1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.0
6 * GDB now supports access to the guarded-storage-control registers and the
7 software-based guarded-storage broadcast control registers on IBM z14.
9 * On Unix systems, GDB now supports transmitting environment variables
10 that are to be set or unset to GDBserver. These variables will
11 affect the environment to be passed to the remote inferior.
13 To inform GDB of environment variables that are to be transmitted to
14 GDBserver, use the "set environment" command. Only user set
15 environment variables are sent to GDBserver.
17 To inform GDB of environment variables that are to be unset before
18 the remote inferior is started by the GDBserver, use the "unset
23 ** New events gdb.new_inferior, gdb.inferior_deleted, and
24 gdb.new_thread are emitted. See the manual for further
27 * New features in the GDB remote stub, GDBserver
29 ** New "--selftest" command line option runs some GDBserver self
30 tests. These self tests are disabled in releases.
32 ** On Unix systems, GDBserver now does globbing expansion and variable
33 substitution in inferior command line arguments.
35 This is done by starting inferiors using a shell, like GDB does.
36 See "set startup-with-shell" in the user manual for how to disable
37 this from GDB when using "target extended-remote". When using
38 "target remote", you can disable the startup with shell by using the
39 new "--no-startup-with-shell" GDBserver command line option.
41 ** On Unix systems, GDBserver now supports receiving environment
42 variables that are to be set or unset from GDB. These variables
43 will affect the environment to be passed to the inferior.
47 QEnvironmentHexEncoded
48 Inform GDBserver of an environment variable that is to be passed to
49 the inferior when starting it.
52 Inform GDBserver of an environment variable that is to be unset
53 before starting the remote inferior.
56 Inform GDBserver that the environment should be reset (i.e.,
57 user-set environment variables should be unset).
60 Indicates whether the inferior must be started with a shell or not.
62 * The "maintenance print c-tdesc" command now takes an optional
63 argument which is the file name of XML target description.
65 * The "maintenance selftest" command now takes an optional argument to
66 filter the tests to be run.
71 Set and show compilation command used for compiling and injecting code
72 with the 'compile' commands.
74 set debug separate-debug-file
75 show debug separate-debug-file
76 Control the display of debug output about separate debug file search.
79 List the registered selftests.
82 Start the debugged program stopping at the first instruction.
84 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
87 * Safer/improved support for debugging with no debug info
89 GDB no longer assumes functions with no debug information return
92 This means that GDB now refuses to call such functions unless you
93 tell it the function's type, by either casting the call to the
94 declared return type, or by casting the function to a function
95 pointer of the right type, and calling that:
97 (gdb) p getenv ("PATH")
98 'getenv' has unknown return type; cast the call to its declared return type
99 (gdb) p (char *) getenv ("PATH")
100 $1 = 0x7fffffffe "/usr/local/bin:/"...
101 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
102 $2 = 0x7fffffffe "/usr/local/bin:/"...
104 Similarly, GDB no longer assumes that global variables with no debug
105 info have type 'int', and refuses to print the variable's value
106 unless you tell it the variable's type:
109 'var' has unknown type; cast it to its declared type
113 * New native configurations
115 FreeBSD/aarch64 aarch64*-*-freebsd*
119 FreeBSD/aarch64 aarch64*-*-freebsd*
121 * Removed targets and native configurations
123 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
125 *** Changes in GDB 8.0
127 * GDB now supports access to the PKU register on GNU/Linux. The register is
128 added by the Memory Protection Keys for Userspace feature which will be
129 available in future Intel CPUs.
131 * GDB now supports C++11 rvalue references.
135 ** New functions to start, stop and access a running btrace recording.
136 ** Rvalue references are now supported in gdb.Type.
138 * GDB now supports recording and replaying rdrand and rdseed Intel 64
141 * Building GDB and GDBserver now requires a C++11 compiler.
143 For example, GCC 4.8 or later.
145 It is no longer possible to build GDB or GDBserver with a C
146 compiler. The --disable-build-with-cxx configure option has been
149 * Building GDB and GDBserver now requires GNU make >= 3.81.
151 It is no longer supported to build GDB or GDBserver with another
152 implementation of the make program or an earlier version of GNU make.
154 * Native debugging on MS-Windows supports command-line redirection
156 Command-line arguments used for starting programs on MS-Windows can
157 now include redirection symbols supported by native Windows shells,
158 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
159 as "run", "start", and "set args", as well as the corresponding MI
162 * Support for thread names on MS-Windows.
164 GDB now catches and handles the special exception that programs
165 running on MS-Windows use to assign names to threads in the
168 * Support for Java programs compiled with gcj has been removed.
170 * User commands now accept an unlimited number of arguments.
171 Previously, only up to 10 was accepted.
173 * The "eval" command now expands user-defined command arguments.
175 This makes it easier to process a variable number of arguments:
180 eval "print $arg%d", $i
185 * Target descriptions can now describe registers for sparc32 and sparc64.
187 * GDB now supports DWARF version 5 (debug information format).
188 Its .debug_names index is not yet supported.
190 * New native configurations
192 FreeBSD/mips mips*-*-freebsd
196 Synopsys ARC arc*-*-elf32
197 FreeBSD/mips mips*-*-freebsd
199 * Removed targets and native configurations
201 Alpha running FreeBSD alpha*-*-freebsd*
202 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
207 Erases all the flash memory regions reported by the target.
209 maint print arc arc-instruction address
210 Print internal disassembler information about instruction at a given address.
214 set disassembler-options
215 show disassembler-options
216 Controls the passing of target specific information to the disassembler.
217 If it is necessary to specify more than one disassembler option then
218 multiple options can be placed together into a comma separated list.
219 The default value is the empty string. Currently, the only supported
220 targets are ARM, PowerPC and S/390.
225 Erases all the flash memory regions reported by the target. This is
226 equivalent to the CLI command flash-erase.
228 -file-list-shared-libraries
229 List the shared libraries in the program. This is
230 equivalent to the CLI command "info shared".
232 *** Changes in GDB 7.12
234 * GDB and GDBserver now build with a C++ compiler by default.
236 The --enable-build-with-cxx configure option is now enabled by
237 default. One must now explicitly configure with
238 --disable-build-with-cxx in order to build with a C compiler. This
239 option will be removed in a future release.
241 * GDBserver now supports recording btrace without maintaining an active
244 * GDB now supports a negative repeat count in the 'x' command to examine
245 memory backward from the given address. For example:
248 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
249 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
250 (gdb) x/-5i 0x0000000000400580
251 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
252 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
253 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
254 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
255 0x40057b <main(int, char**)+25>:
256 callq 0x400536 <Func1(int, char const*)>
258 * Fortran: Support structures with fields of dynamic types and
259 arrays of dynamic types.
261 * The symbol dumping maintenance commands have new syntax.
262 maint print symbols [-pc address] [--] [filename]
263 maint print symbols [-objfile objfile] [-source source] [--] [filename]
264 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
265 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
266 maint print msymbols [-objfile objfile] [--] [filename]
268 * GDB now supports multibit bitfields and enums in target register
271 * New Python-based convenience function $_as_string(val), which returns
272 the textual representation of a value. This function is especially
273 useful to obtain the text label of an enum value.
275 * Intel MPX bound violation handling.
277 Segmentation faults caused by a Intel MPX boundary violation
278 now display the kind of violation (upper or lower), the memory
279 address accessed and the memory bounds, along with the usual
280 signal received and code location.
284 Program received signal SIGSEGV, Segmentation fault
285 Upper bound violation while accessing address 0x7fffffffc3b3
286 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
287 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
289 * Rust language support.
290 GDB now supports debugging programs written in the Rust programming
291 language. See https://www.rust-lang.org/ for more information about
294 * Support for running interpreters on specified input/output devices
296 GDB now supports a new mechanism that allows frontends to provide
297 fully featured GDB console views, as a better alternative to
298 building such views on top of the "-interpreter-exec console"
299 command. See the new "new-ui" command below. With that command,
300 frontends can now start GDB in the traditional command-line mode
301 running in an embedded terminal emulator widget, and create a
302 separate MI interpreter running on a specified i/o device. In this
303 way, GDB handles line editing, history, tab completion, etc. in the
304 console all by itself, and the GUI uses the separate MI interpreter
305 for its own control and synchronization, invisible to the command
308 * The "catch syscall" command catches groups of related syscalls.
310 The "catch syscall" command now supports catching a group of related
311 syscalls using the 'group:' or 'g:' prefix.
316 skip -gfile file-glob-pattern
317 skip -function function
318 skip -rfunction regular-expression
319 A generalized form of the skip command, with new support for
320 glob-style file names and regular expressions for function names.
321 Additionally, a file spec and a function spec may now be combined.
323 maint info line-table REGEXP
324 Display the contents of GDB's internal line table data struture.
327 Run any GDB unit tests that were compiled in.
330 Start a new user interface instance running INTERP as interpreter,
331 using the TTY file for input/output.
335 ** gdb.Breakpoint objects have a new attribute "pending", which
336 indicates whether the breakpoint is pending.
337 ** Three new breakpoint-related events have been added:
338 gdb.breakpoint_created, gdb.breakpoint_modified, and
339 gdb.breakpoint_deleted.
342 Signal ("set") the given MS-Windows event object. This is used in
343 conjunction with the Windows JIT debugging (AeDebug) support, where
344 the OS suspends a crashing process until a debugger can attach to
345 it. Resuming the crashing process, in order to debug it, is done by
348 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
349 was added in GDBserver, including JIT compiling fast tracepoint's
350 conditional expression bytecode into native code.
352 * Support for various remote target protocols and ROM monitors has
355 target m32rsdi Remote M32R debugging over SDI
356 target mips MIPS remote debugging protocol
357 target pmon PMON ROM monitor
358 target ddb NEC's DDB variant of PMON for Vr4300
359 target rockhopper NEC RockHopper variant of PMON
360 target lsi LSI variant of PMO
362 * Support for tracepoints and fast tracepoints on powerpc-linux,
363 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
364 including JIT compiling fast tracepoint's conditional expression
365 bytecode into native code.
367 * MI async record =record-started now includes the method and format used for
368 recording. For example:
370 =record-started,thread-group="i1",method="btrace",format="bts"
372 * MI async record =thread-selected now includes the frame field. For example:
374 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
378 Andes NDS32 nds32*-*-elf
380 *** Changes in GDB 7.11
382 * GDB now supports debugging kernel-based threads on FreeBSD.
384 * Per-inferior thread numbers
386 Thread numbers are now per inferior instead of global. If you're
387 debugging multiple inferiors, GDB displays thread IDs using a
388 qualified INF_NUM.THR_NUM form. For example:
392 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
393 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
394 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
395 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
397 As consequence, thread numbers as visible in the $_thread
398 convenience variable and in Python's InferiorThread.num attribute
399 are no longer unique between inferiors.
401 GDB now maintains a second thread ID per thread, referred to as the
402 global thread ID, which is the new equivalent of thread numbers in
403 previous releases. See also $_gthread below.
405 For backwards compatibility, MI's thread IDs always refer to global
408 * Commands that accept thread IDs now accept the qualified
409 INF_NUM.THR_NUM form as well. For example:
412 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
415 * In commands that accept a list of thread IDs, you can now refer to
416 all threads of an inferior using a star wildcard. GDB accepts
417 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
418 refer to all threads of the current inferior. For example, "info
421 * You can use "info threads -gid" to display the global thread ID of
424 * The new convenience variable $_gthread holds the global number of
427 * The new convenience variable $_inferior holds the number of the
430 * GDB now displays the ID and name of the thread that hit a breakpoint
431 or received a signal, if your program is multi-threaded. For
434 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
435 Thread 1 "main" received signal SIGINT, Interrupt.
437 * Record btrace now supports non-stop mode.
439 * Support for tracepoints on aarch64-linux was added in GDBserver.
441 * The 'record instruction-history' command now indicates speculative execution
442 when using the Intel Processor Trace recording format.
444 * GDB now allows users to specify explicit locations, bypassing
445 the linespec parser. This feature is also available to GDB/MI
448 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
449 GDB now is able to debug both AArch64 applications and ARM applications
452 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
453 including JIT compiling fast tracepoint's conditional expression bytecode
456 * GDB now supports displaced stepping on AArch64 GNU/Linux.
458 * "info threads", "info inferiors", "info display", "info checkpoints"
459 and "maint info program-spaces" now list the corresponding items in
460 ascending ID order, for consistency with all other "info" commands.
462 * In Ada, the overloads selection menu has been enhanced to display the
463 parameter types and the return types for the matching overloaded subprograms.
467 maint set target-non-stop (on|off|auto)
468 maint show target-non-stop
469 Control whether GDB targets always operate in non-stop mode even if
470 "set non-stop" is "off". The default is "auto", meaning non-stop
471 mode is enabled if supported by the target.
473 maint set bfd-sharing
474 maint show bfd-sharing
475 Control the reuse of bfd objects.
479 Control display of debugging info regarding bfd caching.
483 Control display of debugging info regarding FreeBSD threads.
485 set remote multiprocess-extensions-packet
486 show remote multiprocess-extensions-packet
487 Set/show the use of the remote protocol multiprocess extensions.
489 set remote thread-events
490 show remote thread-events
491 Set/show the use of thread create/exit events.
493 set ada print-signatures on|off
494 show ada print-signatures"
495 Control whether parameter types and return types are displayed in overloads
496 selection menus. It is activaled (@code{on}) by default.
500 Controls the maximum size of memory, in bytes, that GDB will
501 allocate for value contents. Prevents incorrect programs from
502 causing GDB to allocate overly large buffers. Default is 64k.
