1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.11
6 * GDB now supports a negative repeat count in the 'x' command to examine
7 memory backward from the given address. For example:
10 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
11 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
12 (gdb) x/-5i 0x0000000000400580
13 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
14 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
15 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
16 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
17 0x40057b <main(int, char**)+25>:
18 callq 0x400536 <Func1(int, char const*)>
20 * Fortran: Support structures with fields of dynamic types and
21 arrays of dynamic types.
23 * GDB now supports multibit bitfields and enums in target register
26 * New Python-based convenience function $_as_string(val), which returns
27 the textual representation of a value. This function is especially
28 useful to obtain the text label of an enum value.
30 * Intel MPX bound violation handling.
32 Segmentation faults caused by a Intel MPX boundary violation
33 now display the kind of violation (upper or lower), the memory
34 address accessed and the memory bounds, along with the usual
35 signal received and code location.
39 Program received signal SIGSEGV, Segmentation fault
40 Upper bound violation while accessing address 0x7fffffffc3b3
41 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
42 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
44 * Rust language support.
45 GDB now supports debugging programs written in the Rust programming
46 language. See https://www.rust-lang.org/ for more information about
49 * Support for running interpreters on specified input/output devices
51 GDB now supports a new mechanism that allows frontends to provide
52 fully featured GDB console views, as a better alternative to
53 building such views on top of the "-interpreter-exec console"
54 command. See the new "new-ui" command below. With that command,
55 frontends can now start GDB in the traditional command-line mode
56 running in an embedded terminal emulator widget, and create a
57 separate MI interpreter running on a specified i/o device. In this
58 way, GDB handles line editing, history, tab completion, etc. in the
59 console all by itself, and the GUI uses the separate MI interpreter
60 for its own control and synchronization, invisible to the command
66 skip -gfile file-glob-pattern
67 skip -function function
68 skip -rfunction regular-expression
69 A generalized form of the skip command, with new support for
70 glob-style file names and regular expressions for function names.
71 Additionally, a file spec and a function spec may now be combined.
73 maint info line-table REGEXP
74 Display the contents of GDB's internal line table data struture.
77 Run any GDB unit tests that were compiled in.
80 Start a new user interface instance running INTERP as interpreter,
81 using the TTY file for input/output.
83 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
84 was added in GDBserver, including JIT compiling fast tracepoint's
85 conditional expression bytecode into native code.
87 * Support for various remote target protocols and ROM monitors has
90 target m32rsdi Remote M32R debugging over SDI
91 target mips MIPS remote debugging protocol
92 target pmon PMON ROM monitor
93 target ddb NEC's DDB variant of PMON for Vr4300
94 target rockhopper NEC RockHopper variant of PMON
95 target lsi LSI variant of PMO
97 * Support for tracepoints and fast tracepoints on powerpc-linux,
98 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
99 including JIT compiling fast tracepoint's conditional expression
100 bytecode into native code.
102 * MI async record =record-started now includes the method and format used for
103 recording. For example:
105 =record-started,thread-group="i1",method="btrace",format="bts"
109 Andes NDS32 nds32*-*-elf
111 *** Changes in GDB 7.11
113 * GDB now supports debugging kernel-based threads on FreeBSD.
115 * Per-inferior thread numbers
117 Thread numbers are now per inferior instead of global. If you're
118 debugging multiple inferiors, GDB displays thread IDs using a
119 qualified INF_NUM.THR_NUM form. For example:
123 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
124 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
125 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
126 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
128 As consequence, thread numbers as visible in the $_thread
129 convenience variable and in Python's InferiorThread.num attribute
130 are no longer unique between inferiors.
132 GDB now maintains a second thread ID per thread, referred to as the
133 global thread ID, which is the new equivalent of thread numbers in
134 previous releases. See also $_gthread below.
136 For backwards compatibility, MI's thread IDs always refer to global
139 * Commands that accept thread IDs now accept the qualified
140 INF_NUM.THR_NUM form as well. For example:
143 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
146 * In commands that accept a list of thread IDs, you can now refer to
147 all threads of an inferior using a star wildcard. GDB accepts
148 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
149 refer to all threads of the current inferior. For example, "info
152 * You can use "info threads -gid" to display the global thread ID of
155 * The new convenience variable $_gthread holds the global number of
158 * The new convenience variable $_inferior holds the number of the
161 * GDB now displays the ID and name of the thread that hit a breakpoint
162 or received a signal, if your program is multi-threaded. For
165 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
166 Thread 1 "main" received signal SIGINT, Interrupt.
168 * Record btrace now supports non-stop mode.
170 * Support for tracepoints on aarch64-linux was added in GDBserver.
172 * The 'record instruction-history' command now indicates speculative execution
173 when using the Intel Processor Trace recording format.
175 * GDB now allows users to specify explicit locations, bypassing
176 the linespec parser. This feature is also available to GDB/MI
179 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
180 GDB now is able to debug both AArch64 applications and ARM applications
183 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
184 including JIT compiling fast tracepoint's conditional expression bytecode
187 * GDB now supports displaced stepping on AArch64 GNU/Linux.
189 * "info threads", "info inferiors", "info display", "info checkpoints"
190 and "maint info program-spaces" now list the corresponding items in
191 ascending ID order, for consistency with all other "info" commands.
193 * In Ada, the overloads selection menu has been enhanced to display the
194 parameter types and the return types for the matching overloaded subprograms.
198 maint set target-non-stop (on|off|auto)
199 maint show target-non-stop
200 Control whether GDB targets always operate in non-stop mode even if
201 "set non-stop" is "off". The default is "auto", meaning non-stop
202 mode is enabled if supported by the target.
204 maint set bfd-sharing
205 maint show bfd-sharing
206 Control the reuse of bfd objects.
210 Control display of debugging info regarding bfd caching.
214 Control display of debugging info regarding FreeBSD threads.
216 set remote multiprocess-extensions-packet
217 show remote multiprocess-extensions-packet
218 Set/show the use of the remote protocol multiprocess extensions.
220 set remote thread-events
221 show remote thread-events
222 Set/show the use of thread create/exit events.
224 set ada print-signatures on|off
225 show ada print-signatures"
226 Control whether parameter types and return types are displayed in overloads
227 selection menus. It is activaled (@code{on}) by default.
231 Controls the maximum size of memory, in bytes, that GDB will
232 allocate for value contents. Prevents incorrect programs from
233 causing GDB to allocate overly large buffers. Default is 64k.
235 * The "disassemble" command accepts a new modifier: /s.
236 It prints mixed source+disassembly like /m with two differences:
237 - disassembled instructions are now printed in program order, and
238 - and source for all relevant files is now printed.
239 The "/m" option is now considered deprecated: its "source-centric"
240 output hasn't proved useful in practice.
242 * The "record instruction-history" command accepts a new modifier: /s.
243 It behaves exactly like /m and prints mixed source+disassembly.
245 * The "set scheduler-locking" command supports a new mode "replay".
246 It behaves like "off" in record mode and like "on" in replay mode.
248 * Support for various ROM monitors has been removed:
250 target dbug dBUG ROM monitor for Motorola ColdFire
251 target picobug Motorola picobug monitor
252 target dink32 DINK32 ROM monitor for PowerPC
253 target m32r Renesas M32R/D ROM monitor
254 target mon2000 mon2000 ROM monitor
255 target ppcbug PPCBUG ROM monitor for PowerPC
257 * Support for reading/writing memory and extracting values on architectures
258 whose memory is addressable in units of any integral multiple of 8 bits.
263 Indicates that an exec system call was executed.
265 exec-events feature in qSupported
266 The qSupported packet allows GDB to request support for exec
267 events using the new 'gdbfeature' exec-event, and the qSupported
268 response can contain the corresponding 'stubfeature'. Set and
269 show commands can be used to display whether these features are enabled.
272 Equivalent to interrupting with the ^C character, but works in
275 thread created stop reason (T05 create:...)
276 Indicates that the thread was just created and is stopped at entry.
278 thread exit stop reply (w exitcode;tid)
279 Indicates that the thread has terminated.
282 Enables/disables thread create and exit event reporting. For
283 example, this is used in non-stop mode when GDB stops a set of
284 threads and synchronously waits for the their corresponding stop
285 replies. Without exit events, if one of the threads exits, GDB
286 would hang forever not knowing that it should no longer expect a
287 stop for that same thread.
290 Indicates that there are no resumed threads left in the target (all
291 threads are stopped). The remote stub reports support for this stop
292 reply to GDB's qSupported query.
295 Enables/disables catching syscalls from the inferior process.
296 The remote stub reports support for this packet to GDB's qSupported query.
298 syscall_entry stop reason
299 Indicates that a syscall was just called.
301 syscall_return stop reason
302 Indicates that a syscall just returned.
304 * Extended-remote exec events
306 ** GDB now has support for exec events on extended-remote Linux targets.
307 For such targets with Linux kernels 2.5.46 and later, this enables
308 follow-exec-mode and exec catchpoints.
310 set remote exec-event-feature-packet
311 show remote exec-event-feature-packet
312 Set/show the use of the remote exec event feature.
314 * Thread names in remote protocol
316 The reply to qXfer:threads:read may now include a name attribute for each
319 * Target remote mode fork and exec events
321 ** GDB now has support for fork and exec events on target remote mode
322 Linux targets. For such targets with Linux kernels 2.5.46 and later,
323 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
324 fork and exec catchpoints.
326 * Remote syscall events
328 ** GDB now has support for catch syscall on remote Linux targets,
329 currently enabled on x86/x86_64 architectures.
331 set remote catch-syscall-packet
332 show remote catch-syscall-packet
333 Set/show the use of the remote catch syscall feature.
337 ** The -var-set-format command now accepts the zero-hexadecimal
338 format. It outputs data in hexadecimal format with zero-padding on the
343 ** gdb.InferiorThread objects have a new attribute "global_num",
344 which refers to the thread's global thread ID. The existing
345 "num" attribute now refers to the thread's per-inferior number.
346 See "Per-inferior thread numbers" above.
347 ** gdb.InferiorThread objects have a new attribute "inferior", which
348 is the Inferior object the thread belongs to.
350 *** Changes in GDB 7.10
352 * Support for process record-replay and reverse debugging on aarch64*-linux*
353 targets has been added. GDB now supports recording of A64 instruction set
354 including advance SIMD instructions.
356 * Support for Sun's version of the "stabs" debug file format has been removed.
358 * GDB now honors the content of the file /proc/PID/coredump_filter
359 (PID is the process ID) on GNU/Linux systems. This file can be used
360 to specify the types of memory mappings that will be included in a
361 corefile. For more information, please refer to the manual page of
362 "core(5)". GDB also has a new command: "set use-coredump-filter
363 on|off". It allows to set whether GDB will read the content of the
364 /proc/PID/coredump_filter file when generating a corefile.
366 * The "info os" command on GNU/Linux can now display information on
368 "info os cpus" Listing of all cpus/cores on the system
370 * GDB has two new commands: "set serial parity odd|even|none" and
371 "show serial parity". These allows to set or show parity for the
374 * The "info source" command now displays the producer string if it was
375 present in the debug info. This typically includes the compiler version
376 and may include things like its command line arguments.
378 * The "info dll", an alias of the "info sharedlibrary" command,
379 is now available on all platforms.
381 * Directory names supplied to the "set sysroot" commands may be
382 prefixed with "target:" to tell GDB to access shared libraries from
383 the target system, be it local or remote. This replaces the prefix
384 "remote:". The default sysroot has been changed from "" to
385 "target:". "remote:" is automatically converted to "target:" for
386 backward compatibility.
388 * The system root specified by "set sysroot" will be prepended to the
389 filename of the main executable (if reported to GDB as absolute by
390 the operating system) when starting processes remotely, and when
391 attaching to already-running local or remote processes.
393 * GDB now supports automatic location and retrieval of executable
394 files from remote targets. Remote debugging can now be initiated
395 using only a "target remote" or "target extended-remote" command
396 (no "set sysroot" or "file" commands are required). See "New remote
399 * The "dump" command now supports verilog hex format.
401 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
403 * On GNU/Linux, GDB and gdbserver are now able to access executable
404 and shared library files without a "set sysroot" command when
405 attaching to processes running in different mount namespaces from
406 the debugger. This makes it possible to attach to processes in
407 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
408 See "New remote packets" below.
410 * The "tui reg" command now provides completion for all of the
411 available register groups, including target specific groups.
413 * The HISTSIZE environment variable is no longer read when determining
414 the size of GDB's command history. GDB now instead reads the dedicated
415 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
416 disables truncation of command history. Non-numeric values of GDBHISTSIZE
421 ** Memory ports can now be unbuffered.
425 ** gdb.Objfile objects have a new attribute "username",
426 which is the name of the objfile as specified by the user,
427 without, for example, resolving symlinks.
428 ** You can now write frame unwinders in Python.
429 ** gdb.Type objects have a new method "optimized_out",
430 returning optimized out gdb.Value instance of this type.
431 ** gdb.Value objects have new methods "reference_value" and
432 "const_value" which return a reference to the value and a
433 "const" version of the value respectively.
437 maint print symbol-cache
438 Print the contents of the symbol cache.
440 maint print symbol-cache-statistics
441 Print statistics of symbol cache usage.
443 maint flush-symbol-cache
444 Flush the contents of the symbol cache.
448 Start branch trace recording using Branch Trace Store (BTS) format.
451 Evaluate expression by using the compiler and print result.
455 Explicit commands for enabling and disabling tui mode.
458 set mpx bound on i386 and amd64
459 Support for bound table investigation on Intel MPX enabled applications.
463 Start branch trace recording using Intel Processor Trace format.
466 Print information about branch tracing internals.
468 maint btrace packet-history
469 Print the raw branch tracing data.
471 maint btrace clear-packet-history
472 Discard the stored raw branch tracing data.
475 Discard all branch tracing data. It will be fetched and processed
476 anew by the next "record" command.
481 Renamed from "set debug dwarf2-die".
483 Renamed from "show debug dwarf2-die".
486 Renamed from "set debug dwarf2-read".
487 show debug dwarf-read
488 Renamed from "show debug dwarf2-read".
490 maint set dwarf always-disassemble
491 Renamed from "maint set dwarf2 always-disassemble".
492 maint show dwarf always-disassemble
493 Renamed from "maint show dwarf2 always-disassemble".
495 maint set dwarf max-cache-age
496 Renamed from "maint set dwarf2 max-cache-age".
497 maint show dwarf max-cache-age
498 Renamed from "maint show dwarf2 max-cache-age".
501 show debug dwarf-line
502 Control display of debugging info regarding DWARF line processing.
506 Set the maximum number of candidates to be considered during
507 completion. The default value is 200. This limit allows GDB
508 to avoid generating large completion lists, the computation of
509 which can cause the debugger to become temporarily unresponsive.
511 set history remove-duplicates
512 show history remove-duplicates
513 Control the removal of duplicate history entries.
515 maint set symbol-cache-size
516 maint show symbol-cache-size
517 Control the size of the symbol cache.
519 set|show record btrace bts buffer-size
520 Set and show the size of the ring buffer used for branch tracing in
522 The obtained size may differ from the requested size. Use "info
523 record" to see the obtained buffer size.
525 set debug linux-namespaces
526 show debug linux-namespaces
527 Control display of debugging info regarding Linux namespaces.
529 set|show record btrace pt buffer-size
530 Set and show the size of the ring buffer used for branch tracing in
531 Intel Processor Trace format.
532 The obtained size may differ from the requested size. Use "info
533 record" to see the obtained buffer size.
535 maint set|show btrace pt skip-pad
536 Set and show whether PAD packets are skipped when computing the
539 * The command 'thread apply all' can now support new option '-ascending'
540 to call its specified command for all threads in ascending order.
542 * Python/Guile scripting
544 ** GDB now supports auto-loading of Python/Guile scripts contained in the
545 special section named `.debug_gdb_scripts'.
549 qXfer:btrace-conf:read
550 Return the branch trace configuration for the current thread.
552 Qbtrace-conf:bts:size
553 Set the requested ring buffer size for branch tracing in BTS format.
556 Enable Intel Procesor Trace-based branch tracing for the current
557 process. The remote stub reports support for this packet to GDB's
561 Set the requested ring buffer size for branch tracing in Intel Processor
565 Indicates a memory breakpoint instruction was executed, irrespective
566 of whether it was GDB that planted the breakpoint or the breakpoint
567 is hardcoded in the program. This is required for correct non-stop
571 Indicates the target stopped for a hardware breakpoint. This is
572 required for correct non-stop mode operation.
575 Return information about files on the remote system.
578 Return the full absolute name of the file that was executed to
579 create a process running on the remote system.
582 Select the filesystem on which vFile: operations with filename
583 arguments will operate. This is required for GDB to be able to
584 access files on remote targets where the remote stub does not
585 share a common filesystem with the inferior(s).
588 Indicates that a fork system call was executed.
591 Indicates that a vfork system call was executed.
593 vforkdone stop reason
594 Indicates that a vfork child of the specified process has executed
595 an exec or exit, allowing the vfork parent to resume execution.
597 fork-events and vfork-events features in qSupported
598 The qSupported packet allows GDB to request support for fork and
599 vfork events using new 'gdbfeatures' fork-events and vfork-events,
600 and the qSupported response can contain the corresponding
601 'stubfeatures'. Set and show commands can be used to display
602 whether these features are enabled.
604 * Extended-remote fork events
606 ** GDB now has support for fork events on extended-remote Linux
607 targets. For targets with Linux kernels 2.5.60 and later, this
608 enables follow-fork-mode and detach-on-fork for both fork and
609 vfork, as well as fork and vfork catchpoints.
611 * The info record command now shows the recording format and the
612 branch tracing configuration for the current thread when using
613 the btrace record target.
614 For the BTS format, it shows the ring buffer size.
616 * GDB now has support for DTrace USDT (Userland Static Defined
617 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
619 * GDB now supports access to vector registers on S/390 GNU/Linux
622 * Removed command line options
624 -xdb HP-UX XDB compatibility mode.
626 * Removed targets and native configurations
628 HP/PA running HP-UX hppa*-*-hpux*
629 Itanium running HP-UX ia64-*-hpux*
631 * New configure options
634 This configure option allows the user to build GDB with support for
635 Intel Processor Trace (default: auto). This requires libipt.
637 --with-libipt-prefix=PATH
638 Specify the path to the version of libipt that GDB should use.
639 $PATH/include should contain the intel-pt.h header and
640 $PATH/lib should contain the libipt.so library.
642 *** Changes in GDB 7.9.1
646 ** Xmethods can now specify a result type.
648 *** Changes in GDB 7.9
650 * GDB now supports hardware watchpoints on x86 GNU Hurd.
654 ** You can now access frame registers from Python scripts.
655 ** New attribute 'producer' for gdb.Symtab objects.
656 ** gdb.Objfile objects have a new attribute "progspace",
657 which is the gdb.Progspace object of the containing program space.
658 ** gdb.Objfile objects have a new attribute "owner".
659 ** gdb.Objfile objects have a new attribute "build_id",
660 which is the build ID generated when the file was built.
661 ** gdb.Objfile objects have a new method "add_separate_debug_file".
662 ** A new event "gdb.clear_objfiles" has been added, triggered when
663 selecting a new file to debug.
664 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
665 ** New function gdb.lookup_objfile.
667 New events which are triggered when GDB modifies the state of the
670 ** gdb.events.inferior_call_pre: Function call is about to be made.
671 ** gdb.events.inferior_call_post: Function call has just been made.
672 ** gdb.events.memory_changed: A memory location has been altered.
673 ** gdb.events.register_changed: A register has been altered.
675 * New Python-based convenience functions:
677 ** $_caller_is(name [, number_of_frames])
678 ** $_caller_matches(regexp [, number_of_frames])
679 ** $_any_caller_is(name [, number_of_frames])
680 ** $_any_caller_matches(regexp [, number_of_frames])
682 * GDB now supports the compilation and injection of source code into
683 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
684 to compile the source code to object code, and if successful, inject
685 and execute that code within the current context of the inferior.
686 Currently the C language is supported. The commands used to
687 interface with this new feature are:
689 compile code [-raw|-r] [--] [source code]
690 compile file [-raw|-r] filename
694 demangle [-l language] [--] name
695 Demangle "name" in the specified language, or the current language
696 if elided. This command is renamed from the "maint demangle" command.
697 The latter is kept as a no-op to avoid "maint demangle" being interpreted
698 as "maint demangler-warning".
700 queue-signal signal-name-or-number
701 Queue a signal to be delivered to the thread when it is resumed.
703 add-auto-load-scripts-directory directory
704 Add entries to the list of directories from which to load auto-loaded
707 maint print user-registers
708 List all currently available "user" registers.
710 compile code [-r|-raw] [--] [source code]
711 Compile, inject, and execute in the inferior the executable object
712 code produced by compiling the provided source code.
714 compile file [-r|-raw] filename
715 Compile and inject into the inferior the executable object code
716 produced by compiling the source code stored in the filename
719 * On resume, GDB now always passes the signal the program had stopped
720 for to the thread the signal was sent to, even if the user changed
721 threads before resuming. Previously GDB would often (but not
722 always) deliver the signal to the thread that happens to be current
725 * Conversely, the "signal" command now consistently delivers the
726 requested signal to the current thread. GDB now asks for
727 confirmation if the program had stopped for a signal and the user
728 switched threads meanwhile.
730 * "breakpoint always-inserted" modes "off" and "auto" merged.
732 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
733 won't remove breakpoints from the target until all threads stop,
734 even in non-stop mode. The "auto" mode has been removed, and "off"
735 is now the default mode.
739 set debug symbol-lookup
740 show debug symbol-lookup
741 Control display of debugging info regarding symbol lookup.
745 ** The -list-thread-groups command outputs an exit-code field for
746 inferiors that have exited.
750 MIPS SDE mips*-sde*-elf*
754 Support for these obsolete configurations has been removed.
756 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
757 SGI Irix-5.x mips-*-irix5*
758 SGI Irix-6.x mips-*-irix6*
759 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
760 VAX running Ultrix vax-*-ultrix*
762 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
763 and "assf"), have been removed. Use the "sharedlibrary" command, or
764 its alias "share", instead.
766 *** Changes in GDB 7.8
768 * New command line options
771 This is an alias for the --data-directory option.
773 * GDB supports printing and modifying of variable length automatic arrays
774 as specified in ISO C99.
776 * The ARM simulator now supports instruction level tracing
777 with or without disassembly.
781 GDB now has support for scripting using Guile. Whether this is
782 available is determined at configure time.
783 Guile version 2.0 or greater is required.
784 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
786 * New commands (for set/show, see "New options" below)
790 Invoke CODE by passing it to the Guile interpreter.
794 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
796 info auto-load guile-scripts [regexp]
797 Print the list of automatically loaded Guile scripts.
799 * The source command is now capable of sourcing Guile scripts.
800 This feature is dependent on the debugger being built with Guile support.
804 set print symbol-loading (off|brief|full)
805 show print symbol-loading
806 Control whether to print informational messages when loading symbol
807 information for a file. The default is "full", but when debugging
808 programs with large numbers of shared libraries the amount of output
811 set guile print-stack (none|message|full)
812 show guile print-stack
813 Show a stack trace when an error is encountered in a Guile script.
815 set auto-load guile-scripts (on|off)
816 show auto-load guile-scripts
817 Control auto-loading of Guile script files.
819 maint ada set ignore-descriptive-types (on|off)
820 maint ada show ignore-descriptive-types
821 Control whether the debugger should ignore descriptive types in Ada
822 programs. The default is not to ignore the descriptive types. See
823 the user manual for more details on descriptive types and the intended
824 usage of this option.
826 set auto-connect-native-target
828 Control whether GDB is allowed to automatically connect to the
829 native target for the run, attach, etc. commands when not connected
830 to any target yet. See also "target native" below.
832 set record btrace replay-memory-access (read-only|read-write)
833 show record btrace replay-memory-access
834 Control what memory accesses are allowed during replay.
836 maint set target-async (on|off)
837 maint show target-async
838 This controls whether GDB targets operate in synchronous or
839 asynchronous mode. Normally the default is asynchronous, if it is
840 available; but this can be changed to more easily debug problems
841 occurring only in synchronous mode.
843 set mi-async (on|off)
845 Control whether MI asynchronous mode is preferred. This supersedes
846 "set target-async" of previous GDB versions.
848 * "set target-async" is deprecated as a CLI option and is now an alias
849 for "set mi-async" (only puts MI into async mode).
851 * Background execution commands (e.g., "c&", "s&", etc.) are now
852 possible ``out of the box'' if the target supports them. Previously
853 the user would need to explicitly enable the possibility with the
854 "set target-async on" command.
