1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.0
6 * New features in the GDB remote stub, GDBserver
8 ** New "--selftest" command line option runs some GDBserver self
9 tests. These self tests are disabled in releases.
11 ** On Unix systems, GDBserver now does globbing expansion and variable
12 substitution in inferior command line arguments.
14 This is done by starting inferiors using a shell, like GDB does.
15 See "set startup-with-shell" in the user manual for how to disable
16 this from GDB when using "target extended-remote". When using
17 "target remote", you can disable the startup with shell by using the
18 new "--no-startup-with-shell" GDBserver command line option.
23 Indicates whether the inferior must be started with a shell or not.
25 * The "maintenance print c-tdesc" command now takes an optional
26 argument which is the file name of XML target description.
31 Set and show compilation command used for compiling and injecting code
32 with the 'compile' commands.
34 set debug separate-debug-file
35 show debug separate-debug-file
36 Control the display of debug output about separate debug file search.
38 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
41 *** Changes in GDB 8.0
43 * GDB now supports access to the PKU register on GNU/Linux. The register is
44 added by the Memory Protection Keys for Userspace feature which will be
45 available in future Intel CPUs.
47 * GDB now supports C++11 rvalue references.
51 ** New functions to start, stop and access a running btrace recording.
52 ** Rvalue references are now supported in gdb.Type.
54 * GDB now supports recording and replaying rdrand and rdseed Intel 64
57 * Building GDB and GDBserver now requires a C++11 compiler.
59 For example, GCC 4.8 or later.
61 It is no longer possible to build GDB or GDBserver with a C
62 compiler. The --disable-build-with-cxx configure option has been
65 * Building GDB and GDBserver now requires GNU make >= 3.81.
67 It is no longer supported to build GDB or GDBserver with another
68 implementation of the make program or an earlier version of GNU make.
70 * Native debugging on MS-Windows supports command-line redirection
72 Command-line arguments used for starting programs on MS-Windows can
73 now include redirection symbols supported by native Windows shells,
74 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
75 as "run", "start", and "set args", as well as the corresponding MI
78 * Support for thread names on MS-Windows.
80 GDB now catches and handles the special exception that programs
81 running on MS-Windows use to assign names to threads in the
84 * Support for Java programs compiled with gcj has been removed.
86 * User commands now accept an unlimited number of arguments.
87 Previously, only up to 10 was accepted.
89 * The "eval" command now expands user-defined command arguments.
91 This makes it easier to process a variable number of arguments:
96 eval "print $arg%d", $i
101 * Target descriptions can now describe registers for sparc32 and sparc64.
103 * GDB now supports DWARF version 5 (debug information format).
104 Its .debug_names index is not yet supported.
106 * New native configurations
108 FreeBSD/mips mips*-*-freebsd
112 Synopsys ARC arc*-*-elf32
113 FreeBSD/mips mips*-*-freebsd
115 * Removed targets and native configurations
117 Alpha running FreeBSD alpha*-*-freebsd*
118 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
123 Erases all the flash memory regions reported by the target.
125 maint print arc arc-instruction address
126 Print internal disassembler information about instruction at a given address.
130 set disassembler-options
131 show disassembler-options
132 Controls the passing of target specific information to the disassembler.
133 If it is necessary to specify more than one disassembler option then
134 multiple options can be placed together into a comma separated list.
135 The default value is the empty string. Currently, the only supported
136 targets are ARM, PowerPC and S/390.
141 Erases all the flash memory regions reported by the target. This is
142 equivalent to the CLI command flash-erase.
144 -file-list-shared-libraries
145 List the shared libraries in the program. This is
146 equivalent to the CLI command "info shared".
148 *** Changes in GDB 7.12
150 * GDB and GDBserver now build with a C++ compiler by default.
152 The --enable-build-with-cxx configure option is now enabled by
153 default. One must now explicitly configure with
154 --disable-build-with-cxx in order to build with a C compiler. This
155 option will be removed in a future release.
157 * GDBserver now supports recording btrace without maintaining an active
160 * GDB now supports a negative repeat count in the 'x' command to examine
161 memory backward from the given address. For example:
164 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
165 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
166 (gdb) x/-5i 0x0000000000400580
167 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
168 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
169 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
170 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
171 0x40057b <main(int, char**)+25>:
172 callq 0x400536 <Func1(int, char const*)>
174 * Fortran: Support structures with fields of dynamic types and
175 arrays of dynamic types.
177 * The symbol dumping maintenance commands have new syntax.
178 maint print symbols [-pc address] [--] [filename]
179 maint print symbols [-objfile objfile] [-source source] [--] [filename]
180 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
181 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
182 maint print msymbols [-objfile objfile] [--] [filename]
184 * GDB now supports multibit bitfields and enums in target register
187 * New Python-based convenience function $_as_string(val), which returns
188 the textual representation of a value. This function is especially
189 useful to obtain the text label of an enum value.
191 * Intel MPX bound violation handling.
193 Segmentation faults caused by a Intel MPX boundary violation
194 now display the kind of violation (upper or lower), the memory
195 address accessed and the memory bounds, along with the usual
196 signal received and code location.
200 Program received signal SIGSEGV, Segmentation fault
201 Upper bound violation while accessing address 0x7fffffffc3b3
202 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
203 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
205 * Rust language support.
206 GDB now supports debugging programs written in the Rust programming
207 language. See https://www.rust-lang.org/ for more information about
210 * Support for running interpreters on specified input/output devices
212 GDB now supports a new mechanism that allows frontends to provide
213 fully featured GDB console views, as a better alternative to
214 building such views on top of the "-interpreter-exec console"
215 command. See the new "new-ui" command below. With that command,
216 frontends can now start GDB in the traditional command-line mode
217 running in an embedded terminal emulator widget, and create a
218 separate MI interpreter running on a specified i/o device. In this
219 way, GDB handles line editing, history, tab completion, etc. in the
220 console all by itself, and the GUI uses the separate MI interpreter
221 for its own control and synchronization, invisible to the command
224 * The "catch syscall" command catches groups of related syscalls.
226 The "catch syscall" command now supports catching a group of related
227 syscalls using the 'group:' or 'g:' prefix.
232 skip -gfile file-glob-pattern
233 skip -function function
234 skip -rfunction regular-expression
235 A generalized form of the skip command, with new support for
236 glob-style file names and regular expressions for function names.
237 Additionally, a file spec and a function spec may now be combined.
239 maint info line-table REGEXP
240 Display the contents of GDB's internal line table data struture.
243 Run any GDB unit tests that were compiled in.
246 Start a new user interface instance running INTERP as interpreter,
247 using the TTY file for input/output.
251 ** gdb.Breakpoint objects have a new attribute "pending", which
252 indicates whether the breakpoint is pending.
253 ** Three new breakpoint-related events have been added:
254 gdb.breakpoint_created, gdb.breakpoint_modified, and
255 gdb.breakpoint_deleted.
258 Signal ("set") the given MS-Windows event object. This is used in
259 conjunction with the Windows JIT debugging (AeDebug) support, where
260 the OS suspends a crashing process until a debugger can attach to
261 it. Resuming the crashing process, in order to debug it, is done by
264 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
265 was added in GDBserver, including JIT compiling fast tracepoint's
266 conditional expression bytecode into native code.
268 * Support for various remote target protocols and ROM monitors has
271 target m32rsdi Remote M32R debugging over SDI
272 target mips MIPS remote debugging protocol
273 target pmon PMON ROM monitor
274 target ddb NEC's DDB variant of PMON for Vr4300
275 target rockhopper NEC RockHopper variant of PMON
276 target lsi LSI variant of PMO
278 * Support for tracepoints and fast tracepoints on powerpc-linux,
279 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
280 including JIT compiling fast tracepoint's conditional expression
281 bytecode into native code.
283 * MI async record =record-started now includes the method and format used for
284 recording. For example:
286 =record-started,thread-group="i1",method="btrace",format="bts"
288 * MI async record =thread-selected now includes the frame field. For example:
290 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
294 Andes NDS32 nds32*-*-elf
296 *** Changes in GDB 7.11
298 * GDB now supports debugging kernel-based threads on FreeBSD.
300 * Per-inferior thread numbers
302 Thread numbers are now per inferior instead of global. If you're
303 debugging multiple inferiors, GDB displays thread IDs using a
304 qualified INF_NUM.THR_NUM form. For example:
308 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
309 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
310 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
311 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
313 As consequence, thread numbers as visible in the $_thread
314 convenience variable and in Python's InferiorThread.num attribute
315 are no longer unique between inferiors.
317 GDB now maintains a second thread ID per thread, referred to as the
318 global thread ID, which is the new equivalent of thread numbers in
319 previous releases. See also $_gthread below.
321 For backwards compatibility, MI's thread IDs always refer to global
324 * Commands that accept thread IDs now accept the qualified
325 INF_NUM.THR_NUM form as well. For example:
328 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
331 * In commands that accept a list of thread IDs, you can now refer to
332 all threads of an inferior using a star wildcard. GDB accepts
333 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
334 refer to all threads of the current inferior. For example, "info
337 * You can use "info threads -gid" to display the global thread ID of
340 * The new convenience variable $_gthread holds the global number of
343 * The new convenience variable $_inferior holds the number of the
346 * GDB now displays the ID and name of the thread that hit a breakpoint
347 or received a signal, if your program is multi-threaded. For
350 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
351 Thread 1 "main" received signal SIGINT, Interrupt.
353 * Record btrace now supports non-stop mode.
355 * Support for tracepoints on aarch64-linux was added in GDBserver.
357 * The 'record instruction-history' command now indicates speculative execution
358 when using the Intel Processor Trace recording format.
360 * GDB now allows users to specify explicit locations, bypassing
361 the linespec parser. This feature is also available to GDB/MI
364 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
365 GDB now is able to debug both AArch64 applications and ARM applications
368 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
369 including JIT compiling fast tracepoint's conditional expression bytecode
372 * GDB now supports displaced stepping on AArch64 GNU/Linux.
374 * "info threads", "info inferiors", "info display", "info checkpoints"
375 and "maint info program-spaces" now list the corresponding items in
376 ascending ID order, for consistency with all other "info" commands.
378 * In Ada, the overloads selection menu has been enhanced to display the
379 parameter types and the return types for the matching overloaded subprograms.
383 maint set target-non-stop (on|off|auto)
384 maint show target-non-stop
385 Control whether GDB targets always operate in non-stop mode even if
386 "set non-stop" is "off". The default is "auto", meaning non-stop
387 mode is enabled if supported by the target.
389 maint set bfd-sharing
390 maint show bfd-sharing
391 Control the reuse of bfd objects.
395 Control display of debugging info regarding bfd caching.
399 Control display of debugging info regarding FreeBSD threads.
401 set remote multiprocess-extensions-packet
402 show remote multiprocess-extensions-packet
403 Set/show the use of the remote protocol multiprocess extensions.
405 set remote thread-events
406 show remote thread-events
407 Set/show the use of thread create/exit events.
409 set ada print-signatures on|off
410 show ada print-signatures"
411 Control whether parameter types and return types are displayed in overloads
412 selection menus. It is activaled (@code{on}) by default.
416 Controls the maximum size of memory, in bytes, that GDB will
417 allocate for value contents. Prevents incorrect programs from
418 causing GDB to allocate overly large buffers. Default is 64k.
420 * The "disassemble" command accepts a new modifier: /s.
421 It prints mixed source+disassembly like /m with two differences:
422 - disassembled instructions are now printed in program order, and
423 - and source for all relevant files is now printed.
424 The "/m" option is now considered deprecated: its "source-centric"
425 output hasn't proved useful in practice.
427 * The "record instruction-history" command accepts a new modifier: /s.
428 It behaves exactly like /m and prints mixed source+disassembly.
430 * The "set scheduler-locking" command supports a new mode "replay".
431 It behaves like "off" in record mode and like "on" in replay mode.
433 * Support for various ROM monitors has been removed:
435 target dbug dBUG ROM monitor for Motorola ColdFire
436 target picobug Motorola picobug monitor
437 target dink32 DINK32 ROM monitor for PowerPC
438 target m32r Renesas M32R/D ROM monitor
439 target mon2000 mon2000 ROM monitor
440 target ppcbug PPCBUG ROM monitor for PowerPC
442 * Support for reading/writing memory and extracting values on architectures
443 whose memory is addressable in units of any integral multiple of 8 bits.
448 Indicates whether the inferior must be started with a shell or not.
451 Indicates that an exec system call was executed.
453 exec-events feature in qSupported
454 The qSupported packet allows GDB to request support for exec
455 events using the new 'gdbfeature' exec-event, and the qSupported
456 response can contain the corresponding 'stubfeature'. Set and
457 show commands can be used to display whether these features are enabled.
460 Equivalent to interrupting with the ^C character, but works in
463 thread created stop reason (T05 create:...)
464 Indicates that the thread was just created and is stopped at entry.
466 thread exit stop reply (w exitcode;tid)
467 Indicates that the thread has terminated.
470 Enables/disables thread create and exit event reporting. For
471 example, this is used in non-stop mode when GDB stops a set of
472 threads and synchronously waits for the their corresponding stop
473 replies. Without exit events, if one of the threads exits, GDB
474 would hang forever not knowing that it should no longer expect a
475 stop for that same thread.
478 Indicates that there are no resumed threads left in the target (all
479 threads are stopped). The remote stub reports support for this stop
480 reply to GDB's qSupported query.
483 Enables/disables catching syscalls from the inferior process.
484 The remote stub reports support for this packet to GDB's qSupported query.
486 syscall_entry stop reason
487 Indicates that a syscall was just called.
489 syscall_return stop reason
490 Indicates that a syscall just returned.
492 * Extended-remote exec events
494 ** GDB now has support for exec events on extended-remote Linux targets.
495 For such targets with Linux kernels 2.5.46 and later, this enables
496 follow-exec-mode and exec catchpoints.
498 set remote exec-event-feature-packet
499 show remote exec-event-feature-packet
500 Set/show the use of the remote exec event feature.
502 * Thread names in remote protocol
504 The reply to qXfer:threads:read may now include a name attribute for each
507 * Target remote mode fork and exec events
509 ** GDB now has support for fork and exec events on target remote mode
510 Linux targets. For such targets with Linux kernels 2.5.46 and later,
511 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
512 fork and exec catchpoints.
514 * Remote syscall events
516 ** GDB now has support for catch syscall on remote Linux targets,
517 currently enabled on x86/x86_64 architectures.
519 set remote catch-syscall-packet
520 show remote catch-syscall-packet
521 Set/show the use of the remote catch syscall feature.
525 ** The -var-set-format command now accepts the zero-hexadecimal
526 format. It outputs data in hexadecimal format with zero-padding on the
531 ** gdb.InferiorThread objects have a new attribute "global_num",
532 which refers to the thread's global thread ID. The existing
533 "num" attribute now refers to the thread's per-inferior number.
534 See "Per-inferior thread numbers" above.
535 ** gdb.InferiorThread objects have a new attribute "inferior", which
536 is the Inferior object the thread belongs to.
538 *** Changes in GDB 7.10
540 * Support for process record-replay and reverse debugging on aarch64*-linux*
541 targets has been added. GDB now supports recording of A64 instruction set
542 including advance SIMD instructions.
544 * Support for Sun's version of the "stabs" debug file format has been removed.
546 * GDB now honors the content of the file /proc/PID/coredump_filter
547 (PID is the process ID) on GNU/Linux systems. This file can be used
548 to specify the types of memory mappings that will be included in a
549 corefile. For more information, please refer to the manual page of
550 "core(5)". GDB also has a new command: "set use-coredump-filter
551 on|off". It allows to set whether GDB will read the content of the
552 /proc/PID/coredump_filter file when generating a corefile.
554 * The "info os" command on GNU/Linux can now display information on
556 "info os cpus" Listing of all cpus/cores on the system
558 * GDB has two new commands: "set serial parity odd|even|none" and
559 "show serial parity". These allows to set or show parity for the
562 * The "info source" command now displays the producer string if it was
563 present in the debug info. This typically includes the compiler version
564 and may include things like its command line arguments.
566 * The "info dll", an alias of the "info sharedlibrary" command,
567 is now available on all platforms.
569 * Directory names supplied to the "set sysroot" commands may be
570 prefixed with "target:" to tell GDB to access shared libraries from
571 the target system, be it local or remote. This replaces the prefix
572 "remote:". The default sysroot has been changed from "" to
573 "target:". "remote:" is automatically converted to "target:" for
574 backward compatibility.
576 * The system root specified by "set sysroot" will be prepended to the
577 filename of the main executable (if reported to GDB as absolute by
578 the operating system) when starting processes remotely, and when
579 attaching to already-running local or remote processes.
581 * GDB now supports automatic location and retrieval of executable
582 files from remote targets. Remote debugging can now be initiated
583 using only a "target remote" or "target extended-remote" command
584 (no "set sysroot" or "file" commands are required). See "New remote
587 * The "dump" command now supports verilog hex format.
589 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
591 * On GNU/Linux, GDB and gdbserver are now able to access executable
592 and shared library files without a "set sysroot" command when
593 attaching to processes running in different mount namespaces from
594 the debugger. This makes it possible to attach to processes in
595 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
596 See "New remote packets" below.
598 * The "tui reg" command now provides completion for all of the
599 available register groups, including target specific groups.
601 * The HISTSIZE environment variable is no longer read when determining
602 the size of GDB's command history. GDB now instead reads the dedicated
603 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
604 disables truncation of command history. Non-numeric values of GDBHISTSIZE
609 ** Memory ports can now be unbuffered.
613 ** gdb.Objfile objects have a new attribute "username",
614 which is the name of the objfile as specified by the user,
615 without, for example, resolving symlinks.
616 ** You can now write frame unwinders in Python.
617 ** gdb.Type objects have a new method "optimized_out",
618 returning optimized out gdb.Value instance of this type.
619 ** gdb.Value objects have new methods "reference_value" and
620 "const_value" which return a reference to the value and a
621 "const" version of the value respectively.
625 maint print symbol-cache
626 Print the contents of the symbol cache.
628 maint print symbol-cache-statistics
629 Print statistics of symbol cache usage.
631 maint flush-symbol-cache
632 Flush the contents of the symbol cache.
636 Start branch trace recording using Branch Trace Store (BTS) format.
639 Evaluate expression by using the compiler and print result.
643 Explicit commands for enabling and disabling tui mode.
646 set mpx bound on i386 and amd64
647 Support for bound table investigation on Intel MPX enabled applications.
651 Start branch trace recording using Intel Processor Trace format.
654 Print information about branch tracing internals.
656 maint btrace packet-history
657 Print the raw branch tracing data.
659 maint btrace clear-packet-history
660 Discard the stored raw branch tracing data.
663 Discard all branch tracing data. It will be fetched and processed
664 anew by the next "record" command.
669 Renamed from "set debug dwarf2-die".
671 Renamed from "show debug dwarf2-die".
674 Renamed from "set debug dwarf2-read".
675 show debug dwarf-read
676 Renamed from "show debug dwarf2-read".
678 maint set dwarf always-disassemble
679 Renamed from "maint set dwarf2 always-disassemble".
680 maint show dwarf always-disassemble
681 Renamed from "maint show dwarf2 always-disassemble".
683 maint set dwarf max-cache-age
684 Renamed from "maint set dwarf2 max-cache-age".
685 maint show dwarf max-cache-age
686 Renamed from "maint show dwarf2 max-cache-age".
689 show debug dwarf-line
690 Control display of debugging info regarding DWARF line processing.
694 Set the maximum number of candidates to be considered during
695 completion. The default value is 200. This limit allows GDB
696 to avoid generating large completion lists, the computation of
697 which can cause the debugger to become temporarily unresponsive.
699 set history remove-duplicates
700 show history remove-duplicates
701 Control the removal of duplicate history entries.
703 maint set symbol-cache-size
704 maint show symbol-cache-size
705 Control the size of the symbol cache.
707 set|show record btrace bts buffer-size
708 Set and show the size of the ring buffer used for branch tracing in
710 The obtained size may differ from the requested size. Use "info
711 record" to see the obtained buffer size.
713 set debug linux-namespaces
714 show debug linux-namespaces
715 Control display of debugging info regarding Linux namespaces.
717 set|show record btrace pt buffer-size
718 Set and show the size of the ring buffer used for branch tracing in
719 Intel Processor Trace format.
720 The obtained size may differ from the requested size. Use "info
721 record" to see the obtained buffer size.
723 maint set|show btrace pt skip-pad
724 Set and show whether PAD packets are skipped when computing the
727 * The command 'thread apply all' can now support new option '-ascending'
728 to call its specified command for all threads in ascending order.
730 * Python/Guile scripting
732 ** GDB now supports auto-loading of Python/Guile scripts contained in the
733 special section named `.debug_gdb_scripts'.
737 qXfer:btrace-conf:read
738 Return the branch trace configuration for the current thread.
740 Qbtrace-conf:bts:size
741 Set the requested ring buffer size for branch tracing in BTS format.
744 Enable Intel Procesor Trace-based branch tracing for the current
745 process. The remote stub reports support for this packet to GDB's
749 Set the requested ring buffer size for branch tracing in Intel Processor
753 Indicates a memory breakpoint instruction was executed, irrespective
754 of whether it was GDB that planted the breakpoint or the breakpoint
755 is hardcoded in the program. This is required for correct non-stop
759 Indicates the target stopped for a hardware breakpoint. This is
760 required for correct non-stop mode operation.
763 Return information about files on the remote system.
766 Return the full absolute name of the file that was executed to
767 create a process running on the remote system.
770 Select the filesystem on which vFile: operations with filename
771 arguments will operate. This is required for GDB to be able to
772 access files on remote targets where the remote stub does not
773 share a common filesystem with the inferior(s).
776 Indicates that a fork system call was executed.
779 Indicates that a vfork system call was executed.
781 vforkdone stop reason
782 Indicates that a vfork child of the specified process has executed
783 an exec or exit, allowing the vfork parent to resume execution.
785 fork-events and vfork-events features in qSupported
786 The qSupported packet allows GDB to request support for fork and
787 vfork events using new 'gdbfeatures' fork-events and vfork-events,
788 and the qSupported response can contain the corresponding
789 'stubfeatures'. Set and show commands can be used to display
790 whether these features are enabled.
792 * Extended-remote fork events
794 ** GDB now has support for fork events on extended-remote Linux
795 targets. For targets with Linux kernels 2.5.60 and later, this
796 enables follow-fork-mode and detach-on-fork for both fork and
797 vfork, as well as fork and vfork catchpoints.
799 * The info record command now shows the recording format and the
800 branch tracing configuration for the current thread when using
801 the btrace record target.
802 For the BTS format, it shows the ring buffer size.
804 * GDB now has support for DTrace USDT (Userland Static Defined
805 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
807 * GDB now supports access to vector registers on S/390 GNU/Linux
810 * Removed command line options
812 -xdb HP-UX XDB compatibility mode.
814 * Removed targets and native configurations
816 HP/PA running HP-UX hppa*-*-hpux*
817 Itanium running HP-UX ia64-*-hpux*
819 * New configure options
822 This configure option allows the user to build GDB with support for
823 Intel Processor Trace (default: auto). This requires libipt.
825 --with-libipt-prefix=PATH
826 Specify the path to the version of libipt that GDB should use.
827 $PATH/include should contain the intel-pt.h header and
828 $PATH/lib should contain the libipt.so library.
830 *** Changes in GDB 7.9.1
834 ** Xmethods can now specify a result type.
836 *** Changes in GDB 7.9
838 * GDB now supports hardware watchpoints on x86 GNU Hurd.
842 ** You can now access frame registers from Python scripts.
843 ** New attribute 'producer' for gdb.Symtab objects.
844 ** gdb.Objfile objects have a new attribute "progspace",
845 which is the gdb.Progspace object of the containing program space.
846 ** gdb.Objfile objects have a new attribute "owner".
847 ** gdb.Objfile objects have a new attribute "build_id",
848 which is the build ID generated when the file was built.
849 ** gdb.Objfile objects have a new method "add_separate_debug_file".
850 ** A new event "gdb.clear_objfiles" has been added, triggered when
851 selecting a new file to debug.
852 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
853 ** New function gdb.lookup_objfile.
855 New events which are triggered when GDB modifies the state of the
858 ** gdb.events.inferior_call_pre: Function call is about to be made.
859 ** gdb.events.inferior_call_post: Function call has just been made.
860 ** gdb.events.memory_changed: A memory location has been altered.
861 ** gdb.events.register_changed: A register has been altered.
863 * New Python-based convenience functions:
865 ** $_caller_is(name [, number_of_frames])
866 ** $_caller_matches(regexp [, number_of_frames])
867 ** $_any_caller_is(name [, number_of_frames])
868 ** $_any_caller_matches(regexp [, number_of_frames])
870 * GDB now supports the compilation and injection of source code into
871 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
872 to compile the source code to object code, and if successful, inject
873 and execute that code within the current context of the inferior.
874 Currently the C language is supported. The commands used to
875 interface with this new feature are:
877 compile code [-raw|-r] [--] [source code]
878 compile file [-raw|-r] filename
882 demangle [-l language] [--] name
883 Demangle "name" in the specified language, or the current language
884 if elided. This command is renamed from the "maint demangle" command.
885 The latter is kept as a no-op to avoid "maint demangle" being interpreted
886 as "maint demangler-warning".
