1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.0
6 * GDB now supports access to the guarded-storage-control registers and the
7 software-based guarded-storage broadcast control registers on IBM z14.
9 * On Unix systems, GDB now supports transmitting environment variables
10 that are to be set or unset to GDBserver. These variables will
11 affect the environment to be passed to the remote inferior.
13 To inform GDB of environment variables that are to be transmitted to
14 GDBserver, use the "set environment" command. Only user set
15 environment variables are sent to GDBserver.
17 To inform GDB of environment variables that are to be unset before
18 the remote inferior is started by the GDBserver, use the "unset
23 ** New events gdb.new_inferior, gdb.inferior_deleted, and
24 gdb.new_thread are emitted. See the manual for further
27 * New features in the GDB remote stub, GDBserver
29 ** GDBserver is now able to start inferior processes with a
30 specified initial working directory.
32 The user can set the desired working directory to be used from
33 GDB using the new "set cwd" command.
35 ** New "--selftest" command line option runs some GDBserver self
36 tests. These self tests are disabled in releases.
38 ** On Unix systems, GDBserver now does globbing expansion and variable
39 substitution in inferior command line arguments.
41 This is done by starting inferiors using a shell, like GDB does.
42 See "set startup-with-shell" in the user manual for how to disable
43 this from GDB when using "target extended-remote". When using
44 "target remote", you can disable the startup with shell by using the
45 new "--no-startup-with-shell" GDBserver command line option.
47 ** On Unix systems, GDBserver now supports receiving environment
48 variables that are to be set or unset from GDB. These variables
49 will affect the environment to be passed to the inferior.
53 QEnvironmentHexEncoded
54 Inform GDBserver of an environment variable that is to be passed to
55 the inferior when starting it.
58 Inform GDBserver of an environment variable that is to be unset
59 before starting the remote inferior.
62 Inform GDBserver that the environment should be reset (i.e.,
63 user-set environment variables should be unset).
66 Indicates whether the inferior must be started with a shell or not.
69 Tell GDBserver that the inferior to be started should use a specific
72 * The "maintenance print c-tdesc" command now takes an optional
73 argument which is the file name of XML target description.
75 * The "maintenance selftest" command now takes an optional argument to
76 filter the tests to be run.
81 Set and show the current working directory for the inferior.
84 Set and show compilation command used for compiling and injecting code
85 with the 'compile' commands.
87 set debug separate-debug-file
88 show debug separate-debug-file
89 Control the display of debug output about separate debug file search.
92 List the registered selftests.
95 Start the debugged program stopping at the first instruction.
97 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
100 * Safer/improved support for debugging with no debug info
102 GDB no longer assumes functions with no debug information return
105 This means that GDB now refuses to call such functions unless you
106 tell it the function's type, by either casting the call to the
107 declared return type, or by casting the function to a function
108 pointer of the right type, and calling that:
110 (gdb) p getenv ("PATH")
111 'getenv' has unknown return type; cast the call to its declared return type
112 (gdb) p (char *) getenv ("PATH")
113 $1 = 0x7fffffffe "/usr/local/bin:/"...
114 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
115 $2 = 0x7fffffffe "/usr/local/bin:/"...
117 Similarly, GDB no longer assumes that global variables with no debug
118 info have type 'int', and refuses to print the variable's value
119 unless you tell it the variable's type:
122 'var' has unknown type; cast it to its declared type
126 * New native configurations
128 FreeBSD/aarch64 aarch64*-*-freebsd*
129 FreeBSD/arm arm*-*-freebsd*
133 FreeBSD/aarch64 aarch64*-*-freebsd*
134 FreeBSD/arm arm*-*-freebsd*
136 * Removed targets and native configurations
138 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
140 *** Changes in GDB 8.0
142 * GDB now supports access to the PKU register on GNU/Linux. The register is
143 added by the Memory Protection Keys for Userspace feature which will be
144 available in future Intel CPUs.
146 * GDB now supports C++11 rvalue references.
150 ** New functions to start, stop and access a running btrace recording.
151 ** Rvalue references are now supported in gdb.Type.
153 * GDB now supports recording and replaying rdrand and rdseed Intel 64
156 * Building GDB and GDBserver now requires a C++11 compiler.
158 For example, GCC 4.8 or later.
160 It is no longer possible to build GDB or GDBserver with a C
161 compiler. The --disable-build-with-cxx configure option has been
164 * Building GDB and GDBserver now requires GNU make >= 3.81.
166 It is no longer supported to build GDB or GDBserver with another
167 implementation of the make program or an earlier version of GNU make.
169 * Native debugging on MS-Windows supports command-line redirection
171 Command-line arguments used for starting programs on MS-Windows can
172 now include redirection symbols supported by native Windows shells,
173 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
174 as "run", "start", and "set args", as well as the corresponding MI
177 * Support for thread names on MS-Windows.
179 GDB now catches and handles the special exception that programs
180 running on MS-Windows use to assign names to threads in the
183 * Support for Java programs compiled with gcj has been removed.
185 * User commands now accept an unlimited number of arguments.
186 Previously, only up to 10 was accepted.
188 * The "eval" command now expands user-defined command arguments.
190 This makes it easier to process a variable number of arguments:
195 eval "print $arg%d", $i
200 * Target descriptions can now describe registers for sparc32 and sparc64.
202 * GDB now supports DWARF version 5 (debug information format).
203 Its .debug_names index is not yet supported.
205 * New native configurations
207 FreeBSD/mips mips*-*-freebsd
211 Synopsys ARC arc*-*-elf32
212 FreeBSD/mips mips*-*-freebsd
214 * Removed targets and native configurations
216 Alpha running FreeBSD alpha*-*-freebsd*
217 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
222 Erases all the flash memory regions reported by the target.
224 maint print arc arc-instruction address
225 Print internal disassembler information about instruction at a given address.
229 set disassembler-options
230 show disassembler-options
231 Controls the passing of target specific information to the disassembler.
232 If it is necessary to specify more than one disassembler option then
233 multiple options can be placed together into a comma separated list.
234 The default value is the empty string. Currently, the only supported
235 targets are ARM, PowerPC and S/390.
240 Erases all the flash memory regions reported by the target. This is
241 equivalent to the CLI command flash-erase.
243 -file-list-shared-libraries
244 List the shared libraries in the program. This is
245 equivalent to the CLI command "info shared".
247 *** Changes in GDB 7.12
249 * GDB and GDBserver now build with a C++ compiler by default.
251 The --enable-build-with-cxx configure option is now enabled by
252 default. One must now explicitly configure with
253 --disable-build-with-cxx in order to build with a C compiler. This
254 option will be removed in a future release.
256 * GDBserver now supports recording btrace without maintaining an active
259 * GDB now supports a negative repeat count in the 'x' command to examine
260 memory backward from the given address. For example:
263 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
264 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
265 (gdb) x/-5i 0x0000000000400580
266 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
267 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
268 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
269 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
270 0x40057b <main(int, char**)+25>:
271 callq 0x400536 <Func1(int, char const*)>
273 * Fortran: Support structures with fields of dynamic types and
274 arrays of dynamic types.
276 * The symbol dumping maintenance commands have new syntax.
277 maint print symbols [-pc address] [--] [filename]
278 maint print symbols [-objfile objfile] [-source source] [--] [filename]
279 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
280 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
281 maint print msymbols [-objfile objfile] [--] [filename]
283 * GDB now supports multibit bitfields and enums in target register
286 * New Python-based convenience function $_as_string(val), which returns
287 the textual representation of a value. This function is especially
288 useful to obtain the text label of an enum value.
290 * Intel MPX bound violation handling.
292 Segmentation faults caused by a Intel MPX boundary violation
293 now display the kind of violation (upper or lower), the memory
294 address accessed and the memory bounds, along with the usual
295 signal received and code location.
299 Program received signal SIGSEGV, Segmentation fault
300 Upper bound violation while accessing address 0x7fffffffc3b3
301 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
302 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
304 * Rust language support.
305 GDB now supports debugging programs written in the Rust programming
306 language. See https://www.rust-lang.org/ for more information about
309 * Support for running interpreters on specified input/output devices
311 GDB now supports a new mechanism that allows frontends to provide
312 fully featured GDB console views, as a better alternative to
313 building such views on top of the "-interpreter-exec console"
314 command. See the new "new-ui" command below. With that command,
315 frontends can now start GDB in the traditional command-line mode
316 running in an embedded terminal emulator widget, and create a
317 separate MI interpreter running on a specified i/o device. In this
318 way, GDB handles line editing, history, tab completion, etc. in the
319 console all by itself, and the GUI uses the separate MI interpreter
320 for its own control and synchronization, invisible to the command
323 * The "catch syscall" command catches groups of related syscalls.
325 The "catch syscall" command now supports catching a group of related
326 syscalls using the 'group:' or 'g:' prefix.
331 skip -gfile file-glob-pattern
332 skip -function function
333 skip -rfunction regular-expression
334 A generalized form of the skip command, with new support for
335 glob-style file names and regular expressions for function names.
336 Additionally, a file spec and a function spec may now be combined.
338 maint info line-table REGEXP
339 Display the contents of GDB's internal line table data struture.
342 Run any GDB unit tests that were compiled in.
345 Start a new user interface instance running INTERP as interpreter,
346 using the TTY file for input/output.
350 ** gdb.Breakpoint objects have a new attribute "pending", which
351 indicates whether the breakpoint is pending.
352 ** Three new breakpoint-related events have been added:
353 gdb.breakpoint_created, gdb.breakpoint_modified, and
354 gdb.breakpoint_deleted.
357 Signal ("set") the given MS-Windows event object. This is used in
358 conjunction with the Windows JIT debugging (AeDebug) support, where
359 the OS suspends a crashing process until a debugger can attach to
360 it. Resuming the crashing process, in order to debug it, is done by
363 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
364 was added in GDBserver, including JIT compiling fast tracepoint's
365 conditional expression bytecode into native code.
367 * Support for various remote target protocols and ROM monitors has
370 target m32rsdi Remote M32R debugging over SDI
371 target mips MIPS remote debugging protocol
372 target pmon PMON ROM monitor
373 target ddb NEC's DDB variant of PMON for Vr4300
374 target rockhopper NEC RockHopper variant of PMON
375 target lsi LSI variant of PMO
377 * Support for tracepoints and fast tracepoints on powerpc-linux,
378 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
379 including JIT compiling fast tracepoint's conditional expression
380 bytecode into native code.
382 * MI async record =record-started now includes the method and format used for
383 recording. For example:
385 =record-started,thread-group="i1",method="btrace",format="bts"
387 * MI async record =thread-selected now includes the frame field. For example:
389 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
393 Andes NDS32 nds32*-*-elf
395 *** Changes in GDB 7.11
397 * GDB now supports debugging kernel-based threads on FreeBSD.
399 * Per-inferior thread numbers
401 Thread numbers are now per inferior instead of global. If you're
402 debugging multiple inferiors, GDB displays thread IDs using a
403 qualified INF_NUM.THR_NUM form. For example:
407 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
408 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
409 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
410 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
412 As consequence, thread numbers as visible in the $_thread
413 convenience variable and in Python's InferiorThread.num attribute
414 are no longer unique between inferiors.
416 GDB now maintains a second thread ID per thread, referred to as the
417 global thread ID, which is the new equivalent of thread numbers in
418 previous releases. See also $_gthread below.
420 For backwards compatibility, MI's thread IDs always refer to global
423 * Commands that accept thread IDs now accept the qualified
424 INF_NUM.THR_NUM form as well. For example:
427 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
430 * In commands that accept a list of thread IDs, you can now refer to
431 all threads of an inferior using a star wildcard. GDB accepts
432 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
433 refer to all threads of the current inferior. For example, "info
436 * You can use "info threads -gid" to display the global thread ID of
439 * The new convenience variable $_gthread holds the global number of
442 * The new convenience variable $_inferior holds the number of the
445 * GDB now displays the ID and name of the thread that hit a breakpoint
446 or received a signal, if your program is multi-threaded. For
449 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
450 Thread 1 "main" received signal SIGINT, Interrupt.
452 * Record btrace now supports non-stop mode.
454 * Support for tracepoints on aarch64-linux was added in GDBserver.
456 * The 'record instruction-history' command now indicates speculative execution
457 when using the Intel Processor Trace recording format.
459 * GDB now allows users to specify explicit locations, bypassing
460 the linespec parser. This feature is also available to GDB/MI
463 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
464 GDB now is able to debug both AArch64 applications and ARM applications
467 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
468 including JIT compiling fast tracepoint's conditional expression bytecode
471 * GDB now supports displaced stepping on AArch64 GNU/Linux.
473 * "info threads", "info inferiors", "info display", "info checkpoints"
474 and "maint info program-spaces" now list the corresponding items in
475 ascending ID order, for consistency with all other "info" commands.
477 * In Ada, the overloads selection menu has been enhanced to display the
478 parameter types and the return types for the matching overloaded subprograms.
482 maint set target-non-stop (on|off|auto)
483 maint show target-non-stop
484 Control whether GDB targets always operate in non-stop mode even if
485 "set non-stop" is "off". The default is "auto", meaning non-stop
486 mode is enabled if supported by the target.
488 maint set bfd-sharing
489 maint show bfd-sharing
490 Control the reuse of bfd objects.
494 Control display of debugging info regarding bfd caching.
498 Control display of debugging info regarding FreeBSD threads.
500 set remote multiprocess-extensions-packet
501 show remote multiprocess-extensions-packet
502 Set/show the use of the remote protocol multiprocess extensions.
504 set remote thread-events
505 show remote thread-events
506 Set/show the use of thread create/exit events.
508 set ada print-signatures on|off
509 show ada print-signatures"
510 Control whether parameter types and return types are displayed in overloads
511 selection menus. It is activaled (@code{on}) by default.
515 Controls the maximum size of memory, in bytes, that GDB will
516 allocate for value contents. Prevents incorrect programs from
517 causing GDB to allocate overly large buffers. Default is 64k.
519 * The "disassemble" command accepts a new modifier: /s.
520 It prints mixed source+disassembly like /m with two differences:
521 - disassembled instructions are now printed in program order, and
522 - and source for all relevant files is now printed.
523 The "/m" option is now considered deprecated: its "source-centric"
524 output hasn't proved useful in practice.
526 * The "record instruction-history" command accepts a new modifier: /s.
527 It behaves exactly like /m and prints mixed source+disassembly.
529 * The "set scheduler-locking" command supports a new mode "replay".
530 It behaves like "off" in record mode and like "on" in replay mode.
532 * Support for various ROM monitors has been removed:
534 target dbug dBUG ROM monitor for Motorola ColdFire
535 target picobug Motorola picobug monitor
536 target dink32 DINK32 ROM monitor for PowerPC
537 target m32r Renesas M32R/D ROM monitor
538 target mon2000 mon2000 ROM monitor
539 target ppcbug PPCBUG ROM monitor for PowerPC
541 * Support for reading/writing memory and extracting values on architectures
542 whose memory is addressable in units of any integral multiple of 8 bits.
547 Indicates that an exec system call was executed.
549 exec-events feature in qSupported
550 The qSupported packet allows GDB to request support for exec
551 events using the new 'gdbfeature' exec-event, and the qSupported
552 response can contain the corresponding 'stubfeature'. Set and
553 show commands can be used to display whether these features are enabled.
556 Equivalent to interrupting with the ^C character, but works in
559 thread created stop reason (T05 create:...)
560 Indicates that the thread was just created and is stopped at entry.
562 thread exit stop reply (w exitcode;tid)
563 Indicates that the thread has terminated.
566 Enables/disables thread create and exit event reporting. For
567 example, this is used in non-stop mode when GDB stops a set of
568 threads and synchronously waits for the their corresponding stop
569 replies. Without exit events, if one of the threads exits, GDB
570 would hang forever not knowing that it should no longer expect a
571 stop for that same thread.
574 Indicates that there are no resumed threads left in the target (all
575 threads are stopped). The remote stub reports support for this stop
576 reply to GDB's qSupported query.
579 Enables/disables catching syscalls from the inferior process.
580 The remote stub reports support for this packet to GDB's qSupported query.
582 syscall_entry stop reason
583 Indicates that a syscall was just called.
585 syscall_return stop reason
586 Indicates that a syscall just returned.
588 * Extended-remote exec events
590 ** GDB now has support for exec events on extended-remote Linux targets.
591 For such targets with Linux kernels 2.5.46 and later, this enables
592 follow-exec-mode and exec catchpoints.
594 set remote exec-event-feature-packet
595 show remote exec-event-feature-packet
596 Set/show the use of the remote exec event feature.
598 * Thread names in remote protocol
600 The reply to qXfer:threads:read may now include a name attribute for each
603 * Target remote mode fork and exec events
605 ** GDB now has support for fork and exec events on target remote mode
606 Linux targets. For such targets with Linux kernels 2.5.46 and later,
607 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
608 fork and exec catchpoints.
610 * Remote syscall events
612 ** GDB now has support for catch syscall on remote Linux targets,
613 currently enabled on x86/x86_64 architectures.
615 set remote catch-syscall-packet
616 show remote catch-syscall-packet
617 Set/show the use of the remote catch syscall feature.
621 ** The -var-set-format command now accepts the zero-hexadecimal
622 format. It outputs data in hexadecimal format with zero-padding on the
627 ** gdb.InferiorThread objects have a new attribute "global_num",
628 which refers to the thread's global thread ID. The existing
629 "num" attribute now refers to the thread's per-inferior number.
630 See "Per-inferior thread numbers" above.
631 ** gdb.InferiorThread objects have a new attribute "inferior", which
632 is the Inferior object the thread belongs to.
634 *** Changes in GDB 7.10
636 * Support for process record-replay and reverse debugging on aarch64*-linux*
637 targets has been added. GDB now supports recording of A64 instruction set
638 including advance SIMD instructions.
640 * Support for Sun's version of the "stabs" debug file format has been removed.
642 * GDB now honors the content of the file /proc/PID/coredump_filter
643 (PID is the process ID) on GNU/Linux systems. This file can be used
644 to specify the types of memory mappings that will be included in a
645 corefile. For more information, please refer to the manual page of
646 "core(5)". GDB also has a new command: "set use-coredump-filter
647 on|off". It allows to set whether GDB will read the content of the
648 /proc/PID/coredump_filter file when generating a corefile.
650 * The "info os" command on GNU/Linux can now display information on
652 "info os cpus" Listing of all cpus/cores on the system
654 * GDB has two new commands: "set serial parity odd|even|none" and
655 "show serial parity". These allows to set or show parity for the
658 * The "info source" command now displays the producer string if it was
659 present in the debug info. This typically includes the compiler version
660 and may include things like its command line arguments.
662 * The "info dll", an alias of the "info sharedlibrary" command,
663 is now available on all platforms.
665 * Directory names supplied to the "set sysroot" commands may be
666 prefixed with "target:" to tell GDB to access shared libraries from
667 the target system, be it local or remote. This replaces the prefix
668 "remote:". The default sysroot has been changed from "" to
669 "target:". "remote:" is automatically converted to "target:" for
670 backward compatibility.
672 * The system root specified by "set sysroot" will be prepended to the
673 filename of the main executable (if reported to GDB as absolute by
674 the operating system) when starting processes remotely, and when
675 attaching to already-running local or remote processes.
677 * GDB now supports automatic location and retrieval of executable
678 files from remote targets. Remote debugging can now be initiated
679 using only a "target remote" or "target extended-remote" command
680 (no "set sysroot" or "file" commands are required). See "New remote
683 * The "dump" command now supports verilog hex format.
685 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
687 * On GNU/Linux, GDB and gdbserver are now able to access executable
688 and shared library files without a "set sysroot" command when
689 attaching to processes running in different mount namespaces from
690 the debugger. This makes it possible to attach to processes in
691 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
692 See "New remote packets" below.
694 * The "tui reg" command now provides completion for all of the
695 available register groups, including target specific groups.
697 * The HISTSIZE environment variable is no longer read when determining
698 the size of GDB's command history. GDB now instead reads the dedicated
699 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
700 disables truncation of command history. Non-numeric values of GDBHISTSIZE
705 ** Memory ports can now be unbuffered.
709 ** gdb.Objfile objects have a new attribute "username",
710 which is the name of the objfile as specified by the user,
711 without, for example, resolving symlinks.
712 ** You can now write frame unwinders in Python.
713 ** gdb.Type objects have a new method "optimized_out",
714 returning optimized out gdb.Value instance of this type.
715 ** gdb.Value objects have new methods "reference_value" and
716 "const_value" which return a reference to the value and a
717 "const" version of the value respectively.
721 maint print symbol-cache
722 Print the contents of the symbol cache.
724 maint print symbol-cache-statistics
725 Print statistics of symbol cache usage.
727 maint flush-symbol-cache
728 Flush the contents of the symbol cache.
732 Start branch trace recording using Branch Trace Store (BTS) format.
735 Evaluate expression by using the compiler and print result.
739 Explicit commands for enabling and disabling tui mode.
742 set mpx bound on i386 and amd64
743 Support for bound table investigation on Intel MPX enabled applications.
747 Start branch trace recording using Intel Processor Trace format.
750 Print information about branch tracing internals.
752 maint btrace packet-history
753 Print the raw branch tracing data.
755 maint btrace clear-packet-history
756 Discard the stored raw branch tracing data.
759 Discard all branch tracing data. It will be fetched and processed
760 anew by the next "record" command.
765 Renamed from "set debug dwarf2-die".
767 Renamed from "show debug dwarf2-die".
770 Renamed from "set debug dwarf2-read".
771 show debug dwarf-read
772 Renamed from "show debug dwarf2-read".
774 maint set dwarf always-disassemble
775 Renamed from "maint set dwarf2 always-disassemble".
776 maint show dwarf always-disassemble
777 Renamed from "maint show dwarf2 always-disassemble".
779 maint set dwarf max-cache-age
780 Renamed from "maint set dwarf2 max-cache-age".
781 maint show dwarf max-cache-age
782 Renamed from "maint show dwarf2 max-cache-age".
785 show debug dwarf-line
786 Control display of debugging info regarding DWARF line processing.
790 Set the maximum number of candidates to be considered during
791 completion. The default value is 200. This limit allows GDB
792 to avoid generating large completion lists, the computation of
793 which can cause the debugger to become temporarily unresponsive.
795 set history remove-duplicates
796 show history remove-duplicates
797 Control the removal of duplicate history entries.
799 maint set symbol-cache-size
800 maint show symbol-cache-size
801 Control the size of the symbol cache.
803 set|show record btrace bts buffer-size
804 Set and show the size of the ring buffer used for branch tracing in
806 The obtained size may differ from the requested size. Use "info
807 record" to see the obtained buffer size.
809 set debug linux-namespaces
810 show debug linux-namespaces
811 Control display of debugging info regarding Linux namespaces.
813 set|show record btrace pt buffer-size
814 Set and show the size of the ring buffer used for branch tracing in
815 Intel Processor Trace format.
816 The obtained size may differ from the requested size. Use "info
817 record" to see the obtained buffer size.
819 maint set|show btrace pt skip-pad
820 Set and show whether PAD packets are skipped when computing the
823 * The command 'thread apply all' can now support new option '-ascending'
824 to call its specified command for all threads in ascending order.
826 * Python/Guile scripting
828 ** GDB now supports auto-loading of Python/Guile scripts contained in the
829 special section named `.debug_gdb_scripts'.
833 qXfer:btrace-conf:read
834 Return the branch trace configuration for the current thread.
836 Qbtrace-conf:bts:size
837 Set the requested ring buffer size for branch tracing in BTS format.
840 Enable Intel Procesor Trace-based branch tracing for the current
841 process. The remote stub reports support for this packet to GDB's
845 Set the requested ring buffer size for branch tracing in Intel Processor
849 Indicates a memory breakpoint instruction was executed, irrespective
850 of whether it was GDB that planted the breakpoint or the breakpoint
851 is hardcoded in the program. This is required for correct non-stop
855 Indicates the target stopped for a hardware breakpoint. This is
856 required for correct non-stop mode operation.
859 Return information about files on the remote system.
862 Return the full absolute name of the file that was executed to
863 create a process running on the remote system.
866 Select the filesystem on which vFile: operations with filename
867 arguments will operate. This is required for GDB to be able to
868 access files on remote targets where the remote stub does not
869 share a common filesystem with the inferior(s).
872 Indicates that a fork system call was executed.
875 Indicates that a vfork system call was executed.
877 vforkdone stop reason
878 Indicates that a vfork child of the specified process has executed
879 an exec or exit, allowing the vfork parent to resume execution.
881 fork-events and vfork-events features in qSupported
882 The qSupported packet allows GDB to request support for fork and
883 vfork events using new 'gdbfeatures' fork-events and vfork-events,
884 and the qSupported response can contain the corresponding
885 'stubfeatures'. Set and show commands can be used to display
886 whether these features are enabled.
888 * Extended-remote fork events
890 ** GDB now has support for fork events on extended-remote Linux
891 targets. For targets with Linux kernels 2.5.60 and later, this
892 enables follow-fork-mode and detach-on-fork for both fork and
893 vfork, as well as fork and vfork catchpoints.
895 * The info record command now shows the recording format and the
896 branch tracing configuration for the current thread when using
897 the btrace record target.
898 For the BTS format, it shows the ring buffer size.
900 * GDB now has support for DTrace USDT (Userland Static Defined
901 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
903 * GDB now supports access to vector registers on S/390 GNU/Linux
906 * Removed command line options
908 -xdb HP-UX XDB compatibility mode.