856 * New features in the GDB remote stub, GDBserver
858 ** New option --debug-format=option1[,option2,...] allows one to add
859 additional text to each output. At present only timestamps
860 are supported: --debug-format=timestamps.
861 Timestamps can also be turned on with the
862 "monitor set debug-format timestamps" command from GDB.
864 * The 'record instruction-history' command now starts counting instructions
865 at one. This also affects the instruction ranges reported by the
866 'record function-call-history' command when given the /i modifier.
868 * The command 'record function-call-history' supports a new modifier '/c' to
869 indent the function names based on their call stack depth.
870 The fields for the '/i' and '/l' modifier have been reordered.
871 The source line range is now prefixed with 'at'.
872 The instruction range is now prefixed with 'inst'.
873 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
874 "record instruction-history" and "list" commands.
876 * The ranges given as arguments to the 'record function-call-history' and
877 'record instruction-history' commands are now inclusive.
879 * The btrace record target now supports the 'record goto' command.
880 For locations inside the execution trace, the back trace is computed
881 based on the information stored in the execution trace.
883 * The btrace record target supports limited reverse execution and replay.
884 The target does not record data and therefore does not allow reading
887 * The "catch syscall" command now works on s390*-linux* targets.
889 * The "compare-sections" command is no longer specific to target
890 remote. It now works with all targets.
892 * All native targets are now consistently called "native".
893 Consequently, the "target child", "target GNU", "target djgpp",
894 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
895 commands have been replaced with "target native". The QNX/NTO port
896 leaves the "procfs" target in place and adds a "native" target for
897 consistency with other ports. The impact on users should be minimal
898 as these commands previously either throwed an error, or were
899 no-ops. The target's name is visible in the output of the following
900 commands: "help target", "info target", "info files", "maint print
903 * The "target native" command now connects to the native target. This
904 can be used to launch native programs even when "set
905 auto-connect-native-target" is set to off.
907 * GDB now supports access to Intel MPX registers on GNU/Linux.
909 * Support for Intel AVX-512 registers on GNU/Linux.
910 Support displaying and modifying Intel AVX-512 registers
911 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
915 qXfer:btrace:read's annex
916 The qXfer:btrace:read packet supports a new annex 'delta' to read
917 branch trace incrementally.
921 ** Valid Python operations on gdb.Value objects representing
922 structs/classes invoke the corresponding overloaded operators if
924 ** New `Xmethods' feature in the Python API. Xmethods are
925 additional methods or replacements for existing methods of a C++
926 class. This feature is useful for those cases where a method
927 defined in C++ source code could be inlined or optimized out by
928 the compiler, making it unavailable to GDB.
931 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
933 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
934 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
935 its alias "share", instead.
937 * The commands "set remotebaud" and "show remotebaud" are no longer
938 supported. Use "set serial baud" and "show serial baud" (respectively)
943 ** A new option "-gdb-set mi-async" replaces "-gdb-set
944 target-async". The latter is left as a deprecated alias of the
945 former for backward compatibility. If the target supports it,
946 CLI background execution commands are now always possible by
947 default, independently of whether the frontend stated a
948 preference for asynchronous execution with "-gdb-set mi-async".
949 Previously "-gdb-set target-async off" affected both MI execution
950 commands and CLI execution commands.
952 *** Changes in GDB 7.7
954 * Improved support for process record-replay and reverse debugging on
955 arm*-linux* targets. Support for thumb32 and syscall instruction
956 recording has been added.
958 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
960 * GDB now supports Fission DWP file format version 2.
961 http://gcc.gnu.org/wiki/DebugFission
963 * New convenience function "$_isvoid", to check whether an expression
964 is void. A void expression is an expression where the type of the
965 result is "void". For example, some convenience variables may be
966 "void" when evaluated (e.g., "$_exitcode" before the execution of
967 the program being debugged; or an undefined convenience variable).
968 Another example, when calling a function whose return type is
971 * The "maintenance print objfiles" command now takes an optional regexp.
973 * The "catch syscall" command now works on arm*-linux* targets.
975 * GDB now consistently shows "<not saved>" when printing values of
976 registers the debug info indicates have not been saved in the frame
977 and there's nowhere to retrieve them from
978 (callee-saved/call-clobbered registers):
983 (gdb) info registers rax
986 Before, the former would print "<optimized out>", and the latter
987 "*value not available*".
989 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
994 ** Frame filters and frame decorators have been added.
995 ** Temporary breakpoints are now supported.
996 ** Line tables representation has been added.
997 ** New attribute 'parent_type' for gdb.Field objects.
998 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
999 ** New attribute 'name' for gdb.Type objects.
1003 Nios II ELF nios2*-*-elf
1004 Nios II GNU/Linux nios2*-*-linux
1005 Texas Instruments MSP430 msp430*-*-elf
1007 * Removed native configurations
1009 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1010 been removed. ELF variants of these configurations are kept supported.
1012 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1013 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1014 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1015 i[34567]86-*-openbsd3.[0-3]
1016 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1017 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1018 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1022 Like "catch throw", but catches a re-thrown exception.
1023 maint check-psymtabs
1024 Renamed from old "maint check-symtabs".
1026 Perform consistency checks on symtabs.
1027 maint expand-symtabs
1028 Expand symtabs matching an optional regexp.
1031 Display the details of GDB configure-time options.
1033 maint set|show per-command
1034 maint set|show per-command space
1035 maint set|show per-command time
1036 maint set|show per-command symtab
1037 Enable display of per-command gdb resource usage.
1039 remove-symbol-file FILENAME
1040 remove-symbol-file -a ADDRESS
1041 Remove a symbol file added via add-symbol-file. The file to remove
1042 can be identified by its filename or by an address that lies within
1043 the boundaries of this symbol file in memory.
1046 info exceptions REGEXP
1047 Display the list of Ada exceptions defined in the program being
1048 debugged. If provided, only the exceptions whose names match REGEXP
1053 set debug symfile off|on
1055 Control display of debugging info regarding reading symbol files and
1056 symbol tables within those files
1058 set print raw frame-arguments
1059 show print raw frame-arguments
1060 Set/show whether to print frame arguments in raw mode,
1061 disregarding any defined pretty-printers.
1063 set remote trace-status-packet
1064 show remote trace-status-packet
1065 Set/show the use of remote protocol qTStatus packet.
1069 Control display of debugging messages related to Nios II targets.
1073 Control whether target-assisted range stepping is enabled.
1075 set startup-with-shell
1076 show startup-with-shell
1077 Specifies whether Unix child processes are started via a shell or
1082 Use the target memory cache for accesses to the code segment. This
1083 improves performance of remote debugging (particularly disassembly).
1085 * You can now use a literal value 'unlimited' for options that
1086 interpret 0 or -1 as meaning "unlimited". E.g., "set
1087 trace-buffer-size unlimited" is now an alias for "set
1088 trace-buffer-size -1" and "set height unlimited" is now an alias for
1091 * The "set debug symtab-create" debugging option of GDB has been changed to
1092 accept a verbosity level. 0 means "off", 1 provides basic debugging
1093 output, and values of 2 or greater provides more verbose output.
1095 * New command-line options
1097 Display the details of GDB configure-time options.
1099 * The command 'tsave' can now support new option '-ctf' to save trace
1100 buffer in Common Trace Format.
1102 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1105 * GDB now implements the the C++ 'typeid' operator.
1107 * The new convenience variable $_exception holds the exception being
1108 thrown or caught at an exception-related catchpoint.
1110 * The exception-related catchpoints, like "catch throw", now accept a
1111 regular expression which can be used to filter exceptions by type.
1113 * The new convenience variable $_exitsignal is automatically set to
1114 the terminating signal number when the program being debugged dies
1115 due to an uncaught signal.
1119 ** All MI commands now accept an optional "--language" option.
1120 Support for this feature can be verified by using the "-list-features"
1121 command, which should contain "language-option".
1123 ** The new command -info-gdb-mi-command allows the user to determine
1124 whether a GDB/MI command is supported or not.
1126 ** The "^error" result record returned when trying to execute an undefined
1127 GDB/MI command now provides a variable named "code" whose content is the
1128 "undefined-command" error code. Support for this feature can be verified
1129 by using the "-list-features" command, which should contain
1130 "undefined-command-error-code".
1132 ** The -trace-save MI command can optionally save trace buffer in Common
1135 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1137 ** The command -data-list-register-values now accepts an optional
1138 "--skip-unavailable" option. When used, only the available registers
1141 ** The new command -trace-frame-collected dumps collected variables,
1142 computed expressions, tvars, memory and registers in a traceframe.
1144 ** The commands -stack-list-locals, -stack-list-arguments and
1145 -stack-list-variables now accept an option "--skip-unavailable".
1146 When used, only the available locals or arguments are displayed.
1148 ** The -exec-run command now accepts an optional "--start" option.
1149 When used, the command follows the same semantics as the "start"
1150 command, stopping the program's execution at the start of its
1151 main subprogram. Support for this feature can be verified using
1152 the "-list-features" command, which should contain
1153 "exec-run-start-option".
1155 ** The new commands -catch-assert and -catch-exceptions insert
1156 catchpoints stopping the program when Ada exceptions are raised.
1158 ** The new command -info-ada-exceptions provides the equivalent of
1159 the new "info exceptions" command.
1161 * New system-wide configuration scripts
1162 A GDB installation now provides scripts suitable for use as system-wide
1163 configuration scripts for the following systems:
1167 * GDB now supports target-assigned range stepping with remote targets.
1168 This improves the performance of stepping source lines by reducing
1169 the number of control packets from/to GDB. See "New remote packets"
1172 * GDB now understands the element 'tvar' in the XML traceframe info.
1173 It has the id of the collected trace state variables.
1175 * On S/390 targets that provide the transactional-execution feature,
1176 the program interruption transaction diagnostic block (TDB) is now
1177 represented as a number of additional "registers" in GDB.
1179 * New remote packets
1183 The vCont packet supports a new 'r' action, that tells the remote
1184 stub to step through an address range itself, without GDB
1185 involvemement at each single-step.
1187 qXfer:libraries-svr4:read's annex
1188 The previously unused annex of the qXfer:libraries-svr4:read packet
1189 is now used to support passing an argument list. The remote stub
1190 reports support for this argument list to GDB's qSupported query.
1191 The defined arguments are "start" and "prev", used to reduce work
1192 necessary for library list updating, resulting in significant
1195 * New features in the GDB remote stub, GDBserver
1197 ** GDBserver now supports target-assisted range stepping. Currently
1198 enabled on x86/x86_64 GNU/Linux targets.
1200 ** GDBserver now adds element 'tvar' in the XML in the reply to
1201 'qXfer:traceframe-info:read'. It has the id of the collected
1202 trace state variables.
1204 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1207 * New 'z' formatter for printing and examining memory, this displays the
1208 value as hexadecimal zero padded on the left to the size of the type.
1210 * GDB can now use Windows x64 unwinding data.
1212 * The "set remotebaud" command has been replaced by "set serial baud".
1213 Similarly, "show remotebaud" has been replaced by "show serial baud".
1214 The "set remotebaud" and "show remotebaud" commands are still available
1215 to provide backward compatibility with older versions of GDB.
1217 *** Changes in GDB 7.6
1219 * Target record has been renamed to record-full.
1220 Record/replay is now enabled with the "record full" command.
1221 This also affects settings that are associated with full record/replay
1222 that have been moved from "set/show record" to "set/show record full":
1224 set|show record full insn-number-max
1225 set|show record full stop-at-limit
1226 set|show record full memory-query
1228 * A new record target "record-btrace" has been added. The new target
1229 uses hardware support to record the control-flow of a process. It
1230 does not support replaying the execution, but it implements the
1231 below new commands for investigating the recorded execution log.
1232 This new recording method can be enabled using:
1236 The "record-btrace" target is only available on Intel Atom processors
1237 and requires a Linux kernel 2.6.32 or later.
1239 * Two new commands have been added for record/replay to give information
1240 about the recorded execution without having to replay the execution.
1241 The commands are only supported by "record btrace".
1243 record instruction-history prints the execution history at
1244 instruction granularity
1246 record function-call-history prints the execution history at
1247 function granularity
1249 * New native configurations
1251 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1252 FreeBSD/powerpc powerpc*-*-freebsd
1253 x86_64/Cygwin x86_64-*-cygwin*
1254 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1258 ARM AArch64 aarch64*-*-elf
1259 ARM AArch64 GNU/Linux aarch64*-*-linux
1260 Lynx 178 PowerPC powerpc-*-lynx*178
1261 x86_64/Cygwin x86_64-*-cygwin*
1262 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1264 * If the configured location of system.gdbinit file (as given by the
1265 --with-system-gdbinit option at configure time) is in the
1266 data-directory (as specified by --with-gdb-datadir at configure
1267 time) or in one of its subdirectories, then GDB will look for the
1268 system-wide init file in the directory specified by the
1269 --data-directory command-line option.
1271 * New command line options:
1273 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1274 other initialization files, unlike -nx which disables all of them.
1276 * Removed command line options
1278 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1281 * The 'ptype' and 'whatis' commands now accept an argument to control
1284 * 'info proc' now works on some core files.
1288 ** Vectors can be created with gdb.Type.vector.
1290 ** Python's atexit.register now works in GDB.
1292 ** Types can be pretty-printed via a Python API.
1294 ** Python 3 is now supported (in addition to Python 2.4 or later)
1296 ** New class gdb.Architecture exposes GDB's internal representation
1297 of architecture in the Python API.
1299 ** New method Frame.architecture returns the gdb.Architecture object
1300 corresponding to the frame's architecture.
1302 * New Python-based convenience functions:
1304 ** $_memeq(buf1, buf2, length)
1305 ** $_streq(str1, str2)
1307 ** $_regex(str, regex)
1309 * The 'cd' command now defaults to using '~' (the home directory) if not
1312 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1313 default for GCC since November 2000.
1315 * The command 'forward-search' can now be abbreviated as 'fo'.
1317 * The command 'info tracepoints' can now display 'installed on target'
1318 or 'not installed on target' for each non-pending location of tracepoint.
1320 * New configure options
1322 --enable-libmcheck/--disable-libmcheck
1323 By default, development versions are built with -lmcheck on hosts
1324 that support it, in order to help track memory corruption issues.
1325 Release versions, on the other hand, are built without -lmcheck
1326 by default. The --enable-libmcheck/--disable-libmcheck configure
1327 options allow the user to override that default.
1328 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1329 This configure option allows the user to build GDB with
1330 libbabeltrace using which GDB can read Common Trace Format data.
1332 * New commands (for set/show, see "New options" below)
1335 Catch signals. This is similar to "handle", but allows commands and
1336 conditions to be attached.
1339 List the BFDs known to GDB.
1341 python-interactive [command]
1343 Start a Python interactive prompt, or evaluate the optional command
1344 and print the result of expressions.
1347 "py" is a new alias for "python".
1349 enable type-printer [name]...
1350 disable type-printer [name]...
1351 Enable or disable type printers.
1355 ** For the Renesas Super-H architecture, the "regs" command has been removed
1356 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1361 set print type methods (on|off)
1362 show print type methods
1363 Control whether method declarations are displayed by "ptype".
1364 The default is to show them.
1366 set print type typedefs (on|off)
1367 show print type typedefs
1368 Control whether typedef definitions are displayed by "ptype".
1369 The default is to show them.
1371 set filename-display basename|relative|absolute
1372 show filename-display
1373 Control the way in which filenames is displayed.
1374 The default is "relative", which preserves previous behavior.
1376 set trace-buffer-size
1377 show trace-buffer-size
1378 Request target to change the size of trace buffer.
1380 set remote trace-buffer-size-packet auto|on|off
1381 show remote trace-buffer-size-packet
1382 Control the use of the remote protocol `QTBuffer:size' packet.
1386 Control display of debugging messages related to ARM AArch64.
1389 set debug coff-pe-read
1390 show debug coff-pe-read
1391 Control display of debugging messages related to reading of COFF/PE
1396 Control display of debugging messages related to Mach-O symbols
1399 set debug notification
1400 show debug notification
1401 Control display of debugging info for async remote notification.
1405 ** Command parameter changes are now notified using new async record
1406 "=cmd-param-changed".
1407 ** Trace frame changes caused by command "tfind" are now notified using
1408 new async record "=traceframe-changed".
1409 ** The creation, deletion and modification of trace state variables
1410 are now notified using new async records "=tsv-created",
1411 "=tsv-deleted" and "=tsv-modified".
1412 ** The start and stop of process record are now notified using new
1413 async record "=record-started" and "=record-stopped".
1414 ** Memory changes are now notified using new async record
1416 ** The data-disassemble command response will include a "fullname" field
1417 containing the absolute file name when source has been requested.
1418 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1419 command, to allow pattern filling of memory areas.
1420 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1421 library load/unload events.
1422 ** The response to breakpoint commands and breakpoint async records
1423 includes an "installed" field containing a boolean state about each
1424 non-pending tracepoint location is whether installed on target or not.
1425 ** Output of the "-trace-status" command includes a "trace-file" field
1426 containing the name of the trace file being examined. This field is
1427 optional, and only present when examining a trace file.
1428 ** The "fullname" field is now always present along with the "file" field,
1429 even if the file cannot be found by GDB.
1431 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1432 You must have the LZMA library available when configuring GDB for this
1433 feature to be enabled. For more information, see:
1434 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1436 * New remote packets
1439 Set the size of trace buffer. The remote stub reports support for this
1440 packet to gdb's qSupported query.
1443 Enable Branch Trace Store (BTS)-based branch tracing for the current
1444 thread. The remote stub reports support for this packet to gdb's
1448 Disable branch tracing for the current thread. The remote stub reports
1449 support for this packet to gdb's qSupported query.
1452 Read the traced branches for the current thread. The remote stub
1453 reports support for this packet to gdb's qSupported query.
1455 *** Changes in GDB 7.5
1457 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1458 for more x32 ABI info.
1460 * GDB now supports access to MIPS DSP registers on Linux targets.
1462 * GDB now supports debugging microMIPS binaries.
1464 * The "info os" command on GNU/Linux can now display information on
1465 several new classes of objects managed by the operating system:
1466 "info os procgroups" lists process groups
1467 "info os files" lists file descriptors
1468 "info os sockets" lists internet-domain sockets
1469 "info os shm" lists shared-memory regions
1470 "info os semaphores" lists semaphores
1471 "info os msg" lists message queues
1472 "info os modules" lists loaded kernel modules
1474 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1475 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1476 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1477 options and inspect the probe arguments using the new $_probe_arg family
1478 of convenience variables. You can obtain more information about SystemTap
1479 in <http://sourceware.org/systemtap/>.
1481 * GDB now supports reversible debugging on ARM, it allows you to
1482 debug basic ARM and THUMB instructions, and provides
1483 record/replay support.
1485 * The option "symbol-reloading" has been deleted as it is no longer used.
1489 ** GDB commands implemented in Python can now be put in command class
1492 ** The "maint set python print-stack on|off" is now deleted.
1494 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1495 apply "flag enum"-style pretty-printing to any enum.
1497 ** gdb.lookup_symbol can now work when there is no current frame.
1499 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1500 the source at which the symbol was defined.
1502 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1503 method 'value'. The former indicates whether the symbol needs a
1504 frame in order to compute its value, and the latter computes the
1507 ** A new method 'referenced_value' on gdb.Value objects which can
1508 dereference pointer as well as C++ reference values.
1510 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1511 which return the global and static blocks (as gdb.Block objects),
1512 of the underlying symbol table, respectively.
1514 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1515 object associated with a PC value.
1517 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1518 of the address range occupied by code for the current source line.
1520 * Go language support.
1521 GDB now supports debugging programs written in the Go programming
1524 * GDBserver now supports stdio connections.
1525 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1527 * The binary "gdbtui" can no longer be built or installed.
1528 Use "gdb -tui" instead.
1530 * GDB will now print "flag" enums specially. A flag enum is one where
1531 all the enumerator values have no bits in common when pairwise
1532 "and"ed. When printing a value whose type is a flag enum, GDB will
1533 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1534 (gdb) print (enum E) 3
1537 * The filename part of a linespec will now match trailing components
1538 of a source file name. For example, "break gcc/expr.c:1000" will
1539 now set a breakpoint in build/gcc/expr.c, but not
1540 build/libcpp/expr.c.
1542 * The "info proc" and "generate-core-file" commands will now also
1543 work on remote targets connected to GDBserver on Linux.
1545 * The command "info catch" has been removed. It has been disabled
1546 since December 2007.
1548 * The "catch exception" and "catch assert" commands now accept
1549 a condition at the end of the command, much like the "break"
1550 command does. For instance:
1552 (gdb) catch exception Constraint_Error if Barrier = True
1554 Previously, it was possible to add a condition to such catchpoints,
1555 but it had to be done as a second step, after the catchpoint had been
1556 created, using the "condition" command.
1558 * The "info static-tracepoint-marker" command will now also work on
1559 native Linux targets with in-process agent.
1561 * GDB can now set breakpoints on inlined functions.
1563 * The .gdb_index section has been updated to include symbols for
1564 inlined functions. GDB will ignore older .gdb_index sections by
1565 default, which could cause symbol files to be loaded more slowly
1566 until their .gdb_index sections can be recreated. The new command
1567 "set use-deprecated-index-sections on" will cause GDB to use any older
1568 .gdb_index sections it finds. This will restore performance, but the
1569 ability to set breakpoints on inlined functions will be lost in symbol
1570 files with older .gdb_index sections.
1572 The .gdb_index section has also been updated to record more information
1573 about each symbol. This speeds up the "info variables", "info functions"
1574 and "info types" commands when used with programs having the .gdb_index
1575 section, as well as speeding up debugging with shared libraries using
1576 the .gdb_index section.
1578 * Ada support for GDB/MI Variable Objects has been added.
1580 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1585 ** New command -info-os is the MI equivalent of "info os".
1587 ** Output logs ("set logging" and related) now include MI output.
1591 ** "set use-deprecated-index-sections on|off"
1592 "show use-deprecated-index-sections on|off"
1593 Controls the use of deprecated .gdb_index sections.
1595 ** "catch load" and "catch unload" can be used to stop when a shared
1596 library is loaded or unloaded, respectively.
1598 ** "enable count" can be used to auto-disable a breakpoint after
1601 ** "info vtbl" can be used to show the virtual method tables for
1602 C++ and Java objects.
1604 ** "explore" and its sub commands "explore value" and "explore type"
1605 can be used to recursively explore values and types of
1606 expressions. These commands are available only if GDB is
1607 configured with '--with-python'.
1609 ** "info auto-load" shows status of all kinds of auto-loaded files,
1610 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1611 sequences of commands files, "info auto-load python-scripts"
1612 shows status of auto-loading Python script files,
1613 "info auto-load local-gdbinit" shows status of loading init file
1614 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1615 status of inferior specific thread debugging shared library loading.
1617 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1618 and "show auto-load-scripts" commands have been deprecated, use their
1619 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1620 and "show auto-load python-scripts" counterparts instead.
1622 ** "dprintf location,format,args..." creates a dynamic printf, which
1623 is basically a breakpoint that does a printf and immediately
1624 resumes your program's execution, so it is like a printf that you
1625 can insert dynamically at runtime instead of at compiletime.
1627 ** "set print symbol"
1629 Controls whether GDB attempts to display the symbol, if any,
1630 corresponding to addresses it prints. This defaults to "on", but
1631 you can set it to "off" to restore GDB's previous behavior.
1633 * Deprecated commands
1635 ** For the Renesas Super-H architecture, the "regs" command has been
1636 deprecated, and "info all-registers" should be used instead.
1640 Renesas RL78 rl78-*-elf
1641 HP OpenVMS ia64 ia64-hp-openvms*
1643 * GDBserver supports evaluation of breakpoint conditions. When
1644 support is advertised by GDBserver, GDB may be told to send the
1645 breakpoint conditions in bytecode form to GDBserver. GDBserver
1646 will only report the breakpoint trigger to GDB when its condition
1651 set mips compression
1652 show mips compression
1653 Select the compressed ISA encoding used in functions that have no symbol
1654 information available. The encoding can be set to either of:
1657 and is updated automatically from ELF file flags if available.
1659 set breakpoint condition-evaluation
1660 show breakpoint condition-evaluation
1661 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1662 GDBserver ("target"). Default option "auto" chooses the most efficient
1664 This option can improve debugger efficiency depending on the speed of the
1668 Disable auto-loading globally.
1671 Show auto-loading setting of all kinds of auto-loaded files.
1673 set auto-load gdb-scripts on|off
1674 show auto-load gdb-scripts
1675 Control auto-loading of GDB canned sequences of commands files.
1677 set auto-load python-scripts on|off
1678 show auto-load python-scripts
1679 Control auto-loading of Python script files.
1681 set auto-load local-gdbinit on|off
1682 show auto-load local-gdbinit
1683 Control loading of init file (.gdbinit) from current directory.
1685 set auto-load libthread-db on|off
1686 show auto-load libthread-db
1687 Control auto-loading of inferior specific thread debugging shared library.
1689 set auto-load scripts-directory <dir1>[:<dir2>...]
