1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.12
6 * Building GDB and GDBserver now requires a C++11 compiler.
8 For example, GCC 4.8 or later.
10 It is no longer possible to build GDB or GDBserver with a C
11 compiler. The --disable-build-with-cxx configure option has been
14 * Native debugging on MS-Windows supports command-line redirection
16 Command-line arguments used for starting programs on MS-Windows can
17 now include redirection symbols supported by native Windows shells,
18 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
19 as "run", "start", and "set args", as well as the corresponding MI
22 * Support for thread names on MS-Windows.
24 GDB now catches and handles the special exception that programs
25 running on MS-Windows use to assign names to threads in the
28 * Support for Java programs compiled with gcj has been removed.
32 Synopsys ARC arc*-*-elf32
34 *** Changes in GDB 7.12
36 * GDB and GDBserver now build with a C++ compiler by default.
38 The --enable-build-with-cxx configure option is now enabled by
39 default. One must now explicitly configure with
40 --disable-build-with-cxx in order to build with a C compiler. This
41 option will be removed in a future release.
43 * GDBserver now supports recording btrace without maintaining an active
46 * GDB now supports a negative repeat count in the 'x' command to examine
47 memory backward from the given address. For example:
50 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
51 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
52 (gdb) x/-5i 0x0000000000400580
53 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
54 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
55 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
56 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
57 0x40057b <main(int, char**)+25>:
58 callq 0x400536 <Func1(int, char const*)>
60 * Fortran: Support structures with fields of dynamic types and
61 arrays of dynamic types.
63 * GDB now supports multibit bitfields and enums in target register
66 * New Python-based convenience function $_as_string(val), which returns
67 the textual representation of a value. This function is especially
68 useful to obtain the text label of an enum value.
70 * Intel MPX bound violation handling.
72 Segmentation faults caused by a Intel MPX boundary violation
73 now display the kind of violation (upper or lower), the memory
74 address accessed and the memory bounds, along with the usual
75 signal received and code location.
79 Program received signal SIGSEGV, Segmentation fault
80 Upper bound violation while accessing address 0x7fffffffc3b3
81 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
82 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
84 * Rust language support.
85 GDB now supports debugging programs written in the Rust programming
86 language. See https://www.rust-lang.org/ for more information about
89 * Support for running interpreters on specified input/output devices
91 GDB now supports a new mechanism that allows frontends to provide
92 fully featured GDB console views, as a better alternative to
93 building such views on top of the "-interpreter-exec console"
94 command. See the new "new-ui" command below. With that command,
95 frontends can now start GDB in the traditional command-line mode
96 running in an embedded terminal emulator widget, and create a
97 separate MI interpreter running on a specified i/o device. In this
98 way, GDB handles line editing, history, tab completion, etc. in the
99 console all by itself, and the GUI uses the separate MI interpreter
100 for its own control and synchronization, invisible to the command
103 * The "catch syscall" command catches groups of related syscalls.
105 The "catch syscall" command now supports catching a group of related
106 syscalls using the 'group:' or 'g:' prefix.
111 skip -gfile file-glob-pattern
112 skip -function function
113 skip -rfunction regular-expression
114 A generalized form of the skip command, with new support for
115 glob-style file names and regular expressions for function names.
116 Additionally, a file spec and a function spec may now be combined.
118 maint info line-table REGEXP
119 Display the contents of GDB's internal line table data struture.
122 Run any GDB unit tests that were compiled in.
125 Start a new user interface instance running INTERP as interpreter,
126 using the TTY file for input/output.
130 ** gdb.Breakpoint objects have a new attribute "pending", which
131 indicates whether the breakpoint is pending.
132 ** Three new breakpoint-related events have been added:
133 gdb.breakpoint_created, gdb.breakpoint_modified, and
134 gdb.breakpoint_deleted.
137 Signal ("set") the given MS-Windows event object. This is used in
138 conjunction with the Windows JIT debugging (AeDebug) support, where
139 the OS suspends a crashing process until a debugger can attach to
140 it. Resuming the crashing process, in order to debug it, is done by
143 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
144 was added in GDBserver, including JIT compiling fast tracepoint's
145 conditional expression bytecode into native code.
147 * Support for various remote target protocols and ROM monitors has
150 target m32rsdi Remote M32R debugging over SDI
151 target mips MIPS remote debugging protocol
152 target pmon PMON ROM monitor
153 target ddb NEC's DDB variant of PMON for Vr4300
154 target rockhopper NEC RockHopper variant of PMON
155 target lsi LSI variant of PMO
157 * Support for tracepoints and fast tracepoints on powerpc-linux,
158 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
159 including JIT compiling fast tracepoint's conditional expression
160 bytecode into native code.
162 * MI async record =record-started now includes the method and format used for
163 recording. For example:
165 =record-started,thread-group="i1",method="btrace",format="bts"
167 * MI async record =thread-selected now includes the frame field. For example:
169 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
173 Andes NDS32 nds32*-*-elf
175 *** Changes in GDB 7.11
177 * GDB now supports debugging kernel-based threads on FreeBSD.
179 * Per-inferior thread numbers
181 Thread numbers are now per inferior instead of global. If you're
182 debugging multiple inferiors, GDB displays thread IDs using a
183 qualified INF_NUM.THR_NUM form. For example:
187 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
188 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
189 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
190 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
192 As consequence, thread numbers as visible in the $_thread
193 convenience variable and in Python's InferiorThread.num attribute
194 are no longer unique between inferiors.
196 GDB now maintains a second thread ID per thread, referred to as the
197 global thread ID, which is the new equivalent of thread numbers in
198 previous releases. See also $_gthread below.
200 For backwards compatibility, MI's thread IDs always refer to global
203 * Commands that accept thread IDs now accept the qualified
204 INF_NUM.THR_NUM form as well. For example:
207 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
210 * In commands that accept a list of thread IDs, you can now refer to
211 all threads of an inferior using a star wildcard. GDB accepts
212 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
213 refer to all threads of the current inferior. For example, "info
216 * You can use "info threads -gid" to display the global thread ID of
219 * The new convenience variable $_gthread holds the global number of
222 * The new convenience variable $_inferior holds the number of the
225 * GDB now displays the ID and name of the thread that hit a breakpoint
226 or received a signal, if your program is multi-threaded. For
229 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
230 Thread 1 "main" received signal SIGINT, Interrupt.
232 * Record btrace now supports non-stop mode.
234 * Support for tracepoints on aarch64-linux was added in GDBserver.
236 * The 'record instruction-history' command now indicates speculative execution
237 when using the Intel Processor Trace recording format.
239 * GDB now allows users to specify explicit locations, bypassing
240 the linespec parser. This feature is also available to GDB/MI
243 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
244 GDB now is able to debug both AArch64 applications and ARM applications
247 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
248 including JIT compiling fast tracepoint's conditional expression bytecode
251 * GDB now supports displaced stepping on AArch64 GNU/Linux.
253 * "info threads", "info inferiors", "info display", "info checkpoints"
254 and "maint info program-spaces" now list the corresponding items in
255 ascending ID order, for consistency with all other "info" commands.
257 * In Ada, the overloads selection menu has been enhanced to display the
258 parameter types and the return types for the matching overloaded subprograms.
262 maint set target-non-stop (on|off|auto)
263 maint show target-non-stop
264 Control whether GDB targets always operate in non-stop mode even if
265 "set non-stop" is "off". The default is "auto", meaning non-stop
266 mode is enabled if supported by the target.
268 maint set bfd-sharing
269 maint show bfd-sharing
270 Control the reuse of bfd objects.
274 Control display of debugging info regarding bfd caching.
278 Control display of debugging info regarding FreeBSD threads.
280 set remote multiprocess-extensions-packet
281 show remote multiprocess-extensions-packet
282 Set/show the use of the remote protocol multiprocess extensions.
284 set remote thread-events
285 show remote thread-events
286 Set/show the use of thread create/exit events.
288 set ada print-signatures on|off
289 show ada print-signatures"
290 Control whether parameter types and return types are displayed in overloads
291 selection menus. It is activaled (@code{on}) by default.
295 Controls the maximum size of memory, in bytes, that GDB will
296 allocate for value contents. Prevents incorrect programs from
297 causing GDB to allocate overly large buffers. Default is 64k.
299 * The "disassemble" command accepts a new modifier: /s.
300 It prints mixed source+disassembly like /m with two differences:
301 - disassembled instructions are now printed in program order, and
302 - and source for all relevant files is now printed.
303 The "/m" option is now considered deprecated: its "source-centric"
304 output hasn't proved useful in practice.
306 * The "record instruction-history" command accepts a new modifier: /s.
307 It behaves exactly like /m and prints mixed source+disassembly.
309 * The "set scheduler-locking" command supports a new mode "replay".
310 It behaves like "off" in record mode and like "on" in replay mode.
312 * Support for various ROM monitors has been removed:
314 target dbug dBUG ROM monitor for Motorola ColdFire
315 target picobug Motorola picobug monitor
316 target dink32 DINK32 ROM monitor for PowerPC
317 target m32r Renesas M32R/D ROM monitor
318 target mon2000 mon2000 ROM monitor
319 target ppcbug PPCBUG ROM monitor for PowerPC
321 * Support for reading/writing memory and extracting values on architectures
322 whose memory is addressable in units of any integral multiple of 8 bits.
327 Indicates that an exec system call was executed.
329 exec-events feature in qSupported
330 The qSupported packet allows GDB to request support for exec
331 events using the new 'gdbfeature' exec-event, and the qSupported
332 response can contain the corresponding 'stubfeature'. Set and
333 show commands can be used to display whether these features are enabled.
336 Equivalent to interrupting with the ^C character, but works in
339 thread created stop reason (T05 create:...)
340 Indicates that the thread was just created and is stopped at entry.
342 thread exit stop reply (w exitcode;tid)
343 Indicates that the thread has terminated.
346 Enables/disables thread create and exit event reporting. For
347 example, this is used in non-stop mode when GDB stops a set of
348 threads and synchronously waits for the their corresponding stop
349 replies. Without exit events, if one of the threads exits, GDB
350 would hang forever not knowing that it should no longer expect a
351 stop for that same thread.
354 Indicates that there are no resumed threads left in the target (all
355 threads are stopped). The remote stub reports support for this stop
356 reply to GDB's qSupported query.
359 Enables/disables catching syscalls from the inferior process.
360 The remote stub reports support for this packet to GDB's qSupported query.
362 syscall_entry stop reason
363 Indicates that a syscall was just called.
365 syscall_return stop reason
366 Indicates that a syscall just returned.
368 * Extended-remote exec events
370 ** GDB now has support for exec events on extended-remote Linux targets.
371 For such targets with Linux kernels 2.5.46 and later, this enables
372 follow-exec-mode and exec catchpoints.
374 set remote exec-event-feature-packet
375 show remote exec-event-feature-packet
376 Set/show the use of the remote exec event feature.
378 * Thread names in remote protocol
380 The reply to qXfer:threads:read may now include a name attribute for each
383 * Target remote mode fork and exec events
385 ** GDB now has support for fork and exec events on target remote mode
386 Linux targets. For such targets with Linux kernels 2.5.46 and later,
387 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
388 fork and exec catchpoints.
390 * Remote syscall events
392 ** GDB now has support for catch syscall on remote Linux targets,
393 currently enabled on x86/x86_64 architectures.
395 set remote catch-syscall-packet
396 show remote catch-syscall-packet
397 Set/show the use of the remote catch syscall feature.
401 ** The -var-set-format command now accepts the zero-hexadecimal
402 format. It outputs data in hexadecimal format with zero-padding on the
407 ** gdb.InferiorThread objects have a new attribute "global_num",
408 which refers to the thread's global thread ID. The existing
409 "num" attribute now refers to the thread's per-inferior number.
410 See "Per-inferior thread numbers" above.
411 ** gdb.InferiorThread objects have a new attribute "inferior", which
412 is the Inferior object the thread belongs to.
414 *** Changes in GDB 7.10
416 * Support for process record-replay and reverse debugging on aarch64*-linux*
417 targets has been added. GDB now supports recording of A64 instruction set
418 including advance SIMD instructions.
420 * Support for Sun's version of the "stabs" debug file format has been removed.
422 * GDB now honors the content of the file /proc/PID/coredump_filter
423 (PID is the process ID) on GNU/Linux systems. This file can be used
424 to specify the types of memory mappings that will be included in a
425 corefile. For more information, please refer to the manual page of
426 "core(5)". GDB also has a new command: "set use-coredump-filter
427 on|off". It allows to set whether GDB will read the content of the
428 /proc/PID/coredump_filter file when generating a corefile.
430 * The "info os" command on GNU/Linux can now display information on
432 "info os cpus" Listing of all cpus/cores on the system
434 * GDB has two new commands: "set serial parity odd|even|none" and
435 "show serial parity". These allows to set or show parity for the
438 * The "info source" command now displays the producer string if it was
439 present in the debug info. This typically includes the compiler version
440 and may include things like its command line arguments.
442 * The "info dll", an alias of the "info sharedlibrary" command,
443 is now available on all platforms.
445 * Directory names supplied to the "set sysroot" commands may be
446 prefixed with "target:" to tell GDB to access shared libraries from
447 the target system, be it local or remote. This replaces the prefix
448 "remote:". The default sysroot has been changed from "" to
449 "target:". "remote:" is automatically converted to "target:" for
450 backward compatibility.
452 * The system root specified by "set sysroot" will be prepended to the
453 filename of the main executable (if reported to GDB as absolute by
454 the operating system) when starting processes remotely, and when
455 attaching to already-running local or remote processes.
457 * GDB now supports automatic location and retrieval of executable
458 files from remote targets. Remote debugging can now be initiated
459 using only a "target remote" or "target extended-remote" command
460 (no "set sysroot" or "file" commands are required). See "New remote
463 * The "dump" command now supports verilog hex format.
465 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
467 * On GNU/Linux, GDB and gdbserver are now able to access executable
468 and shared library files without a "set sysroot" command when
469 attaching to processes running in different mount namespaces from
470 the debugger. This makes it possible to attach to processes in
471 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
472 See "New remote packets" below.
474 * The "tui reg" command now provides completion for all of the
475 available register groups, including target specific groups.
477 * The HISTSIZE environment variable is no longer read when determining
478 the size of GDB's command history. GDB now instead reads the dedicated
479 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
480 disables truncation of command history. Non-numeric values of GDBHISTSIZE
485 ** Memory ports can now be unbuffered.
489 ** gdb.Objfile objects have a new attribute "username",
490 which is the name of the objfile as specified by the user,
491 without, for example, resolving symlinks.
492 ** You can now write frame unwinders in Python.
493 ** gdb.Type objects have a new method "optimized_out",
494 returning optimized out gdb.Value instance of this type.
495 ** gdb.Value objects have new methods "reference_value" and
496 "const_value" which return a reference to the value and a
497 "const" version of the value respectively.
501 maint print symbol-cache
502 Print the contents of the symbol cache.
504 maint print symbol-cache-statistics
505 Print statistics of symbol cache usage.
507 maint flush-symbol-cache
508 Flush the contents of the symbol cache.
512 Start branch trace recording using Branch Trace Store (BTS) format.
515 Evaluate expression by using the compiler and print result.
519 Explicit commands for enabling and disabling tui mode.
522 set mpx bound on i386 and amd64
523 Support for bound table investigation on Intel MPX enabled applications.
527 Start branch trace recording using Intel Processor Trace format.
530 Print information about branch tracing internals.
532 maint btrace packet-history
533 Print the raw branch tracing data.
535 maint btrace clear-packet-history
536 Discard the stored raw branch tracing data.
539 Discard all branch tracing data. It will be fetched and processed
540 anew by the next "record" command.
545 Renamed from "set debug dwarf2-die".
547 Renamed from "show debug dwarf2-die".
550 Renamed from "set debug dwarf2-read".
551 show debug dwarf-read
552 Renamed from "show debug dwarf2-read".
554 maint set dwarf always-disassemble
555 Renamed from "maint set dwarf2 always-disassemble".
556 maint show dwarf always-disassemble
557 Renamed from "maint show dwarf2 always-disassemble".
559 maint set dwarf max-cache-age
560 Renamed from "maint set dwarf2 max-cache-age".
561 maint show dwarf max-cache-age
562 Renamed from "maint show dwarf2 max-cache-age".
565 show debug dwarf-line
566 Control display of debugging info regarding DWARF line processing.
570 Set the maximum number of candidates to be considered during
571 completion. The default value is 200. This limit allows GDB
572 to avoid generating large completion lists, the computation of
573 which can cause the debugger to become temporarily unresponsive.
575 set history remove-duplicates
576 show history remove-duplicates
577 Control the removal of duplicate history entries.
579 maint set symbol-cache-size
580 maint show symbol-cache-size
581 Control the size of the symbol cache.
583 set|show record btrace bts buffer-size
584 Set and show the size of the ring buffer used for branch tracing in
586 The obtained size may differ from the requested size. Use "info
587 record" to see the obtained buffer size.
589 set debug linux-namespaces
590 show debug linux-namespaces
591 Control display of debugging info regarding Linux namespaces.
593 set|show record btrace pt buffer-size
594 Set and show the size of the ring buffer used for branch tracing in
595 Intel Processor Trace format.
596 The obtained size may differ from the requested size. Use "info
597 record" to see the obtained buffer size.
599 maint set|show btrace pt skip-pad
600 Set and show whether PAD packets are skipped when computing the
603 * The command 'thread apply all' can now support new option '-ascending'
604 to call its specified command for all threads in ascending order.
606 * Python/Guile scripting
608 ** GDB now supports auto-loading of Python/Guile scripts contained in the
609 special section named `.debug_gdb_scripts'.
613 qXfer:btrace-conf:read
614 Return the branch trace configuration for the current thread.
616 Qbtrace-conf:bts:size
617 Set the requested ring buffer size for branch tracing in BTS format.
620 Enable Intel Procesor Trace-based branch tracing for the current
621 process. The remote stub reports support for this packet to GDB's
625 Set the requested ring buffer size for branch tracing in Intel Processor
629 Indicates a memory breakpoint instruction was executed, irrespective
630 of whether it was GDB that planted the breakpoint or the breakpoint
631 is hardcoded in the program. This is required for correct non-stop
635 Indicates the target stopped for a hardware breakpoint. This is
636 required for correct non-stop mode operation.
639 Return information about files on the remote system.
642 Return the full absolute name of the file that was executed to
643 create a process running on the remote system.
646 Select the filesystem on which vFile: operations with filename
647 arguments will operate. This is required for GDB to be able to
648 access files on remote targets where the remote stub does not
649 share a common filesystem with the inferior(s).
652 Indicates that a fork system call was executed.
655 Indicates that a vfork system call was executed.
657 vforkdone stop reason
658 Indicates that a vfork child of the specified process has executed
659 an exec or exit, allowing the vfork parent to resume execution.
661 fork-events and vfork-events features in qSupported
662 The qSupported packet allows GDB to request support for fork and
663 vfork events using new 'gdbfeatures' fork-events and vfork-events,
664 and the qSupported response can contain the corresponding
665 'stubfeatures'. Set and show commands can be used to display
666 whether these features are enabled.
668 * Extended-remote fork events
670 ** GDB now has support for fork events on extended-remote Linux
671 targets. For targets with Linux kernels 2.5.60 and later, this
672 enables follow-fork-mode and detach-on-fork for both fork and
673 vfork, as well as fork and vfork catchpoints.
675 * The info record command now shows the recording format and the
676 branch tracing configuration for the current thread when using
677 the btrace record target.
678 For the BTS format, it shows the ring buffer size.
680 * GDB now has support for DTrace USDT (Userland Static Defined
681 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
683 * GDB now supports access to vector registers on S/390 GNU/Linux
686 * Removed command line options
688 -xdb HP-UX XDB compatibility mode.
690 * Removed targets and native configurations
692 HP/PA running HP-UX hppa*-*-hpux*
693 Itanium running HP-UX ia64-*-hpux*
695 * New configure options
698 This configure option allows the user to build GDB with support for
699 Intel Processor Trace (default: auto). This requires libipt.
701 --with-libipt-prefix=PATH
702 Specify the path to the version of libipt that GDB should use.
703 $PATH/include should contain the intel-pt.h header and
704 $PATH/lib should contain the libipt.so library.
706 *** Changes in GDB 7.9.1
710 ** Xmethods can now specify a result type.
712 *** Changes in GDB 7.9
714 * GDB now supports hardware watchpoints on x86 GNU Hurd.
718 ** You can now access frame registers from Python scripts.
719 ** New attribute 'producer' for gdb.Symtab objects.
720 ** gdb.Objfile objects have a new attribute "progspace",
721 which is the gdb.Progspace object of the containing program space.
722 ** gdb.Objfile objects have a new attribute "owner".
723 ** gdb.Objfile objects have a new attribute "build_id",
724 which is the build ID generated when the file was built.
725 ** gdb.Objfile objects have a new method "add_separate_debug_file".
726 ** A new event "gdb.clear_objfiles" has been added, triggered when
727 selecting a new file to debug.
728 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
729 ** New function gdb.lookup_objfile.
731 New events which are triggered when GDB modifies the state of the
734 ** gdb.events.inferior_call_pre: Function call is about to be made.
735 ** gdb.events.inferior_call_post: Function call has just been made.
736 ** gdb.events.memory_changed: A memory location has been altered.
737 ** gdb.events.register_changed: A register has been altered.
739 * New Python-based convenience functions:
741 ** $_caller_is(name [, number_of_frames])
742 ** $_caller_matches(regexp [, number_of_frames])
743 ** $_any_caller_is(name [, number_of_frames])
744 ** $_any_caller_matches(regexp [, number_of_frames])
746 * GDB now supports the compilation and injection of source code into
747 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
748 to compile the source code to object code, and if successful, inject
749 and execute that code within the current context of the inferior.
750 Currently the C language is supported. The commands used to
751 interface with this new feature are:
753 compile code [-raw|-r] [--] [source code]
754 compile file [-raw|-r] filename
758 demangle [-l language] [--] name
759 Demangle "name" in the specified language, or the current language
760 if elided. This command is renamed from the "maint demangle" command.
761 The latter is kept as a no-op to avoid "maint demangle" being interpreted
762 as "maint demangler-warning".
764 queue-signal signal-name-or-number
765 Queue a signal to be delivered to the thread when it is resumed.
767 add-auto-load-scripts-directory directory
768 Add entries to the list of directories from which to load auto-loaded
771 maint print user-registers
772 List all currently available "user" registers.
774 compile code [-r|-raw] [--] [source code]
775 Compile, inject, and execute in the inferior the executable object
776 code produced by compiling the provided source code.
778 compile file [-r|-raw] filename
779 Compile and inject into the inferior the executable object code
780 produced by compiling the source code stored in the filename
783 * On resume, GDB now always passes the signal the program had stopped
784 for to the thread the signal was sent to, even if the user changed
785 threads before resuming. Previously GDB would often (but not
786 always) deliver the signal to the thread that happens to be current
789 * Conversely, the "signal" command now consistently delivers the
790 requested signal to the current thread. GDB now asks for
791 confirmation if the program had stopped for a signal and the user
792 switched threads meanwhile.
794 * "breakpoint always-inserted" modes "off" and "auto" merged.
796 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
797 won't remove breakpoints from the target until all threads stop,
798 even in non-stop mode. The "auto" mode has been removed, and "off"
799 is now the default mode.
803 set debug symbol-lookup
804 show debug symbol-lookup
805 Control display of debugging info regarding symbol lookup.
809 ** The -list-thread-groups command outputs an exit-code field for
810 inferiors that have exited.
814 MIPS SDE mips*-sde*-elf*
818 Support for these obsolete configurations has been removed.
820 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
821 SGI Irix-5.x mips-*-irix5*
822 SGI Irix-6.x mips-*-irix6*
823 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
824 VAX running Ultrix vax-*-ultrix*
826 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
827 and "assf"), have been removed. Use the "sharedlibrary" command, or
828 its alias "share", instead.
830 *** Changes in GDB 7.8
832 * New command line options
835 This is an alias for the --data-directory option.
837 * GDB supports printing and modifying of variable length automatic arrays
838 as specified in ISO C99.
840 * The ARM simulator now supports instruction level tracing
841 with or without disassembly.
845 GDB now has support for scripting using Guile. Whether this is
846 available is determined at configure time.
847 Guile version 2.0 or greater is required.
848 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
850 * New commands (for set/show, see "New options" below)
854 Invoke CODE by passing it to the Guile interpreter.
858 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
860 info auto-load guile-scripts [regexp]
861 Print the list of automatically loaded Guile scripts.
863 * The source command is now capable of sourcing Guile scripts.