910 * Removed targets and native configurations
912 HP/PA running HP-UX hppa*-*-hpux*
913 Itanium running HP-UX ia64-*-hpux*
915 * New configure options
918 This configure option allows the user to build GDB with support for
919 Intel Processor Trace (default: auto). This requires libipt.
921 --with-libipt-prefix=PATH
922 Specify the path to the version of libipt that GDB should use.
923 $PATH/include should contain the intel-pt.h header and
924 $PATH/lib should contain the libipt.so library.
926 *** Changes in GDB 7.9.1
930 ** Xmethods can now specify a result type.
932 *** Changes in GDB 7.9
934 * GDB now supports hardware watchpoints on x86 GNU Hurd.
938 ** You can now access frame registers from Python scripts.
939 ** New attribute 'producer' for gdb.Symtab objects.
940 ** gdb.Objfile objects have a new attribute "progspace",
941 which is the gdb.Progspace object of the containing program space.
942 ** gdb.Objfile objects have a new attribute "owner".
943 ** gdb.Objfile objects have a new attribute "build_id",
944 which is the build ID generated when the file was built.
945 ** gdb.Objfile objects have a new method "add_separate_debug_file".
946 ** A new event "gdb.clear_objfiles" has been added, triggered when
947 selecting a new file to debug.
948 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
949 ** New function gdb.lookup_objfile.
951 New events which are triggered when GDB modifies the state of the
954 ** gdb.events.inferior_call_pre: Function call is about to be made.
955 ** gdb.events.inferior_call_post: Function call has just been made.
956 ** gdb.events.memory_changed: A memory location has been altered.
957 ** gdb.events.register_changed: A register has been altered.
959 * New Python-based convenience functions:
961 ** $_caller_is(name [, number_of_frames])
962 ** $_caller_matches(regexp [, number_of_frames])
963 ** $_any_caller_is(name [, number_of_frames])
964 ** $_any_caller_matches(regexp [, number_of_frames])
966 * GDB now supports the compilation and injection of source code into
967 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
968 to compile the source code to object code, and if successful, inject
969 and execute that code within the current context of the inferior.
970 Currently the C language is supported. The commands used to
971 interface with this new feature are:
973 compile code [-raw|-r] [--] [source code]
974 compile file [-raw|-r] filename
978 demangle [-l language] [--] name
979 Demangle "name" in the specified language, or the current language
980 if elided. This command is renamed from the "maint demangle" command.
981 The latter is kept as a no-op to avoid "maint demangle" being interpreted
982 as "maint demangler-warning".
984 queue-signal signal-name-or-number
985 Queue a signal to be delivered to the thread when it is resumed.
987 add-auto-load-scripts-directory directory
988 Add entries to the list of directories from which to load auto-loaded
991 maint print user-registers
992 List all currently available "user" registers.
994 compile code [-r|-raw] [--] [source code]
995 Compile, inject, and execute in the inferior the executable object
996 code produced by compiling the provided source code.
998 compile file [-r|-raw] filename
999 Compile and inject into the inferior the executable object code
1000 produced by compiling the source code stored in the filename
1003 * On resume, GDB now always passes the signal the program had stopped
1004 for to the thread the signal was sent to, even if the user changed
1005 threads before resuming. Previously GDB would often (but not
1006 always) deliver the signal to the thread that happens to be current
1009 * Conversely, the "signal" command now consistently delivers the
1010 requested signal to the current thread. GDB now asks for
1011 confirmation if the program had stopped for a signal and the user
1012 switched threads meanwhile.
1014 * "breakpoint always-inserted" modes "off" and "auto" merged.
1016 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1017 won't remove breakpoints from the target until all threads stop,
1018 even in non-stop mode. The "auto" mode has been removed, and "off"
1019 is now the default mode.
1023 set debug symbol-lookup
1024 show debug symbol-lookup
1025 Control display of debugging info regarding symbol lookup.
1029 ** The -list-thread-groups command outputs an exit-code field for
1030 inferiors that have exited.
1034 MIPS SDE mips*-sde*-elf*
1038 Support for these obsolete configurations has been removed.
1040 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1041 SGI Irix-5.x mips-*-irix5*
1042 SGI Irix-6.x mips-*-irix6*
1043 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1044 VAX running Ultrix vax-*-ultrix*
1046 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1047 and "assf"), have been removed. Use the "sharedlibrary" command, or
1048 its alias "share", instead.
1050 *** Changes in GDB 7.8
1052 * New command line options
1055 This is an alias for the --data-directory option.
1057 * GDB supports printing and modifying of variable length automatic arrays
1058 as specified in ISO C99.
1060 * The ARM simulator now supports instruction level tracing
1061 with or without disassembly.
1065 GDB now has support for scripting using Guile. Whether this is
1066 available is determined at configure time.
1067 Guile version 2.0 or greater is required.
1068 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1070 * New commands (for set/show, see "New options" below)
1074 Invoke CODE by passing it to the Guile interpreter.
1078 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1080 info auto-load guile-scripts [regexp]
1081 Print the list of automatically loaded Guile scripts.
1083 * The source command is now capable of sourcing Guile scripts.
1084 This feature is dependent on the debugger being built with Guile support.
1088 set print symbol-loading (off|brief|full)
1089 show print symbol-loading
1090 Control whether to print informational messages when loading symbol
1091 information for a file. The default is "full", but when debugging
1092 programs with large numbers of shared libraries the amount of output
1093 becomes less useful.
1095 set guile print-stack (none|message|full)
1096 show guile print-stack
1097 Show a stack trace when an error is encountered in a Guile script.
1099 set auto-load guile-scripts (on|off)
1100 show auto-load guile-scripts
1101 Control auto-loading of Guile script files.
1103 maint ada set ignore-descriptive-types (on|off)
1104 maint ada show ignore-descriptive-types
1105 Control whether the debugger should ignore descriptive types in Ada
1106 programs. The default is not to ignore the descriptive types. See
1107 the user manual for more details on descriptive types and the intended
1108 usage of this option.
1110 set auto-connect-native-target
1112 Control whether GDB is allowed to automatically connect to the
1113 native target for the run, attach, etc. commands when not connected
1114 to any target yet. See also "target native" below.
1116 set record btrace replay-memory-access (read-only|read-write)
1117 show record btrace replay-memory-access
1118 Control what memory accesses are allowed during replay.
1120 maint set target-async (on|off)
1121 maint show target-async
1122 This controls whether GDB targets operate in synchronous or
1123 asynchronous mode. Normally the default is asynchronous, if it is
1124 available; but this can be changed to more easily debug problems
1125 occurring only in synchronous mode.
1127 set mi-async (on|off)
1129 Control whether MI asynchronous mode is preferred. This supersedes
1130 "set target-async" of previous GDB versions.
1132 * "set target-async" is deprecated as a CLI option and is now an alias
1133 for "set mi-async" (only puts MI into async mode).
1135 * Background execution commands (e.g., "c&", "s&", etc.) are now
1136 possible ``out of the box'' if the target supports them. Previously
1137 the user would need to explicitly enable the possibility with the
1138 "set target-async on" command.
1140 * New features in the GDB remote stub, GDBserver
1142 ** New option --debug-format=option1[,option2,...] allows one to add
1143 additional text to each output. At present only timestamps
1144 are supported: --debug-format=timestamps.
1145 Timestamps can also be turned on with the
1146 "monitor set debug-format timestamps" command from GDB.
1148 * The 'record instruction-history' command now starts counting instructions
1149 at one. This also affects the instruction ranges reported by the
1150 'record function-call-history' command when given the /i modifier.
1152 * The command 'record function-call-history' supports a new modifier '/c' to
1153 indent the function names based on their call stack depth.
1154 The fields for the '/i' and '/l' modifier have been reordered.
1155 The source line range is now prefixed with 'at'.
1156 The instruction range is now prefixed with 'inst'.
1157 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1158 "record instruction-history" and "list" commands.
1160 * The ranges given as arguments to the 'record function-call-history' and
1161 'record instruction-history' commands are now inclusive.
1163 * The btrace record target now supports the 'record goto' command.
1164 For locations inside the execution trace, the back trace is computed
1165 based on the information stored in the execution trace.
1167 * The btrace record target supports limited reverse execution and replay.
1168 The target does not record data and therefore does not allow reading
1169 memory or registers.
1171 * The "catch syscall" command now works on s390*-linux* targets.
1173 * The "compare-sections" command is no longer specific to target
1174 remote. It now works with all targets.
1176 * All native targets are now consistently called "native".
1177 Consequently, the "target child", "target GNU", "target djgpp",
1178 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1179 commands have been replaced with "target native". The QNX/NTO port
1180 leaves the "procfs" target in place and adds a "native" target for
1181 consistency with other ports. The impact on users should be minimal
1182 as these commands previously either throwed an error, or were
1183 no-ops. The target's name is visible in the output of the following
1184 commands: "help target", "info target", "info files", "maint print
1187 * The "target native" command now connects to the native target. This
1188 can be used to launch native programs even when "set
1189 auto-connect-native-target" is set to off.
1191 * GDB now supports access to Intel MPX registers on GNU/Linux.
1193 * Support for Intel AVX-512 registers on GNU/Linux.
1194 Support displaying and modifying Intel AVX-512 registers
1195 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1197 * New remote packets
1199 qXfer:btrace:read's annex
1200 The qXfer:btrace:read packet supports a new annex 'delta' to read
1201 branch trace incrementally.
1205 ** Valid Python operations on gdb.Value objects representing
1206 structs/classes invoke the corresponding overloaded operators if
1208 ** New `Xmethods' feature in the Python API. Xmethods are
1209 additional methods or replacements for existing methods of a C++
1210 class. This feature is useful for those cases where a method
1211 defined in C++ source code could be inlined or optimized out by
1212 the compiler, making it unavailable to GDB.
1215 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1217 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1218 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1219 its alias "share", instead.
1221 * The commands "set remotebaud" and "show remotebaud" are no longer
1222 supported. Use "set serial baud" and "show serial baud" (respectively)
1227 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1228 target-async". The latter is left as a deprecated alias of the
1229 former for backward compatibility. If the target supports it,
1230 CLI background execution commands are now always possible by
1231 default, independently of whether the frontend stated a
1232 preference for asynchronous execution with "-gdb-set mi-async".
1233 Previously "-gdb-set target-async off" affected both MI execution
1234 commands and CLI execution commands.
1236 *** Changes in GDB 7.7
1238 * Improved support for process record-replay and reverse debugging on
1239 arm*-linux* targets. Support for thumb32 and syscall instruction
1240 recording has been added.
1242 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1244 * GDB now supports Fission DWP file format version 2.
1245 http://gcc.gnu.org/wiki/DebugFission
1247 * New convenience function "$_isvoid", to check whether an expression
1248 is void. A void expression is an expression where the type of the
1249 result is "void". For example, some convenience variables may be
1250 "void" when evaluated (e.g., "$_exitcode" before the execution of
1251 the program being debugged; or an undefined convenience variable).
1252 Another example, when calling a function whose return type is
1255 * The "maintenance print objfiles" command now takes an optional regexp.
1257 * The "catch syscall" command now works on arm*-linux* targets.
1259 * GDB now consistently shows "<not saved>" when printing values of
1260 registers the debug info indicates have not been saved in the frame
1261 and there's nowhere to retrieve them from
1262 (callee-saved/call-clobbered registers):
1267 (gdb) info registers rax
1270 Before, the former would print "<optimized out>", and the latter
1271 "*value not available*".
1273 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1278 ** Frame filters and frame decorators have been added.
1279 ** Temporary breakpoints are now supported.
1280 ** Line tables representation has been added.
1281 ** New attribute 'parent_type' for gdb.Field objects.
1282 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1283 ** New attribute 'name' for gdb.Type objects.
1287 Nios II ELF nios2*-*-elf
1288 Nios II GNU/Linux nios2*-*-linux
1289 Texas Instruments MSP430 msp430*-*-elf
1291 * Removed native configurations
1293 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1294 been removed. ELF variants of these configurations are kept supported.
1296 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1297 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1298 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1299 i[34567]86-*-openbsd3.[0-3]
1300 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1301 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1302 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1306 Like "catch throw", but catches a re-thrown exception.
1307 maint check-psymtabs
1308 Renamed from old "maint check-symtabs".
1310 Perform consistency checks on symtabs.
1311 maint expand-symtabs
1312 Expand symtabs matching an optional regexp.
1315 Display the details of GDB configure-time options.
1317 maint set|show per-command
1318 maint set|show per-command space
1319 maint set|show per-command time
1320 maint set|show per-command symtab
1321 Enable display of per-command gdb resource usage.
1323 remove-symbol-file FILENAME
1324 remove-symbol-file -a ADDRESS
1325 Remove a symbol file added via add-symbol-file. The file to remove
1326 can be identified by its filename or by an address that lies within
1327 the boundaries of this symbol file in memory.
1330 info exceptions REGEXP
1331 Display the list of Ada exceptions defined in the program being
1332 debugged. If provided, only the exceptions whose names match REGEXP
1337 set debug symfile off|on
1339 Control display of debugging info regarding reading symbol files and
1340 symbol tables within those files
1342 set print raw frame-arguments
1343 show print raw frame-arguments
1344 Set/show whether to print frame arguments in raw mode,
1345 disregarding any defined pretty-printers.
1347 set remote trace-status-packet
1348 show remote trace-status-packet
1349 Set/show the use of remote protocol qTStatus packet.
1353 Control display of debugging messages related to Nios II targets.
1357 Control whether target-assisted range stepping is enabled.
1359 set startup-with-shell
1360 show startup-with-shell
1361 Specifies whether Unix child processes are started via a shell or
1366 Use the target memory cache for accesses to the code segment. This
1367 improves performance of remote debugging (particularly disassembly).
1369 * You can now use a literal value 'unlimited' for options that
1370 interpret 0 or -1 as meaning "unlimited". E.g., "set
1371 trace-buffer-size unlimited" is now an alias for "set
1372 trace-buffer-size -1" and "set height unlimited" is now an alias for
1375 * The "set debug symtab-create" debugging option of GDB has been changed to
1376 accept a verbosity level. 0 means "off", 1 provides basic debugging
1377 output, and values of 2 or greater provides more verbose output.
1379 * New command-line options
1381 Display the details of GDB configure-time options.
1383 * The command 'tsave' can now support new option '-ctf' to save trace
1384 buffer in Common Trace Format.
1386 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1389 * GDB now implements the the C++ 'typeid' operator.
1391 * The new convenience variable $_exception holds the exception being
1392 thrown or caught at an exception-related catchpoint.
1394 * The exception-related catchpoints, like "catch throw", now accept a
1395 regular expression which can be used to filter exceptions by type.
1397 * The new convenience variable $_exitsignal is automatically set to
1398 the terminating signal number when the program being debugged dies
1399 due to an uncaught signal.
1403 ** All MI commands now accept an optional "--language" option.
1404 Support for this feature can be verified by using the "-list-features"
1405 command, which should contain "language-option".
1407 ** The new command -info-gdb-mi-command allows the user to determine
1408 whether a GDB/MI command is supported or not.
1410 ** The "^error" result record returned when trying to execute an undefined
1411 GDB/MI command now provides a variable named "code" whose content is the
1412 "undefined-command" error code. Support for this feature can be verified
1413 by using the "-list-features" command, which should contain
1414 "undefined-command-error-code".
1416 ** The -trace-save MI command can optionally save trace buffer in Common
1419 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1421 ** The command -data-list-register-values now accepts an optional
1422 "--skip-unavailable" option. When used, only the available registers
1425 ** The new command -trace-frame-collected dumps collected variables,
1426 computed expressions, tvars, memory and registers in a traceframe.
1428 ** The commands -stack-list-locals, -stack-list-arguments and
1429 -stack-list-variables now accept an option "--skip-unavailable".
1430 When used, only the available locals or arguments are displayed.
1432 ** The -exec-run command now accepts an optional "--start" option.
1433 When used, the command follows the same semantics as the "start"
1434 command, stopping the program's execution at the start of its
1435 main subprogram. Support for this feature can be verified using
1436 the "-list-features" command, which should contain
1437 "exec-run-start-option".
1439 ** The new commands -catch-assert and -catch-exceptions insert
1440 catchpoints stopping the program when Ada exceptions are raised.
1442 ** The new command -info-ada-exceptions provides the equivalent of
1443 the new "info exceptions" command.
1445 * New system-wide configuration scripts
1446 A GDB installation now provides scripts suitable for use as system-wide
1447 configuration scripts for the following systems:
1451 * GDB now supports target-assigned range stepping with remote targets.
1452 This improves the performance of stepping source lines by reducing
1453 the number of control packets from/to GDB. See "New remote packets"
1456 * GDB now understands the element 'tvar' in the XML traceframe info.
1457 It has the id of the collected trace state variables.
1459 * On S/390 targets that provide the transactional-execution feature,
1460 the program interruption transaction diagnostic block (TDB) is now
1461 represented as a number of additional "registers" in GDB.
1463 * New remote packets
1467 The vCont packet supports a new 'r' action, that tells the remote
1468 stub to step through an address range itself, without GDB
1469 involvemement at each single-step.
1471 qXfer:libraries-svr4:read's annex
1472 The previously unused annex of the qXfer:libraries-svr4:read packet
1473 is now used to support passing an argument list. The remote stub
1474 reports support for this argument list to GDB's qSupported query.
1475 The defined arguments are "start" and "prev", used to reduce work
1476 necessary for library list updating, resulting in significant
1479 * New features in the GDB remote stub, GDBserver
1481 ** GDBserver now supports target-assisted range stepping. Currently
1482 enabled on x86/x86_64 GNU/Linux targets.
1484 ** GDBserver now adds element 'tvar' in the XML in the reply to
1485 'qXfer:traceframe-info:read'. It has the id of the collected
1486 trace state variables.
1488 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1491 * New 'z' formatter for printing and examining memory, this displays the
1492 value as hexadecimal zero padded on the left to the size of the type.
1494 * GDB can now use Windows x64 unwinding data.
1496 * The "set remotebaud" command has been replaced by "set serial baud".
1497 Similarly, "show remotebaud" has been replaced by "show serial baud".
1498 The "set remotebaud" and "show remotebaud" commands are still available
1499 to provide backward compatibility with older versions of GDB.
1501 *** Changes in GDB 7.6
1503 * Target record has been renamed to record-full.
1504 Record/replay is now enabled with the "record full" command.
1505 This also affects settings that are associated with full record/replay
1506 that have been moved from "set/show record" to "set/show record full":
1508 set|show record full insn-number-max
1509 set|show record full stop-at-limit
1510 set|show record full memory-query
1512 * A new record target "record-btrace" has been added. The new target
1513 uses hardware support to record the control-flow of a process. It
1514 does not support replaying the execution, but it implements the
1515 below new commands for investigating the recorded execution log.
1516 This new recording method can be enabled using:
1520 The "record-btrace" target is only available on Intel Atom processors
1521 and requires a Linux kernel 2.6.32 or later.
1523 * Two new commands have been added for record/replay to give information
1524 about the recorded execution without having to replay the execution.
1525 The commands are only supported by "record btrace".
1527 record instruction-history prints the execution history at
1528 instruction granularity
1530 record function-call-history prints the execution history at
1531 function granularity
1533 * New native configurations
1535 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1536 FreeBSD/powerpc powerpc*-*-freebsd
1537 x86_64/Cygwin x86_64-*-cygwin*
1538 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1542 ARM AArch64 aarch64*-*-elf
1543 ARM AArch64 GNU/Linux aarch64*-*-linux
1544 Lynx 178 PowerPC powerpc-*-lynx*178
1545 x86_64/Cygwin x86_64-*-cygwin*
1546 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1548 * If the configured location of system.gdbinit file (as given by the
1549 --with-system-gdbinit option at configure time) is in the
1550 data-directory (as specified by --with-gdb-datadir at configure
1551 time) or in one of its subdirectories, then GDB will look for the
1552 system-wide init file in the directory specified by the
1553 --data-directory command-line option.
1555 * New command line options:
1557 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1558 other initialization files, unlike -nx which disables all of them.
1560 * Removed command line options
1562 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1565 * The 'ptype' and 'whatis' commands now accept an argument to control
1568 * 'info proc' now works on some core files.
1572 ** Vectors can be created with gdb.Type.vector.
1574 ** Python's atexit.register now works in GDB.
1576 ** Types can be pretty-printed via a Python API.
1578 ** Python 3 is now supported (in addition to Python 2.4 or later)
1580 ** New class gdb.Architecture exposes GDB's internal representation
1581 of architecture in the Python API.
1583 ** New method Frame.architecture returns the gdb.Architecture object
1584 corresponding to the frame's architecture.
1586 * New Python-based convenience functions:
1588 ** $_memeq(buf1, buf2, length)
1589 ** $_streq(str1, str2)
1591 ** $_regex(str, regex)
1593 * The 'cd' command now defaults to using '~' (the home directory) if not
1596 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1597 default for GCC since November 2000.
1599 * The command 'forward-search' can now be abbreviated as 'fo'.
1601 * The command 'info tracepoints' can now display 'installed on target'
1602 or 'not installed on target' for each non-pending location of tracepoint.
1604 * New configure options
1606 --enable-libmcheck/--disable-libmcheck
1607 By default, development versions are built with -lmcheck on hosts
1608 that support it, in order to help track memory corruption issues.
1609 Release versions, on the other hand, are built without -lmcheck
1610 by default. The --enable-libmcheck/--disable-libmcheck configure
1611 options allow the user to override that default.
1612 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1613 This configure option allows the user to build GDB with
1614 libbabeltrace using which GDB can read Common Trace Format data.
1616 * New commands (for set/show, see "New options" below)
1619 Catch signals. This is similar to "handle", but allows commands and
1620 conditions to be attached.
1623 List the BFDs known to GDB.
1625 python-interactive [command]
1627 Start a Python interactive prompt, or evaluate the optional command
1628 and print the result of expressions.
1631 "py" is a new alias for "python".
1633 enable type-printer [name]...
1634 disable type-printer [name]...
1635 Enable or disable type printers.
1639 ** For the Renesas Super-H architecture, the "regs" command has been removed
1640 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1645 set print type methods (on|off)
1646 show print type methods
1647 Control whether method declarations are displayed by "ptype".
1648 The default is to show them.
1650 set print type typedefs (on|off)
1651 show print type typedefs
1652 Control whether typedef definitions are displayed by "ptype".
1653 The default is to show them.
1655 set filename-display basename|relative|absolute
1656 show filename-display
1657 Control the way in which filenames is displayed.
1658 The default is "relative", which preserves previous behavior.
1660 set trace-buffer-size
1661 show trace-buffer-size
1662 Request target to change the size of trace buffer.
1664 set remote trace-buffer-size-packet auto|on|off
1665 show remote trace-buffer-size-packet
1666 Control the use of the remote protocol `QTBuffer:size' packet.
1670 Control display of debugging messages related to ARM AArch64.
1673 set debug coff-pe-read
1674 show debug coff-pe-read
1675 Control display of debugging messages related to reading of COFF/PE
1680 Control display of debugging messages related to Mach-O symbols
1683 set debug notification
1684 show debug notification
1685 Control display of debugging info for async remote notification.
1689 ** Command parameter changes are now notified using new async record
1690 "=cmd-param-changed".
1691 ** Trace frame changes caused by command "tfind" are now notified using
1692 new async record "=traceframe-changed".
1693 ** The creation, deletion and modification of trace state variables
1694 are now notified using new async records "=tsv-created",
1695 "=tsv-deleted" and "=tsv-modified".
1696 ** The start and stop of process record are now notified using new
1697 async record "=record-started" and "=record-stopped".
1698 ** Memory changes are now notified using new async record
1700 ** The data-disassemble command response will include a "fullname" field
1701 containing the absolute file name when source has been requested.
1702 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1703 command, to allow pattern filling of memory areas.
1704 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1705 library load/unload events.
1706 ** The response to breakpoint commands and breakpoint async records
1707 includes an "installed" field containing a boolean state about each
1708 non-pending tracepoint location is whether installed on target or not.
1709 ** Output of the "-trace-status" command includes a "trace-file" field
1710 containing the name of the trace file being examined. This field is
1711 optional, and only present when examining a trace file.
1712 ** The "fullname" field is now always present along with the "file" field,
1713 even if the file cannot be found by GDB.
1715 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1716 You must have the LZMA library available when configuring GDB for this
1717 feature to be enabled. For more information, see:
1718 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1720 * New remote packets
1723 Set the size of trace buffer. The remote stub reports support for this
1724 packet to gdb's qSupported query.
1727 Enable Branch Trace Store (BTS)-based branch tracing for the current
1728 thread. The remote stub reports support for this packet to gdb's
1732 Disable branch tracing for the current thread. The remote stub reports
1733 support for this packet to gdb's qSupported query.
1736 Read the traced branches for the current thread. The remote stub
1737 reports support for this packet to gdb's qSupported query.
1739 *** Changes in GDB 7.5
1741 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1742 for more x32 ABI info.
1744 * GDB now supports access to MIPS DSP registers on Linux targets.
1746 * GDB now supports debugging microMIPS binaries.
1748 * The "info os" command on GNU/Linux can now display information on
1749 several new classes of objects managed by the operating system:
1750 "info os procgroups" lists process groups
1751 "info os files" lists file descriptors
1752 "info os sockets" lists internet-domain sockets
1753 "info os shm" lists shared-memory regions
1754 "info os semaphores" lists semaphores
1755 "info os msg" lists message queues
1756 "info os modules" lists loaded kernel modules
1758 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1759 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1760 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1761 options and inspect the probe arguments using the new $_probe_arg family
1762 of convenience variables. You can obtain more information about SystemTap
1763 in <http://sourceware.org/systemtap/>.
