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.
37 Synopsys ARC arc*-*-elf32
39 *** Changes in GDB 7.12
41 * GDB and GDBserver now build with a C++ compiler by default.
43 The --enable-build-with-cxx configure option is now enabled by
44 default. One must now explicitly configure with
45 --disable-build-with-cxx in order to build with a C compiler. This
46 option will be removed in a future release.
48 * GDBserver now supports recording btrace without maintaining an active
51 * GDB now supports a negative repeat count in the 'x' command to examine
52 memory backward from the given address. For example:
55 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
56 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
57 (gdb) x/-5i 0x0000000000400580
58 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
59 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
60 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
61 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
62 0x40057b <main(int, char**)+25>:
63 callq 0x400536 <Func1(int, char const*)>
65 * Fortran: Support structures with fields of dynamic types and
66 arrays of dynamic types.
68 * GDB now supports multibit bitfields and enums in target register
71 * New Python-based convenience function $_as_string(val), which returns
72 the textual representation of a value. This function is especially
73 useful to obtain the text label of an enum value.
75 * Intel MPX bound violation handling.
77 Segmentation faults caused by a Intel MPX boundary violation
78 now display the kind of violation (upper or lower), the memory
79 address accessed and the memory bounds, along with the usual
80 signal received and code location.
84 Program received signal SIGSEGV, Segmentation fault
85 Upper bound violation while accessing address 0x7fffffffc3b3
86 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
87 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
89 * Rust language support.
90 GDB now supports debugging programs written in the Rust programming
91 language. See https://www.rust-lang.org/ for more information about
94 * Support for running interpreters on specified input/output devices
96 GDB now supports a new mechanism that allows frontends to provide
97 fully featured GDB console views, as a better alternative to
98 building such views on top of the "-interpreter-exec console"
99 command. See the new "new-ui" command below. With that command,
100 frontends can now start GDB in the traditional command-line mode
101 running in an embedded terminal emulator widget, and create a
102 separate MI interpreter running on a specified i/o device. In this
103 way, GDB handles line editing, history, tab completion, etc. in the
104 console all by itself, and the GUI uses the separate MI interpreter
105 for its own control and synchronization, invisible to the command
108 * The "catch syscall" command catches groups of related syscalls.
110 The "catch syscall" command now supports catching a group of related
111 syscalls using the 'group:' or 'g:' prefix.
116 skip -gfile file-glob-pattern
117 skip -function function
118 skip -rfunction regular-expression
119 A generalized form of the skip command, with new support for
120 glob-style file names and regular expressions for function names.
121 Additionally, a file spec and a function spec may now be combined.
123 maint info line-table REGEXP
124 Display the contents of GDB's internal line table data struture.
127 Run any GDB unit tests that were compiled in.
130 Start a new user interface instance running INTERP as interpreter,
131 using the TTY file for input/output.
135 ** gdb.Breakpoint objects have a new attribute "pending", which
136 indicates whether the breakpoint is pending.
137 ** Three new breakpoint-related events have been added:
138 gdb.breakpoint_created, gdb.breakpoint_modified, and
139 gdb.breakpoint_deleted.
142 Signal ("set") the given MS-Windows event object. This is used in
143 conjunction with the Windows JIT debugging (AeDebug) support, where
144 the OS suspends a crashing process until a debugger can attach to
145 it. Resuming the crashing process, in order to debug it, is done by
148 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
149 was added in GDBserver, including JIT compiling fast tracepoint's
150 conditional expression bytecode into native code.
152 * Support for various remote target protocols and ROM monitors has
155 target m32rsdi Remote M32R debugging over SDI
156 target mips MIPS remote debugging protocol
157 target pmon PMON ROM monitor
158 target ddb NEC's DDB variant of PMON for Vr4300
159 target rockhopper NEC RockHopper variant of PMON
160 target lsi LSI variant of PMO
162 * Support for tracepoints and fast tracepoints on powerpc-linux,
163 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
164 including JIT compiling fast tracepoint's conditional expression
165 bytecode into native code.
167 * MI async record =record-started now includes the method and format used for
168 recording. For example:
170 =record-started,thread-group="i1",method="btrace",format="bts"
172 * MI async record =thread-selected now includes the frame field. For example:
174 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
178 Andes NDS32 nds32*-*-elf
180 *** Changes in GDB 7.11
182 * GDB now supports debugging kernel-based threads on FreeBSD.
184 * Per-inferior thread numbers
186 Thread numbers are now per inferior instead of global. If you're
187 debugging multiple inferiors, GDB displays thread IDs using a
188 qualified INF_NUM.THR_NUM form. For example:
192 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
193 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
194 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
195 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
197 As consequence, thread numbers as visible in the $_thread
198 convenience variable and in Python's InferiorThread.num attribute
199 are no longer unique between inferiors.
201 GDB now maintains a second thread ID per thread, referred to as the
202 global thread ID, which is the new equivalent of thread numbers in
203 previous releases. See also $_gthread below.
205 For backwards compatibility, MI's thread IDs always refer to global
208 * Commands that accept thread IDs now accept the qualified
209 INF_NUM.THR_NUM form as well. For example:
212 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
215 * In commands that accept a list of thread IDs, you can now refer to
216 all threads of an inferior using a star wildcard. GDB accepts
217 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
218 refer to all threads of the current inferior. For example, "info
221 * You can use "info threads -gid" to display the global thread ID of
224 * The new convenience variable $_gthread holds the global number of
227 * The new convenience variable $_inferior holds the number of the
230 * GDB now displays the ID and name of the thread that hit a breakpoint
231 or received a signal, if your program is multi-threaded. For
234 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
235 Thread 1 "main" received signal SIGINT, Interrupt.
237 * Record btrace now supports non-stop mode.
239 * Support for tracepoints on aarch64-linux was added in GDBserver.
241 * The 'record instruction-history' command now indicates speculative execution
242 when using the Intel Processor Trace recording format.
244 * GDB now allows users to specify explicit locations, bypassing
245 the linespec parser. This feature is also available to GDB/MI
248 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
249 GDB now is able to debug both AArch64 applications and ARM applications
252 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
253 including JIT compiling fast tracepoint's conditional expression bytecode
256 * GDB now supports displaced stepping on AArch64 GNU/Linux.
258 * "info threads", "info inferiors", "info display", "info checkpoints"
259 and "maint info program-spaces" now list the corresponding items in
260 ascending ID order, for consistency with all other "info" commands.
262 * In Ada, the overloads selection menu has been enhanced to display the
263 parameter types and the return types for the matching overloaded subprograms.
267 maint set target-non-stop (on|off|auto)
268 maint show target-non-stop
269 Control whether GDB targets always operate in non-stop mode even if
270 "set non-stop" is "off". The default is "auto", meaning non-stop
271 mode is enabled if supported by the target.
273 maint set bfd-sharing
274 maint show bfd-sharing
275 Control the reuse of bfd objects.
279 Control display of debugging info regarding bfd caching.
283 Control display of debugging info regarding FreeBSD threads.
285 set remote multiprocess-extensions-packet
286 show remote multiprocess-extensions-packet
287 Set/show the use of the remote protocol multiprocess extensions.
289 set remote thread-events
290 show remote thread-events
291 Set/show the use of thread create/exit events.
293 set ada print-signatures on|off
294 show ada print-signatures"
295 Control whether parameter types and return types are displayed in overloads
296 selection menus. It is activaled (@code{on}) by default.
300 Controls the maximum size of memory, in bytes, that GDB will
301 allocate for value contents. Prevents incorrect programs from
302 causing GDB to allocate overly large buffers. Default is 64k.
304 * The "disassemble" command accepts a new modifier: /s.
305 It prints mixed source+disassembly like /m with two differences:
306 - disassembled instructions are now printed in program order, and
307 - and source for all relevant files is now printed.
308 The "/m" option is now considered deprecated: its "source-centric"
309 output hasn't proved useful in practice.
311 * The "record instruction-history" command accepts a new modifier: /s.
312 It behaves exactly like /m and prints mixed source+disassembly.
314 * The "set scheduler-locking" command supports a new mode "replay".
315 It behaves like "off" in record mode and like "on" in replay mode.
317 * Support for various ROM monitors has been removed:
319 target dbug dBUG ROM monitor for Motorola ColdFire
320 target picobug Motorola picobug monitor
321 target dink32 DINK32 ROM monitor for PowerPC
322 target m32r Renesas M32R/D ROM monitor
323 target mon2000 mon2000 ROM monitor
324 target ppcbug PPCBUG ROM monitor for PowerPC
326 * Support for reading/writing memory and extracting values on architectures
327 whose memory is addressable in units of any integral multiple of 8 bits.
332 Indicates that an exec system call was executed.
334 exec-events feature in qSupported
335 The qSupported packet allows GDB to request support for exec
336 events using the new 'gdbfeature' exec-event, and the qSupported
337 response can contain the corresponding 'stubfeature'. Set and
338 show commands can be used to display whether these features are enabled.
341 Equivalent to interrupting with the ^C character, but works in
344 thread created stop reason (T05 create:...)
345 Indicates that the thread was just created and is stopped at entry.
347 thread exit stop reply (w exitcode;tid)
348 Indicates that the thread has terminated.
351 Enables/disables thread create and exit event reporting. For
352 example, this is used in non-stop mode when GDB stops a set of
353 threads and synchronously waits for the their corresponding stop
354 replies. Without exit events, if one of the threads exits, GDB
355 would hang forever not knowing that it should no longer expect a
356 stop for that same thread.
359 Indicates that there are no resumed threads left in the target (all
360 threads are stopped). The remote stub reports support for this stop
361 reply to GDB's qSupported query.
364 Enables/disables catching syscalls from the inferior process.
365 The remote stub reports support for this packet to GDB's qSupported query.
367 syscall_entry stop reason
368 Indicates that a syscall was just called.
370 syscall_return stop reason
371 Indicates that a syscall just returned.
373 * Extended-remote exec events
375 ** GDB now has support for exec events on extended-remote Linux targets.
376 For such targets with Linux kernels 2.5.46 and later, this enables
377 follow-exec-mode and exec catchpoints.
379 set remote exec-event-feature-packet
380 show remote exec-event-feature-packet
381 Set/show the use of the remote exec event feature.
383 * Thread names in remote protocol
385 The reply to qXfer:threads:read may now include a name attribute for each
388 * Target remote mode fork and exec events
390 ** GDB now has support for fork and exec events on target remote mode
391 Linux targets. For such targets with Linux kernels 2.5.46 and later,
392 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
393 fork and exec catchpoints.
395 * Remote syscall events
397 ** GDB now has support for catch syscall on remote Linux targets,
398 currently enabled on x86/x86_64 architectures.
400 set remote catch-syscall-packet
401 show remote catch-syscall-packet
402 Set/show the use of the remote catch syscall feature.
406 ** The -var-set-format command now accepts the zero-hexadecimal
407 format. It outputs data in hexadecimal format with zero-padding on the
412 ** gdb.InferiorThread objects have a new attribute "global_num",
413 which refers to the thread's global thread ID. The existing
414 "num" attribute now refers to the thread's per-inferior number.
415 See "Per-inferior thread numbers" above.
416 ** gdb.InferiorThread objects have a new attribute "inferior", which
417 is the Inferior object the thread belongs to.
419 *** Changes in GDB 7.10
421 * Support for process record-replay and reverse debugging on aarch64*-linux*
422 targets has been added. GDB now supports recording of A64 instruction set
423 including advance SIMD instructions.
425 * Support for Sun's version of the "stabs" debug file format has been removed.
427 * GDB now honors the content of the file /proc/PID/coredump_filter
428 (PID is the process ID) on GNU/Linux systems. This file can be used
429 to specify the types of memory mappings that will be included in a
430 corefile. For more information, please refer to the manual page of
431 "core(5)". GDB also has a new command: "set use-coredump-filter
432 on|off". It allows to set whether GDB will read the content of the
433 /proc/PID/coredump_filter file when generating a corefile.
435 * The "info os" command on GNU/Linux can now display information on
437 "info os cpus" Listing of all cpus/cores on the system
439 * GDB has two new commands: "set serial parity odd|even|none" and
440 "show serial parity". These allows to set or show parity for the
443 * The "info source" command now displays the producer string if it was
444 present in the debug info. This typically includes the compiler version
445 and may include things like its command line arguments.
447 * The "info dll", an alias of the "info sharedlibrary" command,
448 is now available on all platforms.
450 * Directory names supplied to the "set sysroot" commands may be
451 prefixed with "target:" to tell GDB to access shared libraries from
452 the target system, be it local or remote. This replaces the prefix
453 "remote:". The default sysroot has been changed from "" to
454 "target:". "remote:" is automatically converted to "target:" for
455 backward compatibility.
457 * The system root specified by "set sysroot" will be prepended to the
458 filename of the main executable (if reported to GDB as absolute by
459 the operating system) when starting processes remotely, and when
460 attaching to already-running local or remote processes.
462 * GDB now supports automatic location and retrieval of executable
463 files from remote targets. Remote debugging can now be initiated
464 using only a "target remote" or "target extended-remote" command
465 (no "set sysroot" or "file" commands are required). See "New remote
468 * The "dump" command now supports verilog hex format.
470 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
472 * On GNU/Linux, GDB and gdbserver are now able to access executable
473 and shared library files without a "set sysroot" command when
474 attaching to processes running in different mount namespaces from
475 the debugger. This makes it possible to attach to processes in
476 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
477 See "New remote packets" below.
479 * The "tui reg" command now provides completion for all of the
480 available register groups, including target specific groups.
482 * The HISTSIZE environment variable is no longer read when determining
483 the size of GDB's command history. GDB now instead reads the dedicated
484 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
485 disables truncation of command history. Non-numeric values of GDBHISTSIZE
490 ** Memory ports can now be unbuffered.
494 ** gdb.Objfile objects have a new attribute "username",
495 which is the name of the objfile as specified by the user,
496 without, for example, resolving symlinks.
497 ** You can now write frame unwinders in Python.
498 ** gdb.Type objects have a new method "optimized_out",
499 returning optimized out gdb.Value instance of this type.
500 ** gdb.Value objects have new methods "reference_value" and
501 "const_value" which return a reference to the value and a
502 "const" version of the value respectively.
506 maint print symbol-cache
507 Print the contents of the symbol cache.
509 maint print symbol-cache-statistics
510 Print statistics of symbol cache usage.
512 maint flush-symbol-cache
513 Flush the contents of the symbol cache.
517 Start branch trace recording using Branch Trace Store (BTS) format.
520 Evaluate expression by using the compiler and print result.
524 Explicit commands for enabling and disabling tui mode.
527 set mpx bound on i386 and amd64
528 Support for bound table investigation on Intel MPX enabled applications.
532 Start branch trace recording using Intel Processor Trace format.
535 Print information about branch tracing internals.
537 maint btrace packet-history
538 Print the raw branch tracing data.
540 maint btrace clear-packet-history
541 Discard the stored raw branch tracing data.
544 Discard all branch tracing data. It will be fetched and processed
545 anew by the next "record" command.
550 Renamed from "set debug dwarf2-die".
552 Renamed from "show debug dwarf2-die".
555 Renamed from "set debug dwarf2-read".
556 show debug dwarf-read
557 Renamed from "show debug dwarf2-read".
559 maint set dwarf always-disassemble
560 Renamed from "maint set dwarf2 always-disassemble".
561 maint show dwarf always-disassemble
562 Renamed from "maint show dwarf2 always-disassemble".
564 maint set dwarf max-cache-age
565 Renamed from "maint set dwarf2 max-cache-age".
566 maint show dwarf max-cache-age
567 Renamed from "maint show dwarf2 max-cache-age".
570 show debug dwarf-line
571 Control display of debugging info regarding DWARF line processing.
575 Set the maximum number of candidates to be considered during
576 completion. The default value is 200. This limit allows GDB
577 to avoid generating large completion lists, the computation of
578 which can cause the debugger to become temporarily unresponsive.
580 set history remove-duplicates
581 show history remove-duplicates
582 Control the removal of duplicate history entries.
584 maint set symbol-cache-size
585 maint show symbol-cache-size
586 Control the size of the symbol cache.
588 set|show record btrace bts buffer-size
589 Set and show the size of the ring buffer used for branch tracing in
591 The obtained size may differ from the requested size. Use "info
592 record" to see the obtained buffer size.
594 set debug linux-namespaces
595 show debug linux-namespaces
596 Control display of debugging info regarding Linux namespaces.
598 set|show record btrace pt buffer-size
599 Set and show the size of the ring buffer used for branch tracing in
600 Intel Processor Trace format.
601 The obtained size may differ from the requested size. Use "info
602 record" to see the obtained buffer size.
604 maint set|show btrace pt skip-pad
605 Set and show whether PAD packets are skipped when computing the
608 * The command 'thread apply all' can now support new option '-ascending'
609 to call its specified command for all threads in ascending order.
611 * Python/Guile scripting
613 ** GDB now supports auto-loading of Python/Guile scripts contained in the
614 special section named `.debug_gdb_scripts'.
618 qXfer:btrace-conf:read
619 Return the branch trace configuration for the current thread.
621 Qbtrace-conf:bts:size
622 Set the requested ring buffer size for branch tracing in BTS format.
625 Enable Intel Procesor Trace-based branch tracing for the current
626 process. The remote stub reports support for this packet to GDB's
630 Set the requested ring buffer size for branch tracing in Intel Processor
634 Indicates a memory breakpoint instruction was executed, irrespective
635 of whether it was GDB that planted the breakpoint or the breakpoint
636 is hardcoded in the program. This is required for correct non-stop
640 Indicates the target stopped for a hardware breakpoint. This is
641 required for correct non-stop mode operation.
644 Return information about files on the remote system.
647 Return the full absolute name of the file that was executed to
648 create a process running on the remote system.
651 Select the filesystem on which vFile: operations with filename
652 arguments will operate. This is required for GDB to be able to
653 access files on remote targets where the remote stub does not
654 share a common filesystem with the inferior(s).
657 Indicates that a fork system call was executed.
660 Indicates that a vfork system call was executed.
662 vforkdone stop reason
663 Indicates that a vfork child of the specified process has executed
664 an exec or exit, allowing the vfork parent to resume execution.
666 fork-events and vfork-events features in qSupported
667 The qSupported packet allows GDB to request support for fork and
668 vfork events using new 'gdbfeatures' fork-events and vfork-events,
669 and the qSupported response can contain the corresponding
670 'stubfeatures'. Set and show commands can be used to display
671 whether these features are enabled.
673 * Extended-remote fork events
675 ** GDB now has support for fork events on extended-remote Linux
676 targets. For targets with Linux kernels 2.5.60 and later, this
677 enables follow-fork-mode and detach-on-fork for both fork and
678 vfork, as well as fork and vfork catchpoints.
680 * The info record command now shows the recording format and the
681 branch tracing configuration for the current thread when using
682 the btrace record target.
683 For the BTS format, it shows the ring buffer size.
685 * GDB now has support for DTrace USDT (Userland Static Defined
686 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
688 * GDB now supports access to vector registers on S/390 GNU/Linux
691 * Removed command line options
693 -xdb HP-UX XDB compatibility mode.
695 * Removed targets and native configurations
697 HP/PA running HP-UX hppa*-*-hpux*
698 Itanium running HP-UX ia64-*-hpux*
700 * New configure options
703 This configure option allows the user to build GDB with support for
704 Intel Processor Trace (default: auto). This requires libipt.
706 --with-libipt-prefix=PATH
707 Specify the path to the version of libipt that GDB should use.
708 $PATH/include should contain the intel-pt.h header and
709 $PATH/lib should contain the libipt.so library.
711 *** Changes in GDB 7.9.1
715 ** Xmethods can now specify a result type.
717 *** Changes in GDB 7.9
719 * GDB now supports hardware watchpoints on x86 GNU Hurd.
723 ** You can now access frame registers from Python scripts.
724 ** New attribute 'producer' for gdb.Symtab objects.
725 ** gdb.Objfile objects have a new attribute "progspace",
726 which is the gdb.Progspace object of the containing program space.
727 ** gdb.Objfile objects have a new attribute "owner".
728 ** gdb.Objfile objects have a new attribute "build_id",
729 which is the build ID generated when the file was built.
730 ** gdb.Objfile objects have a new method "add_separate_debug_file".
731 ** A new event "gdb.clear_objfiles" has been added, triggered when
732 selecting a new file to debug.
733 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
734 ** New function gdb.lookup_objfile.
736 New events which are triggered when GDB modifies the state of the
739 ** gdb.events.inferior_call_pre: Function call is about to be made.
740 ** gdb.events.inferior_call_post: Function call has just been made.
741 ** gdb.events.memory_changed: A memory location has been altered.
742 ** gdb.events.register_changed: A register has been altered.
744 * New Python-based convenience functions:
746 ** $_caller_is(name [, number_of_frames])
747 ** $_caller_matches(regexp [, number_of_frames])
748 ** $_any_caller_is(name [, number_of_frames])
749 ** $_any_caller_matches(regexp [, number_of_frames])
751 * GDB now supports the compilation and injection of source code into
752 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
753 to compile the source code to object code, and if successful, inject
754 and execute that code within the current context of the inferior.
755 Currently the C language is supported. The commands used to
756 interface with this new feature are:
758 compile code [-raw|-r] [--] [source code]
759 compile file [-raw|-r] filename
763 demangle [-l language] [--] name
764 Demangle "name" in the specified language, or the current language
765 if elided. This command is renamed from the "maint demangle" command.
766 The latter is kept as a no-op to avoid "maint demangle" being interpreted
767 as "maint demangler-warning".
769 queue-signal signal-name-or-number
770 Queue a signal to be delivered to the thread when it is resumed.
772 add-auto-load-scripts-directory directory
773 Add entries to the list of directories from which to load auto-loaded
776 maint print user-registers
777 List all currently available "user" registers.
779 compile code [-r|-raw] [--] [source code]
780 Compile, inject, and execute in the inferior the executable object
781 code produced by compiling the provided source code.
783 compile file [-r|-raw] filename
784 Compile and inject into the inferior the executable object code
785 produced by compiling the source code stored in the filename
788 * On resume, GDB now always passes the signal the program had stopped
789 for to the thread the signal was sent to, even if the user changed
790 threads before resuming. Previously GDB would often (but not
791 always) deliver the signal to the thread that happens to be current
794 * Conversely, the "signal" command now consistently delivers the
795 requested signal to the current thread. GDB now asks for
796 confirmation if the program had stopped for a signal and the user
797 switched threads meanwhile.
799 * "breakpoint always-inserted" modes "off" and "auto" merged.
801 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
802 won't remove breakpoints from the target until all threads stop,
803 even in non-stop mode. The "auto" mode has been removed, and "off"
804 is now the default mode.
808 set debug symbol-lookup
809 show debug symbol-lookup
810 Control display of debugging info regarding symbol lookup.
814 ** The -list-thread-groups command outputs an exit-code field for
815 inferiors that have exited.
819 MIPS SDE mips*-sde*-elf*
823 Support for these obsolete configurations has been removed.
825 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
826 SGI Irix-5.x mips-*-irix5*
827 SGI Irix-6.x mips-*-irix6*
828 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
829 VAX running Ultrix vax-*-ultrix*
831 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
832 and "assf"), have been removed. Use the "sharedlibrary" command, or
833 its alias "share", instead.
835 *** Changes in GDB 7.8
837 * New command line options
840 This is an alias for the --data-directory option.
842 * GDB supports printing and modifying of variable length automatic arrays
843 as specified in ISO C99.
845 * The ARM simulator now supports instruction level tracing
846 with or without disassembly.
850 GDB now has support for scripting using Guile. Whether this is
851 available is determined at configure time.
852 Guile version 2.0 or greater is required.
853 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
855 * New commands (for set/show, see "New options" below)
859 Invoke CODE by passing it to the Guile interpreter.
863 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
865 info auto-load guile-scripts [regexp]
866 Print the list of automatically loaded Guile scripts.
868 * The source command is now capable of sourcing Guile scripts.
869 This feature is dependent on the debugger being built with Guile support.
873 set print symbol-loading (off|brief|full)
874 show print symbol-loading
875 Control whether to print informational messages when loading symbol
876 information for a file. The default is "full", but when debugging
877 programs with large numbers of shared libraries the amount of output
880 set guile print-stack (none|message|full)
881 show guile print-stack
882 Show a stack trace when an error is encountered in a Guile script.
884 set auto-load guile-scripts (on|off)
885 show auto-load guile-scripts
886 Control auto-loading of Guile script files.
888 maint ada set ignore-descriptive-types (on|off)
889 maint ada show ignore-descriptive-types
890 Control whether the debugger should ignore descriptive types in Ada
891 programs. The default is not to ignore the descriptive types. See
892 the user manual for more details on descriptive types and the intended
893 usage of this option.