864 This feature is dependent on the debugger being built with Guile support.
868 set print symbol-loading (off|brief|full)
869 show print symbol-loading
870 Control whether to print informational messages when loading symbol
871 information for a file. The default is "full", but when debugging
872 programs with large numbers of shared libraries the amount of output
875 set guile print-stack (none|message|full)
876 show guile print-stack
877 Show a stack trace when an error is encountered in a Guile script.
879 set auto-load guile-scripts (on|off)
880 show auto-load guile-scripts
881 Control auto-loading of Guile script files.
883 maint ada set ignore-descriptive-types (on|off)
884 maint ada show ignore-descriptive-types
885 Control whether the debugger should ignore descriptive types in Ada
886 programs. The default is not to ignore the descriptive types. See
887 the user manual for more details on descriptive types and the intended
888 usage of this option.
890 set auto-connect-native-target
892 Control whether GDB is allowed to automatically connect to the
893 native target for the run, attach, etc. commands when not connected
894 to any target yet. See also "target native" below.
896 set record btrace replay-memory-access (read-only|read-write)
897 show record btrace replay-memory-access
898 Control what memory accesses are allowed during replay.
900 maint set target-async (on|off)
901 maint show target-async
902 This controls whether GDB targets operate in synchronous or
903 asynchronous mode. Normally the default is asynchronous, if it is
904 available; but this can be changed to more easily debug problems
905 occurring only in synchronous mode.
907 set mi-async (on|off)
909 Control whether MI asynchronous mode is preferred. This supersedes
910 "set target-async" of previous GDB versions.
912 * "set target-async" is deprecated as a CLI option and is now an alias
913 for "set mi-async" (only puts MI into async mode).
915 * Background execution commands (e.g., "c&", "s&", etc.) are now
916 possible ``out of the box'' if the target supports them. Previously
917 the user would need to explicitly enable the possibility with the
918 "set target-async on" command.
920 * New features in the GDB remote stub, GDBserver
922 ** New option --debug-format=option1[,option2,...] allows one to add
923 additional text to each output. At present only timestamps
924 are supported: --debug-format=timestamps.
925 Timestamps can also be turned on with the
926 "monitor set debug-format timestamps" command from GDB.
928 * The 'record instruction-history' command now starts counting instructions
929 at one. This also affects the instruction ranges reported by the
930 'record function-call-history' command when given the /i modifier.
932 * The command 'record function-call-history' supports a new modifier '/c' to
933 indent the function names based on their call stack depth.
934 The fields for the '/i' and '/l' modifier have been reordered.
935 The source line range is now prefixed with 'at'.
936 The instruction range is now prefixed with 'inst'.
937 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
938 "record instruction-history" and "list" commands.
940 * The ranges given as arguments to the 'record function-call-history' and
941 'record instruction-history' commands are now inclusive.
943 * The btrace record target now supports the 'record goto' command.
944 For locations inside the execution trace, the back trace is computed
945 based on the information stored in the execution trace.
947 * The btrace record target supports limited reverse execution and replay.
948 The target does not record data and therefore does not allow reading
951 * The "catch syscall" command now works on s390*-linux* targets.
953 * The "compare-sections" command is no longer specific to target
954 remote. It now works with all targets.
956 * All native targets are now consistently called "native".
957 Consequently, the "target child", "target GNU", "target djgpp",
958 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
959 commands have been replaced with "target native". The QNX/NTO port
960 leaves the "procfs" target in place and adds a "native" target for
961 consistency with other ports. The impact on users should be minimal
962 as these commands previously either throwed an error, or were
963 no-ops. The target's name is visible in the output of the following
964 commands: "help target", "info target", "info files", "maint print
967 * The "target native" command now connects to the native target. This
968 can be used to launch native programs even when "set
969 auto-connect-native-target" is set to off.
971 * GDB now supports access to Intel MPX registers on GNU/Linux.
973 * Support for Intel AVX-512 registers on GNU/Linux.
974 Support displaying and modifying Intel AVX-512 registers
975 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
979 qXfer:btrace:read's annex
980 The qXfer:btrace:read packet supports a new annex 'delta' to read
981 branch trace incrementally.
985 ** Valid Python operations on gdb.Value objects representing
986 structs/classes invoke the corresponding overloaded operators if
988 ** New `Xmethods' feature in the Python API. Xmethods are
989 additional methods or replacements for existing methods of a C++
990 class. This feature is useful for those cases where a method
991 defined in C++ source code could be inlined or optimized out by
992 the compiler, making it unavailable to GDB.
995 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
997 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
998 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
999 its alias "share", instead.
1001 * The commands "set remotebaud" and "show remotebaud" are no longer
1002 supported. Use "set serial baud" and "show serial baud" (respectively)
1007 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1008 target-async". The latter is left as a deprecated alias of the
1009 former for backward compatibility. If the target supports it,
1010 CLI background execution commands are now always possible by
1011 default, independently of whether the frontend stated a
1012 preference for asynchronous execution with "-gdb-set mi-async".
1013 Previously "-gdb-set target-async off" affected both MI execution
1014 commands and CLI execution commands.
1016 *** Changes in GDB 7.7
1018 * Improved support for process record-replay and reverse debugging on
1019 arm*-linux* targets. Support for thumb32 and syscall instruction
1020 recording has been added.
1022 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1024 * GDB now supports Fission DWP file format version 2.
1025 http://gcc.gnu.org/wiki/DebugFission
1027 * New convenience function "$_isvoid", to check whether an expression
1028 is void. A void expression is an expression where the type of the
1029 result is "void". For example, some convenience variables may be
1030 "void" when evaluated (e.g., "$_exitcode" before the execution of
1031 the program being debugged; or an undefined convenience variable).
1032 Another example, when calling a function whose return type is
1035 * The "maintenance print objfiles" command now takes an optional regexp.
1037 * The "catch syscall" command now works on arm*-linux* targets.
1039 * GDB now consistently shows "<not saved>" when printing values of
1040 registers the debug info indicates have not been saved in the frame
1041 and there's nowhere to retrieve them from
1042 (callee-saved/call-clobbered registers):
1047 (gdb) info registers rax
1050 Before, the former would print "<optimized out>", and the latter
1051 "*value not available*".
1053 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1058 ** Frame filters and frame decorators have been added.
1059 ** Temporary breakpoints are now supported.
1060 ** Line tables representation has been added.
1061 ** New attribute 'parent_type' for gdb.Field objects.
1062 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1063 ** New attribute 'name' for gdb.Type objects.
1067 Nios II ELF nios2*-*-elf
1068 Nios II GNU/Linux nios2*-*-linux
1069 Texas Instruments MSP430 msp430*-*-elf
1071 * Removed native configurations
1073 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1074 been removed. ELF variants of these configurations are kept supported.
1076 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1077 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1078 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1079 i[34567]86-*-openbsd3.[0-3]
1080 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1081 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1082 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1086 Like "catch throw", but catches a re-thrown exception.
1087 maint check-psymtabs
1088 Renamed from old "maint check-symtabs".
1090 Perform consistency checks on symtabs.
1091 maint expand-symtabs
1092 Expand symtabs matching an optional regexp.
1095 Display the details of GDB configure-time options.
1097 maint set|show per-command
1098 maint set|show per-command space
1099 maint set|show per-command time
1100 maint set|show per-command symtab
1101 Enable display of per-command gdb resource usage.
1103 remove-symbol-file FILENAME
1104 remove-symbol-file -a ADDRESS
1105 Remove a symbol file added via add-symbol-file. The file to remove
1106 can be identified by its filename or by an address that lies within
1107 the boundaries of this symbol file in memory.
1110 info exceptions REGEXP
1111 Display the list of Ada exceptions defined in the program being
1112 debugged. If provided, only the exceptions whose names match REGEXP
1117 set debug symfile off|on
1119 Control display of debugging info regarding reading symbol files and
1120 symbol tables within those files
1122 set print raw frame-arguments
1123 show print raw frame-arguments
1124 Set/show whether to print frame arguments in raw mode,
1125 disregarding any defined pretty-printers.
1127 set remote trace-status-packet
1128 show remote trace-status-packet
1129 Set/show the use of remote protocol qTStatus packet.
1133 Control display of debugging messages related to Nios II targets.
1137 Control whether target-assisted range stepping is enabled.
1139 set startup-with-shell
1140 show startup-with-shell
1141 Specifies whether Unix child processes are started via a shell or
1146 Use the target memory cache for accesses to the code segment. This
1147 improves performance of remote debugging (particularly disassembly).
1149 * You can now use a literal value 'unlimited' for options that
1150 interpret 0 or -1 as meaning "unlimited". E.g., "set
1151 trace-buffer-size unlimited" is now an alias for "set
1152 trace-buffer-size -1" and "set height unlimited" is now an alias for
1155 * The "set debug symtab-create" debugging option of GDB has been changed to
1156 accept a verbosity level. 0 means "off", 1 provides basic debugging
1157 output, and values of 2 or greater provides more verbose output.
1159 * New command-line options
1161 Display the details of GDB configure-time options.
1163 * The command 'tsave' can now support new option '-ctf' to save trace
1164 buffer in Common Trace Format.
1166 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1169 * GDB now implements the the C++ 'typeid' operator.
1171 * The new convenience variable $_exception holds the exception being
1172 thrown or caught at an exception-related catchpoint.
1174 * The exception-related catchpoints, like "catch throw", now accept a
1175 regular expression which can be used to filter exceptions by type.
1177 * The new convenience variable $_exitsignal is automatically set to
1178 the terminating signal number when the program being debugged dies
1179 due to an uncaught signal.
1183 ** All MI commands now accept an optional "--language" option.
1184 Support for this feature can be verified by using the "-list-features"
1185 command, which should contain "language-option".
1187 ** The new command -info-gdb-mi-command allows the user to determine
1188 whether a GDB/MI command is supported or not.
1190 ** The "^error" result record returned when trying to execute an undefined
1191 GDB/MI command now provides a variable named "code" whose content is the
1192 "undefined-command" error code. Support for this feature can be verified
1193 by using the "-list-features" command, which should contain
1194 "undefined-command-error-code".
1196 ** The -trace-save MI command can optionally save trace buffer in Common
1199 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1201 ** The command -data-list-register-values now accepts an optional
1202 "--skip-unavailable" option. When used, only the available registers
1205 ** The new command -trace-frame-collected dumps collected variables,
1206 computed expressions, tvars, memory and registers in a traceframe.
1208 ** The commands -stack-list-locals, -stack-list-arguments and
1209 -stack-list-variables now accept an option "--skip-unavailable".
1210 When used, only the available locals or arguments are displayed.
1212 ** The -exec-run command now accepts an optional "--start" option.
1213 When used, the command follows the same semantics as the "start"
1214 command, stopping the program's execution at the start of its
1215 main subprogram. Support for this feature can be verified using
1216 the "-list-features" command, which should contain
1217 "exec-run-start-option".
1219 ** The new commands -catch-assert and -catch-exceptions insert
1220 catchpoints stopping the program when Ada exceptions are raised.
1222 ** The new command -info-ada-exceptions provides the equivalent of
1223 the new "info exceptions" command.
1225 * New system-wide configuration scripts
1226 A GDB installation now provides scripts suitable for use as system-wide
1227 configuration scripts for the following systems:
1231 * GDB now supports target-assigned range stepping with remote targets.
1232 This improves the performance of stepping source lines by reducing
1233 the number of control packets from/to GDB. See "New remote packets"
1236 * GDB now understands the element 'tvar' in the XML traceframe info.
1237 It has the id of the collected trace state variables.
1239 * On S/390 targets that provide the transactional-execution feature,
1240 the program interruption transaction diagnostic block (TDB) is now
1241 represented as a number of additional "registers" in GDB.
1243 * New remote packets
1247 The vCont packet supports a new 'r' action, that tells the remote
1248 stub to step through an address range itself, without GDB
1249 involvemement at each single-step.
1251 qXfer:libraries-svr4:read's annex
1252 The previously unused annex of the qXfer:libraries-svr4:read packet
1253 is now used to support passing an argument list. The remote stub
1254 reports support for this argument list to GDB's qSupported query.
1255 The defined arguments are "start" and "prev", used to reduce work
1256 necessary for library list updating, resulting in significant
1259 * New features in the GDB remote stub, GDBserver
1261 ** GDBserver now supports target-assisted range stepping. Currently
1262 enabled on x86/x86_64 GNU/Linux targets.
1264 ** GDBserver now adds element 'tvar' in the XML in the reply to
1265 'qXfer:traceframe-info:read'. It has the id of the collected
1266 trace state variables.
1268 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1271 * New 'z' formatter for printing and examining memory, this displays the
1272 value as hexadecimal zero padded on the left to the size of the type.
1274 * GDB can now use Windows x64 unwinding data.
1276 * The "set remotebaud" command has been replaced by "set serial baud".
1277 Similarly, "show remotebaud" has been replaced by "show serial baud".
1278 The "set remotebaud" and "show remotebaud" commands are still available
1279 to provide backward compatibility with older versions of GDB.
1281 *** Changes in GDB 7.6
1283 * Target record has been renamed to record-full.
1284 Record/replay is now enabled with the "record full" command.
1285 This also affects settings that are associated with full record/replay
1286 that have been moved from "set/show record" to "set/show record full":
1288 set|show record full insn-number-max
1289 set|show record full stop-at-limit
1290 set|show record full memory-query
1292 * A new record target "record-btrace" has been added. The new target
1293 uses hardware support to record the control-flow of a process. It
1294 does not support replaying the execution, but it implements the
1295 below new commands for investigating the recorded execution log.
1296 This new recording method can be enabled using:
1300 The "record-btrace" target is only available on Intel Atom processors
1301 and requires a Linux kernel 2.6.32 or later.
1303 * Two new commands have been added for record/replay to give information
1304 about the recorded execution without having to replay the execution.
1305 The commands are only supported by "record btrace".
1307 record instruction-history prints the execution history at
1308 instruction granularity
1310 record function-call-history prints the execution history at
1311 function granularity
1313 * New native configurations
1315 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1316 FreeBSD/powerpc powerpc*-*-freebsd
1317 x86_64/Cygwin x86_64-*-cygwin*
1318 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1322 ARM AArch64 aarch64*-*-elf
1323 ARM AArch64 GNU/Linux aarch64*-*-linux
1324 Lynx 178 PowerPC powerpc-*-lynx*178
1325 x86_64/Cygwin x86_64-*-cygwin*
1326 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1328 * If the configured location of system.gdbinit file (as given by the
1329 --with-system-gdbinit option at configure time) is in the
1330 data-directory (as specified by --with-gdb-datadir at configure
1331 time) or in one of its subdirectories, then GDB will look for the
1332 system-wide init file in the directory specified by the
1333 --data-directory command-line option.
1335 * New command line options:
1337 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1338 other initialization files, unlike -nx which disables all of them.
1340 * Removed command line options
1342 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1345 * The 'ptype' and 'whatis' commands now accept an argument to control
1348 * 'info proc' now works on some core files.
1352 ** Vectors can be created with gdb.Type.vector.
1354 ** Python's atexit.register now works in GDB.
1356 ** Types can be pretty-printed via a Python API.
1358 ** Python 3 is now supported (in addition to Python 2.4 or later)
1360 ** New class gdb.Architecture exposes GDB's internal representation
1361 of architecture in the Python API.
1363 ** New method Frame.architecture returns the gdb.Architecture object
1364 corresponding to the frame's architecture.
1366 * New Python-based convenience functions:
1368 ** $_memeq(buf1, buf2, length)
1369 ** $_streq(str1, str2)
1371 ** $_regex(str, regex)
1373 * The 'cd' command now defaults to using '~' (the home directory) if not
1376 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1377 default for GCC since November 2000.
1379 * The command 'forward-search' can now be abbreviated as 'fo'.
1381 * The command 'info tracepoints' can now display 'installed on target'
1382 or 'not installed on target' for each non-pending location of tracepoint.
1384 * New configure options
1386 --enable-libmcheck/--disable-libmcheck
1387 By default, development versions are built with -lmcheck on hosts
1388 that support it, in order to help track memory corruption issues.
1389 Release versions, on the other hand, are built without -lmcheck
1390 by default. The --enable-libmcheck/--disable-libmcheck configure
1391 options allow the user to override that default.
1392 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1393 This configure option allows the user to build GDB with
1394 libbabeltrace using which GDB can read Common Trace Format data.
1396 * New commands (for set/show, see "New options" below)
1399 Catch signals. This is similar to "handle", but allows commands and
1400 conditions to be attached.
1403 List the BFDs known to GDB.
1405 python-interactive [command]
1407 Start a Python interactive prompt, or evaluate the optional command
1408 and print the result of expressions.
1411 "py" is a new alias for "python".
1413 enable type-printer [name]...
1414 disable type-printer [name]...
1415 Enable or disable type printers.
1419 ** For the Renesas Super-H architecture, the "regs" command has been removed
1420 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1425 set print type methods (on|off)
1426 show print type methods
1427 Control whether method declarations are displayed by "ptype".
1428 The default is to show them.
1430 set print type typedefs (on|off)
1431 show print type typedefs
1432 Control whether typedef definitions are displayed by "ptype".
1433 The default is to show them.
1435 set filename-display basename|relative|absolute
1436 show filename-display
1437 Control the way in which filenames is displayed.
1438 The default is "relative", which preserves previous behavior.
1440 set trace-buffer-size
1441 show trace-buffer-size
1442 Request target to change the size of trace buffer.
1444 set remote trace-buffer-size-packet auto|on|off
1445 show remote trace-buffer-size-packet
1446 Control the use of the remote protocol `QTBuffer:size' packet.
1450 Control display of debugging messages related to ARM AArch64.
1453 set debug coff-pe-read
1454 show debug coff-pe-read
1455 Control display of debugging messages related to reading of COFF/PE
1460 Control display of debugging messages related to Mach-O symbols
1463 set debug notification
1464 show debug notification
1465 Control display of debugging info for async remote notification.
1469 ** Command parameter changes are now notified using new async record
1470 "=cmd-param-changed".
1471 ** Trace frame changes caused by command "tfind" are now notified using
1472 new async record "=traceframe-changed".
1473 ** The creation, deletion and modification of trace state variables
1474 are now notified using new async records "=tsv-created",
1475 "=tsv-deleted" and "=tsv-modified".
1476 ** The start and stop of process record are now notified using new
1477 async record "=record-started" and "=record-stopped".
1478 ** Memory changes are now notified using new async record
1480 ** The data-disassemble command response will include a "fullname" field
1481 containing the absolute file name when source has been requested.
1482 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1483 command, to allow pattern filling of memory areas.
1484 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1485 library load/unload events.
1486 ** The response to breakpoint commands and breakpoint async records
1487 includes an "installed" field containing a boolean state about each
1488 non-pending tracepoint location is whether installed on target or not.
1489 ** Output of the "-trace-status" command includes a "trace-file" field
1490 containing the name of the trace file being examined. This field is
1491 optional, and only present when examining a trace file.
1492 ** The "fullname" field is now always present along with the "file" field,
1493 even if the file cannot be found by GDB.
1495 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1496 You must have the LZMA library available when configuring GDB for this
1497 feature to be enabled. For more information, see:
1498 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1500 * New remote packets
1503 Set the size of trace buffer. The remote stub reports support for this
1504 packet to gdb's qSupported query.
1507 Enable Branch Trace Store (BTS)-based branch tracing for the current
1508 thread. The remote stub reports support for this packet to gdb's
1512 Disable branch tracing for the current thread. The remote stub reports
1513 support for this packet to gdb's qSupported query.
1516 Read the traced branches for the current thread. The remote stub
1517 reports support for this packet to gdb's qSupported query.
1519 *** Changes in GDB 7.5
1521 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1522 for more x32 ABI info.
1524 * GDB now supports access to MIPS DSP registers on Linux targets.
1526 * GDB now supports debugging microMIPS binaries.
1528 * The "info os" command on GNU/Linux can now display information on
1529 several new classes of objects managed by the operating system:
1530 "info os procgroups" lists process groups
1531 "info os files" lists file descriptors
1532 "info os sockets" lists internet-domain sockets
1533 "info os shm" lists shared-memory regions
1534 "info os semaphores" lists semaphores
1535 "info os msg" lists message queues
1536 "info os modules" lists loaded kernel modules
1538 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1539 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1540 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1541 options and inspect the probe arguments using the new $_probe_arg family
1542 of convenience variables. You can obtain more information about SystemTap
1543 in <http://sourceware.org/systemtap/>.
1545 * GDB now supports reversible debugging on ARM, it allows you to
1546 debug basic ARM and THUMB instructions, and provides
1547 record/replay support.
1549 * The option "symbol-reloading" has been deleted as it is no longer used.
1553 ** GDB commands implemented in Python can now be put in command class
1556 ** The "maint set python print-stack on|off" is now deleted.
1558 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1559 apply "flag enum"-style pretty-printing to any enum.
1561 ** gdb.lookup_symbol can now work when there is no current frame.
1563 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1564 the source at which the symbol was defined.
1566 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1567 method 'value'. The former indicates whether the symbol needs a
1568 frame in order to compute its value, and the latter computes the
1571 ** A new method 'referenced_value' on gdb.Value objects which can
1572 dereference pointer as well as C++ reference values.
1574 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1575 which return the global and static blocks (as gdb.Block objects),
1576 of the underlying symbol table, respectively.
1578 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1579 object associated with a PC value.
1581 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1582 of the address range occupied by code for the current source line.
1584 * Go language support.
1585 GDB now supports debugging programs written in the Go programming
1588 * GDBserver now supports stdio connections.
1589 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1591 * The binary "gdbtui" can no longer be built or installed.
1592 Use "gdb -tui" instead.
1594 * GDB will now print "flag" enums specially. A flag enum is one where
1595 all the enumerator values have no bits in common when pairwise
1596 "and"ed. When printing a value whose type is a flag enum, GDB will
1597 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1598 (gdb) print (enum E) 3
1601 * The filename part of a linespec will now match trailing components
1602 of a source file name. For example, "break gcc/expr.c:1000" will
1603 now set a breakpoint in build/gcc/expr.c, but not
1604 build/libcpp/expr.c.
1606 * The "info proc" and "generate-core-file" commands will now also
1607 work on remote targets connected to GDBserver on Linux.
1609 * The command "info catch" has been removed. It has been disabled
1610 since December 2007.
1612 * The "catch exception" and "catch assert" commands now accept
1613 a condition at the end of the command, much like the "break"
1614 command does. For instance:
1616 (gdb) catch exception Constraint_Error if Barrier = True
1618 Previously, it was possible to add a condition to such catchpoints,
1619 but it had to be done as a second step, after the catchpoint had been
1620 created, using the "condition" command.
1622 * The "info static-tracepoint-marker" command will now also work on
1623 native Linux targets with in-process agent.
1625 * GDB can now set breakpoints on inlined functions.
1627 * The .gdb_index section has been updated to include symbols for
1628 inlined functions. GDB will ignore older .gdb_index sections by
1629 default, which could cause symbol files to be loaded more slowly
1630 until their .gdb_index sections can be recreated. The new command
1631 "set use-deprecated-index-sections on" will cause GDB to use any older
1632 .gdb_index sections it finds. This will restore performance, but the
1633 ability to set breakpoints on inlined functions will be lost in symbol
1634 files with older .gdb_index sections.
1636 The .gdb_index section has also been updated to record more information
1637 about each symbol. This speeds up the "info variables", "info functions"
1638 and "info types" commands when used with programs having the .gdb_index
1639 section, as well as speeding up debugging with shared libraries using
1640 the .gdb_index section.
1642 * Ada support for GDB/MI Variable Objects has been added.
1644 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1649 ** New command -info-os is the MI equivalent of "info os".
1651 ** Output logs ("set logging" and related) now include MI output.
1655 ** "set use-deprecated-index-sections on|off"
1656 "show use-deprecated-index-sections on|off"
1657 Controls the use of deprecated .gdb_index sections.
1659 ** "catch load" and "catch unload" can be used to stop when a shared
1660 library is loaded or unloaded, respectively.
1662 ** "enable count" can be used to auto-disable a breakpoint after
1665 ** "info vtbl" can be used to show the virtual method tables for
1666 C++ and Java objects.
1668 ** "explore" and its sub commands "explore value" and "explore type"
1669 can be used to recursively explore values and types of
1670 expressions. These commands are available only if GDB is
1671 configured with '--with-python'.
1673 ** "info auto-load" shows status of all kinds of auto-loaded files,
1674 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1675 sequences of commands files, "info auto-load python-scripts"
1676 shows status of auto-loading Python script files,
1677 "info auto-load local-gdbinit" shows status of loading init file
1678 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1679 status of inferior specific thread debugging shared library loading.
1681 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1682 and "show auto-load-scripts" commands have been deprecated, use their
1683 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1684 and "show auto-load python-scripts" counterparts instead.
1686 ** "dprintf location,format,args..." creates a dynamic printf, which
1687 is basically a breakpoint that does a printf and immediately
1688 resumes your program's execution, so it is like a printf that you
1689 can insert dynamically at runtime instead of at compiletime.
