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.
85 ** gdb.Breakpoint objects have a new attribute "pending", which
86 indicates whether the breakpoint is pending.
88 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
89 was added in GDBserver, including JIT compiling fast tracepoint's
90 conditional expression bytecode into native code.
92 * Support for various remote target protocols and ROM monitors has
95 target m32rsdi Remote M32R debugging over SDI
96 target mips MIPS remote debugging protocol
97 target pmon PMON ROM monitor
98 target ddb NEC's DDB variant of PMON for Vr4300
99 target rockhopper NEC RockHopper variant of PMON
100 target lsi LSI variant of PMO
102 * Support for tracepoints and fast tracepoints on powerpc-linux,
103 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
104 including JIT compiling fast tracepoint's conditional expression
105 bytecode into native code.
107 * MI async record =record-started now includes the method and format used for
108 recording. For example:
110 =record-started,thread-group="i1",method="btrace",format="bts"
114 Andes NDS32 nds32*-*-elf
116 *** Changes in GDB 7.11
118 * GDB now supports debugging kernel-based threads on FreeBSD.
120 * Per-inferior thread numbers
122 Thread numbers are now per inferior instead of global. If you're
123 debugging multiple inferiors, GDB displays thread IDs using a
124 qualified INF_NUM.THR_NUM form. For example:
128 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
129 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
130 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
131 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
133 As consequence, thread numbers as visible in the $_thread
134 convenience variable and in Python's InferiorThread.num attribute
135 are no longer unique between inferiors.
137 GDB now maintains a second thread ID per thread, referred to as the
138 global thread ID, which is the new equivalent of thread numbers in
139 previous releases. See also $_gthread below.
141 For backwards compatibility, MI's thread IDs always refer to global
144 * Commands that accept thread IDs now accept the qualified
145 INF_NUM.THR_NUM form as well. For example:
148 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
151 * In commands that accept a list of thread IDs, you can now refer to
152 all threads of an inferior using a star wildcard. GDB accepts
153 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
154 refer to all threads of the current inferior. For example, "info
157 * You can use "info threads -gid" to display the global thread ID of
160 * The new convenience variable $_gthread holds the global number of
163 * The new convenience variable $_inferior holds the number of the
166 * GDB now displays the ID and name of the thread that hit a breakpoint
167 or received a signal, if your program is multi-threaded. For
170 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
171 Thread 1 "main" received signal SIGINT, Interrupt.
173 * Record btrace now supports non-stop mode.
175 * Support for tracepoints on aarch64-linux was added in GDBserver.
177 * The 'record instruction-history' command now indicates speculative execution
178 when using the Intel Processor Trace recording format.
180 * GDB now allows users to specify explicit locations, bypassing
181 the linespec parser. This feature is also available to GDB/MI
184 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
185 GDB now is able to debug both AArch64 applications and ARM applications
188 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
189 including JIT compiling fast tracepoint's conditional expression bytecode
192 * GDB now supports displaced stepping on AArch64 GNU/Linux.
194 * "info threads", "info inferiors", "info display", "info checkpoints"
195 and "maint info program-spaces" now list the corresponding items in
196 ascending ID order, for consistency with all other "info" commands.
198 * In Ada, the overloads selection menu has been enhanced to display the
199 parameter types and the return types for the matching overloaded subprograms.
203 maint set target-non-stop (on|off|auto)
204 maint show target-non-stop
205 Control whether GDB targets always operate in non-stop mode even if
206 "set non-stop" is "off". The default is "auto", meaning non-stop
207 mode is enabled if supported by the target.
209 maint set bfd-sharing
210 maint show bfd-sharing
211 Control the reuse of bfd objects.
215 Control display of debugging info regarding bfd caching.
219 Control display of debugging info regarding FreeBSD threads.
221 set remote multiprocess-extensions-packet
222 show remote multiprocess-extensions-packet
223 Set/show the use of the remote protocol multiprocess extensions.
225 set remote thread-events
226 show remote thread-events
227 Set/show the use of thread create/exit events.
229 set ada print-signatures on|off
230 show ada print-signatures"
231 Control whether parameter types and return types are displayed in overloads
232 selection menus. It is activaled (@code{on}) by default.
236 Controls the maximum size of memory, in bytes, that GDB will
237 allocate for value contents. Prevents incorrect programs from
238 causing GDB to allocate overly large buffers. Default is 64k.
240 * The "disassemble" command accepts a new modifier: /s.
241 It prints mixed source+disassembly like /m with two differences:
242 - disassembled instructions are now printed in program order, and
243 - and source for all relevant files is now printed.
244 The "/m" option is now considered deprecated: its "source-centric"
245 output hasn't proved useful in practice.
247 * The "record instruction-history" command accepts a new modifier: /s.
248 It behaves exactly like /m and prints mixed source+disassembly.
250 * The "set scheduler-locking" command supports a new mode "replay".
251 It behaves like "off" in record mode and like "on" in replay mode.
253 * Support for various ROM monitors has been removed:
255 target dbug dBUG ROM monitor for Motorola ColdFire
256 target picobug Motorola picobug monitor
257 target dink32 DINK32 ROM monitor for PowerPC
258 target m32r Renesas M32R/D ROM monitor
259 target mon2000 mon2000 ROM monitor
260 target ppcbug PPCBUG ROM monitor for PowerPC
262 * Support for reading/writing memory and extracting values on architectures
263 whose memory is addressable in units of any integral multiple of 8 bits.
268 Indicates that an exec system call was executed.
270 exec-events feature in qSupported
271 The qSupported packet allows GDB to request support for exec
272 events using the new 'gdbfeature' exec-event, and the qSupported
273 response can contain the corresponding 'stubfeature'. Set and
274 show commands can be used to display whether these features are enabled.
277 Equivalent to interrupting with the ^C character, but works in
280 thread created stop reason (T05 create:...)
281 Indicates that the thread was just created and is stopped at entry.
283 thread exit stop reply (w exitcode;tid)
284 Indicates that the thread has terminated.
287 Enables/disables thread create and exit event reporting. For
288 example, this is used in non-stop mode when GDB stops a set of
289 threads and synchronously waits for the their corresponding stop
290 replies. Without exit events, if one of the threads exits, GDB
291 would hang forever not knowing that it should no longer expect a
292 stop for that same thread.
295 Indicates that there are no resumed threads left in the target (all
296 threads are stopped). The remote stub reports support for this stop
297 reply to GDB's qSupported query.
300 Enables/disables catching syscalls from the inferior process.
301 The remote stub reports support for this packet to GDB's qSupported query.
303 syscall_entry stop reason
304 Indicates that a syscall was just called.
306 syscall_return stop reason
307 Indicates that a syscall just returned.
309 * Extended-remote exec events
311 ** GDB now has support for exec events on extended-remote Linux targets.
312 For such targets with Linux kernels 2.5.46 and later, this enables
313 follow-exec-mode and exec catchpoints.
315 set remote exec-event-feature-packet
316 show remote exec-event-feature-packet
317 Set/show the use of the remote exec event feature.
319 * Thread names in remote protocol
321 The reply to qXfer:threads:read may now include a name attribute for each
324 * Target remote mode fork and exec events
326 ** GDB now has support for fork and exec events on target remote mode
327 Linux targets. For such targets with Linux kernels 2.5.46 and later,
328 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
329 fork and exec catchpoints.
331 * Remote syscall events
333 ** GDB now has support for catch syscall on remote Linux targets,
334 currently enabled on x86/x86_64 architectures.
336 set remote catch-syscall-packet
337 show remote catch-syscall-packet
338 Set/show the use of the remote catch syscall feature.
342 ** The -var-set-format command now accepts the zero-hexadecimal
343 format. It outputs data in hexadecimal format with zero-padding on the
348 ** gdb.InferiorThread objects have a new attribute "global_num",
349 which refers to the thread's global thread ID. The existing
350 "num" attribute now refers to the thread's per-inferior number.
351 See "Per-inferior thread numbers" above.
352 ** gdb.InferiorThread objects have a new attribute "inferior", which
353 is the Inferior object the thread belongs to.
355 *** Changes in GDB 7.10
357 * Support for process record-replay and reverse debugging on aarch64*-linux*
358 targets has been added. GDB now supports recording of A64 instruction set
359 including advance SIMD instructions.
361 * Support for Sun's version of the "stabs" debug file format has been removed.
363 * GDB now honors the content of the file /proc/PID/coredump_filter
364 (PID is the process ID) on GNU/Linux systems. This file can be used
365 to specify the types of memory mappings that will be included in a
366 corefile. For more information, please refer to the manual page of
367 "core(5)". GDB also has a new command: "set use-coredump-filter
368 on|off". It allows to set whether GDB will read the content of the
369 /proc/PID/coredump_filter file when generating a corefile.
371 * The "info os" command on GNU/Linux can now display information on
373 "info os cpus" Listing of all cpus/cores on the system
375 * GDB has two new commands: "set serial parity odd|even|none" and
376 "show serial parity". These allows to set or show parity for the
379 * The "info source" command now displays the producer string if it was
380 present in the debug info. This typically includes the compiler version
381 and may include things like its command line arguments.
383 * The "info dll", an alias of the "info sharedlibrary" command,
384 is now available on all platforms.
386 * Directory names supplied to the "set sysroot" commands may be
387 prefixed with "target:" to tell GDB to access shared libraries from
388 the target system, be it local or remote. This replaces the prefix
389 "remote:". The default sysroot has been changed from "" to
390 "target:". "remote:" is automatically converted to "target:" for
391 backward compatibility.
393 * The system root specified by "set sysroot" will be prepended to the
394 filename of the main executable (if reported to GDB as absolute by
395 the operating system) when starting processes remotely, and when
396 attaching to already-running local or remote processes.
398 * GDB now supports automatic location and retrieval of executable
399 files from remote targets. Remote debugging can now be initiated
400 using only a "target remote" or "target extended-remote" command
401 (no "set sysroot" or "file" commands are required). See "New remote
404 * The "dump" command now supports verilog hex format.
406 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
408 * On GNU/Linux, GDB and gdbserver are now able to access executable
409 and shared library files without a "set sysroot" command when
410 attaching to processes running in different mount namespaces from
411 the debugger. This makes it possible to attach to processes in
412 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
413 See "New remote packets" below.
415 * The "tui reg" command now provides completion for all of the
416 available register groups, including target specific groups.
418 * The HISTSIZE environment variable is no longer read when determining
419 the size of GDB's command history. GDB now instead reads the dedicated
420 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
421 disables truncation of command history. Non-numeric values of GDBHISTSIZE
426 ** Memory ports can now be unbuffered.
430 ** gdb.Objfile objects have a new attribute "username",
431 which is the name of the objfile as specified by the user,
432 without, for example, resolving symlinks.
433 ** You can now write frame unwinders in Python.
434 ** gdb.Type objects have a new method "optimized_out",
435 returning optimized out gdb.Value instance of this type.
436 ** gdb.Value objects have new methods "reference_value" and
437 "const_value" which return a reference to the value and a
438 "const" version of the value respectively.
442 maint print symbol-cache
443 Print the contents of the symbol cache.
445 maint print symbol-cache-statistics
446 Print statistics of symbol cache usage.
448 maint flush-symbol-cache
449 Flush the contents of the symbol cache.
453 Start branch trace recording using Branch Trace Store (BTS) format.
456 Evaluate expression by using the compiler and print result.
460 Explicit commands for enabling and disabling tui mode.
463 set mpx bound on i386 and amd64
464 Support for bound table investigation on Intel MPX enabled applications.
468 Start branch trace recording using Intel Processor Trace format.
471 Print information about branch tracing internals.
473 maint btrace packet-history
474 Print the raw branch tracing data.
476 maint btrace clear-packet-history
477 Discard the stored raw branch tracing data.
480 Discard all branch tracing data. It will be fetched and processed
481 anew by the next "record" command.
486 Renamed from "set debug dwarf2-die".
488 Renamed from "show debug dwarf2-die".
491 Renamed from "set debug dwarf2-read".
492 show debug dwarf-read
493 Renamed from "show debug dwarf2-read".
495 maint set dwarf always-disassemble
496 Renamed from "maint set dwarf2 always-disassemble".
497 maint show dwarf always-disassemble
498 Renamed from "maint show dwarf2 always-disassemble".
500 maint set dwarf max-cache-age
501 Renamed from "maint set dwarf2 max-cache-age".
502 maint show dwarf max-cache-age
503 Renamed from "maint show dwarf2 max-cache-age".
506 show debug dwarf-line
507 Control display of debugging info regarding DWARF line processing.
511 Set the maximum number of candidates to be considered during
512 completion. The default value is 200. This limit allows GDB
513 to avoid generating large completion lists, the computation of
514 which can cause the debugger to become temporarily unresponsive.
516 set history remove-duplicates
517 show history remove-duplicates
518 Control the removal of duplicate history entries.
520 maint set symbol-cache-size
521 maint show symbol-cache-size
522 Control the size of the symbol cache.
524 set|show record btrace bts buffer-size
525 Set and show the size of the ring buffer used for branch tracing in
527 The obtained size may differ from the requested size. Use "info
528 record" to see the obtained buffer size.
530 set debug linux-namespaces
531 show debug linux-namespaces
532 Control display of debugging info regarding Linux namespaces.
534 set|show record btrace pt buffer-size
535 Set and show the size of the ring buffer used for branch tracing in
536 Intel Processor Trace format.
537 The obtained size may differ from the requested size. Use "info
538 record" to see the obtained buffer size.
540 maint set|show btrace pt skip-pad
541 Set and show whether PAD packets are skipped when computing the
544 * The command 'thread apply all' can now support new option '-ascending'
545 to call its specified command for all threads in ascending order.
547 * Python/Guile scripting
549 ** GDB now supports auto-loading of Python/Guile scripts contained in the
550 special section named `.debug_gdb_scripts'.
554 qXfer:btrace-conf:read
555 Return the branch trace configuration for the current thread.
557 Qbtrace-conf:bts:size
558 Set the requested ring buffer size for branch tracing in BTS format.
561 Enable Intel Procesor Trace-based branch tracing for the current
562 process. The remote stub reports support for this packet to GDB's
566 Set the requested ring buffer size for branch tracing in Intel Processor
570 Indicates a memory breakpoint instruction was executed, irrespective
571 of whether it was GDB that planted the breakpoint or the breakpoint
572 is hardcoded in the program. This is required for correct non-stop
576 Indicates the target stopped for a hardware breakpoint. This is
577 required for correct non-stop mode operation.
580 Return information about files on the remote system.
583 Return the full absolute name of the file that was executed to
584 create a process running on the remote system.
587 Select the filesystem on which vFile: operations with filename
588 arguments will operate. This is required for GDB to be able to
589 access files on remote targets where the remote stub does not
590 share a common filesystem with the inferior(s).
593 Indicates that a fork system call was executed.
596 Indicates that a vfork system call was executed.
598 vforkdone stop reason
599 Indicates that a vfork child of the specified process has executed
600 an exec or exit, allowing the vfork parent to resume execution.
602 fork-events and vfork-events features in qSupported
603 The qSupported packet allows GDB to request support for fork and
604 vfork events using new 'gdbfeatures' fork-events and vfork-events,
605 and the qSupported response can contain the corresponding
606 'stubfeatures'. Set and show commands can be used to display
607 whether these features are enabled.
609 * Extended-remote fork events
611 ** GDB now has support for fork events on extended-remote Linux
612 targets. For targets with Linux kernels 2.5.60 and later, this
613 enables follow-fork-mode and detach-on-fork for both fork and
614 vfork, as well as fork and vfork catchpoints.
616 * The info record command now shows the recording format and the
617 branch tracing configuration for the current thread when using
618 the btrace record target.
619 For the BTS format, it shows the ring buffer size.
621 * GDB now has support for DTrace USDT (Userland Static Defined
622 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
624 * GDB now supports access to vector registers on S/390 GNU/Linux
627 * Removed command line options
629 -xdb HP-UX XDB compatibility mode.
631 * Removed targets and native configurations
633 HP/PA running HP-UX hppa*-*-hpux*
634 Itanium running HP-UX ia64-*-hpux*
636 * New configure options
639 This configure option allows the user to build GDB with support for
640 Intel Processor Trace (default: auto). This requires libipt.
642 --with-libipt-prefix=PATH
643 Specify the path to the version of libipt that GDB should use.
644 $PATH/include should contain the intel-pt.h header and
645 $PATH/lib should contain the libipt.so library.
647 *** Changes in GDB 7.9.1
651 ** Xmethods can now specify a result type.
653 *** Changes in GDB 7.9
655 * GDB now supports hardware watchpoints on x86 GNU Hurd.
659 ** You can now access frame registers from Python scripts.
660 ** New attribute 'producer' for gdb.Symtab objects.
661 ** gdb.Objfile objects have a new attribute "progspace",
662 which is the gdb.Progspace object of the containing program space.
663 ** gdb.Objfile objects have a new attribute "owner".
664 ** gdb.Objfile objects have a new attribute "build_id",
665 which is the build ID generated when the file was built.
666 ** gdb.Objfile objects have a new method "add_separate_debug_file".
667 ** A new event "gdb.clear_objfiles" has been added, triggered when
668 selecting a new file to debug.
669 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
670 ** New function gdb.lookup_objfile.
672 New events which are triggered when GDB modifies the state of the
675 ** gdb.events.inferior_call_pre: Function call is about to be made.
676 ** gdb.events.inferior_call_post: Function call has just been made.
677 ** gdb.events.memory_changed: A memory location has been altered.
678 ** gdb.events.register_changed: A register has been altered.
680 * New Python-based convenience functions:
682 ** $_caller_is(name [, number_of_frames])
683 ** $_caller_matches(regexp [, number_of_frames])
684 ** $_any_caller_is(name [, number_of_frames])
685 ** $_any_caller_matches(regexp [, number_of_frames])
687 * GDB now supports the compilation and injection of source code into
688 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
689 to compile the source code to object code, and if successful, inject
690 and execute that code within the current context of the inferior.
691 Currently the C language is supported. The commands used to
692 interface with this new feature are:
694 compile code [-raw|-r] [--] [source code]
695 compile file [-raw|-r] filename
699 demangle [-l language] [--] name
700 Demangle "name" in the specified language, or the current language
701 if elided. This command is renamed from the "maint demangle" command.
702 The latter is kept as a no-op to avoid "maint demangle" being interpreted
703 as "maint demangler-warning".
705 queue-signal signal-name-or-number
706 Queue a signal to be delivered to the thread when it is resumed.
708 add-auto-load-scripts-directory directory
709 Add entries to the list of directories from which to load auto-loaded
712 maint print user-registers
713 List all currently available "user" registers.
715 compile code [-r|-raw] [--] [source code]
716 Compile, inject, and execute in the inferior the executable object
717 code produced by compiling the provided source code.
719 compile file [-r|-raw] filename
720 Compile and inject into the inferior the executable object code
721 produced by compiling the source code stored in the filename
724 * On resume, GDB now always passes the signal the program had stopped
725 for to the thread the signal was sent to, even if the user changed
726 threads before resuming. Previously GDB would often (but not
727 always) deliver the signal to the thread that happens to be current
730 * Conversely, the "signal" command now consistently delivers the
731 requested signal to the current thread. GDB now asks for
732 confirmation if the program had stopped for a signal and the user
733 switched threads meanwhile.
735 * "breakpoint always-inserted" modes "off" and "auto" merged.
737 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
738 won't remove breakpoints from the target until all threads stop,
739 even in non-stop mode. The "auto" mode has been removed, and "off"
740 is now the default mode.
744 set debug symbol-lookup
745 show debug symbol-lookup
746 Control display of debugging info regarding symbol lookup.
750 ** The -list-thread-groups command outputs an exit-code field for
751 inferiors that have exited.
755 MIPS SDE mips*-sde*-elf*
759 Support for these obsolete configurations has been removed.
761 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
762 SGI Irix-5.x mips-*-irix5*
763 SGI Irix-6.x mips-*-irix6*
764 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
765 VAX running Ultrix vax-*-ultrix*
767 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
768 and "assf"), have been removed. Use the "sharedlibrary" command, or
769 its alias "share", instead.
771 *** Changes in GDB 7.8
773 * New command line options
776 This is an alias for the --data-directory option.
778 * GDB supports printing and modifying of variable length automatic arrays
779 as specified in ISO C99.
781 * The ARM simulator now supports instruction level tracing
782 with or without disassembly.
786 GDB now has support for scripting using Guile. Whether this is
787 available is determined at configure time.
788 Guile version 2.0 or greater is required.
789 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
791 * New commands (for set/show, see "New options" below)
795 Invoke CODE by passing it to the Guile interpreter.
799 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
801 info auto-load guile-scripts [regexp]
802 Print the list of automatically loaded Guile scripts.
804 * The source command is now capable of sourcing Guile scripts.
805 This feature is dependent on the debugger being built with Guile support.
809 set print symbol-loading (off|brief|full)
810 show print symbol-loading
811 Control whether to print informational messages when loading symbol
812 information for a file. The default is "full", but when debugging
813 programs with large numbers of shared libraries the amount of output
816 set guile print-stack (none|message|full)
817 show guile print-stack
818 Show a stack trace when an error is encountered in a Guile script.
820 set auto-load guile-scripts (on|off)
821 show auto-load guile-scripts
822 Control auto-loading of Guile script files.
824 maint ada set ignore-descriptive-types (on|off)
825 maint ada show ignore-descriptive-types
826 Control whether the debugger should ignore descriptive types in Ada
827 programs. The default is not to ignore the descriptive types. See
828 the user manual for more details on descriptive types and the intended
829 usage of this option.
831 set auto-connect-native-target
833 Control whether GDB is allowed to automatically connect to the
834 native target for the run, attach, etc. commands when not connected
835 to any target yet. See also "target native" below.
837 set record btrace replay-memory-access (read-only|read-write)
838 show record btrace replay-memory-access
839 Control what memory accesses are allowed during replay.
841 maint set target-async (on|off)
842 maint show target-async
843 This controls whether GDB targets operate in synchronous or
844 asynchronous mode. Normally the default is asynchronous, if it is
845 available; but this can be changed to more easily debug problems
846 occurring only in synchronous mode.
848 set mi-async (on|off)
850 Control whether MI asynchronous mode is preferred. This supersedes
851 "set target-async" of previous GDB versions.
853 * "set target-async" is deprecated as a CLI option and is now an alias
854 for "set mi-async" (only puts MI into async mode).
856 * Background execution commands (e.g., "c&", "s&", etc.) are now
857 possible ``out of the box'' if the target supports them. Previously
858 the user would need to explicitly enable the possibility with the
859 "set target-async on" command.
861 * New features in the GDB remote stub, GDBserver
863 ** New option --debug-format=option1[,option2,...] allows one to add
864 additional text to each output. At present only timestamps
865 are supported: --debug-format=timestamps.
866 Timestamps can also be turned on with the
867 "monitor set debug-format timestamps" command from GDB.
869 * The 'record instruction-history' command now starts counting instructions
870 at one. This also affects the instruction ranges reported by the
871 'record function-call-history' command when given the /i modifier.
873 * The command 'record function-call-history' supports a new modifier '/c' to
874 indent the function names based on their call stack depth.
875 The fields for the '/i' and '/l' modifier have been reordered.
876 The source line range is now prefixed with 'at'.
877 The instruction range is now prefixed with 'inst'.
878 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
879 "record instruction-history" and "list" commands.
881 * The ranges given as arguments to the 'record function-call-history' and
882 'record instruction-history' commands are now inclusive.
884 * The btrace record target now supports the 'record goto' command.
885 For locations inside the execution trace, the back trace is computed
886 based on the information stored in the execution trace.
888 * The btrace record target supports limited reverse execution and replay.
889 The target does not record data and therefore does not allow reading
892 * The "catch syscall" command now works on s390*-linux* targets.
894 * The "compare-sections" command is no longer specific to target
895 remote. It now works with all targets.
897 * All native targets are now consistently called "native".
898 Consequently, the "target child", "target GNU", "target djgpp",
899 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
900 commands have been replaced with "target native". The QNX/NTO port
901 leaves the "procfs" target in place and adds a "native" target for
902 consistency with other ports. The impact on users should be minimal
903 as these commands previously either throwed an error, or were
904 no-ops. The target's name is visible in the output of the following
905 commands: "help target", "info target", "info files", "maint print
908 * The "target native" command now connects to the native target. This
909 can be used to launch native programs even when "set
910 auto-connect-native-target" is set to off.