888 queue-signal signal-name-or-number
889 Queue a signal to be delivered to the thread when it is resumed.
891 add-auto-load-scripts-directory directory
892 Add entries to the list of directories from which to load auto-loaded
895 maint print user-registers
896 List all currently available "user" registers.
898 compile code [-r|-raw] [--] [source code]
899 Compile, inject, and execute in the inferior the executable object
900 code produced by compiling the provided source code.
902 compile file [-r|-raw] filename
903 Compile and inject into the inferior the executable object code
904 produced by compiling the source code stored in the filename
907 * On resume, GDB now always passes the signal the program had stopped
908 for to the thread the signal was sent to, even if the user changed
909 threads before resuming. Previously GDB would often (but not
910 always) deliver the signal to the thread that happens to be current
913 * Conversely, the "signal" command now consistently delivers the
914 requested signal to the current thread. GDB now asks for
915 confirmation if the program had stopped for a signal and the user
916 switched threads meanwhile.
918 * "breakpoint always-inserted" modes "off" and "auto" merged.
920 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
921 won't remove breakpoints from the target until all threads stop,
922 even in non-stop mode. The "auto" mode has been removed, and "off"
923 is now the default mode.
927 set debug symbol-lookup
928 show debug symbol-lookup
929 Control display of debugging info regarding symbol lookup.
933 ** The -list-thread-groups command outputs an exit-code field for
934 inferiors that have exited.
938 MIPS SDE mips*-sde*-elf*
942 Support for these obsolete configurations has been removed.
944 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
945 SGI Irix-5.x mips-*-irix5*
946 SGI Irix-6.x mips-*-irix6*
947 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
948 VAX running Ultrix vax-*-ultrix*
950 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
951 and "assf"), have been removed. Use the "sharedlibrary" command, or
952 its alias "share", instead.
954 *** Changes in GDB 7.8
956 * New command line options
959 This is an alias for the --data-directory option.
961 * GDB supports printing and modifying of variable length automatic arrays
962 as specified in ISO C99.
964 * The ARM simulator now supports instruction level tracing
965 with or without disassembly.
969 GDB now has support for scripting using Guile. Whether this is
970 available is determined at configure time.
971 Guile version 2.0 or greater is required.
972 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
974 * New commands (for set/show, see "New options" below)
978 Invoke CODE by passing it to the Guile interpreter.
982 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
984 info auto-load guile-scripts [regexp]
985 Print the list of automatically loaded Guile scripts.
987 * The source command is now capable of sourcing Guile scripts.
988 This feature is dependent on the debugger being built with Guile support.
992 set print symbol-loading (off|brief|full)
993 show print symbol-loading
994 Control whether to print informational messages when loading symbol
995 information for a file. The default is "full", but when debugging
996 programs with large numbers of shared libraries the amount of output
999 set guile print-stack (none|message|full)
1000 show guile print-stack
1001 Show a stack trace when an error is encountered in a Guile script.
1003 set auto-load guile-scripts (on|off)
1004 show auto-load guile-scripts
1005 Control auto-loading of Guile script files.
1007 maint ada set ignore-descriptive-types (on|off)
1008 maint ada show ignore-descriptive-types
1009 Control whether the debugger should ignore descriptive types in Ada
1010 programs. The default is not to ignore the descriptive types. See
1011 the user manual for more details on descriptive types and the intended
1012 usage of this option.
1014 set auto-connect-native-target
1016 Control whether GDB is allowed to automatically connect to the
1017 native target for the run, attach, etc. commands when not connected
1018 to any target yet. See also "target native" below.
1020 set record btrace replay-memory-access (read-only|read-write)
1021 show record btrace replay-memory-access
1022 Control what memory accesses are allowed during replay.
1024 maint set target-async (on|off)
1025 maint show target-async
1026 This controls whether GDB targets operate in synchronous or
1027 asynchronous mode. Normally the default is asynchronous, if it is
1028 available; but this can be changed to more easily debug problems
1029 occurring only in synchronous mode.
1031 set mi-async (on|off)
1033 Control whether MI asynchronous mode is preferred. This supersedes
1034 "set target-async" of previous GDB versions.
1036 * "set target-async" is deprecated as a CLI option and is now an alias
1037 for "set mi-async" (only puts MI into async mode).
1039 * Background execution commands (e.g., "c&", "s&", etc.) are now
1040 possible ``out of the box'' if the target supports them. Previously
1041 the user would need to explicitly enable the possibility with the
1042 "set target-async on" command.
1044 * New features in the GDB remote stub, GDBserver
1046 ** New option --debug-format=option1[,option2,...] allows one to add
1047 additional text to each output. At present only timestamps
1048 are supported: --debug-format=timestamps.
1049 Timestamps can also be turned on with the
1050 "monitor set debug-format timestamps" command from GDB.
1052 * The 'record instruction-history' command now starts counting instructions
1053 at one. This also affects the instruction ranges reported by the
1054 'record function-call-history' command when given the /i modifier.
1056 * The command 'record function-call-history' supports a new modifier '/c' to
1057 indent the function names based on their call stack depth.
1058 The fields for the '/i' and '/l' modifier have been reordered.
1059 The source line range is now prefixed with 'at'.
1060 The instruction range is now prefixed with 'inst'.
1061 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1062 "record instruction-history" and "list" commands.
1064 * The ranges given as arguments to the 'record function-call-history' and
1065 'record instruction-history' commands are now inclusive.
1067 * The btrace record target now supports the 'record goto' command.
1068 For locations inside the execution trace, the back trace is computed
1069 based on the information stored in the execution trace.
1071 * The btrace record target supports limited reverse execution and replay.
1072 The target does not record data and therefore does not allow reading
1073 memory or registers.
1075 * The "catch syscall" command now works on s390*-linux* targets.
1077 * The "compare-sections" command is no longer specific to target
1078 remote. It now works with all targets.
1080 * All native targets are now consistently called "native".
1081 Consequently, the "target child", "target GNU", "target djgpp",
1082 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1083 commands have been replaced with "target native". The QNX/NTO port
1084 leaves the "procfs" target in place and adds a "native" target for
1085 consistency with other ports. The impact on users should be minimal
1086 as these commands previously either throwed an error, or were
1087 no-ops. The target's name is visible in the output of the following
1088 commands: "help target", "info target", "info files", "maint print
1091 * The "target native" command now connects to the native target. This
1092 can be used to launch native programs even when "set
1093 auto-connect-native-target" is set to off.
1095 * GDB now supports access to Intel MPX registers on GNU/Linux.
1097 * Support for Intel AVX-512 registers on GNU/Linux.
1098 Support displaying and modifying Intel AVX-512 registers
1099 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1101 * New remote packets
1103 qXfer:btrace:read's annex
1104 The qXfer:btrace:read packet supports a new annex 'delta' to read
1105 branch trace incrementally.
1109 ** Valid Python operations on gdb.Value objects representing
1110 structs/classes invoke the corresponding overloaded operators if
1112 ** New `Xmethods' feature in the Python API. Xmethods are
1113 additional methods or replacements for existing methods of a C++
1114 class. This feature is useful for those cases where a method
1115 defined in C++ source code could be inlined or optimized out by
1116 the compiler, making it unavailable to GDB.
1119 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1121 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1122 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1123 its alias "share", instead.
1125 * The commands "set remotebaud" and "show remotebaud" are no longer
1126 supported. Use "set serial baud" and "show serial baud" (respectively)
1131 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1132 target-async". The latter is left as a deprecated alias of the
1133 former for backward compatibility. If the target supports it,
1134 CLI background execution commands are now always possible by
1135 default, independently of whether the frontend stated a
1136 preference for asynchronous execution with "-gdb-set mi-async".
1137 Previously "-gdb-set target-async off" affected both MI execution
1138 commands and CLI execution commands.
1140 *** Changes in GDB 7.7
1142 * Improved support for process record-replay and reverse debugging on
1143 arm*-linux* targets. Support for thumb32 and syscall instruction
1144 recording has been added.
1146 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1148 * GDB now supports Fission DWP file format version 2.
1149 http://gcc.gnu.org/wiki/DebugFission
1151 * New convenience function "$_isvoid", to check whether an expression
1152 is void. A void expression is an expression where the type of the
1153 result is "void". For example, some convenience variables may be
1154 "void" when evaluated (e.g., "$_exitcode" before the execution of
1155 the program being debugged; or an undefined convenience variable).
1156 Another example, when calling a function whose return type is
1159 * The "maintenance print objfiles" command now takes an optional regexp.
1161 * The "catch syscall" command now works on arm*-linux* targets.
1163 * GDB now consistently shows "<not saved>" when printing values of
1164 registers the debug info indicates have not been saved in the frame
1165 and there's nowhere to retrieve them from
1166 (callee-saved/call-clobbered registers):
1171 (gdb) info registers rax
1174 Before, the former would print "<optimized out>", and the latter
1175 "*value not available*".
1177 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1182 ** Frame filters and frame decorators have been added.
1183 ** Temporary breakpoints are now supported.
1184 ** Line tables representation has been added.
1185 ** New attribute 'parent_type' for gdb.Field objects.
1186 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1187 ** New attribute 'name' for gdb.Type objects.
1191 Nios II ELF nios2*-*-elf
1192 Nios II GNU/Linux nios2*-*-linux
1193 Texas Instruments MSP430 msp430*-*-elf
1195 * Removed native configurations
1197 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1198 been removed. ELF variants of these configurations are kept supported.
1200 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1201 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1202 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1203 i[34567]86-*-openbsd3.[0-3]
1204 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1205 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1206 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1210 Like "catch throw", but catches a re-thrown exception.
1211 maint check-psymtabs
1212 Renamed from old "maint check-symtabs".
1214 Perform consistency checks on symtabs.
1215 maint expand-symtabs
1216 Expand symtabs matching an optional regexp.
1219 Display the details of GDB configure-time options.
1221 maint set|show per-command
1222 maint set|show per-command space
1223 maint set|show per-command time
1224 maint set|show per-command symtab
1225 Enable display of per-command gdb resource usage.
1227 remove-symbol-file FILENAME
1228 remove-symbol-file -a ADDRESS
1229 Remove a symbol file added via add-symbol-file. The file to remove
1230 can be identified by its filename or by an address that lies within
1231 the boundaries of this symbol file in memory.
1234 info exceptions REGEXP
1235 Display the list of Ada exceptions defined in the program being
1236 debugged. If provided, only the exceptions whose names match REGEXP
1241 set debug symfile off|on
1243 Control display of debugging info regarding reading symbol files and
1244 symbol tables within those files
1246 set print raw frame-arguments
1247 show print raw frame-arguments
1248 Set/show whether to print frame arguments in raw mode,
1249 disregarding any defined pretty-printers.
1251 set remote trace-status-packet
1252 show remote trace-status-packet
1253 Set/show the use of remote protocol qTStatus packet.
1257 Control display of debugging messages related to Nios II targets.
1261 Control whether target-assisted range stepping is enabled.
1263 set startup-with-shell
1264 show startup-with-shell
1265 Specifies whether Unix child processes are started via a shell or
1270 Use the target memory cache for accesses to the code segment. This
1271 improves performance of remote debugging (particularly disassembly).
1273 * You can now use a literal value 'unlimited' for options that
1274 interpret 0 or -1 as meaning "unlimited". E.g., "set
1275 trace-buffer-size unlimited" is now an alias for "set
1276 trace-buffer-size -1" and "set height unlimited" is now an alias for
1279 * The "set debug symtab-create" debugging option of GDB has been changed to
1280 accept a verbosity level. 0 means "off", 1 provides basic debugging
1281 output, and values of 2 or greater provides more verbose output.
1283 * New command-line options
1285 Display the details of GDB configure-time options.
1287 * The command 'tsave' can now support new option '-ctf' to save trace
1288 buffer in Common Trace Format.
1290 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1293 * GDB now implements the the C++ 'typeid' operator.
1295 * The new convenience variable $_exception holds the exception being
1296 thrown or caught at an exception-related catchpoint.
1298 * The exception-related catchpoints, like "catch throw", now accept a
1299 regular expression which can be used to filter exceptions by type.
1301 * The new convenience variable $_exitsignal is automatically set to
1302 the terminating signal number when the program being debugged dies
1303 due to an uncaught signal.
1307 ** All MI commands now accept an optional "--language" option.
1308 Support for this feature can be verified by using the "-list-features"
1309 command, which should contain "language-option".
1311 ** The new command -info-gdb-mi-command allows the user to determine
1312 whether a GDB/MI command is supported or not.
1314 ** The "^error" result record returned when trying to execute an undefined
1315 GDB/MI command now provides a variable named "code" whose content is the
1316 "undefined-command" error code. Support for this feature can be verified
1317 by using the "-list-features" command, which should contain
1318 "undefined-command-error-code".
1320 ** The -trace-save MI command can optionally save trace buffer in Common
1323 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1325 ** The command -data-list-register-values now accepts an optional
1326 "--skip-unavailable" option. When used, only the available registers
1329 ** The new command -trace-frame-collected dumps collected variables,
1330 computed expressions, tvars, memory and registers in a traceframe.
1332 ** The commands -stack-list-locals, -stack-list-arguments and
1333 -stack-list-variables now accept an option "--skip-unavailable".
1334 When used, only the available locals or arguments are displayed.
1336 ** The -exec-run command now accepts an optional "--start" option.
1337 When used, the command follows the same semantics as the "start"
1338 command, stopping the program's execution at the start of its
1339 main subprogram. Support for this feature can be verified using
1340 the "-list-features" command, which should contain
1341 "exec-run-start-option".
1343 ** The new commands -catch-assert and -catch-exceptions insert
1344 catchpoints stopping the program when Ada exceptions are raised.
1346 ** The new command -info-ada-exceptions provides the equivalent of
1347 the new "info exceptions" command.
1349 * New system-wide configuration scripts
1350 A GDB installation now provides scripts suitable for use as system-wide
1351 configuration scripts for the following systems:
1355 * GDB now supports target-assigned range stepping with remote targets.
1356 This improves the performance of stepping source lines by reducing
1357 the number of control packets from/to GDB. See "New remote packets"
1360 * GDB now understands the element 'tvar' in the XML traceframe info.
1361 It has the id of the collected trace state variables.
1363 * On S/390 targets that provide the transactional-execution feature,
1364 the program interruption transaction diagnostic block (TDB) is now
1365 represented as a number of additional "registers" in GDB.
1367 * New remote packets
1371 The vCont packet supports a new 'r' action, that tells the remote
1372 stub to step through an address range itself, without GDB
1373 involvemement at each single-step.
1375 qXfer:libraries-svr4:read's annex
1376 The previously unused annex of the qXfer:libraries-svr4:read packet
1377 is now used to support passing an argument list. The remote stub
1378 reports support for this argument list to GDB's qSupported query.
1379 The defined arguments are "start" and "prev", used to reduce work
1380 necessary for library list updating, resulting in significant
1383 * New features in the GDB remote stub, GDBserver
1385 ** GDBserver now supports target-assisted range stepping. Currently
1386 enabled on x86/x86_64 GNU/Linux targets.
1388 ** GDBserver now adds element 'tvar' in the XML in the reply to
1389 'qXfer:traceframe-info:read'. It has the id of the collected
1390 trace state variables.
1392 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1395 * New 'z' formatter for printing and examining memory, this displays the
1396 value as hexadecimal zero padded on the left to the size of the type.
1398 * GDB can now use Windows x64 unwinding data.
1400 * The "set remotebaud" command has been replaced by "set serial baud".
1401 Similarly, "show remotebaud" has been replaced by "show serial baud".
1402 The "set remotebaud" and "show remotebaud" commands are still available
1403 to provide backward compatibility with older versions of GDB.
1405 *** Changes in GDB 7.6
1407 * Target record has been renamed to record-full.
1408 Record/replay is now enabled with the "record full" command.
1409 This also affects settings that are associated with full record/replay
1410 that have been moved from "set/show record" to "set/show record full":
1412 set|show record full insn-number-max
1413 set|show record full stop-at-limit
1414 set|show record full memory-query
1416 * A new record target "record-btrace" has been added. The new target
1417 uses hardware support to record the control-flow of a process. It
1418 does not support replaying the execution, but it implements the
1419 below new commands for investigating the recorded execution log.
1420 This new recording method can be enabled using:
1424 The "record-btrace" target is only available on Intel Atom processors
1425 and requires a Linux kernel 2.6.32 or later.
1427 * Two new commands have been added for record/replay to give information
1428 about the recorded execution without having to replay the execution.
1429 The commands are only supported by "record btrace".
1431 record instruction-history prints the execution history at
1432 instruction granularity
1434 record function-call-history prints the execution history at
1435 function granularity
1437 * New native configurations
1439 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1440 FreeBSD/powerpc powerpc*-*-freebsd
1441 x86_64/Cygwin x86_64-*-cygwin*
1442 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1446 ARM AArch64 aarch64*-*-elf
1447 ARM AArch64 GNU/Linux aarch64*-*-linux
1448 Lynx 178 PowerPC powerpc-*-lynx*178
1449 x86_64/Cygwin x86_64-*-cygwin*
1450 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1452 * If the configured location of system.gdbinit file (as given by the
1453 --with-system-gdbinit option at configure time) is in the
1454 data-directory (as specified by --with-gdb-datadir at configure
1455 time) or in one of its subdirectories, then GDB will look for the
1456 system-wide init file in the directory specified by the
1457 --data-directory command-line option.
1459 * New command line options:
1461 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1462 other initialization files, unlike -nx which disables all of them.
1464 * Removed command line options
1466 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1469 * The 'ptype' and 'whatis' commands now accept an argument to control
1472 * 'info proc' now works on some core files.
1476 ** Vectors can be created with gdb.Type.vector.
1478 ** Python's atexit.register now works in GDB.
1480 ** Types can be pretty-printed via a Python API.
1482 ** Python 3 is now supported (in addition to Python 2.4 or later)
1484 ** New class gdb.Architecture exposes GDB's internal representation
1485 of architecture in the Python API.
1487 ** New method Frame.architecture returns the gdb.Architecture object
1488 corresponding to the frame's architecture.
1490 * New Python-based convenience functions:
1492 ** $_memeq(buf1, buf2, length)
1493 ** $_streq(str1, str2)
1495 ** $_regex(str, regex)
1497 * The 'cd' command now defaults to using '~' (the home directory) if not
1500 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1501 default for GCC since November 2000.
1503 * The command 'forward-search' can now be abbreviated as 'fo'.
1505 * The command 'info tracepoints' can now display 'installed on target'
1506 or 'not installed on target' for each non-pending location of tracepoint.
1508 * New configure options
1510 --enable-libmcheck/--disable-libmcheck
1511 By default, development versions are built with -lmcheck on hosts
1512 that support it, in order to help track memory corruption issues.
1513 Release versions, on the other hand, are built without -lmcheck
1514 by default. The --enable-libmcheck/--disable-libmcheck configure
1515 options allow the user to override that default.
1516 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1517 This configure option allows the user to build GDB with
1518 libbabeltrace using which GDB can read Common Trace Format data.
1520 * New commands (for set/show, see "New options" below)
1523 Catch signals. This is similar to "handle", but allows commands and
1524 conditions to be attached.
1527 List the BFDs known to GDB.
1529 python-interactive [command]
1531 Start a Python interactive prompt, or evaluate the optional command
1532 and print the result of expressions.
1535 "py" is a new alias for "python".
1537 enable type-printer [name]...
1538 disable type-printer [name]...
1539 Enable or disable type printers.
1543 ** For the Renesas Super-H architecture, the "regs" command has been removed
1544 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1549 set print type methods (on|off)
1550 show print type methods
1551 Control whether method declarations are displayed by "ptype".
1552 The default is to show them.
1554 set print type typedefs (on|off)
1555 show print type typedefs
1556 Control whether typedef definitions are displayed by "ptype".
1557 The default is to show them.
1559 set filename-display basename|relative|absolute
1560 show filename-display
1561 Control the way in which filenames is displayed.
1562 The default is "relative", which preserves previous behavior.
1564 set trace-buffer-size
1565 show trace-buffer-size
1566 Request target to change the size of trace buffer.
1568 set remote trace-buffer-size-packet auto|on|off
1569 show remote trace-buffer-size-packet
1570 Control the use of the remote protocol `QTBuffer:size' packet.
1574 Control display of debugging messages related to ARM AArch64.
1577 set debug coff-pe-read
1578 show debug coff-pe-read
1579 Control display of debugging messages related to reading of COFF/PE
1584 Control display of debugging messages related to Mach-O symbols
1587 set debug notification
1588 show debug notification
1589 Control display of debugging info for async remote notification.
1593 ** Command parameter changes are now notified using new async record
1594 "=cmd-param-changed".
1595 ** Trace frame changes caused by command "tfind" are now notified using
1596 new async record "=traceframe-changed".
1597 ** The creation, deletion and modification of trace state variables
1598 are now notified using new async records "=tsv-created",
1599 "=tsv-deleted" and "=tsv-modified".
1600 ** The start and stop of process record are now notified using new
1601 async record "=record-started" and "=record-stopped".
1602 ** Memory changes are now notified using new async record
1604 ** The data-disassemble command response will include a "fullname" field
1605 containing the absolute file name when source has been requested.
1606 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1607 command, to allow pattern filling of memory areas.
1608 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1609 library load/unload events.
1610 ** The response to breakpoint commands and breakpoint async records
1611 includes an "installed" field containing a boolean state about each
1612 non-pending tracepoint location is whether installed on target or not.
1613 ** Output of the "-trace-status" command includes a "trace-file" field
1614 containing the name of the trace file being examined. This field is
1615 optional, and only present when examining a trace file.
1616 ** The "fullname" field is now always present along with the "file" field,
1617 even if the file cannot be found by GDB.
1619 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1620 You must have the LZMA library available when configuring GDB for this
1621 feature to be enabled. For more information, see:
1622 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1624 * New remote packets
1627 Set the size of trace buffer. The remote stub reports support for this
1628 packet to gdb's qSupported query.
1631 Enable Branch Trace Store (BTS)-based branch tracing for the current
1632 thread. The remote stub reports support for this packet to gdb's
1636 Disable branch tracing for the current thread. The remote stub reports
1637 support for this packet to gdb's qSupported query.
1640 Read the traced branches for the current thread. The remote stub
1641 reports support for this packet to gdb's qSupported query.
1643 *** Changes in GDB 7.5
1645 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1646 for more x32 ABI info.
1648 * GDB now supports access to MIPS DSP registers on Linux targets.
1650 * GDB now supports debugging microMIPS binaries.
1652 * The "info os" command on GNU/Linux can now display information on
1653 several new classes of objects managed by the operating system:
1654 "info os procgroups" lists process groups
1655 "info os files" lists file descriptors
1656 "info os sockets" lists internet-domain sockets
1657 "info os shm" lists shared-memory regions
1658 "info os semaphores" lists semaphores
1659 "info os msg" lists message queues
1660 "info os modules" lists loaded kernel modules
1662 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1663 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1664 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1665 options and inspect the probe arguments using the new $_probe_arg family
1666 of convenience variables. You can obtain more information about SystemTap
1667 in <http://sourceware.org/systemtap/>.
1669 * GDB now supports reversible debugging on ARM, it allows you to
1670 debug basic ARM and THUMB instructions, and provides
1671 record/replay support.
1673 * The option "symbol-reloading" has been deleted as it is no longer used.
1677 ** GDB commands implemented in Python can now be put in command class
1680 ** The "maint set python print-stack on|off" is now deleted.
1682 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1683 apply "flag enum"-style pretty-printing to any enum.
1685 ** gdb.lookup_symbol can now work when there is no current frame.
1687 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1688 the source at which the symbol was defined.
1690 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1691 method 'value'. The former indicates whether the symbol needs a
1692 frame in order to compute its value, and the latter computes the
1695 ** A new method 'referenced_value' on gdb.Value objects which can
1696 dereference pointer as well as C++ reference values.
1698 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1699 which return the global and static blocks (as gdb.Block objects),
1700 of the underlying symbol table, respectively.
1702 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1703 object associated with a PC value.
1705 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1706 of the address range occupied by code for the current source line.
1708 * Go language support.
1709 GDB now supports debugging programs written in the Go programming
1712 * GDBserver now supports stdio connections.
1713 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1715 * The binary "gdbtui" can no longer be built or installed.
1716 Use "gdb -tui" instead.
1718 * GDB will now print "flag" enums specially. A flag enum is one where
1719 all the enumerator values have no bits in common when pairwise
1720 "and"ed. When printing a value whose type is a flag enum, GDB will
1721 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1722 (gdb) print (enum E) 3
1725 * The filename part of a linespec will now match trailing components
1726 of a source file name. For example, "break gcc/expr.c:1000" will
1727 now set a breakpoint in build/gcc/expr.c, but not
1728 build/libcpp/expr.c.
1730 * The "info proc" and "generate-core-file" commands will now also
1731 work on remote targets connected to GDBserver on Linux.
1733 * The command "info catch" has been removed. It has been disabled
1734 since December 2007.
1736 * The "catch exception" and "catch assert" commands now accept
1737 a condition at the end of the command, much like the "break"
1738 command does. For instance:
1740 (gdb) catch exception Constraint_Error if Barrier = True
1742 Previously, it was possible to add a condition to such catchpoints,
1743 but it had to be done as a second step, after the catchpoint had been
1744 created, using the "condition" command.