1691 ** "set print symbol"
1693 Controls whether GDB attempts to display the symbol, if any,
1694 corresponding to addresses it prints. This defaults to "on", but
1695 you can set it to "off" to restore GDB's previous behavior.
1697 * Deprecated commands
1699 ** For the Renesas Super-H architecture, the "regs" command has been
1700 deprecated, and "info all-registers" should be used instead.
1704 Renesas RL78 rl78-*-elf
1705 HP OpenVMS ia64 ia64-hp-openvms*
1707 * GDBserver supports evaluation of breakpoint conditions. When
1708 support is advertised by GDBserver, GDB may be told to send the
1709 breakpoint conditions in bytecode form to GDBserver. GDBserver
1710 will only report the breakpoint trigger to GDB when its condition
1715 set mips compression
1716 show mips compression
1717 Select the compressed ISA encoding used in functions that have no symbol
1718 information available. The encoding can be set to either of:
1721 and is updated automatically from ELF file flags if available.
1723 set breakpoint condition-evaluation
1724 show breakpoint condition-evaluation
1725 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1726 GDBserver ("target"). Default option "auto" chooses the most efficient
1728 This option can improve debugger efficiency depending on the speed of the
1732 Disable auto-loading globally.
1735 Show auto-loading setting of all kinds of auto-loaded files.
1737 set auto-load gdb-scripts on|off
1738 show auto-load gdb-scripts
1739 Control auto-loading of GDB canned sequences of commands files.
1741 set auto-load python-scripts on|off
1742 show auto-load python-scripts
1743 Control auto-loading of Python script files.
1745 set auto-load local-gdbinit on|off
1746 show auto-load local-gdbinit
1747 Control loading of init file (.gdbinit) from current directory.
1749 set auto-load libthread-db on|off
1750 show auto-load libthread-db
1751 Control auto-loading of inferior specific thread debugging shared library.
1753 set auto-load scripts-directory <dir1>[:<dir2>...]
1754 show auto-load scripts-directory
1755 Set a list of directories from which to load auto-loaded scripts.
1756 Automatically loaded Python scripts and GDB scripts are located in one
1757 of the directories listed by this option.
1758 The delimiter (':' above) may differ according to the host platform.
1760 set auto-load safe-path <dir1>[:<dir2>...]
1761 show auto-load safe-path
1762 Set a list of directories from which it is safe to auto-load files.
1763 The delimiter (':' above) may differ according to the host platform.
1765 set debug auto-load on|off
1766 show debug auto-load
1767 Control display of debugging info for auto-loading the files above.
1769 set dprintf-style gdb|call|agent
1771 Control the way in which a dynamic printf is performed; "gdb"
1772 requests a GDB printf command, while "call" causes dprintf to call a
1773 function in the inferior. "agent" requests that the target agent
1774 (such as GDBserver) do the printing.
1776 set dprintf-function <expr>
1777 show dprintf-function
1778 set dprintf-channel <expr>
1779 show dprintf-channel
1780 Set the function and optional first argument to the call when using
1781 the "call" style of dynamic printf.
1783 set disconnected-dprintf on|off
1784 show disconnected-dprintf
1785 Control whether agent-style dynamic printfs continue to be in effect
1786 after GDB disconnects.
1788 * New configure options
1790 --with-auto-load-dir
1791 Configure default value for the 'set auto-load scripts-directory'
1792 setting above. It defaults to '$debugdir:$datadir/auto-load',
1793 $debugdir representing global debugging info directories (available
1794 via 'show debug-file-directory') and $datadir representing GDB's data
1795 directory (available via 'show data-directory').
1797 --with-auto-load-safe-path
1798 Configure default value for the 'set auto-load safe-path' setting
1799 above. It defaults to the --with-auto-load-dir setting.
1801 --without-auto-load-safe-path
1802 Set 'set auto-load safe-path' to '/', effectively disabling this
1805 * New remote packets
1807 z0/z1 conditional breakpoints extension
1809 The z0/z1 breakpoint insertion packets have been extended to carry
1810 a list of conditional expressions over to the remote stub depending on the
1811 condition evaluation mode. The use of this extension can be controlled
1812 via the "set remote conditional-breakpoints-packet" command.
1816 Specify the signals which the remote stub may pass to the debugged
1817 program without GDB involvement.
1819 * New command line options
1821 --init-command=FILE, -ix Like --command, -x but execute it
1822 before loading inferior.
1823 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1824 execute it before loading inferior.
1826 *** Changes in GDB 7.4
1828 * GDB now handles ambiguous linespecs more consistently; the existing
1829 FILE:LINE support has been expanded to other types of linespecs. A
1830 breakpoint will now be set on all matching locations in all
1831 inferiors, and locations will be added or removed according to
1834 * GDB now allows you to skip uninteresting functions and files when
1835 stepping with the "skip function" and "skip file" commands.
1837 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1838 and "show remote hardware-watchpoint-length-limit". These allows to
1839 set or show the maximum length limit (in bytes) of a remote
1840 target hardware watchpoint.
1842 This allows e.g. to use "unlimited" hardware watchpoints with the
1843 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1844 watchpoints are slower than real hardware watchpoints but are
1845 significantly faster than gdb software watchpoints.
1849 ** The register_pretty_printer function in module gdb.printing now takes
1850 an optional `replace' argument. If True, the new printer replaces any
1853 ** The "maint set python print-stack on|off" command has been
1854 deprecated and will be deleted in GDB 7.5.
1855 A new command: "set python print-stack none|full|message" has
1856 replaced it. Additionally, the default for "print-stack" is
1857 now "message", which just prints the error message without
1860 ** A prompt substitution hook (prompt_hook) is now available to the
1863 ** A new Python module, gdb.prompt has been added to the GDB Python
1864 modules library. This module provides functionality for
1865 escape sequences in prompts (used by set/show
1866 extended-prompt). These escape sequences are replaced by their
1867 corresponding value.
1869 ** Python commands and convenience-functions located in
1870 'data-directory'/python/gdb/command and
1871 'data-directory'/python/gdb/function are now automatically loaded
1874 ** Blocks now provide four new attributes. global_block and
1875 static_block will return the global and static blocks
1876 respectively. is_static and is_global are boolean attributes
1877 that indicate if the block is one of those two types.
1879 ** Symbols now provide the "type" attribute, the type of the symbol.
1881 ** The "gdb.breakpoint" function has been deprecated in favor of
1884 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1885 of a function. This class is based on the "finish" command
1886 available in the CLI.
1888 ** Type objects for struct and union types now allow access to
1889 the fields using standard Python dictionary (mapping) methods.
1890 For example, "some_type['myfield']" now works, as does
1891 "some_type.items()".
1893 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1896 ** A new function, "deep_items" has been added to the gdb.types
1897 module in the GDB Python modules library. This function returns
1898 an iterator over the fields of a struct or union type. Unlike
1899 the standard Python "iteritems" method, it will recursively traverse
1900 any anonymous fields.
1904 ** "*stopped" events can report several new "reason"s, such as
1907 ** Breakpoint changes are now notified using new async records, like
1908 "=breakpoint-modified".
1910 ** New command -ada-task-info.
1912 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1913 $sdir specifies the default system locations of shared libraries.
1914 $pdir specifies the directory where the libpthread used by the application
1917 GDB no longer looks in $sdir and $pdir after it has searched the directories
1918 mentioned in libthread-db-search-path. If you want to search those
1919 directories, they must be specified in libthread-db-search-path.
1920 The default value of libthread-db-search-path on GNU/Linux and Solaris
1921 systems is now "$sdir:$pdir".
1923 $pdir is not supported by gdbserver, it is currently ignored.
1924 $sdir is supported by gdbserver.
1926 * New configure option --with-iconv-bin.
1927 When using the internationalization support like the one in the GNU C
1928 library, GDB will invoke the "iconv" program to get a list of supported
1929 character sets. If this program lives in a non-standard location, one can
1930 use this option to specify where to find it.
1932 * When natively debugging programs on PowerPC BookE processors running
1933 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1934 watchpoints, which specify a mask in addition to an address to watch.
1935 The mask specifies that some bits of an address (the bits which are
1936 reset in the mask) should be ignored when matching the address accessed
1937 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1938 section in the user manual for more details.
1940 * The new option --once causes GDBserver to stop listening for connections once
1941 the first connection is made. The listening port used by GDBserver will
1942 become available after that.
1944 * New commands "info macros" and "alias" have been added.
1946 * New function parameters suffix @entry specifies value of function parameter
1947 at the time the function got called. Entry values are available only since
1953 "!" is now an alias of the "shell" command.
1954 Note that no space is needed between "!" and SHELL COMMAND.
1958 watch EXPRESSION mask MASK_VALUE
1959 The watch command now supports the mask argument which allows creation
1960 of masked watchpoints, if the current architecture supports this feature.
1962 info auto-load-scripts [REGEXP]
1963 This command was formerly named "maintenance print section-scripts".
1964 It is now generally useful and is no longer a maintenance-only command.
1966 info macro [-all] [--] MACRO
1967 The info macro command has new options `-all' and `--'. The first for
1968 printing all definitions of a macro. The second for explicitly specifying
1969 the end of arguments and the beginning of the macro name in case the macro
1970 name starts with a hyphen.
1972 collect[/s] EXPRESSIONS
1973 The tracepoint collect command now takes an optional modifier "/s"
1974 that directs it to dereference pointer-to-character types and
1975 collect the bytes of memory up to a zero byte. The behavior is
1976 similar to what you see when you use the regular print command on a
1977 string. An optional integer following the "/s" sets a bound on the
1978 number of bytes that will be collected.
1981 The trace start command now interprets any supplied arguments as a
1982 note to be recorded with the trace run, with an effect similar to
1983 setting the variable trace-notes.
1986 The trace stop command now interprets any arguments as a note to be
1987 mentioned along with the tstatus report that the trace was stopped
1988 with a command. The effect is similar to setting the variable
1991 * Tracepoints can now be enabled and disabled at any time after a trace
1992 experiment has been started using the standard "enable" and "disable"
1993 commands. It is now possible to start a trace experiment with no enabled
1994 tracepoints; GDB will display a warning, but will allow the experiment to
1995 begin, assuming that tracepoints will be enabled as needed while the trace
1998 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1999 locations with 4-byte instructions, when they were previously
2000 limited to locations with instructions of 5 bytes or longer.
2004 set debug dwarf2-read
2005 show debug dwarf2-read
2006 Turns on or off display of debugging messages related to reading
2007 DWARF debug info. The default is off.
2009 set debug symtab-create
2010 show debug symtab-create
2011 Turns on or off display of debugging messages related to symbol table
2012 creation. The default is off.
2015 show extended-prompt
2016 Set the GDB prompt, and allow escape sequences to be inserted to
2017 display miscellaneous information (see 'help set extended-prompt'
2018 for the list of sequences). This prompt (and any information
2019 accessed through the escape sequences) is updated every time the
2020 prompt is displayed.
2022 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2023 show print entry-values
2024 Set printing of frame argument values at function entry. In some cases
2025 GDB can determine the value of function argument which was passed by the
2026 function caller, even if the value was modified inside the called function.
2028 set debug entry-values
2029 show debug entry-values
2030 Control display of debugging info for determining frame argument values at
2031 function entry and virtual tail call frames.
2033 set basenames-may-differ
2034 show basenames-may-differ
2035 Set whether a source file may have multiple base names.
2036 (A "base name" is the name of a file with the directory part removed.
2037 Example: The base name of "/home/user/hello.c" is "hello.c".)
2038 If set, GDB will canonicalize file names (e.g., expand symlinks)
2039 before comparing them. Canonicalization is an expensive operation,
2040 but it allows the same file be known by more than one base name.
2041 If not set (the default), all source files are assumed to have just
2042 one base name, and gdb will do file name comparisons more efficiently.
2048 Set a user name and notes for the current and any future trace runs.
2049 This is useful for long-running and/or disconnected traces, to
2050 inform others (or yourself) as to who is running the trace, supply
2051 contact information, or otherwise explain what is going on.
2053 set trace-stop-notes
2054 show trace-stop-notes
2055 Set a note attached to the trace run, that is displayed when the
2056 trace has been stopped by a tstop command. This is useful for
2057 instance as an explanation, if you are stopping a trace run that was
2058 started by someone else.
2060 * New remote packets
2064 Dynamically enable a tracepoint in a started trace experiment.
2068 Dynamically disable a tracepoint in a started trace experiment.
2072 Set the user and notes of the trace run.
2076 Query the current status of a tracepoint.
2080 Query the minimum length of instruction at which a fast tracepoint may
2083 * Dcache size (number of lines) and line-size are now runtime-configurable
2084 via "set dcache line" and "set dcache line-size" commands.
2088 Texas Instruments TMS320C6x tic6x-*-*
2092 Renesas RL78 rl78-*-elf
2094 *** Changes in GDB 7.3.1
2096 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2098 *** Changes in GDB 7.3
2100 * GDB has a new command: "thread find [REGEXP]".
2101 It finds the thread id whose name, target id, or thread extra info
2102 matches the given regular expression.
2104 * The "catch syscall" command now works on mips*-linux* targets.
2106 * The -data-disassemble MI command now supports modes 2 and 3 for
2107 dumping the instruction opcodes.
2109 * New command line options
2111 -data-directory DIR Specify DIR as the "data-directory".
2112 This is mostly for testing purposes.
2114 * The "maint set python auto-load on|off" command has been renamed to
2115 "set auto-load-scripts on|off".
2117 * GDB has a new command: "set directories".
2118 It is like the "dir" command except that it replaces the
2119 source path list instead of augmenting it.
2121 * GDB now understands thread names.
2123 On GNU/Linux, "info threads" will display the thread name as set by
2124 prctl or pthread_setname_np.
2126 There is also a new command, "thread name", which can be used to
2127 assign a name internally for GDB to display.
2130 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2131 has been integrated into GDB.
2135 ** The function gdb.Write now accepts an optional keyword 'stream'.
2136 This keyword, when provided, will direct the output to either
2137 stdout, stderr, or GDB's logging output.
2139 ** Parameters can now be be sub-classed in Python, and in particular
2140 you may implement the get_set_doc and get_show_doc functions.
2141 This improves how Parameter set/show documentation is processed
2142 and allows for more dynamic content.
2144 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2145 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2146 have an is_valid method.
2148 ** Breakpoints can now be sub-classed in Python, and in particular
2149 you may implement a 'stop' function that is executed each time
2150 the inferior reaches that breakpoint.
2152 ** New function gdb.lookup_global_symbol looks up a global symbol.
2154 ** GDB values in Python are now callable if the value represents a
2155 function. For example, if 'some_value' represents a function that
2156 takes two integer parameters and returns a value, you can call
2157 that function like so:
2159 result = some_value (10,20)
2161 ** Module gdb.types has been added.
2162 It contains a collection of utilities for working with gdb.Types objects:
2163 get_basic_type, has_field, make_enum_dict.
2165 ** Module gdb.printing has been added.
2166 It contains utilities for writing and registering pretty-printers.
2167 New classes: PrettyPrinter, SubPrettyPrinter,
2168 RegexpCollectionPrettyPrinter.
2169 New function: register_pretty_printer.
2171 ** New commands "info pretty-printers", "enable pretty-printer" and
2172 "disable pretty-printer" have been added.
2174 ** gdb.parameter("directories") is now available.
2176 ** New function gdb.newest_frame returns the newest frame in the
2179 ** The gdb.InferiorThread class has a new "name" attribute. This
2180 holds the thread's name.
2182 ** Python Support for Inferior events.
2183 Python scripts can add observers to be notified of events
2184 occurring in the process being debugged.
2185 The following events are currently supported:
2186 - gdb.events.cont Continue event.
2187 - gdb.events.exited Inferior exited event.
2188 - gdb.events.stop Signal received, and Breakpoint hit events.
2192 ** GDB now puts template parameters in scope when debugging in an
2193 instantiation. For example, if you have:
2195 template<int X> int func (void) { return X; }
2197 then if you step into func<5>, "print X" will show "5". This
2198 feature requires proper debuginfo support from the compiler; it
2199 was added to GCC 4.5.
2201 ** The motion commands "next", "finish", "until", and "advance" now
2202 work better when exceptions are thrown. In particular, GDB will
2203 no longer lose control of the inferior; instead, the GDB will
2204 stop the inferior at the point at which the exception is caught.
2205 This functionality requires a change in the exception handling
2206 code that was introduced in GCC 4.5.
2208 * GDB now follows GCC's rules on accessing volatile objects when
2209 reading or writing target state during expression evaluation.
2210 One notable difference to prior behavior is that "print x = 0"
2211 no longer generates a read of x; the value of the assignment is
2212 now always taken directly from the value being assigned.
2214 * GDB now has some support for using labels in the program's source in
2215 linespecs. For instance, you can use "advance label" to continue
2216 execution to a label.
2218 * GDB now has support for reading and writing a new .gdb_index
2219 section. This section holds a fast index of DWARF debugging
2220 information and can be used to greatly speed up GDB startup and
2221 operation. See the documentation for `save gdb-index' for details.
2223 * The "watch" command now accepts an optional "-location" argument.
2224 When used, this causes GDB to watch the memory referred to by the
2225 expression. Such a watchpoint is never deleted due to it going out
2228 * GDB now supports thread debugging of core dumps on GNU/Linux.
2230 GDB now activates thread debugging using the libthread_db library
2231 when debugging GNU/Linux core dumps, similarly to when debugging
2232 live processes. As a result, when debugging a core dump file, GDB
2233 is now able to display pthread_t ids of threads. For example, "info
2234 threads" shows the same output as when debugging the process when it
2235 was live. In earlier releases, you'd see something like this:
2238 * 1 LWP 6780 main () at main.c:10
2240 While now you see this:
2243 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2245 It is also now possible to inspect TLS variables when debugging core
2248 When debugging a core dump generated on a machine other than the one
2249 used to run GDB, you may need to point GDB at the correct
2250 libthread_db library with the "set libthread-db-search-path"
2251 command. See the user manual for more details on this command.
2253 * When natively debugging programs on PowerPC BookE processors running
2254 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2255 which stop execution of the inferior whenever it executes an instruction
2256 at any address within the specified range. See the "PowerPC Embedded"
2257 section in the user manual for more details.
2259 * New features in the GDB remote stub, GDBserver
2261 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2262 and i686 LynxOS (version 5.x).
2264 ** GDBserver is now supported on Blackfin Linux.
2266 * New native configurations
2268 ia64 HP-UX ia64-*-hpux*
2272 Analog Devices, Inc. Blackfin Processor bfin-*
2274 * Ada task switching is now supported on sparc-elf targets when
2275 debugging a program using the Ravenscar Profile. For more information,
2276 see the "Tasking Support when using the Ravenscar Profile" section
2277 in the GDB user manual.
2279 * Guile support was removed.
2281 * New features in the GNU simulator
2283 ** The --map-info flag lists all known core mappings.
2285 ** CFI flashes may be simulated via the "cfi" device.
2287 *** Changes in GDB 7.2
2289 * Shared library support for remote targets by default
2291 When GDB is configured for a generic, non-OS specific target, like
2292 for example, --target=arm-eabi or one of the many *-*-elf targets,
2293 GDB now queries remote stubs for loaded shared libraries using the
2294 `qXfer:libraries:read' packet. Previously, shared library support
2295 was always disabled for such configurations.
2299 ** Argument Dependent Lookup (ADL)
2301 In C++ ADL lookup directs function search to the namespaces of its
2302 arguments even if the namespace has not been imported.
2312 Here the compiler will search for `foo' in the namespace of 'b'
2313 and find A::foo. GDB now supports this. This construct is commonly
2314 used in the Standard Template Library for operators.
2316 ** Improved User Defined Operator Support
2318 In addition to member operators, GDB now supports lookup of operators
2319 defined in a namespace and imported with a `using' directive, operators
2320 defined in the global scope, operators imported implicitly from an
2321 anonymous namespace, and the ADL operators mentioned in the previous
2323 GDB now also supports proper overload resolution for all the previously
2324 mentioned flavors of operators.
2326 ** static const class members
2328 Printing of static const class members that are initialized in the
2329 class definition has been fixed.
2331 * Windows Thread Information Block access.
2333 On Windows targets, GDB now supports displaying the Windows Thread
2334 Information Block (TIB) structure. This structure is visible either
2335 by using the new command `info w32 thread-information-block' or, by
2336 dereferencing the new convenience variable named `$_tlb', a
2337 thread-specific pointer to the TIB. This feature is also supported
2338 when remote debugging using GDBserver.
2340 * Static tracepoints
2342 Static tracepoints are calls in the user program into a tracing
2343 library. One such library is a port of the LTTng kernel tracer to
2344 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2345 When debugging with GDBserver, GDB now supports combining the GDB
2346 tracepoint machinery with such libraries. For example: the user can
2347 use GDB to probe a static tracepoint marker (a call from the user
2348 program into the tracing library) with the new "strace" command (see
2349 "New commands" below). This creates a "static tracepoint" in the
2350 breakpoint list, that can be manipulated with the same feature set
2351 as fast and regular tracepoints. E.g., collect registers, local and
2352 global variables, collect trace state variables, and define
2353 tracepoint conditions. In addition, the user can collect extra
2354 static tracepoint marker specific data, by collecting the new
2355 $_sdata internal variable. When analyzing the trace buffer, you can
2356 inspect $_sdata like any other variable available to GDB. For more
2357 information, see the "Tracepoints" chapter in GDB user manual. New
2358 remote packets have been defined to support static tracepoints, see
2359 the "New remote packets" section below.
2361 * Better reconstruction of tracepoints after disconnected tracing
2363 GDB will attempt to download the original source form of tracepoint
2364 definitions when starting a trace run, and then will upload these
2365 upon reconnection to the target, resulting in a more accurate
2366 reconstruction of the tracepoints that are in use on the target.
2370 You can now exercise direct control over the ways that GDB can
2371 affect your program. For instance, you can disallow the setting of
2372 breakpoints, so that the program can run continuously (assuming
2373 non-stop mode). In addition, the "observer" variable is available
2374 to switch all of the different controls; in observer mode, GDB
2375 cannot affect the target's behavior at all, which is useful for
2376 tasks like diagnosing live systems in the field.
2378 * The new convenience variable $_thread holds the number of the
2381 * New remote packets
2385 Return the address of the Windows Thread Information Block of a given thread.
2389 In response to several of the tracepoint packets, the target may now
2390 also respond with a number of intermediate `qRelocInsn' request
2391 packets before the final result packet, to have GDB handle
2392 relocating an instruction to execute at a different address. This
2393 is particularly useful for stubs that support fast tracepoints. GDB
2394 reports support for this feature in the qSupported packet.
2398 List static tracepoint markers in the target program.
2402 List static tracepoint markers at a given address in the target
2405 qXfer:statictrace:read
2407 Read the static trace data collected (by a `collect $_sdata'
2408 tracepoint action). The remote stub reports support for this packet
2409 to gdb's qSupported query.
2413 Send the current settings of GDB's permission flags.
2417 Send part of the source (textual) form of a tracepoint definition,
2418 which includes location, conditional, and action list.
2420 * The source command now accepts a -s option to force searching for the
2421 script in the source search path even if the script name specifies
2424 * New features in the GDB remote stub, GDBserver
2426 - GDBserver now support tracepoints (including fast tracepoints, and
2427 static tracepoints). The feature is currently supported by the
2428 i386-linux and amd64-linux builds. See the "Tracepoints support
2429 in gdbserver" section in the manual for more information.
2431 GDBserver JIT compiles the tracepoint's conditional agent
2432 expression bytecode into native code whenever possible for low
2433 overhead dynamic tracepoints conditionals. For such tracepoints,
2434 an expression that examines program state is evaluated when the
2435 tracepoint is reached, in order to determine whether to capture
2436 trace data. If the condition is simple and false, processing the
2437 tracepoint finishes very quickly and no data is gathered.
2439 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2440 for static tracepoints support.
2442 - GDBserver now supports x86_64 Windows 64-bit debugging.
2444 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2445 it understands register description.
2447 * The --batch flag now disables pagination and queries.
2449 * X86 general purpose registers
2451 GDB now supports reading/writing byte, word and double-word x86
2452 general purpose registers directly. This means you can use, say,
2453 $ah or $ax to refer, respectively, to the byte register AH and
2454 16-bit word register AX that are actually portions of the 32-bit
2455 register EAX or 64-bit register RAX.
2457 * The `commands' command now accepts a range of breakpoints to modify.
2458 A plain `commands' following a command that creates multiple
2459 breakpoints affects all the breakpoints set by that command. This
2460 applies to breakpoints set by `rbreak', and also applies when a
2461 single `break' command creates multiple breakpoints (e.g.,
2462 breakpoints on overloaded c++ functions).
2464 * The `rbreak' command now accepts a filename specification as part of
2465 its argument, limiting the functions selected by the regex to those
2466 in the specified file.
