * GDB now supports target-assigned range stepping with remote targets.
1230 This improves the performance of stepping source lines by reducing
1231 the number of control packets from/to GDB. See "New remote packets"
1234 * GDB now understands the element 'tvar' in the XML traceframe info.
1235 It has the id of the collected trace state variables.
1237 * On S/390 targets that provide the transactional-execution feature,
1238 the program interruption transaction diagnostic block (TDB) is now
1239 represented as a number of additional "registers" in GDB.
1241 * New remote packets
1245 The vCont packet supports a new 'r' action, that tells the remote
1246 stub to step through an address range itself, without GDB
1247 involvemement at each single-step.
1249 qXfer:libraries-svr4:read's annex
1250 The previously unused annex of the qXfer:libraries-svr4:read packet
1251 is now used to support passing an argument list. The remote stub
1252 reports support for this argument list to GDB's qSupported query.
1253 The defined arguments are "start" and "prev", used to reduce work
1254 necessary for library list updating, resulting in significant
1257 * New features in the GDB remote stub, GDBserver
1259 ** GDBserver now supports target-assisted range stepping. Currently
1260 enabled on x86/x86_64 GNU/Linux targets.
1262 ** GDBserver now adds element 'tvar' in the XML in the reply to
1263 'qXfer:traceframe-info:read'. It has the id of the collected
1264 trace state variables.
1266 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1269 * New 'z' formatter for printing and examining memory, this displays the
1270 value as hexadecimal zero padded on the left to the size of the type.
1272 * GDB can now use Windows x64 unwinding data.
1274 * The "set remotebaud" command has been replaced by "set serial baud".
1275 Similarly, "show remotebaud" has been replaced by "show serial baud".
1276 The "set remotebaud" and "show remotebaud" commands are still available
1277 to provide backward compatibility with older versions of GDB.
1279 *** Changes in GDB 7.6
1281 * Target record has been renamed to record-full.
1282 Record/replay is now enabled with the "record full" command.
1283 This also affects settings that are associated with full record/replay
1284 that have been moved from "set/show record" to "set/show record full":
1286 set|show record full insn-number-max
1287 set|show record full stop-at-limit
1288 set|show record full memory-query
1290 * A new record target "record-btrace" has been added. The new target
1291 uses hardware support to record the control-flow of a process. It
1292 does not support replaying the execution, but it implements the
1293 below new commands for investigating the recorded execution log.
1294 This new recording method can be enabled using:
1298 The "record-btrace" target is only available on Intel Atom processors
1299 and requires a Linux kernel 2.6.32 or later.
1301 * Two new commands have been added for record/replay to give information
1302 about the recorded execution without having to replay the execution.
1303 The commands are only supported by "record btrace".
1305 record instruction-history prints the execution history at
1306 instruction granularity
1308 record function-call-history prints the execution history at
1309 function granularity
1311 * New native configurations
1313 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1314 FreeBSD/powerpc powerpc*-*-freebsd
1315 x86_64/Cygwin x86_64-*-cygwin*
1316 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1320 ARM AArch64 aarch64*-*-elf
1321 ARM AArch64 GNU/Linux aarch64*-*-linux
1322 Lynx 178 PowerPC powerpc-*-lynx*178
1323 x86_64/Cygwin x86_64-*-cygwin*
1324 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1326 * If the configured location of system.gdbinit file (as given by the
1327 --with-system-gdbinit option at configure time) is in the
1328 data-directory (as specified by --with-gdb-datadir at configure
1329 time) or in one of its subdirectories, then GDB will look for the
1330 system-wide init file in the directory specified by the
1331 --data-directory command-line option.
1333 * New command line options:
1335 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1336 other initialization files, unlike -nx which disables all of them.
1338 * Removed command line options
1340 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1343 * The 'ptype' and 'whatis' commands now accept an argument to control
1346 * 'info proc' now works on some core files.
1350 ** Vectors can be created with gdb.Type.vector.
1352 ** Python's atexit.register now works in GDB.
1354 ** Types can be pretty-printed via a Python API.
1356 ** Python 3 is now supported (in addition to Python 2.4 or later)
1358 ** New class gdb.Architecture exposes GDB's internal representation
1359 of architecture in the Python API.
1361 ** New method Frame.architecture returns the gdb.Architecture object
1362 corresponding to the frame's architecture.
1364 * New Python-based convenience functions:
1366 ** $_memeq(buf1, buf2, length)
1367 ** $_streq(str1, str2)
1369 ** $_regex(str, regex)
1371 * The 'cd' command now defaults to using '~' (the home directory) if not
1374 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1375 default for GCC since November 2000.
1377 * The command 'forward-search' can now be abbreviated as 'fo'.
1379 * The command 'info tracepoints' can now display 'installed on target'
1380 or 'not installed on target' for each non-pending location of tracepoint.
1382 * New configure options
1384 --enable-libmcheck/--disable-libmcheck
1385 By default, development versions are built with -lmcheck on hosts
1386 that support it, in order to help track memory corruption issues.
1387 Release versions, on the other hand, are built without -lmcheck
1388 by default. The --enable-libmcheck/--disable-libmcheck configure
1389 options allow the user to override that default.
1390 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1391 This configure option allows the user to build GDB with
1392 libbabeltrace using which GDB can read Common Trace Format data.
1394 * New commands (for set/show, see "New options" below)
1397 Catch signals. This is similar to "handle", but allows commands and
1398 conditions to be attached.
1401 List the BFDs known to GDB.
1403 python-interactive [command]
1405 Start a Python interactive prompt, or evaluate the optional command
1406 and print the result of expressions.
1409 "py" is a new alias for "python".
1411 enable type-printer [name]...
1412 disable type-printer [name]...
1413 Enable or disable type printers.
1417 ** For the Renesas Super-H architecture, the "regs" command has been removed
1418 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1423 set print type methods (on|off)
1424 show print type methods
1425 Control whether method declarations are displayed by "ptype".
1426 The default is to show them.
1428 set print type typedefs (on|off)
1429 show print type typedefs
1430 Control whether typedef definitions are displayed by "ptype".
1431 The default is to show them.
1433 set filename-display basename|relative|absolute
1434 show filename-display
1435 Control the way in which filenames is displayed.
1436 The default is "relative", which preserves previous behavior.
1438 set trace-buffer-size
1439 show trace-buffer-size
1440 Request target to change the size of trace buffer.
1442 set remote trace-buffer-size-packet auto|on|off
1443 show remote trace-buffer-size-packet
1444 Control the use of the remote protocol `QTBuffer:size' packet.
1448 Control display of debugging messages related to ARM AArch64.
1451 set debug coff-pe-read
1452 show debug coff-pe-read
1453 Control display of debugging messages related to reading of COFF/PE
1458 Control display of debugging messages related to Mach-O symbols
1461 set debug notification
1462 show debug notification
1463 Control display of debugging info for async remote notification.
1467 ** Command parameter changes are now notified using new async record
1468 "=cmd-param-changed".
1469 ** Trace frame changes caused by command "tfind" are now notified using
1470 new async record "=traceframe-changed".
1471 ** The creation, deletion and modification of trace state variables
1472 are now notified using new async records "=tsv-created",
1473 "=tsv-deleted" and "=tsv-modified".
1474 ** The start and stop of process record are now notified using new
1475 async record "=record-started" and "=record-stopped".
1476 ** Memory changes are now notified using new async record
1478 ** The data-disassemble command response will include a "fullname" field
1479 containing the absolute file name when source has been requested.
1480 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1481 command, to allow pattern filling of memory areas.
1482 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1483 library load/unload events.
1484 ** The response to breakpoint commands and breakpoint async records
1485 includes an "installed" field containing a boolean state about each
1486 non-pending tracepoint location is whether installed on target or not.
1487 ** Output of the "-trace-status" command includes a "trace-file" field
1488 containing the name of the trace file being examined. This field is
1489 optional, and only present when examining a trace file.
1490 ** The "fullname" field is now always present along with the "file" field,
1491 even if the file cannot be found by GDB.
1493 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1494 You must have the LZMA library available when configuring GDB for this
1495 feature to be enabled. For more information, see:
1496 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1498 * New remote packets
1501 Set the size of trace buffer. The remote stub reports support for this
1502 packet to gdb's qSupported query.
1505 Enable Branch Trace Store (BTS)-based branch tracing for the current
1506 thread. The remote stub reports support for this packet to gdb's
1510 Disable branch tracing for the current thread. The remote stub reports
1511 support for this packet to gdb's qSupported query.
1514 Read the traced branches for the current thread. The remote stub
1515 reports support for this packet to gdb's qSupported query.
1517 *** Changes in GDB 7.5
1519 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1520 for more x32 ABI info.
1522 * GDB now supports access to MIPS DSP registers on Linux targets.
1524 * GDB now supports debugging microMIPS binaries.
1526 * The "info os" command on GNU/Linux can now display information on
1527 several new classes of objects managed by the operating system:
1528 "info os procgroups" lists process groups
1529 "info os files" lists file descriptors
1530 "info os sockets" lists internet-domain sockets
1531 "info os shm" lists shared-memory regions
1532 "info os semaphores" lists semaphores
1533 "info os msg" lists message queues
1534 "info os modules" lists loaded kernel modules
1536 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1537 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1538 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1539 options and inspect the probe arguments using the new $_probe_arg family
1540 of convenience variables. You can obtain more information about SystemTap
1541 in <http://sourceware.org/systemtap/>.
1543 * GDB now supports reversible debugging on ARM, it allows you to
1544 debug basic ARM and THUMB instructions, and provides
1545 record/replay support.
1547 * The option "symbol-reloading" has been deleted as it is no longer used.
1551 ** GDB commands implemented in Python can now be put in command class
1554 ** The "maint set python print-stack on|off" is now deleted.
1556 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1557 apply "flag enum"-style pretty-printing to any enum.
1559 ** gdb.lookup_symbol can now work when there is no current frame.
1561 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1562 the source at which the symbol was defined.
1564 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1565 method 'value'. The former indicates whether the symbol needs a
1566 frame in order to compute its value, and the latter computes the
1569 ** A new method 'referenced_value' on gdb.Value objects which can
1570 dereference pointer as well as C++ reference values.
1572 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1573 which return the global and static blocks (as gdb.Block objects),
1574 of the underlying symbol table, respectively.
1576 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1577 object associated with a PC value.
1579 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1580 of the address range occupied by code for the current source line.
1582 * Go language support.
1583 GDB now supports debugging programs written in the Go programming
1586 * GDBserver now supports stdio connections.
1587 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1589 * The binary "gdbtui" can no longer be built or installed.
1590 Use "gdb -tui" instead.
1592 * GDB will now print "flag" enums specially. A flag enum is one where
1593 all the enumerator values have no bits in common when pairwise
1594 "and"ed. When printing a value whose type is a flag enum, GDB will
1595 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1596 (gdb) print (enum E) 3
1599 * The filename part of a linespec will now match trailing components
1600 of a source file name. For example, "break gcc/expr.c:1000" will
1601 now set a breakpoint in build/gcc/expr.c, but not
1602 build/libcpp/expr.c.
1604 * The "info proc" and "generate-core-file" commands will now also
1605 work on remote targets connected to GDBserver on Linux.
1607 * The command "info catch" has been removed. It has been disabled
1608 since December 2007.
1610 * The "catch exception" and "catch assert" commands now accept
1611 a condition at the end of the command, much like the "break"
1612 command does. For instance:
1614 (gdb) catch exception Constraint_Error if Barrier = True
1616 Previously, it was possible to add a condition to such catchpoints,
1617 but it had to be done as a second step, after the catchpoint had been
1618 created, using the "condition" command.
1620 * The "info static-tracepoint-marker" command will now also work on
1621 native Linux targets with in-process agent.
1623 * GDB can now set breakpoints on inlined functions.
1625 * The .gdb_index section has been updated to include symbols for
1626 inlined functions. GDB will ignore older .gdb_index sections by
1627 default, which could cause symbol files to be loaded more slowly
1628 until their .gdb_index sections can be recreated. The new command
1629 "set use-deprecated-index-sections on" will cause GDB to use any older
1630 .gdb_index sections it finds. This will restore performance, but the
1631 ability to set breakpoints on inlined functions will be lost in symbol
1632 files with older .gdb_index sections.
1634 The .gdb_index section has also been updated to record more information
1635 about each symbol. This speeds up the "info variables", "info functions"
1636 and "info types" commands when used with programs having the .gdb_index
1637 section, as well as speeding up debugging with shared libraries using
1638 the .gdb_index section.
1640 * Ada support for GDB/MI Variable Objects has been added.
1642 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1647 ** New command -info-os is the MI equivalent of "info os".
1649 ** Output logs ("set logging" and related) now include MI output.
1653 ** "set use-deprecated-index-sections on|off"
1654 "show use-deprecated-index-sections on|off"
1655 Controls the use of deprecated .gdb_index sections.
1657 ** "catch load" and "catch unload" can be used to stop when a shared
1658 library is loaded or unloaded, respectively.
1660 ** "enable count" can be used to auto-disable a breakpoint after
1663 ** "info vtbl" can be used to show the virtual method tables for
1664 C++ and Java objects.
1666 ** "explore" and its sub commands "explore value" and "explore type"
1667 can be used to recursively explore values and types of
1668 expressions. These commands are available only if GDB is
1669 configured with '--with-python'.
1671 ** "info auto-load" shows status of all kinds of auto-loaded files,
1672 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1673 sequences of commands files, "info auto-load python-scripts"
1674 shows status of auto-loading Python script files,
1675 "info auto-load local-gdbinit" shows status of loading init file
1676 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1677 status of inferior specific thread debugging shared library loading.
1679 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1680 and "show auto-load-scripts" commands have been deprecated, use their
1681 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1682 and "show auto-load python-scripts" counterparts instead.
1684 ** "dprintf location,format,args..." creates a dynamic printf, which
1685 is basically a breakpoint that does a printf and immediately
1686 resumes your program's execution, so it is like a printf that you
1687 can insert dynamically at runtime instead of at compiletime.
1689 ** "set print symbol"
1691 Controls whether GDB attempts to display the symbol, if any,
1692 corresponding to addresses it prints. This defaults to "on", but
1693 you can set it to "off" to restore GDB's previous behavior.
1695 * Deprecated commands
1697 ** For the Renesas Super-H architecture, the "regs" command has been
1698 deprecated, and "info all-registers" should be used instead.
1702 Renesas RL78 rl78-*-elf
1703 HP OpenVMS ia64 ia64-hp-openvms*
1705 * GDBserver supports evaluation of breakpoint conditions. When
1706 support is advertised by GDBserver, GDB may be told to send the
1707 breakpoint conditions in bytecode form to GDBserver. GDBserver
1708 will only report the breakpoint trigger to GDB when its condition
1713 set mips compression
1714 show mips compression
1715 Select the compressed ISA encoding used in functions that have no symbol
1716 information available. The encoding can be set to either of:
1719 and is updated automatically from ELF file flags if available.
1721 set breakpoint condition-evaluation
1722 show breakpoint condition-evaluation
1723 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1724 GDBserver ("target"). Default option "auto" chooses the most efficient
1726 This option can improve debugger efficiency depending on the speed of the
1730 Disable auto-loading globally.
1733 Show auto-loading setting of all kinds of auto-loaded files.
1735 set auto-load gdb-scripts on|off
1736 show auto-load gdb-scripts
1737 Control auto-loading of GDB canned sequences of commands files.
1739 set auto-load python-scripts on|off
1740 show auto-load python-scripts
1741 Control auto-loading of Python script files.
1743 set auto-load local-gdbinit on|off
1744 show auto-load local-gdbinit
1745 Control loading of init file (.gdbinit) from current directory.
1747 set auto-load libthread-db on|off
1748 show auto-load libthread-db
1749 Control auto-loading of inferior specific thread debugging shared library.
1751 set auto-load scripts-directory <dir1>[:<dir2>...]
1752 show auto-load scripts-directory
1753 Set a list of directories from which to load auto-loaded scripts.
1754 Automatically loaded Python scripts and GDB scripts are located in one
1755 of the directories listed by this option.
1756 The delimiter (':' above) may differ according to the host platform.
1758 set auto-load safe-path <dir1>[:<dir2>...]
1759 show auto-load safe-path
1760 Set a list of directories from which it is safe to auto-load files.
1761 The delimiter (':' above) may differ according to the host platform.
1763 set debug auto-load on|off
1764 show debug auto-load
1765 Control display of debugging info for auto-loading the files above.
1767 set dprintf-style gdb|call|agent
1769 Control the way in which a dynamic printf is performed; "gdb"
1770 requests a GDB printf command, while "call" causes dprintf to call a
1771 function in the inferior. "agent" requests that the target agent
1772 (such as GDBserver) do the printing.
1774 set dprintf-function <expr>
1775 show dprintf-function
1776 set dprintf-channel <expr>
1777 show dprintf-channel
1778 Set the function and optional first argument to the call when using
1779 the "call" style of dynamic printf.
1781 set disconnected-dprintf on|off
1782 show disconnected-dprintf
1783 Control whether agent-style dynamic printfs continue to be in effect
1784 after GDB disconnects.
1786 * New configure options
1788 --with-auto-load-dir
1789 Configure default value for the 'set auto-load scripts-directory'
1790 setting above. It defaults to '$debugdir:$datadir/auto-load',
1791 $debugdir representing global debugging info directories (available
1792 via 'show debug-file-directory') and $datadir representing GDB's data
1793 directory (available via 'show data-directory').
1795 --with-auto-load-safe-path
1796 Configure default value for the 'set auto-load safe-path' setting
1797 above. It defaults to the --with-auto-load-dir setting.
1799 --without-auto-load-safe-path
1800 Set 'set auto-load safe-path' to '/', effectively disabling this
1803 * New remote packets
1805 z0/z1 conditional breakpoints extension
1807 The z0/z1 breakpoint insertion packets have been extended to carry
1808 a list of conditional expressions over to the remote stub depending on the
1809 condition evaluation mode. The use of this extension can be controlled
1810 via the "set remote conditional-breakpoints-packet" command.
1814 Specify the signals which the remote stub may pass to the debugged
1815 program without GDB involvement.
1817 * New command line options
1819 --init-command=FILE, -ix Like --command, -x but execute it
1820 before loading inferior.
1821 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1822 execute it before loading inferior.
1824 *** Changes in GDB 7.4
1826 * GDB now handles ambiguous linespecs more consistently; the existing
1827 FILE:LINE support has been expanded to other types of linespecs. A
1828 breakpoint will now be set on all matching locations in all
1829 inferiors, and locations will be added or removed according to
1832 * GDB now allows you to skip uninteresting functions and files when
1833 stepping with the "skip function" and "skip file" commands.
1835 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1836 and "show remote hardware-watchpoint-length-limit". These allows to
1837 set or show the maximum length limit (in bytes) of a remote
1838 target hardware watchpoint.
1840 This allows e.g. to use "unlimited" hardware watchpoints with the
1841 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1842 watchpoints are slower than real hardware watchpoints but are
1843 significantly faster than gdb software watchpoints.
1847 ** The register_pretty_printer function in module gdb.printing now takes
1848 an optional `replace' argument. If True, the new printer replaces any
1851 ** The "maint set python print-stack on|off" command has been
1852 deprecated and will be deleted in GDB 7.5.
1853 A new command: "set python print-stack none|full|message" has
1854 replaced it. Additionally, the default for "print-stack" is
1855 now "message", which just prints the error message without
1858 ** A prompt substitution hook (prompt_hook) is now available to the
1861 ** A new Python module, gdb.prompt has been added to the GDB Python
1862 modules library. This module provides functionality for
1863 escape sequences in prompts (used by set/show
1864 extended-prompt). These escape sequences are replaced by their
1865 corresponding value.
1867 ** Python commands and convenience-functions located in
1868 'data-directory'/python/gdb/command and
1869 'data-directory'/python/gdb/function are now automatically loaded
1872 ** Blocks now provide four new attributes. global_block and
1873 static_block will return the global and static blocks
1874 respectively. is_static and is_global are boolean attributes
1875 that indicate if the block is one of those two types.
1877 ** Symbols now provide the "type" attribute, the type of the symbol.
1879 ** The "gdb.breakpoint" function has been deprecated in favor of
1882 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1883 of a function. This class is based on the "finish" command
1884 available in the CLI.
1886 ** Type objects for struct and union types now allow access to
1887 the fields using standard Python dictionary (mapping) methods.