912 * GDB now supports access to Intel MPX registers on GNU/Linux.
914 * Support for Intel AVX-512 registers on GNU/Linux.
915 Support displaying and modifying Intel AVX-512 registers
916 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
920 qXfer:btrace:read's annex
921 The qXfer:btrace:read packet supports a new annex 'delta' to read
922 branch trace incrementally.
926 ** Valid Python operations on gdb.Value objects representing
927 structs/classes invoke the corresponding overloaded operators if
929 ** New `Xmethods' feature in the Python API. Xmethods are
930 additional methods or replacements for existing methods of a C++
931 class. This feature is useful for those cases where a method
932 defined in C++ source code could be inlined or optimized out by
933 the compiler, making it unavailable to GDB.
936 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
938 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
939 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
940 its alias "share", instead.
942 * The commands "set remotebaud" and "show remotebaud" are no longer
943 supported. Use "set serial baud" and "show serial baud" (respectively)
948 ** A new option "-gdb-set mi-async" replaces "-gdb-set
949 target-async". The latter is left as a deprecated alias of the
950 former for backward compatibility. If the target supports it,
951 CLI background execution commands are now always possible by
952 default, independently of whether the frontend stated a
953 preference for asynchronous execution with "-gdb-set mi-async".
954 Previously "-gdb-set target-async off" affected both MI execution
955 commands and CLI execution commands.
957 *** Changes in GDB 7.7
959 * Improved support for process record-replay and reverse debugging on
960 arm*-linux* targets. Support for thumb32 and syscall instruction
961 recording has been added.
963 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
965 * GDB now supports Fission DWP file format version 2.
966 http://gcc.gnu.org/wiki/DebugFission
968 * New convenience function "$_isvoid", to check whether an expression
969 is void. A void expression is an expression where the type of the
970 result is "void". For example, some convenience variables may be
971 "void" when evaluated (e.g., "$_exitcode" before the execution of
972 the program being debugged; or an undefined convenience variable).
973 Another example, when calling a function whose return type is
976 * The "maintenance print objfiles" command now takes an optional regexp.
978 * The "catch syscall" command now works on arm*-linux* targets.
980 * GDB now consistently shows "<not saved>" when printing values of
981 registers the debug info indicates have not been saved in the frame
982 and there's nowhere to retrieve them from
983 (callee-saved/call-clobbered registers):
988 (gdb) info registers rax
991 Before, the former would print "<optimized out>", and the latter
992 "*value not available*".
994 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
999 ** Frame filters and frame decorators have been added.
1000 ** Temporary breakpoints are now supported.
1001 ** Line tables representation has been added.
1002 ** New attribute 'parent_type' for gdb.Field objects.
1003 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1004 ** New attribute 'name' for gdb.Type objects.
1008 Nios II ELF nios2*-*-elf
1009 Nios II GNU/Linux nios2*-*-linux
1010 Texas Instruments MSP430 msp430*-*-elf
1012 * Removed native configurations
1014 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1015 been removed. ELF variants of these configurations are kept supported.
1017 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1018 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1019 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1020 i[34567]86-*-openbsd3.[0-3]
1021 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1022 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1023 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1027 Like "catch throw", but catches a re-thrown exception.
1028 maint check-psymtabs
1029 Renamed from old "maint check-symtabs".
1031 Perform consistency checks on symtabs.
1032 maint expand-symtabs
1033 Expand symtabs matching an optional regexp.
1036 Display the details of GDB configure-time options.
1038 maint set|show per-command
1039 maint set|show per-command space
1040 maint set|show per-command time
1041 maint set|show per-command symtab
1042 Enable display of per-command gdb resource usage.
1044 remove-symbol-file FILENAME
1045 remove-symbol-file -a ADDRESS
1046 Remove a symbol file added via add-symbol-file. The file to remove
1047 can be identified by its filename or by an address that lies within
1048 the boundaries of this symbol file in memory.
1051 info exceptions REGEXP
1052 Display the list of Ada exceptions defined in the program being
1053 debugged. If provided, only the exceptions whose names match REGEXP
1058 set debug symfile off|on
1060 Control display of debugging info regarding reading symbol files and
1061 symbol tables within those files
1063 set print raw frame-arguments
1064 show print raw frame-arguments
1065 Set/show whether to print frame arguments in raw mode,
1066 disregarding any defined pretty-printers.
1068 set remote trace-status-packet
1069 show remote trace-status-packet
1070 Set/show the use of remote protocol qTStatus packet.
1074 Control display of debugging messages related to Nios II targets.
1078 Control whether target-assisted range stepping is enabled.
1080 set startup-with-shell
1081 show startup-with-shell
1082 Specifies whether Unix child processes are started via a shell or
1087 Use the target memory cache for accesses to the code segment. This
1088 improves performance of remote debugging (particularly disassembly).
1090 * You can now use a literal value 'unlimited' for options that
1091 interpret 0 or -1 as meaning "unlimited". E.g., "set
1092 trace-buffer-size unlimited" is now an alias for "set
1093 trace-buffer-size -1" and "set height unlimited" is now an alias for
1096 * The "set debug symtab-create" debugging option of GDB has been changed to
1097 accept a verbosity level. 0 means "off", 1 provides basic debugging
1098 output, and values of 2 or greater provides more verbose output.
1100 * New command-line options
1102 Display the details of GDB configure-time options.
1104 * The command 'tsave' can now support new option '-ctf' to save trace
1105 buffer in Common Trace Format.
1107 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1110 * GDB now implements the the C++ 'typeid' operator.
1112 * The new convenience variable $_exception holds the exception being
1113 thrown or caught at an exception-related catchpoint.
1115 * The exception-related catchpoints, like "catch throw", now accept a
1116 regular expression which can be used to filter exceptions by type.
1118 * The new convenience variable $_exitsignal is automatically set to
1119 the terminating signal number when the program being debugged dies
1120 due to an uncaught signal.
1124 ** All MI commands now accept an optional "--language" option.
1125 Support for this feature can be verified by using the "-list-features"
1126 command, which should contain "language-option".
1128 ** The new command -info-gdb-mi-command allows the user to determine
1129 whether a GDB/MI command is supported or not.
1131 ** The "^error" result record returned when trying to execute an undefined
1132 GDB/MI command now provides a variable named "code" whose content is the
1133 "undefined-command" error code. Support for this feature can be verified
1134 by using the "-list-features" command, which should contain
1135 "undefined-command-error-code".
1137 ** The -trace-save MI command can optionally save trace buffer in Common
1140 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1142 ** The command -data-list-register-values now accepts an optional
1143 "--skip-unavailable" option. When used, only the available registers
1146 ** The new command -trace-frame-collected dumps collected variables,
1147 computed expressions, tvars, memory and registers in a traceframe.
1149 ** The commands -stack-list-locals, -stack-list-arguments and
1150 -stack-list-variables now accept an option "--skip-unavailable".
1151 When used, only the available locals or arguments are displayed.
1153 ** The -exec-run command now accepts an optional "--start" option.
1154 When used, the command follows the same semantics as the "start"
1155 command, stopping the program's execution at the start of its
1156 main subprogram. Support for this feature can be verified using
1157 the "-list-features" command, which should contain
1158 "exec-run-start-option".
1160 ** The new commands -catch-assert and -catch-exceptions insert
1161 catchpoints stopping the program when Ada exceptions are raised.
1163 ** The new command -info-ada-exceptions provides the equivalent of
1164 the new "info exceptions" command.
1166 * New system-wide configuration scripts
1167 A GDB installation now provides scripts suitable for use as system-wide
1168 configuration scripts for the following systems:
1172 * GDB now supports target-assigned range stepping with remote targets.
1173 This improves the performance of stepping source lines by reducing
1174 the number of control packets from/to GDB. See "New remote packets"
1177 * GDB now understands the element 'tvar' in the XML traceframe info.
1178 It has the id of the collected trace state variables.
1180 * On S/390 targets that provide the transactional-execution feature,
1181 the program interruption transaction diagnostic block (TDB) is now
1182 represented as a number of additional "registers" in GDB.
1184 * New remote packets
1188 The vCont packet supports a new 'r' action, that tells the remote
1189 stub to step through an address range itself, without GDB
1190 involvemement at each single-step.
1192 qXfer:libraries-svr4:read's annex
1193 The previously unused annex of the qXfer:libraries-svr4:read packet
1194 is now used to support passing an argument list. The remote stub
1195 reports support for this argument list to GDB's qSupported query.
1196 The defined arguments are "start" and "prev", used to reduce work
1197 necessary for library list updating, resulting in significant
1200 * New features in the GDB remote stub, GDBserver
1202 ** GDBserver now supports target-assisted range stepping. Currently
1203 enabled on x86/x86_64 GNU/Linux targets.
1205 ** GDBserver now adds element 'tvar' in the XML in the reply to
1206 'qXfer:traceframe-info:read'. It has the id of the collected
1207 trace state variables.
1209 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1212 * New 'z' formatter for printing and examining memory, this displays the
1213 value as hexadecimal zero padded on the left to the size of the type.
1215 * GDB can now use Windows x64 unwinding data.
1217 * The "set remotebaud" command has been replaced by "set serial baud".
1218 Similarly, "show remotebaud" has been replaced by "show serial baud".
1219 The "set remotebaud" and "show remotebaud" commands are still available
1220 to provide backward compatibility with older versions of GDB.
1222 *** Changes in GDB 7.6
1224 * Target record has been renamed to record-full.
1225 Record/replay is now enabled with the "record full" command.
1226 This also affects settings that are associated with full record/replay
1227 that have been moved from "set/show record" to "set/show record full":
1229 set|show record full insn-number-max
1230 set|show record full stop-at-limit
1231 set|show record full memory-query
1233 * A new record target "record-btrace" has been added. The new target
1234 uses hardware support to record the control-flow of a process. It
1235 does not support replaying the execution, but it implements the
1236 below new commands for investigating the recorded execution log.
1237 This new recording method can be enabled using:
1241 The "record-btrace" target is only available on Intel Atom processors
1242 and requires a Linux kernel 2.6.32 or later.
1244 * Two new commands have been added for record/replay to give information
1245 about the recorded execution without having to replay the execution.
1246 The commands are only supported by "record btrace".
1248 record instruction-history prints the execution history at
1249 instruction granularity
1251 record function-call-history prints the execution history at
1252 function granularity
1254 * New native configurations
1256 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1257 FreeBSD/powerpc powerpc*-*-freebsd
1258 x86_64/Cygwin x86_64-*-cygwin*
1259 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1263 ARM AArch64 aarch64*-*-elf
1264 ARM AArch64 GNU/Linux aarch64*-*-linux
1265 Lynx 178 PowerPC powerpc-*-lynx*178
1266 x86_64/Cygwin x86_64-*-cygwin*
1267 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1269 * If the configured location of system.gdbinit file (as given by the
1270 --with-system-gdbinit option at configure time) is in the
1271 data-directory (as specified by --with-gdb-datadir at configure
1272 time) or in one of its subdirectories, then GDB will look for the
1273 system-wide init file in the directory specified by the
1274 --data-directory command-line option.
1276 * New command line options:
1278 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1279 other initialization files, unlike -nx which disables all of them.
1281 * Removed command line options
1283 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1286 * The 'ptype' and 'whatis' commands now accept an argument to control
1289 * 'info proc' now works on some core files.
1293 ** Vectors can be created with gdb.Type.vector.
1295 ** Python's atexit.register now works in GDB.
1297 ** Types can be pretty-printed via a Python API.
1299 ** Python 3 is now supported (in addition to Python 2.4 or later)
1301 ** New class gdb.Architecture exposes GDB's internal representation
1302 of architecture in the Python API.
1304 ** New method Frame.architecture returns the gdb.Architecture object
1305 corresponding to the frame's architecture.
1307 * New Python-based convenience functions:
1309 ** $_memeq(buf1, buf2, length)
1310 ** $_streq(str1, str2)
1312 ** $_regex(str, regex)
1314 * The 'cd' command now defaults to using '~' (the home directory) if not
1317 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1318 default for GCC since November 2000.
1320 * The command 'forward-search' can now be abbreviated as 'fo'.
1322 * The command 'info tracepoints' can now display 'installed on target'
1323 or 'not installed on target' for each non-pending location of tracepoint.
1325 * New configure options
1327 --enable-libmcheck/--disable-libmcheck
1328 By default, development versions are built with -lmcheck on hosts
1329 that support it, in order to help track memory corruption issues.
1330 Release versions, on the other hand, are built without -lmcheck
1331 by default. The --enable-libmcheck/--disable-libmcheck configure
1332 options allow the user to override that default.
1333 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1334 This configure option allows the user to build GDB with
1335 libbabeltrace using which GDB can read Common Trace Format data.
1337 * New commands (for set/show, see "New options" below)
1340 Catch signals. This is similar to "handle", but allows commands and
1341 conditions to be attached.
1344 List the BFDs known to GDB.
1346 python-interactive [command]
1348 Start a Python interactive prompt, or evaluate the optional command
1349 and print the result of expressions.
1352 "py" is a new alias for "python".
1354 enable type-printer [name]...
1355 disable type-printer [name]...
1356 Enable or disable type printers.
1360 ** For the Renesas Super-H architecture, the "regs" command has been removed
1361 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1366 set print type methods (on|off)
1367 show print type methods
1368 Control whether method declarations are displayed by "ptype".
1369 The default is to show them.
1371 set print type typedefs (on|off)
1372 show print type typedefs
1373 Control whether typedef definitions are displayed by "ptype".
1374 The default is to show them.
1376 set filename-display basename|relative|absolute
1377 show filename-display
1378 Control the way in which filenames is displayed.
1379 The default is "relative", which preserves previous behavior.
1381 set trace-buffer-size
1382 show trace-buffer-size
1383 Request target to change the size of trace buffer.
1385 set remote trace-buffer-size-packet auto|on|off
1386 show remote trace-buffer-size-packet
1387 Control the use of the remote protocol `QTBuffer:size' packet.
1391 Control display of debugging messages related to ARM AArch64.
1394 set debug coff-pe-read
1395 show debug coff-pe-read
1396 Control display of debugging messages related to reading of COFF/PE
1401 Control display of debugging messages related to Mach-O symbols
1404 set debug notification
1405 show debug notification
1406 Control display of debugging info for async remote notification.
1410 ** Command parameter changes are now notified using new async record
1411 "=cmd-param-changed".
1412 ** Trace frame changes caused by command "tfind" are now notified using
1413 new async record "=traceframe-changed".
1414 ** The creation, deletion and modification of trace state variables
1415 are now notified using new async records "=tsv-created",
1416 "=tsv-deleted" and "=tsv-modified".
1417 ** The start and stop of process record are now notified using new
1418 async record "=record-started" and "=record-stopped".
1419 ** Memory changes are now notified using new async record
1421 ** The data-disassemble command response will include a "fullname" field
1422 containing the absolute file name when source has been requested.
1423 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1424 command, to allow pattern filling of memory areas.
1425 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1426 library load/unload events.
1427 ** The response to breakpoint commands and breakpoint async records
1428 includes an "installed" field containing a boolean state about each
1429 non-pending tracepoint location is whether installed on target or not.
1430 ** Output of the "-trace-status" command includes a "trace-file" field
1431 containing the name of the trace file being examined. This field is
1432 optional, and only present when examining a trace file.
1433 ** The "fullname" field is now always present along with the "file" field,
1434 even if the file cannot be found by GDB.
1436 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1437 You must have the LZMA library available when configuring GDB for this
1438 feature to be enabled. For more information, see:
1439 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1441 * New remote packets
1444 Set the size of trace buffer. The remote stub reports support for this
1445 packet to gdb's qSupported query.
1448 Enable Branch Trace Store (BTS)-based branch tracing for the current
1449 thread. The remote stub reports support for this packet to gdb's
1453 Disable branch tracing for the current thread. The remote stub reports
1454 support for this packet to gdb's qSupported query.
1457 Read the traced branches for the current thread. The remote stub
1458 reports support for this packet to gdb's qSupported query.
1460 *** Changes in GDB 7.5
1462 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1463 for more x32 ABI info.
1465 * GDB now supports access to MIPS DSP registers on Linux targets.
1467 * GDB now supports debugging microMIPS binaries.
1469 * The "info os" command on GNU/Linux can now display information on
1470 several new classes of objects managed by the operating system:
1471 "info os procgroups" lists process groups
1472 "info os files" lists file descriptors
1473 "info os sockets" lists internet-domain sockets
1474 "info os shm" lists shared-memory regions
1475 "info os semaphores" lists semaphores
1476 "info os msg" lists message queues
1477 "info os modules" lists loaded kernel modules
1479 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1480 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1481 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1482 options and inspect the probe arguments using the new $_probe_arg family
1483 of convenience variables. You can obtain more information about SystemTap
1484 in <http://sourceware.org/systemtap/>.
1486 * GDB now supports reversible debugging on ARM, it allows you to
1487 debug basic ARM and THUMB instructions, and provides
1488 record/replay support.
1490 * The option "symbol-reloading" has been deleted as it is no longer used.
1494 ** GDB commands implemented in Python can now be put in command class
1497 ** The "maint set python print-stack on|off" is now deleted.
1499 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1500 apply "flag enum"-style pretty-printing to any enum.
1502 ** gdb.lookup_symbol can now work when there is no current frame.
1504 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1505 the source at which the symbol was defined.
1507 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1508 method 'value'. The former indicates whether the symbol needs a
1509 frame in order to compute its value, and the latter computes the
1512 ** A new method 'referenced_value' on gdb.Value objects which can
1513 dereference pointer as well as C++ reference values.
1515 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1516 which return the global and static blocks (as gdb.Block objects),
1517 of the underlying symbol table, respectively.
1519 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1520 object associated with a PC value.
1522 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1523 of the address range occupied by code for the current source line.
1525 * Go language support.
1526 GDB now supports debugging programs written in the Go programming
1529 * GDBserver now supports stdio connections.
1530 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1532 * The binary "gdbtui" can no longer be built or installed.
1533 Use "gdb -tui" instead.
1535 * GDB will now print "flag" enums specially. A flag enum is one where
1536 all the enumerator values have no bits in common when pairwise
1537 "and"ed. When printing a value whose type is a flag enum, GDB will
1538 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1539 (gdb) print (enum E) 3
1542 * The filename part of a linespec will now match trailing components
1543 of a source file name. For example, "break gcc/expr.c:1000" will
1544 now set a breakpoint in build/gcc/expr.c, but not
1545 build/libcpp/expr.c.
1547 * The "info proc" and "generate-core-file" commands will now also
1548 work on remote targets connected to GDBserver on Linux.
1550 * The command "info catch" has been removed. It has been disabled
1551 since December 2007.
1553 * The "catch exception" and "catch assert" commands now accept
1554 a condition at the end of the command, much like the "break"
1555 command does. For instance:
1557 (gdb) catch exception Constraint_Error if Barrier = True
1559 Previously, it was possible to add a condition to such catchpoints,
1560 but it had to be done as a second step, after the catchpoint had been
1561 created, using the "condition" command.
1563 * The "info static-tracepoint-marker" command will now also work on
1564 native Linux targets with in-process agent.
1566 * GDB can now set breakpoints on inlined functions.
1568 * The .gdb_index section has been updated to include symbols for
1569 inlined functions. GDB will ignore older .gdb_index sections by
1570 default, which could cause symbol files to be loaded more slowly
1571 until their .gdb_index sections can be recreated. The new command
1572 "set use-deprecated-index-sections on" will cause GDB to use any older
1573 .gdb_index sections it finds. This will restore performance, but the
1574 ability to set breakpoints on inlined functions will be lost in symbol
1575 files with older .gdb_index sections.
1577 The .gdb_index section has also been updated to record more information
1578 about each symbol. This speeds up the "info variables", "info functions"
1579 and "info types" commands when used with programs having the .gdb_index
1580 section, as well as speeding up debugging with shared libraries using
1581 the .gdb_index section.
1583 * Ada support for GDB/MI Variable Objects has been added.
1585 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1590 ** New command -info-os is the MI equivalent of "info os".
1592 ** Output logs ("set logging" and related) now include MI output.
1596 ** "set use-deprecated-index-sections on|off"
1597 "show use-deprecated-index-sections on|off"
1598 Controls the use of deprecated .gdb_index sections.
1600 ** "catch load" and "catch unload" can be used to stop when a shared
1601 library is loaded or unloaded, respectively.
1603 ** "enable count" can be used to auto-disable a breakpoint after
1606 ** "info vtbl" can be used to show the virtual method tables for
1607 C++ and Java objects.
1609 ** "explore" and its sub commands "explore value" and "explore type"
1610 can be used to recursively explore values and types of
1611 expressions. These commands are available only if GDB is
1612 configured with '--with-python'.
1614 ** "info auto-load" shows status of all kinds of auto-loaded files,
1615 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1616 sequences of commands files, "info auto-load python-scripts"
1617 shows status of auto-loading Python script files,
1618 "info auto-load local-gdbinit" shows status of loading init file
1619 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1620 status of inferior specific thread debugging shared library loading.
1622 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1623 and "show auto-load-scripts" commands have been deprecated, use their
1624 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1625 and "show auto-load python-scripts" counterparts instead.
1627 ** "dprintf location,format,args..." creates a dynamic printf, which
1628 is basically a breakpoint that does a printf and immediately
1629 resumes your program's execution, so it is like a printf that you
1630 can insert dynamically at runtime instead of at compiletime.
1632 ** "set print symbol"
1634 Controls whether GDB attempts to display the symbol, if any,
1635 corresponding to addresses it prints. This defaults to "on", but
1636 you can set it to "off" to restore GDB's previous behavior.
1638 * Deprecated commands
1640 ** For the Renesas Super-H architecture, the "regs" command has been
1641 deprecated, and "info all-registers" should be used instead.
1645 Renesas RL78 rl78-*-elf
1646 HP OpenVMS ia64 ia64-hp-openvms*
1648 * GDBserver supports evaluation of breakpoint conditions. When
1649 support is advertised by GDBserver, GDB may be told to send the
1650 breakpoint conditions in bytecode form to GDBserver. GDBserver
1651 will only report the breakpoint trigger to GDB when its condition
1656 set mips compression
1657 show mips compression
1658 Select the compressed ISA encoding used in functions that have no symbol
1659 information available. The encoding can be set to either of:
1662 and is updated automatically from ELF file flags if available.
1664 set breakpoint condition-evaluation
1665 show breakpoint condition-evaluation
1666 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1667 GDBserver ("target"). Default option "auto" chooses the most efficient
1669 This option can improve debugger efficiency depending on the speed of the
1673 Disable auto-loading globally.
1676 Show auto-loading setting of all kinds of auto-loaded files.
1678 set auto-load gdb-scripts on|off
1679 show auto-load gdb-scripts
1680 Control auto-loading of GDB canned sequences of commands files.
1682 set auto-load python-scripts on|off
1683 show auto-load python-scripts
1684 Control auto-loading of Python script files.
1686 set auto-load local-gdbinit on|off
1687 show auto-load local-gdbinit
1688 Control loading of init file (.gdbinit) from current directory.
1690 set auto-load libthread-db on|off
1691 show auto-load libthread-db
1692 Control auto-loading of inferior specific thread debugging shared library.
1694 set auto-load scripts-directory <dir1>[:<dir2>...]
1695 show auto-load scripts-directory
1696 Set a list of directories from which to load auto-loaded scripts.
1697 Automatically loaded Python scripts and GDB scripts are located in one
1698 of the directories listed by this option.
1699 The delimiter (':' above) may differ according to the host platform.
1701 set auto-load safe-path <dir1>[:<dir2>...]
1702 show auto-load safe-path
1703 Set a list of directories from which it is safe to auto-load files.
1704 The delimiter (':' above) may differ according to the host platform.
1706 set debug auto-load on|off
1707 show debug auto-load
1708 Control display of debugging info for auto-loading the files above.
1710 set dprintf-style gdb|call|agent
1712 Control the way in which a dynamic printf is performed; "gdb"
1713 requests a GDB printf command, while "call" causes dprintf to call a
1714 function in the inferior. "agent" requests that the target agent
1715 (such as GDBserver) do the printing.
1717 set dprintf-function <expr>
1718 show dprintf-function
1719 set dprintf-channel <expr>
1720 show dprintf-channel
1721 Set the function and optional first argument to the call when using
1722 the "call" style of dynamic printf.