2468 * Support for remote debugging Windows and SymbianOS shared libraries
2469 from Unix hosts has been improved. Non Windows GDB builds now can
2470 understand target reported file names that follow MS-DOS based file
2471 system semantics, such as file names that include drive letters and
2472 use the backslash character as directory separator. This makes it
2473 possible to transparently use the "set sysroot" and "set
2474 solib-search-path" on Unix hosts to point as host copies of the
2475 target's shared libraries. See the new command "set
2476 target-file-system-kind" described below, and the "Commands to
2477 specify files" section in the user manual for more information.
2481 eval template, expressions...
2482 Convert the values of one or more expressions under the control
2483 of the string template to a command line, and call it.
2485 set target-file-system-kind unix|dos-based|auto
2486 show target-file-system-kind
2487 Set or show the assumed file system kind for target reported file
2490 save breakpoints <filename>
2491 Save all current breakpoint definitions to a file suitable for use
2492 in a later debugging session. To read the saved breakpoint
2493 definitions, use the `source' command.
2495 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2498 info static-tracepoint-markers
2499 Display information about static tracepoint markers in the target.
2501 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2502 Define a static tracepoint by probing a marker at the given
2503 function, line, address, or marker ID.
2507 Enable and disable observer mode.
2509 set may-write-registers on|off
2510 set may-write-memory on|off
2511 set may-insert-breakpoints on|off
2512 set may-insert-tracepoints on|off
2513 set may-insert-fast-tracepoints on|off
2514 set may-interrupt on|off
2515 Set individual permissions for GDB effects on the target. Note that
2516 some of these settings can have undesirable or surprising
2517 consequences, particularly when changed in the middle of a session.
2518 For instance, disabling the writing of memory can prevent
2519 breakpoints from being inserted, cause single-stepping to fail, or
2520 even crash your program, if you disable after breakpoints have been
2521 inserted. However, GDB should not crash.
2523 set record memory-query on|off
2524 show record memory-query
2525 Control whether to stop the inferior if memory changes caused
2526 by an instruction cannot be recorded.
2531 The disassemble command now supports "start,+length" form of two arguments.
2535 ** GDB now provides a new directory location, called the python directory,
2536 where Python scripts written for GDB can be installed. The location
2537 of that directory is <data-directory>/python, where <data-directory>
2538 is the GDB data directory. For more details, see section `Scripting
2539 GDB using Python' in the manual.
2541 ** The GDB Python API now has access to breakpoints, symbols, symbol
2542 tables, program spaces, inferiors, threads and frame's code blocks.
2543 Additionally, GDB Parameters can now be created from the API, and
2544 manipulated via set/show in the CLI.
2546 ** New functions gdb.target_charset, gdb.target_wide_charset,
2547 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2549 ** New exception gdb.GdbError.
2551 ** Pretty-printers are now also looked up in the current program space.
2553 ** Pretty-printers can now be individually enabled and disabled.
2555 ** GDB now looks for names of Python scripts to auto-load in a
2556 special section named `.debug_gdb_scripts', in addition to looking
2557 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2559 * Tracepoint actions were unified with breakpoint commands. In particular,
2560 there are no longer differences in "info break" output for breakpoints and
2561 tracepoints and the "commands" command can be used for both tracepoints and
2562 regular breakpoints.
2566 ARM Symbian arm*-*-symbianelf*
2568 * D language support.
2569 GDB now supports debugging programs written in the D programming
2572 * GDB now supports the extended ptrace interface for PowerPC which is
2573 available since Linux kernel version 2.6.34. This automatically enables
2574 any hardware breakpoints and additional hardware watchpoints available in
2575 the processor. The old ptrace interface exposes just one hardware
2576 watchpoint and no hardware breakpoints.
2578 * GDB is now able to use the Data Value Compare (DVC) register available on
2579 embedded PowerPC processors to implement in hardware simple watchpoint
2580 conditions of the form:
2582 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2584 This works in native GDB running on Linux kernels with the extended ptrace
2585 interface mentioned above.
2587 *** Changes in GDB 7.1
2591 ** Namespace Support
2593 GDB now supports importing of namespaces in C++. This enables the
2594 user to inspect variables from imported namespaces. Support for
2595 namepace aliasing has also been added. So, if a namespace is
2596 aliased in the current scope (e.g. namepace C=A; ) the user can
2597 print variables using the alias (e.g. (gdb) print C::x).
2601 All known bugs relating to the printing of virtual base class were
2602 fixed. It is now possible to call overloaded static methods using a
2607 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2608 and reinterpret_cast<> are now handled by the C++ expression parser.
2612 Xilinx MicroBlaze microblaze-*-*
2617 Xilinx MicroBlaze microblaze
2620 * Multi-program debugging.
2622 GDB now has support for multi-program (a.k.a. multi-executable or
2623 multi-exec) debugging. This allows for debugging multiple inferiors
2624 simultaneously each running a different program under the same GDB
2625 session. See "Debugging Multiple Inferiors and Programs" in the
2626 manual for more information. This implied some user visible changes
2627 in the multi-inferior support. For example, "info inferiors" now
2628 lists inferiors that are not running yet or that have exited
2629 already. See also "New commands" and "New options" below.
2631 * New tracing features
2633 GDB's tracepoint facility now includes several new features:
2635 ** Trace state variables
2637 GDB tracepoints now include support for trace state variables, which
2638 are variables managed by the target agent during a tracing
2639 experiment. They are useful for tracepoints that trigger each
2640 other, so for instance one tracepoint can count hits in a variable,
2641 and then a second tracepoint has a condition that is true when the
2642 count reaches a particular value. Trace state variables share the
2643 $-syntax of GDB convenience variables, and can appear in both
2644 tracepoint actions and condition expressions. Use the "tvariable"
2645 command to create, and "info tvariables" to view; see "Trace State
2646 Variables" in the manual for more detail.
2650 GDB now includes an option for defining fast tracepoints, which
2651 targets may implement more efficiently, such as by installing a jump
2652 into the target agent rather than a trap instruction. The resulting
2653 speedup can be by two orders of magnitude or more, although the
2654 tradeoff is that some program locations on some target architectures
2655 might not allow fast tracepoint installation, for instance if the
2656 instruction to be replaced is shorter than the jump. To request a
2657 fast tracepoint, use the "ftrace" command, with syntax identical to
2658 the regular trace command.
2660 ** Disconnected tracing
2662 It is now possible to detach GDB from the target while it is running
2663 a trace experiment, then reconnect later to see how the experiment
2664 is going. In addition, a new variable disconnected-tracing lets you
2665 tell the target agent whether to continue running a trace if the
2666 connection is lost unexpectedly.
2670 GDB now has the ability to save the trace buffer into a file, and
2671 then use that file as a target, similarly to you can do with
2672 corefiles. You can select trace frames, print data that was
2673 collected in them, and use tstatus to display the state of the
2674 tracing run at the moment that it was saved. To create a trace
2675 file, use "tsave <filename>", and to use it, do "target tfile
2678 ** Circular trace buffer
2680 You can ask the target agent to handle the trace buffer as a
2681 circular buffer, discarding the oldest trace frames to make room for
2682 newer ones, by setting circular-trace-buffer to on. This feature may
2683 not be available for all target agents.
2688 The disassemble command, when invoked with two arguments, now requires
2689 the arguments to be comma-separated.
2692 The info variables command now displays variable definitions. Files
2693 which only declare a variable are not shown.
2696 The source command is now capable of sourcing Python scripts.
2697 This feature is dependent on the debugger being build with Python
2700 Related to this enhancement is also the introduction of a new command
2701 "set script-extension" (see below).
2703 * New commands (for set/show, see "New options" below)
2705 record save [<FILENAME>]
2706 Save a file (in core file format) containing the process record
2707 execution log for replay debugging at a later time.
2709 record restore <FILENAME>
2710 Restore the process record execution log that was saved at an
2711 earlier time, for replay debugging.
2713 add-inferior [-copies <N>] [-exec <FILENAME>]
2716 clone-inferior [-copies <N>] [ID]
2717 Make a new inferior ready to execute the same program another
2718 inferior has loaded.
2723 maint info program-spaces
2724 List the program spaces loaded into GDB.
2726 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2727 show remote interrupt-sequence
2728 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2729 as the sequence to the remote target in order to interrupt the execution.
2730 Ctrl-C is a default. Some system prefers BREAK which is high level of
2731 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2732 Magic SysRq g. It is BREAK signal and character 'g'.
2734 set remote interrupt-on-connect [on | off]
2735 show remote interrupt-on-connect
2736 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2737 remote target when gdb connects to it. This is needed when you debug
2740 set remotebreak [on | off]
2742 Deprecated. Use "set/show remote interrupt-sequence" instead.
2744 tvariable $NAME [ = EXP ]
2745 Create or modify a trace state variable.
2748 List trace state variables and their values.
2750 delete tvariable $NAME ...
2751 Delete one or more trace state variables.
2754 Evaluate the given expressions without collecting anything into the
2755 trace buffer. (Valid in tracepoint actions only.)
2757 ftrace FN / FILE:LINE / *ADDR
2758 Define a fast tracepoint at the given function, line, or address.
2760 * New expression syntax
2762 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2763 GDB now parses 0b101010 identically with 42.
2767 set follow-exec-mode new|same
2768 show follow-exec-mode
2769 Control whether GDB reuses the same inferior across an exec call or
2770 creates a new one. This is useful to be able to restart the old
2771 executable after the inferior having done an exec call.
2773 set default-collect EXPR, ...
2774 show default-collect
2775 Define a list of expressions to be collected at each tracepoint.
2776 This is a useful way to ensure essential items are not overlooked,
2777 such as registers or a critical global variable.
2779 set disconnected-tracing
2780 show disconnected-tracing
2781 If set to 1, the target is instructed to continue tracing if it
2782 loses its connection to GDB. If 0, the target is to stop tracing
2785 set circular-trace-buffer
2786 show circular-trace-buffer
2787 If set to on, the target is instructed to use a circular trace buffer
2788 and discard the oldest trace frames instead of stopping the trace due
2789 to a full trace buffer. If set to off, the trace stops when the buffer
2790 fills up. Some targets may not support this.
2792 set script-extension off|soft|strict
2793 show script-extension
2794 If set to "off", the debugger does not perform any script language
2795 recognition, and all sourced files are assumed to be GDB scripts.
2796 If set to "soft" (the default), files are sourced according to
2797 filename extension, falling back to GDB scripts if the first
2799 If set to "strict", files are sourced according to filename extension.
2801 set ada trust-PAD-over-XVS on|off
2802 show ada trust-PAD-over-XVS
2803 If off, activate a workaround against a bug in the debugging information
2804 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2805 the GCC sources for more information about the GNAT encoding and
2806 PAD types in particular). It is always safe to set this option to
2807 off, but this introduces a slight performance penalty. The default
2810 * Python API Improvements
2812 ** GDB provides the new class gdb.LazyString. This is useful in
2813 some pretty-printing cases. The new method gdb.Value.lazy_string
2814 provides a simple way to create objects of this type.
2816 ** The fields returned by gdb.Type.fields now have an
2817 `is_base_class' attribute.
2819 ** The new method gdb.Type.range returns the range of an array type.
2821 ** The new method gdb.parse_and_eval can be used to parse and
2822 evaluate an expression.
2824 * New remote packets
2827 Define a trace state variable.
2830 Get the current value of a trace state variable.
2833 Set desired tracing behavior upon disconnection.
2836 Set the trace buffer to be linear or circular.
2839 Get data about the tracepoints currently in use.
2843 Process record now works correctly with hardware watchpoints.
2845 Multiple bug fixes have been made to the mips-irix port, making it
2846 much more reliable. In particular:
2847 - Debugging threaded applications is now possible again. Previously,
2848 GDB would hang while starting the program, or while waiting for
2849 the program to stop at a breakpoint.
2850 - Attaching to a running process no longer hangs.
2851 - An error occurring while loading a core file has been fixed.
2852 - Changing the value of the PC register now works again. This fixes
2853 problems observed when using the "jump" command, or when calling
2854 a function from GDB, or even when assigning a new value to $pc.
2855 - With the "finish" and "return" commands, the return value for functions
2856 returning a small array is now correctly printed.
2857 - It is now possible to break on shared library code which gets executed
2858 during a shared library init phase (code executed while executing
2859 their .init section). Previously, the breakpoint would have no effect.
2860 - GDB is now able to backtrace through the signal handler for
2861 non-threaded programs.
2863 PIE (Position Independent Executable) programs debugging is now supported.
2864 This includes debugging execution of PIC (Position Independent Code) shared
2865 libraries although for that, it should be possible to run such libraries as an
2868 *** Changes in GDB 7.0
2870 * GDB now has an interface for JIT compilation. Applications that
2871 dynamically generate code can create symbol files in memory and register
2872 them with GDB. For users, the feature should work transparently, and
2873 for JIT developers, the interface is documented in the GDB manual in the
2874 "JIT Compilation Interface" chapter.
2876 * Tracepoints may now be conditional. The syntax is as for
2877 breakpoints; either an "if" clause appended to the "trace" command,
2878 or the "condition" command is available. GDB sends the condition to
2879 the target for evaluation using the same bytecode format as is used
2880 for tracepoint actions.
2882 * The disassemble command now supports: an optional /r modifier, print the
2883 raw instructions in hex as well as in symbolic form, and an optional /m
2884 modifier to print mixed source+assembly.
2886 * Process record and replay
2888 In a architecture environment that supports ``process record and
2889 replay'', ``process record and replay'' target can record a log of
2890 the process execution, and replay it with both forward and reverse
2893 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2894 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2895 set execution-direction {forward|reverse}, for targets that support
2898 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2899 feature is available with a native GDB running on kernel version
2902 * GDB now has support for multi-byte and wide character sets on the
2903 target. Strings whose character type is wchar_t, char16_t, or
2904 char32_t are now correctly printed. GDB supports wide- and unicode-
2905 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2906 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2907 `printf'. This feature requires iconv to work properly; if your
2908 system does not have a working iconv, GDB can use GNU libiconv. See
2909 the installation instructions for more information.
2911 * GDB now supports automatic retrieval of shared library files from
2912 remote targets. To use this feature, specify a system root that begins
2913 with the `remote:' prefix, either via the `set sysroot' command or via
2914 the `--with-sysroot' configure-time option.
2916 * "info sharedlibrary" now takes an optional regex of libraries to show,
2917 and it now reports if a shared library has no debugging information.
2919 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2920 now complete on file names.
2922 * When completing in expressions, gdb will attempt to limit
2923 completions to allowable structure or union fields, where appropriate.
2924 For instance, consider:
2926 # struct example { int f1; double f2; };
2927 # struct example variable;
2930 If the user types TAB at the end of this command line, the available
2931 completions will be "f1" and "f2".
2933 * Inlined functions are now supported. They show up in backtraces, and
2934 the "step", "next", and "finish" commands handle them automatically.
2936 * GDB now supports the token-splicing (##) and stringification (#)
2937 operators when expanding macros. It also supports variable-arity
2940 * GDB now supports inspecting extra signal information, exported by
2941 the new $_siginfo convenience variable. The feature is currently
2942 implemented on linux ARM, i386 and amd64.
2944 * GDB can now display the VFP floating point registers and NEON vector
2945 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2946 can provide these registers (requires Linux 2.6.30 or later). Remote
2947 and simulator targets may also provide them.
2949 * New remote packets
2952 Search memory for a sequence of bytes.
2955 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2956 operation over reliable transport links. Use of this packet is
2957 controlled by the `set remote noack-packet' command.
2960 Kill the process with the specified process ID. Use this in preference
2961 to `k' when multiprocess protocol extensions are supported.
2964 Obtains additional operating system information
2968 Read or write additional signal information.
2970 * Removed remote protocol undocumented extension
2972 An undocumented extension to the remote protocol's `S' stop reply
2973 packet that permited the stub to pass a process id was removed.
2974 Remote servers should use the `T' stop reply packet instead.
2976 * GDB now supports multiple function calling conventions according to the
2977 DWARF-2 DW_AT_calling_convention function attribute.
2979 * The SH target utilizes the aforementioned change to distinguish between gcc
2980 and Renesas calling convention. It also adds the new CLI commands
2981 `set/show sh calling-convention'.
2983 * GDB can now read compressed debug sections, as produced by GNU gold
2984 with the --compress-debug-sections=zlib flag.
2986 * 64-bit core files are now supported on AIX.
2988 * Thread switching is now supported on Tru64.
2990 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2991 which will be allocated using malloc later in program execution.
2993 * The qXfer:libraries:read remote procotol packet now allows passing a
2994 list of section offsets.
2996 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2997 conditions handling signals delivered during attach or thread creation
2998 have also been fixed.
3000 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3001 From the user's standpoint, all unqualified instances of True and False
3002 are treated as the standard definitions, regardless of context.
3004 * GDB now parses C++ symbol and type names more flexibly. For
3007 template<typename T> class C { };
3010 GDB will now correctly handle all of:
3012 ptype C<char const *>
3013 ptype C<char const*>
3014 ptype C<const char *>
3015 ptype C<const char*>
3017 * New features in the GDB remote stub, gdbserver
3019 - The "--wrapper" command-line argument tells gdbserver to use a
3020 wrapper program to launch programs for debugging.
3022 - On PowerPC and S/390 targets, it is now possible to use a single
3023 gdbserver executable to debug both 32-bit and 64-bit programs.
3024 (This requires gdbserver itself to be built as a 64-bit executable.)
3026 - gdbserver uses the new noack protocol mode for TCP connections to
3027 reduce communications latency, if also supported and enabled in GDB.
3029 - Support for the sparc64-linux-gnu target is now included in
3032 - The amd64-linux build of gdbserver now supports debugging both
3033 32-bit and 64-bit programs.
3035 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3036 now support hardware watchpoints, and will use them automatically
3041 GDB now has support for scripting using Python. Whether this is
3042 available is determined at configure time.
3044 New GDB commands can now be written in Python.
3046 * Ada tasking support
3048 Ada tasks can now be inspected in GDB. The following commands have
3052 Print the list of Ada tasks.
3054 Print detailed information about task number N.
3056 Print the task number of the current task.
3058 Switch the context of debugging to task number N.
3060 * Support for user-defined prefixed commands. The "define" command can
3061 add new commands to existing prefixes, e.g. "target".
3063 * Multi-inferior, multi-process debugging.
3065 GDB now has generalized support for multi-inferior debugging. See
3066 "Debugging Multiple Inferiors" in the manual for more information.
3067 Although availability still depends on target support, the command
3068 set is more uniform now. The GNU/Linux specific multi-forks support
3069 has been migrated to this new framework. This implied some user
3070 visible changes; see "New commands" and also "Removed commands"
3073 * Target descriptions can now describe the target OS ABI. See the
3074 "Target Description Format" section in the user manual for more
3077 * Target descriptions can now describe "compatible" architectures
3078 to indicate that the target can execute applications for a different
3079 architecture in addition to those for the main target architecture.
3080 See the "Target Description Format" section in the user manual for
3083 * Multi-architecture debugging.
3085 GDB now includes general supports for debugging applications on
3086 hybrid systems that use more than one single processor architecture
3087 at the same time. Each such hybrid architecture still requires
3088 specific support to be added. The only hybrid architecture supported
3089 in this version of GDB is the Cell Broadband Engine.
3091 * GDB now supports integrated debugging of Cell/B.E. applications that
3092 use both the PPU and SPU architectures. To enable support for hybrid
3093 Cell/B.E. debugging, you need to configure GDB to support both the
3094 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3095 --enable-targets configure option.
3097 * Non-stop mode debugging.
3099 For some targets, GDB now supports an optional mode of operation in
3100 which you can examine stopped threads while other threads continue
3101 to execute freely. This is referred to as non-stop mode, with the
3102 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3103 section in the user manual for more information.
3105 To be able to support remote non-stop debugging, a remote stub needs
3106 to implement the non-stop mode remote protocol extensions, as
3107 described in the "Remote Non-Stop" section of the user manual. The
3108 GDB remote stub, gdbserver, has been adjusted to support these
3109 extensions on linux targets.
3111 * New commands (for set/show, see "New options" below)
3113 catch syscall [NAME(S) | NUMBER(S)]
3114 Catch system calls. Arguments, which should be names of system
3115 calls or their numbers, mean catch only those syscalls. Without
3116 arguments, every syscall will be caught. When the inferior issues
3117 any of the specified syscalls, GDB will stop and announce the system
3118 call, both when it is called and when its call returns. This
3119 feature is currently available with a native GDB running on the
3120 Linux Kernel, under the following architectures: x86, x86_64,
3121 PowerPC and PowerPC64.
3123 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3125 Search memory for a sequence of bytes.
3127 maint set python print-stack
3128 maint show python print-stack
3129 Show a stack trace when an error is encountered in a Python script.
3132 Invoke CODE by passing it to the Python interpreter.
3137 These allow macros to be defined, undefined, and listed
3141 Show operating system information about processes.
3144 List the inferiors currently under GDB's control.
3147 Switch focus to inferior number NUM.
3150 Detach from inferior number NUM.
3153 Kill inferior number NUM.
3157 set spu stop-on-load
3158 show spu stop-on-load
3159 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3161 set spu auto-flush-cache
3162 show spu auto-flush-cache
3163 Control whether to automatically flush the software-managed cache
3164 during Cell/B.E. debugging.
3166 set sh calling-convention
3167 show sh calling-convention
3168 Control the calling convention used when calling SH target functions.
3171 show debug timestamp
3172 Control display of timestamps with GDB debugging output.
3174 set disassemble-next-line
3175 show disassemble-next-line
3176 Control display of disassembled source lines or instructions when
3179 set remote noack-packet
3180 show remote noack-packet
3181 Set/show the use of remote protocol QStartNoAckMode packet. See above
3182 under "New remote packets."
3184 set remote query-attached-packet
3185 show remote query-attached-packet
3186 Control use of remote protocol `qAttached' (query-attached) packet.
3188 set remote read-siginfo-object
3189 show remote read-siginfo-object
3190 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3193 set remote write-siginfo-object
3194 show remote write-siginfo-object
3195 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3198 set remote reverse-continue
3199 show remote reverse-continue
3200 Control use of remote protocol 'bc' (reverse-continue) packet.
3202 set remote reverse-step
3203 show remote reverse-step
3204 Control use of remote protocol 'bs' (reverse-step) packet.
3206 set displaced-stepping
3207 show displaced-stepping
3208 Control displaced stepping mode. Displaced stepping is a way to
3209 single-step over breakpoints without removing them from the debuggee.
3210 Also known as "out-of-line single-stepping".
3213 show debug displaced
3214 Control display of debugging info for displaced stepping.
3216 maint set internal-error
3217 maint show internal-error
3218 Control what GDB does when an internal error is detected.
3220 maint set internal-warning
3221 maint show internal-warning
3222 Control what GDB does when an internal warning is detected.
3227 Use a wrapper program to launch programs for debugging.
3229 set multiple-symbols (all|ask|cancel)
3230 show multiple-symbols
3231 The value of this variable can be changed to adjust the debugger behavior
3232 when an expression or a breakpoint location contains an ambiguous symbol
3233 name (an overloaded function name, for instance).
3235 set breakpoint always-inserted
3236 show breakpoint always-inserted
3237 Keep breakpoints always inserted in the target, as opposed to inserting
3238 them when resuming the target, and removing them when the target stops.
3239 This option can improve debugger performance on slow remote targets.
3241 set arm fallback-mode (arm|thumb|auto)
3242 show arm fallback-mode
3243 set arm force-mode (arm|thumb|auto)
3245 These commands control how ARM GDB determines whether instructions
3246 are ARM or Thumb. The default for both settings is auto, which uses
3247 the current CPSR value for instructions without symbols; previous
3248 versions of GDB behaved as if "set arm fallback-mode arm".
3250 set disable-randomization
3251 show disable-randomization
3252 Standalone programs run with the virtual address space randomization enabled
3253 by default on some platforms. This option keeps the addresses stable across
3254 multiple debugging sessions.
3258 Control whether other threads are stopped or not when some thread hits
3263 Requests that asynchronous execution is enabled in the target, if available.
3264 In this case, it's possible to resume target in the background, and interact
3265 with GDB while the target is running. "show target-async" displays the
3266 current state of asynchronous execution of the target.
3268 set target-wide-charset
3269 show target-wide-charset
3270 The target-wide-charset is the name of the character set that GDB
3271 uses when printing characters whose type is wchar_t.
3273 set tcp auto-retry (on|off)
3275 set tcp connect-timeout
3276 show tcp connect-timeout
3277 These commands allow GDB to retry failed TCP connections to a remote stub
3278 with a specified timeout period; this is useful if the stub is launched
3279 in parallel with GDB but may not be ready to accept connections immediately.
3281 set libthread-db-search-path
3282 show libthread-db-search-path
3283 Control list of directories which GDB will search for appropriate
3286 set schedule-multiple (on|off)
3287 show schedule-multiple
3288 Allow GDB to resume all threads of all processes or only threads of
3289 the current process.