895 set auto-connect-native-target
897 Control whether GDB is allowed to automatically connect to the
898 native target for the run, attach, etc. commands when not connected
899 to any target yet. See also "target native" below.
901 set record btrace replay-memory-access (read-only|read-write)
902 show record btrace replay-memory-access
903 Control what memory accesses are allowed during replay.
905 maint set target-async (on|off)
906 maint show target-async
907 This controls whether GDB targets operate in synchronous or
908 asynchronous mode. Normally the default is asynchronous, if it is
909 available; but this can be changed to more easily debug problems
910 occurring only in synchronous mode.
912 set mi-async (on|off)
914 Control whether MI asynchronous mode is preferred. This supersedes
915 "set target-async" of previous GDB versions.
917 * "set target-async" is deprecated as a CLI option and is now an alias
918 for "set mi-async" (only puts MI into async mode).
920 * Background execution commands (e.g., "c&", "s&", etc.) are now
921 possible ``out of the box'' if the target supports them. Previously
922 the user would need to explicitly enable the possibility with the
923 "set target-async on" command.
925 * New features in the GDB remote stub, GDBserver
927 ** New option --debug-format=option1[,option2,...] allows one to add
928 additional text to each output. At present only timestamps
929 are supported: --debug-format=timestamps.
930 Timestamps can also be turned on with the
931 "monitor set debug-format timestamps" command from GDB.
933 * The 'record instruction-history' command now starts counting instructions
934 at one. This also affects the instruction ranges reported by the
935 'record function-call-history' command when given the /i modifier.
937 * The command 'record function-call-history' supports a new modifier '/c' to
938 indent the function names based on their call stack depth.
939 The fields for the '/i' and '/l' modifier have been reordered.
940 The source line range is now prefixed with 'at'.
941 The instruction range is now prefixed with 'inst'.
942 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
943 "record instruction-history" and "list" commands.
945 * The ranges given as arguments to the 'record function-call-history' and
946 'record instruction-history' commands are now inclusive.
948 * The btrace record target now supports the 'record goto' command.
949 For locations inside the execution trace, the back trace is computed
950 based on the information stored in the execution trace.
952 * The btrace record target supports limited reverse execution and replay.
953 The target does not record data and therefore does not allow reading
956 * The "catch syscall" command now works on s390*-linux* targets.
958 * The "compare-sections" command is no longer specific to target
959 remote. It now works with all targets.
961 * All native targets are now consistently called "native".
962 Consequently, the "target child", "target GNU", "target djgpp",
963 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
964 commands have been replaced with "target native". The QNX/NTO port
965 leaves the "procfs" target in place and adds a "native" target for
966 consistency with other ports. The impact on users should be minimal
967 as these commands previously either throwed an error, or were
968 no-ops. The target's name is visible in the output of the following
969 commands: "help target", "info target", "info files", "maint print
972 * The "target native" command now connects to the native target. This
973 can be used to launch native programs even when "set
974 auto-connect-native-target" is set to off.
976 * GDB now supports access to Intel MPX registers on GNU/Linux.
978 * Support for Intel AVX-512 registers on GNU/Linux.
979 Support displaying and modifying Intel AVX-512 registers
980 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
984 qXfer:btrace:read's annex
985 The qXfer:btrace:read packet supports a new annex 'delta' to read
986 branch trace incrementally.
990 ** Valid Python operations on gdb.Value objects representing
991 structs/classes invoke the corresponding overloaded operators if
993 ** New `Xmethods' feature in the Python API. Xmethods are
994 additional methods or replacements for existing methods of a C++
995 class. This feature is useful for those cases where a method
996 defined in C++ source code could be inlined or optimized out by
997 the compiler, making it unavailable to GDB.
1000 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1002 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1003 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1004 its alias "share", instead.
1006 * The commands "set remotebaud" and "show remotebaud" are no longer
1007 supported. Use "set serial baud" and "show serial baud" (respectively)
1012 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1013 target-async". The latter is left as a deprecated alias of the
1014 former for backward compatibility. If the target supports it,
1015 CLI background execution commands are now always possible by
1016 default, independently of whether the frontend stated a
1017 preference for asynchronous execution with "-gdb-set mi-async".
1018 Previously "-gdb-set target-async off" affected both MI execution
1019 commands and CLI execution commands.
1021 *** Changes in GDB 7.7
1023 * Improved support for process record-replay and reverse debugging on
1024 arm*-linux* targets. Support for thumb32 and syscall instruction
1025 recording has been added.
1027 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1029 * GDB now supports Fission DWP file format version 2.
1030 http://gcc.gnu.org/wiki/DebugFission
1032 * New convenience function "$_isvoid", to check whether an expression
1033 is void. A void expression is an expression where the type of the
1034 result is "void". For example, some convenience variables may be
1035 "void" when evaluated (e.g., "$_exitcode" before the execution of
1036 the program being debugged; or an undefined convenience variable).
1037 Another example, when calling a function whose return type is
1040 * The "maintenance print objfiles" command now takes an optional regexp.
1042 * The "catch syscall" command now works on arm*-linux* targets.
1044 * GDB now consistently shows "<not saved>" when printing values of
1045 registers the debug info indicates have not been saved in the frame
1046 and there's nowhere to retrieve them from
1047 (callee-saved/call-clobbered registers):
1052 (gdb) info registers rax
1055 Before, the former would print "<optimized out>", and the latter
1056 "*value not available*".
1058 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1063 ** Frame filters and frame decorators have been added.
1064 ** Temporary breakpoints are now supported.
1065 ** Line tables representation has been added.
1066 ** New attribute 'parent_type' for gdb.Field objects.
1067 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1068 ** New attribute 'name' for gdb.Type objects.
1072 Nios II ELF nios2*-*-elf
1073 Nios II GNU/Linux nios2*-*-linux
1074 Texas Instruments MSP430 msp430*-*-elf
1076 * Removed native configurations
1078 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1079 been removed. ELF variants of these configurations are kept supported.
1081 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1082 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1083 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1084 i[34567]86-*-openbsd3.[0-3]
1085 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1086 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1087 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1091 Like "catch throw", but catches a re-thrown exception.
1092 maint check-psymtabs
1093 Renamed from old "maint check-symtabs".
1095 Perform consistency checks on symtabs.
1096 maint expand-symtabs
1097 Expand symtabs matching an optional regexp.
1100 Display the details of GDB configure-time options.
1102 maint set|show per-command
1103 maint set|show per-command space
1104 maint set|show per-command time
1105 maint set|show per-command symtab
1106 Enable display of per-command gdb resource usage.
1108 remove-symbol-file FILENAME
1109 remove-symbol-file -a ADDRESS
1110 Remove a symbol file added via add-symbol-file. The file to remove
1111 can be identified by its filename or by an address that lies within
1112 the boundaries of this symbol file in memory.
1115 info exceptions REGEXP
1116 Display the list of Ada exceptions defined in the program being
1117 debugged. If provided, only the exceptions whose names match REGEXP
1122 set debug symfile off|on
1124 Control display of debugging info regarding reading symbol files and
1125 symbol tables within those files
1127 set print raw frame-arguments
1128 show print raw frame-arguments
1129 Set/show whether to print frame arguments in raw mode,
1130 disregarding any defined pretty-printers.
1132 set remote trace-status-packet
1133 show remote trace-status-packet
1134 Set/show the use of remote protocol qTStatus packet.
1138 Control display of debugging messages related to Nios II targets.
1142 Control whether target-assisted range stepping is enabled.
1144 set startup-with-shell
1145 show startup-with-shell
1146 Specifies whether Unix child processes are started via a shell or
1151 Use the target memory cache for accesses to the code segment. This
1152 improves performance of remote debugging (particularly disassembly).
1154 * You can now use a literal value 'unlimited' for options that
1155 interpret 0 or -1 as meaning "unlimited". E.g., "set
1156 trace-buffer-size unlimited" is now an alias for "set
1157 trace-buffer-size -1" and "set height unlimited" is now an alias for
1160 * The "set debug symtab-create" debugging option of GDB has been changed to
1161 accept a verbosity level. 0 means "off", 1 provides basic debugging
1162 output, and values of 2 or greater provides more verbose output.
1164 * New command-line options
1166 Display the details of GDB configure-time options.
1168 * The command 'tsave' can now support new option '-ctf' to save trace
1169 buffer in Common Trace Format.
1171 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1174 * GDB now implements the the C++ 'typeid' operator.
1176 * The new convenience variable $_exception holds the exception being
1177 thrown or caught at an exception-related catchpoint.
1179 * The exception-related catchpoints, like "catch throw", now accept a
1180 regular expression which can be used to filter exceptions by type.
1182 * The new convenience variable $_exitsignal is automatically set to
1183 the terminating signal number when the program being debugged dies
1184 due to an uncaught signal.
1188 ** All MI commands now accept an optional "--language" option.
1189 Support for this feature can be verified by using the "-list-features"
1190 command, which should contain "language-option".
1192 ** The new command -info-gdb-mi-command allows the user to determine
1193 whether a GDB/MI command is supported or not.
1195 ** The "^error" result record returned when trying to execute an undefined
1196 GDB/MI command now provides a variable named "code" whose content is the
1197 "undefined-command" error code. Support for this feature can be verified
1198 by using the "-list-features" command, which should contain
1199 "undefined-command-error-code".
1201 ** The -trace-save MI command can optionally save trace buffer in Common
1204 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1206 ** The command -data-list-register-values now accepts an optional
1207 "--skip-unavailable" option. When used, only the available registers
1210 ** The new command -trace-frame-collected dumps collected variables,
1211 computed expressions, tvars, memory and registers in a traceframe.
1213 ** The commands -stack-list-locals, -stack-list-arguments and
1214 -stack-list-variables now accept an option "--skip-unavailable".
1215 When used, only the available locals or arguments are displayed.
1217 ** The -exec-run command now accepts an optional "--start" option.
1218 When used, the command follows the same semantics as the "start"
1219 command, stopping the program's execution at the start of its
1220 main subprogram. Support for this feature can be verified using
1221 the "-list-features" command, which should contain
1222 "exec-run-start-option".
1224 ** The new commands -catch-assert and -catch-exceptions insert
1225 catchpoints stopping the program when Ada exceptions are raised.
1227 ** The new command -info-ada-exceptions provides the equivalent of
1228 the new "info exceptions" command.
1230 * New system-wide configuration scripts
1231 A GDB installation now provides scripts suitable for use as system-wide
1232 configuration scripts for the following systems:
1236 * GDB now supports target-assigned range stepping with remote targets.
1237 This improves the performance of stepping source lines by reducing
1238 the number of control packets from/to GDB. See "New remote packets"
1241 * GDB now understands the element 'tvar' in the XML traceframe info.
1242 It has the id of the collected trace state variables.
1244 * On S/390 targets that provide the transactional-execution feature,
1245 the program interruption transaction diagnostic block (TDB) is now
1246 represented as a number of additional "registers" in GDB.
1248 * New remote packets
1252 The vCont packet supports a new 'r' action, that tells the remote
1253 stub to step through an address range itself, without GDB
1254 involvemement at each single-step.
1256 qXfer:libraries-svr4:read's annex
1257 The previously unused annex of the qXfer:libraries-svr4:read packet
1258 is now used to support passing an argument list. The remote stub
1259 reports support for this argument list to GDB's qSupported query.
1260 The defined arguments are "start" and "prev", used to reduce work
1261 necessary for library list updating, resulting in significant
1264 * New features in the GDB remote stub, GDBserver
1266 ** GDBserver now supports target-assisted range stepping. Currently
1267 enabled on x86/x86_64 GNU/Linux targets.
1269 ** GDBserver now adds element 'tvar' in the XML in the reply to
1270 'qXfer:traceframe-info:read'. It has the id of the collected
1271 trace state variables.
1273 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1276 * New 'z' formatter for printing and examining memory, this displays the
1277 value as hexadecimal zero padded on the left to the size of the type.
1279 * GDB can now use Windows x64 unwinding data.
1281 * The "set remotebaud" command has been replaced by "set serial baud".
1282 Similarly, "show remotebaud" has been replaced by "show serial baud".
1283 The "set remotebaud" and "show remotebaud" commands are still available
1284 to provide backward compatibility with older versions of GDB.
1286 *** Changes in GDB 7.6
1288 * Target record has been renamed to record-full.
1289 Record/replay is now enabled with the "record full" command.
1290 This also affects settings that are associated with full record/replay
1291 that have been moved from "set/show record" to "set/show record full":
1293 set|show record full insn-number-max
1294 set|show record full stop-at-limit
1295 set|show record full memory-query
1297 * A new record target "record-btrace" has been added. The new target
1298 uses hardware support to record the control-flow of a process. It
1299 does not support replaying the execution, but it implements the
1300 below new commands for investigating the recorded execution log.
1301 This new recording method can be enabled using:
1305 The "record-btrace" target is only available on Intel Atom processors
1306 and requires a Linux kernel 2.6.32 or later.
1308 * Two new commands have been added for record/replay to give information
1309 about the recorded execution without having to replay the execution.
1310 The commands are only supported by "record btrace".
1312 record instruction-history prints the execution history at
1313 instruction granularity
1315 record function-call-history prints the execution history at
1316 function granularity
1318 * New native configurations
1320 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1321 FreeBSD/powerpc powerpc*-*-freebsd
1322 x86_64/Cygwin x86_64-*-cygwin*
1323 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1327 ARM AArch64 aarch64*-*-elf
1328 ARM AArch64 GNU/Linux aarch64*-*-linux
1329 Lynx 178 PowerPC powerpc-*-lynx*178
1330 x86_64/Cygwin x86_64-*-cygwin*
1331 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1333 * If the configured location of system.gdbinit file (as given by the
1334 --with-system-gdbinit option at configure time) is in the
1335 data-directory (as specified by --with-gdb-datadir at configure
1336 time) or in one of its subdirectories, then GDB will look for the
1337 system-wide init file in the directory specified by the
1338 --data-directory command-line option.
1340 * New command line options:
1342 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1343 other initialization files, unlike -nx which disables all of them.
1345 * Removed command line options
1347 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1350 * The 'ptype' and 'whatis' commands now accept an argument to control
1353 * 'info proc' now works on some core files.
1357 ** Vectors can be created with gdb.Type.vector.
1359 ** Python's atexit.register now works in GDB.
1361 ** Types can be pretty-printed via a Python API.
1363 ** Python 3 is now supported (in addition to Python 2.4 or later)
1365 ** New class gdb.Architecture exposes GDB's internal representation
1366 of architecture in the Python API.
1368 ** New method Frame.architecture returns the gdb.Architecture object
1369 corresponding to the frame's architecture.
1371 * New Python-based convenience functions:
1373 ** $_memeq(buf1, buf2, length)
1374 ** $_streq(str1, str2)
1376 ** $_regex(str, regex)
1378 * The 'cd' command now defaults to using '~' (the home directory) if not
1381 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1382 default for GCC since November 2000.
1384 * The command 'forward-search' can now be abbreviated as 'fo'.
1386 * The command 'info tracepoints' can now display 'installed on target'
1387 or 'not installed on target' for each non-pending location of tracepoint.
1389 * New configure options
1391 --enable-libmcheck/--disable-libmcheck
1392 By default, development versions are built with -lmcheck on hosts
1393 that support it, in order to help track memory corruption issues.
1394 Release versions, on the other hand, are built without -lmcheck
1395 by default. The --enable-libmcheck/--disable-libmcheck configure
1396 options allow the user to override that default.
1397 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1398 This configure option allows the user to build GDB with
1399 libbabeltrace using which GDB can read Common Trace Format data.
1401 * New commands (for set/show, see "New options" below)
1404 Catch signals. This is similar to "handle", but allows commands and
1405 conditions to be attached.
1408 List the BFDs known to GDB.
1410 python-interactive [command]
1412 Start a Python interactive prompt, or evaluate the optional command
1413 and print the result of expressions.
1416 "py" is a new alias for "python".
1418 enable type-printer [name]...
1419 disable type-printer [name]...
1420 Enable or disable type printers.
1424 ** For the Renesas Super-H architecture, the "regs" command has been removed
1425 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1430 set print type methods (on|off)
1431 show print type methods
1432 Control whether method declarations are displayed by "ptype".
1433 The default is to show them.
1435 set print type typedefs (on|off)
1436 show print type typedefs
1437 Control whether typedef definitions are displayed by "ptype".
1438 The default is to show them.
1440 set filename-display basename|relative|absolute
1441 show filename-display
1442 Control the way in which filenames is displayed.
1443 The default is "relative", which preserves previous behavior.
1445 set trace-buffer-size
1446 show trace-buffer-size
1447 Request target to change the size of trace buffer.
1449 set remote trace-buffer-size-packet auto|on|off
1450 show remote trace-buffer-size-packet
1451 Control the use of the remote protocol `QTBuffer:size' packet.
1455 Control display of debugging messages related to ARM AArch64.
1458 set debug coff-pe-read
1459 show debug coff-pe-read
1460 Control display of debugging messages related to reading of COFF/PE
1465 Control display of debugging messages related to Mach-O symbols
1468 set debug notification
1469 show debug notification
1470 Control display of debugging info for async remote notification.
1474 ** Command parameter changes are now notified using new async record
1475 "=cmd-param-changed".
1476 ** Trace frame changes caused by command "tfind" are now notified using
1477 new async record "=traceframe-changed".
1478 ** The creation, deletion and modification of trace state variables
1479 are now notified using new async records "=tsv-created",
1480 "=tsv-deleted" and "=tsv-modified".
1481 ** The start and stop of process record are now notified using new
1482 async record "=record-started" and "=record-stopped".
1483 ** Memory changes are now notified using new async record
1485 ** The data-disassemble command response will include a "fullname" field
1486 containing the absolute file name when source has been requested.
1487 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1488 command, to allow pattern filling of memory areas.
1489 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1490 library load/unload events.
1491 ** The response to breakpoint commands and breakpoint async records
1492 includes an "installed" field containing a boolean state about each
1493 non-pending tracepoint location is whether installed on target or not.
1494 ** Output of the "-trace-status" command includes a "trace-file" field
1495 containing the name of the trace file being examined. This field is
1496 optional, and only present when examining a trace file.
1497 ** The "fullname" field is now always present along with the "file" field,
1498 even if the file cannot be found by GDB.
1500 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1501 You must have the LZMA library available when configuring GDB for this
1502 feature to be enabled. For more information, see:
1503 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1505 * New remote packets
1508 Set the size of trace buffer. The remote stub reports support for this
1509 packet to gdb's qSupported query.
1512 Enable Branch Trace Store (BTS)-based branch tracing for the current
1513 thread. The remote stub reports support for this packet to gdb's
1517 Disable branch tracing for the current thread. The remote stub reports
1518 support for this packet to gdb's qSupported query.
1521 Read the traced branches for the current thread. The remote stub
1522 reports support for this packet to gdb's qSupported query.
1524 *** Changes in GDB 7.5
1526 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1527 for more x32 ABI info.
1529 * GDB now supports access to MIPS DSP registers on Linux targets.
1531 * GDB now supports debugging microMIPS binaries.
1533 * The "info os" command on GNU/Linux can now display information on
1534 several new classes of objects managed by the operating system:
1535 "info os procgroups" lists process groups
1536 "info os files" lists file descriptors
1537 "info os sockets" lists internet-domain sockets
1538 "info os shm" lists shared-memory regions
1539 "info os semaphores" lists semaphores
1540 "info os msg" lists message queues
1541 "info os modules" lists loaded kernel modules
1543 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1544 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1545 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1546 options and inspect the probe arguments using the new $_probe_arg family
1547 of convenience variables. You can obtain more information about SystemTap
1548 in <http://sourceware.org/systemtap/>.
1550 * GDB now supports reversible debugging on ARM, it allows you to
1551 debug basic ARM and THUMB instructions, and provides
1552 record/replay support.
1554 * The option "symbol-reloading" has been deleted as it is no longer used.
1558 ** GDB commands implemented in Python can now be put in command class
1561 ** The "maint set python print-stack on|off" is now deleted.
1563 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1564 apply "flag enum"-style pretty-printing to any enum.
1566 ** gdb.lookup_symbol can now work when there is no current frame.
1568 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1569 the source at which the symbol was defined.
1571 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1572 method 'value'. The former indicates whether the symbol needs a
1573 frame in order to compute its value, and the latter computes the
1576 ** A new method 'referenced_value' on gdb.Value objects which can
1577 dereference pointer as well as C++ reference values.
1579 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1580 which return the global and static blocks (as gdb.Block objects),
1581 of the underlying symbol table, respectively.
1583 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1584 object associated with a PC value.
1586 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1587 of the address range occupied by code for the current source line.
1589 * Go language support.
1590 GDB now supports debugging programs written in the Go programming
1593 * GDBserver now supports stdio connections.
1594 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1596 * The binary "gdbtui" can no longer be built or installed.
1597 Use "gdb -tui" instead.
1599 * GDB will now print "flag" enums specially. A flag enum is one where
1600 all the enumerator values have no bits in common when pairwise
1601 "and"ed. When printing a value whose type is a flag enum, GDB will
1602 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1603 (gdb) print (enum E) 3
1606 * The filename part of a linespec will now match trailing components
1607 of a source file name. For example, "break gcc/expr.c:1000" will
1608 now set a breakpoint in build/gcc/expr.c, but not
1609 build/libcpp/expr.c.
1611 * The "info proc" and "generate-core-file" commands will now also
1612 work on remote targets connected to GDBserver on Linux.
1614 * The command "info catch" has been removed. It has been disabled
1615 since December 2007.
1617 * The "catch exception" and "catch assert" commands now accept
1618 a condition at the end of the command, much like the "break"
1619 command does. For instance:
1621 (gdb) catch exception Constraint_Error if Barrier = True
1623 Previously, it was possible to add a condition to such catchpoints,
1624 but it had to be done as a second step, after the catchpoint had been
1625 created, using the "condition" command.
1627 * The "info static-tracepoint-marker" command will now also work on
1628 native Linux targets with in-process agent.
1630 * GDB can now set breakpoints on inlined functions.
1632 * The .gdb_index section has been updated to include symbols for
1633 inlined functions. GDB will ignore older .gdb_index sections by
1634 default, which could cause symbol files to be loaded more slowly
1635 until their .gdb_index sections can be recreated. The new command
1636 "set use-deprecated-index-sections on" will cause GDB to use any older
1637 .gdb_index sections it finds. This will restore performance, but the
1638 ability to set breakpoints on inlined functions will be lost in symbol
1639 files with older .gdb_index sections.
1641 The .gdb_index section has also been updated to record more information
1642 about each symbol. This speeds up the "info variables", "info functions"
1643 and "info types" commands when used with programs having the .gdb_index
1644 section, as well as speeding up debugging with shared libraries using
1645 the .gdb_index section.
1647 * Ada support for GDB/MI Variable Objects has been added.
1649 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1654 ** New command -info-os is the MI equivalent of "info os".
1656 ** Output logs ("set logging" and related) now include MI output.
1660 ** "set use-deprecated-index-sections on|off"
1661 "show use-deprecated-index-sections on|off"
1662 Controls the use of deprecated .gdb_index sections.
1664 ** "catch load" and "catch unload" can be used to stop when a shared
1665 library is loaded or unloaded, respectively.
1667 ** "enable count" can be used to auto-disable a breakpoint after
1670 ** "info vtbl" can be used to show the virtual method tables for
1671 C++ and Java objects.
1673 ** "explore" and its sub commands "explore value" and "explore type"
1674 can be used to recursively explore values and types of
1675 expressions. These commands are available only if GDB is
1676 configured with '--with-python'.
1678 ** "info auto-load" shows status of all kinds of auto-loaded files,
1679 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1680 sequences of commands files, "info auto-load python-scripts"
1681 shows status of auto-loading Python script files,
1682 "info auto-load local-gdbinit" shows status of loading init file
1683 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1684 status of inferior specific thread debugging shared library loading.
1686 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1687 and "show auto-load-scripts" commands have been deprecated, use their
1688 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1689 and "show auto-load python-scripts" counterparts instead.
1691 ** "dprintf location,format,args..." creates a dynamic printf, which
1692 is basically a breakpoint that does a printf and immediately
1693 resumes your program's execution, so it is like a printf that you
1694 can insert dynamically at runtime instead of at compiletime.
1696 ** "set print symbol"
1698 Controls whether GDB attempts to display the symbol, if any,
1699 corresponding to addresses it prints. This defaults to "on", but
1700 you can set it to "off" to restore GDB's previous behavior.
1702 * Deprecated commands
1704 ** For the Renesas Super-H architecture, the "regs" command has been
1705 deprecated, and "info all-registers" should be used instead.