1888 For example, "some_type['myfield']" now works, as does
1889 "some_type.items()".
1891 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1894 ** A new function, "deep_items" has been added to the gdb.types
1895 module in the GDB Python modules library. This function returns
1896 an iterator over the fields of a struct or union type. Unlike
1897 the standard Python "iteritems" method, it will recursively traverse
1898 any anonymous fields.
1902 ** "*stopped" events can report several new "reason"s, such as
1905 ** Breakpoint changes are now notified using new async records, like
1906 "=breakpoint-modified".
1908 ** New command -ada-task-info.
1910 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1911 $sdir specifies the default system locations of shared libraries.
1912 $pdir specifies the directory where the libpthread used by the application
1915 GDB no longer looks in $sdir and $pdir after it has searched the directories
1916 mentioned in libthread-db-search-path. If you want to search those
1917 directories, they must be specified in libthread-db-search-path.
1918 The default value of libthread-db-search-path on GNU/Linux and Solaris
1919 systems is now "$sdir:$pdir".
1921 $pdir is not supported by gdbserver, it is currently ignored.
1922 $sdir is supported by gdbserver.
1924 * New configure option --with-iconv-bin.
1925 When using the internationalization support like the one in the GNU C
1926 library, GDB will invoke the "iconv" program to get a list of supported
1927 character sets. If this program lives in a non-standard location, one can
1928 use this option to specify where to find it.
1930 * When natively debugging programs on PowerPC BookE processors running
1931 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1932 watchpoints, which specify a mask in addition to an address to watch.
1933 The mask specifies that some bits of an address (the bits which are
1934 reset in the mask) should be ignored when matching the address accessed
1935 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1936 section in the user manual for more details.
1938 * The new option --once causes GDBserver to stop listening for connections once
1939 the first connection is made. The listening port used by GDBserver will
1940 become available after that.
1942 * New commands "info macros" and "alias" have been added.
1944 * New function parameters suffix @entry specifies value of function parameter
1945 at the time the function got called. Entry values are available only since
1951 "!" is now an alias of the "shell" command.
1952 Note that no space is needed between "!" and SHELL COMMAND.
1956 watch EXPRESSION mask MASK_VALUE
1957 The watch command now supports the mask argument which allows creation
1958 of masked watchpoints, if the current architecture supports this feature.
1960 info auto-load-scripts [REGEXP]
1961 This command was formerly named "maintenance print section-scripts".
1962 It is now generally useful and is no longer a maintenance-only command.
1964 info macro [-all] [--] MACRO
1965 The info macro command has new options `-all' and `--'. The first for
1966 printing all definitions of a macro. The second for explicitly specifying
1967 the end of arguments and the beginning of the macro name in case the macro
1968 name starts with a hyphen.
1970 collect[/s] EXPRESSIONS
1971 The tracepoint collect command now takes an optional modifier "/s"
1972 that directs it to dereference pointer-to-character types and
1973 collect the bytes of memory up to a zero byte. The behavior is
1974 similar to what you see when you use the regular print command on a
1975 string. An optional integer following the "/s" sets a bound on the
1976 number of bytes that will be collected.
1979 The trace start command now interprets any supplied arguments as a
1980 note to be recorded with the trace run, with an effect similar to
1981 setting the variable trace-notes.
1984 The trace stop command now interprets any arguments as a note to be
1985 mentioned along with the tstatus report that the trace was stopped
1986 with a command. The effect is similar to setting the variable
1989 * Tracepoints can now be enabled and disabled at any time after a trace
1990 experiment has been started using the standard "enable" and "disable"
1991 commands. It is now possible to start a trace experiment with no enabled
1992 tracepoints; GDB will display a warning, but will allow the experiment to
1993 begin, assuming that tracepoints will be enabled as needed while the trace
1996 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1997 locations with 4-byte instructions, when they were previously
1998 limited to locations with instructions of 5 bytes or longer.
2002 set debug dwarf2-read
2003 show debug dwarf2-read
2004 Turns on or off display of debugging messages related to reading
2005 DWARF debug info. The default is off.
2007 set debug symtab-create
2008 show debug symtab-create
2009 Turns on or off display of debugging messages related to symbol table
2010 creation. The default is off.
2013 show extended-prompt
2014 Set the GDB prompt, and allow escape sequences to be inserted to
2015 display miscellaneous information (see 'help set extended-prompt'
2016 for the list of sequences). This prompt (and any information
2017 accessed through the escape sequences) is updated every time the
2018 prompt is displayed.
2020 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2021 show print entry-values
2022 Set printing of frame argument values at function entry. In some cases
2023 GDB can determine the value of function argument which was passed by the
2024 function caller, even if the value was modified inside the called function.
2026 set debug entry-values
2027 show debug entry-values
2028 Control display of debugging info for determining frame argument values at
2029 function entry and virtual tail call frames.
2031 set basenames-may-differ
2032 show basenames-may-differ
2033 Set whether a source file may have multiple base names.
2034 (A "base name" is the name of a file with the directory part removed.
2035 Example: The base name of "/home/user/hello.c" is "hello.c".)
2036 If set, GDB will canonicalize file names (e.g., expand symlinks)
2037 before comparing them. Canonicalization is an expensive operation,
2038 but it allows the same file be known by more than one base name.
2039 If not set (the default), all source files are assumed to have just
2040 one base name, and gdb will do file name comparisons more efficiently.
2046 Set a user name and notes for the current and any future trace runs.
2047 This is useful for long-running and/or disconnected traces, to
2048 inform others (or yourself) as to who is running the trace, supply
2049 contact information, or otherwise explain what is going on.
2051 set trace-stop-notes
2052 show trace-stop-notes
2053 Set a note attached to the trace run, that is displayed when the
2054 trace has been stopped by a tstop command. This is useful for
2055 instance as an explanation, if you are stopping a trace run that was
2056 started by someone else.
2058 * New remote packets
2062 Dynamically enable a tracepoint in a started trace experiment.
2066 Dynamically disable a tracepoint in a started trace experiment.
2070 Set the user and notes of the trace run.
2074 Query the current status of a tracepoint.
2078 Query the minimum length of instruction at which a fast tracepoint may
2081 * Dcache size (number of lines) and line-size are now runtime-configurable
2082 via "set dcache line" and "set dcache line-size" commands.
2086 Texas Instruments TMS320C6x tic6x-*-*
2090 Renesas RL78 rl78-*-elf
2092 *** Changes in GDB 7.3.1
2094 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2096 *** Changes in GDB 7.3
2098 * GDB has a new command: "thread find [REGEXP]".
2099 It finds the thread id whose name, target id, or thread extra info
2100 matches the given regular expression.
2102 * The "catch syscall" command now works on mips*-linux* targets.
2104 * The -data-disassemble MI command now supports modes 2 and 3 for
2105 dumping the instruction opcodes.
2107 * New command line options
2109 -data-directory DIR Specify DIR as the "data-directory".
2110 This is mostly for testing purposes.
2112 * The "maint set python auto-load on|off" command has been renamed to
2113 "set auto-load-scripts on|off".
2115 * GDB has a new command: "set directories".
2116 It is like the "dir" command except that it replaces the
2117 source path list instead of augmenting it.
2119 * GDB now understands thread names.
2121 On GNU/Linux, "info threads" will display the thread name as set by
2122 prctl or pthread_setname_np.
2124 There is also a new command, "thread name", which can be used to
2125 assign a name internally for GDB to display.
2128 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2129 has been integrated into GDB.
2133 ** The function gdb.Write now accepts an optional keyword 'stream'.
2134 This keyword, when provided, will direct the output to either
2135 stdout, stderr, or GDB's logging output.
2137 ** Parameters can now be be sub-classed in Python, and in particular
2138 you may implement the get_set_doc and get_show_doc functions.
2139 This improves how Parameter set/show documentation is processed
2140 and allows for more dynamic content.
2142 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2143 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2144 have an is_valid method.
2146 ** Breakpoints can now be sub-classed in Python, and in particular
2147 you may implement a 'stop' function that is executed each time
2148 the inferior reaches that breakpoint.
2150 ** New function gdb.lookup_global_symbol looks up a global symbol.
2152 ** GDB values in Python are now callable if the value represents a
2153 function. For example, if 'some_value' represents a function that
2154 takes two integer parameters and returns a value, you can call
2155 that function like so:
2157 result = some_value (10,20)
2159 ** Module gdb.types has been added.
2160 It contains a collection of utilities for working with gdb.Types objects:
2161 get_basic_type, has_field, make_enum_dict.
2163 ** Module gdb.printing has been added.
2164 It contains utilities for writing and registering pretty-printers.
2165 New classes: PrettyPrinter, SubPrettyPrinter,
2166 RegexpCollectionPrettyPrinter.
2167 New function: register_pretty_printer.
2169 ** New commands "info pretty-printers", "enable pretty-printer" and
2170 "disable pretty-printer" have been added.
2172 ** gdb.parameter("directories") is now available.
2174 ** New function gdb.newest_frame returns the newest frame in the
2177 ** The gdb.InferiorThread class has a new "name" attribute. This
2178 holds the thread's name.
2180 ** Python Support for Inferior events.
2181 Python scripts can add observers to be notified of events
2182 occurring in the process being debugged.
2183 The following events are currently supported:
2184 - gdb.events.cont Continue event.
2185 - gdb.events.exited Inferior exited event.
2186 - gdb.events.stop Signal received, and Breakpoint hit events.
2190 ** GDB now puts template parameters in scope when debugging in an
2191 instantiation. For example, if you have:
2193 template<int X> int func (void) { return X; }
2195 then if you step into func<5>, "print X" will show "5". This
2196 feature requires proper debuginfo support from the compiler; it
2197 was added to GCC 4.5.
2199 ** The motion commands "next", "finish", "until", and "advance" now
2200 work better when exceptions are thrown. In particular, GDB will
2201 no longer lose control of the inferior; instead, the GDB will
2202 stop the inferior at the point at which the exception is caught.
2203 This functionality requires a change in the exception handling
2204 code that was introduced in GCC 4.5.
2206 * GDB now follows GCC's rules on accessing volatile objects when
2207 reading or writing target state during expression evaluation.
2208 One notable difference to prior behavior is that "print x = 0"
2209 no longer generates a read of x; the value of the assignment is
2210 now always taken directly from the value being assigned.
2212 * GDB now has some support for using labels in the program's source in
2213 linespecs. For instance, you can use "advance label" to continue
2214 execution to a label.
2216 * GDB now has support for reading and writing a new .gdb_index
2217 section. This section holds a fast index of DWARF debugging
2218 information and can be used to greatly speed up GDB startup and
2219 operation. See the documentation for `save gdb-index' for details.
2221 * The "watch" command now accepts an optional "-location" argument.
2222 When used, this causes GDB to watch the memory referred to by the
2223 expression. Such a watchpoint is never deleted due to it going out
2226 * GDB now supports thread debugging of core dumps on GNU/Linux.
2228 GDB now activates thread debugging using the libthread_db library
2229 when debugging GNU/Linux core dumps, similarly to when debugging
2230 live processes. As a result, when debugging a core dump file, GDB
2231 is now able to display pthread_t ids of threads. For example, "info
2232 threads" shows the same output as when debugging the process when it
2233 was live. In earlier releases, you'd see something like this:
2236 * 1 LWP 6780 main () at main.c:10
2238 While now you see this:
2241 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2243 It is also now possible to inspect TLS variables when debugging core
2246 When debugging a core dump generated on a machine other than the one
2247 used to run GDB, you may need to point GDB at the correct
2248 libthread_db library with the "set libthread-db-search-path"
2249 command. See the user manual for more details on this command.
2251 * When natively debugging programs on PowerPC BookE processors running
2252 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2253 which stop execution of the inferior whenever it executes an instruction
2254 at any address within the specified range. See the "PowerPC Embedded"
2255 section in the user manual for more details.
2257 * New features in the GDB remote stub, GDBserver
2259 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2260 and i686 LynxOS (version 5.x).
2262 ** GDBserver is now supported on Blackfin Linux.
2264 * New native configurations
2266 ia64 HP-UX ia64-*-hpux*
2270 Analog Devices, Inc. Blackfin Processor bfin-*
2272 * Ada task switching is now supported on sparc-elf targets when
2273 debugging a program using the Ravenscar Profile. For more information,
2274 see the "Tasking Support when using the Ravenscar Profile" section
2275 in the GDB user manual.
2277 * Guile support was removed.
2279 * New features in the GNU simulator
2281 ** The --map-info flag lists all known core mappings.
2283 ** CFI flashes may be simulated via the "cfi" device.
2285 *** Changes in GDB 7.2
2287 * Shared library support for remote targets by default
2289 When GDB is configured for a generic, non-OS specific target, like
2290 for example, --target=arm-eabi or one of the many *-*-elf targets,
2291 GDB now queries remote stubs for loaded shared libraries using the
2292 `qXfer:libraries:read' packet. Previously, shared library support
2293 was always disabled for such configurations.
2297 ** Argument Dependent Lookup (ADL)
2299 In C++ ADL lookup directs function search to the namespaces of its
2300 arguments even if the namespace has not been imported.
2310 Here the compiler will search for `foo' in the namespace of 'b'
2311 and find A::foo. GDB now supports this. This construct is commonly
2312 used in the Standard Template Library for operators.
2314 ** Improved User Defined Operator Support
2316 In addition to member operators, GDB now supports lookup of operators
2317 defined in a namespace and imported with a `using' directive, operators
2318 defined in the global scope, operators imported implicitly from an
2319 anonymous namespace, and the ADL operators mentioned in the previous
2321 GDB now also supports proper overload resolution for all the previously
2322 mentioned flavors of operators.
2324 ** static const class members
2326 Printing of static const class members that are initialized in the
2327 class definition has been fixed.
2329 * Windows Thread Information Block access.
2331 On Windows targets, GDB now supports displaying the Windows Thread
2332 Information Block (TIB) structure. This structure is visible either
2333 by using the new command `info w32 thread-information-block' or, by
2334 dereferencing the new convenience variable named `$_tlb', a
2335 thread-specific pointer to the TIB. This feature is also supported
2336 when remote debugging using GDBserver.
2338 * Static tracepoints
2340 Static tracepoints are calls in the user program into a tracing
2341 library. One such library is a port of the LTTng kernel tracer to
2342 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2343 When debugging with GDBserver, GDB now supports combining the GDB
2344 tracepoint machinery with such libraries. For example: the user can
2345 use GDB to probe a static tracepoint marker (a call from the user
2346 program into the tracing library) with the new "strace" command (see
2347 "New commands" below). This creates a "static tracepoint" in the
2348 breakpoint list, that can be manipulated with the same feature set
2349 as fast and regular tracepoints. E.g., collect registers, local and
2350 global variables, collect trace state variables, and define
2351 tracepoint conditions. In addition, the user can collect extra
2352 static tracepoint marker specific data, by collecting the new
2353 $_sdata internal variable. When analyzing the trace buffer, you can
2354 inspect $_sdata like any other variable available to GDB. For more
2355 information, see the "Tracepoints" chapter in GDB user manual. New
2356 remote packets have been defined to support static tracepoints, see
2357 the "New remote packets" section below.
2359 * Better reconstruction of tracepoints after disconnected tracing
2361 GDB will attempt to download the original source form of tracepoint
2362 definitions when starting a trace run, and then will upload these
2363 upon reconnection to the target, resulting in a more accurate
2364 reconstruction of the tracepoints that are in use on the target.
2368 You can now exercise direct control over the ways that GDB can
2369 affect your program. For instance, you can disallow the setting of
2370 breakpoints, so that the program can run continuously (assuming
2371 non-stop mode). In addition, the "observer" variable is available
2372 to switch all of the different controls; in observer mode, GDB
2373 cannot affect the target's behavior at all, which is useful for
2374 tasks like diagnosing live systems in the field.
2376 * The new convenience variable $_thread holds the number of the
2379 * New remote packets
2383 Return the address of the Windows Thread Information Block of a given thread.
2387 In response to several of the tracepoint packets, the target may now
2388 also respond with a number of intermediate `qRelocInsn' request
2389 packets before the final result packet, to have GDB handle
2390 relocating an instruction to execute at a different address. This
2391 is particularly useful for stubs that support fast tracepoints. GDB
2392 reports support for this feature in the qSupported packet.
2396 List static tracepoint markers in the target program.
2400 List static tracepoint markers at a given address in the target
2403 qXfer:statictrace:read
2405 Read the static trace data collected (by a `collect $_sdata'
2406 tracepoint action). The remote stub reports support for this packet
2407 to gdb's qSupported query.
2411 Send the current settings of GDB's permission flags.
2415 Send part of the source (textual) form of a tracepoint definition,
2416 which includes location, conditional, and action list.
2418 * The source command now accepts a -s option to force searching for the
2419 script in the source search path even if the script name specifies
2422 * New features in the GDB remote stub, GDBserver
2424 - GDBserver now support tracepoints (including fast tracepoints, and
2425 static tracepoints). The feature is currently supported by the
2426 i386-linux and amd64-linux builds. See the "Tracepoints support
2427 in gdbserver" section in the manual for more information.
2429 GDBserver JIT compiles the tracepoint's conditional agent
2430 expression bytecode into native code whenever possible for low
2431 overhead dynamic tracepoints conditionals. For such tracepoints,
2432 an expression that examines program state is evaluated when the
2433 tracepoint is reached, in order to determine whether to capture
2434 trace data. If the condition is simple and false, processing the
2435 tracepoint finishes very quickly and no data is gathered.
2437 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2438 for static tracepoints support.
2440 - GDBserver now supports x86_64 Windows 64-bit debugging.
2442 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2443 it understands register description.
2445 * The --batch flag now disables pagination and queries.
2447 * X86 general purpose registers
2449 GDB now supports reading/writing byte, word and double-word x86
2450 general purpose registers directly. This means you can use, say,
2451 $ah or $ax to refer, respectively, to the byte register AH and
2452 16-bit word register AX that are actually portions of the 32-bit
2453 register EAX or 64-bit register RAX.
2455 * The `commands' command now accepts a range of breakpoints to modify.
2456 A plain `commands' following a command that creates multiple
2457 breakpoints affects all the breakpoints set by that command. This
2458 applies to breakpoints set by `rbreak', and also applies when a
2459 single `break' command creates multiple breakpoints (e.g.,
2460 breakpoints on overloaded c++ functions).
2462 * The `rbreak' command now accepts a filename specification as part of
2463 its argument, limiting the functions selected by the regex to those
2464 in the specified file.
2466 * Support for remote debugging Windows and SymbianOS shared libraries
2467 from Unix hosts has been improved. Non Windows GDB builds now can
2468 understand target reported file names that follow MS-DOS based file
2469 system semantics, such as file names that include drive letters and
2470 use the backslash character as directory separator. This makes it
2471 possible to transparently use the "set sysroot" and "set
2472 solib-search-path" on Unix hosts to point as host copies of the
2473 target's shared libraries. See the new command "set
2474 target-file-system-kind" described below, and the "Commands to
2475 specify files" section in the user manual for more information.
2479 eval template, expressions...
2480 Convert the values of one or more expressions under the control
2481 of the string template to a command line, and call it.
2483 set target-file-system-kind unix|dos-based|auto
2484 show target-file-system-kind
2485 Set or show the assumed file system kind for target reported file
2488 save breakpoints <filename>
2489 Save all current breakpoint definitions to a file suitable for use
2490 in a later debugging session. To read the saved breakpoint
2491 definitions, use the `source' command.
2493 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2496 info static-tracepoint-markers
2497 Display information about static tracepoint markers in the target.
2499 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2500 Define a static tracepoint by probing a marker at the given
2501 function, line, address, or marker ID.
2505 Enable and disable observer mode.
2507 set may-write-registers on|off
2508 set may-write-memory on|off
2509 set may-insert-breakpoints on|off
2510 set may-insert-tracepoints on|off
2511 set may-insert-fast-tracepoints on|off
2512 set may-interrupt on|off
2513 Set individual permissions for GDB effects on the target. Note that
2514 some of these settings can have undesirable or surprising
2515 consequences, particularly when changed in the middle of a session.
2516 For instance, disabling the writing of memory can prevent
2517 breakpoints from being inserted, cause single-stepping to fail, or
2518 even crash your program, if you disable after breakpoints have been
2519 inserted. However, GDB should not crash.
2521 set record memory-query on|off
2522 show record memory-query
2523 Control whether to stop the inferior if memory changes caused
2524 by an instruction cannot be recorded.