1746 * The "info static-tracepoint-marker" command will now also work on
1747 native Linux targets with in-process agent.
1749 * GDB can now set breakpoints on inlined functions.
1751 * The .gdb_index section has been updated to include symbols for
1752 inlined functions. GDB will ignore older .gdb_index sections by
1753 default, which could cause symbol files to be loaded more slowly
1754 until their .gdb_index sections can be recreated. The new command
1755 "set use-deprecated-index-sections on" will cause GDB to use any older
1756 .gdb_index sections it finds. This will restore performance, but the
1757 ability to set breakpoints on inlined functions will be lost in symbol
1758 files with older .gdb_index sections.
1760 The .gdb_index section has also been updated to record more information
1761 about each symbol. This speeds up the "info variables", "info functions"
1762 and "info types" commands when used with programs having the .gdb_index
1763 section, as well as speeding up debugging with shared libraries using
1764 the .gdb_index section.
1766 * Ada support for GDB/MI Variable Objects has been added.
1768 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1773 ** New command -info-os is the MI equivalent of "info os".
1775 ** Output logs ("set logging" and related) now include MI output.
1779 ** "set use-deprecated-index-sections on|off"
1780 "show use-deprecated-index-sections on|off"
1781 Controls the use of deprecated .gdb_index sections.
1783 ** "catch load" and "catch unload" can be used to stop when a shared
1784 library is loaded or unloaded, respectively.
1786 ** "enable count" can be used to auto-disable a breakpoint after
1789 ** "info vtbl" can be used to show the virtual method tables for
1790 C++ and Java objects.
1792 ** "explore" and its sub commands "explore value" and "explore type"
1793 can be used to recursively explore values and types of
1794 expressions. These commands are available only if GDB is
1795 configured with '--with-python'.
1797 ** "info auto-load" shows status of all kinds of auto-loaded files,
1798 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1799 sequences of commands files, "info auto-load python-scripts"
1800 shows status of auto-loading Python script files,
1801 "info auto-load local-gdbinit" shows status of loading init file
1802 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1803 status of inferior specific thread debugging shared library loading.
1805 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1806 and "show auto-load-scripts" commands have been deprecated, use their
1807 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1808 and "show auto-load python-scripts" counterparts instead.
1810 ** "dprintf location,format,args..." creates a dynamic printf, which
1811 is basically a breakpoint that does a printf and immediately
1812 resumes your program's execution, so it is like a printf that you
1813 can insert dynamically at runtime instead of at compiletime.
1815 ** "set print symbol"
1817 Controls whether GDB attempts to display the symbol, if any,
1818 corresponding to addresses it prints. This defaults to "on", but
1819 you can set it to "off" to restore GDB's previous behavior.
1821 * Deprecated commands
1823 ** For the Renesas Super-H architecture, the "regs" command has been
1824 deprecated, and "info all-registers" should be used instead.
1828 Renesas RL78 rl78-*-elf
1829 HP OpenVMS ia64 ia64-hp-openvms*
1831 * GDBserver supports evaluation of breakpoint conditions. When
1832 support is advertised by GDBserver, GDB may be told to send the
1833 breakpoint conditions in bytecode form to GDBserver. GDBserver
1834 will only report the breakpoint trigger to GDB when its condition
1839 set mips compression
1840 show mips compression
1841 Select the compressed ISA encoding used in functions that have no symbol
1842 information available. The encoding can be set to either of:
1845 and is updated automatically from ELF file flags if available.
1847 set breakpoint condition-evaluation
1848 show breakpoint condition-evaluation
1849 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1850 GDBserver ("target"). Default option "auto" chooses the most efficient
1852 This option can improve debugger efficiency depending on the speed of the
1856 Disable auto-loading globally.
1859 Show auto-loading setting of all kinds of auto-loaded files.
1861 set auto-load gdb-scripts on|off
1862 show auto-load gdb-scripts
1863 Control auto-loading of GDB canned sequences of commands files.
1865 set auto-load python-scripts on|off
1866 show auto-load python-scripts
1867 Control auto-loading of Python script files.
1869 set auto-load local-gdbinit on|off
1870 show auto-load local-gdbinit
1871 Control loading of init file (.gdbinit) from current directory.
1873 set auto-load libthread-db on|off
1874 show auto-load libthread-db
1875 Control auto-loading of inferior specific thread debugging shared library.
1877 set auto-load scripts-directory <dir1>[:<dir2>...]
1878 show auto-load scripts-directory
1879 Set a list of directories from which to load auto-loaded scripts.
1880 Automatically loaded Python scripts and GDB scripts are located in one
1881 of the directories listed by this option.
1882 The delimiter (':' above) may differ according to the host platform.
1884 set auto-load safe-path <dir1>[:<dir2>...]
1885 show auto-load safe-path
1886 Set a list of directories from which it is safe to auto-load files.
1887 The delimiter (':' above) may differ according to the host platform.
1889 set debug auto-load on|off
1890 show debug auto-load
1891 Control display of debugging info for auto-loading the files above.
1893 set dprintf-style gdb|call|agent
1895 Control the way in which a dynamic printf is performed; "gdb"
1896 requests a GDB printf command, while "call" causes dprintf to call a
1897 function in the inferior. "agent" requests that the target agent
1898 (such as GDBserver) do the printing.
1900 set dprintf-function <expr>
1901 show dprintf-function
1902 set dprintf-channel <expr>
1903 show dprintf-channel
1904 Set the function and optional first argument to the call when using
1905 the "call" style of dynamic printf.
1907 set disconnected-dprintf on|off
1908 show disconnected-dprintf
1909 Control whether agent-style dynamic printfs continue to be in effect
1910 after GDB disconnects.
1912 * New configure options
1914 --with-auto-load-dir
1915 Configure default value for the 'set auto-load scripts-directory'
1916 setting above. It defaults to '$debugdir:$datadir/auto-load',
1917 $debugdir representing global debugging info directories (available
1918 via 'show debug-file-directory') and $datadir representing GDB's data
1919 directory (available via 'show data-directory').
1921 --with-auto-load-safe-path
1922 Configure default value for the 'set auto-load safe-path' setting
1923 above. It defaults to the --with-auto-load-dir setting.
1925 --without-auto-load-safe-path
1926 Set 'set auto-load safe-path' to '/', effectively disabling this
1929 * New remote packets
1931 z0/z1 conditional breakpoints extension
1933 The z0/z1 breakpoint insertion packets have been extended to carry
1934 a list of conditional expressions over to the remote stub depending on the
1935 condition evaluation mode. The use of this extension can be controlled
1936 via the "set remote conditional-breakpoints-packet" command.
1940 Specify the signals which the remote stub may pass to the debugged
1941 program without GDB involvement.
1943 * New command line options
1945 --init-command=FILE, -ix Like --command, -x but execute it
1946 before loading inferior.
1947 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1948 execute it before loading inferior.
1950 *** Changes in GDB 7.4
1952 * GDB now handles ambiguous linespecs more consistently; the existing
1953 FILE:LINE support has been expanded to other types of linespecs. A
1954 breakpoint will now be set on all matching locations in all
1955 inferiors, and locations will be added or removed according to
1958 * GDB now allows you to skip uninteresting functions and files when
1959 stepping with the "skip function" and "skip file" commands.
1961 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1962 and "show remote hardware-watchpoint-length-limit". These allows to
1963 set or show the maximum length limit (in bytes) of a remote
1964 target hardware watchpoint.
1966 This allows e.g. to use "unlimited" hardware watchpoints with the
1967 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1968 watchpoints are slower than real hardware watchpoints but are
1969 significantly faster than gdb software watchpoints.
1973 ** The register_pretty_printer function in module gdb.printing now takes
1974 an optional `replace' argument. If True, the new printer replaces any
1977 ** The "maint set python print-stack on|off" command has been
1978 deprecated and will be deleted in GDB 7.5.
1979 A new command: "set python print-stack none|full|message" has
1980 replaced it. Additionally, the default for "print-stack" is
1981 now "message", which just prints the error message without
1984 ** A prompt substitution hook (prompt_hook) is now available to the
1987 ** A new Python module, gdb.prompt has been added to the GDB Python
1988 modules library. This module provides functionality for
1989 escape sequences in prompts (used by set/show
1990 extended-prompt). These escape sequences are replaced by their
1991 corresponding value.
1993 ** Python commands and convenience-functions located in
1994 'data-directory'/python/gdb/command and
1995 'data-directory'/python/gdb/function are now automatically loaded
1998 ** Blocks now provide four new attributes. global_block and
1999 static_block will return the global and static blocks
2000 respectively. is_static and is_global are boolean attributes
2001 that indicate if the block is one of those two types.
2003 ** Symbols now provide the "type" attribute, the type of the symbol.
2005 ** The "gdb.breakpoint" function has been deprecated in favor of
2008 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2009 of a function. This class is based on the "finish" command
2010 available in the CLI.
2012 ** Type objects for struct and union types now allow access to
2013 the fields using standard Python dictionary (mapping) methods.
2014 For example, "some_type['myfield']" now works, as does
2015 "some_type.items()".
2017 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2020 ** A new function, "deep_items" has been added to the gdb.types
2021 module in the GDB Python modules library. This function returns
2022 an iterator over the fields of a struct or union type. Unlike
2023 the standard Python "iteritems" method, it will recursively traverse
2024 any anonymous fields.
2028 ** "*stopped" events can report several new "reason"s, such as
2031 ** Breakpoint changes are now notified using new async records, like
2032 "=breakpoint-modified".
2034 ** New command -ada-task-info.
2036 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2037 $sdir specifies the default system locations of shared libraries.
2038 $pdir specifies the directory where the libpthread used by the application
2041 GDB no longer looks in $sdir and $pdir after it has searched the directories
2042 mentioned in libthread-db-search-path. If you want to search those
2043 directories, they must be specified in libthread-db-search-path.
2044 The default value of libthread-db-search-path on GNU/Linux and Solaris
2045 systems is now "$sdir:$pdir".
2047 $pdir is not supported by gdbserver, it is currently ignored.
2048 $sdir is supported by gdbserver.
2050 * New configure option --with-iconv-bin.
2051 When using the internationalization support like the one in the GNU C
2052 library, GDB will invoke the "iconv" program to get a list of supported
2053 character sets. If this program lives in a non-standard location, one can
2054 use this option to specify where to find it.
2056 * When natively debugging programs on PowerPC BookE processors running
2057 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2058 watchpoints, which specify a mask in addition to an address to watch.
2059 The mask specifies that some bits of an address (the bits which are
2060 reset in the mask) should be ignored when matching the address accessed
2061 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2062 section in the user manual for more details.
2064 * The new option --once causes GDBserver to stop listening for connections once
2065 the first connection is made. The listening port used by GDBserver will
2066 become available after that.
2068 * New commands "info macros" and "alias" have been added.
2070 * New function parameters suffix @entry specifies value of function parameter
2071 at the time the function got called. Entry values are available only since
2077 "!" is now an alias of the "shell" command.
2078 Note that no space is needed between "!" and SHELL COMMAND.
2082 watch EXPRESSION mask MASK_VALUE
2083 The watch command now supports the mask argument which allows creation
2084 of masked watchpoints, if the current architecture supports this feature.
2086 info auto-load-scripts [REGEXP]
2087 This command was formerly named "maintenance print section-scripts".
2088 It is now generally useful and is no longer a maintenance-only command.
2090 info macro [-all] [--] MACRO
2091 The info macro command has new options `-all' and `--'. The first for
2092 printing all definitions of a macro. The second for explicitly specifying
2093 the end of arguments and the beginning of the macro name in case the macro
2094 name starts with a hyphen.
2096 collect[/s] EXPRESSIONS
2097 The tracepoint collect command now takes an optional modifier "/s"
2098 that directs it to dereference pointer-to-character types and
2099 collect the bytes of memory up to a zero byte. The behavior is
2100 similar to what you see when you use the regular print command on a
2101 string. An optional integer following the "/s" sets a bound on the
2102 number of bytes that will be collected.
2105 The trace start command now interprets any supplied arguments as a
2106 note to be recorded with the trace run, with an effect similar to
2107 setting the variable trace-notes.
2110 The trace stop command now interprets any arguments as a note to be
2111 mentioned along with the tstatus report that the trace was stopped
2112 with a command. The effect is similar to setting the variable
2115 * Tracepoints can now be enabled and disabled at any time after a trace
2116 experiment has been started using the standard "enable" and "disable"
2117 commands. It is now possible to start a trace experiment with no enabled
2118 tracepoints; GDB will display a warning, but will allow the experiment to
2119 begin, assuming that tracepoints will be enabled as needed while the trace
2122 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2123 locations with 4-byte instructions, when they were previously
2124 limited to locations with instructions of 5 bytes or longer.
2128 set debug dwarf2-read
2129 show debug dwarf2-read
2130 Turns on or off display of debugging messages related to reading
2131 DWARF debug info. The default is off.
2133 set debug symtab-create
2134 show debug symtab-create
2135 Turns on or off display of debugging messages related to symbol table
2136 creation. The default is off.
2139 show extended-prompt
2140 Set the GDB prompt, and allow escape sequences to be inserted to
2141 display miscellaneous information (see 'help set extended-prompt'
2142 for the list of sequences). This prompt (and any information
2143 accessed through the escape sequences) is updated every time the
2144 prompt is displayed.
2146 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2147 show print entry-values
2148 Set printing of frame argument values at function entry. In some cases
2149 GDB can determine the value of function argument which was passed by the
2150 function caller, even if the value was modified inside the called function.
2152 set debug entry-values
2153 show debug entry-values
2154 Control display of debugging info for determining frame argument values at
2155 function entry and virtual tail call frames.
2157 set basenames-may-differ
2158 show basenames-may-differ
2159 Set whether a source file may have multiple base names.
2160 (A "base name" is the name of a file with the directory part removed.
2161 Example: The base name of "/home/user/hello.c" is "hello.c".)
2162 If set, GDB will canonicalize file names (e.g., expand symlinks)
2163 before comparing them. Canonicalization is an expensive operation,
2164 but it allows the same file be known by more than one base name.
2165 If not set (the default), all source files are assumed to have just
2166 one base name, and gdb will do file name comparisons more efficiently.
2172 Set a user name and notes for the current and any future trace runs.
2173 This is useful for long-running and/or disconnected traces, to
2174 inform others (or yourself) as to who is running the trace, supply
2175 contact information, or otherwise explain what is going on.
2177 set trace-stop-notes
2178 show trace-stop-notes
2179 Set a note attached to the trace run, that is displayed when the
2180 trace has been stopped by a tstop command. This is useful for
2181 instance as an explanation, if you are stopping a trace run that was
2182 started by someone else.
2184 * New remote packets
2188 Dynamically enable a tracepoint in a started trace experiment.
2192 Dynamically disable a tracepoint in a started trace experiment.
2196 Set the user and notes of the trace run.
2200 Query the current status of a tracepoint.
2204 Query the minimum length of instruction at which a fast tracepoint may
2207 * Dcache size (number of lines) and line-size are now runtime-configurable
2208 via "set dcache line" and "set dcache line-size" commands.
2212 Texas Instruments TMS320C6x tic6x-*-*
2216 Renesas RL78 rl78-*-elf
2218 *** Changes in GDB 7.3.1
2220 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2222 *** Changes in GDB 7.3
2224 * GDB has a new command: "thread find [REGEXP]".
2225 It finds the thread id whose name, target id, or thread extra info
2226 matches the given regular expression.
2228 * The "catch syscall" command now works on mips*-linux* targets.
2230 * The -data-disassemble MI command now supports modes 2 and 3 for
2231 dumping the instruction opcodes.
2233 * New command line options
2235 -data-directory DIR Specify DIR as the "data-directory".
2236 This is mostly for testing purposes.
2238 * The "maint set python auto-load on|off" command has been renamed to
2239 "set auto-load-scripts on|off".
2241 * GDB has a new command: "set directories".
2242 It is like the "dir" command except that it replaces the
2243 source path list instead of augmenting it.
2245 * GDB now understands thread names.
2247 On GNU/Linux, "info threads" will display the thread name as set by
2248 prctl or pthread_setname_np.
2250 There is also a new command, "thread name", which can be used to
2251 assign a name internally for GDB to display.
2254 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2255 has been integrated into GDB.
2259 ** The function gdb.Write now accepts an optional keyword 'stream'.
2260 This keyword, when provided, will direct the output to either
2261 stdout, stderr, or GDB's logging output.
2263 ** Parameters can now be be sub-classed in Python, and in particular
2264 you may implement the get_set_doc and get_show_doc functions.
2265 This improves how Parameter set/show documentation is processed
2266 and allows for more dynamic content.
2268 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2269 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2270 have an is_valid method.
2272 ** Breakpoints can now be sub-classed in Python, and in particular
2273 you may implement a 'stop' function that is executed each time
2274 the inferior reaches that breakpoint.
2276 ** New function gdb.lookup_global_symbol looks up a global symbol.
2278 ** GDB values in Python are now callable if the value represents a
2279 function. For example, if 'some_value' represents a function that
2280 takes two integer parameters and returns a value, you can call
2281 that function like so:
2283 result = some_value (10,20)
2285 ** Module gdb.types has been added.
2286 It contains a collection of utilities for working with gdb.Types objects:
2287 get_basic_type, has_field, make_enum_dict.
2289 ** Module gdb.printing has been added.
2290 It contains utilities for writing and registering pretty-printers.
2291 New classes: PrettyPrinter, SubPrettyPrinter,
2292 RegexpCollectionPrettyPrinter.
2293 New function: register_pretty_printer.
2295 ** New commands "info pretty-printers", "enable pretty-printer" and
2296 "disable pretty-printer" have been added.
2298 ** gdb.parameter("directories") is now available.
2300 ** New function gdb.newest_frame returns the newest frame in the
2303 ** The gdb.InferiorThread class has a new "name" attribute. This
2304 holds the thread's name.
2306 ** Python Support for Inferior events.
2307 Python scripts can add observers to be notified of events
2308 occurring in the process being debugged.
2309 The following events are currently supported:
2310 - gdb.events.cont Continue event.
2311 - gdb.events.exited Inferior exited event.
2312 - gdb.events.stop Signal received, and Breakpoint hit events.
2316 ** GDB now puts template parameters in scope when debugging in an
2317 instantiation. For example, if you have:
2319 template<int X> int func (void) { return X; }
2321 then if you step into func<5>, "print X" will show "5". This
2322 feature requires proper debuginfo support from the compiler; it
2323 was added to GCC 4.5.
2325 ** The motion commands "next", "finish", "until", and "advance" now
2326 work better when exceptions are thrown. In particular, GDB will
2327 no longer lose control of the inferior; instead, the GDB will
2328 stop the inferior at the point at which the exception is caught.
2329 This functionality requires a change in the exception handling
2330 code that was introduced in GCC 4.5.
2332 * GDB now follows GCC's rules on accessing volatile objects when
2333 reading or writing target state during expression evaluation.
2334 One notable difference to prior behavior is that "print x = 0"
2335 no longer generates a read of x; the value of the assignment is
2336 now always taken directly from the value being assigned.
2338 * GDB now has some support for using labels in the program's source in
2339 linespecs. For instance, you can use "advance label" to continue
2340 execution to a label.
2342 * GDB now has support for reading and writing a new .gdb_index
2343 section. This section holds a fast index of DWARF debugging
2344 information and can be used to greatly speed up GDB startup and
2345 operation. See the documentation for `save gdb-index' for details.
2347 * The "watch" command now accepts an optional "-location" argument.
2348 When used, this causes GDB to watch the memory referred to by the
2349 expression. Such a watchpoint is never deleted due to it going out
2352 * GDB now supports thread debugging of core dumps on GNU/Linux.
2354 GDB now activates thread debugging using the libthread_db library
2355 when debugging GNU/Linux core dumps, similarly to when debugging
2356 live processes. As a result, when debugging a core dump file, GDB
2357 is now able to display pthread_t ids of threads. For example, "info
2358 threads" shows the same output as when debugging the process when it
2359 was live. In earlier releases, you'd see something like this:
2362 * 1 LWP 6780 main () at main.c:10
2364 While now you see this:
2367 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2369 It is also now possible to inspect TLS variables when debugging core
2372 When debugging a core dump generated on a machine other than the one
2373 used to run GDB, you may need to point GDB at the correct
2374 libthread_db library with the "set libthread-db-search-path"
2375 command. See the user manual for more details on this command.
2377 * When natively debugging programs on PowerPC BookE processors running
2378 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2379 which stop execution of the inferior whenever it executes an instruction
2380 at any address within the specified range. See the "PowerPC Embedded"
2381 section in the user manual for more details.
2383 * New features in the GDB remote stub, GDBserver
2385 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2386 and i686 LynxOS (version 5.x).
2388 ** GDBserver is now supported on Blackfin Linux.
2390 * New native configurations
2392 ia64 HP-UX ia64-*-hpux*
2396 Analog Devices, Inc. Blackfin Processor bfin-*
2398 * Ada task switching is now supported on sparc-elf targets when
2399 debugging a program using the Ravenscar Profile. For more information,
2400 see the "Tasking Support when using the Ravenscar Profile" section
2401 in the GDB user manual.
2403 * Guile support was removed.
2405 * New features in the GNU simulator
2407 ** The --map-info flag lists all known core mappings.
2409 ** CFI flashes may be simulated via the "cfi" device.
2411 *** Changes in GDB 7.2
2413 * Shared library support for remote targets by default
2415 When GDB is configured for a generic, non-OS specific target, like
2416 for example, --target=arm-eabi or one of the many *-*-elf targets,
2417 GDB now queries remote stubs for loaded shared libraries using the
2418 `qXfer:libraries:read' packet. Previously, shared library support
2419 was always disabled for such configurations.
2423 ** Argument Dependent Lookup (ADL)
2425 In C++ ADL lookup directs function search to the namespaces of its
2426 arguments even if the namespace has not been imported.
2436 Here the compiler will search for `foo' in the namespace of 'b'
2437 and find A::foo. GDB now supports this. This construct is commonly
2438 used in the Standard Template Library for operators.
2440 ** Improved User Defined Operator Support
2442 In addition to member operators, GDB now supports lookup of operators
2443 defined in a namespace and imported with a `using' directive, operators
2444 defined in the global scope, operators imported implicitly from an
2445 anonymous namespace, and the ADL operators mentioned in the previous
2447 GDB now also supports proper overload resolution for all the previously
2448 mentioned flavors of operators.
2450 ** static const class members
2452 Printing of static const class members that are initialized in the
2453 class definition has been fixed.
2455 * Windows Thread Information Block access.
2457 On Windows targets, GDB now supports displaying the Windows Thread
2458 Information Block (TIB) structure. This structure is visible either
2459 by using the new command `info w32 thread-information-block' or, by
2460 dereferencing the new convenience variable named `$_tlb', a
2461 thread-specific pointer to the TIB. This feature is also supported
2462 when remote debugging using GDBserver.
2464 * Static tracepoints
2466 Static tracepoints are calls in the user program into a tracing
2467 library. One such library is a port of the LTTng kernel tracer to
2468 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2469 When debugging with GDBserver, GDB now supports combining the GDB
2470 tracepoint machinery with such libraries. For example: the user can
2471 use GDB to probe a static tracepoint marker (a call from the user
2472 program into the tracing library) with the new "strace" command (see
2473 "New commands" below). This creates a "static tracepoint" in the
2474 breakpoint list, that can be manipulated with the same feature set
2475 as fast and regular tracepoints. E.g., collect registers, local and
2476 global variables, collect trace state variables, and define
2477 tracepoint conditions. In addition, the user can collect extra
2478 static tracepoint marker specific data, by collecting the new
2479 $_sdata internal variable. When analyzing the trace buffer, you can
2480 inspect $_sdata like any other variable available to GDB. For more
2481 information, see the "Tracepoints" chapter in GDB user manual. New
2482 remote packets have been defined to support static tracepoints, see
2483 the "New remote packets" section below.
2485 * Better reconstruction of tracepoints after disconnected tracing
2487 GDB will attempt to download the original source form of tracepoint
2488 definitions when starting a trace run, and then will upload these
2489 upon reconnection to the target, resulting in a more accurate
2490 reconstruction of the tracepoints that are in use on the target.
2494 You can now exercise direct control over the ways that GDB can
2495 affect your program. For instance, you can disallow the setting of
2496 breakpoints, so that the program can run continuously (assuming
2497 non-stop mode). In addition, the "observer" variable is available
2498 to switch all of the different controls; in observer mode, GDB
2499 cannot affect the target's behavior at all, which is useful for
2500 tasks like diagnosing live systems in the field.
2502 * The new convenience variable $_thread holds the number of the
2505 * New remote packets
2509 Return the address of the Windows Thread Information Block of a given thread.
2513 In response to several of the tracepoint packets, the target may now
2514 also respond with a number of intermediate `qRelocInsn' request
2515 packets before the final result packet, to have GDB handle
2516 relocating an instruction to execute at a different address. This
2517 is particularly useful for stubs that support fast tracepoints. GDB
2518 reports support for this feature in the qSupported packet.
2522 List static tracepoint markers in the target program.
2526 List static tracepoint markers at a given address in the target
2529 qXfer:statictrace:read
2531 Read the static trace data collected (by a `collect $_sdata'
2532 tracepoint action). The remote stub reports support for this packet
2533 to gdb's qSupported query.
