1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.12
6 * Building GDB and GDBserver now requires a C++11 compiler.
8 For example, GCC 4.8 or later.
10 It is no longer possible to build GDB or GDBserver with a C
11 compiler. The --disable-build-with-cxx configure option has been
14 * Building GDB and GDBserver now requires GNU make >= 3.81.
16 It is no longer supported to build GDB or GDBserver with another
17 implementation of the make program or an earlier version of GNU make.
19 * Native debugging on MS-Windows supports command-line redirection
21 Command-line arguments used for starting programs on MS-Windows can
22 now include redirection symbols supported by native Windows shells,
23 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
24 as "run", "start", and "set args", as well as the corresponding MI
27 * Support for thread names on MS-Windows.
29 GDB now catches and handles the special exception that programs
30 running on MS-Windows use to assign names to threads in the
33 * Support for Java programs compiled with gcj has been removed.
35 * User commands now accept an unlimited number of arguments.
36 Previously, only up to 10 was accepted.
38 * The "eval" command now expands user-defined command arguments.
40 This makes it easier to process a variable number of arguments:
45 eval "print $arg%d", $i
52 Synopsys ARC arc*-*-elf32
54 *** Changes in GDB 7.12
56 * GDB and GDBserver now build with a C++ compiler by default.
58 The --enable-build-with-cxx configure option is now enabled by
59 default. One must now explicitly configure with
60 --disable-build-with-cxx in order to build with a C compiler. This
61 option will be removed in a future release.
63 * GDBserver now supports recording btrace without maintaining an active
66 * GDB now supports a negative repeat count in the 'x' command to examine
67 memory backward from the given address. For example:
70 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
71 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
72 (gdb) x/-5i 0x0000000000400580
73 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
74 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
75 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
76 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
77 0x40057b <main(int, char**)+25>:
78 callq 0x400536 <Func1(int, char const*)>
80 * Fortran: Support structures with fields of dynamic types and
81 arrays of dynamic types.
83 * The symbol dumping maintenance commands have new syntax.
84 maint print symbols [-pc address] [--] [filename]
85 maint print symbols [-objfile objfile] [-source source] [--] [filename]
86 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
87 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
88 maint print msymbols [-objfile objfile] [--] [filename]
90 * GDB now supports multibit bitfields and enums in target register
93 * New Python-based convenience function $_as_string(val), which returns
94 the textual representation of a value. This function is especially
95 useful to obtain the text label of an enum value.
97 * Intel MPX bound violation handling.
99 Segmentation faults caused by a Intel MPX boundary violation
100 now display the kind of violation (upper or lower), the memory
101 address accessed and the memory bounds, along with the usual
102 signal received and code location.
106 Program received signal SIGSEGV, Segmentation fault
107 Upper bound violation while accessing address 0x7fffffffc3b3
108 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
109 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
111 * Rust language support.
112 GDB now supports debugging programs written in the Rust programming
113 language. See https://www.rust-lang.org/ for more information about
116 * Support for running interpreters on specified input/output devices
118 GDB now supports a new mechanism that allows frontends to provide
119 fully featured GDB console views, as a better alternative to
120 building such views on top of the "-interpreter-exec console"
121 command. See the new "new-ui" command below. With that command,
122 frontends can now start GDB in the traditional command-line mode
123 running in an embedded terminal emulator widget, and create a
124 separate MI interpreter running on a specified i/o device. In this
125 way, GDB handles line editing, history, tab completion, etc. in the
126 console all by itself, and the GUI uses the separate MI interpreter
127 for its own control and synchronization, invisible to the command
130 * The "catch syscall" command catches groups of related syscalls.
132 The "catch syscall" command now supports catching a group of related
133 syscalls using the 'group:' or 'g:' prefix.
138 skip -gfile file-glob-pattern
139 skip -function function
140 skip -rfunction regular-expression
141 A generalized form of the skip command, with new support for
142 glob-style file names and regular expressions for function names.
143 Additionally, a file spec and a function spec may now be combined.
145 maint info line-table REGEXP
146 Display the contents of GDB's internal line table data struture.
149 Run any GDB unit tests that were compiled in.
152 Start a new user interface instance running INTERP as interpreter,
153 using the TTY file for input/output.
157 ** gdb.Breakpoint objects have a new attribute "pending", which
158 indicates whether the breakpoint is pending.
159 ** Three new breakpoint-related events have been added:
160 gdb.breakpoint_created, gdb.breakpoint_modified, and
161 gdb.breakpoint_deleted.
164 Signal ("set") the given MS-Windows event object. This is used in
165 conjunction with the Windows JIT debugging (AeDebug) support, where
166 the OS suspends a crashing process until a debugger can attach to
167 it. Resuming the crashing process, in order to debug it, is done by
170 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
171 was added in GDBserver, including JIT compiling fast tracepoint's
172 conditional expression bytecode into native code.
174 * Support for various remote target protocols and ROM monitors has
177 target m32rsdi Remote M32R debugging over SDI
178 target mips MIPS remote debugging protocol
179 target pmon PMON ROM monitor
180 target ddb NEC's DDB variant of PMON for Vr4300
181 target rockhopper NEC RockHopper variant of PMON
182 target lsi LSI variant of PMO
184 * Support for tracepoints and fast tracepoints on powerpc-linux,
185 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
186 including JIT compiling fast tracepoint's conditional expression
187 bytecode into native code.
189 * MI async record =record-started now includes the method and format used for
190 recording. For example:
192 =record-started,thread-group="i1",method="btrace",format="bts"
194 * MI async record =thread-selected now includes the frame field. For example:
196 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
200 Andes NDS32 nds32*-*-elf
202 *** Changes in GDB 7.11
204 * GDB now supports debugging kernel-based threads on FreeBSD.
206 * Per-inferior thread numbers
208 Thread numbers are now per inferior instead of global. If you're
209 debugging multiple inferiors, GDB displays thread IDs using a
210 qualified INF_NUM.THR_NUM form. For example:
214 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
215 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
216 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
217 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
219 As consequence, thread numbers as visible in the $_thread
220 convenience variable and in Python's InferiorThread.num attribute
221 are no longer unique between inferiors.
223 GDB now maintains a second thread ID per thread, referred to as the
224 global thread ID, which is the new equivalent of thread numbers in
225 previous releases. See also $_gthread below.
227 For backwards compatibility, MI's thread IDs always refer to global
230 * Commands that accept thread IDs now accept the qualified
231 INF_NUM.THR_NUM form as well. For example:
234 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
237 * In commands that accept a list of thread IDs, you can now refer to
238 all threads of an inferior using a star wildcard. GDB accepts
239 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
240 refer to all threads of the current inferior. For example, "info
243 * You can use "info threads -gid" to display the global thread ID of
246 * The new convenience variable $_gthread holds the global number of
249 * The new convenience variable $_inferior holds the number of the
252 * GDB now displays the ID and name of the thread that hit a breakpoint
253 or received a signal, if your program is multi-threaded. For
256 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
257 Thread 1 "main" received signal SIGINT, Interrupt.
259 * Record btrace now supports non-stop mode.
261 * Support for tracepoints on aarch64-linux was added in GDBserver.
263 * The 'record instruction-history' command now indicates speculative execution
264 when using the Intel Processor Trace recording format.
266 * GDB now allows users to specify explicit locations, bypassing
267 the linespec parser. This feature is also available to GDB/MI
270 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
271 GDB now is able to debug both AArch64 applications and ARM applications
274 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
275 including JIT compiling fast tracepoint's conditional expression bytecode
278 * GDB now supports displaced stepping on AArch64 GNU/Linux.
280 * "info threads", "info inferiors", "info display", "info checkpoints"
281 and "maint info program-spaces" now list the corresponding items in
282 ascending ID order, for consistency with all other "info" commands.
284 * In Ada, the overloads selection menu has been enhanced to display the
285 parameter types and the return types for the matching overloaded subprograms.
289 maint set target-non-stop (on|off|auto)
290 maint show target-non-stop
291 Control whether GDB targets always operate in non-stop mode even if
292 "set non-stop" is "off". The default is "auto", meaning non-stop
293 mode is enabled if supported by the target.
295 maint set bfd-sharing
296 maint show bfd-sharing
297 Control the reuse of bfd objects.
301 Control display of debugging info regarding bfd caching.
305 Control display of debugging info regarding FreeBSD threads.
307 set remote multiprocess-extensions-packet
308 show remote multiprocess-extensions-packet
309 Set/show the use of the remote protocol multiprocess extensions.
311 set remote thread-events
312 show remote thread-events
313 Set/show the use of thread create/exit events.
315 set ada print-signatures on|off
316 show ada print-signatures"
317 Control whether parameter types and return types are displayed in overloads
318 selection menus. It is activaled (@code{on}) by default.
322 Controls the maximum size of memory, in bytes, that GDB will
323 allocate for value contents. Prevents incorrect programs from
324 causing GDB to allocate overly large buffers. Default is 64k.
326 * The "disassemble" command accepts a new modifier: /s.
327 It prints mixed source+disassembly like /m with two differences:
328 - disassembled instructions are now printed in program order, and
329 - and source for all relevant files is now printed.
330 The "/m" option is now considered deprecated: its "source-centric"
331 output hasn't proved useful in practice.
333 * The "record instruction-history" command accepts a new modifier: /s.
334 It behaves exactly like /m and prints mixed source+disassembly.
336 * The "set scheduler-locking" command supports a new mode "replay".
337 It behaves like "off" in record mode and like "on" in replay mode.
339 * Support for various ROM monitors has been removed:
341 target dbug dBUG ROM monitor for Motorola ColdFire
342 target picobug Motorola picobug monitor
343 target dink32 DINK32 ROM monitor for PowerPC
344 target m32r Renesas M32R/D ROM monitor
345 target mon2000 mon2000 ROM monitor
346 target ppcbug PPCBUG ROM monitor for PowerPC
348 * Support for reading/writing memory and extracting values on architectures
349 whose memory is addressable in units of any integral multiple of 8 bits.
354 Indicates that an exec system call was executed.
356 exec-events feature in qSupported
357 The qSupported packet allows GDB to request support for exec
358 events using the new 'gdbfeature' exec-event, and the qSupported
359 response can contain the corresponding 'stubfeature'. Set and
360 show commands can be used to display whether these features are enabled.
363 Equivalent to interrupting with the ^C character, but works in
366 thread created stop reason (T05 create:...)
367 Indicates that the thread was just created and is stopped at entry.
369 thread exit stop reply (w exitcode;tid)
370 Indicates that the thread has terminated.
373 Enables/disables thread create and exit event reporting. For
374 example, this is used in non-stop mode when GDB stops a set of
375 threads and synchronously waits for the their corresponding stop
376 replies. Without exit events, if one of the threads exits, GDB
377 would hang forever not knowing that it should no longer expect a
378 stop for that same thread.
381 Indicates that there are no resumed threads left in the target (all
382 threads are stopped). The remote stub reports support for this stop
383 reply to GDB's qSupported query.
386 Enables/disables catching syscalls from the inferior process.
387 The remote stub reports support for this packet to GDB's qSupported query.
389 syscall_entry stop reason
390 Indicates that a syscall was just called.
392 syscall_return stop reason
393 Indicates that a syscall just returned.
395 * Extended-remote exec events
397 ** GDB now has support for exec events on extended-remote Linux targets.
398 For such targets with Linux kernels 2.5.46 and later, this enables
399 follow-exec-mode and exec catchpoints.
401 set remote exec-event-feature-packet
402 show remote exec-event-feature-packet
403 Set/show the use of the remote exec event feature.
405 * Thread names in remote protocol
407 The reply to qXfer:threads:read may now include a name attribute for each
410 * Target remote mode fork and exec events
412 ** GDB now has support for fork and exec events on target remote mode
413 Linux targets. For such targets with Linux kernels 2.5.46 and later,
414 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
415 fork and exec catchpoints.
417 * Remote syscall events
419 ** GDB now has support for catch syscall on remote Linux targets,
420 currently enabled on x86/x86_64 architectures.
422 set remote catch-syscall-packet
423 show remote catch-syscall-packet
424 Set/show the use of the remote catch syscall feature.
428 ** The -var-set-format command now accepts the zero-hexadecimal
429 format. It outputs data in hexadecimal format with zero-padding on the
434 ** gdb.InferiorThread objects have a new attribute "global_num",
435 which refers to the thread's global thread ID. The existing
436 "num" attribute now refers to the thread's per-inferior number.
437 See "Per-inferior thread numbers" above.
438 ** gdb.InferiorThread objects have a new attribute "inferior", which
439 is the Inferior object the thread belongs to.
441 *** Changes in GDB 7.10
443 * Support for process record-replay and reverse debugging on aarch64*-linux*
444 targets has been added. GDB now supports recording of A64 instruction set
445 including advance SIMD instructions.
447 * Support for Sun's version of the "stabs" debug file format has been removed.
449 * GDB now honors the content of the file /proc/PID/coredump_filter
450 (PID is the process ID) on GNU/Linux systems. This file can be used
451 to specify the types of memory mappings that will be included in a
452 corefile. For more information, please refer to the manual page of
453 "core(5)". GDB also has a new command: "set use-coredump-filter
454 on|off". It allows to set whether GDB will read the content of the
455 /proc/PID/coredump_filter file when generating a corefile.
457 * The "info os" command on GNU/Linux can now display information on
459 "info os cpus" Listing of all cpus/cores on the system
461 * GDB has two new commands: "set serial parity odd|even|none" and
462 "show serial parity". These allows to set or show parity for the
465 * The "info source" command now displays the producer string if it was
466 present in the debug info. This typically includes the compiler version
467 and may include things like its command line arguments.
469 * The "info dll", an alias of the "info sharedlibrary" command,
470 is now available on all platforms.
472 * Directory names supplied to the "set sysroot" commands may be
473 prefixed with "target:" to tell GDB to access shared libraries from
474 the target system, be it local or remote. This replaces the prefix
475 "remote:". The default sysroot has been changed from "" to
476 "target:". "remote:" is automatically converted to "target:" for
477 backward compatibility.
479 * The system root specified by "set sysroot" will be prepended to the
480 filename of the main executable (if reported to GDB as absolute by
481 the operating system) when starting processes remotely, and when
482 attaching to already-running local or remote processes.
484 * GDB now supports automatic location and retrieval of executable
485 files from remote targets. Remote debugging can now be initiated
486 using only a "target remote" or "target extended-remote" command
487 (no "set sysroot" or "file" commands are required). See "New remote
490 * The "dump" command now supports verilog hex format.
492 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
494 * On GNU/Linux, GDB and gdbserver are now able to access executable
495 and shared library files without a "set sysroot" command when
496 attaching to processes running in different mount namespaces from
497 the debugger. This makes it possible to attach to processes in
498 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
499 See "New remote packets" below.
501 * The "tui reg" command now provides completion for all of the
502 available register groups, including target specific groups.
504 * The HISTSIZE environment variable is no longer read when determining
505 the size of GDB's command history. GDB now instead reads the dedicated
506 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
507 disables truncation of command history. Non-numeric values of GDBHISTSIZE
512 ** Memory ports can now be unbuffered.
516 ** gdb.Objfile objects have a new attribute "username",
517 which is the name of the objfile as specified by the user,
518 without, for example, resolving symlinks.
519 ** You can now write frame unwinders in Python.
520 ** gdb.Type objects have a new method "optimized_out",
521 returning optimized out gdb.Value instance of this type.
522 ** gdb.Value objects have new methods "reference_value" and
523 "const_value" which return a reference to the value and a
524 "const" version of the value respectively.
528 maint print symbol-cache
529 Print the contents of the symbol cache.
531 maint print symbol-cache-statistics
532 Print statistics of symbol cache usage.
534 maint flush-symbol-cache
535 Flush the contents of the symbol cache.
539 Start branch trace recording using Branch Trace Store (BTS) format.
542 Evaluate expression by using the compiler and print result.
546 Explicit commands for enabling and disabling tui mode.
549 set mpx bound on i386 and amd64
550 Support for bound table investigation on Intel MPX enabled applications.
554 Start branch trace recording using Intel Processor Trace format.
557 Print information about branch tracing internals.
559 maint btrace packet-history
560 Print the raw branch tracing data.
562 maint btrace clear-packet-history
563 Discard the stored raw branch tracing data.
566 Discard all branch tracing data. It will be fetched and processed
567 anew by the next "record" command.
572 Renamed from "set debug dwarf2-die".
574 Renamed from "show debug dwarf2-die".
577 Renamed from "set debug dwarf2-read".
578 show debug dwarf-read
579 Renamed from "show debug dwarf2-read".
581 maint set dwarf always-disassemble
582 Renamed from "maint set dwarf2 always-disassemble".
583 maint show dwarf always-disassemble
584 Renamed from "maint show dwarf2 always-disassemble".
586 maint set dwarf max-cache-age
587 Renamed from "maint set dwarf2 max-cache-age".
588 maint show dwarf max-cache-age
589 Renamed from "maint show dwarf2 max-cache-age".
592 show debug dwarf-line
593 Control display of debugging info regarding DWARF line processing.
597 Set the maximum number of candidates to be considered during
598 completion. The default value is 200. This limit allows GDB
599 to avoid generating large completion lists, the computation of
600 which can cause the debugger to become temporarily unresponsive.
602 set history remove-duplicates
603 show history remove-duplicates
604 Control the removal of duplicate history entries.
606 maint set symbol-cache-size
607 maint show symbol-cache-size
608 Control the size of the symbol cache.
610 set|show record btrace bts buffer-size
611 Set and show the size of the ring buffer used for branch tracing in
613 The obtained size may differ from the requested size. Use "info
614 record" to see the obtained buffer size.
616 set debug linux-namespaces
617 show debug linux-namespaces
618 Control display of debugging info regarding Linux namespaces.
620 set|show record btrace pt buffer-size
621 Set and show the size of the ring buffer used for branch tracing in
622 Intel Processor Trace format.
623 The obtained size may differ from the requested size. Use "info
624 record" to see the obtained buffer size.
626 maint set|show btrace pt skip-pad
627 Set and show whether PAD packets are skipped when computing the
630 * The command 'thread apply all' can now support new option '-ascending'
631 to call its specified command for all threads in ascending order.
633 * Python/Guile scripting
635 ** GDB now supports auto-loading of Python/Guile scripts contained in the
636 special section named `.debug_gdb_scripts'.
640 qXfer:btrace-conf:read
641 Return the branch trace configuration for the current thread.
643 Qbtrace-conf:bts:size
644 Set the requested ring buffer size for branch tracing in BTS format.
647 Enable Intel Procesor Trace-based branch tracing for the current
648 process. The remote stub reports support for this packet to GDB's
652 Set the requested ring buffer size for branch tracing in Intel Processor
656 Indicates a memory breakpoint instruction was executed, irrespective
657 of whether it was GDB that planted the breakpoint or the breakpoint
658 is hardcoded in the program. This is required for correct non-stop
662 Indicates the target stopped for a hardware breakpoint. This is
663 required for correct non-stop mode operation.
666 Return information about files on the remote system.
669 Return the full absolute name of the file that was executed to
670 create a process running on the remote system.
673 Select the filesystem on which vFile: operations with filename
674 arguments will operate. This is required for GDB to be able to
675 access files on remote targets where the remote stub does not
676 share a common filesystem with the inferior(s).
679 Indicates that a fork system call was executed.
682 Indicates that a vfork system call was executed.
684 vforkdone stop reason
685 Indicates that a vfork child of the specified process has executed
686 an exec or exit, allowing the vfork parent to resume execution.
688 fork-events and vfork-events features in qSupported
689 The qSupported packet allows GDB to request support for fork and
690 vfork events using new 'gdbfeatures' fork-events and vfork-events,
691 and the qSupported response can contain the corresponding
692 'stubfeatures'. Set and show commands can be used to display
693 whether these features are enabled.
695 * Extended-remote fork events
697 ** GDB now has support for fork events on extended-remote Linux
698 targets. For targets with Linux kernels 2.5.60 and later, this
699 enables follow-fork-mode and detach-on-fork for both fork and
700 vfork, as well as fork and vfork catchpoints.
702 * The info record command now shows the recording format and the
703 branch tracing configuration for the current thread when using
704 the btrace record target.
705 For the BTS format, it shows the ring buffer size.
707 * GDB now has support for DTrace USDT (Userland Static Defined
708 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
710 * GDB now supports access to vector registers on S/390 GNU/Linux
713 * Removed command line options
715 -xdb HP-UX XDB compatibility mode.
717 * Removed targets and native configurations
719 HP/PA running HP-UX hppa*-*-hpux*
720 Itanium running HP-UX ia64-*-hpux*
722 * New configure options
725 This configure option allows the user to build GDB with support for
726 Intel Processor Trace (default: auto). This requires libipt.
728 --with-libipt-prefix=PATH
729 Specify the path to the version of libipt that GDB should use.
730 $PATH/include should contain the intel-pt.h header and
731 $PATH/lib should contain the libipt.so library.
733 *** Changes in GDB 7.9.1
737 ** Xmethods can now specify a result type.
739 *** Changes in GDB 7.9
741 * GDB now supports hardware watchpoints on x86 GNU Hurd.
745 ** You can now access frame registers from Python scripts.
746 ** New attribute 'producer' for gdb.Symtab objects.
747 ** gdb.Objfile objects have a new attribute "progspace",
748 which is the gdb.Progspace object of the containing program space.
749 ** gdb.Objfile objects have a new attribute "owner".
750 ** gdb.Objfile objects have a new attribute "build_id",
751 which is the build ID generated when the file was built.
752 ** gdb.Objfile objects have a new method "add_separate_debug_file".
753 ** A new event "gdb.clear_objfiles" has been added, triggered when
754 selecting a new file to debug.
755 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
756 ** New function gdb.lookup_objfile.
758 New events which are triggered when GDB modifies the state of the
761 ** gdb.events.inferior_call_pre: Function call is about to be made.
762 ** gdb.events.inferior_call_post: Function call has just been made.
763 ** gdb.events.memory_changed: A memory location has been altered.
764 ** gdb.events.register_changed: A register has been altered.
766 * New Python-based convenience functions:
768 ** $_caller_is(name [, number_of_frames])
769 ** $_caller_matches(regexp [, number_of_frames])
770 ** $_any_caller_is(name [, number_of_frames])
771 ** $_any_caller_matches(regexp [, number_of_frames])
773 * GDB now supports the compilation and injection of source code into
774 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
775 to compile the source code to object code, and if successful, inject
776 and execute that code within the current context of the inferior.
777 Currently the C language is supported. The commands used to
778 interface with this new feature are:
780 compile code [-raw|-r] [--] [source code]
781 compile file [-raw|-r] filename
785 demangle [-l language] [--] name
786 Demangle "name" in the specified language, or the current language
787 if elided. This command is renamed from the "maint demangle" command.
788 The latter is kept as a no-op to avoid "maint demangle" being interpreted
789 as "maint demangler-warning".
791 queue-signal signal-name-or-number
792 Queue a signal to be delivered to the thread when it is resumed.
794 add-auto-load-scripts-directory directory
795 Add entries to the list of directories from which to load auto-loaded
798 maint print user-registers
799 List all currently available "user" registers.
801 compile code [-r|-raw] [--] [source code]
802 Compile, inject, and execute in the inferior the executable object
803 code produced by compiling the provided source code.
805 compile file [-r|-raw] filename
806 Compile and inject into the inferior the executable object code
807 produced by compiling the source code stored in the filename
810 * On resume, GDB now always passes the signal the program had stopped
811 for to the thread the signal was sent to, even if the user changed
812 threads before resuming. Previously GDB would often (but not
813 always) deliver the signal to the thread that happens to be current
816 * Conversely, the "signal" command now consistently delivers the
817 requested signal to the current thread. GDB now asks for
818 confirmation if the program had stopped for a signal and the user
819 switched threads meanwhile.
821 * "breakpoint always-inserted" modes "off" and "auto" merged.
823 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
824 won't remove breakpoints from the target until all threads stop,
825 even in non-stop mode. The "auto" mode has been removed, and "off"
826 is now the default mode.
830 set debug symbol-lookup
831 show debug symbol-lookup
832 Control display of debugging info regarding symbol lookup.
836 ** The -list-thread-groups command outputs an exit-code field for
837 inferiors that have exited.
841 MIPS SDE mips*-sde*-elf*
845 Support for these obsolete configurations has been removed.
847 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
848 SGI Irix-5.x mips-*-irix5*
849 SGI Irix-6.x mips-*-irix6*
850 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
851 VAX running Ultrix vax-*-ultrix*
853 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
854 and "assf"), have been removed. Use the "sharedlibrary" command, or
855 its alias "share", instead.
857 *** Changes in GDB 7.8
859 * New command line options
862 This is an alias for the --data-directory option.
864 * GDB supports printing and modifying of variable length automatic arrays
865 as specified in ISO C99.
867 * The ARM simulator now supports instruction level tracing
868 with or without disassembly.
872 GDB now has support for scripting using Guile. Whether this is
873 available is determined at configure time.