2529 The disassemble command now supports "start,+length" form of two arguments.
2533 ** GDB now provides a new directory location, called the python directory,
2534 where Python scripts written for GDB can be installed. The location
2535 of that directory is <data-directory>/python, where <data-directory>
2536 is the GDB data directory. For more details, see section `Scripting
2537 GDB using Python' in the manual.
2539 ** The GDB Python API now has access to breakpoints, symbols, symbol
2540 tables, program spaces, inferiors, threads and frame's code blocks.
2541 Additionally, GDB Parameters can now be created from the API, and
2542 manipulated via set/show in the CLI.
2544 ** New functions gdb.target_charset, gdb.target_wide_charset,
2545 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2547 ** New exception gdb.GdbError.
2549 ** Pretty-printers are now also looked up in the current program space.
2551 ** Pretty-printers can now be individually enabled and disabled.
2553 ** GDB now looks for names of Python scripts to auto-load in a
2554 special section named `.debug_gdb_scripts', in addition to looking
2555 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2557 * Tracepoint actions were unified with breakpoint commands. In particular,
2558 there are no longer differences in "info break" output for breakpoints and
2559 tracepoints and the "commands" command can be used for both tracepoints and
2560 regular breakpoints.
2564 ARM Symbian arm*-*-symbianelf*
2566 * D language support.
2567 GDB now supports debugging programs written in the D programming
2570 * GDB now supports the extended ptrace interface for PowerPC which is
2571 available since Linux kernel version 2.6.34. This automatically enables
2572 any hardware breakpoints and additional hardware watchpoints available in
2573 the processor. The old ptrace interface exposes just one hardware
2574 watchpoint and no hardware breakpoints.
2576 * GDB is now able to use the Data Value Compare (DVC) register available on
2577 embedded PowerPC processors to implement in hardware simple watchpoint
2578 conditions of the form:
2580 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2582 This works in native GDB running on Linux kernels with the extended ptrace
2583 interface mentioned above.
2585 *** Changes in GDB 7.1
2589 ** Namespace Support
2591 GDB now supports importing of namespaces in C++. This enables the
2592 user to inspect variables from imported namespaces. Support for
2593 namepace aliasing has also been added. So, if a namespace is
2594 aliased in the current scope (e.g. namepace C=A; ) the user can
2595 print variables using the alias (e.g. (gdb) print C::x).
2599 All known bugs relating to the printing of virtual base class were
2600 fixed. It is now possible to call overloaded static methods using a
2605 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2606 and reinterpret_cast<> are now handled by the C++ expression parser.
2610 Xilinx MicroBlaze microblaze-*-*
2615 Xilinx MicroBlaze microblaze
2618 * Multi-program debugging.
2620 GDB now has support for multi-program (a.k.a. multi-executable or
2621 multi-exec) debugging. This allows for debugging multiple inferiors
2622 simultaneously each running a different program under the same GDB
2623 session. See "Debugging Multiple Inferiors and Programs" in the
2624 manual for more information. This implied some user visible changes
2625 in the multi-inferior support. For example, "info inferiors" now
2626 lists inferiors that are not running yet or that have exited
2627 already. See also "New commands" and "New options" below.
2629 * New tracing features
2631 GDB's tracepoint facility now includes several new features:
2633 ** Trace state variables
2635 GDB tracepoints now include support for trace state variables, which
2636 are variables managed by the target agent during a tracing
2637 experiment. They are useful for tracepoints that trigger each
2638 other, so for instance one tracepoint can count hits in a variable,
2639 and then a second tracepoint has a condition that is true when the
2640 count reaches a particular value. Trace state variables share the
2641 $-syntax of GDB convenience variables, and can appear in both
2642 tracepoint actions and condition expressions. Use the "tvariable"
2643 command to create, and "info tvariables" to view; see "Trace State
2644 Variables" in the manual for more detail.
2648 GDB now includes an option for defining fast tracepoints, which
2649 targets may implement more efficiently, such as by installing a jump
2650 into the target agent rather than a trap instruction. The resulting
2651 speedup can be by two orders of magnitude or more, although the
2652 tradeoff is that some program locations on some target architectures
2653 might not allow fast tracepoint installation, for instance if the
2654 instruction to be replaced is shorter than the jump. To request a
2655 fast tracepoint, use the "ftrace" command, with syntax identical to
2656 the regular trace command.
2658 ** Disconnected tracing
2660 It is now possible to detach GDB from the target while it is running
2661 a trace experiment, then reconnect later to see how the experiment
2662 is going. In addition, a new variable disconnected-tracing lets you
2663 tell the target agent whether to continue running a trace if the
2664 connection is lost unexpectedly.
2668 GDB now has the ability to save the trace buffer into a file, and
2669 then use that file as a target, similarly to you can do with
2670 corefiles. You can select trace frames, print data that was
2671 collected in them, and use tstatus to display the state of the
2672 tracing run at the moment that it was saved. To create a trace
2673 file, use "tsave <filename>", and to use it, do "target tfile
2676 ** Circular trace buffer
2678 You can ask the target agent to handle the trace buffer as a
2679 circular buffer, discarding the oldest trace frames to make room for
2680 newer ones, by setting circular-trace-buffer to on. This feature may
2681 not be available for all target agents.
2686 The disassemble command, when invoked with two arguments, now requires
2687 the arguments to be comma-separated.
2690 The info variables command now displays variable definitions. Files
2691 which only declare a variable are not shown.
2694 The source command is now capable of sourcing Python scripts.
2695 This feature is dependent on the debugger being build with Python
2698 Related to this enhancement is also the introduction of a new command
2699 "set script-extension" (see below).
2701 * New commands (for set/show, see "New options" below)
2703 record save [<FILENAME>]
2704 Save a file (in core file format) containing the process record
2705 execution log for replay debugging at a later time.
2707 record restore <FILENAME>
2708 Restore the process record execution log that was saved at an
2709 earlier time, for replay debugging.
2711 add-inferior [-copies <N>] [-exec <FILENAME>]
2714 clone-inferior [-copies <N>] [ID]
2715 Make a new inferior ready to execute the same program another
2716 inferior has loaded.
2721 maint info program-spaces
2722 List the program spaces loaded into GDB.
2724 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2725 show remote interrupt-sequence
2726 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2727 as the sequence to the remote target in order to interrupt the execution.
2728 Ctrl-C is a default. Some system prefers BREAK which is high level of
2729 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2730 Magic SysRq g. It is BREAK signal and character 'g'.
2732 set remote interrupt-on-connect [on | off]
2733 show remote interrupt-on-connect
2734 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2735 remote target when gdb connects to it. This is needed when you debug
2738 set remotebreak [on | off]
2740 Deprecated. Use "set/show remote interrupt-sequence" instead.
2742 tvariable $NAME [ = EXP ]
2743 Create or modify a trace state variable.
2746 List trace state variables and their values.
2748 delete tvariable $NAME ...
2749 Delete one or more trace state variables.
2752 Evaluate the given expressions without collecting anything into the
2753 trace buffer. (Valid in tracepoint actions only.)
2755 ftrace FN / FILE:LINE / *ADDR
2756 Define a fast tracepoint at the given function, line, or address.
2758 * New expression syntax
2760 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2761 GDB now parses 0b101010 identically with 42.
2765 set follow-exec-mode new|same
2766 show follow-exec-mode
2767 Control whether GDB reuses the same inferior across an exec call or
2768 creates a new one. This is useful to be able to restart the old
2769 executable after the inferior having done an exec call.
2771 set default-collect EXPR, ...
2772 show default-collect
2773 Define a list of expressions to be collected at each tracepoint.
2774 This is a useful way to ensure essential items are not overlooked,
2775 such as registers or a critical global variable.
2777 set disconnected-tracing
2778 show disconnected-tracing
2779 If set to 1, the target is instructed to continue tracing if it
2780 loses its connection to GDB. If 0, the target is to stop tracing
2783 set circular-trace-buffer
2784 show circular-trace-buffer
2785 If set to on, the target is instructed to use a circular trace buffer
2786 and discard the oldest trace frames instead of stopping the trace due
2787 to a full trace buffer. If set to off, the trace stops when the buffer
2788 fills up. Some targets may not support this.
2790 set script-extension off|soft|strict
2791 show script-extension
2792 If set to "off", the debugger does not perform any script language
2793 recognition, and all sourced files are assumed to be GDB scripts.
2794 If set to "soft" (the default), files are sourced according to
2795 filename extension, falling back to GDB scripts if the first
2797 If set to "strict", files are sourced according to filename extension.
2799 set ada trust-PAD-over-XVS on|off
2800 show ada trust-PAD-over-XVS
2801 If off, activate a workaround against a bug in the debugging information
2802 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2803 the GCC sources for more information about the GNAT encoding and
2804 PAD types in particular). It is always safe to set this option to
2805 off, but this introduces a slight performance penalty. The default
2808 * Python API Improvements
2810 ** GDB provides the new class gdb.LazyString. This is useful in
2811 some pretty-printing cases. The new method gdb.Value.lazy_string
2812 provides a simple way to create objects of this type.
2814 ** The fields returned by gdb.Type.fields now have an
2815 `is_base_class' attribute.
2817 ** The new method gdb.Type.range returns the range of an array type.
2819 ** The new method gdb.parse_and_eval can be used to parse and
2820 evaluate an expression.
2822 * New remote packets
2825 Define a trace state variable.
2828 Get the current value of a trace state variable.
2831 Set desired tracing behavior upon disconnection.
2834 Set the trace buffer to be linear or circular.
2837 Get data about the tracepoints currently in use.
2841 Process record now works correctly with hardware watchpoints.
2843 Multiple bug fixes have been made to the mips-irix port, making it
2844 much more reliable. In particular:
2845 - Debugging threaded applications is now possible again. Previously,
2846 GDB would hang while starting the program, or while waiting for
2847 the program to stop at a breakpoint.
2848 - Attaching to a running process no longer hangs.
2849 - An error occurring while loading a core file has been fixed.
2850 - Changing the value of the PC register now works again. This fixes
2851 problems observed when using the "jump" command, or when calling
2852 a function from GDB, or even when assigning a new value to $pc.
2853 - With the "finish" and "return" commands, the return value for functions
2854 returning a small array is now correctly printed.
2855 - It is now possible to break on shared library code which gets executed
2856 during a shared library init phase (code executed while executing
2857 their .init section). Previously, the breakpoint would have no effect.
2858 - GDB is now able to backtrace through the signal handler for
2859 non-threaded programs.
2861 PIE (Position Independent Executable) programs debugging is now supported.
2862 This includes debugging execution of PIC (Position Independent Code) shared
2863 libraries although for that, it should be possible to run such libraries as an
2866 *** Changes in GDB 7.0
2868 * GDB now has an interface for JIT compilation. Applications that
2869 dynamically generate code can create symbol files in memory and register
2870 them with GDB. For users, the feature should work transparently, and
2871 for JIT developers, the interface is documented in the GDB manual in the
2872 "JIT Compilation Interface" chapter.
2874 * Tracepoints may now be conditional. The syntax is as for
2875 breakpoints; either an "if" clause appended to the "trace" command,
2876 or the "condition" command is available. GDB sends the condition to
2877 the target for evaluation using the same bytecode format as is used
2878 for tracepoint actions.
2880 * The disassemble command now supports: an optional /r modifier, print the
2881 raw instructions in hex as well as in symbolic form, and an optional /m
2882 modifier to print mixed source+assembly.
2884 * Process record and replay
2886 In a architecture environment that supports ``process record and
2887 replay'', ``process record and replay'' target can record a log of
2888 the process execution, and replay it with both forward and reverse
2891 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2892 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2893 set execution-direction {forward|reverse}, for targets that support
2896 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2897 feature is available with a native GDB running on kernel version
2900 * GDB now has support for multi-byte and wide character sets on the
2901 target. Strings whose character type is wchar_t, char16_t, or
2902 char32_t are now correctly printed. GDB supports wide- and unicode-
2903 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2904 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2905 `printf'. This feature requires iconv to work properly; if your
2906 system does not have a working iconv, GDB can use GNU libiconv. See
2907 the installation instructions for more information.
2909 * GDB now supports automatic retrieval of shared library files from
2910 remote targets. To use this feature, specify a system root that begins
2911 with the `remote:' prefix, either via the `set sysroot' command or via
2912 the `--with-sysroot' configure-time option.
2914 * "info sharedlibrary" now takes an optional regex of libraries to show,
2915 and it now reports if a shared library has no debugging information.
2917 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2918 now complete on file names.
2920 * When completing in expressions, gdb will attempt to limit
2921 completions to allowable structure or union fields, where appropriate.
2922 For instance, consider:
2924 # struct example { int f1; double f2; };
2925 # struct example variable;
2928 If the user types TAB at the end of this command line, the available
2929 completions will be "f1" and "f2".
2931 * Inlined functions are now supported. They show up in backtraces, and
2932 the "step", "next", and "finish" commands handle them automatically.
2934 * GDB now supports the token-splicing (##) and stringification (#)
2935 operators when expanding macros. It also supports variable-arity
2938 * GDB now supports inspecting extra signal information, exported by
2939 the new $_siginfo convenience variable. The feature is currently
2940 implemented on linux ARM, i386 and amd64.
2942 * GDB can now display the VFP floating point registers and NEON vector
2943 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2944 can provide these registers (requires Linux 2.6.30 or later). Remote
2945 and simulator targets may also provide them.
2947 * New remote packets
2950 Search memory for a sequence of bytes.
2953 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2954 operation over reliable transport links. Use of this packet is
2955 controlled by the `set remote noack-packet' command.
2958 Kill the process with the specified process ID. Use this in preference
2959 to `k' when multiprocess protocol extensions are supported.
2962 Obtains additional operating system information
2966 Read or write additional signal information.
2968 * Removed remote protocol undocumented extension
2970 An undocumented extension to the remote protocol's `S' stop reply
2971 packet that permited the stub to pass a process id was removed.
2972 Remote servers should use the `T' stop reply packet instead.
2974 * GDB now supports multiple function calling conventions according to the
2975 DWARF-2 DW_AT_calling_convention function attribute.
2977 * The SH target utilizes the aforementioned change to distinguish between gcc
2978 and Renesas calling convention. It also adds the new CLI commands
2979 `set/show sh calling-convention'.
2981 * GDB can now read compressed debug sections, as produced by GNU gold
2982 with the --compress-debug-sections=zlib flag.
2984 * 64-bit core files are now supported on AIX.
2986 * Thread switching is now supported on Tru64.
2988 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2989 which will be allocated using malloc later in program execution.
2991 * The qXfer:libraries:read remote procotol packet now allows passing a
2992 list of section offsets.
2994 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2995 conditions handling signals delivered during attach or thread creation
2996 have also been fixed.
2998 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2999 From the user's standpoint, all unqualified instances of True and False
3000 are treated as the standard definitions, regardless of context.
3002 * GDB now parses C++ symbol and type names more flexibly. For
3005 template<typename T> class C { };
3008 GDB will now correctly handle all of:
3010 ptype C<char const *>
3011 ptype C<char const*>
3012 ptype C<const char *>
3013 ptype C<const char*>
3015 * New features in the GDB remote stub, gdbserver
3017 - The "--wrapper" command-line argument tells gdbserver to use a
3018 wrapper program to launch programs for debugging.
3020 - On PowerPC and S/390 targets, it is now possible to use a single
3021 gdbserver executable to debug both 32-bit and 64-bit programs.
3022 (This requires gdbserver itself to be built as a 64-bit executable.)
3024 - gdbserver uses the new noack protocol mode for TCP connections to
3025 reduce communications latency, if also supported and enabled in GDB.
3027 - Support for the sparc64-linux-gnu target is now included in
3030 - The amd64-linux build of gdbserver now supports debugging both
3031 32-bit and 64-bit programs.
3033 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3034 now support hardware watchpoints, and will use them automatically
3039 GDB now has support for scripting using Python. Whether this is
3040 available is determined at configure time.
3042 New GDB commands can now be written in Python.
3044 * Ada tasking support
3046 Ada tasks can now be inspected in GDB. The following commands have
3050 Print the list of Ada tasks.
3052 Print detailed information about task number N.
3054 Print the task number of the current task.
3056 Switch the context of debugging to task number N.
3058 * Support for user-defined prefixed commands. The "define" command can
3059 add new commands to existing prefixes, e.g. "target".
3061 * Multi-inferior, multi-process debugging.
3063 GDB now has generalized support for multi-inferior debugging. See
3064 "Debugging Multiple Inferiors" in the manual for more information.
3065 Although availability still depends on target support, the command
3066 set is more uniform now. The GNU/Linux specific multi-forks support
3067 has been migrated to this new framework. This implied some user
3068 visible changes; see "New commands" and also "Removed commands"
3071 * Target descriptions can now describe the target OS ABI. See the
3072 "Target Description Format" section in the user manual for more
3075 * Target descriptions can now describe "compatible" architectures
3076 to indicate that the target can execute applications for a different
3077 architecture in addition to those for the main target architecture.
3078 See the "Target Description Format" section in the user manual for
3081 * Multi-architecture debugging.
3083 GDB now includes general supports for debugging applications on
3084 hybrid systems that use more than one single processor architecture
3085 at the same time. Each such hybrid architecture still requires
3086 specific support to be added. The only hybrid architecture supported
3087 in this version of GDB is the Cell Broadband Engine.
3089 * GDB now supports integrated debugging of Cell/B.E. applications that
3090 use both the PPU and SPU architectures. To enable support for hybrid
3091 Cell/B.E. debugging, you need to configure GDB to support both the
3092 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3093 --enable-targets configure option.
3095 * Non-stop mode debugging.
3097 For some targets, GDB now supports an optional mode of operation in
3098 which you can examine stopped threads while other threads continue
3099 to execute freely. This is referred to as non-stop mode, with the
3100 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3101 section in the user manual for more information.
3103 To be able to support remote non-stop debugging, a remote stub needs
3104 to implement the non-stop mode remote protocol extensions, as
3105 described in the "Remote Non-Stop" section of the user manual. The
3106 GDB remote stub, gdbserver, has been adjusted to support these
3107 extensions on linux targets.
3109 * New commands (for set/show, see "New options" below)
3111 catch syscall [NAME(S) | NUMBER(S)]
3112 Catch system calls. Arguments, which should be names of system
3113 calls or their numbers, mean catch only those syscalls. Without
3114 arguments, every syscall will be caught. When the inferior issues
3115 any of the specified syscalls, GDB will stop and announce the system
3116 call, both when it is called and when its call returns. This
3117 feature is currently available with a native GDB running on the
3118 Linux Kernel, under the following architectures: x86, x86_64,
3119 PowerPC and PowerPC64.
3121 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3123 Search memory for a sequence of bytes.
3125 maint set python print-stack
3126 maint show python print-stack
3127 Show a stack trace when an error is encountered in a Python script.
3130 Invoke CODE by passing it to the Python interpreter.
3135 These allow macros to be defined, undefined, and listed
3139 Show operating system information about processes.
3142 List the inferiors currently under GDB's control.
3145 Switch focus to inferior number NUM.
3148 Detach from inferior number NUM.
3151 Kill inferior number NUM.
3155 set spu stop-on-load
3156 show spu stop-on-load
3157 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3159 set spu auto-flush-cache
3160 show spu auto-flush-cache
3161 Control whether to automatically flush the software-managed cache
3162 during Cell/B.E. debugging.
3164 set sh calling-convention
3165 show sh calling-convention
3166 Control the calling convention used when calling SH target functions.
3169 show debug timestamp
3170 Control display of timestamps with GDB debugging output.
3172 set disassemble-next-line
3173 show disassemble-next-line
3174 Control display of disassembled source lines or instructions when
3177 set remote noack-packet
3178 show remote noack-packet
3179 Set/show the use of remote protocol QStartNoAckMode packet. See above
3180 under "New remote packets."
3182 set remote query-attached-packet
3183 show remote query-attached-packet
3184 Control use of remote protocol `qAttached' (query-attached) packet.
3186 set remote read-siginfo-object
3187 show remote read-siginfo-object
3188 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3191 set remote write-siginfo-object
3192 show remote write-siginfo-object
3193 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3196 set remote reverse-continue
3197 show remote reverse-continue
3198 Control use of remote protocol 'bc' (reverse-continue) packet.
3200 set remote reverse-step
3201 show remote reverse-step
3202 Control use of remote protocol 'bs' (reverse-step) packet.
3204 set displaced-stepping
3205 show displaced-stepping
3206 Control displaced stepping mode. Displaced stepping is a way to
3207 single-step over breakpoints without removing them from the debuggee.