1709 Renesas RL78 rl78-*-elf
1710 HP OpenVMS ia64 ia64-hp-openvms*
1712 * GDBserver supports evaluation of breakpoint conditions. When
1713 support is advertised by GDBserver, GDB may be told to send the
1714 breakpoint conditions in bytecode form to GDBserver. GDBserver
1715 will only report the breakpoint trigger to GDB when its condition
1720 set mips compression
1721 show mips compression
1722 Select the compressed ISA encoding used in functions that have no symbol
1723 information available. The encoding can be set to either of:
1726 and is updated automatically from ELF file flags if available.
1728 set breakpoint condition-evaluation
1729 show breakpoint condition-evaluation
1730 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1731 GDBserver ("target"). Default option "auto" chooses the most efficient
1733 This option can improve debugger efficiency depending on the speed of the
1737 Disable auto-loading globally.
1740 Show auto-loading setting of all kinds of auto-loaded files.
1742 set auto-load gdb-scripts on|off
1743 show auto-load gdb-scripts
1744 Control auto-loading of GDB canned sequences of commands files.
1746 set auto-load python-scripts on|off
1747 show auto-load python-scripts
1748 Control auto-loading of Python script files.
1750 set auto-load local-gdbinit on|off
1751 show auto-load local-gdbinit
1752 Control loading of init file (.gdbinit) from current directory.
1754 set auto-load libthread-db on|off
1755 show auto-load libthread-db
1756 Control auto-loading of inferior specific thread debugging shared library.
1758 set auto-load scripts-directory <dir1>[:<dir2>...]
1759 show auto-load scripts-directory
1760 Set a list of directories from which to load auto-loaded scripts.
1761 Automatically loaded Python scripts and GDB scripts are located in one
1762 of the directories listed by this option.
1763 The delimiter (':' above) may differ according to the host platform.
1765 set auto-load safe-path <dir1>[:<dir2>...]
1766 show auto-load safe-path
1767 Set a list of directories from which it is safe to auto-load files.
1768 The delimiter (':' above) may differ according to the host platform.
1770 set debug auto-load on|off
1771 show debug auto-load
1772 Control display of debugging info for auto-loading the files above.
1774 set dprintf-style gdb|call|agent
1776 Control the way in which a dynamic printf is performed; "gdb"
1777 requests a GDB printf command, while "call" causes dprintf to call a
1778 function in the inferior. "agent" requests that the target agent
1779 (such as GDBserver) do the printing.
1781 set dprintf-function <expr>
1782 show dprintf-function
1783 set dprintf-channel <expr>
1784 show dprintf-channel
1785 Set the function and optional first argument to the call when using
1786 the "call" style of dynamic printf.
1788 set disconnected-dprintf on|off
1789 show disconnected-dprintf
1790 Control whether agent-style dynamic printfs continue to be in effect
1791 after GDB disconnects.
1793 * New configure options
1795 --with-auto-load-dir
1796 Configure default value for the 'set auto-load scripts-directory'
1797 setting above. It defaults to '$debugdir:$datadir/auto-load',
1798 $debugdir representing global debugging info directories (available
1799 via 'show debug-file-directory') and $datadir representing GDB's data
1800 directory (available via 'show data-directory').
1802 --with-auto-load-safe-path
1803 Configure default value for the 'set auto-load safe-path' setting
1804 above. It defaults to the --with-auto-load-dir setting.
1806 --without-auto-load-safe-path
1807 Set 'set auto-load safe-path' to '/', effectively disabling this
1810 * New remote packets
1812 z0/z1 conditional breakpoints extension
1814 The z0/z1 breakpoint insertion packets have been extended to carry
1815 a list of conditional expressions over to the remote stub depending on the
1816 condition evaluation mode. The use of this extension can be controlled
1817 via the "set remote conditional-breakpoints-packet" command.
1821 Specify the signals which the remote stub may pass to the debugged
1822 program without GDB involvement.
1824 * New command line options
1826 --init-command=FILE, -ix Like --command, -x but execute it
1827 before loading inferior.
1828 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1829 execute it before loading inferior.
1831 *** Changes in GDB 7.4
1833 * GDB now handles ambiguous linespecs more consistently; the existing
1834 FILE:LINE support has been expanded to other types of linespecs. A
1835 breakpoint will now be set on all matching locations in all
1836 inferiors, and locations will be added or removed according to
1839 * GDB now allows you to skip uninteresting functions and files when
1840 stepping with the "skip function" and "skip file" commands.
1842 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1843 and "show remote hardware-watchpoint-length-limit". These allows to
1844 set or show the maximum length limit (in bytes) of a remote
1845 target hardware watchpoint.
1847 This allows e.g. to use "unlimited" hardware watchpoints with the
1848 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1849 watchpoints are slower than real hardware watchpoints but are
1850 significantly faster than gdb software watchpoints.
1854 ** The register_pretty_printer function in module gdb.printing now takes
1855 an optional `replace' argument. If True, the new printer replaces any
1858 ** The "maint set python print-stack on|off" command has been
1859 deprecated and will be deleted in GDB 7.5.
1860 A new command: "set python print-stack none|full|message" has
1861 replaced it. Additionally, the default for "print-stack" is
1862 now "message", which just prints the error message without
1865 ** A prompt substitution hook (prompt_hook) is now available to the
1868 ** A new Python module, gdb.prompt has been added to the GDB Python
1869 modules library. This module provides functionality for
1870 escape sequences in prompts (used by set/show
1871 extended-prompt). These escape sequences are replaced by their
1872 corresponding value.
1874 ** Python commands and convenience-functions located in
1875 'data-directory'/python/gdb/command and
1876 'data-directory'/python/gdb/function are now automatically loaded
1879 ** Blocks now provide four new attributes. global_block and
1880 static_block will return the global and static blocks
1881 respectively. is_static and is_global are boolean attributes
1882 that indicate if the block is one of those two types.
1884 ** Symbols now provide the "type" attribute, the type of the symbol.
1886 ** The "gdb.breakpoint" function has been deprecated in favor of
1889 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1890 of a function. This class is based on the "finish" command
1891 available in the CLI.
1893 ** Type objects for struct and union types now allow access to
1894 the fields using standard Python dictionary (mapping) methods.
1895 For example, "some_type['myfield']" now works, as does
1896 "some_type.items()".
1898 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1901 ** A new function, "deep_items" has been added to the gdb.types
1902 module in the GDB Python modules library. This function returns
1903 an iterator over the fields of a struct or union type. Unlike
1904 the standard Python "iteritems" method, it will recursively traverse
1905 any anonymous fields.
1909 ** "*stopped" events can report several new "reason"s, such as
1912 ** Breakpoint changes are now notified using new async records, like
1913 "=breakpoint-modified".
1915 ** New command -ada-task-info.
1917 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1918 $sdir specifies the default system locations of shared libraries.
1919 $pdir specifies the directory where the libpthread used by the application
1922 GDB no longer looks in $sdir and $pdir after it has searched the directories
1923 mentioned in libthread-db-search-path. If you want to search those
1924 directories, they must be specified in libthread-db-search-path.
1925 The default value of libthread-db-search-path on GNU/Linux and Solaris
1926 systems is now "$sdir:$pdir".
1928 $pdir is not supported by gdbserver, it is currently ignored.
1929 $sdir is supported by gdbserver.
1931 * New configure option --with-iconv-bin.
1932 When using the internationalization support like the one in the GNU C
1933 library, GDB will invoke the "iconv" program to get a list of supported
1934 character sets. If this program lives in a non-standard location, one can
1935 use this option to specify where to find it.
1937 * When natively debugging programs on PowerPC BookE processors running
1938 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1939 watchpoints, which specify a mask in addition to an address to watch.
1940 The mask specifies that some bits of an address (the bits which are
1941 reset in the mask) should be ignored when matching the address accessed
1942 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1943 section in the user manual for more details.
1945 * The new option --once causes GDBserver to stop listening for connections once
1946 the first connection is made. The listening port used by GDBserver will
1947 become available after that.
1949 * New commands "info macros" and "alias" have been added.
1951 * New function parameters suffix @entry specifies value of function parameter
1952 at the time the function got called. Entry values are available only since
1958 "!" is now an alias of the "shell" command.
1959 Note that no space is needed between "!" and SHELL COMMAND.
1963 watch EXPRESSION mask MASK_VALUE
1964 The watch command now supports the mask argument which allows creation
1965 of masked watchpoints, if the current architecture supports this feature.
1967 info auto-load-scripts [REGEXP]
1968 This command was formerly named "maintenance print section-scripts".
1969 It is now generally useful and is no longer a maintenance-only command.
1971 info macro [-all] [--] MACRO
1972 The info macro command has new options `-all' and `--'. The first for
1973 printing all definitions of a macro. The second for explicitly specifying
1974 the end of arguments and the beginning of the macro name in case the macro
1975 name starts with a hyphen.
1977 collect[/s] EXPRESSIONS
1978 The tracepoint collect command now takes an optional modifier "/s"
1979 that directs it to dereference pointer-to-character types and
1980 collect the bytes of memory up to a zero byte. The behavior is
1981 similar to what you see when you use the regular print command on a
1982 string. An optional integer following the "/s" sets a bound on the
1983 number of bytes that will be collected.
1986 The trace start command now interprets any supplied arguments as a
1987 note to be recorded with the trace run, with an effect similar to
1988 setting the variable trace-notes.
1991 The trace stop command now interprets any arguments as a note to be
1992 mentioned along with the tstatus report that the trace was stopped
1993 with a command. The effect is similar to setting the variable
1996 * Tracepoints can now be enabled and disabled at any time after a trace
1997 experiment has been started using the standard "enable" and "disable"
1998 commands. It is now possible to start a trace experiment with no enabled
1999 tracepoints; GDB will display a warning, but will allow the experiment to
2000 begin, assuming that tracepoints will be enabled as needed while the trace
2003 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2004 locations with 4-byte instructions, when they were previously
2005 limited to locations with instructions of 5 bytes or longer.
2009 set debug dwarf2-read
2010 show debug dwarf2-read
2011 Turns on or off display of debugging messages related to reading
2012 DWARF debug info. The default is off.
2014 set debug symtab-create
2015 show debug symtab-create
2016 Turns on or off display of debugging messages related to symbol table
2017 creation. The default is off.
2020 show extended-prompt
2021 Set the GDB prompt, and allow escape sequences to be inserted to
2022 display miscellaneous information (see 'help set extended-prompt'
2023 for the list of sequences). This prompt (and any information
2024 accessed through the escape sequences) is updated every time the
2025 prompt is displayed.
2027 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2028 show print entry-values
2029 Set printing of frame argument values at function entry. In some cases
2030 GDB can determine the value of function argument which was passed by the
2031 function caller, even if the value was modified inside the called function.
2033 set debug entry-values
2034 show debug entry-values
2035 Control display of debugging info for determining frame argument values at
2036 function entry and virtual tail call frames.
2038 set basenames-may-differ
2039 show basenames-may-differ
2040 Set whether a source file may have multiple base names.
2041 (A "base name" is the name of a file with the directory part removed.
2042 Example: The base name of "/home/user/hello.c" is "hello.c".)
2043 If set, GDB will canonicalize file names (e.g., expand symlinks)
2044 before comparing them. Canonicalization is an expensive operation,
2045 but it allows the same file be known by more than one base name.
2046 If not set (the default), all source files are assumed to have just
2047 one base name, and gdb will do file name comparisons more efficiently.
2053 Set a user name and notes for the current and any future trace runs.
2054 This is useful for long-running and/or disconnected traces, to
2055 inform others (or yourself) as to who is running the trace, supply
2056 contact information, or otherwise explain what is going on.
2058 set trace-stop-notes
2059 show trace-stop-notes
2060 Set a note attached to the trace run, that is displayed when the
2061 trace has been stopped by a tstop command. This is useful for
2062 instance as an explanation, if you are stopping a trace run that was
2063 started by someone else.
2065 * New remote packets
2069 Dynamically enable a tracepoint in a started trace experiment.
2073 Dynamically disable a tracepoint in a started trace experiment.
2077 Set the user and notes of the trace run.
2081 Query the current status of a tracepoint.
2085 Query the minimum length of instruction at which a fast tracepoint may
2088 * Dcache size (number of lines) and line-size are now runtime-configurable
2089 via "set dcache line" and "set dcache line-size" commands.
2093 Texas Instruments TMS320C6x tic6x-*-*
2097 Renesas RL78 rl78-*-elf
2099 *** Changes in GDB 7.3.1
2101 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2103 *** Changes in GDB 7.3
2105 * GDB has a new command: "thread find [REGEXP]".
2106 It finds the thread id whose name, target id, or thread extra info
2107 matches the given regular expression.
2109 * The "catch syscall" command now works on mips*-linux* targets.
2111 * The -data-disassemble MI command now supports modes 2 and 3 for
2112 dumping the instruction opcodes.
2114 * New command line options
2116 -data-directory DIR Specify DIR as the "data-directory".
2117 This is mostly for testing purposes.
2119 * The "maint set python auto-load on|off" command has been renamed to
2120 "set auto-load-scripts on|off".
2122 * GDB has a new command: "set directories".
2123 It is like the "dir" command except that it replaces the
2124 source path list instead of augmenting it.
2126 * GDB now understands thread names.
2128 On GNU/Linux, "info threads" will display the thread name as set by
2129 prctl or pthread_setname_np.
2131 There is also a new command, "thread name", which can be used to
2132 assign a name internally for GDB to display.
2135 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2136 has been integrated into GDB.
2140 ** The function gdb.Write now accepts an optional keyword 'stream'.
2141 This keyword, when provided, will direct the output to either
2142 stdout, stderr, or GDB's logging output.
2144 ** Parameters can now be be sub-classed in Python, and in particular
2145 you may implement the get_set_doc and get_show_doc functions.
2146 This improves how Parameter set/show documentation is processed
2147 and allows for more dynamic content.
2149 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2150 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2151 have an is_valid method.
2153 ** Breakpoints can now be sub-classed in Python, and in particular
2154 you may implement a 'stop' function that is executed each time
2155 the inferior reaches that breakpoint.
2157 ** New function gdb.lookup_global_symbol looks up a global symbol.
2159 ** GDB values in Python are now callable if the value represents a
2160 function. For example, if 'some_value' represents a function that
2161 takes two integer parameters and returns a value, you can call
2162 that function like so:
2164 result = some_value (10,20)
2166 ** Module gdb.types has been added.
2167 It contains a collection of utilities for working with gdb.Types objects:
2168 get_basic_type, has_field, make_enum_dict.
2170 ** Module gdb.printing has been added.
2171 It contains utilities for writing and registering pretty-printers.
2172 New classes: PrettyPrinter, SubPrettyPrinter,
2173 RegexpCollectionPrettyPrinter.
2174 New function: register_pretty_printer.
2176 ** New commands "info pretty-printers", "enable pretty-printer" and
2177 "disable pretty-printer" have been added.
2179 ** gdb.parameter("directories") is now available.
2181 ** New function gdb.newest_frame returns the newest frame in the
2184 ** The gdb.InferiorThread class has a new "name" attribute. This
2185 holds the thread's name.
2187 ** Python Support for Inferior events.
2188 Python scripts can add observers to be notified of events
2189 occurring in the process being debugged.
2190 The following events are currently supported:
2191 - gdb.events.cont Continue event.
2192 - gdb.events.exited Inferior exited event.
2193 - gdb.events.stop Signal received, and Breakpoint hit events.
2197 ** GDB now puts template parameters in scope when debugging in an
2198 instantiation. For example, if you have:
2200 template<int X> int func (void) { return X; }
2202 then if you step into func<5>, "print X" will show "5". This
2203 feature requires proper debuginfo support from the compiler; it
2204 was added to GCC 4.5.
2206 ** The motion commands "next", "finish", "until", and "advance" now
2207 work better when exceptions are thrown. In particular, GDB will
2208 no longer lose control of the inferior; instead, the GDB will
2209 stop the inferior at the point at which the exception is caught.
2210 This functionality requires a change in the exception handling
2211 code that was introduced in GCC 4.5.
2213 * GDB now follows GCC's rules on accessing volatile objects when
2214 reading or writing target state during expression evaluation.
2215 One notable difference to prior behavior is that "print x = 0"
2216 no longer generates a read of x; the value of the assignment is
2217 now always taken directly from the value being assigned.
2219 * GDB now has some support for using labels in the program's source in
2220 linespecs. For instance, you can use "advance label" to continue
2221 execution to a label.
2223 * GDB now has support for reading and writing a new .gdb_index
2224 section. This section holds a fast index of DWARF debugging
2225 information and can be used to greatly speed up GDB startup and
2226 operation. See the documentation for `save gdb-index' for details.
2228 * The "watch" command now accepts an optional "-location" argument.
2229 When used, this causes GDB to watch the memory referred to by the
2230 expression. Such a watchpoint is never deleted due to it going out
2233 * GDB now supports thread debugging of core dumps on GNU/Linux.
2235 GDB now activates thread debugging using the libthread_db library
2236 when debugging GNU/Linux core dumps, similarly to when debugging
2237 live processes. As a result, when debugging a core dump file, GDB
2238 is now able to display pthread_t ids of threads. For example, "info
2239 threads" shows the same output as when debugging the process when it
2240 was live. In earlier releases, you'd see something like this:
2243 * 1 LWP 6780 main () at main.c:10
2245 While now you see this:
2248 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2250 It is also now possible to inspect TLS variables when debugging core
2253 When debugging a core dump generated on a machine other than the one
2254 used to run GDB, you may need to point GDB at the correct
2255 libthread_db library with the "set libthread-db-search-path"
2256 command. See the user manual for more details on this command.
2258 * When natively debugging programs on PowerPC BookE processors running
2259 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2260 which stop execution of the inferior whenever it executes an instruction
2261 at any address within the specified range. See the "PowerPC Embedded"
2262 section in the user manual for more details.
2264 * New features in the GDB remote stub, GDBserver
2266 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2267 and i686 LynxOS (version 5.x).
2269 ** GDBserver is now supported on Blackfin Linux.
2271 * New native configurations
2273 ia64 HP-UX ia64-*-hpux*
2277 Analog Devices, Inc. Blackfin Processor bfin-*
2279 * Ada task switching is now supported on sparc-elf targets when
2280 debugging a program using the Ravenscar Profile. For more information,
2281 see the "Tasking Support when using the Ravenscar Profile" section
2282 in the GDB user manual.
2284 * Guile support was removed.
2286 * New features in the GNU simulator
2288 ** The --map-info flag lists all known core mappings.
2290 ** CFI flashes may be simulated via the "cfi" device.
2292 *** Changes in GDB 7.2
2294 * Shared library support for remote targets by default
2296 When GDB is configured for a generic, non-OS specific target, like
2297 for example, --target=arm-eabi or one of the many *-*-elf targets,
2298 GDB now queries remote stubs for loaded shared libraries using the
2299 `qXfer:libraries:read' packet. Previously, shared library support
2300 was always disabled for such configurations.
2304 ** Argument Dependent Lookup (ADL)
2306 In C++ ADL lookup directs function search to the namespaces of its
2307 arguments even if the namespace has not been imported.
2317 Here the compiler will search for `foo' in the namespace of 'b'
2318 and find A::foo. GDB now supports this. This construct is commonly
2319 used in the Standard Template Library for operators.
2321 ** Improved User Defined Operator Support
2323 In addition to member operators, GDB now supports lookup of operators
2324 defined in a namespace and imported with a `using' directive, operators
2325 defined in the global scope, operators imported implicitly from an
2326 anonymous namespace, and the ADL operators mentioned in the previous
2328 GDB now also supports proper overload resolution for all the previously
2329 mentioned flavors of operators.
2331 ** static const class members
2333 Printing of static const class members that are initialized in the
2334 class definition has been fixed.
2336 * Windows Thread Information Block access.
2338 On Windows targets, GDB now supports displaying the Windows Thread
2339 Information Block (TIB) structure. This structure is visible either
2340 by using the new command `info w32 thread-information-block' or, by
2341 dereferencing the new convenience variable named `$_tlb', a
2342 thread-specific pointer to the TIB. This feature is also supported
2343 when remote debugging using GDBserver.
2345 * Static tracepoints
2347 Static tracepoints are calls in the user program into a tracing
2348 library. One such library is a port of the LTTng kernel tracer to
2349 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2350 When debugging with GDBserver, GDB now supports combining the GDB
2351 tracepoint machinery with such libraries. For example: the user can
2352 use GDB to probe a static tracepoint marker (a call from the user
2353 program into the tracing library) with the new "strace" command (see
2354 "New commands" below). This creates a "static tracepoint" in the
2355 breakpoint list, that can be manipulated with the same feature set
2356 as fast and regular tracepoints. E.g., collect registers, local and
2357 global variables, collect trace state variables, and define
2358 tracepoint conditions. In addition, the user can collect extra
2359 static tracepoint marker specific data, by collecting the new
2360 $_sdata internal variable. When analyzing the trace buffer, you can
2361 inspect $_sdata like any other variable available to GDB. For more
2362 information, see the "Tracepoints" chapter in GDB user manual. New
2363 remote packets have been defined to support static tracepoints, see
2364 the "New remote packets" section below.
2366 * Better reconstruction of tracepoints after disconnected tracing
2368 GDB will attempt to download the original source form of tracepoint
2369 definitions when starting a trace run, and then will upload these
2370 upon reconnection to the target, resulting in a more accurate
2371 reconstruction of the tracepoints that are in use on the target.
2375 You can now exercise direct control over the ways that GDB can
2376 affect your program. For instance, you can disallow the setting of
2377 breakpoints, so that the program can run continuously (assuming
2378 non-stop mode). In addition, the "observer" variable is available
2379 to switch all of the different controls; in observer mode, GDB
2380 cannot affect the target's behavior at all, which is useful for
2381 tasks like diagnosing live systems in the field.
2383 * The new convenience variable $_thread holds the number of the
2386 * New remote packets
2390 Return the address of the Windows Thread Information Block of a given thread.
2394 In response to several of the tracepoint packets, the target may now
2395 also respond with a number of intermediate `qRelocInsn' request
2396 packets before the final result packet, to have GDB handle
2397 relocating an instruction to execute at a different address. This
2398 is particularly useful for stubs that support fast tracepoints. GDB
2399 reports support for this feature in the qSupported packet.
2403 List static tracepoint markers in the target program.
2407 List static tracepoint markers at a given address in the target
2410 qXfer:statictrace:read
2412 Read the static trace data collected (by a `collect $_sdata'
2413 tracepoint action). The remote stub reports support for this packet
2414 to gdb's qSupported query.
2418 Send the current settings of GDB's permission flags.
2422 Send part of the source (textual) form of a tracepoint definition,
2423 which includes location, conditional, and action list.
2425 * The source command now accepts a -s option to force searching for the
2426 script in the source search path even if the script name specifies
2429 * New features in the GDB remote stub, GDBserver
2431 - GDBserver now support tracepoints (including fast tracepoints, and
2432 static tracepoints). The feature is currently supported by the
2433 i386-linux and amd64-linux builds. See the "Tracepoints support
2434 in gdbserver" section in the manual for more information.
2436 GDBserver JIT compiles the tracepoint's conditional agent
2437 expression bytecode into native code whenever possible for low
2438 overhead dynamic tracepoints conditionals. For such tracepoints,
2439 an expression that examines program state is evaluated when the
2440 tracepoint is reached, in order to determine whether to capture
2441 trace data. If the condition is simple and false, processing the
2442 tracepoint finishes very quickly and no data is gathered.
2444 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2445 for static tracepoints support.
2447 - GDBserver now supports x86_64 Windows 64-bit debugging.
2449 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2450 it understands register description.
2452 * The --batch flag now disables pagination and queries.
2454 * X86 general purpose registers
2456 GDB now supports reading/writing byte, word and double-word x86
2457 general purpose registers directly. This means you can use, say,
2458 $ah or $ax to refer, respectively, to the byte register AH and
2459 16-bit word register AX that are actually portions of the 32-bit
2460 register EAX or 64-bit register RAX.
2462 * The `commands' command now accepts a range of breakpoints to modify.
2463 A plain `commands' following a command that creates multiple
2464 breakpoints affects all the breakpoints set by that command. This
2465 applies to breakpoints set by `rbreak', and also applies when a
2466 single `break' command creates multiple breakpoints (e.g.,
2467 breakpoints on overloaded c++ functions).
2469 * The `rbreak' command now accepts a filename specification as part of
2470 its argument, limiting the functions selected by the regex to those
2471 in the specified file.
2473 * Support for remote debugging Windows and SymbianOS shared libraries
2474 from Unix hosts has been improved. Non Windows GDB builds now can
2475 understand target reported file names that follow MS-DOS based file
2476 system semantics, such as file names that include drive letters and
2477 use the backslash character as directory separator. This makes it
2478 possible to transparently use the "set sysroot" and "set
2479 solib-search-path" on Unix hosts to point as host copies of the
2480 target's shared libraries. See the new command "set
2481 target-file-system-kind" described below, and the "Commands to
2482 specify files" section in the user manual for more information.