874 Guile version 2.0 or greater is required.
875 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
877 * New commands (for set/show, see "New options" below)
881 Invoke CODE by passing it to the Guile interpreter.
885 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
887 info auto-load guile-scripts [regexp]
888 Print the list of automatically loaded Guile scripts.
890 * The source command is now capable of sourcing Guile scripts.
891 This feature is dependent on the debugger being built with Guile support.
895 set print symbol-loading (off|brief|full)
896 show print symbol-loading
897 Control whether to print informational messages when loading symbol
898 information for a file. The default is "full", but when debugging
899 programs with large numbers of shared libraries the amount of output
902 set guile print-stack (none|message|full)
903 show guile print-stack
904 Show a stack trace when an error is encountered in a Guile script.
906 set auto-load guile-scripts (on|off)
907 show auto-load guile-scripts
908 Control auto-loading of Guile script files.
910 maint ada set ignore-descriptive-types (on|off)
911 maint ada show ignore-descriptive-types
912 Control whether the debugger should ignore descriptive types in Ada
913 programs. The default is not to ignore the descriptive types. See
914 the user manual for more details on descriptive types and the intended
915 usage of this option.
917 set auto-connect-native-target
919 Control whether GDB is allowed to automatically connect to the
920 native target for the run, attach, etc. commands when not connected
921 to any target yet. See also "target native" below.
923 set record btrace replay-memory-access (read-only|read-write)
924 show record btrace replay-memory-access
925 Control what memory accesses are allowed during replay.
927 maint set target-async (on|off)
928 maint show target-async
929 This controls whether GDB targets operate in synchronous or
930 asynchronous mode. Normally the default is asynchronous, if it is
931 available; but this can be changed to more easily debug problems
932 occurring only in synchronous mode.
934 set mi-async (on|off)
936 Control whether MI asynchronous mode is preferred. This supersedes
937 "set target-async" of previous GDB versions.
939 * "set target-async" is deprecated as a CLI option and is now an alias
940 for "set mi-async" (only puts MI into async mode).
942 * Background execution commands (e.g., "c&", "s&", etc.) are now
943 possible ``out of the box'' if the target supports them. Previously
944 the user would need to explicitly enable the possibility with the
945 "set target-async on" command.
947 * New features in the GDB remote stub, GDBserver
949 ** New option --debug-format=option1[,option2,...] allows one to add
950 additional text to each output. At present only timestamps
951 are supported: --debug-format=timestamps.
952 Timestamps can also be turned on with the
953 "monitor set debug-format timestamps" command from GDB.
955 * The 'record instruction-history' command now starts counting instructions
956 at one. This also affects the instruction ranges reported by the
957 'record function-call-history' command when given the /i modifier.
959 * The command 'record function-call-history' supports a new modifier '/c' to
960 indent the function names based on their call stack depth.
961 The fields for the '/i' and '/l' modifier have been reordered.
962 The source line range is now prefixed with 'at'.
963 The instruction range is now prefixed with 'inst'.
964 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
965 "record instruction-history" and "list" commands.
967 * The ranges given as arguments to the 'record function-call-history' and
968 'record instruction-history' commands are now inclusive.
970 * The btrace record target now supports the 'record goto' command.
971 For locations inside the execution trace, the back trace is computed
972 based on the information stored in the execution trace.
974 * The btrace record target supports limited reverse execution and replay.
975 The target does not record data and therefore does not allow reading
978 * The "catch syscall" command now works on s390*-linux* targets.
980 * The "compare-sections" command is no longer specific to target
981 remote. It now works with all targets.
983 * All native targets are now consistently called "native".
984 Consequently, the "target child", "target GNU", "target djgpp",
985 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
986 commands have been replaced with "target native". The QNX/NTO port
987 leaves the "procfs" target in place and adds a "native" target for
988 consistency with other ports. The impact on users should be minimal
989 as these commands previously either throwed an error, or were
990 no-ops. The target's name is visible in the output of the following
991 commands: "help target", "info target", "info files", "maint print
994 * The "target native" command now connects to the native target. This
995 can be used to launch native programs even when "set
996 auto-connect-native-target" is set to off.
998 * GDB now supports access to Intel MPX registers on GNU/Linux.
1000 * Support for Intel AVX-512 registers on GNU/Linux.
1001 Support displaying and modifying Intel AVX-512 registers
1002 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1004 * New remote packets
1006 qXfer:btrace:read's annex
1007 The qXfer:btrace:read packet supports a new annex 'delta' to read
1008 branch trace incrementally.
1012 ** Valid Python operations on gdb.Value objects representing
1013 structs/classes invoke the corresponding overloaded operators if
1015 ** New `Xmethods' feature in the Python API. Xmethods are
1016 additional methods or replacements for existing methods of a C++
1017 class. This feature is useful for those cases where a method
1018 defined in C++ source code could be inlined or optimized out by
1019 the compiler, making it unavailable to GDB.
1022 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1024 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1025 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1026 its alias "share", instead.
1028 * The commands "set remotebaud" and "show remotebaud" are no longer
1029 supported. Use "set serial baud" and "show serial baud" (respectively)
1034 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1035 target-async". The latter is left as a deprecated alias of the
1036 former for backward compatibility. If the target supports it,
1037 CLI background execution commands are now always possible by
1038 default, independently of whether the frontend stated a
1039 preference for asynchronous execution with "-gdb-set mi-async".
1040 Previously "-gdb-set target-async off" affected both MI execution
1041 commands and CLI execution commands.
1043 *** Changes in GDB 7.7
1045 * Improved support for process record-replay and reverse debugging on
1046 arm*-linux* targets. Support for thumb32 and syscall instruction
1047 recording has been added.
1049 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1051 * GDB now supports Fission DWP file format version 2.
1052 http://gcc.gnu.org/wiki/DebugFission
1054 * New convenience function "$_isvoid", to check whether an expression
1055 is void. A void expression is an expression where the type of the
1056 result is "void". For example, some convenience variables may be
1057 "void" when evaluated (e.g., "$_exitcode" before the execution of
1058 the program being debugged; or an undefined convenience variable).
1059 Another example, when calling a function whose return type is
1062 * The "maintenance print objfiles" command now takes an optional regexp.
1064 * The "catch syscall" command now works on arm*-linux* targets.
1066 * GDB now consistently shows "<not saved>" when printing values of
1067 registers the debug info indicates have not been saved in the frame
1068 and there's nowhere to retrieve them from
1069 (callee-saved/call-clobbered registers):
1074 (gdb) info registers rax
1077 Before, the former would print "<optimized out>", and the latter
1078 "*value not available*".
1080 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1085 ** Frame filters and frame decorators have been added.
1086 ** Temporary breakpoints are now supported.
1087 ** Line tables representation has been added.
1088 ** New attribute 'parent_type' for gdb.Field objects.
1089 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1090 ** New attribute 'name' for gdb.Type objects.
1094 Nios II ELF nios2*-*-elf
1095 Nios II GNU/Linux nios2*-*-linux
1096 Texas Instruments MSP430 msp430*-*-elf
1098 * Removed native configurations
1100 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1101 been removed. ELF variants of these configurations are kept supported.
1103 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1104 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1105 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1106 i[34567]86-*-openbsd3.[0-3]
1107 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1108 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1109 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1113 Like "catch throw", but catches a re-thrown exception.
1114 maint check-psymtabs
1115 Renamed from old "maint check-symtabs".
1117 Perform consistency checks on symtabs.
1118 maint expand-symtabs
1119 Expand symtabs matching an optional regexp.
1122 Display the details of GDB configure-time options.
1124 maint set|show per-command
1125 maint set|show per-command space
1126 maint set|show per-command time
1127 maint set|show per-command symtab
1128 Enable display of per-command gdb resource usage.
1130 remove-symbol-file FILENAME
1131 remove-symbol-file -a ADDRESS
1132 Remove a symbol file added via add-symbol-file. The file to remove
1133 can be identified by its filename or by an address that lies within
1134 the boundaries of this symbol file in memory.
1137 info exceptions REGEXP
1138 Display the list of Ada exceptions defined in the program being
1139 debugged. If provided, only the exceptions whose names match REGEXP
1144 set debug symfile off|on
1146 Control display of debugging info regarding reading symbol files and
1147 symbol tables within those files
1149 set print raw frame-arguments
1150 show print raw frame-arguments
1151 Set/show whether to print frame arguments in raw mode,
1152 disregarding any defined pretty-printers.
1154 set remote trace-status-packet
1155 show remote trace-status-packet
1156 Set/show the use of remote protocol qTStatus packet.
1160 Control display of debugging messages related to Nios II targets.
1164 Control whether target-assisted range stepping is enabled.
1166 set startup-with-shell
1167 show startup-with-shell
1168 Specifies whether Unix child processes are started via a shell or
1173 Use the target memory cache for accesses to the code segment. This
1174 improves performance of remote debugging (particularly disassembly).
1176 * You can now use a literal value 'unlimited' for options that
1177 interpret 0 or -1 as meaning "unlimited". E.g., "set
1178 trace-buffer-size unlimited" is now an alias for "set
1179 trace-buffer-size -1" and "set height unlimited" is now an alias for
1182 * The "set debug symtab-create" debugging option of GDB has been changed to
1183 accept a verbosity level. 0 means "off", 1 provides basic debugging
1184 output, and values of 2 or greater provides more verbose output.
1186 * New command-line options
1188 Display the details of GDB configure-time options.
1190 * The command 'tsave' can now support new option '-ctf' to save trace
1191 buffer in Common Trace Format.
1193 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1196 * GDB now implements the the C++ 'typeid' operator.
1198 * The new convenience variable $_exception holds the exception being
1199 thrown or caught at an exception-related catchpoint.
1201 * The exception-related catchpoints, like "catch throw", now accept a
1202 regular expression which can be used to filter exceptions by type.
1204 * The new convenience variable $_exitsignal is automatically set to
1205 the terminating signal number when the program being debugged dies
1206 due to an uncaught signal.
1210 ** All MI commands now accept an optional "--language" option.
1211 Support for this feature can be verified by using the "-list-features"
1212 command, which should contain "language-option".
1214 ** The new command -info-gdb-mi-command allows the user to determine
1215 whether a GDB/MI command is supported or not.
1217 ** The "^error" result record returned when trying to execute an undefined
1218 GDB/MI command now provides a variable named "code" whose content is the
1219 "undefined-command" error code. Support for this feature can be verified
1220 by using the "-list-features" command, which should contain
1221 "undefined-command-error-code".
1223 ** The -trace-save MI command can optionally save trace buffer in Common
1226 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1228 ** The command -data-list-register-values now accepts an optional
1229 "--skip-unavailable" option. When used, only the available registers
1232 ** The new command -trace-frame-collected dumps collected variables,
1233 computed expressions, tvars, memory and registers in a traceframe.
1235 ** The commands -stack-list-locals, -stack-list-arguments and
1236 -stack-list-variables now accept an option "--skip-unavailable".
1237 When used, only the available locals or arguments are displayed.
1239 ** The -exec-run command now accepts an optional "--start" option.
1240 When used, the command follows the same semantics as the "start"
1241 command, stopping the program's execution at the start of its
1242 main subprogram. Support for this feature can be verified using
1243 the "-list-features" command, which should contain
1244 "exec-run-start-option".
1246 ** The new commands -catch-assert and -catch-exceptions insert
1247 catchpoints stopping the program when Ada exceptions are raised.
1249 ** The new command -info-ada-exceptions provides the equivalent of
1250 the new "info exceptions" command.
1252 * New system-wide configuration scripts
1253 A GDB installation now provides scripts suitable for use as system-wide
1254 configuration scripts for the following systems:
1258 * GDB now supports target-assigned range stepping with remote targets.
1259 This improves the performance of stepping source lines by reducing
1260 the number of control packets from/to GDB. See "New remote packets"
1263 * GDB now understands the element 'tvar' in the XML traceframe info.
1264 It has the id of the collected trace state variables.
1266 * On S/390 targets that provide the transactional-execution feature,
1267 the program interruption transaction diagnostic block (TDB) is now
1268 represented as a number of additional "registers" in GDB.
1270 * New remote packets
1274 The vCont packet supports a new 'r' action, that tells the remote
1275 stub to step through an address range itself, without GDB
1276 involvemement at each single-step.
1278 qXfer:libraries-svr4:read's annex
1279 The previously unused annex of the qXfer:libraries-svr4:read packet
1280 is now used to support passing an argument list. The remote stub
1281 reports support for this argument list to GDB's qSupported query.
1282 The defined arguments are "start" and "prev", used to reduce work
1283 necessary for library list updating, resulting in significant
1286 * New features in the GDB remote stub, GDBserver
1288 ** GDBserver now supports target-assisted range stepping. Currently
1289 enabled on x86/x86_64 GNU/Linux targets.
1291 ** GDBserver now adds element 'tvar' in the XML in the reply to
1292 'qXfer:traceframe-info:read'. It has the id of the collected
1293 trace state variables.
1295 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1298 * New 'z' formatter for printing and examining memory, this displays the
1299 value as hexadecimal zero padded on the left to the size of the type.
1301 * GDB can now use Windows x64 unwinding data.
1303 * The "set remotebaud" command has been replaced by "set serial baud".
1304 Similarly, "show remotebaud" has been replaced by "show serial baud".
1305 The "set remotebaud" and "show remotebaud" commands are still available
1306 to provide backward compatibility with older versions of GDB.
1308 *** Changes in GDB 7.6
1310 * Target record has been renamed to record-full.
1311 Record/replay is now enabled with the "record full" command.
1312 This also affects settings that are associated with full record/replay
1313 that have been moved from "set/show record" to "set/show record full":
1315 set|show record full insn-number-max
1316 set|show record full stop-at-limit
1317 set|show record full memory-query
1319 * A new record target "record-btrace" has been added. The new target
1320 uses hardware support to record the control-flow of a process. It
1321 does not support replaying the execution, but it implements the
1322 below new commands for investigating the recorded execution log.
1323 This new recording method can be enabled using:
1327 The "record-btrace" target is only available on Intel Atom processors
1328 and requires a Linux kernel 2.6.32 or later.
1330 * Two new commands have been added for record/replay to give information
1331 about the recorded execution without having to replay the execution.
1332 The commands are only supported by "record btrace".
1334 record instruction-history prints the execution history at
1335 instruction granularity
1337 record function-call-history prints the execution history at
1338 function granularity
1340 * New native configurations
1342 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1343 FreeBSD/powerpc powerpc*-*-freebsd
1344 x86_64/Cygwin x86_64-*-cygwin*
1345 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1349 ARM AArch64 aarch64*-*-elf
1350 ARM AArch64 GNU/Linux aarch64*-*-linux
1351 Lynx 178 PowerPC powerpc-*-lynx*178
1352 x86_64/Cygwin x86_64-*-cygwin*
1353 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1355 * If the configured location of system.gdbinit file (as given by the
1356 --with-system-gdbinit option at configure time) is in the
1357 data-directory (as specified by --with-gdb-datadir at configure
1358 time) or in one of its subdirectories, then GDB will look for the
1359 system-wide init file in the directory specified by the
1360 --data-directory command-line option.
1362 * New command line options:
1364 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1365 other initialization files, unlike -nx which disables all of them.
1367 * Removed command line options
1369 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1372 * The 'ptype' and 'whatis' commands now accept an argument to control
1375 * 'info proc' now works on some core files.
1379 ** Vectors can be created with gdb.Type.vector.
1381 ** Python's atexit.register now works in GDB.
1383 ** Types can be pretty-printed via a Python API.
1385 ** Python 3 is now supported (in addition to Python 2.4 or later)
1387 ** New class gdb.Architecture exposes GDB's internal representation
1388 of architecture in the Python API.
1390 ** New method Frame.architecture returns the gdb.Architecture object
1391 corresponding to the frame's architecture.
1393 * New Python-based convenience functions:
1395 ** $_memeq(buf1, buf2, length)
1396 ** $_streq(str1, str2)
1398 ** $_regex(str, regex)
1400 * The 'cd' command now defaults to using '~' (the home directory) if not
1403 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1404 default for GCC since November 2000.
1406 * The command 'forward-search' can now be abbreviated as 'fo'.
1408 * The command 'info tracepoints' can now display 'installed on target'
1409 or 'not installed on target' for each non-pending location of tracepoint.
1411 * New configure options
1413 --enable-libmcheck/--disable-libmcheck
1414 By default, development versions are built with -lmcheck on hosts
1415 that support it, in order to help track memory corruption issues.
1416 Release versions, on the other hand, are built without -lmcheck
1417 by default. The --enable-libmcheck/--disable-libmcheck configure
1418 options allow the user to override that default.
1419 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1420 This configure option allows the user to build GDB with
1421 libbabeltrace using which GDB can read Common Trace Format data.
1423 * New commands (for set/show, see "New options" below)
1426 Catch signals. This is similar to "handle", but allows commands and
1427 conditions to be attached.
1430 List the BFDs known to GDB.
1432 python-interactive [command]
1434 Start a Python interactive prompt, or evaluate the optional command
1435 and print the result of expressions.
1438 "py" is a new alias for "python".
1440 enable type-printer [name]...
1441 disable type-printer [name]...
1442 Enable or disable type printers.
1446 ** For the Renesas Super-H architecture, the "regs" command has been removed
1447 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1452 set print type methods (on|off)
1453 show print type methods
1454 Control whether method declarations are displayed by "ptype".
1455 The default is to show them.
1457 set print type typedefs (on|off)
1458 show print type typedefs
1459 Control whether typedef definitions are displayed by "ptype".
1460 The default is to show them.
1462 set filename-display basename|relative|absolute
1463 show filename-display
1464 Control the way in which filenames is displayed.
1465 The default is "relative", which preserves previous behavior.
1467 set trace-buffer-size
1468 show trace-buffer-size
1469 Request target to change the size of trace buffer.
1471 set remote trace-buffer-size-packet auto|on|off
1472 show remote trace-buffer-size-packet
1473 Control the use of the remote protocol `QTBuffer:size' packet.
1477 Control display of debugging messages related to ARM AArch64.
1480 set debug coff-pe-read
1481 show debug coff-pe-read
1482 Control display of debugging messages related to reading of COFF/PE
1487 Control display of debugging messages related to Mach-O symbols
1490 set debug notification
1491 show debug notification
1492 Control display of debugging info for async remote notification.
1496 ** Command parameter changes are now notified using new async record
1497 "=cmd-param-changed".
1498 ** Trace frame changes caused by command "tfind" are now notified using
1499 new async record "=traceframe-changed".
1500 ** The creation, deletion and modification of trace state variables
1501 are now notified using new async records "=tsv-created",
1502 "=tsv-deleted" and "=tsv-modified".
1503 ** The start and stop of process record are now notified using new
1504 async record "=record-started" and "=record-stopped".
1505 ** Memory changes are now notified using new async record
1507 ** The data-disassemble command response will include a "fullname" field
1508 containing the absolute file name when source has been requested.
1509 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1510 command, to allow pattern filling of memory areas.
1511 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1512 library load/unload events.
1513 ** The response to breakpoint commands and breakpoint async records
1514 includes an "installed" field containing a boolean state about each
1515 non-pending tracepoint location is whether installed on target or not.
1516 ** Output of the "-trace-status" command includes a "trace-file" field
1517 containing the name of the trace file being examined. This field is
1518 optional, and only present when examining a trace file.
1519 ** The "fullname" field is now always present along with the "file" field,
1520 even if the file cannot be found by GDB.
1522 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1523 You must have the LZMA library available when configuring GDB for this
1524 feature to be enabled. For more information, see:
1525 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1527 * New remote packets
1530 Set the size of trace buffer. The remote stub reports support for this
1531 packet to gdb's qSupported query.
1534 Enable Branch Trace Store (BTS)-based branch tracing for the current
1535 thread. The remote stub reports support for this packet to gdb's
1539 Disable branch tracing for the current thread. The remote stub reports
1540 support for this packet to gdb's qSupported query.
1543 Read the traced branches for the current thread. The remote stub
1544 reports support for this packet to gdb's qSupported query.
1546 *** Changes in GDB 7.5
1548 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1549 for more x32 ABI info.
1551 * GDB now supports access to MIPS DSP registers on Linux targets.
1553 * GDB now supports debugging microMIPS binaries.
1555 * The "info os" command on GNU/Linux can now display information on
1556 several new classes of objects managed by the operating system:
1557 "info os procgroups" lists process groups
1558 "info os files" lists file descriptors
1559 "info os sockets" lists internet-domain sockets
1560 "info os shm" lists shared-memory regions
1561 "info os semaphores" lists semaphores
1562 "info os msg" lists message queues
1563 "info os modules" lists loaded kernel modules
1565 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1566 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1567 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1568 options and inspect the probe arguments using the new $_probe_arg family
1569 of convenience variables. You can obtain more information about SystemTap
1570 in <http://sourceware.org/systemtap/>.
1572 * GDB now supports reversible debugging on ARM, it allows you to
1573 debug basic ARM and THUMB instructions, and provides
1574 record/replay support.
1576 * The option "symbol-reloading" has been deleted as it is no longer used.
1580 ** GDB commands implemented in Python can now be put in command class
1583 ** The "maint set python print-stack on|off" is now deleted.
1585 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1586 apply "flag enum"-style pretty-printing to any enum.
1588 ** gdb.lookup_symbol can now work when there is no current frame.
1590 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1591 the source at which the symbol was defined.
1593 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1594 method 'value'. The former indicates whether the symbol needs a
1595 frame in order to compute its value, and the latter computes the
1598 ** A new method 'referenced_value' on gdb.Value objects which can
1599 dereference pointer as well as C++ reference values.
1601 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1602 which return the global and static blocks (as gdb.Block objects),
1603 of the underlying symbol table, respectively.
1605 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1606 object associated with a PC value.
1608 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1609 of the address range occupied by code for the current source line.
1611 * Go language support.
1612 GDB now supports debugging programs written in the Go programming
1615 * GDBserver now supports stdio connections.
1616 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1618 * The binary "gdbtui" can no longer be built or installed.
1619 Use "gdb -tui" instead.
1621 * GDB will now print "flag" enums specially. A flag enum is one where
1622 all the enumerator values have no bits in common when pairwise
1623 "and"ed. When printing a value whose type is a flag enum, GDB will
1624 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1625 (gdb) print (enum E) 3
1628 * The filename part of a linespec will now match trailing components
1629 of a source file name. For example, "break gcc/expr.c:1000" will
1630 now set a breakpoint in build/gcc/expr.c, but not
1631 build/libcpp/expr.c.
1633 * The "info proc" and "generate-core-file" commands will now also
1634 work on remote targets connected to GDBserver on Linux.
1636 * The command "info catch" has been removed. It has been disabled
1637 since December 2007.
1639 * The "catch exception" and "catch assert" commands now accept
1640 a condition at the end of the command, much like the "break"
1641 command does. For instance:
1643 (gdb) catch exception Constraint_Error if Barrier = True
1645 Previously, it was possible to add a condition to such catchpoints,
1646 but it had to be done as a second step, after the catchpoint had been
1647 created, using the "condition" command.
1649 * The "info static-tracepoint-marker" command will now also work on
1650 native Linux targets with in-process agent.
1652 * GDB can now set breakpoints on inlined functions.
1654 * The .gdb_index section has been updated to include symbols for
1655 inlined functions. GDB will ignore older .gdb_index sections by
1656 default, which could cause symbol files to be loaded more slowly
1657 until their .gdb_index sections can be recreated. The new command
1658 "set use-deprecated-index-sections on" will cause GDB to use any older
1659 .gdb_index sections it finds. This will restore performance, but the
1660 ability to set breakpoints on inlined functions will be lost in symbol
1661 files with older .gdb_index sections.
1663 The .gdb_index section has also been updated to record more information
1664 about each symbol. This speeds up the "info variables", "info functions"
1665 and "info types" commands when used with programs having the .gdb_index
1666 section, as well as speeding up debugging with shared libraries using
1667 the .gdb_index section.
1669 * Ada support for GDB/MI Variable Objects has been added.
1671 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1676 ** New command -info-os is the MI equivalent of "info os".
1678 ** Output logs ("set logging" and related) now include MI output.
1682 ** "set use-deprecated-index-sections on|off"
1683 "show use-deprecated-index-sections on|off"
1684 Controls the use of deprecated .gdb_index sections.
1686 ** "catch load" and "catch unload" can be used to stop when a shared
1687 library is loaded or unloaded, respectively.
1689 ** "enable count" can be used to auto-disable a breakpoint after
1692 ** "info vtbl" can be used to show the virtual method tables for
1693 C++ and Java objects.
1695 ** "explore" and its sub commands "explore value" and "explore type"
1696 can be used to recursively explore values and types of
1697 expressions. These commands are available only if GDB is
1698 configured with '--with-python'.
1700 ** "info auto-load" shows status of all kinds of auto-loaded files,
1701 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1702 sequences of commands files, "info auto-load python-scripts"
1703 shows status of auto-loading Python script files,
1704 "info auto-load local-gdbinit" shows status of loading init file
1705 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1706 status of inferior specific thread debugging shared library loading.