1690 show auto-load scripts-directory
1691 Set a list of directories from which to load auto-loaded scripts.
1692 Automatically loaded Python scripts and GDB scripts are located in one
1693 of the directories listed by this option.
1694 The delimiter (':' above) may differ according to the host platform.
1696 set auto-load safe-path <dir1>[:<dir2>...]
1697 show auto-load safe-path
1698 Set a list of directories from which it is safe to auto-load files.
1699 The delimiter (':' above) may differ according to the host platform.
1701 set debug auto-load on|off
1702 show debug auto-load
1703 Control display of debugging info for auto-loading the files above.
1705 set dprintf-style gdb|call|agent
1707 Control the way in which a dynamic printf is performed; "gdb"
1708 requests a GDB printf command, while "call" causes dprintf to call a
1709 function in the inferior. "agent" requests that the target agent
1710 (such as GDBserver) do the printing.
1712 set dprintf-function <expr>
1713 show dprintf-function
1714 set dprintf-channel <expr>
1715 show dprintf-channel
1716 Set the function and optional first argument to the call when using
1717 the "call" style of dynamic printf.
1719 set disconnected-dprintf on|off
1720 show disconnected-dprintf
1721 Control whether agent-style dynamic printfs continue to be in effect
1722 after GDB disconnects.
1724 * New configure options
1726 --with-auto-load-dir
1727 Configure default value for the 'set auto-load scripts-directory'
1728 setting above. It defaults to '$debugdir:$datadir/auto-load',
1729 $debugdir representing global debugging info directories (available
1730 via 'show debug-file-directory') and $datadir representing GDB's data
1731 directory (available via 'show data-directory').
1733 --with-auto-load-safe-path
1734 Configure default value for the 'set auto-load safe-path' setting
1735 above. It defaults to the --with-auto-load-dir setting.
1737 --without-auto-load-safe-path
1738 Set 'set auto-load safe-path' to '/', effectively disabling this
1741 * New remote packets
1743 z0/z1 conditional breakpoints extension
1745 The z0/z1 breakpoint insertion packets have been extended to carry
1746 a list of conditional expressions over to the remote stub depending on the
1747 condition evaluation mode. The use of this extension can be controlled
1748 via the "set remote conditional-breakpoints-packet" command.
1752 Specify the signals which the remote stub may pass to the debugged
1753 program without GDB involvement.
1755 * New command line options
1757 --init-command=FILE, -ix Like --command, -x but execute it
1758 before loading inferior.
1759 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1760 execute it before loading inferior.
1762 *** Changes in GDB 7.4
1764 * GDB now handles ambiguous linespecs more consistently; the existing
1765 FILE:LINE support has been expanded to other types of linespecs. A
1766 breakpoint will now be set on all matching locations in all
1767 inferiors, and locations will be added or removed according to
1770 * GDB now allows you to skip uninteresting functions and files when
1771 stepping with the "skip function" and "skip file" commands.
1773 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1774 and "show remote hardware-watchpoint-length-limit". These allows to
1775 set or show the maximum length limit (in bytes) of a remote
1776 target hardware watchpoint.
1778 This allows e.g. to use "unlimited" hardware watchpoints with the
1779 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1780 watchpoints are slower than real hardware watchpoints but are
1781 significantly faster than gdb software watchpoints.
1785 ** The register_pretty_printer function in module gdb.printing now takes
1786 an optional `replace' argument. If True, the new printer replaces any
1789 ** The "maint set python print-stack on|off" command has been
1790 deprecated and will be deleted in GDB 7.5.
1791 A new command: "set python print-stack none|full|message" has
1792 replaced it. Additionally, the default for "print-stack" is
1793 now "message", which just prints the error message without
1796 ** A prompt substitution hook (prompt_hook) is now available to the
1799 ** A new Python module, gdb.prompt has been added to the GDB Python
1800 modules library. This module provides functionality for
1801 escape sequences in prompts (used by set/show
1802 extended-prompt). These escape sequences are replaced by their
1803 corresponding value.
1805 ** Python commands and convenience-functions located in
1806 'data-directory'/python/gdb/command and
1807 'data-directory'/python/gdb/function are now automatically loaded
1810 ** Blocks now provide four new attributes. global_block and
1811 static_block will return the global and static blocks
1812 respectively. is_static and is_global are boolean attributes
1813 that indicate if the block is one of those two types.
1815 ** Symbols now provide the "type" attribute, the type of the symbol.
1817 ** The "gdb.breakpoint" function has been deprecated in favor of
1820 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1821 of a function. This class is based on the "finish" command
1822 available in the CLI.
1824 ** Type objects for struct and union types now allow access to
1825 the fields using standard Python dictionary (mapping) methods.
1826 For example, "some_type['myfield']" now works, as does
1827 "some_type.items()".
1829 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1832 ** A new function, "deep_items" has been added to the gdb.types
1833 module in the GDB Python modules library. This function returns
1834 an iterator over the fields of a struct or union type. Unlike
1835 the standard Python "iteritems" method, it will recursively traverse
1836 any anonymous fields.
1840 ** "*stopped" events can report several new "reason"s, such as
1843 ** Breakpoint changes are now notified using new async records, like
1844 "=breakpoint-modified".
1846 ** New command -ada-task-info.
1848 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1849 $sdir specifies the default system locations of shared libraries.
1850 $pdir specifies the directory where the libpthread used by the application
1853 GDB no longer looks in $sdir and $pdir after it has searched the directories
1854 mentioned in libthread-db-search-path. If you want to search those
1855 directories, they must be specified in libthread-db-search-path.
1856 The default value of libthread-db-search-path on GNU/Linux and Solaris
1857 systems is now "$sdir:$pdir".
1859 $pdir is not supported by gdbserver, it is currently ignored.
1860 $sdir is supported by gdbserver.
1862 * New configure option --with-iconv-bin.
1863 When using the internationalization support like the one in the GNU C
1864 library, GDB will invoke the "iconv" program to get a list of supported
1865 character sets. If this program lives in a non-standard location, one can
1866 use this option to specify where to find it.
1868 * When natively debugging programs on PowerPC BookE processors running
1869 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1870 watchpoints, which specify a mask in addition to an address to watch.
1871 The mask specifies that some bits of an address (the bits which are
1872 reset in the mask) should be ignored when matching the address accessed
1873 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1874 section in the user manual for more details.
1876 * The new option --once causes GDBserver to stop listening for connections once
1877 the first connection is made. The listening port used by GDBserver will
1878 become available after that.
1880 * New commands "info macros" and "alias" have been added.
1882 * New function parameters suffix @entry specifies value of function parameter
1883 at the time the function got called. Entry values are available only since
1889 "!" is now an alias of the "shell" command.
1890 Note that no space is needed between "!" and SHELL COMMAND.
1894 watch EXPRESSION mask MASK_VALUE
1895 The watch command now supports the mask argument which allows creation
1896 of masked watchpoints, if the current architecture supports this feature.
1898 info auto-load-scripts [REGEXP]
1899 This command was formerly named "maintenance print section-scripts".
1900 It is now generally useful and is no longer a maintenance-only command.
1902 info macro [-all] [--] MACRO
1903 The info macro command has new options `-all' and `--'. The first for
1904 printing all definitions of a macro. The second for explicitly specifying
1905 the end of arguments and the beginning of the macro name in case the macro
1906 name starts with a hyphen.
1908 collect[/s] EXPRESSIONS
1909 The tracepoint collect command now takes an optional modifier "/s"
1910 that directs it to dereference pointer-to-character types and
1911 collect the bytes of memory up to a zero byte. The behavior is
1912 similar to what you see when you use the regular print command on a
1913 string. An optional integer following the "/s" sets a bound on the
1914 number of bytes that will be collected.
1917 The trace start command now interprets any supplied arguments as a
1918 note to be recorded with the trace run, with an effect similar to
1919 setting the variable trace-notes.
1922 The trace stop command now interprets any arguments as a note to be
1923 mentioned along with the tstatus report that the trace was stopped
1924 with a command. The effect is similar to setting the variable
1927 * Tracepoints can now be enabled and disabled at any time after a trace
1928 experiment has been started using the standard "enable" and "disable"
1929 commands. It is now possible to start a trace experiment with no enabled
1930 tracepoints; GDB will display a warning, but will allow the experiment to
1931 begin, assuming that tracepoints will be enabled as needed while the trace
1934 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1935 locations with 4-byte instructions, when they were previously
1936 limited to locations with instructions of 5 bytes or longer.
1940 set debug dwarf2-read
1941 show debug dwarf2-read
1942 Turns on or off display of debugging messages related to reading
1943 DWARF debug info. The default is off.
1945 set debug symtab-create
1946 show debug symtab-create
1947 Turns on or off display of debugging messages related to symbol table
1948 creation. The default is off.
1951 show extended-prompt
1952 Set the GDB prompt, and allow escape sequences to be inserted to
1953 display miscellaneous information (see 'help set extended-prompt'
1954 for the list of sequences). This prompt (and any information
1955 accessed through the escape sequences) is updated every time the
1956 prompt is displayed.
1958 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1959 show print entry-values
1960 Set printing of frame argument values at function entry. In some cases
1961 GDB can determine the value of function argument which was passed by the
1962 function caller, even if the value was modified inside the called function.
1964 set debug entry-values
1965 show debug entry-values
1966 Control display of debugging info for determining frame argument values at
1967 function entry and virtual tail call frames.
1969 set basenames-may-differ
1970 show basenames-may-differ
1971 Set whether a source file may have multiple base names.
1972 (A "base name" is the name of a file with the directory part removed.
1973 Example: The base name of "/home/user/hello.c" is "hello.c".)
1974 If set, GDB will canonicalize file names (e.g., expand symlinks)
1975 before comparing them. Canonicalization is an expensive operation,
1976 but it allows the same file be known by more than one base name.
1977 If not set (the default), all source files are assumed to have just
1978 one base name, and gdb will do file name comparisons more efficiently.
1984 Set a user name and notes for the current and any future trace runs.
1985 This is useful for long-running and/or disconnected traces, to
1986 inform others (or yourself) as to who is running the trace, supply
1987 contact information, or otherwise explain what is going on.
1989 set trace-stop-notes
1990 show trace-stop-notes
1991 Set a note attached to the trace run, that is displayed when the
1992 trace has been stopped by a tstop command. This is useful for
1993 instance as an explanation, if you are stopping a trace run that was
1994 started by someone else.
1996 * New remote packets
2000 Dynamically enable a tracepoint in a started trace experiment.
2004 Dynamically disable a tracepoint in a started trace experiment.
2008 Set the user and notes of the trace run.
2012 Query the current status of a tracepoint.
2016 Query the minimum length of instruction at which a fast tracepoint may
2019 * Dcache size (number of lines) and line-size are now runtime-configurable
2020 via "set dcache line" and "set dcache line-size" commands.
2024 Texas Instruments TMS320C6x tic6x-*-*
2028 Renesas RL78 rl78-*-elf
2030 *** Changes in GDB 7.3.1
2032 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2034 *** Changes in GDB 7.3
2036 * GDB has a new command: "thread find [REGEXP]".
2037 It finds the thread id whose name, target id, or thread extra info
2038 matches the given regular expression.
2040 * The "catch syscall" command now works on mips*-linux* targets.
2042 * The -data-disassemble MI command now supports modes 2 and 3 for
2043 dumping the instruction opcodes.
2045 * New command line options
2047 -data-directory DIR Specify DIR as the "data-directory".
2048 This is mostly for testing purposes.
2050 * The "maint set python auto-load on|off" command has been renamed to
2051 "set auto-load-scripts on|off".
2053 * GDB has a new command: "set directories".
2054 It is like the "dir" command except that it replaces the
2055 source path list instead of augmenting it.
2057 * GDB now understands thread names.
2059 On GNU/Linux, "info threads" will display the thread name as set by
2060 prctl or pthread_setname_np.
2062 There is also a new command, "thread name", which can be used to
2063 assign a name internally for GDB to display.
2066 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2067 has been integrated into GDB.
2071 ** The function gdb.Write now accepts an optional keyword 'stream'.
2072 This keyword, when provided, will direct the output to either
2073 stdout, stderr, or GDB's logging output.
2075 ** Parameters can now be be sub-classed in Python, and in particular
2076 you may implement the get_set_doc and get_show_doc functions.
2077 This improves how Parameter set/show documentation is processed
2078 and allows for more dynamic content.
2080 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2081 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2082 have an is_valid method.
2084 ** Breakpoints can now be sub-classed in Python, and in particular
2085 you may implement a 'stop' function that is executed each time
2086 the inferior reaches that breakpoint.
2088 ** New function gdb.lookup_global_symbol looks up a global symbol.
2090 ** GDB values in Python are now callable if the value represents a
2091 function. For example, if 'some_value' represents a function that
2092 takes two integer parameters and returns a value, you can call
2093 that function like so:
2095 result = some_value (10,20)
2097 ** Module gdb.types has been added.
2098 It contains a collection of utilities for working with gdb.Types objects:
2099 get_basic_type, has_field, make_enum_dict.
2101 ** Module gdb.printing has been added.
2102 It contains utilities for writing and registering pretty-printers.
2103 New classes: PrettyPrinter, SubPrettyPrinter,
2104 RegexpCollectionPrettyPrinter.
2105 New function: register_pretty_printer.
2107 ** New commands "info pretty-printers", "enable pretty-printer" and
2108 "disable pretty-printer" have been added.
2110 ** gdb.parameter("directories") is now available.
2112 ** New function gdb.newest_frame returns the newest frame in the
2115 ** The gdb.InferiorThread class has a new "name" attribute. This
2116 holds the thread's name.
2118 ** Python Support for Inferior events.
2119 Python scripts can add observers to be notified of events
2120 occurring in the process being debugged.
2121 The following events are currently supported:
2122 - gdb.events.cont Continue event.
2123 - gdb.events.exited Inferior exited event.
2124 - gdb.events.stop Signal received, and Breakpoint hit events.
2128 ** GDB now puts template parameters in scope when debugging in an
2129 instantiation. For example, if you have:
2131 template<int X> int func (void) { return X; }
2133 then if you step into func<5>, "print X" will show "5". This
2134 feature requires proper debuginfo support from the compiler; it
2135 was added to GCC 4.5.
2137 ** The motion commands "next", "finish", "until", and "advance" now
2138 work better when exceptions are thrown. In particular, GDB will
2139 no longer lose control of the inferior; instead, the GDB will
2140 stop the inferior at the point at which the exception is caught.
2141 This functionality requires a change in the exception handling
2142 code that was introduced in GCC 4.5.
2144 * GDB now follows GCC's rules on accessing volatile objects when
2145 reading or writing target state during expression evaluation.
2146 One notable difference to prior behavior is that "print x = 0"
2147 no longer generates a read of x; the value of the assignment is
2148 now always taken directly from the value being assigned.
2150 * GDB now has some support for using labels in the program's source in
2151 linespecs. For instance, you can use "advance label" to continue
2152 execution to a label.
2154 * GDB now has support for reading and writing a new .gdb_index
2155 section. This section holds a fast index of DWARF debugging
2156 information and can be used to greatly speed up GDB startup and
2157 operation. See the documentation for `save gdb-index' for details.
2159 * The "watch" command now accepts an optional "-location" argument.
2160 When used, this causes GDB to watch the memory referred to by the
2161 expression. Such a watchpoint is never deleted due to it going out
2164 * GDB now supports thread debugging of core dumps on GNU/Linux.
2166 GDB now activates thread debugging using the libthread_db library
2167 when debugging GNU/Linux core dumps, similarly to when debugging
2168 live processes. As a result, when debugging a core dump file, GDB
2169 is now able to display pthread_t ids of threads. For example, "info
2170 threads" shows the same output as when debugging the process when it
2171 was live. In earlier releases, you'd see something like this:
2174 * 1 LWP 6780 main () at main.c:10
2176 While now you see this:
2179 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2181 It is also now possible to inspect TLS variables when debugging core
2184 When debugging a core dump generated on a machine other than the one
2185 used to run GDB, you may need to point GDB at the correct
2186 libthread_db library with the "set libthread-db-search-path"
2187 command. See the user manual for more details on this command.
2189 * When natively debugging programs on PowerPC BookE processors running
2190 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2191 which stop execution of the inferior whenever it executes an instruction
2192 at any address within the specified range. See the "PowerPC Embedded"
2193 section in the user manual for more details.
2195 * New features in the GDB remote stub, GDBserver
2197 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2198 and i686 LynxOS (version 5.x).
2200 ** GDBserver is now supported on Blackfin Linux.
2202 * New native configurations
2204 ia64 HP-UX ia64-*-hpux*
2208 Analog Devices, Inc. Blackfin Processor bfin-*
2210 * Ada task switching is now supported on sparc-elf targets when
2211 debugging a program using the Ravenscar Profile. For more information,
2212 see the "Tasking Support when using the Ravenscar Profile" section
2213 in the GDB user manual.
2215 * Guile support was removed.
2217 * New features in the GNU simulator
2219 ** The --map-info flag lists all known core mappings.
2221 ** CFI flashes may be simulated via the "cfi" device.
2223 *** Changes in GDB 7.2
2225 * Shared library support for remote targets by default
2227 When GDB is configured for a generic, non-OS specific target, like
2228 for example, --target=arm-eabi or one of the many *-*-elf targets,
2229 GDB now queries remote stubs for loaded shared libraries using the
2230 `qXfer:libraries:read' packet. Previously, shared library support
2231 was always disabled for such configurations.
2235 ** Argument Dependent Lookup (ADL)
2237 In C++ ADL lookup directs function search to the namespaces of its
2238 arguments even if the namespace has not been imported.
2248 Here the compiler will search for `foo' in the namespace of 'b'
2249 and find A::foo. GDB now supports this. This construct is commonly
2250 used in the Standard Template Library for operators.
2252 ** Improved User Defined Operator Support
2254 In addition to member operators, GDB now supports lookup of operators
2255 defined in a namespace and imported with a `using' directive, operators
2256 defined in the global scope, operators imported implicitly from an
2257 anonymous namespace, and the ADL operators mentioned in the previous
2259 GDB now also supports proper overload resolution for all the previously
2260 mentioned flavors of operators.
2262 ** static const class members
2264 Printing of static const class members that are initialized in the
2265 class definition has been fixed.
2267 * Windows Thread Information Block access.
2269 On Windows targets, GDB now supports displaying the Windows Thread
2270 Information Block (TIB) structure. This structure is visible either
2271 by using the new command `info w32 thread-information-block' or, by
2272 dereferencing the new convenience variable named `$_tlb', a
2273 thread-specific pointer to the TIB. This feature is also supported
2274 when remote debugging using GDBserver.
2276 * Static tracepoints
2278 Static tracepoints are calls in the user program into a tracing
2279 library. One such library is a port of the LTTng kernel tracer to
2280 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2281 When debugging with GDBserver, GDB now supports combining the GDB
2282 tracepoint machinery with such libraries. For example: the user can
2283 use GDB to probe a static tracepoint marker (a call from the user
2284 program into the tracing library) with the new "strace" command (see
2285 "New commands" below). This creates a "static tracepoint" in the
2286 breakpoint list, that can be manipulated with the same feature set
2287 as fast and regular tracepoints. E.g., collect registers, local and
2288 global variables, collect trace state variables, and define
2289 tracepoint conditions. In addition, the user can collect extra
2290 static tracepoint marker specific data, by collecting the new
2291 $_sdata internal variable. When analyzing the trace buffer, you can
2292 inspect $_sdata like any other variable available to GDB. For more
2293 information, see the "Tracepoints" chapter in GDB user manual. New
2294 remote packets have been defined to support static tracepoints, see
2295 the "New remote packets" section below.
2297 * Better reconstruction of tracepoints after disconnected tracing
2299 GDB will attempt to download the original source form of tracepoint
2300 definitions when starting a trace run, and then will upload these
2301 upon reconnection to the target, resulting in a more accurate
2302 reconstruction of the tracepoints that are in use on the target.
2306 You can now exercise direct control over the ways that GDB can
2307 affect your program. For instance, you can disallow the setting of
2308 breakpoints, so that the program can run continuously (assuming
2309 non-stop mode). In addition, the "observer" variable is available
2310 to switch all of the different controls; in observer mode, GDB
2311 cannot affect the target's behavior at all, which is useful for
2312 tasks like diagnosing live systems in the field.
2314 * The new convenience variable $_thread holds the number of the
2317 * New remote packets
2321 Return the address of the Windows Thread Information Block of a given thread.
2325 In response to several of the tracepoint packets, the target may now
2326 also respond with a number of intermediate `qRelocInsn' request
2327 packets before the final result packet, to have GDB handle
2328 relocating an instruction to execute at a different address. This
2329 is particularly useful for stubs that support fast tracepoints. GDB
2330 reports support for this feature in the qSupported packet.
2334 List static tracepoint markers in the target program.
2338 List static tracepoint markers at a given address in the target
2341 qXfer:statictrace:read
2343 Read the static trace data collected (by a `collect $_sdata'
2344 tracepoint action). The remote stub reports support for this packet
2345 to gdb's qSupported query.
2349 Send the current settings of GDB's permission flags.
2353 Send part of the source (textual) form of a tracepoint definition,
2354 which includes location, conditional, and action list.
2356 * The source command now accepts a -s option to force searching for the
2357 script in the source search path even if the script name specifies
2360 * New features in the GDB remote stub, GDBserver
2362 - GDBserver now support tracepoints (including fast tracepoints, and
2363 static tracepoints). The feature is currently supported by the
2364 i386-linux and amd64-linux builds. See the "Tracepoints support
2365 in gdbserver" section in the manual for more information.
2367 GDBserver JIT compiles the tracepoint's conditional agent
2368 expression bytecode into native code whenever possible for low
2369 overhead dynamic tracepoints conditionals. For such tracepoints,
2370 an expression that examines program state is evaluated when the
2371 tracepoint is reached, in order to determine whether to capture
2372 trace data. If the condition is simple and false, processing the
2373 tracepoint finishes very quickly and no data is gathered.
2375 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2376 for static tracepoints support.
2378 - GDBserver now supports x86_64 Windows 64-bit debugging.
2380 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2381 it understands register description.
2383 * The --batch flag now disables pagination and queries.
2385 * X86 general purpose registers
2387 GDB now supports reading/writing byte, word and double-word x86
2388 general purpose registers directly. This means you can use, say,
2389 $ah or $ax to refer, respectively, to the byte register AH and
2390 16-bit word register AX that are actually portions of the 32-bit
2391 register EAX or 64-bit register RAX.
2393 * The `commands' command now accepts a range of breakpoints to modify.
2394 A plain `commands' following a command that creates multiple
2395 breakpoints affects all the breakpoints set by that command. This
2396 applies to breakpoints set by `rbreak', and also applies when a
2397 single `break' command creates multiple breakpoints (e.g.,
2398 breakpoints on overloaded c++ functions).
2400 * The `rbreak' command now accepts a filename specification as part of
2401 its argument, limiting the functions selected by the regex to those
2402 in the specified file.
2404 * Support for remote debugging Windows and SymbianOS shared libraries
2405 from Unix hosts has been improved. Non Windows GDB builds now can
2406 understand target reported file names that follow MS-DOS based file
2407 system semantics, such as file names that include drive letters and
2408 use the backslash character as directory separator. This makes it
2409 possible to transparently use the "set sysroot" and "set
2410 solib-search-path" on Unix hosts to point as host copies of the
2411 target's shared libraries. See the new command "set
2412 target-file-system-kind" described below, and the "Commands to
2413 specify files" section in the user manual for more information.
2417 eval template, expressions...
2418 Convert the values of one or more expressions under the control
2419 of the string template to a command line, and call it.
2421 set target-file-system-kind unix|dos-based|auto
2422 show target-file-system-kind
2423 Set or show the assumed file system kind for target reported file
2426 save breakpoints <filename>
2427 Save all current breakpoint definitions to a file suitable for use
2428 in a later debugging session. To read the saved breakpoint
2429 definitions, use the `source' command.
2431 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2434 info static-tracepoint-markers
2435 Display information about static tracepoint markers in the target.
2437 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2438 Define a static tracepoint by probing a marker at the given
2439 function, line, address, or marker ID.