1765 * GDB now supports reversible debugging on ARM, it allows you to
1766 debug basic ARM and THUMB instructions, and provides
1767 record/replay support.
1769 * The option "symbol-reloading" has been deleted as it is no longer used.
1773 ** GDB commands implemented in Python can now be put in command class
1776 ** The "maint set python print-stack on|off" is now deleted.
1778 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1779 apply "flag enum"-style pretty-printing to any enum.
1781 ** gdb.lookup_symbol can now work when there is no current frame.
1783 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1784 the source at which the symbol was defined.
1786 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1787 method 'value'. The former indicates whether the symbol needs a
1788 frame in order to compute its value, and the latter computes the
1791 ** A new method 'referenced_value' on gdb.Value objects which can
1792 dereference pointer as well as C++ reference values.
1794 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1795 which return the global and static blocks (as gdb.Block objects),
1796 of the underlying symbol table, respectively.
1798 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1799 object associated with a PC value.
1801 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1802 of the address range occupied by code for the current source line.
1804 * Go language support.
1805 GDB now supports debugging programs written in the Go programming
1808 * GDBserver now supports stdio connections.
1809 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1811 * The binary "gdbtui" can no longer be built or installed.
1812 Use "gdb -tui" instead.
1814 * GDB will now print "flag" enums specially. A flag enum is one where
1815 all the enumerator values have no bits in common when pairwise
1816 "and"ed. When printing a value whose type is a flag enum, GDB will
1817 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1818 (gdb) print (enum E) 3
1821 * The filename part of a linespec will now match trailing components
1822 of a source file name. For example, "break gcc/expr.c:1000" will
1823 now set a breakpoint in build/gcc/expr.c, but not
1824 build/libcpp/expr.c.
1826 * The "info proc" and "generate-core-file" commands will now also
1827 work on remote targets connected to GDBserver on Linux.
1829 * The command "info catch" has been removed. It has been disabled
1830 since December 2007.
1832 * The "catch exception" and "catch assert" commands now accept
1833 a condition at the end of the command, much like the "break"
1834 command does. For instance:
1836 (gdb) catch exception Constraint_Error if Barrier = True
1838 Previously, it was possible to add a condition to such catchpoints,
1839 but it had to be done as a second step, after the catchpoint had been
1840 created, using the "condition" command.
1842 * The "info static-tracepoint-marker" command will now also work on
1843 native Linux targets with in-process agent.
1845 * GDB can now set breakpoints on inlined functions.
1847 * The .gdb_index section has been updated to include symbols for
1848 inlined functions. GDB will ignore older .gdb_index sections by
1849 default, which could cause symbol files to be loaded more slowly
1850 until their .gdb_index sections can be recreated. The new command
1851 "set use-deprecated-index-sections on" will cause GDB to use any older
1852 .gdb_index sections it finds. This will restore performance, but the
1853 ability to set breakpoints on inlined functions will be lost in symbol
1854 files with older .gdb_index sections.
1856 The .gdb_index section has also been updated to record more information
1857 about each symbol. This speeds up the "info variables", "info functions"
1858 and "info types" commands when used with programs having the .gdb_index
1859 section, as well as speeding up debugging with shared libraries using
1860 the .gdb_index section.
1862 * Ada support for GDB/MI Variable Objects has been added.
1864 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1869 ** New command -info-os is the MI equivalent of "info os".
1871 ** Output logs ("set logging" and related) now include MI output.
1875 ** "set use-deprecated-index-sections on|off"
1876 "show use-deprecated-index-sections on|off"
1877 Controls the use of deprecated .gdb_index sections.
1879 ** "catch load" and "catch unload" can be used to stop when a shared
1880 library is loaded or unloaded, respectively.
1882 ** "enable count" can be used to auto-disable a breakpoint after
1885 ** "info vtbl" can be used to show the virtual method tables for
1886 C++ and Java objects.
1888 ** "explore" and its sub commands "explore value" and "explore type"
1889 can be used to recursively explore values and types of
1890 expressions. These commands are available only if GDB is
1891 configured with '--with-python'.
1893 ** "info auto-load" shows status of all kinds of auto-loaded files,
1894 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1895 sequences of commands files, "info auto-load python-scripts"
1896 shows status of auto-loading Python script files,
1897 "info auto-load local-gdbinit" shows status of loading init file
1898 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1899 status of inferior specific thread debugging shared library loading.
1901 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1902 and "show auto-load-scripts" commands have been deprecated, use their
1903 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1904 and "show auto-load python-scripts" counterparts instead.
1906 ** "dprintf location,format,args..." creates a dynamic printf, which
1907 is basically a breakpoint that does a printf and immediately
1908 resumes your program's execution, so it is like a printf that you
1909 can insert dynamically at runtime instead of at compiletime.
1911 ** "set print symbol"
1913 Controls whether GDB attempts to display the symbol, if any,
1914 corresponding to addresses it prints. This defaults to "on", but
1915 you can set it to "off" to restore GDB's previous behavior.
1917 * Deprecated commands
1919 ** For the Renesas Super-H architecture, the "regs" command has been
1920 deprecated, and "info all-registers" should be used instead.
1924 Renesas RL78 rl78-*-elf
1925 HP OpenVMS ia64 ia64-hp-openvms*
1927 * GDBserver supports evaluation of breakpoint conditions. When
1928 support is advertised by GDBserver, GDB may be told to send the
1929 breakpoint conditions in bytecode form to GDBserver. GDBserver
1930 will only report the breakpoint trigger to GDB when its condition
1935 set mips compression
1936 show mips compression
1937 Select the compressed ISA encoding used in functions that have no symbol
1938 information available. The encoding can be set to either of:
1941 and is updated automatically from ELF file flags if available.
1943 set breakpoint condition-evaluation
1944 show breakpoint condition-evaluation
1945 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1946 GDBserver ("target"). Default option "auto" chooses the most efficient
1948 This option can improve debugger efficiency depending on the speed of the
1952 Disable auto-loading globally.
1955 Show auto-loading setting of all kinds of auto-loaded files.
1957 set auto-load gdb-scripts on|off
1958 show auto-load gdb-scripts
1959 Control auto-loading of GDB canned sequences of commands files.
1961 set auto-load python-scripts on|off
1962 show auto-load python-scripts
1963 Control auto-loading of Python script files.
1965 set auto-load local-gdbinit on|off
1966 show auto-load local-gdbinit
1967 Control loading of init file (.gdbinit) from current directory.
1969 set auto-load libthread-db on|off
1970 show auto-load libthread-db
1971 Control auto-loading of inferior specific thread debugging shared library.
1973 set auto-load scripts-directory <dir1>[:<dir2>...]
1974 show auto-load scripts-directory
1975 Set a list of directories from which to load auto-loaded scripts.
1976 Automatically loaded Python scripts and GDB scripts are located in one
1977 of the directories listed by this option.
1978 The delimiter (':' above) may differ according to the host platform.
1980 set auto-load safe-path <dir1>[:<dir2>...]
1981 show auto-load safe-path
1982 Set a list of directories from which it is safe to auto-load files.
1983 The delimiter (':' above) may differ according to the host platform.
1985 set debug auto-load on|off
1986 show debug auto-load
1987 Control display of debugging info for auto-loading the files above.
1989 set dprintf-style gdb|call|agent
1991 Control the way in which a dynamic printf is performed; "gdb"
1992 requests a GDB printf command, while "call" causes dprintf to call a
1993 function in the inferior. "agent" requests that the target agent
1994 (such as GDBserver) do the printing.
1996 set dprintf-function <expr>
1997 show dprintf-function
1998 set dprintf-channel <expr>
1999 show dprintf-channel
2000 Set the function and optional first argument to the call when using
2001 the "call" style of dynamic printf.
2003 set disconnected-dprintf on|off
2004 show disconnected-dprintf
2005 Control whether agent-style dynamic printfs continue to be in effect
2006 after GDB disconnects.
2008 * New configure options
2010 --with-auto-load-dir
2011 Configure default value for the 'set auto-load scripts-directory'
2012 setting above. It defaults to '$debugdir:$datadir/auto-load',
2013 $debugdir representing global debugging info directories (available
2014 via 'show debug-file-directory') and $datadir representing GDB's data
2015 directory (available via 'show data-directory').
2017 --with-auto-load-safe-path
2018 Configure default value for the 'set auto-load safe-path' setting
2019 above. It defaults to the --with-auto-load-dir setting.
2021 --without-auto-load-safe-path
2022 Set 'set auto-load safe-path' to '/', effectively disabling this
2025 * New remote packets
2027 z0/z1 conditional breakpoints extension
2029 The z0/z1 breakpoint insertion packets have been extended to carry
2030 a list of conditional expressions over to the remote stub depending on the
2031 condition evaluation mode. The use of this extension can be controlled
2032 via the "set remote conditional-breakpoints-packet" command.
2036 Specify the signals which the remote stub may pass to the debugged
2037 program without GDB involvement.
2039 * New command line options
2041 --init-command=FILE, -ix Like --command, -x but execute it
2042 before loading inferior.
2043 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2044 execute it before loading inferior.
2046 *** Changes in GDB 7.4
2048 * GDB now handles ambiguous linespecs more consistently; the existing
2049 FILE:LINE support has been expanded to other types of linespecs. A
2050 breakpoint will now be set on all matching locations in all
2051 inferiors, and locations will be added or removed according to
2054 * GDB now allows you to skip uninteresting functions and files when
2055 stepping with the "skip function" and "skip file" commands.
2057 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2058 and "show remote hardware-watchpoint-length-limit". These allows to
2059 set or show the maximum length limit (in bytes) of a remote
2060 target hardware watchpoint.
2062 This allows e.g. to use "unlimited" hardware watchpoints with the
2063 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2064 watchpoints are slower than real hardware watchpoints but are
2065 significantly faster than gdb software watchpoints.
2069 ** The register_pretty_printer function in module gdb.printing now takes
2070 an optional `replace' argument. If True, the new printer replaces any
2073 ** The "maint set python print-stack on|off" command has been
2074 deprecated and will be deleted in GDB 7.5.
2075 A new command: "set python print-stack none|full|message" has
2076 replaced it. Additionally, the default for "print-stack" is
2077 now "message", which just prints the error message without
2080 ** A prompt substitution hook (prompt_hook) is now available to the
2083 ** A new Python module, gdb.prompt has been added to the GDB Python
2084 modules library. This module provides functionality for
2085 escape sequences in prompts (used by set/show
2086 extended-prompt). These escape sequences are replaced by their
2087 corresponding value.
2089 ** Python commands and convenience-functions located in
2090 'data-directory'/python/gdb/command and
2091 'data-directory'/python/gdb/function are now automatically loaded
2094 ** Blocks now provide four new attributes. global_block and
2095 static_block will return the global and static blocks
2096 respectively. is_static and is_global are boolean attributes
2097 that indicate if the block is one of those two types.
2099 ** Symbols now provide the "type" attribute, the type of the symbol.
2101 ** The "gdb.breakpoint" function has been deprecated in favor of
2104 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2105 of a function. This class is based on the "finish" command
2106 available in the CLI.
2108 ** Type objects for struct and union types now allow access to
2109 the fields using standard Python dictionary (mapping) methods.
2110 For example, "some_type['myfield']" now works, as does
2111 "some_type.items()".
2113 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2116 ** A new function, "deep_items" has been added to the gdb.types
2117 module in the GDB Python modules library. This function returns
2118 an iterator over the fields of a struct or union type. Unlike
2119 the standard Python "iteritems" method, it will recursively traverse
2120 any anonymous fields.
2124 ** "*stopped" events can report several new "reason"s, such as
2127 ** Breakpoint changes are now notified using new async records, like
2128 "=breakpoint-modified".
2130 ** New command -ada-task-info.
2132 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2133 $sdir specifies the default system locations of shared libraries.
2134 $pdir specifies the directory where the libpthread used by the application
2137 GDB no longer looks in $sdir and $pdir after it has searched the directories
2138 mentioned in libthread-db-search-path. If you want to search those
2139 directories, they must be specified in libthread-db-search-path.
2140 The default value of libthread-db-search-path on GNU/Linux and Solaris
2141 systems is now "$sdir:$pdir".
2143 $pdir is not supported by gdbserver, it is currently ignored.
2144 $sdir is supported by gdbserver.
2146 * New configure option --with-iconv-bin.
2147 When using the internationalization support like the one in the GNU C
2148 library, GDB will invoke the "iconv" program to get a list of supported
2149 character sets. If this program lives in a non-standard location, one can
2150 use this option to specify where to find it.
2152 * When natively debugging programs on PowerPC BookE processors running
2153 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2154 watchpoints, which specify a mask in addition to an address to watch.
2155 The mask specifies that some bits of an address (the bits which are
2156 reset in the mask) should be ignored when matching the address accessed
2157 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2158 section in the user manual for more details.
2160 * The new option --once causes GDBserver to stop listening for connections once
2161 the first connection is made. The listening port used by GDBserver will
2162 become available after that.
2164 * New commands "info macros" and "alias" have been added.
2166 * New function parameters suffix @entry specifies value of function parameter
2167 at the time the function got called. Entry values are available only since
2173 "!" is now an alias of the "shell" command.
2174 Note that no space is needed between "!" and SHELL COMMAND.
2178 watch EXPRESSION mask MASK_VALUE
2179 The watch command now supports the mask argument which allows creation
2180 of masked watchpoints, if the current architecture supports this feature.
2182 info auto-load-scripts [REGEXP]
2183 This command was formerly named "maintenance print section-scripts".
2184 It is now generally useful and is no longer a maintenance-only command.
2186 info macro [-all] [--] MACRO
2187 The info macro command has new options `-all' and `--'. The first for
2188 printing all definitions of a macro. The second for explicitly specifying
2189 the end of arguments and the beginning of the macro name in case the macro
2190 name starts with a hyphen.
2192 collect[/s] EXPRESSIONS
2193 The tracepoint collect command now takes an optional modifier "/s"
2194 that directs it to dereference pointer-to-character types and
2195 collect the bytes of memory up to a zero byte. The behavior is
2196 similar to what you see when you use the regular print command on a
2197 string. An optional integer following the "/s" sets a bound on the
2198 number of bytes that will be collected.
2201 The trace start command now interprets any supplied arguments as a
2202 note to be recorded with the trace run, with an effect similar to
2203 setting the variable trace-notes.
2206 The trace stop command now interprets any arguments as a note to be
2207 mentioned along with the tstatus report that the trace was stopped
2208 with a command. The effect is similar to setting the variable
2211 * Tracepoints can now be enabled and disabled at any time after a trace
2212 experiment has been started using the standard "enable" and "disable"
2213 commands. It is now possible to start a trace experiment with no enabled
2214 tracepoints; GDB will display a warning, but will allow the experiment to
2215 begin, assuming that tracepoints will be enabled as needed while the trace
2218 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2219 locations with 4-byte instructions, when they were previously
2220 limited to locations with instructions of 5 bytes or longer.
2224 set debug dwarf2-read
2225 show debug dwarf2-read
2226 Turns on or off display of debugging messages related to reading
2227 DWARF debug info. The default is off.
2229 set debug symtab-create
2230 show debug symtab-create
2231 Turns on or off display of debugging messages related to symbol table
2232 creation. The default is off.
2235 show extended-prompt
2236 Set the GDB prompt, and allow escape sequences to be inserted to
2237 display miscellaneous information (see 'help set extended-prompt'
2238 for the list of sequences). This prompt (and any information
2239 accessed through the escape sequences) is updated every time the
2240 prompt is displayed.
2242 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2243 show print entry-values
2244 Set printing of frame argument values at function entry. In some cases
2245 GDB can determine the value of function argument which was passed by the
2246 function caller, even if the value was modified inside the called function.
2248 set debug entry-values
2249 show debug entry-values
2250 Control display of debugging info for determining frame argument values at
2251 function entry and virtual tail call frames.
2253 set basenames-may-differ
2254 show basenames-may-differ
2255 Set whether a source file may have multiple base names.
2256 (A "base name" is the name of a file with the directory part removed.
2257 Example: The base name of "/home/user/hello.c" is "hello.c".)
2258 If set, GDB will canonicalize file names (e.g., expand symlinks)
2259 before comparing them. Canonicalization is an expensive operation,
2260 but it allows the same file be known by more than one base name.
2261 If not set (the default), all source files are assumed to have just
2262 one base name, and gdb will do file name comparisons more efficiently.
2268 Set a user name and notes for the current and any future trace runs.
2269 This is useful for long-running and/or disconnected traces, to
2270 inform others (or yourself) as to who is running the trace, supply
2271 contact information, or otherwise explain what is going on.
2273 set trace-stop-notes
2274 show trace-stop-notes
2275 Set a note attached to the trace run, that is displayed when the
2276 trace has been stopped by a tstop command. This is useful for
2277 instance as an explanation, if you are stopping a trace run that was
2278 started by someone else.
2280 * New remote packets
2284 Dynamically enable a tracepoint in a started trace experiment.
2288 Dynamically disable a tracepoint in a started trace experiment.
2292 Set the user and notes of the trace run.
2296 Query the current status of a tracepoint.
2300 Query the minimum length of instruction at which a fast tracepoint may
2303 * Dcache size (number of lines) and line-size are now runtime-configurable
2304 via "set dcache line" and "set dcache line-size" commands.
2308 Texas Instruments TMS320C6x tic6x-*-*
2312 Renesas RL78 rl78-*-elf
2314 *** Changes in GDB 7.3.1
2316 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2318 *** Changes in GDB 7.3
2320 * GDB has a new command: "thread find [REGEXP]".
2321 It finds the thread id whose name, target id, or thread extra info
2322 matches the given regular expression.
2324 * The "catch syscall" command now works on mips*-linux* targets.
2326 * The -data-disassemble MI command now supports modes 2 and 3 for
2327 dumping the instruction opcodes.
2329 * New command line options
2331 -data-directory DIR Specify DIR as the "data-directory".
2332 This is mostly for testing purposes.
2334 * The "maint set python auto-load on|off" command has been renamed to
2335 "set auto-load-scripts on|off".
2337 * GDB has a new command: "set directories".
2338 It is like the "dir" command except that it replaces the
2339 source path list instead of augmenting it.
2341 * GDB now understands thread names.
2343 On GNU/Linux, "info threads" will display the thread name as set by
2344 prctl or pthread_setname_np.
2346 There is also a new command, "thread name", which can be used to
2347 assign a name internally for GDB to display.
2350 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2351 has been integrated into GDB.
2355 ** The function gdb.Write now accepts an optional keyword 'stream'.
2356 This keyword, when provided, will direct the output to either
2357 stdout, stderr, or GDB's logging output.
2359 ** Parameters can now be be sub-classed in Python, and in particular
2360 you may implement the get_set_doc and get_show_doc functions.
2361 This improves how Parameter set/show documentation is processed
2362 and allows for more dynamic content.
2364 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2365 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2366 have an is_valid method.
2368 ** Breakpoints can now be sub-classed in Python, and in particular
2369 you may implement a 'stop' function that is executed each time
2370 the inferior reaches that breakpoint.
2372 ** New function gdb.lookup_global_symbol looks up a global symbol.
2374 ** GDB values in Python are now callable if the value represents a
2375 function. For example, if 'some_value' represents a function that
2376 takes two integer parameters and returns a value, you can call
2377 that function like so:
2379 result = some_value (10,20)
2381 ** Module gdb.types has been added.
2382 It contains a collection of utilities for working with gdb.Types objects:
2383 get_basic_type, has_field, make_enum_dict.
2385 ** Module gdb.printing has been added.
2386 It contains utilities for writing and registering pretty-printers.
2387 New classes: PrettyPrinter, SubPrettyPrinter,
2388 RegexpCollectionPrettyPrinter.
2389 New function: register_pretty_printer.
2391 ** New commands "info pretty-printers", "enable pretty-printer" and
2392 "disable pretty-printer" have been added.
2394 ** gdb.parameter("directories") is now available.
2396 ** New function gdb.newest_frame returns the newest frame in the
2399 ** The gdb.InferiorThread class has a new "name" attribute. This
2400 holds the thread's name.
2402 ** Python Support for Inferior events.
2403 Python scripts can add observers to be notified of events
2404 occurring in the process being debugged.
2405 The following events are currently supported:
2406 - gdb.events.cont Continue event.
2407 - gdb.events.exited Inferior exited event.
2408 - gdb.events.stop Signal received, and Breakpoint hit events.
2412 ** GDB now puts template parameters in scope when debugging in an
2413 instantiation. For example, if you have:
2415 template<int X> int func (void) { return X; }
2417 then if you step into func<5>, "print X" will show "5". This
2418 feature requires proper debuginfo support from the compiler; it
2419 was added to GCC 4.5.
2421 ** The motion commands "next", "finish", "until", and "advance" now
2422 work better when exceptions are thrown. In particular, GDB will
2423 no longer lose control of the inferior; instead, the GDB will
2424 stop the inferior at the point at which the exception is caught.
2425 This functionality requires a change in the exception handling
2426 code that was introduced in GCC 4.5.
2428 * GDB now follows GCC's rules on accessing volatile objects when
2429 reading or writing target state during expression evaluation.
2430 One notable difference to prior behavior is that "print x = 0"
2431 no longer generates a read of x; the value of the assignment is
2432 now always taken directly from the value being assigned.
2434 * GDB now has some support for using labels in the program's source in
2435 linespecs. For instance, you can use "advance label" to continue
2436 execution to a label.
2438 * GDB now has support for reading and writing a new .gdb_index
2439 section. This section holds a fast index of DWARF debugging
2440 information and can be used to greatly speed up GDB startup and
2441 operation. See the documentation for `save gdb-index' for details.
2443 * The "watch" command now accepts an optional "-location" argument.
2444 When used, this causes GDB to watch the memory referred to by the
2445 expression. Such a watchpoint is never deleted due to it going out
2448 * GDB now supports thread debugging of core dumps on GNU/Linux.
2450 GDB now activates thread debugging using the libthread_db library
2451 when debugging GNU/Linux core dumps, similarly to when debugging
2452 live processes. As a result, when debugging a core dump file, GDB
2453 is now able to display pthread_t ids of threads. For example, "info
2454 threads" shows the same output as when debugging the process when it
2455 was live. In earlier releases, you'd see something like this:
2458 * 1 LWP 6780 main () at main.c:10
2460 While now you see this:
2463 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2465 It is also now possible to inspect TLS variables when debugging core
2468 When debugging a core dump generated on a machine other than the one
2469 used to run GDB, you may need to point GDB at the correct
2470 libthread_db library with the "set libthread-db-search-path"
2471 command. See the user manual for more details on this command.
2473 * When natively debugging programs on PowerPC BookE processors running
2474 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2475 which stop execution of the inferior whenever it executes an instruction
2476 at any address within the specified range. See the "PowerPC Embedded"
2477 section in the user manual for more details.
2479 * New features in the GDB remote stub, GDBserver
2481 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2482 and i686 LynxOS (version 5.x).
2484 ** GDBserver is now supported on Blackfin Linux.
2486 * New native configurations
2488 ia64 HP-UX ia64-*-hpux*
2492 Analog Devices, Inc. Blackfin Processor bfin-*
2494 * Ada task switching is now supported on sparc-elf targets when
2495 debugging a program using the Ravenscar Profile. For more information,
2496 see the "Tasking Support when using the Ravenscar Profile" section
2497 in the GDB user manual.
2499 * Guile support was removed.
2501 * New features in the GNU simulator
2503 ** The --map-info flag lists all known core mappings.
2505 ** CFI flashes may be simulated via the "cfi" device.
2507 *** Changes in GDB 7.2
2509 * Shared library support for remote targets by default
2511 When GDB is configured for a generic, non-OS specific target, like
2512 for example, --target=arm-eabi or one of the many *-*-elf targets,
2513 GDB now queries remote stubs for loaded shared libraries using the
2514 `qXfer:libraries:read' packet. Previously, shared library support
2515 was always disabled for such configurations.
2519 ** Argument Dependent Lookup (ADL)
2521 In C++ ADL lookup directs function search to the namespaces of its
2522 arguments even if the namespace has not been imported.
2532 Here the compiler will search for `foo' in the namespace of 'b'
2533 and find A::foo. GDB now supports this. This construct is commonly
2534 used in the Standard Template Library for operators.
2536 ** Improved User Defined Operator Support
2538 In addition to member operators, GDB now supports lookup of operators
2539 defined in a namespace and imported with a `using' directive, operators
2540 defined in the global scope, operators imported implicitly from an
2541 anonymous namespace, and the ADL operators mentioned in the previous
2543 GDB now also supports proper overload resolution for all the previously
2544 mentioned flavors of operators.
2546 ** static const class members
2548 Printing of static const class members that are initialized in the
2549 class definition has been fixed.
2551 * Windows Thread Information Block access.
2553 On Windows targets, GDB now supports displaying the Windows Thread
2554 Information Block (TIB) structure. This structure is visible either
2555 by using the new command `info w32 thread-information-block' or, by
2556 dereferencing the new convenience variable named `$_tlb', a
2557 thread-specific pointer to the TIB. This feature is also supported
2558 when remote debugging using GDBserver.
2560 * Static tracepoints
2562 Static tracepoints are calls in the user program into a tracing
2563 library. One such library is a port of the LTTng kernel tracer to
2564 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2565 When debugging with GDBserver, GDB now supports combining the GDB
2566 tracepoint machinery with such libraries. For example: the user can
2567 use GDB to probe a static tracepoint marker (a call from the user
2568 program into the tracing library) with the new "strace" command (see
2569 "New commands" below). This creates a "static tracepoint" in the
2570 breakpoint list, that can be manipulated with the same feature set
2571 as fast and regular tracepoints. E.g., collect registers, local and
2572 global variables, collect trace state variables, and define
2573 tracepoint conditions. In addition, the user can collect extra
2574 static tracepoint marker specific data, by collecting the new
2575 $_sdata internal variable. When analyzing the trace buffer, you can
2576 inspect $_sdata like any other variable available to GDB. For more
2577 information, see the "Tracepoints" chapter in GDB user manual. New
2578 remote packets have been defined to support static tracepoints, see
2579 the "New remote packets" section below.