1708 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1709 and "show auto-load-scripts" commands have been deprecated, use their
1710 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1711 and "show auto-load python-scripts" counterparts instead.
1713 ** "dprintf location,format,args..." creates a dynamic printf, which
1714 is basically a breakpoint that does a printf and immediately
1715 resumes your program's execution, so it is like a printf that you
1716 can insert dynamically at runtime instead of at compiletime.
1718 ** "set print symbol"
1720 Controls whether GDB attempts to display the symbol, if any,
1721 corresponding to addresses it prints. This defaults to "on", but
1722 you can set it to "off" to restore GDB's previous behavior.
1724 * Deprecated commands
1726 ** For the Renesas Super-H architecture, the "regs" command has been
1727 deprecated, and "info all-registers" should be used instead.
1731 Renesas RL78 rl78-*-elf
1732 HP OpenVMS ia64 ia64-hp-openvms*
1734 * GDBserver supports evaluation of breakpoint conditions. When
1735 support is advertised by GDBserver, GDB may be told to send the
1736 breakpoint conditions in bytecode form to GDBserver. GDBserver
1737 will only report the breakpoint trigger to GDB when its condition
1742 set mips compression
1743 show mips compression
1744 Select the compressed ISA encoding used in functions that have no symbol
1745 information available. The encoding can be set to either of:
1748 and is updated automatically from ELF file flags if available.
1750 set breakpoint condition-evaluation
1751 show breakpoint condition-evaluation
1752 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1753 GDBserver ("target"). Default option "auto" chooses the most efficient
1755 This option can improve debugger efficiency depending on the speed of the
1759 Disable auto-loading globally.
1762 Show auto-loading setting of all kinds of auto-loaded files.
1764 set auto-load gdb-scripts on|off
1765 show auto-load gdb-scripts
1766 Control auto-loading of GDB canned sequences of commands files.
1768 set auto-load python-scripts on|off
1769 show auto-load python-scripts
1770 Control auto-loading of Python script files.
1772 set auto-load local-gdbinit on|off
1773 show auto-load local-gdbinit
1774 Control loading of init file (.gdbinit) from current directory.
1776 set auto-load libthread-db on|off
1777 show auto-load libthread-db
1778 Control auto-loading of inferior specific thread debugging shared library.
1780 set auto-load scripts-directory <dir1>[:<dir2>...]
1781 show auto-load scripts-directory
1782 Set a list of directories from which to load auto-loaded scripts.
1783 Automatically loaded Python scripts and GDB scripts are located in one
1784 of the directories listed by this option.
1785 The delimiter (':' above) may differ according to the host platform.
1787 set auto-load safe-path <dir1>[:<dir2>...]
1788 show auto-load safe-path
1789 Set a list of directories from which it is safe to auto-load files.
1790 The delimiter (':' above) may differ according to the host platform.
1792 set debug auto-load on|off
1793 show debug auto-load
1794 Control display of debugging info for auto-loading the files above.
1796 set dprintf-style gdb|call|agent
1798 Control the way in which a dynamic printf is performed; "gdb"
1799 requests a GDB printf command, while "call" causes dprintf to call a
1800 function in the inferior. "agent" requests that the target agent
1801 (such as GDBserver) do the printing.
1803 set dprintf-function <expr>
1804 show dprintf-function
1805 set dprintf-channel <expr>
1806 show dprintf-channel
1807 Set the function and optional first argument to the call when using
1808 the "call" style of dynamic printf.
1810 set disconnected-dprintf on|off
1811 show disconnected-dprintf
1812 Control whether agent-style dynamic printfs continue to be in effect
1813 after GDB disconnects.
1815 * New configure options
1817 --with-auto-load-dir
1818 Configure default value for the 'set auto-load scripts-directory'
1819 setting above. It defaults to '$debugdir:$datadir/auto-load',
1820 $debugdir representing global debugging info directories (available
1821 via 'show debug-file-directory') and $datadir representing GDB's data
1822 directory (available via 'show data-directory').
1824 --with-auto-load-safe-path
1825 Configure default value for the 'set auto-load safe-path' setting
1826 above. It defaults to the --with-auto-load-dir setting.
1828 --without-auto-load-safe-path
1829 Set 'set auto-load safe-path' to '/', effectively disabling this
1832 * New remote packets
1834 z0/z1 conditional breakpoints extension
1836 The z0/z1 breakpoint insertion packets have been extended to carry
1837 a list of conditional expressions over to the remote stub depending on the
1838 condition evaluation mode. The use of this extension can be controlled
1839 via the "set remote conditional-breakpoints-packet" command.
1843 Specify the signals which the remote stub may pass to the debugged
1844 program without GDB involvement.
1846 * New command line options
1848 --init-command=FILE, -ix Like --command, -x but execute it
1849 before loading inferior.
1850 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1851 execute it before loading inferior.
1853 *** Changes in GDB 7.4
1855 * GDB now handles ambiguous linespecs more consistently; the existing
1856 FILE:LINE support has been expanded to other types of linespecs. A
1857 breakpoint will now be set on all matching locations in all
1858 inferiors, and locations will be added or removed according to
1861 * GDB now allows you to skip uninteresting functions and files when
1862 stepping with the "skip function" and "skip file" commands.
1864 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1865 and "show remote hardware-watchpoint-length-limit". These allows to
1866 set or show the maximum length limit (in bytes) of a remote
1867 target hardware watchpoint.
1869 This allows e.g. to use "unlimited" hardware watchpoints with the
1870 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1871 watchpoints are slower than real hardware watchpoints but are
1872 significantly faster than gdb software watchpoints.
1876 ** The register_pretty_printer function in module gdb.printing now takes
1877 an optional `replace' argument. If True, the new printer replaces any
1880 ** The "maint set python print-stack on|off" command has been
1881 deprecated and will be deleted in GDB 7.5.
1882 A new command: "set python print-stack none|full|message" has
1883 replaced it. Additionally, the default for "print-stack" is
1884 now "message", which just prints the error message without
1887 ** A prompt substitution hook (prompt_hook) is now available to the
1890 ** A new Python module, gdb.prompt has been added to the GDB Python
1891 modules library. This module provides functionality for
1892 escape sequences in prompts (used by set/show
1893 extended-prompt). These escape sequences are replaced by their
1894 corresponding value.
1896 ** Python commands and convenience-functions located in
1897 'data-directory'/python/gdb/command and
1898 'data-directory'/python/gdb/function are now automatically loaded
1901 ** Blocks now provide four new attributes. global_block and
1902 static_block will return the global and static blocks
1903 respectively. is_static and is_global are boolean attributes
1904 that indicate if the block is one of those two types.
1906 ** Symbols now provide the "type" attribute, the type of the symbol.
1908 ** The "gdb.breakpoint" function has been deprecated in favor of
1911 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1912 of a function. This class is based on the "finish" command
1913 available in the CLI.
1915 ** Type objects for struct and union types now allow access to
1916 the fields using standard Python dictionary (mapping) methods.
1917 For example, "some_type['myfield']" now works, as does
1918 "some_type.items()".
1920 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1923 ** A new function, "deep_items" has been added to the gdb.types
1924 module in the GDB Python modules library. This function returns
1925 an iterator over the fields of a struct or union type. Unlike
1926 the standard Python "iteritems" method, it will recursively traverse
1927 any anonymous fields.
1931 ** "*stopped" events can report several new "reason"s, such as
1934 ** Breakpoint changes are now notified using new async records, like
1935 "=breakpoint-modified".
1937 ** New command -ada-task-info.
1939 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1940 $sdir specifies the default system locations of shared libraries.
1941 $pdir specifies the directory where the libpthread used by the application
1944 GDB no longer looks in $sdir and $pdir after it has searched the directories
1945 mentioned in libthread-db-search-path. If you want to search those
1946 directories, they must be specified in libthread-db-search-path.
1947 The default value of libthread-db-search-path on GNU/Linux and Solaris
1948 systems is now "$sdir:$pdir".
1950 $pdir is not supported by gdbserver, it is currently ignored.
1951 $sdir is supported by gdbserver.
1953 * New configure option --with-iconv-bin.
1954 When using the internationalization support like the one in the GNU C
1955 library, GDB will invoke the "iconv" program to get a list of supported
1956 character sets. If this program lives in a non-standard location, one can
1957 use this option to specify where to find it.
1959 * When natively debugging programs on PowerPC BookE processors running
1960 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1961 watchpoints, which specify a mask in addition to an address to watch.
1962 The mask specifies that some bits of an address (the bits which are
1963 reset in the mask) should be ignored when matching the address accessed
1964 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1965 section in the user manual for more details.
1967 * The new option --once causes GDBserver to stop listening for connections once
1968 the first connection is made. The listening port used by GDBserver will
1969 become available after that.
1971 * New commands "info macros" and "alias" have been added.
1973 * New function parameters suffix @entry specifies value of function parameter
1974 at the time the function got called. Entry values are available only since
1980 "!" is now an alias of the "shell" command.
1981 Note that no space is needed between "!" and SHELL COMMAND.
1985 watch EXPRESSION mask MASK_VALUE
1986 The watch command now supports the mask argument which allows creation
1987 of masked watchpoints, if the current architecture supports this feature.
1989 info auto-load-scripts [REGEXP]
1990 This command was formerly named "maintenance print section-scripts".
1991 It is now generally useful and is no longer a maintenance-only command.
1993 info macro [-all] [--] MACRO
1994 The info macro command has new options `-all' and `--'. The first for
1995 printing all definitions of a macro. The second for explicitly specifying
1996 the end of arguments and the beginning of the macro name in case the macro
1997 name starts with a hyphen.
1999 collect[/s] EXPRESSIONS
2000 The tracepoint collect command now takes an optional modifier "/s"
2001 that directs it to dereference pointer-to-character types and
2002 collect the bytes of memory up to a zero byte. The behavior is
2003 similar to what you see when you use the regular print command on a
2004 string. An optional integer following the "/s" sets a bound on the
2005 number of bytes that will be collected.
2008 The trace start command now interprets any supplied arguments as a
2009 note to be recorded with the trace run, with an effect similar to
2010 setting the variable trace-notes.
2013 The trace stop command now interprets any arguments as a note to be
2014 mentioned along with the tstatus report that the trace was stopped
2015 with a command. The effect is similar to setting the variable
2018 * Tracepoints can now be enabled and disabled at any time after a trace
2019 experiment has been started using the standard "enable" and "disable"
2020 commands. It is now possible to start a trace experiment with no enabled
2021 tracepoints; GDB will display a warning, but will allow the experiment to
2022 begin, assuming that tracepoints will be enabled as needed while the trace
2025 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2026 locations with 4-byte instructions, when they were previously
2027 limited to locations with instructions of 5 bytes or longer.
2031 set debug dwarf2-read
2032 show debug dwarf2-read
2033 Turns on or off display of debugging messages related to reading
2034 DWARF debug info. The default is off.
2036 set debug symtab-create
2037 show debug symtab-create
2038 Turns on or off display of debugging messages related to symbol table
2039 creation. The default is off.
2042 show extended-prompt
2043 Set the GDB prompt, and allow escape sequences to be inserted to
2044 display miscellaneous information (see 'help set extended-prompt'
2045 for the list of sequences). This prompt (and any information
2046 accessed through the escape sequences) is updated every time the
2047 prompt is displayed.
2049 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2050 show print entry-values
2051 Set printing of frame argument values at function entry. In some cases
2052 GDB can determine the value of function argument which was passed by the
2053 function caller, even if the value was modified inside the called function.
2055 set debug entry-values
2056 show debug entry-values
2057 Control display of debugging info for determining frame argument values at
2058 function entry and virtual tail call frames.
2060 set basenames-may-differ
2061 show basenames-may-differ
2062 Set whether a source file may have multiple base names.
2063 (A "base name" is the name of a file with the directory part removed.
2064 Example: The base name of "/home/user/hello.c" is "hello.c".)
2065 If set, GDB will canonicalize file names (e.g., expand symlinks)
2066 before comparing them. Canonicalization is an expensive operation,
2067 but it allows the same file be known by more than one base name.
2068 If not set (the default), all source files are assumed to have just
2069 one base name, and gdb will do file name comparisons more efficiently.
2075 Set a user name and notes for the current and any future trace runs.
2076 This is useful for long-running and/or disconnected traces, to
2077 inform others (or yourself) as to who is running the trace, supply
2078 contact information, or otherwise explain what is going on.
2080 set trace-stop-notes
2081 show trace-stop-notes
2082 Set a note attached to the trace run, that is displayed when the
2083 trace has been stopped by a tstop command. This is useful for
2084 instance as an explanation, if you are stopping a trace run that was
2085 started by someone else.
2087 * New remote packets
2091 Dynamically enable a tracepoint in a started trace experiment.
2095 Dynamically disable a tracepoint in a started trace experiment.
2099 Set the user and notes of the trace run.
2103 Query the current status of a tracepoint.
2107 Query the minimum length of instruction at which a fast tracepoint may
2110 * Dcache size (number of lines) and line-size are now runtime-configurable
2111 via "set dcache line" and "set dcache line-size" commands.
2115 Texas Instruments TMS320C6x tic6x-*-*
2119 Renesas RL78 rl78-*-elf
2121 *** Changes in GDB 7.3.1
2123 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2125 *** Changes in GDB 7.3
2127 * GDB has a new command: "thread find [REGEXP]".
2128 It finds the thread id whose name, target id, or thread extra info
2129 matches the given regular expression.
2131 * The "catch syscall" command now works on mips*-linux* targets.
2133 * The -data-disassemble MI command now supports modes 2 and 3 for
2134 dumping the instruction opcodes.
2136 * New command line options
2138 -data-directory DIR Specify DIR as the "data-directory".
2139 This is mostly for testing purposes.
2141 * The "maint set python auto-load on|off" command has been renamed to
2142 "set auto-load-scripts on|off".
2144 * GDB has a new command: "set directories".
2145 It is like the "dir" command except that it replaces the
2146 source path list instead of augmenting it.
2148 * GDB now understands thread names.
2150 On GNU/Linux, "info threads" will display the thread name as set by
2151 prctl or pthread_setname_np.
2153 There is also a new command, "thread name", which can be used to
2154 assign a name internally for GDB to display.
2157 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2158 has been integrated into GDB.
2162 ** The function gdb.Write now accepts an optional keyword 'stream'.
2163 This keyword, when provided, will direct the output to either
2164 stdout, stderr, or GDB's logging output.
2166 ** Parameters can now be be sub-classed in Python, and in particular
2167 you may implement the get_set_doc and get_show_doc functions.
2168 This improves how Parameter set/show documentation is processed
2169 and allows for more dynamic content.
2171 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2172 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2173 have an is_valid method.
2175 ** Breakpoints can now be sub-classed in Python, and in particular
2176 you may implement a 'stop' function that is executed each time
2177 the inferior reaches that breakpoint.
2179 ** New function gdb.lookup_global_symbol looks up a global symbol.
2181 ** GDB values in Python are now callable if the value represents a
2182 function. For example, if 'some_value' represents a function that
2183 takes two integer parameters and returns a value, you can call
2184 that function like so:
2186 result = some_value (10,20)
2188 ** Module gdb.types has been added.
2189 It contains a collection of utilities for working with gdb.Types objects:
2190 get_basic_type, has_field, make_enum_dict.
2192 ** Module gdb.printing has been added.
2193 It contains utilities for writing and registering pretty-printers.
2194 New classes: PrettyPrinter, SubPrettyPrinter,
2195 RegexpCollectionPrettyPrinter.
2196 New function: register_pretty_printer.
2198 ** New commands "info pretty-printers", "enable pretty-printer" and
2199 "disable pretty-printer" have been added.
2201 ** gdb.parameter("directories") is now available.
2203 ** New function gdb.newest_frame returns the newest frame in the
2206 ** The gdb.InferiorThread class has a new "name" attribute. This
2207 holds the thread's name.
2209 ** Python Support for Inferior events.
2210 Python scripts can add observers to be notified of events
2211 occurring in the process being debugged.
2212 The following events are currently supported:
2213 - gdb.events.cont Continue event.
2214 - gdb.events.exited Inferior exited event.
2215 - gdb.events.stop Signal received, and Breakpoint hit events.
2219 ** GDB now puts template parameters in scope when debugging in an
2220 instantiation. For example, if you have:
2222 template<int X> int func (void) { return X; }
2224 then if you step into func<5>, "print X" will show "5". This
2225 feature requires proper debuginfo support from the compiler; it
2226 was added to GCC 4.5.
2228 ** The motion commands "next", "finish", "until", and "advance" now
2229 work better when exceptions are thrown. In particular, GDB will
2230 no longer lose control of the inferior; instead, the GDB will
2231 stop the inferior at the point at which the exception is caught.
2232 This functionality requires a change in the exception handling
2233 code that was introduced in GCC 4.5.
2235 * GDB now follows GCC's rules on accessing volatile objects when
2236 reading or writing target state during expression evaluation.
2237 One notable difference to prior behavior is that "print x = 0"
2238 no longer generates a read of x; the value of the assignment is
2239 now always taken directly from the value being assigned.
2241 * GDB now has some support for using labels in the program's source in
2242 linespecs. For instance, you can use "advance label" to continue
2243 execution to a label.
2245 * GDB now has support for reading and writing a new .gdb_index
2246 section. This section holds a fast index of DWARF debugging
2247 information and can be used to greatly speed up GDB startup and
2248 operation. See the documentation for `save gdb-index' for details.
2250 * The "watch" command now accepts an optional "-location" argument.
2251 When used, this causes GDB to watch the memory referred to by the
2252 expression. Such a watchpoint is never deleted due to it going out
2255 * GDB now supports thread debugging of core dumps on GNU/Linux.
2257 GDB now activates thread debugging using the libthread_db library
2258 when debugging GNU/Linux core dumps, similarly to when debugging
2259 live processes. As a result, when debugging a core dump file, GDB
2260 is now able to display pthread_t ids of threads. For example, "info
2261 threads" shows the same output as when debugging the process when it
2262 was live. In earlier releases, you'd see something like this:
2265 * 1 LWP 6780 main () at main.c:10
2267 While now you see this:
2270 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2272 It is also now possible to inspect TLS variables when debugging core
2275 When debugging a core dump generated on a machine other than the one
2276 used to run GDB, you may need to point GDB at the correct
2277 libthread_db library with the "set libthread-db-search-path"
2278 command. See the user manual for more details on this command.
2280 * When natively debugging programs on PowerPC BookE processors running
2281 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2282 which stop execution of the inferior whenever it executes an instruction
2283 at any address within the specified range. See the "PowerPC Embedded"
2284 section in the user manual for more details.
2286 * New features in the GDB remote stub, GDBserver
2288 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2289 and i686 LynxOS (version 5.x).
2291 ** GDBserver is now supported on Blackfin Linux.
2293 * New native configurations
2295 ia64 HP-UX ia64-*-hpux*
2299 Analog Devices, Inc. Blackfin Processor bfin-*
2301 * Ada task switching is now supported on sparc-elf targets when
2302 debugging a program using the Ravenscar Profile. For more information,
2303 see the "Tasking Support when using the Ravenscar Profile" section
2304 in the GDB user manual.
2306 * Guile support was removed.
2308 * New features in the GNU simulator
2310 ** The --map-info flag lists all known core mappings.
2312 ** CFI flashes may be simulated via the "cfi" device.
2314 *** Changes in GDB 7.2
2316 * Shared library support for remote targets by default
2318 When GDB is configured for a generic, non-OS specific target, like
2319 for example, --target=arm-eabi or one of the many *-*-elf targets,
2320 GDB now queries remote stubs for loaded shared libraries using the
2321 `qXfer:libraries:read' packet. Previously, shared library support
2322 was always disabled for such configurations.
2326 ** Argument Dependent Lookup (ADL)
2328 In C++ ADL lookup directs function search to the namespaces of its
2329 arguments even if the namespace has not been imported.
2339 Here the compiler will search for `foo' in the namespace of 'b'
2340 and find A::foo. GDB now supports this. This construct is commonly
2341 used in the Standard Template Library for operators.
2343 ** Improved User Defined Operator Support
2345 In addition to member operators, GDB now supports lookup of operators
2346 defined in a namespace and imported with a `using' directive, operators
2347 defined in the global scope, operators imported implicitly from an
2348 anonymous namespace, and the ADL operators mentioned in the previous
2350 GDB now also supports proper overload resolution for all the previously
2351 mentioned flavors of operators.
2353 ** static const class members
2355 Printing of static const class members that are initialized in the
2356 class definition has been fixed.
2358 * Windows Thread Information Block access.
2360 On Windows targets, GDB now supports displaying the Windows Thread
2361 Information Block (TIB) structure. This structure is visible either
2362 by using the new command `info w32 thread-information-block' or, by
2363 dereferencing the new convenience variable named `$_tlb', a
2364 thread-specific pointer to the TIB. This feature is also supported
2365 when remote debugging using GDBserver.
2367 * Static tracepoints
2369 Static tracepoints are calls in the user program into a tracing
2370 library. One such library is a port of the LTTng kernel tracer to
2371 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2372 When debugging with GDBserver, GDB now supports combining the GDB
2373 tracepoint machinery with such libraries. For example: the user can
2374 use GDB to probe a static tracepoint marker (a call from the user
2375 program into the tracing library) with the new "strace" command (see
2376 "New commands" below). This creates a "static tracepoint" in the
2377 breakpoint list, that can be manipulated with the same feature set
2378 as fast and regular tracepoints. E.g., collect registers, local and
2379 global variables, collect trace state variables, and define
2380 tracepoint conditions. In addition, the user can collect extra
2381 static tracepoint marker specific data, by collecting the new
2382 $_sdata internal variable. When analyzing the trace buffer, you can
2383 inspect $_sdata like any other variable available to GDB. For more
2384 information, see the "Tracepoints" chapter in GDB user manual. New
2385 remote packets have been defined to support static tracepoints, see
2386 the "New remote packets" section below.
2388 * Better reconstruction of tracepoints after disconnected tracing
2390 GDB will attempt to download the original source form of tracepoint
2391 definitions when starting a trace run, and then will upload these
2392 upon reconnection to the target, resulting in a more accurate
2393 reconstruction of the tracepoints that are in use on the target.
2397 You can now exercise direct control over the ways that GDB can
2398 affect your program. For instance, you can disallow the setting of
2399 breakpoints, so that the program can run continuously (assuming
2400 non-stop mode). In addition, the "observer" variable is available
2401 to switch all of the different controls; in observer mode, GDB
2402 cannot affect the target's behavior at all, which is useful for
2403 tasks like diagnosing live systems in the field.
2405 * The new convenience variable $_thread holds the number of the
2408 * New remote packets
2412 Return the address of the Windows Thread Information Block of a given thread.
2416 In response to several of the tracepoint packets, the target may now
2417 also respond with a number of intermediate `qRelocInsn' request
2418 packets before the final result packet, to have GDB handle
2419 relocating an instruction to execute at a different address. This
2420 is particularly useful for stubs that support fast tracepoints. GDB
2421 reports support for this feature in the qSupported packet.
2425 List static tracepoint markers in the target program.
2429 List static tracepoint markers at a given address in the target
2432 qXfer:statictrace:read
2434 Read the static trace data collected (by a `collect $_sdata'
2435 tracepoint action). The remote stub reports support for this packet
2436 to gdb's qSupported query.
2440 Send the current settings of GDB's permission flags.
2444 Send part of the source (textual) form of a tracepoint definition,
2445 which includes location, conditional, and action list.
2447 * The source command now accepts a -s option to force searching for the
2448 script in the source search path even if the script name specifies
2451 * New features in the GDB remote stub, GDBserver
2453 - GDBserver now support tracepoints (including fast tracepoints, and
2454 static tracepoints). The feature is currently supported by the
2455 i386-linux and amd64-linux builds. See the "Tracepoints support
2456 in gdbserver" section in the manual for more information.
2458 GDBserver JIT compiles the tracepoint's conditional agent
2459 expression bytecode into native code whenever possible for low
2460 overhead dynamic tracepoints conditionals. For such tracepoints,
2461 an expression that examines program state is evaluated when the
2462 tracepoint is reached, in order to determine whether to capture
2463 trace data. If the condition is simple and false, processing the
2464 tracepoint finishes very quickly and no data is gathered.
2466 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2467 for static tracepoints support.
2469 - GDBserver now supports x86_64 Windows 64-bit debugging.
2471 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2472 it understands register description.
2474 * The --batch flag now disables pagination and queries.
2476 * X86 general purpose registers
2478 GDB now supports reading/writing byte, word and double-word x86
2479 general purpose registers directly. This means you can use, say,
2480 $ah or $ax to refer, respectively, to the byte register AH and
2481 16-bit word register AX that are actually portions of the 32-bit
2482 register EAX or 64-bit register RAX.
2484 * The `commands' command now accepts a range of breakpoints to modify.