3208 Also known as "out-of-line single-stepping".
3211 show debug displaced
3212 Control display of debugging info for displaced stepping.
3214 maint set internal-error
3215 maint show internal-error
3216 Control what GDB does when an internal error is detected.
3218 maint set internal-warning
3219 maint show internal-warning
3220 Control what GDB does when an internal warning is detected.
3225 Use a wrapper program to launch programs for debugging.
3227 set multiple-symbols (all|ask|cancel)
3228 show multiple-symbols
3229 The value of this variable can be changed to adjust the debugger behavior
3230 when an expression or a breakpoint location contains an ambiguous symbol
3231 name (an overloaded function name, for instance).
3233 set breakpoint always-inserted
3234 show breakpoint always-inserted
3235 Keep breakpoints always inserted in the target, as opposed to inserting
3236 them when resuming the target, and removing them when the target stops.
3237 This option can improve debugger performance on slow remote targets.
3239 set arm fallback-mode (arm|thumb|auto)
3240 show arm fallback-mode
3241 set arm force-mode (arm|thumb|auto)
3243 These commands control how ARM GDB determines whether instructions
3244 are ARM or Thumb. The default for both settings is auto, which uses
3245 the current CPSR value for instructions without symbols; previous
3246 versions of GDB behaved as if "set arm fallback-mode arm".
3248 set disable-randomization
3249 show disable-randomization
3250 Standalone programs run with the virtual address space randomization enabled
3251 by default on some platforms. This option keeps the addresses stable across
3252 multiple debugging sessions.
3256 Control whether other threads are stopped or not when some thread hits
3261 Requests that asynchronous execution is enabled in the target, if available.
3262 In this case, it's possible to resume target in the background, and interact
3263 with GDB while the target is running. "show target-async" displays the
3264 current state of asynchronous execution of the target.
3266 set target-wide-charset
3267 show target-wide-charset
3268 The target-wide-charset is the name of the character set that GDB
3269 uses when printing characters whose type is wchar_t.
3271 set tcp auto-retry (on|off)
3273 set tcp connect-timeout
3274 show tcp connect-timeout
3275 These commands allow GDB to retry failed TCP connections to a remote stub
3276 with a specified timeout period; this is useful if the stub is launched
3277 in parallel with GDB but may not be ready to accept connections immediately.
3279 set libthread-db-search-path
3280 show libthread-db-search-path
3281 Control list of directories which GDB will search for appropriate
3284 set schedule-multiple (on|off)
3285 show schedule-multiple
3286 Allow GDB to resume all threads of all processes or only threads of
3287 the current process.
3291 Use more aggressive caching for accesses to the stack. This improves
3292 performance of remote debugging (particularly backtraces) without
3293 affecting correctness.
3295 set interactive-mode (on|off|auto)
3296 show interactive-mode
3297 Control whether GDB runs in interactive mode (on) or not (off).
3298 When in interactive mode, GDB waits for the user to answer all
3299 queries. Otherwise, GDB does not wait and assumes the default
3300 answer. When set to auto (the default), GDB determines which
3301 mode to use based on the stdin settings.
3306 For program forks, this is replaced by the new more generic `info
3307 inferiors' command. To list checkpoints, you can still use the
3308 `info checkpoints' command, which was an alias for the `info forks'
3312 Replaced by the new `inferior' command. To switch between
3313 checkpoints, you can still use the `restart' command, which was an
3314 alias for the `fork' command.
3317 This is removed, since some targets don't have a notion of
3318 processes. To switch between processes, you can still use the
3319 `inferior' command using GDB's own inferior number.
3322 For program forks, this is replaced by the new more generic `kill
3323 inferior' command. To delete a checkpoint, you can still use the
3324 `delete checkpoint' command, which was an alias for the `delete
3328 For program forks, this is replaced by the new more generic `detach
3329 inferior' command. To detach a checkpoint, you can still use the
3330 `detach checkpoint' command, which was an alias for the `detach
3333 * New native configurations
3335 x86/x86_64 Darwin i[34567]86-*-darwin*
3337 x86_64 MinGW x86_64-*-mingw*
3341 Lattice Mico32 lm32-*
3342 x86 DICOS i[34567]86-*-dicos*
3343 x86_64 DICOS x86_64-*-dicos*
3346 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3347 (mingw32ce) debugging.
3353 These commands were actually not implemented on any target.
3355 *** Changes in GDB 6.8
3357 * New native configurations
3359 NetBSD/hppa hppa*-*netbsd*
3360 Xtensa GNU/Linux xtensa*-*-linux*
3364 NetBSD/hppa hppa*-*-netbsd*
3365 Xtensa GNU/Lunux xtensa*-*-linux*
3367 * Change in command line behavior -- corefiles vs. process ids.
3369 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3370 attaching to process NUMBER fails, GDB no longer attempts to open a
3371 core file named NUMBER. Attaching to a program using the -c option
3372 is no longer supported. Instead, use the '-p' or '--pid' options.
3374 * GDB can now be built as a native debugger for debugging Windows x86
3375 (mingw32) Portable Executable (PE) programs.
3377 * Pending breakpoints no longer change their number when their address
3380 * GDB now supports breakpoints with multiple locations,
3381 including breakpoints on C++ constructors, inside C++ templates,
3382 and in inlined functions.
3384 * GDB's ability to debug optimized code has been improved. GDB more
3385 accurately identifies function bodies and lexical blocks that occupy
3386 more than one contiguous range of addresses.
3388 * Target descriptions can now describe registers for PowerPC.
3390 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3391 registers on PowerPC targets.
3393 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3394 targets even when the libthread_db library is not available.
3396 * The GDB remote stub, gdbserver, now supports the new file transfer
3397 commands (remote put, remote get, and remote delete).
3399 * The GDB remote stub, gdbserver, now supports run and attach in
3400 extended-remote mode.
3402 * hppa*64*-*-hpux11* target broken
3403 The debugger is unable to start a program and fails with the following
3404 error: "Error trying to get information about dynamic linker".
3405 The gdb-6.7 release is also affected.
3407 * GDB now supports the --enable-targets= configure option to allow
3408 building a single GDB executable that supports multiple remote
3409 target architectures.
3411 * GDB now supports debugging C and C++ programs which use the
3412 Decimal Floating Point extension. In addition, the PowerPC target
3413 now has a set of pseudo-registers to inspect decimal float values
3414 stored in two consecutive float registers.
3416 * The -break-insert MI command can optionally create pending
3419 * Improved support for debugging Ada
3420 Many improvements to the Ada language support have been made. These
3422 - Better support for Ada2005 interface types
3423 - Improved handling of arrays and slices in general
3424 - Better support for Taft-amendment types
3425 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3427 - Improved command completion in Ada
3430 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3435 set print frame-arguments (all|scalars|none)
3436 show print frame-arguments
3437 The value of this variable can be changed to control which argument
3438 values should be printed by the debugger when displaying a frame.
3443 Transfer files to and from a remote target, and delete remote files.
3450 Transfer files to and from a remote target, and delete remote files.
3452 * New remote packets
3459 Open, close, read, write, and delete files on the remote system.
3462 Attach to an existing process on the remote system, in extended-remote
3466 Run a new process on the remote system, in extended-remote mode.
3468 *** Changes in GDB 6.7
3470 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3471 bfd, libiberty and opcodes, as revealed by static analysis donated by
3472 Coverity, Inc. (http://scan.coverity.com).
3474 * When looking up multiply-defined global symbols, GDB will now prefer the
3475 symbol definition in the current shared library if it was built using the
3476 -Bsymbolic linker option.
3478 * When the Text User Interface (TUI) is not configured, GDB will now
3479 recognize the -tui command-line option and print a message that the TUI
3482 * The GDB remote stub, gdbserver, now has lower overhead for high
3483 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3485 * GDB for MIPS targets now autodetects whether a remote target provides
3486 32-bit or 64-bit register values.
3488 * Support for C++ member pointers has been improved.
3490 * GDB now understands XML target descriptions, which specify the
3491 target's overall architecture. GDB can read a description from
3492 a local file or over the remote serial protocol.
3494 * Vectors of single-byte data use a new integer type which is not
3495 automatically displayed as character or string data.
3497 * The /s format now works with the print command. It displays
3498 arrays of single-byte integers and pointers to single-byte integers
3501 * Target descriptions can now describe target-specific registers,
3502 for architectures which have implemented the support (currently
3503 only ARM, M68K, and MIPS).
3505 * GDB and the GDB remote stub, gdbserver, now support the XScale
3508 * The GDB remote stub, gdbserver, has been updated to support
3509 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3510 has been rewritten to use the standard GDB remote protocol.
3512 * GDB can now step into C++ functions which are called through thunks.
3514 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3516 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3517 layout. It also supports a TextSeg= and DataSeg= response when only
3518 segment base addresses (rather than offsets) are available.
3520 * The /i format now outputs any trailing branch delay slot instructions
3521 immediately following the last instruction within the count specified.
3523 * The GDB remote protocol "T" stop reply packet now supports a
3524 "library" response. Combined with the new "qXfer:libraries:read"
3525 packet, this response allows GDB to debug shared libraries on targets
3526 where the operating system manages the list of loaded libraries (e.g.
3527 Windows and SymbianOS).
3529 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3530 (DLLs) on Windows and Windows CE targets.
3532 * GDB now supports a faster verification that a .debug file matches its binary
3533 according to its build-id signature, if the signature is present.
3539 Enable or disable hardware flow control (RTS/CTS) on the serial port
3540 when debugging using remote targets.
3542 set mem inaccessible-by-default
3543 show mem inaccessible-by-default
3544 If the target supplies a memory map, for instance via the remote
3545 protocol's "qXfer:memory-map:read" packet, setting this variable
3546 prevents GDB from accessing memory outside the memory map. This
3547 is useful for targets with memory mapped registers or which react
3548 badly to accesses of unmapped address space.
3550 set breakpoint auto-hw
3551 show breakpoint auto-hw
3552 If the target supplies a memory map, for instance via the remote
3553 protocol's "qXfer:memory-map:read" packet, setting this variable
3554 lets GDB use hardware breakpoints automatically for memory regions
3555 where it can not use software breakpoints. This covers both the
3556 "break" command and internal breakpoints used for other commands
3557 including "next" and "finish".
3560 catch exception unhandled
3561 Stop the program execution when Ada exceptions are raised.
3564 Stop the program execution when an Ada assertion failed.
3568 Set an alternate system root for target files. This is a more
3569 general version of "set solib-absolute-prefix", which is now
3570 an alias to "set sysroot".
3573 Provide extended SPU facility status information. This set of
3574 commands is available only when debugging the Cell/B.E. SPU
3577 * New native configurations
3579 OpenBSD/sh sh*-*openbsd*
3582 unset tdesc filename
3584 Use the specified local file as an XML target description, and do
3585 not query the target for its built-in description.
3589 OpenBSD/sh sh*-*-openbsd*
3590 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3591 Toshiba Media Processor mep-elf
3593 * New remote packets
3596 Ignore the specified signals; pass them directly to the debugged program
3597 without stopping other threads or reporting them to GDB.
3599 qXfer:features:read:
3600 Read an XML target description from the target, which describes its
3605 Read or write contents of an spufs file on the target system. These
3606 packets are available only on the Cell/B.E. SPU architecture.
3608 qXfer:libraries:read:
3609 Report the loaded shared libraries. Combined with new "T" packet
3610 response, this packet allows GDB to debug shared libraries on
3611 targets where the operating system manages the list of loaded
3612 libraries (e.g. Windows and SymbianOS).
3616 Support for these obsolete configurations has been removed.
3624 i[34567]86-*-lynxos*
3625 i[34567]86-*-netware*
3626 i[34567]86-*-sco3.2v5*
3627 i[34567]86-*-sco3.2v4*
3629 i[34567]86-*-sysv4.2*
3632 i[34567]86-*-unixware2*
3633 i[34567]86-*-unixware*
3642 * Other removed features
3649 Various m68k-only ROM monitors.
3656 Various Renesas ROM monitors and debugging interfaces for SH and
3661 Support for a Macraigor serial interface to on-chip debugging.
3662 GDB does not directly support the newer parallel or USB
3667 A debug information format. The predecessor to DWARF 2 and
3668 DWARF 3, which are still supported.
3670 Support for the HP aCC compiler on HP-UX/PA-RISC
3672 SOM-encapsulated symbolic debugging information, automatic
3673 invocation of pxdb, and the aCC custom C++ ABI. This does not
3674 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3675 with aCC can still be debugged on an assembly level.
3677 MIPS ".pdr" sections
3679 A MIPS-specific format used to describe stack frame layout
3680 in debugging information.
3684 GDB could work with an older version of Guile to debug
3685 the interpreter and Scheme programs running in it.
3687 set mips stack-arg-size
3688 set mips saved-gpreg-size
3690 Use "set mips abi" to control parameter passing for MIPS.
3692 *** Changes in GDB 6.6
3697 Cell Broadband Engine SPU spu-elf
3699 * GDB can now be configured as a cross-debugger targeting native Windows
3700 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3701 running on a Windows system over TCP/IP to debug Windows programs.
3703 * The GDB remote stub, gdbserver, has been updated to support Windows and
3704 Cygwin debugging. Both single-threaded and multi-threaded programs are
3707 * The "set trust-readonly-sections" command works again. This command was
3708 broken in GDB 6.3, 6.4, and 6.5.
3710 * The "load" command now supports writing to flash memory, if the remote
3711 stub provides the required support.
3713 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3714 longer requires symbolic debug information (e.g. DWARF-2).
3719 unset substitute-path
3720 show substitute-path
3721 Manage a list of substitution rules that GDB uses to rewrite the name
3722 of the directories where the sources are located. This can be useful
3723 for instance when the sources were moved to a different location
3724 between compilation and debugging.
3728 Print each CLI command as it is executed. Each command is prefixed with
3729 a number of `+' symbols representing the nesting depth.
3730 The source command now has a `-v' option to enable the same feature.
3734 The ARM Demon monitor support (RDP protocol, "target rdp").
3736 Kernel Object Display, an embedded debugging feature which only worked with
3737 an obsolete version of Cisco IOS.
3739 The 'set download-write-size' and 'show download-write-size' commands.
3741 * New remote packets
3744 Tell a stub about GDB client features, and request remote target features.
3745 The first feature implemented is PacketSize, which allows the target to
3746 specify the size of packets it can handle - to minimize the number of
3747 packets required and improve performance when connected to a remote
3751 Fetch an OS auxilliary vector from the remote stub. This packet is a
3752 more efficient replacement for qPart:auxv:read.
3754 qXfer:memory-map:read:
3755 Fetch a memory map from the remote stub, including information about
3756 RAM, ROM, and flash memory devices.
3761 Erase and program a flash memory device.
3763 * Removed remote packets
3766 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3767 used it, and only gdbserver implemented it.
3769 *** Changes in GDB 6.5
3773 Renesas M32C/M16C m32c-elf
3775 Morpho Technologies ms1 ms1-elf
3779 init-if-undefined Initialize a convenience variable, but
3780 only if it doesn't already have a value.
3782 The following commands are presently only implemented for native GNU/Linux:
3784 checkpoint Save a snapshot of the program state.
3786 restart <n> Return the program state to a
3787 previously saved state.
3789 info checkpoints List currently saved checkpoints.
3791 delete-checkpoint <n> Delete a previously saved checkpoint.
3793 set|show detach-on-fork Tell gdb whether to detach from a newly
3794 forked process, or to keep debugging it.
3796 info forks List forks of the user program that
3797 are available to be debugged.
3799 fork <n> Switch to debugging one of several
3800 forks of the user program that are
3801 available to be debugged.
3803 delete-fork <n> Delete a fork from the list of forks
3804 that are available to be debugged (and
3805 kill the forked process).
3807 detach-fork <n> Delete a fork from the list of forks
3808 that are available to be debugged (and
3809 allow the process to continue).
3813 Morpho Technologies ms2 ms1-elf
3815 * Improved Windows host support
3817 GDB now builds as a cross debugger hosted on i686-mingw32, including
3818 native console support, and remote communications using either
3819 network sockets or serial ports.
3821 * Improved Modula-2 language support
3823 GDB can now print most types in the Modula-2 syntax. This includes:
3824 basic types, set types, record types, enumerated types, range types,
3825 pointer types and ARRAY types. Procedure var parameters are correctly
3826 printed and hexadecimal addresses and character constants are also
3827 written in the Modula-2 syntax. Best results can be obtained by using
3828 GNU Modula-2 together with the -gdwarf-2 command line option.
3832 The ARM rdi-share module.
3834 The Netware NLM debug server.
3836 *** Changes in GDB 6.4
3838 * New native configurations
3840 OpenBSD/arm arm*-*-openbsd*
3841 OpenBSD/mips64 mips64-*-openbsd*
3845 Morpho Technologies ms1 ms1-elf
3847 * New command line options
3849 --batch-silent As for --batch, but totally silent.
3850 --return-child-result The debugger will exist with the same value
3851 the child (debugged) program exited with.
3852 --eval-command COMMAND, -ex COMMAND
3853 Execute a single GDB CLI command. This may be
3854 specified multiple times and in conjunction
3855 with the --command (-x) option.
3857 * Deprecated commands removed
3859 The following commands, that were deprecated in 2000, have been
3863 set|show arm disassembly-flavor set|show arm disassembler
3864 othernames set arm disassembler
3865 set|show remotedebug set|show debug remote
3866 set|show archdebug set|show debug arch
3867 set|show eventdebug set|show debug event
3870 * New BSD user-level threads support
3872 It is now possible to debug programs using the user-level threads
3873 library on OpenBSD and FreeBSD. Currently supported (target)
3876 FreeBSD/amd64 x86_64-*-freebsd*
3877 FreeBSD/i386 i386-*-freebsd*
3878 OpenBSD/i386 i386-*-openbsd*
3880 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3881 are not yet supported.
3883 * New support for Matsushita MN10300 w/sim added
3884 (Work in progress). mn10300-elf.
3886 * REMOVED configurations and files
3888 VxWorks and the XDR protocol *-*-vxworks
3889 Motorola MCORE mcore-*-*
3890 National Semiconductor NS32000 ns32k-*-*
3892 * New "set print array-indexes" command
3894 After turning this setting "on", GDB prints the index of each element
3895 when displaying arrays. The default is "off" to preserve the previous
3898 * VAX floating point support
3900 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3902 * User-defined command support
3904 In addition to using $arg0..$arg9 for argument passing, it is now possible
3905 to use $argc to determine now many arguments have been passed. See the
3906 section on user-defined commands in the user manual for more information.
3908 *** Changes in GDB 6.3:
3910 * New command line option
3912 GDB now accepts -l followed by a number to set the timeout for remote
3915 * GDB works with GCC -feliminate-dwarf2-dups
3917 GDB now supports a more compact representation of DWARF-2 debug
3918 information using DW_FORM_ref_addr references. These are produced
3919 by GCC with the option -feliminate-dwarf2-dups and also by some
3920 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3921 to use -feliminate-dwarf2-dups.
3923 * Internationalization
3925 When supported by the host system, GDB will be built with
3926 internationalization (libintl). The task of marking up the sources is
3927 continued, we're looking forward to our first translation.
3931 Initial support for debugging programs compiled with the GNAT
3932 implementation of the Ada programming language has been integrated
3933 into GDB. In this release, support is limited to expression evaluation.
3935 * New native configurations
3937 GNU/Linux/m32r m32r-*-linux-gnu
3941 GDB's remote protocol now includes support for the 'p' packet. This
3942 packet is used to fetch individual registers from a remote inferior.
3944 * END-OF-LIFE registers[] compatibility module
3946 GDB's internal register infrastructure has been completely rewritten.
3947 The new infrastructure making possible the implementation of key new
3948 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3951 GDB 6.3 will be the last release to include the the registers[]
3952 compatibility module that allowed out-of-date configurations to
3953 continue to work. This change directly impacts the following
3963 powerpc bdm protocol
3965 Unless there is activity to revive these configurations, they will be
3966 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3968 * OBSOLETE configurations and files
3970 Configurations that have been declared obsolete in this release have
3971 been commented out. Unless there is activity to revive these
3972 configurations, the next release of GDB will have their sources
3973 permanently REMOVED.