1724 set disconnected-dprintf on|off
1725 show disconnected-dprintf
1726 Control whether agent-style dynamic printfs continue to be in effect
1727 after GDB disconnects.
1729 * New configure options
1731 --with-auto-load-dir
1732 Configure default value for the 'set auto-load scripts-directory'
1733 setting above. It defaults to '$debugdir:$datadir/auto-load',
1734 $debugdir representing global debugging info directories (available
1735 via 'show debug-file-directory') and $datadir representing GDB's data
1736 directory (available via 'show data-directory').
1738 --with-auto-load-safe-path
1739 Configure default value for the 'set auto-load safe-path' setting
1740 above. It defaults to the --with-auto-load-dir setting.
1742 --without-auto-load-safe-path
1743 Set 'set auto-load safe-path' to '/', effectively disabling this
1746 * New remote packets
1748 z0/z1 conditional breakpoints extension
1750 The z0/z1 breakpoint insertion packets have been extended to carry
1751 a list of conditional expressions over to the remote stub depending on the
1752 condition evaluation mode. The use of this extension can be controlled
1753 via the "set remote conditional-breakpoints-packet" command.
1757 Specify the signals which the remote stub may pass to the debugged
1758 program without GDB involvement.
1760 * New command line options
1762 --init-command=FILE, -ix Like --command, -x but execute it
1763 before loading inferior.
1764 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1765 execute it before loading inferior.
1767 *** Changes in GDB 7.4
1769 * GDB now handles ambiguous linespecs more consistently; the existing
1770 FILE:LINE support has been expanded to other types of linespecs. A
1771 breakpoint will now be set on all matching locations in all
1772 inferiors, and locations will be added or removed according to
1775 * GDB now allows you to skip uninteresting functions and files when
1776 stepping with the "skip function" and "skip file" commands.
1778 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1779 and "show remote hardware-watchpoint-length-limit". These allows to
1780 set or show the maximum length limit (in bytes) of a remote
1781 target hardware watchpoint.
1783 This allows e.g. to use "unlimited" hardware watchpoints with the
1784 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1785 watchpoints are slower than real hardware watchpoints but are
1786 significantly faster than gdb software watchpoints.
1790 ** The register_pretty_printer function in module gdb.printing now takes
1791 an optional `replace' argument. If True, the new printer replaces any
1794 ** The "maint set python print-stack on|off" command has been
1795 deprecated and will be deleted in GDB 7.5.
1796 A new command: "set python print-stack none|full|message" has
1797 replaced it. Additionally, the default for "print-stack" is
1798 now "message", which just prints the error message without
1801 ** A prompt substitution hook (prompt_hook) is now available to the
1804 ** A new Python module, gdb.prompt has been added to the GDB Python
1805 modules library. This module provides functionality for
1806 escape sequences in prompts (used by set/show
1807 extended-prompt). These escape sequences are replaced by their
1808 corresponding value.
1810 ** Python commands and convenience-functions located in
1811 'data-directory'/python/gdb/command and
1812 'data-directory'/python/gdb/function are now automatically loaded
1815 ** Blocks now provide four new attributes. global_block and
1816 static_block will return the global and static blocks
1817 respectively. is_static and is_global are boolean attributes
1818 that indicate if the block is one of those two types.
1820 ** Symbols now provide the "type" attribute, the type of the symbol.
1822 ** The "gdb.breakpoint" function has been deprecated in favor of
1825 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1826 of a function. This class is based on the "finish" command
1827 available in the CLI.
1829 ** Type objects for struct and union types now allow access to
1830 the fields using standard Python dictionary (mapping) methods.
1831 For example, "some_type['myfield']" now works, as does
1832 "some_type.items()".
1834 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1837 ** A new function, "deep_items" has been added to the gdb.types
1838 module in the GDB Python modules library. This function returns
1839 an iterator over the fields of a struct or union type. Unlike
1840 the standard Python "iteritems" method, it will recursively traverse
1841 any anonymous fields.
1845 ** "*stopped" events can report several new "reason"s, such as
1848 ** Breakpoint changes are now notified using new async records, like
1849 "=breakpoint-modified".
1851 ** New command -ada-task-info.
1853 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1854 $sdir specifies the default system locations of shared libraries.
1855 $pdir specifies the directory where the libpthread used by the application
1858 GDB no longer looks in $sdir and $pdir after it has searched the directories
1859 mentioned in libthread-db-search-path. If you want to search those
1860 directories, they must be specified in libthread-db-search-path.
1861 The default value of libthread-db-search-path on GNU/Linux and Solaris
1862 systems is now "$sdir:$pdir".
1864 $pdir is not supported by gdbserver, it is currently ignored.
1865 $sdir is supported by gdbserver.
1867 * New configure option --with-iconv-bin.
1868 When using the internationalization support like the one in the GNU C
1869 library, GDB will invoke the "iconv" program to get a list of supported
1870 character sets. If this program lives in a non-standard location, one can
1871 use this option to specify where to find it.
1873 * When natively debugging programs on PowerPC BookE processors running
1874 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1875 watchpoints, which specify a mask in addition to an address to watch.
1876 The mask specifies that some bits of an address (the bits which are
1877 reset in the mask) should be ignored when matching the address accessed
1878 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1879 section in the user manual for more details.
1881 * The new option --once causes GDBserver to stop listening for connections once
1882 the first connection is made. The listening port used by GDBserver will
1883 become available after that.
1885 * New commands "info macros" and "alias" have been added.
1887 * New function parameters suffix @entry specifies value of function parameter
1888 at the time the function got called. Entry values are available only since
1894 "!" is now an alias of the "shell" command.
1895 Note that no space is needed between "!" and SHELL COMMAND.
1899 watch EXPRESSION mask MASK_VALUE
1900 The watch command now supports the mask argument which allows creation
1901 of masked watchpoints, if the current architecture supports this feature.
1903 info auto-load-scripts [REGEXP]
1904 This command was formerly named "maintenance print section-scripts".
1905 It is now generally useful and is no longer a maintenance-only command.
1907 info macro [-all] [--] MACRO
1908 The info macro command has new options `-all' and `--'. The first for
1909 printing all definitions of a macro. The second for explicitly specifying
1910 the end of arguments and the beginning of the macro name in case the macro
1911 name starts with a hyphen.
1913 collect[/s] EXPRESSIONS
1914 The tracepoint collect command now takes an optional modifier "/s"
1915 that directs it to dereference pointer-to-character types and
1916 collect the bytes of memory up to a zero byte. The behavior is
1917 similar to what you see when you use the regular print command on a
1918 string. An optional integer following the "/s" sets a bound on the
1919 number of bytes that will be collected.
1922 The trace start command now interprets any supplied arguments as a
1923 note to be recorded with the trace run, with an effect similar to
1924 setting the variable trace-notes.
1927 The trace stop command now interprets any arguments as a note to be
1928 mentioned along with the tstatus report that the trace was stopped
1929 with a command. The effect is similar to setting the variable
1932 * Tracepoints can now be enabled and disabled at any time after a trace
1933 experiment has been started using the standard "enable" and "disable"
1934 commands. It is now possible to start a trace experiment with no enabled
1935 tracepoints; GDB will display a warning, but will allow the experiment to
1936 begin, assuming that tracepoints will be enabled as needed while the trace
1939 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1940 locations with 4-byte instructions, when they were previously
1941 limited to locations with instructions of 5 bytes or longer.
1945 set debug dwarf2-read
1946 show debug dwarf2-read
1947 Turns on or off display of debugging messages related to reading
1948 DWARF debug info. The default is off.
1950 set debug symtab-create
1951 show debug symtab-create
1952 Turns on or off display of debugging messages related to symbol table
1953 creation. The default is off.
1956 show extended-prompt
1957 Set the GDB prompt, and allow escape sequences to be inserted to
1958 display miscellaneous information (see 'help set extended-prompt'
1959 for the list of sequences). This prompt (and any information
1960 accessed through the escape sequences) is updated every time the
1961 prompt is displayed.
1963 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1964 show print entry-values
1965 Set printing of frame argument values at function entry. In some cases
1966 GDB can determine the value of function argument which was passed by the
1967 function caller, even if the value was modified inside the called function.
1969 set debug entry-values
1970 show debug entry-values
1971 Control display of debugging info for determining frame argument values at
1972 function entry and virtual tail call frames.
1974 set basenames-may-differ
1975 show basenames-may-differ
1976 Set whether a source file may have multiple base names.
1977 (A "base name" is the name of a file with the directory part removed.
1978 Example: The base name of "/home/user/hello.c" is "hello.c".)
1979 If set, GDB will canonicalize file names (e.g., expand symlinks)
1980 before comparing them. Canonicalization is an expensive operation,
1981 but it allows the same file be known by more than one base name.
1982 If not set (the default), all source files are assumed to have just
1983 one base name, and gdb will do file name comparisons more efficiently.
1989 Set a user name and notes for the current and any future trace runs.
1990 This is useful for long-running and/or disconnected traces, to
1991 inform others (or yourself) as to who is running the trace, supply
1992 contact information, or otherwise explain what is going on.
1994 set trace-stop-notes
1995 show trace-stop-notes
1996 Set a note attached to the trace run, that is displayed when the
1997 trace has been stopped by a tstop command. This is useful for
1998 instance as an explanation, if you are stopping a trace run that was
1999 started by someone else.
2001 * New remote packets
2005 Dynamically enable a tracepoint in a started trace experiment.
2009 Dynamically disable a tracepoint in a started trace experiment.
2013 Set the user and notes of the trace run.
2017 Query the current status of a tracepoint.
2021 Query the minimum length of instruction at which a fast tracepoint may
2024 * Dcache size (number of lines) and line-size are now runtime-configurable
2025 via "set dcache line" and "set dcache line-size" commands.
2029 Texas Instruments TMS320C6x tic6x-*-*
2033 Renesas RL78 rl78-*-elf
2035 *** Changes in GDB 7.3.1
2037 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2039 *** Changes in GDB 7.3
2041 * GDB has a new command: "thread find [REGEXP]".
2042 It finds the thread id whose name, target id, or thread extra info
2043 matches the given regular expression.
2045 * The "catch syscall" command now works on mips*-linux* targets.
2047 * The -data-disassemble MI command now supports modes 2 and 3 for
2048 dumping the instruction opcodes.
2050 * New command line options
2052 -data-directory DIR Specify DIR as the "data-directory".
2053 This is mostly for testing purposes.
2055 * The "maint set python auto-load on|off" command has been renamed to
2056 "set auto-load-scripts on|off".
2058 * GDB has a new command: "set directories".
2059 It is like the "dir" command except that it replaces the
2060 source path list instead of augmenting it.
2062 * GDB now understands thread names.
2064 On GNU/Linux, "info threads" will display the thread name as set by
2065 prctl or pthread_setname_np.
2067 There is also a new command, "thread name", which can be used to
2068 assign a name internally for GDB to display.
2071 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2072 has been integrated into GDB.
2076 ** The function gdb.Write now accepts an optional keyword 'stream'.
2077 This keyword, when provided, will direct the output to either
2078 stdout, stderr, or GDB's logging output.
2080 ** Parameters can now be be sub-classed in Python, and in particular
2081 you may implement the get_set_doc and get_show_doc functions.
2082 This improves how Parameter set/show documentation is processed
2083 and allows for more dynamic content.
2085 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2086 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2087 have an is_valid method.
2089 ** Breakpoints can now be sub-classed in Python, and in particular
2090 you may implement a 'stop' function that is executed each time
2091 the inferior reaches that breakpoint.
2093 ** New function gdb.lookup_global_symbol looks up a global symbol.
2095 ** GDB values in Python are now callable if the value represents a
2096 function. For example, if 'some_value' represents a function that
2097 takes two integer parameters and returns a value, you can call
2098 that function like so:
2100 result = some_value (10,20)
2102 ** Module gdb.types has been added.
2103 It contains a collection of utilities for working with gdb.Types objects:
2104 get_basic_type, has_field, make_enum_dict.
2106 ** Module gdb.printing has been added.
2107 It contains utilities for writing and registering pretty-printers.
2108 New classes: PrettyPrinter, SubPrettyPrinter,
2109 RegexpCollectionPrettyPrinter.
2110 New function: register_pretty_printer.
2112 ** New commands "info pretty-printers", "enable pretty-printer" and
2113 "disable pretty-printer" have been added.
2115 ** gdb.parameter("directories") is now available.
2117 ** New function gdb.newest_frame returns the newest frame in the
2120 ** The gdb.InferiorThread class has a new "name" attribute. This
2121 holds the thread's name.
2123 ** Python Support for Inferior events.
2124 Python scripts can add observers to be notified of events
2125 occurring in the process being debugged.
2126 The following events are currently supported:
2127 - gdb.events.cont Continue event.
2128 - gdb.events.exited Inferior exited event.
2129 - gdb.events.stop Signal received, and Breakpoint hit events.
2133 ** GDB now puts template parameters in scope when debugging in an
2134 instantiation. For example, if you have:
2136 template<int X> int func (void) { return X; }
2138 then if you step into func<5>, "print X" will show "5". This
2139 feature requires proper debuginfo support from the compiler; it
2140 was added to GCC 4.5.
2142 ** The motion commands "next", "finish", "until", and "advance" now
2143 work better when exceptions are thrown. In particular, GDB will
2144 no longer lose control of the inferior; instead, the GDB will
2145 stop the inferior at the point at which the exception is caught.
2146 This functionality requires a change in the exception handling
2147 code that was introduced in GCC 4.5.
2149 * GDB now follows GCC's rules on accessing volatile objects when
2150 reading or writing target state during expression evaluation.
2151 One notable difference to prior behavior is that "print x = 0"
2152 no longer generates a read of x; the value of the assignment is
2153 now always taken directly from the value being assigned.
2155 * GDB now has some support for using labels in the program's source in
2156 linespecs. For instance, you can use "advance label" to continue
2157 execution to a label.
2159 * GDB now has support for reading and writing a new .gdb_index
2160 section. This section holds a fast index of DWARF debugging
2161 information and can be used to greatly speed up GDB startup and
2162 operation. See the documentation for `save gdb-index' for details.
2164 * The "watch" command now accepts an optional "-location" argument.
2165 When used, this causes GDB to watch the memory referred to by the
2166 expression. Such a watchpoint is never deleted due to it going out
2169 * GDB now supports thread debugging of core dumps on GNU/Linux.
2171 GDB now activates thread debugging using the libthread_db library
2172 when debugging GNU/Linux core dumps, similarly to when debugging
2173 live processes. As a result, when debugging a core dump file, GDB
2174 is now able to display pthread_t ids of threads. For example, "info
2175 threads" shows the same output as when debugging the process when it
2176 was live. In earlier releases, you'd see something like this:
2179 * 1 LWP 6780 main () at main.c:10
2181 While now you see this:
2184 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2186 It is also now possible to inspect TLS variables when debugging core
2189 When debugging a core dump generated on a machine other than the one
2190 used to run GDB, you may need to point GDB at the correct
2191 libthread_db library with the "set libthread-db-search-path"
2192 command. See the user manual for more details on this command.
2194 * When natively debugging programs on PowerPC BookE processors running
2195 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2196 which stop execution of the inferior whenever it executes an instruction
2197 at any address within the specified range. See the "PowerPC Embedded"
2198 section in the user manual for more details.
2200 * New features in the GDB remote stub, GDBserver
2202 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2203 and i686 LynxOS (version 5.x).
2205 ** GDBserver is now supported on Blackfin Linux.
2207 * New native configurations
2209 ia64 HP-UX ia64-*-hpux*
2213 Analog Devices, Inc. Blackfin Processor bfin-*
2215 * Ada task switching is now supported on sparc-elf targets when
2216 debugging a program using the Ravenscar Profile. For more information,
2217 see the "Tasking Support when using the Ravenscar Profile" section
2218 in the GDB user manual.
2220 * Guile support was removed.
2222 * New features in the GNU simulator
2224 ** The --map-info flag lists all known core mappings.
2226 ** CFI flashes may be simulated via the "cfi" device.
2228 *** Changes in GDB 7.2
2230 * Shared library support for remote targets by default
2232 When GDB is configured for a generic, non-OS specific target, like
2233 for example, --target=arm-eabi or one of the many *-*-elf targets,
2234 GDB now queries remote stubs for loaded shared libraries using the
2235 `qXfer:libraries:read' packet. Previously, shared library support
2236 was always disabled for such configurations.
2240 ** Argument Dependent Lookup (ADL)
2242 In C++ ADL lookup directs function search to the namespaces of its
2243 arguments even if the namespace has not been imported.
2253 Here the compiler will search for `foo' in the namespace of 'b'
2254 and find A::foo. GDB now supports this. This construct is commonly
2255 used in the Standard Template Library for operators.
2257 ** Improved User Defined Operator Support
2259 In addition to member operators, GDB now supports lookup of operators
2260 defined in a namespace and imported with a `using' directive, operators
2261 defined in the global scope, operators imported implicitly from an
2262 anonymous namespace, and the ADL operators mentioned in the previous
2264 GDB now also supports proper overload resolution for all the previously
2265 mentioned flavors of operators.
2267 ** static const class members
2269 Printing of static const class members that are initialized in the
2270 class definition has been fixed.
2272 * Windows Thread Information Block access.
2274 On Windows targets, GDB now supports displaying the Windows Thread
2275 Information Block (TIB) structure. This structure is visible either
2276 by using the new command `info w32 thread-information-block' or, by
2277 dereferencing the new convenience variable named `$_tlb', a
2278 thread-specific pointer to the TIB. This feature is also supported
2279 when remote debugging using GDBserver.
2281 * Static tracepoints
2283 Static tracepoints are calls in the user program into a tracing
2284 library. One such library is a port of the LTTng kernel tracer to
2285 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2286 When debugging with GDBserver, GDB now supports combining the GDB
2287 tracepoint machinery with such libraries. For example: the user can
2288 use GDB to probe a static tracepoint marker (a call from the user
2289 program into the tracing library) with the new "strace" command (see
2290 "New commands" below). This creates a "static tracepoint" in the
2291 breakpoint list, that can be manipulated with the same feature set
2292 as fast and regular tracepoints. E.g., collect registers, local and
2293 global variables, collect trace state variables, and define
2294 tracepoint conditions. In addition, the user can collect extra
2295 static tracepoint marker specific data, by collecting the new
2296 $_sdata internal variable. When analyzing the trace buffer, you can
2297 inspect $_sdata like any other variable available to GDB. For more
2298 information, see the "Tracepoints" chapter in GDB user manual. New
2299 remote packets have been defined to support static tracepoints, see
2300 the "New remote packets" section below.
2302 * Better reconstruction of tracepoints after disconnected tracing
2304 GDB will attempt to download the original source form of tracepoint
2305 definitions when starting a trace run, and then will upload these
2306 upon reconnection to the target, resulting in a more accurate
2307 reconstruction of the tracepoints that are in use on the target.
2311 You can now exercise direct control over the ways that GDB can
2312 affect your program. For instance, you can disallow the setting of
2313 breakpoints, so that the program can run continuously (assuming
2314 non-stop mode). In addition, the "observer" variable is available
2315 to switch all of the different controls; in observer mode, GDB
2316 cannot affect the target's behavior at all, which is useful for
2317 tasks like diagnosing live systems in the field.
2319 * The new convenience variable $_thread holds the number of the
2322 * New remote packets
2326 Return the address of the Windows Thread Information Block of a given thread.
2330 In response to several of the tracepoint packets, the target may now
2331 also respond with a number of intermediate `qRelocInsn' request
2332 packets before the final result packet, to have GDB handle
2333 relocating an instruction to execute at a different address. This
2334 is particularly useful for stubs that support fast tracepoints. GDB
2335 reports support for this feature in the qSupported packet.
2339 List static tracepoint markers in the target program.
2343 List static tracepoint markers at a given address in the target
2346 qXfer:statictrace:read
2348 Read the static trace data collected (by a `collect $_sdata'
2349 tracepoint action). The remote stub reports support for this packet
2350 to gdb's qSupported query.
2354 Send the current settings of GDB's permission flags.
2358 Send part of the source (textual) form of a tracepoint definition,
2359 which includes location, conditional, and action list.
2361 * The source command now accepts a -s option to force searching for the
2362 script in the source search path even if the script name specifies
2365 * New features in the GDB remote stub, GDBserver
2367 - GDBserver now support tracepoints (including fast tracepoints, and
2368 static tracepoints). The feature is currently supported by the
2369 i386-linux and amd64-linux builds. See the "Tracepoints support
2370 in gdbserver" section in the manual for more information.
2372 GDBserver JIT compiles the tracepoint's conditional agent
2373 expression bytecode into native code whenever possible for low
2374 overhead dynamic tracepoints conditionals. For such tracepoints,
2375 an expression that examines program state is evaluated when the
2376 tracepoint is reached, in order to determine whether to capture
2377 trace data. If the condition is simple and false, processing the
2378 tracepoint finishes very quickly and no data is gathered.
2380 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2381 for static tracepoints support.
2383 - GDBserver now supports x86_64 Windows 64-bit debugging.
2385 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2386 it understands register description.
2388 * The --batch flag now disables pagination and queries.
2390 * X86 general purpose registers
2392 GDB now supports reading/writing byte, word and double-word x86
2393 general purpose registers directly. This means you can use, say,
2394 $ah or $ax to refer, respectively, to the byte register AH and
2395 16-bit word register AX that are actually portions of the 32-bit
2396 register EAX or 64-bit register RAX.
2398 * The `commands' command now accepts a range of breakpoints to modify.
2399 A plain `commands' following a command that creates multiple
2400 breakpoints affects all the breakpoints set by that command. This
2401 applies to breakpoints set by `rbreak', and also applies when a
2402 single `break' command creates multiple breakpoints (e.g.,
2403 breakpoints on overloaded c++ functions).
2405 * The `rbreak' command now accepts a filename specification as part of
2406 its argument, limiting the functions selected by the regex to those
2407 in the specified file.
2409 * Support for remote debugging Windows and SymbianOS shared libraries
2410 from Unix hosts has been improved. Non Windows GDB builds now can
2411 understand target reported file names that follow MS-DOS based file
2412 system semantics, such as file names that include drive letters and
2413 use the backslash character as directory separator. This makes it
2414 possible to transparently use the "set sysroot" and "set
2415 solib-search-path" on Unix hosts to point as host copies of the
2416 target's shared libraries. See the new command "set
2417 target-file-system-kind" described below, and the "Commands to
2418 specify files" section in the user manual for more information.
2422 eval template, expressions...
2423 Convert the values of one or more expressions under the control
2424 of the string template to a command line, and call it.
2426 set target-file-system-kind unix|dos-based|auto
2427 show target-file-system-kind
2428 Set or show the assumed file system kind for target reported file
2431 save breakpoints <filename>
2432 Save all current breakpoint definitions to a file suitable for use
2433 in a later debugging session. To read the saved breakpoint
2434 definitions, use the `source' command.
2436 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2439 info static-tracepoint-markers
2440 Display information about static tracepoint markers in the target.
2442 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2443 Define a static tracepoint by probing a marker at the given
2444 function, line, address, or marker ID.
2448 Enable and disable observer mode.
2450 set may-write-registers on|off
2451 set may-write-memory on|off
2452 set may-insert-breakpoints on|off
2453 set may-insert-tracepoints on|off
2454 set may-insert-fast-tracepoints on|off
2455 set may-interrupt on|off
2456 Set individual permissions for GDB effects on the target. Note that
2457 some of these settings can have undesirable or surprising
2458 consequences, particularly when changed in the middle of a session.
2459 For instance, disabling the writing of memory can prevent
2460 breakpoints from being inserted, cause single-stepping to fail, or
2461 even crash your program, if you disable after breakpoints have been
2462 inserted. However, GDB should not crash.
2464 set record memory-query on|off
2465 show record memory-query
2466 Control whether to stop the inferior if memory changes caused
2467 by an instruction cannot be recorded.
2472 The disassemble command now supports "start,+length" form of two arguments.
2476 ** GDB now provides a new directory location, called the python directory,
2477 where Python scripts written for GDB can be installed. The location
2478 of that directory is <data-directory>/python, where <data-directory>
2479 is the GDB data directory. For more details, see section `Scripting
2480 GDB using Python' in the manual.
2482 ** The GDB Python API now has access to breakpoints, symbols, symbol
2483 tables, program spaces, inferiors, threads and frame's code blocks.