2486 eval template, expressions...
2487 Convert the values of one or more expressions under the control
2488 of the string template to a command line, and call it.
2490 set target-file-system-kind unix|dos-based|auto
2491 show target-file-system-kind
2492 Set or show the assumed file system kind for target reported file
2495 save breakpoints <filename>
2496 Save all current breakpoint definitions to a file suitable for use
2497 in a later debugging session. To read the saved breakpoint
2498 definitions, use the `source' command.
2500 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2503 info static-tracepoint-markers
2504 Display information about static tracepoint markers in the target.
2506 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2507 Define a static tracepoint by probing a marker at the given
2508 function, line, address, or marker ID.
2512 Enable and disable observer mode.
2514 set may-write-registers on|off
2515 set may-write-memory on|off
2516 set may-insert-breakpoints on|off
2517 set may-insert-tracepoints on|off
2518 set may-insert-fast-tracepoints on|off
2519 set may-interrupt on|off
2520 Set individual permissions for GDB effects on the target. Note that
2521 some of these settings can have undesirable or surprising
2522 consequences, particularly when changed in the middle of a session.
2523 For instance, disabling the writing of memory can prevent
2524 breakpoints from being inserted, cause single-stepping to fail, or
2525 even crash your program, if you disable after breakpoints have been
2526 inserted. However, GDB should not crash.
2528 set record memory-query on|off
2529 show record memory-query
2530 Control whether to stop the inferior if memory changes caused
2531 by an instruction cannot be recorded.
2536 The disassemble command now supports "start,+length" form of two arguments.
2540 ** GDB now provides a new directory location, called the python directory,
2541 where Python scripts written for GDB can be installed. The location
2542 of that directory is <data-directory>/python, where <data-directory>
2543 is the GDB data directory. For more details, see section `Scripting
2544 GDB using Python' in the manual.
2546 ** The GDB Python API now has access to breakpoints, symbols, symbol
2547 tables, program spaces, inferiors, threads and frame's code blocks.
2548 Additionally, GDB Parameters can now be created from the API, and
2549 manipulated via set/show in the CLI.
2551 ** New functions gdb.target_charset, gdb.target_wide_charset,
2552 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2554 ** New exception gdb.GdbError.
2556 ** Pretty-printers are now also looked up in the current program space.
2558 ** Pretty-printers can now be individually enabled and disabled.
2560 ** GDB now looks for names of Python scripts to auto-load in a
2561 special section named `.debug_gdb_scripts', in addition to looking
2562 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2564 * Tracepoint actions were unified with breakpoint commands. In particular,
2565 there are no longer differences in "info break" output for breakpoints and
2566 tracepoints and the "commands" command can be used for both tracepoints and
2567 regular breakpoints.
2571 ARM Symbian arm*-*-symbianelf*
2573 * D language support.
2574 GDB now supports debugging programs written in the D programming
2577 * GDB now supports the extended ptrace interface for PowerPC which is
2578 available since Linux kernel version 2.6.34. This automatically enables
2579 any hardware breakpoints and additional hardware watchpoints available in
2580 the processor. The old ptrace interface exposes just one hardware
2581 watchpoint and no hardware breakpoints.
2583 * GDB is now able to use the Data Value Compare (DVC) register available on
2584 embedded PowerPC processors to implement in hardware simple watchpoint
2585 conditions of the form:
2587 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2589 This works in native GDB running on Linux kernels with the extended ptrace
2590 interface mentioned above.
2592 *** Changes in GDB 7.1
2596 ** Namespace Support
2598 GDB now supports importing of namespaces in C++. This enables the
2599 user to inspect variables from imported namespaces. Support for
2600 namepace aliasing has also been added. So, if a namespace is
2601 aliased in the current scope (e.g. namepace C=A; ) the user can
2602 print variables using the alias (e.g. (gdb) print C::x).
2606 All known bugs relating to the printing of virtual base class were
2607 fixed. It is now possible to call overloaded static methods using a
2612 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2613 and reinterpret_cast<> are now handled by the C++ expression parser.
2617 Xilinx MicroBlaze microblaze-*-*
2622 Xilinx MicroBlaze microblaze
2625 * Multi-program debugging.
2627 GDB now has support for multi-program (a.k.a. multi-executable or
2628 multi-exec) debugging. This allows for debugging multiple inferiors
2629 simultaneously each running a different program under the same GDB
2630 session. See "Debugging Multiple Inferiors and Programs" in the
2631 manual for more information. This implied some user visible changes
2632 in the multi-inferior support. For example, "info inferiors" now
2633 lists inferiors that are not running yet or that have exited
2634 already. See also "New commands" and "New options" below.
2636 * New tracing features
2638 GDB's tracepoint facility now includes several new features:
2640 ** Trace state variables
2642 GDB tracepoints now include support for trace state variables, which
2643 are variables managed by the target agent during a tracing
2644 experiment. They are useful for tracepoints that trigger each
2645 other, so for instance one tracepoint can count hits in a variable,
2646 and then a second tracepoint has a condition that is true when the
2647 count reaches a particular value. Trace state variables share the
2648 $-syntax of GDB convenience variables, and can appear in both
2649 tracepoint actions and condition expressions. Use the "tvariable"
2650 command to create, and "info tvariables" to view; see "Trace State
2651 Variables" in the manual for more detail.
2655 GDB now includes an option for defining fast tracepoints, which
2656 targets may implement more efficiently, such as by installing a jump
2657 into the target agent rather than a trap instruction. The resulting
2658 speedup can be by two orders of magnitude or more, although the
2659 tradeoff is that some program locations on some target architectures
2660 might not allow fast tracepoint installation, for instance if the
2661 instruction to be replaced is shorter than the jump. To request a
2662 fast tracepoint, use the "ftrace" command, with syntax identical to
2663 the regular trace command.
2665 ** Disconnected tracing
2667 It is now possible to detach GDB from the target while it is running
2668 a trace experiment, then reconnect later to see how the experiment
2669 is going. In addition, a new variable disconnected-tracing lets you
2670 tell the target agent whether to continue running a trace if the
2671 connection is lost unexpectedly.
2675 GDB now has the ability to save the trace buffer into a file, and
2676 then use that file as a target, similarly to you can do with
2677 corefiles. You can select trace frames, print data that was
2678 collected in them, and use tstatus to display the state of the
2679 tracing run at the moment that it was saved. To create a trace
2680 file, use "tsave <filename>", and to use it, do "target tfile
2683 ** Circular trace buffer
2685 You can ask the target agent to handle the trace buffer as a
2686 circular buffer, discarding the oldest trace frames to make room for
2687 newer ones, by setting circular-trace-buffer to on. This feature may
2688 not be available for all target agents.
2693 The disassemble command, when invoked with two arguments, now requires
2694 the arguments to be comma-separated.
2697 The info variables command now displays variable definitions. Files
2698 which only declare a variable are not shown.
2701 The source command is now capable of sourcing Python scripts.
2702 This feature is dependent on the debugger being build with Python
2705 Related to this enhancement is also the introduction of a new command
2706 "set script-extension" (see below).
2708 * New commands (for set/show, see "New options" below)
2710 record save [<FILENAME>]
2711 Save a file (in core file format) containing the process record
2712 execution log for replay debugging at a later time.
2714 record restore <FILENAME>
2715 Restore the process record execution log that was saved at an
2716 earlier time, for replay debugging.
2718 add-inferior [-copies <N>] [-exec <FILENAME>]
2721 clone-inferior [-copies <N>] [ID]
2722 Make a new inferior ready to execute the same program another
2723 inferior has loaded.
2728 maint info program-spaces
2729 List the program spaces loaded into GDB.
2731 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2732 show remote interrupt-sequence
2733 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2734 as the sequence to the remote target in order to interrupt the execution.
2735 Ctrl-C is a default. Some system prefers BREAK which is high level of
2736 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2737 Magic SysRq g. It is BREAK signal and character 'g'.
2739 set remote interrupt-on-connect [on | off]
2740 show remote interrupt-on-connect
2741 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2742 remote target when gdb connects to it. This is needed when you debug
2745 set remotebreak [on | off]
2747 Deprecated. Use "set/show remote interrupt-sequence" instead.
2749 tvariable $NAME [ = EXP ]
2750 Create or modify a trace state variable.
2753 List trace state variables and their values.
2755 delete tvariable $NAME ...
2756 Delete one or more trace state variables.
2759 Evaluate the given expressions without collecting anything into the
2760 trace buffer. (Valid in tracepoint actions only.)
2762 ftrace FN / FILE:LINE / *ADDR
2763 Define a fast tracepoint at the given function, line, or address.
2765 * New expression syntax
2767 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2768 GDB now parses 0b101010 identically with 42.
2772 set follow-exec-mode new|same
2773 show follow-exec-mode
2774 Control whether GDB reuses the same inferior across an exec call or
2775 creates a new one. This is useful to be able to restart the old
2776 executable after the inferior having done an exec call.
2778 set default-collect EXPR, ...
2779 show default-collect
2780 Define a list of expressions to be collected at each tracepoint.
2781 This is a useful way to ensure essential items are not overlooked,
2782 such as registers or a critical global variable.
2784 set disconnected-tracing
2785 show disconnected-tracing
2786 If set to 1, the target is instructed to continue tracing if it
2787 loses its connection to GDB. If 0, the target is to stop tracing
2790 set circular-trace-buffer
2791 show circular-trace-buffer
2792 If set to on, the target is instructed to use a circular trace buffer
2793 and discard the oldest trace frames instead of stopping the trace due
2794 to a full trace buffer. If set to off, the trace stops when the buffer
2795 fills up. Some targets may not support this.
2797 set script-extension off|soft|strict
2798 show script-extension
2799 If set to "off", the debugger does not perform any script language
2800 recognition, and all sourced files are assumed to be GDB scripts.
2801 If set to "soft" (the default), files are sourced according to
2802 filename extension, falling back to GDB scripts if the first
2804 If set to "strict", files are sourced according to filename extension.
2806 set ada trust-PAD-over-XVS on|off
2807 show ada trust-PAD-over-XVS
2808 If off, activate a workaround against a bug in the debugging information
2809 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2810 the GCC sources for more information about the GNAT encoding and
2811 PAD types in particular). It is always safe to set this option to
2812 off, but this introduces a slight performance penalty. The default
2815 * Python API Improvements
2817 ** GDB provides the new class gdb.LazyString. This is useful in
2818 some pretty-printing cases. The new method gdb.Value.lazy_string
2819 provides a simple way to create objects of this type.
2821 ** The fields returned by gdb.Type.fields now have an
2822 `is_base_class' attribute.
2824 ** The new method gdb.Type.range returns the range of an array type.
2826 ** The new method gdb.parse_and_eval can be used to parse and
2827 evaluate an expression.
2829 * New remote packets
2832 Define a trace state variable.
2835 Get the current value of a trace state variable.
2838 Set desired tracing behavior upon disconnection.
2841 Set the trace buffer to be linear or circular.
2844 Get data about the tracepoints currently in use.
2848 Process record now works correctly with hardware watchpoints.
2850 Multiple bug fixes have been made to the mips-irix port, making it
2851 much more reliable. In particular:
2852 - Debugging threaded applications is now possible again. Previously,
2853 GDB would hang while starting the program, or while waiting for
2854 the program to stop at a breakpoint.
2855 - Attaching to a running process no longer hangs.
2856 - An error occurring while loading a core file has been fixed.
2857 - Changing the value of the PC register now works again. This fixes
2858 problems observed when using the "jump" command, or when calling
2859 a function from GDB, or even when assigning a new value to $pc.
2860 - With the "finish" and "return" commands, the return value for functions
2861 returning a small array is now correctly printed.
2862 - It is now possible to break on shared library code which gets executed
2863 during a shared library init phase (code executed while executing
2864 their .init section). Previously, the breakpoint would have no effect.
2865 - GDB is now able to backtrace through the signal handler for
2866 non-threaded programs.
2868 PIE (Position Independent Executable) programs debugging is now supported.
2869 This includes debugging execution of PIC (Position Independent Code) shared
2870 libraries although for that, it should be possible to run such libraries as an
2873 *** Changes in GDB 7.0
2875 * GDB now has an interface for JIT compilation. Applications that
2876 dynamically generate code can create symbol files in memory and register
2877 them with GDB. For users, the feature should work transparently, and
2878 for JIT developers, the interface is documented in the GDB manual in the
2879 "JIT Compilation Interface" chapter.
2881 * Tracepoints may now be conditional. The syntax is as for
2882 breakpoints; either an "if" clause appended to the "trace" command,
2883 or the "condition" command is available. GDB sends the condition to
2884 the target for evaluation using the same bytecode format as is used
2885 for tracepoint actions.
2887 * The disassemble command now supports: an optional /r modifier, print the
2888 raw instructions in hex as well as in symbolic form, and an optional /m
2889 modifier to print mixed source+assembly.
2891 * Process record and replay
2893 In a architecture environment that supports ``process record and
2894 replay'', ``process record and replay'' target can record a log of
2895 the process execution, and replay it with both forward and reverse
2898 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2899 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2900 set execution-direction {forward|reverse}, for targets that support
2903 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2904 feature is available with a native GDB running on kernel version
2907 * GDB now has support for multi-byte and wide character sets on the
2908 target. Strings whose character type is wchar_t, char16_t, or
2909 char32_t are now correctly printed. GDB supports wide- and unicode-
2910 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2911 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2912 `printf'. This feature requires iconv to work properly; if your
2913 system does not have a working iconv, GDB can use GNU libiconv. See
2914 the installation instructions for more information.
2916 * GDB now supports automatic retrieval of shared library files from
2917 remote targets. To use this feature, specify a system root that begins
2918 with the `remote:' prefix, either via the `set sysroot' command or via
2919 the `--with-sysroot' configure-time option.
2921 * "info sharedlibrary" now takes an optional regex of libraries to show,
2922 and it now reports if a shared library has no debugging information.
2924 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2925 now complete on file names.
2927 * When completing in expressions, gdb will attempt to limit
2928 completions to allowable structure or union fields, where appropriate.
2929 For instance, consider:
2931 # struct example { int f1; double f2; };
2932 # struct example variable;
2935 If the user types TAB at the end of this command line, the available
2936 completions will be "f1" and "f2".
2938 * Inlined functions are now supported. They show up in backtraces, and
2939 the "step", "next", and "finish" commands handle them automatically.
2941 * GDB now supports the token-splicing (##) and stringification (#)
2942 operators when expanding macros. It also supports variable-arity
2945 * GDB now supports inspecting extra signal information, exported by
2946 the new $_siginfo convenience variable. The feature is currently
2947 implemented on linux ARM, i386 and amd64.
2949 * GDB can now display the VFP floating point registers and NEON vector
2950 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2951 can provide these registers (requires Linux 2.6.30 or later). Remote
2952 and simulator targets may also provide them.
2954 * New remote packets
2957 Search memory for a sequence of bytes.
2960 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2961 operation over reliable transport links. Use of this packet is
2962 controlled by the `set remote noack-packet' command.
2965 Kill the process with the specified process ID. Use this in preference
2966 to `k' when multiprocess protocol extensions are supported.
2969 Obtains additional operating system information
2973 Read or write additional signal information.
2975 * Removed remote protocol undocumented extension
2977 An undocumented extension to the remote protocol's `S' stop reply
2978 packet that permited the stub to pass a process id was removed.
2979 Remote servers should use the `T' stop reply packet instead.
2981 * GDB now supports multiple function calling conventions according to the
2982 DWARF-2 DW_AT_calling_convention function attribute.
2984 * The SH target utilizes the aforementioned change to distinguish between gcc
2985 and Renesas calling convention. It also adds the new CLI commands
2986 `set/show sh calling-convention'.
2988 * GDB can now read compressed debug sections, as produced by GNU gold
2989 with the --compress-debug-sections=zlib flag.
2991 * 64-bit core files are now supported on AIX.
2993 * Thread switching is now supported on Tru64.
2995 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2996 which will be allocated using malloc later in program execution.
2998 * The qXfer:libraries:read remote procotol packet now allows passing a
2999 list of section offsets.
3001 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3002 conditions handling signals delivered during attach or thread creation
3003 have also been fixed.
3005 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3006 From the user's standpoint, all unqualified instances of True and False
3007 are treated as the standard definitions, regardless of context.
3009 * GDB now parses C++ symbol and type names more flexibly. For
3012 template<typename T> class C { };
3015 GDB will now correctly handle all of:
3017 ptype C<char const *>
3018 ptype C<char const*>
3019 ptype C<const char *>
3020 ptype C<const char*>
3022 * New features in the GDB remote stub, gdbserver
3024 - The "--wrapper" command-line argument tells gdbserver to use a
3025 wrapper program to launch programs for debugging.
3027 - On PowerPC and S/390 targets, it is now possible to use a single
3028 gdbserver executable to debug both 32-bit and 64-bit programs.
3029 (This requires gdbserver itself to be built as a 64-bit executable.)
3031 - gdbserver uses the new noack protocol mode for TCP connections to
3032 reduce communications latency, if also supported and enabled in GDB.
3034 - Support for the sparc64-linux-gnu target is now included in
3037 - The amd64-linux build of gdbserver now supports debugging both
3038 32-bit and 64-bit programs.
3040 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3041 now support hardware watchpoints, and will use them automatically
3046 GDB now has support for scripting using Python. Whether this is
3047 available is determined at configure time.
3049 New GDB commands can now be written in Python.
3051 * Ada tasking support
3053 Ada tasks can now be inspected in GDB. The following commands have
3057 Print the list of Ada tasks.
3059 Print detailed information about task number N.
3061 Print the task number of the current task.
3063 Switch the context of debugging to task number N.
3065 * Support for user-defined prefixed commands. The "define" command can
3066 add new commands to existing prefixes, e.g. "target".
3068 * Multi-inferior, multi-process debugging.
3070 GDB now has generalized support for multi-inferior debugging. See
3071 "Debugging Multiple Inferiors" in the manual for more information.
3072 Although availability still depends on target support, the command
3073 set is more uniform now. The GNU/Linux specific multi-forks support
3074 has been migrated to this new framework. This implied some user
3075 visible changes; see "New commands" and also "Removed commands"
3078 * Target descriptions can now describe the target OS ABI. See the
3079 "Target Description Format" section in the user manual for more
3082 * Target descriptions can now describe "compatible" architectures
3083 to indicate that the target can execute applications for a different
3084 architecture in addition to those for the main target architecture.
3085 See the "Target Description Format" section in the user manual for
3088 * Multi-architecture debugging.
3090 GDB now includes general supports for debugging applications on
3091 hybrid systems that use more than one single processor architecture
3092 at the same time. Each such hybrid architecture still requires
3093 specific support to be added. The only hybrid architecture supported
3094 in this version of GDB is the Cell Broadband Engine.
3096 * GDB now supports integrated debugging of Cell/B.E. applications that
3097 use both the PPU and SPU architectures. To enable support for hybrid
3098 Cell/B.E. debugging, you need to configure GDB to support both the
3099 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3100 --enable-targets configure option.
3102 * Non-stop mode debugging.
3104 For some targets, GDB now supports an optional mode of operation in
3105 which you can examine stopped threads while other threads continue
3106 to execute freely. This is referred to as non-stop mode, with the
3107 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3108 section in the user manual for more information.
3110 To be able to support remote non-stop debugging, a remote stub needs
3111 to implement the non-stop mode remote protocol extensions, as
3112 described in the "Remote Non-Stop" section of the user manual. The
3113 GDB remote stub, gdbserver, has been adjusted to support these
3114 extensions on linux targets.
3116 * New commands (for set/show, see "New options" below)
3118 catch syscall [NAME(S) | NUMBER(S)]
3119 Catch system calls. Arguments, which should be names of system
3120 calls or their numbers, mean catch only those syscalls. Without
3121 arguments, every syscall will be caught. When the inferior issues
3122 any of the specified syscalls, GDB will stop and announce the system
3123 call, both when it is called and when its call returns. This
3124 feature is currently available with a native GDB running on the
3125 Linux Kernel, under the following architectures: x86, x86_64,
3126 PowerPC and PowerPC64.
3128 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3130 Search memory for a sequence of bytes.
3132 maint set python print-stack
3133 maint show python print-stack
3134 Show a stack trace when an error is encountered in a Python script.
3137 Invoke CODE by passing it to the Python interpreter.
3142 These allow macros to be defined, undefined, and listed
3146 Show operating system information about processes.
3149 List the inferiors currently under GDB's control.
3152 Switch focus to inferior number NUM.
3155 Detach from inferior number NUM.
3158 Kill inferior number NUM.
3162 set spu stop-on-load
3163 show spu stop-on-load
3164 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3166 set spu auto-flush-cache
3167 show spu auto-flush-cache
3168 Control whether to automatically flush the software-managed cache
3169 during Cell/B.E. debugging.
3171 set sh calling-convention
3172 show sh calling-convention
3173 Control the calling convention used when calling SH target functions.
3176 show debug timestamp
3177 Control display of timestamps with GDB debugging output.
3179 set disassemble-next-line
3180 show disassemble-next-line
3181 Control display of disassembled source lines or instructions when
3184 set remote noack-packet
3185 show remote noack-packet
3186 Set/show the use of remote protocol QStartNoAckMode packet. See above
3187 under "New remote packets."
3189 set remote query-attached-packet
3190 show remote query-attached-packet
3191 Control use of remote protocol `qAttached' (query-attached) packet.
3193 set remote read-siginfo-object
3194 show remote read-siginfo-object
3195 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3198 set remote write-siginfo-object
3199 show remote write-siginfo-object
3200 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3203 set remote reverse-continue
3204 show remote reverse-continue
3205 Control use of remote protocol 'bc' (reverse-continue) packet.
3207 set remote reverse-step
3208 show remote reverse-step
3209 Control use of remote protocol 'bs' (reverse-step) packet.
3211 set displaced-stepping
3212 show displaced-stepping
3213 Control displaced stepping mode. Displaced stepping is a way to
3214 single-step over breakpoints without removing them from the debuggee.
3215 Also known as "out-of-line single-stepping".
3218 show debug displaced
3219 Control display of debugging info for displaced stepping.
3221 maint set internal-error
3222 maint show internal-error
3223 Control what GDB does when an internal error is detected.
3225 maint set internal-warning
3226 maint show internal-warning
3227 Control what GDB does when an internal warning is detected.
3232 Use a wrapper program to launch programs for debugging.
3234 set multiple-symbols (all|ask|cancel)
3235 show multiple-symbols
3236 The value of this variable can be changed to adjust the debugger behavior
3237 when an expression or a breakpoint location contains an ambiguous symbol
3238 name (an overloaded function name, for instance).
3240 set breakpoint always-inserted
3241 show breakpoint always-inserted
3242 Keep breakpoints always inserted in the target, as opposed to inserting
3243 them when resuming the target, and removing them when the target stops.
3244 This option can improve debugger performance on slow remote targets.
3246 set arm fallback-mode (arm|thumb|auto)
3247 show arm fallback-mode
3248 set arm force-mode (arm|thumb|auto)
3250 These commands control how ARM GDB determines whether instructions
3251 are ARM or Thumb. The default for both settings is auto, which uses
3252 the current CPSR value for instructions without symbols; previous
3253 versions of GDB behaved as if "set arm fallback-mode arm".
3255 set disable-randomization
3256 show disable-randomization
3257 Standalone programs run with the virtual address space randomization enabled
3258 by default on some platforms. This option keeps the addresses stable across
3259 multiple debugging sessions.
3263 Control whether other threads are stopped or not when some thread hits
3268 Requests that asynchronous execution is enabled in the target, if available.
3269 In this case, it's possible to resume target in the background, and interact
3270 with GDB while the target is running. "show target-async" displays the
3271 current state of asynchronous execution of the target.
3273 set target-wide-charset
3274 show target-wide-charset
3275 The target-wide-charset is the name of the character set that GDB
3276 uses when printing characters whose type is wchar_t.
3278 set tcp auto-retry (on|off)
3280 set tcp connect-timeout
3281 show tcp connect-timeout
3282 These commands allow GDB to retry failed TCP connections to a remote stub
3283 with a specified timeout period; this is useful if the stub is launched
3284 in parallel with GDB but may not be ready to accept connections immediately.
3286 set libthread-db-search-path
3287 show libthread-db-search-path
3288 Control list of directories which GDB will search for appropriate
3291 set schedule-multiple (on|off)
3292 show schedule-multiple
3293 Allow GDB to resume all threads of all processes or only threads of
3294 the current process.
3298 Use more aggressive caching for accesses to the stack. This improves
3299 performance of remote debugging (particularly backtraces) without
3300 affecting correctness.