504 * The "disassemble" command accepts a new modifier: /s.
505 It prints mixed source+disassembly like /m with two differences:
506 - disassembled instructions are now printed in program order, and
507 - and source for all relevant files is now printed.
508 The "/m" option is now considered deprecated: its "source-centric"
509 output hasn't proved useful in practice.
511 * The "record instruction-history" command accepts a new modifier: /s.
512 It behaves exactly like /m and prints mixed source+disassembly.
514 * The "set scheduler-locking" command supports a new mode "replay".
515 It behaves like "off" in record mode and like "on" in replay mode.
517 * Support for various ROM monitors has been removed:
519 target dbug dBUG ROM monitor for Motorola ColdFire
520 target picobug Motorola picobug monitor
521 target dink32 DINK32 ROM monitor for PowerPC
522 target m32r Renesas M32R/D ROM monitor
523 target mon2000 mon2000 ROM monitor
524 target ppcbug PPCBUG ROM monitor for PowerPC
526 * Support for reading/writing memory and extracting values on architectures
527 whose memory is addressable in units of any integral multiple of 8 bits.
532 Indicates that an exec system call was executed.
534 exec-events feature in qSupported
535 The qSupported packet allows GDB to request support for exec
536 events using the new 'gdbfeature' exec-event, and the qSupported
537 response can contain the corresponding 'stubfeature'. Set and
538 show commands can be used to display whether these features are enabled.
541 Equivalent to interrupting with the ^C character, but works in
544 thread created stop reason (T05 create:...)
545 Indicates that the thread was just created and is stopped at entry.
547 thread exit stop reply (w exitcode;tid)
548 Indicates that the thread has terminated.
551 Enables/disables thread create and exit event reporting. For
552 example, this is used in non-stop mode when GDB stops a set of
553 threads and synchronously waits for the their corresponding stop
554 replies. Without exit events, if one of the threads exits, GDB
555 would hang forever not knowing that it should no longer expect a
556 stop for that same thread.
559 Indicates that there are no resumed threads left in the target (all
560 threads are stopped). The remote stub reports support for this stop
561 reply to GDB's qSupported query.
564 Enables/disables catching syscalls from the inferior process.
565 The remote stub reports support for this packet to GDB's qSupported query.
567 syscall_entry stop reason
568 Indicates that a syscall was just called.
570 syscall_return stop reason
571 Indicates that a syscall just returned.
573 * Extended-remote exec events
575 ** GDB now has support for exec events on extended-remote Linux targets.
576 For such targets with Linux kernels 2.5.46 and later, this enables
577 follow-exec-mode and exec catchpoints.
579 set remote exec-event-feature-packet
580 show remote exec-event-feature-packet
581 Set/show the use of the remote exec event feature.
583 * Thread names in remote protocol
585 The reply to qXfer:threads:read may now include a name attribute for each
588 * Target remote mode fork and exec events
590 ** GDB now has support for fork and exec events on target remote mode
591 Linux targets. For such targets with Linux kernels 2.5.46 and later,
592 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
593 fork and exec catchpoints.
595 * Remote syscall events
597 ** GDB now has support for catch syscall on remote Linux targets,
598 currently enabled on x86/x86_64 architectures.
600 set remote catch-syscall-packet
601 show remote catch-syscall-packet
602 Set/show the use of the remote catch syscall feature.
606 ** The -var-set-format command now accepts the zero-hexadecimal
607 format. It outputs data in hexadecimal format with zero-padding on the
612 ** gdb.InferiorThread objects have a new attribute "global_num",
613 which refers to the thread's global thread ID. The existing
614 "num" attribute now refers to the thread's per-inferior number.
615 See "Per-inferior thread numbers" above.
616 ** gdb.InferiorThread objects have a new attribute "inferior", which
617 is the Inferior object the thread belongs to.
619 *** Changes in GDB 7.10
621 * Support for process record-replay and reverse debugging on aarch64*-linux*
622 targets has been added. GDB now supports recording of A64 instruction set
623 including advance SIMD instructions.
625 * Support for Sun's version of the "stabs" debug file format has been removed.
627 * GDB now honors the content of the file /proc/PID/coredump_filter
628 (PID is the process ID) on GNU/Linux systems. This file can be used
629 to specify the types of memory mappings that will be included in a
630 corefile. For more information, please refer to the manual page of
631 "core(5)". GDB also has a new command: "set use-coredump-filter
632 on|off". It allows to set whether GDB will read the content of the
633 /proc/PID/coredump_filter file when generating a corefile.
635 * The "info os" command on GNU/Linux can now display information on
637 "info os cpus" Listing of all cpus/cores on the system
639 * GDB has two new commands: "set serial parity odd|even|none" and
640 "show serial parity". These allows to set or show parity for the
643 * The "info source" command now displays the producer string if it was
644 present in the debug info. This typically includes the compiler version
645 and may include things like its command line arguments.
647 * The "info dll", an alias of the "info sharedlibrary" command,
648 is now available on all platforms.
650 * Directory names supplied to the "set sysroot" commands may be
651 prefixed with "target:" to tell GDB to access shared libraries from
652 the target system, be it local or remote. This replaces the prefix
653 "remote:". The default sysroot has been changed from "" to
654 "target:". "remote:" is automatically converted to "target:" for
655 backward compatibility.
657 * The system root specified by "set sysroot" will be prepended to the
658 filename of the main executable (if reported to GDB as absolute by
659 the operating system) when starting processes remotely, and when
660 attaching to already-running local or remote processes.
662 * GDB now supports automatic location and retrieval of executable
663 files from remote targets. Remote debugging can now be initiated
664 using only a "target remote" or "target extended-remote" command
665 (no "set sysroot" or "file" commands are required). See "New remote
668 * The "dump" command now supports verilog hex format.
670 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
672 * On GNU/Linux, GDB and gdbserver are now able to access executable
673 and shared library files without a "set sysroot" command when
674 attaching to processes running in different mount namespaces from
675 the debugger. This makes it possible to attach to processes in
676 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
677 See "New remote packets" below.
679 * The "tui reg" command now provides completion for all of the
680 available register groups, including target specific groups.
682 * The HISTSIZE environment variable is no longer read when determining
683 the size of GDB's command history. GDB now instead reads the dedicated
684 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
685 disables truncation of command history. Non-numeric values of GDBHISTSIZE
690 ** Memory ports can now be unbuffered.
694 ** gdb.Objfile objects have a new attribute "username",
695 which is the name of the objfile as specified by the user,
696 without, for example, resolving symlinks.
697 ** You can now write frame unwinders in Python.
698 ** gdb.Type objects have a new method "optimized_out",
699 returning optimized out gdb.Value instance of this type.
700 ** gdb.Value objects have new methods "reference_value" and
701 "const_value" which return a reference to the value and a
702 "const" version of the value respectively.
706 maint print symbol-cache
707 Print the contents of the symbol cache.
709 maint print symbol-cache-statistics
710 Print statistics of symbol cache usage.
712 maint flush-symbol-cache
713 Flush the contents of the symbol cache.
717 Start branch trace recording using Branch Trace Store (BTS) format.
720 Evaluate expression by using the compiler and print result.
724 Explicit commands for enabling and disabling tui mode.
727 set mpx bound on i386 and amd64
728 Support for bound table investigation on Intel MPX enabled applications.
732 Start branch trace recording using Intel Processor Trace format.
735 Print information about branch tracing internals.
737 maint btrace packet-history
738 Print the raw branch tracing data.
740 maint btrace clear-packet-history
741 Discard the stored raw branch tracing data.
744 Discard all branch tracing data. It will be fetched and processed
745 anew by the next "record" command.
750 Renamed from "set debug dwarf2-die".
752 Renamed from "show debug dwarf2-die".
755 Renamed from "set debug dwarf2-read".
756 show debug dwarf-read
757 Renamed from "show debug dwarf2-read".
759 maint set dwarf always-disassemble
760 Renamed from "maint set dwarf2 always-disassemble".
761 maint show dwarf always-disassemble
762 Renamed from "maint show dwarf2 always-disassemble".
764 maint set dwarf max-cache-age
765 Renamed from "maint set dwarf2 max-cache-age".
766 maint show dwarf max-cache-age
767 Renamed from "maint show dwarf2 max-cache-age".
770 show debug dwarf-line
771 Control display of debugging info regarding DWARF line processing.
775 Set the maximum number of candidates to be considered during
776 completion. The default value is 200. This limit allows GDB
777 to avoid generating large completion lists, the computation of
778 which can cause the debugger to become temporarily unresponsive.
780 set history remove-duplicates
781 show history remove-duplicates
782 Control the removal of duplicate history entries.
784 maint set symbol-cache-size
785 maint show symbol-cache-size
786 Control the size of the symbol cache.
788 set|show record btrace bts buffer-size
789 Set and show the size of the ring buffer used for branch tracing in
791 The obtained size may differ from the requested size. Use "info
792 record" to see the obtained buffer size.
794 set debug linux-namespaces
795 show debug linux-namespaces
796 Control display of debugging info regarding Linux namespaces.
798 set|show record btrace pt buffer-size
799 Set and show the size of the ring buffer used for branch tracing in
800 Intel Processor Trace format.
801 The obtained size may differ from the requested size. Use "info
802 record" to see the obtained buffer size.
804 maint set|show btrace pt skip-pad
805 Set and show whether PAD packets are skipped when computing the
808 * The command 'thread apply all' can now support new option '-ascending'
809 to call its specified command for all threads in ascending order.
811 * Python/Guile scripting
813 ** GDB now supports auto-loading of Python/Guile scripts contained in the
814 special section named `.debug_gdb_scripts'.
818 qXfer:btrace-conf:read
819 Return the branch trace configuration for the current thread.
821 Qbtrace-conf:bts:size
822 Set the requested ring buffer size for branch tracing in BTS format.
825 Enable Intel Procesor Trace-based branch tracing for the current
826 process. The remote stub reports support for this packet to GDB's
830 Set the requested ring buffer size for branch tracing in Intel Processor
834 Indicates a memory breakpoint instruction was executed, irrespective
835 of whether it was GDB that planted the breakpoint or the breakpoint
836 is hardcoded in the program. This is required for correct non-stop
840 Indicates the target stopped for a hardware breakpoint. This is
841 required for correct non-stop mode operation.
844 Return information about files on the remote system.
847 Return the full absolute name of the file that was executed to
848 create a process running on the remote system.
851 Select the filesystem on which vFile: operations with filename
852 arguments will operate. This is required for GDB to be able to
853 access files on remote targets where the remote stub does not
854 share a common filesystem with the inferior(s).
857 Indicates that a fork system call was executed.
860 Indicates that a vfork system call was executed.
862 vforkdone stop reason
863 Indicates that a vfork child of the specified process has executed
864 an exec or exit, allowing the vfork parent to resume execution.
866 fork-events and vfork-events features in qSupported
867 The qSupported packet allows GDB to request support for fork and
868 vfork events using new 'gdbfeatures' fork-events and vfork-events,
869 and the qSupported response can contain the corresponding
870 'stubfeatures'. Set and show commands can be used to display
871 whether these features are enabled.
873 * Extended-remote fork events
875 ** GDB now has support for fork events on extended-remote Linux
876 targets. For targets with Linux kernels 2.5.60 and later, this
877 enables follow-fork-mode and detach-on-fork for both fork and
878 vfork, as well as fork and vfork catchpoints.
880 * The info record command now shows the recording format and the
881 branch tracing configuration for the current thread when using
882 the btrace record target.
883 For the BTS format, it shows the ring buffer size.
885 * GDB now has support for DTrace USDT (Userland Static Defined
886 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
888 * GDB now supports access to vector registers on S/390 GNU/Linux
891 * Removed command line options
893 -xdb HP-UX XDB compatibility mode.
895 * Removed targets and native configurations
897 HP/PA running HP-UX hppa*-*-hpux*
898 Itanium running HP-UX ia64-*-hpux*
900 * New configure options
903 This configure option allows the user to build GDB with support for
904 Intel Processor Trace (default: auto). This requires libipt.
906 --with-libipt-prefix=PATH
907 Specify the path to the version of libipt that GDB should use.
908 $PATH/include should contain the intel-pt.h header and
909 $PATH/lib should contain the libipt.so library.
911 *** Changes in GDB 7.9.1
915 ** Xmethods can now specify a result type.
917 *** Changes in GDB 7.9
919 * GDB now supports hardware watchpoints on x86 GNU Hurd.
923 ** You can now access frame registers from Python scripts.
924 ** New attribute 'producer' for gdb.Symtab objects.
925 ** gdb.Objfile objects have a new attribute "progspace",
926 which is the gdb.Progspace object of the containing program space.
927 ** gdb.Objfile objects have a new attribute "owner".
928 ** gdb.Objfile objects have a new attribute "build_id",
929 which is the build ID generated when the file was built.
930 ** gdb.Objfile objects have a new method "add_separate_debug_file".
931 ** A new event "gdb.clear_objfiles" has been added, triggered when
932 selecting a new file to debug.
933 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
934 ** New function gdb.lookup_objfile.
936 New events which are triggered when GDB modifies the state of the
939 ** gdb.events.inferior_call_pre: Function call is about to be made.
940 ** gdb.events.inferior_call_post: Function call has just been made.
941 ** gdb.events.memory_changed: A memory location has been altered.
942 ** gdb.events.register_changed: A register has been altered.