2484 Additionally, GDB Parameters can now be created from the API, and
2485 manipulated via set/show in the CLI.
2487 ** New functions gdb.target_charset, gdb.target_wide_charset,
2488 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2490 ** New exception gdb.GdbError.
2492 ** Pretty-printers are now also looked up in the current program space.
2494 ** Pretty-printers can now be individually enabled and disabled.
2496 ** GDB now looks for names of Python scripts to auto-load in a
2497 special section named `.debug_gdb_scripts', in addition to looking
2498 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2500 * Tracepoint actions were unified with breakpoint commands. In particular,
2501 there are no longer differences in "info break" output for breakpoints and
2502 tracepoints and the "commands" command can be used for both tracepoints and
2503 regular breakpoints.
2507 ARM Symbian arm*-*-symbianelf*
2509 * D language support.
2510 GDB now supports debugging programs written in the D programming
2513 * GDB now supports the extended ptrace interface for PowerPC which is
2514 available since Linux kernel version 2.6.34. This automatically enables
2515 any hardware breakpoints and additional hardware watchpoints available in
2516 the processor. The old ptrace interface exposes just one hardware
2517 watchpoint and no hardware breakpoints.
2519 * GDB is now able to use the Data Value Compare (DVC) register available on
2520 embedded PowerPC processors to implement in hardware simple watchpoint
2521 conditions of the form:
2523 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2525 This works in native GDB running on Linux kernels with the extended ptrace
2526 interface mentioned above.
2528 *** Changes in GDB 7.1
2532 ** Namespace Support
2534 GDB now supports importing of namespaces in C++. This enables the
2535 user to inspect variables from imported namespaces. Support for
2536 namepace aliasing has also been added. So, if a namespace is
2537 aliased in the current scope (e.g. namepace C=A; ) the user can
2538 print variables using the alias (e.g. (gdb) print C::x).
2542 All known bugs relating to the printing of virtual base class were
2543 fixed. It is now possible to call overloaded static methods using a
2548 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2549 and reinterpret_cast<> are now handled by the C++ expression parser.
2553 Xilinx MicroBlaze microblaze-*-*
2558 Xilinx MicroBlaze microblaze
2561 * Multi-program debugging.
2563 GDB now has support for multi-program (a.k.a. multi-executable or
2564 multi-exec) debugging. This allows for debugging multiple inferiors
2565 simultaneously each running a different program under the same GDB
2566 session. See "Debugging Multiple Inferiors and Programs" in the
2567 manual for more information. This implied some user visible changes
2568 in the multi-inferior support. For example, "info inferiors" now
2569 lists inferiors that are not running yet or that have exited
2570 already. See also "New commands" and "New options" below.
2572 * New tracing features
2574 GDB's tracepoint facility now includes several new features:
2576 ** Trace state variables
2578 GDB tracepoints now include support for trace state variables, which
2579 are variables managed by the target agent during a tracing
2580 experiment. They are useful for tracepoints that trigger each
2581 other, so for instance one tracepoint can count hits in a variable,
2582 and then a second tracepoint has a condition that is true when the
2583 count reaches a particular value. Trace state variables share the
2584 $-syntax of GDB convenience variables, and can appear in both
2585 tracepoint actions and condition expressions. Use the "tvariable"
2586 command to create, and "info tvariables" to view; see "Trace State
2587 Variables" in the manual for more detail.
2591 GDB now includes an option for defining fast tracepoints, which
2592 targets may implement more efficiently, such as by installing a jump
2593 into the target agent rather than a trap instruction. The resulting
2594 speedup can be by two orders of magnitude or more, although the
2595 tradeoff is that some program locations on some target architectures
2596 might not allow fast tracepoint installation, for instance if the
2597 instruction to be replaced is shorter than the jump. To request a
2598 fast tracepoint, use the "ftrace" command, with syntax identical to
2599 the regular trace command.
2601 ** Disconnected tracing
2603 It is now possible to detach GDB from the target while it is running
2604 a trace experiment, then reconnect later to see how the experiment
2605 is going. In addition, a new variable disconnected-tracing lets you
2606 tell the target agent whether to continue running a trace if the
2607 connection is lost unexpectedly.
2611 GDB now has the ability to save the trace buffer into a file, and
2612 then use that file as a target, similarly to you can do with
2613 corefiles. You can select trace frames, print data that was
2614 collected in them, and use tstatus to display the state of the
2615 tracing run at the moment that it was saved. To create a trace
2616 file, use "tsave <filename>", and to use it, do "target tfile
2619 ** Circular trace buffer
2621 You can ask the target agent to handle the trace buffer as a
2622 circular buffer, discarding the oldest trace frames to make room for
2623 newer ones, by setting circular-trace-buffer to on. This feature may
2624 not be available for all target agents.
2629 The disassemble command, when invoked with two arguments, now requires
2630 the arguments to be comma-separated.
2633 The info variables command now displays variable definitions. Files
2634 which only declare a variable are not shown.
2637 The source command is now capable of sourcing Python scripts.
2638 This feature is dependent on the debugger being build with Python
2641 Related to this enhancement is also the introduction of a new command
2642 "set script-extension" (see below).
2644 * New commands (for set/show, see "New options" below)
2646 record save [<FILENAME>]
2647 Save a file (in core file format) containing the process record
2648 execution log for replay debugging at a later time.
2650 record restore <FILENAME>
2651 Restore the process record execution log that was saved at an
2652 earlier time, for replay debugging.
2654 add-inferior [-copies <N>] [-exec <FILENAME>]
2657 clone-inferior [-copies <N>] [ID]
2658 Make a new inferior ready to execute the same program another
2659 inferior has loaded.
2664 maint info program-spaces
2665 List the program spaces loaded into GDB.
2667 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2668 show remote interrupt-sequence
2669 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2670 as the sequence to the remote target in order to interrupt the execution.
2671 Ctrl-C is a default. Some system prefers BREAK which is high level of
2672 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2673 Magic SysRq g. It is BREAK signal and character 'g'.
2675 set remote interrupt-on-connect [on | off]
2676 show remote interrupt-on-connect
2677 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2678 remote target when gdb connects to it. This is needed when you debug
2681 set remotebreak [on | off]
2683 Deprecated. Use "set/show remote interrupt-sequence" instead.
2685 tvariable $NAME [ = EXP ]
2686 Create or modify a trace state variable.
2689 List trace state variables and their values.
2691 delete tvariable $NAME ...
2692 Delete one or more trace state variables.
2695 Evaluate the given expressions without collecting anything into the
2696 trace buffer. (Valid in tracepoint actions only.)
2698 ftrace FN / FILE:LINE / *ADDR
2699 Define a fast tracepoint at the given function, line, or address.
2701 * New expression syntax
2703 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2704 GDB now parses 0b101010 identically with 42.
2708 set follow-exec-mode new|same
2709 show follow-exec-mode
2710 Control whether GDB reuses the same inferior across an exec call or
2711 creates a new one. This is useful to be able to restart the old
2712 executable after the inferior having done an exec call.
2714 set default-collect EXPR, ...
2715 show default-collect
2716 Define a list of expressions to be collected at each tracepoint.
2717 This is a useful way to ensure essential items are not overlooked,
2718 such as registers or a critical global variable.
2720 set disconnected-tracing
2721 show disconnected-tracing
2722 If set to 1, the target is instructed to continue tracing if it
2723 loses its connection to GDB. If 0, the target is to stop tracing
2726 set circular-trace-buffer
2727 show circular-trace-buffer
2728 If set to on, the target is instructed to use a circular trace buffer
2729 and discard the oldest trace frames instead of stopping the trace due
2730 to a full trace buffer. If set to off, the trace stops when the buffer
2731 fills up. Some targets may not support this.
2733 set script-extension off|soft|strict
2734 show script-extension
2735 If set to "off", the debugger does not perform any script language
2736 recognition, and all sourced files are assumed to be GDB scripts.
2737 If set to "soft" (the default), files are sourced according to
2738 filename extension, falling back to GDB scripts if the first
2740 If set to "strict", files are sourced according to filename extension.
2742 set ada trust-PAD-over-XVS on|off
2743 show ada trust-PAD-over-XVS
2744 If off, activate a workaround against a bug in the debugging information
2745 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2746 the GCC sources for more information about the GNAT encoding and
2747 PAD types in particular). It is always safe to set this option to
2748 off, but this introduces a slight performance penalty. The default
2751 * Python API Improvements
2753 ** GDB provides the new class gdb.LazyString. This is useful in
2754 some pretty-printing cases. The new method gdb.Value.lazy_string
2755 provides a simple way to create objects of this type.
2757 ** The fields returned by gdb.Type.fields now have an
2758 `is_base_class' attribute.
2760 ** The new method gdb.Type.range returns the range of an array type.
2762 ** The new method gdb.parse_and_eval can be used to parse and
2763 evaluate an expression.
2765 * New remote packets
2768 Define a trace state variable.
2771 Get the current value of a trace state variable.
2774 Set desired tracing behavior upon disconnection.
2777 Set the trace buffer to be linear or circular.
2780 Get data about the tracepoints currently in use.
2784 Process record now works correctly with hardware watchpoints.
2786 Multiple bug fixes have been made to the mips-irix port, making it
2787 much more reliable. In particular:
2788 - Debugging threaded applications is now possible again. Previously,
2789 GDB would hang while starting the program, or while waiting for
2790 the program to stop at a breakpoint.
2791 - Attaching to a running process no longer hangs.
2792 - An error occurring while loading a core file has been fixed.
2793 - Changing the value of the PC register now works again. This fixes
2794 problems observed when using the "jump" command, or when calling
2795 a function from GDB, or even when assigning a new value to $pc.
2796 - With the "finish" and "return" commands, the return value for functions
2797 returning a small array is now correctly printed.
2798 - It is now possible to break on shared library code which gets executed
2799 during a shared library init phase (code executed while executing
2800 their .init section). Previously, the breakpoint would have no effect.
2801 - GDB is now able to backtrace through the signal handler for
2802 non-threaded programs.
2804 PIE (Position Independent Executable) programs debugging is now supported.
2805 This includes debugging execution of PIC (Position Independent Code) shared
2806 libraries although for that, it should be possible to run such libraries as an
2809 *** Changes in GDB 7.0
2811 * GDB now has an interface for JIT compilation. Applications that
2812 dynamically generate code can create symbol files in memory and register
2813 them with GDB. For users, the feature should work transparently, and
2814 for JIT developers, the interface is documented in the GDB manual in the
2815 "JIT Compilation Interface" chapter.
2817 * Tracepoints may now be conditional. The syntax is as for
2818 breakpoints; either an "if" clause appended to the "trace" command,
2819 or the "condition" command is available. GDB sends the condition to
2820 the target for evaluation using the same bytecode format as is used
2821 for tracepoint actions.
2823 * The disassemble command now supports: an optional /r modifier, print the
2824 raw instructions in hex as well as in symbolic form, and an optional /m
2825 modifier to print mixed source+assembly.
2827 * Process record and replay
2829 In a architecture environment that supports ``process record and
2830 replay'', ``process record and replay'' target can record a log of
2831 the process execution, and replay it with both forward and reverse
2834 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2835 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2836 set execution-direction {forward|reverse}, for targets that support
2839 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2840 feature is available with a native GDB running on kernel version
2843 * GDB now has support for multi-byte and wide character sets on the
2844 target. Strings whose character type is wchar_t, char16_t, or
2845 char32_t are now correctly printed. GDB supports wide- and unicode-
2846 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2847 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2848 `printf'. This feature requires iconv to work properly; if your
2849 system does not have a working iconv, GDB can use GNU libiconv. See
2850 the installation instructions for more information.
2852 * GDB now supports automatic retrieval of shared library files from
2853 remote targets. To use this feature, specify a system root that begins
2854 with the `remote:' prefix, either via the `set sysroot' command or via
2855 the `--with-sysroot' configure-time option.
2857 * "info sharedlibrary" now takes an optional regex of libraries to show,
2858 and it now reports if a shared library has no debugging information.
2860 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2861 now complete on file names.
2863 * When completing in expressions, gdb will attempt to limit
2864 completions to allowable structure or union fields, where appropriate.
2865 For instance, consider:
2867 # struct example { int f1; double f2; };
2868 # struct example variable;
2871 If the user types TAB at the end of this command line, the available
2872 completions will be "f1" and "f2".
2874 * Inlined functions are now supported. They show up in backtraces, and
2875 the "step", "next", and "finish" commands handle them automatically.
2877 * GDB now supports the token-splicing (##) and stringification (#)
2878 operators when expanding macros. It also supports variable-arity
2881 * GDB now supports inspecting extra signal information, exported by
2882 the new $_siginfo convenience variable. The feature is currently
2883 implemented on linux ARM, i386 and amd64.
2885 * GDB can now display the VFP floating point registers and NEON vector
2886 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2887 can provide these registers (requires Linux 2.6.30 or later). Remote
2888 and simulator targets may also provide them.
2890 * New remote packets
2893 Search memory for a sequence of bytes.
2896 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2897 operation over reliable transport links. Use of this packet is
2898 controlled by the `set remote noack-packet' command.
2901 Kill the process with the specified process ID. Use this in preference
2902 to `k' when multiprocess protocol extensions are supported.
2905 Obtains additional operating system information
2909 Read or write additional signal information.
2911 * Removed remote protocol undocumented extension
2913 An undocumented extension to the remote protocol's `S' stop reply
2914 packet that permited the stub to pass a process id was removed.
2915 Remote servers should use the `T' stop reply packet instead.
2917 * GDB now supports multiple function calling conventions according to the
2918 DWARF-2 DW_AT_calling_convention function attribute.
2920 * The SH target utilizes the aforementioned change to distinguish between gcc
2921 and Renesas calling convention. It also adds the new CLI commands
2922 `set/show sh calling-convention'.
2924 * GDB can now read compressed debug sections, as produced by GNU gold
2925 with the --compress-debug-sections=zlib flag.
2927 * 64-bit core files are now supported on AIX.
2929 * Thread switching is now supported on Tru64.
2931 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2932 which will be allocated using malloc later in program execution.
2934 * The qXfer:libraries:read remote procotol packet now allows passing a
2935 list of section offsets.
2937 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2938 conditions handling signals delivered during attach or thread creation
2939 have also been fixed.
2941 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2942 From the user's standpoint, all unqualified instances of True and False
2943 are treated as the standard definitions, regardless of context.
2945 * GDB now parses C++ symbol and type names more flexibly. For
2948 template<typename T> class C { };
2951 GDB will now correctly handle all of:
2953 ptype C<char const *>
2954 ptype C<char const*>
2955 ptype C<const char *>
2956 ptype C<const char*>
2958 * New features in the GDB remote stub, gdbserver
2960 - The "--wrapper" command-line argument tells gdbserver to use a
2961 wrapper program to launch programs for debugging.
2963 - On PowerPC and S/390 targets, it is now possible to use a single
2964 gdbserver executable to debug both 32-bit and 64-bit programs.
2965 (This requires gdbserver itself to be built as a 64-bit executable.)
2967 - gdbserver uses the new noack protocol mode for TCP connections to
2968 reduce communications latency, if also supported and enabled in GDB.
2970 - Support for the sparc64-linux-gnu target is now included in
2973 - The amd64-linux build of gdbserver now supports debugging both
2974 32-bit and 64-bit programs.
2976 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2977 now support hardware watchpoints, and will use them automatically
2982 GDB now has support for scripting using Python. Whether this is
2983 available is determined at configure time.
2985 New GDB commands can now be written in Python.
2987 * Ada tasking support
2989 Ada tasks can now be inspected in GDB. The following commands have
2993 Print the list of Ada tasks.
2995 Print detailed information about task number N.
2997 Print the task number of the current task.
2999 Switch the context of debugging to task number N.
3001 * Support for user-defined prefixed commands. The "define" command can
3002 add new commands to existing prefixes, e.g. "target".
3004 * Multi-inferior, multi-process debugging.
3006 GDB now has generalized support for multi-inferior debugging. See
3007 "Debugging Multiple Inferiors" in the manual for more information.
3008 Although availability still depends on target support, the command
3009 set is more uniform now. The GNU/Linux specific multi-forks support
3010 has been migrated to this new framework. This implied some user
3011 visible changes; see "New commands" and also "Removed commands"
3014 * Target descriptions can now describe the target OS ABI. See the
3015 "Target Description Format" section in the user manual for more
3018 * Target descriptions can now describe "compatible" architectures
3019 to indicate that the target can execute applications for a different
3020 architecture in addition to those for the main target architecture.
3021 See the "Target Description Format" section in the user manual for
3024 * Multi-architecture debugging.
3026 GDB now includes general supports for debugging applications on
3027 hybrid systems that use more than one single processor architecture
3028 at the same time. Each such hybrid architecture still requires
3029 specific support to be added. The only hybrid architecture supported
3030 in this version of GDB is the Cell Broadband Engine.
3032 * GDB now supports integrated debugging of Cell/B.E. applications that
3033 use both the PPU and SPU architectures. To enable support for hybrid
3034 Cell/B.E. debugging, you need to configure GDB to support both the
3035 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3036 --enable-targets configure option.
3038 * Non-stop mode debugging.
3040 For some targets, GDB now supports an optional mode of operation in
3041 which you can examine stopped threads while other threads continue
3042 to execute freely. This is referred to as non-stop mode, with the
3043 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3044 section in the user manual for more information.
3046 To be able to support remote non-stop debugging, a remote stub needs
3047 to implement the non-stop mode remote protocol extensions, as
3048 described in the "Remote Non-Stop" section of the user manual. The
3049 GDB remote stub, gdbserver, has been adjusted to support these
3050 extensions on linux targets.
3052 * New commands (for set/show, see "New options" below)
3054 catch syscall [NAME(S) | NUMBER(S)]
3055 Catch system calls. Arguments, which should be names of system
3056 calls or their numbers, mean catch only those syscalls. Without
3057 arguments, every syscall will be caught. When the inferior issues
3058 any of the specified syscalls, GDB will stop and announce the system
3059 call, both when it is called and when its call returns. This
3060 feature is currently available with a native GDB running on the
3061 Linux Kernel, under the following architectures: x86, x86_64,
3062 PowerPC and PowerPC64.
3064 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3066 Search memory for a sequence of bytes.
3068 maint set python print-stack
3069 maint show python print-stack
3070 Show a stack trace when an error is encountered in a Python script.
3073 Invoke CODE by passing it to the Python interpreter.
3078 These allow macros to be defined, undefined, and listed
3082 Show operating system information about processes.
3085 List the inferiors currently under GDB's control.
3088 Switch focus to inferior number NUM.
3091 Detach from inferior number NUM.
3094 Kill inferior number NUM.
3098 set spu stop-on-load
3099 show spu stop-on-load
3100 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3102 set spu auto-flush-cache
3103 show spu auto-flush-cache
3104 Control whether to automatically flush the software-managed cache
3105 during Cell/B.E. debugging.
3107 set sh calling-convention
3108 show sh calling-convention
3109 Control the calling convention used when calling SH target functions.
3112 show debug timestamp
3113 Control display of timestamps with GDB debugging output.
3115 set disassemble-next-line
3116 show disassemble-next-line
3117 Control display of disassembled source lines or instructions when
3120 set remote noack-packet
3121 show remote noack-packet
3122 Set/show the use of remote protocol QStartNoAckMode packet. See above
3123 under "New remote packets."
3125 set remote query-attached-packet
3126 show remote query-attached-packet
3127 Control use of remote protocol `qAttached' (query-attached) packet.
3129 set remote read-siginfo-object
3130 show remote read-siginfo-object
3131 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3134 set remote write-siginfo-object
3135 show remote write-siginfo-object
3136 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3139 set remote reverse-continue
3140 show remote reverse-continue
3141 Control use of remote protocol 'bc' (reverse-continue) packet.
3143 set remote reverse-step
3144 show remote reverse-step
3145 Control use of remote protocol 'bs' (reverse-step) packet.
3147 set displaced-stepping
3148 show displaced-stepping
3149 Control displaced stepping mode. Displaced stepping is a way to
3150 single-step over breakpoints without removing them from the debuggee.
3151 Also known as "out-of-line single-stepping".
3154 show debug displaced
3155 Control display of debugging info for displaced stepping.
3157 maint set internal-error
3158 maint show internal-error
3159 Control what GDB does when an internal error is detected.
3161 maint set internal-warning
3162 maint show internal-warning
3163 Control what GDB does when an internal warning is detected.
3168 Use a wrapper program to launch programs for debugging.
3170 set multiple-symbols (all|ask|cancel)
3171 show multiple-symbols
3172 The value of this variable can be changed to adjust the debugger behavior
3173 when an expression or a breakpoint location contains an ambiguous symbol
3174 name (an overloaded function name, for instance).
3176 set breakpoint always-inserted
3177 show breakpoint always-inserted
3178 Keep breakpoints always inserted in the target, as opposed to inserting
3179 them when resuming the target, and removing them when the target stops.
3180 This option can improve debugger performance on slow remote targets.
3182 set arm fallback-mode (arm|thumb|auto)
3183 show arm fallback-mode
3184 set arm force-mode (arm|thumb|auto)
3186 These commands control how ARM GDB determines whether instructions
3187 are ARM or Thumb. The default for both settings is auto, which uses
3188 the current CPSR value for instructions without symbols; previous
3189 versions of GDB behaved as if "set arm fallback-mode arm".
3191 set disable-randomization
3192 show disable-randomization
3193 Standalone programs run with the virtual address space randomization enabled
3194 by default on some platforms. This option keeps the addresses stable across
3195 multiple debugging sessions.
3199 Control whether other threads are stopped or not when some thread hits
3204 Requests that asynchronous execution is enabled in the target, if available.
3205 In this case, it's possible to resume target in the background, and interact
3206 with GDB while the target is running. "show target-async" displays the
3207 current state of asynchronous execution of the target.
3209 set target-wide-charset
3210 show target-wide-charset
3211 The target-wide-charset is the name of the character set that GDB
3212 uses when printing characters whose type is wchar_t.
3214 set tcp auto-retry (on|off)
3216 set tcp connect-timeout
3217 show tcp connect-timeout
3218 These commands allow GDB to retry failed TCP connections to a remote stub
3219 with a specified timeout period; this is useful if the stub is launched
3220 in parallel with GDB but may not be ready to accept connections immediately.
3222 set libthread-db-search-path
3223 show libthread-db-search-path
3224 Control list of directories which GDB will search for appropriate
3227 set schedule-multiple (on|off)
3228 show schedule-multiple
3229 Allow GDB to resume all threads of all processes or only threads of
3230 the current process.
3234 Use more aggressive caching for accesses to the stack. This improves
3235 performance of remote debugging (particularly backtraces) without
3236 affecting correctness.
3238 set interactive-mode (on|off|auto)
3239 show interactive-mode
3240 Control whether GDB runs in interactive mode (on) or not (off).
3241 When in interactive mode, GDB waits for the user to answer all
3242 queries. Otherwise, GDB does not wait and assumes the default
3243 answer. When set to auto (the default), GDB determines which
3244 mode to use based on the stdin settings.
3249 For program forks, this is replaced by the new more generic `info
3250 inferiors' command. To list checkpoints, you can still use the
3251 `info checkpoints' command, which was an alias for the `info forks'
3255 Replaced by the new `inferior' command. To switch between
3256 checkpoints, you can still use the `restart' command, which was an
3257 alias for the `fork' command.
3260 This is removed, since some targets don't have a notion of
3261 processes. To switch between processes, you can still use the
3262 `inferior' command using GDB's own inferior number.
3265 For program forks, this is replaced by the new more generic `kill
3266 inferior' command. To delete a checkpoint, you can still use the
3267 `delete checkpoint' command, which was an alias for the `delete
3271 For program forks, this is replaced by the new more generic `detach
3272 inferior' command. To detach a checkpoint, you can still use the
3273 `detach checkpoint' command, which was an alias for the `detach
3276 * New native configurations
3278 x86/x86_64 Darwin i[34567]86-*-darwin*
3280 x86_64 MinGW x86_64-*-mingw*
3284 Lattice Mico32 lm32-*
3285 x86 DICOS i[34567]86-*-dicos*
3286 x86_64 DICOS x86_64-*-dicos*
3289 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3290 (mingw32ce) debugging.