2485 A plain `commands' following a command that creates multiple
2486 breakpoints affects all the breakpoints set by that command. This
2487 applies to breakpoints set by `rbreak', and also applies when a
2488 single `break' command creates multiple breakpoints (e.g.,
2489 breakpoints on overloaded c++ functions).
2491 * The `rbreak' command now accepts a filename specification as part of
2492 its argument, limiting the functions selected by the regex to those
2493 in the specified file.
2495 * Support for remote debugging Windows and SymbianOS shared libraries
2496 from Unix hosts has been improved. Non Windows GDB builds now can
2497 understand target reported file names that follow MS-DOS based file
2498 system semantics, such as file names that include drive letters and
2499 use the backslash character as directory separator. This makes it
2500 possible to transparently use the "set sysroot" and "set
2501 solib-search-path" on Unix hosts to point as host copies of the
2502 target's shared libraries. See the new command "set
2503 target-file-system-kind" described below, and the "Commands to
2504 specify files" section in the user manual for more information.
2508 eval template, expressions...
2509 Convert the values of one or more expressions under the control
2510 of the string template to a command line, and call it.
2512 set target-file-system-kind unix|dos-based|auto
2513 show target-file-system-kind
2514 Set or show the assumed file system kind for target reported file
2517 save breakpoints <filename>
2518 Save all current breakpoint definitions to a file suitable for use
2519 in a later debugging session. To read the saved breakpoint
2520 definitions, use the `source' command.
2522 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2525 info static-tracepoint-markers
2526 Display information about static tracepoint markers in the target.
2528 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2529 Define a static tracepoint by probing a marker at the given
2530 function, line, address, or marker ID.
2534 Enable and disable observer mode.
2536 set may-write-registers on|off
2537 set may-write-memory on|off
2538 set may-insert-breakpoints on|off
2539 set may-insert-tracepoints on|off
2540 set may-insert-fast-tracepoints on|off
2541 set may-interrupt on|off
2542 Set individual permissions for GDB effects on the target. Note that
2543 some of these settings can have undesirable or surprising
2544 consequences, particularly when changed in the middle of a session.
2545 For instance, disabling the writing of memory can prevent
2546 breakpoints from being inserted, cause single-stepping to fail, or
2547 even crash your program, if you disable after breakpoints have been
2548 inserted. However, GDB should not crash.
2550 set record memory-query on|off
2551 show record memory-query
2552 Control whether to stop the inferior if memory changes caused
2553 by an instruction cannot be recorded.
2558 The disassemble command now supports "start,+length" form of two arguments.
2562 ** GDB now provides a new directory location, called the python directory,
2563 where Python scripts written for GDB can be installed. The location
2564 of that directory is <data-directory>/python, where <data-directory>
2565 is the GDB data directory. For more details, see section `Scripting
2566 GDB using Python' in the manual.
2568 ** The GDB Python API now has access to breakpoints, symbols, symbol
2569 tables, program spaces, inferiors, threads and frame's code blocks.
2570 Additionally, GDB Parameters can now be created from the API, and
2571 manipulated via set/show in the CLI.
2573 ** New functions gdb.target_charset, gdb.target_wide_charset,
2574 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2576 ** New exception gdb.GdbError.
2578 ** Pretty-printers are now also looked up in the current program space.
2580 ** Pretty-printers can now be individually enabled and disabled.
2582 ** GDB now looks for names of Python scripts to auto-load in a
2583 special section named `.debug_gdb_scripts', in addition to looking
2584 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2586 * Tracepoint actions were unified with breakpoint commands. In particular,
2587 there are no longer differences in "info break" output for breakpoints and
2588 tracepoints and the "commands" command can be used for both tracepoints and
2589 regular breakpoints.
2593 ARM Symbian arm*-*-symbianelf*
2595 * D language support.
2596 GDB now supports debugging programs written in the D programming
2599 * GDB now supports the extended ptrace interface for PowerPC which is
2600 available since Linux kernel version 2.6.34. This automatically enables
2601 any hardware breakpoints and additional hardware watchpoints available in
2602 the processor. The old ptrace interface exposes just one hardware
2603 watchpoint and no hardware breakpoints.
2605 * GDB is now able to use the Data Value Compare (DVC) register available on
2606 embedded PowerPC processors to implement in hardware simple watchpoint
2607 conditions of the form:
2609 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2611 This works in native GDB running on Linux kernels with the extended ptrace
2612 interface mentioned above.
2614 *** Changes in GDB 7.1
2618 ** Namespace Support
2620 GDB now supports importing of namespaces in C++. This enables the
2621 user to inspect variables from imported namespaces. Support for
2622 namepace aliasing has also been added. So, if a namespace is
2623 aliased in the current scope (e.g. namepace C=A; ) the user can
2624 print variables using the alias (e.g. (gdb) print C::x).
2628 All known bugs relating to the printing of virtual base class were
2629 fixed. It is now possible to call overloaded static methods using a
2634 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2635 and reinterpret_cast<> are now handled by the C++ expression parser.
2639 Xilinx MicroBlaze microblaze-*-*
2644 Xilinx MicroBlaze microblaze
2647 * Multi-program debugging.
2649 GDB now has support for multi-program (a.k.a. multi-executable or
2650 multi-exec) debugging. This allows for debugging multiple inferiors
2651 simultaneously each running a different program under the same GDB
2652 session. See "Debugging Multiple Inferiors and Programs" in the
2653 manual for more information. This implied some user visible changes
2654 in the multi-inferior support. For example, "info inferiors" now
2655 lists inferiors that are not running yet or that have exited
2656 already. See also "New commands" and "New options" below.
2658 * New tracing features
2660 GDB's tracepoint facility now includes several new features:
2662 ** Trace state variables
2664 GDB tracepoints now include support for trace state variables, which
2665 are variables managed by the target agent during a tracing
2666 experiment. They are useful for tracepoints that trigger each
2667 other, so for instance one tracepoint can count hits in a variable,
2668 and then a second tracepoint has a condition that is true when the
2669 count reaches a particular value. Trace state variables share the
2670 $-syntax of GDB convenience variables, and can appear in both
2671 tracepoint actions and condition expressions. Use the "tvariable"
2672 command to create, and "info tvariables" to view; see "Trace State
2673 Variables" in the manual for more detail.
2677 GDB now includes an option for defining fast tracepoints, which
2678 targets may implement more efficiently, such as by installing a jump
2679 into the target agent rather than a trap instruction. The resulting
2680 speedup can be by two orders of magnitude or more, although the
2681 tradeoff is that some program locations on some target architectures
2682 might not allow fast tracepoint installation, for instance if the
2683 instruction to be replaced is shorter than the jump. To request a
2684 fast tracepoint, use the "ftrace" command, with syntax identical to
2685 the regular trace command.
2687 ** Disconnected tracing
2689 It is now possible to detach GDB from the target while it is running
2690 a trace experiment, then reconnect later to see how the experiment
2691 is going. In addition, a new variable disconnected-tracing lets you
2692 tell the target agent whether to continue running a trace if the
2693 connection is lost unexpectedly.
2697 GDB now has the ability to save the trace buffer into a file, and
2698 then use that file as a target, similarly to you can do with
2699 corefiles. You can select trace frames, print data that was
2700 collected in them, and use tstatus to display the state of the
2701 tracing run at the moment that it was saved. To create a trace
2702 file, use "tsave <filename>", and to use it, do "target tfile
2705 ** Circular trace buffer
2707 You can ask the target agent to handle the trace buffer as a
2708 circular buffer, discarding the oldest trace frames to make room for
2709 newer ones, by setting circular-trace-buffer to on. This feature may
2710 not be available for all target agents.
2715 The disassemble command, when invoked with two arguments, now requires
2716 the arguments to be comma-separated.
2719 The info variables command now displays variable definitions. Files
2720 which only declare a variable are not shown.
2723 The source command is now capable of sourcing Python scripts.
2724 This feature is dependent on the debugger being build with Python
2727 Related to this enhancement is also the introduction of a new command
2728 "set script-extension" (see below).
2730 * New commands (for set/show, see "New options" below)
2732 record save [<FILENAME>]
2733 Save a file (in core file format) containing the process record
2734 execution log for replay debugging at a later time.
2736 record restore <FILENAME>
2737 Restore the process record execution log that was saved at an
2738 earlier time, for replay debugging.
2740 add-inferior [-copies <N>] [-exec <FILENAME>]
2743 clone-inferior [-copies <N>] [ID]
2744 Make a new inferior ready to execute the same program another
2745 inferior has loaded.
2750 maint info program-spaces
2751 List the program spaces loaded into GDB.
2753 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2754 show remote interrupt-sequence
2755 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2756 as the sequence to the remote target in order to interrupt the execution.
2757 Ctrl-C is a default. Some system prefers BREAK which is high level of
2758 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2759 Magic SysRq g. It is BREAK signal and character 'g'.
2761 set remote interrupt-on-connect [on | off]
2762 show remote interrupt-on-connect
2763 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2764 remote target when gdb connects to it. This is needed when you debug
2767 set remotebreak [on | off]
2769 Deprecated. Use "set/show remote interrupt-sequence" instead.
2771 tvariable $NAME [ = EXP ]
2772 Create or modify a trace state variable.
2775 List trace state variables and their values.
2777 delete tvariable $NAME ...
2778 Delete one or more trace state variables.
2781 Evaluate the given expressions without collecting anything into the
2782 trace buffer. (Valid in tracepoint actions only.)
2784 ftrace FN / FILE:LINE / *ADDR
2785 Define a fast tracepoint at the given function, line, or address.
2787 * New expression syntax
2789 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2790 GDB now parses 0b101010 identically with 42.
2794 set follow-exec-mode new|same
2795 show follow-exec-mode
2796 Control whether GDB reuses the same inferior across an exec call or
2797 creates a new one. This is useful to be able to restart the old
2798 executable after the inferior having done an exec call.
2800 set default-collect EXPR, ...
2801 show default-collect
2802 Define a list of expressions to be collected at each tracepoint.
2803 This is a useful way to ensure essential items are not overlooked,
2804 such as registers or a critical global variable.
2806 set disconnected-tracing
2807 show disconnected-tracing
2808 If set to 1, the target is instructed to continue tracing if it
2809 loses its connection to GDB. If 0, the target is to stop tracing
2812 set circular-trace-buffer
2813 show circular-trace-buffer
2814 If set to on, the target is instructed to use a circular trace buffer
2815 and discard the oldest trace frames instead of stopping the trace due
2816 to a full trace buffer. If set to off, the trace stops when the buffer
2817 fills up. Some targets may not support this.
2819 set script-extension off|soft|strict
2820 show script-extension
2821 If set to "off", the debugger does not perform any script language
2822 recognition, and all sourced files are assumed to be GDB scripts.
2823 If set to "soft" (the default), files are sourced according to
2824 filename extension, falling back to GDB scripts if the first
2826 If set to "strict", files are sourced according to filename extension.
2828 set ada trust-PAD-over-XVS on|off
2829 show ada trust-PAD-over-XVS
2830 If off, activate a workaround against a bug in the debugging information
2831 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2832 the GCC sources for more information about the GNAT encoding and
2833 PAD types in particular). It is always safe to set this option to
2834 off, but this introduces a slight performance penalty. The default
2837 * Python API Improvements
2839 ** GDB provides the new class gdb.LazyString. This is useful in
2840 some pretty-printing cases. The new method gdb.Value.lazy_string
2841 provides a simple way to create objects of this type.
2843 ** The fields returned by gdb.Type.fields now have an
2844 `is_base_class' attribute.
2846 ** The new method gdb.Type.range returns the range of an array type.
2848 ** The new method gdb.parse_and_eval can be used to parse and
2849 evaluate an expression.
2851 * New remote packets
2854 Define a trace state variable.
2857 Get the current value of a trace state variable.
2860 Set desired tracing behavior upon disconnection.
2863 Set the trace buffer to be linear or circular.
2866 Get data about the tracepoints currently in use.
2870 Process record now works correctly with hardware watchpoints.
2872 Multiple bug fixes have been made to the mips-irix port, making it
2873 much more reliable. In particular:
2874 - Debugging threaded applications is now possible again. Previously,
2875 GDB would hang while starting the program, or while waiting for
2876 the program to stop at a breakpoint.
2877 - Attaching to a running process no longer hangs.
2878 - An error occurring while loading a core file has been fixed.
2879 - Changing the value of the PC register now works again. This fixes
2880 problems observed when using the "jump" command, or when calling
2881 a function from GDB, or even when assigning a new value to $pc.
2882 - With the "finish" and "return" commands, the return value for functions
2883 returning a small array is now correctly printed.
2884 - It is now possible to break on shared library code which gets executed
2885 during a shared library init phase (code executed while executing
2886 their .init section). Previously, the breakpoint would have no effect.
2887 - GDB is now able to backtrace through the signal handler for
2888 non-threaded programs.
2890 PIE (Position Independent Executable) programs debugging is now supported.
2891 This includes debugging execution of PIC (Position Independent Code) shared
2892 libraries although for that, it should be possible to run such libraries as an
2895 *** Changes in GDB 7.0
2897 * GDB now has an interface for JIT compilation. Applications that
2898 dynamically generate code can create symbol files in memory and register
2899 them with GDB. For users, the feature should work transparently, and
2900 for JIT developers, the interface is documented in the GDB manual in the
2901 "JIT Compilation Interface" chapter.
2903 * Tracepoints may now be conditional. The syntax is as for
2904 breakpoints; either an "if" clause appended to the "trace" command,
2905 or the "condition" command is available. GDB sends the condition to
2906 the target for evaluation using the same bytecode format as is used
2907 for tracepoint actions.
2909 * The disassemble command now supports: an optional /r modifier, print the
2910 raw instructions in hex as well as in symbolic form, and an optional /m
2911 modifier to print mixed source+assembly.
2913 * Process record and replay
2915 In a architecture environment that supports ``process record and
2916 replay'', ``process record and replay'' target can record a log of
2917 the process execution, and replay it with both forward and reverse
2920 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2921 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2922 set execution-direction {forward|reverse}, for targets that support
2925 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2926 feature is available with a native GDB running on kernel version
2929 * GDB now has support for multi-byte and wide character sets on the
2930 target. Strings whose character type is wchar_t, char16_t, or
2931 char32_t are now correctly printed. GDB supports wide- and unicode-
2932 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2933 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2934 `printf'. This feature requires iconv to work properly; if your
2935 system does not have a working iconv, GDB can use GNU libiconv. See
2936 the installation instructions for more information.
2938 * GDB now supports automatic retrieval of shared library files from
2939 remote targets. To use this feature, specify a system root that begins
2940 with the `remote:' prefix, either via the `set sysroot' command or via
2941 the `--with-sysroot' configure-time option.
2943 * "info sharedlibrary" now takes an optional regex of libraries to show,
2944 and it now reports if a shared library has no debugging information.
2946 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2947 now complete on file names.
2949 * When completing in expressions, gdb will attempt to limit
2950 completions to allowable structure or union fields, where appropriate.
2951 For instance, consider:
2953 # struct example { int f1; double f2; };
2954 # struct example variable;
2957 If the user types TAB at the end of this command line, the available
2958 completions will be "f1" and "f2".
2960 * Inlined functions are now supported. They show up in backtraces, and
2961 the "step", "next", and "finish" commands handle them automatically.
2963 * GDB now supports the token-splicing (##) and stringification (#)
2964 operators when expanding macros. It also supports variable-arity
2967 * GDB now supports inspecting extra signal information, exported by
2968 the new $_siginfo convenience variable. The feature is currently
2969 implemented on linux ARM, i386 and amd64.
2971 * GDB can now display the VFP floating point registers and NEON vector
2972 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2973 can provide these registers (requires Linux 2.6.30 or later). Remote
2974 and simulator targets may also provide them.
2976 * New remote packets
2979 Search memory for a sequence of bytes.
2982 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2983 operation over reliable transport links. Use of this packet is
2984 controlled by the `set remote noack-packet' command.
2987 Kill the process with the specified process ID. Use this in preference
2988 to `k' when multiprocess protocol extensions are supported.
2991 Obtains additional operating system information
2995 Read or write additional signal information.
2997 * Removed remote protocol undocumented extension
2999 An undocumented extension to the remote protocol's `S' stop reply
3000 packet that permited the stub to pass a process id was removed.
3001 Remote servers should use the `T' stop reply packet instead.
3003 * GDB now supports multiple function calling conventions according to the
3004 DWARF-2 DW_AT_calling_convention function attribute.
3006 * The SH target utilizes the aforementioned change to distinguish between gcc
3007 and Renesas calling convention. It also adds the new CLI commands
3008 `set/show sh calling-convention'.
3010 * GDB can now read compressed debug sections, as produced by GNU gold
3011 with the --compress-debug-sections=zlib flag.
3013 * 64-bit core files are now supported on AIX.
3015 * Thread switching is now supported on Tru64.
3017 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3018 which will be allocated using malloc later in program execution.
3020 * The qXfer:libraries:read remote procotol packet now allows passing a
3021 list of section offsets.
3023 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3024 conditions handling signals delivered during attach or thread creation
3025 have also been fixed.
3027 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3028 From the user's standpoint, all unqualified instances of True and False
3029 are treated as the standard definitions, regardless of context.
3031 * GDB now parses C++ symbol and type names more flexibly. For
3034 template<typename T> class C { };
3037 GDB will now correctly handle all of:
3039 ptype C<char const *>
3040 ptype C<char const*>
3041 ptype C<const char *>
3042 ptype C<const char*>
3044 * New features in the GDB remote stub, gdbserver
3046 - The "--wrapper" command-line argument tells gdbserver to use a
3047 wrapper program to launch programs for debugging.
3049 - On PowerPC and S/390 targets, it is now possible to use a single
3050 gdbserver executable to debug both 32-bit and 64-bit programs.
3051 (This requires gdbserver itself to be built as a 64-bit executable.)
3053 - gdbserver uses the new noack protocol mode for TCP connections to
3054 reduce communications latency, if also supported and enabled in GDB.
3056 - Support for the sparc64-linux-gnu target is now included in
3059 - The amd64-linux build of gdbserver now supports debugging both
3060 32-bit and 64-bit programs.
3062 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3063 now support hardware watchpoints, and will use them automatically
3068 GDB now has support for scripting using Python. Whether this is
3069 available is determined at configure time.
3071 New GDB commands can now be written in Python.
3073 * Ada tasking support
3075 Ada tasks can now be inspected in GDB. The following commands have
3079 Print the list of Ada tasks.
3081 Print detailed information about task number N.
3083 Print the task number of the current task.
3085 Switch the context of debugging to task number N.
3087 * Support for user-defined prefixed commands. The "define" command can
3088 add new commands to existing prefixes, e.g. "target".
3090 * Multi-inferior, multi-process debugging.
3092 GDB now has generalized support for multi-inferior debugging. See
3093 "Debugging Multiple Inferiors" in the manual for more information.
3094 Although availability still depends on target support, the command
3095 set is more uniform now. The GNU/Linux specific multi-forks support
3096 has been migrated to this new framework. This implied some user
3097 visible changes; see "New commands" and also "Removed commands"
3100 * Target descriptions can now describe the target OS ABI. See the
3101 "Target Description Format" section in the user manual for more
3104 * Target descriptions can now describe "compatible" architectures
3105 to indicate that the target can execute applications for a different
3106 architecture in addition to those for the main target architecture.
3107 See the "Target Description Format" section in the user manual for
3110 * Multi-architecture debugging.
3112 GDB now includes general supports for debugging applications on
3113 hybrid systems that use more than one single processor architecture
3114 at the same time. Each such hybrid architecture still requires
3115 specific support to be added. The only hybrid architecture supported
3116 in this version of GDB is the Cell Broadband Engine.
3118 * GDB now supports integrated debugging of Cell/B.E. applications that
3119 use both the PPU and SPU architectures. To enable support for hybrid
3120 Cell/B.E. debugging, you need to configure GDB to support both the
3121 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3122 --enable-targets configure option.
3124 * Non-stop mode debugging.
3126 For some targets, GDB now supports an optional mode of operation in
3127 which you can examine stopped threads while other threads continue
3128 to execute freely. This is referred to as non-stop mode, with the
3129 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3130 section in the user manual for more information.
3132 To be able to support remote non-stop debugging, a remote stub needs
3133 to implement the non-stop mode remote protocol extensions, as
3134 described in the "Remote Non-Stop" section of the user manual. The
3135 GDB remote stub, gdbserver, has been adjusted to support these
3136 extensions on linux targets.
3138 * New commands (for set/show, see "New options" below)
3140 catch syscall [NAME(S) | NUMBER(S)]
3141 Catch system calls. Arguments, which should be names of system
3142 calls or their numbers, mean catch only those syscalls. Without
3143 arguments, every syscall will be caught. When the inferior issues
3144 any of the specified syscalls, GDB will stop and announce the system
3145 call, both when it is called and when its call returns. This
3146 feature is currently available with a native GDB running on the
3147 Linux Kernel, under the following architectures: x86, x86_64,
3148 PowerPC and PowerPC64.
3150 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3152 Search memory for a sequence of bytes.
3154 maint set python print-stack
3155 maint show python print-stack
3156 Show a stack trace when an error is encountered in a Python script.
3159 Invoke CODE by passing it to the Python interpreter.
3164 These allow macros to be defined, undefined, and listed
3168 Show operating system information about processes.
3171 List the inferiors currently under GDB's control.
3174 Switch focus to inferior number NUM.
3177 Detach from inferior number NUM.
3180 Kill inferior number NUM.
3184 set spu stop-on-load
3185 show spu stop-on-load
3186 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3188 set spu auto-flush-cache
3189 show spu auto-flush-cache
3190 Control whether to automatically flush the software-managed cache
3191 during Cell/B.E. debugging.
3193 set sh calling-convention
3194 show sh calling-convention
3195 Control the calling convention used when calling SH target functions.
3198 show debug timestamp
3199 Control display of timestamps with GDB debugging output.
3201 set disassemble-next-line
3202 show disassemble-next-line
3203 Control display of disassembled source lines or instructions when
3206 set remote noack-packet
3207 show remote noack-packet
3208 Set/show the use of remote protocol QStartNoAckMode packet. See above
3209 under "New remote packets."
3211 set remote query-attached-packet
3212 show remote query-attached-packet
3213 Control use of remote protocol `qAttached' (query-attached) packet.
3215 set remote read-siginfo-object
3216 show remote read-siginfo-object
3217 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3220 set remote write-siginfo-object
3221 show remote write-siginfo-object
3222 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3225 set remote reverse-continue
3226 show remote reverse-continue
3227 Control use of remote protocol 'bc' (reverse-continue) packet.
3229 set remote reverse-step
3230 show remote reverse-step
3231 Control use of remote protocol 'bs' (reverse-step) packet.
3233 set displaced-stepping
3234 show displaced-stepping
3235 Control displaced stepping mode. Displaced stepping is a way to
3236 single-step over breakpoints without removing them from the debuggee.
3237 Also known as "out-of-line single-stepping".
3240 show debug displaced
3241 Control display of debugging info for displaced stepping.
3243 maint set internal-error
3244 maint show internal-error
3245 Control what GDB does when an internal error is detected.
3247 maint set internal-warning
3248 maint show internal-warning
3249 Control what GDB does when an internal warning is detected.
3254 Use a wrapper program to launch programs for debugging.
3256 set multiple-symbols (all|ask|cancel)
3257 show multiple-symbols
3258 The value of this variable can be changed to adjust the debugger behavior
3259 when an expression or a breakpoint location contains an ambiguous symbol
3260 name (an overloaded function name, for instance).
3262 set breakpoint always-inserted
3263 show breakpoint always-inserted
3264 Keep breakpoints always inserted in the target, as opposed to inserting
3265 them when resuming the target, and removing them when the target stops.
3266 This option can improve debugger performance on slow remote targets.
3268 set arm fallback-mode (arm|thumb|auto)
3269 show arm fallback-mode
3270 set arm force-mode (arm|thumb|auto)
3272 These commands control how ARM GDB determines whether instructions
3273 are ARM or Thumb. The default for both settings is auto, which uses
3274 the current CPSR value for instructions without symbols; previous
3275 versions of GDB behaved as if "set arm fallback-mode arm".
3277 set disable-randomization
3278 show disable-randomization
3279 Standalone programs run with the virtual address space randomization enabled
3280 by default on some platforms. This option keeps the addresses stable across
3281 multiple debugging sessions.
3285 Control whether other threads are stopped or not when some thread hits
3290 Requests that asynchronous execution is enabled in the target, if available.
3291 In this case, it's possible to resume target in the background, and interact
3292 with GDB while the target is running. "show target-async" displays the
3293 current state of asynchronous execution of the target.
3295 set target-wide-charset
3296 show target-wide-charset
3297 The target-wide-charset is the name of the character set that GDB
3298 uses when printing characters whose type is wchar_t.