2581 * Better reconstruction of tracepoints after disconnected tracing
2583 GDB will attempt to download the original source form of tracepoint
2584 definitions when starting a trace run, and then will upload these
2585 upon reconnection to the target, resulting in a more accurate
2586 reconstruction of the tracepoints that are in use on the target.
2590 You can now exercise direct control over the ways that GDB can
2591 affect your program. For instance, you can disallow the setting of
2592 breakpoints, so that the program can run continuously (assuming
2593 non-stop mode). In addition, the "observer" variable is available
2594 to switch all of the different controls; in observer mode, GDB
2595 cannot affect the target's behavior at all, which is useful for
2596 tasks like diagnosing live systems in the field.
2598 * The new convenience variable $_thread holds the number of the
2601 * New remote packets
2605 Return the address of the Windows Thread Information Block of a given thread.
2609 In response to several of the tracepoint packets, the target may now
2610 also respond with a number of intermediate `qRelocInsn' request
2611 packets before the final result packet, to have GDB handle
2612 relocating an instruction to execute at a different address. This
2613 is particularly useful for stubs that support fast tracepoints. GDB
2614 reports support for this feature in the qSupported packet.
2618 List static tracepoint markers in the target program.
2622 List static tracepoint markers at a given address in the target
2625 qXfer:statictrace:read
2627 Read the static trace data collected (by a `collect $_sdata'
2628 tracepoint action). The remote stub reports support for this packet
2629 to gdb's qSupported query.
2633 Send the current settings of GDB's permission flags.
2637 Send part of the source (textual) form of a tracepoint definition,
2638 which includes location, conditional, and action list.
2640 * The source command now accepts a -s option to force searching for the
2641 script in the source search path even if the script name specifies
2644 * New features in the GDB remote stub, GDBserver
2646 - GDBserver now support tracepoints (including fast tracepoints, and
2647 static tracepoints). The feature is currently supported by the
2648 i386-linux and amd64-linux builds. See the "Tracepoints support
2649 in gdbserver" section in the manual for more information.
2651 GDBserver JIT compiles the tracepoint's conditional agent
2652 expression bytecode into native code whenever possible for low
2653 overhead dynamic tracepoints conditionals. For such tracepoints,
2654 an expression that examines program state is evaluated when the
2655 tracepoint is reached, in order to determine whether to capture
2656 trace data. If the condition is simple and false, processing the
2657 tracepoint finishes very quickly and no data is gathered.
2659 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2660 for static tracepoints support.
2662 - GDBserver now supports x86_64 Windows 64-bit debugging.
2664 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2665 it understands register description.
2667 * The --batch flag now disables pagination and queries.
2669 * X86 general purpose registers
2671 GDB now supports reading/writing byte, word and double-word x86
2672 general purpose registers directly. This means you can use, say,
2673 $ah or $ax to refer, respectively, to the byte register AH and
2674 16-bit word register AX that are actually portions of the 32-bit
2675 register EAX or 64-bit register RAX.
2677 * The `commands' command now accepts a range of breakpoints to modify.
2678 A plain `commands' following a command that creates multiple
2679 breakpoints affects all the breakpoints set by that command. This
2680 applies to breakpoints set by `rbreak', and also applies when a
2681 single `break' command creates multiple breakpoints (e.g.,
2682 breakpoints on overloaded c++ functions).
2684 * The `rbreak' command now accepts a filename specification as part of
2685 its argument, limiting the functions selected by the regex to those
2686 in the specified file.
2688 * Support for remote debugging Windows and SymbianOS shared libraries
2689 from Unix hosts has been improved. Non Windows GDB builds now can
2690 understand target reported file names that follow MS-DOS based file
2691 system semantics, such as file names that include drive letters and
2692 use the backslash character as directory separator. This makes it
2693 possible to transparently use the "set sysroot" and "set
2694 solib-search-path" on Unix hosts to point as host copies of the
2695 target's shared libraries. See the new command "set
2696 target-file-system-kind" described below, and the "Commands to
2697 specify files" section in the user manual for more information.
2701 eval template, expressions...
2702 Convert the values of one or more expressions under the control
2703 of the string template to a command line, and call it.
2705 set target-file-system-kind unix|dos-based|auto
2706 show target-file-system-kind
2707 Set or show the assumed file system kind for target reported file
2710 save breakpoints <filename>
2711 Save all current breakpoint definitions to a file suitable for use
2712 in a later debugging session. To read the saved breakpoint
2713 definitions, use the `source' command.
2715 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2718 info static-tracepoint-markers
2719 Display information about static tracepoint markers in the target.
2721 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2722 Define a static tracepoint by probing a marker at the given
2723 function, line, address, or marker ID.
2727 Enable and disable observer mode.
2729 set may-write-registers on|off
2730 set may-write-memory on|off
2731 set may-insert-breakpoints on|off
2732 set may-insert-tracepoints on|off
2733 set may-insert-fast-tracepoints on|off
2734 set may-interrupt on|off
2735 Set individual permissions for GDB effects on the target. Note that
2736 some of these settings can have undesirable or surprising
2737 consequences, particularly when changed in the middle of a session.
2738 For instance, disabling the writing of memory can prevent
2739 breakpoints from being inserted, cause single-stepping to fail, or
2740 even crash your program, if you disable after breakpoints have been
2741 inserted. However, GDB should not crash.
2743 set record memory-query on|off
2744 show record memory-query
2745 Control whether to stop the inferior if memory changes caused
2746 by an instruction cannot be recorded.
2751 The disassemble command now supports "start,+length" form of two arguments.
2755 ** GDB now provides a new directory location, called the python directory,
2756 where Python scripts written for GDB can be installed. The location
2757 of that directory is <data-directory>/python, where <data-directory>
2758 is the GDB data directory. For more details, see section `Scripting
2759 GDB using Python' in the manual.
2761 ** The GDB Python API now has access to breakpoints, symbols, symbol
2762 tables, program spaces, inferiors, threads and frame's code blocks.
2763 Additionally, GDB Parameters can now be created from the API, and
2764 manipulated via set/show in the CLI.
2766 ** New functions gdb.target_charset, gdb.target_wide_charset,
2767 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2769 ** New exception gdb.GdbError.
2771 ** Pretty-printers are now also looked up in the current program space.
2773 ** Pretty-printers can now be individually enabled and disabled.
2775 ** GDB now looks for names of Python scripts to auto-load in a
2776 special section named `.debug_gdb_scripts', in addition to looking
2777 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2779 * Tracepoint actions were unified with breakpoint commands. In particular,
2780 there are no longer differences in "info break" output for breakpoints and
2781 tracepoints and the "commands" command can be used for both tracepoints and
2782 regular breakpoints.
2786 ARM Symbian arm*-*-symbianelf*
2788 * D language support.
2789 GDB now supports debugging programs written in the D programming
2792 * GDB now supports the extended ptrace interface for PowerPC which is
2793 available since Linux kernel version 2.6.34. This automatically enables
2794 any hardware breakpoints and additional hardware watchpoints available in
2795 the processor. The old ptrace interface exposes just one hardware
2796 watchpoint and no hardware breakpoints.
2798 * GDB is now able to use the Data Value Compare (DVC) register available on
2799 embedded PowerPC processors to implement in hardware simple watchpoint
2800 conditions of the form:
2802 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2804 This works in native GDB running on Linux kernels with the extended ptrace
2805 interface mentioned above.
2807 *** Changes in GDB 7.1
2811 ** Namespace Support
2813 GDB now supports importing of namespaces in C++. This enables the
2814 user to inspect variables from imported namespaces. Support for
2815 namepace aliasing has also been added. So, if a namespace is
2816 aliased in the current scope (e.g. namepace C=A; ) the user can
2817 print variables using the alias (e.g. (gdb) print C::x).
2821 All known bugs relating to the printing of virtual base class were
2822 fixed. It is now possible to call overloaded static methods using a
2827 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2828 and reinterpret_cast<> are now handled by the C++ expression parser.
2832 Xilinx MicroBlaze microblaze-*-*
2837 Xilinx MicroBlaze microblaze
2840 * Multi-program debugging.
2842 GDB now has support for multi-program (a.k.a. multi-executable or
2843 multi-exec) debugging. This allows for debugging multiple inferiors
2844 simultaneously each running a different program under the same GDB
2845 session. See "Debugging Multiple Inferiors and Programs" in the
2846 manual for more information. This implied some user visible changes
2847 in the multi-inferior support. For example, "info inferiors" now
2848 lists inferiors that are not running yet or that have exited
2849 already. See also "New commands" and "New options" below.
2851 * New tracing features
2853 GDB's tracepoint facility now includes several new features:
2855 ** Trace state variables
2857 GDB tracepoints now include support for trace state variables, which
2858 are variables managed by the target agent during a tracing
2859 experiment. They are useful for tracepoints that trigger each
2860 other, so for instance one tracepoint can count hits in a variable,
2861 and then a second tracepoint has a condition that is true when the
2862 count reaches a particular value. Trace state variables share the
2863 $-syntax of GDB convenience variables, and can appear in both
2864 tracepoint actions and condition expressions. Use the "tvariable"
2865 command to create, and "info tvariables" to view; see "Trace State
2866 Variables" in the manual for more detail.
2870 GDB now includes an option for defining fast tracepoints, which
2871 targets may implement more efficiently, such as by installing a jump
2872 into the target agent rather than a trap instruction. The resulting
2873 speedup can be by two orders of magnitude or more, although the
2874 tradeoff is that some program locations on some target architectures
2875 might not allow fast tracepoint installation, for instance if the
2876 instruction to be replaced is shorter than the jump. To request a
2877 fast tracepoint, use the "ftrace" command, with syntax identical to
2878 the regular trace command.
2880 ** Disconnected tracing
2882 It is now possible to detach GDB from the target while it is running
2883 a trace experiment, then reconnect later to see how the experiment
2884 is going. In addition, a new variable disconnected-tracing lets you
2885 tell the target agent whether to continue running a trace if the
2886 connection is lost unexpectedly.
2890 GDB now has the ability to save the trace buffer into a file, and
2891 then use that file as a target, similarly to you can do with
2892 corefiles. You can select trace frames, print data that was
2893 collected in them, and use tstatus to display the state of the
2894 tracing run at the moment that it was saved. To create a trace
2895 file, use "tsave <filename>", and to use it, do "target tfile
2898 ** Circular trace buffer
2900 You can ask the target agent to handle the trace buffer as a
2901 circular buffer, discarding the oldest trace frames to make room for
2902 newer ones, by setting circular-trace-buffer to on. This feature may
2903 not be available for all target agents.
2908 The disassemble command, when invoked with two arguments, now requires
2909 the arguments to be comma-separated.
2912 The info variables command now displays variable definitions. Files
2913 which only declare a variable are not shown.
2916 The source command is now capable of sourcing Python scripts.
2917 This feature is dependent on the debugger being build with Python
2920 Related to this enhancement is also the introduction of a new command
2921 "set script-extension" (see below).
2923 * New commands (for set/show, see "New options" below)
2925 record save [<FILENAME>]
2926 Save a file (in core file format) containing the process record
2927 execution log for replay debugging at a later time.
2929 record restore <FILENAME>
2930 Restore the process record execution log that was saved at an
2931 earlier time, for replay debugging.
2933 add-inferior [-copies <N>] [-exec <FILENAME>]
2936 clone-inferior [-copies <N>] [ID]
2937 Make a new inferior ready to execute the same program another
2938 inferior has loaded.
2943 maint info program-spaces
2944 List the program spaces loaded into GDB.
2946 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2947 show remote interrupt-sequence
2948 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2949 as the sequence to the remote target in order to interrupt the execution.
2950 Ctrl-C is a default. Some system prefers BREAK which is high level of
2951 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2952 Magic SysRq g. It is BREAK signal and character 'g'.
2954 set remote interrupt-on-connect [on | off]
2955 show remote interrupt-on-connect
2956 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2957 remote target when gdb connects to it. This is needed when you debug
2960 set remotebreak [on | off]
2962 Deprecated. Use "set/show remote interrupt-sequence" instead.
2964 tvariable $NAME [ = EXP ]
2965 Create or modify a trace state variable.
2968 List trace state variables and their values.
2970 delete tvariable $NAME ...
2971 Delete one or more trace state variables.
2974 Evaluate the given expressions without collecting anything into the
2975 trace buffer. (Valid in tracepoint actions only.)
2977 ftrace FN / FILE:LINE / *ADDR
2978 Define a fast tracepoint at the given function, line, or address.
2980 * New expression syntax
2982 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2983 GDB now parses 0b101010 identically with 42.
2987 set follow-exec-mode new|same
2988 show follow-exec-mode
2989 Control whether GDB reuses the same inferior across an exec call or
2990 creates a new one. This is useful to be able to restart the old
2991 executable after the inferior having done an exec call.
2993 set default-collect EXPR, ...
2994 show default-collect
2995 Define a list of expressions to be collected at each tracepoint.
2996 This is a useful way to ensure essential items are not overlooked,
2997 such as registers or a critical global variable.
2999 set disconnected-tracing
3000 show disconnected-tracing
3001 If set to 1, the target is instructed to continue tracing if it
3002 loses its connection to GDB. If 0, the target is to stop tracing
3005 set circular-trace-buffer
3006 show circular-trace-buffer
3007 If set to on, the target is instructed to use a circular trace buffer
3008 and discard the oldest trace frames instead of stopping the trace due
3009 to a full trace buffer. If set to off, the trace stops when the buffer
3010 fills up. Some targets may not support this.
3012 set script-extension off|soft|strict
3013 show script-extension
3014 If set to "off", the debugger does not perform any script language
3015 recognition, and all sourced files are assumed to be GDB scripts.
3016 If set to "soft" (the default), files are sourced according to
3017 filename extension, falling back to GDB scripts if the first
3019 If set to "strict", files are sourced according to filename extension.
3021 set ada trust-PAD-over-XVS on|off
3022 show ada trust-PAD-over-XVS
3023 If off, activate a workaround against a bug in the debugging information
3024 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3025 the GCC sources for more information about the GNAT encoding and
3026 PAD types in particular). It is always safe to set this option to
3027 off, but this introduces a slight performance penalty. The default
3030 * Python API Improvements
3032 ** GDB provides the new class gdb.LazyString. This is useful in
3033 some pretty-printing cases. The new method gdb.Value.lazy_string
3034 provides a simple way to create objects of this type.
3036 ** The fields returned by gdb.Type.fields now have an
3037 `is_base_class' attribute.
3039 ** The new method gdb.Type.range returns the range of an array type.
3041 ** The new method gdb.parse_and_eval can be used to parse and
3042 evaluate an expression.
3044 * New remote packets
3047 Define a trace state variable.
3050 Get the current value of a trace state variable.
3053 Set desired tracing behavior upon disconnection.
3056 Set the trace buffer to be linear or circular.
3059 Get data about the tracepoints currently in use.
3063 Process record now works correctly with hardware watchpoints.
3065 Multiple bug fixes have been made to the mips-irix port, making it
3066 much more reliable. In particular:
3067 - Debugging threaded applications is now possible again. Previously,
3068 GDB would hang while starting the program, or while waiting for
3069 the program to stop at a breakpoint.
3070 - Attaching to a running process no longer hangs.
3071 - An error occurring while loading a core file has been fixed.
3072 - Changing the value of the PC register now works again. This fixes
3073 problems observed when using the "jump" command, or when calling
3074 a function from GDB, or even when assigning a new value to $pc.
3075 - With the "finish" and "return" commands, the return value for functions
3076 returning a small array is now correctly printed.
3077 - It is now possible to break on shared library code which gets executed
3078 during a shared library init phase (code executed while executing
3079 their .init section). Previously, the breakpoint would have no effect.
3080 - GDB is now able to backtrace through the signal handler for
3081 non-threaded programs.
3083 PIE (Position Independent Executable) programs debugging is now supported.
3084 This includes debugging execution of PIC (Position Independent Code) shared
3085 libraries although for that, it should be possible to run such libraries as an
3088 *** Changes in GDB 7.0
3090 * GDB now has an interface for JIT compilation. Applications that
3091 dynamically generate code can create symbol files in memory and register
3092 them with GDB. For users, the feature should work transparently, and
3093 for JIT developers, the interface is documented in the GDB manual in the
3094 "JIT Compilation Interface" chapter.
3096 * Tracepoints may now be conditional. The syntax is as for
3097 breakpoints; either an "if" clause appended to the "trace" command,
3098 or the "condition" command is available. GDB sends the condition to
3099 the target for evaluation using the same bytecode format as is used
3100 for tracepoint actions.
3102 * The disassemble command now supports: an optional /r modifier, print the
3103 raw instructions in hex as well as in symbolic form, and an optional /m
3104 modifier to print mixed source+assembly.
3106 * Process record and replay
3108 In a architecture environment that supports ``process record and
3109 replay'', ``process record and replay'' target can record a log of
3110 the process execution, and replay it with both forward and reverse
3113 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3114 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3115 set execution-direction {forward|reverse}, for targets that support
3118 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3119 feature is available with a native GDB running on kernel version
3122 * GDB now has support for multi-byte and wide character sets on the
3123 target. Strings whose character type is wchar_t, char16_t, or
3124 char32_t are now correctly printed. GDB supports wide- and unicode-
3125 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3126 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3127 `printf'. This feature requires iconv to work properly; if your
3128 system does not have a working iconv, GDB can use GNU libiconv. See
3129 the installation instructions for more information.
3131 * GDB now supports automatic retrieval of shared library files from
3132 remote targets. To use this feature, specify a system root that begins
3133 with the `remote:' prefix, either via the `set sysroot' command or via
3134 the `--with-sysroot' configure-time option.
3136 * "info sharedlibrary" now takes an optional regex of libraries to show,
3137 and it now reports if a shared library has no debugging information.
3139 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3140 now complete on file names.
3142 * When completing in expressions, gdb will attempt to limit
3143 completions to allowable structure or union fields, where appropriate.
3144 For instance, consider:
3146 # struct example { int f1; double f2; };
3147 # struct example variable;
3150 If the user types TAB at the end of this command line, the available
3151 completions will be "f1" and "f2".
3153 * Inlined functions are now supported. They show up in backtraces, and
3154 the "step", "next", and "finish" commands handle them automatically.
3156 * GDB now supports the token-splicing (##) and stringification (#)
3157 operators when expanding macros. It also supports variable-arity
3160 * GDB now supports inspecting extra signal information, exported by
3161 the new $_siginfo convenience variable. The feature is currently
3162 implemented on linux ARM, i386 and amd64.
3164 * GDB can now display the VFP floating point registers and NEON vector
3165 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3166 can provide these registers (requires Linux 2.6.30 or later). Remote
3167 and simulator targets may also provide them.
3169 * New remote packets
3172 Search memory for a sequence of bytes.
3175 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3176 operation over reliable transport links. Use of this packet is
3177 controlled by the `set remote noack-packet' command.
3180 Kill the process with the specified process ID. Use this in preference
3181 to `k' when multiprocess protocol extensions are supported.
3184 Obtains additional operating system information
3188 Read or write additional signal information.
3190 * Removed remote protocol undocumented extension
3192 An undocumented extension to the remote protocol's `S' stop reply
3193 packet that permited the stub to pass a process id was removed.
3194 Remote servers should use the `T' stop reply packet instead.
3196 * GDB now supports multiple function calling conventions according to the
3197 DWARF-2 DW_AT_calling_convention function attribute.
3199 * The SH target utilizes the aforementioned change to distinguish between gcc
3200 and Renesas calling convention. It also adds the new CLI commands
3201 `set/show sh calling-convention'.
3203 * GDB can now read compressed debug sections, as produced by GNU gold
3204 with the --compress-debug-sections=zlib flag.
3206 * 64-bit core files are now supported on AIX.
3208 * Thread switching is now supported on Tru64.
3210 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3211 which will be allocated using malloc later in program execution.
3213 * The qXfer:libraries:read remote procotol packet now allows passing a
3214 list of section offsets.
3216 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3217 conditions handling signals delivered during attach or thread creation
3218 have also been fixed.
3220 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3221 From the user's standpoint, all unqualified instances of True and False
3222 are treated as the standard definitions, regardless of context.
3224 * GDB now parses C++ symbol and type names more flexibly. For
3227 template<typename T> class C { };
3230 GDB will now correctly handle all of:
3232 ptype C<char const *>
3233 ptype C<char const*>
3234 ptype C<const char *>
3235 ptype C<const char*>
3237 * New features in the GDB remote stub, gdbserver
3239 - The "--wrapper" command-line argument tells gdbserver to use a
3240 wrapper program to launch programs for debugging.
3242 - On PowerPC and S/390 targets, it is now possible to use a single
3243 gdbserver executable to debug both 32-bit and 64-bit programs.
3244 (This requires gdbserver itself to be built as a 64-bit executable.)
3246 - gdbserver uses the new noack protocol mode for TCP connections to
3247 reduce communications latency, if also supported and enabled in GDB.
3249 - Support for the sparc64-linux-gnu target is now included in
3252 - The amd64-linux build of gdbserver now supports debugging both
3253 32-bit and 64-bit programs.
3255 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3256 now support hardware watchpoints, and will use them automatically
3261 GDB now has support for scripting using Python. Whether this is
3262 available is determined at configure time.
3264 New GDB commands can now be written in Python.
3266 * Ada tasking support
3268 Ada tasks can now be inspected in GDB. The following commands have
3272 Print the list of Ada tasks.
3274 Print detailed information about task number N.
3276 Print the task number of the current task.
3278 Switch the context of debugging to task number N.
3280 * Support for user-defined prefixed commands. The "define" command can
3281 add new commands to existing prefixes, e.g. "target".
3283 * Multi-inferior, multi-process debugging.
3285 GDB now has generalized support for multi-inferior debugging. See
3286 "Debugging Multiple Inferiors" in the manual for more information.
3287 Although availability still depends on target support, the command
3288 set is more uniform now. The GNU/Linux specific multi-forks support
3289 has been migrated to this new framework. This implied some user
3290 visible changes; see "New commands" and also "Removed commands"
3293 * Target descriptions can now describe the target OS ABI. See the
3294 "Target Description Format" section in the user manual for more
3297 * Target descriptions can now describe "compatible" architectures
3298 to indicate that the target can execute applications for a different
3299 architecture in addition to those for the main target architecture.
3300 See the "Target Description Format" section in the user manual for
3303 * Multi-architecture debugging.
3305 GDB now includes general supports for debugging applications on
3306 hybrid systems that use more than one single processor architecture
3307 at the same time. Each such hybrid architecture still requires
3308 specific support to be added. The only hybrid architecture supported
3309 in this version of GDB is the Cell Broadband Engine.
3311 * GDB now supports integrated debugging of Cell/B.E. applications that
3312 use both the PPU and SPU architectures. To enable support for hybrid
3313 Cell/B.E. debugging, you need to configure GDB to support both the
3314 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3315 --enable-targets configure option.
3317 * Non-stop mode debugging.
3319 For some targets, GDB now supports an optional mode of operation in
3320 which you can examine stopped threads while other threads continue
3321 to execute freely. This is referred to as non-stop mode, with the
3322 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3323 section in the user manual for more information.
3325 To be able to support remote non-stop debugging, a remote stub needs
3326 to implement the non-stop mode remote protocol extensions, as
3327 described in the "Remote Non-Stop" section of the user manual. The
3328 GDB remote stub, gdbserver, has been adjusted to support these
3329 extensions on linux targets.
3331 * New commands (for set/show, see "New options" below)
3333 catch syscall [NAME(S) | NUMBER(S)]
3334 Catch system calls. Arguments, which should be names of system
3335 calls or their numbers, mean catch only those syscalls. Without
3336 arguments, every syscall will be caught. When the inferior issues
3337 any of the specified syscalls, GDB will stop and announce the system
3338 call, both when it is called and when its call returns. This
3339 feature is currently available with a native GDB running on the
3340 Linux Kernel, under the following architectures: x86, x86_64,
3341 PowerPC and PowerPC64.
3343 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3345 Search memory for a sequence of bytes.
3347 maint set python print-stack
3348 maint show python print-stack
3349 Show a stack trace when an error is encountered in a Python script.
3352 Invoke CODE by passing it to the Python interpreter.
3357 These allow macros to be defined, undefined, and listed
3361 Show operating system information about processes.
3364 List the inferiors currently under GDB's control.
3367 Switch focus to inferior number NUM.
3370 Detach from inferior number NUM.
3373 Kill inferior number NUM.
3377 set spu stop-on-load
3378 show spu stop-on-load
3379 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3381 set spu auto-flush-cache
3382 show spu auto-flush-cache
3383 Control whether to automatically flush the software-managed cache
3384 during Cell/B.E. debugging.
3386 set sh calling-convention
3387 show sh calling-convention
3388 Control the calling convention used when calling SH target functions.
3391 show debug timestamp
3392 Control display of timestamps with GDB debugging output.
3394 set disassemble-next-line
3395 show disassemble-next-line
3396 Control display of disassembled source lines or instructions when
3399 set remote noack-packet
3400 show remote noack-packet
3401 Set/show the use of remote protocol QStartNoAckMode packet. See above
3402 under "New remote packets."