944 * New Python-based convenience functions:
946 ** $_caller_is(name [, number_of_frames])
947 ** $_caller_matches(regexp [, number_of_frames])
948 ** $_any_caller_is(name [, number_of_frames])
949 ** $_any_caller_matches(regexp [, number_of_frames])
951 * GDB now supports the compilation and injection of source code into
952 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
953 to compile the source code to object code, and if successful, inject
954 and execute that code within the current context of the inferior.
955 Currently the C language is supported. The commands used to
956 interface with this new feature are:
958 compile code [-raw|-r] [--] [source code]
959 compile file [-raw|-r] filename
963 demangle [-l language] [--] name
964 Demangle "name" in the specified language, or the current language
965 if elided. This command is renamed from the "maint demangle" command.
966 The latter is kept as a no-op to avoid "maint demangle" being interpreted
967 as "maint demangler-warning".
969 queue-signal signal-name-or-number
970 Queue a signal to be delivered to the thread when it is resumed.
972 add-auto-load-scripts-directory directory
973 Add entries to the list of directories from which to load auto-loaded
976 maint print user-registers
977 List all currently available "user" registers.
979 compile code [-r|-raw] [--] [source code]
980 Compile, inject, and execute in the inferior the executable object
981 code produced by compiling the provided source code.
983 compile file [-r|-raw] filename
984 Compile and inject into the inferior the executable object code
985 produced by compiling the source code stored in the filename
988 * On resume, GDB now always passes the signal the program had stopped
989 for to the thread the signal was sent to, even if the user changed
990 threads before resuming. Previously GDB would often (but not
991 always) deliver the signal to the thread that happens to be current
994 * Conversely, the "signal" command now consistently delivers the
995 requested signal to the current thread. GDB now asks for
996 confirmation if the program had stopped for a signal and the user
997 switched threads meanwhile.
999 * "breakpoint always-inserted" modes "off" and "auto" merged.
1001 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1002 won't remove breakpoints from the target until all threads stop,
1003 even in non-stop mode. The "auto" mode has been removed, and "off"
1004 is now the default mode.
1008 set debug symbol-lookup
1009 show debug symbol-lookup
1010 Control display of debugging info regarding symbol lookup.
1014 ** The -list-thread-groups command outputs an exit-code field for
1015 inferiors that have exited.
1019 MIPS SDE mips*-sde*-elf*
1023 Support for these obsolete configurations has been removed.
1025 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1026 SGI Irix-5.x mips-*-irix5*
1027 SGI Irix-6.x mips-*-irix6*
1028 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1029 VAX running Ultrix vax-*-ultrix*
1031 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1032 and "assf"), have been removed. Use the "sharedlibrary" command, or
1033 its alias "share", instead.
1035 *** Changes in GDB 7.8
1037 * New command line options
1040 This is an alias for the --data-directory option.
1042 * GDB supports printing and modifying of variable length automatic arrays
1043 as specified in ISO C99.
1045 * The ARM simulator now supports instruction level tracing
1046 with or without disassembly.
1050 GDB now has support for scripting using Guile. Whether this is
1051 available is determined at configure time.
1052 Guile version 2.0 or greater is required.
1053 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1055 * New commands (for set/show, see "New options" below)
1059 Invoke CODE by passing it to the Guile interpreter.
1063 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1065 info auto-load guile-scripts [regexp]
1066 Print the list of automatically loaded Guile scripts.
1068 * The source command is now capable of sourcing Guile scripts.
1069 This feature is dependent on the debugger being built with Guile support.
1073 set print symbol-loading (off|brief|full)
1074 show print symbol-loading
1075 Control whether to print informational messages when loading symbol
1076 information for a file. The default is "full", but when debugging
1077 programs with large numbers of shared libraries the amount of output
1078 becomes less useful.
1080 set guile print-stack (none|message|full)
1081 show guile print-stack
1082 Show a stack trace when an error is encountered in a Guile script.
1084 set auto-load guile-scripts (on|off)
1085 show auto-load guile-scripts
1086 Control auto-loading of Guile script files.
1088 maint ada set ignore-descriptive-types (on|off)
1089 maint ada show ignore-descriptive-types
1090 Control whether the debugger should ignore descriptive types in Ada
1091 programs. The default is not to ignore the descriptive types. See
1092 the user manual for more details on descriptive types and the intended
1093 usage of this option.
1095 set auto-connect-native-target
1097 Control whether GDB is allowed to automatically connect to the
1098 native target for the run, attach, etc. commands when not connected
1099 to any target yet. See also "target native" below.
1101 set record btrace replay-memory-access (read-only|read-write)
1102 show record btrace replay-memory-access
1103 Control what memory accesses are allowed during replay.
1105 maint set target-async (on|off)
1106 maint show target-async
1107 This controls whether GDB targets operate in synchronous or
1108 asynchronous mode. Normally the default is asynchronous, if it is
1109 available; but this can be changed to more easily debug problems
1110 occurring only in synchronous mode.
1112 set mi-async (on|off)
1114 Control whether MI asynchronous mode is preferred. This supersedes
1115 "set target-async" of previous GDB versions.
1117 * "set target-async" is deprecated as a CLI option and is now an alias
1118 for "set mi-async" (only puts MI into async mode).
1120 * Background execution commands (e.g., "c&", "s&", etc.) are now
1121 possible ``out of the box'' if the target supports them. Previously
1122 the user would need to explicitly enable the possibility with the
1123 "set target-async on" command.
1125 * New features in the GDB remote stub, GDBserver
1127 ** New option --debug-format=option1[,option2,...] allows one to add
1128 additional text to each output. At present only timestamps
1129 are supported: --debug-format=timestamps.
1130 Timestamps can also be turned on with the
1131 "monitor set debug-format timestamps" command from GDB.
1133 * The 'record instruction-history' command now starts counting instructions
1134 at one. This also affects the instruction ranges reported by the
1135 'record function-call-history' command when given the /i modifier.
1137 * The command 'record function-call-history' supports a new modifier '/c' to
1138 indent the function names based on their call stack depth.
1139 The fields for the '/i' and '/l' modifier have been reordered.
1140 The source line range is now prefixed with 'at'.
1141 The instruction range is now prefixed with 'inst'.
1142 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1143 "record instruction-history" and "list" commands.
1145 * The ranges given as arguments to the 'record function-call-history' and
1146 'record instruction-history' commands are now inclusive.
1148 * The btrace record target now supports the 'record goto' command.
1149 For locations inside the execution trace, the back trace is computed
1150 based on the information stored in the execution trace.
1152 * The btrace record target supports limited reverse execution and replay.
1153 The target does not record data and therefore does not allow reading
1154 memory or registers.
1156 * The "catch syscall" command now works on s390*-linux* targets.
1158 * The "compare-sections" command is no longer specific to target
1159 remote. It now works with all targets.
1161 * All native targets are now consistently called "native".
1162 Consequently, the "target child", "target GNU", "target djgpp",
1163 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1164 commands have been replaced with "target native". The QNX/NTO port
1165 leaves the "procfs" target in place and adds a "native" target for
1166 consistency with other ports. The impact on users should be minimal
1167 as these commands previously either throwed an error, or were
1168 no-ops. The target's name is visible in the output of the following
1169 commands: "help target", "info target", "info files", "maint print
1172 * The "target native" command now connects to the native target. This
1173 can be used to launch native programs even when "set
1174 auto-connect-native-target" is set to off.
1176 * GDB now supports access to Intel MPX registers on GNU/Linux.
1178 * Support for Intel AVX-512 registers on GNU/Linux.
1179 Support displaying and modifying Intel AVX-512 registers
1180 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1182 * New remote packets
1184 qXfer:btrace:read's annex
1185 The qXfer:btrace:read packet supports a new annex 'delta' to read
1186 branch trace incrementally.
1190 ** Valid Python operations on gdb.Value objects representing
1191 structs/classes invoke the corresponding overloaded operators if
1193 ** New `Xmethods' feature in the Python API. Xmethods are
1194 additional methods or replacements for existing methods of a C++
1195 class. This feature is useful for those cases where a method
1196 defined in C++ source code could be inlined or optimized out by
1197 the compiler, making it unavailable to GDB.
1200 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1202 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1203 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1204 its alias "share", instead.
1206 * The commands "set remotebaud" and "show remotebaud" are no longer
1207 supported. Use "set serial baud" and "show serial baud" (respectively)
1212 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1213 target-async". The latter is left as a deprecated alias of the
1214 former for backward compatibility. If the target supports it,
1215 CLI background execution commands are now always possible by
1216 default, independently of whether the frontend stated a
1217 preference for asynchronous execution with "-gdb-set mi-async".
1218 Previously "-gdb-set target-async off" affected both MI execution
1219 commands and CLI execution commands.
1221 *** Changes in GDB 7.7
1223 * Improved support for process record-replay and reverse debugging on
1224 arm*-linux* targets. Support for thumb32 and syscall instruction
1225 recording has been added.
1227 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1229 * GDB now supports Fission DWP file format version 2.
1230 http://gcc.gnu.org/wiki/DebugFission
1232 * New convenience function "$_isvoid", to check whether an expression
1233 is void. A void expression is an expression where the type of the
1234 result is "void". For example, some convenience variables may be
1235 "void" when evaluated (e.g., "$_exitcode" before the execution of
1236 the program being debugged; or an undefined convenience variable).
1237 Another example, when calling a function whose return type is
1240 * The "maintenance print objfiles" command now takes an optional regexp.
1242 * The "catch syscall" command now works on arm*-linux* targets.
1244 * GDB now consistently shows "<not saved>" when printing values of
1245 registers the debug info indicates have not been saved in the frame
1246 and there's nowhere to retrieve them from
1247 (callee-saved/call-clobbered registers):
1252 (gdb) info registers rax
1255 Before, the former would print "<optimized out>", and the latter
1256 "*value not available*".
1258 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1263 ** Frame filters and frame decorators have been added.
1264 ** Temporary breakpoints are now supported.
1265 ** Line tables representation has been added.
1266 ** New attribute 'parent_type' for gdb.Field objects.
1267 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1268 ** New attribute 'name' for gdb.Type objects.
1272 Nios II ELF nios2*-*-elf
1273 Nios II GNU/Linux nios2*-*-linux
1274 Texas Instruments MSP430 msp430*-*-elf
1276 * Removed native configurations
1278 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1279 been removed. ELF variants of these configurations are kept supported.
1281 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1282 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1283 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1284 i[34567]86-*-openbsd3.[0-3]
1285 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1286 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1287 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1291 Like "catch throw", but catches a re-thrown exception.
1292 maint check-psymtabs
1293 Renamed from old "maint check-symtabs".
1295 Perform consistency checks on symtabs.
1296 maint expand-symtabs
1297 Expand symtabs matching an optional regexp.
1300 Display the details of GDB configure-time options.
1302 maint set|show per-command
1303 maint set|show per-command space
1304 maint set|show per-command time
1305 maint set|show per-command symtab
1306 Enable display of per-command gdb resource usage.
1308 remove-symbol-file FILENAME
1309 remove-symbol-file -a ADDRESS
1310 Remove a symbol file added via add-symbol-file. The file to remove
1311 can be identified by its filename or by an address that lies within
1312 the boundaries of this symbol file in memory.
1315 info exceptions REGEXP
1316 Display the list of Ada exceptions defined in the program being
1317 debugged. If provided, only the exceptions whose names match REGEXP
1322 set debug symfile off|on
1324 Control display of debugging info regarding reading symbol files and
1325 symbol tables within those files
1327 set print raw frame-arguments
1328 show print raw frame-arguments
1329 Set/show whether to print frame arguments in raw mode,
1330 disregarding any defined pretty-printers.
1332 set remote trace-status-packet
1333 show remote trace-status-packet
1334 Set/show the use of remote protocol qTStatus packet.
1338 Control display of debugging messages related to Nios II targets.
1342 Control whether target-assisted range stepping is enabled.
1344 set startup-with-shell
1345 show startup-with-shell
1346 Specifies whether Unix child processes are started via a shell or
1351 Use the target memory cache for accesses to the code segment. This
1352 improves performance of remote debugging (particularly disassembly).
1354 * You can now use a literal value 'unlimited' for options that
1355 interpret 0 or -1 as meaning "unlimited". E.g., "set
1356 trace-buffer-size unlimited" is now an alias for "set
1357 trace-buffer-size -1" and "set height unlimited" is now an alias for
1360 * The "set debug symtab-create" debugging option of GDB has been changed to
1361 accept a verbosity level. 0 means "off", 1 provides basic debugging
1362 output, and values of 2 or greater provides more verbose output.
1364 * New command-line options
1366 Display the details of GDB configure-time options.
1368 * The command 'tsave' can now support new option '-ctf' to save trace
1369 buffer in Common Trace Format.
1371 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1374 * GDB now implements the the C++ 'typeid' operator.
1376 * The new convenience variable $_exception holds the exception being
1377 thrown or caught at an exception-related catchpoint.
1379 * The exception-related catchpoints, like "catch throw", now accept a
1380 regular expression which can be used to filter exceptions by type.
1382 * The new convenience variable $_exitsignal is automatically set to
1383 the terminating signal number when the program being debugged dies
1384 due to an uncaught signal.
1388 ** All MI commands now accept an optional "--language" option.
1389 Support for this feature can be verified by using the "-list-features"
1390 command, which should contain "language-option".
1392 ** The new command -info-gdb-mi-command allows the user to determine
1393 whether a GDB/MI command is supported or not.