3300 set tcp auto-retry (on|off)
3302 set tcp connect-timeout
3303 show tcp connect-timeout
3304 These commands allow GDB to retry failed TCP connections to a remote stub
3305 with a specified timeout period; this is useful if the stub is launched
3306 in parallel with GDB but may not be ready to accept connections immediately.
3308 set libthread-db-search-path
3309 show libthread-db-search-path
3310 Control list of directories which GDB will search for appropriate
3313 set schedule-multiple (on|off)
3314 show schedule-multiple
3315 Allow GDB to resume all threads of all processes or only threads of
3316 the current process.
3320 Use more aggressive caching for accesses to the stack. This improves
3321 performance of remote debugging (particularly backtraces) without
3322 affecting correctness.
3324 set interactive-mode (on|off|auto)
3325 show interactive-mode
3326 Control whether GDB runs in interactive mode (on) or not (off).
3327 When in interactive mode, GDB waits for the user to answer all
3328 queries. Otherwise, GDB does not wait and assumes the default
3329 answer. When set to auto (the default), GDB determines which
3330 mode to use based on the stdin settings.
3335 For program forks, this is replaced by the new more generic `info
3336 inferiors' command. To list checkpoints, you can still use the
3337 `info checkpoints' command, which was an alias for the `info forks'
3341 Replaced by the new `inferior' command. To switch between
3342 checkpoints, you can still use the `restart' command, which was an
3343 alias for the `fork' command.
3346 This is removed, since some targets don't have a notion of
3347 processes. To switch between processes, you can still use the
3348 `inferior' command using GDB's own inferior number.
3351 For program forks, this is replaced by the new more generic `kill
3352 inferior' command. To delete a checkpoint, you can still use the
3353 `delete checkpoint' command, which was an alias for the `delete
3357 For program forks, this is replaced by the new more generic `detach
3358 inferior' command. To detach a checkpoint, you can still use the
3359 `detach checkpoint' command, which was an alias for the `detach
3362 * New native configurations
3364 x86/x86_64 Darwin i[34567]86-*-darwin*
3366 x86_64 MinGW x86_64-*-mingw*
3370 Lattice Mico32 lm32-*
3371 x86 DICOS i[34567]86-*-dicos*
3372 x86_64 DICOS x86_64-*-dicos*
3375 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3376 (mingw32ce) debugging.
3382 These commands were actually not implemented on any target.
3384 *** Changes in GDB 6.8
3386 * New native configurations
3388 NetBSD/hppa hppa*-*netbsd*
3389 Xtensa GNU/Linux xtensa*-*-linux*
3393 NetBSD/hppa hppa*-*-netbsd*
3394 Xtensa GNU/Lunux xtensa*-*-linux*
3396 * Change in command line behavior -- corefiles vs. process ids.
3398 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3399 attaching to process NUMBER fails, GDB no longer attempts to open a
3400 core file named NUMBER. Attaching to a program using the -c option
3401 is no longer supported. Instead, use the '-p' or '--pid' options.
3403 * GDB can now be built as a native debugger for debugging Windows x86
3404 (mingw32) Portable Executable (PE) programs.
3406 * Pending breakpoints no longer change their number when their address
3409 * GDB now supports breakpoints with multiple locations,
3410 including breakpoints on C++ constructors, inside C++ templates,
3411 and in inlined functions.
3413 * GDB's ability to debug optimized code has been improved. GDB more
3414 accurately identifies function bodies and lexical blocks that occupy
3415 more than one contiguous range of addresses.
3417 * Target descriptions can now describe registers for PowerPC.
3419 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3420 registers on PowerPC targets.
3422 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3423 targets even when the libthread_db library is not available.
3425 * The GDB remote stub, gdbserver, now supports the new file transfer
3426 commands (remote put, remote get, and remote delete).
3428 * The GDB remote stub, gdbserver, now supports run and attach in
3429 extended-remote mode.
3431 * hppa*64*-*-hpux11* target broken
3432 The debugger is unable to start a program and fails with the following
3433 error: "Error trying to get information about dynamic linker".
3434 The gdb-6.7 release is also affected.
3436 * GDB now supports the --enable-targets= configure option to allow
3437 building a single GDB executable that supports multiple remote
3438 target architectures.
3440 * GDB now supports debugging C and C++ programs which use the
3441 Decimal Floating Point extension. In addition, the PowerPC target
3442 now has a set of pseudo-registers to inspect decimal float values
3443 stored in two consecutive float registers.
3445 * The -break-insert MI command can optionally create pending
3448 * Improved support for debugging Ada
3449 Many improvements to the Ada language support have been made. These
3451 - Better support for Ada2005 interface types
3452 - Improved handling of arrays and slices in general
3453 - Better support for Taft-amendment types
3454 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3456 - Improved command completion in Ada
3459 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3464 set print frame-arguments (all|scalars|none)
3465 show print frame-arguments
3466 The value of this variable can be changed to control which argument
3467 values should be printed by the debugger when displaying a frame.
3472 Transfer files to and from a remote target, and delete remote files.
3479 Transfer files to and from a remote target, and delete remote files.
3481 * New remote packets
3488 Open, close, read, write, and delete files on the remote system.
3491 Attach to an existing process on the remote system, in extended-remote
3495 Run a new process on the remote system, in extended-remote mode.
3497 *** Changes in GDB 6.7
3499 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3500 bfd, libiberty and opcodes, as revealed by static analysis donated by
3501 Coverity, Inc. (http://scan.coverity.com).
3503 * When looking up multiply-defined global symbols, GDB will now prefer the
3504 symbol definition in the current shared library if it was built using the
3505 -Bsymbolic linker option.
3507 * When the Text User Interface (TUI) is not configured, GDB will now
3508 recognize the -tui command-line option and print a message that the TUI
3511 * The GDB remote stub, gdbserver, now has lower overhead for high
3512 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3514 * GDB for MIPS targets now autodetects whether a remote target provides
3515 32-bit or 64-bit register values.
3517 * Support for C++ member pointers has been improved.
3519 * GDB now understands XML target descriptions, which specify the
3520 target's overall architecture. GDB can read a description from
3521 a local file or over the remote serial protocol.
3523 * Vectors of single-byte data use a new integer type which is not
3524 automatically displayed as character or string data.
3526 * The /s format now works with the print command. It displays
3527 arrays of single-byte integers and pointers to single-byte integers
3530 * Target descriptions can now describe target-specific registers,
3531 for architectures which have implemented the support (currently
3532 only ARM, M68K, and MIPS).
3534 * GDB and the GDB remote stub, gdbserver, now support the XScale
3537 * The GDB remote stub, gdbserver, has been updated to support
3538 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3539 has been rewritten to use the standard GDB remote protocol.
3541 * GDB can now step into C++ functions which are called through thunks.
3543 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3545 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3546 layout. It also supports a TextSeg= and DataSeg= response when only
3547 segment base addresses (rather than offsets) are available.
3549 * The /i format now outputs any trailing branch delay slot instructions
3550 immediately following the last instruction within the count specified.
3552 * The GDB remote protocol "T" stop reply packet now supports a
3553 "library" response. Combined with the new "qXfer:libraries:read"
3554 packet, this response allows GDB to debug shared libraries on targets
3555 where the operating system manages the list of loaded libraries (e.g.
3556 Windows and SymbianOS).
3558 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3559 (DLLs) on Windows and Windows CE targets.
3561 * GDB now supports a faster verification that a .debug file matches its binary
3562 according to its build-id signature, if the signature is present.
3568 Enable or disable hardware flow control (RTS/CTS) on the serial port
3569 when debugging using remote targets.
3571 set mem inaccessible-by-default
3572 show mem inaccessible-by-default
3573 If the target supplies a memory map, for instance via the remote
3574 protocol's "qXfer:memory-map:read" packet, setting this variable
3575 prevents GDB from accessing memory outside the memory map. This
3576 is useful for targets with memory mapped registers or which react
3577 badly to accesses of unmapped address space.
3579 set breakpoint auto-hw
3580 show breakpoint auto-hw
3581 If the target supplies a memory map, for instance via the remote
3582 protocol's "qXfer:memory-map:read" packet, setting this variable
3583 lets GDB use hardware breakpoints automatically for memory regions
3584 where it can not use software breakpoints. This covers both the
3585 "break" command and internal breakpoints used for other commands
3586 including "next" and "finish".
3589 catch exception unhandled
3590 Stop the program execution when Ada exceptions are raised.
3593 Stop the program execution when an Ada assertion failed.
3597 Set an alternate system root for target files. This is a more
3598 general version of "set solib-absolute-prefix", which is now
3599 an alias to "set sysroot".
3602 Provide extended SPU facility status information. This set of
3603 commands is available only when debugging the Cell/B.E. SPU
3606 * New native configurations
3608 OpenBSD/sh sh*-*openbsd*
3611 unset tdesc filename
3613 Use the specified local file as an XML target description, and do
3614 not query the target for its built-in description.
3618 OpenBSD/sh sh*-*-openbsd*
3619 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3620 Toshiba Media Processor mep-elf
3622 * New remote packets
3625 Ignore the specified signals; pass them directly to the debugged program
3626 without stopping other threads or reporting them to GDB.
3628 qXfer:features:read:
3629 Read an XML target description from the target, which describes its
3634 Read or write contents of an spufs file on the target system. These
3635 packets are available only on the Cell/B.E. SPU architecture.
3637 qXfer:libraries:read:
3638 Report the loaded shared libraries. Combined with new "T" packet
3639 response, this packet allows GDB to debug shared libraries on
3640 targets where the operating system manages the list of loaded
3641 libraries (e.g. Windows and SymbianOS).
3645 Support for these obsolete configurations has been removed.
3653 i[34567]86-*-lynxos*
3654 i[34567]86-*-netware*
3655 i[34567]86-*-sco3.2v5*
3656 i[34567]86-*-sco3.2v4*
3658 i[34567]86-*-sysv4.2*
3661 i[34567]86-*-unixware2*
3662 i[34567]86-*-unixware*
3671 * Other removed features
3678 Various m68k-only ROM monitors.
3685 Various Renesas ROM monitors and debugging interfaces for SH and
3690 Support for a Macraigor serial interface to on-chip debugging.
3691 GDB does not directly support the newer parallel or USB
3696 A debug information format. The predecessor to DWARF 2 and
3697 DWARF 3, which are still supported.
3699 Support for the HP aCC compiler on HP-UX/PA-RISC
3701 SOM-encapsulated symbolic debugging information, automatic
3702 invocation of pxdb, and the aCC custom C++ ABI. This does not
3703 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3704 with aCC can still be debugged on an assembly level.
3706 MIPS ".pdr" sections
3708 A MIPS-specific format used to describe stack frame layout
3709 in debugging information.
3713 GDB could work with an older version of Guile to debug
3714 the interpreter and Scheme programs running in it.
3716 set mips stack-arg-size
3717 set mips saved-gpreg-size
3719 Use "set mips abi" to control parameter passing for MIPS.
3721 *** Changes in GDB 6.6
3726 Cell Broadband Engine SPU spu-elf
3728 * GDB can now be configured as a cross-debugger targeting native Windows
3729 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3730 running on a Windows system over TCP/IP to debug Windows programs.
3732 * The GDB remote stub, gdbserver, has been updated to support Windows and
3733 Cygwin debugging. Both single-threaded and multi-threaded programs are
3736 * The "set trust-readonly-sections" command works again. This command was
3737 broken in GDB 6.3, 6.4, and 6.5.
3739 * The "load" command now supports writing to flash memory, if the remote
3740 stub provides the required support.
3742 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3743 longer requires symbolic debug information (e.g. DWARF-2).
3748 unset substitute-path
3749 show substitute-path
3750 Manage a list of substitution rules that GDB uses to rewrite the name
3751 of the directories where the sources are located. This can be useful
3752 for instance when the sources were moved to a different location
3753 between compilation and debugging.
3757 Print each CLI command as it is executed. Each command is prefixed with
3758 a number of `+' symbols representing the nesting depth.
3759 The source command now has a `-v' option to enable the same feature.
3763 The ARM Demon monitor support (RDP protocol, "target rdp").
3765 Kernel Object Display, an embedded debugging feature which only worked with
3766 an obsolete version of Cisco IOS.
3768 The 'set download-write-size' and 'show download-write-size' commands.
3770 * New remote packets
3773 Tell a stub about GDB client features, and request remote target features.
3774 The first feature implemented is PacketSize, which allows the target to
3775 specify the size of packets it can handle - to minimize the number of
3776 packets required and improve performance when connected to a remote
3780 Fetch an OS auxilliary vector from the remote stub. This packet is a
3781 more efficient replacement for qPart:auxv:read.
3783 qXfer:memory-map:read:
3784 Fetch a memory map from the remote stub, including information about
3785 RAM, ROM, and flash memory devices.
3790 Erase and program a flash memory device.
3792 * Removed remote packets
3795 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3796 used it, and only gdbserver implemented it.
3798 *** Changes in GDB 6.5
3802 Renesas M32C/M16C m32c-elf
3804 Morpho Technologies ms1 ms1-elf
3808 init-if-undefined Initialize a convenience variable, but
3809 only if it doesn't already have a value.
3811 The following commands are presently only implemented for native GNU/Linux:
3813 checkpoint Save a snapshot of the program state.
3815 restart <n> Return the program state to a
3816 previously saved state.
3818 info checkpoints List currently saved checkpoints.
3820 delete-checkpoint <n> Delete a previously saved checkpoint.
3822 set|show detach-on-fork Tell gdb whether to detach from a newly
3823 forked process, or to keep debugging it.
3825 info forks List forks of the user program that
3826 are available to be debugged.
3828 fork <n> Switch to debugging one of several
3829 forks of the user program that are
3830 available to be debugged.
3832 delete-fork <n> Delete a fork from the list of forks
3833 that are available to be debugged (and
3834 kill the forked process).
3836 detach-fork <n> Delete a fork from the list of forks
3837 that are available to be debugged (and
3838 allow the process to continue).
3842 Morpho Technologies ms2 ms1-elf
3844 * Improved Windows host support
3846 GDB now builds as a cross debugger hosted on i686-mingw32, including
3847 native console support, and remote communications using either
3848 network sockets or serial ports.
3850 * Improved Modula-2 language support
3852 GDB can now print most types in the Modula-2 syntax. This includes:
3853 basic types, set types, record types, enumerated types, range types,
3854 pointer types and ARRAY types. Procedure var parameters are correctly
3855 printed and hexadecimal addresses and character constants are also
3856 written in the Modula-2 syntax. Best results can be obtained by using
3857 GNU Modula-2 together with the -gdwarf-2 command line option.
3861 The ARM rdi-share module.
3863 The Netware NLM debug server.
3865 *** Changes in GDB 6.4
3867 * New native configurations
3869 OpenBSD/arm arm*-*-openbsd*
3870 OpenBSD/mips64 mips64-*-openbsd*
3874 Morpho Technologies ms1 ms1-elf
3876 * New command line options
3878 --batch-silent As for --batch, but totally silent.
3879 --return-child-result The debugger will exist with the same value
3880 the child (debugged) program exited with.
3881 --eval-command COMMAND, -ex COMMAND
3882 Execute a single GDB CLI command. This may be
3883 specified multiple times and in conjunction
3884 with the --command (-x) option.
3886 * Deprecated commands removed
3888 The following commands, that were deprecated in 2000, have been
3892 set|show arm disassembly-flavor set|show arm disassembler
3893 othernames set arm disassembler
3894 set|show remotedebug set|show debug remote
3895 set|show archdebug set|show debug arch
3896 set|show eventdebug set|show debug event
3899 * New BSD user-level threads support
3901 It is now possible to debug programs using the user-level threads
3902 library on OpenBSD and FreeBSD. Currently supported (target)
3905 FreeBSD/amd64 x86_64-*-freebsd*
3906 FreeBSD/i386 i386-*-freebsd*
3907 OpenBSD/i386 i386-*-openbsd*
3909 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3910 are not yet supported.
3912 * New support for Matsushita MN10300 w/sim added
3913 (Work in progress). mn10300-elf.
3915 * REMOVED configurations and files
3917 VxWorks and the XDR protocol *-*-vxworks
3918 Motorola MCORE mcore-*-*
3919 National Semiconductor NS32000 ns32k-*-*
3921 * New "set print array-indexes" command
3923 After turning this setting "on", GDB prints the index of each element
3924 when displaying arrays. The default is "off" to preserve the previous
3927 * VAX floating point support
3929 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3931 * User-defined command support
3933 In addition to using $arg0..$arg9 for argument passing, it is now possible
3934 to use $argc to determine now many arguments have been passed. See the
3935 section on user-defined commands in the user manual for more information.
3937 *** Changes in GDB 6.3:
3939 * New command line option
3941 GDB now accepts -l followed by a number to set the timeout for remote
3944 * GDB works with GCC -feliminate-dwarf2-dups
3946 GDB now supports a more compact representation of DWARF-2 debug
3947 information using DW_FORM_ref_addr references. These are produced
3948 by GCC with the option -feliminate-dwarf2-dups and also by some
3949 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3950 to use -feliminate-dwarf2-dups.
3952 * Internationalization
3954 When supported by the host system, GDB will be built with
3955 internationalization (libintl). The task of marking up the sources is
3956 continued, we're looking forward to our first translation.
3960 Initial support for debugging programs compiled with the GNAT
3961 implementation of the Ada programming language has been integrated
3962 into GDB. In this release, support is limited to expression evaluation.
3964 * New native configurations
3966 GNU/Linux/m32r m32r-*-linux-gnu
3970 GDB's remote protocol now includes support for the 'p' packet. This
3971 packet is used to fetch individual registers from a remote inferior.
3973 * END-OF-LIFE registers[] compatibility module
3975 GDB's internal register infrastructure has been completely rewritten.
3976 The new infrastructure making possible the implementation of key new
3977 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3980 GDB 6.3 will be the last release to include the the registers[]
3981 compatibility module that allowed out-of-date configurations to
3982 continue to work. This change directly impacts the following
3992 powerpc bdm protocol
3994 Unless there is activity to revive these configurations, they will be
3995 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3997 * OBSOLETE configurations and files
3999 Configurations that have been declared obsolete in this release have
4000 been commented out. Unless there is activity to revive these
4001 configurations, the next release of GDB will have their sources
4002 permanently REMOVED.
4011 *** Changes in GDB 6.2.1:
4013 * MIPS `break main; run' gave an heuristic-fence-post warning
4015 When attempting to run even a simple program, a warning about
4016 heuristic-fence-post being hit would be reported. This problem has
4019 * MIPS IRIX 'long double' crashed GDB
4021 When examining a long double variable, GDB would get a segmentation
4022 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4023 IRIX long double values).
4027 A bug in the VAX stack code was causing problems with the "next"
4028 command. This problem has been fixed.
4030 *** Changes in GDB 6.2:
4032 * Fix for ``many threads''
4034 On GNU/Linux systems that use the NPTL threads library, a program
4035 rapidly creating and deleting threads would confuse GDB leading to the
4038 ptrace: No such process.
4039 thread_db_get_info: cannot get thread info: generic error
4041 This problem has been fixed.
4043 * "-async" and "-noasync" options removed.
4045 Support for the broken "-noasync" option has been removed (it caused
4048 * New ``start'' command.
4050 This command runs the program until the begining of the main procedure.
4052 * New BSD Kernel Data Access Library (libkvm) interface
4054 Using ``target kvm'' it is now possible to debug kernel core dumps and
4055 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4056 platforms. Currently supported (native-only) configurations are:
4058 FreeBSD/amd64 x86_64-*-freebsd*
4059 FreeBSD/i386 i?86-*-freebsd*
4060 NetBSD/i386 i?86-*-netbsd*
4061 NetBSD/m68k m68*-*-netbsd*
4062 NetBSD/sparc sparc-*-netbsd*
4063 OpenBSD/amd64 x86_64-*-openbsd*
4064 OpenBSD/i386 i?86-*-openbsd*
4065 OpenBSD/m68k m68*-openbsd*
4066 OpenBSD/sparc sparc-*-openbsd*
4068 * Signal trampoline code overhauled
4070 Many generic problems with GDB's signal handling code have been fixed.
4071 These include: backtraces through non-contiguous stacks; recognition
4072 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4073 call; backtrace through a signal trampoline; step into and out of
4074 signal handlers; and single-stepping in the signal trampoline.
4076 Please note that kernel bugs are a limiting factor here. These
4077 features have been shown to work on an s390 GNU/Linux system that
4078 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4080 * Cygwin support for DWARF 2 added.
4082 * New native configurations
4084 GNU/Linux/hppa hppa*-*-linux*
4085 OpenBSD/hppa hppa*-*-openbsd*
4086 OpenBSD/m68k m68*-*-openbsd*
4087 OpenBSD/m88k m88*-*-openbsd*
4088 OpenBSD/powerpc powerpc-*-openbsd*
4089 NetBSD/vax vax-*-netbsd*
4090 OpenBSD/vax vax-*-openbsd*
4092 * END-OF-LIFE frame compatibility module
4094 GDB's internal frame infrastructure has been completely rewritten.
4095 The new infrastructure making it possible to support key new features
4096 including DWARF 2 Call Frame Information. To aid in the task of
4097 migrating old configurations to this new infrastructure, a
4098 compatibility module, that allowed old configurations to continue to
4099 work, was also included.
4101 GDB 6.2 will be the last release to include this frame compatibility
4102 module. This change directly impacts the following configurations:
4112 Unless there is activity to revive these configurations, they will be
4113 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4115 * REMOVED configurations and files
4117 Sun 3, running SunOS 3 m68*-*-sunos3*
4118 Sun 3, running SunOS 4 m68*-*-sunos4*
4119 Sun 2, running SunOS 3 m68000-*-sunos3*
4120 Sun 2, running SunOS 4 m68000-*-sunos4*
4121 Motorola 680x0 running LynxOS m68*-*-lynxos*
4122 AT&T 3b1/Unix pc m68*-att-*
4123 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4124 decstation mips-dec-* mips-little-*
4125 riscos mips-*-riscos* mips-*-sysv*
4126 sonymips mips-sony-*
4127 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4129 *** Changes in GDB 6.1.1:
4131 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4133 The TUI (Text-mode User Interface) is now built as part of a default
4134 GDB configuration. It is enabled by either selecting the TUI with the
4135 command line option "-i=tui" or by running the separate "gdbtui"
4136 program. For more information on the TUI, see the manual "Debugging
4139 * Pending breakpoint support (also included in GDB 6.1)
4141 Support has been added to allow you to specify breakpoints in shared
4142 libraries that have not yet been loaded. If a breakpoint location
4143 cannot be found, and the "breakpoint pending" option is set to auto,
4144 GDB queries you if you wish to make the breakpoint pending on a future
4145 shared-library load. If and when GDB resolves the breakpoint symbol,
4146 the pending breakpoint is removed as one or more regular breakpoints
4149 Pending breakpoints are very useful for GCJ Java debugging.
4151 * Fixed ISO-C build problems
4153 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4154 non ISO-C code that stopped them being built using a more strict ISO-C
4155 compiler (e.g., IBM's C compiler).
4157 * Fixed build problem on IRIX 5
4159 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4160 wasn't able to compile compile on an IRIX 5 system.
4162 * Added execute permission to gdb/gdbserver/configure
4164 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4165 permission. This bug would cause configure to fail on a number of
4166 systems (Solaris, IRIX). Ref: server/519.
4168 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4170 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4171 has been updated to use constant array sizes.
4173 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4175 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4176 its generated DWARF Call Frame Info. This encoding was causing GDB to
4177 panic, that panic has been fixed. Ref: gdb/1628.
4179 * Fixed a problem when examining parameters in shared library code.
4181 When examining parameters in optimized shared library code generated
4182 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4183 not available''. GDB now correctly displays the variable's value.
4185 *** Changes in GDB 6.1:
4187 * Removed --with-mmalloc
4189 Support for the mmalloc memory manager has been removed, as it
4190 conflicted with the internal gdb byte cache.
4192 * Changes in AMD64 configurations
4194 The AMD64 target now includes the %cs and %ss registers. As a result
4195 the AMD64 remote protocol has changed; this affects the floating-point
4196 and SSE registers. If you rely on those registers for your debugging,
4197 you should upgrade gdbserver on the remote side.
4199 * Revised SPARC target
4201 The SPARC target has been completely revised, incorporating the
4202 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4203 support for LynxOS and SunOS 4 has been dropped. Calling functions
4204 from within GDB on operating systems with a non-executable stack
4205 (Solaris, OpenBSD) now works.
4209 GDB has a new C++ demangler which does a better job on the mangled
4210 names generated by current versions of g++. It also runs faster, so
4211 with this and other changes gdb should now start faster on large C++
4214 * DWARF 2 Location Expressions
4216 GDB support for location expressions has been extended to support function
4217 arguments and frame bases. Older versions of GDB could crash when they
4220 * C++ nested types and namespaces
4222 GDB's support for nested types and namespaces in C++ has been
4223 improved, especially if you use the DWARF 2 debugging format. (This
4224 is the default for recent versions of GCC on most platforms.)