3404 set remote query-attached-packet
3405 show remote query-attached-packet
3406 Control use of remote protocol `qAttached' (query-attached) packet.
3408 set remote read-siginfo-object
3409 show remote read-siginfo-object
3410 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3413 set remote write-siginfo-object
3414 show remote write-siginfo-object
3415 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3418 set remote reverse-continue
3419 show remote reverse-continue
3420 Control use of remote protocol 'bc' (reverse-continue) packet.
3422 set remote reverse-step
3423 show remote reverse-step
3424 Control use of remote protocol 'bs' (reverse-step) packet.
3426 set displaced-stepping
3427 show displaced-stepping
3428 Control displaced stepping mode. Displaced stepping is a way to
3429 single-step over breakpoints without removing them from the debuggee.
3430 Also known as "out-of-line single-stepping".
3433 show debug displaced
3434 Control display of debugging info for displaced stepping.
3436 maint set internal-error
3437 maint show internal-error
3438 Control what GDB does when an internal error is detected.
3440 maint set internal-warning
3441 maint show internal-warning
3442 Control what GDB does when an internal warning is detected.
3447 Use a wrapper program to launch programs for debugging.
3449 set multiple-symbols (all|ask|cancel)
3450 show multiple-symbols
3451 The value of this variable can be changed to adjust the debugger behavior
3452 when an expression or a breakpoint location contains an ambiguous symbol
3453 name (an overloaded function name, for instance).
3455 set breakpoint always-inserted
3456 show breakpoint always-inserted
3457 Keep breakpoints always inserted in the target, as opposed to inserting
3458 them when resuming the target, and removing them when the target stops.
3459 This option can improve debugger performance on slow remote targets.
3461 set arm fallback-mode (arm|thumb|auto)
3462 show arm fallback-mode
3463 set arm force-mode (arm|thumb|auto)
3465 These commands control how ARM GDB determines whether instructions
3466 are ARM or Thumb. The default for both settings is auto, which uses
3467 the current CPSR value for instructions without symbols; previous
3468 versions of GDB behaved as if "set arm fallback-mode arm".
3470 set disable-randomization
3471 show disable-randomization
3472 Standalone programs run with the virtual address space randomization enabled
3473 by default on some platforms. This option keeps the addresses stable across
3474 multiple debugging sessions.
3478 Control whether other threads are stopped or not when some thread hits
3483 Requests that asynchronous execution is enabled in the target, if available.
3484 In this case, it's possible to resume target in the background, and interact
3485 with GDB while the target is running. "show target-async" displays the
3486 current state of asynchronous execution of the target.
3488 set target-wide-charset
3489 show target-wide-charset
3490 The target-wide-charset is the name of the character set that GDB
3491 uses when printing characters whose type is wchar_t.
3493 set tcp auto-retry (on|off)
3495 set tcp connect-timeout
3496 show tcp connect-timeout
3497 These commands allow GDB to retry failed TCP connections to a remote stub
3498 with a specified timeout period; this is useful if the stub is launched
3499 in parallel with GDB but may not be ready to accept connections immediately.
3501 set libthread-db-search-path
3502 show libthread-db-search-path
3503 Control list of directories which GDB will search for appropriate
3506 set schedule-multiple (on|off)
3507 show schedule-multiple
3508 Allow GDB to resume all threads of all processes or only threads of
3509 the current process.
3513 Use more aggressive caching for accesses to the stack. This improves
3514 performance of remote debugging (particularly backtraces) without
3515 affecting correctness.
3517 set interactive-mode (on|off|auto)
3518 show interactive-mode
3519 Control whether GDB runs in interactive mode (on) or not (off).
3520 When in interactive mode, GDB waits for the user to answer all
3521 queries. Otherwise, GDB does not wait and assumes the default
3522 answer. When set to auto (the default), GDB determines which
3523 mode to use based on the stdin settings.
3528 For program forks, this is replaced by the new more generic `info
3529 inferiors' command. To list checkpoints, you can still use the
3530 `info checkpoints' command, which was an alias for the `info forks'
3534 Replaced by the new `inferior' command. To switch between
3535 checkpoints, you can still use the `restart' command, which was an
3536 alias for the `fork' command.
3539 This is removed, since some targets don't have a notion of
3540 processes. To switch between processes, you can still use the
3541 `inferior' command using GDB's own inferior number.
3544 For program forks, this is replaced by the new more generic `kill
3545 inferior' command. To delete a checkpoint, you can still use the
3546 `delete checkpoint' command, which was an alias for the `delete
3550 For program forks, this is replaced by the new more generic `detach
3551 inferior' command. To detach a checkpoint, you can still use the
3552 `detach checkpoint' command, which was an alias for the `detach
3555 * New native configurations
3557 x86/x86_64 Darwin i[34567]86-*-darwin*
3559 x86_64 MinGW x86_64-*-mingw*
3563 Lattice Mico32 lm32-*
3564 x86 DICOS i[34567]86-*-dicos*
3565 x86_64 DICOS x86_64-*-dicos*
3568 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3569 (mingw32ce) debugging.
3575 These commands were actually not implemented on any target.
3577 *** Changes in GDB 6.8
3579 * New native configurations
3581 NetBSD/hppa hppa*-*netbsd*
3582 Xtensa GNU/Linux xtensa*-*-linux*
3586 NetBSD/hppa hppa*-*-netbsd*
3587 Xtensa GNU/Lunux xtensa*-*-linux*
3589 * Change in command line behavior -- corefiles vs. process ids.
3591 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3592 attaching to process NUMBER fails, GDB no longer attempts to open a
3593 core file named NUMBER. Attaching to a program using the -c option
3594 is no longer supported. Instead, use the '-p' or '--pid' options.
3596 * GDB can now be built as a native debugger for debugging Windows x86
3597 (mingw32) Portable Executable (PE) programs.
3599 * Pending breakpoints no longer change their number when their address
3602 * GDB now supports breakpoints with multiple locations,
3603 including breakpoints on C++ constructors, inside C++ templates,
3604 and in inlined functions.
3606 * GDB's ability to debug optimized code has been improved. GDB more
3607 accurately identifies function bodies and lexical blocks that occupy
3608 more than one contiguous range of addresses.
3610 * Target descriptions can now describe registers for PowerPC.
3612 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3613 registers on PowerPC targets.
3615 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3616 targets even when the libthread_db library is not available.
3618 * The GDB remote stub, gdbserver, now supports the new file transfer
3619 commands (remote put, remote get, and remote delete).
3621 * The GDB remote stub, gdbserver, now supports run and attach in
3622 extended-remote mode.
3624 * hppa*64*-*-hpux11* target broken
3625 The debugger is unable to start a program and fails with the following
3626 error: "Error trying to get information about dynamic linker".
3627 The gdb-6.7 release is also affected.
3629 * GDB now supports the --enable-targets= configure option to allow
3630 building a single GDB executable that supports multiple remote
3631 target architectures.
3633 * GDB now supports debugging C and C++ programs which use the
3634 Decimal Floating Point extension. In addition, the PowerPC target
3635 now has a set of pseudo-registers to inspect decimal float values
3636 stored in two consecutive float registers.
3638 * The -break-insert MI command can optionally create pending
3641 * Improved support for debugging Ada
3642 Many improvements to the Ada language support have been made. These
3644 - Better support for Ada2005 interface types
3645 - Improved handling of arrays and slices in general
3646 - Better support for Taft-amendment types
3647 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3649 - Improved command completion in Ada
3652 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3657 set print frame-arguments (all|scalars|none)
3658 show print frame-arguments
3659 The value of this variable can be changed to control which argument
3660 values should be printed by the debugger when displaying a frame.
3665 Transfer files to and from a remote target, and delete remote files.
3672 Transfer files to and from a remote target, and delete remote files.
3674 * New remote packets
3681 Open, close, read, write, and delete files on the remote system.
3684 Attach to an existing process on the remote system, in extended-remote
3688 Run a new process on the remote system, in extended-remote mode.
3690 *** Changes in GDB 6.7
3692 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3693 bfd, libiberty and opcodes, as revealed by static analysis donated by
3694 Coverity, Inc. (http://scan.coverity.com).
3696 * When looking up multiply-defined global symbols, GDB will now prefer the
3697 symbol definition in the current shared library if it was built using the
3698 -Bsymbolic linker option.
3700 * When the Text User Interface (TUI) is not configured, GDB will now
3701 recognize the -tui command-line option and print a message that the TUI
3704 * The GDB remote stub, gdbserver, now has lower overhead for high
3705 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3707 * GDB for MIPS targets now autodetects whether a remote target provides
3708 32-bit or 64-bit register values.
3710 * Support for C++ member pointers has been improved.
3712 * GDB now understands XML target descriptions, which specify the
3713 target's overall architecture. GDB can read a description from
3714 a local file or over the remote serial protocol.
3716 * Vectors of single-byte data use a new integer type which is not
3717 automatically displayed as character or string data.
3719 * The /s format now works with the print command. It displays
3720 arrays of single-byte integers and pointers to single-byte integers
3723 * Target descriptions can now describe target-specific registers,
3724 for architectures which have implemented the support (currently
3725 only ARM, M68K, and MIPS).
3727 * GDB and the GDB remote stub, gdbserver, now support the XScale
3730 * The GDB remote stub, gdbserver, has been updated to support
3731 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3732 has been rewritten to use the standard GDB remote protocol.
3734 * GDB can now step into C++ functions which are called through thunks.
3736 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3738 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3739 layout. It also supports a TextSeg= and DataSeg= response when only
3740 segment base addresses (rather than offsets) are available.
3742 * The /i format now outputs any trailing branch delay slot instructions
3743 immediately following the last instruction within the count specified.
3745 * The GDB remote protocol "T" stop reply packet now supports a
3746 "library" response. Combined with the new "qXfer:libraries:read"
3747 packet, this response allows GDB to debug shared libraries on targets
3748 where the operating system manages the list of loaded libraries (e.g.
3749 Windows and SymbianOS).
3751 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3752 (DLLs) on Windows and Windows CE targets.
3754 * GDB now supports a faster verification that a .debug file matches its binary
3755 according to its build-id signature, if the signature is present.
3761 Enable or disable hardware flow control (RTS/CTS) on the serial port
3762 when debugging using remote targets.
3764 set mem inaccessible-by-default
3765 show mem inaccessible-by-default
3766 If the target supplies a memory map, for instance via the remote
3767 protocol's "qXfer:memory-map:read" packet, setting this variable
3768 prevents GDB from accessing memory outside the memory map. This
3769 is useful for targets with memory mapped registers or which react
3770 badly to accesses of unmapped address space.
3772 set breakpoint auto-hw
3773 show breakpoint auto-hw
3774 If the target supplies a memory map, for instance via the remote
3775 protocol's "qXfer:memory-map:read" packet, setting this variable
3776 lets GDB use hardware breakpoints automatically for memory regions
3777 where it can not use software breakpoints. This covers both the
3778 "break" command and internal breakpoints used for other commands
3779 including "next" and "finish".
3782 catch exception unhandled
3783 Stop the program execution when Ada exceptions are raised.
3786 Stop the program execution when an Ada assertion failed.
3790 Set an alternate system root for target files. This is a more
3791 general version of "set solib-absolute-prefix", which is now
3792 an alias to "set sysroot".
3795 Provide extended SPU facility status information. This set of
3796 commands is available only when debugging the Cell/B.E. SPU
3799 * New native configurations
3801 OpenBSD/sh sh*-*openbsd*
3804 unset tdesc filename
3806 Use the specified local file as an XML target description, and do
3807 not query the target for its built-in description.
3811 OpenBSD/sh sh*-*-openbsd*
3812 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3813 Toshiba Media Processor mep-elf
3815 * New remote packets
3818 Ignore the specified signals; pass them directly to the debugged program
3819 without stopping other threads or reporting them to GDB.
3821 qXfer:features:read:
3822 Read an XML target description from the target, which describes its
3827 Read or write contents of an spufs file on the target system. These
3828 packets are available only on the Cell/B.E. SPU architecture.
3830 qXfer:libraries:read:
3831 Report the loaded shared libraries. Combined with new "T" packet
3832 response, this packet allows GDB to debug shared libraries on
3833 targets where the operating system manages the list of loaded
3834 libraries (e.g. Windows and SymbianOS).
3838 Support for these obsolete configurations has been removed.
3846 i[34567]86-*-lynxos*
3847 i[34567]86-*-netware*
3848 i[34567]86-*-sco3.2v5*
3849 i[34567]86-*-sco3.2v4*
3851 i[34567]86-*-sysv4.2*
3854 i[34567]86-*-unixware2*
3855 i[34567]86-*-unixware*
3864 * Other removed features
3871 Various m68k-only ROM monitors.
3878 Various Renesas ROM monitors and debugging interfaces for SH and
3883 Support for a Macraigor serial interface to on-chip debugging.
3884 GDB does not directly support the newer parallel or USB
3889 A debug information format. The predecessor to DWARF 2 and
3890 DWARF 3, which are still supported.
3892 Support for the HP aCC compiler on HP-UX/PA-RISC
3894 SOM-encapsulated symbolic debugging information, automatic
3895 invocation of pxdb, and the aCC custom C++ ABI. This does not
3896 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3897 with aCC can still be debugged on an assembly level.
3899 MIPS ".pdr" sections
3901 A MIPS-specific format used to describe stack frame layout
3902 in debugging information.
3906 GDB could work with an older version of Guile to debug
3907 the interpreter and Scheme programs running in it.
3909 set mips stack-arg-size
3910 set mips saved-gpreg-size
3912 Use "set mips abi" to control parameter passing for MIPS.
3914 *** Changes in GDB 6.6
3919 Cell Broadband Engine SPU spu-elf
3921 * GDB can now be configured as a cross-debugger targeting native Windows
3922 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3923 running on a Windows system over TCP/IP to debug Windows programs.
3925 * The GDB remote stub, gdbserver, has been updated to support Windows and
3926 Cygwin debugging. Both single-threaded and multi-threaded programs are
3929 * The "set trust-readonly-sections" command works again. This command was
3930 broken in GDB 6.3, 6.4, and 6.5.
3932 * The "load" command now supports writing to flash memory, if the remote
3933 stub provides the required support.
3935 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3936 longer requires symbolic debug information (e.g. DWARF-2).
3941 unset substitute-path
3942 show substitute-path
3943 Manage a list of substitution rules that GDB uses to rewrite the name
3944 of the directories where the sources are located. This can be useful
3945 for instance when the sources were moved to a different location
3946 between compilation and debugging.
3950 Print each CLI command as it is executed. Each command is prefixed with
3951 a number of `+' symbols representing the nesting depth.
3952 The source command now has a `-v' option to enable the same feature.
3956 The ARM Demon monitor support (RDP protocol, "target rdp").
3958 Kernel Object Display, an embedded debugging feature which only worked with
3959 an obsolete version of Cisco IOS.
3961 The 'set download-write-size' and 'show download-write-size' commands.
3963 * New remote packets
3966 Tell a stub about GDB client features, and request remote target features.
3967 The first feature implemented is PacketSize, which allows the target to
3968 specify the size of packets it can handle - to minimize the number of
3969 packets required and improve performance when connected to a remote
3973 Fetch an OS auxilliary vector from the remote stub. This packet is a
3974 more efficient replacement for qPart:auxv:read.
3976 qXfer:memory-map:read:
3977 Fetch a memory map from the remote stub, including information about
3978 RAM, ROM, and flash memory devices.
3983 Erase and program a flash memory device.
3985 * Removed remote packets
3988 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3989 used it, and only gdbserver implemented it.
3991 *** Changes in GDB 6.5
3995 Renesas M32C/M16C m32c-elf
3997 Morpho Technologies ms1 ms1-elf
4001 init-if-undefined Initialize a convenience variable, but
4002 only if it doesn't already have a value.
4004 The following commands are presently only implemented for native GNU/Linux:
4006 checkpoint Save a snapshot of the program state.
4008 restart <n> Return the program state to a
4009 previously saved state.
4011 info checkpoints List currently saved checkpoints.
4013 delete-checkpoint <n> Delete a previously saved checkpoint.
4015 set|show detach-on-fork Tell gdb whether to detach from a newly
4016 forked process, or to keep debugging it.
4018 info forks List forks of the user program that
4019 are available to be debugged.
4021 fork <n> Switch to debugging one of several
4022 forks of the user program that are
4023 available to be debugged.
4025 delete-fork <n> Delete a fork from the list of forks
4026 that are available to be debugged (and
4027 kill the forked process).
4029 detach-fork <n> Delete a fork from the list of forks
4030 that are available to be debugged (and
4031 allow the process to continue).
4035 Morpho Technologies ms2 ms1-elf
4037 * Improved Windows host support
4039 GDB now builds as a cross debugger hosted on i686-mingw32, including
4040 native console support, and remote communications using either
4041 network sockets or serial ports.
4043 * Improved Modula-2 language support
4045 GDB can now print most types in the Modula-2 syntax. This includes:
4046 basic types, set types, record types, enumerated types, range types,
4047 pointer types and ARRAY types. Procedure var parameters are correctly
4048 printed and hexadecimal addresses and character constants are also
4049 written in the Modula-2 syntax. Best results can be obtained by using
4050 GNU Modula-2 together with the -gdwarf-2 command line option.
4054 The ARM rdi-share module.
4056 The Netware NLM debug server.
4058 *** Changes in GDB 6.4
4060 * New native configurations
4062 OpenBSD/arm arm*-*-openbsd*
4063 OpenBSD/mips64 mips64-*-openbsd*
4067 Morpho Technologies ms1 ms1-elf
4069 * New command line options
4071 --batch-silent As for --batch, but totally silent.
4072 --return-child-result The debugger will exist with the same value
4073 the child (debugged) program exited with.
4074 --eval-command COMMAND, -ex COMMAND
4075 Execute a single GDB CLI command. This may be
4076 specified multiple times and in conjunction
4077 with the --command (-x) option.
4079 * Deprecated commands removed
4081 The following commands, that were deprecated in 2000, have been
4085 set|show arm disassembly-flavor set|show arm disassembler
4086 othernames set arm disassembler
4087 set|show remotedebug set|show debug remote
4088 set|show archdebug set|show debug arch
4089 set|show eventdebug set|show debug event
4092 * New BSD user-level threads support
4094 It is now possible to debug programs using the user-level threads
4095 library on OpenBSD and FreeBSD. Currently supported (target)
4098 FreeBSD/amd64 x86_64-*-freebsd*
4099 FreeBSD/i386 i386-*-freebsd*
4100 OpenBSD/i386 i386-*-openbsd*
4102 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4103 are not yet supported.
4105 * New support for Matsushita MN10300 w/sim added
4106 (Work in progress). mn10300-elf.
4108 * REMOVED configurations and files
4110 VxWorks and the XDR protocol *-*-vxworks
4111 Motorola MCORE mcore-*-*
4112 National Semiconductor NS32000 ns32k-*-*
4114 * New "set print array-indexes" command
4116 After turning this setting "on", GDB prints the index of each element
4117 when displaying arrays. The default is "off" to preserve the previous
4120 * VAX floating point support
4122 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4124 * User-defined command support
4126 In addition to using $arg0..$arg9 for argument passing, it is now possible
4127 to use $argc to determine now many arguments have been passed. See the
4128 section on user-defined commands in the user manual for more information.
4130 *** Changes in GDB 6.3:
4132 * New command line option
4134 GDB now accepts -l followed by a number to set the timeout for remote
4137 * GDB works with GCC -feliminate-dwarf2-dups
4139 GDB now supports a more compact representation of DWARF-2 debug
4140 information using DW_FORM_ref_addr references. These are produced
4141 by GCC with the option -feliminate-dwarf2-dups and also by some
4142 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4143 to use -feliminate-dwarf2-dups.
4145 * Internationalization
4147 When supported by the host system, GDB will be built with
4148 internationalization (libintl). The task of marking up the sources is
4149 continued, we're looking forward to our first translation.
4153 Initial support for debugging programs compiled with the GNAT
4154 implementation of the Ada programming language has been integrated
4155 into GDB. In this release, support is limited to expression evaluation.
4157 * New native configurations
4159 GNU/Linux/m32r m32r-*-linux-gnu
4163 GDB's remote protocol now includes support for the 'p' packet. This
4164 packet is used to fetch individual registers from a remote inferior.
4166 * END-OF-LIFE registers[] compatibility module
4168 GDB's internal register infrastructure has been completely rewritten.
4169 The new infrastructure making possible the implementation of key new
4170 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4173 GDB 6.3 will be the last release to include the the registers[]
4174 compatibility module that allowed out-of-date configurations to
4175 continue to work. This change directly impacts the following
4185 powerpc bdm protocol
4187 Unless there is activity to revive these configurations, they will be
4188 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4190 * OBSOLETE configurations and files
4192 Configurations that have been declared obsolete in this release have
4193 been commented out. Unless there is activity to revive these
4194 configurations, the next release of GDB will have their sources
4195 permanently REMOVED.
4204 *** Changes in GDB 6.2.1:
4206 * MIPS `break main; run' gave an heuristic-fence-post warning
4208 When attempting to run even a simple program, a warning about
4209 heuristic-fence-post being hit would be reported. This problem has
4212 * MIPS IRIX 'long double' crashed GDB
4214 When examining a long double variable, GDB would get a segmentation
4215 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4216 IRIX long double values).
4220 A bug in the VAX stack code was causing problems with the "next"
4221 command. This problem has been fixed.
4223 *** Changes in GDB 6.2:
4225 * Fix for ``many threads''
4227 On GNU/Linux systems that use the NPTL threads library, a program
4228 rapidly creating and deleting threads would confuse GDB leading to the
4231 ptrace: No such process.
4232 thread_db_get_info: cannot get thread info: generic error
4234 This problem has been fixed.
4236 * "-async" and "-noasync" options removed.
4238 Support for the broken "-noasync" option has been removed (it caused
4241 * New ``start'' command.
4243 This command runs the program until the begining of the main procedure.
4245 * New BSD Kernel Data Access Library (libkvm) interface
4247 Using ``target kvm'' it is now possible to debug kernel core dumps and
4248 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4249 platforms. Currently supported (native-only) configurations are:
4251 FreeBSD/amd64 x86_64-*-freebsd*
4252 FreeBSD/i386 i?86-*-freebsd*
4253 NetBSD/i386 i?86-*-netbsd*
4254 NetBSD/m68k m68*-*-netbsd*
4255 NetBSD/sparc sparc-*-netbsd*
4256 OpenBSD/amd64 x86_64-*-openbsd*
4257 OpenBSD/i386 i?86-*-openbsd*
4258 OpenBSD/m68k m68*-openbsd*
4259 OpenBSD/sparc sparc-*-openbsd*
4261 * Signal trampoline code overhauled
4263 Many generic problems with GDB's signal handling code have been fixed.
4264 These include: backtraces through non-contiguous stacks; recognition
4265 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4266 call; backtrace through a signal trampoline; step into and out of
4267 signal handlers; and single-stepping in the signal trampoline.
4269 Please note that kernel bugs are a limiting factor here. These
4270 features have been shown to work on an s390 GNU/Linux system that
4271 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4273 * Cygwin support for DWARF 2 added.
4275 * New native configurations
4277 GNU/Linux/hppa hppa*-*-linux*
4278 OpenBSD/hppa hppa*-*-openbsd*
4279 OpenBSD/m68k m68*-*-openbsd*
4280 OpenBSD/m88k m88*-*-openbsd*
4281 OpenBSD/powerpc powerpc-*-openbsd*
4282 NetBSD/vax vax-*-netbsd*
4283 OpenBSD/vax vax-*-openbsd*
4285 * END-OF-LIFE frame compatibility module
4287 GDB's internal frame infrastructure has been completely rewritten.
4288 The new infrastructure making it possible to support key new features
4289 including DWARF 2 Call Frame Information. To aid in the task of
4290 migrating old configurations to this new infrastructure, a
4291 compatibility module, that allowed old configurations to continue to
4292 work, was also included.
4294 GDB 6.2 will be the last release to include this frame compatibility
4295 module. This change directly impacts the following configurations:
4305 Unless there is activity to revive these configurations, they will be
4306 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4308 * REMOVED configurations and files
4310 Sun 3, running SunOS 3 m68*-*-sunos3*
4311 Sun 3, running SunOS 4 m68*-*-sunos4*
4312 Sun 2, running SunOS 3 m68000-*-sunos3*
4313 Sun 2, running SunOS 4 m68000-*-sunos4*
4314 Motorola 680x0 running LynxOS m68*-*-lynxos*
4315 AT&T 3b1/Unix pc m68*-att-*
4316 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4317 decstation mips-dec-* mips-little-*
4318 riscos mips-*-riscos* mips-*-sysv*
4319 sonymips mips-sony-*
4320 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4322 *** Changes in GDB 6.1.1:
4324 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4326 The TUI (Text-mode User Interface) is now built as part of a default
4327 GDB configuration. It is enabled by either selecting the TUI with the
4328 command line option "-i=tui" or by running the separate "gdbtui"
4329 program. For more information on the TUI, see the manual "Debugging
4332 * Pending breakpoint support (also included in GDB 6.1)
4334 Support has been added to allow you to specify breakpoints in shared
4335 libraries that have not yet been loaded. If a breakpoint location
4336 cannot be found, and the "breakpoint pending" option is set to auto,
4337 GDB queries you if you wish to make the breakpoint pending on a future
4338 shared-library load. If and when GDB resolves the breakpoint symbol,
4339 the pending breakpoint is removed as one or more regular breakpoints
4342 Pending breakpoints are very useful for GCJ Java debugging.
4344 * Fixed ISO-C build problems
4346 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4347 non ISO-C code that stopped them being built using a more strict ISO-C
4348 compiler (e.g., IBM's C compiler).