3302 set interactive-mode (on|off|auto)
3303 show interactive-mode
3304 Control whether GDB runs in interactive mode (on) or not (off).
3305 When in interactive mode, GDB waits for the user to answer all
3306 queries. Otherwise, GDB does not wait and assumes the default
3307 answer. When set to auto (the default), GDB determines which
3308 mode to use based on the stdin settings.
3313 For program forks, this is replaced by the new more generic `info
3314 inferiors' command. To list checkpoints, you can still use the
3315 `info checkpoints' command, which was an alias for the `info forks'
3319 Replaced by the new `inferior' command. To switch between
3320 checkpoints, you can still use the `restart' command, which was an
3321 alias for the `fork' command.
3324 This is removed, since some targets don't have a notion of
3325 processes. To switch between processes, you can still use the
3326 `inferior' command using GDB's own inferior number.
3329 For program forks, this is replaced by the new more generic `kill
3330 inferior' command. To delete a checkpoint, you can still use the
3331 `delete checkpoint' command, which was an alias for the `delete
3335 For program forks, this is replaced by the new more generic `detach
3336 inferior' command. To detach a checkpoint, you can still use the
3337 `detach checkpoint' command, which was an alias for the `detach
3340 * New native configurations
3342 x86/x86_64 Darwin i[34567]86-*-darwin*
3344 x86_64 MinGW x86_64-*-mingw*
3348 Lattice Mico32 lm32-*
3349 x86 DICOS i[34567]86-*-dicos*
3350 x86_64 DICOS x86_64-*-dicos*
3353 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3354 (mingw32ce) debugging.
3360 These commands were actually not implemented on any target.
3362 *** Changes in GDB 6.8
3364 * New native configurations
3366 NetBSD/hppa hppa*-*netbsd*
3367 Xtensa GNU/Linux xtensa*-*-linux*
3371 NetBSD/hppa hppa*-*-netbsd*
3372 Xtensa GNU/Lunux xtensa*-*-linux*
3374 * Change in command line behavior -- corefiles vs. process ids.
3376 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3377 attaching to process NUMBER fails, GDB no longer attempts to open a
3378 core file named NUMBER. Attaching to a program using the -c option
3379 is no longer supported. Instead, use the '-p' or '--pid' options.
3381 * GDB can now be built as a native debugger for debugging Windows x86
3382 (mingw32) Portable Executable (PE) programs.
3384 * Pending breakpoints no longer change their number when their address
3387 * GDB now supports breakpoints with multiple locations,
3388 including breakpoints on C++ constructors, inside C++ templates,
3389 and in inlined functions.
3391 * GDB's ability to debug optimized code has been improved. GDB more
3392 accurately identifies function bodies and lexical blocks that occupy
3393 more than one contiguous range of addresses.
3395 * Target descriptions can now describe registers for PowerPC.
3397 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3398 registers on PowerPC targets.
3400 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3401 targets even when the libthread_db library is not available.
3403 * The GDB remote stub, gdbserver, now supports the new file transfer
3404 commands (remote put, remote get, and remote delete).
3406 * The GDB remote stub, gdbserver, now supports run and attach in
3407 extended-remote mode.
3409 * hppa*64*-*-hpux11* target broken
3410 The debugger is unable to start a program and fails with the following
3411 error: "Error trying to get information about dynamic linker".
3412 The gdb-6.7 release is also affected.
3414 * GDB now supports the --enable-targets= configure option to allow
3415 building a single GDB executable that supports multiple remote
3416 target architectures.
3418 * GDB now supports debugging C and C++ programs which use the
3419 Decimal Floating Point extension. In addition, the PowerPC target
3420 now has a set of pseudo-registers to inspect decimal float values
3421 stored in two consecutive float registers.
3423 * The -break-insert MI command can optionally create pending
3426 * Improved support for debugging Ada
3427 Many improvements to the Ada language support have been made. These
3429 - Better support for Ada2005 interface types
3430 - Improved handling of arrays and slices in general
3431 - Better support for Taft-amendment types
3432 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3434 - Improved command completion in Ada
3437 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3442 set print frame-arguments (all|scalars|none)
3443 show print frame-arguments
3444 The value of this variable can be changed to control which argument
3445 values should be printed by the debugger when displaying a frame.
3450 Transfer files to and from a remote target, and delete remote files.
3457 Transfer files to and from a remote target, and delete remote files.
3459 * New remote packets
3466 Open, close, read, write, and delete files on the remote system.
3469 Attach to an existing process on the remote system, in extended-remote
3473 Run a new process on the remote system, in extended-remote mode.
3475 *** Changes in GDB 6.7
3477 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3478 bfd, libiberty and opcodes, as revealed by static analysis donated by
3479 Coverity, Inc. (http://scan.coverity.com).
3481 * When looking up multiply-defined global symbols, GDB will now prefer the
3482 symbol definition in the current shared library if it was built using the
3483 -Bsymbolic linker option.
3485 * When the Text User Interface (TUI) is not configured, GDB will now
3486 recognize the -tui command-line option and print a message that the TUI
3489 * The GDB remote stub, gdbserver, now has lower overhead for high
3490 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3492 * GDB for MIPS targets now autodetects whether a remote target provides
3493 32-bit or 64-bit register values.
3495 * Support for C++ member pointers has been improved.
3497 * GDB now understands XML target descriptions, which specify the
3498 target's overall architecture. GDB can read a description from
3499 a local file or over the remote serial protocol.
3501 * Vectors of single-byte data use a new integer type which is not
3502 automatically displayed as character or string data.
3504 * The /s format now works with the print command. It displays
3505 arrays of single-byte integers and pointers to single-byte integers
3508 * Target descriptions can now describe target-specific registers,
3509 for architectures which have implemented the support (currently
3510 only ARM, M68K, and MIPS).
3512 * GDB and the GDB remote stub, gdbserver, now support the XScale
3515 * The GDB remote stub, gdbserver, has been updated to support
3516 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3517 has been rewritten to use the standard GDB remote protocol.
3519 * GDB can now step into C++ functions which are called through thunks.
3521 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3523 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3524 layout. It also supports a TextSeg= and DataSeg= response when only
3525 segment base addresses (rather than offsets) are available.
3527 * The /i format now outputs any trailing branch delay slot instructions
3528 immediately following the last instruction within the count specified.
3530 * The GDB remote protocol "T" stop reply packet now supports a
3531 "library" response. Combined with the new "qXfer:libraries:read"
3532 packet, this response allows GDB to debug shared libraries on targets
3533 where the operating system manages the list of loaded libraries (e.g.
3534 Windows and SymbianOS).
3536 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3537 (DLLs) on Windows and Windows CE targets.
3539 * GDB now supports a faster verification that a .debug file matches its binary
3540 according to its build-id signature, if the signature is present.
3546 Enable or disable hardware flow control (RTS/CTS) on the serial port
3547 when debugging using remote targets.
3549 set mem inaccessible-by-default
3550 show mem inaccessible-by-default
3551 If the target supplies a memory map, for instance via the remote
3552 protocol's "qXfer:memory-map:read" packet, setting this variable
3553 prevents GDB from accessing memory outside the memory map. This
3554 is useful for targets with memory mapped registers or which react
3555 badly to accesses of unmapped address space.
3557 set breakpoint auto-hw
3558 show breakpoint auto-hw
3559 If the target supplies a memory map, for instance via the remote
3560 protocol's "qXfer:memory-map:read" packet, setting this variable
3561 lets GDB use hardware breakpoints automatically for memory regions
3562 where it can not use software breakpoints. This covers both the
3563 "break" command and internal breakpoints used for other commands
3564 including "next" and "finish".
3567 catch exception unhandled
3568 Stop the program execution when Ada exceptions are raised.
3571 Stop the program execution when an Ada assertion failed.
3575 Set an alternate system root for target files. This is a more
3576 general version of "set solib-absolute-prefix", which is now
3577 an alias to "set sysroot".
3580 Provide extended SPU facility status information. This set of
3581 commands is available only when debugging the Cell/B.E. SPU
3584 * New native configurations
3586 OpenBSD/sh sh*-*openbsd*
3589 unset tdesc filename
3591 Use the specified local file as an XML target description, and do
3592 not query the target for its built-in description.
3596 OpenBSD/sh sh*-*-openbsd*
3597 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3598 Toshiba Media Processor mep-elf
3600 * New remote packets
3603 Ignore the specified signals; pass them directly to the debugged program
3604 without stopping other threads or reporting them to GDB.
3606 qXfer:features:read:
3607 Read an XML target description from the target, which describes its
3612 Read or write contents of an spufs file on the target system. These
3613 packets are available only on the Cell/B.E. SPU architecture.
3615 qXfer:libraries:read:
3616 Report the loaded shared libraries. Combined with new "T" packet
3617 response, this packet allows GDB to debug shared libraries on
3618 targets where the operating system manages the list of loaded
3619 libraries (e.g. Windows and SymbianOS).
3623 Support for these obsolete configurations has been removed.
3631 i[34567]86-*-lynxos*
3632 i[34567]86-*-netware*
3633 i[34567]86-*-sco3.2v5*
3634 i[34567]86-*-sco3.2v4*
3636 i[34567]86-*-sysv4.2*
3639 i[34567]86-*-unixware2*
3640 i[34567]86-*-unixware*
3649 * Other removed features
3656 Various m68k-only ROM monitors.
3663 Various Renesas ROM monitors and debugging interfaces for SH and
3668 Support for a Macraigor serial interface to on-chip debugging.
3669 GDB does not directly support the newer parallel or USB
3674 A debug information format. The predecessor to DWARF 2 and
3675 DWARF 3, which are still supported.
3677 Support for the HP aCC compiler on HP-UX/PA-RISC
3679 SOM-encapsulated symbolic debugging information, automatic
3680 invocation of pxdb, and the aCC custom C++ ABI. This does not
3681 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3682 with aCC can still be debugged on an assembly level.
3684 MIPS ".pdr" sections
3686 A MIPS-specific format used to describe stack frame layout
3687 in debugging information.
3691 GDB could work with an older version of Guile to debug
3692 the interpreter and Scheme programs running in it.
3694 set mips stack-arg-size
3695 set mips saved-gpreg-size
3697 Use "set mips abi" to control parameter passing for MIPS.
3699 *** Changes in GDB 6.6
3704 Cell Broadband Engine SPU spu-elf
3706 * GDB can now be configured as a cross-debugger targeting native Windows
3707 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3708 running on a Windows system over TCP/IP to debug Windows programs.
3710 * The GDB remote stub, gdbserver, has been updated to support Windows and
3711 Cygwin debugging. Both single-threaded and multi-threaded programs are
3714 * The "set trust-readonly-sections" command works again. This command was
3715 broken in GDB 6.3, 6.4, and 6.5.
3717 * The "load" command now supports writing to flash memory, if the remote
3718 stub provides the required support.
3720 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3721 longer requires symbolic debug information (e.g. DWARF-2).
3726 unset substitute-path
3727 show substitute-path
3728 Manage a list of substitution rules that GDB uses to rewrite the name
3729 of the directories where the sources are located. This can be useful
3730 for instance when the sources were moved to a different location
3731 between compilation and debugging.
3735 Print each CLI command as it is executed. Each command is prefixed with
3736 a number of `+' symbols representing the nesting depth.
3737 The source command now has a `-v' option to enable the same feature.
3741 The ARM Demon monitor support (RDP protocol, "target rdp").
3743 Kernel Object Display, an embedded debugging feature which only worked with
3744 an obsolete version of Cisco IOS.
3746 The 'set download-write-size' and 'show download-write-size' commands.
3748 * New remote packets
3751 Tell a stub about GDB client features, and request remote target features.
3752 The first feature implemented is PacketSize, which allows the target to
3753 specify the size of packets it can handle - to minimize the number of
3754 packets required and improve performance when connected to a remote
3758 Fetch an OS auxilliary vector from the remote stub. This packet is a
3759 more efficient replacement for qPart:auxv:read.
3761 qXfer:memory-map:read:
3762 Fetch a memory map from the remote stub, including information about
3763 RAM, ROM, and flash memory devices.
3768 Erase and program a flash memory device.
3770 * Removed remote packets
3773 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3774 used it, and only gdbserver implemented it.
3776 *** Changes in GDB 6.5
3780 Renesas M32C/M16C m32c-elf
3782 Morpho Technologies ms1 ms1-elf
3786 init-if-undefined Initialize a convenience variable, but
3787 only if it doesn't already have a value.
3789 The following commands are presently only implemented for native GNU/Linux:
3791 checkpoint Save a snapshot of the program state.
3793 restart <n> Return the program state to a
3794 previously saved state.
3796 info checkpoints List currently saved checkpoints.
3798 delete-checkpoint <n> Delete a previously saved checkpoint.
3800 set|show detach-on-fork Tell gdb whether to detach from a newly
3801 forked process, or to keep debugging it.
3803 info forks List forks of the user program that
3804 are available to be debugged.
3806 fork <n> Switch to debugging one of several
3807 forks of the user program that are
3808 available to be debugged.
3810 delete-fork <n> Delete a fork from the list of forks
3811 that are available to be debugged (and
3812 kill the forked process).
3814 detach-fork <n> Delete a fork from the list of forks
3815 that are available to be debugged (and
3816 allow the process to continue).
3820 Morpho Technologies ms2 ms1-elf
3822 * Improved Windows host support
3824 GDB now builds as a cross debugger hosted on i686-mingw32, including
3825 native console support, and remote communications using either
3826 network sockets or serial ports.
3828 * Improved Modula-2 language support
3830 GDB can now print most types in the Modula-2 syntax. This includes:
3831 basic types, set types, record types, enumerated types, range types,
3832 pointer types and ARRAY types. Procedure var parameters are correctly
3833 printed and hexadecimal addresses and character constants are also
3834 written in the Modula-2 syntax. Best results can be obtained by using
3835 GNU Modula-2 together with the -gdwarf-2 command line option.
3839 The ARM rdi-share module.
3841 The Netware NLM debug server.
3843 *** Changes in GDB 6.4
3845 * New native configurations
3847 OpenBSD/arm arm*-*-openbsd*
3848 OpenBSD/mips64 mips64-*-openbsd*
3852 Morpho Technologies ms1 ms1-elf
3854 * New command line options
3856 --batch-silent As for --batch, but totally silent.
3857 --return-child-result The debugger will exist with the same value
3858 the child (debugged) program exited with.
3859 --eval-command COMMAND, -ex COMMAND
3860 Execute a single GDB CLI command. This may be
3861 specified multiple times and in conjunction
3862 with the --command (-x) option.
3864 * Deprecated commands removed
3866 The following commands, that were deprecated in 2000, have been
3870 set|show arm disassembly-flavor set|show arm disassembler
3871 othernames set arm disassembler
3872 set|show remotedebug set|show debug remote
3873 set|show archdebug set|show debug arch
3874 set|show eventdebug set|show debug event
3877 * New BSD user-level threads support
3879 It is now possible to debug programs using the user-level threads
3880 library on OpenBSD and FreeBSD. Currently supported (target)
3883 FreeBSD/amd64 x86_64-*-freebsd*
3884 FreeBSD/i386 i386-*-freebsd*
3885 OpenBSD/i386 i386-*-openbsd*
3887 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3888 are not yet supported.
3890 * New support for Matsushita MN10300 w/sim added
3891 (Work in progress). mn10300-elf.
3893 * REMOVED configurations and files
3895 VxWorks and the XDR protocol *-*-vxworks
3896 Motorola MCORE mcore-*-*
3897 National Semiconductor NS32000 ns32k-*-*
3899 * New "set print array-indexes" command
3901 After turning this setting "on", GDB prints the index of each element
3902 when displaying arrays. The default is "off" to preserve the previous
3905 * VAX floating point support
3907 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3909 * User-defined command support
3911 In addition to using $arg0..$arg9 for argument passing, it is now possible
3912 to use $argc to determine now many arguments have been passed. See the
3913 section on user-defined commands in the user manual for more information.
3915 *** Changes in GDB 6.3:
3917 * New command line option
3919 GDB now accepts -l followed by a number to set the timeout for remote
3922 * GDB works with GCC -feliminate-dwarf2-dups
3924 GDB now supports a more compact representation of DWARF-2 debug
3925 information using DW_FORM_ref_addr references. These are produced
3926 by GCC with the option -feliminate-dwarf2-dups and also by some
3927 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3928 to use -feliminate-dwarf2-dups.
3930 * Internationalization
3932 When supported by the host system, GDB will be built with
3933 internationalization (libintl). The task of marking up the sources is
3934 continued, we're looking forward to our first translation.
3938 Initial support for debugging programs compiled with the GNAT
3939 implementation of the Ada programming language has been integrated
3940 into GDB. In this release, support is limited to expression evaluation.
3942 * New native configurations
3944 GNU/Linux/m32r m32r-*-linux-gnu
3948 GDB's remote protocol now includes support for the 'p' packet. This
3949 packet is used to fetch individual registers from a remote inferior.
3951 * END-OF-LIFE registers[] compatibility module
3953 GDB's internal register infrastructure has been completely rewritten.
3954 The new infrastructure making possible the implementation of key new
3955 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3958 GDB 6.3 will be the last release to include the the registers[]
3959 compatibility module that allowed out-of-date configurations to
3960 continue to work. This change directly impacts the following
3970 powerpc bdm protocol
3972 Unless there is activity to revive these configurations, they will be
3973 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3975 * OBSOLETE configurations and files
3977 Configurations that have been declared obsolete in this release have
3978 been commented out. Unless there is activity to revive these
3979 configurations, the next release of GDB will have their sources
3980 permanently REMOVED.
3989 *** Changes in GDB 6.2.1:
3991 * MIPS `break main; run' gave an heuristic-fence-post warning
3993 When attempting to run even a simple program, a warning about
3994 heuristic-fence-post being hit would be reported. This problem has
3997 * MIPS IRIX 'long double' crashed GDB
3999 When examining a long double variable, GDB would get a segmentation
4000 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4001 IRIX long double values).
4005 A bug in the VAX stack code was causing problems with the "next"
4006 command. This problem has been fixed.
4008 *** Changes in GDB 6.2:
4010 * Fix for ``many threads''
4012 On GNU/Linux systems that use the NPTL threads library, a program
4013 rapidly creating and deleting threads would confuse GDB leading to the
4016 ptrace: No such process.
4017 thread_db_get_info: cannot get thread info: generic error
4019 This problem has been fixed.
4021 * "-async" and "-noasync" options removed.
4023 Support for the broken "-noasync" option has been removed (it caused
4026 * New ``start'' command.
4028 This command runs the program until the begining of the main procedure.
4030 * New BSD Kernel Data Access Library (libkvm) interface
4032 Using ``target kvm'' it is now possible to debug kernel core dumps and
4033 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4034 platforms. Currently supported (native-only) configurations are:
4036 FreeBSD/amd64 x86_64-*-freebsd*
4037 FreeBSD/i386 i?86-*-freebsd*
4038 NetBSD/i386 i?86-*-netbsd*
4039 NetBSD/m68k m68*-*-netbsd*
4040 NetBSD/sparc sparc-*-netbsd*
4041 OpenBSD/amd64 x86_64-*-openbsd*
4042 OpenBSD/i386 i?86-*-openbsd*
4043 OpenBSD/m68k m68*-openbsd*
4044 OpenBSD/sparc sparc-*-openbsd*
4046 * Signal trampoline code overhauled
4048 Many generic problems with GDB's signal handling code have been fixed.
4049 These include: backtraces through non-contiguous stacks; recognition
4050 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4051 call; backtrace through a signal trampoline; step into and out of
4052 signal handlers; and single-stepping in the signal trampoline.
4054 Please note that kernel bugs are a limiting factor here. These
4055 features have been shown to work on an s390 GNU/Linux system that
4056 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4058 * Cygwin support for DWARF 2 added.
4060 * New native configurations
4062 GNU/Linux/hppa hppa*-*-linux*
4063 OpenBSD/hppa hppa*-*-openbsd*
4064 OpenBSD/m68k m68*-*-openbsd*
4065 OpenBSD/m88k m88*-*-openbsd*
4066 OpenBSD/powerpc powerpc-*-openbsd*
4067 NetBSD/vax vax-*-netbsd*
4068 OpenBSD/vax vax-*-openbsd*
4070 * END-OF-LIFE frame compatibility module
4072 GDB's internal frame infrastructure has been completely rewritten.
4073 The new infrastructure making it possible to support key new features
4074 including DWARF 2 Call Frame Information. To aid in the task of
4075 migrating old configurations to this new infrastructure, a
4076 compatibility module, that allowed old configurations to continue to
4077 work, was also included.
4079 GDB 6.2 will be the last release to include this frame compatibility
4080 module. This change directly impacts the following configurations:
4090 Unless there is activity to revive these configurations, they will be
4091 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4093 * REMOVED configurations and files
4095 Sun 3, running SunOS 3 m68*-*-sunos3*
4096 Sun 3, running SunOS 4 m68*-*-sunos4*
4097 Sun 2, running SunOS 3 m68000-*-sunos3*
4098 Sun 2, running SunOS 4 m68000-*-sunos4*
4099 Motorola 680x0 running LynxOS m68*-*-lynxos*
4100 AT&T 3b1/Unix pc m68*-att-*
4101 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4102 decstation mips-dec-* mips-little-*
4103 riscos mips-*-riscos* mips-*-sysv*
4104 sonymips mips-sony-*
4105 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4107 *** Changes in GDB 6.1.1:
4109 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4111 The TUI (Text-mode User Interface) is now built as part of a default
4112 GDB configuration. It is enabled by either selecting the TUI with the
4113 command line option "-i=tui" or by running the separate "gdbtui"
4114 program. For more information on the TUI, see the manual "Debugging
4117 * Pending breakpoint support (also included in GDB 6.1)
4119 Support has been added to allow you to specify breakpoints in shared
4120 libraries that have not yet been loaded. If a breakpoint location
4121 cannot be found, and the "breakpoint pending" option is set to auto,
4122 GDB queries you if you wish to make the breakpoint pending on a future
4123 shared-library load. If and when GDB resolves the breakpoint symbol,
4124 the pending breakpoint is removed as one or more regular breakpoints
4127 Pending breakpoints are very useful for GCJ Java debugging.
4129 * Fixed ISO-C build problems
4131 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4132 non ISO-C code that stopped them being built using a more strict ISO-C
4133 compiler (e.g., IBM's C compiler).
4135 * Fixed build problem on IRIX 5
4137 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4138 wasn't able to compile compile on an IRIX 5 system.
4140 * Added execute permission to gdb/gdbserver/configure
4142 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4143 permission. This bug would cause configure to fail on a number of
4144 systems (Solaris, IRIX). Ref: server/519.
4146 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4148 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4149 has been updated to use constant array sizes.
4151 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4153 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4154 its generated DWARF Call Frame Info. This encoding was causing GDB to
4155 panic, that panic has been fixed. Ref: gdb/1628.
4157 * Fixed a problem when examining parameters in shared library code.
4159 When examining parameters in optimized shared library code generated
4160 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4161 not available''. GDB now correctly displays the variable's value.
4163 *** Changes in GDB 6.1:
4165 * Removed --with-mmalloc
4167 Support for the mmalloc memory manager has been removed, as it
4168 conflicted with the internal gdb byte cache.
4170 * Changes in AMD64 configurations
4172 The AMD64 target now includes the %cs and %ss registers. As a result
4173 the AMD64 remote protocol has changed; this affects the floating-point
4174 and SSE registers. If you rely on those registers for your debugging,
4175 you should upgrade gdbserver on the remote side.
4177 * Revised SPARC target
4179 The SPARC target has been completely revised, incorporating the
4180 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4181 support for LynxOS and SunOS 4 has been dropped. Calling functions
4182 from within GDB on operating systems with a non-executable stack
4183 (Solaris, OpenBSD) now works.
4187 GDB has a new C++ demangler which does a better job on the mangled
4188 names generated by current versions of g++. It also runs faster, so
4189 with this and other changes gdb should now start faster on large C++
4192 * DWARF 2 Location Expressions
4194 GDB support for location expressions has been extended to support function
4195 arguments and frame bases. Older versions of GDB could crash when they
4198 * C++ nested types and namespaces
4200 GDB's support for nested types and namespaces in C++ has been
4201 improved, especially if you use the DWARF 2 debugging format. (This
4202 is the default for recent versions of GCC on most platforms.)
4203 Specifically, if you have a class "Inner" defined within a class or
4204 namespace "Outer", then GDB realizes that the class's name is
4205 "Outer::Inner", not simply "Inner". This should greatly reduce the
4206 frequency of complaints about not finding RTTI symbols. In addition,
4207 if you are stopped at inside of a function defined within a namespace,
4208 GDB modifies its name lookup accordingly.
4210 * New native configurations
4212 NetBSD/amd64 x86_64-*-netbsd*
4213 OpenBSD/amd64 x86_64-*-openbsd*
4214 OpenBSD/alpha alpha*-*-openbsd*
4215 OpenBSD/sparc sparc-*-openbsd*
4216 OpenBSD/sparc64 sparc64-*-openbsd*
4218 * New debugging protocols
4220 M32R with SDI protocol m32r-*-elf*
4222 * "set prompt-escape-char" command deleted.