4225 Specifically, if you have a class "Inner" defined within a class or
4226 namespace "Outer", then GDB realizes that the class's name is
4227 "Outer::Inner", not simply "Inner". This should greatly reduce the
4228 frequency of complaints about not finding RTTI symbols. In addition,
4229 if you are stopped at inside of a function defined within a namespace,
4230 GDB modifies its name lookup accordingly.
4232 * New native configurations
4234 NetBSD/amd64 x86_64-*-netbsd*
4235 OpenBSD/amd64 x86_64-*-openbsd*
4236 OpenBSD/alpha alpha*-*-openbsd*
4237 OpenBSD/sparc sparc-*-openbsd*
4238 OpenBSD/sparc64 sparc64-*-openbsd*
4240 * New debugging protocols
4242 M32R with SDI protocol m32r-*-elf*
4244 * "set prompt-escape-char" command deleted.
4246 The command "set prompt-escape-char" has been deleted. This command,
4247 and its very obscure effet on GDB's prompt, was never documented,
4248 tested, nor mentioned in the NEWS file.
4250 * OBSOLETE configurations and files
4252 Configurations that have been declared obsolete in this release have
4253 been commented out. Unless there is activity to revive these
4254 configurations, the next release of GDB will have their sources
4255 permanently REMOVED.
4257 Sun 3, running SunOS 3 m68*-*-sunos3*
4258 Sun 3, running SunOS 4 m68*-*-sunos4*
4259 Sun 2, running SunOS 3 m68000-*-sunos3*
4260 Sun 2, running SunOS 4 m68000-*-sunos4*
4261 Motorola 680x0 running LynxOS m68*-*-lynxos*
4262 AT&T 3b1/Unix pc m68*-att-*
4263 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4264 decstation mips-dec-* mips-little-*
4265 riscos mips-*-riscos* mips-*-sysv*
4266 sonymips mips-sony-*
4267 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4269 * REMOVED configurations and files
4271 SGI Irix-4.x mips-sgi-irix4 or iris4
4272 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4273 Z8000 simulator z8k-zilog-none or z8ksim
4274 Matsushita MN10200 w/simulator mn10200-*-*
4275 H8/500 simulator h8500-hitachi-hms or h8500hms
4276 HP/PA running BSD hppa*-*-bsd*
4277 HP/PA running OSF/1 hppa*-*-osf*
4278 HP/PA Pro target hppa*-*-pro*
4279 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4280 386BSD i[3456]86-*-bsd*
4281 Sequent family i[3456]86-sequent-sysv4*
4282 i[3456]86-sequent-sysv*
4283 i[3456]86-sequent-bsd*
4284 SPARC running LynxOS sparc-*-lynxos*
4285 SPARC running SunOS 4 sparc-*-sunos4*
4286 Tsqware Sparclet sparclet-*-*
4287 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4289 *** Changes in GDB 6.0:
4293 Support for debugging the Objective-C programming language has been
4294 integrated into GDB.
4296 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4298 DWARF 2's Call Frame Information makes available compiler generated
4299 information that more exactly describes the program's run-time stack.
4300 By using this information, GDB is able to provide more robust stack
4303 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4304 have been updated to use a new backtrace mechanism which includes
4305 DWARF 2 CFI support.
4309 GDB's remote protocol has been extended to include support for hosted
4310 file I/O (where the remote target uses GDB's file system). See GDB's
4311 remote protocol documentation for details.
4313 * All targets using the new architecture framework.
4315 All of GDB's targets have been updated to use the new internal
4316 architecture framework. The way is now open for future GDB releases
4317 to include cross-architecture native debugging support (i386 on amd64,
4320 * GNU/Linux's Thread Local Storage (TLS)
4322 GDB now includes support for for the GNU/Linux implementation of
4323 per-thread variables.
4325 * GNU/Linux's Native POSIX Thread Library (NPTL)
4327 GDB's thread code has been updated to work with either the new
4328 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4330 * Separate debug info.
4332 GDB, in conjunction with BINUTILS, now supports a mechanism for
4333 automatically loading debug information from a separate file. Instead
4334 of shipping full debug and non-debug versions of system libraries,
4335 system integrators can now instead ship just the stripped libraries
4336 and optional debug files.
4338 * DWARF 2 Location Expressions
4340 DWARF 2 Location Expressions allow the compiler to more completely
4341 describe the location of variables (even in optimized code) to the
4344 GDB now includes preliminary support for location expressions (support
4345 for DW_OP_piece is still missing).
4349 A number of long standing bugs that caused GDB to die while starting a
4350 Java application have been fixed. GDB's Java support is now
4351 considered "useable".
4353 * GNU/Linux support for fork, vfork, and exec.
4355 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4356 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4359 * GDB supports logging output to a file
4361 There are two new commands, "set logging" and "show logging", which can be
4362 used to capture GDB's output to a file.
4364 * The meaning of "detach" has changed for gdbserver
4366 The "detach" command will now resume the application, as documented. To
4367 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4370 * d10v, m68hc11 `regs' command deprecated
4372 The `info registers' command has been updated so that it displays the
4373 registers using a format identical to the old `regs' command.
4377 A new command, "maint set profile on/off", has been added. This command can
4378 be used to enable or disable profiling while running GDB, to profile a
4379 session or a set of commands. In addition there is a new configure switch,
4380 "--enable-profiling", which will cause GDB to be compiled with profiling
4381 data, for more informative profiling results.
4383 * Default MI syntax changed to "mi2".
4385 The default MI (machine interface) syntax, enabled by the command line
4386 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4387 "mi1", can be enabled by specifying the option "-i=mi1".
4389 Support for the original "mi0" syntax (included in GDB 5.0) has been
4392 Fix for gdb/192: removed extraneous space when displaying frame level.
4393 Fix for gdb/672: update changelist is now output in mi list format.
4394 Fix for gdb/702: a -var-assign that updates the value now shows up
4395 in a subsequent -var-update.
4397 * New native configurations.
4399 FreeBSD/amd64 x86_64-*-freebsd*
4401 * Multi-arched targets.
4403 HP/PA HPUX11 hppa*-*-hpux*
4404 Renesas M32R/D w/simulator m32r-*-elf*
4406 * OBSOLETE configurations and files
4408 Configurations that have been declared obsolete in this release have
4409 been commented out. Unless there is activity to revive these
4410 configurations, the next release of GDB will have their sources
4411 permanently REMOVED.
4413 Z8000 simulator z8k-zilog-none or z8ksim
4414 Matsushita MN10200 w/simulator mn10200-*-*
4415 H8/500 simulator h8500-hitachi-hms or h8500hms
4416 HP/PA running BSD hppa*-*-bsd*
4417 HP/PA running OSF/1 hppa*-*-osf*
4418 HP/PA Pro target hppa*-*-pro*
4419 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4420 Sequent family i[3456]86-sequent-sysv4*
4421 i[3456]86-sequent-sysv*
4422 i[3456]86-sequent-bsd*
4423 Tsqware Sparclet sparclet-*-*
4424 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4426 * REMOVED configurations and files
4429 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4430 IBM AIX PS/2 i[3456]86-*-aix
4431 i386 running Mach 3.0 i[3456]86-*-mach3*
4432 i386 running Mach i[3456]86-*-mach*
4433 i386 running OSF/1 i[3456]86-*osf1mk*
4434 HP/Apollo 68k Family m68*-apollo*-sysv*,
4436 m68*-hp-bsd*, m68*-hp-hpux*
4437 Argonaut Risc Chip (ARC) arc-*-*
4438 Mitsubishi D30V d30v-*-*
4439 Fujitsu FR30 fr30-*-elf*
4440 OS/9000 i[34]86-*-os9k
4441 I960 with MON960 i960-*-coff
4443 * MIPS $fp behavior changed
4445 The convenience variable $fp, for the MIPS, now consistently returns
4446 the address of the current frame's base. Previously, depending on the
4447 context, $fp could refer to either $sp or the current frame's base
4448 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4449 The GNU Source-Level Debugger''.
4451 *** Changes in GDB 5.3:
4453 * GNU/Linux shared library multi-threaded performance improved.
4455 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4456 `/proc', in preference to `ptrace' for memory reads. This may result
4457 in an improvement in the start-up time of multi-threaded, shared
4458 library applications when run under GDB. One GDB user writes: ``loads
4459 shared libs like mad''.
4461 * ``gdbserver'' now supports multi-threaded applications on some targets
4463 Support for debugging multi-threaded applications which use
4464 the GNU/Linux LinuxThreads package has been added for
4465 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4466 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4468 * GDB now supports C/C++ preprocessor macros.
4470 GDB now expands preprocessor macro invocations in C/C++ expressions,
4471 and provides various commands for showing macro definitions and how
4474 The new command `macro expand EXPRESSION' expands any macro
4475 invocations in expression, and shows the result.
4477 The new command `show macro MACRO-NAME' shows the definition of the
4478 macro named MACRO-NAME, and where it was defined.
4480 Most compilers don't include information about macros in the debugging
4481 information by default. In GCC 3.1, for example, you need to compile
4482 your program with the options `-gdwarf-2 -g3'. If the macro
4483 information is present in the executable, GDB will read it.
4485 * Multi-arched targets.
4487 DEC Alpha (partial) alpha*-*-*
4488 DEC VAX (partial) vax-*-*
4490 National Semiconductor NS32000 (partial) ns32k-*-*
4491 Motorola 68000 (partial) m68k-*-*
4492 Motorola MCORE mcore-*-*
4496 Fujitsu FRV architecture added by Red Hat frv*-*-*
4499 * New native configurations
4501 Alpha NetBSD alpha*-*-netbsd*
4502 SH NetBSD sh*-*-netbsdelf*
4503 MIPS NetBSD mips*-*-netbsd*
4504 UltraSPARC NetBSD sparc64-*-netbsd*
4506 * OBSOLETE configurations and files
4508 Configurations that have been declared obsolete in this release have
4509 been commented out. Unless there is activity to revive these
4510 configurations, the next release of GDB will have their sources
4511 permanently REMOVED.
4513 Mitsubishi D30V d30v-*-*
4514 OS/9000 i[34]86-*-os9k
4515 IBM AIX PS/2 i[3456]86-*-aix
4516 Fujitsu FR30 fr30-*-elf*
4517 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4518 Argonaut Risc Chip (ARC) arc-*-*
4519 i386 running Mach 3.0 i[3456]86-*-mach3*
4520 i386 running Mach i[3456]86-*-mach*
4521 i386 running OSF/1 i[3456]86-*osf1mk*
4522 HP/Apollo 68k Family m68*-apollo*-sysv*,
4524 m68*-hp-bsd*, m68*-hp-hpux*
4525 I960 with MON960 i960-*-coff
4527 * OBSOLETE languages
4529 CHILL, a Pascal like language used by telecommunications companies.
4531 * REMOVED configurations and files
4533 AMD 29k family via UDI a29k-amd-udi, udi29k
4534 A29K VxWorks a29k-*-vxworks
4535 AMD 29000 embedded, using EBMON a29k-none-none
4536 AMD 29000 embedded with COFF a29k-none-coff
4537 AMD 29000 embedded with a.out a29k-none-aout
4539 testsuite/gdb.hp/gdb.threads-hp/ directory
4541 * New command "set max-user-call-depth <nnn>"
4543 This command allows the user to limit the call depth of user-defined
4544 commands. The default is 1024.
4546 * Changes in FreeBSD/i386 native debugging.
4548 Support for the "generate-core-file" has been added.
4550 * New commands "dump", "append", and "restore".
4552 These commands allow data to be copied from target memory
4553 to a bfd-format or binary file (dump and append), and back
4554 from a file into memory (restore).
4556 * Improved "next/step" support on multi-processor Alpha Tru64.
4558 The previous single-step mechanism could cause unpredictable problems,
4559 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4560 of a software single-step mechanism prevents this.
4562 *** Changes in GDB 5.2.1:
4570 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4571 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4572 Fix, by Joel Brobecker imported from mainline.
4574 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4575 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4576 Fix, by Fred Fish, imported from mainline.
4578 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4579 Surprisingly enough, it works now.
4580 By Michal Ludvig, imported from mainline.
4582 i386 hardware watchpoint support:
4583 avoid misses on second run for some targets.
4584 By Pierre Muller, imported from mainline.
4586 *** Changes in GDB 5.2:
4588 * New command "set trust-readonly-sections on[off]".
4590 This command is a hint that tells gdb that read-only sections
4591 really are read-only (ie. that their contents will not change).
4592 In this mode, gdb will go to the object file rather than the
4593 target to read memory from read-only sections (such as ".text").
4594 This can be a significant performance improvement on some
4595 (notably embedded) targets.
4597 * New command "generate-core-file" (or "gcore").
4599 This new gdb command allows the user to drop a core file of the child
4600 process state at any time. So far it's been implemented only for
4601 GNU/Linux and Solaris, but should be relatively easily ported to other
4602 hosts. Argument is core file name (defaults to core.<pid>).
4604 * New command line option
4606 GDB now accepts --pid or -p followed by a process id.
4608 * Change in command line behavior -- corefiles vs. process ids.
4610 There is a subtle behavior in the way in which GDB handles
4611 command line arguments. The first non-flag argument is always
4612 a program to debug, but the second non-flag argument may either
4613 be a corefile or a process id. Previously, GDB would attempt to
4614 open the second argument as a corefile, and if that failed, would
4615 issue a superfluous error message and then attempt to attach it as
4616 a process. Now, if the second argument begins with a non-digit,
4617 it will be treated as a corefile. If it begins with a digit,
4618 GDB will attempt to attach it as a process, and if no such process
4619 is found, will then attempt to open it as a corefile.
4621 * Changes in ARM configurations.
4623 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4624 configuration is fully multi-arch.
4626 * New native configurations
4628 ARM NetBSD arm*-*-netbsd*
4629 x86 OpenBSD i[3456]86-*-openbsd*
4630 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4631 Sparc64 running FreeBSD sparc64-*-freebsd*
4635 Sanyo XStormy16 xstormy16-elf
4637 * OBSOLETE configurations and files
4639 Configurations that have been declared obsolete in this release have
4640 been commented out. Unless there is activity to revive these
4641 configurations, the next release of GDB will have their sources
4642 permanently REMOVED.
4644 AMD 29k family via UDI a29k-amd-udi, udi29k
4645 A29K VxWorks a29k-*-vxworks
4646 AMD 29000 embedded, using EBMON a29k-none-none
4647 AMD 29000 embedded with COFF a29k-none-coff
4648 AMD 29000 embedded with a.out a29k-none-aout
4650 testsuite/gdb.hp/gdb.threads-hp/ directory
4652 * REMOVED configurations and files
4654 TI TMS320C80 tic80-*-*
4656 PowerPC Solaris powerpcle-*-solaris*
4657 PowerPC Windows NT powerpcle-*-cygwin32
4658 PowerPC Netware powerpc-*-netware*
4659 Harris/CXUX m88k m88*-harris-cxux*
4660 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4661 ns32k-utek-sysv* ns32k-utek-*
4662 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4663 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4664 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4665 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4666 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4668 * Changes to command line processing
4670 The new `--args' feature can be used to specify command-line arguments
4671 for the inferior from gdb's command line.
4673 * Changes to key bindings
4675 There is a new `operate-and-get-next' function bound to `C-o'.
4677 *** Changes in GDB 5.1.1
4679 Fix compile problem on DJGPP.
4681 Fix a problem with floating-point registers on the i386 being
4684 Fix to stop GDB crashing on .debug_str debug info.
4686 Numerous documentation fixes.
4688 Numerous testsuite fixes.
4690 *** Changes in GDB 5.1:
4692 * New native configurations
4694 Alpha FreeBSD alpha*-*-freebsd*
4695 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4696 MIPS GNU/Linux mips*-*-linux*
4697 MIPS SGI Irix 6.x mips*-sgi-irix6*
4698 ia64 AIX ia64-*-aix*
4699 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4703 Motorola 68HC11 and 68HC12 m68hc11-elf
4705 UltraSparc running GNU/Linux sparc64-*-linux*
4707 * OBSOLETE configurations and files
4709 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4710 Harris/CXUX m88k m88*-harris-cxux*
4711 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4712 ns32k-utek-sysv* ns32k-utek-*
4713 TI TMS320C80 tic80-*-*
4715 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4716 PowerPC Solaris powerpcle-*-solaris*
4717 PowerPC Windows NT powerpcle-*-cygwin32
4718 PowerPC Netware powerpc-*-netware*
4719 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4720 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4721 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4722 Apple Macintosh (MPW) host N/A
4724 stuff.c (Program to stuff files into a specially prepared space in kdb)
4725 kdb-start.c (Main loop for the standalone kernel debugger)
4727 Configurations that have been declared obsolete in this release have
4728 been commented out. Unless there is activity to revive these
4729 configurations, the next release of GDB will have their sources
4730 permanently REMOVED.
4732 * REMOVED configurations and files
4734 Altos 3068 m68*-altos-*
4735 Convex c1-*-*, c2-*-*
4737 ARM RISCix arm-*-* (as host)
4741 * GDB has been converted to ISO C.
4743 GDB's source code has been converted to ISO C. In particular, the
4744 sources are fully protoized, and rely on standard headers being
4749 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4751 * The MI enabled by default.
4753 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4754 revised and enabled by default. Packages which use GDB as a debugging
4755 engine behind a UI or another front end are encouraged to switch to
4756 using the GDB/MI interface, instead of the old annotations interface
4757 which is now deprecated.
4759 * Support for debugging Pascal programs.
4761 GDB now includes support for debugging Pascal programs. The following
4762 main features are supported:
4764 - Pascal-specific data types such as sets;
4766 - automatic recognition of Pascal sources based on file-name
4769 - Pascal-style display of data types, variables, and functions;
4771 - a Pascal expression parser.
4773 However, some important features are not yet supported.
4775 - Pascal string operations are not supported at all;
4777 - there are some problems with boolean types;
4779 - Pascal type hexadecimal constants are not supported
4780 because they conflict with the internal variables format;
4782 - support for Pascal objects and classes is not full yet;
4784 - unlike Pascal, GDB is case-sensitive for symbol names.
4786 * Changes in completion.
4788 Commands such as `shell', `run' and `set args', which pass arguments
4789 to inferior programs, now complete on file names, similar to what
4790 users expect at the shell prompt.
4792 Commands which accept locations, such as `disassemble', `print',
4793 `breakpoint', `until', etc. now complete on filenames as well as
4794 program symbols. Thus, if you type "break foob TAB", and the source
4795 files linked into the programs include `foobar.c', that file name will
4796 be one of the candidates for completion. However, file names are not
4797 considered for completion after you typed a colon that delimits a file
4798 name from a name of a function in that file, as in "break foo.c:bar".
4800 `set demangle-style' completes on available demangling styles.
4802 * New platform-independent commands:
4804 It is now possible to define a post-hook for a command as well as a
4805 hook that runs before the command. For more details, see the
4806 documentation of `hookpost' in the GDB manual.
4808 * Changes in GNU/Linux native debugging.
4810 Support for debugging multi-threaded programs has been completely
4811 revised for all platforms except m68k and sparc. You can now debug as
4812 many threads as your system allows you to have.
4814 Attach/detach is supported for multi-threaded programs.
4816 Support for SSE registers was added for x86. This doesn't work for
4817 multi-threaded programs though.
4819 * Changes in MIPS configurations.
4821 Multi-arch support is enabled for all MIPS configurations.
4823 GDB can now be built as native debugger on SGI Irix 6.x systems for
4824 debugging n32 executables. (Debugging 64-bit executables is not yet
4827 * Unified support for hardware watchpoints in all x86 configurations.
4829 Most (if not all) native x86 configurations support hardware-assisted
4830 breakpoints and watchpoints in a unified manner. This support
4831 implements debug register sharing between watchpoints, which allows to
4832 put a virtually infinite number of watchpoints on the same address,
4833 and also supports watching regions up to 16 bytes with several debug
4836 The new maintenance command `maintenance show-debug-regs' toggles
4837 debugging print-outs in functions that insert, remove, and test
4838 watchpoints and hardware breakpoints.
4840 * Changes in the DJGPP native configuration.
4842 New command ``info dos sysinfo'' displays assorted information about
4843 the CPU, OS, memory, and DPMI server.
4845 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4846 display information about segment descriptors stored in GDT, LDT, and
4849 New commands ``info dos pde'' and ``info dos pte'' display entries
4850 from Page Directory and Page Tables (for now works with CWSDPMI only).
4851 New command ``info dos address-pte'' displays the Page Table entry for
4852 a given linear address.
4854 GDB can now pass command lines longer than 126 characters to the
4855 program being debugged (requires an update to the libdbg.a library
4856 which is part of the DJGPP development kit).
4858 DWARF2 debug info is now supported.
4860 It is now possible to `step' and `next' through calls to `longjmp'.
4862 * Changes in documentation.
4864 All GDB documentation was converted to GFDL, the GNU Free
4865 Documentation License.
4867 Tracepoints-related commands are now fully documented in the GDB
4870 TUI, the Text-mode User Interface, is now documented in the manual.
4872 Tracepoints-related commands are now fully documented in the GDB
4875 The "GDB Internals" manual now has an index. It also includes
4876 documentation of `ui_out' functions, GDB coding standards, x86
4877 hardware watchpoints, and memory region attributes.
4879 * GDB's version number moved to ``version.in''
4881 The Makefile variable VERSION has been replaced by the file
4882 ``version.in''. People creating GDB distributions should update the
4883 contents of this file.
4887 GUD support is now a standard part of the EMACS distribution.
4889 *** Changes in GDB 5.0:
4891 * Improved support for debugging FP programs on x86 targets
4893 Unified and much-improved support for debugging floating-point
4894 programs on all x86 targets. In particular, ``info float'' now
4895 displays the FP registers in the same format on all x86 targets, with
4896 greater level of detail.
4898 * Improvements and bugfixes in hardware-assisted watchpoints
4900 It is now possible to watch array elements, struct members, and
4901 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4902 on x86 targets no longer erroneously trigger when the address is
4905 * Improvements in the native DJGPP version of GDB
4907 The distribution now includes all the scripts and auxiliary files
4908 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4909 machines ``out of the box''.
4911 The DJGPP version can now debug programs that use signals. It is
4912 possible to catch signals that happened in the debuggee, deliver
4913 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4914 would kill the program being debugged.) Programs that hook hardware
4915 interrupts (keyboard, timer, etc.) can also be debugged.
4917 It is now possible to debug DJGPP programs that redirect their
4918 standard handles or switch them to raw (as opposed to cooked) mode, or
4919 even close them. The command ``run < foo > bar'' works as expected,
4920 and ``info terminal'' reports useful information about the debuggee's
4921 terminal, including raw/cooked mode, redirection, etc.
4923 The DJGPP version now uses termios functions for console I/O, which
4924 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4927 DOS-style file names with drive letters are now fully supported by
4930 It is now possible to debug DJGPP programs that switch their working
4931 directory. It is also possible to rerun the debuggee any number of
4932 times without restarting GDB; thus, you can use the same setup,
4933 breakpoints, etc. for many debugging sessions.
4935 * New native configurations
4937 ARM GNU/Linux arm*-*-linux*
4938 PowerPC GNU/Linux powerpc-*-linux*
4942 Motorola MCore mcore-*-*
4943 x86 VxWorks i[3456]86-*-vxworks*
4944 PowerPC VxWorks powerpc-*-vxworks*
4945 TI TMS320C80 tic80-*-*
4947 * OBSOLETE configurations
4949 Altos 3068 m68*-altos-*
4950 Convex c1-*-*, c2-*-*
4952 ARM RISCix arm-*-* (as host)
4955 Configurations that have been declared obsolete will be commented out,
4956 but the code will be left in place. If there is no activity to revive
4957 these configurations before the next release of GDB, the sources will
4958 be permanently REMOVED.
4960 * Gould support removed
4962 Support for the Gould PowerNode and NP1 has been removed.
4964 * New features for SVR4
4966 On SVR4 native platforms (such as Solaris), if you attach to a process
4967 without first loading a symbol file, GDB will now attempt to locate and
4968 load symbols from the running process's executable file.
4970 * Many C++ enhancements
4972 C++ support has been greatly improved. Overload resolution now works properly
4973 in almost all cases. RTTI support is on the way.
4975 * Remote targets can connect to a sub-program
4977 A popen(3) style serial-device has been added. This device starts a
4978 sub-process (such as a stand-alone simulator) and then communicates
4979 with that. The sub-program to run is specified using the syntax
4980 ``|<program> <args>'' vis:
4982 (gdb) set remotedebug 1
4983 (gdb) target extended-remote |mn10300-elf-sim program-args
4985 * MIPS 64 remote protocol
4987 A long standing bug in the mips64 remote protocol where by GDB
4988 expected certain 32 bit registers (ex SR) to be transfered as 32
4989 instead of 64 bits has been fixed.
4991 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4992 added to provide backward compatibility with older versions of GDB.