3293 Use more aggressive caching for accesses to the stack. This improves
3294 performance of remote debugging (particularly backtraces) without
3295 affecting correctness.
3297 set interactive-mode (on|off|auto)
3298 show interactive-mode
3299 Control whether GDB runs in interactive mode (on) or not (off).
3300 When in interactive mode, GDB waits for the user to answer all
3301 queries. Otherwise, GDB does not wait and assumes the default
3302 answer. When set to auto (the default), GDB determines which
3303 mode to use based on the stdin settings.
3308 For program forks, this is replaced by the new more generic `info
3309 inferiors' command. To list checkpoints, you can still use the
3310 `info checkpoints' command, which was an alias for the `info forks'
3314 Replaced by the new `inferior' command. To switch between
3315 checkpoints, you can still use the `restart' command, which was an
3316 alias for the `fork' command.
3319 This is removed, since some targets don't have a notion of
3320 processes. To switch between processes, you can still use the
3321 `inferior' command using GDB's own inferior number.
3324 For program forks, this is replaced by the new more generic `kill
3325 inferior' command. To delete a checkpoint, you can still use the
3326 `delete checkpoint' command, which was an alias for the `delete
3330 For program forks, this is replaced by the new more generic `detach
3331 inferior' command. To detach a checkpoint, you can still use the
3332 `detach checkpoint' command, which was an alias for the `detach
3335 * New native configurations
3337 x86/x86_64 Darwin i[34567]86-*-darwin*
3339 x86_64 MinGW x86_64-*-mingw*
3343 Lattice Mico32 lm32-*
3344 x86 DICOS i[34567]86-*-dicos*
3345 x86_64 DICOS x86_64-*-dicos*
3348 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3349 (mingw32ce) debugging.
3355 These commands were actually not implemented on any target.
3357 *** Changes in GDB 6.8
3359 * New native configurations
3361 NetBSD/hppa hppa*-*netbsd*
3362 Xtensa GNU/Linux xtensa*-*-linux*
3366 NetBSD/hppa hppa*-*-netbsd*
3367 Xtensa GNU/Lunux xtensa*-*-linux*
3369 * Change in command line behavior -- corefiles vs. process ids.
3371 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3372 attaching to process NUMBER fails, GDB no longer attempts to open a
3373 core file named NUMBER. Attaching to a program using the -c option
3374 is no longer supported. Instead, use the '-p' or '--pid' options.
3376 * GDB can now be built as a native debugger for debugging Windows x86
3377 (mingw32) Portable Executable (PE) programs.
3379 * Pending breakpoints no longer change their number when their address
3382 * GDB now supports breakpoints with multiple locations,
3383 including breakpoints on C++ constructors, inside C++ templates,
3384 and in inlined functions.
3386 * GDB's ability to debug optimized code has been improved. GDB more
3387 accurately identifies function bodies and lexical blocks that occupy
3388 more than one contiguous range of addresses.
3390 * Target descriptions can now describe registers for PowerPC.
3392 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3393 registers on PowerPC targets.
3395 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3396 targets even when the libthread_db library is not available.
3398 * The GDB remote stub, gdbserver, now supports the new file transfer
3399 commands (remote put, remote get, and remote delete).
3401 * The GDB remote stub, gdbserver, now supports run and attach in
3402 extended-remote mode.
3404 * hppa*64*-*-hpux11* target broken
3405 The debugger is unable to start a program and fails with the following
3406 error: "Error trying to get information about dynamic linker".
3407 The gdb-6.7 release is also affected.
3409 * GDB now supports the --enable-targets= configure option to allow
3410 building a single GDB executable that supports multiple remote
3411 target architectures.
3413 * GDB now supports debugging C and C++ programs which use the
3414 Decimal Floating Point extension. In addition, the PowerPC target
3415 now has a set of pseudo-registers to inspect decimal float values
3416 stored in two consecutive float registers.
3418 * The -break-insert MI command can optionally create pending
3421 * Improved support for debugging Ada
3422 Many improvements to the Ada language support have been made. These
3424 - Better support for Ada2005 interface types
3425 - Improved handling of arrays and slices in general
3426 - Better support for Taft-amendment types
3427 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3429 - Improved command completion in Ada
3432 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3437 set print frame-arguments (all|scalars|none)
3438 show print frame-arguments
3439 The value of this variable can be changed to control which argument
3440 values should be printed by the debugger when displaying a frame.
3445 Transfer files to and from a remote target, and delete remote files.
3452 Transfer files to and from a remote target, and delete remote files.
3454 * New remote packets
3461 Open, close, read, write, and delete files on the remote system.
3464 Attach to an existing process on the remote system, in extended-remote
3468 Run a new process on the remote system, in extended-remote mode.
3470 *** Changes in GDB 6.7
3472 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3473 bfd, libiberty and opcodes, as revealed by static analysis donated by
3474 Coverity, Inc. (http://scan.coverity.com).
3476 * When looking up multiply-defined global symbols, GDB will now prefer the
3477 symbol definition in the current shared library if it was built using the
3478 -Bsymbolic linker option.
3480 * When the Text User Interface (TUI) is not configured, GDB will now
3481 recognize the -tui command-line option and print a message that the TUI
3484 * The GDB remote stub, gdbserver, now has lower overhead for high
3485 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3487 * GDB for MIPS targets now autodetects whether a remote target provides
3488 32-bit or 64-bit register values.
3490 * Support for C++ member pointers has been improved.
3492 * GDB now understands XML target descriptions, which specify the
3493 target's overall architecture. GDB can read a description from
3494 a local file or over the remote serial protocol.
3496 * Vectors of single-byte data use a new integer type which is not
3497 automatically displayed as character or string data.
3499 * The /s format now works with the print command. It displays
3500 arrays of single-byte integers and pointers to single-byte integers
3503 * Target descriptions can now describe target-specific registers,
3504 for architectures which have implemented the support (currently
3505 only ARM, M68K, and MIPS).
3507 * GDB and the GDB remote stub, gdbserver, now support the XScale
3510 * The GDB remote stub, gdbserver, has been updated to support
3511 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3512 has been rewritten to use the standard GDB remote protocol.
3514 * GDB can now step into C++ functions which are called through thunks.
3516 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3518 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3519 layout. It also supports a TextSeg= and DataSeg= response when only
3520 segment base addresses (rather than offsets) are available.
3522 * The /i format now outputs any trailing branch delay slot instructions
3523 immediately following the last instruction within the count specified.
3525 * The GDB remote protocol "T" stop reply packet now supports a
3526 "library" response. Combined with the new "qXfer:libraries:read"
3527 packet, this response allows GDB to debug shared libraries on targets
3528 where the operating system manages the list of loaded libraries (e.g.
3529 Windows and SymbianOS).
3531 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3532 (DLLs) on Windows and Windows CE targets.
3534 * GDB now supports a faster verification that a .debug file matches its binary
3535 according to its build-id signature, if the signature is present.
3541 Enable or disable hardware flow control (RTS/CTS) on the serial port
3542 when debugging using remote targets.
3544 set mem inaccessible-by-default
3545 show mem inaccessible-by-default
3546 If the target supplies a memory map, for instance via the remote
3547 protocol's "qXfer:memory-map:read" packet, setting this variable
3548 prevents GDB from accessing memory outside the memory map. This
3549 is useful for targets with memory mapped registers or which react
3550 badly to accesses of unmapped address space.
3552 set breakpoint auto-hw
3553 show breakpoint auto-hw
3554 If the target supplies a memory map, for instance via the remote
3555 protocol's "qXfer:memory-map:read" packet, setting this variable
3556 lets GDB use hardware breakpoints automatically for memory regions
3557 where it can not use software breakpoints. This covers both the
3558 "break" command and internal breakpoints used for other commands
3559 including "next" and "finish".
3562 catch exception unhandled
3563 Stop the program execution when Ada exceptions are raised.
3566 Stop the program execution when an Ada assertion failed.
3570 Set an alternate system root for target files. This is a more
3571 general version of "set solib-absolute-prefix", which is now
3572 an alias to "set sysroot".
3575 Provide extended SPU facility status information. This set of
3576 commands is available only when debugging the Cell/B.E. SPU
3579 * New native configurations
3581 OpenBSD/sh sh*-*openbsd*
3584 unset tdesc filename
3586 Use the specified local file as an XML target description, and do
3587 not query the target for its built-in description.
3591 OpenBSD/sh sh*-*-openbsd*
3592 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3593 Toshiba Media Processor mep-elf
3595 * New remote packets
3598 Ignore the specified signals; pass them directly to the debugged program
3599 without stopping other threads or reporting them to GDB.
3601 qXfer:features:read:
3602 Read an XML target description from the target, which describes its
3607 Read or write contents of an spufs file on the target system. These
3608 packets are available only on the Cell/B.E. SPU architecture.
3610 qXfer:libraries:read:
3611 Report the loaded shared libraries. Combined with new "T" packet
3612 response, this packet allows GDB to debug shared libraries on
3613 targets where the operating system manages the list of loaded
3614 libraries (e.g. Windows and SymbianOS).
3618 Support for these obsolete configurations has been removed.
3626 i[34567]86-*-lynxos*
3627 i[34567]86-*-netware*
3628 i[34567]86-*-sco3.2v5*
3629 i[34567]86-*-sco3.2v4*
3631 i[34567]86-*-sysv4.2*
3634 i[34567]86-*-unixware2*
3635 i[34567]86-*-unixware*
3644 * Other removed features
3651 Various m68k-only ROM monitors.
3658 Various Renesas ROM monitors and debugging interfaces for SH and
3663 Support for a Macraigor serial interface to on-chip debugging.
3664 GDB does not directly support the newer parallel or USB
3669 A debug information format. The predecessor to DWARF 2 and
3670 DWARF 3, which are still supported.
3672 Support for the HP aCC compiler on HP-UX/PA-RISC
3674 SOM-encapsulated symbolic debugging information, automatic
3675 invocation of pxdb, and the aCC custom C++ ABI. This does not
3676 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3677 with aCC can still be debugged on an assembly level.
3679 MIPS ".pdr" sections
3681 A MIPS-specific format used to describe stack frame layout
3682 in debugging information.
3686 GDB could work with an older version of Guile to debug
3687 the interpreter and Scheme programs running in it.
3689 set mips stack-arg-size
3690 set mips saved-gpreg-size
3692 Use "set mips abi" to control parameter passing for MIPS.
3694 *** Changes in GDB 6.6
3699 Cell Broadband Engine SPU spu-elf
3701 * GDB can now be configured as a cross-debugger targeting native Windows
3702 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3703 running on a Windows system over TCP/IP to debug Windows programs.
3705 * The GDB remote stub, gdbserver, has been updated to support Windows and
3706 Cygwin debugging. Both single-threaded and multi-threaded programs are
3709 * The "set trust-readonly-sections" command works again. This command was
3710 broken in GDB 6.3, 6.4, and 6.5.
3712 * The "load" command now supports writing to flash memory, if the remote
3713 stub provides the required support.
3715 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3716 longer requires symbolic debug information (e.g. DWARF-2).
3721 unset substitute-path
3722 show substitute-path
3723 Manage a list of substitution rules that GDB uses to rewrite the name
3724 of the directories where the sources are located. This can be useful
3725 for instance when the sources were moved to a different location
3726 between compilation and debugging.
3730 Print each CLI command as it is executed. Each command is prefixed with
3731 a number of `+' symbols representing the nesting depth.
3732 The source command now has a `-v' option to enable the same feature.
3736 The ARM Demon monitor support (RDP protocol, "target rdp").
3738 Kernel Object Display, an embedded debugging feature which only worked with
3739 an obsolete version of Cisco IOS.
3741 The 'set download-write-size' and 'show download-write-size' commands.
3743 * New remote packets
3746 Tell a stub about GDB client features, and request remote target features.
3747 The first feature implemented is PacketSize, which allows the target to
3748 specify the size of packets it can handle - to minimize the number of
3749 packets required and improve performance when connected to a remote
3753 Fetch an OS auxilliary vector from the remote stub. This packet is a
3754 more efficient replacement for qPart:auxv:read.
3756 qXfer:memory-map:read:
3757 Fetch a memory map from the remote stub, including information about
3758 RAM, ROM, and flash memory devices.
3763 Erase and program a flash memory device.
3765 * Removed remote packets
3768 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3769 used it, and only gdbserver implemented it.
3771 *** Changes in GDB 6.5
3775 Renesas M32C/M16C m32c-elf
3777 Morpho Technologies ms1 ms1-elf
3781 init-if-undefined Initialize a convenience variable, but
3782 only if it doesn't already have a value.
3784 The following commands are presently only implemented for native GNU/Linux:
3786 checkpoint Save a snapshot of the program state.
3788 restart <n> Return the program state to a
3789 previously saved state.
3791 info checkpoints List currently saved checkpoints.
3793 delete-checkpoint <n> Delete a previously saved checkpoint.
3795 set|show detach-on-fork Tell gdb whether to detach from a newly
3796 forked process, or to keep debugging it.
3798 info forks List forks of the user program that
3799 are available to be debugged.
3801 fork <n> Switch to debugging one of several
3802 forks of the user program that are
3803 available to be debugged.
3805 delete-fork <n> Delete a fork from the list of forks
3806 that are available to be debugged (and
3807 kill the forked process).
3809 detach-fork <n> Delete a fork from the list of forks
3810 that are available to be debugged (and
3811 allow the process to continue).
3815 Morpho Technologies ms2 ms1-elf
3817 * Improved Windows host support
3819 GDB now builds as a cross debugger hosted on i686-mingw32, including
3820 native console support, and remote communications using either
3821 network sockets or serial ports.
3823 * Improved Modula-2 language support
3825 GDB can now print most types in the Modula-2 syntax. This includes:
3826 basic types, set types, record types, enumerated types, range types,
3827 pointer types and ARRAY types. Procedure var parameters are correctly
3828 printed and hexadecimal addresses and character constants are also
3829 written in the Modula-2 syntax. Best results can be obtained by using
3830 GNU Modula-2 together with the -gdwarf-2 command line option.
3834 The ARM rdi-share module.
3836 The Netware NLM debug server.
3838 *** Changes in GDB 6.4
3840 * New native configurations
3842 OpenBSD/arm arm*-*-openbsd*
3843 OpenBSD/mips64 mips64-*-openbsd*
3847 Morpho Technologies ms1 ms1-elf
3849 * New command line options
3851 --batch-silent As for --batch, but totally silent.
3852 --return-child-result The debugger will exist with the same value
3853 the child (debugged) program exited with.
3854 --eval-command COMMAND, -ex COMMAND
3855 Execute a single GDB CLI command. This may be
3856 specified multiple times and in conjunction
3857 with the --command (-x) option.
3859 * Deprecated commands removed
3861 The following commands, that were deprecated in 2000, have been
3865 set|show arm disassembly-flavor set|show arm disassembler
3866 othernames set arm disassembler
3867 set|show remotedebug set|show debug remote
3868 set|show archdebug set|show debug arch
3869 set|show eventdebug set|show debug event
3872 * New BSD user-level threads support
3874 It is now possible to debug programs using the user-level threads
3875 library on OpenBSD and FreeBSD. Currently supported (target)
3878 FreeBSD/amd64 x86_64-*-freebsd*
3879 FreeBSD/i386 i386-*-freebsd*
3880 OpenBSD/i386 i386-*-openbsd*
3882 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3883 are not yet supported.
3885 * New support for Matsushita MN10300 w/sim added
3886 (Work in progress). mn10300-elf.
3888 * REMOVED configurations and files
3890 VxWorks and the XDR protocol *-*-vxworks
3891 Motorola MCORE mcore-*-*
3892 National Semiconductor NS32000 ns32k-*-*
3894 * New "set print array-indexes" command
3896 After turning this setting "on", GDB prints the index of each element
3897 when displaying arrays. The default is "off" to preserve the previous
3900 * VAX floating point support
3902 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3904 * User-defined command support
3906 In addition to using $arg0..$arg9 for argument passing, it is now possible
3907 to use $argc to determine now many arguments have been passed. See the
3908 section on user-defined commands in the user manual for more information.
3910 *** Changes in GDB 6.3:
3912 * New command line option
3914 GDB now accepts -l followed by a number to set the timeout for remote
3917 * GDB works with GCC -feliminate-dwarf2-dups
3919 GDB now supports a more compact representation of DWARF-2 debug
3920 information using DW_FORM_ref_addr references. These are produced
3921 by GCC with the option -feliminate-dwarf2-dups and also by some
3922 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3923 to use -feliminate-dwarf2-dups.
3925 * Internationalization
3927 When supported by the host system, GDB will be built with
3928 internationalization (libintl). The task of marking up the sources is
3929 continued, we're looking forward to our first translation.
3933 Initial support for debugging programs compiled with the GNAT
3934 implementation of the Ada programming language has been integrated
3935 into GDB. In this release, support is limited to expression evaluation.
3937 * New native configurations
3939 GNU/Linux/m32r m32r-*-linux-gnu
3943 GDB's remote protocol now includes support for the 'p' packet. This
3944 packet is used to fetch individual registers from a remote inferior.
3946 * END-OF-LIFE registers[] compatibility module
3948 GDB's internal register infrastructure has been completely rewritten.
3949 The new infrastructure making possible the implementation of key new
3950 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3953 GDB 6.3 will be the last release to include the the registers[]
3954 compatibility module that allowed out-of-date configurations to
3955 continue to work. This change directly impacts the following
3965 powerpc bdm protocol
3967 Unless there is activity to revive these configurations, they will be
3968 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3970 * OBSOLETE configurations and files
3972 Configurations that have been declared obsolete in this release have
3973 been commented out. Unless there is activity to revive these
3974 configurations, the next release of GDB will have their sources
3975 permanently REMOVED.
3984 *** Changes in GDB 6.2.1:
3986 * MIPS `break main; run' gave an heuristic-fence-post warning
3988 When attempting to run even a simple program, a warning about
3989 heuristic-fence-post being hit would be reported. This problem has
3992 * MIPS IRIX 'long double' crashed GDB
3994 When examining a long double variable, GDB would get a segmentation
3995 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3996 IRIX long double values).
4000 A bug in the VAX stack code was causing problems with the "next"
4001 command. This problem has been fixed.
4003 *** Changes in GDB 6.2:
4005 * Fix for ``many threads''
4007 On GNU/Linux systems that use the NPTL threads library, a program
4008 rapidly creating and deleting threads would confuse GDB leading to the
4011 ptrace: No such process.
4012 thread_db_get_info: cannot get thread info: generic error
4014 This problem has been fixed.
4016 * "-async" and "-noasync" options removed.
4018 Support for the broken "-noasync" option has been removed (it caused
4021 * New ``start'' command.
4023 This command runs the program until the begining of the main procedure.
4025 * New BSD Kernel Data Access Library (libkvm) interface
4027 Using ``target kvm'' it is now possible to debug kernel core dumps and
4028 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4029 platforms. Currently supported (native-only) configurations are:
4031 FreeBSD/amd64 x86_64-*-freebsd*
4032 FreeBSD/i386 i?86-*-freebsd*
4033 NetBSD/i386 i?86-*-netbsd*
4034 NetBSD/m68k m68*-*-netbsd*
4035 NetBSD/sparc sparc-*-netbsd*
4036 OpenBSD/amd64 x86_64-*-openbsd*
4037 OpenBSD/i386 i?86-*-openbsd*
4038 OpenBSD/m68k m68*-openbsd*
4039 OpenBSD/sparc sparc-*-openbsd*
4041 * Signal trampoline code overhauled
4043 Many generic problems with GDB's signal handling code have been fixed.
4044 These include: backtraces through non-contiguous stacks; recognition
4045 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4046 call; backtrace through a signal trampoline; step into and out of
4047 signal handlers; and single-stepping in the signal trampoline.
4049 Please note that kernel bugs are a limiting factor here. These
4050 features have been shown to work on an s390 GNU/Linux system that
4051 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4053 * Cygwin support for DWARF 2 added.
4055 * New native configurations
4057 GNU/Linux/hppa hppa*-*-linux*
4058 OpenBSD/hppa hppa*-*-openbsd*
4059 OpenBSD/m68k m68*-*-openbsd*
4060 OpenBSD/m88k m88*-*-openbsd*
4061 OpenBSD/powerpc powerpc-*-openbsd*
4062 NetBSD/vax vax-*-netbsd*
4063 OpenBSD/vax vax-*-openbsd*
4065 * END-OF-LIFE frame compatibility module
4067 GDB's internal frame infrastructure has been completely rewritten.
4068 The new infrastructure making it possible to support key new features
4069 including DWARF 2 Call Frame Information. To aid in the task of
4070 migrating old configurations to this new infrastructure, a
4071 compatibility module, that allowed old configurations to continue to
4072 work, was also included.
4074 GDB 6.2 will be the last release to include this frame compatibility
4075 module. This change directly impacts the following configurations:
4085 Unless there is activity to revive these configurations, they will be
4086 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4088 * REMOVED configurations and files
4090 Sun 3, running SunOS 3 m68*-*-sunos3*
4091 Sun 3, running SunOS 4 m68*-*-sunos4*
4092 Sun 2, running SunOS 3 m68000-*-sunos3*
4093 Sun 2, running SunOS 4 m68000-*-sunos4*
4094 Motorola 680x0 running LynxOS m68*-*-lynxos*
4095 AT&T 3b1/Unix pc m68*-att-*
4096 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4097 decstation mips-dec-* mips-little-*
4098 riscos mips-*-riscos* mips-*-sysv*
4099 sonymips mips-sony-*
4100 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4102 *** Changes in GDB 6.1.1:
4104 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4106 The TUI (Text-mode User Interface) is now built as part of a default
4107 GDB configuration. It is enabled by either selecting the TUI with the
4108 command line option "-i=tui" or by running the separate "gdbtui"
4109 program. For more information on the TUI, see the manual "Debugging
4112 * Pending breakpoint support (also included in GDB 6.1)
4114 Support has been added to allow you to specify breakpoints in shared
4115 libraries that have not yet been loaded. If a breakpoint location
4116 cannot be found, and the "breakpoint pending" option is set to auto,
4117 GDB queries you if you wish to make the breakpoint pending on a future
4118 shared-library load. If and when GDB resolves the breakpoint symbol,
4119 the pending breakpoint is removed as one or more regular breakpoints
4122 Pending breakpoints are very useful for GCJ Java debugging.
4124 * Fixed ISO-C build problems
4126 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4127 non ISO-C code that stopped them being built using a more strict ISO-C
4128 compiler (e.g., IBM's C compiler).
4130 * Fixed build problem on IRIX 5
4132 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4133 wasn't able to compile compile on an IRIX 5 system.
4135 * Added execute permission to gdb/gdbserver/configure
4137 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4138 permission. This bug would cause configure to fail on a number of
4139 systems (Solaris, IRIX). Ref: server/519.
4141 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4143 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4144 has been updated to use constant array sizes.
4146 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4148 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4149 its generated DWARF Call Frame Info. This encoding was causing GDB to
4150 panic, that panic has been fixed. Ref: gdb/1628.
4152 * Fixed a problem when examining parameters in shared library code.
4154 When examining parameters in optimized shared library code generated
4155 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4156 not available''. GDB now correctly displays the variable's value.
4158 *** Changes in GDB 6.1:
4160 * Removed --with-mmalloc
4162 Support for the mmalloc memory manager has been removed, as it
4163 conflicted with the internal gdb byte cache.
4165 * Changes in AMD64 configurations
4167 The AMD64 target now includes the %cs and %ss registers. As a result
4168 the AMD64 remote protocol has changed; this affects the floating-point
4169 and SSE registers. If you rely on those registers for your debugging,
4170 you should upgrade gdbserver on the remote side.
4172 * Revised SPARC target
4174 The SPARC target has been completely revised, incorporating the
4175 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4176 support for LynxOS and SunOS 4 has been dropped. Calling functions
4177 from within GDB on operating systems with a non-executable stack
4178 (Solaris, OpenBSD) now works.
4182 GDB has a new C++ demangler which does a better job on the mangled
4183 names generated by current versions of g++. It also runs faster, so
4184 with this and other changes gdb should now start faster on large C++
4187 * DWARF 2 Location Expressions
4189 GDB support for location expressions has been extended to support function
4190 arguments and frame bases. Older versions of GDB could crash when they
4193 * C++ nested types and namespaces
4195 GDB's support for nested types and namespaces in C++ has been
4196 improved, especially if you use the DWARF 2 debugging format. (This
4197 is the default for recent versions of GCC on most platforms.)