4224 The command "set prompt-escape-char" has been deleted. This command,
4225 and its very obscure effet on GDB's prompt, was never documented,
4226 tested, nor mentioned in the NEWS file.
4228 * OBSOLETE configurations and files
4230 Configurations that have been declared obsolete in this release have
4231 been commented out. Unless there is activity to revive these
4232 configurations, the next release of GDB will have their sources
4233 permanently REMOVED.
4235 Sun 3, running SunOS 3 m68*-*-sunos3*
4236 Sun 3, running SunOS 4 m68*-*-sunos4*
4237 Sun 2, running SunOS 3 m68000-*-sunos3*
4238 Sun 2, running SunOS 4 m68000-*-sunos4*
4239 Motorola 680x0 running LynxOS m68*-*-lynxos*
4240 AT&T 3b1/Unix pc m68*-att-*
4241 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4242 decstation mips-dec-* mips-little-*
4243 riscos mips-*-riscos* mips-*-sysv*
4244 sonymips mips-sony-*
4245 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4247 * REMOVED configurations and files
4249 SGI Irix-4.x mips-sgi-irix4 or iris4
4250 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4251 Z8000 simulator z8k-zilog-none or z8ksim
4252 Matsushita MN10200 w/simulator mn10200-*-*
4253 H8/500 simulator h8500-hitachi-hms or h8500hms
4254 HP/PA running BSD hppa*-*-bsd*
4255 HP/PA running OSF/1 hppa*-*-osf*
4256 HP/PA Pro target hppa*-*-pro*
4257 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4258 386BSD i[3456]86-*-bsd*
4259 Sequent family i[3456]86-sequent-sysv4*
4260 i[3456]86-sequent-sysv*
4261 i[3456]86-sequent-bsd*
4262 SPARC running LynxOS sparc-*-lynxos*
4263 SPARC running SunOS 4 sparc-*-sunos4*
4264 Tsqware Sparclet sparclet-*-*
4265 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4267 *** Changes in GDB 6.0:
4271 Support for debugging the Objective-C programming language has been
4272 integrated into GDB.
4274 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4276 DWARF 2's Call Frame Information makes available compiler generated
4277 information that more exactly describes the program's run-time stack.
4278 By using this information, GDB is able to provide more robust stack
4281 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4282 have been updated to use a new backtrace mechanism which includes
4283 DWARF 2 CFI support.
4287 GDB's remote protocol has been extended to include support for hosted
4288 file I/O (where the remote target uses GDB's file system). See GDB's
4289 remote protocol documentation for details.
4291 * All targets using the new architecture framework.
4293 All of GDB's targets have been updated to use the new internal
4294 architecture framework. The way is now open for future GDB releases
4295 to include cross-architecture native debugging support (i386 on amd64,
4298 * GNU/Linux's Thread Local Storage (TLS)
4300 GDB now includes support for for the GNU/Linux implementation of
4301 per-thread variables.
4303 * GNU/Linux's Native POSIX Thread Library (NPTL)
4305 GDB's thread code has been updated to work with either the new
4306 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4308 * Separate debug info.
4310 GDB, in conjunction with BINUTILS, now supports a mechanism for
4311 automatically loading debug information from a separate file. Instead
4312 of shipping full debug and non-debug versions of system libraries,
4313 system integrators can now instead ship just the stripped libraries
4314 and optional debug files.
4316 * DWARF 2 Location Expressions
4318 DWARF 2 Location Expressions allow the compiler to more completely
4319 describe the location of variables (even in optimized code) to the
4322 GDB now includes preliminary support for location expressions (support
4323 for DW_OP_piece is still missing).
4327 A number of long standing bugs that caused GDB to die while starting a
4328 Java application have been fixed. GDB's Java support is now
4329 considered "useable".
4331 * GNU/Linux support for fork, vfork, and exec.
4333 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4334 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4337 * GDB supports logging output to a file
4339 There are two new commands, "set logging" and "show logging", which can be
4340 used to capture GDB's output to a file.
4342 * The meaning of "detach" has changed for gdbserver
4344 The "detach" command will now resume the application, as documented. To
4345 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4348 * d10v, m68hc11 `regs' command deprecated
4350 The `info registers' command has been updated so that it displays the
4351 registers using a format identical to the old `regs' command.
4355 A new command, "maint set profile on/off", has been added. This command can
4356 be used to enable or disable profiling while running GDB, to profile a
4357 session or a set of commands. In addition there is a new configure switch,
4358 "--enable-profiling", which will cause GDB to be compiled with profiling
4359 data, for more informative profiling results.
4361 * Default MI syntax changed to "mi2".
4363 The default MI (machine interface) syntax, enabled by the command line
4364 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4365 "mi1", can be enabled by specifying the option "-i=mi1".
4367 Support for the original "mi0" syntax (included in GDB 5.0) has been
4370 Fix for gdb/192: removed extraneous space when displaying frame level.
4371 Fix for gdb/672: update changelist is now output in mi list format.
4372 Fix for gdb/702: a -var-assign that updates the value now shows up
4373 in a subsequent -var-update.
4375 * New native configurations.
4377 FreeBSD/amd64 x86_64-*-freebsd*
4379 * Multi-arched targets.
4381 HP/PA HPUX11 hppa*-*-hpux*
4382 Renesas M32R/D w/simulator m32r-*-elf*
4384 * OBSOLETE configurations and files
4386 Configurations that have been declared obsolete in this release have
4387 been commented out. Unless there is activity to revive these
4388 configurations, the next release of GDB will have their sources
4389 permanently REMOVED.
4391 Z8000 simulator z8k-zilog-none or z8ksim
4392 Matsushita MN10200 w/simulator mn10200-*-*
4393 H8/500 simulator h8500-hitachi-hms or h8500hms
4394 HP/PA running BSD hppa*-*-bsd*
4395 HP/PA running OSF/1 hppa*-*-osf*
4396 HP/PA Pro target hppa*-*-pro*
4397 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4398 Sequent family i[3456]86-sequent-sysv4*
4399 i[3456]86-sequent-sysv*
4400 i[3456]86-sequent-bsd*
4401 Tsqware Sparclet sparclet-*-*
4402 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4404 * REMOVED configurations and files
4407 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4408 IBM AIX PS/2 i[3456]86-*-aix
4409 i386 running Mach 3.0 i[3456]86-*-mach3*
4410 i386 running Mach i[3456]86-*-mach*
4411 i386 running OSF/1 i[3456]86-*osf1mk*
4412 HP/Apollo 68k Family m68*-apollo*-sysv*,
4414 m68*-hp-bsd*, m68*-hp-hpux*
4415 Argonaut Risc Chip (ARC) arc-*-*
4416 Mitsubishi D30V d30v-*-*
4417 Fujitsu FR30 fr30-*-elf*
4418 OS/9000 i[34]86-*-os9k
4419 I960 with MON960 i960-*-coff
4421 * MIPS $fp behavior changed
4423 The convenience variable $fp, for the MIPS, now consistently returns
4424 the address of the current frame's base. Previously, depending on the
4425 context, $fp could refer to either $sp or the current frame's base
4426 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4427 The GNU Source-Level Debugger''.
4429 *** Changes in GDB 5.3:
4431 * GNU/Linux shared library multi-threaded performance improved.
4433 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4434 `/proc', in preference to `ptrace' for memory reads. This may result
4435 in an improvement in the start-up time of multi-threaded, shared
4436 library applications when run under GDB. One GDB user writes: ``loads
4437 shared libs like mad''.
4439 * ``gdbserver'' now supports multi-threaded applications on some targets
4441 Support for debugging multi-threaded applications which use
4442 the GNU/Linux LinuxThreads package has been added for
4443 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4444 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4446 * GDB now supports C/C++ preprocessor macros.
4448 GDB now expands preprocessor macro invocations in C/C++ expressions,
4449 and provides various commands for showing macro definitions and how
4452 The new command `macro expand EXPRESSION' expands any macro
4453 invocations in expression, and shows the result.
4455 The new command `show macro MACRO-NAME' shows the definition of the
4456 macro named MACRO-NAME, and where it was defined.
4458 Most compilers don't include information about macros in the debugging
4459 information by default. In GCC 3.1, for example, you need to compile
4460 your program with the options `-gdwarf-2 -g3'. If the macro
4461 information is present in the executable, GDB will read it.
4463 * Multi-arched targets.
4465 DEC Alpha (partial) alpha*-*-*
4466 DEC VAX (partial) vax-*-*
4468 National Semiconductor NS32000 (partial) ns32k-*-*
4469 Motorola 68000 (partial) m68k-*-*
4470 Motorola MCORE mcore-*-*
4474 Fujitsu FRV architecture added by Red Hat frv*-*-*
4477 * New native configurations
4479 Alpha NetBSD alpha*-*-netbsd*
4480 SH NetBSD sh*-*-netbsdelf*
4481 MIPS NetBSD mips*-*-netbsd*
4482 UltraSPARC NetBSD sparc64-*-netbsd*
4484 * OBSOLETE configurations and files
4486 Configurations that have been declared obsolete in this release have
4487 been commented out. Unless there is activity to revive these
4488 configurations, the next release of GDB will have their sources
4489 permanently REMOVED.
4491 Mitsubishi D30V d30v-*-*
4492 OS/9000 i[34]86-*-os9k
4493 IBM AIX PS/2 i[3456]86-*-aix
4494 Fujitsu FR30 fr30-*-elf*
4495 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4496 Argonaut Risc Chip (ARC) arc-*-*
4497 i386 running Mach 3.0 i[3456]86-*-mach3*
4498 i386 running Mach i[3456]86-*-mach*
4499 i386 running OSF/1 i[3456]86-*osf1mk*
4500 HP/Apollo 68k Family m68*-apollo*-sysv*,
4502 m68*-hp-bsd*, m68*-hp-hpux*
4503 I960 with MON960 i960-*-coff
4505 * OBSOLETE languages
4507 CHILL, a Pascal like language used by telecommunications companies.
4509 * REMOVED configurations and files
4511 AMD 29k family via UDI a29k-amd-udi, udi29k
4512 A29K VxWorks a29k-*-vxworks
4513 AMD 29000 embedded, using EBMON a29k-none-none
4514 AMD 29000 embedded with COFF a29k-none-coff
4515 AMD 29000 embedded with a.out a29k-none-aout
4517 testsuite/gdb.hp/gdb.threads-hp/ directory
4519 * New command "set max-user-call-depth <nnn>"
4521 This command allows the user to limit the call depth of user-defined
4522 commands. The default is 1024.
4524 * Changes in FreeBSD/i386 native debugging.
4526 Support for the "generate-core-file" has been added.
4528 * New commands "dump", "append", and "restore".
4530 These commands allow data to be copied from target memory
4531 to a bfd-format or binary file (dump and append), and back
4532 from a file into memory (restore).
4534 * Improved "next/step" support on multi-processor Alpha Tru64.
4536 The previous single-step mechanism could cause unpredictable problems,
4537 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4538 of a software single-step mechanism prevents this.
4540 *** Changes in GDB 5.2.1:
4548 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4549 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4550 Fix, by Joel Brobecker imported from mainline.
4552 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4553 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4554 Fix, by Fred Fish, imported from mainline.
4556 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4557 Surprisingly enough, it works now.
4558 By Michal Ludvig, imported from mainline.
4560 i386 hardware watchpoint support:
4561 avoid misses on second run for some targets.
4562 By Pierre Muller, imported from mainline.
4564 *** Changes in GDB 5.2:
4566 * New command "set trust-readonly-sections on[off]".
4568 This command is a hint that tells gdb that read-only sections
4569 really are read-only (ie. that their contents will not change).
4570 In this mode, gdb will go to the object file rather than the
4571 target to read memory from read-only sections (such as ".text").
4572 This can be a significant performance improvement on some
4573 (notably embedded) targets.
4575 * New command "generate-core-file" (or "gcore").
4577 This new gdb command allows the user to drop a core file of the child
4578 process state at any time. So far it's been implemented only for
4579 GNU/Linux and Solaris, but should be relatively easily ported to other
4580 hosts. Argument is core file name (defaults to core.<pid>).
4582 * New command line option
4584 GDB now accepts --pid or -p followed by a process id.
4586 * Change in command line behavior -- corefiles vs. process ids.
4588 There is a subtle behavior in the way in which GDB handles
4589 command line arguments. The first non-flag argument is always
4590 a program to debug, but the second non-flag argument may either
4591 be a corefile or a process id. Previously, GDB would attempt to
4592 open the second argument as a corefile, and if that failed, would
4593 issue a superfluous error message and then attempt to attach it as
4594 a process. Now, if the second argument begins with a non-digit,
4595 it will be treated as a corefile. If it begins with a digit,
4596 GDB will attempt to attach it as a process, and if no such process
4597 is found, will then attempt to open it as a corefile.
4599 * Changes in ARM configurations.
4601 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4602 configuration is fully multi-arch.
4604 * New native configurations
4606 ARM NetBSD arm*-*-netbsd*
4607 x86 OpenBSD i[3456]86-*-openbsd*
4608 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4609 Sparc64 running FreeBSD sparc64-*-freebsd*
4613 Sanyo XStormy16 xstormy16-elf
4615 * OBSOLETE configurations and files
4617 Configurations that have been declared obsolete in this release have
4618 been commented out. Unless there is activity to revive these
4619 configurations, the next release of GDB will have their sources
4620 permanently REMOVED.
4622 AMD 29k family via UDI a29k-amd-udi, udi29k
4623 A29K VxWorks a29k-*-vxworks
4624 AMD 29000 embedded, using EBMON a29k-none-none
4625 AMD 29000 embedded with COFF a29k-none-coff
4626 AMD 29000 embedded with a.out a29k-none-aout
4628 testsuite/gdb.hp/gdb.threads-hp/ directory
4630 * REMOVED configurations and files
4632 TI TMS320C80 tic80-*-*
4634 PowerPC Solaris powerpcle-*-solaris*
4635 PowerPC Windows NT powerpcle-*-cygwin32
4636 PowerPC Netware powerpc-*-netware*
4637 Harris/CXUX m88k m88*-harris-cxux*
4638 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4639 ns32k-utek-sysv* ns32k-utek-*
4640 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4641 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4642 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4643 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4644 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4646 * Changes to command line processing
4648 The new `--args' feature can be used to specify command-line arguments
4649 for the inferior from gdb's command line.
4651 * Changes to key bindings
4653 There is a new `operate-and-get-next' function bound to `C-o'.
4655 *** Changes in GDB 5.1.1
4657 Fix compile problem on DJGPP.
4659 Fix a problem with floating-point registers on the i386 being
4662 Fix to stop GDB crashing on .debug_str debug info.
4664 Numerous documentation fixes.
4666 Numerous testsuite fixes.
4668 *** Changes in GDB 5.1:
4670 * New native configurations
4672 Alpha FreeBSD alpha*-*-freebsd*
4673 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4674 MIPS GNU/Linux mips*-*-linux*
4675 MIPS SGI Irix 6.x mips*-sgi-irix6*
4676 ia64 AIX ia64-*-aix*
4677 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4681 Motorola 68HC11 and 68HC12 m68hc11-elf
4683 UltraSparc running GNU/Linux sparc64-*-linux*
4685 * OBSOLETE configurations and files
4687 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4688 Harris/CXUX m88k m88*-harris-cxux*
4689 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4690 ns32k-utek-sysv* ns32k-utek-*
4691 TI TMS320C80 tic80-*-*
4693 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4694 PowerPC Solaris powerpcle-*-solaris*
4695 PowerPC Windows NT powerpcle-*-cygwin32
4696 PowerPC Netware powerpc-*-netware*
4697 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4698 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4699 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4700 Apple Macintosh (MPW) host N/A
4702 stuff.c (Program to stuff files into a specially prepared space in kdb)
4703 kdb-start.c (Main loop for the standalone kernel debugger)
4705 Configurations that have been declared obsolete in this release have
4706 been commented out. Unless there is activity to revive these
4707 configurations, the next release of GDB will have their sources
4708 permanently REMOVED.
4710 * REMOVED configurations and files
4712 Altos 3068 m68*-altos-*
4713 Convex c1-*-*, c2-*-*
4715 ARM RISCix arm-*-* (as host)
4719 * GDB has been converted to ISO C.
4721 GDB's source code has been converted to ISO C. In particular, the
4722 sources are fully protoized, and rely on standard headers being
4727 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4729 * The MI enabled by default.
4731 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4732 revised and enabled by default. Packages which use GDB as a debugging
4733 engine behind a UI or another front end are encouraged to switch to
4734 using the GDB/MI interface, instead of the old annotations interface
4735 which is now deprecated.
4737 * Support for debugging Pascal programs.
4739 GDB now includes support for debugging Pascal programs. The following
4740 main features are supported:
4742 - Pascal-specific data types such as sets;
4744 - automatic recognition of Pascal sources based on file-name
4747 - Pascal-style display of data types, variables, and functions;
4749 - a Pascal expression parser.
4751 However, some important features are not yet supported.
4753 - Pascal string operations are not supported at all;
4755 - there are some problems with boolean types;
4757 - Pascal type hexadecimal constants are not supported
4758 because they conflict with the internal variables format;
4760 - support for Pascal objects and classes is not full yet;
4762 - unlike Pascal, GDB is case-sensitive for symbol names.
4764 * Changes in completion.
4766 Commands such as `shell', `run' and `set args', which pass arguments
4767 to inferior programs, now complete on file names, similar to what
4768 users expect at the shell prompt.
4770 Commands which accept locations, such as `disassemble', `print',
4771 `breakpoint', `until', etc. now complete on filenames as well as
4772 program symbols. Thus, if you type "break foob TAB", and the source
4773 files linked into the programs include `foobar.c', that file name will
4774 be one of the candidates for completion. However, file names are not
4775 considered for completion after you typed a colon that delimits a file
4776 name from a name of a function in that file, as in "break foo.c:bar".
4778 `set demangle-style' completes on available demangling styles.
4780 * New platform-independent commands:
4782 It is now possible to define a post-hook for a command as well as a
4783 hook that runs before the command. For more details, see the
4784 documentation of `hookpost' in the GDB manual.
4786 * Changes in GNU/Linux native debugging.
4788 Support for debugging multi-threaded programs has been completely
4789 revised for all platforms except m68k and sparc. You can now debug as
4790 many threads as your system allows you to have.
4792 Attach/detach is supported for multi-threaded programs.
4794 Support for SSE registers was added for x86. This doesn't work for
4795 multi-threaded programs though.
4797 * Changes in MIPS configurations.
4799 Multi-arch support is enabled for all MIPS configurations.
4801 GDB can now be built as native debugger on SGI Irix 6.x systems for
4802 debugging n32 executables. (Debugging 64-bit executables is not yet
4805 * Unified support for hardware watchpoints in all x86 configurations.
4807 Most (if not all) native x86 configurations support hardware-assisted
4808 breakpoints and watchpoints in a unified manner. This support
4809 implements debug register sharing between watchpoints, which allows to
4810 put a virtually infinite number of watchpoints on the same address,
4811 and also supports watching regions up to 16 bytes with several debug
4814 The new maintenance command `maintenance show-debug-regs' toggles
4815 debugging print-outs in functions that insert, remove, and test
4816 watchpoints and hardware breakpoints.
4818 * Changes in the DJGPP native configuration.
4820 New command ``info dos sysinfo'' displays assorted information about
4821 the CPU, OS, memory, and DPMI server.
4823 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4824 display information about segment descriptors stored in GDT, LDT, and
4827 New commands ``info dos pde'' and ``info dos pte'' display entries
4828 from Page Directory and Page Tables (for now works with CWSDPMI only).
4829 New command ``info dos address-pte'' displays the Page Table entry for
4830 a given linear address.
4832 GDB can now pass command lines longer than 126 characters to the
4833 program being debugged (requires an update to the libdbg.a library
4834 which is part of the DJGPP development kit).
4836 DWARF2 debug info is now supported.
4838 It is now possible to `step' and `next' through calls to `longjmp'.
4840 * Changes in documentation.
4842 All GDB documentation was converted to GFDL, the GNU Free
4843 Documentation License.
4845 Tracepoints-related commands are now fully documented in the GDB
4848 TUI, the Text-mode User Interface, is now documented in the manual.
4850 Tracepoints-related commands are now fully documented in the GDB
4853 The "GDB Internals" manual now has an index. It also includes
4854 documentation of `ui_out' functions, GDB coding standards, x86
4855 hardware watchpoints, and memory region attributes.
4857 * GDB's version number moved to ``version.in''
4859 The Makefile variable VERSION has been replaced by the file
4860 ``version.in''. People creating GDB distributions should update the
4861 contents of this file.
4865 GUD support is now a standard part of the EMACS distribution.
4867 *** Changes in GDB 5.0:
4869 * Improved support for debugging FP programs on x86 targets
4871 Unified and much-improved support for debugging floating-point
4872 programs on all x86 targets. In particular, ``info float'' now
4873 displays the FP registers in the same format on all x86 targets, with
4874 greater level of detail.
4876 * Improvements and bugfixes in hardware-assisted watchpoints
4878 It is now possible to watch array elements, struct members, and
4879 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4880 on x86 targets no longer erroneously trigger when the address is
4883 * Improvements in the native DJGPP version of GDB
4885 The distribution now includes all the scripts and auxiliary files
4886 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4887 machines ``out of the box''.
4889 The DJGPP version can now debug programs that use signals. It is
4890 possible to catch signals that happened in the debuggee, deliver
4891 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4892 would kill the program being debugged.) Programs that hook hardware
4893 interrupts (keyboard, timer, etc.) can also be debugged.
4895 It is now possible to debug DJGPP programs that redirect their
4896 standard handles or switch them to raw (as opposed to cooked) mode, or
4897 even close them. The command ``run < foo > bar'' works as expected,
4898 and ``info terminal'' reports useful information about the debuggee's
4899 terminal, including raw/cooked mode, redirection, etc.
4901 The DJGPP version now uses termios functions for console I/O, which
4902 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4905 DOS-style file names with drive letters are now fully supported by
4908 It is now possible to debug DJGPP programs that switch their working
4909 directory. It is also possible to rerun the debuggee any number of
4910 times without restarting GDB; thus, you can use the same setup,
4911 breakpoints, etc. for many debugging sessions.
4913 * New native configurations
4915 ARM GNU/Linux arm*-*-linux*
4916 PowerPC GNU/Linux powerpc-*-linux*
4920 Motorola MCore mcore-*-*
4921 x86 VxWorks i[3456]86-*-vxworks*
4922 PowerPC VxWorks powerpc-*-vxworks*
4923 TI TMS320C80 tic80-*-*
4925 * OBSOLETE configurations
4927 Altos 3068 m68*-altos-*
4928 Convex c1-*-*, c2-*-*
4930 ARM RISCix arm-*-* (as host)
4933 Configurations that have been declared obsolete will be commented out,
4934 but the code will be left in place. If there is no activity to revive
4935 these configurations before the next release of GDB, the sources will
4936 be permanently REMOVED.
4938 * Gould support removed
4940 Support for the Gould PowerNode and NP1 has been removed.
4942 * New features for SVR4
4944 On SVR4 native platforms (such as Solaris), if you attach to a process
4945 without first loading a symbol file, GDB will now attempt to locate and
4946 load symbols from the running process's executable file.
4948 * Many C++ enhancements
4950 C++ support has been greatly improved. Overload resolution now works properly
4951 in almost all cases. RTTI support is on the way.
4953 * Remote targets can connect to a sub-program
4955 A popen(3) style serial-device has been added. This device starts a
4956 sub-process (such as a stand-alone simulator) and then communicates
4957 with that. The sub-program to run is specified using the syntax
4958 ``|<program> <args>'' vis:
4960 (gdb) set remotedebug 1
4961 (gdb) target extended-remote |mn10300-elf-sim program-args
4963 * MIPS 64 remote protocol
4965 A long standing bug in the mips64 remote protocol where by GDB
4966 expected certain 32 bit registers (ex SR) to be transfered as 32
4967 instead of 64 bits has been fixed.
4969 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4970 added to provide backward compatibility with older versions of GDB.
4972 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4974 The command ``set remotebinarydownload'' command has been replaced by
4975 ``set remote X-packet''. Other commands in ``set remote'' family
4976 include ``set remote P-packet''.
4978 * Breakpoint commands accept ranges.
4980 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4981 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4982 ``tracepoint passcount'' also accepts a range of tracepoints.
4984 * ``apropos'' command added.