4350 * Fixed build problem on IRIX 5
4352 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4353 wasn't able to compile compile on an IRIX 5 system.
4355 * Added execute permission to gdb/gdbserver/configure
4357 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4358 permission. This bug would cause configure to fail on a number of
4359 systems (Solaris, IRIX). Ref: server/519.
4361 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4363 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4364 has been updated to use constant array sizes.
4366 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4368 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4369 its generated DWARF Call Frame Info. This encoding was causing GDB to
4370 panic, that panic has been fixed. Ref: gdb/1628.
4372 * Fixed a problem when examining parameters in shared library code.
4374 When examining parameters in optimized shared library code generated
4375 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4376 not available''. GDB now correctly displays the variable's value.
4378 *** Changes in GDB 6.1:
4380 * Removed --with-mmalloc
4382 Support for the mmalloc memory manager has been removed, as it
4383 conflicted with the internal gdb byte cache.
4385 * Changes in AMD64 configurations
4387 The AMD64 target now includes the %cs and %ss registers. As a result
4388 the AMD64 remote protocol has changed; this affects the floating-point
4389 and SSE registers. If you rely on those registers for your debugging,
4390 you should upgrade gdbserver on the remote side.
4392 * Revised SPARC target
4394 The SPARC target has been completely revised, incorporating the
4395 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4396 support for LynxOS and SunOS 4 has been dropped. Calling functions
4397 from within GDB on operating systems with a non-executable stack
4398 (Solaris, OpenBSD) now works.
4402 GDB has a new C++ demangler which does a better job on the mangled
4403 names generated by current versions of g++. It also runs faster, so
4404 with this and other changes gdb should now start faster on large C++
4407 * DWARF 2 Location Expressions
4409 GDB support for location expressions has been extended to support function
4410 arguments and frame bases. Older versions of GDB could crash when they
4413 * C++ nested types and namespaces
4415 GDB's support for nested types and namespaces in C++ has been
4416 improved, especially if you use the DWARF 2 debugging format. (This
4417 is the default for recent versions of GCC on most platforms.)
4418 Specifically, if you have a class "Inner" defined within a class or
4419 namespace "Outer", then GDB realizes that the class's name is
4420 "Outer::Inner", not simply "Inner". This should greatly reduce the
4421 frequency of complaints about not finding RTTI symbols. In addition,
4422 if you are stopped at inside of a function defined within a namespace,
4423 GDB modifies its name lookup accordingly.
4425 * New native configurations
4427 NetBSD/amd64 x86_64-*-netbsd*
4428 OpenBSD/amd64 x86_64-*-openbsd*
4429 OpenBSD/alpha alpha*-*-openbsd*
4430 OpenBSD/sparc sparc-*-openbsd*
4431 OpenBSD/sparc64 sparc64-*-openbsd*
4433 * New debugging protocols
4435 M32R with SDI protocol m32r-*-elf*
4437 * "set prompt-escape-char" command deleted.
4439 The command "set prompt-escape-char" has been deleted. This command,
4440 and its very obscure effet on GDB's prompt, was never documented,
4441 tested, nor mentioned in the NEWS file.
4443 * OBSOLETE configurations and files
4445 Configurations that have been declared obsolete in this release have
4446 been commented out. Unless there is activity to revive these
4447 configurations, the next release of GDB will have their sources
4448 permanently REMOVED.
4450 Sun 3, running SunOS 3 m68*-*-sunos3*
4451 Sun 3, running SunOS 4 m68*-*-sunos4*
4452 Sun 2, running SunOS 3 m68000-*-sunos3*
4453 Sun 2, running SunOS 4 m68000-*-sunos4*
4454 Motorola 680x0 running LynxOS m68*-*-lynxos*
4455 AT&T 3b1/Unix pc m68*-att-*
4456 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4457 decstation mips-dec-* mips-little-*
4458 riscos mips-*-riscos* mips-*-sysv*
4459 sonymips mips-sony-*
4460 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4462 * REMOVED configurations and files
4464 SGI Irix-4.x mips-sgi-irix4 or iris4
4465 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4466 Z8000 simulator z8k-zilog-none or z8ksim
4467 Matsushita MN10200 w/simulator mn10200-*-*
4468 H8/500 simulator h8500-hitachi-hms or h8500hms
4469 HP/PA running BSD hppa*-*-bsd*
4470 HP/PA running OSF/1 hppa*-*-osf*
4471 HP/PA Pro target hppa*-*-pro*
4472 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4473 386BSD i[3456]86-*-bsd*
4474 Sequent family i[3456]86-sequent-sysv4*
4475 i[3456]86-sequent-sysv*
4476 i[3456]86-sequent-bsd*
4477 SPARC running LynxOS sparc-*-lynxos*
4478 SPARC running SunOS 4 sparc-*-sunos4*
4479 Tsqware Sparclet sparclet-*-*
4480 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4482 *** Changes in GDB 6.0:
4486 Support for debugging the Objective-C programming language has been
4487 integrated into GDB.
4489 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4491 DWARF 2's Call Frame Information makes available compiler generated
4492 information that more exactly describes the program's run-time stack.
4493 By using this information, GDB is able to provide more robust stack
4496 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4497 have been updated to use a new backtrace mechanism which includes
4498 DWARF 2 CFI support.
4502 GDB's remote protocol has been extended to include support for hosted
4503 file I/O (where the remote target uses GDB's file system). See GDB's
4504 remote protocol documentation for details.
4506 * All targets using the new architecture framework.
4508 All of GDB's targets have been updated to use the new internal
4509 architecture framework. The way is now open for future GDB releases
4510 to include cross-architecture native debugging support (i386 on amd64,
4513 * GNU/Linux's Thread Local Storage (TLS)
4515 GDB now includes support for for the GNU/Linux implementation of
4516 per-thread variables.
4518 * GNU/Linux's Native POSIX Thread Library (NPTL)
4520 GDB's thread code has been updated to work with either the new
4521 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4523 * Separate debug info.
4525 GDB, in conjunction with BINUTILS, now supports a mechanism for
4526 automatically loading debug information from a separate file. Instead
4527 of shipping full debug and non-debug versions of system libraries,
4528 system integrators can now instead ship just the stripped libraries
4529 and optional debug files.
4531 * DWARF 2 Location Expressions
4533 DWARF 2 Location Expressions allow the compiler to more completely
4534 describe the location of variables (even in optimized code) to the
4537 GDB now includes preliminary support for location expressions (support
4538 for DW_OP_piece is still missing).
4542 A number of long standing bugs that caused GDB to die while starting a
4543 Java application have been fixed. GDB's Java support is now
4544 considered "useable".
4546 * GNU/Linux support for fork, vfork, and exec.
4548 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4549 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4552 * GDB supports logging output to a file
4554 There are two new commands, "set logging" and "show logging", which can be
4555 used to capture GDB's output to a file.
4557 * The meaning of "detach" has changed for gdbserver
4559 The "detach" command will now resume the application, as documented. To
4560 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4563 * d10v, m68hc11 `regs' command deprecated
4565 The `info registers' command has been updated so that it displays the
4566 registers using a format identical to the old `regs' command.
4570 A new command, "maint set profile on/off", has been added. This command can
4571 be used to enable or disable profiling while running GDB, to profile a
4572 session or a set of commands. In addition there is a new configure switch,
4573 "--enable-profiling", which will cause GDB to be compiled with profiling
4574 data, for more informative profiling results.
4576 * Default MI syntax changed to "mi2".
4578 The default MI (machine interface) syntax, enabled by the command line
4579 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4580 "mi1", can be enabled by specifying the option "-i=mi1".
4582 Support for the original "mi0" syntax (included in GDB 5.0) has been
4585 Fix for gdb/192: removed extraneous space when displaying frame level.
4586 Fix for gdb/672: update changelist is now output in mi list format.
4587 Fix for gdb/702: a -var-assign that updates the value now shows up
4588 in a subsequent -var-update.
4590 * New native configurations.
4592 FreeBSD/amd64 x86_64-*-freebsd*
4594 * Multi-arched targets.
4596 HP/PA HPUX11 hppa*-*-hpux*
4597 Renesas M32R/D w/simulator m32r-*-elf*
4599 * OBSOLETE configurations and files
4601 Configurations that have been declared obsolete in this release have
4602 been commented out. Unless there is activity to revive these
4603 configurations, the next release of GDB will have their sources
4604 permanently REMOVED.
4606 Z8000 simulator z8k-zilog-none or z8ksim
4607 Matsushita MN10200 w/simulator mn10200-*-*
4608 H8/500 simulator h8500-hitachi-hms or h8500hms
4609 HP/PA running BSD hppa*-*-bsd*
4610 HP/PA running OSF/1 hppa*-*-osf*
4611 HP/PA Pro target hppa*-*-pro*
4612 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4613 Sequent family i[3456]86-sequent-sysv4*
4614 i[3456]86-sequent-sysv*
4615 i[3456]86-sequent-bsd*
4616 Tsqware Sparclet sparclet-*-*
4617 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4619 * REMOVED configurations and files
4622 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4623 IBM AIX PS/2 i[3456]86-*-aix
4624 i386 running Mach 3.0 i[3456]86-*-mach3*
4625 i386 running Mach i[3456]86-*-mach*
4626 i386 running OSF/1 i[3456]86-*osf1mk*
4627 HP/Apollo 68k Family m68*-apollo*-sysv*,
4629 m68*-hp-bsd*, m68*-hp-hpux*
4630 Argonaut Risc Chip (ARC) arc-*-*
4631 Mitsubishi D30V d30v-*-*
4632 Fujitsu FR30 fr30-*-elf*
4633 OS/9000 i[34]86-*-os9k
4634 I960 with MON960 i960-*-coff
4636 * MIPS $fp behavior changed
4638 The convenience variable $fp, for the MIPS, now consistently returns
4639 the address of the current frame's base. Previously, depending on the
4640 context, $fp could refer to either $sp or the current frame's base
4641 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4642 The GNU Source-Level Debugger''.
4644 *** Changes in GDB 5.3:
4646 * GNU/Linux shared library multi-threaded performance improved.
4648 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4649 `/proc', in preference to `ptrace' for memory reads. This may result
4650 in an improvement in the start-up time of multi-threaded, shared
4651 library applications when run under GDB. One GDB user writes: ``loads
4652 shared libs like mad''.
4654 * ``gdbserver'' now supports multi-threaded applications on some targets
4656 Support for debugging multi-threaded applications which use
4657 the GNU/Linux LinuxThreads package has been added for
4658 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4659 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4661 * GDB now supports C/C++ preprocessor macros.
4663 GDB now expands preprocessor macro invocations in C/C++ expressions,
4664 and provides various commands for showing macro definitions and how
4667 The new command `macro expand EXPRESSION' expands any macro
4668 invocations in expression, and shows the result.
4670 The new command `show macro MACRO-NAME' shows the definition of the
4671 macro named MACRO-NAME, and where it was defined.
4673 Most compilers don't include information about macros in the debugging
4674 information by default. In GCC 3.1, for example, you need to compile
4675 your program with the options `-gdwarf-2 -g3'. If the macro
4676 information is present in the executable, GDB will read it.
4678 * Multi-arched targets.
4680 DEC Alpha (partial) alpha*-*-*
4681 DEC VAX (partial) vax-*-*
4683 National Semiconductor NS32000 (partial) ns32k-*-*
4684 Motorola 68000 (partial) m68k-*-*
4685 Motorola MCORE mcore-*-*
4689 Fujitsu FRV architecture added by Red Hat frv*-*-*
4692 * New native configurations
4694 Alpha NetBSD alpha*-*-netbsd*
4695 SH NetBSD sh*-*-netbsdelf*
4696 MIPS NetBSD mips*-*-netbsd*
4697 UltraSPARC NetBSD sparc64-*-netbsd*
4699 * OBSOLETE configurations and files
4701 Configurations that have been declared obsolete in this release have
4702 been commented out. Unless there is activity to revive these
4703 configurations, the next release of GDB will have their sources
4704 permanently REMOVED.
4706 Mitsubishi D30V d30v-*-*
4707 OS/9000 i[34]86-*-os9k
4708 IBM AIX PS/2 i[3456]86-*-aix
4709 Fujitsu FR30 fr30-*-elf*
4710 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4711 Argonaut Risc Chip (ARC) arc-*-*
4712 i386 running Mach 3.0 i[3456]86-*-mach3*
4713 i386 running Mach i[3456]86-*-mach*
4714 i386 running OSF/1 i[3456]86-*osf1mk*
4715 HP/Apollo 68k Family m68*-apollo*-sysv*,
4717 m68*-hp-bsd*, m68*-hp-hpux*
4718 I960 with MON960 i960-*-coff
4720 * OBSOLETE languages
4722 CHILL, a Pascal like language used by telecommunications companies.
4724 * REMOVED configurations and files
4726 AMD 29k family via UDI a29k-amd-udi, udi29k
4727 A29K VxWorks a29k-*-vxworks
4728 AMD 29000 embedded, using EBMON a29k-none-none
4729 AMD 29000 embedded with COFF a29k-none-coff
4730 AMD 29000 embedded with a.out a29k-none-aout
4732 testsuite/gdb.hp/gdb.threads-hp/ directory
4734 * New command "set max-user-call-depth <nnn>"
4736 This command allows the user to limit the call depth of user-defined
4737 commands. The default is 1024.
4739 * Changes in FreeBSD/i386 native debugging.
4741 Support for the "generate-core-file" has been added.
4743 * New commands "dump", "append", and "restore".
4745 These commands allow data to be copied from target memory
4746 to a bfd-format or binary file (dump and append), and back
4747 from a file into memory (restore).
4749 * Improved "next/step" support on multi-processor Alpha Tru64.
4751 The previous single-step mechanism could cause unpredictable problems,
4752 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4753 of a software single-step mechanism prevents this.
4755 *** Changes in GDB 5.2.1:
4763 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4764 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4765 Fix, by Joel Brobecker imported from mainline.
4767 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4768 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4769 Fix, by Fred Fish, imported from mainline.
4771 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4772 Surprisingly enough, it works now.
4773 By Michal Ludvig, imported from mainline.
4775 i386 hardware watchpoint support:
4776 avoid misses on second run for some targets.
4777 By Pierre Muller, imported from mainline.
4779 *** Changes in GDB 5.2:
4781 * New command "set trust-readonly-sections on[off]".
4783 This command is a hint that tells gdb that read-only sections
4784 really are read-only (ie. that their contents will not change).
4785 In this mode, gdb will go to the object file rather than the
4786 target to read memory from read-only sections (such as ".text").
4787 This can be a significant performance improvement on some
4788 (notably embedded) targets.
4790 * New command "generate-core-file" (or "gcore").
4792 This new gdb command allows the user to drop a core file of the child
4793 process state at any time. So far it's been implemented only for
4794 GNU/Linux and Solaris, but should be relatively easily ported to other
4795 hosts. Argument is core file name (defaults to core.<pid>).
4797 * New command line option
4799 GDB now accepts --pid or -p followed by a process id.
4801 * Change in command line behavior -- corefiles vs. process ids.
4803 There is a subtle behavior in the way in which GDB handles
4804 command line arguments. The first non-flag argument is always
4805 a program to debug, but the second non-flag argument may either
4806 be a corefile or a process id. Previously, GDB would attempt to
4807 open the second argument as a corefile, and if that failed, would
4808 issue a superfluous error message and then attempt to attach it as
4809 a process. Now, if the second argument begins with a non-digit,
4810 it will be treated as a corefile. If it begins with a digit,
4811 GDB will attempt to attach it as a process, and if no such process
4812 is found, will then attempt to open it as a corefile.
4814 * Changes in ARM configurations.
4816 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4817 configuration is fully multi-arch.
4819 * New native configurations
4821 ARM NetBSD arm*-*-netbsd*
4822 x86 OpenBSD i[3456]86-*-openbsd*
4823 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4824 Sparc64 running FreeBSD sparc64-*-freebsd*
4828 Sanyo XStormy16 xstormy16-elf
4830 * OBSOLETE configurations and files
4832 Configurations that have been declared obsolete in this release have
4833 been commented out. Unless there is activity to revive these
4834 configurations, the next release of GDB will have their sources
4835 permanently REMOVED.
4837 AMD 29k family via UDI a29k-amd-udi, udi29k
4838 A29K VxWorks a29k-*-vxworks
4839 AMD 29000 embedded, using EBMON a29k-none-none
4840 AMD 29000 embedded with COFF a29k-none-coff
4841 AMD 29000 embedded with a.out a29k-none-aout
4843 testsuite/gdb.hp/gdb.threads-hp/ directory
4845 * REMOVED configurations and files
4847 TI TMS320C80 tic80-*-*
4849 PowerPC Solaris powerpcle-*-solaris*
4850 PowerPC Windows NT powerpcle-*-cygwin32
4851 PowerPC Netware powerpc-*-netware*
4852 Harris/CXUX m88k m88*-harris-cxux*
4853 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4854 ns32k-utek-sysv* ns32k-utek-*
4855 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4856 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4857 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4858 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4859 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4861 * Changes to command line processing
4863 The new `--args' feature can be used to specify command-line arguments
4864 for the inferior from gdb's command line.
4866 * Changes to key bindings
4868 There is a new `operate-and-get-next' function bound to `C-o'.
4870 *** Changes in GDB 5.1.1
4872 Fix compile problem on DJGPP.
4874 Fix a problem with floating-point registers on the i386 being
4877 Fix to stop GDB crashing on .debug_str debug info.
4879 Numerous documentation fixes.
4881 Numerous testsuite fixes.
4883 *** Changes in GDB 5.1:
4885 * New native configurations
4887 Alpha FreeBSD alpha*-*-freebsd*
4888 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4889 MIPS GNU/Linux mips*-*-linux*
4890 MIPS SGI Irix 6.x mips*-sgi-irix6*
4891 ia64 AIX ia64-*-aix*
4892 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4896 Motorola 68HC11 and 68HC12 m68hc11-elf
4898 UltraSparc running GNU/Linux sparc64-*-linux*
4900 * OBSOLETE configurations and files
4902 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4903 Harris/CXUX m88k m88*-harris-cxux*
4904 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4905 ns32k-utek-sysv* ns32k-utek-*
4906 TI TMS320C80 tic80-*-*
4908 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4909 PowerPC Solaris powerpcle-*-solaris*
4910 PowerPC Windows NT powerpcle-*-cygwin32
4911 PowerPC Netware powerpc-*-netware*
4912 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4913 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4914 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4915 Apple Macintosh (MPW) host N/A
4917 stuff.c (Program to stuff files into a specially prepared space in kdb)
4918 kdb-start.c (Main loop for the standalone kernel debugger)
4920 Configurations that have been declared obsolete in this release have
4921 been commented out. Unless there is activity to revive these
4922 configurations, the next release of GDB will have their sources
4923 permanently REMOVED.
4925 * REMOVED configurations and files
4927 Altos 3068 m68*-altos-*
4928 Convex c1-*-*, c2-*-*
4930 ARM RISCix arm-*-* (as host)
4934 * GDB has been converted to ISO C.
4936 GDB's source code has been converted to ISO C. In particular, the
4937 sources are fully protoized, and rely on standard headers being
4942 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4944 * The MI enabled by default.
4946 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4947 revised and enabled by default. Packages which use GDB as a debugging
4948 engine behind a UI or another front end are encouraged to switch to
4949 using the GDB/MI interface, instead of the old annotations interface
4950 which is now deprecated.
4952 * Support for debugging Pascal programs.
4954 GDB now includes support for debugging Pascal programs. The following
4955 main features are supported:
4957 - Pascal-specific data types such as sets;
4959 - automatic recognition of Pascal sources based on file-name
4962 - Pascal-style display of data types, variables, and functions;
4964 - a Pascal expression parser.
4966 However, some important features are not yet supported.
4968 - Pascal string operations are not supported at all;
4970 - there are some problems with boolean types;
4972 - Pascal type hexadecimal constants are not supported
4973 because they conflict with the internal variables format;
4975 - support for Pascal objects and classes is not full yet;
4977 - unlike Pascal, GDB is case-sensitive for symbol names.
4979 * Changes in completion.
4981 Commands such as `shell', `run' and `set args', which pass arguments
4982 to inferior programs, now complete on file names, similar to what
4983 users expect at the shell prompt.
4985 Commands which accept locations, such as `disassemble', `print',
4986 `breakpoint', `until', etc. now complete on filenames as well as
4987 program symbols. Thus, if you type "break foob TAB", and the source
4988 files linked into the programs include `foobar.c', that file name will
4989 be one of the candidates for completion. However, file names are not
4990 considered for completion after you typed a colon that delimits a file
4991 name from a name of a function in that file, as in "break foo.c:bar".
4993 `set demangle-style' completes on available demangling styles.
4995 * New platform-independent commands:
4997 It is now possible to define a post-hook for a command as well as a
4998 hook that runs before the command. For more details, see the
4999 documentation of `hookpost' in the GDB manual.
5001 * Changes in GNU/Linux native debugging.
5003 Support for debugging multi-threaded programs has been completely
5004 revised for all platforms except m68k and sparc. You can now debug as
5005 many threads as your system allows you to have.
5007 Attach/detach is supported for multi-threaded programs.
5009 Support for SSE registers was added for x86. This doesn't work for
5010 multi-threaded programs though.
5012 * Changes in MIPS configurations.
5014 Multi-arch support is enabled for all MIPS configurations.
5016 GDB can now be built as native debugger on SGI Irix 6.x systems for
5017 debugging n32 executables. (Debugging 64-bit executables is not yet
5020 * Unified support for hardware watchpoints in all x86 configurations.
5022 Most (if not all) native x86 configurations support hardware-assisted
5023 breakpoints and watchpoints in a unified manner. This support
5024 implements debug register sharing between watchpoints, which allows to
5025 put a virtually infinite number of watchpoints on the same address,
5026 and also supports watching regions up to 16 bytes with several debug
5029 The new maintenance command `maintenance show-debug-regs' toggles
5030 debugging print-outs in functions that insert, remove, and test
5031 watchpoints and hardware breakpoints.
5033 * Changes in the DJGPP native configuration.
5035 New command ``info dos sysinfo'' displays assorted information about
5036 the CPU, OS, memory, and DPMI server.
5038 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5039 display information about segment descriptors stored in GDT, LDT, and
5042 New commands ``info dos pde'' and ``info dos pte'' display entries
5043 from Page Directory and Page Tables (for now works with CWSDPMI only).
5044 New command ``info dos address-pte'' displays the Page Table entry for
5045 a given linear address.
5047 GDB can now pass command lines longer than 126 characters to the
5048 program being debugged (requires an update to the libdbg.a library
5049 which is part of the DJGPP development kit).
5051 DWARF2 debug info is now supported.
5053 It is now possible to `step' and `next' through calls to `longjmp'.
5055 * Changes in documentation.
5057 All GDB documentation was converted to GFDL, the GNU Free
5058 Documentation License.
5060 Tracepoints-related commands are now fully documented in the GDB
5063 TUI, the Text-mode User Interface, is now documented in the manual.
5065 Tracepoints-related commands are now fully documented in the GDB
5068 The "GDB Internals" manual now has an index. It also includes
5069 documentation of `ui_out' functions, GDB coding standards, x86
5070 hardware watchpoints, and memory region attributes.
5072 * GDB's version number moved to ``version.in''
5074 The Makefile variable VERSION has been replaced by the file
5075 ``version.in''. People creating GDB distributions should update the
5076 contents of this file.
5080 GUD support is now a standard part of the EMACS distribution.
5082 *** Changes in GDB 5.0:
5084 * Improved support for debugging FP programs on x86 targets
5086 Unified and much-improved support for debugging floating-point
5087 programs on all x86 targets. In particular, ``info float'' now
5088 displays the FP registers in the same format on all x86 targets, with
5089 greater level of detail.
5091 * Improvements and bugfixes in hardware-assisted watchpoints
5093 It is now possible to watch array elements, struct members, and
5094 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5095 on x86 targets no longer erroneously trigger when the address is
5098 * Improvements in the native DJGPP version of GDB
5100 The distribution now includes all the scripts and auxiliary files
5101 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5102 machines ``out of the box''.
5104 The DJGPP version can now debug programs that use signals. It is
5105 possible to catch signals that happened in the debuggee, deliver
5106 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5107 would kill the program being debugged.) Programs that hook hardware
5108 interrupts (keyboard, timer, etc.) can also be debugged.
5110 It is now possible to debug DJGPP programs that redirect their
5111 standard handles or switch them to raw (as opposed to cooked) mode, or
5112 even close them. The command ``run < foo > bar'' works as expected,
5113 and ``info terminal'' reports useful information about the debuggee's
5114 terminal, including raw/cooked mode, redirection, etc.
5116 The DJGPP version now uses termios functions for console I/O, which
5117 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5120 DOS-style file names with drive letters are now fully supported by
5123 It is now possible to debug DJGPP programs that switch their working
5124 directory. It is also possible to rerun the debuggee any number of
5125 times without restarting GDB; thus, you can use the same setup,
5126 breakpoints, etc. for many debugging sessions.
5128 * New native configurations
5130 ARM GNU/Linux arm*-*-linux*
5131 PowerPC GNU/Linux powerpc-*-linux*
5135 Motorola MCore mcore-*-*
5136 x86 VxWorks i[3456]86-*-vxworks*
5137 PowerPC VxWorks powerpc-*-vxworks*
5138 TI TMS320C80 tic80-*-*
5140 * OBSOLETE configurations
5142 Altos 3068 m68*-altos-*
5143 Convex c1-*-*, c2-*-*
5145 ARM RISCix arm-*-* (as host)
5148 Configurations that have been declared obsolete will be commented out,
5149 but the code will be left in place. If there is no activity to revive
5150 these configurations before the next release of GDB, the sources will
5151 be permanently REMOVED.