1395 ** The "^error" result record returned when trying to execute an undefined
1396 GDB/MI command now provides a variable named "code" whose content is the
1397 "undefined-command" error code. Support for this feature can be verified
1398 by using the "-list-features" command, which should contain
1399 "undefined-command-error-code".
1401 ** The -trace-save MI command can optionally save trace buffer in Common
1404 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1406 ** The command -data-list-register-values now accepts an optional
1407 "--skip-unavailable" option. When used, only the available registers
1410 ** The new command -trace-frame-collected dumps collected variables,
1411 computed expressions, tvars, memory and registers in a traceframe.
1413 ** The commands -stack-list-locals, -stack-list-arguments and
1414 -stack-list-variables now accept an option "--skip-unavailable".
1415 When used, only the available locals or arguments are displayed.
1417 ** The -exec-run command now accepts an optional "--start" option.
1418 When used, the command follows the same semantics as the "start"
1419 command, stopping the program's execution at the start of its
1420 main subprogram. Support for this feature can be verified using
1421 the "-list-features" command, which should contain
1422 "exec-run-start-option".
1424 ** The new commands -catch-assert and -catch-exceptions insert
1425 catchpoints stopping the program when Ada exceptions are raised.
1427 ** The new command -info-ada-exceptions provides the equivalent of
1428 the new "info exceptions" command.
1430 * New system-wide configuration scripts
1431 A GDB installation now provides scripts suitable for use as system-wide
1432 configuration scripts for the following systems:
1436 * GDB now supports target-assigned range stepping with remote targets.
1437 This improves the performance of stepping source lines by reducing
1438 the number of control packets from/to GDB. See "New remote packets"
1441 * GDB now understands the element 'tvar' in the XML traceframe info.
1442 It has the id of the collected trace state variables.
1444 * On S/390 targets that provide the transactional-execution feature,
1445 the program interruption transaction diagnostic block (TDB) is now
1446 represented as a number of additional "registers" in GDB.
1448 * New remote packets
1452 The vCont packet supports a new 'r' action, that tells the remote
1453 stub to step through an address range itself, without GDB
1454 involvemement at each single-step.
1456 qXfer:libraries-svr4:read's annex
1457 The previously unused annex of the qXfer:libraries-svr4:read packet
1458 is now used to support passing an argument list. The remote stub
1459 reports support for this argument list to GDB's qSupported query.
1460 The defined arguments are "start" and "prev", used to reduce work
1461 necessary for library list updating, resulting in significant
1464 * New features in the GDB remote stub, GDBserver
1466 ** GDBserver now supports target-assisted range stepping. Currently
1467 enabled on x86/x86_64 GNU/Linux targets.
1469 ** GDBserver now adds element 'tvar' in the XML in the reply to
1470 'qXfer:traceframe-info:read'. It has the id of the collected
1471 trace state variables.
1473 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1476 * New 'z' formatter for printing and examining memory, this displays the
1477 value as hexadecimal zero padded on the left to the size of the type.
1479 * GDB can now use Windows x64 unwinding data.
1481 * The "set remotebaud" command has been replaced by "set serial baud".
1482 Similarly, "show remotebaud" has been replaced by "show serial baud".
1483 The "set remotebaud" and "show remotebaud" commands are still available
1484 to provide backward compatibility with older versions of GDB.
1486 *** Changes in GDB 7.6
1488 * Target record has been renamed to record-full.
1489 Record/replay is now enabled with the "record full" command.
1490 This also affects settings that are associated with full record/replay
1491 that have been moved from "set/show record" to "set/show record full":
1493 set|show record full insn-number-max
1494 set|show record full stop-at-limit
1495 set|show record full memory-query
1497 * A new record target "record-btrace" has been added. The new target
1498 uses hardware support to record the control-flow of a process. It
1499 does not support replaying the execution, but it implements the
1500 below new commands for investigating the recorded execution log.
1501 This new recording method can be enabled using:
1505 The "record-btrace" target is only available on Intel Atom processors
1506 and requires a Linux kernel 2.6.32 or later.
1508 * Two new commands have been added for record/replay to give information
1509 about the recorded execution without having to replay the execution.
1510 The commands are only supported by "record btrace".
1512 record instruction-history prints the execution history at
1513 instruction granularity
1515 record function-call-history prints the execution history at
1516 function granularity
1518 * New native configurations
1520 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1521 FreeBSD/powerpc powerpc*-*-freebsd
1522 x86_64/Cygwin x86_64-*-cygwin*
1523 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1527 ARM AArch64 aarch64*-*-elf
1528 ARM AArch64 GNU/Linux aarch64*-*-linux
1529 Lynx 178 PowerPC powerpc-*-lynx*178
1530 x86_64/Cygwin x86_64-*-cygwin*
1531 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1533 * If the configured location of system.gdbinit file (as given by the
1534 --with-system-gdbinit option at configure time) is in the
1535 data-directory (as specified by --with-gdb-datadir at configure
1536 time) or in one of its subdirectories, then GDB will look for the
1537 system-wide init file in the directory specified by the
1538 --data-directory command-line option.
1540 * New command line options:
1542 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1543 other initialization files, unlike -nx which disables all of them.
1545 * Removed command line options
1547 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1550 * The 'ptype' and 'whatis' commands now accept an argument to control
1553 * 'info proc' now works on some core files.
1557 ** Vectors can be created with gdb.Type.vector.
1559 ** Python's atexit.register now works in GDB.
1561 ** Types can be pretty-printed via a Python API.
1563 ** Python 3 is now supported (in addition to Python 2.4 or later)
1565 ** New class gdb.Architecture exposes GDB's internal representation
1566 of architecture in the Python API.
1568 ** New method Frame.architecture returns the gdb.Architecture object
1569 corresponding to the frame's architecture.
1571 * New Python-based convenience functions:
1573 ** $_memeq(buf1, buf2, length)
1574 ** $_streq(str1, str2)
1576 ** $_regex(str, regex)
1578 * The 'cd' command now defaults to using '~' (the home directory) if not
1581 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1582 default for GCC since November 2000.
1584 * The command 'forward-search' can now be abbreviated as 'fo'.
1586 * The command 'info tracepoints' can now display 'installed on target'
1587 or 'not installed on target' for each non-pending location of tracepoint.
1589 * New configure options
1591 --enable-libmcheck/--disable-libmcheck
1592 By default, development versions are built with -lmcheck on hosts
1593 that support it, in order to help track memory corruption issues.
1594 Release versions, on the other hand, are built without -lmcheck
1595 by default. The --enable-libmcheck/--disable-libmcheck configure
1596 options allow the user to override that default.
1597 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1598 This configure option allows the user to build GDB with
1599 libbabeltrace using which GDB can read Common Trace Format data.
1601 * New commands (for set/show, see "New options" below)
1604 Catch signals. This is similar to "handle", but allows commands and
1605 conditions to be attached.
1608 List the BFDs known to GDB.
1610 python-interactive [command]
1612 Start a Python interactive prompt, or evaluate the optional command
1613 and print the result of expressions.
1616 "py" is a new alias for "python".
1618 enable type-printer [name]...
1619 disable type-printer [name]...
1620 Enable or disable type printers.
1624 ** For the Renesas Super-H architecture, the "regs" command has been removed
1625 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1630 set print type methods (on|off)
1631 show print type methods
1632 Control whether method declarations are displayed by "ptype".
1633 The default is to show them.
1635 set print type typedefs (on|off)
1636 show print type typedefs
1637 Control whether typedef definitions are displayed by "ptype".
1638 The default is to show them.
1640 set filename-display basename|relative|absolute
1641 show filename-display
1642 Control the way in which filenames is displayed.
1643 The default is "relative", which preserves previous behavior.
1645 set trace-buffer-size
1646 show trace-buffer-size
1647 Request target to change the size of trace buffer.
1649 set remote trace-buffer-size-packet auto|on|off
1650 show remote trace-buffer-size-packet
1651 Control the use of the remote protocol `QTBuffer:size' packet.
1655 Control display of debugging messages related to ARM AArch64.
1658 set debug coff-pe-read
1659 show debug coff-pe-read
1660 Control display of debugging messages related to reading of COFF/PE
1665 Control display of debugging messages related to Mach-O symbols
1668 set debug notification
1669 show debug notification
1670 Control display of debugging info for async remote notification.
1674 ** Command parameter changes are now notified using new async record
1675 "=cmd-param-changed".
1676 ** Trace frame changes caused by command "tfind" are now notified using
1677 new async record "=traceframe-changed".
1678 ** The creation, deletion and modification of trace state variables
1679 are now notified using new async records "=tsv-created",
1680 "=tsv-deleted" and "=tsv-modified".
1681 ** The start and stop of process record are now notified using new
1682 async record "=record-started" and "=record-stopped".
1683 ** Memory changes are now notified using new async record
1685 ** The data-disassemble command response will include a "fullname" field
1686 containing the absolute file name when source has been requested.
1687 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1688 command, to allow pattern filling of memory areas.
1689 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1690 library load/unload events.
1691 ** The response to breakpoint commands and breakpoint async records
1692 includes an "installed" field containing a boolean state about each
1693 non-pending tracepoint location is whether installed on target or not.
1694 ** Output of the "-trace-status" command includes a "trace-file" field
1695 containing the name of the trace file being examined. This field is
1696 optional, and only present when examining a trace file.
1697 ** The "fullname" field is now always present along with the "file" field,
1698 even if the file cannot be found by GDB.
1700 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1701 You must have the LZMA library available when configuring GDB for this
1702 feature to be enabled. For more information, see:
1703 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1705 * New remote packets
1708 Set the size of trace buffer. The remote stub reports support for this
1709 packet to gdb's qSupported query.
1712 Enable Branch Trace Store (BTS)-based branch tracing for the current
1713 thread. The remote stub reports support for this packet to gdb's
1717 Disable branch tracing for the current thread. The remote stub reports
1718 support for this packet to gdb's qSupported query.
1721 Read the traced branches for the current thread. The remote stub
1722 reports support for this packet to gdb's qSupported query.
1724 *** Changes in GDB 7.5
1726 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1727 for more x32 ABI info.
1729 * GDB now supports access to MIPS DSP registers on Linux targets.
1731 * GDB now supports debugging microMIPS binaries.
1733 * The "info os" command on GNU/Linux can now display information on
1734 several new classes of objects managed by the operating system:
1735 "info os procgroups" lists process groups
1736 "info os files" lists file descriptors
1737 "info os sockets" lists internet-domain sockets
1738 "info os shm" lists shared-memory regions
1739 "info os semaphores" lists semaphores
1740 "info os msg" lists message queues
1741 "info os modules" lists loaded kernel modules
1743 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1744 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1745 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1746 options and inspect the probe arguments using the new $_probe_arg family
1747 of convenience variables. You can obtain more information about SystemTap
1748 in <http://sourceware.org/systemtap/>.
1750 * GDB now supports reversible debugging on ARM, it allows you to
1751 debug basic ARM and THUMB instructions, and provides
1752 record/replay support.
1754 * The option "symbol-reloading" has been deleted as it is no longer used.
1758 ** GDB commands implemented in Python can now be put in command class
1761 ** The "maint set python print-stack on|off" is now deleted.
1763 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1764 apply "flag enum"-style pretty-printing to any enum.
1766 ** gdb.lookup_symbol can now work when there is no current frame.
1768 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1769 the source at which the symbol was defined.
1771 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1772 method 'value'. The former indicates whether the symbol needs a
1773 frame in order to compute its value, and the latter computes the
1776 ** A new method 'referenced_value' on gdb.Value objects which can
1777 dereference pointer as well as C++ reference values.
1779 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1780 which return the global and static blocks (as gdb.Block objects),
1781 of the underlying symbol table, respectively.
1783 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1784 object associated with a PC value.
1786 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1787 of the address range occupied by code for the current source line.
1789 * Go language support.
1790 GDB now supports debugging programs written in the Go programming
1793 * GDBserver now supports stdio connections.
1794 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1796 * The binary "gdbtui" can no longer be built or installed.
1797 Use "gdb -tui" instead.
1799 * GDB will now print "flag" enums specially. A flag enum is one where
1800 all the enumerator values have no bits in common when pairwise
1801 "and"ed. When printing a value whose type is a flag enum, GDB will
1802 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1803 (gdb) print (enum E) 3
1806 * The filename part of a linespec will now match trailing components
1807 of a source file name. For example, "break gcc/expr.c:1000" will
1808 now set a breakpoint in build/gcc/expr.c, but not
1809 build/libcpp/expr.c.
1811 * The "info proc" and "generate-core-file" commands will now also
1812 work on remote targets connected to GDBserver on Linux.
1814 * The command "info catch" has been removed. It has been disabled
1815 since December 2007.
1817 * The "catch exception" and "catch assert" commands now accept
1818 a condition at the end of the command, much like the "break"
1819 command does. For instance:
1821 (gdb) catch exception Constraint_Error if Barrier = True
1823 Previously, it was possible to add a condition to such catchpoints,
1824 but it had to be done as a second step, after the catchpoint had been
1825 created, using the "condition" command.
1827 * The "info static-tracepoint-marker" command will now also work on
1828 native Linux targets with in-process agent.
1830 * GDB can now set breakpoints on inlined functions.
1832 * The .gdb_index section has been updated to include symbols for
1833 inlined functions. GDB will ignore older .gdb_index sections by
1834 default, which could cause symbol files to be loaded more slowly
1835 until their .gdb_index sections can be recreated. The new command
1836 "set use-deprecated-index-sections on" will cause GDB to use any older
1837 .gdb_index sections it finds. This will restore performance, but the
1838 ability to set breakpoints on inlined functions will be lost in symbol
1839 files with older .gdb_index sections.