4986 The ``apropos'' command searches through command names and
4987 documentation strings, printing out matches, making it much easier to
4988 try to find a command that does what you are looking for.
4992 A new machine oriented interface (MI) has been added to GDB. This
4993 interface is designed for debug environments running GDB as a separate
4994 process. This is part of the long term libGDB project. See the
4995 "GDB/MI" chapter of the GDB manual for further information. It can be
4996 enabled by configuring with:
4998 .../configure --enable-gdbmi
5000 *** Changes in GDB-4.18:
5002 * New native configurations
5004 HP-UX 10.20 hppa*-*-hpux10.20
5005 HP-UX 11.x hppa*-*-hpux11.0*
5006 M68K GNU/Linux m68*-*-linux*
5010 Fujitsu FR30 fr30-*-elf*
5011 Intel StrongARM strongarm-*-*
5012 Mitsubishi D30V d30v-*-*
5014 * OBSOLETE configurations
5016 Gould PowerNode, NP1 np1-*-*, pn-*-*
5018 Configurations that have been declared obsolete will be commented out,
5019 but the code will be left in place. If there is no activity to revive
5020 these configurations before the next release of GDB, the sources will
5021 be permanently REMOVED.
5025 As a compatibility experiment, GDB's source files buildsym.h and
5026 buildsym.c have been converted to pure standard C, no longer
5027 containing any K&R compatibility code. We believe that all systems in
5028 use today either come with a standard C compiler, or have a GCC port
5029 available. If this is not true, please report the affected
5030 configuration to bug-gdb@gnu.org immediately. See the README file for
5031 information about getting a standard C compiler if you don't have one
5036 GDB now uses readline 2.2.
5038 * set extension-language
5040 You can now control the mapping between filename extensions and source
5041 languages by using the `set extension-language' command. For instance,
5042 you can ask GDB to treat .c files as C++ by saying
5043 set extension-language .c c++
5044 The command `info extensions' lists all of the recognized extensions
5045 and their associated languages.
5047 * Setting processor type for PowerPC and RS/6000
5049 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5050 you can use the `set processor' command to specify what variant of the
5051 PowerPC family you are debugging. The command
5055 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5056 following PowerPC and RS6000 variants:
5058 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5059 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5061 403GC IBM PowerPC 403GC
5062 505 Motorola PowerPC 505
5063 860 Motorola PowerPC 860 or 850
5064 601 Motorola PowerPC 601
5065 602 Motorola PowerPC 602
5066 603 Motorola/IBM PowerPC 603 or 603e
5067 604 Motorola PowerPC 604 or 604e
5068 750 Motorola/IBM PowerPC 750 or 750
5070 At the moment, this command just tells GDB what to name the
5071 special-purpose processor registers. Since almost all the affected
5072 registers are inaccessible to user-level programs, this command is
5073 only useful for remote debugging in its present form.
5077 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5078 more extensive support for HP-UX. Added features include shared
5079 library support, kernel threads and hardware watchpoints for 11.00,
5080 support for HP's ANSI C and C++ compilers, and a compatibility mode
5081 for xdb and dbx commands.
5085 HP's donation includes the new concept of catchpoints, which is a
5086 generalization of the old catch command. On HP-UX, it is now possible
5087 to catch exec, fork, and vfork, as well as library loading.
5089 This means that the existing catch command has changed; its first
5090 argument now specifies the type of catch to be set up. See the
5091 output of "help catch" for a list of catchpoint types.
5093 * Debugging across forks
5095 On HP-UX, you can choose which process to debug when a fork() happens
5100 HP has donated a curses-based terminal user interface (TUI). To get
5101 it, build with --enable-tui. Although this can be enabled for any
5102 configuration, at present it only works for native HP debugging.
5104 * GDB remote protocol additions
5106 A new protocol packet 'X' that writes binary data is now available.
5107 Default behavior is to try 'X', then drop back to 'M' if the stub
5108 fails to respond. The settable variable `remotebinarydownload'
5109 allows explicit control over the use of 'X'.
5111 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5112 full 64-bit address. The command
5114 set remoteaddresssize 32
5116 can be used to revert to the old behaviour. For existing remote stubs
5117 the change should not be noticed, as the additional address information
5120 In order to assist in debugging stubs, you may use the maintenance
5121 command `packet' to send any text string to the stub. For instance,
5123 maint packet heythere
5125 sends the packet "$heythere#<checksum>". Note that it is very easy to
5126 disrupt a debugging session by sending the wrong packet at the wrong
5129 The compare-sections command allows you to compare section data on the
5130 target to what is in the executable file without uploading or
5131 downloading, by comparing CRC checksums.
5133 * Tracing can collect general expressions
5135 You may now collect general expressions at tracepoints. This requires
5136 further additions to the target-side stub; see tracepoint.c and
5137 doc/agentexpr.texi for further details.
5139 * mask-address variable for Mips
5141 For Mips targets, you may control the zeroing of the upper 32 bits of
5142 a 64-bit address by entering `set mask-address on'. This is mainly
5143 of interest to users of embedded R4xxx and R5xxx processors.
5145 * Higher serial baud rates
5147 GDB's serial code now allows you to specify baud rates 57600, 115200,
5148 230400, and 460800 baud. (Note that your host system may not be able
5149 to achieve all of these rates.)
5153 The i960 configuration now includes an initial implementation of a
5154 builtin simulator, contributed by Jim Wilson.
5157 *** Changes in GDB-4.17:
5159 * New native configurations
5161 Alpha GNU/Linux alpha*-*-linux*
5162 Unixware 2.x i[3456]86-unixware2*
5163 Irix 6.x mips*-sgi-irix6*
5164 PowerPC GNU/Linux powerpc-*-linux*
5165 PowerPC Solaris powerpcle-*-solaris*
5166 Sparc GNU/Linux sparc-*-linux*
5167 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5171 Argonaut Risc Chip (ARC) arc-*-*
5172 Hitachi H8/300S h8300*-*-*
5173 Matsushita MN10200 w/simulator mn10200-*-*
5174 Matsushita MN10300 w/simulator mn10300-*-*
5175 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5176 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5177 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5178 Mitsubishi D10V w/simulator d10v-*-*
5179 Mitsubishi M32R/D w/simulator m32r-*-elf*
5180 Tsqware Sparclet sparclet-*-*
5181 NEC V850 w/simulator v850-*-*
5183 * New debugging protocols
5185 ARM with RDI protocol arm*-*-*
5186 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5187 DDB and LSI variants of PMON protocol mips*-*-*
5188 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5189 PowerPC with SDS protocol powerpc{,le}-*-eabi
5190 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5194 All configurations can now understand and use the DWARF 2 debugging
5195 format. The choice is automatic, if the symbol file contains DWARF 2
5200 GDB now includes basic Java language support. This support is
5201 only useful with Java compilers that produce native machine code.
5203 * solib-absolute-prefix and solib-search-path
5205 For SunOS and SVR4 shared libraries, you may now set the prefix for
5206 loading absolute shared library symbol files, and the search path for
5207 locating non-absolute shared library symbol files.
5209 * Live range splitting
5211 GDB can now effectively debug code for which GCC has performed live
5212 range splitting as part of its optimization. See gdb/doc/LRS for
5213 more details on the expected format of the stabs information.
5217 GDB's support for the GNU Hurd, including thread debugging, has been
5218 updated to work with current versions of the Hurd.
5222 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5223 instruction set. ARM GDB automatically detects when Thumb
5224 instructions are in use, and adjusts disassembly and backtracing
5229 GDB's MIPS target configurations now handle the MIP16 16-bit
5234 GDB now includes support for overlays; if an executable has been
5235 linked such that multiple sections are based at the same address, GDB
5236 will decide which section to use for symbolic info. You can choose to
5237 control the decision manually, using overlay commands, or implement
5238 additional target-side support and use "overlay load-target" to bring
5239 in the overlay mapping. Do "help overlay" for more detail.
5243 The command "info symbol <address>" displays information about
5244 the symbol at the specified address.
5248 The standard remote protocol now includes an extension that allows
5249 asynchronous collection and display of trace data. This requires
5250 extensive support in the target-side debugging stub. Tracing mode
5251 includes a new interaction mode in GDB and new commands: see the
5252 file tracepoint.c for more details.
5256 Configurations for embedded MIPS now include a simulator contributed
5257 by Cygnus Solutions. The simulator supports the instruction sets
5258 of most MIPS variants.
5262 Sparc configurations may now include the ERC32 simulator contributed
5263 by the European Space Agency. The simulator is not built into
5264 Sparc targets by default; configure with --enable-sim to include it.
5268 For target configurations that may include multiple variants of a
5269 basic architecture (such as MIPS and SH), you may now set the
5270 architecture explicitly. "set arch" sets, "info arch" lists
5271 the possible architectures.
5273 *** Changes in GDB-4.16:
5275 * New native configurations
5277 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5278 M68K NetBSD m68k-*-netbsd*
5279 PowerPC AIX 4.x powerpc-*-aix*
5280 PowerPC MacOS powerpc-*-macos*
5281 PowerPC Windows NT powerpcle-*-cygwin32
5282 RS/6000 AIX 4.x rs6000-*-aix4*
5286 ARM with RDP protocol arm-*-*
5287 I960 with MON960 i960-*-coff
5288 MIPS VxWorks mips*-*-vxworks*
5289 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5290 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5292 Matra Sparclet sparclet-*-*
5296 The powerpc-eabi configuration now includes the PSIM simulator,
5297 contributed by Andrew Cagney, with assistance from Mike Meissner.
5298 PSIM is a very elaborate model of the PowerPC, including not only
5299 basic instruction set execution, but also details of execution unit
5300 performance and I/O hardware. See sim/ppc/README for more details.
5304 GDB now works with Solaris 2.5.
5306 * Windows 95/NT native
5308 GDB will now work as a native debugger on Windows 95 and Windows NT.
5309 To build it from source, you must use the "gnu-win32" environment,
5310 which uses a DLL to emulate enough of Unix to run the GNU tools.
5311 Further information, binaries, and sources are available at
5312 ftp.cygnus.com, under pub/gnu-win32.
5314 * dont-repeat command
5316 If a user-defined command includes the command `dont-repeat', then the
5317 command will not be repeated if the user just types return. This is
5318 useful if the command is time-consuming to run, so that accidental
5319 extra keystrokes don't run the same command many times.
5321 * Send break instead of ^C
5323 The standard remote protocol now includes an option to send a break
5324 rather than a ^C to the target in order to interrupt it. By default,
5325 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5327 * Remote protocol timeout
5329 The standard remote protocol includes a new variable `remotetimeout'
5330 that allows you to set the number of seconds before GDB gives up trying
5331 to read from the target. The default value is 2.
5333 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5335 By default GDB will automatically keep track of objects as they are
5336 loaded and unloaded by the dynamic linker. By using the command `set
5337 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5338 when shared library events occur, thus allowing you to set breakpoints
5339 in shared libraries which are explicitly loaded by the inferior.
5341 Note this feature does not work on hpux8. On hpux9 you must link
5342 /usr/lib/end.o into your program. This feature should work
5343 automatically on hpux10.
5345 * Irix 5.x hardware watchpoint support
5347 Irix 5 configurations now support the use of hardware watchpoints.
5349 * Mips protocol "SYN garbage limit"
5351 When debugging a Mips target using the `target mips' protocol, you
5352 may set the number of characters that GDB will ignore by setting
5353 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5354 every character. The default value is 1050.
5356 * Recording and replaying remote debug sessions
5358 If you set `remotelogfile' to the name of a file, gdb will write to it
5359 a recording of a remote debug session. This recording may then be
5360 replayed back to gdb using "gdbreplay". See gdbserver/README for
5361 details. This is useful when you have a problem with GDB while doing
5362 remote debugging; you can make a recording of the session and send it
5363 to someone else, who can then recreate the problem.
5365 * Speedups for remote debugging
5367 GDB includes speedups for downloading and stepping MIPS systems using
5368 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5369 and more efficient S-record downloading.
5371 * Memory use reductions and statistics collection
5373 GDB now uses less memory and reports statistics about memory usage.
5374 Try the `maint print statistics' command, for example.
5376 *** Changes in GDB-4.15:
5378 * Psymtabs for XCOFF
5380 The symbol reader for AIX GDB now uses partial symbol tables. This
5381 can greatly improve startup time, especially for large executables.
5383 * Remote targets use caching
5385 Remote targets now use a data cache to speed up communication with the
5386 remote side. The data cache could lead to incorrect results because
5387 it doesn't know about volatile variables, thus making it impossible to
5388 debug targets which use memory mapped I/O devices. `set remotecache
5389 off' turns the the data cache off.
5391 * Remote targets may have threads
5393 The standard remote protocol now includes support for multiple threads
5394 in the target system, using new protocol commands 'H' and 'T'. See
5395 gdb/remote.c for details.
5399 If GDB is configured with `--enable-netrom', then it will include
5400 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5401 acts as though it is a bank of ROM on the target board, but you can
5402 write into it over the network. GDB's support consists only of
5403 support for fast loading into the emulated ROM; to debug, you must use
5404 another protocol, such as standard remote protocol. The usual
5405 sequence is something like
5407 target nrom <netrom-hostname>
5409 target remote <netrom-hostname>:1235
5413 GDB now includes support for the Apple Macintosh, as a host only. It
5414 may be run as either an MPW tool or as a standalone application, and
5415 it can debug through the serial port. All the usual GDB commands are
5416 available, but to the target command, you must supply "serial" as the
5417 device type instead of "/dev/ttyXX". See mpw-README in the main
5418 directory for more information on how to build. The MPW configuration
5419 scripts */mpw-config.in support only a few targets, and only the
5420 mips-idt-ecoff target has been tested.
5424 GDB configuration now uses autoconf. This is not user-visible,
5425 but does simplify configuration and building.
5429 GDB now supports hpux10.
5431 *** Changes in GDB-4.14:
5433 * New native configurations
5435 x86 FreeBSD i[345]86-*-freebsd
5436 x86 NetBSD i[345]86-*-netbsd
5437 NS32k NetBSD ns32k-*-netbsd
5438 Sparc NetBSD sparc-*-netbsd
5442 A29K VxWorks a29k-*-vxworks
5443 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5444 CPU32 EST-300 emulator m68*-*-est*
5445 PowerPC ELF powerpc-*-elf
5448 * Alpha OSF/1 support for procfs
5450 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5451 possible to attach to running processes. As the mounting of the /proc
5452 filesystem is optional on the Alpha, GDB automatically determines
5453 the availability of /proc during startup. This can lead to problems
5454 if /proc is unmounted after GDB has been started.
5456 * Arguments to user-defined commands
5458 User commands may accept up to 10 arguments separated by whitespace.
5459 Arguments are accessed within the user command via $arg0..$arg9. A
5462 print $arg0 + $arg1 + $arg2
5464 To execute the command use:
5467 Defines the command "adder" which prints the sum of its three arguments.
5468 Note the arguments are text substitutions, so they may reference variables,
5469 use complex expressions, or even perform inferior function calls.
5471 * New `if' and `while' commands
5473 This makes it possible to write more sophisticated user-defined
5474 commands. Both commands take a single argument, which is the
5475 expression to evaluate, and must be followed by the commands to
5476 execute, one per line, if the expression is nonzero, the list being
5477 terminated by the word `end'. The `if' command list may include an
5478 `else' word, which causes the following commands to be executed only
5479 if the expression is zero.
5481 * Fortran source language mode
5483 GDB now includes partial support for Fortran 77. It will recognize
5484 Fortran programs and can evaluate a subset of Fortran expressions, but
5485 variables and functions may not be handled correctly. GDB will work
5486 with G77, but does not yet know much about symbols emitted by other
5489 * Better HPUX support
5491 Most debugging facilities now work on dynamic executables for HPPAs
5492 running hpux9 or later. You can attach to running dynamically linked
5493 processes, but by default the dynamic libraries will be read-only, so
5494 for instance you won't be able to put breakpoints in them. To change
5495 that behavior do the following before running the program:
5501 This will cause the libraries to be mapped private and read-write.
5502 To revert to the normal behavior, do this:
5508 You cannot set breakpoints or examine data in the library until after
5509 the library is loaded if the function/data symbols do not have
5512 GDB can now also read debug symbols produced by the HP C compiler on
5513 HPPAs (sorry, no C++, Fortran or 68k support).
5515 * Target byte order now dynamically selectable
5517 You can choose which byte order to use with a target system, via the
5518 commands "set endian big" and "set endian little", and you can see the
5519 current setting by using "show endian". You can also give the command
5520 "set endian auto", in which case GDB will use the byte order
5521 associated with the executable. Currently, only embedded MIPS
5522 configurations support dynamic selection of target byte order.
5524 * New DOS host serial code
5526 This version uses DPMI interrupts to handle buffered I/O, so you
5527 no longer need to run asynctsr when debugging boards connected to
5530 *** Changes in GDB-4.13:
5532 * New "complete" command
5534 This lists all the possible completions for the rest of the line, if it
5535 were to be given as a command itself. This is intended for use by emacs.
5537 * Trailing space optional in prompt
5539 "set prompt" no longer adds a space for you after the prompt you set. This
5540 allows you to set a prompt which ends in a space or one that does not.
5542 * Breakpoint hit counts
5544 "info break" now displays a count of the number of times the breakpoint
5545 has been hit. This is especially useful in conjunction with "ignore"; you
5546 can ignore a large number of breakpoint hits, look at the breakpoint info
5547 to see how many times the breakpoint was hit, then run again, ignoring one
5548 less than that number, and this will get you quickly to the last hit of
5551 * Ability to stop printing at NULL character
5553 "set print null-stop" will cause GDB to stop printing the characters of
5554 an array when the first NULL is encountered. This is useful when large
5555 arrays actually contain only short strings.
5557 * Shared library breakpoints
5559 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5560 breakpoints in shared libraries before the executable is run.
5562 * Hardware watchpoints
5564 There is a new hardware breakpoint for the watch command for sparclite
5565 targets. See gdb/sparclite/hw_breakpoint.note.
5567 Hardware watchpoints are also now supported under GNU/Linux.
5571 Annotations have been added. These are for use with graphical interfaces,
5572 and are still experimental. Currently only gdba.el uses these.
5574 * Improved Irix 5 support
5576 GDB now works properly with Irix 5.2.
5578 * Improved HPPA support
5580 GDB now works properly with the latest GCC and GAS.
5582 * New native configurations
5584 Sequent PTX4 i[34]86-sequent-ptx4
5585 HPPA running OSF/1 hppa*-*-osf*
5586 Atari TT running SVR4 m68*-*-sysv4*
5587 RS/6000 LynxOS rs6000-*-lynxos*
5591 OS/9000 i[34]86-*-os9k
5592 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5595 * Hitachi SH7000 and E7000-PC ICE support
5597 There is now support for communicating with the Hitachi E7000-PC ICE.
5598 This is available automatically when GDB is configured for the SH.
5602 As usual, a variety of small fixes and improvements, both generic
5603 and configuration-specific. See the ChangeLog for more detail.
5605 *** Changes in GDB-4.12:
5607 * Irix 5 is now supported
5611 GDB-4.12 on the HPPA has a number of changes which make it unable
5612 to debug the output from the currently released versions of GCC and
5613 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5614 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5615 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5618 *** Changes in GDB-4.11:
5620 * User visible changes:
5624 The "set remotedebug" option is now consistent between the mips remote
5625 target, remote targets using the gdb-specific protocol, UDI (AMD's
5626 debug protocol for the 29k) and the 88k bug monitor. It is now an
5627 integer specifying a debug level (normally 0 or 1, but 2 means more
5628 debugging info for the mips target).
5630 * DEC Alpha native support
5632 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5633 debug info, but GDB works fairly well with the DEC compiler and should
5634 work with a future GCC release. See the README file for a few
5635 Alpha-specific notes.
5637 * Preliminary thread implementation
5639 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5641 * LynxOS native and target support for 386
5643 This release has been hosted on LynxOS 2.2, and also can be configured
5644 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5647 * Improvements in C++ mangling/demangling.
5649 This release has much better g++ debugging, specifically in name
5650 mangling/demangling, virtual function calls, print virtual table,
5651 call methods, ...etc.
5653 *** Changes in GDB-4.10:
5655 * User visible changes:
5657 Remote debugging using the GDB-specific (`target remote') protocol now
5658 supports the `load' command. This is only useful if you have some
5659 other way of getting the stub to the target system, and you can put it
5660 somewhere in memory where it won't get clobbered by the download.
5662 Filename completion now works.
5664 When run under emacs mode, the "info line" command now causes the
5665 arrow to point to the line specified. Also, "info line" prints
5666 addresses in symbolic form (as well as hex).
5668 All vxworks based targets now support a user settable option, called
5669 vxworks-timeout. This option represents the number of seconds gdb
5670 should wait for responses to rpc's. You might want to use this if
5671 your vxworks target is, perhaps, a slow software simulator or happens
5672 to be on the far side of a thin network line.
5676 This release contains support for using a DEC alpha as a GDB host for
5677 cross debugging. Native alpha debugging is not supported yet.
5680 *** Changes in GDB-4.9:
5684 This is the first GDB release which is accompanied by a matching testsuite.
5685 The testsuite requires installation of dejagnu, which should be available
5686 via ftp from most sites that carry GNU software.
5690 'Cfront' style demangling has had its name changed to 'ARM' style, to
5691 emphasize that it was written from the specifications in the C++ Annotated
5692 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5693 disclaimers, it still generated too much confusion with users attempting to
5694 use gdb with AT&T cfront.
5698 GDB now uses a standard remote interface to a simulator library.
5699 So far, the library contains simulators for the Zilog Z8001/2, the
5700 Hitachi H8/300, H8/500 and Super-H.
5702 * New targets supported
5704 H8/300 simulator h8300-hitachi-hms or h8300hms
5705 H8/500 simulator h8500-hitachi-hms or h8500hms
5706 SH simulator sh-hitachi-hms or sh
5707 Z8000 simulator z8k-zilog-none or z8ksim
5708 IDT MIPS board over serial line mips-idt-ecoff
5710 Cross-debugging to GO32 targets is supported. It requires a custom
5711 version of the i386-stub.c module which is integrated with the
5712 GO32 memory extender.
5714 * New remote protocols
5716 MIPS remote debugging protocol.
5718 * New source languages supported
5720 This version includes preliminary support for Chill, a Pascal like language
5721 used by telecommunications companies. Chill support is also being integrated
5722 into the GNU compiler, but we don't know when it will be publically available.
5725 *** Changes in GDB-4.8:
5727 * HP Precision Architecture supported
5729 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5730 version of this support was available as a set of patches from the
5731 University of Utah. GDB does not support debugging of programs
5732 compiled with the HP compiler, because HP will not document their file
5733 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5734 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5736 Many problems in the preliminary version have been fixed.
5738 * Faster and better demangling
5740 We have improved template demangling and fixed numerous bugs in the GNU style
5741 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5742 character types (wchar_t) are now supported. Demangling of each symbol is now
5743 only done once, and is cached when the symbol table for a file is read in.
5744 This results in a small increase in memory usage for C programs, a moderate
5745 increase in memory usage for C++ programs, and a fantastic speedup in
5748 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5749 from the specifications in the Annotated Reference Manual, which AT&T's
5750 compiler does not actually implement.
5752 * G++ multiple inheritance compiler problem
5754 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5755 inheritance lattices was reworked to properly discover ambiguities. We
5756 recently found an example which causes this new algorithm to fail in a
5757 very subtle way, producing bad debug information for those classes.
5758 The file 'gcc.patch' (in this directory) can be applied to gcc to
5759 circumvent the problem. A future GCC release will contain a complete
5762 The previous G++ debug info problem (mentioned below for the gdb-4.7
5763 release) is fixed in gcc version 2.3.2.
5765 * Improved configure script
5767 The `configure' script will now attempt to guess your system type if
5768 you don't supply a host system type. The old scheme of supplying a
5769 host system triplet is preferable over using this. All the magic is
5770 done in the new `config.guess' script. Examine it for details.
5772 We have also brought our configure script much more in line with the FSF's
5773 version. It now supports the --with-xxx options. In particular,
5774 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5775 The resulting GDB will not be able to read arbitrary object file formats --
5776 only the format ``expected'' to be used on the configured target system.
5777 We hope to make this the default in a future release.
5779 * Documentation improvements
5781 There's new internal documentation on how to modify GDB, and how to
5782 produce clean changes to the code. We implore people to read it
5783 before submitting changes.
5785 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5786 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5787 `info' files are also provided. To build `info' files from scratch,
5788 you will need the latest `makeinfo' release, which will be available in
5789 a future texinfo-X.Y release.
5791 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5792 We're not sure exactly which versions have this problem, but it has
5793 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5794 or better. If that isn't possible, there is a patch in
5795 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5796 around this problem.