3296 These commands were actually not implemented on any target.
3298 *** Changes in GDB 6.8
3300 * New native configurations
3302 NetBSD/hppa hppa*-*netbsd*
3303 Xtensa GNU/Linux xtensa*-*-linux*
3307 NetBSD/hppa hppa*-*-netbsd*
3308 Xtensa GNU/Lunux xtensa*-*-linux*
3310 * Change in command line behavior -- corefiles vs. process ids.
3312 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3313 attaching to process NUMBER fails, GDB no longer attempts to open a
3314 core file named NUMBER. Attaching to a program using the -c option
3315 is no longer supported. Instead, use the '-p' or '--pid' options.
3317 * GDB can now be built as a native debugger for debugging Windows x86
3318 (mingw32) Portable Executable (PE) programs.
3320 * Pending breakpoints no longer change their number when their address
3323 * GDB now supports breakpoints with multiple locations,
3324 including breakpoints on C++ constructors, inside C++ templates,
3325 and in inlined functions.
3327 * GDB's ability to debug optimized code has been improved. GDB more
3328 accurately identifies function bodies and lexical blocks that occupy
3329 more than one contiguous range of addresses.
3331 * Target descriptions can now describe registers for PowerPC.
3333 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3334 registers on PowerPC targets.
3336 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3337 targets even when the libthread_db library is not available.
3339 * The GDB remote stub, gdbserver, now supports the new file transfer
3340 commands (remote put, remote get, and remote delete).
3342 * The GDB remote stub, gdbserver, now supports run and attach in
3343 extended-remote mode.
3345 * hppa*64*-*-hpux11* target broken
3346 The debugger is unable to start a program and fails with the following
3347 error: "Error trying to get information about dynamic linker".
3348 The gdb-6.7 release is also affected.
3350 * GDB now supports the --enable-targets= configure option to allow
3351 building a single GDB executable that supports multiple remote
3352 target architectures.
3354 * GDB now supports debugging C and C++ programs which use the
3355 Decimal Floating Point extension. In addition, the PowerPC target
3356 now has a set of pseudo-registers to inspect decimal float values
3357 stored in two consecutive float registers.
3359 * The -break-insert MI command can optionally create pending
3362 * Improved support for debugging Ada
3363 Many improvements to the Ada language support have been made. These
3365 - Better support for Ada2005 interface types
3366 - Improved handling of arrays and slices in general
3367 - Better support for Taft-amendment types
3368 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3370 - Improved command completion in Ada
3373 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3378 set print frame-arguments (all|scalars|none)
3379 show print frame-arguments
3380 The value of this variable can be changed to control which argument
3381 values should be printed by the debugger when displaying a frame.
3386 Transfer files to and from a remote target, and delete remote files.
3393 Transfer files to and from a remote target, and delete remote files.
3395 * New remote packets
3402 Open, close, read, write, and delete files on the remote system.
3405 Attach to an existing process on the remote system, in extended-remote
3409 Run a new process on the remote system, in extended-remote mode.
3411 *** Changes in GDB 6.7
3413 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3414 bfd, libiberty and opcodes, as revealed by static analysis donated by
3415 Coverity, Inc. (http://scan.coverity.com).
3417 * When looking up multiply-defined global symbols, GDB will now prefer the
3418 symbol definition in the current shared library if it was built using the
3419 -Bsymbolic linker option.
3421 * When the Text User Interface (TUI) is not configured, GDB will now
3422 recognize the -tui command-line option and print a message that the TUI
3425 * The GDB remote stub, gdbserver, now has lower overhead for high
3426 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3428 * GDB for MIPS targets now autodetects whether a remote target provides
3429 32-bit or 64-bit register values.
3431 * Support for C++ member pointers has been improved.
3433 * GDB now understands XML target descriptions, which specify the
3434 target's overall architecture. GDB can read a description from
3435 a local file or over the remote serial protocol.
3437 * Vectors of single-byte data use a new integer type which is not
3438 automatically displayed as character or string data.
3440 * The /s format now works with the print command. It displays
3441 arrays of single-byte integers and pointers to single-byte integers
3444 * Target descriptions can now describe target-specific registers,
3445 for architectures which have implemented the support (currently
3446 only ARM, M68K, and MIPS).
3448 * GDB and the GDB remote stub, gdbserver, now support the XScale
3451 * The GDB remote stub, gdbserver, has been updated to support
3452 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3453 has been rewritten to use the standard GDB remote protocol.
3455 * GDB can now step into C++ functions which are called through thunks.
3457 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3459 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3460 layout. It also supports a TextSeg= and DataSeg= response when only
3461 segment base addresses (rather than offsets) are available.
3463 * The /i format now outputs any trailing branch delay slot instructions
3464 immediately following the last instruction within the count specified.
3466 * The GDB remote protocol "T" stop reply packet now supports a
3467 "library" response. Combined with the new "qXfer:libraries:read"
3468 packet, this response allows GDB to debug shared libraries on targets
3469 where the operating system manages the list of loaded libraries (e.g.
3470 Windows and SymbianOS).
3472 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3473 (DLLs) on Windows and Windows CE targets.
3475 * GDB now supports a faster verification that a .debug file matches its binary
3476 according to its build-id signature, if the signature is present.
3482 Enable or disable hardware flow control (RTS/CTS) on the serial port
3483 when debugging using remote targets.
3485 set mem inaccessible-by-default
3486 show mem inaccessible-by-default
3487 If the target supplies a memory map, for instance via the remote
3488 protocol's "qXfer:memory-map:read" packet, setting this variable
3489 prevents GDB from accessing memory outside the memory map. This
3490 is useful for targets with memory mapped registers or which react
3491 badly to accesses of unmapped address space.
3493 set breakpoint auto-hw
3494 show breakpoint auto-hw
3495 If the target supplies a memory map, for instance via the remote
3496 protocol's "qXfer:memory-map:read" packet, setting this variable
3497 lets GDB use hardware breakpoints automatically for memory regions
3498 where it can not use software breakpoints. This covers both the
3499 "break" command and internal breakpoints used for other commands
3500 including "next" and "finish".
3503 catch exception unhandled
3504 Stop the program execution when Ada exceptions are raised.
3507 Stop the program execution when an Ada assertion failed.
3511 Set an alternate system root for target files. This is a more
3512 general version of "set solib-absolute-prefix", which is now
3513 an alias to "set sysroot".
3516 Provide extended SPU facility status information. This set of
3517 commands is available only when debugging the Cell/B.E. SPU
3520 * New native configurations
3522 OpenBSD/sh sh*-*openbsd*
3525 unset tdesc filename
3527 Use the specified local file as an XML target description, and do
3528 not query the target for its built-in description.
3532 OpenBSD/sh sh*-*-openbsd*
3533 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3534 Toshiba Media Processor mep-elf
3536 * New remote packets
3539 Ignore the specified signals; pass them directly to the debugged program
3540 without stopping other threads or reporting them to GDB.
3542 qXfer:features:read:
3543 Read an XML target description from the target, which describes its
3548 Read or write contents of an spufs file on the target system. These
3549 packets are available only on the Cell/B.E. SPU architecture.
3551 qXfer:libraries:read:
3552 Report the loaded shared libraries. Combined with new "T" packet
3553 response, this packet allows GDB to debug shared libraries on
3554 targets where the operating system manages the list of loaded
3555 libraries (e.g. Windows and SymbianOS).
3559 Support for these obsolete configurations has been removed.
3567 i[34567]86-*-lynxos*
3568 i[34567]86-*-netware*
3569 i[34567]86-*-sco3.2v5*
3570 i[34567]86-*-sco3.2v4*
3572 i[34567]86-*-sysv4.2*
3575 i[34567]86-*-unixware2*
3576 i[34567]86-*-unixware*
3585 * Other removed features
3592 Various m68k-only ROM monitors.
3599 Various Renesas ROM monitors and debugging interfaces for SH and
3604 Support for a Macraigor serial interface to on-chip debugging.
3605 GDB does not directly support the newer parallel or USB
3610 A debug information format. The predecessor to DWARF 2 and
3611 DWARF 3, which are still supported.
3613 Support for the HP aCC compiler on HP-UX/PA-RISC
3615 SOM-encapsulated symbolic debugging information, automatic
3616 invocation of pxdb, and the aCC custom C++ ABI. This does not
3617 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3618 with aCC can still be debugged on an assembly level.
3620 MIPS ".pdr" sections
3622 A MIPS-specific format used to describe stack frame layout
3623 in debugging information.
3627 GDB could work with an older version of Guile to debug
3628 the interpreter and Scheme programs running in it.
3630 set mips stack-arg-size
3631 set mips saved-gpreg-size
3633 Use "set mips abi" to control parameter passing for MIPS.
3635 *** Changes in GDB 6.6
3640 Cell Broadband Engine SPU spu-elf
3642 * GDB can now be configured as a cross-debugger targeting native Windows
3643 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3644 running on a Windows system over TCP/IP to debug Windows programs.
3646 * The GDB remote stub, gdbserver, has been updated to support Windows and
3647 Cygwin debugging. Both single-threaded and multi-threaded programs are
3650 * The "set trust-readonly-sections" command works again. This command was
3651 broken in GDB 6.3, 6.4, and 6.5.
3653 * The "load" command now supports writing to flash memory, if the remote
3654 stub provides the required support.
3656 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3657 longer requires symbolic debug information (e.g. DWARF-2).
3662 unset substitute-path
3663 show substitute-path
3664 Manage a list of substitution rules that GDB uses to rewrite the name
3665 of the directories where the sources are located. This can be useful
3666 for instance when the sources were moved to a different location
3667 between compilation and debugging.
3671 Print each CLI command as it is executed. Each command is prefixed with
3672 a number of `+' symbols representing the nesting depth.
3673 The source command now has a `-v' option to enable the same feature.
3677 The ARM Demon monitor support (RDP protocol, "target rdp").
3679 Kernel Object Display, an embedded debugging feature which only worked with
3680 an obsolete version of Cisco IOS.
3682 The 'set download-write-size' and 'show download-write-size' commands.
3684 * New remote packets
3687 Tell a stub about GDB client features, and request remote target features.
3688 The first feature implemented is PacketSize, which allows the target to
3689 specify the size of packets it can handle - to minimize the number of
3690 packets required and improve performance when connected to a remote
3694 Fetch an OS auxilliary vector from the remote stub. This packet is a
3695 more efficient replacement for qPart:auxv:read.
3697 qXfer:memory-map:read:
3698 Fetch a memory map from the remote stub, including information about
3699 RAM, ROM, and flash memory devices.
3704 Erase and program a flash memory device.
3706 * Removed remote packets
3709 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3710 used it, and only gdbserver implemented it.
3712 *** Changes in GDB 6.5
3716 Renesas M32C/M16C m32c-elf
3718 Morpho Technologies ms1 ms1-elf
3722 init-if-undefined Initialize a convenience variable, but
3723 only if it doesn't already have a value.
3725 The following commands are presently only implemented for native GNU/Linux:
3727 checkpoint Save a snapshot of the program state.
3729 restart <n> Return the program state to a
3730 previously saved state.
3732 info checkpoints List currently saved checkpoints.
3734 delete-checkpoint <n> Delete a previously saved checkpoint.
3736 set|show detach-on-fork Tell gdb whether to detach from a newly
3737 forked process, or to keep debugging it.
3739 info forks List forks of the user program that
3740 are available to be debugged.
3742 fork <n> Switch to debugging one of several
3743 forks of the user program that are
3744 available to be debugged.
3746 delete-fork <n> Delete a fork from the list of forks
3747 that are available to be debugged (and
3748 kill the forked process).
3750 detach-fork <n> Delete a fork from the list of forks
3751 that are available to be debugged (and
3752 allow the process to continue).
3756 Morpho Technologies ms2 ms1-elf
3758 * Improved Windows host support
3760 GDB now builds as a cross debugger hosted on i686-mingw32, including
3761 native console support, and remote communications using either
3762 network sockets or serial ports.
3764 * Improved Modula-2 language support
3766 GDB can now print most types in the Modula-2 syntax. This includes:
3767 basic types, set types, record types, enumerated types, range types,
3768 pointer types and ARRAY types. Procedure var parameters are correctly
3769 printed and hexadecimal addresses and character constants are also
3770 written in the Modula-2 syntax. Best results can be obtained by using
3771 GNU Modula-2 together with the -gdwarf-2 command line option.
3775 The ARM rdi-share module.
3777 The Netware NLM debug server.
3779 *** Changes in GDB 6.4
3781 * New native configurations
3783 OpenBSD/arm arm*-*-openbsd*
3784 OpenBSD/mips64 mips64-*-openbsd*
3788 Morpho Technologies ms1 ms1-elf
3790 * New command line options
3792 --batch-silent As for --batch, but totally silent.
3793 --return-child-result The debugger will exist with the same value
3794 the child (debugged) program exited with.
3795 --eval-command COMMAND, -ex COMMAND
3796 Execute a single GDB CLI command. This may be
3797 specified multiple times and in conjunction
3798 with the --command (-x) option.
3800 * Deprecated commands removed
3802 The following commands, that were deprecated in 2000, have been
3806 set|show arm disassembly-flavor set|show arm disassembler
3807 othernames set arm disassembler
3808 set|show remotedebug set|show debug remote
3809 set|show archdebug set|show debug arch
3810 set|show eventdebug set|show debug event
3813 * New BSD user-level threads support
3815 It is now possible to debug programs using the user-level threads
3816 library on OpenBSD and FreeBSD. Currently supported (target)
3819 FreeBSD/amd64 x86_64-*-freebsd*
3820 FreeBSD/i386 i386-*-freebsd*
3821 OpenBSD/i386 i386-*-openbsd*
3823 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3824 are not yet supported.
3826 * New support for Matsushita MN10300 w/sim added
3827 (Work in progress). mn10300-elf.
3829 * REMOVED configurations and files
3831 VxWorks and the XDR protocol *-*-vxworks
3832 Motorola MCORE mcore-*-*
3833 National Semiconductor NS32000 ns32k-*-*
3835 * New "set print array-indexes" command
3837 After turning this setting "on", GDB prints the index of each element
3838 when displaying arrays. The default is "off" to preserve the previous
3841 * VAX floating point support
3843 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3845 * User-defined command support
3847 In addition to using $arg0..$arg9 for argument passing, it is now possible
3848 to use $argc to determine now many arguments have been passed. See the
3849 section on user-defined commands in the user manual for more information.
3851 *** Changes in GDB 6.3:
3853 * New command line option
3855 GDB now accepts -l followed by a number to set the timeout for remote
3858 * GDB works with GCC -feliminate-dwarf2-dups
3860 GDB now supports a more compact representation of DWARF-2 debug
3861 information using DW_FORM_ref_addr references. These are produced
3862 by GCC with the option -feliminate-dwarf2-dups and also by some
3863 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3864 to use -feliminate-dwarf2-dups.
3866 * Internationalization
3868 When supported by the host system, GDB will be built with
3869 internationalization (libintl). The task of marking up the sources is
3870 continued, we're looking forward to our first translation.
3874 Initial support for debugging programs compiled with the GNAT
3875 implementation of the Ada programming language has been integrated
3876 into GDB. In this release, support is limited to expression evaluation.
3878 * New native configurations
3880 GNU/Linux/m32r m32r-*-linux-gnu
3884 GDB's remote protocol now includes support for the 'p' packet. This
3885 packet is used to fetch individual registers from a remote inferior.
3887 * END-OF-LIFE registers[] compatibility module
3889 GDB's internal register infrastructure has been completely rewritten.
3890 The new infrastructure making possible the implementation of key new
3891 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3894 GDB 6.3 will be the last release to include the the registers[]
3895 compatibility module that allowed out-of-date configurations to
3896 continue to work. This change directly impacts the following
3906 powerpc bdm protocol
3908 Unless there is activity to revive these configurations, they will be
3909 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3911 * OBSOLETE configurations and files
3913 Configurations that have been declared obsolete in this release have
3914 been commented out. Unless there is activity to revive these
3915 configurations, the next release of GDB will have their sources
3916 permanently REMOVED.
3925 *** Changes in GDB 6.2.1:
3927 * MIPS `break main; run' gave an heuristic-fence-post warning
3929 When attempting to run even a simple program, a warning about
3930 heuristic-fence-post being hit would be reported. This problem has
3933 * MIPS IRIX 'long double' crashed GDB
3935 When examining a long double variable, GDB would get a segmentation
3936 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3937 IRIX long double values).
3941 A bug in the VAX stack code was causing problems with the "next"
3942 command. This problem has been fixed.
3944 *** Changes in GDB 6.2:
3946 * Fix for ``many threads''
3948 On GNU/Linux systems that use the NPTL threads library, a program
3949 rapidly creating and deleting threads would confuse GDB leading to the
3952 ptrace: No such process.
3953 thread_db_get_info: cannot get thread info: generic error
3955 This problem has been fixed.
3957 * "-async" and "-noasync" options removed.
3959 Support for the broken "-noasync" option has been removed (it caused
3962 * New ``start'' command.
3964 This command runs the program until the begining of the main procedure.
3966 * New BSD Kernel Data Access Library (libkvm) interface
3968 Using ``target kvm'' it is now possible to debug kernel core dumps and
3969 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3970 platforms. Currently supported (native-only) configurations are:
3972 FreeBSD/amd64 x86_64-*-freebsd*
3973 FreeBSD/i386 i?86-*-freebsd*
3974 NetBSD/i386 i?86-*-netbsd*
3975 NetBSD/m68k m68*-*-netbsd*
3976 NetBSD/sparc sparc-*-netbsd*
3977 OpenBSD/amd64 x86_64-*-openbsd*
3978 OpenBSD/i386 i?86-*-openbsd*
3979 OpenBSD/m68k m68*-openbsd*
3980 OpenBSD/sparc sparc-*-openbsd*
3982 * Signal trampoline code overhauled
3984 Many generic problems with GDB's signal handling code have been fixed.
3985 These include: backtraces through non-contiguous stacks; recognition
3986 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3987 call; backtrace through a signal trampoline; step into and out of
3988 signal handlers; and single-stepping in the signal trampoline.
3990 Please note that kernel bugs are a limiting factor here. These
3991 features have been shown to work on an s390 GNU/Linux system that
3992 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3994 * Cygwin support for DWARF 2 added.
3996 * New native configurations
3998 GNU/Linux/hppa hppa*-*-linux*
3999 OpenBSD/hppa hppa*-*-openbsd*
4000 OpenBSD/m68k m68*-*-openbsd*
4001 OpenBSD/m88k m88*-*-openbsd*
4002 OpenBSD/powerpc powerpc-*-openbsd*
4003 NetBSD/vax vax-*-netbsd*
4004 OpenBSD/vax vax-*-openbsd*
4006 * END-OF-LIFE frame compatibility module
4008 GDB's internal frame infrastructure has been completely rewritten.
4009 The new infrastructure making it possible to support key new features
4010 including DWARF 2 Call Frame Information. To aid in the task of
4011 migrating old configurations to this new infrastructure, a
4012 compatibility module, that allowed old configurations to continue to
4013 work, was also included.
4015 GDB 6.2 will be the last release to include this frame compatibility
4016 module. This change directly impacts the following configurations:
4026 Unless there is activity to revive these configurations, they will be
4027 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4029 * REMOVED configurations and files
4031 Sun 3, running SunOS 3 m68*-*-sunos3*
4032 Sun 3, running SunOS 4 m68*-*-sunos4*
4033 Sun 2, running SunOS 3 m68000-*-sunos3*
4034 Sun 2, running SunOS 4 m68000-*-sunos4*
4035 Motorola 680x0 running LynxOS m68*-*-lynxos*
4036 AT&T 3b1/Unix pc m68*-att-*
4037 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4038 decstation mips-dec-* mips-little-*
4039 riscos mips-*-riscos* mips-*-sysv*
4040 sonymips mips-sony-*
4041 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4043 *** Changes in GDB 6.1.1:
4045 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4047 The TUI (Text-mode User Interface) is now built as part of a default
4048 GDB configuration. It is enabled by either selecting the TUI with the
4049 command line option "-i=tui" or by running the separate "gdbtui"
4050 program. For more information on the TUI, see the manual "Debugging
4053 * Pending breakpoint support (also included in GDB 6.1)
4055 Support has been added to allow you to specify breakpoints in shared
4056 libraries that have not yet been loaded. If a breakpoint location
4057 cannot be found, and the "breakpoint pending" option is set to auto,
4058 GDB queries you if you wish to make the breakpoint pending on a future
4059 shared-library load. If and when GDB resolves the breakpoint symbol,
4060 the pending breakpoint is removed as one or more regular breakpoints
4063 Pending breakpoints are very useful for GCJ Java debugging.
4065 * Fixed ISO-C build problems
4067 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4068 non ISO-C code that stopped them being built using a more strict ISO-C
4069 compiler (e.g., IBM's C compiler).
4071 * Fixed build problem on IRIX 5
4073 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4074 wasn't able to compile compile on an IRIX 5 system.
4076 * Added execute permission to gdb/gdbserver/configure
4078 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4079 permission. This bug would cause configure to fail on a number of
4080 systems (Solaris, IRIX). Ref: server/519.
4082 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4084 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4085 has been updated to use constant array sizes.
4087 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4089 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4090 its generated DWARF Call Frame Info. This encoding was causing GDB to
4091 panic, that panic has been fixed. Ref: gdb/1628.
4093 * Fixed a problem when examining parameters in shared library code.
4095 When examining parameters in optimized shared library code generated
4096 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4097 not available''. GDB now correctly displays the variable's value.
4099 *** Changes in GDB 6.1:
4101 * Removed --with-mmalloc
4103 Support for the mmalloc memory manager has been removed, as it
4104 conflicted with the internal gdb byte cache.
4106 * Changes in AMD64 configurations
4108 The AMD64 target now includes the %cs and %ss registers. As a result
4109 the AMD64 remote protocol has changed; this affects the floating-point
4110 and SSE registers. If you rely on those registers for your debugging,
4111 you should upgrade gdbserver on the remote side.
4113 * Revised SPARC target
4115 The SPARC target has been completely revised, incorporating the
4116 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4117 support for LynxOS and SunOS 4 has been dropped. Calling functions
4118 from within GDB on operating systems with a non-executable stack
4119 (Solaris, OpenBSD) now works.
4123 GDB has a new C++ demangler which does a better job on the mangled
4124 names generated by current versions of g++. It also runs faster, so
4125 with this and other changes gdb should now start faster on large C++
4128 * DWARF 2 Location Expressions
4130 GDB support for location expressions has been extended to support function
4131 arguments and frame bases. Older versions of GDB could crash when they
4134 * C++ nested types and namespaces
4136 GDB's support for nested types and namespaces in C++ has been
4137 improved, especially if you use the DWARF 2 debugging format. (This
4138 is the default for recent versions of GCC on most platforms.)
4139 Specifically, if you have a class "Inner" defined within a class or
4140 namespace "Outer", then GDB realizes that the class's name is
4141 "Outer::Inner", not simply "Inner". This should greatly reduce the
4142 frequency of complaints about not finding RTTI symbols. In addition,
4143 if you are stopped at inside of a function defined within a namespace,
4144 GDB modifies its name lookup accordingly.
4146 * New native configurations
4148 NetBSD/amd64 x86_64-*-netbsd*
4149 OpenBSD/amd64 x86_64-*-openbsd*
4150 OpenBSD/alpha alpha*-*-openbsd*
4151 OpenBSD/sparc sparc-*-openbsd*
4152 OpenBSD/sparc64 sparc64-*-openbsd*
4154 * New debugging protocols
4156 M32R with SDI protocol m32r-*-elf*
4158 * "set prompt-escape-char" command deleted.
4160 The command "set prompt-escape-char" has been deleted. This command,
4161 and its very obscure effet on GDB's prompt, was never documented,
4162 tested, nor mentioned in the NEWS file.
4164 * OBSOLETE configurations and files
4166 Configurations that have been declared obsolete in this release have
4167 been commented out. Unless there is activity to revive these
4168 configurations, the next release of GDB will have their sources
4169 permanently REMOVED.