2537 Send the current settings of GDB's permission flags.
2541 Send part of the source (textual) form of a tracepoint definition,
2542 which includes location, conditional, and action list.
2544 * The source command now accepts a -s option to force searching for the
2545 script in the source search path even if the script name specifies
2548 * New features in the GDB remote stub, GDBserver
2550 - GDBserver now support tracepoints (including fast tracepoints, and
2551 static tracepoints). The feature is currently supported by the
2552 i386-linux and amd64-linux builds. See the "Tracepoints support
2553 in gdbserver" section in the manual for more information.
2555 GDBserver JIT compiles the tracepoint's conditional agent
2556 expression bytecode into native code whenever possible for low
2557 overhead dynamic tracepoints conditionals. For such tracepoints,
2558 an expression that examines program state is evaluated when the
2559 tracepoint is reached, in order to determine whether to capture
2560 trace data. If the condition is simple and false, processing the
2561 tracepoint finishes very quickly and no data is gathered.
2563 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2564 for static tracepoints support.
2566 - GDBserver now supports x86_64 Windows 64-bit debugging.
2568 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2569 it understands register description.
2571 * The --batch flag now disables pagination and queries.
2573 * X86 general purpose registers
2575 GDB now supports reading/writing byte, word and double-word x86
2576 general purpose registers directly. This means you can use, say,
2577 $ah or $ax to refer, respectively, to the byte register AH and
2578 16-bit word register AX that are actually portions of the 32-bit
2579 register EAX or 64-bit register RAX.
2581 * The `commands' command now accepts a range of breakpoints to modify.
2582 A plain `commands' following a command that creates multiple
2583 breakpoints affects all the breakpoints set by that command. This
2584 applies to breakpoints set by `rbreak', and also applies when a
2585 single `break' command creates multiple breakpoints (e.g.,
2586 breakpoints on overloaded c++ functions).
2588 * The `rbreak' command now accepts a filename specification as part of
2589 its argument, limiting the functions selected by the regex to those
2590 in the specified file.
2592 * Support for remote debugging Windows and SymbianOS shared libraries
2593 from Unix hosts has been improved. Non Windows GDB builds now can
2594 understand target reported file names that follow MS-DOS based file
2595 system semantics, such as file names that include drive letters and
2596 use the backslash character as directory separator. This makes it
2597 possible to transparently use the "set sysroot" and "set
2598 solib-search-path" on Unix hosts to point as host copies of the
2599 target's shared libraries. See the new command "set
2600 target-file-system-kind" described below, and the "Commands to
2601 specify files" section in the user manual for more information.
2605 eval template, expressions...
2606 Convert the values of one or more expressions under the control
2607 of the string template to a command line, and call it.
2609 set target-file-system-kind unix|dos-based|auto
2610 show target-file-system-kind
2611 Set or show the assumed file system kind for target reported file
2614 save breakpoints <filename>
2615 Save all current breakpoint definitions to a file suitable for use
2616 in a later debugging session. To read the saved breakpoint
2617 definitions, use the `source' command.
2619 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2622 info static-tracepoint-markers
2623 Display information about static tracepoint markers in the target.
2625 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2626 Define a static tracepoint by probing a marker at the given
2627 function, line, address, or marker ID.
2631 Enable and disable observer mode.
2633 set may-write-registers on|off
2634 set may-write-memory on|off
2635 set may-insert-breakpoints on|off
2636 set may-insert-tracepoints on|off
2637 set may-insert-fast-tracepoints on|off
2638 set may-interrupt on|off
2639 Set individual permissions for GDB effects on the target. Note that
2640 some of these settings can have undesirable or surprising
2641 consequences, particularly when changed in the middle of a session.
2642 For instance, disabling the writing of memory can prevent
2643 breakpoints from being inserted, cause single-stepping to fail, or
2644 even crash your program, if you disable after breakpoints have been
2645 inserted. However, GDB should not crash.
2647 set record memory-query on|off
2648 show record memory-query
2649 Control whether to stop the inferior if memory changes caused
2650 by an instruction cannot be recorded.
2655 The disassemble command now supports "start,+length" form of two arguments.
2659 ** GDB now provides a new directory location, called the python directory,
2660 where Python scripts written for GDB can be installed. The location
2661 of that directory is <data-directory>/python, where <data-directory>
2662 is the GDB data directory. For more details, see section `Scripting
2663 GDB using Python' in the manual.
2665 ** The GDB Python API now has access to breakpoints, symbols, symbol
2666 tables, program spaces, inferiors, threads and frame's code blocks.
2667 Additionally, GDB Parameters can now be created from the API, and
2668 manipulated via set/show in the CLI.
2670 ** New functions gdb.target_charset, gdb.target_wide_charset,
2671 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2673 ** New exception gdb.GdbError.
2675 ** Pretty-printers are now also looked up in the current program space.
2677 ** Pretty-printers can now be individually enabled and disabled.
2679 ** GDB now looks for names of Python scripts to auto-load in a
2680 special section named `.debug_gdb_scripts', in addition to looking
2681 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2683 * Tracepoint actions were unified with breakpoint commands. In particular,
2684 there are no longer differences in "info break" output for breakpoints and
2685 tracepoints and the "commands" command can be used for both tracepoints and
2686 regular breakpoints.
2690 ARM Symbian arm*-*-symbianelf*
2692 * D language support.
2693 GDB now supports debugging programs written in the D programming
2696 * GDB now supports the extended ptrace interface for PowerPC which is
2697 available since Linux kernel version 2.6.34. This automatically enables
2698 any hardware breakpoints and additional hardware watchpoints available in
2699 the processor. The old ptrace interface exposes just one hardware
2700 watchpoint and no hardware breakpoints.
2702 * GDB is now able to use the Data Value Compare (DVC) register available on
2703 embedded PowerPC processors to implement in hardware simple watchpoint
2704 conditions of the form:
2706 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2708 This works in native GDB running on Linux kernels with the extended ptrace
2709 interface mentioned above.
2711 *** Changes in GDB 7.1
2715 ** Namespace Support
2717 GDB now supports importing of namespaces in C++. This enables the
2718 user to inspect variables from imported namespaces. Support for
2719 namepace aliasing has also been added. So, if a namespace is
2720 aliased in the current scope (e.g. namepace C=A; ) the user can
2721 print variables using the alias (e.g. (gdb) print C::x).
2725 All known bugs relating to the printing of virtual base class were
2726 fixed. It is now possible to call overloaded static methods using a
2731 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2732 and reinterpret_cast<> are now handled by the C++ expression parser.
2736 Xilinx MicroBlaze microblaze-*-*
2741 Xilinx MicroBlaze microblaze
2744 * Multi-program debugging.
2746 GDB now has support for multi-program (a.k.a. multi-executable or
2747 multi-exec) debugging. This allows for debugging multiple inferiors
2748 simultaneously each running a different program under the same GDB
2749 session. See "Debugging Multiple Inferiors and Programs" in the
2750 manual for more information. This implied some user visible changes
2751 in the multi-inferior support. For example, "info inferiors" now
2752 lists inferiors that are not running yet or that have exited
2753 already. See also "New commands" and "New options" below.
2755 * New tracing features
2757 GDB's tracepoint facility now includes several new features:
2759 ** Trace state variables
2761 GDB tracepoints now include support for trace state variables, which
2762 are variables managed by the target agent during a tracing
2763 experiment. They are useful for tracepoints that trigger each
2764 other, so for instance one tracepoint can count hits in a variable,
2765 and then a second tracepoint has a condition that is true when the
2766 count reaches a particular value. Trace state variables share the
2767 $-syntax of GDB convenience variables, and can appear in both
2768 tracepoint actions and condition expressions. Use the "tvariable"
2769 command to create, and "info tvariables" to view; see "Trace State
2770 Variables" in the manual for more detail.
2774 GDB now includes an option for defining fast tracepoints, which
2775 targets may implement more efficiently, such as by installing a jump
2776 into the target agent rather than a trap instruction. The resulting
2777 speedup can be by two orders of magnitude or more, although the
2778 tradeoff is that some program locations on some target architectures
2779 might not allow fast tracepoint installation, for instance if the
2780 instruction to be replaced is shorter than the jump. To request a
2781 fast tracepoint, use the "ftrace" command, with syntax identical to
2782 the regular trace command.
2784 ** Disconnected tracing
2786 It is now possible to detach GDB from the target while it is running
2787 a trace experiment, then reconnect later to see how the experiment
2788 is going. In addition, a new variable disconnected-tracing lets you
2789 tell the target agent whether to continue running a trace if the
2790 connection is lost unexpectedly.
2794 GDB now has the ability to save the trace buffer into a file, and
2795 then use that file as a target, similarly to you can do with
2796 corefiles. You can select trace frames, print data that was
2797 collected in them, and use tstatus to display the state of the
2798 tracing run at the moment that it was saved. To create a trace
2799 file, use "tsave <filename>", and to use it, do "target tfile
2802 ** Circular trace buffer
2804 You can ask the target agent to handle the trace buffer as a
2805 circular buffer, discarding the oldest trace frames to make room for
2806 newer ones, by setting circular-trace-buffer to on. This feature may
2807 not be available for all target agents.
2812 The disassemble command, when invoked with two arguments, now requires
2813 the arguments to be comma-separated.
2816 The info variables command now displays variable definitions. Files
2817 which only declare a variable are not shown.
2820 The source command is now capable of sourcing Python scripts.
2821 This feature is dependent on the debugger being build with Python
2824 Related to this enhancement is also the introduction of a new command
2825 "set script-extension" (see below).
2827 * New commands (for set/show, see "New options" below)
2829 record save [<FILENAME>]
2830 Save a file (in core file format) containing the process record
2831 execution log for replay debugging at a later time.
2833 record restore <FILENAME>
2834 Restore the process record execution log that was saved at an
2835 earlier time, for replay debugging.
2837 add-inferior [-copies <N>] [-exec <FILENAME>]
2840 clone-inferior [-copies <N>] [ID]
2841 Make a new inferior ready to execute the same program another
2842 inferior has loaded.
2847 maint info program-spaces
2848 List the program spaces loaded into GDB.
2850 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2851 show remote interrupt-sequence
2852 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2853 as the sequence to the remote target in order to interrupt the execution.
2854 Ctrl-C is a default. Some system prefers BREAK which is high level of
2855 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2856 Magic SysRq g. It is BREAK signal and character 'g'.
2858 set remote interrupt-on-connect [on | off]
2859 show remote interrupt-on-connect
2860 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2861 remote target when gdb connects to it. This is needed when you debug
2864 set remotebreak [on | off]
2866 Deprecated. Use "set/show remote interrupt-sequence" instead.
2868 tvariable $NAME [ = EXP ]
2869 Create or modify a trace state variable.
2872 List trace state variables and their values.
2874 delete tvariable $NAME ...
2875 Delete one or more trace state variables.
2878 Evaluate the given expressions without collecting anything into the
2879 trace buffer. (Valid in tracepoint actions only.)
2881 ftrace FN / FILE:LINE / *ADDR
2882 Define a fast tracepoint at the given function, line, or address.
2884 * New expression syntax
2886 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2887 GDB now parses 0b101010 identically with 42.
2891 set follow-exec-mode new|same
2892 show follow-exec-mode
2893 Control whether GDB reuses the same inferior across an exec call or
2894 creates a new one. This is useful to be able to restart the old
2895 executable after the inferior having done an exec call.
2897 set default-collect EXPR, ...
2898 show default-collect
2899 Define a list of expressions to be collected at each tracepoint.
2900 This is a useful way to ensure essential items are not overlooked,
2901 such as registers or a critical global variable.
2903 set disconnected-tracing
2904 show disconnected-tracing
2905 If set to 1, the target is instructed to continue tracing if it
2906 loses its connection to GDB. If 0, the target is to stop tracing
2909 set circular-trace-buffer
2910 show circular-trace-buffer
2911 If set to on, the target is instructed to use a circular trace buffer
2912 and discard the oldest trace frames instead of stopping the trace due
2913 to a full trace buffer. If set to off, the trace stops when the buffer
2914 fills up. Some targets may not support this.
2916 set script-extension off|soft|strict
2917 show script-extension
2918 If set to "off", the debugger does not perform any script language
2919 recognition, and all sourced files are assumed to be GDB scripts.
2920 If set to "soft" (the default), files are sourced according to
2921 filename extension, falling back to GDB scripts if the first
2923 If set to "strict", files are sourced according to filename extension.
2925 set ada trust-PAD-over-XVS on|off
2926 show ada trust-PAD-over-XVS
2927 If off, activate a workaround against a bug in the debugging information
2928 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2929 the GCC sources for more information about the GNAT encoding and
2930 PAD types in particular). It is always safe to set this option to
2931 off, but this introduces a slight performance penalty. The default
2934 * Python API Improvements
2936 ** GDB provides the new class gdb.LazyString. This is useful in
2937 some pretty-printing cases. The new method gdb.Value.lazy_string
2938 provides a simple way to create objects of this type.
2940 ** The fields returned by gdb.Type.fields now have an
2941 `is_base_class' attribute.
2943 ** The new method gdb.Type.range returns the range of an array type.
2945 ** The new method gdb.parse_and_eval can be used to parse and
2946 evaluate an expression.
2948 * New remote packets
2951 Define a trace state variable.
2954 Get the current value of a trace state variable.
2957 Set desired tracing behavior upon disconnection.
2960 Set the trace buffer to be linear or circular.
2963 Get data about the tracepoints currently in use.
2967 Process record now works correctly with hardware watchpoints.
2969 Multiple bug fixes have been made to the mips-irix port, making it
2970 much more reliable. In particular:
2971 - Debugging threaded applications is now possible again. Previously,
2972 GDB would hang while starting the program, or while waiting for
2973 the program to stop at a breakpoint.
2974 - Attaching to a running process no longer hangs.
2975 - An error occurring while loading a core file has been fixed.
2976 - Changing the value of the PC register now works again. This fixes
2977 problems observed when using the "jump" command, or when calling
2978 a function from GDB, or even when assigning a new value to $pc.
2979 - With the "finish" and "return" commands, the return value for functions
2980 returning a small array is now correctly printed.
2981 - It is now possible to break on shared library code which gets executed
2982 during a shared library init phase (code executed while executing
2983 their .init section). Previously, the breakpoint would have no effect.
2984 - GDB is now able to backtrace through the signal handler for
2985 non-threaded programs.
2987 PIE (Position Independent Executable) programs debugging is now supported.
2988 This includes debugging execution of PIC (Position Independent Code) shared
2989 libraries although for that, it should be possible to run such libraries as an
2992 *** Changes in GDB 7.0
2994 * GDB now has an interface for JIT compilation. Applications that
2995 dynamically generate code can create symbol files in memory and register
2996 them with GDB. For users, the feature should work transparently, and
2997 for JIT developers, the interface is documented in the GDB manual in the
2998 "JIT Compilation Interface" chapter.
3000 * Tracepoints may now be conditional. The syntax is as for
3001 breakpoints; either an "if" clause appended to the "trace" command,
3002 or the "condition" command is available. GDB sends the condition to
3003 the target for evaluation using the same bytecode format as is used
3004 for tracepoint actions.
3006 * The disassemble command now supports: an optional /r modifier, print the
3007 raw instructions in hex as well as in symbolic form, and an optional /m
3008 modifier to print mixed source+assembly.
3010 * Process record and replay
3012 In a architecture environment that supports ``process record and
3013 replay'', ``process record and replay'' target can record a log of
3014 the process execution, and replay it with both forward and reverse
3017 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3018 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3019 set execution-direction {forward|reverse}, for targets that support
3022 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3023 feature is available with a native GDB running on kernel version
3026 * GDB now has support for multi-byte and wide character sets on the
3027 target. Strings whose character type is wchar_t, char16_t, or
3028 char32_t are now correctly printed. GDB supports wide- and unicode-
3029 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3030 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3031 `printf'. This feature requires iconv to work properly; if your
3032 system does not have a working iconv, GDB can use GNU libiconv. See
3033 the installation instructions for more information.
3035 * GDB now supports automatic retrieval of shared library files from
3036 remote targets. To use this feature, specify a system root that begins
3037 with the `remote:' prefix, either via the `set sysroot' command or via
3038 the `--with-sysroot' configure-time option.
3040 * "info sharedlibrary" now takes an optional regex of libraries to show,
3041 and it now reports if a shared library has no debugging information.
3043 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3044 now complete on file names.
3046 * When completing in expressions, gdb will attempt to limit
3047 completions to allowable structure or union fields, where appropriate.
3048 For instance, consider:
3050 # struct example { int f1; double f2; };
3051 # struct example variable;
3054 If the user types TAB at the end of this command line, the available
3055 completions will be "f1" and "f2".
3057 * Inlined functions are now supported. They show up in backtraces, and
3058 the "step", "next", and "finish" commands handle them automatically.
3060 * GDB now supports the token-splicing (##) and stringification (#)
3061 operators when expanding macros. It also supports variable-arity
3064 * GDB now supports inspecting extra signal information, exported by
3065 the new $_siginfo convenience variable. The feature is currently
3066 implemented on linux ARM, i386 and amd64.
3068 * GDB can now display the VFP floating point registers and NEON vector
3069 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3070 can provide these registers (requires Linux 2.6.30 or later). Remote
3071 and simulator targets may also provide them.
3073 * New remote packets
3076 Search memory for a sequence of bytes.
3079 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3080 operation over reliable transport links. Use of this packet is
3081 controlled by the `set remote noack-packet' command.
3084 Kill the process with the specified process ID. Use this in preference
3085 to `k' when multiprocess protocol extensions are supported.
3088 Obtains additional operating system information
3092 Read or write additional signal information.
3094 * Removed remote protocol undocumented extension
3096 An undocumented extension to the remote protocol's `S' stop reply
3097 packet that permited the stub to pass a process id was removed.
3098 Remote servers should use the `T' stop reply packet instead.
3100 * GDB now supports multiple function calling conventions according to the
3101 DWARF-2 DW_AT_calling_convention function attribute.
3103 * The SH target utilizes the aforementioned change to distinguish between gcc
3104 and Renesas calling convention. It also adds the new CLI commands
3105 `set/show sh calling-convention'.
3107 * GDB can now read compressed debug sections, as produced by GNU gold
3108 with the --compress-debug-sections=zlib flag.
3110 * 64-bit core files are now supported on AIX.
3112 * Thread switching is now supported on Tru64.
3114 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3115 which will be allocated using malloc later in program execution.
3117 * The qXfer:libraries:read remote procotol packet now allows passing a
3118 list of section offsets.
3120 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3121 conditions handling signals delivered during attach or thread creation
3122 have also been fixed.
3124 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3125 From the user's standpoint, all unqualified instances of True and False
3126 are treated as the standard definitions, regardless of context.
3128 * GDB now parses C++ symbol and type names more flexibly. For
3131 template<typename T> class C { };
3134 GDB will now correctly handle all of:
3136 ptype C<char const *>
3137 ptype C<char const*>
3138 ptype C<const char *>
3139 ptype C<const char*>
3141 * New features in the GDB remote stub, gdbserver
3143 - The "--wrapper" command-line argument tells gdbserver to use a
3144 wrapper program to launch programs for debugging.
3146 - On PowerPC and S/390 targets, it is now possible to use a single
3147 gdbserver executable to debug both 32-bit and 64-bit programs.
3148 (This requires gdbserver itself to be built as a 64-bit executable.)
3150 - gdbserver uses the new noack protocol mode for TCP connections to
3151 reduce communications latency, if also supported and enabled in GDB.
3153 - Support for the sparc64-linux-gnu target is now included in
3156 - The amd64-linux build of gdbserver now supports debugging both
3157 32-bit and 64-bit programs.
3159 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3160 now support hardware watchpoints, and will use them automatically
3165 GDB now has support for scripting using Python. Whether this is
3166 available is determined at configure time.
3168 New GDB commands can now be written in Python.
3170 * Ada tasking support
3172 Ada tasks can now be inspected in GDB. The following commands have
3176 Print the list of Ada tasks.
3178 Print detailed information about task number N.
3180 Print the task number of the current task.
3182 Switch the context of debugging to task number N.
3184 * Support for user-defined prefixed commands. The "define" command can
3185 add new commands to existing prefixes, e.g. "target".
3187 * Multi-inferior, multi-process debugging.
3189 GDB now has generalized support for multi-inferior debugging. See
3190 "Debugging Multiple Inferiors" in the manual for more information.
3191 Although availability still depends on target support, the command
3192 set is more uniform now. The GNU/Linux specific multi-forks support
3193 has been migrated to this new framework. This implied some user
3194 visible changes; see "New commands" and also "Removed commands"
3197 * Target descriptions can now describe the target OS ABI. See the
3198 "Target Description Format" section in the user manual for more
3201 * Target descriptions can now describe "compatible" architectures
3202 to indicate that the target can execute applications for a different
3203 architecture in addition to those for the main target architecture.
3204 See the "Target Description Format" section in the user manual for
3207 * Multi-architecture debugging.
3209 GDB now includes general supports for debugging applications on
3210 hybrid systems that use more than one single processor architecture
3211 at the same time. Each such hybrid architecture still requires
3212 specific support to be added. The only hybrid architecture supported
3213 in this version of GDB is the Cell Broadband Engine.
3215 * GDB now supports integrated debugging of Cell/B.E. applications that
3216 use both the PPU and SPU architectures. To enable support for hybrid
3217 Cell/B.E. debugging, you need to configure GDB to support both the
3218 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3219 --enable-targets configure option.
3221 * Non-stop mode debugging.
3223 For some targets, GDB now supports an optional mode of operation in
3224 which you can examine stopped threads while other threads continue
3225 to execute freely. This is referred to as non-stop mode, with the
3226 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3227 section in the user manual for more information.
3229 To be able to support remote non-stop debugging, a remote stub needs
3230 to implement the non-stop mode remote protocol extensions, as
3231 described in the "Remote Non-Stop" section of the user manual. The
3232 GDB remote stub, gdbserver, has been adjusted to support these
3233 extensions on linux targets.
3235 * New commands (for set/show, see "New options" below)
3237 catch syscall [NAME(S) | NUMBER(S)]
3238 Catch system calls. Arguments, which should be names of system
3239 calls or their numbers, mean catch only those syscalls. Without
3240 arguments, every syscall will be caught. When the inferior issues
3241 any of the specified syscalls, GDB will stop and announce the system
3242 call, both when it is called and when its call returns. This
3243 feature is currently available with a native GDB running on the
3244 Linux Kernel, under the following architectures: x86, x86_64,
3245 PowerPC and PowerPC64.
3247 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3249 Search memory for a sequence of bytes.
3251 maint set python print-stack
3252 maint show python print-stack
3253 Show a stack trace when an error is encountered in a Python script.
3256 Invoke CODE by passing it to the Python interpreter.
3261 These allow macros to be defined, undefined, and listed
3265 Show operating system information about processes.
3268 List the inferiors currently under GDB's control.
3271 Switch focus to inferior number NUM.
3274 Detach from inferior number NUM.
3277 Kill inferior number NUM.
3281 set spu stop-on-load
3282 show spu stop-on-load
3283 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3285 set spu auto-flush-cache
3286 show spu auto-flush-cache
3287 Control whether to automatically flush the software-managed cache
3288 during Cell/B.E. debugging.
3290 set sh calling-convention
3291 show sh calling-convention
3292 Control the calling convention used when calling SH target functions.
3295 show debug timestamp
3296 Control display of timestamps with GDB debugging output.
3298 set disassemble-next-line
3299 show disassemble-next-line
3300 Control display of disassembled source lines or instructions when
3303 set remote noack-packet
3304 show remote noack-packet
3305 Set/show the use of remote protocol QStartNoAckMode packet. See above
3306 under "New remote packets."
3308 set remote query-attached-packet
3309 show remote query-attached-packet
3310 Control use of remote protocol `qAttached' (query-attached) packet.
3312 set remote read-siginfo-object
3313 show remote read-siginfo-object
3314 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3317 set remote write-siginfo-object
3318 show remote write-siginfo-object
3319 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3322 set remote reverse-continue
3323 show remote reverse-continue
3324 Control use of remote protocol 'bc' (reverse-continue) packet.
3326 set remote reverse-step
3327 show remote reverse-step
3328 Control use of remote protocol 'bs' (reverse-step) packet.
3330 set displaced-stepping
3331 show displaced-stepping
3332 Control displaced stepping mode. Displaced stepping is a way to
3333 single-step over breakpoints without removing them from the debuggee.
3334 Also known as "out-of-line single-stepping".
3337 show debug displaced
3338 Control display of debugging info for displaced stepping.
3340 maint set internal-error
3341 maint show internal-error
3342 Control what GDB does when an internal error is detected.
3344 maint set internal-warning
3345 maint show internal-warning
3346 Control what GDB does when an internal warning is detected.
3351 Use a wrapper program to launch programs for debugging.
3353 set multiple-symbols (all|ask|cancel)
3354 show multiple-symbols
3355 The value of this variable can be changed to adjust the debugger behavior
3356 when an expression or a breakpoint location contains an ambiguous symbol
3357 name (an overloaded function name, for instance).