5800 GDB now supports array constants that can be used in expressions typed in by
5801 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5802 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5805 The new directory `gdb/sparclite' contains a program that demonstrates
5806 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5808 * New native hosts supported
5810 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5811 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5813 * New targets supported
5815 AMD 29k family via UDI a29k-amd-udi or udi29k
5817 * New file formats supported
5819 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5820 HPUX core files, and SCO 3.2v2 core files.
5824 Attaching to processes now works again; thanks for the many bug reports.
5826 We have also stomped on a bunch of core dumps caused by
5827 printf_filtered("%s") problems.
5829 We eliminated a copyright problem on the rpc and ptrace header files
5830 for VxWorks, which was discovered at the last minute during the 4.7
5831 release. You should now be able to build a VxWorks GDB.
5833 You can now interrupt gdb while an attached process is running. This
5834 will cause the attached process to stop, and give control back to GDB.
5836 We fixed problems caused by using too many file descriptors
5837 for reading symbols from object files and libraries. This was
5838 especially a problem for programs that used many (~100) shared
5841 The `step' command now only enters a subroutine if there is line number
5842 information for the subroutine. Otherwise it acts like the `next'
5843 command. Previously, `step' would enter subroutines if there was
5844 any debugging information about the routine. This avoids problems
5845 when using `cc -g1' on MIPS machines.
5847 * Internal improvements
5849 GDB's internal interfaces have been improved to make it easier to support
5850 debugging of multiple languages in the future.
5852 GDB now uses a common structure for symbol information internally.
5853 Minimal symbols (derived from linkage symbols in object files), partial
5854 symbols (from a quick scan of debug information), and full symbols
5855 contain a common subset of information, making it easier to write
5856 shared code that handles any of them.
5858 * New command line options
5860 We now accept --silent as an alias for --quiet.
5864 The memory-mapped-malloc library is now licensed under the GNU Library
5865 General Public License.
5867 *** Changes in GDB-4.7:
5869 * Host/native/target split
5871 GDB has had some major internal surgery to untangle the support for
5872 hosts and remote targets. Now, when you configure GDB for a remote
5873 target, it will no longer load in all of the support for debugging
5874 local programs on the host. When fully completed and tested, this will
5875 ensure that arbitrary host/target combinations are possible.
5877 The primary conceptual shift is to separate the non-portable code in
5878 GDB into three categories. Host specific code is required any time GDB
5879 is compiled on that host, regardless of the target. Target specific
5880 code relates to the peculiarities of the target, but can be compiled on
5881 any host. Native specific code is everything else: it can only be
5882 built when the host and target are the same system. Child process
5883 handling and core file support are two common `native' examples.
5885 GDB's use of /proc for controlling Unix child processes is now cleaner.
5886 It has been split out into a single module under the `target_ops' vector,
5887 plus two native-dependent functions for each system that uses /proc.
5889 * New hosts supported
5891 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5892 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5893 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5895 * New targets supported
5897 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5898 68030 and CPU32 m68030-*-*, m68332-*-*
5900 * New native hosts supported
5902 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5903 (386bsd is not well tested yet)
5904 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5906 * New file formats supported
5908 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5909 supports reading of `a.out.adobe' object files, which are an a.out
5910 format extended with minimal information about multiple sections.
5914 `show copying' is the same as the old `info copying'.
5915 `show warranty' is the same as `info warrantee'.
5916 These were renamed for consistency. The old commands continue to work.
5918 `info handle' is a new alias for `info signals'.
5920 You can now define pre-command hooks, which attach arbitrary command
5921 scripts to any command. The commands in the hook will be executed
5922 prior to the user's command. You can also create a hook which will be
5923 executed whenever the program stops. See gdb.texinfo.
5927 We now deal with Cfront style name mangling, and can even extract type
5928 info from mangled symbols. GDB can automatically figure out which
5929 symbol mangling style your C++ compiler uses.
5931 Calling of methods and virtual functions has been improved as well.
5935 The crash that occured when debugging Sun Ansi-C compiled binaries is
5936 fixed. This was due to mishandling of the extra N_SO stabs output
5939 We also finally got Ultrix 4.2 running in house, and fixed core file
5940 support, with help from a dozen people on the net.
5942 John M. Farrell discovered that the reason that single-stepping was so
5943 slow on all of the Mips based platforms (primarily SGI and DEC) was
5944 that we were trying to demangle and lookup a symbol used for internal
5945 purposes on every instruction that was being stepped through. Changing
5946 the name of that symbol so that it couldn't be mistaken for a C++
5947 mangled symbol sped things up a great deal.
5949 Rich Pixley sped up symbol lookups in general by getting much smarter
5950 about when C++ symbol mangling is necessary. This should make symbol
5951 completion (TAB on the command line) much faster. It's not as fast as
5952 we'd like, but it's significantly faster than gdb-4.6.
5956 A new user controllable variable 'call_scratch_address' can
5957 specify the location of a scratch area to be used when GDB
5958 calls a function in the target. This is necessary because the
5959 usual method of putting the scratch area on the stack does not work
5960 in systems that have separate instruction and data spaces.
5962 We integrated changes to support the 29k UDI (Universal Debugger
5963 Interface), but discovered at the last minute that we didn't have all
5964 of the appropriate copyright paperwork. We are working with AMD to
5965 resolve this, and hope to have it available soon.
5969 We have sped up the remote serial line protocol, especially for targets
5970 with lots of registers. It now supports a new `expedited status' ('T')
5971 message which can be used in place of the existing 'S' status message.
5972 This allows the remote stub to send only the registers that GDB
5973 needs to make a quick decision about single-stepping or conditional
5974 breakpoints, eliminating the need to fetch the entire register set for
5975 each instruction being stepped through.
5977 The GDB remote serial protocol now implements a write-through cache for
5978 registers, only re-reading the registers if the target has run.
5980 There is also a new remote serial stub for SPARC processors. You can
5981 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5982 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5983 processor with a serial port.
5987 Configure.in files have become much easier to read and modify. A new
5988 `table driven' format makes it more obvious what configurations are
5989 supported, and what files each one uses.
5993 There is a new opcodes library which will eventually contain all of the
5994 disassembly routines and opcode tables. At present, it only contains
5995 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5996 disassembler (binutils/objdump) to share these routines.
5998 The libiberty library is now copylefted under the GNU Library General
5999 Public License. This allows more liberal use, and was done so libg++
6000 can use it. This makes no difference to GDB, since the Library License
6001 grants all the rights from the General Public License.
6005 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6006 reference to the stabs symbol info used by the debugger. It is (as far
6007 as we know) the only published document on this fascinating topic. We
6008 encourage you to read it, compare it to the stabs information on your
6009 system, and send improvements on the document in general (to
6010 bug-gdb@prep.ai.mit.edu).
6012 And, of course, many bugs have been fixed.
6015 *** Changes in GDB-4.6:
6017 * Better support for C++ function names
6019 GDB now accepts as input the "demangled form" of C++ overloaded function
6020 names and member function names, and can do command completion on such names
6021 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6022 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6023 Make use of command completion, it is your friend.
6025 GDB also now accepts a variety of C++ mangled symbol formats. They are
6026 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6027 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6028 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6029 for the list of formats.
6031 * G++ symbol mangling problem
6033 Recent versions of gcc have a bug in how they emit debugging information for
6034 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6035 directory) can be applied to gcc to fix the problem. Alternatively, if you
6036 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6037 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6038 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6041 * New 'maintenance' command
6043 All of the commands related to hacking GDB internals have been moved out of
6044 the main command set, and now live behind the 'maintenance' command. This
6045 can also be abbreviated as 'mt'. The following changes were made:
6047 dump-me -> maintenance dump-me
6048 info all-breakpoints -> maintenance info breakpoints
6049 printmsyms -> maintenance print msyms
6050 printobjfiles -> maintenance print objfiles
6051 printpsyms -> maintenance print psymbols
6052 printsyms -> maintenance print symbols
6054 The following commands are new:
6056 maintenance demangle Call internal GDB demangler routine to
6057 demangle a C++ link name and prints the result.
6058 maintenance print type Print a type chain for a given symbol
6060 * Change to .gdbinit file processing
6062 We now read the $HOME/.gdbinit file before processing the argv arguments
6063 (e.g. reading symbol files or core files). This allows global parameters to
6064 be set, which will apply during the symbol reading. The ./.gdbinit is still
6065 read after argv processing.
6067 * New hosts supported
6069 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6071 GNU/Linux support i386-unknown-linux or linux
6073 We are also including code to support the HP/PA running BSD and HPUX. This
6074 is almost guaranteed not to work, as we didn't have time to test or build it
6075 for this release. We are including it so that the more adventurous (or
6076 masochistic) of you can play with it. We also had major problems with the
6077 fact that the compiler that we got from HP doesn't support the -g option.
6080 * New targets supported
6082 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6084 * More smarts about finding #include files
6086 GDB now remembers the compilation directory for all include files, and for
6087 all files from which C is generated (like yacc and lex sources). This
6088 greatly improves GDB's ability to find yacc/lex sources, and include files,
6089 especially if you are debugging your program from a directory different from
6090 the one that contains your sources.
6092 We also fixed a bug which caused difficulty with listing and setting
6093 breakpoints in include files which contain C code. (In the past, you had to
6094 try twice in order to list an include file that you hadn't looked at before.)
6096 * Interesting infernals change
6098 GDB now deals with arbitrary numbers of sections, where the symbols for each
6099 section must be relocated relative to that section's landing place in the
6100 target's address space. This work was needed to support ELF with embedded
6101 stabs used by Solaris-2.0.
6103 * Bug fixes (of course!)
6105 There have been loads of fixes for the following things:
6106 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6107 i960, stabs, DOS(GO32), procfs, etc...
6109 See the ChangeLog for details.
6111 *** Changes in GDB-4.5:
6113 * New machines supported (host and target)
6115 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6117 SGI Irix-4.x mips-sgi-irix4 or iris4
6119 * New malloc package
6121 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6122 Mmalloc is capable of handling mutiple heaps of memory. It is also
6123 capable of saving a heap to a file, and then mapping it back in later.
6124 This can be used to greatly speedup the startup of GDB by using a
6125 pre-parsed symbol table which lives in a mmalloc managed heap. For
6126 more details, please read mmalloc/mmalloc.texi.
6130 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6131 'help info proc' for details.
6133 * MIPS ecoff symbol table format
6135 The code that reads MIPS symbol table format is now supported on all hosts.
6136 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6139 * File name changes for MS-DOS
6141 Many files in the config directories have been renamed to make it easier to
6142 support GDB on MS-DOSe systems (which have very restrictive file name
6143 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6144 environment) is close to working but has some remaining problems. Note
6145 that debugging of DOS programs is not supported, due to limitations
6146 in the ``operating system'', but it can be used to host cross-debugging.
6148 * Cross byte order fixes
6150 Many fixes have been made to support cross debugging of Sparc and MIPS
6151 targets from hosts whose byte order differs.
6153 * New -mapped and -readnow options
6155 If memory-mapped files are available on your system through the 'mmap'
6156 system call, you can use the -mapped option on the `file' or
6157 `symbol-file' commands to cause GDB to write the symbols from your
6158 program into a reusable file. If the program you are debugging is
6159 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6160 Future GDB debugging sessions will notice the presence of this file,
6161 and will quickly map in symbol information from it, rather than reading
6162 the symbol table from the executable program. Using the '-mapped'
6163 option in a GDB `file' or `symbol-file' command has the same effect as
6164 starting GDB with the '-mapped' command-line option.
6166 You can cause GDB to read the entire symbol table immediately by using
6167 the '-readnow' option with any of the commands that load symbol table
6168 information (or on the GDB command line). This makes the command
6169 slower, but makes future operations faster.
6171 The -mapped and -readnow options are typically combined in order to
6172 build a `fred.syms' file that contains complete symbol information.
6173 A simple GDB invocation to do nothing but build a `.syms' file for future
6176 gdb -batch -nx -mapped -readnow programname
6178 The `.syms' file is specific to the host machine on which GDB is run.
6179 It holds an exact image of GDB's internal symbol table. It cannot be
6180 shared across multiple host platforms.
6182 * longjmp() handling
6184 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6185 siglongjmp() without losing control. This feature has not yet been ported to
6186 all systems. It currently works on many 386 platforms, all MIPS-based
6187 platforms (SGI, DECstation, etc), and Sun3/4.
6191 Preliminary work has been put in to support the new Solaris OS from Sun. At
6192 this time, it can control and debug processes, but it is not capable of
6197 As always, many many bug fixes. The major areas were with g++, and mipsread.
6198 People using the MIPS-based platforms should experience fewer mysterious
6199 crashes and trashed symbol tables.
6201 *** Changes in GDB-4.4:
6203 * New machines supported (host and target)
6205 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6207 BSD Reno on Vax vax-dec-bsd
6208 Ultrix on Vax vax-dec-ultrix
6210 * New machines supported (target)
6212 AMD 29000 embedded, using EBMON a29k-none-none
6216 GDB continues to improve its handling of C++. `References' work better.
6217 The demangler has also been improved, and now deals with symbols mangled as
6218 per the Annotated C++ Reference Guide.
6220 GDB also now handles `stabs' symbol information embedded in MIPS
6221 `ecoff' symbol tables. Since the ecoff format was not easily
6222 extensible to handle new languages such as C++, this appeared to be a
6223 good way to put C++ debugging info into MIPS binaries. This option
6224 will be supported in the GNU C compiler, version 2, when it is
6227 * New features for SVR4
6229 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6230 shared libraries. Debugging dynamically linked programs should present
6231 only minor differences from debugging statically linked programs.
6233 The `info proc' command will print out information about any process
6234 on an SVR4 system (including the one you are debugging). At the moment,
6235 it prints the address mappings of the process.
6237 If you bring up GDB on another SVR4 system, please send mail to
6238 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6240 * Better dynamic linking support in SunOS
6242 Reading symbols from shared libraries which contain debugging symbols
6243 now works properly. However, there remain issues such as automatic
6244 skipping of `transfer vector' code during function calls, which
6245 make it harder to debug code in a shared library, than to debug the
6246 same code linked statically.
6250 GDB is now using the latest `getopt' routines from the FSF. This
6251 version accepts the -- prefix for options with long names. GDB will
6252 continue to accept the old forms (-option and +option) as well.
6253 Various single letter abbreviations for options have been explicity
6254 added to the option table so that they won't get overshadowed in the
6255 future by other options that begin with the same letter.
6259 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6260 Many assorted bugs have been handled. Many more remain to be handled.
6261 See the various ChangeLog files (primarily in gdb and bfd) for details.
6264 *** Changes in GDB-4.3:
6266 * New machines supported (host and target)
6268 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6269 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6270 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6272 * Almost SCO Unix support
6274 We had hoped to support:
6275 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6276 (except for core file support), but we discovered very late in the release
6277 that it has problems with process groups that render gdb unusable. Sorry
6278 about that. I encourage people to fix it and post the fixes.
6280 * Preliminary ELF and DWARF support
6282 GDB can read ELF object files on System V Release 4, and can handle
6283 debugging records for C, in DWARF format, in ELF files. This support
6284 is preliminary. If you bring up GDB on another SVR4 system, please
6285 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6290 GDB now uses the latest `readline' library. One user-visible change
6291 is that two tabs will list possible command completions, which previously
6292 required typing M-? (meta-question mark, or ESC ?).
6296 The `stepi' bug that many of you noticed has been squashed.
6297 Many bugs in C++ have been handled. Many more remain to be handled.
6298 See the various ChangeLog files (primarily in gdb and bfd) for details.
6300 * State of the MIPS world (in case you wondered):
6302 GDB can understand the symbol tables emitted by the compilers
6303 supplied by most vendors of MIPS-based machines, including DEC. These
6304 symbol tables are in a format that essentially nobody else uses.
6306 Some versions of gcc come with an assembler post-processor called
6307 mips-tfile. This program is required if you want to do source-level
6308 debugging of gcc-compiled programs. I believe FSF does not ship
6309 mips-tfile with gcc version 1, but it will eventually come with gcc
6312 Debugging of g++ output remains a problem. g++ version 1.xx does not
6313 really support it at all. (If you're lucky, you should be able to get
6314 line numbers and stack traces to work, but no parameters or local
6315 variables.) With some work it should be possible to improve the
6318 When gcc version 2 is released, you will have somewhat better luck.
6319 However, even then you will get confusing results for inheritance and
6322 We will eventually provide full debugging of g++ output on
6323 DECstations. This will probably involve some kind of stabs-in-ecoff
6324 encapulation, but the details have not been worked out yet.
6327 *** Changes in GDB-4.2:
6329 * Improved configuration
6331 Only one copy of `configure' exists now, and it is not self-modifying.
6332 Porting BFD is simpler.
6336 The `step' and `next' commands now only stop at the first instruction
6337 of a source line. This prevents the multiple stops that used to occur
6338 in switch statements, for-loops, etc. `Step' continues to stop if a
6339 function that has debugging information is called within the line.
6343 Lots of small bugs fixed. More remain.
6345 * New host supported (not target)
6347 Intel 386 PC clone running Mach i386-none-mach
6350 *** Changes in GDB-4.1:
6352 * Multiple source language support
6354 GDB now has internal scaffolding to handle several source languages.
6355 It determines the type of each source file from its filename extension,
6356 and will switch expression parsing and number formatting to match the
6357 language of the function in the currently selected stack frame.
6358 You can also specifically set the language to be used, with
6359 `set language c' or `set language modula-2'.
6363 GDB now has preliminary support for the GNU Modula-2 compiler,
6364 currently under development at the State University of New York at
6365 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6366 continue through the fall of 1991 and into 1992.
6368 Other Modula-2 compilers are currently not supported, and attempting to
6369 debug programs compiled with them will likely result in an error as the
6370 symbol table is read. Feel free to work on it, though!
6372 There are hooks in GDB for strict type checking and range checking,
6373 in the `Modula-2 philosophy', but they do not currently work.
6377 GDB can now write to executable and core files (e.g. patch
6378 a variable's value). You must turn this switch on, specify
6379 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6380 by assigning a new value to a variable. Modifications take
6383 * Automatic SunOS shared library reading
6385 When you run your program, GDB automatically determines where its
6386 shared libraries (if any) have been loaded, and reads their symbols.
6387 The `share' command is no longer needed. This also works when
6388 examining core files.
6392 You can specify the number of lines that the `list' command shows.
6395 * New machines supported (host and target)
6397 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6398 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6399 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6401 * New hosts supported (not targets)
6403 IBM RT/PC: romp-ibm-aix or rtpc
6405 * New targets supported (not hosts)
6407 AMD 29000 embedded with COFF a29k-none-coff
6408 AMD 29000 embedded with a.out a29k-none-aout
6409 Ultracomputer remote kernel debug a29k-nyu-kern
6411 * New remote interfaces
6417 *** Changes in GDB-4.0:
6421 Wide output is wrapped at good places to make the output more readable.
6423 Gdb now supports cross-debugging from a host machine of one type to a
6424 target machine of another type. Communication with the target system
6425 is over serial lines. The ``target'' command handles connecting to the
6426 remote system; the ``load'' command will download a program into the
6427 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6428 also supports debugging of realtime processes running under VxWorks,
6429 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6430 stub on the target system.
6432 New CPUs supported include the AMD 29000 and Intel 960.
6434 GDB now reads object files and symbol tables via a ``binary file''
6435 library, which allows a single copy of GDB to debug programs of multiple
6436 object file types such as a.out and coff.
6438 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6439 refcard.dvi and refcard.ps are available to format it).
6442 * Control-Variable user interface simplified
6444 All variables that control the operation of the debugger can be set
6445 by the ``set'' command, and displayed by the ``show'' command.
6447 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6448 ``Show prompt'' produces the response:
6449 Gdb's prompt is new-gdb=>.
6451 What follows are the NEW set commands. The command ``help set'' will
6452 print a complete list of old and new set commands. ``help set FOO''
6453 will give a longer description of the variable FOO. ``show'' will show
6454 all of the variable descriptions and their current settings.
6456 confirm on/off: Enables warning questions for operations that are
6457 hard to recover from, e.g. rerunning the program while
6458 it is already running. Default is ON.
6460 editing on/off: Enables EMACS style command line editing
6461 of input. Previous lines can be recalled with
6462 control-P, the current line can be edited with control-B,
6463 you can search for commands with control-R, etc.
6466 history filename NAME: NAME is where the gdb command history
6467 will be stored. The default is .gdb_history,
6468 or the value of the environment variable
6471 history size N: The size, in commands, of the command history. The
6472 default is 256, or the value of the environment variable
6475 history save on/off: If this value is set to ON, the history file will
6476 be saved after exiting gdb. If set to OFF, the
6477 file will not be saved. The default is OFF.
6479 history expansion on/off: If this value is set to ON, then csh-like
6480 history expansion will be performed on
6481 command line input. The default is OFF.
6483 radix N: Sets the default radix for input and output. It can be set
6484 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6485 in the current radix, so "set radix 10" is always a no-op.
6487 height N: This integer value is the number of lines on a page. Default
6488 is 24, the current `stty rows'' setting, or the ``li#''
6489 setting from the termcap entry matching the environment
6492 width N: This integer value is the number of characters on a line.
6493 Default is 80, the current `stty cols'' setting, or the ``co#''
6494 setting from the termcap entry matching the environment
6497 Note: ``set screensize'' is obsolete. Use ``set height'' and
6498 ``set width'' instead.
6500 print address on/off: Print memory addresses in various command displays,
6501 such as stack traces and structure values. Gdb looks
6502 more ``symbolic'' if you turn this off; it looks more
6503 ``machine level'' with it on. Default is ON.
6505 print array on/off: Prettyprint arrays. New convenient format! Default
6508 print demangle on/off: Print C++ symbols in "source" form if on,
6511 print asm-demangle on/off: Same, for assembler level printouts
6514 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6517 * Support for Epoch Environment.
6519 The epoch environment is a version of Emacs v18 with windowing. One
6520 new command, ``inspect'', is identical to ``print'', except that if you
6521 are running in the epoch environment, the value is printed in its own
6525 * Support for Shared Libraries
6527 GDB can now debug programs and core files that use SunOS shared libraries.
6528 Symbols from a shared library cannot be referenced
6529 before the shared library has been linked with the program (this
6530 happens after you type ``run'' and before the function main() is entered).
6531 At any time after this linking (including when examining core files
6532 from dynamically linked programs), gdb reads the symbols from each
6533 shared library when you type the ``sharedlibrary'' command.
6534 It can be abbreviated ``share''.
6536 sharedlibrary REGEXP: Load shared object library symbols for files
6537 matching a unix regular expression. No argument
6538 indicates to load symbols for all shared libraries.
6540 info sharedlibrary: Status of loaded shared libraries.
6545 A watchpoint stops execution of a program whenever the value of an
6546 expression changes. Checking for this slows down execution
6547 tremendously whenever you are in the scope of the expression, but is
6548 quite useful for catching tough ``bit-spreader'' or pointer misuse
6549 problems. Some machines such as the 386 have hardware for doing this
6550 more quickly, and future versions of gdb will use this hardware.
6552 watch EXP: Set a watchpoint (breakpoint) for an expression.
6554 info watchpoints: Information about your watchpoints.
6556 delete N: Deletes watchpoint number N (same as breakpoints).
6557 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6558 enable N: Re-enables watchpoint number N (same as breakpoints).
6561 * C++ multiple inheritance
6563 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6566 * C++ exception handling
6568 Gdb now supports limited C++ exception handling. Besides the existing
6569 ability to breakpoint on an exception handler, gdb can breakpoint on
6570 the raising of an exception (before the stack is peeled back to the
6573 catch FOO: If there is a FOO exception handler in the dynamic scope,
6574 set a breakpoint to catch exceptions which may be raised there.
6575 Multiple exceptions (``catch foo bar baz'') may be caught.
6577 info catch: Lists all exceptions which may be caught in the
6578 current stack frame.
6581 * Minor command changes
6583 The command ``call func (arg, arg, ...)'' now acts like the print
6584 command, except it does not print or save a value if the function's result
6585 is void. This is similar to dbx usage.
6587 The ``up'' and ``down'' commands now always print the frame they end up
6588 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6589 frames without printing.
6591 * New directory command
6593 'dir' now adds directories to the FRONT of the source search path.
6594 The path starts off empty. Source files that contain debug information
6595 about the directory in which they were compiled can be found even
6596 with an empty path; Sun CC and GCC include this information. If GDB can't
6597 find your source file in the current directory, type "dir .".
6599 * Configuring GDB for compilation
6601 For normal use, type ``./configure host''. See README or gdb.texinfo
6604 GDB now handles cross debugging. If you are remotely debugging between
6605 two different machines, type ``./configure host -target=targ''.
6606 Host is the machine where GDB will run; targ is the machine
6607 where the program that you are debugging will run.