4994 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4996 The command ``set remotebinarydownload'' command has been replaced by
4997 ``set remote X-packet''. Other commands in ``set remote'' family
4998 include ``set remote P-packet''.
5000 * Breakpoint commands accept ranges.
5002 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5003 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5004 ``tracepoint passcount'' also accepts a range of tracepoints.
5006 * ``apropos'' command added.
5008 The ``apropos'' command searches through command names and
5009 documentation strings, printing out matches, making it much easier to
5010 try to find a command that does what you are looking for.
5014 A new machine oriented interface (MI) has been added to GDB. This
5015 interface is designed for debug environments running GDB as a separate
5016 process. This is part of the long term libGDB project. See the
5017 "GDB/MI" chapter of the GDB manual for further information. It can be
5018 enabled by configuring with:
5020 .../configure --enable-gdbmi
5022 *** Changes in GDB-4.18:
5024 * New native configurations
5026 HP-UX 10.20 hppa*-*-hpux10.20
5027 HP-UX 11.x hppa*-*-hpux11.0*
5028 M68K GNU/Linux m68*-*-linux*
5032 Fujitsu FR30 fr30-*-elf*
5033 Intel StrongARM strongarm-*-*
5034 Mitsubishi D30V d30v-*-*
5036 * OBSOLETE configurations
5038 Gould PowerNode, NP1 np1-*-*, pn-*-*
5040 Configurations that have been declared obsolete will be commented out,
5041 but the code will be left in place. If there is no activity to revive
5042 these configurations before the next release of GDB, the sources will
5043 be permanently REMOVED.
5047 As a compatibility experiment, GDB's source files buildsym.h and
5048 buildsym.c have been converted to pure standard C, no longer
5049 containing any K&R compatibility code. We believe that all systems in
5050 use today either come with a standard C compiler, or have a GCC port
5051 available. If this is not true, please report the affected
5052 configuration to bug-gdb@gnu.org immediately. See the README file for
5053 information about getting a standard C compiler if you don't have one
5058 GDB now uses readline 2.2.
5060 * set extension-language
5062 You can now control the mapping between filename extensions and source
5063 languages by using the `set extension-language' command. For instance,
5064 you can ask GDB to treat .c files as C++ by saying
5065 set extension-language .c c++
5066 The command `info extensions' lists all of the recognized extensions
5067 and their associated languages.
5069 * Setting processor type for PowerPC and RS/6000
5071 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5072 you can use the `set processor' command to specify what variant of the
5073 PowerPC family you are debugging. The command
5077 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5078 following PowerPC and RS6000 variants:
5080 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5081 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5083 403GC IBM PowerPC 403GC
5084 505 Motorola PowerPC 505
5085 860 Motorola PowerPC 860 or 850
5086 601 Motorola PowerPC 601
5087 602 Motorola PowerPC 602
5088 603 Motorola/IBM PowerPC 603 or 603e
5089 604 Motorola PowerPC 604 or 604e
5090 750 Motorola/IBM PowerPC 750 or 750
5092 At the moment, this command just tells GDB what to name the
5093 special-purpose processor registers. Since almost all the affected
5094 registers are inaccessible to user-level programs, this command is
5095 only useful for remote debugging in its present form.
5099 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5100 more extensive support for HP-UX. Added features include shared
5101 library support, kernel threads and hardware watchpoints for 11.00,
5102 support for HP's ANSI C and C++ compilers, and a compatibility mode
5103 for xdb and dbx commands.
5107 HP's donation includes the new concept of catchpoints, which is a
5108 generalization of the old catch command. On HP-UX, it is now possible
5109 to catch exec, fork, and vfork, as well as library loading.
5111 This means that the existing catch command has changed; its first
5112 argument now specifies the type of catch to be set up. See the
5113 output of "help catch" for a list of catchpoint types.
5115 * Debugging across forks
5117 On HP-UX, you can choose which process to debug when a fork() happens
5122 HP has donated a curses-based terminal user interface (TUI). To get
5123 it, build with --enable-tui. Although this can be enabled for any
5124 configuration, at present it only works for native HP debugging.
5126 * GDB remote protocol additions
5128 A new protocol packet 'X' that writes binary data is now available.
5129 Default behavior is to try 'X', then drop back to 'M' if the stub
5130 fails to respond. The settable variable `remotebinarydownload'
5131 allows explicit control over the use of 'X'.
5133 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5134 full 64-bit address. The command
5136 set remoteaddresssize 32
5138 can be used to revert to the old behaviour. For existing remote stubs
5139 the change should not be noticed, as the additional address information
5142 In order to assist in debugging stubs, you may use the maintenance
5143 command `packet' to send any text string to the stub. For instance,
5145 maint packet heythere
5147 sends the packet "$heythere#<checksum>". Note that it is very easy to
5148 disrupt a debugging session by sending the wrong packet at the wrong
5151 The compare-sections command allows you to compare section data on the
5152 target to what is in the executable file without uploading or
5153 downloading, by comparing CRC checksums.
5155 * Tracing can collect general expressions
5157 You may now collect general expressions at tracepoints. This requires
5158 further additions to the target-side stub; see tracepoint.c and
5159 doc/agentexpr.texi for further details.
5161 * mask-address variable for Mips
5163 For Mips targets, you may control the zeroing of the upper 32 bits of
5164 a 64-bit address by entering `set mask-address on'. This is mainly
5165 of interest to users of embedded R4xxx and R5xxx processors.
5167 * Higher serial baud rates
5169 GDB's serial code now allows you to specify baud rates 57600, 115200,
5170 230400, and 460800 baud. (Note that your host system may not be able
5171 to achieve all of these rates.)
5175 The i960 configuration now includes an initial implementation of a
5176 builtin simulator, contributed by Jim Wilson.
5179 *** Changes in GDB-4.17:
5181 * New native configurations
5183 Alpha GNU/Linux alpha*-*-linux*
5184 Unixware 2.x i[3456]86-unixware2*
5185 Irix 6.x mips*-sgi-irix6*
5186 PowerPC GNU/Linux powerpc-*-linux*
5187 PowerPC Solaris powerpcle-*-solaris*
5188 Sparc GNU/Linux sparc-*-linux*
5189 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5193 Argonaut Risc Chip (ARC) arc-*-*
5194 Hitachi H8/300S h8300*-*-*
5195 Matsushita MN10200 w/simulator mn10200-*-*
5196 Matsushita MN10300 w/simulator mn10300-*-*
5197 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5198 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5199 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5200 Mitsubishi D10V w/simulator d10v-*-*
5201 Mitsubishi M32R/D w/simulator m32r-*-elf*
5202 Tsqware Sparclet sparclet-*-*
5203 NEC V850 w/simulator v850-*-*
5205 * New debugging protocols
5207 ARM with RDI protocol arm*-*-*
5208 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5209 DDB and LSI variants of PMON protocol mips*-*-*
5210 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5211 PowerPC with SDS protocol powerpc{,le}-*-eabi
5212 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5216 All configurations can now understand and use the DWARF 2 debugging
5217 format. The choice is automatic, if the symbol file contains DWARF 2
5222 GDB now includes basic Java language support. This support is
5223 only useful with Java compilers that produce native machine code.
5225 * solib-absolute-prefix and solib-search-path
5227 For SunOS and SVR4 shared libraries, you may now set the prefix for
5228 loading absolute shared library symbol files, and the search path for
5229 locating non-absolute shared library symbol files.
5231 * Live range splitting
5233 GDB can now effectively debug code for which GCC has performed live
5234 range splitting as part of its optimization. See gdb/doc/LRS for
5235 more details on the expected format of the stabs information.
5239 GDB's support for the GNU Hurd, including thread debugging, has been
5240 updated to work with current versions of the Hurd.
5244 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5245 instruction set. ARM GDB automatically detects when Thumb
5246 instructions are in use, and adjusts disassembly and backtracing
5251 GDB's MIPS target configurations now handle the MIP16 16-bit
5256 GDB now includes support for overlays; if an executable has been
5257 linked such that multiple sections are based at the same address, GDB
5258 will decide which section to use for symbolic info. You can choose to
5259 control the decision manually, using overlay commands, or implement
5260 additional target-side support and use "overlay load-target" to bring
5261 in the overlay mapping. Do "help overlay" for more detail.
5265 The command "info symbol <address>" displays information about
5266 the symbol at the specified address.
5270 The standard remote protocol now includes an extension that allows
5271 asynchronous collection and display of trace data. This requires
5272 extensive support in the target-side debugging stub. Tracing mode
5273 includes a new interaction mode in GDB and new commands: see the
5274 file tracepoint.c for more details.
5278 Configurations for embedded MIPS now include a simulator contributed
5279 by Cygnus Solutions. The simulator supports the instruction sets
5280 of most MIPS variants.
5284 Sparc configurations may now include the ERC32 simulator contributed
5285 by the European Space Agency. The simulator is not built into
5286 Sparc targets by default; configure with --enable-sim to include it.
5290 For target configurations that may include multiple variants of a
5291 basic architecture (such as MIPS and SH), you may now set the
5292 architecture explicitly. "set arch" sets, "info arch" lists
5293 the possible architectures.
5295 *** Changes in GDB-4.16:
5297 * New native configurations
5299 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5300 M68K NetBSD m68k-*-netbsd*
5301 PowerPC AIX 4.x powerpc-*-aix*
5302 PowerPC MacOS powerpc-*-macos*
5303 PowerPC Windows NT powerpcle-*-cygwin32
5304 RS/6000 AIX 4.x rs6000-*-aix4*
5308 ARM with RDP protocol arm-*-*
5309 I960 with MON960 i960-*-coff
5310 MIPS VxWorks mips*-*-vxworks*
5311 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5312 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5314 Matra Sparclet sparclet-*-*
5318 The powerpc-eabi configuration now includes the PSIM simulator,
5319 contributed by Andrew Cagney, with assistance from Mike Meissner.
5320 PSIM is a very elaborate model of the PowerPC, including not only
5321 basic instruction set execution, but also details of execution unit
5322 performance and I/O hardware. See sim/ppc/README for more details.
5326 GDB now works with Solaris 2.5.
5328 * Windows 95/NT native
5330 GDB will now work as a native debugger on Windows 95 and Windows NT.
5331 To build it from source, you must use the "gnu-win32" environment,
5332 which uses a DLL to emulate enough of Unix to run the GNU tools.
5333 Further information, binaries, and sources are available at
5334 ftp.cygnus.com, under pub/gnu-win32.
5336 * dont-repeat command
5338 If a user-defined command includes the command `dont-repeat', then the
5339 command will not be repeated if the user just types return. This is
5340 useful if the command is time-consuming to run, so that accidental
5341 extra keystrokes don't run the same command many times.
5343 * Send break instead of ^C
5345 The standard remote protocol now includes an option to send a break
5346 rather than a ^C to the target in order to interrupt it. By default,
5347 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5349 * Remote protocol timeout
5351 The standard remote protocol includes a new variable `remotetimeout'
5352 that allows you to set the number of seconds before GDB gives up trying
5353 to read from the target. The default value is 2.
5355 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5357 By default GDB will automatically keep track of objects as they are
5358 loaded and unloaded by the dynamic linker. By using the command `set
5359 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5360 when shared library events occur, thus allowing you to set breakpoints
5361 in shared libraries which are explicitly loaded by the inferior.
5363 Note this feature does not work on hpux8. On hpux9 you must link
5364 /usr/lib/end.o into your program. This feature should work
5365 automatically on hpux10.
5367 * Irix 5.x hardware watchpoint support
5369 Irix 5 configurations now support the use of hardware watchpoints.
5371 * Mips protocol "SYN garbage limit"
5373 When debugging a Mips target using the `target mips' protocol, you
5374 may set the number of characters that GDB will ignore by setting
5375 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5376 every character. The default value is 1050.
5378 * Recording and replaying remote debug sessions
5380 If you set `remotelogfile' to the name of a file, gdb will write to it
5381 a recording of a remote debug session. This recording may then be
5382 replayed back to gdb using "gdbreplay". See gdbserver/README for
5383 details. This is useful when you have a problem with GDB while doing
5384 remote debugging; you can make a recording of the session and send it
5385 to someone else, who can then recreate the problem.
5387 * Speedups for remote debugging
5389 GDB includes speedups for downloading and stepping MIPS systems using
5390 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5391 and more efficient S-record downloading.
5393 * Memory use reductions and statistics collection
5395 GDB now uses less memory and reports statistics about memory usage.
5396 Try the `maint print statistics' command, for example.
5398 *** Changes in GDB-4.15:
5400 * Psymtabs for XCOFF
5402 The symbol reader for AIX GDB now uses partial symbol tables. This
5403 can greatly improve startup time, especially for large executables.
5405 * Remote targets use caching
5407 Remote targets now use a data cache to speed up communication with the
5408 remote side. The data cache could lead to incorrect results because
5409 it doesn't know about volatile variables, thus making it impossible to
5410 debug targets which use memory mapped I/O devices. `set remotecache
5411 off' turns the the data cache off.
5413 * Remote targets may have threads
5415 The standard remote protocol now includes support for multiple threads
5416 in the target system, using new protocol commands 'H' and 'T'. See
5417 gdb/remote.c for details.
5421 If GDB is configured with `--enable-netrom', then it will include
5422 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5423 acts as though it is a bank of ROM on the target board, but you can
5424 write into it over the network. GDB's support consists only of
5425 support for fast loading into the emulated ROM; to debug, you must use
5426 another protocol, such as standard remote protocol. The usual
5427 sequence is something like
5429 target nrom <netrom-hostname>
5431 target remote <netrom-hostname>:1235
5435 GDB now includes support for the Apple Macintosh, as a host only. It
5436 may be run as either an MPW tool or as a standalone application, and
5437 it can debug through the serial port. All the usual GDB commands are
5438 available, but to the target command, you must supply "serial" as the
5439 device type instead of "/dev/ttyXX". See mpw-README in the main
5440 directory for more information on how to build. The MPW configuration
5441 scripts */mpw-config.in support only a few targets, and only the
5442 mips-idt-ecoff target has been tested.
5446 GDB configuration now uses autoconf. This is not user-visible,
5447 but does simplify configuration and building.
5451 GDB now supports hpux10.
5453 *** Changes in GDB-4.14:
5455 * New native configurations
5457 x86 FreeBSD i[345]86-*-freebsd
5458 x86 NetBSD i[345]86-*-netbsd
5459 NS32k NetBSD ns32k-*-netbsd
5460 Sparc NetBSD sparc-*-netbsd
5464 A29K VxWorks a29k-*-vxworks
5465 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5466 CPU32 EST-300 emulator m68*-*-est*
5467 PowerPC ELF powerpc-*-elf
5470 * Alpha OSF/1 support for procfs
5472 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5473 possible to attach to running processes. As the mounting of the /proc
5474 filesystem is optional on the Alpha, GDB automatically determines
5475 the availability of /proc during startup. This can lead to problems
5476 if /proc is unmounted after GDB has been started.
5478 * Arguments to user-defined commands
5480 User commands may accept up to 10 arguments separated by whitespace.
5481 Arguments are accessed within the user command via $arg0..$arg9. A
5484 print $arg0 + $arg1 + $arg2
5486 To execute the command use:
5489 Defines the command "adder" which prints the sum of its three arguments.
5490 Note the arguments are text substitutions, so they may reference variables,
5491 use complex expressions, or even perform inferior function calls.
5493 * New `if' and `while' commands
5495 This makes it possible to write more sophisticated user-defined
5496 commands. Both commands take a single argument, which is the
5497 expression to evaluate, and must be followed by the commands to
5498 execute, one per line, if the expression is nonzero, the list being
5499 terminated by the word `end'. The `if' command list may include an
5500 `else' word, which causes the following commands to be executed only
5501 if the expression is zero.
5503 * Fortran source language mode
5505 GDB now includes partial support for Fortran 77. It will recognize
5506 Fortran programs and can evaluate a subset of Fortran expressions, but
5507 variables and functions may not be handled correctly. GDB will work
5508 with G77, but does not yet know much about symbols emitted by other
5511 * Better HPUX support
5513 Most debugging facilities now work on dynamic executables for HPPAs
5514 running hpux9 or later. You can attach to running dynamically linked
5515 processes, but by default the dynamic libraries will be read-only, so
5516 for instance you won't be able to put breakpoints in them. To change
5517 that behavior do the following before running the program:
5523 This will cause the libraries to be mapped private and read-write.
5524 To revert to the normal behavior, do this:
5530 You cannot set breakpoints or examine data in the library until after
5531 the library is loaded if the function/data symbols do not have
5534 GDB can now also read debug symbols produced by the HP C compiler on
5535 HPPAs (sorry, no C++, Fortran or 68k support).
5537 * Target byte order now dynamically selectable
5539 You can choose which byte order to use with a target system, via the
5540 commands "set endian big" and "set endian little", and you can see the
5541 current setting by using "show endian". You can also give the command
5542 "set endian auto", in which case GDB will use the byte order
5543 associated with the executable. Currently, only embedded MIPS
5544 configurations support dynamic selection of target byte order.
5546 * New DOS host serial code
5548 This version uses DPMI interrupts to handle buffered I/O, so you
5549 no longer need to run asynctsr when debugging boards connected to
5552 *** Changes in GDB-4.13:
5554 * New "complete" command
5556 This lists all the possible completions for the rest of the line, if it
5557 were to be given as a command itself. This is intended for use by emacs.
5559 * Trailing space optional in prompt
5561 "set prompt" no longer adds a space for you after the prompt you set. This
5562 allows you to set a prompt which ends in a space or one that does not.
5564 * Breakpoint hit counts
5566 "info break" now displays a count of the number of times the breakpoint
5567 has been hit. This is especially useful in conjunction with "ignore"; you
5568 can ignore a large number of breakpoint hits, look at the breakpoint info
5569 to see how many times the breakpoint was hit, then run again, ignoring one
5570 less than that number, and this will get you quickly to the last hit of
5573 * Ability to stop printing at NULL character
5575 "set print null-stop" will cause GDB to stop printing the characters of
5576 an array when the first NULL is encountered. This is useful when large
5577 arrays actually contain only short strings.
5579 * Shared library breakpoints
5581 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5582 breakpoints in shared libraries before the executable is run.
5584 * Hardware watchpoints
5586 There is a new hardware breakpoint for the watch command for sparclite
5587 targets. See gdb/sparclite/hw_breakpoint.note.
5589 Hardware watchpoints are also now supported under GNU/Linux.
5593 Annotations have been added. These are for use with graphical interfaces,
5594 and are still experimental. Currently only gdba.el uses these.
5596 * Improved Irix 5 support
5598 GDB now works properly with Irix 5.2.
5600 * Improved HPPA support
5602 GDB now works properly with the latest GCC and GAS.
5604 * New native configurations
5606 Sequent PTX4 i[34]86-sequent-ptx4
5607 HPPA running OSF/1 hppa*-*-osf*
5608 Atari TT running SVR4 m68*-*-sysv4*
5609 RS/6000 LynxOS rs6000-*-lynxos*
5613 OS/9000 i[34]86-*-os9k
5614 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5617 * Hitachi SH7000 and E7000-PC ICE support
5619 There is now support for communicating with the Hitachi E7000-PC ICE.
5620 This is available automatically when GDB is configured for the SH.
5624 As usual, a variety of small fixes and improvements, both generic
5625 and configuration-specific. See the ChangeLog for more detail.
5627 *** Changes in GDB-4.12:
5629 * Irix 5 is now supported
5633 GDB-4.12 on the HPPA has a number of changes which make it unable
5634 to debug the output from the currently released versions of GCC and
5635 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5636 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5637 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5640 *** Changes in GDB-4.11:
5642 * User visible changes:
5646 The "set remotedebug" option is now consistent between the mips remote
5647 target, remote targets using the gdb-specific protocol, UDI (AMD's
5648 debug protocol for the 29k) and the 88k bug monitor. It is now an
5649 integer specifying a debug level (normally 0 or 1, but 2 means more
5650 debugging info for the mips target).
5652 * DEC Alpha native support
5654 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5655 debug info, but GDB works fairly well with the DEC compiler and should
5656 work with a future GCC release. See the README file for a few
5657 Alpha-specific notes.
5659 * Preliminary thread implementation
5661 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5663 * LynxOS native and target support for 386
5665 This release has been hosted on LynxOS 2.2, and also can be configured
5666 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5669 * Improvements in C++ mangling/demangling.
5671 This release has much better g++ debugging, specifically in name
5672 mangling/demangling, virtual function calls, print virtual table,
5673 call methods, ...etc.
5675 *** Changes in GDB-4.10:
5677 * User visible changes:
5679 Remote debugging using the GDB-specific (`target remote') protocol now
5680 supports the `load' command. This is only useful if you have some
5681 other way of getting the stub to the target system, and you can put it
5682 somewhere in memory where it won't get clobbered by the download.
5684 Filename completion now works.
5686 When run under emacs mode, the "info line" command now causes the
5687 arrow to point to the line specified. Also, "info line" prints
5688 addresses in symbolic form (as well as hex).
5690 All vxworks based targets now support a user settable option, called
5691 vxworks-timeout. This option represents the number of seconds gdb
5692 should wait for responses to rpc's. You might want to use this if
5693 your vxworks target is, perhaps, a slow software simulator or happens
5694 to be on the far side of a thin network line.
5698 This release contains support for using a DEC alpha as a GDB host for
5699 cross debugging. Native alpha debugging is not supported yet.
5702 *** Changes in GDB-4.9:
5706 This is the first GDB release which is accompanied by a matching testsuite.
5707 The testsuite requires installation of dejagnu, which should be available
5708 via ftp from most sites that carry GNU software.
5712 'Cfront' style demangling has had its name changed to 'ARM' style, to
5713 emphasize that it was written from the specifications in the C++ Annotated
5714 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5715 disclaimers, it still generated too much confusion with users attempting to
5716 use gdb with AT&T cfront.
5720 GDB now uses a standard remote interface to a simulator library.
5721 So far, the library contains simulators for the Zilog Z8001/2, the
5722 Hitachi H8/300, H8/500 and Super-H.
5724 * New targets supported
5726 H8/300 simulator h8300-hitachi-hms or h8300hms
5727 H8/500 simulator h8500-hitachi-hms or h8500hms
5728 SH simulator sh-hitachi-hms or sh
5729 Z8000 simulator z8k-zilog-none or z8ksim
5730 IDT MIPS board over serial line mips-idt-ecoff
5732 Cross-debugging to GO32 targets is supported. It requires a custom
5733 version of the i386-stub.c module which is integrated with the
5734 GO32 memory extender.
5736 * New remote protocols
5738 MIPS remote debugging protocol.
5740 * New source languages supported
5742 This version includes preliminary support for Chill, a Pascal like language
5743 used by telecommunications companies. Chill support is also being integrated
5744 into the GNU compiler, but we don't know when it will be publically available.
5747 *** Changes in GDB-4.8:
5749 * HP Precision Architecture supported
5751 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5752 version of this support was available as a set of patches from the
5753 University of Utah. GDB does not support debugging of programs
5754 compiled with the HP compiler, because HP will not document their file
5755 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5756 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5758 Many problems in the preliminary version have been fixed.
5760 * Faster and better demangling
5762 We have improved template demangling and fixed numerous bugs in the GNU style
5763 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5764 character types (wchar_t) are now supported. Demangling of each symbol is now
5765 only done once, and is cached when the symbol table for a file is read in.
5766 This results in a small increase in memory usage for C programs, a moderate
5767 increase in memory usage for C++ programs, and a fantastic speedup in
5770 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5771 from the specifications in the Annotated Reference Manual, which AT&T's
5772 compiler does not actually implement.
5774 * G++ multiple inheritance compiler problem
5776 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5777 inheritance lattices was reworked to properly discover ambiguities. We
5778 recently found an example which causes this new algorithm to fail in a
5779 very subtle way, producing bad debug information for those classes.
5780 The file 'gcc.patch' (in this directory) can be applied to gcc to
5781 circumvent the problem. A future GCC release will contain a complete
5784 The previous G++ debug info problem (mentioned below for the gdb-4.7
5785 release) is fixed in gcc version 2.3.2.
5787 * Improved configure script
5789 The `configure' script will now attempt to guess your system type if
5790 you don't supply a host system type. The old scheme of supplying a
5791 host system triplet is preferable over using this. All the magic is
5792 done in the new `config.guess' script. Examine it for details.
5794 We have also brought our configure script much more in line with the FSF's
5795 version. It now supports the --with-xxx options. In particular,
5796 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5797 The resulting GDB will not be able to read arbitrary object file formats --
5798 only the format ``expected'' to be used on the configured target system.
5799 We hope to make this the default in a future release.
5801 * Documentation improvements
5803 There's new internal documentation on how to modify GDB, and how to
5804 produce clean changes to the code. We implore people to read it
5805 before submitting changes.
5807 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5808 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5809 `info' files are also provided. To build `info' files from scratch,
5810 you will need the latest `makeinfo' release, which will be available in
5811 a future texinfo-X.Y release.