3359 set breakpoint always-inserted
3360 show breakpoint always-inserted
3361 Keep breakpoints always inserted in the target, as opposed to inserting
3362 them when resuming the target, and removing them when the target stops.
3363 This option can improve debugger performance on slow remote targets.
3365 set arm fallback-mode (arm|thumb|auto)
3366 show arm fallback-mode
3367 set arm force-mode (arm|thumb|auto)
3369 These commands control how ARM GDB determines whether instructions
3370 are ARM or Thumb. The default for both settings is auto, which uses
3371 the current CPSR value for instructions without symbols; previous
3372 versions of GDB behaved as if "set arm fallback-mode arm".
3374 set disable-randomization
3375 show disable-randomization
3376 Standalone programs run with the virtual address space randomization enabled
3377 by default on some platforms. This option keeps the addresses stable across
3378 multiple debugging sessions.
3382 Control whether other threads are stopped or not when some thread hits
3387 Requests that asynchronous execution is enabled in the target, if available.
3388 In this case, it's possible to resume target in the background, and interact
3389 with GDB while the target is running. "show target-async" displays the
3390 current state of asynchronous execution of the target.
3392 set target-wide-charset
3393 show target-wide-charset
3394 The target-wide-charset is the name of the character set that GDB
3395 uses when printing characters whose type is wchar_t.
3397 set tcp auto-retry (on|off)
3399 set tcp connect-timeout
3400 show tcp connect-timeout
3401 These commands allow GDB to retry failed TCP connections to a remote stub
3402 with a specified timeout period; this is useful if the stub is launched
3403 in parallel with GDB but may not be ready to accept connections immediately.
3405 set libthread-db-search-path
3406 show libthread-db-search-path
3407 Control list of directories which GDB will search for appropriate
3410 set schedule-multiple (on|off)
3411 show schedule-multiple
3412 Allow GDB to resume all threads of all processes or only threads of
3413 the current process.
3417 Use more aggressive caching for accesses to the stack. This improves
3418 performance of remote debugging (particularly backtraces) without
3419 affecting correctness.
3421 set interactive-mode (on|off|auto)
3422 show interactive-mode
3423 Control whether GDB runs in interactive mode (on) or not (off).
3424 When in interactive mode, GDB waits for the user to answer all
3425 queries. Otherwise, GDB does not wait and assumes the default
3426 answer. When set to auto (the default), GDB determines which
3427 mode to use based on the stdin settings.
3432 For program forks, this is replaced by the new more generic `info
3433 inferiors' command. To list checkpoints, you can still use the
3434 `info checkpoints' command, which was an alias for the `info forks'
3438 Replaced by the new `inferior' command. To switch between
3439 checkpoints, you can still use the `restart' command, which was an
3440 alias for the `fork' command.
3443 This is removed, since some targets don't have a notion of
3444 processes. To switch between processes, you can still use the
3445 `inferior' command using GDB's own inferior number.
3448 For program forks, this is replaced by the new more generic `kill
3449 inferior' command. To delete a checkpoint, you can still use the
3450 `delete checkpoint' command, which was an alias for the `delete
3454 For program forks, this is replaced by the new more generic `detach
3455 inferior' command. To detach a checkpoint, you can still use the
3456 `detach checkpoint' command, which was an alias for the `detach
3459 * New native configurations
3461 x86/x86_64 Darwin i[34567]86-*-darwin*
3463 x86_64 MinGW x86_64-*-mingw*
3467 Lattice Mico32 lm32-*
3468 x86 DICOS i[34567]86-*-dicos*
3469 x86_64 DICOS x86_64-*-dicos*
3472 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3473 (mingw32ce) debugging.
3479 These commands were actually not implemented on any target.
3481 *** Changes in GDB 6.8
3483 * New native configurations
3485 NetBSD/hppa hppa*-*netbsd*
3486 Xtensa GNU/Linux xtensa*-*-linux*
3490 NetBSD/hppa hppa*-*-netbsd*
3491 Xtensa GNU/Lunux xtensa*-*-linux*
3493 * Change in command line behavior -- corefiles vs. process ids.
3495 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3496 attaching to process NUMBER fails, GDB no longer attempts to open a
3497 core file named NUMBER. Attaching to a program using the -c option
3498 is no longer supported. Instead, use the '-p' or '--pid' options.
3500 * GDB can now be built as a native debugger for debugging Windows x86
3501 (mingw32) Portable Executable (PE) programs.
3503 * Pending breakpoints no longer change their number when their address
3506 * GDB now supports breakpoints with multiple locations,
3507 including breakpoints on C++ constructors, inside C++ templates,
3508 and in inlined functions.
3510 * GDB's ability to debug optimized code has been improved. GDB more
3511 accurately identifies function bodies and lexical blocks that occupy
3512 more than one contiguous range of addresses.
3514 * Target descriptions can now describe registers for PowerPC.
3516 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3517 registers on PowerPC targets.
3519 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3520 targets even when the libthread_db library is not available.
3522 * The GDB remote stub, gdbserver, now supports the new file transfer
3523 commands (remote put, remote get, and remote delete).
3525 * The GDB remote stub, gdbserver, now supports run and attach in
3526 extended-remote mode.
3528 * hppa*64*-*-hpux11* target broken
3529 The debugger is unable to start a program and fails with the following
3530 error: "Error trying to get information about dynamic linker".
3531 The gdb-6.7 release is also affected.
3533 * GDB now supports the --enable-targets= configure option to allow
3534 building a single GDB executable that supports multiple remote
3535 target architectures.
3537 * GDB now supports debugging C and C++ programs which use the
3538 Decimal Floating Point extension. In addition, the PowerPC target
3539 now has a set of pseudo-registers to inspect decimal float values
3540 stored in two consecutive float registers.
3542 * The -break-insert MI command can optionally create pending
3545 * Improved support for debugging Ada
3546 Many improvements to the Ada language support have been made. These
3548 - Better support for Ada2005 interface types
3549 - Improved handling of arrays and slices in general
3550 - Better support for Taft-amendment types
3551 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3553 - Improved command completion in Ada
3556 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3561 set print frame-arguments (all|scalars|none)
3562 show print frame-arguments
3563 The value of this variable can be changed to control which argument
3564 values should be printed by the debugger when displaying a frame.
3569 Transfer files to and from a remote target, and delete remote files.
3576 Transfer files to and from a remote target, and delete remote files.
3578 * New remote packets
3585 Open, close, read, write, and delete files on the remote system.
3588 Attach to an existing process on the remote system, in extended-remote
3592 Run a new process on the remote system, in extended-remote mode.
3594 *** Changes in GDB 6.7
3596 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3597 bfd, libiberty and opcodes, as revealed by static analysis donated by
3598 Coverity, Inc. (http://scan.coverity.com).
3600 * When looking up multiply-defined global symbols, GDB will now prefer the
3601 symbol definition in the current shared library if it was built using the
3602 -Bsymbolic linker option.
3604 * When the Text User Interface (TUI) is not configured, GDB will now
3605 recognize the -tui command-line option and print a message that the TUI
3608 * The GDB remote stub, gdbserver, now has lower overhead for high
3609 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3611 * GDB for MIPS targets now autodetects whether a remote target provides
3612 32-bit or 64-bit register values.
3614 * Support for C++ member pointers has been improved.
3616 * GDB now understands XML target descriptions, which specify the
3617 target's overall architecture. GDB can read a description from
3618 a local file or over the remote serial protocol.
3620 * Vectors of single-byte data use a new integer type which is not
3621 automatically displayed as character or string data.
3623 * The /s format now works with the print command. It displays
3624 arrays of single-byte integers and pointers to single-byte integers
3627 * Target descriptions can now describe target-specific registers,
3628 for architectures which have implemented the support (currently
3629 only ARM, M68K, and MIPS).
3631 * GDB and the GDB remote stub, gdbserver, now support the XScale
3634 * The GDB remote stub, gdbserver, has been updated to support
3635 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3636 has been rewritten to use the standard GDB remote protocol.
3638 * GDB can now step into C++ functions which are called through thunks.
3640 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3642 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3643 layout. It also supports a TextSeg= and DataSeg= response when only
3644 segment base addresses (rather than offsets) are available.
3646 * The /i format now outputs any trailing branch delay slot instructions
3647 immediately following the last instruction within the count specified.
3649 * The GDB remote protocol "T" stop reply packet now supports a
3650 "library" response. Combined with the new "qXfer:libraries:read"
3651 packet, this response allows GDB to debug shared libraries on targets
3652 where the operating system manages the list of loaded libraries (e.g.
3653 Windows and SymbianOS).
3655 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3656 (DLLs) on Windows and Windows CE targets.
3658 * GDB now supports a faster verification that a .debug file matches its binary
3659 according to its build-id signature, if the signature is present.
3665 Enable or disable hardware flow control (RTS/CTS) on the serial port
3666 when debugging using remote targets.
3668 set mem inaccessible-by-default
3669 show mem inaccessible-by-default
3670 If the target supplies a memory map, for instance via the remote
3671 protocol's "qXfer:memory-map:read" packet, setting this variable
3672 prevents GDB from accessing memory outside the memory map. This
3673 is useful for targets with memory mapped registers or which react
3674 badly to accesses of unmapped address space.
3676 set breakpoint auto-hw
3677 show breakpoint auto-hw
3678 If the target supplies a memory map, for instance via the remote
3679 protocol's "qXfer:memory-map:read" packet, setting this variable
3680 lets GDB use hardware breakpoints automatically for memory regions
3681 where it can not use software breakpoints. This covers both the
3682 "break" command and internal breakpoints used for other commands
3683 including "next" and "finish".
3686 catch exception unhandled
3687 Stop the program execution when Ada exceptions are raised.
3690 Stop the program execution when an Ada assertion failed.
3694 Set an alternate system root for target files. This is a more
3695 general version of "set solib-absolute-prefix", which is now
3696 an alias to "set sysroot".
3699 Provide extended SPU facility status information. This set of
3700 commands is available only when debugging the Cell/B.E. SPU
3703 * New native configurations
3705 OpenBSD/sh sh*-*openbsd*
3708 unset tdesc filename
3710 Use the specified local file as an XML target description, and do
3711 not query the target for its built-in description.
3715 OpenBSD/sh sh*-*-openbsd*
3716 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3717 Toshiba Media Processor mep-elf
3719 * New remote packets
3722 Ignore the specified signals; pass them directly to the debugged program
3723 without stopping other threads or reporting them to GDB.
3725 qXfer:features:read:
3726 Read an XML target description from the target, which describes its
3731 Read or write contents of an spufs file on the target system. These
3732 packets are available only on the Cell/B.E. SPU architecture.
3734 qXfer:libraries:read:
3735 Report the loaded shared libraries. Combined with new "T" packet
3736 response, this packet allows GDB to debug shared libraries on
3737 targets where the operating system manages the list of loaded
3738 libraries (e.g. Windows and SymbianOS).
3742 Support for these obsolete configurations has been removed.
3750 i[34567]86-*-lynxos*
3751 i[34567]86-*-netware*
3752 i[34567]86-*-sco3.2v5*
3753 i[34567]86-*-sco3.2v4*
3755 i[34567]86-*-sysv4.2*
3758 i[34567]86-*-unixware2*
3759 i[34567]86-*-unixware*
3768 * Other removed features
3775 Various m68k-only ROM monitors.
3782 Various Renesas ROM monitors and debugging interfaces for SH and
3787 Support for a Macraigor serial interface to on-chip debugging.
3788 GDB does not directly support the newer parallel or USB
3793 A debug information format. The predecessor to DWARF 2 and
3794 DWARF 3, which are still supported.
3796 Support for the HP aCC compiler on HP-UX/PA-RISC
3798 SOM-encapsulated symbolic debugging information, automatic
3799 invocation of pxdb, and the aCC custom C++ ABI. This does not
3800 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3801 with aCC can still be debugged on an assembly level.
3803 MIPS ".pdr" sections
3805 A MIPS-specific format used to describe stack frame layout
3806 in debugging information.
3810 GDB could work with an older version of Guile to debug
3811 the interpreter and Scheme programs running in it.
3813 set mips stack-arg-size
3814 set mips saved-gpreg-size
3816 Use "set mips abi" to control parameter passing for MIPS.
3818 *** Changes in GDB 6.6
3823 Cell Broadband Engine SPU spu-elf
3825 * GDB can now be configured as a cross-debugger targeting native Windows
3826 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3827 running on a Windows system over TCP/IP to debug Windows programs.
3829 * The GDB remote stub, gdbserver, has been updated to support Windows and
3830 Cygwin debugging. Both single-threaded and multi-threaded programs are
3833 * The "set trust-readonly-sections" command works again. This command was
3834 broken in GDB 6.3, 6.4, and 6.5.
3836 * The "load" command now supports writing to flash memory, if the remote
3837 stub provides the required support.
3839 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3840 longer requires symbolic debug information (e.g. DWARF-2).
3845 unset substitute-path
3846 show substitute-path
3847 Manage a list of substitution rules that GDB uses to rewrite the name
3848 of the directories where the sources are located. This can be useful
3849 for instance when the sources were moved to a different location
3850 between compilation and debugging.
3854 Print each CLI command as it is executed. Each command is prefixed with
3855 a number of `+' symbols representing the nesting depth.
3856 The source command now has a `-v' option to enable the same feature.
3860 The ARM Demon monitor support (RDP protocol, "target rdp").
3862 Kernel Object Display, an embedded debugging feature which only worked with
3863 an obsolete version of Cisco IOS.
3865 The 'set download-write-size' and 'show download-write-size' commands.
3867 * New remote packets
3870 Tell a stub about GDB client features, and request remote target features.
3871 The first feature implemented is PacketSize, which allows the target to
3872 specify the size of packets it can handle - to minimize the number of
3873 packets required and improve performance when connected to a remote
3877 Fetch an OS auxilliary vector from the remote stub. This packet is a
3878 more efficient replacement for qPart:auxv:read.
3880 qXfer:memory-map:read:
3881 Fetch a memory map from the remote stub, including information about
3882 RAM, ROM, and flash memory devices.
3887 Erase and program a flash memory device.
3889 * Removed remote packets
3892 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3893 used it, and only gdbserver implemented it.
3895 *** Changes in GDB 6.5
3899 Renesas M32C/M16C m32c-elf
3901 Morpho Technologies ms1 ms1-elf
3905 init-if-undefined Initialize a convenience variable, but
3906 only if it doesn't already have a value.
3908 The following commands are presently only implemented for native GNU/Linux:
3910 checkpoint Save a snapshot of the program state.
3912 restart <n> Return the program state to a
3913 previously saved state.
3915 info checkpoints List currently saved checkpoints.
3917 delete-checkpoint <n> Delete a previously saved checkpoint.
3919 set|show detach-on-fork Tell gdb whether to detach from a newly
3920 forked process, or to keep debugging it.
3922 info forks List forks of the user program that
3923 are available to be debugged.
3925 fork <n> Switch to debugging one of several
3926 forks of the user program that are
3927 available to be debugged.
3929 delete-fork <n> Delete a fork from the list of forks
3930 that are available to be debugged (and
3931 kill the forked process).
3933 detach-fork <n> Delete a fork from the list of forks
3934 that are available to be debugged (and
3935 allow the process to continue).
3939 Morpho Technologies ms2 ms1-elf
3941 * Improved Windows host support
3943 GDB now builds as a cross debugger hosted on i686-mingw32, including
3944 native console support, and remote communications using either
3945 network sockets or serial ports.
3947 * Improved Modula-2 language support
3949 GDB can now print most types in the Modula-2 syntax. This includes:
3950 basic types, set types, record types, enumerated types, range types,
3951 pointer types and ARRAY types. Procedure var parameters are correctly
3952 printed and hexadecimal addresses and character constants are also
3953 written in the Modula-2 syntax. Best results can be obtained by using
3954 GNU Modula-2 together with the -gdwarf-2 command line option.
3958 The ARM rdi-share module.
3960 The Netware NLM debug server.
3962 *** Changes in GDB 6.4
3964 * New native configurations
3966 OpenBSD/arm arm*-*-openbsd*
3967 OpenBSD/mips64 mips64-*-openbsd*
3971 Morpho Technologies ms1 ms1-elf
3973 * New command line options
3975 --batch-silent As for --batch, but totally silent.
3976 --return-child-result The debugger will exist with the same value
3977 the child (debugged) program exited with.
3978 --eval-command COMMAND, -ex COMMAND
3979 Execute a single GDB CLI command. This may be
3980 specified multiple times and in conjunction
3981 with the --command (-x) option.
3983 * Deprecated commands removed
3985 The following commands, that were deprecated in 2000, have been
3989 set|show arm disassembly-flavor set|show arm disassembler
3990 othernames set arm disassembler
3991 set|show remotedebug set|show debug remote
3992 set|show archdebug set|show debug arch
3993 set|show eventdebug set|show debug event
3996 * New BSD user-level threads support
3998 It is now possible to debug programs using the user-level threads
3999 library on OpenBSD and FreeBSD. Currently supported (target)
4002 FreeBSD/amd64 x86_64-*-freebsd*
4003 FreeBSD/i386 i386-*-freebsd*
4004 OpenBSD/i386 i386-*-openbsd*
4006 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4007 are not yet supported.
4009 * New support for Matsushita MN10300 w/sim added
4010 (Work in progress). mn10300-elf.
4012 * REMOVED configurations and files
4014 VxWorks and the XDR protocol *-*-vxworks
4015 Motorola MCORE mcore-*-*
4016 National Semiconductor NS32000 ns32k-*-*
4018 * New "set print array-indexes" command
4020 After turning this setting "on", GDB prints the index of each element
4021 when displaying arrays. The default is "off" to preserve the previous
4024 * VAX floating point support
4026 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4028 * User-defined command support
4030 In addition to using $arg0..$arg9 for argument passing, it is now possible
4031 to use $argc to determine now many arguments have been passed. See the
4032 section on user-defined commands in the user manual for more information.
4034 *** Changes in GDB 6.3:
4036 * New command line option
4038 GDB now accepts -l followed by a number to set the timeout for remote
4041 * GDB works with GCC -feliminate-dwarf2-dups
4043 GDB now supports a more compact representation of DWARF-2 debug
4044 information using DW_FORM_ref_addr references. These are produced
4045 by GCC with the option -feliminate-dwarf2-dups and also by some
4046 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4047 to use -feliminate-dwarf2-dups.
4049 * Internationalization
4051 When supported by the host system, GDB will be built with
4052 internationalization (libintl). The task of marking up the sources is
4053 continued, we're looking forward to our first translation.
4057 Initial support for debugging programs compiled with the GNAT
4058 implementation of the Ada programming language has been integrated
4059 into GDB. In this release, support is limited to expression evaluation.
4061 * New native configurations
4063 GNU/Linux/m32r m32r-*-linux-gnu
4067 GDB's remote protocol now includes support for the 'p' packet. This
4068 packet is used to fetch individual registers from a remote inferior.
4070 * END-OF-LIFE registers[] compatibility module
4072 GDB's internal register infrastructure has been completely rewritten.
4073 The new infrastructure making possible the implementation of key new
4074 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4077 GDB 6.3 will be the last release to include the the registers[]
4078 compatibility module that allowed out-of-date configurations to
4079 continue to work. This change directly impacts the following
4089 powerpc bdm protocol
4091 Unless there is activity to revive these configurations, they will be
4092 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4094 * OBSOLETE configurations and files
4096 Configurations that have been declared obsolete in this release have
4097 been commented out. Unless there is activity to revive these
4098 configurations, the next release of GDB will have their sources
4099 permanently REMOVED.
4108 *** Changes in GDB 6.2.1:
4110 * MIPS `break main; run' gave an heuristic-fence-post warning
4112 When attempting to run even a simple program, a warning about
4113 heuristic-fence-post being hit would be reported. This problem has
4116 * MIPS IRIX 'long double' crashed GDB
4118 When examining a long double variable, GDB would get a segmentation
4119 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4120 IRIX long double values).
4124 A bug in the VAX stack code was causing problems with the "next"
4125 command. This problem has been fixed.
4127 *** Changes in GDB 6.2:
4129 * Fix for ``many threads''
4131 On GNU/Linux systems that use the NPTL threads library, a program
4132 rapidly creating and deleting threads would confuse GDB leading to the
4135 ptrace: No such process.
4136 thread_db_get_info: cannot get thread info: generic error
4138 This problem has been fixed.
4140 * "-async" and "-noasync" options removed.
4142 Support for the broken "-noasync" option has been removed (it caused
4145 * New ``start'' command.
4147 This command runs the program until the begining of the main procedure.
4149 * New BSD Kernel Data Access Library (libkvm) interface
4151 Using ``target kvm'' it is now possible to debug kernel core dumps and
4152 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4153 platforms. Currently supported (native-only) configurations are:
4155 FreeBSD/amd64 x86_64-*-freebsd*
4156 FreeBSD/i386 i?86-*-freebsd*
4157 NetBSD/i386 i?86-*-netbsd*
4158 NetBSD/m68k m68*-*-netbsd*
4159 NetBSD/sparc sparc-*-netbsd*
4160 OpenBSD/amd64 x86_64-*-openbsd*
4161 OpenBSD/i386 i?86-*-openbsd*
4162 OpenBSD/m68k m68*-openbsd*
4163 OpenBSD/sparc sparc-*-openbsd*
4165 * Signal trampoline code overhauled
4167 Many generic problems with GDB's signal handling code have been fixed.
4168 These include: backtraces through non-contiguous stacks; recognition
4169 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4170 call; backtrace through a signal trampoline; step into and out of
4171 signal handlers; and single-stepping in the signal trampoline.
4173 Please note that kernel bugs are a limiting factor here. These
4174 features have been shown to work on an s390 GNU/Linux system that
4175 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4177 * Cygwin support for DWARF 2 added.
4179 * New native configurations
4181 GNU/Linux/hppa hppa*-*-linux*
4182 OpenBSD/hppa hppa*-*-openbsd*
4183 OpenBSD/m68k m68*-*-openbsd*
4184 OpenBSD/m88k m88*-*-openbsd*
4185 OpenBSD/powerpc powerpc-*-openbsd*
4186 NetBSD/vax vax-*-netbsd*
4187 OpenBSD/vax vax-*-openbsd*
4189 * END-OF-LIFE frame compatibility module
4191 GDB's internal frame infrastructure has been completely rewritten.
4192 The new infrastructure making it possible to support key new features
4193 including DWARF 2 Call Frame Information. To aid in the task of
4194 migrating old configurations to this new infrastructure, a
4195 compatibility module, that allowed old configurations to continue to
4196 work, was also included.
4198 GDB 6.2 will be the last release to include this frame compatibility
4199 module. This change directly impacts the following configurations:
4209 Unless there is activity to revive these configurations, they will be
4210 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4212 * REMOVED configurations and files
4214 Sun 3, running SunOS 3 m68*-*-sunos3*
4215 Sun 3, running SunOS 4 m68*-*-sunos4*
4216 Sun 2, running SunOS 3 m68000-*-sunos3*
4217 Sun 2, running SunOS 4 m68000-*-sunos4*
4218 Motorola 680x0 running LynxOS m68*-*-lynxos*
4219 AT&T 3b1/Unix pc m68*-att-*
4220 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4221 decstation mips-dec-* mips-little-*
4222 riscos mips-*-riscos* mips-*-sysv*
4223 sonymips mips-sony-*
4224 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4226 *** Changes in GDB 6.1.1:
4228 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4230 The TUI (Text-mode User Interface) is now built as part of a default
4231 GDB configuration. It is enabled by either selecting the TUI with the
4232 command line option "-i=tui" or by running the separate "gdbtui"
4233 program. For more information on the TUI, see the manual "Debugging
4236 * Pending breakpoint support (also included in GDB 6.1)
4238 Support has been added to allow you to specify breakpoints in shared
4239 libraries that have not yet been loaded. If a breakpoint location
4240 cannot be found, and the "breakpoint pending" option is set to auto,
4241 GDB queries you if you wish to make the breakpoint pending on a future
4242 shared-library load. If and when GDB resolves the breakpoint symbol,
4243 the pending breakpoint is removed as one or more regular breakpoints
4246 Pending breakpoints are very useful for GCJ Java debugging.
4248 * Fixed ISO-C build problems
4250 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4251 non ISO-C code that stopped them being built using a more strict ISO-C
4252 compiler (e.g., IBM's C compiler).
4254 * Fixed build problem on IRIX 5
4256 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4257 wasn't able to compile compile on an IRIX 5 system.
4259 * Added execute permission to gdb/gdbserver/configure
4261 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4262 permission. This bug would cause configure to fail on a number of
4263 systems (Solaris, IRIX). Ref: server/519.
4265 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4267 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4268 has been updated to use constant array sizes.
4270 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4272 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4273 its generated DWARF Call Frame Info. This encoding was causing GDB to
4274 panic, that panic has been fixed. Ref: gdb/1628.
4276 * Fixed a problem when examining parameters in shared library code.
4278 When examining parameters in optimized shared library code generated
4279 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4280 not available''. GDB now correctly displays the variable's value.
4282 *** Changes in GDB 6.1:
4284 * Removed --with-mmalloc
4286 Support for the mmalloc memory manager has been removed, as it
4287 conflicted with the internal gdb byte cache.