2443 Enable and disable observer mode.
2445 set may-write-registers on|off
2446 set may-write-memory on|off
2447 set may-insert-breakpoints on|off
2448 set may-insert-tracepoints on|off
2449 set may-insert-fast-tracepoints on|off
2450 set may-interrupt on|off
2451 Set individual permissions for GDB effects on the target. Note that
2452 some of these settings can have undesirable or surprising
2453 consequences, particularly when changed in the middle of a session.
2454 For instance, disabling the writing of memory can prevent
2455 breakpoints from being inserted, cause single-stepping to fail, or
2456 even crash your program, if you disable after breakpoints have been
2457 inserted. However, GDB should not crash.
2459 set record memory-query on|off
2460 show record memory-query
2461 Control whether to stop the inferior if memory changes caused
2462 by an instruction cannot be recorded.
2467 The disassemble command now supports "start,+length" form of two arguments.
2471 ** GDB now provides a new directory location, called the python directory,
2472 where Python scripts written for GDB can be installed. The location
2473 of that directory is <data-directory>/python, where <data-directory>
2474 is the GDB data directory. For more details, see section `Scripting
2475 GDB using Python' in the manual.
2477 ** The GDB Python API now has access to breakpoints, symbols, symbol
2478 tables, program spaces, inferiors, threads and frame's code blocks.
2479 Additionally, GDB Parameters can now be created from the API, and
2480 manipulated via set/show in the CLI.
2482 ** New functions gdb.target_charset, gdb.target_wide_charset,
2483 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2485 ** New exception gdb.GdbError.
2487 ** Pretty-printers are now also looked up in the current program space.
2489 ** Pretty-printers can now be individually enabled and disabled.
2491 ** GDB now looks for names of Python scripts to auto-load in a
2492 special section named `.debug_gdb_scripts', in addition to looking
2493 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2495 * Tracepoint actions were unified with breakpoint commands. In particular,
2496 there are no longer differences in "info break" output for breakpoints and
2497 tracepoints and the "commands" command can be used for both tracepoints and
2498 regular breakpoints.
2502 ARM Symbian arm*-*-symbianelf*
2504 * D language support.
2505 GDB now supports debugging programs written in the D programming
2508 * GDB now supports the extended ptrace interface for PowerPC which is
2509 available since Linux kernel version 2.6.34. This automatically enables
2510 any hardware breakpoints and additional hardware watchpoints available in
2511 the processor. The old ptrace interface exposes just one hardware
2512 watchpoint and no hardware breakpoints.
2514 * GDB is now able to use the Data Value Compare (DVC) register available on
2515 embedded PowerPC processors to implement in hardware simple watchpoint
2516 conditions of the form:
2518 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2520 This works in native GDB running on Linux kernels with the extended ptrace
2521 interface mentioned above.
2523 *** Changes in GDB 7.1
2527 ** Namespace Support
2529 GDB now supports importing of namespaces in C++. This enables the
2530 user to inspect variables from imported namespaces. Support for
2531 namepace aliasing has also been added. So, if a namespace is
2532 aliased in the current scope (e.g. namepace C=A; ) the user can
2533 print variables using the alias (e.g. (gdb) print C::x).
2537 All known bugs relating to the printing of virtual base class were
2538 fixed. It is now possible to call overloaded static methods using a
2543 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2544 and reinterpret_cast<> are now handled by the C++ expression parser.
2548 Xilinx MicroBlaze microblaze-*-*
2553 Xilinx MicroBlaze microblaze
2556 * Multi-program debugging.
2558 GDB now has support for multi-program (a.k.a. multi-executable or
2559 multi-exec) debugging. This allows for debugging multiple inferiors
2560 simultaneously each running a different program under the same GDB
2561 session. See "Debugging Multiple Inferiors and Programs" in the
2562 manual for more information. This implied some user visible changes
2563 in the multi-inferior support. For example, "info inferiors" now
2564 lists inferiors that are not running yet or that have exited
2565 already. See also "New commands" and "New options" below.
2567 * New tracing features
2569 GDB's tracepoint facility now includes several new features:
2571 ** Trace state variables
2573 GDB tracepoints now include support for trace state variables, which
2574 are variables managed by the target agent during a tracing
2575 experiment. They are useful for tracepoints that trigger each
2576 other, so for instance one tracepoint can count hits in a variable,
2577 and then a second tracepoint has a condition that is true when the
2578 count reaches a particular value. Trace state variables share the
2579 $-syntax of GDB convenience variables, and can appear in both
2580 tracepoint actions and condition expressions. Use the "tvariable"
2581 command to create, and "info tvariables" to view; see "Trace State
2582 Variables" in the manual for more detail.
2586 GDB now includes an option for defining fast tracepoints, which
2587 targets may implement more efficiently, such as by installing a jump
2588 into the target agent rather than a trap instruction. The resulting
2589 speedup can be by two orders of magnitude or more, although the
2590 tradeoff is that some program locations on some target architectures
2591 might not allow fast tracepoint installation, for instance if the
2592 instruction to be replaced is shorter than the jump. To request a
2593 fast tracepoint, use the "ftrace" command, with syntax identical to
2594 the regular trace command.
2596 ** Disconnected tracing
2598 It is now possible to detach GDB from the target while it is running
2599 a trace experiment, then reconnect later to see how the experiment
2600 is going. In addition, a new variable disconnected-tracing lets you
2601 tell the target agent whether to continue running a trace if the
2602 connection is lost unexpectedly.
2606 GDB now has the ability to save the trace buffer into a file, and
2607 then use that file as a target, similarly to you can do with
2608 corefiles. You can select trace frames, print data that was
2609 collected in them, and use tstatus to display the state of the
2610 tracing run at the moment that it was saved. To create a trace
2611 file, use "tsave <filename>", and to use it, do "target tfile
2614 ** Circular trace buffer
2616 You can ask the target agent to handle the trace buffer as a
2617 circular buffer, discarding the oldest trace frames to make room for
2618 newer ones, by setting circular-trace-buffer to on. This feature may
2619 not be available for all target agents.
2624 The disassemble command, when invoked with two arguments, now requires
2625 the arguments to be comma-separated.
2628 The info variables command now displays variable definitions. Files
2629 which only declare a variable are not shown.
2632 The source command is now capable of sourcing Python scripts.
2633 This feature is dependent on the debugger being build with Python
2636 Related to this enhancement is also the introduction of a new command
2637 "set script-extension" (see below).
2639 * New commands (for set/show, see "New options" below)
2641 record save [<FILENAME>]
2642 Save a file (in core file format) containing the process record
2643 execution log for replay debugging at a later time.
2645 record restore <FILENAME>
2646 Restore the process record execution log that was saved at an
2647 earlier time, for replay debugging.
2649 add-inferior [-copies <N>] [-exec <FILENAME>]
2652 clone-inferior [-copies <N>] [ID]
2653 Make a new inferior ready to execute the same program another
2654 inferior has loaded.
2659 maint info program-spaces
2660 List the program spaces loaded into GDB.
2662 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2663 show remote interrupt-sequence
2664 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2665 as the sequence to the remote target in order to interrupt the execution.
2666 Ctrl-C is a default. Some system prefers BREAK which is high level of
2667 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2668 Magic SysRq g. It is BREAK signal and character 'g'.
2670 set remote interrupt-on-connect [on | off]
2671 show remote interrupt-on-connect
2672 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2673 remote target when gdb connects to it. This is needed when you debug
2676 set remotebreak [on | off]
2678 Deprecated. Use "set/show remote interrupt-sequence" instead.
2680 tvariable $NAME [ = EXP ]
2681 Create or modify a trace state variable.
2684 List trace state variables and their values.
2686 delete tvariable $NAME ...
2687 Delete one or more trace state variables.
2690 Evaluate the given expressions without collecting anything into the
2691 trace buffer. (Valid in tracepoint actions only.)
2693 ftrace FN / FILE:LINE / *ADDR
2694 Define a fast tracepoint at the given function, line, or address.
2696 * New expression syntax
2698 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2699 GDB now parses 0b101010 identically with 42.
2703 set follow-exec-mode new|same
2704 show follow-exec-mode
2705 Control whether GDB reuses the same inferior across an exec call or
2706 creates a new one. This is useful to be able to restart the old
2707 executable after the inferior having done an exec call.
2709 set default-collect EXPR, ...
2710 show default-collect
2711 Define a list of expressions to be collected at each tracepoint.
2712 This is a useful way to ensure essential items are not overlooked,
2713 such as registers or a critical global variable.
2715 set disconnected-tracing
2716 show disconnected-tracing
2717 If set to 1, the target is instructed to continue tracing if it
2718 loses its connection to GDB. If 0, the target is to stop tracing
2721 set circular-trace-buffer
2722 show circular-trace-buffer
2723 If set to on, the target is instructed to use a circular trace buffer
2724 and discard the oldest trace frames instead of stopping the trace due
2725 to a full trace buffer. If set to off, the trace stops when the buffer
2726 fills up. Some targets may not support this.
2728 set script-extension off|soft|strict
2729 show script-extension
2730 If set to "off", the debugger does not perform any script language
2731 recognition, and all sourced files are assumed to be GDB scripts.
2732 If set to "soft" (the default), files are sourced according to
2733 filename extension, falling back to GDB scripts if the first
2735 If set to "strict", files are sourced according to filename extension.
2737 set ada trust-PAD-over-XVS on|off
2738 show ada trust-PAD-over-XVS
2739 If off, activate a workaround against a bug in the debugging information
2740 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2741 the GCC sources for more information about the GNAT encoding and
2742 PAD types in particular). It is always safe to set this option to
2743 off, but this introduces a slight performance penalty. The default
2746 * Python API Improvements
2748 ** GDB provides the new class gdb.LazyString. This is useful in
2749 some pretty-printing cases. The new method gdb.Value.lazy_string
2750 provides a simple way to create objects of this type.
2752 ** The fields returned by gdb.Type.fields now have an
2753 `is_base_class' attribute.
2755 ** The new method gdb.Type.range returns the range of an array type.
2757 ** The new method gdb.parse_and_eval can be used to parse and
2758 evaluate an expression.
2760 * New remote packets
2763 Define a trace state variable.
2766 Get the current value of a trace state variable.
2769 Set desired tracing behavior upon disconnection.
2772 Set the trace buffer to be linear or circular.
2775 Get data about the tracepoints currently in use.
2779 Process record now works correctly with hardware watchpoints.
2781 Multiple bug fixes have been made to the mips-irix port, making it
2782 much more reliable. In particular:
2783 - Debugging threaded applications is now possible again. Previously,
2784 GDB would hang while starting the program, or while waiting for
2785 the program to stop at a breakpoint.
2786 - Attaching to a running process no longer hangs.
2787 - An error occurring while loading a core file has been fixed.
2788 - Changing the value of the PC register now works again. This fixes
2789 problems observed when using the "jump" command, or when calling
2790 a function from GDB, or even when assigning a new value to $pc.
2791 - With the "finish" and "return" commands, the return value for functions
2792 returning a small array is now correctly printed.
2793 - It is now possible to break on shared library code which gets executed
2794 during a shared library init phase (code executed while executing
2795 their .init section). Previously, the breakpoint would have no effect.
2796 - GDB is now able to backtrace through the signal handler for
2797 non-threaded programs.
2799 PIE (Position Independent Executable) programs debugging is now supported.
2800 This includes debugging execution of PIC (Position Independent Code) shared
2801 libraries although for that, it should be possible to run such libraries as an
2804 *** Changes in GDB 7.0
2806 * GDB now has an interface for JIT compilation. Applications that
2807 dynamically generate code can create symbol files in memory and register
2808 them with GDB. For users, the feature should work transparently, and
2809 for JIT developers, the interface is documented in the GDB manual in the
2810 "JIT Compilation Interface" chapter.
2812 * Tracepoints may now be conditional. The syntax is as for
2813 breakpoints; either an "if" clause appended to the "trace" command,
2814 or the "condition" command is available. GDB sends the condition to
2815 the target for evaluation using the same bytecode format as is used
2816 for tracepoint actions.
2818 * The disassemble command now supports: an optional /r modifier, print the
2819 raw instructions in hex as well as in symbolic form, and an optional /m
2820 modifier to print mixed source+assembly.
2822 * Process record and replay
2824 In a architecture environment that supports ``process record and
2825 replay'', ``process record and replay'' target can record a log of
2826 the process execution, and replay it with both forward and reverse
2829 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2830 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2831 set execution-direction {forward|reverse}, for targets that support
2834 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2835 feature is available with a native GDB running on kernel version
2838 * GDB now has support for multi-byte and wide character sets on the
2839 target. Strings whose character type is wchar_t, char16_t, or
2840 char32_t are now correctly printed. GDB supports wide- and unicode-
2841 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2842 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2843 `printf'. This feature requires iconv to work properly; if your
2844 system does not have a working iconv, GDB can use GNU libiconv. See
2845 the installation instructions for more information.
2847 * GDB now supports automatic retrieval of shared library files from
2848 remote targets. To use this feature, specify a system root that begins
2849 with the `remote:' prefix, either via the `set sysroot' command or via
2850 the `--with-sysroot' configure-time option.
2852 * "info sharedlibrary" now takes an optional regex of libraries to show,
2853 and it now reports if a shared library has no debugging information.
2855 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2856 now complete on file names.
2858 * When completing in expressions, gdb will attempt to limit
2859 completions to allowable structure or union fields, where appropriate.
2860 For instance, consider:
2862 # struct example { int f1; double f2; };
2863 # struct example variable;
2866 If the user types TAB at the end of this command line, the available
2867 completions will be "f1" and "f2".
2869 * Inlined functions are now supported. They show up in backtraces, and
2870 the "step", "next", and "finish" commands handle them automatically.
2872 * GDB now supports the token-splicing (##) and stringification (#)
2873 operators when expanding macros. It also supports variable-arity
2876 * GDB now supports inspecting extra signal information, exported by
2877 the new $_siginfo convenience variable. The feature is currently
2878 implemented on linux ARM, i386 and amd64.
2880 * GDB can now display the VFP floating point registers and NEON vector
2881 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2882 can provide these registers (requires Linux 2.6.30 or later). Remote
2883 and simulator targets may also provide them.
2885 * New remote packets
2888 Search memory for a sequence of bytes.
2891 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2892 operation over reliable transport links. Use of this packet is
2893 controlled by the `set remote noack-packet' command.
2896 Kill the process with the specified process ID. Use this in preference
2897 to `k' when multiprocess protocol extensions are supported.
2900 Obtains additional operating system information
2904 Read or write additional signal information.
2906 * Removed remote protocol undocumented extension
2908 An undocumented extension to the remote protocol's `S' stop reply
2909 packet that permited the stub to pass a process id was removed.
2910 Remote servers should use the `T' stop reply packet instead.
2912 * GDB now supports multiple function calling conventions according to the
2913 DWARF-2 DW_AT_calling_convention function attribute.
2915 * The SH target utilizes the aforementioned change to distinguish between gcc
2916 and Renesas calling convention. It also adds the new CLI commands
2917 `set/show sh calling-convention'.
2919 * GDB can now read compressed debug sections, as produced by GNU gold
2920 with the --compress-debug-sections=zlib flag.
2922 * 64-bit core files are now supported on AIX.
2924 * Thread switching is now supported on Tru64.
2926 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2927 which will be allocated using malloc later in program execution.
2929 * The qXfer:libraries:read remote procotol packet now allows passing a
2930 list of section offsets.
2932 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2933 conditions handling signals delivered during attach or thread creation
2934 have also been fixed.
2936 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2937 From the user's standpoint, all unqualified instances of True and False
2938 are treated as the standard definitions, regardless of context.
2940 * GDB now parses C++ symbol and type names more flexibly. For
2943 template<typename T> class C { };
2946 GDB will now correctly handle all of:
2948 ptype C<char const *>
2949 ptype C<char const*>
2950 ptype C<const char *>
2951 ptype C<const char*>
2953 * New features in the GDB remote stub, gdbserver
2955 - The "--wrapper" command-line argument tells gdbserver to use a
2956 wrapper program to launch programs for debugging.
2958 - On PowerPC and S/390 targets, it is now possible to use a single
2959 gdbserver executable to debug both 32-bit and 64-bit programs.
2960 (This requires gdbserver itself to be built as a 64-bit executable.)
2962 - gdbserver uses the new noack protocol mode for TCP connections to
2963 reduce communications latency, if also supported and enabled in GDB.
2965 - Support for the sparc64-linux-gnu target is now included in
2968 - The amd64-linux build of gdbserver now supports debugging both
2969 32-bit and 64-bit programs.
2971 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2972 now support hardware watchpoints, and will use them automatically
2977 GDB now has support for scripting using Python. Whether this is
2978 available is determined at configure time.
2980 New GDB commands can now be written in Python.
2982 * Ada tasking support
2984 Ada tasks can now be inspected in GDB. The following commands have
2988 Print the list of Ada tasks.
2990 Print detailed information about task number N.
2992 Print the task number of the current task.
2994 Switch the context of debugging to task number N.
2996 * Support for user-defined prefixed commands. The "define" command can
2997 add new commands to existing prefixes, e.g. "target".
2999 * Multi-inferior, multi-process debugging.
3001 GDB now has generalized support for multi-inferior debugging. See
3002 "Debugging Multiple Inferiors" in the manual for more information.
3003 Although availability still depends on target support, the command
3004 set is more uniform now. The GNU/Linux specific multi-forks support
3005 has been migrated to this new framework. This implied some user
3006 visible changes; see "New commands" and also "Removed commands"
3009 * Target descriptions can now describe the target OS ABI. See the
3010 "Target Description Format" section in the user manual for more
3013 * Target descriptions can now describe "compatible" architectures
3014 to indicate that the target can execute applications for a different
3015 architecture in addition to those for the main target architecture.
3016 See the "Target Description Format" section in the user manual for
3019 * Multi-architecture debugging.
3021 GDB now includes general supports for debugging applications on
3022 hybrid systems that use more than one single processor architecture
3023 at the same time. Each such hybrid architecture still requires
3024 specific support to be added. The only hybrid architecture supported
3025 in this version of GDB is the Cell Broadband Engine.
3027 * GDB now supports integrated debugging of Cell/B.E. applications that
3028 use both the PPU and SPU architectures. To enable support for hybrid
3029 Cell/B.E. debugging, you need to configure GDB to support both the
3030 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3031 --enable-targets configure option.
3033 * Non-stop mode debugging.
3035 For some targets, GDB now supports an optional mode of operation in
3036 which you can examine stopped threads while other threads continue
3037 to execute freely. This is referred to as non-stop mode, with the
3038 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3039 section in the user manual for more information.
3041 To be able to support remote non-stop debugging, a remote stub needs
3042 to implement the non-stop mode remote protocol extensions, as
3043 described in the "Remote Non-Stop" section of the user manual. The
3044 GDB remote stub, gdbserver, has been adjusted to support these
3045 extensions on linux targets.
3047 * New commands (for set/show, see "New options" below)
3049 catch syscall [NAME(S) | NUMBER(S)]
3050 Catch system calls. Arguments, which should be names of system
3051 calls or their numbers, mean catch only those syscalls. Without
3052 arguments, every syscall will be caught. When the inferior issues
3053 any of the specified syscalls, GDB will stop and announce the system
3054 call, both when it is called and when its call returns. This
3055 feature is currently available with a native GDB running on the
3056 Linux Kernel, under the following architectures: x86, x86_64,
3057 PowerPC and PowerPC64.
3059 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3061 Search memory for a sequence of bytes.
3063 maint set python print-stack
3064 maint show python print-stack
3065 Show a stack trace when an error is encountered in a Python script.
3068 Invoke CODE by passing it to the Python interpreter.
3073 These allow macros to be defined, undefined, and listed
3077 Show operating system information about processes.
3080 List the inferiors currently under GDB's control.
3083 Switch focus to inferior number NUM.
3086 Detach from inferior number NUM.
3089 Kill inferior number NUM.
3093 set spu stop-on-load
3094 show spu stop-on-load
3095 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3097 set spu auto-flush-cache
3098 show spu auto-flush-cache
3099 Control whether to automatically flush the software-managed cache
3100 during Cell/B.E. debugging.
3102 set sh calling-convention
3103 show sh calling-convention
3104 Control the calling convention used when calling SH target functions.
3107 show debug timestamp
3108 Control display of timestamps with GDB debugging output.
3110 set disassemble-next-line
3111 show disassemble-next-line
3112 Control display of disassembled source lines or instructions when
3115 set remote noack-packet
3116 show remote noack-packet
3117 Set/show the use of remote protocol QStartNoAckMode packet. See above
3118 under "New remote packets."
3120 set remote query-attached-packet
3121 show remote query-attached-packet
3122 Control use of remote protocol `qAttached' (query-attached) packet.
3124 set remote read-siginfo-object
3125 show remote read-siginfo-object
3126 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3129 set remote write-siginfo-object
3130 show remote write-siginfo-object
3131 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3134 set remote reverse-continue
3135 show remote reverse-continue
3136 Control use of remote protocol 'bc' (reverse-continue) packet.
3138 set remote reverse-step
3139 show remote reverse-step
3140 Control use of remote protocol 'bs' (reverse-step) packet.
3142 set displaced-stepping
3143 show displaced-stepping
3144 Control displaced stepping mode. Displaced stepping is a way to
3145 single-step over breakpoints without removing them from the debuggee.
3146 Also known as "out-of-line single-stepping".
3149 show debug displaced
3150 Control display of debugging info for displaced stepping.
3152 maint set internal-error
3153 maint show internal-error
3154 Control what GDB does when an internal error is detected.
3156 maint set internal-warning
3157 maint show internal-warning
3158 Control what GDB does when an internal warning is detected.
3163 Use a wrapper program to launch programs for debugging.
3165 set multiple-symbols (all|ask|cancel)
3166 show multiple-symbols
3167 The value of this variable can be changed to adjust the debugger behavior
3168 when an expression or a breakpoint location contains an ambiguous symbol
3169 name (an overloaded function name, for instance).
3171 set breakpoint always-inserted
3172 show breakpoint always-inserted
3173 Keep breakpoints always inserted in the target, as opposed to inserting
3174 them when resuming the target, and removing them when the target stops.
3175 This option can improve debugger performance on slow remote targets.
3177 set arm fallback-mode (arm|thumb|auto)
3178 show arm fallback-mode
3179 set arm force-mode (arm|thumb|auto)
3181 These commands control how ARM GDB determines whether instructions
3182 are ARM or Thumb. The default for both settings is auto, which uses
3183 the current CPSR value for instructions without symbols; previous
3184 versions of GDB behaved as if "set arm fallback-mode arm".
3186 set disable-randomization
3187 show disable-randomization
3188 Standalone programs run with the virtual address space randomization enabled
3189 by default on some platforms. This option keeps the addresses stable across
3190 multiple debugging sessions.
3194 Control whether other threads are stopped or not when some thread hits
3199 Requests that asynchronous execution is enabled in the target, if available.
3200 In this case, it's possible to resume target in the background, and interact
3201 with GDB while the target is running. "show target-async" displays the
3202 current state of asynchronous execution of the target.
3204 set target-wide-charset
3205 show target-wide-charset
3206 The target-wide-charset is the name of the character set that GDB
3207 uses when printing characters whose type is wchar_t.
3209 set tcp auto-retry (on|off)
3211 set tcp connect-timeout
3212 show tcp connect-timeout
3213 These commands allow GDB to retry failed TCP connections to a remote stub
3214 with a specified timeout period; this is useful if the stub is launched
3215 in parallel with GDB but may not be ready to accept connections immediately.
3217 set libthread-db-search-path
3218 show libthread-db-search-path
3219 Control list of directories which GDB will search for appropriate
3222 set schedule-multiple (on|off)
3223 show schedule-multiple
3224 Allow GDB to resume all threads of all processes or only threads of
3225 the current process.
3229 Use more aggressive caching for accesses to the stack. This improves
3230 performance of remote debugging (particularly backtraces) without
3231 affecting correctness.
3233 set interactive-mode (on|off|auto)
3234 show interactive-mode
3235 Control whether GDB runs in interactive mode (on) or not (off).
3236 When in interactive mode, GDB waits for the user to answer all
3237 queries. Otherwise, GDB does not wait and assumes the default
3238 answer. When set to auto (the default), GDB determines which
3239 mode to use based on the stdin settings.
3244 For program forks, this is replaced by the new more generic `info
3245 inferiors' command. To list checkpoints, you can still use the
3246 `info checkpoints' command, which was an alias for the `info forks'
3250 Replaced by the new `inferior' command. To switch between
3251 checkpoints, you can still use the `restart' command, which was an
3252 alias for the `fork' command.