4198 Specifically, if you have a class "Inner" defined within a class or
4199 namespace "Outer", then GDB realizes that the class's name is
4200 "Outer::Inner", not simply "Inner". This should greatly reduce the
4201 frequency of complaints about not finding RTTI symbols. In addition,
4202 if you are stopped at inside of a function defined within a namespace,
4203 GDB modifies its name lookup accordingly.
4205 * New native configurations
4207 NetBSD/amd64 x86_64-*-netbsd*
4208 OpenBSD/amd64 x86_64-*-openbsd*
4209 OpenBSD/alpha alpha*-*-openbsd*
4210 OpenBSD/sparc sparc-*-openbsd*
4211 OpenBSD/sparc64 sparc64-*-openbsd*
4213 * New debugging protocols
4215 M32R with SDI protocol m32r-*-elf*
4217 * "set prompt-escape-char" command deleted.
4219 The command "set prompt-escape-char" has been deleted. This command,
4220 and its very obscure effet on GDB's prompt, was never documented,
4221 tested, nor mentioned in the NEWS file.
4223 * OBSOLETE configurations and files
4225 Configurations that have been declared obsolete in this release have
4226 been commented out. Unless there is activity to revive these
4227 configurations, the next release of GDB will have their sources
4228 permanently REMOVED.
4230 Sun 3, running SunOS 3 m68*-*-sunos3*
4231 Sun 3, running SunOS 4 m68*-*-sunos4*
4232 Sun 2, running SunOS 3 m68000-*-sunos3*
4233 Sun 2, running SunOS 4 m68000-*-sunos4*
4234 Motorola 680x0 running LynxOS m68*-*-lynxos*
4235 AT&T 3b1/Unix pc m68*-att-*
4236 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4237 decstation mips-dec-* mips-little-*
4238 riscos mips-*-riscos* mips-*-sysv*
4239 sonymips mips-sony-*
4240 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4242 * REMOVED configurations and files
4244 SGI Irix-4.x mips-sgi-irix4 or iris4
4245 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4246 Z8000 simulator z8k-zilog-none or z8ksim
4247 Matsushita MN10200 w/simulator mn10200-*-*
4248 H8/500 simulator h8500-hitachi-hms or h8500hms
4249 HP/PA running BSD hppa*-*-bsd*
4250 HP/PA running OSF/1 hppa*-*-osf*
4251 HP/PA Pro target hppa*-*-pro*
4252 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4253 386BSD i[3456]86-*-bsd*
4254 Sequent family i[3456]86-sequent-sysv4*
4255 i[3456]86-sequent-sysv*
4256 i[3456]86-sequent-bsd*
4257 SPARC running LynxOS sparc-*-lynxos*
4258 SPARC running SunOS 4 sparc-*-sunos4*
4259 Tsqware Sparclet sparclet-*-*
4260 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4262 *** Changes in GDB 6.0:
4266 Support for debugging the Objective-C programming language has been
4267 integrated into GDB.
4269 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4271 DWARF 2's Call Frame Information makes available compiler generated
4272 information that more exactly describes the program's run-time stack.
4273 By using this information, GDB is able to provide more robust stack
4276 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4277 have been updated to use a new backtrace mechanism which includes
4278 DWARF 2 CFI support.
4282 GDB's remote protocol has been extended to include support for hosted
4283 file I/O (where the remote target uses GDB's file system). See GDB's
4284 remote protocol documentation for details.
4286 * All targets using the new architecture framework.
4288 All of GDB's targets have been updated to use the new internal
4289 architecture framework. The way is now open for future GDB releases
4290 to include cross-architecture native debugging support (i386 on amd64,
4293 * GNU/Linux's Thread Local Storage (TLS)
4295 GDB now includes support for for the GNU/Linux implementation of
4296 per-thread variables.
4298 * GNU/Linux's Native POSIX Thread Library (NPTL)
4300 GDB's thread code has been updated to work with either the new
4301 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4303 * Separate debug info.
4305 GDB, in conjunction with BINUTILS, now supports a mechanism for
4306 automatically loading debug information from a separate file. Instead
4307 of shipping full debug and non-debug versions of system libraries,
4308 system integrators can now instead ship just the stripped libraries
4309 and optional debug files.
4311 * DWARF 2 Location Expressions
4313 DWARF 2 Location Expressions allow the compiler to more completely
4314 describe the location of variables (even in optimized code) to the
4317 GDB now includes preliminary support for location expressions (support
4318 for DW_OP_piece is still missing).
4322 A number of long standing bugs that caused GDB to die while starting a
4323 Java application have been fixed. GDB's Java support is now
4324 considered "useable".
4326 * GNU/Linux support for fork, vfork, and exec.
4328 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4329 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4332 * GDB supports logging output to a file
4334 There are two new commands, "set logging" and "show logging", which can be
4335 used to capture GDB's output to a file.
4337 * The meaning of "detach" has changed for gdbserver
4339 The "detach" command will now resume the application, as documented. To
4340 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4343 * d10v, m68hc11 `regs' command deprecated
4345 The `info registers' command has been updated so that it displays the
4346 registers using a format identical to the old `regs' command.
4350 A new command, "maint set profile on/off", has been added. This command can
4351 be used to enable or disable profiling while running GDB, to profile a
4352 session or a set of commands. In addition there is a new configure switch,
4353 "--enable-profiling", which will cause GDB to be compiled with profiling
4354 data, for more informative profiling results.
4356 * Default MI syntax changed to "mi2".
4358 The default MI (machine interface) syntax, enabled by the command line
4359 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4360 "mi1", can be enabled by specifying the option "-i=mi1".
4362 Support for the original "mi0" syntax (included in GDB 5.0) has been
4365 Fix for gdb/192: removed extraneous space when displaying frame level.
4366 Fix for gdb/672: update changelist is now output in mi list format.
4367 Fix for gdb/702: a -var-assign that updates the value now shows up
4368 in a subsequent -var-update.
4370 * New native configurations.
4372 FreeBSD/amd64 x86_64-*-freebsd*
4374 * Multi-arched targets.
4376 HP/PA HPUX11 hppa*-*-hpux*
4377 Renesas M32R/D w/simulator m32r-*-elf*
4379 * OBSOLETE configurations and files
4381 Configurations that have been declared obsolete in this release have
4382 been commented out. Unless there is activity to revive these
4383 configurations, the next release of GDB will have their sources
4384 permanently REMOVED.
4386 Z8000 simulator z8k-zilog-none or z8ksim
4387 Matsushita MN10200 w/simulator mn10200-*-*
4388 H8/500 simulator h8500-hitachi-hms or h8500hms
4389 HP/PA running BSD hppa*-*-bsd*
4390 HP/PA running OSF/1 hppa*-*-osf*
4391 HP/PA Pro target hppa*-*-pro*
4392 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4393 Sequent family i[3456]86-sequent-sysv4*
4394 i[3456]86-sequent-sysv*
4395 i[3456]86-sequent-bsd*
4396 Tsqware Sparclet sparclet-*-*
4397 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4399 * REMOVED configurations and files
4402 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4403 IBM AIX PS/2 i[3456]86-*-aix
4404 i386 running Mach 3.0 i[3456]86-*-mach3*
4405 i386 running Mach i[3456]86-*-mach*
4406 i386 running OSF/1 i[3456]86-*osf1mk*
4407 HP/Apollo 68k Family m68*-apollo*-sysv*,
4409 m68*-hp-bsd*, m68*-hp-hpux*
4410 Argonaut Risc Chip (ARC) arc-*-*
4411 Mitsubishi D30V d30v-*-*
4412 Fujitsu FR30 fr30-*-elf*
4413 OS/9000 i[34]86-*-os9k
4414 I960 with MON960 i960-*-coff
4416 * MIPS $fp behavior changed
4418 The convenience variable $fp, for the MIPS, now consistently returns
4419 the address of the current frame's base. Previously, depending on the
4420 context, $fp could refer to either $sp or the current frame's base
4421 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4422 The GNU Source-Level Debugger''.
4424 *** Changes in GDB 5.3:
4426 * GNU/Linux shared library multi-threaded performance improved.
4428 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4429 `/proc', in preference to `ptrace' for memory reads. This may result
4430 in an improvement in the start-up time of multi-threaded, shared
4431 library applications when run under GDB. One GDB user writes: ``loads
4432 shared libs like mad''.
4434 * ``gdbserver'' now supports multi-threaded applications on some targets
4436 Support for debugging multi-threaded applications which use
4437 the GNU/Linux LinuxThreads package has been added for
4438 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4439 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4441 * GDB now supports C/C++ preprocessor macros.
4443 GDB now expands preprocessor macro invocations in C/C++ expressions,
4444 and provides various commands for showing macro definitions and how
4447 The new command `macro expand EXPRESSION' expands any macro
4448 invocations in expression, and shows the result.
4450 The new command `show macro MACRO-NAME' shows the definition of the
4451 macro named MACRO-NAME, and where it was defined.
4453 Most compilers don't include information about macros in the debugging
4454 information by default. In GCC 3.1, for example, you need to compile
4455 your program with the options `-gdwarf-2 -g3'. If the macro
4456 information is present in the executable, GDB will read it.
4458 * Multi-arched targets.
4460 DEC Alpha (partial) alpha*-*-*
4461 DEC VAX (partial) vax-*-*
4463 National Semiconductor NS32000 (partial) ns32k-*-*
4464 Motorola 68000 (partial) m68k-*-*
4465 Motorola MCORE mcore-*-*
4469 Fujitsu FRV architecture added by Red Hat frv*-*-*
4472 * New native configurations
4474 Alpha NetBSD alpha*-*-netbsd*
4475 SH NetBSD sh*-*-netbsdelf*
4476 MIPS NetBSD mips*-*-netbsd*
4477 UltraSPARC NetBSD sparc64-*-netbsd*
4479 * OBSOLETE configurations and files
4481 Configurations that have been declared obsolete in this release have
4482 been commented out. Unless there is activity to revive these
4483 configurations, the next release of GDB will have their sources
4484 permanently REMOVED.
4486 Mitsubishi D30V d30v-*-*
4487 OS/9000 i[34]86-*-os9k
4488 IBM AIX PS/2 i[3456]86-*-aix
4489 Fujitsu FR30 fr30-*-elf*
4490 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4491 Argonaut Risc Chip (ARC) arc-*-*
4492 i386 running Mach 3.0 i[3456]86-*-mach3*
4493 i386 running Mach i[3456]86-*-mach*
4494 i386 running OSF/1 i[3456]86-*osf1mk*
4495 HP/Apollo 68k Family m68*-apollo*-sysv*,
4497 m68*-hp-bsd*, m68*-hp-hpux*
4498 I960 with MON960 i960-*-coff
4500 * OBSOLETE languages
4502 CHILL, a Pascal like language used by telecommunications companies.
4504 * REMOVED configurations and files
4506 AMD 29k family via UDI a29k-amd-udi, udi29k
4507 A29K VxWorks a29k-*-vxworks
4508 AMD 29000 embedded, using EBMON a29k-none-none
4509 AMD 29000 embedded with COFF a29k-none-coff
4510 AMD 29000 embedded with a.out a29k-none-aout
4512 testsuite/gdb.hp/gdb.threads-hp/ directory
4514 * New command "set max-user-call-depth <nnn>"
4516 This command allows the user to limit the call depth of user-defined
4517 commands. The default is 1024.
4519 * Changes in FreeBSD/i386 native debugging.
4521 Support for the "generate-core-file" has been added.
4523 * New commands "dump", "append", and "restore".
4525 These commands allow data to be copied from target memory
4526 to a bfd-format or binary file (dump and append), and back
4527 from a file into memory (restore).
4529 * Improved "next/step" support on multi-processor Alpha Tru64.
4531 The previous single-step mechanism could cause unpredictable problems,
4532 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4533 of a software single-step mechanism prevents this.
4535 *** Changes in GDB 5.2.1:
4543 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4544 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4545 Fix, by Joel Brobecker imported from mainline.
4547 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4548 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4549 Fix, by Fred Fish, imported from mainline.
4551 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4552 Surprisingly enough, it works now.
4553 By Michal Ludvig, imported from mainline.
4555 i386 hardware watchpoint support:
4556 avoid misses on second run for some targets.
4557 By Pierre Muller, imported from mainline.
4559 *** Changes in GDB 5.2:
4561 * New command "set trust-readonly-sections on[off]".
4563 This command is a hint that tells gdb that read-only sections
4564 really are read-only (ie. that their contents will not change).
4565 In this mode, gdb will go to the object file rather than the
4566 target to read memory from read-only sections (such as ".text").
4567 This can be a significant performance improvement on some
4568 (notably embedded) targets.
4570 * New command "generate-core-file" (or "gcore").
4572 This new gdb command allows the user to drop a core file of the child
4573 process state at any time. So far it's been implemented only for
4574 GNU/Linux and Solaris, but should be relatively easily ported to other
4575 hosts. Argument is core file name (defaults to core.<pid>).
4577 * New command line option
4579 GDB now accepts --pid or -p followed by a process id.
4581 * Change in command line behavior -- corefiles vs. process ids.
4583 There is a subtle behavior in the way in which GDB handles
4584 command line arguments. The first non-flag argument is always
4585 a program to debug, but the second non-flag argument may either
4586 be a corefile or a process id. Previously, GDB would attempt to
4587 open the second argument as a corefile, and if that failed, would
4588 issue a superfluous error message and then attempt to attach it as
4589 a process. Now, if the second argument begins with a non-digit,
4590 it will be treated as a corefile. If it begins with a digit,
4591 GDB will attempt to attach it as a process, and if no such process
4592 is found, will then attempt to open it as a corefile.
4594 * Changes in ARM configurations.
4596 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4597 configuration is fully multi-arch.
4599 * New native configurations
4601 ARM NetBSD arm*-*-netbsd*
4602 x86 OpenBSD i[3456]86-*-openbsd*
4603 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4604 Sparc64 running FreeBSD sparc64-*-freebsd*
4608 Sanyo XStormy16 xstormy16-elf
4610 * OBSOLETE configurations and files
4612 Configurations that have been declared obsolete in this release have
4613 been commented out. Unless there is activity to revive these
4614 configurations, the next release of GDB will have their sources
4615 permanently REMOVED.
4617 AMD 29k family via UDI a29k-amd-udi, udi29k
4618 A29K VxWorks a29k-*-vxworks
4619 AMD 29000 embedded, using EBMON a29k-none-none
4620 AMD 29000 embedded with COFF a29k-none-coff
4621 AMD 29000 embedded with a.out a29k-none-aout
4623 testsuite/gdb.hp/gdb.threads-hp/ directory
4625 * REMOVED configurations and files
4627 TI TMS320C80 tic80-*-*
4629 PowerPC Solaris powerpcle-*-solaris*
4630 PowerPC Windows NT powerpcle-*-cygwin32
4631 PowerPC Netware powerpc-*-netware*
4632 Harris/CXUX m88k m88*-harris-cxux*
4633 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4634 ns32k-utek-sysv* ns32k-utek-*
4635 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4636 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4637 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4638 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4639 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4641 * Changes to command line processing
4643 The new `--args' feature can be used to specify command-line arguments
4644 for the inferior from gdb's command line.
4646 * Changes to key bindings
4648 There is a new `operate-and-get-next' function bound to `C-o'.
4650 *** Changes in GDB 5.1.1
4652 Fix compile problem on DJGPP.
4654 Fix a problem with floating-point registers on the i386 being
4657 Fix to stop GDB crashing on .debug_str debug info.
4659 Numerous documentation fixes.
4661 Numerous testsuite fixes.
4663 *** Changes in GDB 5.1:
4665 * New native configurations
4667 Alpha FreeBSD alpha*-*-freebsd*
4668 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4669 MIPS GNU/Linux mips*-*-linux*
4670 MIPS SGI Irix 6.x mips*-sgi-irix6*
4671 ia64 AIX ia64-*-aix*
4672 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4676 Motorola 68HC11 and 68HC12 m68hc11-elf
4678 UltraSparc running GNU/Linux sparc64-*-linux*
4680 * OBSOLETE configurations and files
4682 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4683 Harris/CXUX m88k m88*-harris-cxux*
4684 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4685 ns32k-utek-sysv* ns32k-utek-*
4686 TI TMS320C80 tic80-*-*
4688 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4689 PowerPC Solaris powerpcle-*-solaris*
4690 PowerPC Windows NT powerpcle-*-cygwin32
4691 PowerPC Netware powerpc-*-netware*
4692 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4693 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4694 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4695 Apple Macintosh (MPW) host N/A
4697 stuff.c (Program to stuff files into a specially prepared space in kdb)
4698 kdb-start.c (Main loop for the standalone kernel debugger)
4700 Configurations that have been declared obsolete in this release have
4701 been commented out. Unless there is activity to revive these
4702 configurations, the next release of GDB will have their sources
4703 permanently REMOVED.
4705 * REMOVED configurations and files
4707 Altos 3068 m68*-altos-*
4708 Convex c1-*-*, c2-*-*
4710 ARM RISCix arm-*-* (as host)
4714 * GDB has been converted to ISO C.
4716 GDB's source code has been converted to ISO C. In particular, the
4717 sources are fully protoized, and rely on standard headers being
4722 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4724 * The MI enabled by default.
4726 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4727 revised and enabled by default. Packages which use GDB as a debugging
4728 engine behind a UI or another front end are encouraged to switch to
4729 using the GDB/MI interface, instead of the old annotations interface
4730 which is now deprecated.
4732 * Support for debugging Pascal programs.
4734 GDB now includes support for debugging Pascal programs. The following
4735 main features are supported:
4737 - Pascal-specific data types such as sets;
4739 - automatic recognition of Pascal sources based on file-name
4742 - Pascal-style display of data types, variables, and functions;
4744 - a Pascal expression parser.
4746 However, some important features are not yet supported.
4748 - Pascal string operations are not supported at all;
4750 - there are some problems with boolean types;
4752 - Pascal type hexadecimal constants are not supported
4753 because they conflict with the internal variables format;
4755 - support for Pascal objects and classes is not full yet;
4757 - unlike Pascal, GDB is case-sensitive for symbol names.
4759 * Changes in completion.
4761 Commands such as `shell', `run' and `set args', which pass arguments
4762 to inferior programs, now complete on file names, similar to what
4763 users expect at the shell prompt.
4765 Commands which accept locations, such as `disassemble', `print',
4766 `breakpoint', `until', etc. now complete on filenames as well as
4767 program symbols. Thus, if you type "break foob TAB", and the source
4768 files linked into the programs include `foobar.c', that file name will
4769 be one of the candidates for completion. However, file names are not
4770 considered for completion after you typed a colon that delimits a file
4771 name from a name of a function in that file, as in "break foo.c:bar".
4773 `set demangle-style' completes on available demangling styles.
4775 * New platform-independent commands:
4777 It is now possible to define a post-hook for a command as well as a
4778 hook that runs before the command. For more details, see the
4779 documentation of `hookpost' in the GDB manual.
4781 * Changes in GNU/Linux native debugging.
4783 Support for debugging multi-threaded programs has been completely
4784 revised for all platforms except m68k and sparc. You can now debug as
4785 many threads as your system allows you to have.
4787 Attach/detach is supported for multi-threaded programs.
4789 Support for SSE registers was added for x86. This doesn't work for
4790 multi-threaded programs though.
4792 * Changes in MIPS configurations.
4794 Multi-arch support is enabled for all MIPS configurations.
4796 GDB can now be built as native debugger on SGI Irix 6.x systems for
4797 debugging n32 executables. (Debugging 64-bit executables is not yet
4800 * Unified support for hardware watchpoints in all x86 configurations.
4802 Most (if not all) native x86 configurations support hardware-assisted
4803 breakpoints and watchpoints in a unified manner. This support
4804 implements debug register sharing between watchpoints, which allows to
4805 put a virtually infinite number of watchpoints on the same address,
4806 and also supports watching regions up to 16 bytes with several debug
4809 The new maintenance command `maintenance show-debug-regs' toggles
4810 debugging print-outs in functions that insert, remove, and test
4811 watchpoints and hardware breakpoints.
4813 * Changes in the DJGPP native configuration.
4815 New command ``info dos sysinfo'' displays assorted information about
4816 the CPU, OS, memory, and DPMI server.
4818 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4819 display information about segment descriptors stored in GDT, LDT, and
4822 New commands ``info dos pde'' and ``info dos pte'' display entries
4823 from Page Directory and Page Tables (for now works with CWSDPMI only).
4824 New command ``info dos address-pte'' displays the Page Table entry for
4825 a given linear address.
4827 GDB can now pass command lines longer than 126 characters to the
4828 program being debugged (requires an update to the libdbg.a library
4829 which is part of the DJGPP development kit).
4831 DWARF2 debug info is now supported.
4833 It is now possible to `step' and `next' through calls to `longjmp'.
4835 * Changes in documentation.
4837 All GDB documentation was converted to GFDL, the GNU Free
4838 Documentation License.
4840 Tracepoints-related commands are now fully documented in the GDB
4843 TUI, the Text-mode User Interface, is now documented in the manual.
4845 Tracepoints-related commands are now fully documented in the GDB
4848 The "GDB Internals" manual now has an index. It also includes
4849 documentation of `ui_out' functions, GDB coding standards, x86
4850 hardware watchpoints, and memory region attributes.
4852 * GDB's version number moved to ``version.in''
4854 The Makefile variable VERSION has been replaced by the file
4855 ``version.in''. People creating GDB distributions should update the
4856 contents of this file.
4860 GUD support is now a standard part of the EMACS distribution.
4862 *** Changes in GDB 5.0:
4864 * Improved support for debugging FP programs on x86 targets
4866 Unified and much-improved support for debugging floating-point
4867 programs on all x86 targets. In particular, ``info float'' now
4868 displays the FP registers in the same format on all x86 targets, with
4869 greater level of detail.
4871 * Improvements and bugfixes in hardware-assisted watchpoints
4873 It is now possible to watch array elements, struct members, and
4874 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4875 on x86 targets no longer erroneously trigger when the address is
4878 * Improvements in the native DJGPP version of GDB
4880 The distribution now includes all the scripts and auxiliary files
4881 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4882 machines ``out of the box''.
4884 The DJGPP version can now debug programs that use signals. It is
4885 possible to catch signals that happened in the debuggee, deliver
4886 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4887 would kill the program being debugged.) Programs that hook hardware
4888 interrupts (keyboard, timer, etc.) can also be debugged.
4890 It is now possible to debug DJGPP programs that redirect their
4891 standard handles or switch them to raw (as opposed to cooked) mode, or
4892 even close them. The command ``run < foo > bar'' works as expected,
4893 and ``info terminal'' reports useful information about the debuggee's
4894 terminal, including raw/cooked mode, redirection, etc.
4896 The DJGPP version now uses termios functions for console I/O, which
4897 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4900 DOS-style file names with drive letters are now fully supported by
4903 It is now possible to debug DJGPP programs that switch their working
4904 directory. It is also possible to rerun the debuggee any number of
4905 times without restarting GDB; thus, you can use the same setup,
4906 breakpoints, etc. for many debugging sessions.
4908 * New native configurations
4910 ARM GNU/Linux arm*-*-linux*
4911 PowerPC GNU/Linux powerpc-*-linux*
4915 Motorola MCore mcore-*-*
4916 x86 VxWorks i[3456]86-*-vxworks*
4917 PowerPC VxWorks powerpc-*-vxworks*
4918 TI TMS320C80 tic80-*-*
4920 * OBSOLETE configurations
4922 Altos 3068 m68*-altos-*
4923 Convex c1-*-*, c2-*-*
4925 ARM RISCix arm-*-* (as host)
4928 Configurations that have been declared obsolete will be commented out,
4929 but the code will be left in place. If there is no activity to revive
4930 these configurations before the next release of GDB, the sources will
4931 be permanently REMOVED.
4933 * Gould support removed
4935 Support for the Gould PowerNode and NP1 has been removed.
4937 * New features for SVR4
4939 On SVR4 native platforms (such as Solaris), if you attach to a process
4940 without first loading a symbol file, GDB will now attempt to locate and
4941 load symbols from the running process's executable file.
4943 * Many C++ enhancements
4945 C++ support has been greatly improved. Overload resolution now works properly
4946 in almost all cases. RTTI support is on the way.
4948 * Remote targets can connect to a sub-program
4950 A popen(3) style serial-device has been added. This device starts a
4951 sub-process (such as a stand-alone simulator) and then communicates
4952 with that. The sub-program to run is specified using the syntax
4953 ``|<program> <args>'' vis:
4955 (gdb) set remotedebug 1
4956 (gdb) target extended-remote |mn10300-elf-sim program-args
4958 * MIPS 64 remote protocol
4960 A long standing bug in the mips64 remote protocol where by GDB
4961 expected certain 32 bit registers (ex SR) to be transfered as 32
4962 instead of 64 bits has been fixed.
4964 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4965 added to provide backward compatibility with older versions of GDB.
4967 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4969 The command ``set remotebinarydownload'' command has been replaced by
4970 ``set remote X-packet''. Other commands in ``set remote'' family
4971 include ``set remote P-packet''.
4973 * Breakpoint commands accept ranges.