1841 The .gdb_index section has also been updated to record more information
1842 about each symbol. This speeds up the "info variables", "info functions"
1843 and "info types" commands when used with programs having the .gdb_index
1844 section, as well as speeding up debugging with shared libraries using
1845 the .gdb_index section.
1847 * Ada support for GDB/MI Variable Objects has been added.
1849 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1854 ** New command -info-os is the MI equivalent of "info os".
1856 ** Output logs ("set logging" and related) now include MI output.
1860 ** "set use-deprecated-index-sections on|off"
1861 "show use-deprecated-index-sections on|off"
1862 Controls the use of deprecated .gdb_index sections.
1864 ** "catch load" and "catch unload" can be used to stop when a shared
1865 library is loaded or unloaded, respectively.
1867 ** "enable count" can be used to auto-disable a breakpoint after
1870 ** "info vtbl" can be used to show the virtual method tables for
1871 C++ and Java objects.
1873 ** "explore" and its sub commands "explore value" and "explore type"
1874 can be used to recursively explore values and types of
1875 expressions. These commands are available only if GDB is
1876 configured with '--with-python'.
1878 ** "info auto-load" shows status of all kinds of auto-loaded files,
1879 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1880 sequences of commands files, "info auto-load python-scripts"
1881 shows status of auto-loading Python script files,
1882 "info auto-load local-gdbinit" shows status of loading init file
1883 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1884 status of inferior specific thread debugging shared library loading.
1886 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1887 and "show auto-load-scripts" commands have been deprecated, use their
1888 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1889 and "show auto-load python-scripts" counterparts instead.
1891 ** "dprintf location,format,args..." creates a dynamic printf, which
1892 is basically a breakpoint that does a printf and immediately
1893 resumes your program's execution, so it is like a printf that you
1894 can insert dynamically at runtime instead of at compiletime.
1896 ** "set print symbol"
1898 Controls whether GDB attempts to display the symbol, if any,
1899 corresponding to addresses it prints. This defaults to "on", but
1900 you can set it to "off" to restore GDB's previous behavior.
1902 * Deprecated commands
1904 ** For the Renesas Super-H architecture, the "regs" command has been
1905 deprecated, and "info all-registers" should be used instead.
1909 Renesas RL78 rl78-*-elf
1910 HP OpenVMS ia64 ia64-hp-openvms*
1912 * GDBserver supports evaluation of breakpoint conditions. When
1913 support is advertised by GDBserver, GDB may be told to send the
1914 breakpoint conditions in bytecode form to GDBserver. GDBserver
1915 will only report the breakpoint trigger to GDB when its condition
1920 set mips compression
1921 show mips compression
1922 Select the compressed ISA encoding used in functions that have no symbol
1923 information available. The encoding can be set to either of:
1926 and is updated automatically from ELF file flags if available.
1928 set breakpoint condition-evaluation
1929 show breakpoint condition-evaluation
1930 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1931 GDBserver ("target"). Default option "auto" chooses the most efficient
1933 This option can improve debugger efficiency depending on the speed of the
1937 Disable auto-loading globally.
1940 Show auto-loading setting of all kinds of auto-loaded files.
1942 set auto-load gdb-scripts on|off
1943 show auto-load gdb-scripts
1944 Control auto-loading of GDB canned sequences of commands files.
1946 set auto-load python-scripts on|off
1947 show auto-load python-scripts
1948 Control auto-loading of Python script files.
1950 set auto-load local-gdbinit on|off
1951 show auto-load local-gdbinit
1952 Control loading of init file (.gdbinit) from current directory.
1954 set auto-load libthread-db on|off
1955 show auto-load libthread-db
1956 Control auto-loading of inferior specific thread debugging shared library.
1958 set auto-load scripts-directory <dir1>[:<dir2>...]
1959 show auto-load scripts-directory
1960 Set a list of directories from which to load auto-loaded scripts.
1961 Automatically loaded Python scripts and GDB scripts are located in one
1962 of the directories listed by this option.
1963 The delimiter (':' above) may differ according to the host platform.
1965 set auto-load safe-path <dir1>[:<dir2>...]
1966 show auto-load safe-path
1967 Set a list of directories from which it is safe to auto-load files.
1968 The delimiter (':' above) may differ according to the host platform.
1970 set debug auto-load on|off
1971 show debug auto-load
1972 Control display of debugging info for auto-loading the files above.
1974 set dprintf-style gdb|call|agent
1976 Control the way in which a dynamic printf is performed; "gdb"
1977 requests a GDB printf command, while "call" causes dprintf to call a
1978 function in the inferior. "agent" requests that the target agent
1979 (such as GDBserver) do the printing.
1981 set dprintf-function <expr>
1982 show dprintf-function
1983 set dprintf-channel <expr>
1984 show dprintf-channel
1985 Set the function and optional first argument to the call when using
1986 the "call" style of dynamic printf.
1988 set disconnected-dprintf on|off
1989 show disconnected-dprintf
1990 Control whether agent-style dynamic printfs continue to be in effect
1991 after GDB disconnects.
1993 * New configure options
1995 --with-auto-load-dir
1996 Configure default value for the 'set auto-load scripts-directory'
1997 setting above. It defaults to '$debugdir:$datadir/auto-load',
1998 $debugdir representing global debugging info directories (available
1999 via 'show debug-file-directory') and $datadir representing GDB's data
2000 directory (available via 'show data-directory').
2002 --with-auto-load-safe-path
2003 Configure default value for the 'set auto-load safe-path' setting
2004 above. It defaults to the --with-auto-load-dir setting.
2006 --without-auto-load-safe-path
2007 Set 'set auto-load safe-path' to '/', effectively disabling this
2010 * New remote packets
2012 z0/z1 conditional breakpoints extension
2014 The z0/z1 breakpoint insertion packets have been extended to carry
2015 a list of conditional expressions over to the remote stub depending on the
2016 condition evaluation mode. The use of this extension can be controlled
2017 via the "set remote conditional-breakpoints-packet" command.
2021 Specify the signals which the remote stub may pass to the debugged
2022 program without GDB involvement.
2024 * New command line options
2026 --init-command=FILE, -ix Like --command, -x but execute it
2027 before loading inferior.
2028 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2029 execute it before loading inferior.
2031 *** Changes in GDB 7.4
2033 * GDB now handles ambiguous linespecs more consistently; the existing
2034 FILE:LINE support has been expanded to other types of linespecs. A
2035 breakpoint will now be set on all matching locations in all
2036 inferiors, and locations will be added or removed according to
2039 * GDB now allows you to skip uninteresting functions and files when
2040 stepping with the "skip function" and "skip file" commands.
2042 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2043 and "show remote hardware-watchpoint-length-limit". These allows to
2044 set or show the maximum length limit (in bytes) of a remote
2045 target hardware watchpoint.
2047 This allows e.g. to use "unlimited" hardware watchpoints with the
2048 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2049 watchpoints are slower than real hardware watchpoints but are
2050 significantly faster than gdb software watchpoints.
2054 ** The register_pretty_printer function in module gdb.printing now takes
2055 an optional `replace' argument. If True, the new printer replaces any
2058 ** The "maint set python print-stack on|off" command has been
2059 deprecated and will be deleted in GDB 7.5.
2060 A new command: "set python print-stack none|full|message" has
2061 replaced it. Additionally, the default for "print-stack" is
2062 now "message", which just prints the error message without
2065 ** A prompt substitution hook (prompt_hook) is now available to the
2068 ** A new Python module, gdb.prompt has been added to the GDB Python
2069 modules library. This module provides functionality for
2070 escape sequences in prompts (used by set/show
2071 extended-prompt). These escape sequences are replaced by their
2072 corresponding value.
2074 ** Python commands and convenience-functions located in
2075 'data-directory'/python/gdb/command and
2076 'data-directory'/python/gdb/function are now automatically loaded
2079 ** Blocks now provide four new attributes. global_block and
2080 static_block will return the global and static blocks
2081 respectively. is_static and is_global are boolean attributes
2082 that indicate if the block is one of those two types.
2084 ** Symbols now provide the "type" attribute, the type of the symbol.
2086 ** The "gdb.breakpoint" function has been deprecated in favor of
2089 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2090 of a function. This class is based on the "finish" command
2091 available in the CLI.
2093 ** Type objects for struct and union types now allow access to
2094 the fields using standard Python dictionary (mapping) methods.
2095 For example, "some_type['myfield']" now works, as does
2096 "some_type.items()".
2098 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2101 ** A new function, "deep_items" has been added to the gdb.types
2102 module in the GDB Python modules library. This function returns
2103 an iterator over the fields of a struct or union type. Unlike
2104 the standard Python "iteritems" method, it will recursively traverse
2105 any anonymous fields.
2109 ** "*stopped" events can report several new "reason"s, such as
2112 ** Breakpoint changes are now notified using new async records, like
2113 "=breakpoint-modified".
2115 ** New command -ada-task-info.
2117 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2118 $sdir specifies the default system locations of shared libraries.
2119 $pdir specifies the directory where the libpthread used by the application
2122 GDB no longer looks in $sdir and $pdir after it has searched the directories
2123 mentioned in libthread-db-search-path. If you want to search those
2124 directories, they must be specified in libthread-db-search-path.
2125 The default value of libthread-db-search-path on GNU/Linux and Solaris
2126 systems is now "$sdir:$pdir".
2128 $pdir is not supported by gdbserver, it is currently ignored.
2129 $sdir is supported by gdbserver.
2131 * New configure option --with-iconv-bin.
2132 When using the internationalization support like the one in the GNU C
2133 library, GDB will invoke the "iconv" program to get a list of supported
2134 character sets. If this program lives in a non-standard location, one can
2135 use this option to specify where to find it.
2137 * When natively debugging programs on PowerPC BookE processors running
2138 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2139 watchpoints, which specify a mask in addition to an address to watch.
2140 The mask specifies that some bits of an address (the bits which are
2141 reset in the mask) should be ignored when matching the address accessed
2142 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2143 section in the user manual for more details.
2145 * The new option --once causes GDBserver to stop listening for connections once
2146 the first connection is made. The listening port used by GDBserver will
2147 become available after that.
2149 * New commands "info macros" and "alias" have been added.
2151 * New function parameters suffix @entry specifies value of function parameter
2152 at the time the function got called. Entry values are available only since
2158 "!" is now an alias of the "shell" command.
2159 Note that no space is needed between "!" and SHELL COMMAND.
2163 watch EXPRESSION mask MASK_VALUE
2164 The watch command now supports the mask argument which allows creation
2165 of masked watchpoints, if the current architecture supports this feature.
2167 info auto-load-scripts [REGEXP]
2168 This command was formerly named "maintenance print section-scripts".
2169 It is now generally useful and is no longer a maintenance-only command.
2171 info macro [-all] [--] MACRO
2172 The info macro command has new options `-all' and `--'. The first for
2173 printing all definitions of a macro. The second for explicitly specifying
2174 the end of arguments and the beginning of the macro name in case the macro
2175 name starts with a hyphen.
2177 collect[/s] EXPRESSIONS
2178 The tracepoint collect command now takes an optional modifier "/s"
2179 that directs it to dereference pointer-to-character types and
2180 collect the bytes of memory up to a zero byte. The behavior is
2181 similar to what you see when you use the regular print command on a
2182 string. An optional integer following the "/s" sets a bound on the
2183 number of bytes that will be collected.
2186 The trace start command now interprets any supplied arguments as a
2187 note to be recorded with the trace run, with an effect similar to
2188 setting the variable trace-notes.
2191 The trace stop command now interprets any arguments as a note to be
2192 mentioned along with the tstatus report that the trace was stopped
2193 with a command. The effect is similar to setting the variable
2196 * Tracepoints can now be enabled and disabled at any time after a trace
2197 experiment has been started using the standard "enable" and "disable"
2198 commands. It is now possible to start a trace experiment with no enabled
2199 tracepoints; GDB will display a warning, but will allow the experiment to
2200 begin, assuming that tracepoints will be enabled as needed while the trace
2203 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2204 locations with 4-byte instructions, when they were previously
2205 limited to locations with instructions of 5 bytes or longer.
2209 set debug dwarf2-read
2210 show debug dwarf2-read
2211 Turns on or off display of debugging messages related to reading
2212 DWARF debug info. The default is off.
2214 set debug symtab-create
2215 show debug symtab-create
2216 Turns on or off display of debugging messages related to symbol table
2217 creation. The default is off.
2220 show extended-prompt
2221 Set the GDB prompt, and allow escape sequences to be inserted to
2222 display miscellaneous information (see 'help set extended-prompt'
2223 for the list of sequences). This prompt (and any information
2224 accessed through the escape sequences) is updated every time the
2225 prompt is displayed.
2227 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2228 show print entry-values
2229 Set printing of frame argument values at function entry. In some cases
2230 GDB can determine the value of function argument which was passed by the
2231 function caller, even if the value was modified inside the called function.
2233 set debug entry-values
2234 show debug entry-values
2235 Control display of debugging info for determining frame argument values at
2236 function entry and virtual tail call frames.
2238 set basenames-may-differ
2239 show basenames-may-differ
2240 Set whether a source file may have multiple base names.
2241 (A "base name" is the name of a file with the directory part removed.
2242 Example: The base name of "/home/user/hello.c" is "hello.c".)
2243 If set, GDB will canonicalize file names (e.g., expand symlinks)
2244 before comparing them. Canonicalization is an expensive operation,
2245 but it allows the same file be known by more than one base name.