4289 * Changes in AMD64 configurations
4291 The AMD64 target now includes the %cs and %ss registers. As a result
4292 the AMD64 remote protocol has changed; this affects the floating-point
4293 and SSE registers. If you rely on those registers for your debugging,
4294 you should upgrade gdbserver on the remote side.
4296 * Revised SPARC target
4298 The SPARC target has been completely revised, incorporating the
4299 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4300 support for LynxOS and SunOS 4 has been dropped. Calling functions
4301 from within GDB on operating systems with a non-executable stack
4302 (Solaris, OpenBSD) now works.
4306 GDB has a new C++ demangler which does a better job on the mangled
4307 names generated by current versions of g++. It also runs faster, so
4308 with this and other changes gdb should now start faster on large C++
4311 * DWARF 2 Location Expressions
4313 GDB support for location expressions has been extended to support function
4314 arguments and frame bases. Older versions of GDB could crash when they
4317 * C++ nested types and namespaces
4319 GDB's support for nested types and namespaces in C++ has been
4320 improved, especially if you use the DWARF 2 debugging format. (This
4321 is the default for recent versions of GCC on most platforms.)
4322 Specifically, if you have a class "Inner" defined within a class or
4323 namespace "Outer", then GDB realizes that the class's name is
4324 "Outer::Inner", not simply "Inner". This should greatly reduce the
4325 frequency of complaints about not finding RTTI symbols. In addition,
4326 if you are stopped at inside of a function defined within a namespace,
4327 GDB modifies its name lookup accordingly.
4329 * New native configurations
4331 NetBSD/amd64 x86_64-*-netbsd*
4332 OpenBSD/amd64 x86_64-*-openbsd*
4333 OpenBSD/alpha alpha*-*-openbsd*
4334 OpenBSD/sparc sparc-*-openbsd*
4335 OpenBSD/sparc64 sparc64-*-openbsd*
4337 * New debugging protocols
4339 M32R with SDI protocol m32r-*-elf*
4341 * "set prompt-escape-char" command deleted.
4343 The command "set prompt-escape-char" has been deleted. This command,
4344 and its very obscure effet on GDB's prompt, was never documented,
4345 tested, nor mentioned in the NEWS file.
4347 * OBSOLETE configurations and files
4349 Configurations that have been declared obsolete in this release have
4350 been commented out. Unless there is activity to revive these
4351 configurations, the next release of GDB will have their sources
4352 permanently REMOVED.
4354 Sun 3, running SunOS 3 m68*-*-sunos3*
4355 Sun 3, running SunOS 4 m68*-*-sunos4*
4356 Sun 2, running SunOS 3 m68000-*-sunos3*
4357 Sun 2, running SunOS 4 m68000-*-sunos4*
4358 Motorola 680x0 running LynxOS m68*-*-lynxos*
4359 AT&T 3b1/Unix pc m68*-att-*
4360 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4361 decstation mips-dec-* mips-little-*
4362 riscos mips-*-riscos* mips-*-sysv*
4363 sonymips mips-sony-*
4364 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4366 * REMOVED configurations and files
4368 SGI Irix-4.x mips-sgi-irix4 or iris4
4369 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4370 Z8000 simulator z8k-zilog-none or z8ksim
4371 Matsushita MN10200 w/simulator mn10200-*-*
4372 H8/500 simulator h8500-hitachi-hms or h8500hms
4373 HP/PA running BSD hppa*-*-bsd*
4374 HP/PA running OSF/1 hppa*-*-osf*
4375 HP/PA Pro target hppa*-*-pro*
4376 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4377 386BSD i[3456]86-*-bsd*
4378 Sequent family i[3456]86-sequent-sysv4*
4379 i[3456]86-sequent-sysv*
4380 i[3456]86-sequent-bsd*
4381 SPARC running LynxOS sparc-*-lynxos*
4382 SPARC running SunOS 4 sparc-*-sunos4*
4383 Tsqware Sparclet sparclet-*-*
4384 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4386 *** Changes in GDB 6.0:
4390 Support for debugging the Objective-C programming language has been
4391 integrated into GDB.
4393 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4395 DWARF 2's Call Frame Information makes available compiler generated
4396 information that more exactly describes the program's run-time stack.
4397 By using this information, GDB is able to provide more robust stack
4400 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4401 have been updated to use a new backtrace mechanism which includes
4402 DWARF 2 CFI support.
4406 GDB's remote protocol has been extended to include support for hosted
4407 file I/O (where the remote target uses GDB's file system). See GDB's
4408 remote protocol documentation for details.
4410 * All targets using the new architecture framework.
4412 All of GDB's targets have been updated to use the new internal
4413 architecture framework. The way is now open for future GDB releases
4414 to include cross-architecture native debugging support (i386 on amd64,
4417 * GNU/Linux's Thread Local Storage (TLS)
4419 GDB now includes support for for the GNU/Linux implementation of
4420 per-thread variables.
4422 * GNU/Linux's Native POSIX Thread Library (NPTL)
4424 GDB's thread code has been updated to work with either the new
4425 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4427 * Separate debug info.
4429 GDB, in conjunction with BINUTILS, now supports a mechanism for
4430 automatically loading debug information from a separate file. Instead
4431 of shipping full debug and non-debug versions of system libraries,
4432 system integrators can now instead ship just the stripped libraries
4433 and optional debug files.
4435 * DWARF 2 Location Expressions
4437 DWARF 2 Location Expressions allow the compiler to more completely
4438 describe the location of variables (even in optimized code) to the
4441 GDB now includes preliminary support for location expressions (support
4442 for DW_OP_piece is still missing).
4446 A number of long standing bugs that caused GDB to die while starting a
4447 Java application have been fixed. GDB's Java support is now
4448 considered "useable".
4450 * GNU/Linux support for fork, vfork, and exec.
4452 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4453 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4456 * GDB supports logging output to a file
4458 There are two new commands, "set logging" and "show logging", which can be
4459 used to capture GDB's output to a file.
4461 * The meaning of "detach" has changed for gdbserver
4463 The "detach" command will now resume the application, as documented. To
4464 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4467 * d10v, m68hc11 `regs' command deprecated
4469 The `info registers' command has been updated so that it displays the
4470 registers using a format identical to the old `regs' command.
4474 A new command, "maint set profile on/off", has been added. This command can
4475 be used to enable or disable profiling while running GDB, to profile a
4476 session or a set of commands. In addition there is a new configure switch,
4477 "--enable-profiling", which will cause GDB to be compiled with profiling
4478 data, for more informative profiling results.
4480 * Default MI syntax changed to "mi2".
4482 The default MI (machine interface) syntax, enabled by the command line
4483 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4484 "mi1", can be enabled by specifying the option "-i=mi1".
4486 Support for the original "mi0" syntax (included in GDB 5.0) has been
4489 Fix for gdb/192: removed extraneous space when displaying frame level.
4490 Fix for gdb/672: update changelist is now output in mi list format.
4491 Fix for gdb/702: a -var-assign that updates the value now shows up
4492 in a subsequent -var-update.
4494 * New native configurations.
4496 FreeBSD/amd64 x86_64-*-freebsd*
4498 * Multi-arched targets.
4500 HP/PA HPUX11 hppa*-*-hpux*
4501 Renesas M32R/D w/simulator m32r-*-elf*
4503 * OBSOLETE configurations and files
4505 Configurations that have been declared obsolete in this release have
4506 been commented out. Unless there is activity to revive these
4507 configurations, the next release of GDB will have their sources
4508 permanently REMOVED.
4510 Z8000 simulator z8k-zilog-none or z8ksim
4511 Matsushita MN10200 w/simulator mn10200-*-*
4512 H8/500 simulator h8500-hitachi-hms or h8500hms
4513 HP/PA running BSD hppa*-*-bsd*
4514 HP/PA running OSF/1 hppa*-*-osf*
4515 HP/PA Pro target hppa*-*-pro*
4516 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4517 Sequent family i[3456]86-sequent-sysv4*
4518 i[3456]86-sequent-sysv*
4519 i[3456]86-sequent-bsd*
4520 Tsqware Sparclet sparclet-*-*
4521 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4523 * REMOVED configurations and files
4526 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4527 IBM AIX PS/2 i[3456]86-*-aix
4528 i386 running Mach 3.0 i[3456]86-*-mach3*
4529 i386 running Mach i[3456]86-*-mach*
4530 i386 running OSF/1 i[3456]86-*osf1mk*
4531 HP/Apollo 68k Family m68*-apollo*-sysv*,
4533 m68*-hp-bsd*, m68*-hp-hpux*
4534 Argonaut Risc Chip (ARC) arc-*-*
4535 Mitsubishi D30V d30v-*-*
4536 Fujitsu FR30 fr30-*-elf*
4537 OS/9000 i[34]86-*-os9k
4538 I960 with MON960 i960-*-coff
4540 * MIPS $fp behavior changed
4542 The convenience variable $fp, for the MIPS, now consistently returns
4543 the address of the current frame's base. Previously, depending on the
4544 context, $fp could refer to either $sp or the current frame's base
4545 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4546 The GNU Source-Level Debugger''.
4548 *** Changes in GDB 5.3:
4550 * GNU/Linux shared library multi-threaded performance improved.
4552 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4553 `/proc', in preference to `ptrace' for memory reads. This may result
4554 in an improvement in the start-up time of multi-threaded, shared
4555 library applications when run under GDB. One GDB user writes: ``loads
4556 shared libs like mad''.
4558 * ``gdbserver'' now supports multi-threaded applications on some targets
4560 Support for debugging multi-threaded applications which use
4561 the GNU/Linux LinuxThreads package has been added for
4562 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4563 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4565 * GDB now supports C/C++ preprocessor macros.
4567 GDB now expands preprocessor macro invocations in C/C++ expressions,
4568 and provides various commands for showing macro definitions and how
4571 The new command `macro expand EXPRESSION' expands any macro
4572 invocations in expression, and shows the result.
4574 The new command `show macro MACRO-NAME' shows the definition of the
4575 macro named MACRO-NAME, and where it was defined.
4577 Most compilers don't include information about macros in the debugging
4578 information by default. In GCC 3.1, for example, you need to compile
4579 your program with the options `-gdwarf-2 -g3'. If the macro
4580 information is present in the executable, GDB will read it.
4582 * Multi-arched targets.
4584 DEC Alpha (partial) alpha*-*-*
4585 DEC VAX (partial) vax-*-*
4587 National Semiconductor NS32000 (partial) ns32k-*-*
4588 Motorola 68000 (partial) m68k-*-*
4589 Motorola MCORE mcore-*-*
4593 Fujitsu FRV architecture added by Red Hat frv*-*-*
4596 * New native configurations
4598 Alpha NetBSD alpha*-*-netbsd*
4599 SH NetBSD sh*-*-netbsdelf*
4600 MIPS NetBSD mips*-*-netbsd*
4601 UltraSPARC NetBSD sparc64-*-netbsd*
4603 * OBSOLETE configurations and files
4605 Configurations that have been declared obsolete in this release have
4606 been commented out. Unless there is activity to revive these
4607 configurations, the next release of GDB will have their sources
4608 permanently REMOVED.
4610 Mitsubishi D30V d30v-*-*
4611 OS/9000 i[34]86-*-os9k
4612 IBM AIX PS/2 i[3456]86-*-aix
4613 Fujitsu FR30 fr30-*-elf*
4614 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4615 Argonaut Risc Chip (ARC) arc-*-*
4616 i386 running Mach 3.0 i[3456]86-*-mach3*
4617 i386 running Mach i[3456]86-*-mach*
4618 i386 running OSF/1 i[3456]86-*osf1mk*
4619 HP/Apollo 68k Family m68*-apollo*-sysv*,
4621 m68*-hp-bsd*, m68*-hp-hpux*
4622 I960 with MON960 i960-*-coff
4624 * OBSOLETE languages
4626 CHILL, a Pascal like language used by telecommunications companies.
4628 * REMOVED configurations and files
4630 AMD 29k family via UDI a29k-amd-udi, udi29k
4631 A29K VxWorks a29k-*-vxworks
4632 AMD 29000 embedded, using EBMON a29k-none-none
4633 AMD 29000 embedded with COFF a29k-none-coff
4634 AMD 29000 embedded with a.out a29k-none-aout
4636 testsuite/gdb.hp/gdb.threads-hp/ directory
4638 * New command "set max-user-call-depth <nnn>"
4640 This command allows the user to limit the call depth of user-defined
4641 commands. The default is 1024.
4643 * Changes in FreeBSD/i386 native debugging.
4645 Support for the "generate-core-file" has been added.
4647 * New commands "dump", "append", and "restore".
4649 These commands allow data to be copied from target memory
4650 to a bfd-format or binary file (dump and append), and back
4651 from a file into memory (restore).
4653 * Improved "next/step" support on multi-processor Alpha Tru64.
4655 The previous single-step mechanism could cause unpredictable problems,
4656 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4657 of a software single-step mechanism prevents this.
4659 *** Changes in GDB 5.2.1:
4667 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4668 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4669 Fix, by Joel Brobecker imported from mainline.
4671 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4672 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4673 Fix, by Fred Fish, imported from mainline.
4675 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4676 Surprisingly enough, it works now.
4677 By Michal Ludvig, imported from mainline.
4679 i386 hardware watchpoint support:
4680 avoid misses on second run for some targets.
4681 By Pierre Muller, imported from mainline.
4683 *** Changes in GDB 5.2:
4685 * New command "set trust-readonly-sections on[off]".
4687 This command is a hint that tells gdb that read-only sections
4688 really are read-only (ie. that their contents will not change).
4689 In this mode, gdb will go to the object file rather than the
4690 target to read memory from read-only sections (such as ".text").
4691 This can be a significant performance improvement on some
4692 (notably embedded) targets.
4694 * New command "generate-core-file" (or "gcore").
4696 This new gdb command allows the user to drop a core file of the child
4697 process state at any time. So far it's been implemented only for
4698 GNU/Linux and Solaris, but should be relatively easily ported to other
4699 hosts. Argument is core file name (defaults to core.<pid>).
4701 * New command line option
4703 GDB now accepts --pid or -p followed by a process id.
4705 * Change in command line behavior -- corefiles vs. process ids.
4707 There is a subtle behavior in the way in which GDB handles
4708 command line arguments. The first non-flag argument is always
4709 a program to debug, but the second non-flag argument may either
4710 be a corefile or a process id. Previously, GDB would attempt to
4711 open the second argument as a corefile, and if that failed, would
4712 issue a superfluous error message and then attempt to attach it as
4713 a process. Now, if the second argument begins with a non-digit,
4714 it will be treated as a corefile. If it begins with a digit,
4715 GDB will attempt to attach it as a process, and if no such process
4716 is found, will then attempt to open it as a corefile.
4718 * Changes in ARM configurations.
4720 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4721 configuration is fully multi-arch.
4723 * New native configurations
4725 ARM NetBSD arm*-*-netbsd*
4726 x86 OpenBSD i[3456]86-*-openbsd*
4727 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4728 Sparc64 running FreeBSD sparc64-*-freebsd*
4732 Sanyo XStormy16 xstormy16-elf
4734 * OBSOLETE configurations and files
4736 Configurations that have been declared obsolete in this release have
4737 been commented out. Unless there is activity to revive these
4738 configurations, the next release of GDB will have their sources
4739 permanently REMOVED.
4741 AMD 29k family via UDI a29k-amd-udi, udi29k
4742 A29K VxWorks a29k-*-vxworks
4743 AMD 29000 embedded, using EBMON a29k-none-none
4744 AMD 29000 embedded with COFF a29k-none-coff
4745 AMD 29000 embedded with a.out a29k-none-aout
4747 testsuite/gdb.hp/gdb.threads-hp/ directory
4749 * REMOVED configurations and files
4751 TI TMS320C80 tic80-*-*
4753 PowerPC Solaris powerpcle-*-solaris*
4754 PowerPC Windows NT powerpcle-*-cygwin32
4755 PowerPC Netware powerpc-*-netware*
4756 Harris/CXUX m88k m88*-harris-cxux*
4757 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4758 ns32k-utek-sysv* ns32k-utek-*
4759 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4760 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4761 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4762 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4763 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4765 * Changes to command line processing
4767 The new `--args' feature can be used to specify command-line arguments
4768 for the inferior from gdb's command line.
4770 * Changes to key bindings
4772 There is a new `operate-and-get-next' function bound to `C-o'.
4774 *** Changes in GDB 5.1.1
4776 Fix compile problem on DJGPP.
4778 Fix a problem with floating-point registers on the i386 being
4781 Fix to stop GDB crashing on .debug_str debug info.
4783 Numerous documentation fixes.
4785 Numerous testsuite fixes.
4787 *** Changes in GDB 5.1:
4789 * New native configurations
4791 Alpha FreeBSD alpha*-*-freebsd*
4792 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4793 MIPS GNU/Linux mips*-*-linux*
4794 MIPS SGI Irix 6.x mips*-sgi-irix6*
4795 ia64 AIX ia64-*-aix*
4796 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4800 Motorola 68HC11 and 68HC12 m68hc11-elf
4802 UltraSparc running GNU/Linux sparc64-*-linux*
4804 * OBSOLETE configurations and files
4806 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4807 Harris/CXUX m88k m88*-harris-cxux*
4808 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4809 ns32k-utek-sysv* ns32k-utek-*
4810 TI TMS320C80 tic80-*-*
4812 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4813 PowerPC Solaris powerpcle-*-solaris*
4814 PowerPC Windows NT powerpcle-*-cygwin32
4815 PowerPC Netware powerpc-*-netware*
4816 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4817 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4818 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4819 Apple Macintosh (MPW) host N/A
4821 stuff.c (Program to stuff files into a specially prepared space in kdb)
4822 kdb-start.c (Main loop for the standalone kernel debugger)
4824 Configurations that have been declared obsolete in this release have
4825 been commented out. Unless there is activity to revive these
4826 configurations, the next release of GDB will have their sources
4827 permanently REMOVED.
4829 * REMOVED configurations and files
4831 Altos 3068 m68*-altos-*
4832 Convex c1-*-*, c2-*-*
4834 ARM RISCix arm-*-* (as host)
4838 * GDB has been converted to ISO C.
4840 GDB's source code has been converted to ISO C. In particular, the
4841 sources are fully protoized, and rely on standard headers being
4846 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4848 * The MI enabled by default.
4850 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4851 revised and enabled by default. Packages which use GDB as a debugging
4852 engine behind a UI or another front end are encouraged to switch to
4853 using the GDB/MI interface, instead of the old annotations interface
4854 which is now deprecated.
4856 * Support for debugging Pascal programs.
4858 GDB now includes support for debugging Pascal programs. The following
4859 main features are supported:
4861 - Pascal-specific data types such as sets;
4863 - automatic recognition of Pascal sources based on file-name
4866 - Pascal-style display of data types, variables, and functions;
4868 - a Pascal expression parser.
4870 However, some important features are not yet supported.
4872 - Pascal string operations are not supported at all;
4874 - there are some problems with boolean types;
4876 - Pascal type hexadecimal constants are not supported
4877 because they conflict with the internal variables format;
4879 - support for Pascal objects and classes is not full yet;
4881 - unlike Pascal, GDB is case-sensitive for symbol names.
4883 * Changes in completion.
4885 Commands such as `shell', `run' and `set args', which pass arguments
4886 to inferior programs, now complete on file names, similar to what
4887 users expect at the shell prompt.
4889 Commands which accept locations, such as `disassemble', `print',
4890 `breakpoint', `until', etc. now complete on filenames as well as
4891 program symbols. Thus, if you type "break foob TAB", and the source
4892 files linked into the programs include `foobar.c', that file name will
4893 be one of the candidates for completion. However, file names are not
4894 considered for completion after you typed a colon that delimits a file
4895 name from a name of a function in that file, as in "break foo.c:bar".
4897 `set demangle-style' completes on available demangling styles.
4899 * New platform-independent commands:
4901 It is now possible to define a post-hook for a command as well as a
4902 hook that runs before the command. For more details, see the
4903 documentation of `hookpost' in the GDB manual.
4905 * Changes in GNU/Linux native debugging.
4907 Support for debugging multi-threaded programs has been completely
4908 revised for all platforms except m68k and sparc. You can now debug as
4909 many threads as your system allows you to have.
4911 Attach/detach is supported for multi-threaded programs.
4913 Support for SSE registers was added for x86. This doesn't work for
4914 multi-threaded programs though.
4916 * Changes in MIPS configurations.
4918 Multi-arch support is enabled for all MIPS configurations.
4920 GDB can now be built as native debugger on SGI Irix 6.x systems for
4921 debugging n32 executables. (Debugging 64-bit executables is not yet
4924 * Unified support for hardware watchpoints in all x86 configurations.
4926 Most (if not all) native x86 configurations support hardware-assisted
4927 breakpoints and watchpoints in a unified manner. This support
4928 implements debug register sharing between watchpoints, which allows to
4929 put a virtually infinite number of watchpoints on the same address,
4930 and also supports watching regions up to 16 bytes with several debug
4933 The new maintenance command `maintenance show-debug-regs' toggles
4934 debugging print-outs in functions that insert, remove, and test
4935 watchpoints and hardware breakpoints.
4937 * Changes in the DJGPP native configuration.
4939 New command ``info dos sysinfo'' displays assorted information about
4940 the CPU, OS, memory, and DPMI server.
4942 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4943 display information about segment descriptors stored in GDT, LDT, and
4946 New commands ``info dos pde'' and ``info dos pte'' display entries
4947 from Page Directory and Page Tables (for now works with CWSDPMI only).
4948 New command ``info dos address-pte'' displays the Page Table entry for
4949 a given linear address.
4951 GDB can now pass command lines longer than 126 characters to the
4952 program being debugged (requires an update to the libdbg.a library
4953 which is part of the DJGPP development kit).
4955 DWARF2 debug info is now supported.
4957 It is now possible to `step' and `next' through calls to `longjmp'.
4959 * Changes in documentation.
4961 All GDB documentation was converted to GFDL, the GNU Free
4962 Documentation License.
4964 Tracepoints-related commands are now fully documented in the GDB
4967 TUI, the Text-mode User Interface, is now documented in the manual.
4969 Tracepoints-related commands are now fully documented in the GDB
4972 The "GDB Internals" manual now has an index. It also includes
4973 documentation of `ui_out' functions, GDB coding standards, x86
4974 hardware watchpoints, and memory region attributes.
4976 * GDB's version number moved to ``version.in''
4978 The Makefile variable VERSION has been replaced by the file
4979 ``version.in''. People creating GDB distributions should update the
4980 contents of this file.
4984 GUD support is now a standard part of the EMACS distribution.
4986 *** Changes in GDB 5.0:
4988 * Improved support for debugging FP programs on x86 targets
4990 Unified and much-improved support for debugging floating-point
4991 programs on all x86 targets. In particular, ``info float'' now
4992 displays the FP registers in the same format on all x86 targets, with
4993 greater level of detail.
4995 * Improvements and bugfixes in hardware-assisted watchpoints
4997 It is now possible to watch array elements, struct members, and
4998 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4999 on x86 targets no longer erroneously trigger when the address is
5002 * Improvements in the native DJGPP version of GDB
5004 The distribution now includes all the scripts and auxiliary files
5005 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5006 machines ``out of the box''.
5008 The DJGPP version can now debug programs that use signals. It is
5009 possible to catch signals that happened in the debuggee, deliver
5010 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5011 would kill the program being debugged.) Programs that hook hardware
5012 interrupts (keyboard, timer, etc.) can also be debugged.
5014 It is now possible to debug DJGPP programs that redirect their
5015 standard handles or switch them to raw (as opposed to cooked) mode, or
5016 even close them. The command ``run < foo > bar'' works as expected,
5017 and ``info terminal'' reports useful information about the debuggee's
5018 terminal, including raw/cooked mode, redirection, etc.
5020 The DJGPP version now uses termios functions for console I/O, which
5021 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5024 DOS-style file names with drive letters are now fully supported by
5027 It is now possible to debug DJGPP programs that switch their working
5028 directory. It is also possible to rerun the debuggee any number of
5029 times without restarting GDB; thus, you can use the same setup,
5030 breakpoints, etc. for many debugging sessions.
5032 * New native configurations
5034 ARM GNU/Linux arm*-*-linux*
5035 PowerPC GNU/Linux powerpc-*-linux*
5039 Motorola MCore mcore-*-*
5040 x86 VxWorks i[3456]86-*-vxworks*
5041 PowerPC VxWorks powerpc-*-vxworks*
5042 TI TMS320C80 tic80-*-*
5044 * OBSOLETE configurations
5046 Altos 3068 m68*-altos-*
5047 Convex c1-*-*, c2-*-*
5049 ARM RISCix arm-*-* (as host)
5052 Configurations that have been declared obsolete will be commented out,
5053 but the code will be left in place. If there is no activity to revive
5054 these configurations before the next release of GDB, the sources will
5055 be permanently REMOVED.
5057 * Gould support removed
5059 Support for the Gould PowerNode and NP1 has been removed.
5061 * New features for SVR4
5063 On SVR4 native platforms (such as Solaris), if you attach to a process
5064 without first loading a symbol file, GDB will now attempt to locate and
5065 load symbols from the running process's executable file.
5067 * Many C++ enhancements
5069 C++ support has been greatly improved. Overload resolution now works properly
5070 in almost all cases. RTTI support is on the way.