4975 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4976 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4977 ``tracepoint passcount'' also accepts a range of tracepoints.
4979 * ``apropos'' command added.
4981 The ``apropos'' command searches through command names and
4982 documentation strings, printing out matches, making it much easier to
4983 try to find a command that does what you are looking for.
4987 A new machine oriented interface (MI) has been added to GDB. This
4988 interface is designed for debug environments running GDB as a separate
4989 process. This is part of the long term libGDB project. See the
4990 "GDB/MI" chapter of the GDB manual for further information. It can be
4991 enabled by configuring with:
4993 .../configure --enable-gdbmi
4995 *** Changes in GDB-4.18:
4997 * New native configurations
4999 HP-UX 10.20 hppa*-*-hpux10.20
5000 HP-UX 11.x hppa*-*-hpux11.0*
5001 M68K GNU/Linux m68*-*-linux*
5005 Fujitsu FR30 fr30-*-elf*
5006 Intel StrongARM strongarm-*-*
5007 Mitsubishi D30V d30v-*-*
5009 * OBSOLETE configurations
5011 Gould PowerNode, NP1 np1-*-*, pn-*-*
5013 Configurations that have been declared obsolete will be commented out,
5014 but the code will be left in place. If there is no activity to revive
5015 these configurations before the next release of GDB, the sources will
5016 be permanently REMOVED.
5020 As a compatibility experiment, GDB's source files buildsym.h and
5021 buildsym.c have been converted to pure standard C, no longer
5022 containing any K&R compatibility code. We believe that all systems in
5023 use today either come with a standard C compiler, or have a GCC port
5024 available. If this is not true, please report the affected
5025 configuration to bug-gdb@gnu.org immediately. See the README file for
5026 information about getting a standard C compiler if you don't have one
5031 GDB now uses readline 2.2.
5033 * set extension-language
5035 You can now control the mapping between filename extensions and source
5036 languages by using the `set extension-language' command. For instance,
5037 you can ask GDB to treat .c files as C++ by saying
5038 set extension-language .c c++
5039 The command `info extensions' lists all of the recognized extensions
5040 and their associated languages.
5042 * Setting processor type for PowerPC and RS/6000
5044 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5045 you can use the `set processor' command to specify what variant of the
5046 PowerPC family you are debugging. The command
5050 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5051 following PowerPC and RS6000 variants:
5053 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5054 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5056 403GC IBM PowerPC 403GC
5057 505 Motorola PowerPC 505
5058 860 Motorola PowerPC 860 or 850
5059 601 Motorola PowerPC 601
5060 602 Motorola PowerPC 602
5061 603 Motorola/IBM PowerPC 603 or 603e
5062 604 Motorola PowerPC 604 or 604e
5063 750 Motorola/IBM PowerPC 750 or 750
5065 At the moment, this command just tells GDB what to name the
5066 special-purpose processor registers. Since almost all the affected
5067 registers are inaccessible to user-level programs, this command is
5068 only useful for remote debugging in its present form.
5072 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5073 more extensive support for HP-UX. Added features include shared
5074 library support, kernel threads and hardware watchpoints for 11.00,
5075 support for HP's ANSI C and C++ compilers, and a compatibility mode
5076 for xdb and dbx commands.
5080 HP's donation includes the new concept of catchpoints, which is a
5081 generalization of the old catch command. On HP-UX, it is now possible
5082 to catch exec, fork, and vfork, as well as library loading.
5084 This means that the existing catch command has changed; its first
5085 argument now specifies the type of catch to be set up. See the
5086 output of "help catch" for a list of catchpoint types.
5088 * Debugging across forks
5090 On HP-UX, you can choose which process to debug when a fork() happens
5095 HP has donated a curses-based terminal user interface (TUI). To get
5096 it, build with --enable-tui. Although this can be enabled for any
5097 configuration, at present it only works for native HP debugging.
5099 * GDB remote protocol additions
5101 A new protocol packet 'X' that writes binary data is now available.
5102 Default behavior is to try 'X', then drop back to 'M' if the stub
5103 fails to respond. The settable variable `remotebinarydownload'
5104 allows explicit control over the use of 'X'.
5106 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5107 full 64-bit address. The command
5109 set remoteaddresssize 32
5111 can be used to revert to the old behaviour. For existing remote stubs
5112 the change should not be noticed, as the additional address information
5115 In order to assist in debugging stubs, you may use the maintenance
5116 command `packet' to send any text string to the stub. For instance,
5118 maint packet heythere
5120 sends the packet "$heythere#<checksum>". Note that it is very easy to
5121 disrupt a debugging session by sending the wrong packet at the wrong
5124 The compare-sections command allows you to compare section data on the
5125 target to what is in the executable file without uploading or
5126 downloading, by comparing CRC checksums.
5128 * Tracing can collect general expressions
5130 You may now collect general expressions at tracepoints. This requires
5131 further additions to the target-side stub; see tracepoint.c and
5132 doc/agentexpr.texi for further details.
5134 * mask-address variable for Mips
5136 For Mips targets, you may control the zeroing of the upper 32 bits of
5137 a 64-bit address by entering `set mask-address on'. This is mainly
5138 of interest to users of embedded R4xxx and R5xxx processors.
5140 * Higher serial baud rates
5142 GDB's serial code now allows you to specify baud rates 57600, 115200,
5143 230400, and 460800 baud. (Note that your host system may not be able
5144 to achieve all of these rates.)
5148 The i960 configuration now includes an initial implementation of a
5149 builtin simulator, contributed by Jim Wilson.
5152 *** Changes in GDB-4.17:
5154 * New native configurations
5156 Alpha GNU/Linux alpha*-*-linux*
5157 Unixware 2.x i[3456]86-unixware2*
5158 Irix 6.x mips*-sgi-irix6*
5159 PowerPC GNU/Linux powerpc-*-linux*
5160 PowerPC Solaris powerpcle-*-solaris*
5161 Sparc GNU/Linux sparc-*-linux*
5162 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5166 Argonaut Risc Chip (ARC) arc-*-*
5167 Hitachi H8/300S h8300*-*-*
5168 Matsushita MN10200 w/simulator mn10200-*-*
5169 Matsushita MN10300 w/simulator mn10300-*-*
5170 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5171 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5172 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5173 Mitsubishi D10V w/simulator d10v-*-*
5174 Mitsubishi M32R/D w/simulator m32r-*-elf*
5175 Tsqware Sparclet sparclet-*-*
5176 NEC V850 w/simulator v850-*-*
5178 * New debugging protocols
5180 ARM with RDI protocol arm*-*-*
5181 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5182 DDB and LSI variants of PMON protocol mips*-*-*
5183 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5184 PowerPC with SDS protocol powerpc{,le}-*-eabi
5185 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5189 All configurations can now understand and use the DWARF 2 debugging
5190 format. The choice is automatic, if the symbol file contains DWARF 2
5195 GDB now includes basic Java language support. This support is
5196 only useful with Java compilers that produce native machine code.
5198 * solib-absolute-prefix and solib-search-path
5200 For SunOS and SVR4 shared libraries, you may now set the prefix for
5201 loading absolute shared library symbol files, and the search path for
5202 locating non-absolute shared library symbol files.
5204 * Live range splitting
5206 GDB can now effectively debug code for which GCC has performed live
5207 range splitting as part of its optimization. See gdb/doc/LRS for
5208 more details on the expected format of the stabs information.
5212 GDB's support for the GNU Hurd, including thread debugging, has been
5213 updated to work with current versions of the Hurd.
5217 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5218 instruction set. ARM GDB automatically detects when Thumb
5219 instructions are in use, and adjusts disassembly and backtracing
5224 GDB's MIPS target configurations now handle the MIP16 16-bit
5229 GDB now includes support for overlays; if an executable has been
5230 linked such that multiple sections are based at the same address, GDB
5231 will decide which section to use for symbolic info. You can choose to
5232 control the decision manually, using overlay commands, or implement
5233 additional target-side support and use "overlay load-target" to bring
5234 in the overlay mapping. Do "help overlay" for more detail.
5238 The command "info symbol <address>" displays information about
5239 the symbol at the specified address.
5243 The standard remote protocol now includes an extension that allows
5244 asynchronous collection and display of trace data. This requires
5245 extensive support in the target-side debugging stub. Tracing mode
5246 includes a new interaction mode in GDB and new commands: see the
5247 file tracepoint.c for more details.
5251 Configurations for embedded MIPS now include a simulator contributed
5252 by Cygnus Solutions. The simulator supports the instruction sets
5253 of most MIPS variants.
5257 Sparc configurations may now include the ERC32 simulator contributed
5258 by the European Space Agency. The simulator is not built into
5259 Sparc targets by default; configure with --enable-sim to include it.
5263 For target configurations that may include multiple variants of a
5264 basic architecture (such as MIPS and SH), you may now set the
5265 architecture explicitly. "set arch" sets, "info arch" lists
5266 the possible architectures.
5268 *** Changes in GDB-4.16:
5270 * New native configurations
5272 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5273 M68K NetBSD m68k-*-netbsd*
5274 PowerPC AIX 4.x powerpc-*-aix*
5275 PowerPC MacOS powerpc-*-macos*
5276 PowerPC Windows NT powerpcle-*-cygwin32
5277 RS/6000 AIX 4.x rs6000-*-aix4*
5281 ARM with RDP protocol arm-*-*
5282 I960 with MON960 i960-*-coff
5283 MIPS VxWorks mips*-*-vxworks*
5284 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5285 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5287 Matra Sparclet sparclet-*-*
5291 The powerpc-eabi configuration now includes the PSIM simulator,
5292 contributed by Andrew Cagney, with assistance from Mike Meissner.
5293 PSIM is a very elaborate model of the PowerPC, including not only
5294 basic instruction set execution, but also details of execution unit
5295 performance and I/O hardware. See sim/ppc/README for more details.
5299 GDB now works with Solaris 2.5.
5301 * Windows 95/NT native
5303 GDB will now work as a native debugger on Windows 95 and Windows NT.
5304 To build it from source, you must use the "gnu-win32" environment,
5305 which uses a DLL to emulate enough of Unix to run the GNU tools.
5306 Further information, binaries, and sources are available at
5307 ftp.cygnus.com, under pub/gnu-win32.
5309 * dont-repeat command
5311 If a user-defined command includes the command `dont-repeat', then the
5312 command will not be repeated if the user just types return. This is
5313 useful if the command is time-consuming to run, so that accidental
5314 extra keystrokes don't run the same command many times.
5316 * Send break instead of ^C
5318 The standard remote protocol now includes an option to send a break
5319 rather than a ^C to the target in order to interrupt it. By default,
5320 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5322 * Remote protocol timeout
5324 The standard remote protocol includes a new variable `remotetimeout'
5325 that allows you to set the number of seconds before GDB gives up trying
5326 to read from the target. The default value is 2.
5328 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5330 By default GDB will automatically keep track of objects as they are
5331 loaded and unloaded by the dynamic linker. By using the command `set
5332 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5333 when shared library events occur, thus allowing you to set breakpoints
5334 in shared libraries which are explicitly loaded by the inferior.
5336 Note this feature does not work on hpux8. On hpux9 you must link
5337 /usr/lib/end.o into your program. This feature should work
5338 automatically on hpux10.
5340 * Irix 5.x hardware watchpoint support
5342 Irix 5 configurations now support the use of hardware watchpoints.
5344 * Mips protocol "SYN garbage limit"
5346 When debugging a Mips target using the `target mips' protocol, you
5347 may set the number of characters that GDB will ignore by setting
5348 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5349 every character. The default value is 1050.
5351 * Recording and replaying remote debug sessions
5353 If you set `remotelogfile' to the name of a file, gdb will write to it
5354 a recording of a remote debug session. This recording may then be
5355 replayed back to gdb using "gdbreplay". See gdbserver/README for
5356 details. This is useful when you have a problem with GDB while doing
5357 remote debugging; you can make a recording of the session and send it
5358 to someone else, who can then recreate the problem.
5360 * Speedups for remote debugging
5362 GDB includes speedups for downloading and stepping MIPS systems using
5363 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5364 and more efficient S-record downloading.
5366 * Memory use reductions and statistics collection
5368 GDB now uses less memory and reports statistics about memory usage.
5369 Try the `maint print statistics' command, for example.
5371 *** Changes in GDB-4.15:
5373 * Psymtabs for XCOFF
5375 The symbol reader for AIX GDB now uses partial symbol tables. This
5376 can greatly improve startup time, especially for large executables.
5378 * Remote targets use caching
5380 Remote targets now use a data cache to speed up communication with the
5381 remote side. The data cache could lead to incorrect results because
5382 it doesn't know about volatile variables, thus making it impossible to
5383 debug targets which use memory mapped I/O devices. `set remotecache
5384 off' turns the the data cache off.
5386 * Remote targets may have threads
5388 The standard remote protocol now includes support for multiple threads
5389 in the target system, using new protocol commands 'H' and 'T'. See
5390 gdb/remote.c for details.
5394 If GDB is configured with `--enable-netrom', then it will include
5395 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5396 acts as though it is a bank of ROM on the target board, but you can
5397 write into it over the network. GDB's support consists only of
5398 support for fast loading into the emulated ROM; to debug, you must use
5399 another protocol, such as standard remote protocol. The usual
5400 sequence is something like
5402 target nrom <netrom-hostname>
5404 target remote <netrom-hostname>:1235
5408 GDB now includes support for the Apple Macintosh, as a host only. It
5409 may be run as either an MPW tool or as a standalone application, and
5410 it can debug through the serial port. All the usual GDB commands are
5411 available, but to the target command, you must supply "serial" as the
5412 device type instead of "/dev/ttyXX". See mpw-README in the main
5413 directory for more information on how to build. The MPW configuration
5414 scripts */mpw-config.in support only a few targets, and only the
5415 mips-idt-ecoff target has been tested.
5419 GDB configuration now uses autoconf. This is not user-visible,
5420 but does simplify configuration and building.
5424 GDB now supports hpux10.
5426 *** Changes in GDB-4.14:
5428 * New native configurations
5430 x86 FreeBSD i[345]86-*-freebsd
5431 x86 NetBSD i[345]86-*-netbsd
5432 NS32k NetBSD ns32k-*-netbsd
5433 Sparc NetBSD sparc-*-netbsd
5437 A29K VxWorks a29k-*-vxworks
5438 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5439 CPU32 EST-300 emulator m68*-*-est*
5440 PowerPC ELF powerpc-*-elf
5443 * Alpha OSF/1 support for procfs
5445 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5446 possible to attach to running processes. As the mounting of the /proc
5447 filesystem is optional on the Alpha, GDB automatically determines
5448 the availability of /proc during startup. This can lead to problems
5449 if /proc is unmounted after GDB has been started.
5451 * Arguments to user-defined commands
5453 User commands may accept up to 10 arguments separated by whitespace.
5454 Arguments are accessed within the user command via $arg0..$arg9. A
5457 print $arg0 + $arg1 + $arg2
5459 To execute the command use:
5462 Defines the command "adder" which prints the sum of its three arguments.
5463 Note the arguments are text substitutions, so they may reference variables,
5464 use complex expressions, or even perform inferior function calls.
5466 * New `if' and `while' commands
5468 This makes it possible to write more sophisticated user-defined
5469 commands. Both commands take a single argument, which is the
5470 expression to evaluate, and must be followed by the commands to
5471 execute, one per line, if the expression is nonzero, the list being
5472 terminated by the word `end'. The `if' command list may include an
5473 `else' word, which causes the following commands to be executed only
5474 if the expression is zero.
5476 * Fortran source language mode
5478 GDB now includes partial support for Fortran 77. It will recognize
5479 Fortran programs and can evaluate a subset of Fortran expressions, but
5480 variables and functions may not be handled correctly. GDB will work
5481 with G77, but does not yet know much about symbols emitted by other
5484 * Better HPUX support
5486 Most debugging facilities now work on dynamic executables for HPPAs
5487 running hpux9 or later. You can attach to running dynamically linked
5488 processes, but by default the dynamic libraries will be read-only, so
5489 for instance you won't be able to put breakpoints in them. To change
5490 that behavior do the following before running the program:
5496 This will cause the libraries to be mapped private and read-write.
5497 To revert to the normal behavior, do this:
5503 You cannot set breakpoints or examine data in the library until after
5504 the library is loaded if the function/data symbols do not have
5507 GDB can now also read debug symbols produced by the HP C compiler on
5508 HPPAs (sorry, no C++, Fortran or 68k support).
5510 * Target byte order now dynamically selectable
5512 You can choose which byte order to use with a target system, via the
5513 commands "set endian big" and "set endian little", and you can see the
5514 current setting by using "show endian". You can also give the command
5515 "set endian auto", in which case GDB will use the byte order
5516 associated with the executable. Currently, only embedded MIPS
5517 configurations support dynamic selection of target byte order.
5519 * New DOS host serial code
5521 This version uses DPMI interrupts to handle buffered I/O, so you
5522 no longer need to run asynctsr when debugging boards connected to
5525 *** Changes in GDB-4.13:
5527 * New "complete" command
5529 This lists all the possible completions for the rest of the line, if it
5530 were to be given as a command itself. This is intended for use by emacs.
5532 * Trailing space optional in prompt
5534 "set prompt" no longer adds a space for you after the prompt you set. This
5535 allows you to set a prompt which ends in a space or one that does not.
5537 * Breakpoint hit counts
5539 "info break" now displays a count of the number of times the breakpoint
5540 has been hit. This is especially useful in conjunction with "ignore"; you
5541 can ignore a large number of breakpoint hits, look at the breakpoint info
5542 to see how many times the breakpoint was hit, then run again, ignoring one
5543 less than that number, and this will get you quickly to the last hit of
5546 * Ability to stop printing at NULL character
5548 "set print null-stop" will cause GDB to stop printing the characters of
5549 an array when the first NULL is encountered. This is useful when large
5550 arrays actually contain only short strings.
5552 * Shared library breakpoints
5554 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5555 breakpoints in shared libraries before the executable is run.
5557 * Hardware watchpoints
5559 There is a new hardware breakpoint for the watch command for sparclite
5560 targets. See gdb/sparclite/hw_breakpoint.note.
5562 Hardware watchpoints are also now supported under GNU/Linux.
5566 Annotations have been added. These are for use with graphical interfaces,
5567 and are still experimental. Currently only gdba.el uses these.
5569 * Improved Irix 5 support
5571 GDB now works properly with Irix 5.2.
5573 * Improved HPPA support
5575 GDB now works properly with the latest GCC and GAS.
5577 * New native configurations
5579 Sequent PTX4 i[34]86-sequent-ptx4
5580 HPPA running OSF/1 hppa*-*-osf*
5581 Atari TT running SVR4 m68*-*-sysv4*
5582 RS/6000 LynxOS rs6000-*-lynxos*
5586 OS/9000 i[34]86-*-os9k
5587 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5590 * Hitachi SH7000 and E7000-PC ICE support
5592 There is now support for communicating with the Hitachi E7000-PC ICE.
5593 This is available automatically when GDB is configured for the SH.
5597 As usual, a variety of small fixes and improvements, both generic
5598 and configuration-specific. See the ChangeLog for more detail.
5600 *** Changes in GDB-4.12:
5602 * Irix 5 is now supported
5606 GDB-4.12 on the HPPA has a number of changes which make it unable
5607 to debug the output from the currently released versions of GCC and
5608 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5609 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5610 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5613 *** Changes in GDB-4.11:
5615 * User visible changes:
5619 The "set remotedebug" option is now consistent between the mips remote
5620 target, remote targets using the gdb-specific protocol, UDI (AMD's
5621 debug protocol for the 29k) and the 88k bug monitor. It is now an
5622 integer specifying a debug level (normally 0 or 1, but 2 means more
5623 debugging info for the mips target).
5625 * DEC Alpha native support
5627 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5628 debug info, but GDB works fairly well with the DEC compiler and should
5629 work with a future GCC release. See the README file for a few
5630 Alpha-specific notes.
5632 * Preliminary thread implementation
5634 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5636 * LynxOS native and target support for 386
5638 This release has been hosted on LynxOS 2.2, and also can be configured
5639 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5642 * Improvements in C++ mangling/demangling.
5644 This release has much better g++ debugging, specifically in name
5645 mangling/demangling, virtual function calls, print virtual table,
5646 call methods, ...etc.
5648 *** Changes in GDB-4.10:
5650 * User visible changes:
5652 Remote debugging using the GDB-specific (`target remote') protocol now
5653 supports the `load' command. This is only useful if you have some
5654 other way of getting the stub to the target system, and you can put it
5655 somewhere in memory where it won't get clobbered by the download.
5657 Filename completion now works.
5659 When run under emacs mode, the "info line" command now causes the
5660 arrow to point to the line specified. Also, "info line" prints
5661 addresses in symbolic form (as well as hex).
5663 All vxworks based targets now support a user settable option, called
5664 vxworks-timeout. This option represents the number of seconds gdb
5665 should wait for responses to rpc's. You might want to use this if
5666 your vxworks target is, perhaps, a slow software simulator or happens
5667 to be on the far side of a thin network line.
5671 This release contains support for using a DEC alpha as a GDB host for
5672 cross debugging. Native alpha debugging is not supported yet.
5675 *** Changes in GDB-4.9:
5679 This is the first GDB release which is accompanied by a matching testsuite.
5680 The testsuite requires installation of dejagnu, which should be available
5681 via ftp from most sites that carry GNU software.
5685 'Cfront' style demangling has had its name changed to 'ARM' style, to
5686 emphasize that it was written from the specifications in the C++ Annotated
5687 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5688 disclaimers, it still generated too much confusion with users attempting to
5689 use gdb with AT&T cfront.
5693 GDB now uses a standard remote interface to a simulator library.
5694 So far, the library contains simulators for the Zilog Z8001/2, the
5695 Hitachi H8/300, H8/500 and Super-H.
5697 * New targets supported
5699 H8/300 simulator h8300-hitachi-hms or h8300hms
5700 H8/500 simulator h8500-hitachi-hms or h8500hms
5701 SH simulator sh-hitachi-hms or sh
5702 Z8000 simulator z8k-zilog-none or z8ksim
5703 IDT MIPS board over serial line mips-idt-ecoff
5705 Cross-debugging to GO32 targets is supported. It requires a custom
5706 version of the i386-stub.c module which is integrated with the
5707 GO32 memory extender.
5709 * New remote protocols
5711 MIPS remote debugging protocol.
5713 * New source languages supported
5715 This version includes preliminary support for Chill, a Pascal like language
5716 used by telecommunications companies. Chill support is also being integrated
5717 into the GNU compiler, but we don't know when it will be publically available.
5720 *** Changes in GDB-4.8:
5722 * HP Precision Architecture supported
5724 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5725 version of this support was available as a set of patches from the
5726 University of Utah. GDB does not support debugging of programs
5727 compiled with the HP compiler, because HP will not document their file
5728 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5729 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5731 Many problems in the preliminary version have been fixed.
5733 * Faster and better demangling
5735 We have improved template demangling and fixed numerous bugs in the GNU style
5736 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5737 character types (wchar_t) are now supported. Demangling of each symbol is now
5738 only done once, and is cached when the symbol table for a file is read in.
5739 This results in a small increase in memory usage for C programs, a moderate
5740 increase in memory usage for C++ programs, and a fantastic speedup in
5743 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5744 from the specifications in the Annotated Reference Manual, which AT&T's
5745 compiler does not actually implement.
5747 * G++ multiple inheritance compiler problem
5749 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5750 inheritance lattices was reworked to properly discover ambiguities. We
5751 recently found an example which causes this new algorithm to fail in a
5752 very subtle way, producing bad debug information for those classes.
5753 The file 'gcc.patch' (in this directory) can be applied to gcc to
5754 circumvent the problem. A future GCC release will contain a complete
5757 The previous G++ debug info problem (mentioned below for the gdb-4.7
5758 release) is fixed in gcc version 2.3.2.
5760 * Improved configure script
5762 The `configure' script will now attempt to guess your system type if
5763 you don't supply a host system type. The old scheme of supplying a
5764 host system triplet is preferable over using this. All the magic is
5765 done in the new `config.guess' script. Examine it for details.
5767 We have also brought our configure script much more in line with the FSF's
5768 version. It now supports the --with-xxx options. In particular,
5769 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5770 The resulting GDB will not be able to read arbitrary object file formats --
5771 only the format ``expected'' to be used on the configured target system.
5772 We hope to make this the default in a future release.
5774 * Documentation improvements
5776 There's new internal documentation on how to modify GDB, and how to
5777 produce clean changes to the code. We implore people to read it
5778 before submitting changes.
5780 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5781 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5782 `info' files are also provided. To build `info' files from scratch,
5783 you will need the latest `makeinfo' release, which will be available in
5784 a future texinfo-X.Y release.
5786 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5787 We're not sure exactly which versions have this problem, but it has
5788 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5789 or better. If that isn't possible, there is a patch in
5790 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5791 around this problem.