2246 If not set (the default), all source files are assumed to have just
2247 one base name, and gdb will do file name comparisons more efficiently.
2253 Set a user name and notes for the current and any future trace runs.
2254 This is useful for long-running and/or disconnected traces, to
2255 inform others (or yourself) as to who is running the trace, supply
2256 contact information, or otherwise explain what is going on.
2258 set trace-stop-notes
2259 show trace-stop-notes
2260 Set a note attached to the trace run, that is displayed when the
2261 trace has been stopped by a tstop command. This is useful for
2262 instance as an explanation, if you are stopping a trace run that was
2263 started by someone else.
2265 * New remote packets
2269 Dynamically enable a tracepoint in a started trace experiment.
2273 Dynamically disable a tracepoint in a started trace experiment.
2277 Set the user and notes of the trace run.
2281 Query the current status of a tracepoint.
2285 Query the minimum length of instruction at which a fast tracepoint may
2288 * Dcache size (number of lines) and line-size are now runtime-configurable
2289 via "set dcache line" and "set dcache line-size" commands.
2293 Texas Instruments TMS320C6x tic6x-*-*
2297 Renesas RL78 rl78-*-elf
2299 *** Changes in GDB 7.3.1
2301 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2303 *** Changes in GDB 7.3
2305 * GDB has a new command: "thread find [REGEXP]".
2306 It finds the thread id whose name, target id, or thread extra info
2307 matches the given regular expression.
2309 * The "catch syscall" command now works on mips*-linux* targets.
2311 * The -data-disassemble MI command now supports modes 2 and 3 for
2312 dumping the instruction opcodes.
2314 * New command line options
2316 -data-directory DIR Specify DIR as the "data-directory".
2317 This is mostly for testing purposes.
2319 * The "maint set python auto-load on|off" command has been renamed to
2320 "set auto-load-scripts on|off".
2322 * GDB has a new command: "set directories".
2323 It is like the "dir" command except that it replaces the
2324 source path list instead of augmenting it.
2326 * GDB now understands thread names.
2328 On GNU/Linux, "info threads" will display the thread name as set by
2329 prctl or pthread_setname_np.
2331 There is also a new command, "thread name", which can be used to
2332 assign a name internally for GDB to display.
2335 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2336 has been integrated into GDB.
2340 ** The function gdb.Write now accepts an optional keyword 'stream'.
2341 This keyword, when provided, will direct the output to either
2342 stdout, stderr, or GDB's logging output.
2344 ** Parameters can now be be sub-classed in Python, and in particular
2345 you may implement the get_set_doc and get_show_doc functions.
2346 This improves how Parameter set/show documentation is processed
2347 and allows for more dynamic content.
2349 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2350 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2351 have an is_valid method.
2353 ** Breakpoints can now be sub-classed in Python, and in particular
2354 you may implement a 'stop' function that is executed each time
2355 the inferior reaches that breakpoint.
2357 ** New function gdb.lookup_global_symbol looks up a global symbol.
2359 ** GDB values in Python are now callable if the value represents a
2360 function. For example, if 'some_value' represents a function that
2361 takes two integer parameters and returns a value, you can call
2362 that function like so:
2364 result = some_value (10,20)
2366 ** Module gdb.types has been added.
2367 It contains a collection of utilities for working with gdb.Types objects:
2368 get_basic_type, has_field, make_enum_dict.
2370 ** Module gdb.printing has been added.
2371 It contains utilities for writing and registering pretty-printers.
2372 New classes: PrettyPrinter, SubPrettyPrinter,
2373 RegexpCollectionPrettyPrinter.
2374 New function: register_pretty_printer.
2376 ** New commands "info pretty-printers", "enable pretty-printer" and
2377 "disable pretty-printer" have been added.
2379 ** gdb.parameter("directories") is now available.
2381 ** New function gdb.newest_frame returns the newest frame in the
2384 ** The gdb.InferiorThread class has a new "name" attribute. This
2385 holds the thread's name.
2387 ** Python Support for Inferior events.
2388 Python scripts can add observers to be notified of events
2389 occurring in the process being debugged.
2390 The following events are currently supported:
2391 - gdb.events.cont Continue event.
2392 - gdb.events.exited Inferior exited event.
2393 - gdb.events.stop Signal received, and Breakpoint hit events.
2397 ** GDB now puts template parameters in scope when debugging in an
2398 instantiation. For example, if you have:
2400 template<int X> int func (void) { return X; }
2402 then if you step into func<5>, "print X" will show "5". This
2403 feature requires proper debuginfo support from the compiler; it
2404 was added to GCC 4.5.
2406 ** The motion commands "next", "finish", "until", and "advance" now
2407 work better when exceptions are thrown. In particular, GDB will
2408 no longer lose control of the inferior; instead, the GDB will
2409 stop the inferior at the point at which the exception is caught.
2410 This functionality requires a change in the exception handling
2411 code that was introduced in GCC 4.5.
2413 * GDB now follows GCC's rules on accessing volatile objects when
2414 reading or writing target state during expression evaluation.
2415 One notable difference to prior behavior is that "print x = 0"
2416 no longer generates a read of x; the value of the assignment is
2417 now always taken directly from the value being assigned.
2419 * GDB now has some support for using labels in the program's source in
2420 linespecs. For instance, you can use "advance label" to continue
2421 execution to a label.
2423 * GDB now has support for reading and writing a new .gdb_index
2424 section. This section holds a fast index of DWARF debugging
2425 information and can be used to greatly speed up GDB startup and
2426 operation. See the documentation for `save gdb-index' for details.
2428 * The "watch" command now accepts an optional "-location" argument.
2429 When used, this causes GDB to watch the memory referred to by the
2430 expression. Such a watchpoint is never deleted due to it going out
2433 * GDB now supports thread debugging of core dumps on GNU/Linux.
2435 GDB now activates thread debugging using the libthread_db library
2436 when debugging GNU/Linux core dumps, similarly to when debugging
2437 live processes. As a result, when debugging a core dump file, GDB
2438 is now able to display pthread_t ids of threads. For example, "info
2439 threads" shows the same output as when debugging the process when it
2440 was live. In earlier releases, you'd see something like this:
2443 * 1 LWP 6780 main () at main.c:10
2445 While now you see this:
2448 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2450 It is also now possible to inspect TLS variables when debugging core
2453 When debugging a core dump generated on a machine other than the one
2454 used to run GDB, you may need to point GDB at the correct
2455 libthread_db library with the "set libthread-db-search-path"
2456 command. See the user manual for more details on this command.
2458 * When natively debugging programs on PowerPC BookE processors running
2459 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2460 which stop execution of the inferior whenever it executes an instruction
2461 at any address within the specified range. See the "PowerPC Embedded"
2462 section in the user manual for more details.
2464 * New features in the GDB remote stub, GDBserver
2466 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2467 and i686 LynxOS (version 5.x).
2469 ** GDBserver is now supported on Blackfin Linux.
2471 * New native configurations
2473 ia64 HP-UX ia64-*-hpux*
2477 Analog Devices, Inc. Blackfin Processor bfin-*
2479 * Ada task switching is now supported on sparc-elf targets when
2480 debugging a program using the Ravenscar Profile. For more information,
2481 see the "Tasking Support when using the Ravenscar Profile" section
2482 in the GDB user manual.
2484 * Guile support was removed.
2486 * New features in the GNU simulator
2488 ** The --map-info flag lists all known core mappings.
2490 ** CFI flashes may be simulated via the "cfi" device.
2492 *** Changes in GDB 7.2
2494 * Shared library support for remote targets by default
2496 When GDB is configured for a generic, non-OS specific target, like
2497 for example, --target=arm-eabi or one of the many *-*-elf targets,
2498 GDB now queries remote stubs for loaded shared libraries using the
2499 `qXfer:libraries:read' packet. Previously, shared library support
2500 was always disabled for such configurations.
2504 ** Argument Dependent Lookup (ADL)
2506 In C++ ADL lookup directs function search to the namespaces of its
2507 arguments even if the namespace has not been imported.
2517 Here the compiler will search for `foo' in the namespace of 'b'
2518 and find A::foo. GDB now supports this. This construct is commonly
2519 used in the Standard Template Library for operators.
2521 ** Improved User Defined Operator Support
2523 In addition to member operators, GDB now supports lookup of operators
2524 defined in a namespace and imported with a `using' directive, operators
2525 defined in the global scope, operators imported implicitly from an
2526 anonymous namespace, and the ADL operators mentioned in the previous
2528 GDB now also supports proper overload resolution for all the previously
2529 mentioned flavors of operators.
2531 ** static const class members
2533 Printing of static const class members that are initialized in the
2534 class definition has been fixed.
2536 * Windows Thread Information Block access.
2538 On Windows targets, GDB now supports displaying the Windows Thread
2539 Information Block (TIB) structure. This structure is visible either
2540 by using the new command `info w32 thread-information-block' or, by
2541 dereferencing the new convenience variable named `$_tlb', a
2542 thread-specific pointer to the TIB. This feature is also supported
2543 when remote debugging using GDBserver.
2545 * Static tracepoints
2547 Static tracepoints are calls in the user program into a tracing
2548 library. One such library is a port of the LTTng kernel tracer to
2549 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2550 When debugging with GDBserver, GDB now supports combining the GDB
2551 tracepoint machinery with such libraries. For example: the user can
2552 use GDB to probe a static tracepoint marker (a call from the user
2553 program into the tracing library) with the new "strace" command (see
2554 "New commands" below). This creates a "static tracepoint" in the
2555 breakpoint list, that can be manipulated with the same feature set
2556 as fast and regular tracepoints. E.g., collect registers, local and
2557 global variables, collect trace state variables, and define
2558 tracepoint conditions. In addition, the user can collect extra
2559 static tracepoint marker specific data, by collecting the new
2560 $_sdata internal variable. When analyzing the trace buffer, you can
2561 inspect $_sdata like any other variable available to GDB. For more
2562 information, see the "Tracepoints" chapter in GDB user manual. New
2563 remote packets have been defined to support static tracepoints, see
2564 the "New remote packets" section below.
2566 * Better reconstruction of tracepoints after disconnected tracing
2568 GDB will attempt to download the original source form of tracepoint
2569 definitions when starting a trace run, and then will upload these
2570 upon reconnection to the target, resulting in a more accurate
2571 reconstruction of the tracepoints that are in use on the target.
2575 You can now exercise direct control over the ways that GDB can
2576 affect your program. For instance, you can disallow the setting of
2577 breakpoints, so that the program can run continuously (assuming
2578 non-stop mode). In addition, the "observer" variable is available
2579 to switch all of the different controls; in observer mode, GDB
2580 cannot affect the target's behavior at all, which is useful for
2581 tasks like diagnosing live systems in the field.
2583 * The new convenience variable $_thread holds the number of the
2586 * New remote packets
2590 Return the address of the Windows Thread Information Block of a given thread.
2594 In response to several of the tracepoint packets, the target may now
2595 also respond with a number of intermediate `qRelocInsn' request
2596 packets before the final result packet, to have GDB handle
2597 relocating an instruction to execute at a different address. This
2598 is particularly useful for stubs that support fast tracepoints. GDB
2599 reports support for this feature in the qSupported packet.
2603 List static tracepoint markers in the target program.
2607 List static tracepoint markers at a given address in the target
2610 qXfer:statictrace:read
2612 Read the static trace data collected (by a `collect $_sdata'
2613 tracepoint action). The remote stub reports support for this packet
2614 to gdb's qSupported query.
2618 Send the current settings of GDB's permission flags.
2622 Send part of the source (textual) form of a tracepoint definition,
2623 which includes location, conditional, and action list.
2625 * The source command now accepts a -s option to force searching for the
2626 script in the source search path even if the script name specifies
2629 * New features in the GDB remote stub, GDBserver
2631 - GDBserver now support tracepoints (including fast tracepoints, and
2632 static tracepoints). The feature is currently supported by the
2633 i386-linux and amd64-linux builds. See the "Tracepoints support
2634 in gdbserver" section in the manual for more information.
2636 GDBserver JIT compiles the tracepoint's conditional agent
2637 expression bytecode into native code whenever possible for low
2638 overhead dynamic tracepoints conditionals. For such tracepoints,
2639 an expression that examines program state is evaluated when the
2640 tracepoint is reached, in order to determine whether to capture
2641 trace data. If the condition is simple and false, processing the
2642 tracepoint finishes very quickly and no data is gathered.
2644 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2645 for static tracepoints support.
2647 - GDBserver now supports x86_64 Windows 64-bit debugging.
2649 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2650 it understands register description.
2652 * The --batch flag now disables pagination and queries.
2654 * X86 general purpose registers
2656 GDB now supports reading/writing byte, word and double-word x86
2657 general purpose registers directly. This means you can use, say,
2658 $ah or $ax to refer, respectively, to the byte register AH and
2659 16-bit word register AX that are actually portions of the 32-bit
2660 register EAX or 64-bit register RAX.
2662 * The `commands' command now accepts a range of breakpoints to modify.
2663 A plain `commands' following a command that creates multiple
2664 breakpoints affects all the breakpoints set by that command. This
2665 applies to breakpoints set by `rbreak', and also applies when a
2666 single `break' command creates multiple breakpoints (e.g.,
2667 breakpoints on overloaded c++ functions).
2669 * The `rbreak' command now accepts a filename specification as part of
2670 its argument, limiting the functions selected by the regex to those
2671 in the specified file.