5153 * Gould support removed
5155 Support for the Gould PowerNode and NP1 has been removed.
5157 * New features for SVR4
5159 On SVR4 native platforms (such as Solaris), if you attach to a process
5160 without first loading a symbol file, GDB will now attempt to locate and
5161 load symbols from the running process's executable file.
5163 * Many C++ enhancements
5165 C++ support has been greatly improved. Overload resolution now works properly
5166 in almost all cases. RTTI support is on the way.
5168 * Remote targets can connect to a sub-program
5170 A popen(3) style serial-device has been added. This device starts a
5171 sub-process (such as a stand-alone simulator) and then communicates
5172 with that. The sub-program to run is specified using the syntax
5173 ``|<program> <args>'' vis:
5175 (gdb) set remotedebug 1
5176 (gdb) target extended-remote |mn10300-elf-sim program-args
5178 * MIPS 64 remote protocol
5180 A long standing bug in the mips64 remote protocol where by GDB
5181 expected certain 32 bit registers (ex SR) to be transfered as 32
5182 instead of 64 bits has been fixed.
5184 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5185 added to provide backward compatibility with older versions of GDB.
5187 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5189 The command ``set remotebinarydownload'' command has been replaced by
5190 ``set remote X-packet''. Other commands in ``set remote'' family
5191 include ``set remote P-packet''.
5193 * Breakpoint commands accept ranges.
5195 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5196 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5197 ``tracepoint passcount'' also accepts a range of tracepoints.
5199 * ``apropos'' command added.
5201 The ``apropos'' command searches through command names and
5202 documentation strings, printing out matches, making it much easier to
5203 try to find a command that does what you are looking for.
5207 A new machine oriented interface (MI) has been added to GDB. This
5208 interface is designed for debug environments running GDB as a separate
5209 process. This is part of the long term libGDB project. See the
5210 "GDB/MI" chapter of the GDB manual for further information. It can be
5211 enabled by configuring with:
5213 .../configure --enable-gdbmi
5215 *** Changes in GDB-4.18:
5217 * New native configurations
5219 HP-UX 10.20 hppa*-*-hpux10.20
5220 HP-UX 11.x hppa*-*-hpux11.0*
5221 M68K GNU/Linux m68*-*-linux*
5225 Fujitsu FR30 fr30-*-elf*
5226 Intel StrongARM strongarm-*-*
5227 Mitsubishi D30V d30v-*-*
5229 * OBSOLETE configurations
5231 Gould PowerNode, NP1 np1-*-*, pn-*-*
5233 Configurations that have been declared obsolete will be commented out,
5234 but the code will be left in place. If there is no activity to revive
5235 these configurations before the next release of GDB, the sources will
5236 be permanently REMOVED.
5240 As a compatibility experiment, GDB's source files buildsym.h and
5241 buildsym.c have been converted to pure standard C, no longer
5242 containing any K&R compatibility code. We believe that all systems in
5243 use today either come with a standard C compiler, or have a GCC port
5244 available. If this is not true, please report the affected
5245 configuration to bug-gdb@gnu.org immediately. See the README file for
5246 information about getting a standard C compiler if you don't have one
5251 GDB now uses readline 2.2.
5253 * set extension-language
5255 You can now control the mapping between filename extensions and source
5256 languages by using the `set extension-language' command. For instance,
5257 you can ask GDB to treat .c files as C++ by saying
5258 set extension-language .c c++
5259 The command `info extensions' lists all of the recognized extensions
5260 and their associated languages.
5262 * Setting processor type for PowerPC and RS/6000
5264 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5265 you can use the `set processor' command to specify what variant of the
5266 PowerPC family you are debugging. The command
5270 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5271 following PowerPC and RS6000 variants:
5273 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5274 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5276 403GC IBM PowerPC 403GC
5277 505 Motorola PowerPC 505
5278 860 Motorola PowerPC 860 or 850
5279 601 Motorola PowerPC 601
5280 602 Motorola PowerPC 602
5281 603 Motorola/IBM PowerPC 603 or 603e
5282 604 Motorola PowerPC 604 or 604e
5283 750 Motorola/IBM PowerPC 750 or 750
5285 At the moment, this command just tells GDB what to name the
5286 special-purpose processor registers. Since almost all the affected
5287 registers are inaccessible to user-level programs, this command is
5288 only useful for remote debugging in its present form.
5292 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5293 more extensive support for HP-UX. Added features include shared
5294 library support, kernel threads and hardware watchpoints for 11.00,
5295 support for HP's ANSI C and C++ compilers, and a compatibility mode
5296 for xdb and dbx commands.
5300 HP's donation includes the new concept of catchpoints, which is a
5301 generalization of the old catch command. On HP-UX, it is now possible
5302 to catch exec, fork, and vfork, as well as library loading.
5304 This means that the existing catch command has changed; its first
5305 argument now specifies the type of catch to be set up. See the
5306 output of "help catch" for a list of catchpoint types.
5308 * Debugging across forks
5310 On HP-UX, you can choose which process to debug when a fork() happens
5315 HP has donated a curses-based terminal user interface (TUI). To get
5316 it, build with --enable-tui. Although this can be enabled for any
5317 configuration, at present it only works for native HP debugging.
5319 * GDB remote protocol additions
5321 A new protocol packet 'X' that writes binary data is now available.
5322 Default behavior is to try 'X', then drop back to 'M' if the stub
5323 fails to respond. The settable variable `remotebinarydownload'
5324 allows explicit control over the use of 'X'.
5326 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5327 full 64-bit address. The command
5329 set remoteaddresssize 32
5331 can be used to revert to the old behaviour. For existing remote stubs
5332 the change should not be noticed, as the additional address information
5335 In order to assist in debugging stubs, you may use the maintenance
5336 command `packet' to send any text string to the stub. For instance,
5338 maint packet heythere
5340 sends the packet "$heythere#<checksum>". Note that it is very easy to
5341 disrupt a debugging session by sending the wrong packet at the wrong
5344 The compare-sections command allows you to compare section data on the
5345 target to what is in the executable file without uploading or
5346 downloading, by comparing CRC checksums.
5348 * Tracing can collect general expressions
5350 You may now collect general expressions at tracepoints. This requires
5351 further additions to the target-side stub; see tracepoint.c and
5352 doc/agentexpr.texi for further details.
5354 * mask-address variable for Mips
5356 For Mips targets, you may control the zeroing of the upper 32 bits of
5357 a 64-bit address by entering `set mask-address on'. This is mainly
5358 of interest to users of embedded R4xxx and R5xxx processors.
5360 * Higher serial baud rates
5362 GDB's serial code now allows you to specify baud rates 57600, 115200,
5363 230400, and 460800 baud. (Note that your host system may not be able
5364 to achieve all of these rates.)
5368 The i960 configuration now includes an initial implementation of a
5369 builtin simulator, contributed by Jim Wilson.
5372 *** Changes in GDB-4.17:
5374 * New native configurations
5376 Alpha GNU/Linux alpha*-*-linux*
5377 Unixware 2.x i[3456]86-unixware2*
5378 Irix 6.x mips*-sgi-irix6*
5379 PowerPC GNU/Linux powerpc-*-linux*
5380 PowerPC Solaris powerpcle-*-solaris*
5381 Sparc GNU/Linux sparc-*-linux*
5382 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5386 Argonaut Risc Chip (ARC) arc-*-*
5387 Hitachi H8/300S h8300*-*-*
5388 Matsushita MN10200 w/simulator mn10200-*-*
5389 Matsushita MN10300 w/simulator mn10300-*-*
5390 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5391 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5392 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5393 Mitsubishi D10V w/simulator d10v-*-*
5394 Mitsubishi M32R/D w/simulator m32r-*-elf*
5395 Tsqware Sparclet sparclet-*-*
5396 NEC V850 w/simulator v850-*-*
5398 * New debugging protocols
5400 ARM with RDI protocol arm*-*-*
5401 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5402 DDB and LSI variants of PMON protocol mips*-*-*
5403 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5404 PowerPC with SDS protocol powerpc{,le}-*-eabi
5405 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5409 All configurations can now understand and use the DWARF 2 debugging
5410 format. The choice is automatic, if the symbol file contains DWARF 2
5415 GDB now includes basic Java language support. This support is
5416 only useful with Java compilers that produce native machine code.
5418 * solib-absolute-prefix and solib-search-path
5420 For SunOS and SVR4 shared libraries, you may now set the prefix for
5421 loading absolute shared library symbol files, and the search path for
5422 locating non-absolute shared library symbol files.
5424 * Live range splitting
5426 GDB can now effectively debug code for which GCC has performed live
5427 range splitting as part of its optimization. See gdb/doc/LRS for
5428 more details on the expected format of the stabs information.
5432 GDB's support for the GNU Hurd, including thread debugging, has been
5433 updated to work with current versions of the Hurd.
5437 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5438 instruction set. ARM GDB automatically detects when Thumb
5439 instructions are in use, and adjusts disassembly and backtracing
5444 GDB's MIPS target configurations now handle the MIP16 16-bit
5449 GDB now includes support for overlays; if an executable has been
5450 linked such that multiple sections are based at the same address, GDB
5451 will decide which section to use for symbolic info. You can choose to
5452 control the decision manually, using overlay commands, or implement
5453 additional target-side support and use "overlay load-target" to bring
5454 in the overlay mapping. Do "help overlay" for more detail.
5458 The command "info symbol <address>" displays information about
5459 the symbol at the specified address.
5463 The standard remote protocol now includes an extension that allows
5464 asynchronous collection and display of trace data. This requires
5465 extensive support in the target-side debugging stub. Tracing mode
5466 includes a new interaction mode in GDB and new commands: see the
5467 file tracepoint.c for more details.
5471 Configurations for embedded MIPS now include a simulator contributed
5472 by Cygnus Solutions. The simulator supports the instruction sets
5473 of most MIPS variants.
5477 Sparc configurations may now include the ERC32 simulator contributed
5478 by the European Space Agency. The simulator is not built into
5479 Sparc targets by default; configure with --enable-sim to include it.
5483 For target configurations that may include multiple variants of a
5484 basic architecture (such as MIPS and SH), you may now set the
5485 architecture explicitly. "set arch" sets, "info arch" lists
5486 the possible architectures.
5488 *** Changes in GDB-4.16:
5490 * New native configurations
5492 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5493 M68K NetBSD m68k-*-netbsd*
5494 PowerPC AIX 4.x powerpc-*-aix*
5495 PowerPC MacOS powerpc-*-macos*
5496 PowerPC Windows NT powerpcle-*-cygwin32
5497 RS/6000 AIX 4.x rs6000-*-aix4*
5501 ARM with RDP protocol arm-*-*
5502 I960 with MON960 i960-*-coff
5503 MIPS VxWorks mips*-*-vxworks*
5504 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5505 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5507 Matra Sparclet sparclet-*-*
5511 The powerpc-eabi configuration now includes the PSIM simulator,
5512 contributed by Andrew Cagney, with assistance from Mike Meissner.
5513 PSIM is a very elaborate model of the PowerPC, including not only
5514 basic instruction set execution, but also details of execution unit
5515 performance and I/O hardware. See sim/ppc/README for more details.
5519 GDB now works with Solaris 2.5.
5521 * Windows 95/NT native
5523 GDB will now work as a native debugger on Windows 95 and Windows NT.
5524 To build it from source, you must use the "gnu-win32" environment,
5525 which uses a DLL to emulate enough of Unix to run the GNU tools.
5526 Further information, binaries, and sources are available at
5527 ftp.cygnus.com, under pub/gnu-win32.
5529 * dont-repeat command
5531 If a user-defined command includes the command `dont-repeat', then the
5532 command will not be repeated if the user just types return. This is
5533 useful if the command is time-consuming to run, so that accidental
5534 extra keystrokes don't run the same command many times.
5536 * Send break instead of ^C
5538 The standard remote protocol now includes an option to send a break
5539 rather than a ^C to the target in order to interrupt it. By default,
5540 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5542 * Remote protocol timeout
5544 The standard remote protocol includes a new variable `remotetimeout'
5545 that allows you to set the number of seconds before GDB gives up trying
5546 to read from the target. The default value is 2.
5548 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5550 By default GDB will automatically keep track of objects as they are
5551 loaded and unloaded by the dynamic linker. By using the command `set
5552 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5553 when shared library events occur, thus allowing you to set breakpoints
5554 in shared libraries which are explicitly loaded by the inferior.
5556 Note this feature does not work on hpux8. On hpux9 you must link
5557 /usr/lib/end.o into your program. This feature should work
5558 automatically on hpux10.
5560 * Irix 5.x hardware watchpoint support
5562 Irix 5 configurations now support the use of hardware watchpoints.
5564 * Mips protocol "SYN garbage limit"
5566 When debugging a Mips target using the `target mips' protocol, you
5567 may set the number of characters that GDB will ignore by setting
5568 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5569 every character. The default value is 1050.
5571 * Recording and replaying remote debug sessions
5573 If you set `remotelogfile' to the name of a file, gdb will write to it
5574 a recording of a remote debug session. This recording may then be
5575 replayed back to gdb using "gdbreplay". See gdbserver/README for
5576 details. This is useful when you have a problem with GDB while doing
5577 remote debugging; you can make a recording of the session and send it
5578 to someone else, who can then recreate the problem.
5580 * Speedups for remote debugging
5582 GDB includes speedups for downloading and stepping MIPS systems using
5583 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5584 and more efficient S-record downloading.
5586 * Memory use reductions and statistics collection
5588 GDB now uses less memory and reports statistics about memory usage.
5589 Try the `maint print statistics' command, for example.
5591 *** Changes in GDB-4.15:
5593 * Psymtabs for XCOFF
5595 The symbol reader for AIX GDB now uses partial symbol tables. This
5596 can greatly improve startup time, especially for large executables.
5598 * Remote targets use caching
5600 Remote targets now use a data cache to speed up communication with the
5601 remote side. The data cache could lead to incorrect results because
5602 it doesn't know about volatile variables, thus making it impossible to
5603 debug targets which use memory mapped I/O devices. `set remotecache
5604 off' turns the the data cache off.
5606 * Remote targets may have threads
5608 The standard remote protocol now includes support for multiple threads
5609 in the target system, using new protocol commands 'H' and 'T'. See
5610 gdb/remote.c for details.
5614 If GDB is configured with `--enable-netrom', then it will include
5615 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5616 acts as though it is a bank of ROM on the target board, but you can
5617 write into it over the network. GDB's support consists only of
5618 support for fast loading into the emulated ROM; to debug, you must use
5619 another protocol, such as standard remote protocol. The usual
5620 sequence is something like
5622 target nrom <netrom-hostname>
5624 target remote <netrom-hostname>:1235
5628 GDB now includes support for the Apple Macintosh, as a host only. It
5629 may be run as either an MPW tool or as a standalone application, and
5630 it can debug through the serial port. All the usual GDB commands are
5631 available, but to the target command, you must supply "serial" as the
5632 device type instead of "/dev/ttyXX". See mpw-README in the main
5633 directory for more information on how to build. The MPW configuration
5634 scripts */mpw-config.in support only a few targets, and only the
5635 mips-idt-ecoff target has been tested.
5639 GDB configuration now uses autoconf. This is not user-visible,
5640 but does simplify configuration and building.
5644 GDB now supports hpux10.
5646 *** Changes in GDB-4.14:
5648 * New native configurations
5650 x86 FreeBSD i[345]86-*-freebsd
5651 x86 NetBSD i[345]86-*-netbsd
5652 NS32k NetBSD ns32k-*-netbsd
5653 Sparc NetBSD sparc-*-netbsd
5657 A29K VxWorks a29k-*-vxworks
5658 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5659 CPU32 EST-300 emulator m68*-*-est*
5660 PowerPC ELF powerpc-*-elf
5663 * Alpha OSF/1 support for procfs
5665 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5666 possible to attach to running processes. As the mounting of the /proc
5667 filesystem is optional on the Alpha, GDB automatically determines
5668 the availability of /proc during startup. This can lead to problems
5669 if /proc is unmounted after GDB has been started.
5671 * Arguments to user-defined commands
5673 User commands may accept up to 10 arguments separated by whitespace.
5674 Arguments are accessed within the user command via $arg0..$arg9. A
5677 print $arg0 + $arg1 + $arg2
5679 To execute the command use:
5682 Defines the command "adder" which prints the sum of its three arguments.
5683 Note the arguments are text substitutions, so they may reference variables,
5684 use complex expressions, or even perform inferior function calls.
5686 * New `if' and `while' commands
5688 This makes it possible to write more sophisticated user-defined
5689 commands. Both commands take a single argument, which is the
5690 expression to evaluate, and must be followed by the commands to
5691 execute, one per line, if the expression is nonzero, the list being
5692 terminated by the word `end'. The `if' command list may include an
5693 `else' word, which causes the following commands to be executed only
5694 if the expression is zero.
5696 * Fortran source language mode
5698 GDB now includes partial support for Fortran 77. It will recognize
5699 Fortran programs and can evaluate a subset of Fortran expressions, but
5700 variables and functions may not be handled correctly. GDB will work
5701 with G77, but does not yet know much about symbols emitted by other
5704 * Better HPUX support
5706 Most debugging facilities now work on dynamic executables for HPPAs
5707 running hpux9 or later. You can attach to running dynamically linked
5708 processes, but by default the dynamic libraries will be read-only, so
5709 for instance you won't be able to put breakpoints in them. To change
5710 that behavior do the following before running the program:
5716 This will cause the libraries to be mapped private and read-write.
5717 To revert to the normal behavior, do this:
5723 You cannot set breakpoints or examine data in the library until after
5724 the library is loaded if the function/data symbols do not have
5727 GDB can now also read debug symbols produced by the HP C compiler on
5728 HPPAs (sorry, no C++, Fortran or 68k support).
5730 * Target byte order now dynamically selectable
5732 You can choose which byte order to use with a target system, via the
5733 commands "set endian big" and "set endian little", and you can see the
5734 current setting by using "show endian". You can also give the command
5735 "set endian auto", in which case GDB will use the byte order
5736 associated with the executable. Currently, only embedded MIPS
5737 configurations support dynamic selection of target byte order.
5739 * New DOS host serial code
5741 This version uses DPMI interrupts to handle buffered I/O, so you
5742 no longer need to run asynctsr when debugging boards connected to
5745 *** Changes in GDB-4.13:
5747 * New "complete" command
5749 This lists all the possible completions for the rest of the line, if it
5750 were to be given as a command itself. This is intended for use by emacs.
5752 * Trailing space optional in prompt
5754 "set prompt" no longer adds a space for you after the prompt you set. This
5755 allows you to set a prompt which ends in a space or one that does not.
5757 * Breakpoint hit counts
5759 "info break" now displays a count of the number of times the breakpoint
5760 has been hit. This is especially useful in conjunction with "ignore"; you
5761 can ignore a large number of breakpoint hits, look at the breakpoint info
5762 to see how many times the breakpoint was hit, then run again, ignoring one
5763 less than that number, and this will get you quickly to the last hit of
5766 * Ability to stop printing at NULL character
5768 "set print null-stop" will cause GDB to stop printing the characters of
5769 an array when the first NULL is encountered. This is useful when large
5770 arrays actually contain only short strings.
5772 * Shared library breakpoints
5774 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5775 breakpoints in shared libraries before the executable is run.
5777 * Hardware watchpoints
5779 There is a new hardware breakpoint for the watch command for sparclite
5780 targets. See gdb/sparclite/hw_breakpoint.note.
5782 Hardware watchpoints are also now supported under GNU/Linux.
5786 Annotations have been added. These are for use with graphical interfaces,
5787 and are still experimental. Currently only gdba.el uses these.
5789 * Improved Irix 5 support
5791 GDB now works properly with Irix 5.2.
5793 * Improved HPPA support
5795 GDB now works properly with the latest GCC and GAS.
5797 * New native configurations
5799 Sequent PTX4 i[34]86-sequent-ptx4
5800 HPPA running OSF/1 hppa*-*-osf*
5801 Atari TT running SVR4 m68*-*-sysv4*
5802 RS/6000 LynxOS rs6000-*-lynxos*
5806 OS/9000 i[34]86-*-os9k
5807 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5810 * Hitachi SH7000 and E7000-PC ICE support
5812 There is now support for communicating with the Hitachi E7000-PC ICE.
5813 This is available automatically when GDB is configured for the SH.
5817 As usual, a variety of small fixes and improvements, both generic
5818 and configuration-specific. See the ChangeLog for more detail.
5820 *** Changes in GDB-4.12:
5822 * Irix 5 is now supported
5826 GDB-4.12 on the HPPA has a number of changes which make it unable
5827 to debug the output from the currently released versions of GCC and
5828 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5829 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5830 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5833 *** Changes in GDB-4.11:
5835 * User visible changes:
5839 The "set remotedebug" option is now consistent between the mips remote
5840 target, remote targets using the gdb-specific protocol, UDI (AMD's
5841 debug protocol for the 29k) and the 88k bug monitor. It is now an
5842 integer specifying a debug level (normally 0 or 1, but 2 means more
5843 debugging info for the mips target).
5845 * DEC Alpha native support
5847 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5848 debug info, but GDB works fairly well with the DEC compiler and should
5849 work with a future GCC release. See the README file for a few
5850 Alpha-specific notes.
5852 * Preliminary thread implementation
5854 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5856 * LynxOS native and target support for 386
5858 This release has been hosted on LynxOS 2.2, and also can be configured
5859 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5862 * Improvements in C++ mangling/demangling.
5864 This release has much better g++ debugging, specifically in name
5865 mangling/demangling, virtual function calls, print virtual table,
5866 call methods, ...etc.
5868 *** Changes in GDB-4.10:
5870 * User visible changes:
5872 Remote debugging using the GDB-specific (`target remote') protocol now
5873 supports the `load' command. This is only useful if you have some
5874 other way of getting the stub to the target system, and you can put it
5875 somewhere in memory where it won't get clobbered by the download.
5877 Filename completion now works.
5879 When run under emacs mode, the "info line" command now causes the
5880 arrow to point to the line specified. Also, "info line" prints
5881 addresses in symbolic form (as well as hex).
5883 All vxworks based targets now support a user settable option, called
5884 vxworks-timeout. This option represents the number of seconds gdb
5885 should wait for responses to rpc's. You might want to use this if
5886 your vxworks target is, perhaps, a slow software simulator or happens
5887 to be on the far side of a thin network line.
5891 This release contains support for using a DEC alpha as a GDB host for
5892 cross debugging. Native alpha debugging is not supported yet.
5895 *** Changes in GDB-4.9:
5899 This is the first GDB release which is accompanied by a matching testsuite.
5900 The testsuite requires installation of dejagnu, which should be available
5901 via ftp from most sites that carry GNU software.
5905 'Cfront' style demangling has had its name changed to 'ARM' style, to
5906 emphasize that it was written from the specifications in the C++ Annotated
5907 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5908 disclaimers, it still generated too much confusion with users attempting to
5909 use gdb with AT&T cfront.
5913 GDB now uses a standard remote interface to a simulator library.
5914 So far, the library contains simulators for the Zilog Z8001/2, the
5915 Hitachi H8/300, H8/500 and Super-H.
5917 * New targets supported
5919 H8/300 simulator h8300-hitachi-hms or h8300hms
5920 H8/500 simulator h8500-hitachi-hms or h8500hms
5921 SH simulator sh-hitachi-hms or sh
5922 Z8000 simulator z8k-zilog-none or z8ksim
5923 IDT MIPS board over serial line mips-idt-ecoff
5925 Cross-debugging to GO32 targets is supported. It requires a custom
5926 version of the i386-stub.c module which is integrated with the
5927 GO32 memory extender.
5929 * New remote protocols
5931 MIPS remote debugging protocol.
5933 * New source languages supported
5935 This version includes preliminary support for Chill, a Pascal like language
5936 used by telecommunications companies. Chill support is also being integrated
5937 into the GNU compiler, but we don't know when it will be publically available.
5940 *** Changes in GDB-4.8:
5942 * HP Precision Architecture supported
5944 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5945 version of this support was available as a set of patches from the
5946 University of Utah. GDB does not support debugging of programs
5947 compiled with the HP compiler, because HP will not document their file
5948 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5949 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5951 Many problems in the preliminary version have been fixed.
5953 * Faster and better demangling
5955 We have improved template demangling and fixed numerous bugs in the GNU style
5956 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5957 character types (wchar_t) are now supported. Demangling of each symbol is now
5958 only done once, and is cached when the symbol table for a file is read in.
5959 This results in a small increase in memory usage for C programs, a moderate
5960 increase in memory usage for C++ programs, and a fantastic speedup in
5963 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5964 from the specifications in the Annotated Reference Manual, which AT&T's
5965 compiler does not actually implement.
5967 * G++ multiple inheritance compiler problem
5969 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5970 inheritance lattices was reworked to properly discover ambiguities. We
5971 recently found an example which causes this new algorithm to fail in a
5972 very subtle way, producing bad debug information for those classes.
5973 The file 'gcc.patch' (in this directory) can be applied to gcc to
5974 circumvent the problem. A future GCC release will contain a complete
5977 The previous G++ debug info problem (mentioned below for the gdb-4.7
5978 release) is fixed in gcc version 2.3.2.
5980 * Improved configure script
5982 The `configure' script will now attempt to guess your system type if
5983 you don't supply a host system type. The old scheme of supplying a
5984 host system triplet is preferable over using this. All the magic is
5985 done in the new `config.guess' script. Examine it for details.