5795 GDB now supports array constants that can be used in expressions typed in by
5796 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5797 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5800 The new directory `gdb/sparclite' contains a program that demonstrates
5801 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5803 * New native hosts supported
5805 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5806 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5808 * New targets supported
5810 AMD 29k family via UDI a29k-amd-udi or udi29k
5812 * New file formats supported
5814 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5815 HPUX core files, and SCO 3.2v2 core files.
5819 Attaching to processes now works again; thanks for the many bug reports.
5821 We have also stomped on a bunch of core dumps caused by
5822 printf_filtered("%s") problems.
5824 We eliminated a copyright problem on the rpc and ptrace header files
5825 for VxWorks, which was discovered at the last minute during the 4.7
5826 release. You should now be able to build a VxWorks GDB.
5828 You can now interrupt gdb while an attached process is running. This
5829 will cause the attached process to stop, and give control back to GDB.
5831 We fixed problems caused by using too many file descriptors
5832 for reading symbols from object files and libraries. This was
5833 especially a problem for programs that used many (~100) shared
5836 The `step' command now only enters a subroutine if there is line number
5837 information for the subroutine. Otherwise it acts like the `next'
5838 command. Previously, `step' would enter subroutines if there was
5839 any debugging information about the routine. This avoids problems
5840 when using `cc -g1' on MIPS machines.
5842 * Internal improvements
5844 GDB's internal interfaces have been improved to make it easier to support
5845 debugging of multiple languages in the future.
5847 GDB now uses a common structure for symbol information internally.
5848 Minimal symbols (derived from linkage symbols in object files), partial
5849 symbols (from a quick scan of debug information), and full symbols
5850 contain a common subset of information, making it easier to write
5851 shared code that handles any of them.
5853 * New command line options
5855 We now accept --silent as an alias for --quiet.
5859 The memory-mapped-malloc library is now licensed under the GNU Library
5860 General Public License.
5862 *** Changes in GDB-4.7:
5864 * Host/native/target split
5866 GDB has had some major internal surgery to untangle the support for
5867 hosts and remote targets. Now, when you configure GDB for a remote
5868 target, it will no longer load in all of the support for debugging
5869 local programs on the host. When fully completed and tested, this will
5870 ensure that arbitrary host/target combinations are possible.
5872 The primary conceptual shift is to separate the non-portable code in
5873 GDB into three categories. Host specific code is required any time GDB
5874 is compiled on that host, regardless of the target. Target specific
5875 code relates to the peculiarities of the target, but can be compiled on
5876 any host. Native specific code is everything else: it can only be
5877 built when the host and target are the same system. Child process
5878 handling and core file support are two common `native' examples.
5880 GDB's use of /proc for controlling Unix child processes is now cleaner.
5881 It has been split out into a single module under the `target_ops' vector,
5882 plus two native-dependent functions for each system that uses /proc.
5884 * New hosts supported
5886 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5887 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5888 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5890 * New targets supported
5892 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5893 68030 and CPU32 m68030-*-*, m68332-*-*
5895 * New native hosts supported
5897 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5898 (386bsd is not well tested yet)
5899 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5901 * New file formats supported
5903 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5904 supports reading of `a.out.adobe' object files, which are an a.out
5905 format extended with minimal information about multiple sections.
5909 `show copying' is the same as the old `info copying'.
5910 `show warranty' is the same as `info warrantee'.
5911 These were renamed for consistency. The old commands continue to work.
5913 `info handle' is a new alias for `info signals'.
5915 You can now define pre-command hooks, which attach arbitrary command
5916 scripts to any command. The commands in the hook will be executed
5917 prior to the user's command. You can also create a hook which will be
5918 executed whenever the program stops. See gdb.texinfo.
5922 We now deal with Cfront style name mangling, and can even extract type
5923 info from mangled symbols. GDB can automatically figure out which
5924 symbol mangling style your C++ compiler uses.
5926 Calling of methods and virtual functions has been improved as well.
5930 The crash that occured when debugging Sun Ansi-C compiled binaries is
5931 fixed. This was due to mishandling of the extra N_SO stabs output
5934 We also finally got Ultrix 4.2 running in house, and fixed core file
5935 support, with help from a dozen people on the net.
5937 John M. Farrell discovered that the reason that single-stepping was so
5938 slow on all of the Mips based platforms (primarily SGI and DEC) was
5939 that we were trying to demangle and lookup a symbol used for internal
5940 purposes on every instruction that was being stepped through. Changing
5941 the name of that symbol so that it couldn't be mistaken for a C++
5942 mangled symbol sped things up a great deal.
5944 Rich Pixley sped up symbol lookups in general by getting much smarter
5945 about when C++ symbol mangling is necessary. This should make symbol
5946 completion (TAB on the command line) much faster. It's not as fast as
5947 we'd like, but it's significantly faster than gdb-4.6.
5951 A new user controllable variable 'call_scratch_address' can
5952 specify the location of a scratch area to be used when GDB
5953 calls a function in the target. This is necessary because the
5954 usual method of putting the scratch area on the stack does not work
5955 in systems that have separate instruction and data spaces.
5957 We integrated changes to support the 29k UDI (Universal Debugger
5958 Interface), but discovered at the last minute that we didn't have all
5959 of the appropriate copyright paperwork. We are working with AMD to
5960 resolve this, and hope to have it available soon.
5964 We have sped up the remote serial line protocol, especially for targets
5965 with lots of registers. It now supports a new `expedited status' ('T')
5966 message which can be used in place of the existing 'S' status message.
5967 This allows the remote stub to send only the registers that GDB
5968 needs to make a quick decision about single-stepping or conditional
5969 breakpoints, eliminating the need to fetch the entire register set for
5970 each instruction being stepped through.
5972 The GDB remote serial protocol now implements a write-through cache for
5973 registers, only re-reading the registers if the target has run.
5975 There is also a new remote serial stub for SPARC processors. You can
5976 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5977 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5978 processor with a serial port.
5982 Configure.in files have become much easier to read and modify. A new
5983 `table driven' format makes it more obvious what configurations are
5984 supported, and what files each one uses.
5988 There is a new opcodes library which will eventually contain all of the
5989 disassembly routines and opcode tables. At present, it only contains
5990 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5991 disassembler (binutils/objdump) to share these routines.
5993 The libiberty library is now copylefted under the GNU Library General
5994 Public License. This allows more liberal use, and was done so libg++
5995 can use it. This makes no difference to GDB, since the Library License
5996 grants all the rights from the General Public License.
6000 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6001 reference to the stabs symbol info used by the debugger. It is (as far
6002 as we know) the only published document on this fascinating topic. We
6003 encourage you to read it, compare it to the stabs information on your
6004 system, and send improvements on the document in general (to
6005 bug-gdb@prep.ai.mit.edu).
6007 And, of course, many bugs have been fixed.
6010 *** Changes in GDB-4.6:
6012 * Better support for C++ function names
6014 GDB now accepts as input the "demangled form" of C++ overloaded function
6015 names and member function names, and can do command completion on such names
6016 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6017 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6018 Make use of command completion, it is your friend.
6020 GDB also now accepts a variety of C++ mangled symbol formats. They are
6021 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6022 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6023 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6024 for the list of formats.
6026 * G++ symbol mangling problem
6028 Recent versions of gcc have a bug in how they emit debugging information for
6029 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6030 directory) can be applied to gcc to fix the problem. Alternatively, if you
6031 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6032 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6033 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6036 * New 'maintenance' command
6038 All of the commands related to hacking GDB internals have been moved out of
6039 the main command set, and now live behind the 'maintenance' command. This
6040 can also be abbreviated as 'mt'. The following changes were made:
6042 dump-me -> maintenance dump-me
6043 info all-breakpoints -> maintenance info breakpoints
6044 printmsyms -> maintenance print msyms
6045 printobjfiles -> maintenance print objfiles
6046 printpsyms -> maintenance print psymbols
6047 printsyms -> maintenance print symbols
6049 The following commands are new:
6051 maintenance demangle Call internal GDB demangler routine to
6052 demangle a C++ link name and prints the result.
6053 maintenance print type Print a type chain for a given symbol
6055 * Change to .gdbinit file processing
6057 We now read the $HOME/.gdbinit file before processing the argv arguments
6058 (e.g. reading symbol files or core files). This allows global parameters to
6059 be set, which will apply during the symbol reading. The ./.gdbinit is still
6060 read after argv processing.
6062 * New hosts supported
6064 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6066 GNU/Linux support i386-unknown-linux or linux
6068 We are also including code to support the HP/PA running BSD and HPUX. This
6069 is almost guaranteed not to work, as we didn't have time to test or build it
6070 for this release. We are including it so that the more adventurous (or
6071 masochistic) of you can play with it. We also had major problems with the
6072 fact that the compiler that we got from HP doesn't support the -g option.
6075 * New targets supported
6077 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6079 * More smarts about finding #include files
6081 GDB now remembers the compilation directory for all include files, and for
6082 all files from which C is generated (like yacc and lex sources). This
6083 greatly improves GDB's ability to find yacc/lex sources, and include files,
6084 especially if you are debugging your program from a directory different from
6085 the one that contains your sources.
6087 We also fixed a bug which caused difficulty with listing and setting
6088 breakpoints in include files which contain C code. (In the past, you had to
6089 try twice in order to list an include file that you hadn't looked at before.)
6091 * Interesting infernals change
6093 GDB now deals with arbitrary numbers of sections, where the symbols for each
6094 section must be relocated relative to that section's landing place in the
6095 target's address space. This work was needed to support ELF with embedded
6096 stabs used by Solaris-2.0.
6098 * Bug fixes (of course!)
6100 There have been loads of fixes for the following things:
6101 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6102 i960, stabs, DOS(GO32), procfs, etc...
6104 See the ChangeLog for details.
6106 *** Changes in GDB-4.5:
6108 * New machines supported (host and target)
6110 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6112 SGI Irix-4.x mips-sgi-irix4 or iris4
6114 * New malloc package
6116 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6117 Mmalloc is capable of handling mutiple heaps of memory. It is also
6118 capable of saving a heap to a file, and then mapping it back in later.
6119 This can be used to greatly speedup the startup of GDB by using a
6120 pre-parsed symbol table which lives in a mmalloc managed heap. For
6121 more details, please read mmalloc/mmalloc.texi.
6125 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6126 'help info proc' for details.
6128 * MIPS ecoff symbol table format
6130 The code that reads MIPS symbol table format is now supported on all hosts.
6131 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6134 * File name changes for MS-DOS
6136 Many files in the config directories have been renamed to make it easier to
6137 support GDB on MS-DOSe systems (which have very restrictive file name
6138 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6139 environment) is close to working but has some remaining problems. Note
6140 that debugging of DOS programs is not supported, due to limitations
6141 in the ``operating system'', but it can be used to host cross-debugging.
6143 * Cross byte order fixes
6145 Many fixes have been made to support cross debugging of Sparc and MIPS
6146 targets from hosts whose byte order differs.
6148 * New -mapped and -readnow options
6150 If memory-mapped files are available on your system through the 'mmap'
6151 system call, you can use the -mapped option on the `file' or
6152 `symbol-file' commands to cause GDB to write the symbols from your
6153 program into a reusable file. If the program you are debugging is
6154 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6155 Future GDB debugging sessions will notice the presence of this file,
6156 and will quickly map in symbol information from it, rather than reading
6157 the symbol table from the executable program. Using the '-mapped'
6158 option in a GDB `file' or `symbol-file' command has the same effect as
6159 starting GDB with the '-mapped' command-line option.
6161 You can cause GDB to read the entire symbol table immediately by using
6162 the '-readnow' option with any of the commands that load symbol table
6163 information (or on the GDB command line). This makes the command
6164 slower, but makes future operations faster.
6166 The -mapped and -readnow options are typically combined in order to
6167 build a `fred.syms' file that contains complete symbol information.
6168 A simple GDB invocation to do nothing but build a `.syms' file for future
6171 gdb -batch -nx -mapped -readnow programname
6173 The `.syms' file is specific to the host machine on which GDB is run.
6174 It holds an exact image of GDB's internal symbol table. It cannot be
6175 shared across multiple host platforms.
6177 * longjmp() handling
6179 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6180 siglongjmp() without losing control. This feature has not yet been ported to
6181 all systems. It currently works on many 386 platforms, all MIPS-based
6182 platforms (SGI, DECstation, etc), and Sun3/4.
6186 Preliminary work has been put in to support the new Solaris OS from Sun. At
6187 this time, it can control and debug processes, but it is not capable of
6192 As always, many many bug fixes. The major areas were with g++, and mipsread.
6193 People using the MIPS-based platforms should experience fewer mysterious
6194 crashes and trashed symbol tables.
6196 *** Changes in GDB-4.4:
6198 * New machines supported (host and target)
6200 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6202 BSD Reno on Vax vax-dec-bsd
6203 Ultrix on Vax vax-dec-ultrix
6205 * New machines supported (target)
6207 AMD 29000 embedded, using EBMON a29k-none-none
6211 GDB continues to improve its handling of C++. `References' work better.
6212 The demangler has also been improved, and now deals with symbols mangled as
6213 per the Annotated C++ Reference Guide.
6215 GDB also now handles `stabs' symbol information embedded in MIPS
6216 `ecoff' symbol tables. Since the ecoff format was not easily
6217 extensible to handle new languages such as C++, this appeared to be a
6218 good way to put C++ debugging info into MIPS binaries. This option
6219 will be supported in the GNU C compiler, version 2, when it is
6222 * New features for SVR4
6224 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6225 shared libraries. Debugging dynamically linked programs should present
6226 only minor differences from debugging statically linked programs.
6228 The `info proc' command will print out information about any process
6229 on an SVR4 system (including the one you are debugging). At the moment,
6230 it prints the address mappings of the process.
6232 If you bring up GDB on another SVR4 system, please send mail to
6233 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6235 * Better dynamic linking support in SunOS
6237 Reading symbols from shared libraries which contain debugging symbols
6238 now works properly. However, there remain issues such as automatic
6239 skipping of `transfer vector' code during function calls, which
6240 make it harder to debug code in a shared library, than to debug the
6241 same code linked statically.
6245 GDB is now using the latest `getopt' routines from the FSF. This
6246 version accepts the -- prefix for options with long names. GDB will
6247 continue to accept the old forms (-option and +option) as well.
6248 Various single letter abbreviations for options have been explicity
6249 added to the option table so that they won't get overshadowed in the
6250 future by other options that begin with the same letter.
6254 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6255 Many assorted bugs have been handled. Many more remain to be handled.
6256 See the various ChangeLog files (primarily in gdb and bfd) for details.
6259 *** Changes in GDB-4.3:
6261 * New machines supported (host and target)
6263 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6264 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6265 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6267 * Almost SCO Unix support
6269 We had hoped to support:
6270 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6271 (except for core file support), but we discovered very late in the release
6272 that it has problems with process groups that render gdb unusable. Sorry
6273 about that. I encourage people to fix it and post the fixes.
6275 * Preliminary ELF and DWARF support
6277 GDB can read ELF object files on System V Release 4, and can handle
6278 debugging records for C, in DWARF format, in ELF files. This support
6279 is preliminary. If you bring up GDB on another SVR4 system, please
6280 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6285 GDB now uses the latest `readline' library. One user-visible change
6286 is that two tabs will list possible command completions, which previously
6287 required typing M-? (meta-question mark, or ESC ?).
6291 The `stepi' bug that many of you noticed has been squashed.
6292 Many bugs in C++ have been handled. Many more remain to be handled.
6293 See the various ChangeLog files (primarily in gdb and bfd) for details.
6295 * State of the MIPS world (in case you wondered):
6297 GDB can understand the symbol tables emitted by the compilers
6298 supplied by most vendors of MIPS-based machines, including DEC. These
6299 symbol tables are in a format that essentially nobody else uses.
6301 Some versions of gcc come with an assembler post-processor called
6302 mips-tfile. This program is required if you want to do source-level
6303 debugging of gcc-compiled programs. I believe FSF does not ship
6304 mips-tfile with gcc version 1, but it will eventually come with gcc
6307 Debugging of g++ output remains a problem. g++ version 1.xx does not
6308 really support it at all. (If you're lucky, you should be able to get
6309 line numbers and stack traces to work, but no parameters or local
6310 variables.) With some work it should be possible to improve the
6313 When gcc version 2 is released, you will have somewhat better luck.
6314 However, even then you will get confusing results for inheritance and
6317 We will eventually provide full debugging of g++ output on
6318 DECstations. This will probably involve some kind of stabs-in-ecoff
6319 encapulation, but the details have not been worked out yet.
6322 *** Changes in GDB-4.2:
6324 * Improved configuration
6326 Only one copy of `configure' exists now, and it is not self-modifying.
6327 Porting BFD is simpler.
6331 The `step' and `next' commands now only stop at the first instruction
6332 of a source line. This prevents the multiple stops that used to occur
6333 in switch statements, for-loops, etc. `Step' continues to stop if a
6334 function that has debugging information is called within the line.
6338 Lots of small bugs fixed. More remain.
6340 * New host supported (not target)
6342 Intel 386 PC clone running Mach i386-none-mach
6345 *** Changes in GDB-4.1:
6347 * Multiple source language support
6349 GDB now has internal scaffolding to handle several source languages.
6350 It determines the type of each source file from its filename extension,
6351 and will switch expression parsing and number formatting to match the
6352 language of the function in the currently selected stack frame.
6353 You can also specifically set the language to be used, with
6354 `set language c' or `set language modula-2'.
6358 GDB now has preliminary support for the GNU Modula-2 compiler,
6359 currently under development at the State University of New York at
6360 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6361 continue through the fall of 1991 and into 1992.
6363 Other Modula-2 compilers are currently not supported, and attempting to
6364 debug programs compiled with them will likely result in an error as the
6365 symbol table is read. Feel free to work on it, though!
6367 There are hooks in GDB for strict type checking and range checking,
6368 in the `Modula-2 philosophy', but they do not currently work.
6372 GDB can now write to executable and core files (e.g. patch
6373 a variable's value). You must turn this switch on, specify
6374 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6375 by assigning a new value to a variable. Modifications take
6378 * Automatic SunOS shared library reading
6380 When you run your program, GDB automatically determines where its
6381 shared libraries (if any) have been loaded, and reads their symbols.
6382 The `share' command is no longer needed. This also works when
6383 examining core files.
6387 You can specify the number of lines that the `list' command shows.
6390 * New machines supported (host and target)
6392 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6393 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6394 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6396 * New hosts supported (not targets)
6398 IBM RT/PC: romp-ibm-aix or rtpc
6400 * New targets supported (not hosts)
6402 AMD 29000 embedded with COFF a29k-none-coff
6403 AMD 29000 embedded with a.out a29k-none-aout
6404 Ultracomputer remote kernel debug a29k-nyu-kern
6406 * New remote interfaces
6412 *** Changes in GDB-4.0:
6416 Wide output is wrapped at good places to make the output more readable.
6418 Gdb now supports cross-debugging from a host machine of one type to a
6419 target machine of another type. Communication with the target system
6420 is over serial lines. The ``target'' command handles connecting to the
6421 remote system; the ``load'' command will download a program into the
6422 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6423 also supports debugging of realtime processes running under VxWorks,
6424 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6425 stub on the target system.
6427 New CPUs supported include the AMD 29000 and Intel 960.
6429 GDB now reads object files and symbol tables via a ``binary file''
6430 library, which allows a single copy of GDB to debug programs of multiple
6431 object file types such as a.out and coff.
6433 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6434 refcard.dvi and refcard.ps are available to format it).
6437 * Control-Variable user interface simplified
6439 All variables that control the operation of the debugger can be set
6440 by the ``set'' command, and displayed by the ``show'' command.
6442 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6443 ``Show prompt'' produces the response:
6444 Gdb's prompt is new-gdb=>.
6446 What follows are the NEW set commands. The command ``help set'' will
6447 print a complete list of old and new set commands. ``help set FOO''
6448 will give a longer description of the variable FOO. ``show'' will show
6449 all of the variable descriptions and their current settings.
6451 confirm on/off: Enables warning questions for operations that are
6452 hard to recover from, e.g. rerunning the program while
6453 it is already running. Default is ON.
6455 editing on/off: Enables EMACS style command line editing
6456 of input. Previous lines can be recalled with
6457 control-P, the current line can be edited with control-B,
6458 you can search for commands with control-R, etc.
6461 history filename NAME: NAME is where the gdb command history
6462 will be stored. The default is .gdb_history,
6463 or the value of the environment variable
6466 history size N: The size, in commands, of the command history. The
6467 default is 256, or the value of the environment variable
6470 history save on/off: If this value is set to ON, the history file will
6471 be saved after exiting gdb. If set to OFF, the
6472 file will not be saved. The default is OFF.
6474 history expansion on/off: If this value is set to ON, then csh-like
6475 history expansion will be performed on
6476 command line input. The default is OFF.
6478 radix N: Sets the default radix for input and output. It can be set
6479 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6480 in the current radix, so "set radix 10" is always a no-op.
6482 height N: This integer value is the number of lines on a page. Default
6483 is 24, the current `stty rows'' setting, or the ``li#''
6484 setting from the termcap entry matching the environment
6487 width N: This integer value is the number of characters on a line.
6488 Default is 80, the current `stty cols'' setting, or the ``co#''
6489 setting from the termcap entry matching the environment
6492 Note: ``set screensize'' is obsolete. Use ``set height'' and
6493 ``set width'' instead.
6495 print address on/off: Print memory addresses in various command displays,
6496 such as stack traces and structure values. Gdb looks
6497 more ``symbolic'' if you turn this off; it looks more
6498 ``machine level'' with it on. Default is ON.
6500 print array on/off: Prettyprint arrays. New convenient format! Default
6503 print demangle on/off: Print C++ symbols in "source" form if on,
6506 print asm-demangle on/off: Same, for assembler level printouts
6509 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6512 * Support for Epoch Environment.
6514 The epoch environment is a version of Emacs v18 with windowing. One
6515 new command, ``inspect'', is identical to ``print'', except that if you
6516 are running in the epoch environment, the value is printed in its own
6520 * Support for Shared Libraries
6522 GDB can now debug programs and core files that use SunOS shared libraries.
6523 Symbols from a shared library cannot be referenced
6524 before the shared library has been linked with the program (this
6525 happens after you type ``run'' and before the function main() is entered).
6526 At any time after this linking (including when examining core files
6527 from dynamically linked programs), gdb reads the symbols from each
6528 shared library when you type the ``sharedlibrary'' command.
6529 It can be abbreviated ``share''.
6531 sharedlibrary REGEXP: Load shared object library symbols for files
6532 matching a unix regular expression. No argument
6533 indicates to load symbols for all shared libraries.
6535 info sharedlibrary: Status of loaded shared libraries.
6540 A watchpoint stops execution of a program whenever the value of an
6541 expression changes. Checking for this slows down execution
6542 tremendously whenever you are in the scope of the expression, but is
6543 quite useful for catching tough ``bit-spreader'' or pointer misuse
6544 problems. Some machines such as the 386 have hardware for doing this
6545 more quickly, and future versions of gdb will use this hardware.
6547 watch EXP: Set a watchpoint (breakpoint) for an expression.
6549 info watchpoints: Information about your watchpoints.
6551 delete N: Deletes watchpoint number N (same as breakpoints).
6552 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6553 enable N: Re-enables watchpoint number N (same as breakpoints).
6556 * C++ multiple inheritance
6558 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6561 * C++ exception handling
6563 Gdb now supports limited C++ exception handling. Besides the existing
6564 ability to breakpoint on an exception handler, gdb can breakpoint on
6565 the raising of an exception (before the stack is peeled back to the
6568 catch FOO: If there is a FOO exception handler in the dynamic scope,
6569 set a breakpoint to catch exceptions which may be raised there.
6570 Multiple exceptions (``catch foo bar baz'') may be caught.
6572 info catch: Lists all exceptions which may be caught in the
6573 current stack frame.
6576 * Minor command changes
6578 The command ``call func (arg, arg, ...)'' now acts like the print
6579 command, except it does not print or save a value if the function's result
6580 is void. This is similar to dbx usage.
6582 The ``up'' and ``down'' commands now always print the frame they end up
6583 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6584 frames without printing.
6586 * New directory command
6588 'dir' now adds directories to the FRONT of the source search path.
6589 The path starts off empty. Source files that contain debug information
6590 about the directory in which they were compiled can be found even
6591 with an empty path; Sun CC and GCC include this information. If GDB can't
6592 find your source file in the current directory, type "dir .".
6594 * Configuring GDB for compilation
6596 For normal use, type ``./configure host''. See README or gdb.texinfo
6599 GDB now handles cross debugging. If you are remotely debugging between
6600 two different machines, type ``./configure host -target=targ''.
6601 Host is the machine where GDB will run; targ is the machine
6602 where the program that you are debugging will run.