2673 * Support for remote debugging Windows and SymbianOS shared libraries
2674 from Unix hosts has been improved. Non Windows GDB builds now can
2675 understand target reported file names that follow MS-DOS based file
2676 system semantics, such as file names that include drive letters and
2677 use the backslash character as directory separator. This makes it
2678 possible to transparently use the "set sysroot" and "set
2679 solib-search-path" on Unix hosts to point as host copies of the
2680 target's shared libraries. See the new command "set
2681 target-file-system-kind" described below, and the "Commands to
2682 specify files" section in the user manual for more information.
2686 eval template, expressions...
2687 Convert the values of one or more expressions under the control
2688 of the string template to a command line, and call it.
2690 set target-file-system-kind unix|dos-based|auto
2691 show target-file-system-kind
2692 Set or show the assumed file system kind for target reported file
2695 save breakpoints <filename>
2696 Save all current breakpoint definitions to a file suitable for use
2697 in a later debugging session. To read the saved breakpoint
2698 definitions, use the `source' command.
2700 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2703 info static-tracepoint-markers
2704 Display information about static tracepoint markers in the target.
2706 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2707 Define a static tracepoint by probing a marker at the given
2708 function, line, address, or marker ID.
2712 Enable and disable observer mode.
2714 set may-write-registers on|off
2715 set may-write-memory on|off
2716 set may-insert-breakpoints on|off
2717 set may-insert-tracepoints on|off
2718 set may-insert-fast-tracepoints on|off
2719 set may-interrupt on|off
2720 Set individual permissions for GDB effects on the target. Note that
2721 some of these settings can have undesirable or surprising
2722 consequences, particularly when changed in the middle of a session.
2723 For instance, disabling the writing of memory can prevent
2724 breakpoints from being inserted, cause single-stepping to fail, or
2725 even crash your program, if you disable after breakpoints have been
2726 inserted. However, GDB should not crash.
2728 set record memory-query on|off
2729 show record memory-query
2730 Control whether to stop the inferior if memory changes caused
2731 by an instruction cannot be recorded.
2736 The disassemble command now supports "start,+length" form of two arguments.
2740 ** GDB now provides a new directory location, called the python directory,
2741 where Python scripts written for GDB can be installed. The location
2742 of that directory is <data-directory>/python, where <data-directory>
2743 is the GDB data directory. For more details, see section `Scripting
2744 GDB using Python' in the manual.
2746 ** The GDB Python API now has access to breakpoints, symbols, symbol
2747 tables, program spaces, inferiors, threads and frame's code blocks.
2748 Additionally, GDB Parameters can now be created from the API, and
2749 manipulated via set/show in the CLI.
2751 ** New functions gdb.target_charset, gdb.target_wide_charset,
2752 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2754 ** New exception gdb.GdbError.
2756 ** Pretty-printers are now also looked up in the current program space.
2758 ** Pretty-printers can now be individually enabled and disabled.
2760 ** GDB now looks for names of Python scripts to auto-load in a
2761 special section named `.debug_gdb_scripts', in addition to looking
2762 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2764 * Tracepoint actions were unified with breakpoint commands. In particular,
2765 there are no longer differences in "info break" output for breakpoints and
2766 tracepoints and the "commands" command can be used for both tracepoints and
2767 regular breakpoints.
2771 ARM Symbian arm*-*-symbianelf*
2773 * D language support.
2774 GDB now supports debugging programs written in the D programming
2777 * GDB now supports the extended ptrace interface for PowerPC which is
2778 available since Linux kernel version 2.6.34. This automatically enables
2779 any hardware breakpoints and additional hardware watchpoints available in
2780 the processor. The old ptrace interface exposes just one hardware
2781 watchpoint and no hardware breakpoints.
2783 * GDB is now able to use the Data Value Compare (DVC) register available on
2784 embedded PowerPC processors to implement in hardware simple watchpoint
2785 conditions of the form:
2787 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2789 This works in native GDB running on Linux kernels with the extended ptrace
2790 interface mentioned above.
2792 *** Changes in GDB 7.1
2796 ** Namespace Support
2798 GDB now supports importing of namespaces in C++. This enables the
2799 user to inspect variables from imported namespaces. Support for
2800 namepace aliasing has also been added. So, if a namespace is
2801 aliased in the current scope (e.g. namepace C=A; ) the user can
2802 print variables using the alias (e.g. (gdb) print C::x).
2806 All known bugs relating to the printing of virtual base class were
2807 fixed. It is now possible to call overloaded static methods using a
2812 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2813 and reinterpret_cast<> are now handled by the C++ expression parser.
2817 Xilinx MicroBlaze microblaze-*-*
2822 Xilinx MicroBlaze microblaze
2825 * Multi-program debugging.
2827 GDB now has support for multi-program (a.k.a. multi-executable or
2828 multi-exec) debugging. This allows for debugging multiple inferiors
2829 simultaneously each running a different program under the same GDB
2830 session. See "Debugging Multiple Inferiors and Programs" in the
2831 manual for more information. This implied some user visible changes
2832 in the multi-inferior support. For example, "info inferiors" now
2833 lists inferiors that are not running yet or that have exited
2834 already. See also "New commands" and "New options" below.
2836 * New tracing features
2838 GDB's tracepoint facility now includes several new features:
2840 ** Trace state variables
2842 GDB tracepoints now include support for trace state variables, which
2843 are variables managed by the target agent during a tracing
2844 experiment. They are useful for tracepoints that trigger each
2845 other, so for instance one tracepoint can count hits in a variable,
2846 and then a second tracepoint has a condition that is true when the
2847 count reaches a particular value. Trace state variables share the
2848 $-syntax of GDB convenience variables, and can appear in both
2849 tracepoint actions and condition expressions. Use the "tvariable"
2850 command to create, and "info tvariables" to view; see "Trace State
2851 Variables" in the manual for more detail.
2855 GDB now includes an option for defining fast tracepoints, which
2856 targets may implement more efficiently, such as by installing a jump
2857 into the target agent rather than a trap instruction. The resulting
2858 speedup can be by two orders of magnitude or more, although the
2859 tradeoff is that some program locations on some target architectures
2860 might not allow fast tracepoint installation, for instance if the
2861 instruction to be replaced is shorter than the jump. To request a
2862 fast tracepoint, use the "ftrace" command, with syntax identical to
2863 the regular trace command.
2865 ** Disconnected tracing
2867 It is now possible to detach GDB from the target while it is running
2868 a trace experiment, then reconnect later to see how the experiment
2869 is going. In addition, a new variable disconnected-tracing lets you
2870 tell the target agent whether to continue running a trace if the
2871 connection is lost unexpectedly.
2875 GDB now has the ability to save the trace buffer into a file, and
2876 then use that file as a target, similarly to you can do with
2877 corefiles. You can select trace frames, print data that was
2878 collected in them, and use tstatus to display the state of the
2879 tracing run at the moment that it was saved. To create a trace
2880 file, use "tsave <filename>", and to use it, do "target tfile
2883 ** Circular trace buffer
2885 You can ask the target agent to handle the trace buffer as a
2886 circular buffer, discarding the oldest trace frames to make room for
2887 newer ones, by setting circular-trace-buffer to on. This feature may
2888 not be available for all target agents.
2893 The disassemble command, when invoked with two arguments, now requires
2894 the arguments to be comma-separated.
2897 The info variables command now displays variable definitions. Files
2898 which only declare a variable are not shown.
2901 The source command is now capable of sourcing Python scripts.
2902 This feature is dependent on the debugger being build with Python
2905 Related to this enhancement is also the introduction of a new command
2906 "set script-extension" (see below).
2908 * New commands (for set/show, see "New options" below)
2910 record save [<FILENAME>]
2911 Save a file (in core file format) containing the process record
2912 execution log for replay debugging at a later time.
2914 record restore <FILENAME>
2915 Restore the process record execution log that was saved at an
2916 earlier time, for replay debugging.
2918 add-inferior [-copies <N>] [-exec <FILENAME>]
2921 clone-inferior [-copies <N>] [ID]
2922 Make a new inferior ready to execute the same program another
2923 inferior has loaded.
2928 maint info program-spaces
2929 List the program spaces loaded into GDB.
2931 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2932 show remote interrupt-sequence
2933 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2934 as the sequence to the remote target in order to interrupt the execution.
2935 Ctrl-C is a default. Some system prefers BREAK which is high level of
2936 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2937 Magic SysRq g. It is BREAK signal and character 'g'.
2939 set remote interrupt-on-connect [on | off]
2940 show remote interrupt-on-connect
2941 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2942 remote target when gdb connects to it. This is needed when you debug
2945 set remotebreak [on | off]
2947 Deprecated. Use "set/show remote interrupt-sequence" instead.
2949 tvariable $NAME [ = EXP ]
2950 Create or modify a trace state variable.
2953 List trace state variables and their values.
2955 delete tvariable $NAME ...
2956 Delete one or more trace state variables.
2959 Evaluate the given expressions without collecting anything into the
2960 trace buffer. (Valid in tracepoint actions only.)
2962 ftrace FN / FILE:LINE / *ADDR
2963 Define a fast tracepoint at the given function, line, or address.
2965 * New expression syntax
2967 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2968 GDB now parses 0b101010 identically with 42.
2972 set follow-exec-mode new|same
2973 show follow-exec-mode
2974 Control whether GDB reuses the same inferior across an exec call or
2975 creates a new one. This is useful to be able to restart the old
2976 executable after the inferior having done an exec call.
2978 set default-collect EXPR, ...
2979 show default-collect
2980 Define a list of expressions to be collected at each tracepoint.
2981 This is a useful way to ensure essential items are not overlooked,
2982 such as registers or a critical global variable.
2984 set disconnected-tracing
2985 show disconnected-tracing
2986 If set to 1, the target is instructed to continue tracing if it
2987 loses its connection to GDB. If 0, the target is to stop tracing
2990 set circular-trace-buffer
2991 show circular-trace-buffer
2992 If set to on, the target is instructed to use a circular trace buffer
2993 and discard the oldest trace frames instead of stopping the trace due
2994 to a full trace buffer. If set to off, the trace stops when the buffer
2995 fills up. Some targets may not support this.
2997 set script-extension off|soft|strict
2998 show script-extension
2999 If set to "off", the debugger does not perform any script language
3000 recognition, and all sourced files are assumed to be GDB scripts.
3001 If set to "soft" (the default), files are sourced according to
3002 filename extension, falling back to GDB scripts if the first
3004 If set to "strict", files are sourced according to filename extension.
3006 set ada trust-PAD-over-XVS on|off
3007 show ada trust-PAD-over-XVS
3008 If off, activate a workaround against a bug in the debugging information
3009 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3010 the GCC sources for more information about the GNAT encoding and
3011 PAD types in particular). It is always safe to set this option to
3012 off, but this introduces a slight performance penalty. The default
3015 * Python API Improvements
3017 ** GDB provides the new class gdb.LazyString. This is useful in
3018 some pretty-printing cases. The new method gdb.Value.lazy_string
3019 provides a simple way to create objects of this type.
3021 ** The fields returned by gdb.Type.fields now have an
3022 `is_base_class' attribute.
3024 ** The new method gdb.Type.range returns the range of an array type.
3026 ** The new method gdb.parse_and_eval can be used to parse and
3027 evaluate an expression.
3029 * New remote packets
3032 Define a trace state variable.
3035 Get the current value of a trace state variable.
3038 Set desired tracing behavior upon disconnection.
3041 Set the trace buffer to be linear or circular.
3044 Get data about the tracepoints currently in use.
3048 Process record now works correctly with hardware watchpoints.
3050 Multiple bug fixes have been made to the mips-irix port, making it
3051 much more reliable. In particular:
3052 - Debugging threaded applications is now possible again. Previously,
3053 GDB would hang while starting the program, or while waiting for
3054 the program to stop at a breakpoint.
3055 - Attaching to a running process no longer hangs.
3056 - An error occurring while loading a core file has been fixed.
3057 - Changing the value of the PC register now works again. This fixes
3058 problems observed when using the "jump" command, or when calling
3059 a function from GDB, or even when assigning a new value to $pc.
3060 - With the "finish" and "return" commands, the return value for functions
3061 returning a small array is now correctly printed.
3062 - It is now possible to break on shared library code which gets executed
3063 during a shared library init phase (code executed while executing
3064 their .init section). Previously, the breakpoint would have no effect.
3065 - GDB is now able to backtrace through the signal handler for
3066 non-threaded programs.
3068 PIE (Position Independent Executable) programs debugging is now supported.
3069 This includes debugging execution of PIC (Position Independent Code) shared
3070 libraries although for that, it should be possible to run such libraries as an
3073 *** Changes in GDB 7.0
3075 * GDB now has an interface for JIT compilation. Applications that
3076 dynamically generate code can create symbol files in memory and register
3077 them with GDB. For users, the feature should work transparently, and
3078 for JIT developers, the interface is documented in the GDB manual in the
3079 "JIT Compilation Interface" chapter.
3081 * Tracepoints may now be conditional. The syntax is as for
3082 breakpoints; either an "if" clause appended to the "trace" command,
3083 or the "condition" command is available. GDB sends the condition to
3084 the target for evaluation using the same bytecode format as is used
3085 for tracepoint actions.
3087 * The disassemble command now supports: an optional /r modifier, print the
3088 raw instructions in hex as well as in symbolic form, and an optional /m
3089 modifier to print mixed source+assembly.