5987 We have also brought our configure script much more in line with the FSF's
5988 version. It now supports the --with-xxx options. In particular,
5989 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5990 The resulting GDB will not be able to read arbitrary object file formats --
5991 only the format ``expected'' to be used on the configured target system.
5992 We hope to make this the default in a future release.
5994 * Documentation improvements
5996 There's new internal documentation on how to modify GDB, and how to
5997 produce clean changes to the code. We implore people to read it
5998 before submitting changes.
6000 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6001 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6002 `info' files are also provided. To build `info' files from scratch,
6003 you will need the latest `makeinfo' release, which will be available in
6004 a future texinfo-X.Y release.
6006 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6007 We're not sure exactly which versions have this problem, but it has
6008 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6009 or better. If that isn't possible, there is a patch in
6010 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6011 around this problem.
6015 GDB now supports array constants that can be used in expressions typed in by
6016 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6017 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6020 The new directory `gdb/sparclite' contains a program that demonstrates
6021 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6023 * New native hosts supported
6025 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6026 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6028 * New targets supported
6030 AMD 29k family via UDI a29k-amd-udi or udi29k
6032 * New file formats supported
6034 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6035 HPUX core files, and SCO 3.2v2 core files.
6039 Attaching to processes now works again; thanks for the many bug reports.
6041 We have also stomped on a bunch of core dumps caused by
6042 printf_filtered("%s") problems.
6044 We eliminated a copyright problem on the rpc and ptrace header files
6045 for VxWorks, which was discovered at the last minute during the 4.7
6046 release. You should now be able to build a VxWorks GDB.
6048 You can now interrupt gdb while an attached process is running. This
6049 will cause the attached process to stop, and give control back to GDB.
6051 We fixed problems caused by using too many file descriptors
6052 for reading symbols from object files and libraries. This was
6053 especially a problem for programs that used many (~100) shared
6056 The `step' command now only enters a subroutine if there is line number
6057 information for the subroutine. Otherwise it acts like the `next'
6058 command. Previously, `step' would enter subroutines if there was
6059 any debugging information about the routine. This avoids problems
6060 when using `cc -g1' on MIPS machines.
6062 * Internal improvements
6064 GDB's internal interfaces have been improved to make it easier to support
6065 debugging of multiple languages in the future.
6067 GDB now uses a common structure for symbol information internally.
6068 Minimal symbols (derived from linkage symbols in object files), partial
6069 symbols (from a quick scan of debug information), and full symbols
6070 contain a common subset of information, making it easier to write
6071 shared code that handles any of them.
6073 * New command line options
6075 We now accept --silent as an alias for --quiet.
6079 The memory-mapped-malloc library is now licensed under the GNU Library
6080 General Public License.
6082 *** Changes in GDB-4.7:
6084 * Host/native/target split
6086 GDB has had some major internal surgery to untangle the support for
6087 hosts and remote targets. Now, when you configure GDB for a remote
6088 target, it will no longer load in all of the support for debugging
6089 local programs on the host. When fully completed and tested, this will
6090 ensure that arbitrary host/target combinations are possible.
6092 The primary conceptual shift is to separate the non-portable code in
6093 GDB into three categories. Host specific code is required any time GDB
6094 is compiled on that host, regardless of the target. Target specific
6095 code relates to the peculiarities of the target, but can be compiled on
6096 any host. Native specific code is everything else: it can only be
6097 built when the host and target are the same system. Child process
6098 handling and core file support are two common `native' examples.
6100 GDB's use of /proc for controlling Unix child processes is now cleaner.
6101 It has been split out into a single module under the `target_ops' vector,
6102 plus two native-dependent functions for each system that uses /proc.
6104 * New hosts supported
6106 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6107 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6108 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6110 * New targets supported
6112 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6113 68030 and CPU32 m68030-*-*, m68332-*-*
6115 * New native hosts supported
6117 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6118 (386bsd is not well tested yet)
6119 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6121 * New file formats supported
6123 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6124 supports reading of `a.out.adobe' object files, which are an a.out
6125 format extended with minimal information about multiple sections.
6129 `show copying' is the same as the old `info copying'.
6130 `show warranty' is the same as `info warrantee'.
6131 These were renamed for consistency. The old commands continue to work.
6133 `info handle' is a new alias for `info signals'.
6135 You can now define pre-command hooks, which attach arbitrary command
6136 scripts to any command. The commands in the hook will be executed
6137 prior to the user's command. You can also create a hook which will be
6138 executed whenever the program stops. See gdb.texinfo.
6142 We now deal with Cfront style name mangling, and can even extract type
6143 info from mangled symbols. GDB can automatically figure out which
6144 symbol mangling style your C++ compiler uses.
6146 Calling of methods and virtual functions has been improved as well.
6150 The crash that occured when debugging Sun Ansi-C compiled binaries is
6151 fixed. This was due to mishandling of the extra N_SO stabs output
6154 We also finally got Ultrix 4.2 running in house, and fixed core file
6155 support, with help from a dozen people on the net.
6157 John M. Farrell discovered that the reason that single-stepping was so
6158 slow on all of the Mips based platforms (primarily SGI and DEC) was
6159 that we were trying to demangle and lookup a symbol used for internal
6160 purposes on every instruction that was being stepped through. Changing
6161 the name of that symbol so that it couldn't be mistaken for a C++
6162 mangled symbol sped things up a great deal.
6164 Rich Pixley sped up symbol lookups in general by getting much smarter
6165 about when C++ symbol mangling is necessary. This should make symbol
6166 completion (TAB on the command line) much faster. It's not as fast as
6167 we'd like, but it's significantly faster than gdb-4.6.
6171 A new user controllable variable 'call_scratch_address' can
6172 specify the location of a scratch area to be used when GDB
6173 calls a function in the target. This is necessary because the
6174 usual method of putting the scratch area on the stack does not work
6175 in systems that have separate instruction and data spaces.
6177 We integrated changes to support the 29k UDI (Universal Debugger
6178 Interface), but discovered at the last minute that we didn't have all
6179 of the appropriate copyright paperwork. We are working with AMD to
6180 resolve this, and hope to have it available soon.
6184 We have sped up the remote serial line protocol, especially for targets
6185 with lots of registers. It now supports a new `expedited status' ('T')
6186 message which can be used in place of the existing 'S' status message.
6187 This allows the remote stub to send only the registers that GDB
6188 needs to make a quick decision about single-stepping or conditional
6189 breakpoints, eliminating the need to fetch the entire register set for
6190 each instruction being stepped through.
6192 The GDB remote serial protocol now implements a write-through cache for
6193 registers, only re-reading the registers if the target has run.
6195 There is also a new remote serial stub for SPARC processors. You can
6196 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6197 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6198 processor with a serial port.
6202 Configure.in files have become much easier to read and modify. A new
6203 `table driven' format makes it more obvious what configurations are
6204 supported, and what files each one uses.
6208 There is a new opcodes library which will eventually contain all of the
6209 disassembly routines and opcode tables. At present, it only contains
6210 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6211 disassembler (binutils/objdump) to share these routines.
6213 The libiberty library is now copylefted under the GNU Library General
6214 Public License. This allows more liberal use, and was done so libg++
6215 can use it. This makes no difference to GDB, since the Library License
6216 grants all the rights from the General Public License.
6220 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6221 reference to the stabs symbol info used by the debugger. It is (as far
6222 as we know) the only published document on this fascinating topic. We
6223 encourage you to read it, compare it to the stabs information on your
6224 system, and send improvements on the document in general (to
6225 bug-gdb@prep.ai.mit.edu).
6227 And, of course, many bugs have been fixed.
6230 *** Changes in GDB-4.6:
6232 * Better support for C++ function names
6234 GDB now accepts as input the "demangled form" of C++ overloaded function
6235 names and member function names, and can do command completion on such names
6236 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6237 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6238 Make use of command completion, it is your friend.
6240 GDB also now accepts a variety of C++ mangled symbol formats. They are
6241 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6242 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6243 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6244 for the list of formats.
6246 * G++ symbol mangling problem
6248 Recent versions of gcc have a bug in how they emit debugging information for
6249 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6250 directory) can be applied to gcc to fix the problem. Alternatively, if you
6251 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6252 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6253 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6256 * New 'maintenance' command
6258 All of the commands related to hacking GDB internals have been moved out of
6259 the main command set, and now live behind the 'maintenance' command. This
6260 can also be abbreviated as 'mt'. The following changes were made:
6262 dump-me -> maintenance dump-me
6263 info all-breakpoints -> maintenance info breakpoints
6264 printmsyms -> maintenance print msyms
6265 printobjfiles -> maintenance print objfiles
6266 printpsyms -> maintenance print psymbols
6267 printsyms -> maintenance print symbols
6269 The following commands are new:
6271 maintenance demangle Call internal GDB demangler routine to
6272 demangle a C++ link name and prints the result.
6273 maintenance print type Print a type chain for a given symbol
6275 * Change to .gdbinit file processing
6277 We now read the $HOME/.gdbinit file before processing the argv arguments
6278 (e.g. reading symbol files or core files). This allows global parameters to
6279 be set, which will apply during the symbol reading. The ./.gdbinit is still
6280 read after argv processing.
6282 * New hosts supported
6284 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6286 GNU/Linux support i386-unknown-linux or linux
6288 We are also including code to support the HP/PA running BSD and HPUX. This
6289 is almost guaranteed not to work, as we didn't have time to test or build it
6290 for this release. We are including it so that the more adventurous (or
6291 masochistic) of you can play with it. We also had major problems with the
6292 fact that the compiler that we got from HP doesn't support the -g option.
6295 * New targets supported
6297 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6299 * More smarts about finding #include files
6301 GDB now remembers the compilation directory for all include files, and for
6302 all files from which C is generated (like yacc and lex sources). This
6303 greatly improves GDB's ability to find yacc/lex sources, and include files,
6304 especially if you are debugging your program from a directory different from
6305 the one that contains your sources.
6307 We also fixed a bug which caused difficulty with listing and setting
6308 breakpoints in include files which contain C code. (In the past, you had to
6309 try twice in order to list an include file that you hadn't looked at before.)
6311 * Interesting infernals change
6313 GDB now deals with arbitrary numbers of sections, where the symbols for each
6314 section must be relocated relative to that section's landing place in the
6315 target's address space. This work was needed to support ELF with embedded
6316 stabs used by Solaris-2.0.
6318 * Bug fixes (of course!)
6320 There have been loads of fixes for the following things:
6321 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6322 i960, stabs, DOS(GO32), procfs, etc...
6324 See the ChangeLog for details.
6326 *** Changes in GDB-4.5:
6328 * New machines supported (host and target)
6330 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6332 SGI Irix-4.x mips-sgi-irix4 or iris4
6334 * New malloc package
6336 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6337 Mmalloc is capable of handling mutiple heaps of memory. It is also
6338 capable of saving a heap to a file, and then mapping it back in later.
6339 This can be used to greatly speedup the startup of GDB by using a
6340 pre-parsed symbol table which lives in a mmalloc managed heap. For
6341 more details, please read mmalloc/mmalloc.texi.
6345 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6346 'help info proc' for details.
6348 * MIPS ecoff symbol table format
6350 The code that reads MIPS symbol table format is now supported on all hosts.
6351 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6354 * File name changes for MS-DOS
6356 Many files in the config directories have been renamed to make it easier to
6357 support GDB on MS-DOSe systems (which have very restrictive file name
6358 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6359 environment) is close to working but has some remaining problems. Note
6360 that debugging of DOS programs is not supported, due to limitations
6361 in the ``operating system'', but it can be used to host cross-debugging.
6363 * Cross byte order fixes
6365 Many fixes have been made to support cross debugging of Sparc and MIPS
6366 targets from hosts whose byte order differs.
6368 * New -mapped and -readnow options
6370 If memory-mapped files are available on your system through the 'mmap'
6371 system call, you can use the -mapped option on the `file' or
6372 `symbol-file' commands to cause GDB to write the symbols from your
6373 program into a reusable file. If the program you are debugging is
6374 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6375 Future GDB debugging sessions will notice the presence of this file,
6376 and will quickly map in symbol information from it, rather than reading
6377 the symbol table from the executable program. Using the '-mapped'
6378 option in a GDB `file' or `symbol-file' command has the same effect as
6379 starting GDB with the '-mapped' command-line option.
6381 You can cause GDB to read the entire symbol table immediately by using
6382 the '-readnow' option with any of the commands that load symbol table
6383 information (or on the GDB command line). This makes the command
6384 slower, but makes future operations faster.
6386 The -mapped and -readnow options are typically combined in order to
6387 build a `fred.syms' file that contains complete symbol information.
6388 A simple GDB invocation to do nothing but build a `.syms' file for future
6391 gdb -batch -nx -mapped -readnow programname
6393 The `.syms' file is specific to the host machine on which GDB is run.
6394 It holds an exact image of GDB's internal symbol table. It cannot be
6395 shared across multiple host platforms.
6397 * longjmp() handling
6399 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6400 siglongjmp() without losing control. This feature has not yet been ported to
6401 all systems. It currently works on many 386 platforms, all MIPS-based
6402 platforms (SGI, DECstation, etc), and Sun3/4.
6406 Preliminary work has been put in to support the new Solaris OS from Sun. At
6407 this time, it can control and debug processes, but it is not capable of
6412 As always, many many bug fixes. The major areas were with g++, and mipsread.
6413 People using the MIPS-based platforms should experience fewer mysterious
6414 crashes and trashed symbol tables.
6416 *** Changes in GDB-4.4:
6418 * New machines supported (host and target)
6420 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6422 BSD Reno on Vax vax-dec-bsd
6423 Ultrix on Vax vax-dec-ultrix
6425 * New machines supported (target)
6427 AMD 29000 embedded, using EBMON a29k-none-none
6431 GDB continues to improve its handling of C++. `References' work better.
6432 The demangler has also been improved, and now deals with symbols mangled as
6433 per the Annotated C++ Reference Guide.
6435 GDB also now handles `stabs' symbol information embedded in MIPS
6436 `ecoff' symbol tables. Since the ecoff format was not easily
6437 extensible to handle new languages such as C++, this appeared to be a
6438 good way to put C++ debugging info into MIPS binaries. This option
6439 will be supported in the GNU C compiler, version 2, when it is
6442 * New features for SVR4
6444 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6445 shared libraries. Debugging dynamically linked programs should present
6446 only minor differences from debugging statically linked programs.
6448 The `info proc' command will print out information about any process
6449 on an SVR4 system (including the one you are debugging). At the moment,
6450 it prints the address mappings of the process.
6452 If you bring up GDB on another SVR4 system, please send mail to
6453 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6455 * Better dynamic linking support in SunOS
6457 Reading symbols from shared libraries which contain debugging symbols
6458 now works properly. However, there remain issues such as automatic
6459 skipping of `transfer vector' code during function calls, which
6460 make it harder to debug code in a shared library, than to debug the
6461 same code linked statically.
6465 GDB is now using the latest `getopt' routines from the FSF. This
6466 version accepts the -- prefix for options with long names. GDB will
6467 continue to accept the old forms (-option and +option) as well.
6468 Various single letter abbreviations for options have been explicity
6469 added to the option table so that they won't get overshadowed in the
6470 future by other options that begin with the same letter.
6474 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6475 Many assorted bugs have been handled. Many more remain to be handled.
6476 See the various ChangeLog files (primarily in gdb and bfd) for details.
6479 *** Changes in GDB-4.3:
6481 * New machines supported (host and target)
6483 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6484 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6485 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6487 * Almost SCO Unix support
6489 We had hoped to support:
6490 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6491 (except for core file support), but we discovered very late in the release
6492 that it has problems with process groups that render gdb unusable. Sorry
6493 about that. I encourage people to fix it and post the fixes.
6495 * Preliminary ELF and DWARF support
6497 GDB can read ELF object files on System V Release 4, and can handle
6498 debugging records for C, in DWARF format, in ELF files. This support
6499 is preliminary. If you bring up GDB on another SVR4 system, please
6500 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6505 GDB now uses the latest `readline' library. One user-visible change
6506 is that two tabs will list possible command completions, which previously
6507 required typing M-? (meta-question mark, or ESC ?).
6511 The `stepi' bug that many of you noticed has been squashed.
6512 Many bugs in C++ have been handled. Many more remain to be handled.
6513 See the various ChangeLog files (primarily in gdb and bfd) for details.
6515 * State of the MIPS world (in case you wondered):
6517 GDB can understand the symbol tables emitted by the compilers
6518 supplied by most vendors of MIPS-based machines, including DEC. These
6519 symbol tables are in a format that essentially nobody else uses.
6521 Some versions of gcc come with an assembler post-processor called
6522 mips-tfile. This program is required if you want to do source-level
6523 debugging of gcc-compiled programs. I believe FSF does not ship
6524 mips-tfile with gcc version 1, but it will eventually come with gcc
6527 Debugging of g++ output remains a problem. g++ version 1.xx does not
6528 really support it at all. (If you're lucky, you should be able to get
6529 line numbers and stack traces to work, but no parameters or local
6530 variables.) With some work it should be possible to improve the
6533 When gcc version 2 is released, you will have somewhat better luck.
6534 However, even then you will get confusing results for inheritance and
6537 We will eventually provide full debugging of g++ output on
6538 DECstations. This will probably involve some kind of stabs-in-ecoff
6539 encapulation, but the details have not been worked out yet.
6542 *** Changes in GDB-4.2:
6544 * Improved configuration
6546 Only one copy of `configure' exists now, and it is not self-modifying.
6547 Porting BFD is simpler.
6551 The `step' and `next' commands now only stop at the first instruction
6552 of a source line. This prevents the multiple stops that used to occur
6553 in switch statements, for-loops, etc. `Step' continues to stop if a
6554 function that has debugging information is called within the line.
6558 Lots of small bugs fixed. More remain.
6560 * New host supported (not target)
6562 Intel 386 PC clone running Mach i386-none-mach
6565 *** Changes in GDB-4.1:
6567 * Multiple source language support
6569 GDB now has internal scaffolding to handle several source languages.
6570 It determines the type of each source file from its filename extension,
6571 and will switch expression parsing and number formatting to match the
6572 language of the function in the currently selected stack frame.
6573 You can also specifically set the language to be used, with
6574 `set language c' or `set language modula-2'.
6578 GDB now has preliminary support for the GNU Modula-2 compiler,
6579 currently under development at the State University of New York at
6580 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6581 continue through the fall of 1991 and into 1992.
6583 Other Modula-2 compilers are currently not supported, and attempting to
6584 debug programs compiled with them will likely result in an error as the
6585 symbol table is read. Feel free to work on it, though!
6587 There are hooks in GDB for strict type checking and range checking,
6588 in the `Modula-2 philosophy', but they do not currently work.
6592 GDB can now write to executable and core files (e.g. patch
6593 a variable's value). You must turn this switch on, specify
6594 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6595 by assigning a new value to a variable. Modifications take
6598 * Automatic SunOS shared library reading
6600 When you run your program, GDB automatically determines where its
6601 shared libraries (if any) have been loaded, and reads their symbols.
6602 The `share' command is no longer needed. This also works when
6603 examining core files.
6607 You can specify the number of lines that the `list' command shows.
6610 * New machines supported (host and target)
6612 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6613 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6614 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6616 * New hosts supported (not targets)
6618 IBM RT/PC: romp-ibm-aix or rtpc
6620 * New targets supported (not hosts)
6622 AMD 29000 embedded with COFF a29k-none-coff
6623 AMD 29000 embedded with a.out a29k-none-aout
6624 Ultracomputer remote kernel debug a29k-nyu-kern
6626 * New remote interfaces
6632 *** Changes in GDB-4.0:
6636 Wide output is wrapped at good places to make the output more readable.
6638 Gdb now supports cross-debugging from a host machine of one type to a
6639 target machine of another type. Communication with the target system
6640 is over serial lines. The ``target'' command handles connecting to the
6641 remote system; the ``load'' command will download a program into the
6642 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6643 also supports debugging of realtime processes running under VxWorks,
6644 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6645 stub on the target system.
6647 New CPUs supported include the AMD 29000 and Intel 960.
6649 GDB now reads object files and symbol tables via a ``binary file''
6650 library, which allows a single copy of GDB to debug programs of multiple
6651 object file types such as a.out and coff.
6653 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6654 refcard.dvi and refcard.ps are available to format it).
6657 * Control-Variable user interface simplified
6659 All variables that control the operation of the debugger can be set
6660 by the ``set'' command, and displayed by the ``show'' command.
6662 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6663 ``Show prompt'' produces the response:
6664 Gdb's prompt is new-gdb=>.
6666 What follows are the NEW set commands. The command ``help set'' will
6667 print a complete list of old and new set commands. ``help set FOO''
6668 will give a longer description of the variable FOO. ``show'' will show
6669 all of the variable descriptions and their current settings.
6671 confirm on/off: Enables warning questions for operations that are
6672 hard to recover from, e.g. rerunning the program while
6673 it is already running. Default is ON.
6675 editing on/off: Enables EMACS style command line editing
6676 of input. Previous lines can be recalled with
6677 control-P, the current line can be edited with control-B,
6678 you can search for commands with control-R, etc.
6681 history filename NAME: NAME is where the gdb command history
6682 will be stored. The default is .gdb_history,
6683 or the value of the environment variable
6686 history size N: The size, in commands, of the command history. The
6687 default is 256, or the value of the environment variable
6690 history save on/off: If this value is set to ON, the history file will
6691 be saved after exiting gdb. If set to OFF, the
6692 file will not be saved. The default is OFF.
6694 history expansion on/off: If this value is set to ON, then csh-like
6695 history expansion will be performed on
6696 command line input. The default is OFF.
6698 radix N: Sets the default radix for input and output. It can be set
6699 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6700 in the current radix, so "set radix 10" is always a no-op.
6702 height N: This integer value is the number of lines on a page. Default
6703 is 24, the current `stty rows'' setting, or the ``li#''
6704 setting from the termcap entry matching the environment
6707 width N: This integer value is the number of characters on a line.
6708 Default is 80, the current `stty cols'' setting, or the ``co#''
6709 setting from the termcap entry matching the environment
6712 Note: ``set screensize'' is obsolete. Use ``set height'' and
6713 ``set width'' instead.
6715 print address on/off: Print memory addresses in various command displays,
6716 such as stack traces and structure values. Gdb looks
6717 more ``symbolic'' if you turn this off; it looks more
6718 ``machine level'' with it on. Default is ON.
6720 print array on/off: Prettyprint arrays. New convenient format! Default
6723 print demangle on/off: Print C++ symbols in "source" form if on,
6726 print asm-demangle on/off: Same, for assembler level printouts
6729 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6732 * Support for Epoch Environment.
6734 The epoch environment is a version of Emacs v18 with windowing. One
6735 new command, ``inspect'', is identical to ``print'', except that if you
6736 are running in the epoch environment, the value is printed in its own
6740 * Support for Shared Libraries
6742 GDB can now debug programs and core files that use SunOS shared libraries.
6743 Symbols from a shared library cannot be referenced
6744 before the shared library has been linked with the program (this
6745 happens after you type ``run'' and before the function main() is entered).
6746 At any time after this linking (including when examining core files
6747 from dynamically linked programs), gdb reads the symbols from each
6748 shared library when you type the ``sharedlibrary'' command.
6749 It can be abbreviated ``share''.
6751 sharedlibrary REGEXP: Load shared object library symbols for files
6752 matching a unix regular expression. No argument
6753 indicates to load symbols for all shared libraries.
6755 info sharedlibrary: Status of loaded shared libraries.
6760 A watchpoint stops execution of a program whenever the value of an
6761 expression changes. Checking for this slows down execution
6762 tremendously whenever you are in the scope of the expression, but is
6763 quite useful for catching tough ``bit-spreader'' or pointer misuse
6764 problems. Some machines such as the 386 have hardware for doing this
6765 more quickly, and future versions of gdb will use this hardware.
6767 watch EXP: Set a watchpoint (breakpoint) for an expression.
6769 info watchpoints: Information about your watchpoints.
6771 delete N: Deletes watchpoint number N (same as breakpoints).
6772 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6773 enable N: Re-enables watchpoint number N (same as breakpoints).
6776 * C++ multiple inheritance
6778 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6781 * C++ exception handling
6783 Gdb now supports limited C++ exception handling. Besides the existing
6784 ability to breakpoint on an exception handler, gdb can breakpoint on
6785 the raising of an exception (before the stack is peeled back to the
6788 catch FOO: If there is a FOO exception handler in the dynamic scope,
6789 set a breakpoint to catch exceptions which may be raised there.
6790 Multiple exceptions (``catch foo bar baz'') may be caught.
6792 info catch: Lists all exceptions which may be caught in the
6793 current stack frame.
6796 * Minor command changes
6798 The command ``call func (arg, arg, ...)'' now acts like the print
6799 command, except it does not print or save a value if the function's result
6800 is void. This is similar to dbx usage.
6802 The ``up'' and ``down'' commands now always print the frame they end up
6803 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6804 frames without printing.
6806 * New directory command
6808 'dir' now adds directories to the FRONT of the source search path.
6809 The path starts off empty. Source files that contain debug information
6810 about the directory in which they were compiled can be found even
6811 with an empty path; Sun CC and GCC include this information. If GDB can't
6812 find your source file in the current directory, type "dir .".
6814 * Configuring GDB for compilation
6816 For normal use, type ``./configure host''. See README or gdb.texinfo
6819 GDB now handles cross debugging. If you are remotely debugging between
6820 two different machines, type ``./configure host -target=targ''.
6821 Host is the machine where GDB will run; targ is the machine
6822 where the program that you are debugging will run.