3255 This is removed, since some targets don't have a notion of
3256 processes. To switch between processes, you can still use the
3257 `inferior' command using GDB's own inferior number.
3260 For program forks, this is replaced by the new more generic `kill
3261 inferior' command. To delete a checkpoint, you can still use the
3262 `delete checkpoint' command, which was an alias for the `delete
3266 For program forks, this is replaced by the new more generic `detach
3267 inferior' command. To detach a checkpoint, you can still use the
3268 `detach checkpoint' command, which was an alias for the `detach
3271 * New native configurations
3273 x86/x86_64 Darwin i[34567]86-*-darwin*
3275 x86_64 MinGW x86_64-*-mingw*
3279 Lattice Mico32 lm32-*
3280 x86 DICOS i[34567]86-*-dicos*
3281 x86_64 DICOS x86_64-*-dicos*
3284 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3285 (mingw32ce) debugging.
3291 These commands were actually not implemented on any target.
3293 *** Changes in GDB 6.8
3295 * New native configurations
3297 NetBSD/hppa hppa*-*netbsd*
3298 Xtensa GNU/Linux xtensa*-*-linux*
3302 NetBSD/hppa hppa*-*-netbsd*
3303 Xtensa GNU/Lunux xtensa*-*-linux*
3305 * Change in command line behavior -- corefiles vs. process ids.
3307 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3308 attaching to process NUMBER fails, GDB no longer attempts to open a
3309 core file named NUMBER. Attaching to a program using the -c option
3310 is no longer supported. Instead, use the '-p' or '--pid' options.
3312 * GDB can now be built as a native debugger for debugging Windows x86
3313 (mingw32) Portable Executable (PE) programs.
3315 * Pending breakpoints no longer change their number when their address
3318 * GDB now supports breakpoints with multiple locations,
3319 including breakpoints on C++ constructors, inside C++ templates,
3320 and in inlined functions.
3322 * GDB's ability to debug optimized code has been improved. GDB more
3323 accurately identifies function bodies and lexical blocks that occupy
3324 more than one contiguous range of addresses.
3326 * Target descriptions can now describe registers for PowerPC.
3328 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3329 registers on PowerPC targets.
3331 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3332 targets even when the libthread_db library is not available.
3334 * The GDB remote stub, gdbserver, now supports the new file transfer
3335 commands (remote put, remote get, and remote delete).
3337 * The GDB remote stub, gdbserver, now supports run and attach in
3338 extended-remote mode.
3340 * hppa*64*-*-hpux11* target broken
3341 The debugger is unable to start a program and fails with the following
3342 error: "Error trying to get information about dynamic linker".
3343 The gdb-6.7 release is also affected.
3345 * GDB now supports the --enable-targets= configure option to allow
3346 building a single GDB executable that supports multiple remote
3347 target architectures.
3349 * GDB now supports debugging C and C++ programs which use the
3350 Decimal Floating Point extension. In addition, the PowerPC target
3351 now has a set of pseudo-registers to inspect decimal float values
3352 stored in two consecutive float registers.
3354 * The -break-insert MI command can optionally create pending
3357 * Improved support for debugging Ada
3358 Many improvements to the Ada language support have been made. These
3360 - Better support for Ada2005 interface types
3361 - Improved handling of arrays and slices in general
3362 - Better support for Taft-amendment types
3363 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3365 - Improved command completion in Ada
3368 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3373 set print frame-arguments (all|scalars|none)
3374 show print frame-arguments
3375 The value of this variable can be changed to control which argument
3376 values should be printed by the debugger when displaying a frame.
3381 Transfer files to and from a remote target, and delete remote files.
3388 Transfer files to and from a remote target, and delete remote files.
3390 * New remote packets
3397 Open, close, read, write, and delete files on the remote system.
3400 Attach to an existing process on the remote system, in extended-remote
3404 Run a new process on the remote system, in extended-remote mode.
3406 *** Changes in GDB 6.7
3408 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3409 bfd, libiberty and opcodes, as revealed by static analysis donated by
3410 Coverity, Inc. (http://scan.coverity.com).
3412 * When looking up multiply-defined global symbols, GDB will now prefer the
3413 symbol definition in the current shared library if it was built using the
3414 -Bsymbolic linker option.
3416 * When the Text User Interface (TUI) is not configured, GDB will now
3417 recognize the -tui command-line option and print a message that the TUI
3420 * The GDB remote stub, gdbserver, now has lower overhead for high
3421 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3423 * GDB for MIPS targets now autodetects whether a remote target provides
3424 32-bit or 64-bit register values.
3426 * Support for C++ member pointers has been improved.
3428 * GDB now understands XML target descriptions, which specify the
3429 target's overall architecture. GDB can read a description from
3430 a local file or over the remote serial protocol.
3432 * Vectors of single-byte data use a new integer type which is not
3433 automatically displayed as character or string data.
3435 * The /s format now works with the print command. It displays
3436 arrays of single-byte integers and pointers to single-byte integers
3439 * Target descriptions can now describe target-specific registers,
3440 for architectures which have implemented the support (currently
3441 only ARM, M68K, and MIPS).
3443 * GDB and the GDB remote stub, gdbserver, now support the XScale
3446 * The GDB remote stub, gdbserver, has been updated to support
3447 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3448 has been rewritten to use the standard GDB remote protocol.
3450 * GDB can now step into C++ functions which are called through thunks.
3452 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3454 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3455 layout. It also supports a TextSeg= and DataSeg= response when only
3456 segment base addresses (rather than offsets) are available.
3458 * The /i format now outputs any trailing branch delay slot instructions
3459 immediately following the last instruction within the count specified.
3461 * The GDB remote protocol "T" stop reply packet now supports a
3462 "library" response. Combined with the new "qXfer:libraries:read"
3463 packet, this response allows GDB to debug shared libraries on targets
3464 where the operating system manages the list of loaded libraries (e.g.
3465 Windows and SymbianOS).
3467 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3468 (DLLs) on Windows and Windows CE targets.
3470 * GDB now supports a faster verification that a .debug file matches its binary
3471 according to its build-id signature, if the signature is present.
3477 Enable or disable hardware flow control (RTS/CTS) on the serial port
3478 when debugging using remote targets.
3480 set mem inaccessible-by-default
3481 show mem inaccessible-by-default
3482 If the target supplies a memory map, for instance via the remote
3483 protocol's "qXfer:memory-map:read" packet, setting this variable
3484 prevents GDB from accessing memory outside the memory map. This
3485 is useful for targets with memory mapped registers or which react
3486 badly to accesses of unmapped address space.
3488 set breakpoint auto-hw
3489 show breakpoint auto-hw
3490 If the target supplies a memory map, for instance via the remote
3491 protocol's "qXfer:memory-map:read" packet, setting this variable
3492 lets GDB use hardware breakpoints automatically for memory regions
3493 where it can not use software breakpoints. This covers both the
3494 "break" command and internal breakpoints used for other commands
3495 including "next" and "finish".
3498 catch exception unhandled
3499 Stop the program execution when Ada exceptions are raised.
3502 Stop the program execution when an Ada assertion failed.
3506 Set an alternate system root for target files. This is a more
3507 general version of "set solib-absolute-prefix", which is now
3508 an alias to "set sysroot".
3511 Provide extended SPU facility status information. This set of
3512 commands is available only when debugging the Cell/B.E. SPU
3515 * New native configurations
3517 OpenBSD/sh sh*-*openbsd*
3520 unset tdesc filename
3522 Use the specified local file as an XML target description, and do
3523 not query the target for its built-in description.
3527 OpenBSD/sh sh*-*-openbsd*
3528 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3529 Toshiba Media Processor mep-elf
3531 * New remote packets
3534 Ignore the specified signals; pass them directly to the debugged program
3535 without stopping other threads or reporting them to GDB.
3537 qXfer:features:read:
3538 Read an XML target description from the target, which describes its
3543 Read or write contents of an spufs file on the target system. These
3544 packets are available only on the Cell/B.E. SPU architecture.
3546 qXfer:libraries:read:
3547 Report the loaded shared libraries. Combined with new "T" packet
3548 response, this packet allows GDB to debug shared libraries on
3549 targets where the operating system manages the list of loaded
3550 libraries (e.g. Windows and SymbianOS).
3554 Support for these obsolete configurations has been removed.
3562 i[34567]86-*-lynxos*
3563 i[34567]86-*-netware*
3564 i[34567]86-*-sco3.2v5*
3565 i[34567]86-*-sco3.2v4*
3567 i[34567]86-*-sysv4.2*
3570 i[34567]86-*-unixware2*
3571 i[34567]86-*-unixware*
3580 * Other removed features
3587 Various m68k-only ROM monitors.
3594 Various Renesas ROM monitors and debugging interfaces for SH and
3599 Support for a Macraigor serial interface to on-chip debugging.
3600 GDB does not directly support the newer parallel or USB
3605 A debug information format. The predecessor to DWARF 2 and
3606 DWARF 3, which are still supported.
3608 Support for the HP aCC compiler on HP-UX/PA-RISC
3610 SOM-encapsulated symbolic debugging information, automatic
3611 invocation of pxdb, and the aCC custom C++ ABI. This does not
3612 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3613 with aCC can still be debugged on an assembly level.
3615 MIPS ".pdr" sections
3617 A MIPS-specific format used to describe stack frame layout
3618 in debugging information.
3622 GDB could work with an older version of Guile to debug
3623 the interpreter and Scheme programs running in it.
3625 set mips stack-arg-size
3626 set mips saved-gpreg-size
3628 Use "set mips abi" to control parameter passing for MIPS.
3630 *** Changes in GDB 6.6
3635 Cell Broadband Engine SPU spu-elf
3637 * GDB can now be configured as a cross-debugger targeting native Windows
3638 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3639 running on a Windows system over TCP/IP to debug Windows programs.
3641 * The GDB remote stub, gdbserver, has been updated to support Windows and
3642 Cygwin debugging. Both single-threaded and multi-threaded programs are
3645 * The "set trust-readonly-sections" command works again. This command was
3646 broken in GDB 6.3, 6.4, and 6.5.
3648 * The "load" command now supports writing to flash memory, if the remote
3649 stub provides the required support.
3651 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3652 longer requires symbolic debug information (e.g. DWARF-2).
3657 unset substitute-path
3658 show substitute-path
3659 Manage a list of substitution rules that GDB uses to rewrite the name
3660 of the directories where the sources are located. This can be useful
3661 for instance when the sources were moved to a different location
3662 between compilation and debugging.
3666 Print each CLI command as it is executed. Each command is prefixed with
3667 a number of `+' symbols representing the nesting depth.
3668 The source command now has a `-v' option to enable the same feature.
3672 The ARM Demon monitor support (RDP protocol, "target rdp").
3674 Kernel Object Display, an embedded debugging feature which only worked with
3675 an obsolete version of Cisco IOS.
3677 The 'set download-write-size' and 'show download-write-size' commands.
3679 * New remote packets
3682 Tell a stub about GDB client features, and request remote target features.
3683 The first feature implemented is PacketSize, which allows the target to
3684 specify the size of packets it can handle - to minimize the number of
3685 packets required and improve performance when connected to a remote
3689 Fetch an OS auxilliary vector from the remote stub. This packet is a
3690 more efficient replacement for qPart:auxv:read.
3692 qXfer:memory-map:read:
3693 Fetch a memory map from the remote stub, including information about
3694 RAM, ROM, and flash memory devices.
3699 Erase and program a flash memory device.
3701 * Removed remote packets
3704 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3705 used it, and only gdbserver implemented it.
3707 *** Changes in GDB 6.5
3711 Renesas M32C/M16C m32c-elf
3713 Morpho Technologies ms1 ms1-elf
3717 init-if-undefined Initialize a convenience variable, but
3718 only if it doesn't already have a value.
3720 The following commands are presently only implemented for native GNU/Linux:
3722 checkpoint Save a snapshot of the program state.
3724 restart <n> Return the program state to a
3725 previously saved state.
3727 info checkpoints List currently saved checkpoints.
3729 delete-checkpoint <n> Delete a previously saved checkpoint.
3731 set|show detach-on-fork Tell gdb whether to detach from a newly
3732 forked process, or to keep debugging it.
3734 info forks List forks of the user program that
3735 are available to be debugged.
3737 fork <n> Switch to debugging one of several
3738 forks of the user program that are
3739 available to be debugged.
3741 delete-fork <n> Delete a fork from the list of forks
3742 that are available to be debugged (and
3743 kill the forked process).
3745 detach-fork <n> Delete a fork from the list of forks
3746 that are available to be debugged (and
3747 allow the process to continue).
3751 Morpho Technologies ms2 ms1-elf
3753 * Improved Windows host support
3755 GDB now builds as a cross debugger hosted on i686-mingw32, including
3756 native console support, and remote communications using either
3757 network sockets or serial ports.
3759 * Improved Modula-2 language support
3761 GDB can now print most types in the Modula-2 syntax. This includes:
3762 basic types, set types, record types, enumerated types, range types,
3763 pointer types and ARRAY types. Procedure var parameters are correctly
3764 printed and hexadecimal addresses and character constants are also
3765 written in the Modula-2 syntax. Best results can be obtained by using
3766 GNU Modula-2 together with the -gdwarf-2 command line option.
3770 The ARM rdi-share module.
3772 The Netware NLM debug server.
3774 *** Changes in GDB 6.4
3776 * New native configurations
3778 OpenBSD/arm arm*-*-openbsd*
3779 OpenBSD/mips64 mips64-*-openbsd*
3783 Morpho Technologies ms1 ms1-elf
3785 * New command line options
3787 --batch-silent As for --batch, but totally silent.
3788 --return-child-result The debugger will exist with the same value
3789 the child (debugged) program exited with.
3790 --eval-command COMMAND, -ex COMMAND
3791 Execute a single GDB CLI command. This may be
3792 specified multiple times and in conjunction
3793 with the --command (-x) option.
3795 * Deprecated commands removed
3797 The following commands, that were deprecated in 2000, have been
3801 set|show arm disassembly-flavor set|show arm disassembler
3802 othernames set arm disassembler
3803 set|show remotedebug set|show debug remote
3804 set|show archdebug set|show debug arch
3805 set|show eventdebug set|show debug event
3808 * New BSD user-level threads support
3810 It is now possible to debug programs using the user-level threads
3811 library on OpenBSD and FreeBSD. Currently supported (target)
3814 FreeBSD/amd64 x86_64-*-freebsd*
3815 FreeBSD/i386 i386-*-freebsd*
3816 OpenBSD/i386 i386-*-openbsd*
3818 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3819 are not yet supported.
3821 * New support for Matsushita MN10300 w/sim added
3822 (Work in progress). mn10300-elf.
3824 * REMOVED configurations and files
3826 VxWorks and the XDR protocol *-*-vxworks
3827 Motorola MCORE mcore-*-*
3828 National Semiconductor NS32000 ns32k-*-*
3830 * New "set print array-indexes" command
3832 After turning this setting "on", GDB prints the index of each element
3833 when displaying arrays. The default is "off" to preserve the previous
3836 * VAX floating point support
3838 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3840 * User-defined command support
3842 In addition to using $arg0..$arg9 for argument passing, it is now possible
3843 to use $argc to determine now many arguments have been passed. See the
3844 section on user-defined commands in the user manual for more information.
3846 *** Changes in GDB 6.3:
3848 * New command line option
3850 GDB now accepts -l followed by a number to set the timeout for remote
3853 * GDB works with GCC -feliminate-dwarf2-dups
3855 GDB now supports a more compact representation of DWARF-2 debug
3856 information using DW_FORM_ref_addr references. These are produced
3857 by GCC with the option -feliminate-dwarf2-dups and also by some
3858 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3859 to use -feliminate-dwarf2-dups.
3861 * Internationalization
3863 When supported by the host system, GDB will be built with
3864 internationalization (libintl). The task of marking up the sources is
3865 continued, we're looking forward to our first translation.
3869 Initial support for debugging programs compiled with the GNAT
3870 implementation of the Ada programming language has been integrated
3871 into GDB. In this release, support is limited to expression evaluation.
3873 * New native configurations
3875 GNU/Linux/m32r m32r-*-linux-gnu
3879 GDB's remote protocol now includes support for the 'p' packet. This
3880 packet is used to fetch individual registers from a remote inferior.
3882 * END-OF-LIFE registers[] compatibility module
3884 GDB's internal register infrastructure has been completely rewritten.
3885 The new infrastructure making possible the implementation of key new
3886 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3889 GDB 6.3 will be the last release to include the the registers[]
3890 compatibility module that allowed out-of-date configurations to
3891 continue to work. This change directly impacts the following
3901 powerpc bdm protocol
3903 Unless there is activity to revive these configurations, they will be
3904 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3906 * OBSOLETE configurations and files
3908 Configurations that have been declared obsolete in this release have
3909 been commented out. Unless there is activity to revive these
3910 configurations, the next release of GDB will have their sources
3911 permanently REMOVED.
3920 *** Changes in GDB 6.2.1:
3922 * MIPS `break main; run' gave an heuristic-fence-post warning
3924 When attempting to run even a simple program, a warning about
3925 heuristic-fence-post being hit would be reported. This problem has
3928 * MIPS IRIX 'long double' crashed GDB
3930 When examining a long double variable, GDB would get a segmentation
3931 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3932 IRIX long double values).
3936 A bug in the VAX stack code was causing problems with the "next"
3937 command. This problem has been fixed.
3939 *** Changes in GDB 6.2:
3941 * Fix for ``many threads''
3943 On GNU/Linux systems that use the NPTL threads library, a program
3944 rapidly creating and deleting threads would confuse GDB leading to the
3947 ptrace: No such process.
3948 thread_db_get_info: cannot get thread info: generic error
3950 This problem has been fixed.
3952 * "-async" and "-noasync" options removed.
3954 Support for the broken "-noasync" option has been removed (it caused
3957 * New ``start'' command.
3959 This command runs the program until the begining of the main procedure.
3961 * New BSD Kernel Data Access Library (libkvm) interface
3963 Using ``target kvm'' it is now possible to debug kernel core dumps and
3964 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3965 platforms. Currently supported (native-only) configurations are:
3967 FreeBSD/amd64 x86_64-*-freebsd*
3968 FreeBSD/i386 i?86-*-freebsd*
3969 NetBSD/i386 i?86-*-netbsd*
3970 NetBSD/m68k m68*-*-netbsd*
3971 NetBSD/sparc sparc-*-netbsd*
3972 OpenBSD/amd64 x86_64-*-openbsd*
3973 OpenBSD/i386 i?86-*-openbsd*
3974 OpenBSD/m68k m68*-openbsd*
3975 OpenBSD/sparc sparc-*-openbsd*
3977 * Signal trampoline code overhauled
3979 Many generic problems with GDB's signal handling code have been fixed.
3980 These include: backtraces through non-contiguous stacks; recognition
3981 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3982 call; backtrace through a signal trampoline; step into and out of
3983 signal handlers; and single-stepping in the signal trampoline.
3985 Please note that kernel bugs are a limiting factor here. These
3986 features have been shown to work on an s390 GNU/Linux system that
3987 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3989 * Cygwin support for DWARF 2 added.
3991 * New native configurations
3993 GNU/Linux/hppa hppa*-*-linux*
3994 OpenBSD/hppa hppa*-*-openbsd*
3995 OpenBSD/m68k m68*-*-openbsd*
3996 OpenBSD/m88k m88*-*-openbsd*
3997 OpenBSD/powerpc powerpc-*-openbsd*
3998 NetBSD/vax vax-*-netbsd*
3999 OpenBSD/vax vax-*-openbsd*
4001 * END-OF-LIFE frame compatibility module
4003 GDB's internal frame infrastructure has been completely rewritten.
4004 The new infrastructure making it possible to support key new features
4005 including DWARF 2 Call Frame Information. To aid in the task of
4006 migrating old configurations to this new infrastructure, a
4007 compatibility module, that allowed old configurations to continue to
4008 work, was also included.
4010 GDB 6.2 will be the last release to include this frame compatibility
4011 module. This change directly impacts the following configurations:
4021 Unless there is activity to revive these configurations, they will be
4022 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4024 * REMOVED configurations and files
4026 Sun 3, running SunOS 3 m68*-*-sunos3*
4027 Sun 3, running SunOS 4 m68*-*-sunos4*
4028 Sun 2, running SunOS 3 m68000-*-sunos3*
4029 Sun 2, running SunOS 4 m68000-*-sunos4*
4030 Motorola 680x0 running LynxOS m68*-*-lynxos*
4031 AT&T 3b1/Unix pc m68*-att-*
4032 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4033 decstation mips-dec-* mips-little-*
4034 riscos mips-*-riscos* mips-*-sysv*
4035 sonymips mips-sony-*
4036 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4038 *** Changes in GDB 6.1.1:
4040 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4042 The TUI (Text-mode User Interface) is now built as part of a default
4043 GDB configuration. It is enabled by either selecting the TUI with the
4044 command line option "-i=tui" or by running the separate "gdbtui"
4045 program. For more information on the TUI, see the manual "Debugging
4048 * Pending breakpoint support (also included in GDB 6.1)
4050 Support has been added to allow you to specify breakpoints in shared
4051 libraries that have not yet been loaded. If a breakpoint location
4052 cannot be found, and the "breakpoint pending" option is set to auto,
4053 GDB queries you if you wish to make the breakpoint pending on a future
4054 shared-library load. If and when GDB resolves the breakpoint symbol,
4055 the pending breakpoint is removed as one or more regular breakpoints
4058 Pending breakpoints are very useful for GCJ Java debugging.
4060 * Fixed ISO-C build problems
4062 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4063 non ISO-C code that stopped them being built using a more strict ISO-C
4064 compiler (e.g., IBM's C compiler).
4066 * Fixed build problem on IRIX 5
4068 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4069 wasn't able to compile compile on an IRIX 5 system.
4071 * Added execute permission to gdb/gdbserver/configure
4073 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4074 permission. This bug would cause configure to fail on a number of
4075 systems (Solaris, IRIX). Ref: server/519.
4077 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4079 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4080 has been updated to use constant array sizes.
4082 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4084 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4085 its generated DWARF Call Frame Info. This encoding was causing GDB to
4086 panic, that panic has been fixed. Ref: gdb/1628.
4088 * Fixed a problem when examining parameters in shared library code.
4090 When examining parameters in optimized shared library code generated
4091 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4092 not available''. GDB now correctly displays the variable's value.
4094 *** Changes in GDB 6.1:
4096 * Removed --with-mmalloc
4098 Support for the mmalloc memory manager has been removed, as it
4099 conflicted with the internal gdb byte cache.
4101 * Changes in AMD64 configurations
4103 The AMD64 target now includes the %cs and %ss registers. As a result
4104 the AMD64 remote protocol has changed; this affects the floating-point
4105 and SSE registers. If you rely on those registers for your debugging,
4106 you should upgrade gdbserver on the remote side.
4108 * Revised SPARC target
4110 The SPARC target has been completely revised, incorporating the
4111 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4112 support for LynxOS and SunOS 4 has been dropped. Calling functions
4113 from within GDB on operating systems with a non-executable stack
4114 (Solaris, OpenBSD) now works.
4118 GDB has a new C++ demangler which does a better job on the mangled
4119 names generated by current versions of g++. It also runs faster, so
4120 with this and other changes gdb should now start faster on large C++
4123 * DWARF 2 Location Expressions
4125 GDB support for location expressions has been extended to support function
4126 arguments and frame bases. Older versions of GDB could crash when they
4129 * C++ nested types and namespaces
4131 GDB's support for nested types and namespaces in C++ has been
4132 improved, especially if you use the DWARF 2 debugging format. (This
4133 is the default for recent versions of GCC on most platforms.)
4134 Specifically, if you have a class "Inner" defined within a class or
4135 namespace "Outer", then GDB realizes that the class's name is
4136 "Outer::Inner", not simply "Inner". This should greatly reduce the
4137 frequency of complaints about not finding RTTI symbols. In addition,
4138 if you are stopped at inside of a function defined within a namespace,
4139 GDB modifies its name lookup accordingly.
4141 * New native configurations
4143 NetBSD/amd64 x86_64-*-netbsd*
4144 OpenBSD/amd64 x86_64-*-openbsd*
4145 OpenBSD/alpha alpha*-*-openbsd*
4146 OpenBSD/sparc sparc-*-openbsd*
4147 OpenBSD/sparc64 sparc64-*-openbsd*
4149 * New debugging protocols
4151 M32R with SDI protocol m32r-*-elf*
4153 * "set prompt-escape-char" command deleted.
4155 The command "set prompt-escape-char" has been deleted. This command,
4156 and its very obscure effet on GDB's prompt, was never documented,
4157 tested, nor mentioned in the NEWS file.