4171 Sun 3, running SunOS 3 m68*-*-sunos3*
4172 Sun 3, running SunOS 4 m68*-*-sunos4*
4173 Sun 2, running SunOS 3 m68000-*-sunos3*
4174 Sun 2, running SunOS 4 m68000-*-sunos4*
4175 Motorola 680x0 running LynxOS m68*-*-lynxos*
4176 AT&T 3b1/Unix pc m68*-att-*
4177 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4178 decstation mips-dec-* mips-little-*
4179 riscos mips-*-riscos* mips-*-sysv*
4180 sonymips mips-sony-*
4181 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4183 * REMOVED configurations and files
4185 SGI Irix-4.x mips-sgi-irix4 or iris4
4186 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4187 Z8000 simulator z8k-zilog-none or z8ksim
4188 Matsushita MN10200 w/simulator mn10200-*-*
4189 H8/500 simulator h8500-hitachi-hms or h8500hms
4190 HP/PA running BSD hppa*-*-bsd*
4191 HP/PA running OSF/1 hppa*-*-osf*
4192 HP/PA Pro target hppa*-*-pro*
4193 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4194 386BSD i[3456]86-*-bsd*
4195 Sequent family i[3456]86-sequent-sysv4*
4196 i[3456]86-sequent-sysv*
4197 i[3456]86-sequent-bsd*
4198 SPARC running LynxOS sparc-*-lynxos*
4199 SPARC running SunOS 4 sparc-*-sunos4*
4200 Tsqware Sparclet sparclet-*-*
4201 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4203 *** Changes in GDB 6.0:
4207 Support for debugging the Objective-C programming language has been
4208 integrated into GDB.
4210 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4212 DWARF 2's Call Frame Information makes available compiler generated
4213 information that more exactly describes the program's run-time stack.
4214 By using this information, GDB is able to provide more robust stack
4217 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4218 have been updated to use a new backtrace mechanism which includes
4219 DWARF 2 CFI support.
4223 GDB's remote protocol has been extended to include support for hosted
4224 file I/O (where the remote target uses GDB's file system). See GDB's
4225 remote protocol documentation for details.
4227 * All targets using the new architecture framework.
4229 All of GDB's targets have been updated to use the new internal
4230 architecture framework. The way is now open for future GDB releases
4231 to include cross-architecture native debugging support (i386 on amd64,
4234 * GNU/Linux's Thread Local Storage (TLS)
4236 GDB now includes support for for the GNU/Linux implementation of
4237 per-thread variables.
4239 * GNU/Linux's Native POSIX Thread Library (NPTL)
4241 GDB's thread code has been updated to work with either the new
4242 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4244 * Separate debug info.
4246 GDB, in conjunction with BINUTILS, now supports a mechanism for
4247 automatically loading debug information from a separate file. Instead
4248 of shipping full debug and non-debug versions of system libraries,
4249 system integrators can now instead ship just the stripped libraries
4250 and optional debug files.
4252 * DWARF 2 Location Expressions
4254 DWARF 2 Location Expressions allow the compiler to more completely
4255 describe the location of variables (even in optimized code) to the
4258 GDB now includes preliminary support for location expressions (support
4259 for DW_OP_piece is still missing).
4263 A number of long standing bugs that caused GDB to die while starting a
4264 Java application have been fixed. GDB's Java support is now
4265 considered "useable".
4267 * GNU/Linux support for fork, vfork, and exec.
4269 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4270 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4273 * GDB supports logging output to a file
4275 There are two new commands, "set logging" and "show logging", which can be
4276 used to capture GDB's output to a file.
4278 * The meaning of "detach" has changed for gdbserver
4280 The "detach" command will now resume the application, as documented. To
4281 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4284 * d10v, m68hc11 `regs' command deprecated
4286 The `info registers' command has been updated so that it displays the
4287 registers using a format identical to the old `regs' command.
4291 A new command, "maint set profile on/off", has been added. This command can
4292 be used to enable or disable profiling while running GDB, to profile a
4293 session or a set of commands. In addition there is a new configure switch,
4294 "--enable-profiling", which will cause GDB to be compiled with profiling
4295 data, for more informative profiling results.
4297 * Default MI syntax changed to "mi2".
4299 The default MI (machine interface) syntax, enabled by the command line
4300 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4301 "mi1", can be enabled by specifying the option "-i=mi1".
4303 Support for the original "mi0" syntax (included in GDB 5.0) has been
4306 Fix for gdb/192: removed extraneous space when displaying frame level.
4307 Fix for gdb/672: update changelist is now output in mi list format.
4308 Fix for gdb/702: a -var-assign that updates the value now shows up
4309 in a subsequent -var-update.
4311 * New native configurations.
4313 FreeBSD/amd64 x86_64-*-freebsd*
4315 * Multi-arched targets.
4317 HP/PA HPUX11 hppa*-*-hpux*
4318 Renesas M32R/D w/simulator m32r-*-elf*
4320 * OBSOLETE configurations and files
4322 Configurations that have been declared obsolete in this release have
4323 been commented out. Unless there is activity to revive these
4324 configurations, the next release of GDB will have their sources
4325 permanently REMOVED.
4327 Z8000 simulator z8k-zilog-none or z8ksim
4328 Matsushita MN10200 w/simulator mn10200-*-*
4329 H8/500 simulator h8500-hitachi-hms or h8500hms
4330 HP/PA running BSD hppa*-*-bsd*
4331 HP/PA running OSF/1 hppa*-*-osf*
4332 HP/PA Pro target hppa*-*-pro*
4333 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4334 Sequent family i[3456]86-sequent-sysv4*
4335 i[3456]86-sequent-sysv*
4336 i[3456]86-sequent-bsd*
4337 Tsqware Sparclet sparclet-*-*
4338 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4340 * REMOVED configurations and files
4343 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4344 IBM AIX PS/2 i[3456]86-*-aix
4345 i386 running Mach 3.0 i[3456]86-*-mach3*
4346 i386 running Mach i[3456]86-*-mach*
4347 i386 running OSF/1 i[3456]86-*osf1mk*
4348 HP/Apollo 68k Family m68*-apollo*-sysv*,
4350 m68*-hp-bsd*, m68*-hp-hpux*
4351 Argonaut Risc Chip (ARC) arc-*-*
4352 Mitsubishi D30V d30v-*-*
4353 Fujitsu FR30 fr30-*-elf*
4354 OS/9000 i[34]86-*-os9k
4355 I960 with MON960 i960-*-coff
4357 * MIPS $fp behavior changed
4359 The convenience variable $fp, for the MIPS, now consistently returns
4360 the address of the current frame's base. Previously, depending on the
4361 context, $fp could refer to either $sp or the current frame's base
4362 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4363 The GNU Source-Level Debugger''.
4365 *** Changes in GDB 5.3:
4367 * GNU/Linux shared library multi-threaded performance improved.
4369 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4370 `/proc', in preference to `ptrace' for memory reads. This may result
4371 in an improvement in the start-up time of multi-threaded, shared
4372 library applications when run under GDB. One GDB user writes: ``loads
4373 shared libs like mad''.
4375 * ``gdbserver'' now supports multi-threaded applications on some targets
4377 Support for debugging multi-threaded applications which use
4378 the GNU/Linux LinuxThreads package has been added for
4379 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4380 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4382 * GDB now supports C/C++ preprocessor macros.
4384 GDB now expands preprocessor macro invocations in C/C++ expressions,
4385 and provides various commands for showing macro definitions and how
4388 The new command `macro expand EXPRESSION' expands any macro
4389 invocations in expression, and shows the result.
4391 The new command `show macro MACRO-NAME' shows the definition of the
4392 macro named MACRO-NAME, and where it was defined.
4394 Most compilers don't include information about macros in the debugging
4395 information by default. In GCC 3.1, for example, you need to compile
4396 your program with the options `-gdwarf-2 -g3'. If the macro
4397 information is present in the executable, GDB will read it.
4399 * Multi-arched targets.
4401 DEC Alpha (partial) alpha*-*-*
4402 DEC VAX (partial) vax-*-*
4404 National Semiconductor NS32000 (partial) ns32k-*-*
4405 Motorola 68000 (partial) m68k-*-*
4406 Motorola MCORE mcore-*-*
4410 Fujitsu FRV architecture added by Red Hat frv*-*-*
4413 * New native configurations
4415 Alpha NetBSD alpha*-*-netbsd*
4416 SH NetBSD sh*-*-netbsdelf*
4417 MIPS NetBSD mips*-*-netbsd*
4418 UltraSPARC NetBSD sparc64-*-netbsd*
4420 * OBSOLETE configurations and files
4422 Configurations that have been declared obsolete in this release have
4423 been commented out. Unless there is activity to revive these
4424 configurations, the next release of GDB will have their sources
4425 permanently REMOVED.
4427 Mitsubishi D30V d30v-*-*
4428 OS/9000 i[34]86-*-os9k
4429 IBM AIX PS/2 i[3456]86-*-aix
4430 Fujitsu FR30 fr30-*-elf*
4431 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4432 Argonaut Risc Chip (ARC) arc-*-*
4433 i386 running Mach 3.0 i[3456]86-*-mach3*
4434 i386 running Mach i[3456]86-*-mach*
4435 i386 running OSF/1 i[3456]86-*osf1mk*
4436 HP/Apollo 68k Family m68*-apollo*-sysv*,
4438 m68*-hp-bsd*, m68*-hp-hpux*
4439 I960 with MON960 i960-*-coff
4441 * OBSOLETE languages
4443 CHILL, a Pascal like language used by telecommunications companies.
4445 * REMOVED configurations and files
4447 AMD 29k family via UDI a29k-amd-udi, udi29k
4448 A29K VxWorks a29k-*-vxworks
4449 AMD 29000 embedded, using EBMON a29k-none-none
4450 AMD 29000 embedded with COFF a29k-none-coff
4451 AMD 29000 embedded with a.out a29k-none-aout
4453 testsuite/gdb.hp/gdb.threads-hp/ directory
4455 * New command "set max-user-call-depth <nnn>"
4457 This command allows the user to limit the call depth of user-defined
4458 commands. The default is 1024.
4460 * Changes in FreeBSD/i386 native debugging.
4462 Support for the "generate-core-file" has been added.
4464 * New commands "dump", "append", and "restore".
4466 These commands allow data to be copied from target memory
4467 to a bfd-format or binary file (dump and append), and back
4468 from a file into memory (restore).
4470 * Improved "next/step" support on multi-processor Alpha Tru64.
4472 The previous single-step mechanism could cause unpredictable problems,
4473 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4474 of a software single-step mechanism prevents this.
4476 *** Changes in GDB 5.2.1:
4484 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4485 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4486 Fix, by Joel Brobecker imported from mainline.
4488 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4489 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4490 Fix, by Fred Fish, imported from mainline.
4492 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4493 Surprisingly enough, it works now.
4494 By Michal Ludvig, imported from mainline.
4496 i386 hardware watchpoint support:
4497 avoid misses on second run for some targets.
4498 By Pierre Muller, imported from mainline.
4500 *** Changes in GDB 5.2:
4502 * New command "set trust-readonly-sections on[off]".
4504 This command is a hint that tells gdb that read-only sections
4505 really are read-only (ie. that their contents will not change).
4506 In this mode, gdb will go to the object file rather than the
4507 target to read memory from read-only sections (such as ".text").
4508 This can be a significant performance improvement on some
4509 (notably embedded) targets.
4511 * New command "generate-core-file" (or "gcore").
4513 This new gdb command allows the user to drop a core file of the child
4514 process state at any time. So far it's been implemented only for
4515 GNU/Linux and Solaris, but should be relatively easily ported to other
4516 hosts. Argument is core file name (defaults to core.<pid>).
4518 * New command line option
4520 GDB now accepts --pid or -p followed by a process id.
4522 * Change in command line behavior -- corefiles vs. process ids.
4524 There is a subtle behavior in the way in which GDB handles
4525 command line arguments. The first non-flag argument is always
4526 a program to debug, but the second non-flag argument may either
4527 be a corefile or a process id. Previously, GDB would attempt to
4528 open the second argument as a corefile, and if that failed, would
4529 issue a superfluous error message and then attempt to attach it as
4530 a process. Now, if the second argument begins with a non-digit,
4531 it will be treated as a corefile. If it begins with a digit,
4532 GDB will attempt to attach it as a process, and if no such process
4533 is found, will then attempt to open it as a corefile.
4535 * Changes in ARM configurations.
4537 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4538 configuration is fully multi-arch.
4540 * New native configurations
4542 ARM NetBSD arm*-*-netbsd*
4543 x86 OpenBSD i[3456]86-*-openbsd*
4544 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4545 Sparc64 running FreeBSD sparc64-*-freebsd*
4549 Sanyo XStormy16 xstormy16-elf
4551 * OBSOLETE configurations and files
4553 Configurations that have been declared obsolete in this release have
4554 been commented out. Unless there is activity to revive these
4555 configurations, the next release of GDB will have their sources
4556 permanently REMOVED.
4558 AMD 29k family via UDI a29k-amd-udi, udi29k
4559 A29K VxWorks a29k-*-vxworks
4560 AMD 29000 embedded, using EBMON a29k-none-none
4561 AMD 29000 embedded with COFF a29k-none-coff
4562 AMD 29000 embedded with a.out a29k-none-aout
4564 testsuite/gdb.hp/gdb.threads-hp/ directory
4566 * REMOVED configurations and files
4568 TI TMS320C80 tic80-*-*
4570 PowerPC Solaris powerpcle-*-solaris*
4571 PowerPC Windows NT powerpcle-*-cygwin32
4572 PowerPC Netware powerpc-*-netware*
4573 Harris/CXUX m88k m88*-harris-cxux*
4574 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4575 ns32k-utek-sysv* ns32k-utek-*
4576 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4577 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4578 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4579 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4580 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4582 * Changes to command line processing
4584 The new `--args' feature can be used to specify command-line arguments
4585 for the inferior from gdb's command line.
4587 * Changes to key bindings
4589 There is a new `operate-and-get-next' function bound to `C-o'.
4591 *** Changes in GDB 5.1.1
4593 Fix compile problem on DJGPP.
4595 Fix a problem with floating-point registers on the i386 being
4598 Fix to stop GDB crashing on .debug_str debug info.
4600 Numerous documentation fixes.
4602 Numerous testsuite fixes.
4604 *** Changes in GDB 5.1:
4606 * New native configurations
4608 Alpha FreeBSD alpha*-*-freebsd*
4609 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4610 MIPS GNU/Linux mips*-*-linux*
4611 MIPS SGI Irix 6.x mips*-sgi-irix6*
4612 ia64 AIX ia64-*-aix*
4613 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4617 Motorola 68HC11 and 68HC12 m68hc11-elf
4619 UltraSparc running GNU/Linux sparc64-*-linux*
4621 * OBSOLETE configurations and files
4623 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4624 Harris/CXUX m88k m88*-harris-cxux*
4625 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4626 ns32k-utek-sysv* ns32k-utek-*
4627 TI TMS320C80 tic80-*-*
4629 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4630 PowerPC Solaris powerpcle-*-solaris*
4631 PowerPC Windows NT powerpcle-*-cygwin32
4632 PowerPC Netware powerpc-*-netware*
4633 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4634 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4635 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4636 Apple Macintosh (MPW) host N/A
4638 stuff.c (Program to stuff files into a specially prepared space in kdb)
4639 kdb-start.c (Main loop for the standalone kernel debugger)
4641 Configurations that have been declared obsolete in this release have
4642 been commented out. Unless there is activity to revive these
4643 configurations, the next release of GDB will have their sources
4644 permanently REMOVED.
4646 * REMOVED configurations and files
4648 Altos 3068 m68*-altos-*
4649 Convex c1-*-*, c2-*-*
4651 ARM RISCix arm-*-* (as host)
4655 * GDB has been converted to ISO C.
4657 GDB's source code has been converted to ISO C. In particular, the
4658 sources are fully protoized, and rely on standard headers being
4663 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4665 * The MI enabled by default.
4667 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4668 revised and enabled by default. Packages which use GDB as a debugging
4669 engine behind a UI or another front end are encouraged to switch to
4670 using the GDB/MI interface, instead of the old annotations interface
4671 which is now deprecated.
4673 * Support for debugging Pascal programs.
4675 GDB now includes support for debugging Pascal programs. The following
4676 main features are supported:
4678 - Pascal-specific data types such as sets;
4680 - automatic recognition of Pascal sources based on file-name
4683 - Pascal-style display of data types, variables, and functions;
4685 - a Pascal expression parser.
4687 However, some important features are not yet supported.
4689 - Pascal string operations are not supported at all;
4691 - there are some problems with boolean types;
4693 - Pascal type hexadecimal constants are not supported
4694 because they conflict with the internal variables format;
4696 - support for Pascal objects and classes is not full yet;
4698 - unlike Pascal, GDB is case-sensitive for symbol names.
4700 * Changes in completion.
4702 Commands such as `shell', `run' and `set args', which pass arguments
4703 to inferior programs, now complete on file names, similar to what
4704 users expect at the shell prompt.
4706 Commands which accept locations, such as `disassemble', `print',
4707 `breakpoint', `until', etc. now complete on filenames as well as
4708 program symbols. Thus, if you type "break foob TAB", and the source
4709 files linked into the programs include `foobar.c', that file name will
4710 be one of the candidates for completion. However, file names are not
4711 considered for completion after you typed a colon that delimits a file
4712 name from a name of a function in that file, as in "break foo.c:bar".
4714 `set demangle-style' completes on available demangling styles.
4716 * New platform-independent commands:
4718 It is now possible to define a post-hook for a command as well as a
4719 hook that runs before the command. For more details, see the
4720 documentation of `hookpost' in the GDB manual.
4722 * Changes in GNU/Linux native debugging.
4724 Support for debugging multi-threaded programs has been completely
4725 revised for all platforms except m68k and sparc. You can now debug as
4726 many threads as your system allows you to have.
4728 Attach/detach is supported for multi-threaded programs.
4730 Support for SSE registers was added for x86. This doesn't work for
4731 multi-threaded programs though.
4733 * Changes in MIPS configurations.
4735 Multi-arch support is enabled for all MIPS configurations.
4737 GDB can now be built as native debugger on SGI Irix 6.x systems for
4738 debugging n32 executables. (Debugging 64-bit executables is not yet
4741 * Unified support for hardware watchpoints in all x86 configurations.
4743 Most (if not all) native x86 configurations support hardware-assisted
4744 breakpoints and watchpoints in a unified manner. This support
4745 implements debug register sharing between watchpoints, which allows to
4746 put a virtually infinite number of watchpoints on the same address,
4747 and also supports watching regions up to 16 bytes with several debug
4750 The new maintenance command `maintenance show-debug-regs' toggles
4751 debugging print-outs in functions that insert, remove, and test
4752 watchpoints and hardware breakpoints.
4754 * Changes in the DJGPP native configuration.
4756 New command ``info dos sysinfo'' displays assorted information about
4757 the CPU, OS, memory, and DPMI server.
4759 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4760 display information about segment descriptors stored in GDT, LDT, and
4763 New commands ``info dos pde'' and ``info dos pte'' display entries
4764 from Page Directory and Page Tables (for now works with CWSDPMI only).
4765 New command ``info dos address-pte'' displays the Page Table entry for
4766 a given linear address.
4768 GDB can now pass command lines longer than 126 characters to the
4769 program being debugged (requires an update to the libdbg.a library
4770 which is part of the DJGPP development kit).
4772 DWARF2 debug info is now supported.
4774 It is now possible to `step' and `next' through calls to `longjmp'.
4776 * Changes in documentation.
4778 All GDB documentation was converted to GFDL, the GNU Free
4779 Documentation License.
4781 Tracepoints-related commands are now fully documented in the GDB
4784 TUI, the Text-mode User Interface, is now documented in the manual.
4786 Tracepoints-related commands are now fully documented in the GDB
4789 The "GDB Internals" manual now has an index. It also includes
4790 documentation of `ui_out' functions, GDB coding standards, x86
4791 hardware watchpoints, and memory region attributes.
4793 * GDB's version number moved to ``version.in''
4795 The Makefile variable VERSION has been replaced by the file
4796 ``version.in''. People creating GDB distributions should update the
4797 contents of this file.
4801 GUD support is now a standard part of the EMACS distribution.
4803 *** Changes in GDB 5.0:
4805 * Improved support for debugging FP programs on x86 targets
4807 Unified and much-improved support for debugging floating-point
4808 programs on all x86 targets. In particular, ``info float'' now
4809 displays the FP registers in the same format on all x86 targets, with
4810 greater level of detail.
4812 * Improvements and bugfixes in hardware-assisted watchpoints
4814 It is now possible to watch array elements, struct members, and
4815 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4816 on x86 targets no longer erroneously trigger when the address is
4819 * Improvements in the native DJGPP version of GDB
4821 The distribution now includes all the scripts and auxiliary files
4822 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4823 machines ``out of the box''.
4825 The DJGPP version can now debug programs that use signals. It is
4826 possible to catch signals that happened in the debuggee, deliver
4827 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4828 would kill the program being debugged.) Programs that hook hardware
4829 interrupts (keyboard, timer, etc.) can also be debugged.
4831 It is now possible to debug DJGPP programs that redirect their
4832 standard handles or switch them to raw (as opposed to cooked) mode, or
4833 even close them. The command ``run < foo > bar'' works as expected,
4834 and ``info terminal'' reports useful information about the debuggee's
4835 terminal, including raw/cooked mode, redirection, etc.
4837 The DJGPP version now uses termios functions for console I/O, which
4838 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4841 DOS-style file names with drive letters are now fully supported by
4844 It is now possible to debug DJGPP programs that switch their working
4845 directory. It is also possible to rerun the debuggee any number of
4846 times without restarting GDB; thus, you can use the same setup,
4847 breakpoints, etc. for many debugging sessions.
4849 * New native configurations
4851 ARM GNU/Linux arm*-*-linux*
4852 PowerPC GNU/Linux powerpc-*-linux*
4856 Motorola MCore mcore-*-*
4857 x86 VxWorks i[3456]86-*-vxworks*
4858 PowerPC VxWorks powerpc-*-vxworks*
4859 TI TMS320C80 tic80-*-*
4861 * OBSOLETE configurations
4863 Altos 3068 m68*-altos-*
4864 Convex c1-*-*, c2-*-*
4866 ARM RISCix arm-*-* (as host)
4869 Configurations that have been declared obsolete will be commented out,
4870 but the code will be left in place. If there is no activity to revive
4871 these configurations before the next release of GDB, the sources will
4872 be permanently REMOVED.
4874 * Gould support removed
4876 Support for the Gould PowerNode and NP1 has been removed.
4878 * New features for SVR4
4880 On SVR4 native platforms (such as Solaris), if you attach to a process
4881 without first loading a symbol file, GDB will now attempt to locate and
4882 load symbols from the running process's executable file.
4884 * Many C++ enhancements
4886 C++ support has been greatly improved. Overload resolution now works properly
4887 in almost all cases. RTTI support is on the way.
4889 * Remote targets can connect to a sub-program
4891 A popen(3) style serial-device has been added. This device starts a
4892 sub-process (such as a stand-alone simulator) and then communicates
4893 with that. The sub-program to run is specified using the syntax
4894 ``|<program> <args>'' vis:
4896 (gdb) set remotedebug 1
4897 (gdb) target extended-remote |mn10300-elf-sim program-args
4899 * MIPS 64 remote protocol
4901 A long standing bug in the mips64 remote protocol where by GDB
4902 expected certain 32 bit registers (ex SR) to be transfered as 32
4903 instead of 64 bits has been fixed.
4905 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4906 added to provide backward compatibility with older versions of GDB.
4908 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4910 The command ``set remotebinarydownload'' command has been replaced by
4911 ``set remote X-packet''. Other commands in ``set remote'' family
4912 include ``set remote P-packet''.
4914 * Breakpoint commands accept ranges.
4916 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4917 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4918 ``tracepoint passcount'' also accepts a range of tracepoints.
4920 * ``apropos'' command added.
4922 The ``apropos'' command searches through command names and
4923 documentation strings, printing out matches, making it much easier to
4924 try to find a command that does what you are looking for.
4928 A new machine oriented interface (MI) has been added to GDB. This
4929 interface is designed for debug environments running GDB as a separate
4930 process. This is part of the long term libGDB project. See the
4931 "GDB/MI" chapter of the GDB manual for further information. It can be
4932 enabled by configuring with:
4934 .../configure --enable-gdbmi
4936 *** Changes in GDB-4.18:
4938 * New native configurations
4940 HP-UX 10.20 hppa*-*-hpux10.20
4941 HP-UX 11.x hppa*-*-hpux11.0*
4942 M68K GNU/Linux m68*-*-linux*
4946 Fujitsu FR30 fr30-*-elf*
4947 Intel StrongARM strongarm-*-*
4948 Mitsubishi D30V d30v-*-*
4950 * OBSOLETE configurations
4952 Gould PowerNode, NP1 np1-*-*, pn-*-*
4954 Configurations that have been declared obsolete will be commented out,
4955 but the code will be left in place. If there is no activity to revive
4956 these configurations before the next release of GDB, the sources will
4957 be permanently REMOVED.