5813 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5814 We're not sure exactly which versions have this problem, but it has
5815 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5816 or better. If that isn't possible, there is a patch in
5817 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5818 around this problem.
5822 GDB now supports array constants that can be used in expressions typed in by
5823 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5824 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5827 The new directory `gdb/sparclite' contains a program that demonstrates
5828 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5830 * New native hosts supported
5832 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5833 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5835 * New targets supported
5837 AMD 29k family via UDI a29k-amd-udi or udi29k
5839 * New file formats supported
5841 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5842 HPUX core files, and SCO 3.2v2 core files.
5846 Attaching to processes now works again; thanks for the many bug reports.
5848 We have also stomped on a bunch of core dumps caused by
5849 printf_filtered("%s") problems.
5851 We eliminated a copyright problem on the rpc and ptrace header files
5852 for VxWorks, which was discovered at the last minute during the 4.7
5853 release. You should now be able to build a VxWorks GDB.
5855 You can now interrupt gdb while an attached process is running. This
5856 will cause the attached process to stop, and give control back to GDB.
5858 We fixed problems caused by using too many file descriptors
5859 for reading symbols from object files and libraries. This was
5860 especially a problem for programs that used many (~100) shared
5863 The `step' command now only enters a subroutine if there is line number
5864 information for the subroutine. Otherwise it acts like the `next'
5865 command. Previously, `step' would enter subroutines if there was
5866 any debugging information about the routine. This avoids problems
5867 when using `cc -g1' on MIPS machines.
5869 * Internal improvements
5871 GDB's internal interfaces have been improved to make it easier to support
5872 debugging of multiple languages in the future.
5874 GDB now uses a common structure for symbol information internally.
5875 Minimal symbols (derived from linkage symbols in object files), partial
5876 symbols (from a quick scan of debug information), and full symbols
5877 contain a common subset of information, making it easier to write
5878 shared code that handles any of them.
5880 * New command line options
5882 We now accept --silent as an alias for --quiet.
5886 The memory-mapped-malloc library is now licensed under the GNU Library
5887 General Public License.
5889 *** Changes in GDB-4.7:
5891 * Host/native/target split
5893 GDB has had some major internal surgery to untangle the support for
5894 hosts and remote targets. Now, when you configure GDB for a remote
5895 target, it will no longer load in all of the support for debugging
5896 local programs on the host. When fully completed and tested, this will
5897 ensure that arbitrary host/target combinations are possible.
5899 The primary conceptual shift is to separate the non-portable code in
5900 GDB into three categories. Host specific code is required any time GDB
5901 is compiled on that host, regardless of the target. Target specific
5902 code relates to the peculiarities of the target, but can be compiled on
5903 any host. Native specific code is everything else: it can only be
5904 built when the host and target are the same system. Child process
5905 handling and core file support are two common `native' examples.
5907 GDB's use of /proc for controlling Unix child processes is now cleaner.
5908 It has been split out into a single module under the `target_ops' vector,
5909 plus two native-dependent functions for each system that uses /proc.
5911 * New hosts supported
5913 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5914 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5915 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5917 * New targets supported
5919 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5920 68030 and CPU32 m68030-*-*, m68332-*-*
5922 * New native hosts supported
5924 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5925 (386bsd is not well tested yet)
5926 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5928 * New file formats supported
5930 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5931 supports reading of `a.out.adobe' object files, which are an a.out
5932 format extended with minimal information about multiple sections.
5936 `show copying' is the same as the old `info copying'.
5937 `show warranty' is the same as `info warrantee'.
5938 These were renamed for consistency. The old commands continue to work.
5940 `info handle' is a new alias for `info signals'.
5942 You can now define pre-command hooks, which attach arbitrary command
5943 scripts to any command. The commands in the hook will be executed
5944 prior to the user's command. You can also create a hook which will be
5945 executed whenever the program stops. See gdb.texinfo.
5949 We now deal with Cfront style name mangling, and can even extract type
5950 info from mangled symbols. GDB can automatically figure out which
5951 symbol mangling style your C++ compiler uses.
5953 Calling of methods and virtual functions has been improved as well.
5957 The crash that occured when debugging Sun Ansi-C compiled binaries is
5958 fixed. This was due to mishandling of the extra N_SO stabs output
5961 We also finally got Ultrix 4.2 running in house, and fixed core file
5962 support, with help from a dozen people on the net.
5964 John M. Farrell discovered that the reason that single-stepping was so
5965 slow on all of the Mips based platforms (primarily SGI and DEC) was
5966 that we were trying to demangle and lookup a symbol used for internal
5967 purposes on every instruction that was being stepped through. Changing
5968 the name of that symbol so that it couldn't be mistaken for a C++
5969 mangled symbol sped things up a great deal.
5971 Rich Pixley sped up symbol lookups in general by getting much smarter
5972 about when C++ symbol mangling is necessary. This should make symbol
5973 completion (TAB on the command line) much faster. It's not as fast as
5974 we'd like, but it's significantly faster than gdb-4.6.
5978 A new user controllable variable 'call_scratch_address' can
5979 specify the location of a scratch area to be used when GDB
5980 calls a function in the target. This is necessary because the
5981 usual method of putting the scratch area on the stack does not work
5982 in systems that have separate instruction and data spaces.
5984 We integrated changes to support the 29k UDI (Universal Debugger
5985 Interface), but discovered at the last minute that we didn't have all
5986 of the appropriate copyright paperwork. We are working with AMD to
5987 resolve this, and hope to have it available soon.
5991 We have sped up the remote serial line protocol, especially for targets
5992 with lots of registers. It now supports a new `expedited status' ('T')
5993 message which can be used in place of the existing 'S' status message.
5994 This allows the remote stub to send only the registers that GDB
5995 needs to make a quick decision about single-stepping or conditional
5996 breakpoints, eliminating the need to fetch the entire register set for
5997 each instruction being stepped through.
5999 The GDB remote serial protocol now implements a write-through cache for
6000 registers, only re-reading the registers if the target has run.
6002 There is also a new remote serial stub for SPARC processors. You can
6003 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6004 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6005 processor with a serial port.
6009 Configure.in files have become much easier to read and modify. A new
6010 `table driven' format makes it more obvious what configurations are
6011 supported, and what files each one uses.
6015 There is a new opcodes library which will eventually contain all of the
6016 disassembly routines and opcode tables. At present, it only contains
6017 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6018 disassembler (binutils/objdump) to share these routines.
6020 The libiberty library is now copylefted under the GNU Library General
6021 Public License. This allows more liberal use, and was done so libg++
6022 can use it. This makes no difference to GDB, since the Library License
6023 grants all the rights from the General Public License.
6027 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6028 reference to the stabs symbol info used by the debugger. It is (as far
6029 as we know) the only published document on this fascinating topic. We
6030 encourage you to read it, compare it to the stabs information on your
6031 system, and send improvements on the document in general (to
6032 bug-gdb@prep.ai.mit.edu).
6034 And, of course, many bugs have been fixed.
6037 *** Changes in GDB-4.6:
6039 * Better support for C++ function names
6041 GDB now accepts as input the "demangled form" of C++ overloaded function
6042 names and member function names, and can do command completion on such names
6043 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6044 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6045 Make use of command completion, it is your friend.
6047 GDB also now accepts a variety of C++ mangled symbol formats. They are
6048 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6049 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6050 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6051 for the list of formats.
6053 * G++ symbol mangling problem
6055 Recent versions of gcc have a bug in how they emit debugging information for
6056 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6057 directory) can be applied to gcc to fix the problem. Alternatively, if you
6058 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6059 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6060 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6063 * New 'maintenance' command
6065 All of the commands related to hacking GDB internals have been moved out of
6066 the main command set, and now live behind the 'maintenance' command. This
6067 can also be abbreviated as 'mt'. The following changes were made:
6069 dump-me -> maintenance dump-me
6070 info all-breakpoints -> maintenance info breakpoints
6071 printmsyms -> maintenance print msyms
6072 printobjfiles -> maintenance print objfiles
6073 printpsyms -> maintenance print psymbols
6074 printsyms -> maintenance print symbols
6076 The following commands are new:
6078 maintenance demangle Call internal GDB demangler routine to
6079 demangle a C++ link name and prints the result.
6080 maintenance print type Print a type chain for a given symbol
6082 * Change to .gdbinit file processing
6084 We now read the $HOME/.gdbinit file before processing the argv arguments
6085 (e.g. reading symbol files or core files). This allows global parameters to
6086 be set, which will apply during the symbol reading. The ./.gdbinit is still
6087 read after argv processing.
6089 * New hosts supported
6091 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6093 GNU/Linux support i386-unknown-linux or linux
6095 We are also including code to support the HP/PA running BSD and HPUX. This
6096 is almost guaranteed not to work, as we didn't have time to test or build it
6097 for this release. We are including it so that the more adventurous (or
6098 masochistic) of you can play with it. We also had major problems with the
6099 fact that the compiler that we got from HP doesn't support the -g option.
6102 * New targets supported
6104 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6106 * More smarts about finding #include files
6108 GDB now remembers the compilation directory for all include files, and for
6109 all files from which C is generated (like yacc and lex sources). This
6110 greatly improves GDB's ability to find yacc/lex sources, and include files,
6111 especially if you are debugging your program from a directory different from
6112 the one that contains your sources.
6114 We also fixed a bug which caused difficulty with listing and setting
6115 breakpoints in include files which contain C code. (In the past, you had to
6116 try twice in order to list an include file that you hadn't looked at before.)
6118 * Interesting infernals change
6120 GDB now deals with arbitrary numbers of sections, where the symbols for each
6121 section must be relocated relative to that section's landing place in the
6122 target's address space. This work was needed to support ELF with embedded
6123 stabs used by Solaris-2.0.
6125 * Bug fixes (of course!)
6127 There have been loads of fixes for the following things:
6128 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6129 i960, stabs, DOS(GO32), procfs, etc...
6131 See the ChangeLog for details.
6133 *** Changes in GDB-4.5:
6135 * New machines supported (host and target)
6137 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6139 SGI Irix-4.x mips-sgi-irix4 or iris4
6141 * New malloc package
6143 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6144 Mmalloc is capable of handling mutiple heaps of memory. It is also
6145 capable of saving a heap to a file, and then mapping it back in later.
6146 This can be used to greatly speedup the startup of GDB by using a
6147 pre-parsed symbol table which lives in a mmalloc managed heap. For
6148 more details, please read mmalloc/mmalloc.texi.
6152 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6153 'help info proc' for details.
6155 * MIPS ecoff symbol table format
6157 The code that reads MIPS symbol table format is now supported on all hosts.
6158 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6161 * File name changes for MS-DOS
6163 Many files in the config directories have been renamed to make it easier to
6164 support GDB on MS-DOSe systems (which have very restrictive file name
6165 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6166 environment) is close to working but has some remaining problems. Note
6167 that debugging of DOS programs is not supported, due to limitations
6168 in the ``operating system'', but it can be used to host cross-debugging.
6170 * Cross byte order fixes
6172 Many fixes have been made to support cross debugging of Sparc and MIPS
6173 targets from hosts whose byte order differs.
6175 * New -mapped and -readnow options
6177 If memory-mapped files are available on your system through the 'mmap'
6178 system call, you can use the -mapped option on the `file' or
6179 `symbol-file' commands to cause GDB to write the symbols from your
6180 program into a reusable file. If the program you are debugging is
6181 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6182 Future GDB debugging sessions will notice the presence of this file,
6183 and will quickly map in symbol information from it, rather than reading
6184 the symbol table from the executable program. Using the '-mapped'
6185 option in a GDB `file' or `symbol-file' command has the same effect as
6186 starting GDB with the '-mapped' command-line option.
6188 You can cause GDB to read the entire symbol table immediately by using
6189 the '-readnow' option with any of the commands that load symbol table
6190 information (or on the GDB command line). This makes the command
6191 slower, but makes future operations faster.
6193 The -mapped and -readnow options are typically combined in order to
6194 build a `fred.syms' file that contains complete symbol information.
6195 A simple GDB invocation to do nothing but build a `.syms' file for future
6198 gdb -batch -nx -mapped -readnow programname
6200 The `.syms' file is specific to the host machine on which GDB is run.
6201 It holds an exact image of GDB's internal symbol table. It cannot be
6202 shared across multiple host platforms.
6204 * longjmp() handling
6206 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6207 siglongjmp() without losing control. This feature has not yet been ported to
6208 all systems. It currently works on many 386 platforms, all MIPS-based
6209 platforms (SGI, DECstation, etc), and Sun3/4.
6213 Preliminary work has been put in to support the new Solaris OS from Sun. At
6214 this time, it can control and debug processes, but it is not capable of
6219 As always, many many bug fixes. The major areas were with g++, and mipsread.
6220 People using the MIPS-based platforms should experience fewer mysterious
6221 crashes and trashed symbol tables.
6223 *** Changes in GDB-4.4:
6225 * New machines supported (host and target)
6227 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6229 BSD Reno on Vax vax-dec-bsd
6230 Ultrix on Vax vax-dec-ultrix
6232 * New machines supported (target)
6234 AMD 29000 embedded, using EBMON a29k-none-none
6238 GDB continues to improve its handling of C++. `References' work better.
6239 The demangler has also been improved, and now deals with symbols mangled as
6240 per the Annotated C++ Reference Guide.
6242 GDB also now handles `stabs' symbol information embedded in MIPS
6243 `ecoff' symbol tables. Since the ecoff format was not easily
6244 extensible to handle new languages such as C++, this appeared to be a
6245 good way to put C++ debugging info into MIPS binaries. This option
6246 will be supported in the GNU C compiler, version 2, when it is
6249 * New features for SVR4
6251 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6252 shared libraries. Debugging dynamically linked programs should present
6253 only minor differences from debugging statically linked programs.
6255 The `info proc' command will print out information about any process
6256 on an SVR4 system (including the one you are debugging). At the moment,
6257 it prints the address mappings of the process.
6259 If you bring up GDB on another SVR4 system, please send mail to
6260 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6262 * Better dynamic linking support in SunOS
6264 Reading symbols from shared libraries which contain debugging symbols
6265 now works properly. However, there remain issues such as automatic
6266 skipping of `transfer vector' code during function calls, which
6267 make it harder to debug code in a shared library, than to debug the
6268 same code linked statically.
6272 GDB is now using the latest `getopt' routines from the FSF. This
6273 version accepts the -- prefix for options with long names. GDB will
6274 continue to accept the old forms (-option and +option) as well.
6275 Various single letter abbreviations for options have been explicity
6276 added to the option table so that they won't get overshadowed in the
6277 future by other options that begin with the same letter.
6281 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6282 Many assorted bugs have been handled. Many more remain to be handled.
6283 See the various ChangeLog files (primarily in gdb and bfd) for details.
6286 *** Changes in GDB-4.3:
6288 * New machines supported (host and target)
6290 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6291 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6292 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6294 * Almost SCO Unix support
6296 We had hoped to support:
6297 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6298 (except for core file support), but we discovered very late in the release
6299 that it has problems with process groups that render gdb unusable. Sorry
6300 about that. I encourage people to fix it and post the fixes.
6302 * Preliminary ELF and DWARF support
6304 GDB can read ELF object files on System V Release 4, and can handle
6305 debugging records for C, in DWARF format, in ELF files. This support
6306 is preliminary. If you bring up GDB on another SVR4 system, please
6307 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6312 GDB now uses the latest `readline' library. One user-visible change
6313 is that two tabs will list possible command completions, which previously
6314 required typing M-? (meta-question mark, or ESC ?).
6318 The `stepi' bug that many of you noticed has been squashed.
6319 Many bugs in C++ have been handled. Many more remain to be handled.
6320 See the various ChangeLog files (primarily in gdb and bfd) for details.
6322 * State of the MIPS world (in case you wondered):
6324 GDB can understand the symbol tables emitted by the compilers
6325 supplied by most vendors of MIPS-based machines, including DEC. These
6326 symbol tables are in a format that essentially nobody else uses.
6328 Some versions of gcc come with an assembler post-processor called
6329 mips-tfile. This program is required if you want to do source-level
6330 debugging of gcc-compiled programs. I believe FSF does not ship
6331 mips-tfile with gcc version 1, but it will eventually come with gcc
6334 Debugging of g++ output remains a problem. g++ version 1.xx does not
6335 really support it at all. (If you're lucky, you should be able to get
6336 line numbers and stack traces to work, but no parameters or local
6337 variables.) With some work it should be possible to improve the
6340 When gcc version 2 is released, you will have somewhat better luck.
6341 However, even then you will get confusing results for inheritance and
6344 We will eventually provide full debugging of g++ output on
6345 DECstations. This will probably involve some kind of stabs-in-ecoff
6346 encapulation, but the details have not been worked out yet.
6349 *** Changes in GDB-4.2:
6351 * Improved configuration
6353 Only one copy of `configure' exists now, and it is not self-modifying.
6354 Porting BFD is simpler.
6358 The `step' and `next' commands now only stop at the first instruction
6359 of a source line. This prevents the multiple stops that used to occur
6360 in switch statements, for-loops, etc. `Step' continues to stop if a
6361 function that has debugging information is called within the line.
6365 Lots of small bugs fixed. More remain.
6367 * New host supported (not target)
6369 Intel 386 PC clone running Mach i386-none-mach
6372 *** Changes in GDB-4.1:
6374 * Multiple source language support
6376 GDB now has internal scaffolding to handle several source languages.
6377 It determines the type of each source file from its filename extension,
6378 and will switch expression parsing and number formatting to match the
6379 language of the function in the currently selected stack frame.
6380 You can also specifically set the language to be used, with
6381 `set language c' or `set language modula-2'.
6385 GDB now has preliminary support for the GNU Modula-2 compiler,
6386 currently under development at the State University of New York at
6387 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6388 continue through the fall of 1991 and into 1992.
6390 Other Modula-2 compilers are currently not supported, and attempting to
6391 debug programs compiled with them will likely result in an error as the
6392 symbol table is read. Feel free to work on it, though!
6394 There are hooks in GDB for strict type checking and range checking,
6395 in the `Modula-2 philosophy', but they do not currently work.
6399 GDB can now write to executable and core files (e.g. patch
6400 a variable's value). You must turn this switch on, specify
6401 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6402 by assigning a new value to a variable. Modifications take
6405 * Automatic SunOS shared library reading
6407 When you run your program, GDB automatically determines where its
6408 shared libraries (if any) have been loaded, and reads their symbols.
6409 The `share' command is no longer needed. This also works when
6410 examining core files.
6414 You can specify the number of lines that the `list' command shows.
6417 * New machines supported (host and target)
6419 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6420 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6421 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6423 * New hosts supported (not targets)
6425 IBM RT/PC: romp-ibm-aix or rtpc
6427 * New targets supported (not hosts)
6429 AMD 29000 embedded with COFF a29k-none-coff
6430 AMD 29000 embedded with a.out a29k-none-aout
6431 Ultracomputer remote kernel debug a29k-nyu-kern
6433 * New remote interfaces
6439 *** Changes in GDB-4.0:
6443 Wide output is wrapped at good places to make the output more readable.
6445 Gdb now supports cross-debugging from a host machine of one type to a
6446 target machine of another type. Communication with the target system
6447 is over serial lines. The ``target'' command handles connecting to the
6448 remote system; the ``load'' command will download a program into the
6449 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6450 also supports debugging of realtime processes running under VxWorks,
6451 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6452 stub on the target system.
6454 New CPUs supported include the AMD 29000 and Intel 960.
6456 GDB now reads object files and symbol tables via a ``binary file''
6457 library, which allows a single copy of GDB to debug programs of multiple
6458 object file types such as a.out and coff.
6460 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6461 refcard.dvi and refcard.ps are available to format it).
6464 * Control-Variable user interface simplified
6466 All variables that control the operation of the debugger can be set
6467 by the ``set'' command, and displayed by the ``show'' command.
6469 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6470 ``Show prompt'' produces the response:
6471 Gdb's prompt is new-gdb=>.
6473 What follows are the NEW set commands. The command ``help set'' will
6474 print a complete list of old and new set commands. ``help set FOO''
6475 will give a longer description of the variable FOO. ``show'' will show
6476 all of the variable descriptions and their current settings.
6478 confirm on/off: Enables warning questions for operations that are
6479 hard to recover from, e.g. rerunning the program while
6480 it is already running. Default is ON.
6482 editing on/off: Enables EMACS style command line editing
6483 of input. Previous lines can be recalled with
6484 control-P, the current line can be edited with control-B,
6485 you can search for commands with control-R, etc.
6488 history filename NAME: NAME is where the gdb command history
6489 will be stored. The default is .gdb_history,
6490 or the value of the environment variable
6493 history size N: The size, in commands, of the command history. The
6494 default is 256, or the value of the environment variable
6497 history save on/off: If this value is set to ON, the history file will
6498 be saved after exiting gdb. If set to OFF, the
6499 file will not be saved. The default is OFF.
6501 history expansion on/off: If this value is set to ON, then csh-like
6502 history expansion will be performed on
6503 command line input. The default is OFF.
6505 radix N: Sets the default radix for input and output. It can be set
6506 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6507 in the current radix, so "set radix 10" is always a no-op.
6509 height N: This integer value is the number of lines on a page. Default
6510 is 24, the current `stty rows'' setting, or the ``li#''
6511 setting from the termcap entry matching the environment
6514 width N: This integer value is the number of characters on a line.
6515 Default is 80, the current `stty cols'' setting, or the ``co#''
6516 setting from the termcap entry matching the environment
6519 Note: ``set screensize'' is obsolete. Use ``set height'' and
6520 ``set width'' instead.
6522 print address on/off: Print memory addresses in various command displays,
6523 such as stack traces and structure values. Gdb looks
6524 more ``symbolic'' if you turn this off; it looks more
6525 ``machine level'' with it on. Default is ON.
6527 print array on/off: Prettyprint arrays. New convenient format! Default
6530 print demangle on/off: Print C++ symbols in "source" form if on,
6533 print asm-demangle on/off: Same, for assembler level printouts
6536 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6539 * Support for Epoch Environment.
6541 The epoch environment is a version of Emacs v18 with windowing. One
6542 new command, ``inspect'', is identical to ``print'', except that if you
6543 are running in the epoch environment, the value is printed in its own
6547 * Support for Shared Libraries
6549 GDB can now debug programs and core files that use SunOS shared libraries.
6550 Symbols from a shared library cannot be referenced
6551 before the shared library has been linked with the program (this
6552 happens after you type ``run'' and before the function main() is entered).
6553 At any time after this linking (including when examining core files
6554 from dynamically linked programs), gdb reads the symbols from each
6555 shared library when you type the ``sharedlibrary'' command.
6556 It can be abbreviated ``share''.
6558 sharedlibrary REGEXP: Load shared object library symbols for files
6559 matching a unix regular expression. No argument
6560 indicates to load symbols for all shared libraries.
6562 info sharedlibrary: Status of loaded shared libraries.
6567 A watchpoint stops execution of a program whenever the value of an
6568 expression changes. Checking for this slows down execution
6569 tremendously whenever you are in the scope of the expression, but is
6570 quite useful for catching tough ``bit-spreader'' or pointer misuse
6571 problems. Some machines such as the 386 have hardware for doing this
6572 more quickly, and future versions of gdb will use this hardware.
6574 watch EXP: Set a watchpoint (breakpoint) for an expression.
6576 info watchpoints: Information about your watchpoints.
6578 delete N: Deletes watchpoint number N (same as breakpoints).
6579 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6580 enable N: Re-enables watchpoint number N (same as breakpoints).
6583 * C++ multiple inheritance
6585 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6588 * C++ exception handling
6590 Gdb now supports limited C++ exception handling. Besides the existing
6591 ability to breakpoint on an exception handler, gdb can breakpoint on
6592 the raising of an exception (before the stack is peeled back to the
6595 catch FOO: If there is a FOO exception handler in the dynamic scope,
6596 set a breakpoint to catch exceptions which may be raised there.
6597 Multiple exceptions (``catch foo bar baz'') may be caught.
6599 info catch: Lists all exceptions which may be caught in the
6600 current stack frame.
6603 * Minor command changes
6605 The command ``call func (arg, arg, ...)'' now acts like the print
6606 command, except it does not print or save a value if the function's result
6607 is void. This is similar to dbx usage.
6609 The ``up'' and ``down'' commands now always print the frame they end up
6610 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6611 frames without printing.
6613 * New directory command
6615 'dir' now adds directories to the FRONT of the source search path.
6616 The path starts off empty. Source files that contain debug information
6617 about the directory in which they were compiled can be found even
6618 with an empty path; Sun CC and GCC include this information. If GDB can't
6619 find your source file in the current directory, type "dir .".
6621 * Configuring GDB for compilation
6623 For normal use, type ``./configure host''. See README or gdb.texinfo
6626 GDB now handles cross debugging. If you are remotely debugging between
6627 two different machines, type ``./configure host -target=targ''.
6628 Host is the machine where GDB will run; targ is the machine
6629 where the program that you are debugging will run.
projects / thirdparty / binutils-gdb.git / blob