4159 * OBSOLETE configurations and files
4161 Configurations that have been declared obsolete in this release have
4162 been commented out. Unless there is activity to revive these
4163 configurations, the next release of GDB will have their sources
4164 permanently REMOVED.
4166 Sun 3, running SunOS 3 m68*-*-sunos3*
4167 Sun 3, running SunOS 4 m68*-*-sunos4*
4168 Sun 2, running SunOS 3 m68000-*-sunos3*
4169 Sun 2, running SunOS 4 m68000-*-sunos4*
4170 Motorola 680x0 running LynxOS m68*-*-lynxos*
4171 AT&T 3b1/Unix pc m68*-att-*
4172 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4173 decstation mips-dec-* mips-little-*
4174 riscos mips-*-riscos* mips-*-sysv*
4175 sonymips mips-sony-*
4176 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4178 * REMOVED configurations and files
4180 SGI Irix-4.x mips-sgi-irix4 or iris4
4181 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4182 Z8000 simulator z8k-zilog-none or z8ksim
4183 Matsushita MN10200 w/simulator mn10200-*-*
4184 H8/500 simulator h8500-hitachi-hms or h8500hms
4185 HP/PA running BSD hppa*-*-bsd*
4186 HP/PA running OSF/1 hppa*-*-osf*
4187 HP/PA Pro target hppa*-*-pro*
4188 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4189 386BSD i[3456]86-*-bsd*
4190 Sequent family i[3456]86-sequent-sysv4*
4191 i[3456]86-sequent-sysv*
4192 i[3456]86-sequent-bsd*
4193 SPARC running LynxOS sparc-*-lynxos*
4194 SPARC running SunOS 4 sparc-*-sunos4*
4195 Tsqware Sparclet sparclet-*-*
4196 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4198 *** Changes in GDB 6.0:
4202 Support for debugging the Objective-C programming language has been
4203 integrated into GDB.
4205 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4207 DWARF 2's Call Frame Information makes available compiler generated
4208 information that more exactly describes the program's run-time stack.
4209 By using this information, GDB is able to provide more robust stack
4212 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4213 have been updated to use a new backtrace mechanism which includes
4214 DWARF 2 CFI support.
4218 GDB's remote protocol has been extended to include support for hosted
4219 file I/O (where the remote target uses GDB's file system). See GDB's
4220 remote protocol documentation for details.
4222 * All targets using the new architecture framework.
4224 All of GDB's targets have been updated to use the new internal
4225 architecture framework. The way is now open for future GDB releases
4226 to include cross-architecture native debugging support (i386 on amd64,
4229 * GNU/Linux's Thread Local Storage (TLS)
4231 GDB now includes support for for the GNU/Linux implementation of
4232 per-thread variables.
4234 * GNU/Linux's Native POSIX Thread Library (NPTL)
4236 GDB's thread code has been updated to work with either the new
4237 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4239 * Separate debug info.
4241 GDB, in conjunction with BINUTILS, now supports a mechanism for
4242 automatically loading debug information from a separate file. Instead
4243 of shipping full debug and non-debug versions of system libraries,
4244 system integrators can now instead ship just the stripped libraries
4245 and optional debug files.
4247 * DWARF 2 Location Expressions
4249 DWARF 2 Location Expressions allow the compiler to more completely
4250 describe the location of variables (even in optimized code) to the
4253 GDB now includes preliminary support for location expressions (support
4254 for DW_OP_piece is still missing).
4258 A number of long standing bugs that caused GDB to die while starting a
4259 Java application have been fixed. GDB's Java support is now
4260 considered "useable".
4262 * GNU/Linux support for fork, vfork, and exec.
4264 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4265 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4268 * GDB supports logging output to a file
4270 There are two new commands, "set logging" and "show logging", which can be
4271 used to capture GDB's output to a file.
4273 * The meaning of "detach" has changed for gdbserver
4275 The "detach" command will now resume the application, as documented. To
4276 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4279 * d10v, m68hc11 `regs' command deprecated
4281 The `info registers' command has been updated so that it displays the
4282 registers using a format identical to the old `regs' command.
4286 A new command, "maint set profile on/off", has been added. This command can
4287 be used to enable or disable profiling while running GDB, to profile a
4288 session or a set of commands. In addition there is a new configure switch,
4289 "--enable-profiling", which will cause GDB to be compiled with profiling
4290 data, for more informative profiling results.
4292 * Default MI syntax changed to "mi2".
4294 The default MI (machine interface) syntax, enabled by the command line
4295 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4296 "mi1", can be enabled by specifying the option "-i=mi1".
4298 Support for the original "mi0" syntax (included in GDB 5.0) has been
4301 Fix for gdb/192: removed extraneous space when displaying frame level.
4302 Fix for gdb/672: update changelist is now output in mi list format.
4303 Fix for gdb/702: a -var-assign that updates the value now shows up
4304 in a subsequent -var-update.
4306 * New native configurations.
4308 FreeBSD/amd64 x86_64-*-freebsd*
4310 * Multi-arched targets.
4312 HP/PA HPUX11 hppa*-*-hpux*
4313 Renesas M32R/D w/simulator m32r-*-elf*
4315 * OBSOLETE configurations and files
4317 Configurations that have been declared obsolete in this release have
4318 been commented out. Unless there is activity to revive these
4319 configurations, the next release of GDB will have their sources
4320 permanently REMOVED.
4322 Z8000 simulator z8k-zilog-none or z8ksim
4323 Matsushita MN10200 w/simulator mn10200-*-*
4324 H8/500 simulator h8500-hitachi-hms or h8500hms
4325 HP/PA running BSD hppa*-*-bsd*
4326 HP/PA running OSF/1 hppa*-*-osf*
4327 HP/PA Pro target hppa*-*-pro*
4328 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4329 Sequent family i[3456]86-sequent-sysv4*
4330 i[3456]86-sequent-sysv*
4331 i[3456]86-sequent-bsd*
4332 Tsqware Sparclet sparclet-*-*
4333 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4335 * REMOVED configurations and files
4338 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4339 IBM AIX PS/2 i[3456]86-*-aix
4340 i386 running Mach 3.0 i[3456]86-*-mach3*
4341 i386 running Mach i[3456]86-*-mach*
4342 i386 running OSF/1 i[3456]86-*osf1mk*
4343 HP/Apollo 68k Family m68*-apollo*-sysv*,
4345 m68*-hp-bsd*, m68*-hp-hpux*
4346 Argonaut Risc Chip (ARC) arc-*-*
4347 Mitsubishi D30V d30v-*-*
4348 Fujitsu FR30 fr30-*-elf*
4349 OS/9000 i[34]86-*-os9k
4350 I960 with MON960 i960-*-coff
4352 * MIPS $fp behavior changed
4354 The convenience variable $fp, for the MIPS, now consistently returns
4355 the address of the current frame's base. Previously, depending on the
4356 context, $fp could refer to either $sp or the current frame's base
4357 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4358 The GNU Source-Level Debugger''.
4360 *** Changes in GDB 5.3:
4362 * GNU/Linux shared library multi-threaded performance improved.
4364 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4365 `/proc', in preference to `ptrace' for memory reads. This may result
4366 in an improvement in the start-up time of multi-threaded, shared
4367 library applications when run under GDB. One GDB user writes: ``loads
4368 shared libs like mad''.
4370 * ``gdbserver'' now supports multi-threaded applications on some targets
4372 Support for debugging multi-threaded applications which use
4373 the GNU/Linux LinuxThreads package has been added for
4374 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4375 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4377 * GDB now supports C/C++ preprocessor macros.
4379 GDB now expands preprocessor macro invocations in C/C++ expressions,
4380 and provides various commands for showing macro definitions and how
4383 The new command `macro expand EXPRESSION' expands any macro
4384 invocations in expression, and shows the result.
4386 The new command `show macro MACRO-NAME' shows the definition of the
4387 macro named MACRO-NAME, and where it was defined.
4389 Most compilers don't include information about macros in the debugging
4390 information by default. In GCC 3.1, for example, you need to compile
4391 your program with the options `-gdwarf-2 -g3'. If the macro
4392 information is present in the executable, GDB will read it.
4394 * Multi-arched targets.
4396 DEC Alpha (partial) alpha*-*-*
4397 DEC VAX (partial) vax-*-*
4399 National Semiconductor NS32000 (partial) ns32k-*-*
4400 Motorola 68000 (partial) m68k-*-*
4401 Motorola MCORE mcore-*-*
4405 Fujitsu FRV architecture added by Red Hat frv*-*-*
4408 * New native configurations
4410 Alpha NetBSD alpha*-*-netbsd*
4411 SH NetBSD sh*-*-netbsdelf*
4412 MIPS NetBSD mips*-*-netbsd*
4413 UltraSPARC NetBSD sparc64-*-netbsd*
4415 * OBSOLETE configurations and files
4417 Configurations that have been declared obsolete in this release have
4418 been commented out. Unless there is activity to revive these
4419 configurations, the next release of GDB will have their sources
4420 permanently REMOVED.
4422 Mitsubishi D30V d30v-*-*
4423 OS/9000 i[34]86-*-os9k
4424 IBM AIX PS/2 i[3456]86-*-aix
4425 Fujitsu FR30 fr30-*-elf*
4426 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4427 Argonaut Risc Chip (ARC) arc-*-*
4428 i386 running Mach 3.0 i[3456]86-*-mach3*
4429 i386 running Mach i[3456]86-*-mach*
4430 i386 running OSF/1 i[3456]86-*osf1mk*
4431 HP/Apollo 68k Family m68*-apollo*-sysv*,
4433 m68*-hp-bsd*, m68*-hp-hpux*
4434 I960 with MON960 i960-*-coff
4436 * OBSOLETE languages
4438 CHILL, a Pascal like language used by telecommunications companies.
4440 * REMOVED configurations and files
4442 AMD 29k family via UDI a29k-amd-udi, udi29k
4443 A29K VxWorks a29k-*-vxworks
4444 AMD 29000 embedded, using EBMON a29k-none-none
4445 AMD 29000 embedded with COFF a29k-none-coff
4446 AMD 29000 embedded with a.out a29k-none-aout
4448 testsuite/gdb.hp/gdb.threads-hp/ directory
4450 * New command "set max-user-call-depth <nnn>"
4452 This command allows the user to limit the call depth of user-defined
4453 commands. The default is 1024.
4455 * Changes in FreeBSD/i386 native debugging.
4457 Support for the "generate-core-file" has been added.
4459 * New commands "dump", "append", and "restore".
4461 These commands allow data to be copied from target memory
4462 to a bfd-format or binary file (dump and append), and back
4463 from a file into memory (restore).
4465 * Improved "next/step" support on multi-processor Alpha Tru64.
4467 The previous single-step mechanism could cause unpredictable problems,
4468 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4469 of a software single-step mechanism prevents this.
4471 *** Changes in GDB 5.2.1:
4479 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4480 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4481 Fix, by Joel Brobecker imported from mainline.
4483 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4484 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4485 Fix, by Fred Fish, imported from mainline.
4487 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4488 Surprisingly enough, it works now.
4489 By Michal Ludvig, imported from mainline.
4491 i386 hardware watchpoint support:
4492 avoid misses on second run for some targets.
4493 By Pierre Muller, imported from mainline.
4495 *** Changes in GDB 5.2:
4497 * New command "set trust-readonly-sections on[off]".
4499 This command is a hint that tells gdb that read-only sections
4500 really are read-only (ie. that their contents will not change).
4501 In this mode, gdb will go to the object file rather than the
4502 target to read memory from read-only sections (such as ".text").
4503 This can be a significant performance improvement on some
4504 (notably embedded) targets.
4506 * New command "generate-core-file" (or "gcore").
4508 This new gdb command allows the user to drop a core file of the child
4509 process state at any time. So far it's been implemented only for
4510 GNU/Linux and Solaris, but should be relatively easily ported to other
4511 hosts. Argument is core file name (defaults to core.<pid>).
4513 * New command line option
4515 GDB now accepts --pid or -p followed by a process id.
4517 * Change in command line behavior -- corefiles vs. process ids.
4519 There is a subtle behavior in the way in which GDB handles
4520 command line arguments. The first non-flag argument is always
4521 a program to debug, but the second non-flag argument may either
4522 be a corefile or a process id. Previously, GDB would attempt to
4523 open the second argument as a corefile, and if that failed, would
4524 issue a superfluous error message and then attempt to attach it as
4525 a process. Now, if the second argument begins with a non-digit,
4526 it will be treated as a corefile. If it begins with a digit,
4527 GDB will attempt to attach it as a process, and if no such process
4528 is found, will then attempt to open it as a corefile.
4530 * Changes in ARM configurations.
4532 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4533 configuration is fully multi-arch.
4535 * New native configurations
4537 ARM NetBSD arm*-*-netbsd*
4538 x86 OpenBSD i[3456]86-*-openbsd*
4539 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4540 Sparc64 running FreeBSD sparc64-*-freebsd*
4544 Sanyo XStormy16 xstormy16-elf
4546 * OBSOLETE configurations and files
4548 Configurations that have been declared obsolete in this release have
4549 been commented out. Unless there is activity to revive these
4550 configurations, the next release of GDB will have their sources
4551 permanently REMOVED.
4553 AMD 29k family via UDI a29k-amd-udi, udi29k
4554 A29K VxWorks a29k-*-vxworks
4555 AMD 29000 embedded, using EBMON a29k-none-none
4556 AMD 29000 embedded with COFF a29k-none-coff
4557 AMD 29000 embedded with a.out a29k-none-aout
4559 testsuite/gdb.hp/gdb.threads-hp/ directory
4561 * REMOVED configurations and files
4563 TI TMS320C80 tic80-*-*
4565 PowerPC Solaris powerpcle-*-solaris*
4566 PowerPC Windows NT powerpcle-*-cygwin32
4567 PowerPC Netware powerpc-*-netware*
4568 Harris/CXUX m88k m88*-harris-cxux*
4569 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4570 ns32k-utek-sysv* ns32k-utek-*
4571 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4572 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4573 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4574 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4575 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4577 * Changes to command line processing
4579 The new `--args' feature can be used to specify command-line arguments
4580 for the inferior from gdb's command line.
4582 * Changes to key bindings
4584 There is a new `operate-and-get-next' function bound to `C-o'.
4586 *** Changes in GDB 5.1.1
4588 Fix compile problem on DJGPP.
4590 Fix a problem with floating-point registers on the i386 being
4593 Fix to stop GDB crashing on .debug_str debug info.
4595 Numerous documentation fixes.
4597 Numerous testsuite fixes.
4599 *** Changes in GDB 5.1:
4601 * New native configurations
4603 Alpha FreeBSD alpha*-*-freebsd*
4604 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4605 MIPS GNU/Linux mips*-*-linux*
4606 MIPS SGI Irix 6.x mips*-sgi-irix6*
4607 ia64 AIX ia64-*-aix*
4608 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4612 Motorola 68HC11 and 68HC12 m68hc11-elf
4614 UltraSparc running GNU/Linux sparc64-*-linux*
4616 * OBSOLETE configurations and files
4618 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4619 Harris/CXUX m88k m88*-harris-cxux*
4620 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4621 ns32k-utek-sysv* ns32k-utek-*
4622 TI TMS320C80 tic80-*-*
4624 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4625 PowerPC Solaris powerpcle-*-solaris*
4626 PowerPC Windows NT powerpcle-*-cygwin32
4627 PowerPC Netware powerpc-*-netware*
4628 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4629 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4630 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4631 Apple Macintosh (MPW) host N/A
4633 stuff.c (Program to stuff files into a specially prepared space in kdb)
4634 kdb-start.c (Main loop for the standalone kernel debugger)
4636 Configurations that have been declared obsolete in this release have
4637 been commented out. Unless there is activity to revive these
4638 configurations, the next release of GDB will have their sources
4639 permanently REMOVED.
4641 * REMOVED configurations and files
4643 Altos 3068 m68*-altos-*
4644 Convex c1-*-*, c2-*-*
4646 ARM RISCix arm-*-* (as host)
4650 * GDB has been converted to ISO C.
4652 GDB's source code has been converted to ISO C. In particular, the
4653 sources are fully protoized, and rely on standard headers being
4658 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4660 * The MI enabled by default.
4662 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4663 revised and enabled by default. Packages which use GDB as a debugging
4664 engine behind a UI or another front end are encouraged to switch to
4665 using the GDB/MI interface, instead of the old annotations interface
4666 which is now deprecated.
4668 * Support for debugging Pascal programs.
4670 GDB now includes support for debugging Pascal programs. The following
4671 main features are supported:
4673 - Pascal-specific data types such as sets;
4675 - automatic recognition of Pascal sources based on file-name
4678 - Pascal-style display of data types, variables, and functions;
4680 - a Pascal expression parser.
4682 However, some important features are not yet supported.
4684 - Pascal string operations are not supported at all;
4686 - there are some problems with boolean types;
4688 - Pascal type hexadecimal constants are not supported
4689 because they conflict with the internal variables format;
4691 - support for Pascal objects and classes is not full yet;
4693 - unlike Pascal, GDB is case-sensitive for symbol names.
4695 * Changes in completion.
4697 Commands such as `shell', `run' and `set args', which pass arguments
4698 to inferior programs, now complete on file names, similar to what
4699 users expect at the shell prompt.
4701 Commands which accept locations, such as `disassemble', `print',
4702 `breakpoint', `until', etc. now complete on filenames as well as
4703 program symbols. Thus, if you type "break foob TAB", and the source
4704 files linked into the programs include `foobar.c', that file name will
4705 be one of the candidates for completion. However, file names are not
4706 considered for completion after you typed a colon that delimits a file
4707 name from a name of a function in that file, as in "break foo.c:bar".
4709 `set demangle-style' completes on available demangling styles.
4711 * New platform-independent commands:
4713 It is now possible to define a post-hook for a command as well as a
4714 hook that runs before the command. For more details, see the
4715 documentation of `hookpost' in the GDB manual.
4717 * Changes in GNU/Linux native debugging.
4719 Support for debugging multi-threaded programs has been completely
4720 revised for all platforms except m68k and sparc. You can now debug as
4721 many threads as your system allows you to have.
4723 Attach/detach is supported for multi-threaded programs.
4725 Support for SSE registers was added for x86. This doesn't work for
4726 multi-threaded programs though.
4728 * Changes in MIPS configurations.
4730 Multi-arch support is enabled for all MIPS configurations.
4732 GDB can now be built as native debugger on SGI Irix 6.x systems for
4733 debugging n32 executables. (Debugging 64-bit executables is not yet
4736 * Unified support for hardware watchpoints in all x86 configurations.
4738 Most (if not all) native x86 configurations support hardware-assisted
4739 breakpoints and watchpoints in a unified manner. This support
4740 implements debug register sharing between watchpoints, which allows to
4741 put a virtually infinite number of watchpoints on the same address,
4742 and also supports watching regions up to 16 bytes with several debug
4745 The new maintenance command `maintenance show-debug-regs' toggles
4746 debugging print-outs in functions that insert, remove, and test
4747 watchpoints and hardware breakpoints.
4749 * Changes in the DJGPP native configuration.
4751 New command ``info dos sysinfo'' displays assorted information about
4752 the CPU, OS, memory, and DPMI server.
4754 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4755 display information about segment descriptors stored in GDT, LDT, and
4758 New commands ``info dos pde'' and ``info dos pte'' display entries
4759 from Page Directory and Page Tables (for now works with CWSDPMI only).
4760 New command ``info dos address-pte'' displays the Page Table entry for
4761 a given linear address.
4763 GDB can now pass command lines longer than 126 characters to the
4764 program being debugged (requires an update to the libdbg.a library
4765 which is part of the DJGPP development kit).
4767 DWARF2 debug info is now supported.
4769 It is now possible to `step' and `next' through calls to `longjmp'.
4771 * Changes in documentation.
4773 All GDB documentation was converted to GFDL, the GNU Free
4774 Documentation License.
4776 Tracepoints-related commands are now fully documented in the GDB
4779 TUI, the Text-mode User Interface, is now documented in the manual.
4781 Tracepoints-related commands are now fully documented in the GDB
4784 The "GDB Internals" manual now has an index. It also includes
4785 documentation of `ui_out' functions, GDB coding standards, x86
4786 hardware watchpoints, and memory region attributes.
4788 * GDB's version number moved to ``version.in''
4790 The Makefile variable VERSION has been replaced by the file
4791 ``version.in''. People creating GDB distributions should update the
4792 contents of this file.
4796 GUD support is now a standard part of the EMACS distribution.
4798 *** Changes in GDB 5.0:
4800 * Improved support for debugging FP programs on x86 targets
4802 Unified and much-improved support for debugging floating-point
4803 programs on all x86 targets. In particular, ``info float'' now
4804 displays the FP registers in the same format on all x86 targets, with
4805 greater level of detail.
4807 * Improvements and bugfixes in hardware-assisted watchpoints
4809 It is now possible to watch array elements, struct members, and
4810 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4811 on x86 targets no longer erroneously trigger when the address is
4814 * Improvements in the native DJGPP version of GDB
4816 The distribution now includes all the scripts and auxiliary files
4817 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4818 machines ``out of the box''.
4820 The DJGPP version can now debug programs that use signals. It is
4821 possible to catch signals that happened in the debuggee, deliver
4822 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4823 would kill the program being debugged.) Programs that hook hardware
4824 interrupts (keyboard, timer, etc.) can also be debugged.
4826 It is now possible to debug DJGPP programs that redirect their
4827 standard handles or switch them to raw (as opposed to cooked) mode, or
4828 even close them. The command ``run < foo > bar'' works as expected,
4829 and ``info terminal'' reports useful information about the debuggee's
4830 terminal, including raw/cooked mode, redirection, etc.
4832 The DJGPP version now uses termios functions for console I/O, which
4833 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4836 DOS-style file names with drive letters are now fully supported by
4839 It is now possible to debug DJGPP programs that switch their working
4840 directory. It is also possible to rerun the debuggee any number of
4841 times without restarting GDB; thus, you can use the same setup,
4842 breakpoints, etc. for many debugging sessions.
4844 * New native configurations
4846 ARM GNU/Linux arm*-*-linux*
4847 PowerPC GNU/Linux powerpc-*-linux*
4851 Motorola MCore mcore-*-*
4852 x86 VxWorks i[3456]86-*-vxworks*
4853 PowerPC VxWorks powerpc-*-vxworks*
4854 TI TMS320C80 tic80-*-*
4856 * OBSOLETE configurations
4858 Altos 3068 m68*-altos-*
4859 Convex c1-*-*, c2-*-*
4861 ARM RISCix arm-*-* (as host)
4864 Configurations that have been declared obsolete will be commented out,
4865 but the code will be left in place. If there is no activity to revive
4866 these configurations before the next release of GDB, the sources will
4867 be permanently REMOVED.
4869 * Gould support removed
4871 Support for the Gould PowerNode and NP1 has been removed.
4873 * New features for SVR4
4875 On SVR4 native platforms (such as Solaris), if you attach to a process
4876 without first loading a symbol file, GDB will now attempt to locate and
4877 load symbols from the running process's executable file.
4879 * Many C++ enhancements
4881 C++ support has been greatly improved. Overload resolution now works properly
4882 in almost all cases. RTTI support is on the way.
4884 * Remote targets can connect to a sub-program
4886 A popen(3) style serial-device has been added. This device starts a
4887 sub-process (such as a stand-alone simulator) and then communicates
4888 with that. The sub-program to run is specified using the syntax
4889 ``|<program> <args>'' vis:
4891 (gdb) set remotedebug 1
4892 (gdb) target extended-remote |mn10300-elf-sim program-args
4894 * MIPS 64 remote protocol
4896 A long standing bug in the mips64 remote protocol where by GDB
4897 expected certain 32 bit registers (ex SR) to be transfered as 32
4898 instead of 64 bits has been fixed.
4900 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4901 added to provide backward compatibility with older versions of GDB.
4903 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4905 The command ``set remotebinarydownload'' command has been replaced by
4906 ``set remote X-packet''. Other commands in ``set remote'' family
4907 include ``set remote P-packet''.
4909 * Breakpoint commands accept ranges.
4911 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4912 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4913 ``tracepoint passcount'' also accepts a range of tracepoints.
4915 * ``apropos'' command added.
4917 The ``apropos'' command searches through command names and
4918 documentation strings, printing out matches, making it much easier to
4919 try to find a command that does what you are looking for.