4961 As a compatibility experiment, GDB's source files buildsym.h and
4962 buildsym.c have been converted to pure standard C, no longer
4963 containing any K&R compatibility code. We believe that all systems in
4964 use today either come with a standard C compiler, or have a GCC port
4965 available. If this is not true, please report the affected
4966 configuration to bug-gdb@gnu.org immediately. See the README file for
4967 information about getting a standard C compiler if you don't have one
4972 GDB now uses readline 2.2.
4974 * set extension-language
4976 You can now control the mapping between filename extensions and source
4977 languages by using the `set extension-language' command. For instance,
4978 you can ask GDB to treat .c files as C++ by saying
4979 set extension-language .c c++
4980 The command `info extensions' lists all of the recognized extensions
4981 and their associated languages.
4983 * Setting processor type for PowerPC and RS/6000
4985 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4986 you can use the `set processor' command to specify what variant of the
4987 PowerPC family you are debugging. The command
4991 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4992 following PowerPC and RS6000 variants:
4994 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4995 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4997 403GC IBM PowerPC 403GC
4998 505 Motorola PowerPC 505
4999 860 Motorola PowerPC 860 or 850
5000 601 Motorola PowerPC 601
5001 602 Motorola PowerPC 602
5002 603 Motorola/IBM PowerPC 603 or 603e
5003 604 Motorola PowerPC 604 or 604e
5004 750 Motorola/IBM PowerPC 750 or 750
5006 At the moment, this command just tells GDB what to name the
5007 special-purpose processor registers. Since almost all the affected
5008 registers are inaccessible to user-level programs, this command is
5009 only useful for remote debugging in its present form.
5013 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5014 more extensive support for HP-UX. Added features include shared
5015 library support, kernel threads and hardware watchpoints for 11.00,
5016 support for HP's ANSI C and C++ compilers, and a compatibility mode
5017 for xdb and dbx commands.
5021 HP's donation includes the new concept of catchpoints, which is a
5022 generalization of the old catch command. On HP-UX, it is now possible
5023 to catch exec, fork, and vfork, as well as library loading.
5025 This means that the existing catch command has changed; its first
5026 argument now specifies the type of catch to be set up. See the
5027 output of "help catch" for a list of catchpoint types.
5029 * Debugging across forks
5031 On HP-UX, you can choose which process to debug when a fork() happens
5036 HP has donated a curses-based terminal user interface (TUI). To get
5037 it, build with --enable-tui. Although this can be enabled for any
5038 configuration, at present it only works for native HP debugging.
5040 * GDB remote protocol additions
5042 A new protocol packet 'X' that writes binary data is now available.
5043 Default behavior is to try 'X', then drop back to 'M' if the stub
5044 fails to respond. The settable variable `remotebinarydownload'
5045 allows explicit control over the use of 'X'.
5047 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5048 full 64-bit address. The command
5050 set remoteaddresssize 32
5052 can be used to revert to the old behaviour. For existing remote stubs
5053 the change should not be noticed, as the additional address information
5056 In order to assist in debugging stubs, you may use the maintenance
5057 command `packet' to send any text string to the stub. For instance,
5059 maint packet heythere
5061 sends the packet "$heythere#<checksum>". Note that it is very easy to
5062 disrupt a debugging session by sending the wrong packet at the wrong
5065 The compare-sections command allows you to compare section data on the
5066 target to what is in the executable file without uploading or
5067 downloading, by comparing CRC checksums.
5069 * Tracing can collect general expressions
5071 You may now collect general expressions at tracepoints. This requires
5072 further additions to the target-side stub; see tracepoint.c and
5073 doc/agentexpr.texi for further details.
5075 * mask-address variable for Mips
5077 For Mips targets, you may control the zeroing of the upper 32 bits of
5078 a 64-bit address by entering `set mask-address on'. This is mainly
5079 of interest to users of embedded R4xxx and R5xxx processors.
5081 * Higher serial baud rates
5083 GDB's serial code now allows you to specify baud rates 57600, 115200,
5084 230400, and 460800 baud. (Note that your host system may not be able
5085 to achieve all of these rates.)
5089 The i960 configuration now includes an initial implementation of a
5090 builtin simulator, contributed by Jim Wilson.
5093 *** Changes in GDB-4.17:
5095 * New native configurations
5097 Alpha GNU/Linux alpha*-*-linux*
5098 Unixware 2.x i[3456]86-unixware2*
5099 Irix 6.x mips*-sgi-irix6*
5100 PowerPC GNU/Linux powerpc-*-linux*
5101 PowerPC Solaris powerpcle-*-solaris*
5102 Sparc GNU/Linux sparc-*-linux*
5103 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5107 Argonaut Risc Chip (ARC) arc-*-*
5108 Hitachi H8/300S h8300*-*-*
5109 Matsushita MN10200 w/simulator mn10200-*-*
5110 Matsushita MN10300 w/simulator mn10300-*-*
5111 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5112 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5113 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5114 Mitsubishi D10V w/simulator d10v-*-*
5115 Mitsubishi M32R/D w/simulator m32r-*-elf*
5116 Tsqware Sparclet sparclet-*-*
5117 NEC V850 w/simulator v850-*-*
5119 * New debugging protocols
5121 ARM with RDI protocol arm*-*-*
5122 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5123 DDB and LSI variants of PMON protocol mips*-*-*
5124 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5125 PowerPC with SDS protocol powerpc{,le}-*-eabi
5126 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5130 All configurations can now understand and use the DWARF 2 debugging
5131 format. The choice is automatic, if the symbol file contains DWARF 2
5136 GDB now includes basic Java language support. This support is
5137 only useful with Java compilers that produce native machine code.
5139 * solib-absolute-prefix and solib-search-path
5141 For SunOS and SVR4 shared libraries, you may now set the prefix for
5142 loading absolute shared library symbol files, and the search path for
5143 locating non-absolute shared library symbol files.
5145 * Live range splitting
5147 GDB can now effectively debug code for which GCC has performed live
5148 range splitting as part of its optimization. See gdb/doc/LRS for
5149 more details on the expected format of the stabs information.
5153 GDB's support for the GNU Hurd, including thread debugging, has been
5154 updated to work with current versions of the Hurd.
5158 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5159 instruction set. ARM GDB automatically detects when Thumb
5160 instructions are in use, and adjusts disassembly and backtracing
5165 GDB's MIPS target configurations now handle the MIP16 16-bit
5170 GDB now includes support for overlays; if an executable has been
5171 linked such that multiple sections are based at the same address, GDB
5172 will decide which section to use for symbolic info. You can choose to
5173 control the decision manually, using overlay commands, or implement
5174 additional target-side support and use "overlay load-target" to bring
5175 in the overlay mapping. Do "help overlay" for more detail.
5179 The command "info symbol <address>" displays information about
5180 the symbol at the specified address.
5184 The standard remote protocol now includes an extension that allows
5185 asynchronous collection and display of trace data. This requires
5186 extensive support in the target-side debugging stub. Tracing mode
5187 includes a new interaction mode in GDB and new commands: see the
5188 file tracepoint.c for more details.
5192 Configurations for embedded MIPS now include a simulator contributed
5193 by Cygnus Solutions. The simulator supports the instruction sets
5194 of most MIPS variants.
5198 Sparc configurations may now include the ERC32 simulator contributed
5199 by the European Space Agency. The simulator is not built into
5200 Sparc targets by default; configure with --enable-sim to include it.
5204 For target configurations that may include multiple variants of a
5205 basic architecture (such as MIPS and SH), you may now set the
5206 architecture explicitly. "set arch" sets, "info arch" lists
5207 the possible architectures.
5209 *** Changes in GDB-4.16:
5211 * New native configurations
5213 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5214 M68K NetBSD m68k-*-netbsd*
5215 PowerPC AIX 4.x powerpc-*-aix*
5216 PowerPC MacOS powerpc-*-macos*
5217 PowerPC Windows NT powerpcle-*-cygwin32
5218 RS/6000 AIX 4.x rs6000-*-aix4*
5222 ARM with RDP protocol arm-*-*
5223 I960 with MON960 i960-*-coff
5224 MIPS VxWorks mips*-*-vxworks*
5225 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5226 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5228 Matra Sparclet sparclet-*-*
5232 The powerpc-eabi configuration now includes the PSIM simulator,
5233 contributed by Andrew Cagney, with assistance from Mike Meissner.
5234 PSIM is a very elaborate model of the PowerPC, including not only
5235 basic instruction set execution, but also details of execution unit
5236 performance and I/O hardware. See sim/ppc/README for more details.
5240 GDB now works with Solaris 2.5.
5242 * Windows 95/NT native
5244 GDB will now work as a native debugger on Windows 95 and Windows NT.
5245 To build it from source, you must use the "gnu-win32" environment,
5246 which uses a DLL to emulate enough of Unix to run the GNU tools.
5247 Further information, binaries, and sources are available at
5248 ftp.cygnus.com, under pub/gnu-win32.
5250 * dont-repeat command
5252 If a user-defined command includes the command `dont-repeat', then the
5253 command will not be repeated if the user just types return. This is
5254 useful if the command is time-consuming to run, so that accidental
5255 extra keystrokes don't run the same command many times.
5257 * Send break instead of ^C
5259 The standard remote protocol now includes an option to send a break
5260 rather than a ^C to the target in order to interrupt it. By default,
5261 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5263 * Remote protocol timeout
5265 The standard remote protocol includes a new variable `remotetimeout'
5266 that allows you to set the number of seconds before GDB gives up trying
5267 to read from the target. The default value is 2.
5269 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5271 By default GDB will automatically keep track of objects as they are
5272 loaded and unloaded by the dynamic linker. By using the command `set
5273 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5274 when shared library events occur, thus allowing you to set breakpoints
5275 in shared libraries which are explicitly loaded by the inferior.
5277 Note this feature does not work on hpux8. On hpux9 you must link
5278 /usr/lib/end.o into your program. This feature should work
5279 automatically on hpux10.
5281 * Irix 5.x hardware watchpoint support
5283 Irix 5 configurations now support the use of hardware watchpoints.
5285 * Mips protocol "SYN garbage limit"
5287 When debugging a Mips target using the `target mips' protocol, you
5288 may set the number of characters that GDB will ignore by setting
5289 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5290 every character. The default value is 1050.
5292 * Recording and replaying remote debug sessions
5294 If you set `remotelogfile' to the name of a file, gdb will write to it
5295 a recording of a remote debug session. This recording may then be
5296 replayed back to gdb using "gdbreplay". See gdbserver/README for
5297 details. This is useful when you have a problem with GDB while doing
5298 remote debugging; you can make a recording of the session and send it
5299 to someone else, who can then recreate the problem.
5301 * Speedups for remote debugging
5303 GDB includes speedups for downloading and stepping MIPS systems using
5304 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5305 and more efficient S-record downloading.
5307 * Memory use reductions and statistics collection
5309 GDB now uses less memory and reports statistics about memory usage.
5310 Try the `maint print statistics' command, for example.
5312 *** Changes in GDB-4.15:
5314 * Psymtabs for XCOFF
5316 The symbol reader for AIX GDB now uses partial symbol tables. This
5317 can greatly improve startup time, especially for large executables.
5319 * Remote targets use caching
5321 Remote targets now use a data cache to speed up communication with the
5322 remote side. The data cache could lead to incorrect results because
5323 it doesn't know about volatile variables, thus making it impossible to
5324 debug targets which use memory mapped I/O devices. `set remotecache
5325 off' turns the the data cache off.
5327 * Remote targets may have threads
5329 The standard remote protocol now includes support for multiple threads
5330 in the target system, using new protocol commands 'H' and 'T'. See
5331 gdb/remote.c for details.
5335 If GDB is configured with `--enable-netrom', then it will include
5336 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5337 acts as though it is a bank of ROM on the target board, but you can
5338 write into it over the network. GDB's support consists only of
5339 support for fast loading into the emulated ROM; to debug, you must use
5340 another protocol, such as standard remote protocol. The usual
5341 sequence is something like
5343 target nrom <netrom-hostname>
5345 target remote <netrom-hostname>:1235
5349 GDB now includes support for the Apple Macintosh, as a host only. It
5350 may be run as either an MPW tool or as a standalone application, and
5351 it can debug through the serial port. All the usual GDB commands are
5352 available, but to the target command, you must supply "serial" as the
5353 device type instead of "/dev/ttyXX". See mpw-README in the main
5354 directory for more information on how to build. The MPW configuration
5355 scripts */mpw-config.in support only a few targets, and only the
5356 mips-idt-ecoff target has been tested.
5360 GDB configuration now uses autoconf. This is not user-visible,
5361 but does simplify configuration and building.
5365 GDB now supports hpux10.
5367 *** Changes in GDB-4.14:
5369 * New native configurations
5371 x86 FreeBSD i[345]86-*-freebsd
5372 x86 NetBSD i[345]86-*-netbsd
5373 NS32k NetBSD ns32k-*-netbsd
5374 Sparc NetBSD sparc-*-netbsd
5378 A29K VxWorks a29k-*-vxworks
5379 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5380 CPU32 EST-300 emulator m68*-*-est*
5381 PowerPC ELF powerpc-*-elf
5384 * Alpha OSF/1 support for procfs
5386 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5387 possible to attach to running processes. As the mounting of the /proc
5388 filesystem is optional on the Alpha, GDB automatically determines
5389 the availability of /proc during startup. This can lead to problems
5390 if /proc is unmounted after GDB has been started.
5392 * Arguments to user-defined commands
5394 User commands may accept up to 10 arguments separated by whitespace.
5395 Arguments are accessed within the user command via $arg0..$arg9. A
5398 print $arg0 + $arg1 + $arg2
5400 To execute the command use:
5403 Defines the command "adder" which prints the sum of its three arguments.
5404 Note the arguments are text substitutions, so they may reference variables,
5405 use complex expressions, or even perform inferior function calls.
5407 * New `if' and `while' commands
5409 This makes it possible to write more sophisticated user-defined
5410 commands. Both commands take a single argument, which is the
5411 expression to evaluate, and must be followed by the commands to
5412 execute, one per line, if the expression is nonzero, the list being
5413 terminated by the word `end'. The `if' command list may include an
5414 `else' word, which causes the following commands to be executed only
5415 if the expression is zero.
5417 * Fortran source language mode
5419 GDB now includes partial support for Fortran 77. It will recognize
5420 Fortran programs and can evaluate a subset of Fortran expressions, but
5421 variables and functions may not be handled correctly. GDB will work
5422 with G77, but does not yet know much about symbols emitted by other
5425 * Better HPUX support
5427 Most debugging facilities now work on dynamic executables for HPPAs
5428 running hpux9 or later. You can attach to running dynamically linked
5429 processes, but by default the dynamic libraries will be read-only, so
5430 for instance you won't be able to put breakpoints in them. To change
5431 that behavior do the following before running the program:
5437 This will cause the libraries to be mapped private and read-write.
5438 To revert to the normal behavior, do this:
5444 You cannot set breakpoints or examine data in the library until after
5445 the library is loaded if the function/data symbols do not have
5448 GDB can now also read debug symbols produced by the HP C compiler on
5449 HPPAs (sorry, no C++, Fortran or 68k support).
5451 * Target byte order now dynamically selectable
5453 You can choose which byte order to use with a target system, via the
5454 commands "set endian big" and "set endian little", and you can see the
5455 current setting by using "show endian". You can also give the command
5456 "set endian auto", in which case GDB will use the byte order
5457 associated with the executable. Currently, only embedded MIPS
5458 configurations support dynamic selection of target byte order.
5460 * New DOS host serial code
5462 This version uses DPMI interrupts to handle buffered I/O, so you
5463 no longer need to run asynctsr when debugging boards connected to
5466 *** Changes in GDB-4.13:
5468 * New "complete" command
5470 This lists all the possible completions for the rest of the line, if it
5471 were to be given as a command itself. This is intended for use by emacs.
5473 * Trailing space optional in prompt
5475 "set prompt" no longer adds a space for you after the prompt you set. This
5476 allows you to set a prompt which ends in a space or one that does not.
5478 * Breakpoint hit counts
5480 "info break" now displays a count of the number of times the breakpoint
5481 has been hit. This is especially useful in conjunction with "ignore"; you
5482 can ignore a large number of breakpoint hits, look at the breakpoint info
5483 to see how many times the breakpoint was hit, then run again, ignoring one
5484 less than that number, and this will get you quickly to the last hit of
5487 * Ability to stop printing at NULL character
5489 "set print null-stop" will cause GDB to stop printing the characters of
5490 an array when the first NULL is encountered. This is useful when large
5491 arrays actually contain only short strings.
5493 * Shared library breakpoints
5495 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5496 breakpoints in shared libraries before the executable is run.
5498 * Hardware watchpoints
5500 There is a new hardware breakpoint for the watch command for sparclite
5501 targets. See gdb/sparclite/hw_breakpoint.note.
5503 Hardware watchpoints are also now supported under GNU/Linux.
5507 Annotations have been added. These are for use with graphical interfaces,
5508 and are still experimental. Currently only gdba.el uses these.
5510 * Improved Irix 5 support
5512 GDB now works properly with Irix 5.2.
5514 * Improved HPPA support
5516 GDB now works properly with the latest GCC and GAS.
5518 * New native configurations
5520 Sequent PTX4 i[34]86-sequent-ptx4
5521 HPPA running OSF/1 hppa*-*-osf*
5522 Atari TT running SVR4 m68*-*-sysv4*
5523 RS/6000 LynxOS rs6000-*-lynxos*
5527 OS/9000 i[34]86-*-os9k
5528 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5531 * Hitachi SH7000 and E7000-PC ICE support
5533 There is now support for communicating with the Hitachi E7000-PC ICE.
5534 This is available automatically when GDB is configured for the SH.
5538 As usual, a variety of small fixes and improvements, both generic
5539 and configuration-specific. See the ChangeLog for more detail.
5541 *** Changes in GDB-4.12:
5543 * Irix 5 is now supported
5547 GDB-4.12 on the HPPA has a number of changes which make it unable
5548 to debug the output from the currently released versions of GCC and
5549 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5550 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5551 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5554 *** Changes in GDB-4.11:
5556 * User visible changes:
5560 The "set remotedebug" option is now consistent between the mips remote
5561 target, remote targets using the gdb-specific protocol, UDI (AMD's
5562 debug protocol for the 29k) and the 88k bug monitor. It is now an
5563 integer specifying a debug level (normally 0 or 1, but 2 means more
5564 debugging info for the mips target).
5566 * DEC Alpha native support
5568 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5569 debug info, but GDB works fairly well with the DEC compiler and should
5570 work with a future GCC release. See the README file for a few
5571 Alpha-specific notes.
5573 * Preliminary thread implementation
5575 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5577 * LynxOS native and target support for 386
5579 This release has been hosted on LynxOS 2.2, and also can be configured
5580 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5583 * Improvements in C++ mangling/demangling.
5585 This release has much better g++ debugging, specifically in name
5586 mangling/demangling, virtual function calls, print virtual table,
5587 call methods, ...etc.
5589 *** Changes in GDB-4.10:
5591 * User visible changes:
5593 Remote debugging using the GDB-specific (`target remote') protocol now
5594 supports the `load' command. This is only useful if you have some
5595 other way of getting the stub to the target system, and you can put it
5596 somewhere in memory where it won't get clobbered by the download.
5598 Filename completion now works.
5600 When run under emacs mode, the "info line" command now causes the
5601 arrow to point to the line specified. Also, "info line" prints
5602 addresses in symbolic form (as well as hex).
5604 All vxworks based targets now support a user settable option, called
5605 vxworks-timeout. This option represents the number of seconds gdb
5606 should wait for responses to rpc's. You might want to use this if
5607 your vxworks target is, perhaps, a slow software simulator or happens
5608 to be on the far side of a thin network line.
5612 This release contains support for using a DEC alpha as a GDB host for
5613 cross debugging. Native alpha debugging is not supported yet.
5616 *** Changes in GDB-4.9:
5620 This is the first GDB release which is accompanied by a matching testsuite.
5621 The testsuite requires installation of dejagnu, which should be available
5622 via ftp from most sites that carry GNU software.
5626 'Cfront' style demangling has had its name changed to 'ARM' style, to
5627 emphasize that it was written from the specifications in the C++ Annotated
5628 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5629 disclaimers, it still generated too much confusion with users attempting to
5630 use gdb with AT&T cfront.
5634 GDB now uses a standard remote interface to a simulator library.
5635 So far, the library contains simulators for the Zilog Z8001/2, the
5636 Hitachi H8/300, H8/500 and Super-H.
5638 * New targets supported
5640 H8/300 simulator h8300-hitachi-hms or h8300hms
5641 H8/500 simulator h8500-hitachi-hms or h8500hms
5642 SH simulator sh-hitachi-hms or sh
5643 Z8000 simulator z8k-zilog-none or z8ksim
5644 IDT MIPS board over serial line mips-idt-ecoff
5646 Cross-debugging to GO32 targets is supported. It requires a custom
5647 version of the i386-stub.c module which is integrated with the
5648 GO32 memory extender.
5650 * New remote protocols
5652 MIPS remote debugging protocol.
5654 * New source languages supported
5656 This version includes preliminary support for Chill, a Pascal like language
5657 used by telecommunications companies. Chill support is also being integrated
5658 into the GNU compiler, but we don't know when it will be publically available.
5661 *** Changes in GDB-4.8:
5663 * HP Precision Architecture supported
5665 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5666 version of this support was available as a set of patches from the
5667 University of Utah. GDB does not support debugging of programs
5668 compiled with the HP compiler, because HP will not document their file
5669 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5670 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5672 Many problems in the preliminary version have been fixed.
5674 * Faster and better demangling
5676 We have improved template demangling and fixed numerous bugs in the GNU style
5677 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5678 character types (wchar_t) are now supported. Demangling of each symbol is now
5679 only done once, and is cached when the symbol table for a file is read in.
5680 This results in a small increase in memory usage for C programs, a moderate
5681 increase in memory usage for C++ programs, and a fantastic speedup in
5684 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5685 from the specifications in the Annotated Reference Manual, which AT&T's
5686 compiler does not actually implement.
5688 * G++ multiple inheritance compiler problem
5690 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5691 inheritance lattices was reworked to properly discover ambiguities. We
5692 recently found an example which causes this new algorithm to fail in a
5693 very subtle way, producing bad debug information for those classes.
5694 The file 'gcc.patch' (in this directory) can be applied to gcc to
5695 circumvent the problem. A future GCC release will contain a complete
5698 The previous G++ debug info problem (mentioned below for the gdb-4.7
5699 release) is fixed in gcc version 2.3.2.
5701 * Improved configure script
5703 The `configure' script will now attempt to guess your system type if
5704 you don't supply a host system type. The old scheme of supplying a
5705 host system triplet is preferable over using this. All the magic is
5706 done in the new `config.guess' script. Examine it for details.
5708 We have also brought our configure script much more in line with the FSF's
5709 version. It now supports the --with-xxx options. In particular,
5710 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5711 The resulting GDB will not be able to read arbitrary object file formats --
5712 only the format ``expected'' to be used on the configured target system.
5713 We hope to make this the default in a future release.
5715 * Documentation improvements
5717 There's new internal documentation on how to modify GDB, and how to
5718 produce clean changes to the code. We implore people to read it
5719 before submitting changes.
5721 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5722 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5723 `info' files are also provided. To build `info' files from scratch,
5724 you will need the latest `makeinfo' release, which will be available in
5725 a future texinfo-X.Y release.
5727 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5728 We're not sure exactly which versions have this problem, but it has
5729 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5730 or better. If that isn't possible, there is a patch in
5731 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5732 around this problem.
5736 GDB now supports array constants that can be used in expressions typed in by
5737 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5738 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5741 The new directory `gdb/sparclite' contains a program that demonstrates
5742 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5744 * New native hosts supported
5746 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5747 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5749 * New targets supported
5751 AMD 29k family via UDI a29k-amd-udi or udi29k
5753 * New file formats supported
5755 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5756 HPUX core files, and SCO 3.2v2 core files.