3982 *** Changes in GDB 6.2.1:
3984 * MIPS `break main; run' gave an heuristic-fence-post warning
3986 When attempting to run even a simple program, a warning about
3987 heuristic-fence-post being hit would be reported. This problem has
3990 * MIPS IRIX 'long double' crashed GDB
3992 When examining a long double variable, GDB would get a segmentation
3993 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3994 IRIX long double values).
3998 A bug in the VAX stack code was causing problems with the "next"
3999 command. This problem has been fixed.
4001 *** Changes in GDB 6.2:
4003 * Fix for ``many threads''
4005 On GNU/Linux systems that use the NPTL threads library, a program
4006 rapidly creating and deleting threads would confuse GDB leading to the
4009 ptrace: No such process.
4010 thread_db_get_info: cannot get thread info: generic error
4012 This problem has been fixed.
4014 * "-async" and "-noasync" options removed.
4016 Support for the broken "-noasync" option has been removed (it caused
4019 * New ``start'' command.
4021 This command runs the program until the begining of the main procedure.
4023 * New BSD Kernel Data Access Library (libkvm) interface
4025 Using ``target kvm'' it is now possible to debug kernel core dumps and
4026 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4027 platforms. Currently supported (native-only) configurations are:
4029 FreeBSD/amd64 x86_64-*-freebsd*
4030 FreeBSD/i386 i?86-*-freebsd*
4031 NetBSD/i386 i?86-*-netbsd*
4032 NetBSD/m68k m68*-*-netbsd*
4033 NetBSD/sparc sparc-*-netbsd*
4034 OpenBSD/amd64 x86_64-*-openbsd*
4035 OpenBSD/i386 i?86-*-openbsd*
4036 OpenBSD/m68k m68*-openbsd*
4037 OpenBSD/sparc sparc-*-openbsd*
4039 * Signal trampoline code overhauled
4041 Many generic problems with GDB's signal handling code have been fixed.
4042 These include: backtraces through non-contiguous stacks; recognition
4043 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4044 call; backtrace through a signal trampoline; step into and out of
4045 signal handlers; and single-stepping in the signal trampoline.
4047 Please note that kernel bugs are a limiting factor here. These
4048 features have been shown to work on an s390 GNU/Linux system that
4049 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4051 * Cygwin support for DWARF 2 added.
4053 * New native configurations
4055 GNU/Linux/hppa hppa*-*-linux*
4056 OpenBSD/hppa hppa*-*-openbsd*
4057 OpenBSD/m68k m68*-*-openbsd*
4058 OpenBSD/m88k m88*-*-openbsd*
4059 OpenBSD/powerpc powerpc-*-openbsd*
4060 NetBSD/vax vax-*-netbsd*
4061 OpenBSD/vax vax-*-openbsd*
4063 * END-OF-LIFE frame compatibility module
4065 GDB's internal frame infrastructure has been completely rewritten.
4066 The new infrastructure making it possible to support key new features
4067 including DWARF 2 Call Frame Information. To aid in the task of
4068 migrating old configurations to this new infrastructure, a
4069 compatibility module, that allowed old configurations to continue to
4070 work, was also included.
4072 GDB 6.2 will be the last release to include this frame compatibility
4073 module. This change directly impacts the following configurations:
4083 Unless there is activity to revive these configurations, they will be
4084 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4086 * REMOVED configurations and files
4088 Sun 3, running SunOS 3 m68*-*-sunos3*
4089 Sun 3, running SunOS 4 m68*-*-sunos4*
4090 Sun 2, running SunOS 3 m68000-*-sunos3*
4091 Sun 2, running SunOS 4 m68000-*-sunos4*
4092 Motorola 680x0 running LynxOS m68*-*-lynxos*
4093 AT&T 3b1/Unix pc m68*-att-*
4094 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4095 decstation mips-dec-* mips-little-*
4096 riscos mips-*-riscos* mips-*-sysv*
4097 sonymips mips-sony-*
4098 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4100 *** Changes in GDB 6.1.1:
4102 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4104 The TUI (Text-mode User Interface) is now built as part of a default
4105 GDB configuration. It is enabled by either selecting the TUI with the
4106 command line option "-i=tui" or by running the separate "gdbtui"
4107 program. For more information on the TUI, see the manual "Debugging
4110 * Pending breakpoint support (also included in GDB 6.1)
4112 Support has been added to allow you to specify breakpoints in shared
4113 libraries that have not yet been loaded. If a breakpoint location
4114 cannot be found, and the "breakpoint pending" option is set to auto,
4115 GDB queries you if you wish to make the breakpoint pending on a future
4116 shared-library load. If and when GDB resolves the breakpoint symbol,
4117 the pending breakpoint is removed as one or more regular breakpoints
4120 Pending breakpoints are very useful for GCJ Java debugging.
4122 * Fixed ISO-C build problems
4124 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4125 non ISO-C code that stopped them being built using a more strict ISO-C
4126 compiler (e.g., IBM's C compiler).
4128 * Fixed build problem on IRIX 5
4130 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4131 wasn't able to compile compile on an IRIX 5 system.
4133 * Added execute permission to gdb/gdbserver/configure
4135 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4136 permission. This bug would cause configure to fail on a number of
4137 systems (Solaris, IRIX). Ref: server/519.
4139 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4141 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4142 has been updated to use constant array sizes.
4144 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4146 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4147 its generated DWARF Call Frame Info. This encoding was causing GDB to
4148 panic, that panic has been fixed. Ref: gdb/1628.
4150 * Fixed a problem when examining parameters in shared library code.
4152 When examining parameters in optimized shared library code generated
4153 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4154 not available''. GDB now correctly displays the variable's value.
4156 *** Changes in GDB 6.1:
4158 * Removed --with-mmalloc
4160 Support for the mmalloc memory manager has been removed, as it
4161 conflicted with the internal gdb byte cache.
4163 * Changes in AMD64 configurations
4165 The AMD64 target now includes the %cs and %ss registers. As a result
4166 the AMD64 remote protocol has changed; this affects the floating-point
4167 and SSE registers. If you rely on those registers for your debugging,
4168 you should upgrade gdbserver on the remote side.
4170 * Revised SPARC target
4172 The SPARC target has been completely revised, incorporating the
4173 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4174 support for LynxOS and SunOS 4 has been dropped. Calling functions
4175 from within GDB on operating systems with a non-executable stack
4176 (Solaris, OpenBSD) now works.
4180 GDB has a new C++ demangler which does a better job on the mangled
4181 names generated by current versions of g++. It also runs faster, so
4182 with this and other changes gdb should now start faster on large C++
4185 * DWARF 2 Location Expressions
4187 GDB support for location expressions has been extended to support function
4188 arguments and frame bases. Older versions of GDB could crash when they
4191 * C++ nested types and namespaces
4193 GDB's support for nested types and namespaces in C++ has been
4194 improved, especially if you use the DWARF 2 debugging format. (This
4195 is the default for recent versions of GCC on most platforms.)
4196 Specifically, if you have a class "Inner" defined within a class or
4197 namespace "Outer", then GDB realizes that the class's name is
4198 "Outer::Inner", not simply "Inner". This should greatly reduce the
4199 frequency of complaints about not finding RTTI symbols. In addition,
4200 if you are stopped at inside of a function defined within a namespace,
4201 GDB modifies its name lookup accordingly.
4203 * New native configurations
4205 NetBSD/amd64 x86_64-*-netbsd*
4206 OpenBSD/amd64 x86_64-*-openbsd*
4207 OpenBSD/alpha alpha*-*-openbsd*
4208 OpenBSD/sparc sparc-*-openbsd*
4209 OpenBSD/sparc64 sparc64-*-openbsd*
4211 * New debugging protocols
4213 M32R with SDI protocol m32r-*-elf*
4215 * "set prompt-escape-char" command deleted.
4217 The command "set prompt-escape-char" has been deleted. This command,
4218 and its very obscure effet on GDB's prompt, was never documented,
4219 tested, nor mentioned in the NEWS file.
4221 * OBSOLETE configurations and files
4223 Configurations that have been declared obsolete in this release have
4224 been commented out. Unless there is activity to revive these
4225 configurations, the next release of GDB will have their sources
4226 permanently REMOVED.
4228 Sun 3, running SunOS 3 m68*-*-sunos3*
4229 Sun 3, running SunOS 4 m68*-*-sunos4*
4230 Sun 2, running SunOS 3 m68000-*-sunos3*
4231 Sun 2, running SunOS 4 m68000-*-sunos4*
4232 Motorola 680x0 running LynxOS m68*-*-lynxos*
4233 AT&T 3b1/Unix pc m68*-att-*
4234 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4235 decstation mips-dec-* mips-little-*
4236 riscos mips-*-riscos* mips-*-sysv*
4237 sonymips mips-sony-*
4238 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4240 * REMOVED configurations and files
4242 SGI Irix-4.x mips-sgi-irix4 or iris4
4243 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4244 Z8000 simulator z8k-zilog-none or z8ksim
4245 Matsushita MN10200 w/simulator mn10200-*-*
4246 H8/500 simulator h8500-hitachi-hms or h8500hms
4247 HP/PA running BSD hppa*-*-bsd*
4248 HP/PA running OSF/1 hppa*-*-osf*
4249 HP/PA Pro target hppa*-*-pro*
4250 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4251 386BSD i[3456]86-*-bsd*
4252 Sequent family i[3456]86-sequent-sysv4*
4253 i[3456]86-sequent-sysv*
4254 i[3456]86-sequent-bsd*
4255 SPARC running LynxOS sparc-*-lynxos*
4256 SPARC running SunOS 4 sparc-*-sunos4*
4257 Tsqware Sparclet sparclet-*-*
4258 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4260 *** Changes in GDB 6.0:
4264 Support for debugging the Objective-C programming language has been
4265 integrated into GDB.
4267 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4269 DWARF 2's Call Frame Information makes available compiler generated
4270 information that more exactly describes the program's run-time stack.
4271 By using this information, GDB is able to provide more robust stack
4274 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4275 have been updated to use a new backtrace mechanism which includes
4276 DWARF 2 CFI support.
4280 GDB's remote protocol has been extended to include support for hosted
4281 file I/O (where the remote target uses GDB's file system). See GDB's
4282 remote protocol documentation for details.
4284 * All targets using the new architecture framework.
4286 All of GDB's targets have been updated to use the new internal
4287 architecture framework. The way is now open for future GDB releases
4288 to include cross-architecture native debugging support (i386 on amd64,
4291 * GNU/Linux's Thread Local Storage (TLS)
4293 GDB now includes support for for the GNU/Linux implementation of
4294 per-thread variables.
4296 * GNU/Linux's Native POSIX Thread Library (NPTL)
4298 GDB's thread code has been updated to work with either the new
4299 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4301 * Separate debug info.
4303 GDB, in conjunction with BINUTILS, now supports a mechanism for
4304 automatically loading debug information from a separate file. Instead
4305 of shipping full debug and non-debug versions of system libraries,
4306 system integrators can now instead ship just the stripped libraries
4307 and optional debug files.
4309 * DWARF 2 Location Expressions
4311 DWARF 2 Location Expressions allow the compiler to more completely
4312 describe the location of variables (even in optimized code) to the
4315 GDB now includes preliminary support for location expressions (support
4316 for DW_OP_piece is still missing).
4320 A number of long standing bugs that caused GDB to die while starting a
4321 Java application have been fixed. GDB's Java support is now
4322 considered "useable".
4324 * GNU/Linux support for fork, vfork, and exec.
4326 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4327 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4330 * GDB supports logging output to a file
4332 There are two new commands, "set logging" and "show logging", which can be
4333 used to capture GDB's output to a file.
4335 * The meaning of "detach" has changed for gdbserver
4337 The "detach" command will now resume the application, as documented. To
4338 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4341 * d10v, m68hc11 `regs' command deprecated
4343 The `info registers' command has been updated so that it displays the
4344 registers using a format identical to the old `regs' command.
4348 A new command, "maint set profile on/off", has been added. This command can
4349 be used to enable or disable profiling while running GDB, to profile a
4350 session or a set of commands. In addition there is a new configure switch,
4351 "--enable-profiling", which will cause GDB to be compiled with profiling
4352 data, for more informative profiling results.
4354 * Default MI syntax changed to "mi2".
4356 The default MI (machine interface) syntax, enabled by the command line
4357 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4358 "mi1", can be enabled by specifying the option "-i=mi1".
4360 Support for the original "mi0" syntax (included in GDB 5.0) has been
4363 Fix for gdb/192: removed extraneous space when displaying frame level.
4364 Fix for gdb/672: update changelist is now output in mi list format.
4365 Fix for gdb/702: a -var-assign that updates the value now shows up
4366 in a subsequent -var-update.
4368 * New native configurations.
4370 FreeBSD/amd64 x86_64-*-freebsd*
4372 * Multi-arched targets.
4374 HP/PA HPUX11 hppa*-*-hpux*
4375 Renesas M32R/D w/simulator m32r-*-elf*
4377 * OBSOLETE configurations and files
4379 Configurations that have been declared obsolete in this release have
4380 been commented out. Unless there is activity to revive these
4381 configurations, the next release of GDB will have their sources
4382 permanently REMOVED.
4384 Z8000 simulator z8k-zilog-none or z8ksim
4385 Matsushita MN10200 w/simulator mn10200-*-*
4386 H8/500 simulator h8500-hitachi-hms or h8500hms
4387 HP/PA running BSD hppa*-*-bsd*
4388 HP/PA running OSF/1 hppa*-*-osf*
4389 HP/PA Pro target hppa*-*-pro*
4390 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4391 Sequent family i[3456]86-sequent-sysv4*
4392 i[3456]86-sequent-sysv*
4393 i[3456]86-sequent-bsd*
4394 Tsqware Sparclet sparclet-*-*
4395 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4397 * REMOVED configurations and files
4400 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4401 IBM AIX PS/2 i[3456]86-*-aix
4402 i386 running Mach 3.0 i[3456]86-*-mach3*
4403 i386 running Mach i[3456]86-*-mach*
4404 i386 running OSF/1 i[3456]86-*osf1mk*
4405 HP/Apollo 68k Family m68*-apollo*-sysv*,
4407 m68*-hp-bsd*, m68*-hp-hpux*
4408 Argonaut Risc Chip (ARC) arc-*-*
4409 Mitsubishi D30V d30v-*-*
4410 Fujitsu FR30 fr30-*-elf*
4411 OS/9000 i[34]86-*-os9k
4412 I960 with MON960 i960-*-coff
4414 * MIPS $fp behavior changed
4416 The convenience variable $fp, for the MIPS, now consistently returns
4417 the address of the current frame's base. Previously, depending on the
4418 context, $fp could refer to either $sp or the current frame's base
4419 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4420 The GNU Source-Level Debugger''.
4422 *** Changes in GDB 5.3:
4424 * GNU/Linux shared library multi-threaded performance improved.
4426 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4427 `/proc', in preference to `ptrace' for memory reads. This may result
4428 in an improvement in the start-up time of multi-threaded, shared
4429 library applications when run under GDB. One GDB user writes: ``loads
4430 shared libs like mad''.
4432 * ``gdbserver'' now supports multi-threaded applications on some targets
4434 Support for debugging multi-threaded applications which use
4435 the GNU/Linux LinuxThreads package has been added for
4436 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4437 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4439 * GDB now supports C/C++ preprocessor macros.
4441 GDB now expands preprocessor macro invocations in C/C++ expressions,
4442 and provides various commands for showing macro definitions and how
4445 The new command `macro expand EXPRESSION' expands any macro
4446 invocations in expression, and shows the result.
4448 The new command `show macro MACRO-NAME' shows the definition of the
4449 macro named MACRO-NAME, and where it was defined.
4451 Most compilers don't include information about macros in the debugging
4452 information by default. In GCC 3.1, for example, you need to compile
4453 your program with the options `-gdwarf-2 -g3'. If the macro
4454 information is present in the executable, GDB will read it.
4456 * Multi-arched targets.
4458 DEC Alpha (partial) alpha*-*-*
4459 DEC VAX (partial) vax-*-*
4461 National Semiconductor NS32000 (partial) ns32k-*-*
4462 Motorola 68000 (partial) m68k-*-*
4463 Motorola MCORE mcore-*-*
4467 Fujitsu FRV architecture added by Red Hat frv*-*-*
4470 * New native configurations
4472 Alpha NetBSD alpha*-*-netbsd*
4473 SH NetBSD sh*-*-netbsdelf*
4474 MIPS NetBSD mips*-*-netbsd*
4475 UltraSPARC NetBSD sparc64-*-netbsd*
4477 * OBSOLETE configurations and files
4479 Configurations that have been declared obsolete in this release have
4480 been commented out. Unless there is activity to revive these
4481 configurations, the next release of GDB will have their sources
4482 permanently REMOVED.
4484 Mitsubishi D30V d30v-*-*
4485 OS/9000 i[34]86-*-os9k
4486 IBM AIX PS/2 i[3456]86-*-aix
4487 Fujitsu FR30 fr30-*-elf*
4488 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4489 Argonaut Risc Chip (ARC) arc-*-*
4490 i386 running Mach 3.0 i[3456]86-*-mach3*
4491 i386 running Mach i[3456]86-*-mach*
4492 i386 running OSF/1 i[3456]86-*osf1mk*
4493 HP/Apollo 68k Family m68*-apollo*-sysv*,
4495 m68*-hp-bsd*, m68*-hp-hpux*
4496 I960 with MON960 i960-*-coff
4498 * OBSOLETE languages
4500 CHILL, a Pascal like language used by telecommunications companies.
4502 * REMOVED configurations and files
4504 AMD 29k family via UDI a29k-amd-udi, udi29k
4505 A29K VxWorks a29k-*-vxworks
4506 AMD 29000 embedded, using EBMON a29k-none-none
4507 AMD 29000 embedded with COFF a29k-none-coff
4508 AMD 29000 embedded with a.out a29k-none-aout
4510 testsuite/gdb.hp/gdb.threads-hp/ directory
4512 * New command "set max-user-call-depth <nnn>"
4514 This command allows the user to limit the call depth of user-defined
4515 commands. The default is 1024.
4517 * Changes in FreeBSD/i386 native debugging.
4519 Support for the "generate-core-file" has been added.
4521 * New commands "dump", "append", and "restore".
4523 These commands allow data to be copied from target memory
4524 to a bfd-format or binary file (dump and append), and back
4525 from a file into memory (restore).
4527 * Improved "next/step" support on multi-processor Alpha Tru64.
4529 The previous single-step mechanism could cause unpredictable problems,
4530 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4531 of a software single-step mechanism prevents this.
4533 *** Changes in GDB 5.2.1:
4541 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4542 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4543 Fix, by Joel Brobecker imported from mainline.
4545 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4546 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4547 Fix, by Fred Fish, imported from mainline.
4549 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4550 Surprisingly enough, it works now.
4551 By Michal Ludvig, imported from mainline.
4553 i386 hardware watchpoint support:
4554 avoid misses on second run for some targets.
4555 By Pierre Muller, imported from mainline.
4557 *** Changes in GDB 5.2:
4559 * New command "set trust-readonly-sections on[off]".
4561 This command is a hint that tells gdb that read-only sections
4562 really are read-only (ie. that their contents will not change).
4563 In this mode, gdb will go to the object file rather than the
4564 target to read memory from read-only sections (such as ".text").
4565 This can be a significant performance improvement on some
4566 (notably embedded) targets.
4568 * New command "generate-core-file" (or "gcore").
4570 This new gdb command allows the user to drop a core file of the child
4571 process state at any time. So far it's been implemented only for
4572 GNU/Linux and Solaris, but should be relatively easily ported to other
4573 hosts. Argument is core file name (defaults to core.<pid>).
4575 * New command line option
4577 GDB now accepts --pid or -p followed by a process id.
4579 * Change in command line behavior -- corefiles vs. process ids.
4581 There is a subtle behavior in the way in which GDB handles
4582 command line arguments. The first non-flag argument is always
4583 a program to debug, but the second non-flag argument may either
4584 be a corefile or a process id. Previously, GDB would attempt to
4585 open the second argument as a corefile, and if that failed, would
4586 issue a superfluous error message and then attempt to attach it as
4587 a process. Now, if the second argument begins with a non-digit,
4588 it will be treated as a corefile. If it begins with a digit,
4589 GDB will attempt to attach it as a process, and if no such process
4590 is found, will then attempt to open it as a corefile.
4592 * Changes in ARM configurations.
4594 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4595 configuration is fully multi-arch.