4923 A new machine oriented interface (MI) has been added to GDB. This
4924 interface is designed for debug environments running GDB as a separate
4925 process. This is part of the long term libGDB project. See the
4926 "GDB/MI" chapter of the GDB manual for further information. It can be
4927 enabled by configuring with:
4929 .../configure --enable-gdbmi
4931 *** Changes in GDB-4.18:
4933 * New native configurations
4935 HP-UX 10.20 hppa*-*-hpux10.20
4936 HP-UX 11.x hppa*-*-hpux11.0*
4937 M68K GNU/Linux m68*-*-linux*
4941 Fujitsu FR30 fr30-*-elf*
4942 Intel StrongARM strongarm-*-*
4943 Mitsubishi D30V d30v-*-*
4945 * OBSOLETE configurations
4947 Gould PowerNode, NP1 np1-*-*, pn-*-*
4949 Configurations that have been declared obsolete will be commented out,
4950 but the code will be left in place. If there is no activity to revive
4951 these configurations before the next release of GDB, the sources will
4952 be permanently REMOVED.
4956 As a compatibility experiment, GDB's source files buildsym.h and
4957 buildsym.c have been converted to pure standard C, no longer
4958 containing any K&R compatibility code. We believe that all systems in
4959 use today either come with a standard C compiler, or have a GCC port
4960 available. If this is not true, please report the affected
4961 configuration to bug-gdb@gnu.org immediately. See the README file for
4962 information about getting a standard C compiler if you don't have one
4967 GDB now uses readline 2.2.
4969 * set extension-language
4971 You can now control the mapping between filename extensions and source
4972 languages by using the `set extension-language' command. For instance,
4973 you can ask GDB to treat .c files as C++ by saying
4974 set extension-language .c c++
4975 The command `info extensions' lists all of the recognized extensions
4976 and their associated languages.
4978 * Setting processor type for PowerPC and RS/6000
4980 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4981 you can use the `set processor' command to specify what variant of the
4982 PowerPC family you are debugging. The command
4986 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4987 following PowerPC and RS6000 variants:
4989 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4990 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4992 403GC IBM PowerPC 403GC
4993 505 Motorola PowerPC 505
4994 860 Motorola PowerPC 860 or 850
4995 601 Motorola PowerPC 601
4996 602 Motorola PowerPC 602
4997 603 Motorola/IBM PowerPC 603 or 603e
4998 604 Motorola PowerPC 604 or 604e
4999 750 Motorola/IBM PowerPC 750 or 750
5001 At the moment, this command just tells GDB what to name the
5002 special-purpose processor registers. Since almost all the affected
5003 registers are inaccessible to user-level programs, this command is
5004 only useful for remote debugging in its present form.
5008 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5009 more extensive support for HP-UX. Added features include shared
5010 library support, kernel threads and hardware watchpoints for 11.00,
5011 support for HP's ANSI C and C++ compilers, and a compatibility mode
5012 for xdb and dbx commands.
5016 HP's donation includes the new concept of catchpoints, which is a
5017 generalization of the old catch command. On HP-UX, it is now possible
5018 to catch exec, fork, and vfork, as well as library loading.
5020 This means that the existing catch command has changed; its first
5021 argument now specifies the type of catch to be set up. See the
5022 output of "help catch" for a list of catchpoint types.
5024 * Debugging across forks
5026 On HP-UX, you can choose which process to debug when a fork() happens
5031 HP has donated a curses-based terminal user interface (TUI). To get
5032 it, build with --enable-tui. Although this can be enabled for any
5033 configuration, at present it only works for native HP debugging.
5035 * GDB remote protocol additions
5037 A new protocol packet 'X' that writes binary data is now available.
5038 Default behavior is to try 'X', then drop back to 'M' if the stub
5039 fails to respond. The settable variable `remotebinarydownload'
5040 allows explicit control over the use of 'X'.
5042 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5043 full 64-bit address. The command
5045 set remoteaddresssize 32
5047 can be used to revert to the old behaviour. For existing remote stubs
5048 the change should not be noticed, as the additional address information
5051 In order to assist in debugging stubs, you may use the maintenance
5052 command `packet' to send any text string to the stub. For instance,
5054 maint packet heythere
5056 sends the packet "$heythere#<checksum>". Note that it is very easy to
5057 disrupt a debugging session by sending the wrong packet at the wrong
5060 The compare-sections command allows you to compare section data on the
5061 target to what is in the executable file without uploading or
5062 downloading, by comparing CRC checksums.
5064 * Tracing can collect general expressions
5066 You may now collect general expressions at tracepoints. This requires
5067 further additions to the target-side stub; see tracepoint.c and
5068 doc/agentexpr.texi for further details.
5070 * mask-address variable for Mips
5072 For Mips targets, you may control the zeroing of the upper 32 bits of
5073 a 64-bit address by entering `set mask-address on'. This is mainly
5074 of interest to users of embedded R4xxx and R5xxx processors.
5076 * Higher serial baud rates
5078 GDB's serial code now allows you to specify baud rates 57600, 115200,
5079 230400, and 460800 baud. (Note that your host system may not be able
5080 to achieve all of these rates.)
5084 The i960 configuration now includes an initial implementation of a
5085 builtin simulator, contributed by Jim Wilson.
5088 *** Changes in GDB-4.17:
5090 * New native configurations
5092 Alpha GNU/Linux alpha*-*-linux*
5093 Unixware 2.x i[3456]86-unixware2*
5094 Irix 6.x mips*-sgi-irix6*
5095 PowerPC GNU/Linux powerpc-*-linux*
5096 PowerPC Solaris powerpcle-*-solaris*
5097 Sparc GNU/Linux sparc-*-linux*
5098 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5102 Argonaut Risc Chip (ARC) arc-*-*
5103 Hitachi H8/300S h8300*-*-*
5104 Matsushita MN10200 w/simulator mn10200-*-*
5105 Matsushita MN10300 w/simulator mn10300-*-*
5106 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5107 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5108 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5109 Mitsubishi D10V w/simulator d10v-*-*
5110 Mitsubishi M32R/D w/simulator m32r-*-elf*
5111 Tsqware Sparclet sparclet-*-*
5112 NEC V850 w/simulator v850-*-*
5114 * New debugging protocols
5116 ARM with RDI protocol arm*-*-*
5117 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5118 DDB and LSI variants of PMON protocol mips*-*-*
5119 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5120 PowerPC with SDS protocol powerpc{,le}-*-eabi
5121 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5125 All configurations can now understand and use the DWARF 2 debugging
5126 format. The choice is automatic, if the symbol file contains DWARF 2
5131 GDB now includes basic Java language support. This support is
5132 only useful with Java compilers that produce native machine code.
5134 * solib-absolute-prefix and solib-search-path
5136 For SunOS and SVR4 shared libraries, you may now set the prefix for
5137 loading absolute shared library symbol files, and the search path for
5138 locating non-absolute shared library symbol files.
5140 * Live range splitting
5142 GDB can now effectively debug code for which GCC has performed live
5143 range splitting as part of its optimization. See gdb/doc/LRS for
5144 more details on the expected format of the stabs information.
5148 GDB's support for the GNU Hurd, including thread debugging, has been
5149 updated to work with current versions of the Hurd.
5153 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5154 instruction set. ARM GDB automatically detects when Thumb
5155 instructions are in use, and adjusts disassembly and backtracing
5160 GDB's MIPS target configurations now handle the MIP16 16-bit
5165 GDB now includes support for overlays; if an executable has been
5166 linked such that multiple sections are based at the same address, GDB
5167 will decide which section to use for symbolic info. You can choose to
5168 control the decision manually, using overlay commands, or implement
5169 additional target-side support and use "overlay load-target" to bring
5170 in the overlay mapping. Do "help overlay" for more detail.
5174 The command "info symbol <address>" displays information about
5175 the symbol at the specified address.
5179 The standard remote protocol now includes an extension that allows
5180 asynchronous collection and display of trace data. This requires
5181 extensive support in the target-side debugging stub. Tracing mode
5182 includes a new interaction mode in GDB and new commands: see the
5183 file tracepoint.c for more details.
5187 Configurations for embedded MIPS now include a simulator contributed
5188 by Cygnus Solutions. The simulator supports the instruction sets
5189 of most MIPS variants.
5193 Sparc configurations may now include the ERC32 simulator contributed
5194 by the European Space Agency. The simulator is not built into
5195 Sparc targets by default; configure with --enable-sim to include it.
5199 For target configurations that may include multiple variants of a
5200 basic architecture (such as MIPS and SH), you may now set the
5201 architecture explicitly. "set arch" sets, "info arch" lists
5202 the possible architectures.
5204 *** Changes in GDB-4.16:
5206 * New native configurations
5208 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5209 M68K NetBSD m68k-*-netbsd*
5210 PowerPC AIX 4.x powerpc-*-aix*
5211 PowerPC MacOS powerpc-*-macos*
5212 PowerPC Windows NT powerpcle-*-cygwin32
5213 RS/6000 AIX 4.x rs6000-*-aix4*
5217 ARM with RDP protocol arm-*-*
5218 I960 with MON960 i960-*-coff
5219 MIPS VxWorks mips*-*-vxworks*
5220 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5221 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5223 Matra Sparclet sparclet-*-*
5227 The powerpc-eabi configuration now includes the PSIM simulator,
5228 contributed by Andrew Cagney, with assistance from Mike Meissner.
5229 PSIM is a very elaborate model of the PowerPC, including not only
5230 basic instruction set execution, but also details of execution unit
5231 performance and I/O hardware. See sim/ppc/README for more details.
5235 GDB now works with Solaris 2.5.
5237 * Windows 95/NT native
5239 GDB will now work as a native debugger on Windows 95 and Windows NT.
5240 To build it from source, you must use the "gnu-win32" environment,
5241 which uses a DLL to emulate enough of Unix to run the GNU tools.
5242 Further information, binaries, and sources are available at
5243 ftp.cygnus.com, under pub/gnu-win32.
5245 * dont-repeat command
5247 If a user-defined command includes the command `dont-repeat', then the
5248 command will not be repeated if the user just types return. This is
5249 useful if the command is time-consuming to run, so that accidental
5250 extra keystrokes don't run the same command many times.
5252 * Send break instead of ^C
5254 The standard remote protocol now includes an option to send a break
5255 rather than a ^C to the target in order to interrupt it. By default,
5256 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5258 * Remote protocol timeout
5260 The standard remote protocol includes a new variable `remotetimeout'
5261 that allows you to set the number of seconds before GDB gives up trying
5262 to read from the target. The default value is 2.
5264 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5266 By default GDB will automatically keep track of objects as they are
5267 loaded and unloaded by the dynamic linker. By using the command `set
5268 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5269 when shared library events occur, thus allowing you to set breakpoints
5270 in shared libraries which are explicitly loaded by the inferior.
5272 Note this feature does not work on hpux8. On hpux9 you must link
5273 /usr/lib/end.o into your program. This feature should work
5274 automatically on hpux10.
5276 * Irix 5.x hardware watchpoint support
5278 Irix 5 configurations now support the use of hardware watchpoints.
5280 * Mips protocol "SYN garbage limit"
5282 When debugging a Mips target using the `target mips' protocol, you
5283 may set the number of characters that GDB will ignore by setting
5284 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5285 every character. The default value is 1050.
5287 * Recording and replaying remote debug sessions
5289 If you set `remotelogfile' to the name of a file, gdb will write to it
5290 a recording of a remote debug session. This recording may then be
5291 replayed back to gdb using "gdbreplay". See gdbserver/README for
5292 details. This is useful when you have a problem with GDB while doing
5293 remote debugging; you can make a recording of the session and send it
5294 to someone else, who can then recreate the problem.
5296 * Speedups for remote debugging
5298 GDB includes speedups for downloading and stepping MIPS systems using
5299 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5300 and more efficient S-record downloading.
5302 * Memory use reductions and statistics collection
5304 GDB now uses less memory and reports statistics about memory usage.
5305 Try the `maint print statistics' command, for example.
5307 *** Changes in GDB-4.15:
5309 * Psymtabs for XCOFF
5311 The symbol reader for AIX GDB now uses partial symbol tables. This
5312 can greatly improve startup time, especially for large executables.
5314 * Remote targets use caching
5316 Remote targets now use a data cache to speed up communication with the
5317 remote side. The data cache could lead to incorrect results because
5318 it doesn't know about volatile variables, thus making it impossible to
5319 debug targets which use memory mapped I/O devices. `set remotecache
5320 off' turns the the data cache off.
5322 * Remote targets may have threads
5324 The standard remote protocol now includes support for multiple threads
5325 in the target system, using new protocol commands 'H' and 'T'. See
5326 gdb/remote.c for details.
5330 If GDB is configured with `--enable-netrom', then it will include
5331 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5332 acts as though it is a bank of ROM on the target board, but you can
5333 write into it over the network. GDB's support consists only of
5334 support for fast loading into the emulated ROM; to debug, you must use
5335 another protocol, such as standard remote protocol. The usual
5336 sequence is something like
5338 target nrom <netrom-hostname>
5340 target remote <netrom-hostname>:1235
5344 GDB now includes support for the Apple Macintosh, as a host only. It
5345 may be run as either an MPW tool or as a standalone application, and
5346 it can debug through the serial port. All the usual GDB commands are
5347 available, but to the target command, you must supply "serial" as the
5348 device type instead of "/dev/ttyXX". See mpw-README in the main
5349 directory for more information on how to build. The MPW configuration
5350 scripts */mpw-config.in support only a few targets, and only the
5351 mips-idt-ecoff target has been tested.
5355 GDB configuration now uses autoconf. This is not user-visible,
5356 but does simplify configuration and building.
5360 GDB now supports hpux10.
5362 *** Changes in GDB-4.14:
5364 * New native configurations
5366 x86 FreeBSD i[345]86-*-freebsd
5367 x86 NetBSD i[345]86-*-netbsd
5368 NS32k NetBSD ns32k-*-netbsd
5369 Sparc NetBSD sparc-*-netbsd
5373 A29K VxWorks a29k-*-vxworks
5374 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5375 CPU32 EST-300 emulator m68*-*-est*
5376 PowerPC ELF powerpc-*-elf
5379 * Alpha OSF/1 support for procfs
5381 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5382 possible to attach to running processes. As the mounting of the /proc
5383 filesystem is optional on the Alpha, GDB automatically determines
5384 the availability of /proc during startup. This can lead to problems
5385 if /proc is unmounted after GDB has been started.
5387 * Arguments to user-defined commands
5389 User commands may accept up to 10 arguments separated by whitespace.
5390 Arguments are accessed within the user command via $arg0..$arg9. A
5393 print $arg0 + $arg1 + $arg2
5395 To execute the command use:
5398 Defines the command "adder" which prints the sum of its three arguments.
5399 Note the arguments are text substitutions, so they may reference variables,
5400 use complex expressions, or even perform inferior function calls.
5402 * New `if' and `while' commands
5404 This makes it possible to write more sophisticated user-defined
5405 commands. Both commands take a single argument, which is the
5406 expression to evaluate, and must be followed by the commands to
5407 execute, one per line, if the expression is nonzero, the list being
5408 terminated by the word `end'. The `if' command list may include an
5409 `else' word, which causes the following commands to be executed only
5410 if the expression is zero.
5412 * Fortran source language mode
5414 GDB now includes partial support for Fortran 77. It will recognize
5415 Fortran programs and can evaluate a subset of Fortran expressions, but
5416 variables and functions may not be handled correctly. GDB will work
5417 with G77, but does not yet know much about symbols emitted by other
5420 * Better HPUX support
5422 Most debugging facilities now work on dynamic executables for HPPAs
5423 running hpux9 or later. You can attach to running dynamically linked
5424 processes, but by default the dynamic libraries will be read-only, so
5425 for instance you won't be able to put breakpoints in them. To change
5426 that behavior do the following before running the program:
5432 This will cause the libraries to be mapped private and read-write.
5433 To revert to the normal behavior, do this:
5439 You cannot set breakpoints or examine data in the library until after
5440 the library is loaded if the function/data symbols do not have
5443 GDB can now also read debug symbols produced by the HP C compiler on
5444 HPPAs (sorry, no C++, Fortran or 68k support).
5446 * Target byte order now dynamically selectable
5448 You can choose which byte order to use with a target system, via the
5449 commands "set endian big" and "set endian little", and you can see the
5450 current setting by using "show endian". You can also give the command
5451 "set endian auto", in which case GDB will use the byte order
5452 associated with the executable. Currently, only embedded MIPS
5453 configurations support dynamic selection of target byte order.
5455 * New DOS host serial code
5457 This version uses DPMI interrupts to handle buffered I/O, so you
5458 no longer need to run asynctsr when debugging boards connected to
5461 *** Changes in GDB-4.13:
5463 * New "complete" command
5465 This lists all the possible completions for the rest of the line, if it
5466 were to be given as a command itself. This is intended for use by emacs.
5468 * Trailing space optional in prompt
5470 "set prompt" no longer adds a space for you after the prompt you set. This
5471 allows you to set a prompt which ends in a space or one that does not.
5473 * Breakpoint hit counts
5475 "info break" now displays a count of the number of times the breakpoint
5476 has been hit. This is especially useful in conjunction with "ignore"; you
5477 can ignore a large number of breakpoint hits, look at the breakpoint info
5478 to see how many times the breakpoint was hit, then run again, ignoring one
5479 less than that number, and this will get you quickly to the last hit of
5482 * Ability to stop printing at NULL character
5484 "set print null-stop" will cause GDB to stop printing the characters of
5485 an array when the first NULL is encountered. This is useful when large
5486 arrays actually contain only short strings.
5488 * Shared library breakpoints
5490 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5491 breakpoints in shared libraries before the executable is run.
5493 * Hardware watchpoints
5495 There is a new hardware breakpoint for the watch command for sparclite
5496 targets. See gdb/sparclite/hw_breakpoint.note.
5498 Hardware watchpoints are also now supported under GNU/Linux.
5502 Annotations have been added. These are for use with graphical interfaces,
5503 and are still experimental. Currently only gdba.el uses these.
5505 * Improved Irix 5 support
5507 GDB now works properly with Irix 5.2.
5509 * Improved HPPA support
5511 GDB now works properly with the latest GCC and GAS.
5513 * New native configurations
5515 Sequent PTX4 i[34]86-sequent-ptx4
5516 HPPA running OSF/1 hppa*-*-osf*
5517 Atari TT running SVR4 m68*-*-sysv4*
5518 RS/6000 LynxOS rs6000-*-lynxos*
5522 OS/9000 i[34]86-*-os9k
5523 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5526 * Hitachi SH7000 and E7000-PC ICE support
5528 There is now support for communicating with the Hitachi E7000-PC ICE.
5529 This is available automatically when GDB is configured for the SH.
5533 As usual, a variety of small fixes and improvements, both generic
5534 and configuration-specific. See the ChangeLog for more detail.
5536 *** Changes in GDB-4.12:
5538 * Irix 5 is now supported
5542 GDB-4.12 on the HPPA has a number of changes which make it unable
5543 to debug the output from the currently released versions of GCC and
5544 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5545 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5546 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5549 *** Changes in GDB-4.11:
5551 * User visible changes:
5555 The "set remotedebug" option is now consistent between the mips remote
5556 target, remote targets using the gdb-specific protocol, UDI (AMD's
5557 debug protocol for the 29k) and the 88k bug monitor. It is now an
5558 integer specifying a debug level (normally 0 or 1, but 2 means more
5559 debugging info for the mips target).
5561 * DEC Alpha native support
5563 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5564 debug info, but GDB works fairly well with the DEC compiler and should
5565 work with a future GCC release. See the README file for a few
5566 Alpha-specific notes.
5568 * Preliminary thread implementation
5570 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5572 * LynxOS native and target support for 386
5574 This release has been hosted on LynxOS 2.2, and also can be configured
5575 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5578 * Improvements in C++ mangling/demangling.
5580 This release has much better g++ debugging, specifically in name
5581 mangling/demangling, virtual function calls, print virtual table,
5582 call methods, ...etc.
5584 *** Changes in GDB-4.10:
5586 * User visible changes:
5588 Remote debugging using the GDB-specific (`target remote') protocol now
5589 supports the `load' command. This is only useful if you have some
5590 other way of getting the stub to the target system, and you can put it
5591 somewhere in memory where it won't get clobbered by the download.
5593 Filename completion now works.
5595 When run under emacs mode, the "info line" command now causes the
5596 arrow to point to the line specified. Also, "info line" prints
5597 addresses in symbolic form (as well as hex).
5599 All vxworks based targets now support a user settable option, called
5600 vxworks-timeout. This option represents the number of seconds gdb
5601 should wait for responses to rpc's. You might want to use this if
5602 your vxworks target is, perhaps, a slow software simulator or happens
5603 to be on the far side of a thin network line.
5607 This release contains support for using a DEC alpha as a GDB host for
5608 cross debugging. Native alpha debugging is not supported yet.
5611 *** Changes in GDB-4.9:
5615 This is the first GDB release which is accompanied by a matching testsuite.
5616 The testsuite requires installation of dejagnu, which should be available
5617 via ftp from most sites that carry GNU software.
5621 'Cfront' style demangling has had its name changed to 'ARM' style, to
5622 emphasize that it was written from the specifications in the C++ Annotated
5623 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5624 disclaimers, it still generated too much confusion with users attempting to
5625 use gdb with AT&T cfront.
5629 GDB now uses a standard remote interface to a simulator library.
5630 So far, the library contains simulators for the Zilog Z8001/2, the
5631 Hitachi H8/300, H8/500 and Super-H.
5633 * New targets supported
5635 H8/300 simulator h8300-hitachi-hms or h8300hms
5636 H8/500 simulator h8500-hitachi-hms or h8500hms
5637 SH simulator sh-hitachi-hms or sh
5638 Z8000 simulator z8k-zilog-none or z8ksim
5639 IDT MIPS board over serial line mips-idt-ecoff
5641 Cross-debugging to GO32 targets is supported. It requires a custom
5642 version of the i386-stub.c module which is integrated with the
5643 GO32 memory extender.
5645 * New remote protocols
5647 MIPS remote debugging protocol.
5649 * New source languages supported
5651 This version includes preliminary support for Chill, a Pascal like language
5652 used by telecommunications companies. Chill support is also being integrated
5653 into the GNU compiler, but we don't know when it will be publically available.
5656 *** Changes in GDB-4.8:
5658 * HP Precision Architecture supported
5660 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5661 version of this support was available as a set of patches from the
5662 University of Utah. GDB does not support debugging of programs
5663 compiled with the HP compiler, because HP will not document their file
5664 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5665 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5667 Many problems in the preliminary version have been fixed.
5669 * Faster and better demangling
5671 We have improved template demangling and fixed numerous bugs in the GNU style
5672 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5673 character types (wchar_t) are now supported. Demangling of each symbol is now
5674 only done once, and is cached when the symbol table for a file is read in.
5675 This results in a small increase in memory usage for C programs, a moderate
5676 increase in memory usage for C++ programs, and a fantastic speedup in
5679 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5680 from the specifications in the Annotated Reference Manual, which AT&T's
5681 compiler does not actually implement.
5683 * G++ multiple inheritance compiler problem
5685 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5686 inheritance lattices was reworked to properly discover ambiguities. We
5687 recently found an example which causes this new algorithm to fail in a
5688 very subtle way, producing bad debug information for those classes.
5689 The file 'gcc.patch' (in this directory) can be applied to gcc to
5690 circumvent the problem. A future GCC release will contain a complete
5693 The previous G++ debug info problem (mentioned below for the gdb-4.7
5694 release) is fixed in gcc version 2.3.2.
5696 * Improved configure script
5698 The `configure' script will now attempt to guess your system type if
5699 you don't supply a host system type. The old scheme of supplying a
5700 host system triplet is preferable over using this. All the magic is
5701 done in the new `config.guess' script. Examine it for details.
5703 We have also brought our configure script much more in line with the FSF's
5704 version. It now supports the --with-xxx options. In particular,
5705 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5706 The resulting GDB will not be able to read arbitrary object file formats --
5707 only the format ``expected'' to be used on the configured target system.
5708 We hope to make this the default in a future release.
5710 * Documentation improvements
5712 There's new internal documentation on how to modify GDB, and how to
5713 produce clean changes to the code. We implore people to read it
5714 before submitting changes.
5716 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5717 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5718 `info' files are also provided. To build `info' files from scratch,
5719 you will need the latest `makeinfo' release, which will be available in
5720 a future texinfo-X.Y release.
5722 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5723 We're not sure exactly which versions have this problem, but it has
5724 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5725 or better. If that isn't possible, there is a patch in
5726 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5727 around this problem.
5731 GDB now supports array constants that can be used in expressions typed in by
5732 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5733 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5736 The new directory `gdb/sparclite' contains a program that demonstrates
5737 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5739 * New native hosts supported
5741 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5742 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5744 * New targets supported
5746 AMD 29k family via UDI a29k-amd-udi or udi29k
5748 * New file formats supported
5750 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5751 HPUX core files, and SCO 3.2v2 core files.