5072 * Remote targets can connect to a sub-program
5074 A popen(3) style serial-device has been added. This device starts a
5075 sub-process (such as a stand-alone simulator) and then communicates
5076 with that. The sub-program to run is specified using the syntax
5077 ``|<program> <args>'' vis:
5079 (gdb) set remotedebug 1
5080 (gdb) target extended-remote |mn10300-elf-sim program-args
5082 * MIPS 64 remote protocol
5084 A long standing bug in the mips64 remote protocol where by GDB
5085 expected certain 32 bit registers (ex SR) to be transfered as 32
5086 instead of 64 bits has been fixed.
5088 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5089 added to provide backward compatibility with older versions of GDB.
5091 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5093 The command ``set remotebinarydownload'' command has been replaced by
5094 ``set remote X-packet''. Other commands in ``set remote'' family
5095 include ``set remote P-packet''.
5097 * Breakpoint commands accept ranges.
5099 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5100 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5101 ``tracepoint passcount'' also accepts a range of tracepoints.
5103 * ``apropos'' command added.
5105 The ``apropos'' command searches through command names and
5106 documentation strings, printing out matches, making it much easier to
5107 try to find a command that does what you are looking for.
5111 A new machine oriented interface (MI) has been added to GDB. This
5112 interface is designed for debug environments running GDB as a separate
5113 process. This is part of the long term libGDB project. See the
5114 "GDB/MI" chapter of the GDB manual for further information. It can be
5115 enabled by configuring with:
5117 .../configure --enable-gdbmi
5119 *** Changes in GDB-4.18:
5121 * New native configurations
5123 HP-UX 10.20 hppa*-*-hpux10.20
5124 HP-UX 11.x hppa*-*-hpux11.0*
5125 M68K GNU/Linux m68*-*-linux*
5129 Fujitsu FR30 fr30-*-elf*
5130 Intel StrongARM strongarm-*-*
5131 Mitsubishi D30V d30v-*-*
5133 * OBSOLETE configurations
5135 Gould PowerNode, NP1 np1-*-*, pn-*-*
5137 Configurations that have been declared obsolete will be commented out,
5138 but the code will be left in place. If there is no activity to revive
5139 these configurations before the next release of GDB, the sources will
5140 be permanently REMOVED.
5144 As a compatibility experiment, GDB's source files buildsym.h and
5145 buildsym.c have been converted to pure standard C, no longer
5146 containing any K&R compatibility code. We believe that all systems in
5147 use today either come with a standard C compiler, or have a GCC port
5148 available. If this is not true, please report the affected
5149 configuration to bug-gdb@gnu.org immediately. See the README file for
5150 information about getting a standard C compiler if you don't have one
5155 GDB now uses readline 2.2.
5157 * set extension-language
5159 You can now control the mapping between filename extensions and source
5160 languages by using the `set extension-language' command. For instance,
5161 you can ask GDB to treat .c files as C++ by saying
5162 set extension-language .c c++
5163 The command `info extensions' lists all of the recognized extensions
5164 and their associated languages.
5166 * Setting processor type for PowerPC and RS/6000
5168 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5169 you can use the `set processor' command to specify what variant of the
5170 PowerPC family you are debugging. The command
5174 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5175 following PowerPC and RS6000 variants:
5177 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5178 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5180 403GC IBM PowerPC 403GC
5181 505 Motorola PowerPC 505
5182 860 Motorola PowerPC 860 or 850
5183 601 Motorola PowerPC 601
5184 602 Motorola PowerPC 602
5185 603 Motorola/IBM PowerPC 603 or 603e
5186 604 Motorola PowerPC 604 or 604e
5187 750 Motorola/IBM PowerPC 750 or 750
5189 At the moment, this command just tells GDB what to name the
5190 special-purpose processor registers. Since almost all the affected
5191 registers are inaccessible to user-level programs, this command is
5192 only useful for remote debugging in its present form.
5196 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5197 more extensive support for HP-UX. Added features include shared
5198 library support, kernel threads and hardware watchpoints for 11.00,
5199 support for HP's ANSI C and C++ compilers, and a compatibility mode
5200 for xdb and dbx commands.
5204 HP's donation includes the new concept of catchpoints, which is a
5205 generalization of the old catch command. On HP-UX, it is now possible
5206 to catch exec, fork, and vfork, as well as library loading.
5208 This means that the existing catch command has changed; its first
5209 argument now specifies the type of catch to be set up. See the
5210 output of "help catch" for a list of catchpoint types.
5212 * Debugging across forks
5214 On HP-UX, you can choose which process to debug when a fork() happens
5219 HP has donated a curses-based terminal user interface (TUI). To get
5220 it, build with --enable-tui. Although this can be enabled for any
5221 configuration, at present it only works for native HP debugging.
5223 * GDB remote protocol additions
5225 A new protocol packet 'X' that writes binary data is now available.
5226 Default behavior is to try 'X', then drop back to 'M' if the stub
5227 fails to respond. The settable variable `remotebinarydownload'
5228 allows explicit control over the use of 'X'.
5230 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5231 full 64-bit address. The command
5233 set remoteaddresssize 32
5235 can be used to revert to the old behaviour. For existing remote stubs
5236 the change should not be noticed, as the additional address information
5239 In order to assist in debugging stubs, you may use the maintenance
5240 command `packet' to send any text string to the stub. For instance,
5242 maint packet heythere
5244 sends the packet "$heythere#<checksum>". Note that it is very easy to
5245 disrupt a debugging session by sending the wrong packet at the wrong
5248 The compare-sections command allows you to compare section data on the
5249 target to what is in the executable file without uploading or
5250 downloading, by comparing CRC checksums.
5252 * Tracing can collect general expressions
5254 You may now collect general expressions at tracepoints. This requires
5255 further additions to the target-side stub; see tracepoint.c and
5256 doc/agentexpr.texi for further details.
5258 * mask-address variable for Mips
5260 For Mips targets, you may control the zeroing of the upper 32 bits of
5261 a 64-bit address by entering `set mask-address on'. This is mainly
5262 of interest to users of embedded R4xxx and R5xxx processors.
5264 * Higher serial baud rates
5266 GDB's serial code now allows you to specify baud rates 57600, 115200,
5267 230400, and 460800 baud. (Note that your host system may not be able
5268 to achieve all of these rates.)
5272 The i960 configuration now includes an initial implementation of a
5273 builtin simulator, contributed by Jim Wilson.
5276 *** Changes in GDB-4.17:
5278 * New native configurations
5280 Alpha GNU/Linux alpha*-*-linux*
5281 Unixware 2.x i[3456]86-unixware2*
5282 Irix 6.x mips*-sgi-irix6*
5283 PowerPC GNU/Linux powerpc-*-linux*
5284 PowerPC Solaris powerpcle-*-solaris*
5285 Sparc GNU/Linux sparc-*-linux*
5286 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5290 Argonaut Risc Chip (ARC) arc-*-*
5291 Hitachi H8/300S h8300*-*-*
5292 Matsushita MN10200 w/simulator mn10200-*-*
5293 Matsushita MN10300 w/simulator mn10300-*-*
5294 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5295 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5296 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5297 Mitsubishi D10V w/simulator d10v-*-*
5298 Mitsubishi M32R/D w/simulator m32r-*-elf*
5299 Tsqware Sparclet sparclet-*-*
5300 NEC V850 w/simulator v850-*-*
5302 * New debugging protocols
5304 ARM with RDI protocol arm*-*-*
5305 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5306 DDB and LSI variants of PMON protocol mips*-*-*
5307 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5308 PowerPC with SDS protocol powerpc{,le}-*-eabi
5309 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5313 All configurations can now understand and use the DWARF 2 debugging
5314 format. The choice is automatic, if the symbol file contains DWARF 2
5319 GDB now includes basic Java language support. This support is
5320 only useful with Java compilers that produce native machine code.
5322 * solib-absolute-prefix and solib-search-path
5324 For SunOS and SVR4 shared libraries, you may now set the prefix for
5325 loading absolute shared library symbol files, and the search path for
5326 locating non-absolute shared library symbol files.
5328 * Live range splitting
5330 GDB can now effectively debug code for which GCC has performed live
5331 range splitting as part of its optimization. See gdb/doc/LRS for
5332 more details on the expected format of the stabs information.
5336 GDB's support for the GNU Hurd, including thread debugging, has been
5337 updated to work with current versions of the Hurd.
5341 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5342 instruction set. ARM GDB automatically detects when Thumb
5343 instructions are in use, and adjusts disassembly and backtracing
5348 GDB's MIPS target configurations now handle the MIP16 16-bit
5353 GDB now includes support for overlays; if an executable has been
5354 linked such that multiple sections are based at the same address, GDB
5355 will decide which section to use for symbolic info. You can choose to
5356 control the decision manually, using overlay commands, or implement
5357 additional target-side support and use "overlay load-target" to bring
5358 in the overlay mapping. Do "help overlay" for more detail.
5362 The command "info symbol <address>" displays information about
5363 the symbol at the specified address.
5367 The standard remote protocol now includes an extension that allows
5368 asynchronous collection and display of trace data. This requires
5369 extensive support in the target-side debugging stub. Tracing mode
5370 includes a new interaction mode in GDB and new commands: see the
5371 file tracepoint.c for more details.
5375 Configurations for embedded MIPS now include a simulator contributed
5376 by Cygnus Solutions. The simulator supports the instruction sets
5377 of most MIPS variants.
5381 Sparc configurations may now include the ERC32 simulator contributed
5382 by the European Space Agency. The simulator is not built into
5383 Sparc targets by default; configure with --enable-sim to include it.
5387 For target configurations that may include multiple variants of a
5388 basic architecture (such as MIPS and SH), you may now set the
5389 architecture explicitly. "set arch" sets, "info arch" lists
5390 the possible architectures.
5392 *** Changes in GDB-4.16:
5394 * New native configurations
5396 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5397 M68K NetBSD m68k-*-netbsd*
5398 PowerPC AIX 4.x powerpc-*-aix*
5399 PowerPC MacOS powerpc-*-macos*
5400 PowerPC Windows NT powerpcle-*-cygwin32
5401 RS/6000 AIX 4.x rs6000-*-aix4*
5405 ARM with RDP protocol arm-*-*
5406 I960 with MON960 i960-*-coff
5407 MIPS VxWorks mips*-*-vxworks*
5408 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5409 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5411 Matra Sparclet sparclet-*-*
5415 The powerpc-eabi configuration now includes the PSIM simulator,
5416 contributed by Andrew Cagney, with assistance from Mike Meissner.
5417 PSIM is a very elaborate model of the PowerPC, including not only
5418 basic instruction set execution, but also details of execution unit
5419 performance and I/O hardware. See sim/ppc/README for more details.
5423 GDB now works with Solaris 2.5.
5425 * Windows 95/NT native
5427 GDB will now work as a native debugger on Windows 95 and Windows NT.
5428 To build it from source, you must use the "gnu-win32" environment,
5429 which uses a DLL to emulate enough of Unix to run the GNU tools.
5430 Further information, binaries, and sources are available at
5431 ftp.cygnus.com, under pub/gnu-win32.
5433 * dont-repeat command
5435 If a user-defined command includes the command `dont-repeat', then the
5436 command will not be repeated if the user just types return. This is
5437 useful if the command is time-consuming to run, so that accidental
5438 extra keystrokes don't run the same command many times.
5440 * Send break instead of ^C
5442 The standard remote protocol now includes an option to send a break
5443 rather than a ^C to the target in order to interrupt it. By default,
5444 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5446 * Remote protocol timeout
5448 The standard remote protocol includes a new variable `remotetimeout'
5449 that allows you to set the number of seconds before GDB gives up trying
5450 to read from the target. The default value is 2.
5452 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5454 By default GDB will automatically keep track of objects as they are
5455 loaded and unloaded by the dynamic linker. By using the command `set
5456 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5457 when shared library events occur, thus allowing you to set breakpoints
5458 in shared libraries which are explicitly loaded by the inferior.
5460 Note this feature does not work on hpux8. On hpux9 you must link
5461 /usr/lib/end.o into your program. This feature should work
5462 automatically on hpux10.
5464 * Irix 5.x hardware watchpoint support
5466 Irix 5 configurations now support the use of hardware watchpoints.
5468 * Mips protocol "SYN garbage limit"
5470 When debugging a Mips target using the `target mips' protocol, you
5471 may set the number of characters that GDB will ignore by setting
5472 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5473 every character. The default value is 1050.
5475 * Recording and replaying remote debug sessions
5477 If you set `remotelogfile' to the name of a file, gdb will write to it
5478 a recording of a remote debug session. This recording may then be
5479 replayed back to gdb using "gdbreplay". See gdbserver/README for
5480 details. This is useful when you have a problem with GDB while doing
5481 remote debugging; you can make a recording of the session and send it
5482 to someone else, who can then recreate the problem.
5484 * Speedups for remote debugging
5486 GDB includes speedups for downloading and stepping MIPS systems using
5487 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5488 and more efficient S-record downloading.
5490 * Memory use reductions and statistics collection
5492 GDB now uses less memory and reports statistics about memory usage.
5493 Try the `maint print statistics' command, for example.
5495 *** Changes in GDB-4.15:
5497 * Psymtabs for XCOFF
5499 The symbol reader for AIX GDB now uses partial symbol tables. This
5500 can greatly improve startup time, especially for large executables.
5502 * Remote targets use caching
5504 Remote targets now use a data cache to speed up communication with the
5505 remote side. The data cache could lead to incorrect results because
5506 it doesn't know about volatile variables, thus making it impossible to
5507 debug targets which use memory mapped I/O devices. `set remotecache
5508 off' turns the the data cache off.
5510 * Remote targets may have threads
5512 The standard remote protocol now includes support for multiple threads
5513 in the target system, using new protocol commands 'H' and 'T'. See
5514 gdb/remote.c for details.
5518 If GDB is configured with `--enable-netrom', then it will include
5519 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5520 acts as though it is a bank of ROM on the target board, but you can
5521 write into it over the network. GDB's support consists only of
5522 support for fast loading into the emulated ROM; to debug, you must use
5523 another protocol, such as standard remote protocol. The usual
5524 sequence is something like
5526 target nrom <netrom-hostname>
5528 target remote <netrom-hostname>:1235
5532 GDB now includes support for the Apple Macintosh, as a host only. It
5533 may be run as either an MPW tool or as a standalone application, and
5534 it can debug through the serial port. All the usual GDB commands are
5535 available, but to the target command, you must supply "serial" as the
5536 device type instead of "/dev/ttyXX". See mpw-README in the main
5537 directory for more information on how to build. The MPW configuration
5538 scripts */mpw-config.in support only a few targets, and only the
5539 mips-idt-ecoff target has been tested.
5543 GDB configuration now uses autoconf. This is not user-visible,
5544 but does simplify configuration and building.
5548 GDB now supports hpux10.
5550 *** Changes in GDB-4.14:
5552 * New native configurations
5554 x86 FreeBSD i[345]86-*-freebsd
5555 x86 NetBSD i[345]86-*-netbsd
5556 NS32k NetBSD ns32k-*-netbsd
5557 Sparc NetBSD sparc-*-netbsd
5561 A29K VxWorks a29k-*-vxworks
5562 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5563 CPU32 EST-300 emulator m68*-*-est*
5564 PowerPC ELF powerpc-*-elf
5567 * Alpha OSF/1 support for procfs
5569 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5570 possible to attach to running processes. As the mounting of the /proc
5571 filesystem is optional on the Alpha, GDB automatically determines
5572 the availability of /proc during startup. This can lead to problems
5573 if /proc is unmounted after GDB has been started.
5575 * Arguments to user-defined commands
5577 User commands may accept up to 10 arguments separated by whitespace.
5578 Arguments are accessed within the user command via $arg0..$arg9. A
5581 print $arg0 + $arg1 + $arg2
5583 To execute the command use:
5586 Defines the command "adder" which prints the sum of its three arguments.
5587 Note the arguments are text substitutions, so they may reference variables,
5588 use complex expressions, or even perform inferior function calls.
5590 * New `if' and `while' commands
5592 This makes it possible to write more sophisticated user-defined
5593 commands. Both commands take a single argument, which is the
5594 expression to evaluate, and must be followed by the commands to
5595 execute, one per line, if the expression is nonzero, the list being
5596 terminated by the word `end'. The `if' command list may include an
5597 `else' word, which causes the following commands to be executed only
5598 if the expression is zero.
5600 * Fortran source language mode
5602 GDB now includes partial support for Fortran 77. It will recognize
5603 Fortran programs and can evaluate a subset of Fortran expressions, but
5604 variables and functions may not be handled correctly. GDB will work
5605 with G77, but does not yet know much about symbols emitted by other
5608 * Better HPUX support
5610 Most debugging facilities now work on dynamic executables for HPPAs
5611 running hpux9 or later. You can attach to running dynamically linked
5612 processes, but by default the dynamic libraries will be read-only, so
5613 for instance you won't be able to put breakpoints in them. To change
5614 that behavior do the following before running the program:
5620 This will cause the libraries to be mapped private and read-write.
5621 To revert to the normal behavior, do this:
5627 You cannot set breakpoints or examine data in the library until after
5628 the library is loaded if the function/data symbols do not have
5631 GDB can now also read debug symbols produced by the HP C compiler on
5632 HPPAs (sorry, no C++, Fortran or 68k support).
5634 * Target byte order now dynamically selectable
5636 You can choose which byte order to use with a target system, via the
5637 commands "set endian big" and "set endian little", and you can see the
5638 current setting by using "show endian". You can also give the command
5639 "set endian auto", in which case GDB will use the byte order
5640 associated with the executable. Currently, only embedded MIPS
5641 configurations support dynamic selection of target byte order.
5643 * New DOS host serial code
5645 This version uses DPMI interrupts to handle buffered I/O, so you
5646 no longer need to run asynctsr when debugging boards connected to
5649 *** Changes in GDB-4.13:
5651 * New "complete" command
5653 This lists all the possible completions for the rest of the line, if it
5654 were to be given as a command itself. This is intended for use by emacs.
5656 * Trailing space optional in prompt
5658 "set prompt" no longer adds a space for you after the prompt you set. This
5659 allows you to set a prompt which ends in a space or one that does not.
5661 * Breakpoint hit counts
5663 "info break" now displays a count of the number of times the breakpoint
5664 has been hit. This is especially useful in conjunction with "ignore"; you
5665 can ignore a large number of breakpoint hits, look at the breakpoint info
5666 to see how many times the breakpoint was hit, then run again, ignoring one
5667 less than that number, and this will get you quickly to the last hit of
5670 * Ability to stop printing at NULL character
5672 "set print null-stop" will cause GDB to stop printing the characters of
5673 an array when the first NULL is encountered. This is useful when large
5674 arrays actually contain only short strings.
5676 * Shared library breakpoints
5678 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5679 breakpoints in shared libraries before the executable is run.
5681 * Hardware watchpoints
5683 There is a new hardware breakpoint for the watch command for sparclite
5684 targets. See gdb/sparclite/hw_breakpoint.note.
5686 Hardware watchpoints are also now supported under GNU/Linux.
5690 Annotations have been added. These are for use with graphical interfaces,
5691 and are still experimental. Currently only gdba.el uses these.
5693 * Improved Irix 5 support
5695 GDB now works properly with Irix 5.2.
5697 * Improved HPPA support
5699 GDB now works properly with the latest GCC and GAS.
5701 * New native configurations
5703 Sequent PTX4 i[34]86-sequent-ptx4
5704 HPPA running OSF/1 hppa*-*-osf*
5705 Atari TT running SVR4 m68*-*-sysv4*
5706 RS/6000 LynxOS rs6000-*-lynxos*
5710 OS/9000 i[34]86-*-os9k
5711 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5714 * Hitachi SH7000 and E7000-PC ICE support
5716 There is now support for communicating with the Hitachi E7000-PC ICE.
5717 This is available automatically when GDB is configured for the SH.
5721 As usual, a variety of small fixes and improvements, both generic
5722 and configuration-specific. See the ChangeLog for more detail.
5724 *** Changes in GDB-4.12:
5726 * Irix 5 is now supported
5730 GDB-4.12 on the HPPA has a number of changes which make it unable
5731 to debug the output from the currently released versions of GCC and
5732 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5733 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5734 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5737 *** Changes in GDB-4.11:
5739 * User visible changes:
5743 The "set remotedebug" option is now consistent between the mips remote
5744 target, remote targets using the gdb-specific protocol, UDI (AMD's
5745 debug protocol for the 29k) and the 88k bug monitor. It is now an
5746 integer specifying a debug level (normally 0 or 1, but 2 means more
5747 debugging info for the mips target).
5749 * DEC Alpha native support
5751 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5752 debug info, but GDB works fairly well with the DEC compiler and should
5753 work with a future GCC release. See the README file for a few
5754 Alpha-specific notes.
5756 * Preliminary thread implementation
5758 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5760 * LynxOS native and target support for 386
5762 This release has been hosted on LynxOS 2.2, and also can be configured
5763 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5766 * Improvements in C++ mangling/demangling.
5768 This release has much better g++ debugging, specifically in name
5769 mangling/demangling, virtual function calls, print virtual table,
5770 call methods, ...etc.
5772 *** Changes in GDB-4.10:
5774 * User visible changes:
5776 Remote debugging using the GDB-specific (`target remote') protocol now
5777 supports the `load' command. This is only useful if you have some
5778 other way of getting the stub to the target system, and you can put it
5779 somewhere in memory where it won't get clobbered by the download.
5781 Filename completion now works.
5783 When run under emacs mode, the "info line" command now causes the
5784 arrow to point to the line specified. Also, "info line" prints
5785 addresses in symbolic form (as well as hex).
5787 All vxworks based targets now support a user settable option, called
5788 vxworks-timeout. This option represents the number of seconds gdb
5789 should wait for responses to rpc's. You might want to use this if
5790 your vxworks target is, perhaps, a slow software simulator or happens
5791 to be on the far side of a thin network line.
5795 This release contains support for using a DEC alpha as a GDB host for
5796 cross debugging. Native alpha debugging is not supported yet.
5799 *** Changes in GDB-4.9:
5803 This is the first GDB release which is accompanied by a matching testsuite.
5804 The testsuite requires installation of dejagnu, which should be available
5805 via ftp from most sites that carry GNU software.
5809 'Cfront' style demangling has had its name changed to 'ARM' style, to
5810 emphasize that it was written from the specifications in the C++ Annotated
5811 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5812 disclaimers, it still generated too much confusion with users attempting to
5813 use gdb with AT&T cfront.
5817 GDB now uses a standard remote interface to a simulator library.
5818 So far, the library contains simulators for the Zilog Z8001/2, the
5819 Hitachi H8/300, H8/500 and Super-H.
5821 * New targets supported
5823 H8/300 simulator h8300-hitachi-hms or h8300hms
5824 H8/500 simulator h8500-hitachi-hms or h8500hms
5825 SH simulator sh-hitachi-hms or sh
5826 Z8000 simulator z8k-zilog-none or z8ksim
5827 IDT MIPS board over serial line mips-idt-ecoff
5829 Cross-debugging to GO32 targets is supported. It requires a custom
5830 version of the i386-stub.c module which is integrated with the
5831 GO32 memory extender.
5833 * New remote protocols
5835 MIPS remote debugging protocol.
5837 * New source languages supported
5839 This version includes preliminary support for Chill, a Pascal like language
5840 used by telecommunications companies. Chill support is also being integrated
5841 into the GNU compiler, but we don't know when it will be publically available.
5844 *** Changes in GDB-4.8:
5846 * HP Precision Architecture supported
5848 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5849 version of this support was available as a set of patches from the
5850 University of Utah. GDB does not support debugging of programs
5851 compiled with the HP compiler, because HP will not document their file
5852 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5853 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5855 Many problems in the preliminary version have been fixed.
5857 * Faster and better demangling
5859 We have improved template demangling and fixed numerous bugs in the GNU style
5860 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5861 character types (wchar_t) are now supported. Demangling of each symbol is now
5862 only done once, and is cached when the symbol table for a file is read in.
5863 This results in a small increase in memory usage for C programs, a moderate
5864 increase in memory usage for C++ programs, and a fantastic speedup in
5867 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5868 from the specifications in the Annotated Reference Manual, which AT&T's
5869 compiler does not actually implement.
5871 * G++ multiple inheritance compiler problem
5873 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5874 inheritance lattices was reworked to properly discover ambiguities. We
5875 recently found an example which causes this new algorithm to fail in a
5876 very subtle way, producing bad debug information for those classes.
5877 The file 'gcc.patch' (in this directory) can be applied to gcc to
5878 circumvent the problem. A future GCC release will contain a complete
5881 The previous G++ debug info problem (mentioned below for the gdb-4.7
5882 release) is fixed in gcc version 2.3.2.
5884 * Improved configure script
5886 The `configure' script will now attempt to guess your system type if
5887 you don't supply a host system type. The old scheme of supplying a
5888 host system triplet is preferable over using this. All the magic is
5889 done in the new `config.guess' script. Examine it for details.
5891 We have also brought our configure script much more in line with the FSF's
5892 version. It now supports the --with-xxx options. In particular,
5893 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5894 The resulting GDB will not be able to read arbitrary object file formats --
5895 only the format ``expected'' to be used on the configured target system.