4597 * New native configurations
4599 ARM NetBSD arm*-*-netbsd*
4600 x86 OpenBSD i[3456]86-*-openbsd*
4601 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4602 Sparc64 running FreeBSD sparc64-*-freebsd*
4606 Sanyo XStormy16 xstormy16-elf
4608 * OBSOLETE configurations and files
4610 Configurations that have been declared obsolete in this release have
4611 been commented out. Unless there is activity to revive these
4612 configurations, the next release of GDB will have their sources
4613 permanently REMOVED.
4615 AMD 29k family via UDI a29k-amd-udi, udi29k
4616 A29K VxWorks a29k-*-vxworks
4617 AMD 29000 embedded, using EBMON a29k-none-none
4618 AMD 29000 embedded with COFF a29k-none-coff
4619 AMD 29000 embedded with a.out a29k-none-aout
4621 testsuite/gdb.hp/gdb.threads-hp/ directory
4623 * REMOVED configurations and files
4625 TI TMS320C80 tic80-*-*
4627 PowerPC Solaris powerpcle-*-solaris*
4628 PowerPC Windows NT powerpcle-*-cygwin32
4629 PowerPC Netware powerpc-*-netware*
4630 Harris/CXUX m88k m88*-harris-cxux*
4631 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4632 ns32k-utek-sysv* ns32k-utek-*
4633 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4634 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4635 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4636 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4637 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4639 * Changes to command line processing
4641 The new `--args' feature can be used to specify command-line arguments
4642 for the inferior from gdb's command line.
4644 * Changes to key bindings
4646 There is a new `operate-and-get-next' function bound to `C-o'.
4648 *** Changes in GDB 5.1.1
4650 Fix compile problem on DJGPP.
4652 Fix a problem with floating-point registers on the i386 being
4655 Fix to stop GDB crashing on .debug_str debug info.
4657 Numerous documentation fixes.
4659 Numerous testsuite fixes.
4661 *** Changes in GDB 5.1:
4663 * New native configurations
4665 Alpha FreeBSD alpha*-*-freebsd*
4666 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4667 MIPS GNU/Linux mips*-*-linux*
4668 MIPS SGI Irix 6.x mips*-sgi-irix6*
4669 ia64 AIX ia64-*-aix*
4670 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4674 Motorola 68HC11 and 68HC12 m68hc11-elf
4676 UltraSparc running GNU/Linux sparc64-*-linux*
4678 * OBSOLETE configurations and files
4680 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4681 Harris/CXUX m88k m88*-harris-cxux*
4682 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4683 ns32k-utek-sysv* ns32k-utek-*
4684 TI TMS320C80 tic80-*-*
4686 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4687 PowerPC Solaris powerpcle-*-solaris*
4688 PowerPC Windows NT powerpcle-*-cygwin32
4689 PowerPC Netware powerpc-*-netware*
4690 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4691 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4692 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4693 Apple Macintosh (MPW) host N/A
4695 stuff.c (Program to stuff files into a specially prepared space in kdb)
4696 kdb-start.c (Main loop for the standalone kernel debugger)
4698 Configurations that have been declared obsolete in this release have
4699 been commented out. Unless there is activity to revive these
4700 configurations, the next release of GDB will have their sources
4701 permanently REMOVED.
4703 * REMOVED configurations and files
4705 Altos 3068 m68*-altos-*
4706 Convex c1-*-*, c2-*-*
4708 ARM RISCix arm-*-* (as host)
4712 * GDB has been converted to ISO C.
4714 GDB's source code has been converted to ISO C. In particular, the
4715 sources are fully protoized, and rely on standard headers being
4720 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4722 * The MI enabled by default.
4724 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4725 revised and enabled by default. Packages which use GDB as a debugging
4726 engine behind a UI or another front end are encouraged to switch to
4727 using the GDB/MI interface, instead of the old annotations interface
4728 which is now deprecated.
4730 * Support for debugging Pascal programs.
4732 GDB now includes support for debugging Pascal programs. The following
4733 main features are supported:
4735 - Pascal-specific data types such as sets;
4737 - automatic recognition of Pascal sources based on file-name
4740 - Pascal-style display of data types, variables, and functions;
4742 - a Pascal expression parser.
4744 However, some important features are not yet supported.
4746 - Pascal string operations are not supported at all;
4748 - there are some problems with boolean types;
4750 - Pascal type hexadecimal constants are not supported
4751 because they conflict with the internal variables format;
4753 - support for Pascal objects and classes is not full yet;
4755 - unlike Pascal, GDB is case-sensitive for symbol names.
4757 * Changes in completion.
4759 Commands such as `shell', `run' and `set args', which pass arguments
4760 to inferior programs, now complete on file names, similar to what
4761 users expect at the shell prompt.
4763 Commands which accept locations, such as `disassemble', `print',
4764 `breakpoint', `until', etc. now complete on filenames as well as
4765 program symbols. Thus, if you type "break foob TAB", and the source
4766 files linked into the programs include `foobar.c', that file name will
4767 be one of the candidates for completion. However, file names are not
4768 considered for completion after you typed a colon that delimits a file
4769 name from a name of a function in that file, as in "break foo.c:bar".
4771 `set demangle-style' completes on available demangling styles.
4773 * New platform-independent commands:
4775 It is now possible to define a post-hook for a command as well as a
4776 hook that runs before the command. For more details, see the
4777 documentation of `hookpost' in the GDB manual.
4779 * Changes in GNU/Linux native debugging.
4781 Support for debugging multi-threaded programs has been completely
4782 revised for all platforms except m68k and sparc. You can now debug as
4783 many threads as your system allows you to have.
4785 Attach/detach is supported for multi-threaded programs.
4787 Support for SSE registers was added for x86. This doesn't work for
4788 multi-threaded programs though.
4790 * Changes in MIPS configurations.
4792 Multi-arch support is enabled for all MIPS configurations.
4794 GDB can now be built as native debugger on SGI Irix 6.x systems for
4795 debugging n32 executables. (Debugging 64-bit executables is not yet
4798 * Unified support for hardware watchpoints in all x86 configurations.
4800 Most (if not all) native x86 configurations support hardware-assisted
4801 breakpoints and watchpoints in a unified manner. This support
4802 implements debug register sharing between watchpoints, which allows to
4803 put a virtually infinite number of watchpoints on the same address,
4804 and also supports watching regions up to 16 bytes with several debug
4807 The new maintenance command `maintenance show-debug-regs' toggles
4808 debugging print-outs in functions that insert, remove, and test
4809 watchpoints and hardware breakpoints.
4811 * Changes in the DJGPP native configuration.
4813 New command ``info dos sysinfo'' displays assorted information about
4814 the CPU, OS, memory, and DPMI server.
4816 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4817 display information about segment descriptors stored in GDT, LDT, and
4820 New commands ``info dos pde'' and ``info dos pte'' display entries
4821 from Page Directory and Page Tables (for now works with CWSDPMI only).
4822 New command ``info dos address-pte'' displays the Page Table entry for
4823 a given linear address.
4825 GDB can now pass command lines longer than 126 characters to the
4826 program being debugged (requires an update to the libdbg.a library
4827 which is part of the DJGPP development kit).
4829 DWARF2 debug info is now supported.
4831 It is now possible to `step' and `next' through calls to `longjmp'.
4833 * Changes in documentation.
4835 All GDB documentation was converted to GFDL, the GNU Free
4836 Documentation License.
4838 Tracepoints-related commands are now fully documented in the GDB
4841 TUI, the Text-mode User Interface, is now documented in the manual.
4843 Tracepoints-related commands are now fully documented in the GDB
4846 The "GDB Internals" manual now has an index. It also includes
4847 documentation of `ui_out' functions, GDB coding standards, x86
4848 hardware watchpoints, and memory region attributes.
4850 * GDB's version number moved to ``version.in''
4852 The Makefile variable VERSION has been replaced by the file
4853 ``version.in''. People creating GDB distributions should update the
4854 contents of this file.
4858 GUD support is now a standard part of the EMACS distribution.
4860 *** Changes in GDB 5.0:
4862 * Improved support for debugging FP programs on x86 targets
4864 Unified and much-improved support for debugging floating-point
4865 programs on all x86 targets. In particular, ``info float'' now
4866 displays the FP registers in the same format on all x86 targets, with
4867 greater level of detail.
4869 * Improvements and bugfixes in hardware-assisted watchpoints
4871 It is now possible to watch array elements, struct members, and
4872 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4873 on x86 targets no longer erroneously trigger when the address is
4876 * Improvements in the native DJGPP version of GDB
4878 The distribution now includes all the scripts and auxiliary files
4879 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4880 machines ``out of the box''.
4882 The DJGPP version can now debug programs that use signals. It is
4883 possible to catch signals that happened in the debuggee, deliver
4884 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4885 would kill the program being debugged.) Programs that hook hardware
4886 interrupts (keyboard, timer, etc.) can also be debugged.
4888 It is now possible to debug DJGPP programs that redirect their
4889 standard handles or switch them to raw (as opposed to cooked) mode, or
4890 even close them. The command ``run < foo > bar'' works as expected,
4891 and ``info terminal'' reports useful information about the debuggee's
4892 terminal, including raw/cooked mode, redirection, etc.
4894 The DJGPP version now uses termios functions for console I/O, which
4895 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4898 DOS-style file names with drive letters are now fully supported by
4901 It is now possible to debug DJGPP programs that switch their working
4902 directory. It is also possible to rerun the debuggee any number of
4903 times without restarting GDB; thus, you can use the same setup,
4904 breakpoints, etc. for many debugging sessions.
4906 * New native configurations
4908 ARM GNU/Linux arm*-*-linux*
4909 PowerPC GNU/Linux powerpc-*-linux*
4913 Motorola MCore mcore-*-*
4914 x86 VxWorks i[3456]86-*-vxworks*
4915 PowerPC VxWorks powerpc-*-vxworks*
4916 TI TMS320C80 tic80-*-*
4918 * OBSOLETE configurations
4920 Altos 3068 m68*-altos-*
4921 Convex c1-*-*, c2-*-*
4923 ARM RISCix arm-*-* (as host)
4926 Configurations that have been declared obsolete will be commented out,
4927 but the code will be left in place. If there is no activity to revive
4928 these configurations before the next release of GDB, the sources will
4929 be permanently REMOVED.
4931 * Gould support removed
4933 Support for the Gould PowerNode and NP1 has been removed.
4935 * New features for SVR4
4937 On SVR4 native platforms (such as Solaris), if you attach to a process
4938 without first loading a symbol file, GDB will now attempt to locate and
4939 load symbols from the running process's executable file.
4941 * Many C++ enhancements
4943 C++ support has been greatly improved. Overload resolution now works properly
4944 in almost all cases. RTTI support is on the way.
4946 * Remote targets can connect to a sub-program
4948 A popen(3) style serial-device has been added. This device starts a
4949 sub-process (such as a stand-alone simulator) and then communicates
4950 with that. The sub-program to run is specified using the syntax
4951 ``|<program> <args>'' vis:
4953 (gdb) set remotedebug 1
4954 (gdb) target extended-remote |mn10300-elf-sim program-args
4956 * MIPS 64 remote protocol
4958 A long standing bug in the mips64 remote protocol where by GDB
4959 expected certain 32 bit registers (ex SR) to be transfered as 32
4960 instead of 64 bits has been fixed.
4962 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4963 added to provide backward compatibility with older versions of GDB.
4965 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4967 The command ``set remotebinarydownload'' command has been replaced by
4968 ``set remote X-packet''. Other commands in ``set remote'' family
4969 include ``set remote P-packet''.
4971 * Breakpoint commands accept ranges.
4973 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4974 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4975 ``tracepoint passcount'' also accepts a range of tracepoints.
4977 * ``apropos'' command added.
4979 The ``apropos'' command searches through command names and
4980 documentation strings, printing out matches, making it much easier to
4981 try to find a command that does what you are looking for.
4985 A new machine oriented interface (MI) has been added to GDB. This
4986 interface is designed for debug environments running GDB as a separate
4987 process. This is part of the long term libGDB project. See the
4988 "GDB/MI" chapter of the GDB manual for further information. It can be
4989 enabled by configuring with:
4991 .../configure --enable-gdbmi
4993 *** Changes in GDB-4.18:
4995 * New native configurations
4997 HP-UX 10.20 hppa*-*-hpux10.20
4998 HP-UX 11.x hppa*-*-hpux11.0*
4999 M68K GNU/Linux m68*-*-linux*
5003 Fujitsu FR30 fr30-*-elf*
5004 Intel StrongARM strongarm-*-*
5005 Mitsubishi D30V d30v-*-*
5007 * OBSOLETE configurations
5009 Gould PowerNode, NP1 np1-*-*, pn-*-*
5011 Configurations that have been declared obsolete will be commented out,
5012 but the code will be left in place. If there is no activity to revive
5013 these configurations before the next release of GDB, the sources will
5014 be permanently REMOVED.
5018 As a compatibility experiment, GDB's source files buildsym.h and
5019 buildsym.c have been converted to pure standard C, no longer
5020 containing any K&R compatibility code. We believe that all systems in
5021 use today either come with a standard C compiler, or have a GCC port
5022 available. If this is not true, please report the affected
5023 configuration to bug-gdb@gnu.org immediately. See the README file for
5024 information about getting a standard C compiler if you don't have one
5029 GDB now uses readline 2.2.
5031 * set extension-language
5033 You can now control the mapping between filename extensions and source
5034 languages by using the `set extension-language' command. For instance,
5035 you can ask GDB to treat .c files as C++ by saying
5036 set extension-language .c c++
5037 The command `info extensions' lists all of the recognized extensions
5038 and their associated languages.
5040 * Setting processor type for PowerPC and RS/6000
5042 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5043 you can use the `set processor' command to specify what variant of the
5044 PowerPC family you are debugging. The command
5048 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5049 following PowerPC and RS6000 variants:
5051 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5052 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5054 403GC IBM PowerPC 403GC
5055 505 Motorola PowerPC 505
5056 860 Motorola PowerPC 860 or 850
5057 601 Motorola PowerPC 601
5058 602 Motorola PowerPC 602
5059 603 Motorola/IBM PowerPC 603 or 603e
5060 604 Motorola PowerPC 604 or 604e
5061 750 Motorola/IBM PowerPC 750 or 750
5063 At the moment, this command just tells GDB what to name the
5064 special-purpose processor registers. Since almost all the affected
5065 registers are inaccessible to user-level programs, this command is
5066 only useful for remote debugging in its present form.
5070 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5071 more extensive support for HP-UX. Added features include shared
5072 library support, kernel threads and hardware watchpoints for 11.00,
5073 support for HP's ANSI C and C++ compilers, and a compatibility mode
5074 for xdb and dbx commands.
5078 HP's donation includes the new concept of catchpoints, which is a
5079 generalization of the old catch command. On HP-UX, it is now possible
5080 to catch exec, fork, and vfork, as well as library loading.
5082 This means that the existing catch command has changed; its first
5083 argument now specifies the type of catch to be set up. See the
5084 output of "help catch" for a list of catchpoint types.
5086 * Debugging across forks
5088 On HP-UX, you can choose which process to debug when a fork() happens
5093 HP has donated a curses-based terminal user interface (TUI). To get
5094 it, build with --enable-tui. Although this can be enabled for any
5095 configuration, at present it only works for native HP debugging.
5097 * GDB remote protocol additions
5099 A new protocol packet 'X' that writes binary data is now available.
5100 Default behavior is to try 'X', then drop back to 'M' if the stub
5101 fails to respond. The settable variable `remotebinarydownload'
5102 allows explicit control over the use of 'X'.
5104 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5105 full 64-bit address. The command
5107 set remoteaddresssize 32
5109 can be used to revert to the old behaviour. For existing remote stubs
5110 the change should not be noticed, as the additional address information
5113 In order to assist in debugging stubs, you may use the maintenance
5114 command `packet' to send any text string to the stub. For instance,
5116 maint packet heythere
5118 sends the packet "$heythere#<checksum>". Note that it is very easy to
5119 disrupt a debugging session by sending the wrong packet at the wrong
5122 The compare-sections command allows you to compare section data on the
5123 target to what is in the executable file without uploading or
5124 downloading, by comparing CRC checksums.
5126 * Tracing can collect general expressions
5128 You may now collect general expressions at tracepoints. This requires
5129 further additions to the target-side stub; see tracepoint.c and
5130 doc/agentexpr.texi for further details.
5132 * mask-address variable for Mips
5134 For Mips targets, you may control the zeroing of the upper 32 bits of
5135 a 64-bit address by entering `set mask-address on'. This is mainly
5136 of interest to users of embedded R4xxx and R5xxx processors.
5138 * Higher serial baud rates
5140 GDB's serial code now allows you to specify baud rates 57600, 115200,
5141 230400, and 460800 baud. (Note that your host system may not be able
5142 to achieve all of these rates.)
5146 The i960 configuration now includes an initial implementation of a
5147 builtin simulator, contributed by Jim Wilson.
5150 *** Changes in GDB-4.17:
5152 * New native configurations
5154 Alpha GNU/Linux alpha*-*-linux*
5155 Unixware 2.x i[3456]86-unixware2*
5156 Irix 6.x mips*-sgi-irix6*
5157 PowerPC GNU/Linux powerpc-*-linux*
5158 PowerPC Solaris powerpcle-*-solaris*
5159 Sparc GNU/Linux sparc-*-linux*
5160 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5164 Argonaut Risc Chip (ARC) arc-*-*
5165 Hitachi H8/300S h8300*-*-*
5166 Matsushita MN10200 w/simulator mn10200-*-*
5167 Matsushita MN10300 w/simulator mn10300-*-*
5168 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5169 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5170 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5171 Mitsubishi D10V w/simulator d10v-*-*
5172 Mitsubishi M32R/D w/simulator m32r-*-elf*
5173 Tsqware Sparclet sparclet-*-*
5174 NEC V850 w/simulator v850-*-*
5176 * New debugging protocols
5178 ARM with RDI protocol arm*-*-*
5179 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5180 DDB and LSI variants of PMON protocol mips*-*-*
5181 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5182 PowerPC with SDS protocol powerpc{,le}-*-eabi
5183 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5187 All configurations can now understand and use the DWARF 2 debugging
5188 format. The choice is automatic, if the symbol file contains DWARF 2
5193 GDB now includes basic Java language support. This support is
5194 only useful with Java compilers that produce native machine code.
5196 * solib-absolute-prefix and solib-search-path
5198 For SunOS and SVR4 shared libraries, you may now set the prefix for
5199 loading absolute shared library symbol files, and the search path for
5200 locating non-absolute shared library symbol files.
5202 * Live range splitting
5204 GDB can now effectively debug code for which GCC has performed live
5205 range splitting as part of its optimization. See gdb/doc/LRS for
5206 more details on the expected format of the stabs information.
5210 GDB's support for the GNU Hurd, including thread debugging, has been
5211 updated to work with current versions of the Hurd.
5215 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5216 instruction set. ARM GDB automatically detects when Thumb
5217 instructions are in use, and adjusts disassembly and backtracing
5222 GDB's MIPS target configurations now handle the MIP16 16-bit
5227 GDB now includes support for overlays; if an executable has been
5228 linked such that multiple sections are based at the same address, GDB
5229 will decide which section to use for symbolic info. You can choose to
5230 control the decision manually, using overlay commands, or implement
5231 additional target-side support and use "overlay load-target" to bring
5232 in the overlay mapping. Do "help overlay" for more detail.
5236 The command "info symbol <address>" displays information about
5237 the symbol at the specified address.
5241 The standard remote protocol now includes an extension that allows
5242 asynchronous collection and display of trace data. This requires
5243 extensive support in the target-side debugging stub. Tracing mode
5244 includes a new interaction mode in GDB and new commands: see the
5245 file tracepoint.c for more details.
5249 Configurations for embedded MIPS now include a simulator contributed
5250 by Cygnus Solutions. The simulator supports the instruction sets
5251 of most MIPS variants.
5255 Sparc configurations may now include the ERC32 simulator contributed
5256 by the European Space Agency. The simulator is not built into
5257 Sparc targets by default; configure with --enable-sim to include it.
5261 For target configurations that may include multiple variants of a
5262 basic architecture (such as MIPS and SH), you may now set the
5263 architecture explicitly. "set arch" sets, "info arch" lists
5264 the possible architectures.