5755 Attaching to processes now works again; thanks for the many bug reports.
5757 We have also stomped on a bunch of core dumps caused by
5758 printf_filtered("%s") problems.
5760 We eliminated a copyright problem on the rpc and ptrace header files
5761 for VxWorks, which was discovered at the last minute during the 4.7
5762 release. You should now be able to build a VxWorks GDB.
5764 You can now interrupt gdb while an attached process is running. This
5765 will cause the attached process to stop, and give control back to GDB.
5767 We fixed problems caused by using too many file descriptors
5768 for reading symbols from object files and libraries. This was
5769 especially a problem for programs that used many (~100) shared
5772 The `step' command now only enters a subroutine if there is line number
5773 information for the subroutine. Otherwise it acts like the `next'
5774 command. Previously, `step' would enter subroutines if there was
5775 any debugging information about the routine. This avoids problems
5776 when using `cc -g1' on MIPS machines.
5778 * Internal improvements
5780 GDB's internal interfaces have been improved to make it easier to support
5781 debugging of multiple languages in the future.
5783 GDB now uses a common structure for symbol information internally.
5784 Minimal symbols (derived from linkage symbols in object files), partial
5785 symbols (from a quick scan of debug information), and full symbols
5786 contain a common subset of information, making it easier to write
5787 shared code that handles any of them.
5789 * New command line options
5791 We now accept --silent as an alias for --quiet.
5795 The memory-mapped-malloc library is now licensed under the GNU Library
5796 General Public License.
5798 *** Changes in GDB-4.7:
5800 * Host/native/target split
5802 GDB has had some major internal surgery to untangle the support for
5803 hosts and remote targets. Now, when you configure GDB for a remote
5804 target, it will no longer load in all of the support for debugging
5805 local programs on the host. When fully completed and tested, this will
5806 ensure that arbitrary host/target combinations are possible.
5808 The primary conceptual shift is to separate the non-portable code in
5809 GDB into three categories. Host specific code is required any time GDB
5810 is compiled on that host, regardless of the target. Target specific
5811 code relates to the peculiarities of the target, but can be compiled on
5812 any host. Native specific code is everything else: it can only be
5813 built when the host and target are the same system. Child process
5814 handling and core file support are two common `native' examples.
5816 GDB's use of /proc for controlling Unix child processes is now cleaner.
5817 It has been split out into a single module under the `target_ops' vector,
5818 plus two native-dependent functions for each system that uses /proc.
5820 * New hosts supported
5822 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5823 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5824 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5826 * New targets supported
5828 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5829 68030 and CPU32 m68030-*-*, m68332-*-*
5831 * New native hosts supported
5833 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5834 (386bsd is not well tested yet)
5835 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5837 * New file formats supported
5839 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5840 supports reading of `a.out.adobe' object files, which are an a.out
5841 format extended with minimal information about multiple sections.
5845 `show copying' is the same as the old `info copying'.
5846 `show warranty' is the same as `info warrantee'.
5847 These were renamed for consistency. The old commands continue to work.
5849 `info handle' is a new alias for `info signals'.
5851 You can now define pre-command hooks, which attach arbitrary command
5852 scripts to any command. The commands in the hook will be executed
5853 prior to the user's command. You can also create a hook which will be
5854 executed whenever the program stops. See gdb.texinfo.
5858 We now deal with Cfront style name mangling, and can even extract type
5859 info from mangled symbols. GDB can automatically figure out which
5860 symbol mangling style your C++ compiler uses.
5862 Calling of methods and virtual functions has been improved as well.
5866 The crash that occured when debugging Sun Ansi-C compiled binaries is
5867 fixed. This was due to mishandling of the extra N_SO stabs output
5870 We also finally got Ultrix 4.2 running in house, and fixed core file
5871 support, with help from a dozen people on the net.
5873 John M. Farrell discovered that the reason that single-stepping was so
5874 slow on all of the Mips based platforms (primarily SGI and DEC) was
5875 that we were trying to demangle and lookup a symbol used for internal
5876 purposes on every instruction that was being stepped through. Changing
5877 the name of that symbol so that it couldn't be mistaken for a C++
5878 mangled symbol sped things up a great deal.
5880 Rich Pixley sped up symbol lookups in general by getting much smarter
5881 about when C++ symbol mangling is necessary. This should make symbol
5882 completion (TAB on the command line) much faster. It's not as fast as
5883 we'd like, but it's significantly faster than gdb-4.6.
5887 A new user controllable variable 'call_scratch_address' can
5888 specify the location of a scratch area to be used when GDB
5889 calls a function in the target. This is necessary because the
5890 usual method of putting the scratch area on the stack does not work
5891 in systems that have separate instruction and data spaces.
5893 We integrated changes to support the 29k UDI (Universal Debugger
5894 Interface), but discovered at the last minute that we didn't have all
5895 of the appropriate copyright paperwork. We are working with AMD to
5896 resolve this, and hope to have it available soon.
5900 We have sped up the remote serial line protocol, especially for targets
5901 with lots of registers. It now supports a new `expedited status' ('T')
5902 message which can be used in place of the existing 'S' status message.
5903 This allows the remote stub to send only the registers that GDB
5904 needs to make a quick decision about single-stepping or conditional
5905 breakpoints, eliminating the need to fetch the entire register set for
5906 each instruction being stepped through.
5908 The GDB remote serial protocol now implements a write-through cache for
5909 registers, only re-reading the registers if the target has run.
5911 There is also a new remote serial stub for SPARC processors. You can
5912 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5913 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5914 processor with a serial port.
5918 Configure.in files have become much easier to read and modify. A new
5919 `table driven' format makes it more obvious what configurations are
5920 supported, and what files each one uses.
5924 There is a new opcodes library which will eventually contain all of the
5925 disassembly routines and opcode tables. At present, it only contains
5926 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5927 disassembler (binutils/objdump) to share these routines.
5929 The libiberty library is now copylefted under the GNU Library General
5930 Public License. This allows more liberal use, and was done so libg++
5931 can use it. This makes no difference to GDB, since the Library License
5932 grants all the rights from the General Public License.
5936 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5937 reference to the stabs symbol info used by the debugger. It is (as far
5938 as we know) the only published document on this fascinating topic. We
5939 encourage you to read it, compare it to the stabs information on your
5940 system, and send improvements on the document in general (to
5941 bug-gdb@prep.ai.mit.edu).
5943 And, of course, many bugs have been fixed.
5946 *** Changes in GDB-4.6:
5948 * Better support for C++ function names
5950 GDB now accepts as input the "demangled form" of C++ overloaded function
5951 names and member function names, and can do command completion on such names
5952 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5953 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5954 Make use of command completion, it is your friend.
5956 GDB also now accepts a variety of C++ mangled symbol formats. They are
5957 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5958 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5959 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5960 for the list of formats.
5962 * G++ symbol mangling problem
5964 Recent versions of gcc have a bug in how they emit debugging information for
5965 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5966 directory) can be applied to gcc to fix the problem. Alternatively, if you
5967 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5968 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5969 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5972 * New 'maintenance' command
5974 All of the commands related to hacking GDB internals have been moved out of
5975 the main command set, and now live behind the 'maintenance' command. This
5976 can also be abbreviated as 'mt'. The following changes were made:
5978 dump-me -> maintenance dump-me
5979 info all-breakpoints -> maintenance info breakpoints
5980 printmsyms -> maintenance print msyms
5981 printobjfiles -> maintenance print objfiles
5982 printpsyms -> maintenance print psymbols
5983 printsyms -> maintenance print symbols
5985 The following commands are new:
5987 maintenance demangle Call internal GDB demangler routine to
5988 demangle a C++ link name and prints the result.
5989 maintenance print type Print a type chain for a given symbol
5991 * Change to .gdbinit file processing
5993 We now read the $HOME/.gdbinit file before processing the argv arguments
5994 (e.g. reading symbol files or core files). This allows global parameters to
5995 be set, which will apply during the symbol reading. The ./.gdbinit is still
5996 read after argv processing.
5998 * New hosts supported
6000 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6002 GNU/Linux support i386-unknown-linux or linux
6004 We are also including code to support the HP/PA running BSD and HPUX. This
6005 is almost guaranteed not to work, as we didn't have time to test or build it
6006 for this release. We are including it so that the more adventurous (or
6007 masochistic) of you can play with it. We also had major problems with the
6008 fact that the compiler that we got from HP doesn't support the -g option.
6011 * New targets supported
6013 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6015 * More smarts about finding #include files
6017 GDB now remembers the compilation directory for all include files, and for
6018 all files from which C is generated (like yacc and lex sources). This
6019 greatly improves GDB's ability to find yacc/lex sources, and include files,
6020 especially if you are debugging your program from a directory different from
6021 the one that contains your sources.
6023 We also fixed a bug which caused difficulty with listing and setting
6024 breakpoints in include files which contain C code. (In the past, you had to
6025 try twice in order to list an include file that you hadn't looked at before.)
6027 * Interesting infernals change
6029 GDB now deals with arbitrary numbers of sections, where the symbols for each
6030 section must be relocated relative to that section's landing place in the
6031 target's address space. This work was needed to support ELF with embedded
6032 stabs used by Solaris-2.0.
6034 * Bug fixes (of course!)
6036 There have been loads of fixes for the following things:
6037 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6038 i960, stabs, DOS(GO32), procfs, etc...
6040 See the ChangeLog for details.
6042 *** Changes in GDB-4.5:
6044 * New machines supported (host and target)
6046 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6048 SGI Irix-4.x mips-sgi-irix4 or iris4
6050 * New malloc package
6052 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6053 Mmalloc is capable of handling mutiple heaps of memory. It is also
6054 capable of saving a heap to a file, and then mapping it back in later.
6055 This can be used to greatly speedup the startup of GDB by using a
6056 pre-parsed symbol table which lives in a mmalloc managed heap. For
6057 more details, please read mmalloc/mmalloc.texi.
6061 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6062 'help info proc' for details.
6064 * MIPS ecoff symbol table format
6066 The code that reads MIPS symbol table format is now supported on all hosts.
6067 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6070 * File name changes for MS-DOS
6072 Many files in the config directories have been renamed to make it easier to
6073 support GDB on MS-DOSe systems (which have very restrictive file name
6074 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6075 environment) is close to working but has some remaining problems. Note
6076 that debugging of DOS programs is not supported, due to limitations
6077 in the ``operating system'', but it can be used to host cross-debugging.
6079 * Cross byte order fixes
6081 Many fixes have been made to support cross debugging of Sparc and MIPS
6082 targets from hosts whose byte order differs.
6084 * New -mapped and -readnow options
6086 If memory-mapped files are available on your system through the 'mmap'
6087 system call, you can use the -mapped option on the `file' or
6088 `symbol-file' commands to cause GDB to write the symbols from your
6089 program into a reusable file. If the program you are debugging is
6090 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6091 Future GDB debugging sessions will notice the presence of this file,
6092 and will quickly map in symbol information from it, rather than reading
6093 the symbol table from the executable program. Using the '-mapped'
6094 option in a GDB `file' or `symbol-file' command has the same effect as
6095 starting GDB with the '-mapped' command-line option.
6097 You can cause GDB to read the entire symbol table immediately by using
6098 the '-readnow' option with any of the commands that load symbol table
6099 information (or on the GDB command line). This makes the command
6100 slower, but makes future operations faster.
6102 The -mapped and -readnow options are typically combined in order to
6103 build a `fred.syms' file that contains complete symbol information.
6104 A simple GDB invocation to do nothing but build a `.syms' file for future
6107 gdb -batch -nx -mapped -readnow programname
6109 The `.syms' file is specific to the host machine on which GDB is run.
6110 It holds an exact image of GDB's internal symbol table. It cannot be
6111 shared across multiple host platforms.
6113 * longjmp() handling
6115 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6116 siglongjmp() without losing control. This feature has not yet been ported to
6117 all systems. It currently works on many 386 platforms, all MIPS-based
6118 platforms (SGI, DECstation, etc), and Sun3/4.
6122 Preliminary work has been put in to support the new Solaris OS from Sun. At
6123 this time, it can control and debug processes, but it is not capable of
6128 As always, many many bug fixes. The major areas were with g++, and mipsread.
6129 People using the MIPS-based platforms should experience fewer mysterious
6130 crashes and trashed symbol tables.
6132 *** Changes in GDB-4.4:
6134 * New machines supported (host and target)
6136 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6138 BSD Reno on Vax vax-dec-bsd
6139 Ultrix on Vax vax-dec-ultrix
6141 * New machines supported (target)
6143 AMD 29000 embedded, using EBMON a29k-none-none
6147 GDB continues to improve its handling of C++. `References' work better.
6148 The demangler has also been improved, and now deals with symbols mangled as
6149 per the Annotated C++ Reference Guide.
6151 GDB also now handles `stabs' symbol information embedded in MIPS
6152 `ecoff' symbol tables. Since the ecoff format was not easily
6153 extensible to handle new languages such as C++, this appeared to be a
6154 good way to put C++ debugging info into MIPS binaries. This option
6155 will be supported in the GNU C compiler, version 2, when it is
6158 * New features for SVR4
6160 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6161 shared libraries. Debugging dynamically linked programs should present
6162 only minor differences from debugging statically linked programs.
6164 The `info proc' command will print out information about any process
6165 on an SVR4 system (including the one you are debugging). At the moment,
6166 it prints the address mappings of the process.
6168 If you bring up GDB on another SVR4 system, please send mail to
6169 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6171 * Better dynamic linking support in SunOS
6173 Reading symbols from shared libraries which contain debugging symbols
6174 now works properly. However, there remain issues such as automatic
6175 skipping of `transfer vector' code during function calls, which
6176 make it harder to debug code in a shared library, than to debug the
6177 same code linked statically.
6181 GDB is now using the latest `getopt' routines from the FSF. This
6182 version accepts the -- prefix for options with long names. GDB will
6183 continue to accept the old forms (-option and +option) as well.
6184 Various single letter abbreviations for options have been explicity
6185 added to the option table so that they won't get overshadowed in the
6186 future by other options that begin with the same letter.
6190 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6191 Many assorted bugs have been handled. Many more remain to be handled.
6192 See the various ChangeLog files (primarily in gdb and bfd) for details.
6195 *** Changes in GDB-4.3:
6197 * New machines supported (host and target)
6199 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6200 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6201 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6203 * Almost SCO Unix support
6205 We had hoped to support:
6206 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6207 (except for core file support), but we discovered very late in the release
6208 that it has problems with process groups that render gdb unusable. Sorry
6209 about that. I encourage people to fix it and post the fixes.
6211 * Preliminary ELF and DWARF support
6213 GDB can read ELF object files on System V Release 4, and can handle
6214 debugging records for C, in DWARF format, in ELF files. This support
6215 is preliminary. If you bring up GDB on another SVR4 system, please
6216 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6221 GDB now uses the latest `readline' library. One user-visible change
6222 is that two tabs will list possible command completions, which previously
6223 required typing M-? (meta-question mark, or ESC ?).
6227 The `stepi' bug that many of you noticed has been squashed.
6228 Many bugs in C++ have been handled. Many more remain to be handled.
6229 See the various ChangeLog files (primarily in gdb and bfd) for details.
6231 * State of the MIPS world (in case you wondered):
6233 GDB can understand the symbol tables emitted by the compilers
6234 supplied by most vendors of MIPS-based machines, including DEC. These
6235 symbol tables are in a format that essentially nobody else uses.
6237 Some versions of gcc come with an assembler post-processor called
6238 mips-tfile. This program is required if you want to do source-level
6239 debugging of gcc-compiled programs. I believe FSF does not ship
6240 mips-tfile with gcc version 1, but it will eventually come with gcc
6243 Debugging of g++ output remains a problem. g++ version 1.xx does not
6244 really support it at all. (If you're lucky, you should be able to get
6245 line numbers and stack traces to work, but no parameters or local
6246 variables.) With some work it should be possible to improve the
6249 When gcc version 2 is released, you will have somewhat better luck.
6250 However, even then you will get confusing results for inheritance and
6253 We will eventually provide full debugging of g++ output on
6254 DECstations. This will probably involve some kind of stabs-in-ecoff
6255 encapulation, but the details have not been worked out yet.
6258 *** Changes in GDB-4.2:
6260 * Improved configuration
6262 Only one copy of `configure' exists now, and it is not self-modifying.
6263 Porting BFD is simpler.
6267 The `step' and `next' commands now only stop at the first instruction
6268 of a source line. This prevents the multiple stops that used to occur
6269 in switch statements, for-loops, etc. `Step' continues to stop if a
6270 function that has debugging information is called within the line.
6274 Lots of small bugs fixed. More remain.
6276 * New host supported (not target)
6278 Intel 386 PC clone running Mach i386-none-mach
6281 *** Changes in GDB-4.1:
6283 * Multiple source language support
6285 GDB now has internal scaffolding to handle several source languages.
6286 It determines the type of each source file from its filename extension,
6287 and will switch expression parsing and number formatting to match the
6288 language of the function in the currently selected stack frame.
6289 You can also specifically set the language to be used, with
6290 `set language c' or `set language modula-2'.
6294 GDB now has preliminary support for the GNU Modula-2 compiler,
6295 currently under development at the State University of New York at
6296 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6297 continue through the fall of 1991 and into 1992.
6299 Other Modula-2 compilers are currently not supported, and attempting to
6300 debug programs compiled with them will likely result in an error as the
6301 symbol table is read. Feel free to work on it, though!
6303 There are hooks in GDB for strict type checking and range checking,
6304 in the `Modula-2 philosophy', but they do not currently work.
6308 GDB can now write to executable and core files (e.g. patch
6309 a variable's value). You must turn this switch on, specify
6310 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6311 by assigning a new value to a variable. Modifications take
6314 * Automatic SunOS shared library reading
6316 When you run your program, GDB automatically determines where its
6317 shared libraries (if any) have been loaded, and reads their symbols.
6318 The `share' command is no longer needed. This also works when
6319 examining core files.
6323 You can specify the number of lines that the `list' command shows.
6326 * New machines supported (host and target)
6328 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6329 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6330 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6332 * New hosts supported (not targets)
6334 IBM RT/PC: romp-ibm-aix or rtpc
6336 * New targets supported (not hosts)
6338 AMD 29000 embedded with COFF a29k-none-coff
6339 AMD 29000 embedded with a.out a29k-none-aout
6340 Ultracomputer remote kernel debug a29k-nyu-kern
6342 * New remote interfaces
6348 *** Changes in GDB-4.0:
6352 Wide output is wrapped at good places to make the output more readable.
6354 Gdb now supports cross-debugging from a host machine of one type to a
6355 target machine of another type. Communication with the target system
6356 is over serial lines. The ``target'' command handles connecting to the
6357 remote system; the ``load'' command will download a program into the
6358 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6359 also supports debugging of realtime processes running under VxWorks,
6360 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6361 stub on the target system.
6363 New CPUs supported include the AMD 29000 and Intel 960.
6365 GDB now reads object files and symbol tables via a ``binary file''
6366 library, which allows a single copy of GDB to debug programs of multiple
6367 object file types such as a.out and coff.
6369 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6370 refcard.dvi and refcard.ps are available to format it).
6373 * Control-Variable user interface simplified
6375 All variables that control the operation of the debugger can be set
6376 by the ``set'' command, and displayed by the ``show'' command.
6378 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6379 ``Show prompt'' produces the response:
6380 Gdb's prompt is new-gdb=>.
6382 What follows are the NEW set commands. The command ``help set'' will
6383 print a complete list of old and new set commands. ``help set FOO''
6384 will give a longer description of the variable FOO. ``show'' will show
6385 all of the variable descriptions and their current settings.
6387 confirm on/off: Enables warning questions for operations that are
6388 hard to recover from, e.g. rerunning the program while
6389 it is already running. Default is ON.
6391 editing on/off: Enables EMACS style command line editing
6392 of input. Previous lines can be recalled with
6393 control-P, the current line can be edited with control-B,
6394 you can search for commands with control-R, etc.
6397 history filename NAME: NAME is where the gdb command history
6398 will be stored. The default is .gdb_history,
6399 or the value of the environment variable
6402 history size N: The size, in commands, of the command history. The
6403 default is 256, or the value of the environment variable
6406 history save on/off: If this value is set to ON, the history file will
6407 be saved after exiting gdb. If set to OFF, the
6408 file will not be saved. The default is OFF.
6410 history expansion on/off: If this value is set to ON, then csh-like
6411 history expansion will be performed on
6412 command line input. The default is OFF.
6414 radix N: Sets the default radix for input and output. It can be set
6415 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6416 in the current radix, so "set radix 10" is always a no-op.
6418 height N: This integer value is the number of lines on a page. Default
6419 is 24, the current `stty rows'' setting, or the ``li#''
6420 setting from the termcap entry matching the environment
6423 width N: This integer value is the number of characters on a line.
6424 Default is 80, the current `stty cols'' setting, or the ``co#''
6425 setting from the termcap entry matching the environment
6428 Note: ``set screensize'' is obsolete. Use ``set height'' and
6429 ``set width'' instead.
6431 print address on/off: Print memory addresses in various command displays,
6432 such as stack traces and structure values. Gdb looks
6433 more ``symbolic'' if you turn this off; it looks more
6434 ``machine level'' with it on. Default is ON.
6436 print array on/off: Prettyprint arrays. New convenient format! Default
6439 print demangle on/off: Print C++ symbols in "source" form if on,
6442 print asm-demangle on/off: Same, for assembler level printouts
6445 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6448 * Support for Epoch Environment.
6450 The epoch environment is a version of Emacs v18 with windowing. One
6451 new command, ``inspect'', is identical to ``print'', except that if you
6452 are running in the epoch environment, the value is printed in its own
6456 * Support for Shared Libraries
6458 GDB can now debug programs and core files that use SunOS shared libraries.
6459 Symbols from a shared library cannot be referenced
6460 before the shared library has been linked with the program (this
6461 happens after you type ``run'' and before the function main() is entered).
6462 At any time after this linking (including when examining core files
6463 from dynamically linked programs), gdb reads the symbols from each
6464 shared library when you type the ``sharedlibrary'' command.
6465 It can be abbreviated ``share''.
6467 sharedlibrary REGEXP: Load shared object library symbols for files
6468 matching a unix regular expression. No argument
6469 indicates to load symbols for all shared libraries.
6471 info sharedlibrary: Status of loaded shared libraries.
6476 A watchpoint stops execution of a program whenever the value of an
6477 expression changes. Checking for this slows down execution
6478 tremendously whenever you are in the scope of the expression, but is
6479 quite useful for catching tough ``bit-spreader'' or pointer misuse
6480 problems. Some machines such as the 386 have hardware for doing this
6481 more quickly, and future versions of gdb will use this hardware.
6483 watch EXP: Set a watchpoint (breakpoint) for an expression.
6485 info watchpoints: Information about your watchpoints.
6487 delete N: Deletes watchpoint number N (same as breakpoints).
6488 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6489 enable N: Re-enables watchpoint number N (same as breakpoints).
6492 * C++ multiple inheritance
6494 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6497 * C++ exception handling
6499 Gdb now supports limited C++ exception handling. Besides the existing
6500 ability to breakpoint on an exception handler, gdb can breakpoint on
6501 the raising of an exception (before the stack is peeled back to the
6504 catch FOO: If there is a FOO exception handler in the dynamic scope,
6505 set a breakpoint to catch exceptions which may be raised there.
6506 Multiple exceptions (``catch foo bar baz'') may be caught.
6508 info catch: Lists all exceptions which may be caught in the
6509 current stack frame.
6512 * Minor command changes
6514 The command ``call func (arg, arg, ...)'' now acts like the print
6515 command, except it does not print or save a value if the function's result
6516 is void. This is similar to dbx usage.
6518 The ``up'' and ``down'' commands now always print the frame they end up
6519 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6520 frames without printing.
6522 * New directory command
6524 'dir' now adds directories to the FRONT of the source search path.
6525 The path starts off empty. Source files that contain debug information
6526 about the directory in which they were compiled can be found even
6527 with an empty path; Sun CC and GCC include this information. If GDB can't
6528 find your source file in the current directory, type "dir .".
6530 * Configuring GDB for compilation
6532 For normal use, type ``./configure host''. See README or gdb.texinfo
6535 GDB now handles cross debugging. If you are remotely debugging between
6536 two different machines, type ``./configure host -target=targ''.
6537 Host is the machine where GDB will run; targ is the machine
6538 where the program that you are debugging will run.
projects / external / binutils.git / blob