5896 We hope to make this the default in a future release.
5898 * Documentation improvements
5900 There's new internal documentation on how to modify GDB, and how to
5901 produce clean changes to the code. We implore people to read it
5902 before submitting changes.
5904 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5905 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5906 `info' files are also provided. To build `info' files from scratch,
5907 you will need the latest `makeinfo' release, which will be available in
5908 a future texinfo-X.Y release.
5910 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5911 We're not sure exactly which versions have this problem, but it has
5912 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5913 or better. If that isn't possible, there is a patch in
5914 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5915 around this problem.
5919 GDB now supports array constants that can be used in expressions typed in by
5920 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5921 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5924 The new directory `gdb/sparclite' contains a program that demonstrates
5925 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5927 * New native hosts supported
5929 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5930 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5932 * New targets supported
5934 AMD 29k family via UDI a29k-amd-udi or udi29k
5936 * New file formats supported
5938 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5939 HPUX core files, and SCO 3.2v2 core files.
5943 Attaching to processes now works again; thanks for the many bug reports.
5945 We have also stomped on a bunch of core dumps caused by
5946 printf_filtered("%s") problems.
5948 We eliminated a copyright problem on the rpc and ptrace header files
5949 for VxWorks, which was discovered at the last minute during the 4.7
5950 release. You should now be able to build a VxWorks GDB.
5952 You can now interrupt gdb while an attached process is running. This
5953 will cause the attached process to stop, and give control back to GDB.
5955 We fixed problems caused by using too many file descriptors
5956 for reading symbols from object files and libraries. This was
5957 especially a problem for programs that used many (~100) shared
5960 The `step' command now only enters a subroutine if there is line number
5961 information for the subroutine. Otherwise it acts like the `next'
5962 command. Previously, `step' would enter subroutines if there was
5963 any debugging information about the routine. This avoids problems
5964 when using `cc -g1' on MIPS machines.
5966 * Internal improvements
5968 GDB's internal interfaces have been improved to make it easier to support
5969 debugging of multiple languages in the future.
5971 GDB now uses a common structure for symbol information internally.
5972 Minimal symbols (derived from linkage symbols in object files), partial
5973 symbols (from a quick scan of debug information), and full symbols
5974 contain a common subset of information, making it easier to write
5975 shared code that handles any of them.
5977 * New command line options
5979 We now accept --silent as an alias for --quiet.
5983 The memory-mapped-malloc library is now licensed under the GNU Library
5984 General Public License.
5986 *** Changes in GDB-4.7:
5988 * Host/native/target split
5990 GDB has had some major internal surgery to untangle the support for
5991 hosts and remote targets. Now, when you configure GDB for a remote
5992 target, it will no longer load in all of the support for debugging
5993 local programs on the host. When fully completed and tested, this will
5994 ensure that arbitrary host/target combinations are possible.
5996 The primary conceptual shift is to separate the non-portable code in
5997 GDB into three categories. Host specific code is required any time GDB
5998 is compiled on that host, regardless of the target. Target specific
5999 code relates to the peculiarities of the target, but can be compiled on
6000 any host. Native specific code is everything else: it can only be
6001 built when the host and target are the same system. Child process
6002 handling and core file support are two common `native' examples.
6004 GDB's use of /proc for controlling Unix child processes is now cleaner.
6005 It has been split out into a single module under the `target_ops' vector,
6006 plus two native-dependent functions for each system that uses /proc.
6008 * New hosts supported
6010 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6011 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6012 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6014 * New targets supported
6016 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6017 68030 and CPU32 m68030-*-*, m68332-*-*
6019 * New native hosts supported
6021 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6022 (386bsd is not well tested yet)
6023 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6025 * New file formats supported
6027 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6028 supports reading of `a.out.adobe' object files, which are an a.out
6029 format extended with minimal information about multiple sections.
6033 `show copying' is the same as the old `info copying'.
6034 `show warranty' is the same as `info warrantee'.
6035 These were renamed for consistency. The old commands continue to work.
6037 `info handle' is a new alias for `info signals'.
6039 You can now define pre-command hooks, which attach arbitrary command
6040 scripts to any command. The commands in the hook will be executed
6041 prior to the user's command. You can also create a hook which will be
6042 executed whenever the program stops. See gdb.texinfo.
6046 We now deal with Cfront style name mangling, and can even extract type
6047 info from mangled symbols. GDB can automatically figure out which
6048 symbol mangling style your C++ compiler uses.
6050 Calling of methods and virtual functions has been improved as well.
6054 The crash that occured when debugging Sun Ansi-C compiled binaries is
6055 fixed. This was due to mishandling of the extra N_SO stabs output
6058 We also finally got Ultrix 4.2 running in house, and fixed core file
6059 support, with help from a dozen people on the net.
6061 John M. Farrell discovered that the reason that single-stepping was so
6062 slow on all of the Mips based platforms (primarily SGI and DEC) was
6063 that we were trying to demangle and lookup a symbol used for internal
6064 purposes on every instruction that was being stepped through. Changing
6065 the name of that symbol so that it couldn't be mistaken for a C++
6066 mangled symbol sped things up a great deal.
6068 Rich Pixley sped up symbol lookups in general by getting much smarter
6069 about when C++ symbol mangling is necessary. This should make symbol
6070 completion (TAB on the command line) much faster. It's not as fast as
6071 we'd like, but it's significantly faster than gdb-4.6.
6075 A new user controllable variable 'call_scratch_address' can
6076 specify the location of a scratch area to be used when GDB
6077 calls a function in the target. This is necessary because the
6078 usual method of putting the scratch area on the stack does not work
6079 in systems that have separate instruction and data spaces.
6081 We integrated changes to support the 29k UDI (Universal Debugger
6082 Interface), but discovered at the last minute that we didn't have all
6083 of the appropriate copyright paperwork. We are working with AMD to
6084 resolve this, and hope to have it available soon.
6088 We have sped up the remote serial line protocol, especially for targets
6089 with lots of registers. It now supports a new `expedited status' ('T')
6090 message which can be used in place of the existing 'S' status message.
6091 This allows the remote stub to send only the registers that GDB
6092 needs to make a quick decision about single-stepping or conditional
6093 breakpoints, eliminating the need to fetch the entire register set for
6094 each instruction being stepped through.
6096 The GDB remote serial protocol now implements a write-through cache for
6097 registers, only re-reading the registers if the target has run.
6099 There is also a new remote serial stub for SPARC processors. You can
6100 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6101 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6102 processor with a serial port.
6106 Configure.in files have become much easier to read and modify. A new
6107 `table driven' format makes it more obvious what configurations are
6108 supported, and what files each one uses.
6112 There is a new opcodes library which will eventually contain all of the
6113 disassembly routines and opcode tables. At present, it only contains
6114 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6115 disassembler (binutils/objdump) to share these routines.
6117 The libiberty library is now copylefted under the GNU Library General
6118 Public License. This allows more liberal use, and was done so libg++
6119 can use it. This makes no difference to GDB, since the Library License
6120 grants all the rights from the General Public License.
6124 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6125 reference to the stabs symbol info used by the debugger. It is (as far
6126 as we know) the only published document on this fascinating topic. We
6127 encourage you to read it, compare it to the stabs information on your
6128 system, and send improvements on the document in general (to
6129 bug-gdb@prep.ai.mit.edu).
6131 And, of course, many bugs have been fixed.
6134 *** Changes in GDB-4.6:
6136 * Better support for C++ function names
6138 GDB now accepts as input the "demangled form" of C++ overloaded function
6139 names and member function names, and can do command completion on such names
6140 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6141 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6142 Make use of command completion, it is your friend.
6144 GDB also now accepts a variety of C++ mangled symbol formats. They are
6145 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6146 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6147 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6148 for the list of formats.
6150 * G++ symbol mangling problem
6152 Recent versions of gcc have a bug in how they emit debugging information for
6153 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6154 directory) can be applied to gcc to fix the problem. Alternatively, if you
6155 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6156 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6157 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6160 * New 'maintenance' command
6162 All of the commands related to hacking GDB internals have been moved out of
6163 the main command set, and now live behind the 'maintenance' command. This
6164 can also be abbreviated as 'mt'. The following changes were made:
6166 dump-me -> maintenance dump-me
6167 info all-breakpoints -> maintenance info breakpoints
6168 printmsyms -> maintenance print msyms
6169 printobjfiles -> maintenance print objfiles
6170 printpsyms -> maintenance print psymbols
6171 printsyms -> maintenance print symbols
6173 The following commands are new:
6175 maintenance demangle Call internal GDB demangler routine to
6176 demangle a C++ link name and prints the result.
6177 maintenance print type Print a type chain for a given symbol
6179 * Change to .gdbinit file processing
6181 We now read the $HOME/.gdbinit file before processing the argv arguments
6182 (e.g. reading symbol files or core files). This allows global parameters to
6183 be set, which will apply during the symbol reading. The ./.gdbinit is still
6184 read after argv processing.
6186 * New hosts supported
6188 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6190 GNU/Linux support i386-unknown-linux or linux
6192 We are also including code to support the HP/PA running BSD and HPUX. This
6193 is almost guaranteed not to work, as we didn't have time to test or build it
6194 for this release. We are including it so that the more adventurous (or
6195 masochistic) of you can play with it. We also had major problems with the
6196 fact that the compiler that we got from HP doesn't support the -g option.
6199 * New targets supported
6201 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6203 * More smarts about finding #include files
6205 GDB now remembers the compilation directory for all include files, and for
6206 all files from which C is generated (like yacc and lex sources). This
6207 greatly improves GDB's ability to find yacc/lex sources, and include files,
6208 especially if you are debugging your program from a directory different from
6209 the one that contains your sources.
6211 We also fixed a bug which caused difficulty with listing and setting
6212 breakpoints in include files which contain C code. (In the past, you had to
6213 try twice in order to list an include file that you hadn't looked at before.)
6215 * Interesting infernals change
6217 GDB now deals with arbitrary numbers of sections, where the symbols for each
6218 section must be relocated relative to that section's landing place in the
6219 target's address space. This work was needed to support ELF with embedded
6220 stabs used by Solaris-2.0.
6222 * Bug fixes (of course!)
6224 There have been loads of fixes for the following things:
6225 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6226 i960, stabs, DOS(GO32), procfs, etc...
6228 See the ChangeLog for details.
6230 *** Changes in GDB-4.5:
6232 * New machines supported (host and target)
6234 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6236 SGI Irix-4.x mips-sgi-irix4 or iris4
6238 * New malloc package
6240 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6241 Mmalloc is capable of handling mutiple heaps of memory. It is also
6242 capable of saving a heap to a file, and then mapping it back in later.
6243 This can be used to greatly speedup the startup of GDB by using a
6244 pre-parsed symbol table which lives in a mmalloc managed heap. For
6245 more details, please read mmalloc/mmalloc.texi.
6249 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6250 'help info proc' for details.
6252 * MIPS ecoff symbol table format
6254 The code that reads MIPS symbol table format is now supported on all hosts.
6255 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6258 * File name changes for MS-DOS
6260 Many files in the config directories have been renamed to make it easier to
6261 support GDB on MS-DOSe systems (which have very restrictive file name
6262 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6263 environment) is close to working but has some remaining problems. Note
6264 that debugging of DOS programs is not supported, due to limitations
6265 in the ``operating system'', but it can be used to host cross-debugging.
6267 * Cross byte order fixes
6269 Many fixes have been made to support cross debugging of Sparc and MIPS
6270 targets from hosts whose byte order differs.
6272 * New -mapped and -readnow options
6274 If memory-mapped files are available on your system through the 'mmap'
6275 system call, you can use the -mapped option on the `file' or
6276 `symbol-file' commands to cause GDB to write the symbols from your
6277 program into a reusable file. If the program you are debugging is
6278 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6279 Future GDB debugging sessions will notice the presence of this file,
6280 and will quickly map in symbol information from it, rather than reading
6281 the symbol table from the executable program. Using the '-mapped'
6282 option in a GDB `file' or `symbol-file' command has the same effect as
6283 starting GDB with the '-mapped' command-line option.
6285 You can cause GDB to read the entire symbol table immediately by using
6286 the '-readnow' option with any of the commands that load symbol table
6287 information (or on the GDB command line). This makes the command
6288 slower, but makes future operations faster.
6290 The -mapped and -readnow options are typically combined in order to
6291 build a `fred.syms' file that contains complete symbol information.
6292 A simple GDB invocation to do nothing but build a `.syms' file for future
6295 gdb -batch -nx -mapped -readnow programname
6297 The `.syms' file is specific to the host machine on which GDB is run.
6298 It holds an exact image of GDB's internal symbol table. It cannot be
6299 shared across multiple host platforms.
6301 * longjmp() handling
6303 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6304 siglongjmp() without losing control. This feature has not yet been ported to
6305 all systems. It currently works on many 386 platforms, all MIPS-based
6306 platforms (SGI, DECstation, etc), and Sun3/4.
6310 Preliminary work has been put in to support the new Solaris OS from Sun. At
6311 this time, it can control and debug processes, but it is not capable of
6316 As always, many many bug fixes. The major areas were with g++, and mipsread.
6317 People using the MIPS-based platforms should experience fewer mysterious
6318 crashes and trashed symbol tables.
6320 *** Changes in GDB-4.4:
6322 * New machines supported (host and target)
6324 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6326 BSD Reno on Vax vax-dec-bsd
6327 Ultrix on Vax vax-dec-ultrix
6329 * New machines supported (target)
6331 AMD 29000 embedded, using EBMON a29k-none-none
6335 GDB continues to improve its handling of C++. `References' work better.
6336 The demangler has also been improved, and now deals with symbols mangled as
6337 per the Annotated C++ Reference Guide.
6339 GDB also now handles `stabs' symbol information embedded in MIPS
6340 `ecoff' symbol tables. Since the ecoff format was not easily
6341 extensible to handle new languages such as C++, this appeared to be a
6342 good way to put C++ debugging info into MIPS binaries. This option
6343 will be supported in the GNU C compiler, version 2, when it is
6346 * New features for SVR4
6348 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6349 shared libraries. Debugging dynamically linked programs should present
6350 only minor differences from debugging statically linked programs.
6352 The `info proc' command will print out information about any process
6353 on an SVR4 system (including the one you are debugging). At the moment,
6354 it prints the address mappings of the process.
6356 If you bring up GDB on another SVR4 system, please send mail to
6357 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6359 * Better dynamic linking support in SunOS
6361 Reading symbols from shared libraries which contain debugging symbols
6362 now works properly. However, there remain issues such as automatic
6363 skipping of `transfer vector' code during function calls, which
6364 make it harder to debug code in a shared library, than to debug the
6365 same code linked statically.
6369 GDB is now using the latest `getopt' routines from the FSF. This
6370 version accepts the -- prefix for options with long names. GDB will
6371 continue to accept the old forms (-option and +option) as well.
6372 Various single letter abbreviations for options have been explicity
6373 added to the option table so that they won't get overshadowed in the
6374 future by other options that begin with the same letter.
6378 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6379 Many assorted bugs have been handled. Many more remain to be handled.
6380 See the various ChangeLog files (primarily in gdb and bfd) for details.
6383 *** Changes in GDB-4.3:
6385 * New machines supported (host and target)
6387 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6388 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6389 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6391 * Almost SCO Unix support
6393 We had hoped to support:
6394 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6395 (except for core file support), but we discovered very late in the release
6396 that it has problems with process groups that render gdb unusable. Sorry
6397 about that. I encourage people to fix it and post the fixes.
6399 * Preliminary ELF and DWARF support
6401 GDB can read ELF object files on System V Release 4, and can handle
6402 debugging records for C, in DWARF format, in ELF files. This support
6403 is preliminary. If you bring up GDB on another SVR4 system, please
6404 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6409 GDB now uses the latest `readline' library. One user-visible change
6410 is that two tabs will list possible command completions, which previously
6411 required typing M-? (meta-question mark, or ESC ?).
6415 The `stepi' bug that many of you noticed has been squashed.
6416 Many bugs in C++ have been handled. Many more remain to be handled.
6417 See the various ChangeLog files (primarily in gdb and bfd) for details.
6419 * State of the MIPS world (in case you wondered):
6421 GDB can understand the symbol tables emitted by the compilers
6422 supplied by most vendors of MIPS-based machines, including DEC. These
6423 symbol tables are in a format that essentially nobody else uses.
6425 Some versions of gcc come with an assembler post-processor called
6426 mips-tfile. This program is required if you want to do source-level
6427 debugging of gcc-compiled programs. I believe FSF does not ship
6428 mips-tfile with gcc version 1, but it will eventually come with gcc
6431 Debugging of g++ output remains a problem. g++ version 1.xx does not
6432 really support it at all. (If you're lucky, you should be able to get
6433 line numbers and stack traces to work, but no parameters or local
6434 variables.) With some work it should be possible to improve the
6437 When gcc version 2 is released, you will have somewhat better luck.
6438 However, even then you will get confusing results for inheritance and
6441 We will eventually provide full debugging of g++ output on
6442 DECstations. This will probably involve some kind of stabs-in-ecoff
6443 encapulation, but the details have not been worked out yet.
6446 *** Changes in GDB-4.2:
6448 * Improved configuration
6450 Only one copy of `configure' exists now, and it is not self-modifying.
6451 Porting BFD is simpler.
6455 The `step' and `next' commands now only stop at the first instruction
6456 of a source line. This prevents the multiple stops that used to occur
6457 in switch statements, for-loops, etc. `Step' continues to stop if a
6458 function that has debugging information is called within the line.
6462 Lots of small bugs fixed. More remain.
6464 * New host supported (not target)
6466 Intel 386 PC clone running Mach i386-none-mach
6469 *** Changes in GDB-4.1:
6471 * Multiple source language support
6473 GDB now has internal scaffolding to handle several source languages.
6474 It determines the type of each source file from its filename extension,
6475 and will switch expression parsing and number formatting to match the
6476 language of the function in the currently selected stack frame.
6477 You can also specifically set the language to be used, with
6478 `set language c' or `set language modula-2'.
6482 GDB now has preliminary support for the GNU Modula-2 compiler,
6483 currently under development at the State University of New York at
6484 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6485 continue through the fall of 1991 and into 1992.
6487 Other Modula-2 compilers are currently not supported, and attempting to
6488 debug programs compiled with them will likely result in an error as the
6489 symbol table is read. Feel free to work on it, though!
6491 There are hooks in GDB for strict type checking and range checking,
6492 in the `Modula-2 philosophy', but they do not currently work.
6496 GDB can now write to executable and core files (e.g. patch
6497 a variable's value). You must turn this switch on, specify
6498 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6499 by assigning a new value to a variable. Modifications take
6502 * Automatic SunOS shared library reading
6504 When you run your program, GDB automatically determines where its
6505 shared libraries (if any) have been loaded, and reads their symbols.
6506 The `share' command is no longer needed. This also works when
6507 examining core files.
6511 You can specify the number of lines that the `list' command shows.
6514 * New machines supported (host and target)
6516 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6517 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6518 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6520 * New hosts supported (not targets)
6522 IBM RT/PC: romp-ibm-aix or rtpc
6524 * New targets supported (not hosts)
6526 AMD 29000 embedded with COFF a29k-none-coff
6527 AMD 29000 embedded with a.out a29k-none-aout
6528 Ultracomputer remote kernel debug a29k-nyu-kern
6530 * New remote interfaces
6536 *** Changes in GDB-4.0:
6540 Wide output is wrapped at good places to make the output more readable.
6542 Gdb now supports cross-debugging from a host machine of one type to a
6543 target machine of another type. Communication with the target system
6544 is over serial lines. The ``target'' command handles connecting to the
6545 remote system; the ``load'' command will download a program into the
6546 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6547 also supports debugging of realtime processes running under VxWorks,
6548 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6549 stub on the target system.
6551 New CPUs supported include the AMD 29000 and Intel 960.
6553 GDB now reads object files and symbol tables via a ``binary file''
6554 library, which allows a single copy of GDB to debug programs of multiple
6555 object file types such as a.out and coff.
6557 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6558 refcard.dvi and refcard.ps are available to format it).
6561 * Control-Variable user interface simplified
6563 All variables that control the operation of the debugger can be set
6564 by the ``set'' command, and displayed by the ``show'' command.
6566 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6567 ``Show prompt'' produces the response:
6568 Gdb's prompt is new-gdb=>.
6570 What follows are the NEW set commands. The command ``help set'' will
6571 print a complete list of old and new set commands. ``help set FOO''
6572 will give a longer description of the variable FOO. ``show'' will show
6573 all of the variable descriptions and their current settings.
6575 confirm on/off: Enables warning questions for operations that are
6576 hard to recover from, e.g. rerunning the program while
6577 it is already running. Default is ON.
6579 editing on/off: Enables EMACS style command line editing
6580 of input. Previous lines can be recalled with
6581 control-P, the current line can be edited with control-B,
6582 you can search for commands with control-R, etc.
6585 history filename NAME: NAME is where the gdb command history
6586 will be stored. The default is .gdb_history,
6587 or the value of the environment variable
6590 history size N: The size, in commands, of the command history. The
6591 default is 256, or the value of the environment variable
6594 history save on/off: If this value is set to ON, the history file will
6595 be saved after exiting gdb. If set to OFF, the
6596 file will not be saved. The default is OFF.
6598 history expansion on/off: If this value is set to ON, then csh-like
6599 history expansion will be performed on
6600 command line input. The default is OFF.
6602 radix N: Sets the default radix for input and output. It can be set
6603 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6604 in the current radix, so "set radix 10" is always a no-op.
6606 height N: This integer value is the number of lines on a page. Default
6607 is 24, the current `stty rows'' setting, or the ``li#''
6608 setting from the termcap entry matching the environment
6611 width N: This integer value is the number of characters on a line.
6612 Default is 80, the current `stty cols'' setting, or the ``co#''
6613 setting from the termcap entry matching the environment
6616 Note: ``set screensize'' is obsolete. Use ``set height'' and
6617 ``set width'' instead.
6619 print address on/off: Print memory addresses in various command displays,
6620 such as stack traces and structure values. Gdb looks
6621 more ``symbolic'' if you turn this off; it looks more
6622 ``machine level'' with it on. Default is ON.
6624 print array on/off: Prettyprint arrays. New convenient format! Default
6627 print demangle on/off: Print C++ symbols in "source" form if on,
6630 print asm-demangle on/off: Same, for assembler level printouts
6633 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6636 * Support for Epoch Environment.
6638 The epoch environment is a version of Emacs v18 with windowing. One
6639 new command, ``inspect'', is identical to ``print'', except that if you
6640 are running in the epoch environment, the value is printed in its own
6644 * Support for Shared Libraries
6646 GDB can now debug programs and core files that use SunOS shared libraries.
6647 Symbols from a shared library cannot be referenced
6648 before the shared library has been linked with the program (this
6649 happens after you type ``run'' and before the function main() is entered).
6650 At any time after this linking (including when examining core files
6651 from dynamically linked programs), gdb reads the symbols from each
6652 shared library when you type the ``sharedlibrary'' command.
6653 It can be abbreviated ``share''.
6655 sharedlibrary REGEXP: Load shared object library symbols for files
6656 matching a unix regular expression. No argument
6657 indicates to load symbols for all shared libraries.
6659 info sharedlibrary: Status of loaded shared libraries.
6664 A watchpoint stops execution of a program whenever the value of an
6665 expression changes. Checking for this slows down execution
6666 tremendously whenever you are in the scope of the expression, but is
6667 quite useful for catching tough ``bit-spreader'' or pointer misuse
6668 problems. Some machines such as the 386 have hardware for doing this
6669 more quickly, and future versions of gdb will use this hardware.
6671 watch EXP: Set a watchpoint (breakpoint) for an expression.
6673 info watchpoints: Information about your watchpoints.
6675 delete N: Deletes watchpoint number N (same as breakpoints).
6676 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6677 enable N: Re-enables watchpoint number N (same as breakpoints).
6680 * C++ multiple inheritance
6682 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6685 * C++ exception handling
6687 Gdb now supports limited C++ exception handling. Besides the existing
6688 ability to breakpoint on an exception handler, gdb can breakpoint on
6689 the raising of an exception (before the stack is peeled back to the
6692 catch FOO: If there is a FOO exception handler in the dynamic scope,
6693 set a breakpoint to catch exceptions which may be raised there.
6694 Multiple exceptions (``catch foo bar baz'') may be caught.
6696 info catch: Lists all exceptions which may be caught in the
6697 current stack frame.
6700 * Minor command changes
6702 The command ``call func (arg, arg, ...)'' now acts like the print
6703 command, except it does not print or save a value if the function's result
6704 is void. This is similar to dbx usage.
6706 The ``up'' and ``down'' commands now always print the frame they end up
6707 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6708 frames without printing.
6710 * New directory command
6712 'dir' now adds directories to the FRONT of the source search path.
6713 The path starts off empty. Source files that contain debug information
6714 about the directory in which they were compiled can be found even
6715 with an empty path; Sun CC and GCC include this information. If GDB can't
6716 find your source file in the current directory, type "dir .".
6718 * Configuring GDB for compilation
6720 For normal use, type ``./configure host''. See README or gdb.texinfo
6723 GDB now handles cross debugging. If you are remotely debugging between
6724 two different machines, type ``./configure host -target=targ''.
6725 Host is the machine where GDB will run; targ is the machine
6726 where the program that you are debugging will run.