5266 *** Changes in GDB-4.16:
5268 * New native configurations
5270 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5271 M68K NetBSD m68k-*-netbsd*
5272 PowerPC AIX 4.x powerpc-*-aix*
5273 PowerPC MacOS powerpc-*-macos*
5274 PowerPC Windows NT powerpcle-*-cygwin32
5275 RS/6000 AIX 4.x rs6000-*-aix4*
5279 ARM with RDP protocol arm-*-*
5280 I960 with MON960 i960-*-coff
5281 MIPS VxWorks mips*-*-vxworks*
5282 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5283 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5285 Matra Sparclet sparclet-*-*
5289 The powerpc-eabi configuration now includes the PSIM simulator,
5290 contributed by Andrew Cagney, with assistance from Mike Meissner.
5291 PSIM is a very elaborate model of the PowerPC, including not only
5292 basic instruction set execution, but also details of execution unit
5293 performance and I/O hardware. See sim/ppc/README for more details.
5297 GDB now works with Solaris 2.5.
5299 * Windows 95/NT native
5301 GDB will now work as a native debugger on Windows 95 and Windows NT.
5302 To build it from source, you must use the "gnu-win32" environment,
5303 which uses a DLL to emulate enough of Unix to run the GNU tools.
5304 Further information, binaries, and sources are available at
5305 ftp.cygnus.com, under pub/gnu-win32.
5307 * dont-repeat command
5309 If a user-defined command includes the command `dont-repeat', then the
5310 command will not be repeated if the user just types return. This is
5311 useful if the command is time-consuming to run, so that accidental
5312 extra keystrokes don't run the same command many times.
5314 * Send break instead of ^C
5316 The standard remote protocol now includes an option to send a break
5317 rather than a ^C to the target in order to interrupt it. By default,
5318 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5320 * Remote protocol timeout
5322 The standard remote protocol includes a new variable `remotetimeout'
5323 that allows you to set the number of seconds before GDB gives up trying
5324 to read from the target. The default value is 2.
5326 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5328 By default GDB will automatically keep track of objects as they are
5329 loaded and unloaded by the dynamic linker. By using the command `set
5330 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5331 when shared library events occur, thus allowing you to set breakpoints
5332 in shared libraries which are explicitly loaded by the inferior.
5334 Note this feature does not work on hpux8. On hpux9 you must link
5335 /usr/lib/end.o into your program. This feature should work
5336 automatically on hpux10.
5338 * Irix 5.x hardware watchpoint support
5340 Irix 5 configurations now support the use of hardware watchpoints.
5342 * Mips protocol "SYN garbage limit"
5344 When debugging a Mips target using the `target mips' protocol, you
5345 may set the number of characters that GDB will ignore by setting
5346 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5347 every character. The default value is 1050.
5349 * Recording and replaying remote debug sessions
5351 If you set `remotelogfile' to the name of a file, gdb will write to it
5352 a recording of a remote debug session. This recording may then be
5353 replayed back to gdb using "gdbreplay". See gdbserver/README for
5354 details. This is useful when you have a problem with GDB while doing
5355 remote debugging; you can make a recording of the session and send it
5356 to someone else, who can then recreate the problem.
5358 * Speedups for remote debugging
5360 GDB includes speedups for downloading and stepping MIPS systems using
5361 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5362 and more efficient S-record downloading.
5364 * Memory use reductions and statistics collection
5366 GDB now uses less memory and reports statistics about memory usage.
5367 Try the `maint print statistics' command, for example.
5369 *** Changes in GDB-4.15:
5371 * Psymtabs for XCOFF
5373 The symbol reader for AIX GDB now uses partial symbol tables. This
5374 can greatly improve startup time, especially for large executables.
5376 * Remote targets use caching
5378 Remote targets now use a data cache to speed up communication with the
5379 remote side. The data cache could lead to incorrect results because
5380 it doesn't know about volatile variables, thus making it impossible to
5381 debug targets which use memory mapped I/O devices. `set remotecache
5382 off' turns the the data cache off.
5384 * Remote targets may have threads
5386 The standard remote protocol now includes support for multiple threads
5387 in the target system, using new protocol commands 'H' and 'T'. See
5388 gdb/remote.c for details.
5392 If GDB is configured with `--enable-netrom', then it will include
5393 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5394 acts as though it is a bank of ROM on the target board, but you can
5395 write into it over the network. GDB's support consists only of
5396 support for fast loading into the emulated ROM; to debug, you must use
5397 another protocol, such as standard remote protocol. The usual
5398 sequence is something like
5400 target nrom <netrom-hostname>
5402 target remote <netrom-hostname>:1235
5406 GDB now includes support for the Apple Macintosh, as a host only. It
5407 may be run as either an MPW tool or as a standalone application, and
5408 it can debug through the serial port. All the usual GDB commands are
5409 available, but to the target command, you must supply "serial" as the
5410 device type instead of "/dev/ttyXX". See mpw-README in the main
5411 directory for more information on how to build. The MPW configuration
5412 scripts */mpw-config.in support only a few targets, and only the
5413 mips-idt-ecoff target has been tested.
5417 GDB configuration now uses autoconf. This is not user-visible,
5418 but does simplify configuration and building.
5422 GDB now supports hpux10.
5424 *** Changes in GDB-4.14:
5426 * New native configurations
5428 x86 FreeBSD i[345]86-*-freebsd
5429 x86 NetBSD i[345]86-*-netbsd
5430 NS32k NetBSD ns32k-*-netbsd
5431 Sparc NetBSD sparc-*-netbsd
5435 A29K VxWorks a29k-*-vxworks
5436 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5437 CPU32 EST-300 emulator m68*-*-est*
5438 PowerPC ELF powerpc-*-elf
5441 * Alpha OSF/1 support for procfs
5443 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5444 possible to attach to running processes. As the mounting of the /proc
5445 filesystem is optional on the Alpha, GDB automatically determines
5446 the availability of /proc during startup. This can lead to problems
5447 if /proc is unmounted after GDB has been started.
5449 * Arguments to user-defined commands
5451 User commands may accept up to 10 arguments separated by whitespace.
5452 Arguments are accessed within the user command via $arg0..$arg9. A
5455 print $arg0 + $arg1 + $arg2
5457 To execute the command use:
5460 Defines the command "adder" which prints the sum of its three arguments.
5461 Note the arguments are text substitutions, so they may reference variables,
5462 use complex expressions, or even perform inferior function calls.
5464 * New `if' and `while' commands
5466 This makes it possible to write more sophisticated user-defined
5467 commands. Both commands take a single argument, which is the
5468 expression to evaluate, and must be followed by the commands to
5469 execute, one per line, if the expression is nonzero, the list being
5470 terminated by the word `end'. The `if' command list may include an
5471 `else' word, which causes the following commands to be executed only
5472 if the expression is zero.
5474 * Fortran source language mode
5476 GDB now includes partial support for Fortran 77. It will recognize
5477 Fortran programs and can evaluate a subset of Fortran expressions, but
5478 variables and functions may not be handled correctly. GDB will work
5479 with G77, but does not yet know much about symbols emitted by other
5482 * Better HPUX support
5484 Most debugging facilities now work on dynamic executables for HPPAs
5485 running hpux9 or later. You can attach to running dynamically linked
5486 processes, but by default the dynamic libraries will be read-only, so
5487 for instance you won't be able to put breakpoints in them. To change
5488 that behavior do the following before running the program:
5494 This will cause the libraries to be mapped private and read-write.
5495 To revert to the normal behavior, do this:
5501 You cannot set breakpoints or examine data in the library until after
5502 the library is loaded if the function/data symbols do not have
5505 GDB can now also read debug symbols produced by the HP C compiler on
5506 HPPAs (sorry, no C++, Fortran or 68k support).
5508 * Target byte order now dynamically selectable
5510 You can choose which byte order to use with a target system, via the
5511 commands "set endian big" and "set endian little", and you can see the
5512 current setting by using "show endian". You can also give the command
5513 "set endian auto", in which case GDB will use the byte order
5514 associated with the executable. Currently, only embedded MIPS
5515 configurations support dynamic selection of target byte order.
5517 * New DOS host serial code
5519 This version uses DPMI interrupts to handle buffered I/O, so you
5520 no longer need to run asynctsr when debugging boards connected to
5523 *** Changes in GDB-4.13:
5525 * New "complete" command
5527 This lists all the possible completions for the rest of the line, if it
5528 were to be given as a command itself. This is intended for use by emacs.
5530 * Trailing space optional in prompt
5532 "set prompt" no longer adds a space for you after the prompt you set. This
5533 allows you to set a prompt which ends in a space or one that does not.
5535 * Breakpoint hit counts
5537 "info break" now displays a count of the number of times the breakpoint
5538 has been hit. This is especially useful in conjunction with "ignore"; you
5539 can ignore a large number of breakpoint hits, look at the breakpoint info
5540 to see how many times the breakpoint was hit, then run again, ignoring one
5541 less than that number, and this will get you quickly to the last hit of
5544 * Ability to stop printing at NULL character
5546 "set print null-stop" will cause GDB to stop printing the characters of
5547 an array when the first NULL is encountered. This is useful when large
5548 arrays actually contain only short strings.
5550 * Shared library breakpoints
5552 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5553 breakpoints in shared libraries before the executable is run.
5555 * Hardware watchpoints
5557 There is a new hardware breakpoint for the watch command for sparclite
5558 targets. See gdb/sparclite/hw_breakpoint.note.
5560 Hardware watchpoints are also now supported under GNU/Linux.
5564 Annotations have been added. These are for use with graphical interfaces,
5565 and are still experimental. Currently only gdba.el uses these.
5567 * Improved Irix 5 support
5569 GDB now works properly with Irix 5.2.
5571 * Improved HPPA support
5573 GDB now works properly with the latest GCC and GAS.
5575 * New native configurations
5577 Sequent PTX4 i[34]86-sequent-ptx4
5578 HPPA running OSF/1 hppa*-*-osf*
5579 Atari TT running SVR4 m68*-*-sysv4*
5580 RS/6000 LynxOS rs6000-*-lynxos*
5584 OS/9000 i[34]86-*-os9k
5585 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5588 * Hitachi SH7000 and E7000-PC ICE support
5590 There is now support for communicating with the Hitachi E7000-PC ICE.
5591 This is available automatically when GDB is configured for the SH.
5595 As usual, a variety of small fixes and improvements, both generic
5596 and configuration-specific. See the ChangeLog for more detail.
5598 *** Changes in GDB-4.12:
5600 * Irix 5 is now supported
5604 GDB-4.12 on the HPPA has a number of changes which make it unable
5605 to debug the output from the currently released versions of GCC and
5606 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5607 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5608 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5611 *** Changes in GDB-4.11:
5613 * User visible changes:
5617 The "set remotedebug" option is now consistent between the mips remote
5618 target, remote targets using the gdb-specific protocol, UDI (AMD's
5619 debug protocol for the 29k) and the 88k bug monitor. It is now an
5620 integer specifying a debug level (normally 0 or 1, but 2 means more
5621 debugging info for the mips target).
5623 * DEC Alpha native support
5625 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5626 debug info, but GDB works fairly well with the DEC compiler and should
5627 work with a future GCC release. See the README file for a few
5628 Alpha-specific notes.
5630 * Preliminary thread implementation
5632 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5634 * LynxOS native and target support for 386
5636 This release has been hosted on LynxOS 2.2, and also can be configured
5637 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5640 * Improvements in C++ mangling/demangling.
5642 This release has much better g++ debugging, specifically in name
5643 mangling/demangling, virtual function calls, print virtual table,
5644 call methods, ...etc.
5646 *** Changes in GDB-4.10:
5648 * User visible changes:
5650 Remote debugging using the GDB-specific (`target remote') protocol now
5651 supports the `load' command. This is only useful if you have some
5652 other way of getting the stub to the target system, and you can put it
5653 somewhere in memory where it won't get clobbered by the download.
5655 Filename completion now works.
5657 When run under emacs mode, the "info line" command now causes the
5658 arrow to point to the line specified. Also, "info line" prints
5659 addresses in symbolic form (as well as hex).
5661 All vxworks based targets now support a user settable option, called
5662 vxworks-timeout. This option represents the number of seconds gdb
5663 should wait for responses to rpc's. You might want to use this if
5664 your vxworks target is, perhaps, a slow software simulator or happens
5665 to be on the far side of a thin network line.
5669 This release contains support for using a DEC alpha as a GDB host for
5670 cross debugging. Native alpha debugging is not supported yet.
5673 *** Changes in GDB-4.9:
5677 This is the first GDB release which is accompanied by a matching testsuite.
5678 The testsuite requires installation of dejagnu, which should be available
5679 via ftp from most sites that carry GNU software.
5683 'Cfront' style demangling has had its name changed to 'ARM' style, to
5684 emphasize that it was written from the specifications in the C++ Annotated
5685 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5686 disclaimers, it still generated too much confusion with users attempting to
5687 use gdb with AT&T cfront.
5691 GDB now uses a standard remote interface to a simulator library.
5692 So far, the library contains simulators for the Zilog Z8001/2, the
5693 Hitachi H8/300, H8/500 and Super-H.
5695 * New targets supported
5697 H8/300 simulator h8300-hitachi-hms or h8300hms
5698 H8/500 simulator h8500-hitachi-hms or h8500hms
5699 SH simulator sh-hitachi-hms or sh
5700 Z8000 simulator z8k-zilog-none or z8ksim
5701 IDT MIPS board over serial line mips-idt-ecoff
5703 Cross-debugging to GO32 targets is supported. It requires a custom
5704 version of the i386-stub.c module which is integrated with the
5705 GO32 memory extender.
5707 * New remote protocols
5709 MIPS remote debugging protocol.
5711 * New source languages supported
5713 This version includes preliminary support for Chill, a Pascal like language
5714 used by telecommunications companies. Chill support is also being integrated
5715 into the GNU compiler, but we don't know when it will be publically available.
5718 *** Changes in GDB-4.8:
5720 * HP Precision Architecture supported
5722 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5723 version of this support was available as a set of patches from the
5724 University of Utah. GDB does not support debugging of programs
5725 compiled with the HP compiler, because HP will not document their file
5726 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5727 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5729 Many problems in the preliminary version have been fixed.
5731 * Faster and better demangling
5733 We have improved template demangling and fixed numerous bugs in the GNU style
5734 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5735 character types (wchar_t) are now supported. Demangling of each symbol is now
5736 only done once, and is cached when the symbol table for a file is read in.
5737 This results in a small increase in memory usage for C programs, a moderate
5738 increase in memory usage for C++ programs, and a fantastic speedup in
5741 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5742 from the specifications in the Annotated Reference Manual, which AT&T's
5743 compiler does not actually implement.
5745 * G++ multiple inheritance compiler problem
5747 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5748 inheritance lattices was reworked to properly discover ambiguities. We
5749 recently found an example which causes this new algorithm to fail in a
5750 very subtle way, producing bad debug information for those classes.
5751 The file 'gcc.patch' (in this directory) can be applied to gcc to
5752 circumvent the problem. A future GCC release will contain a complete
5755 The previous G++ debug info problem (mentioned below for the gdb-4.7
5756 release) is fixed in gcc version 2.3.2.
5758 * Improved configure script
5760 The `configure' script will now attempt to guess your system type if
5761 you don't supply a host system type. The old scheme of supplying a
5762 host system triplet is preferable over using this. All the magic is
5763 done in the new `config.guess' script. Examine it for details.
5765 We have also brought our configure script much more in line with the FSF's
5766 version. It now supports the --with-xxx options. In particular,
5767 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5768 The resulting GDB will not be able to read arbitrary object file formats --
5769 only the format ``expected'' to be used on the configured target system.
5770 We hope to make this the default in a future release.
5772 * Documentation improvements
5774 There's new internal documentation on how to modify GDB, and how to
5775 produce clean changes to the code. We implore people to read it
5776 before submitting changes.
5778 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5779 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5780 `info' files are also provided. To build `info' files from scratch,
5781 you will need the latest `makeinfo' release, which will be available in
5782 a future texinfo-X.Y release.
5784 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5785 We're not sure exactly which versions have this problem, but it has
5786 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5787 or better. If that isn't possible, there is a patch in
5788 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5789 around this problem.
5793 GDB now supports array constants that can be used in expressions typed in by
5794 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5795 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5798 The new directory `gdb/sparclite' contains a program that demonstrates
5799 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5801 * New native hosts supported
5803 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5804 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5806 * New targets supported
5808 AMD 29k family via UDI a29k-amd-udi or udi29k
5810 * New file formats supported
5812 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5813 HPUX core files, and SCO 3.2v2 core files.
5817 Attaching to processes now works again; thanks for the many bug reports.
5819 We have also stomped on a bunch of core dumps caused by
5820 printf_filtered("%s") problems.
5822 We eliminated a copyright problem on the rpc and ptrace header files
5823 for VxWorks, which was discovered at the last minute during the 4.7
5824 release. You should now be able to build a VxWorks GDB.
5826 You can now interrupt gdb while an attached process is running. This
5827 will cause the attached process to stop, and give control back to GDB.
5829 We fixed problems caused by using too many file descriptors
5830 for reading symbols from object files and libraries. This was
5831 especially a problem for programs that used many (~100) shared
5834 The `step' command now only enters a subroutine if there is line number
5835 information for the subroutine. Otherwise it acts like the `next'
5836 command. Previously, `step' would enter subroutines if there was
5837 any debugging information about the routine. This avoids problems
5838 when using `cc -g1' on MIPS machines.
5840 * Internal improvements
5842 GDB's internal interfaces have been improved to make it easier to support
5843 debugging of multiple languages in the future.
5845 GDB now uses a common structure for symbol information internally.
5846 Minimal symbols (derived from linkage symbols in object files), partial
5847 symbols (from a quick scan of debug information), and full symbols
5848 contain a common subset of information, making it easier to write
5849 shared code that handles any of them.
5851 * New command line options
5853 We now accept --silent as an alias for --quiet.
5857 The memory-mapped-malloc library is now licensed under the GNU Library
5858 General Public License.
5860 *** Changes in GDB-4.7:
5862 * Host/native/target split
5864 GDB has had some major internal surgery to untangle the support for
5865 hosts and remote targets. Now, when you configure GDB for a remote
5866 target, it will no longer load in all of the support for debugging
5867 local programs on the host. When fully completed and tested, this will
5868 ensure that arbitrary host/target combinations are possible.
5870 The primary conceptual shift is to separate the non-portable code in
5871 GDB into three categories. Host specific code is required any time GDB
5872 is compiled on that host, regardless of the target. Target specific
5873 code relates to the peculiarities of the target, but can be compiled on
5874 any host. Native specific code is everything else: it can only be
5875 built when the host and target are the same system. Child process
5876 handling and core file support are two common `native' examples.
5878 GDB's use of /proc for controlling Unix child processes is now cleaner.
5879 It has been split out into a single module under the `target_ops' vector,
5880 plus two native-dependent functions for each system that uses /proc.
5882 * New hosts supported
5884 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5885 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5886 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5888 * New targets supported
5890 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5891 68030 and CPU32 m68030-*-*, m68332-*-*
5893 * New native hosts supported
5895 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5896 (386bsd is not well tested yet)
5897 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5899 * New file formats supported
5901 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5902 supports reading of `a.out.adobe' object files, which are an a.out
5903 format extended with minimal information about multiple sections.
5907 `show copying' is the same as the old `info copying'.
5908 `show warranty' is the same as `info warrantee'.
5909 These were renamed for consistency. The old commands continue to work.
5911 `info handle' is a new alias for `info signals'.
5913 You can now define pre-command hooks, which attach arbitrary command
5914 scripts to any command. The commands in the hook will be executed
5915 prior to the user's command. You can also create a hook which will be
5916 executed whenever the program stops. See gdb.texinfo.
5920 We now deal with Cfront style name mangling, and can even extract type
5921 info from mangled symbols. GDB can automatically figure out which
5922 symbol mangling style your C++ compiler uses.
5924 Calling of methods and virtual functions has been improved as well.
5928 The crash that occured when debugging Sun Ansi-C compiled binaries is
5929 fixed. This was due to mishandling of the extra N_SO stabs output
5932 We also finally got Ultrix 4.2 running in house, and fixed core file
5933 support, with help from a dozen people on the net.
5935 John M. Farrell discovered that the reason that single-stepping was so
5936 slow on all of the Mips based platforms (primarily SGI and DEC) was
5937 that we were trying to demangle and lookup a symbol used for internal
5938 purposes on every instruction that was being stepped through. Changing
5939 the name of that symbol so that it couldn't be mistaken for a C++
5940 mangled symbol sped things up a great deal.