5760 Attaching to processes now works again; thanks for the many bug reports.
5762 We have also stomped on a bunch of core dumps caused by
5763 printf_filtered("%s") problems.
5765 We eliminated a copyright problem on the rpc and ptrace header files
5766 for VxWorks, which was discovered at the last minute during the 4.7
5767 release. You should now be able to build a VxWorks GDB.
5769 You can now interrupt gdb while an attached process is running. This
5770 will cause the attached process to stop, and give control back to GDB.
5772 We fixed problems caused by using too many file descriptors
5773 for reading symbols from object files and libraries. This was
5774 especially a problem for programs that used many (~100) shared
5777 The `step' command now only enters a subroutine if there is line number
5778 information for the subroutine. Otherwise it acts like the `next'
5779 command. Previously, `step' would enter subroutines if there was
5780 any debugging information about the routine. This avoids problems
5781 when using `cc -g1' on MIPS machines.
5783 * Internal improvements
5785 GDB's internal interfaces have been improved to make it easier to support
5786 debugging of multiple languages in the future.
5788 GDB now uses a common structure for symbol information internally.
5789 Minimal symbols (derived from linkage symbols in object files), partial
5790 symbols (from a quick scan of debug information), and full symbols
5791 contain a common subset of information, making it easier to write
5792 shared code that handles any of them.
5794 * New command line options
5796 We now accept --silent as an alias for --quiet.
5800 The memory-mapped-malloc library is now licensed under the GNU Library
5801 General Public License.
5803 *** Changes in GDB-4.7:
5805 * Host/native/target split
5807 GDB has had some major internal surgery to untangle the support for
5808 hosts and remote targets. Now, when you configure GDB for a remote
5809 target, it will no longer load in all of the support for debugging
5810 local programs on the host. When fully completed and tested, this will
5811 ensure that arbitrary host/target combinations are possible.
5813 The primary conceptual shift is to separate the non-portable code in
5814 GDB into three categories. Host specific code is required any time GDB
5815 is compiled on that host, regardless of the target. Target specific
5816 code relates to the peculiarities of the target, but can be compiled on
5817 any host. Native specific code is everything else: it can only be
5818 built when the host and target are the same system. Child process
5819 handling and core file support are two common `native' examples.
5821 GDB's use of /proc for controlling Unix child processes is now cleaner.
5822 It has been split out into a single module under the `target_ops' vector,
5823 plus two native-dependent functions for each system that uses /proc.
5825 * New hosts supported
5827 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5828 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5829 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5831 * New targets supported
5833 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5834 68030 and CPU32 m68030-*-*, m68332-*-*
5836 * New native hosts supported
5838 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5839 (386bsd is not well tested yet)
5840 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5842 * New file formats supported
5844 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5845 supports reading of `a.out.adobe' object files, which are an a.out
5846 format extended with minimal information about multiple sections.
5850 `show copying' is the same as the old `info copying'.
5851 `show warranty' is the same as `info warrantee'.
5852 These were renamed for consistency. The old commands continue to work.
5854 `info handle' is a new alias for `info signals'.
5856 You can now define pre-command hooks, which attach arbitrary command
5857 scripts to any command. The commands in the hook will be executed
5858 prior to the user's command. You can also create a hook which will be
5859 executed whenever the program stops. See gdb.texinfo.
5863 We now deal with Cfront style name mangling, and can even extract type
5864 info from mangled symbols. GDB can automatically figure out which
5865 symbol mangling style your C++ compiler uses.
5867 Calling of methods and virtual functions has been improved as well.
5871 The crash that occured when debugging Sun Ansi-C compiled binaries is
5872 fixed. This was due to mishandling of the extra N_SO stabs output
5875 We also finally got Ultrix 4.2 running in house, and fixed core file
5876 support, with help from a dozen people on the net.
5878 John M. Farrell discovered that the reason that single-stepping was so
5879 slow on all of the Mips based platforms (primarily SGI and DEC) was
5880 that we were trying to demangle and lookup a symbol used for internal
5881 purposes on every instruction that was being stepped through. Changing
5882 the name of that symbol so that it couldn't be mistaken for a C++
5883 mangled symbol sped things up a great deal.
5885 Rich Pixley sped up symbol lookups in general by getting much smarter
5886 about when C++ symbol mangling is necessary. This should make symbol
5887 completion (TAB on the command line) much faster. It's not as fast as
5888 we'd like, but it's significantly faster than gdb-4.6.
5892 A new user controllable variable 'call_scratch_address' can
5893 specify the location of a scratch area to be used when GDB
5894 calls a function in the target. This is necessary because the
5895 usual method of putting the scratch area on the stack does not work
5896 in systems that have separate instruction and data spaces.
5898 We integrated changes to support the 29k UDI (Universal Debugger
5899 Interface), but discovered at the last minute that we didn't have all
5900 of the appropriate copyright paperwork. We are working with AMD to
5901 resolve this, and hope to have it available soon.
5905 We have sped up the remote serial line protocol, especially for targets
5906 with lots of registers. It now supports a new `expedited status' ('T')
5907 message which can be used in place of the existing 'S' status message.
5908 This allows the remote stub to send only the registers that GDB
5909 needs to make a quick decision about single-stepping or conditional
5910 breakpoints, eliminating the need to fetch the entire register set for
5911 each instruction being stepped through.
5913 The GDB remote serial protocol now implements a write-through cache for
5914 registers, only re-reading the registers if the target has run.
5916 There is also a new remote serial stub for SPARC processors. You can
5917 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5918 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5919 processor with a serial port.
5923 Configure.in files have become much easier to read and modify. A new
5924 `table driven' format makes it more obvious what configurations are
5925 supported, and what files each one uses.
5929 There is a new opcodes library which will eventually contain all of the
5930 disassembly routines and opcode tables. At present, it only contains
5931 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5932 disassembler (binutils/objdump) to share these routines.
5934 The libiberty library is now copylefted under the GNU Library General
5935 Public License. This allows more liberal use, and was done so libg++
5936 can use it. This makes no difference to GDB, since the Library License
5937 grants all the rights from the General Public License.
5941 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5942 reference to the stabs symbol info used by the debugger. It is (as far
5943 as we know) the only published document on this fascinating topic. We
5944 encourage you to read it, compare it to the stabs information on your
5945 system, and send improvements on the document in general (to
5946 bug-gdb@prep.ai.mit.edu).
5948 And, of course, many bugs have been fixed.
5951 *** Changes in GDB-4.6:
5953 * Better support for C++ function names
5955 GDB now accepts as input the "demangled form" of C++ overloaded function
5956 names and member function names, and can do command completion on such names
5957 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5958 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5959 Make use of command completion, it is your friend.
5961 GDB also now accepts a variety of C++ mangled symbol formats. They are
5962 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5963 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5964 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5965 for the list of formats.
5967 * G++ symbol mangling problem
5969 Recent versions of gcc have a bug in how they emit debugging information for
5970 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5971 directory) can be applied to gcc to fix the problem. Alternatively, if you
5972 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5973 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5974 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5977 * New 'maintenance' command
5979 All of the commands related to hacking GDB internals have been moved out of
5980 the main command set, and now live behind the 'maintenance' command. This
5981 can also be abbreviated as 'mt'. The following changes were made:
5983 dump-me -> maintenance dump-me
5984 info all-breakpoints -> maintenance info breakpoints
5985 printmsyms -> maintenance print msyms
5986 printobjfiles -> maintenance print objfiles
5987 printpsyms -> maintenance print psymbols
5988 printsyms -> maintenance print symbols
5990 The following commands are new:
5992 maintenance demangle Call internal GDB demangler routine to
5993 demangle a C++ link name and prints the result.
5994 maintenance print type Print a type chain for a given symbol
5996 * Change to .gdbinit file processing
5998 We now read the $HOME/.gdbinit file before processing the argv arguments
5999 (e.g. reading symbol files or core files). This allows global parameters to
6000 be set, which will apply during the symbol reading. The ./.gdbinit is still
6001 read after argv processing.
6003 * New hosts supported
6005 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6007 GNU/Linux support i386-unknown-linux or linux
6009 We are also including code to support the HP/PA running BSD and HPUX. This
6010 is almost guaranteed not to work, as we didn't have time to test or build it
6011 for this release. We are including it so that the more adventurous (or
6012 masochistic) of you can play with it. We also had major problems with the
6013 fact that the compiler that we got from HP doesn't support the -g option.
6016 * New targets supported
6018 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6020 * More smarts about finding #include files
6022 GDB now remembers the compilation directory for all include files, and for
6023 all files from which C is generated (like yacc and lex sources). This
6024 greatly improves GDB's ability to find yacc/lex sources, and include files,
6025 especially if you are debugging your program from a directory different from
6026 the one that contains your sources.
6028 We also fixed a bug which caused difficulty with listing and setting
6029 breakpoints in include files which contain C code. (In the past, you had to
6030 try twice in order to list an include file that you hadn't looked at before.)
6032 * Interesting infernals change
6034 GDB now deals with arbitrary numbers of sections, where the symbols for each
6035 section must be relocated relative to that section's landing place in the
6036 target's address space. This work was needed to support ELF with embedded
6037 stabs used by Solaris-2.0.
6039 * Bug fixes (of course!)
6041 There have been loads of fixes for the following things:
6042 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6043 i960, stabs, DOS(GO32), procfs, etc...
6045 See the ChangeLog for details.
6047 *** Changes in GDB-4.5:
6049 * New machines supported (host and target)
6051 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6053 SGI Irix-4.x mips-sgi-irix4 or iris4
6055 * New malloc package
6057 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6058 Mmalloc is capable of handling mutiple heaps of memory. It is also
6059 capable of saving a heap to a file, and then mapping it back in later.
6060 This can be used to greatly speedup the startup of GDB by using a
6061 pre-parsed symbol table which lives in a mmalloc managed heap. For
6062 more details, please read mmalloc/mmalloc.texi.
6066 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6067 'help info proc' for details.
6069 * MIPS ecoff symbol table format
6071 The code that reads MIPS symbol table format is now supported on all hosts.
6072 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6075 * File name changes for MS-DOS
6077 Many files in the config directories have been renamed to make it easier to
6078 support GDB on MS-DOSe systems (which have very restrictive file name
6079 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6080 environment) is close to working but has some remaining problems. Note
6081 that debugging of DOS programs is not supported, due to limitations
6082 in the ``operating system'', but it can be used to host cross-debugging.
6084 * Cross byte order fixes
6086 Many fixes have been made to support cross debugging of Sparc and MIPS
6087 targets from hosts whose byte order differs.
6089 * New -mapped and -readnow options
6091 If memory-mapped files are available on your system through the 'mmap'
6092 system call, you can use the -mapped option on the `file' or
6093 `symbol-file' commands to cause GDB to write the symbols from your
6094 program into a reusable file. If the program you are debugging is
6095 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6096 Future GDB debugging sessions will notice the presence of this file,
6097 and will quickly map in symbol information from it, rather than reading
6098 the symbol table from the executable program. Using the '-mapped'
6099 option in a GDB `file' or `symbol-file' command has the same effect as
6100 starting GDB with the '-mapped' command-line option.
6102 You can cause GDB to read the entire symbol table immediately by using
6103 the '-readnow' option with any of the commands that load symbol table
6104 information (or on the GDB command line). This makes the command
6105 slower, but makes future operations faster.
6107 The -mapped and -readnow options are typically combined in order to
6108 build a `fred.syms' file that contains complete symbol information.
6109 A simple GDB invocation to do nothing but build a `.syms' file for future
6112 gdb -batch -nx -mapped -readnow programname
6114 The `.syms' file is specific to the host machine on which GDB is run.
6115 It holds an exact image of GDB's internal symbol table. It cannot be
6116 shared across multiple host platforms.
6118 * longjmp() handling
6120 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6121 siglongjmp() without losing control. This feature has not yet been ported to
6122 all systems. It currently works on many 386 platforms, all MIPS-based
6123 platforms (SGI, DECstation, etc), and Sun3/4.
6127 Preliminary work has been put in to support the new Solaris OS from Sun. At
6128 this time, it can control and debug processes, but it is not capable of
6133 As always, many many bug fixes. The major areas were with g++, and mipsread.
6134 People using the MIPS-based platforms should experience fewer mysterious
6135 crashes and trashed symbol tables.
6137 *** Changes in GDB-4.4:
6139 * New machines supported (host and target)
6141 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6143 BSD Reno on Vax vax-dec-bsd
6144 Ultrix on Vax vax-dec-ultrix
6146 * New machines supported (target)
6148 AMD 29000 embedded, using EBMON a29k-none-none
6152 GDB continues to improve its handling of C++. `References' work better.
6153 The demangler has also been improved, and now deals with symbols mangled as
6154 per the Annotated C++ Reference Guide.
6156 GDB also now handles `stabs' symbol information embedded in MIPS
6157 `ecoff' symbol tables. Since the ecoff format was not easily
6158 extensible to handle new languages such as C++, this appeared to be a
6159 good way to put C++ debugging info into MIPS binaries. This option
6160 will be supported in the GNU C compiler, version 2, when it is
6163 * New features for SVR4
6165 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6166 shared libraries. Debugging dynamically linked programs should present
6167 only minor differences from debugging statically linked programs.
6169 The `info proc' command will print out information about any process
6170 on an SVR4 system (including the one you are debugging). At the moment,
6171 it prints the address mappings of the process.
6173 If you bring up GDB on another SVR4 system, please send mail to
6174 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6176 * Better dynamic linking support in SunOS
6178 Reading symbols from shared libraries which contain debugging symbols
6179 now works properly. However, there remain issues such as automatic
6180 skipping of `transfer vector' code during function calls, which
6181 make it harder to debug code in a shared library, than to debug the
6182 same code linked statically.
6186 GDB is now using the latest `getopt' routines from the FSF. This
6187 version accepts the -- prefix for options with long names. GDB will
6188 continue to accept the old forms (-option and +option) as well.
6189 Various single letter abbreviations for options have been explicity
6190 added to the option table so that they won't get overshadowed in the
6191 future by other options that begin with the same letter.
6195 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6196 Many assorted bugs have been handled. Many more remain to be handled.
6197 See the various ChangeLog files (primarily in gdb and bfd) for details.
6200 *** Changes in GDB-4.3:
6202 * New machines supported (host and target)
6204 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6205 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6206 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6208 * Almost SCO Unix support
6210 We had hoped to support:
6211 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6212 (except for core file support), but we discovered very late in the release
6213 that it has problems with process groups that render gdb unusable. Sorry
6214 about that. I encourage people to fix it and post the fixes.
6216 * Preliminary ELF and DWARF support
6218 GDB can read ELF object files on System V Release 4, and can handle
6219 debugging records for C, in DWARF format, in ELF files. This support
6220 is preliminary. If you bring up GDB on another SVR4 system, please
6221 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6226 GDB now uses the latest `readline' library. One user-visible change
6227 is that two tabs will list possible command completions, which previously
6228 required typing M-? (meta-question mark, or ESC ?).
6232 The `stepi' bug that many of you noticed has been squashed.
6233 Many bugs in C++ have been handled. Many more remain to be handled.
6234 See the various ChangeLog files (primarily in gdb and bfd) for details.
6236 * State of the MIPS world (in case you wondered):
6238 GDB can understand the symbol tables emitted by the compilers
6239 supplied by most vendors of MIPS-based machines, including DEC. These
6240 symbol tables are in a format that essentially nobody else uses.
6242 Some versions of gcc come with an assembler post-processor called
6243 mips-tfile. This program is required if you want to do source-level
6244 debugging of gcc-compiled programs. I believe FSF does not ship
6245 mips-tfile with gcc version 1, but it will eventually come with gcc
6248 Debugging of g++ output remains a problem. g++ version 1.xx does not
6249 really support it at all. (If you're lucky, you should be able to get
6250 line numbers and stack traces to work, but no parameters or local
6251 variables.) With some work it should be possible to improve the
6254 When gcc version 2 is released, you will have somewhat better luck.
6255 However, even then you will get confusing results for inheritance and
6258 We will eventually provide full debugging of g++ output on
6259 DECstations. This will probably involve some kind of stabs-in-ecoff
6260 encapulation, but the details have not been worked out yet.
6263 *** Changes in GDB-4.2:
6265 * Improved configuration
6267 Only one copy of `configure' exists now, and it is not self-modifying.
6268 Porting BFD is simpler.
6272 The `step' and `next' commands now only stop at the first instruction
6273 of a source line. This prevents the multiple stops that used to occur
6274 in switch statements, for-loops, etc. `Step' continues to stop if a
6275 function that has debugging information is called within the line.
6279 Lots of small bugs fixed. More remain.
6281 * New host supported (not target)
6283 Intel 386 PC clone running Mach i386-none-mach
6286 *** Changes in GDB-4.1:
6288 * Multiple source language support
6290 GDB now has internal scaffolding to handle several source languages.
6291 It determines the type of each source file from its filename extension,
6292 and will switch expression parsing and number formatting to match the
6293 language of the function in the currently selected stack frame.
6294 You can also specifically set the language to be used, with
6295 `set language c' or `set language modula-2'.
6299 GDB now has preliminary support for the GNU Modula-2 compiler,
6300 currently under development at the State University of New York at
6301 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6302 continue through the fall of 1991 and into 1992.
6304 Other Modula-2 compilers are currently not supported, and attempting to
6305 debug programs compiled with them will likely result in an error as the
6306 symbol table is read. Feel free to work on it, though!
6308 There are hooks in GDB for strict type checking and range checking,
6309 in the `Modula-2 philosophy', but they do not currently work.
6313 GDB can now write to executable and core files (e.g. patch
6314 a variable's value). You must turn this switch on, specify
6315 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6316 by assigning a new value to a variable. Modifications take
6319 * Automatic SunOS shared library reading
6321 When you run your program, GDB automatically determines where its
6322 shared libraries (if any) have been loaded, and reads their symbols.
6323 The `share' command is no longer needed. This also works when
6324 examining core files.
6328 You can specify the number of lines that the `list' command shows.
6331 * New machines supported (host and target)
6333 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6334 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6335 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6337 * New hosts supported (not targets)
6339 IBM RT/PC: romp-ibm-aix or rtpc
6341 * New targets supported (not hosts)
6343 AMD 29000 embedded with COFF a29k-none-coff
6344 AMD 29000 embedded with a.out a29k-none-aout
6345 Ultracomputer remote kernel debug a29k-nyu-kern
6347 * New remote interfaces
6353 *** Changes in GDB-4.0:
6357 Wide output is wrapped at good places to make the output more readable.
6359 Gdb now supports cross-debugging from a host machine of one type to a
6360 target machine of another type. Communication with the target system
6361 is over serial lines. The ``target'' command handles connecting to the
6362 remote system; the ``load'' command will download a program into the
6363 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6364 also supports debugging of realtime processes running under VxWorks,
6365 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6366 stub on the target system.
6368 New CPUs supported include the AMD 29000 and Intel 960.
6370 GDB now reads object files and symbol tables via a ``binary file''
6371 library, which allows a single copy of GDB to debug programs of multiple
6372 object file types such as a.out and coff.
6374 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6375 refcard.dvi and refcard.ps are available to format it).
6378 * Control-Variable user interface simplified
6380 All variables that control the operation of the debugger can be set
6381 by the ``set'' command, and displayed by the ``show'' command.
6383 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6384 ``Show prompt'' produces the response:
6385 Gdb's prompt is new-gdb=>.
6387 What follows are the NEW set commands. The command ``help set'' will
6388 print a complete list of old and new set commands. ``help set FOO''
6389 will give a longer description of the variable FOO. ``show'' will show
6390 all of the variable descriptions and their current settings.
6392 confirm on/off: Enables warning questions for operations that are
6393 hard to recover from, e.g. rerunning the program while
6394 it is already running. Default is ON.
6396 editing on/off: Enables EMACS style command line editing
6397 of input. Previous lines can be recalled with
6398 control-P, the current line can be edited with control-B,
6399 you can search for commands with control-R, etc.
6402 history filename NAME: NAME is where the gdb command history
6403 will be stored. The default is .gdb_history,
6404 or the value of the environment variable
6407 history size N: The size, in commands, of the command history. The
6408 default is 256, or the value of the environment variable
6411 history save on/off: If this value is set to ON, the history file will
6412 be saved after exiting gdb. If set to OFF, the
6413 file will not be saved. The default is OFF.
6415 history expansion on/off: If this value is set to ON, then csh-like
6416 history expansion will be performed on
6417 command line input. The default is OFF.
6419 radix N: Sets the default radix for input and output. It can be set
6420 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6421 in the current radix, so "set radix 10" is always a no-op.
6423 height N: This integer value is the number of lines on a page. Default
6424 is 24, the current `stty rows'' setting, or the ``li#''
6425 setting from the termcap entry matching the environment
6428 width N: This integer value is the number of characters on a line.
6429 Default is 80, the current `stty cols'' setting, or the ``co#''
6430 setting from the termcap entry matching the environment
6433 Note: ``set screensize'' is obsolete. Use ``set height'' and
6434 ``set width'' instead.
6436 print address on/off: Print memory addresses in various command displays,
6437 such as stack traces and structure values. Gdb looks
6438 more ``symbolic'' if you turn this off; it looks more
6439 ``machine level'' with it on. Default is ON.
6441 print array on/off: Prettyprint arrays. New convenient format! Default
6444 print demangle on/off: Print C++ symbols in "source" form if on,
6447 print asm-demangle on/off: Same, for assembler level printouts
6450 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6453 * Support for Epoch Environment.
6455 The epoch environment is a version of Emacs v18 with windowing. One
6456 new command, ``inspect'', is identical to ``print'', except that if you
6457 are running in the epoch environment, the value is printed in its own
6461 * Support for Shared Libraries
6463 GDB can now debug programs and core files that use SunOS shared libraries.
6464 Symbols from a shared library cannot be referenced
6465 before the shared library has been linked with the program (this
6466 happens after you type ``run'' and before the function main() is entered).
6467 At any time after this linking (including when examining core files
6468 from dynamically linked programs), gdb reads the symbols from each
6469 shared library when you type the ``sharedlibrary'' command.
6470 It can be abbreviated ``share''.
6472 sharedlibrary REGEXP: Load shared object library symbols for files
6473 matching a unix regular expression. No argument
6474 indicates to load symbols for all shared libraries.
6476 info sharedlibrary: Status of loaded shared libraries.
6481 A watchpoint stops execution of a program whenever the value of an
6482 expression changes. Checking for this slows down execution
6483 tremendously whenever you are in the scope of the expression, but is
6484 quite useful for catching tough ``bit-spreader'' or pointer misuse
6485 problems. Some machines such as the 386 have hardware for doing this
6486 more quickly, and future versions of gdb will use this hardware.
6488 watch EXP: Set a watchpoint (breakpoint) for an expression.
6490 info watchpoints: Information about your watchpoints.
6492 delete N: Deletes watchpoint number N (same as breakpoints).
6493 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6494 enable N: Re-enables watchpoint number N (same as breakpoints).
6497 * C++ multiple inheritance
6499 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6502 * C++ exception handling
6504 Gdb now supports limited C++ exception handling. Besides the existing
6505 ability to breakpoint on an exception handler, gdb can breakpoint on
6506 the raising of an exception (before the stack is peeled back to the
6509 catch FOO: If there is a FOO exception handler in the dynamic scope,
6510 set a breakpoint to catch exceptions which may be raised there.
6511 Multiple exceptions (``catch foo bar baz'') may be caught.
6513 info catch: Lists all exceptions which may be caught in the
6514 current stack frame.
6517 * Minor command changes
6519 The command ``call func (arg, arg, ...)'' now acts like the print
6520 command, except it does not print or save a value if the function's result
6521 is void. This is similar to dbx usage.
6523 The ``up'' and ``down'' commands now always print the frame they end up
6524 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6525 frames without printing.
6527 * New directory command
6529 'dir' now adds directories to the FRONT of the source search path.
6530 The path starts off empty. Source files that contain debug information
6531 about the directory in which they were compiled can be found even
6532 with an empty path; Sun CC and GCC include this information. If GDB can't
6533 find your source file in the current directory, type "dir .".
6535 * Configuring GDB for compilation
6537 For normal use, type ``./configure host''. See README or gdb.texinfo
6540 GDB now handles cross debugging. If you are remotely debugging between
6541 two different machines, type ``./configure host -target=targ''.
6542 Host is the machine where GDB will run; targ is the machine
6543 where the program that you are debugging will run.