5942 Rich Pixley sped up symbol lookups in general by getting much smarter
5943 about when C++ symbol mangling is necessary. This should make symbol
5944 completion (TAB on the command line) much faster. It's not as fast as
5945 we'd like, but it's significantly faster than gdb-4.6.
5949 A new user controllable variable 'call_scratch_address' can
5950 specify the location of a scratch area to be used when GDB
5951 calls a function in the target. This is necessary because the
5952 usual method of putting the scratch area on the stack does not work
5953 in systems that have separate instruction and data spaces.
5955 We integrated changes to support the 29k UDI (Universal Debugger
5956 Interface), but discovered at the last minute that we didn't have all
5957 of the appropriate copyright paperwork. We are working with AMD to
5958 resolve this, and hope to have it available soon.
5962 We have sped up the remote serial line protocol, especially for targets
5963 with lots of registers. It now supports a new `expedited status' ('T')
5964 message which can be used in place of the existing 'S' status message.
5965 This allows the remote stub to send only the registers that GDB
5966 needs to make a quick decision about single-stepping or conditional
5967 breakpoints, eliminating the need to fetch the entire register set for
5968 each instruction being stepped through.
5970 The GDB remote serial protocol now implements a write-through cache for
5971 registers, only re-reading the registers if the target has run.
5973 There is also a new remote serial stub for SPARC processors. You can
5974 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5975 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5976 processor with a serial port.
5980 Configure.in files have become much easier to read and modify. A new
5981 `table driven' format makes it more obvious what configurations are
5982 supported, and what files each one uses.
5986 There is a new opcodes library which will eventually contain all of the
5987 disassembly routines and opcode tables. At present, it only contains
5988 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5989 disassembler (binutils/objdump) to share these routines.
5991 The libiberty library is now copylefted under the GNU Library General
5992 Public License. This allows more liberal use, and was done so libg++
5993 can use it. This makes no difference to GDB, since the Library License
5994 grants all the rights from the General Public License.
5998 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5999 reference to the stabs symbol info used by the debugger. It is (as far
6000 as we know) the only published document on this fascinating topic. We
6001 encourage you to read it, compare it to the stabs information on your
6002 system, and send improvements on the document in general (to
6003 bug-gdb@prep.ai.mit.edu).
6005 And, of course, many bugs have been fixed.
6008 *** Changes in GDB-4.6:
6010 * Better support for C++ function names
6012 GDB now accepts as input the "demangled form" of C++ overloaded function
6013 names and member function names, and can do command completion on such names
6014 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6015 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6016 Make use of command completion, it is your friend.
6018 GDB also now accepts a variety of C++ mangled symbol formats. They are
6019 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6020 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6021 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6022 for the list of formats.
6024 * G++ symbol mangling problem
6026 Recent versions of gcc have a bug in how they emit debugging information for
6027 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6028 directory) can be applied to gcc to fix the problem. Alternatively, if you
6029 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6030 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6031 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6034 * New 'maintenance' command
6036 All of the commands related to hacking GDB internals have been moved out of
6037 the main command set, and now live behind the 'maintenance' command. This
6038 can also be abbreviated as 'mt'. The following changes were made:
6040 dump-me -> maintenance dump-me
6041 info all-breakpoints -> maintenance info breakpoints
6042 printmsyms -> maintenance print msyms
6043 printobjfiles -> maintenance print objfiles
6044 printpsyms -> maintenance print psymbols
6045 printsyms -> maintenance print symbols
6047 The following commands are new:
6049 maintenance demangle Call internal GDB demangler routine to
6050 demangle a C++ link name and prints the result.
6051 maintenance print type Print a type chain for a given symbol
6053 * Change to .gdbinit file processing
6055 We now read the $HOME/.gdbinit file before processing the argv arguments
6056 (e.g. reading symbol files or core files). This allows global parameters to
6057 be set, which will apply during the symbol reading. The ./.gdbinit is still
6058 read after argv processing.
6060 * New hosts supported
6062 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6064 GNU/Linux support i386-unknown-linux or linux
6066 We are also including code to support the HP/PA running BSD and HPUX. This
6067 is almost guaranteed not to work, as we didn't have time to test or build it
6068 for this release. We are including it so that the more adventurous (or
6069 masochistic) of you can play with it. We also had major problems with the
6070 fact that the compiler that we got from HP doesn't support the -g option.
6073 * New targets supported
6075 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6077 * More smarts about finding #include files
6079 GDB now remembers the compilation directory for all include files, and for
6080 all files from which C is generated (like yacc and lex sources). This
6081 greatly improves GDB's ability to find yacc/lex sources, and include files,
6082 especially if you are debugging your program from a directory different from
6083 the one that contains your sources.
6085 We also fixed a bug which caused difficulty with listing and setting
6086 breakpoints in include files which contain C code. (In the past, you had to
6087 try twice in order to list an include file that you hadn't looked at before.)
6089 * Interesting infernals change
6091 GDB now deals with arbitrary numbers of sections, where the symbols for each
6092 section must be relocated relative to that section's landing place in the
6093 target's address space. This work was needed to support ELF with embedded
6094 stabs used by Solaris-2.0.
6096 * Bug fixes (of course!)
6098 There have been loads of fixes for the following things:
6099 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6100 i960, stabs, DOS(GO32), procfs, etc...
6102 See the ChangeLog for details.
6104 *** Changes in GDB-4.5:
6106 * New machines supported (host and target)
6108 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6110 SGI Irix-4.x mips-sgi-irix4 or iris4
6112 * New malloc package
6114 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6115 Mmalloc is capable of handling mutiple heaps of memory. It is also
6116 capable of saving a heap to a file, and then mapping it back in later.
6117 This can be used to greatly speedup the startup of GDB by using a
6118 pre-parsed symbol table which lives in a mmalloc managed heap. For
6119 more details, please read mmalloc/mmalloc.texi.
6123 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6124 'help info proc' for details.
6126 * MIPS ecoff symbol table format
6128 The code that reads MIPS symbol table format is now supported on all hosts.
6129 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6132 * File name changes for MS-DOS
6134 Many files in the config directories have been renamed to make it easier to
6135 support GDB on MS-DOSe systems (which have very restrictive file name
6136 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6137 environment) is close to working but has some remaining problems. Note
6138 that debugging of DOS programs is not supported, due to limitations
6139 in the ``operating system'', but it can be used to host cross-debugging.
6141 * Cross byte order fixes
6143 Many fixes have been made to support cross debugging of Sparc and MIPS
6144 targets from hosts whose byte order differs.
6146 * New -mapped and -readnow options
6148 If memory-mapped files are available on your system through the 'mmap'
6149 system call, you can use the -mapped option on the `file' or
6150 `symbol-file' commands to cause GDB to write the symbols from your
6151 program into a reusable file. If the program you are debugging is
6152 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6153 Future GDB debugging sessions will notice the presence of this file,
6154 and will quickly map in symbol information from it, rather than reading
6155 the symbol table from the executable program. Using the '-mapped'
6156 option in a GDB `file' or `symbol-file' command has the same effect as
6157 starting GDB with the '-mapped' command-line option.
6159 You can cause GDB to read the entire symbol table immediately by using
6160 the '-readnow' option with any of the commands that load symbol table
6161 information (or on the GDB command line). This makes the command
6162 slower, but makes future operations faster.
6164 The -mapped and -readnow options are typically combined in order to
6165 build a `fred.syms' file that contains complete symbol information.
6166 A simple GDB invocation to do nothing but build a `.syms' file for future
6169 gdb -batch -nx -mapped -readnow programname
6171 The `.syms' file is specific to the host machine on which GDB is run.
6172 It holds an exact image of GDB's internal symbol table. It cannot be
6173 shared across multiple host platforms.
6175 * longjmp() handling
6177 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6178 siglongjmp() without losing control. This feature has not yet been ported to
6179 all systems. It currently works on many 386 platforms, all MIPS-based
6180 platforms (SGI, DECstation, etc), and Sun3/4.
6184 Preliminary work has been put in to support the new Solaris OS from Sun. At
6185 this time, it can control and debug processes, but it is not capable of
6190 As always, many many bug fixes. The major areas were with g++, and mipsread.
6191 People using the MIPS-based platforms should experience fewer mysterious
6192 crashes and trashed symbol tables.
6194 *** Changes in GDB-4.4:
6196 * New machines supported (host and target)
6198 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6200 BSD Reno on Vax vax-dec-bsd
6201 Ultrix on Vax vax-dec-ultrix
6203 * New machines supported (target)
6205 AMD 29000 embedded, using EBMON a29k-none-none
6209 GDB continues to improve its handling of C++. `References' work better.
6210 The demangler has also been improved, and now deals with symbols mangled as
6211 per the Annotated C++ Reference Guide.
6213 GDB also now handles `stabs' symbol information embedded in MIPS
6214 `ecoff' symbol tables. Since the ecoff format was not easily
6215 extensible to handle new languages such as C++, this appeared to be a
6216 good way to put C++ debugging info into MIPS binaries. This option
6217 will be supported in the GNU C compiler, version 2, when it is
6220 * New features for SVR4
6222 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6223 shared libraries. Debugging dynamically linked programs should present
6224 only minor differences from debugging statically linked programs.
6226 The `info proc' command will print out information about any process
6227 on an SVR4 system (including the one you are debugging). At the moment,
6228 it prints the address mappings of the process.
6230 If you bring up GDB on another SVR4 system, please send mail to
6231 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6233 * Better dynamic linking support in SunOS
6235 Reading symbols from shared libraries which contain debugging symbols
6236 now works properly. However, there remain issues such as automatic
6237 skipping of `transfer vector' code during function calls, which
6238 make it harder to debug code in a shared library, than to debug the
6239 same code linked statically.
6243 GDB is now using the latest `getopt' routines from the FSF. This
6244 version accepts the -- prefix for options with long names. GDB will
6245 continue to accept the old forms (-option and +option) as well.
6246 Various single letter abbreviations for options have been explicity
6247 added to the option table so that they won't get overshadowed in the
6248 future by other options that begin with the same letter.
6252 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6253 Many assorted bugs have been handled. Many more remain to be handled.
6254 See the various ChangeLog files (primarily in gdb and bfd) for details.
6257 *** Changes in GDB-4.3:
6259 * New machines supported (host and target)
6261 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6262 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6263 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6265 * Almost SCO Unix support
6267 We had hoped to support:
6268 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6269 (except for core file support), but we discovered very late in the release
6270 that it has problems with process groups that render gdb unusable. Sorry
6271 about that. I encourage people to fix it and post the fixes.
6273 * Preliminary ELF and DWARF support
6275 GDB can read ELF object files on System V Release 4, and can handle
6276 debugging records for C, in DWARF format, in ELF files. This support
6277 is preliminary. If you bring up GDB on another SVR4 system, please
6278 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6283 GDB now uses the latest `readline' library. One user-visible change
6284 is that two tabs will list possible command completions, which previously
6285 required typing M-? (meta-question mark, or ESC ?).
6289 The `stepi' bug that many of you noticed has been squashed.
6290 Many bugs in C++ have been handled. Many more remain to be handled.
6291 See the various ChangeLog files (primarily in gdb and bfd) for details.
6293 * State of the MIPS world (in case you wondered):
6295 GDB can understand the symbol tables emitted by the compilers
6296 supplied by most vendors of MIPS-based machines, including DEC. These
6297 symbol tables are in a format that essentially nobody else uses.
6299 Some versions of gcc come with an assembler post-processor called
6300 mips-tfile. This program is required if you want to do source-level
6301 debugging of gcc-compiled programs. I believe FSF does not ship
6302 mips-tfile with gcc version 1, but it will eventually come with gcc
6305 Debugging of g++ output remains a problem. g++ version 1.xx does not
6306 really support it at all. (If you're lucky, you should be able to get
6307 line numbers and stack traces to work, but no parameters or local
6308 variables.) With some work it should be possible to improve the
6311 When gcc version 2 is released, you will have somewhat better luck.
6312 However, even then you will get confusing results for inheritance and
6315 We will eventually provide full debugging of g++ output on
6316 DECstations. This will probably involve some kind of stabs-in-ecoff
6317 encapulation, but the details have not been worked out yet.
6320 *** Changes in GDB-4.2:
6322 * Improved configuration
6324 Only one copy of `configure' exists now, and it is not self-modifying.
6325 Porting BFD is simpler.
6329 The `step' and `next' commands now only stop at the first instruction
6330 of a source line. This prevents the multiple stops that used to occur
6331 in switch statements, for-loops, etc. `Step' continues to stop if a
6332 function that has debugging information is called within the line.
6336 Lots of small bugs fixed. More remain.
6338 * New host supported (not target)
6340 Intel 386 PC clone running Mach i386-none-mach
6343 *** Changes in GDB-4.1:
6345 * Multiple source language support
6347 GDB now has internal scaffolding to handle several source languages.
6348 It determines the type of each source file from its filename extension,
6349 and will switch expression parsing and number formatting to match the
6350 language of the function in the currently selected stack frame.
6351 You can also specifically set the language to be used, with
6352 `set language c' or `set language modula-2'.
6356 GDB now has preliminary support for the GNU Modula-2 compiler,
6357 currently under development at the State University of New York at
6358 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6359 continue through the fall of 1991 and into 1992.
6361 Other Modula-2 compilers are currently not supported, and attempting to
6362 debug programs compiled with them will likely result in an error as the
6363 symbol table is read. Feel free to work on it, though!
6365 There are hooks in GDB for strict type checking and range checking,
6366 in the `Modula-2 philosophy', but they do not currently work.
6370 GDB can now write to executable and core files (e.g. patch
6371 a variable's value). You must turn this switch on, specify
6372 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6373 by assigning a new value to a variable. Modifications take
6376 * Automatic SunOS shared library reading
6378 When you run your program, GDB automatically determines where its
6379 shared libraries (if any) have been loaded, and reads their symbols.
6380 The `share' command is no longer needed. This also works when
6381 examining core files.
6385 You can specify the number of lines that the `list' command shows.
6388 * New machines supported (host and target)
6390 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6391 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6392 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6394 * New hosts supported (not targets)
6396 IBM RT/PC: romp-ibm-aix or rtpc
6398 * New targets supported (not hosts)
6400 AMD 29000 embedded with COFF a29k-none-coff
6401 AMD 29000 embedded with a.out a29k-none-aout
6402 Ultracomputer remote kernel debug a29k-nyu-kern
6404 * New remote interfaces
6410 *** Changes in GDB-4.0:
6414 Wide output is wrapped at good places to make the output more readable.
6416 Gdb now supports cross-debugging from a host machine of one type to a
6417 target machine of another type. Communication with the target system
6418 is over serial lines. The ``target'' command handles connecting to the
6419 remote system; the ``load'' command will download a program into the
6420 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6421 also supports debugging of realtime processes running under VxWorks,
6422 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6423 stub on the target system.
6425 New CPUs supported include the AMD 29000 and Intel 960.
6427 GDB now reads object files and symbol tables via a ``binary file''
6428 library, which allows a single copy of GDB to debug programs of multiple
6429 object file types such as a.out and coff.
6431 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6432 refcard.dvi and refcard.ps are available to format it).
6435 * Control-Variable user interface simplified
6437 All variables that control the operation of the debugger can be set
6438 by the ``set'' command, and displayed by the ``show'' command.
6440 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6441 ``Show prompt'' produces the response:
6442 Gdb's prompt is new-gdb=>.
6444 What follows are the NEW set commands. The command ``help set'' will
6445 print a complete list of old and new set commands. ``help set FOO''
6446 will give a longer description of the variable FOO. ``show'' will show
6447 all of the variable descriptions and their current settings.
6449 confirm on/off: Enables warning questions for operations that are
6450 hard to recover from, e.g. rerunning the program while
6451 it is already running. Default is ON.
6453 editing on/off: Enables EMACS style command line editing
6454 of input. Previous lines can be recalled with
6455 control-P, the current line can be edited with control-B,
6456 you can search for commands with control-R, etc.
6459 history filename NAME: NAME is where the gdb command history
6460 will be stored. The default is .gdb_history,
6461 or the value of the environment variable
6464 history size N: The size, in commands, of the command history. The
6465 default is 256, or the value of the environment variable
6468 history save on/off: If this value is set to ON, the history file will
6469 be saved after exiting gdb. If set to OFF, the
6470 file will not be saved. The default is OFF.
6472 history expansion on/off: If this value is set to ON, then csh-like
6473 history expansion will be performed on
6474 command line input. The default is OFF.
6476 radix N: Sets the default radix for input and output. It can be set
6477 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6478 in the current radix, so "set radix 10" is always a no-op.
6480 height N: This integer value is the number of lines on a page. Default
6481 is 24, the current `stty rows'' setting, or the ``li#''
6482 setting from the termcap entry matching the environment
6485 width N: This integer value is the number of characters on a line.
6486 Default is 80, the current `stty cols'' setting, or the ``co#''
6487 setting from the termcap entry matching the environment
6490 Note: ``set screensize'' is obsolete. Use ``set height'' and
6491 ``set width'' instead.
6493 print address on/off: Print memory addresses in various command displays,
6494 such as stack traces and structure values. Gdb looks
6495 more ``symbolic'' if you turn this off; it looks more
6496 ``machine level'' with it on. Default is ON.
6498 print array on/off: Prettyprint arrays. New convenient format! Default
6501 print demangle on/off: Print C++ symbols in "source" form if on,
6504 print asm-demangle on/off: Same, for assembler level printouts
6507 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6510 * Support for Epoch Environment.
6512 The epoch environment is a version of Emacs v18 with windowing. One
6513 new command, ``inspect'', is identical to ``print'', except that if you
6514 are running in the epoch environment, the value is printed in its own
6518 * Support for Shared Libraries
6520 GDB can now debug programs and core files that use SunOS shared libraries.
6521 Symbols from a shared library cannot be referenced
6522 before the shared library has been linked with the program (this
6523 happens after you type ``run'' and before the function main() is entered).
6524 At any time after this linking (including when examining core files
6525 from dynamically linked programs), gdb reads the symbols from each
6526 shared library when you type the ``sharedlibrary'' command.
6527 It can be abbreviated ``share''.
6529 sharedlibrary REGEXP: Load shared object library symbols for files
6530 matching a unix regular expression. No argument
6531 indicates to load symbols for all shared libraries.
6533 info sharedlibrary: Status of loaded shared libraries.
6538 A watchpoint stops execution of a program whenever the value of an
6539 expression changes. Checking for this slows down execution
6540 tremendously whenever you are in the scope of the expression, but is
6541 quite useful for catching tough ``bit-spreader'' or pointer misuse
6542 problems. Some machines such as the 386 have hardware for doing this
6543 more quickly, and future versions of gdb will use this hardware.
6545 watch EXP: Set a watchpoint (breakpoint) for an expression.
6547 info watchpoints: Information about your watchpoints.
6549 delete N: Deletes watchpoint number N (same as breakpoints).
6550 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6551 enable N: Re-enables watchpoint number N (same as breakpoints).
6554 * C++ multiple inheritance
6556 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6559 * C++ exception handling
6561 Gdb now supports limited C++ exception handling. Besides the existing
6562 ability to breakpoint on an exception handler, gdb can breakpoint on
6563 the raising of an exception (before the stack is peeled back to the
6566 catch FOO: If there is a FOO exception handler in the dynamic scope,
6567 set a breakpoint to catch exceptions which may be raised there.
6568 Multiple exceptions (``catch foo bar baz'') may be caught.
6570 info catch: Lists all exceptions which may be caught in the
6571 current stack frame.
6574 * Minor command changes
6576 The command ``call func (arg, arg, ...)'' now acts like the print
6577 command, except it does not print or save a value if the function's result
6578 is void. This is similar to dbx usage.
6580 The ``up'' and ``down'' commands now always print the frame they end up
6581 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6582 frames without printing.
6584 * New directory command
6586 'dir' now adds directories to the FRONT of the source search path.
6587 The path starts off empty. Source files that contain debug information
6588 about the directory in which they were compiled can be found even
6589 with an empty path; Sun CC and GCC include this information. If GDB can't
6590 find your source file in the current directory, type "dir .".
6592 * Configuring GDB for compilation
6594 For normal use, type ``./configure host''. See README or gdb.texinfo
6597 GDB now handles cross debugging. If you are remotely debugging between
6598 two different machines, type ``./configure host -target=targ''.
6599 Host is the machine where GDB will run; targ is the machine
6600 where the program that you are debugging will run.
projects / external / binutils.git / blob