3091 * Process record and replay
3093 In a architecture environment that supports ``process record and
3094 replay'', ``process record and replay'' target can record a log of
3095 the process execution, and replay it with both forward and reverse
3098 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3099 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3100 set execution-direction {forward|reverse}, for targets that support
3103 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3104 feature is available with a native GDB running on kernel version
3107 * GDB now has support for multi-byte and wide character sets on the
3108 target. Strings whose character type is wchar_t, char16_t, or
3109 char32_t are now correctly printed. GDB supports wide- and unicode-
3110 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3111 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3112 `printf'. This feature requires iconv to work properly; if your
3113 system does not have a working iconv, GDB can use GNU libiconv. See
3114 the installation instructions for more information.
3116 * GDB now supports automatic retrieval of shared library files from
3117 remote targets. To use this feature, specify a system root that begins
3118 with the `remote:' prefix, either via the `set sysroot' command or via
3119 the `--with-sysroot' configure-time option.
3121 * "info sharedlibrary" now takes an optional regex of libraries to show,
3122 and it now reports if a shared library has no debugging information.
3124 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3125 now complete on file names.
3127 * When completing in expressions, gdb will attempt to limit
3128 completions to allowable structure or union fields, where appropriate.
3129 For instance, consider:
3131 # struct example { int f1; double f2; };
3132 # struct example variable;
3135 If the user types TAB at the end of this command line, the available
3136 completions will be "f1" and "f2".
3138 * Inlined functions are now supported. They show up in backtraces, and
3139 the "step", "next", and "finish" commands handle them automatically.
3141 * GDB now supports the token-splicing (##) and stringification (#)
3142 operators when expanding macros. It also supports variable-arity
3145 * GDB now supports inspecting extra signal information, exported by
3146 the new $_siginfo convenience variable. The feature is currently
3147 implemented on linux ARM, i386 and amd64.
3149 * GDB can now display the VFP floating point registers and NEON vector
3150 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3151 can provide these registers (requires Linux 2.6.30 or later). Remote
3152 and simulator targets may also provide them.
3154 * New remote packets
3157 Search memory for a sequence of bytes.
3160 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3161 operation over reliable transport links. Use of this packet is
3162 controlled by the `set remote noack-packet' command.
3165 Kill the process with the specified process ID. Use this in preference
3166 to `k' when multiprocess protocol extensions are supported.
3169 Obtains additional operating system information
3173 Read or write additional signal information.
3175 * Removed remote protocol undocumented extension
3177 An undocumented extension to the remote protocol's `S' stop reply
3178 packet that permited the stub to pass a process id was removed.
3179 Remote servers should use the `T' stop reply packet instead.
3181 * GDB now supports multiple function calling conventions according to the
3182 DWARF-2 DW_AT_calling_convention function attribute.
3184 * The SH target utilizes the aforementioned change to distinguish between gcc
3185 and Renesas calling convention. It also adds the new CLI commands
3186 `set/show sh calling-convention'.
3188 * GDB can now read compressed debug sections, as produced by GNU gold
3189 with the --compress-debug-sections=zlib flag.
3191 * 64-bit core files are now supported on AIX.
3193 * Thread switching is now supported on Tru64.
3195 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3196 which will be allocated using malloc later in program execution.
3198 * The qXfer:libraries:read remote procotol packet now allows passing a
3199 list of section offsets.
3201 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3202 conditions handling signals delivered during attach or thread creation
3203 have also been fixed.
3205 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3206 From the user's standpoint, all unqualified instances of True and False
3207 are treated as the standard definitions, regardless of context.
3209 * GDB now parses C++ symbol and type names more flexibly. For
3212 template<typename T> class C { };
3215 GDB will now correctly handle all of:
3217 ptype C<char const *>
3218 ptype C<char const*>
3219 ptype C<const char *>
3220 ptype C<const char*>
3222 * New features in the GDB remote stub, gdbserver
3224 - The "--wrapper" command-line argument tells gdbserver to use a
3225 wrapper program to launch programs for debugging.
3227 - On PowerPC and S/390 targets, it is now possible to use a single
3228 gdbserver executable to debug both 32-bit and 64-bit programs.
3229 (This requires gdbserver itself to be built as a 64-bit executable.)
3231 - gdbserver uses the new noack protocol mode for TCP connections to
3232 reduce communications latency, if also supported and enabled in GDB.
3234 - Support for the sparc64-linux-gnu target is now included in
3237 - The amd64-linux build of gdbserver now supports debugging both
3238 32-bit and 64-bit programs.
3240 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3241 now support hardware watchpoints, and will use them automatically
3246 GDB now has support for scripting using Python. Whether this is
3247 available is determined at configure time.
3249 New GDB commands can now be written in Python.
3251 * Ada tasking support
3253 Ada tasks can now be inspected in GDB. The following commands have
3257 Print the list of Ada tasks.
3259 Print detailed information about task number N.
3261 Print the task number of the current task.
3263 Switch the context of debugging to task number N.
3265 * Support for user-defined prefixed commands. The "define" command can
3266 add new commands to existing prefixes, e.g. "target".
3268 * Multi-inferior, multi-process debugging.
3270 GDB now has generalized support for multi-inferior debugging. See
3271 "Debugging Multiple Inferiors" in the manual for more information.
3272 Although availability still depends on target support, the command
3273 set is more uniform now. The GNU/Linux specific multi-forks support
3274 has been migrated to this new framework. This implied some user
3275 visible changes; see "New commands" and also "Removed commands"
3278 * Target descriptions can now describe the target OS ABI. See the
3279 "Target Description Format" section in the user manual for more
3282 * Target descriptions can now describe "compatible" architectures
3283 to indicate that the target can execute applications for a different
3284 architecture in addition to those for the main target architecture.
3285 See the "Target Description Format" section in the user manual for
3288 * Multi-architecture debugging.
3290 GDB now includes general supports for debugging applications on
3291 hybrid systems that use more than one single processor architecture
3292 at the same time. Each such hybrid architecture still requires
3293 specific support to be added. The only hybrid architecture supported
3294 in this version of GDB is the Cell Broadband Engine.
3296 * GDB now supports integrated debugging of Cell/B.E. applications that
3297 use both the PPU and SPU architectures. To enable support for hybrid
3298 Cell/B.E. debugging, you need to configure GDB to support both the
3299 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3300 --enable-targets configure option.
3302 * Non-stop mode debugging.
3304 For some targets, GDB now supports an optional mode of operation in
3305 which you can examine stopped threads while other threads continue
3306 to execute freely. This is referred to as non-stop mode, with the
3307 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3308 section in the user manual for more information.
3310 To be able to support remote non-stop debugging, a remote stub needs
3311 to implement the non-stop mode remote protocol extensions, as
3312 described in the "Remote Non-Stop" section of the user manual. The
3313 GDB remote stub, gdbserver, has been adjusted to support these
3314 extensions on linux targets.
3316 * New commands (for set/show, see "New options" below)
3318 catch syscall [NAME(S) | NUMBER(S)]
3319 Catch system calls. Arguments, which should be names of system
3320 calls or their numbers, mean catch only those syscalls. Without
3321 arguments, every syscall will be caught. When the inferior issues
3322 any of the specified syscalls, GDB will stop and announce the system
3323 call, both when it is called and when its call returns. This
3324 feature is currently available with a native GDB running on the
3325 Linux Kernel, under the following architectures: x86, x86_64,
3326 PowerPC and PowerPC64.
3328 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3330 Search memory for a sequence of bytes.
3332 maint set python print-stack
3333 maint show python print-stack
3334 Show a stack trace when an error is encountered in a Python script.
3337 Invoke CODE by passing it to the Python interpreter.
3342 These allow macros to be defined, undefined, and listed
3346 Show operating system information about processes.
3349 List the inferiors currently under GDB's control.
3352 Switch focus to inferior number NUM.
3355 Detach from inferior number NUM.
3358 Kill inferior number NUM.
3362 set spu stop-on-load
3363 show spu stop-on-load
3364 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3366 set spu auto-flush-cache
3367 show spu auto-flush-cache
3368 Control whether to automatically flush the software-managed cache
3369 during Cell/B.E. debugging.
3371 set sh calling-convention
3372 show sh calling-convention
3373 Control the calling convention used when calling SH target functions.
3376 show debug timestamp
3377 Control display of timestamps with GDB debugging output.
3379 set disassemble-next-line
3380 show disassemble-next-line
3381 Control display of disassembled source lines or instructions when
3384 set remote noack-packet
3385 show remote noack-packet
3386 Set/show the use of remote protocol QStartNoAckMode packet. See above
3387 under "New remote packets."
3389 set remote query-attached-packet
3390 show remote query-attached-packet
3391 Control use of remote protocol `qAttached' (query-attached) packet.
3393 set remote read-siginfo-object
3394 show remote read-siginfo-object
3395 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3398 set remote write-siginfo-object
3399 show remote write-siginfo-object
3400 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3403 set remote reverse-continue
3404 show remote reverse-continue
3405 Control use of remote protocol 'bc' (reverse-continue) packet.
3407 set remote reverse-step
3408 show remote reverse-step
3409 Control use of remote protocol 'bs' (reverse-step) packet.
3411 set displaced-stepping
3412 show displaced-stepping
3413 Control displaced stepping mode. Displaced stepping is a way to
3414 single-step over breakpoints without removing them from the debuggee.
3415 Also known as "out-of-line single-stepping".
3418 show debug displaced
3419 Control display of debugging info for displaced stepping.
3421 maint set internal-error
3422 maint show internal-error
3423 Control what GDB does when an internal error is detected.
3425 maint set internal-warning
3426 maint show internal-warning
3427 Control what GDB does when an internal warning is detected.
3432 Use a wrapper program to launch programs for debugging.
3434 set multiple-symbols (all|ask|cancel)
3435 show multiple-symbols
3436 The value of this variable can be changed to adjust the debugger behavior
3437 when an expression or a breakpoint location contains an ambiguous symbol
3438 name (an overloaded function name, for instance).
3440 set breakpoint always-inserted
3441 show breakpoint always-inserted
3442 Keep breakpoints always inserted in the target, as opposed to inserting
3443 them when resuming the target, and removing them when the target stops.
3444 This option can improve debugger performance on slow remote targets.
3446 set arm fallback-mode (arm|thumb|auto)
3447 show arm fallback-mode
3448 set arm force-mode (arm|thumb|auto)
3450 These commands control how ARM GDB determines whether instructions
3451 are ARM or Thumb. The default for both settings is auto, which uses
3452 the current CPSR value for instructions without symbols; previous
3453 versions of GDB behaved as if "set arm fallback-mode arm".
3455 set disable-randomization
3456 show disable-randomization
3457 Standalone programs run with the virtual address space randomization enabled
3458 by default on some platforms. This option keeps the addresses stable across
3459 multiple debugging sessions.
3463 Control whether other threads are stopped or not when some thread hits
3468 Requests that asynchronous execution is enabled in the target, if available.
3469 In this case, it's possible to resume target in the background, and interact
3470 with GDB while the target is running. "show target-async" displays the
3471 current state of asynchronous execution of the target.
3473 set target-wide-charset
3474 show target-wide-charset
3475 The target-wide-charset is the name of the character set that GDB
3476 uses when printing characters whose type is wchar_t.
3478 set tcp auto-retry (on|off)
3480 set tcp connect-timeout
3481 show tcp connect-timeout
3482 These commands allow GDB to retry failed TCP connections to a remote stub
3483 with a specified timeout period; this is useful if the stub is launched
3484 in parallel with GDB but may not be ready to accept connections immediately.
3486 set libthread-db-search-path
3487 show libthread-db-search-path
3488 Control list of directories which GDB will search for appropriate
3491 set schedule-multiple (on|off)
3492 show schedule-multiple
3493 Allow GDB to resume all threads of all processes or only threads of
3494 the current process.
3498 Use more aggressive caching for accesses to the stack. This improves
3499 performance of remote debugging (particularly backtraces) without
3500 affecting correctness.
3502 set interactive-mode (on|off|auto)
3503 show interactive-mode
3504 Control whether GDB runs in interactive mode (on) or not (off).
3505 When in interactive mode, GDB waits for the user to answer all
3506 queries. Otherwise, GDB does not wait and assumes the default
3507 answer. When set to auto (the default), GDB determines which
3508 mode to use based on the stdin settings.
3513 For program forks, this is replaced by the new more generic `info
3514 inferiors' command. To list checkpoints, you can still use the
3515 `info checkpoints' command, which was an alias for the `info forks'
3519 Replaced by the new `inferior' command. To switch between
3520 checkpoints, you can still use the `restart' command, which was an
3521 alias for the `fork' command.
3524 This is removed, since some targets don't have a notion of
3525 processes. To switch between processes, you can still use the
3526 `inferior' command using GDB's own inferior number.
3529 For program forks, this is replaced by the new more generic `kill
3530 inferior' command. To delete a checkpoint, you can still use the
3531 `delete checkpoint' command, which was an alias for the `delete
3535 For program forks, this is replaced by the new more generic `detach
3536 inferior' command. To detach a checkpoint, you can still use the
3537 `detach checkpoint' command, which was an alias for the `detach
3540 * New native configurations
3542 x86/x86_64 Darwin i[34567]86-*-darwin*
3544 x86_64 MinGW x86_64-*-mingw*
3548 Lattice Mico32 lm32-*
3549 x86 DICOS i[34567]86-*-dicos*
3550 x86_64 DICOS x86_64-*-dicos*
3553 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3554 (mingw32ce) debugging.
3560 These commands were actually not implemented on any target.
3562 *** Changes in GDB 6.8
3564 * New native configurations
3566 NetBSD/hppa hppa*-*netbsd*
3567 Xtensa GNU/Linux xtensa*-*-linux*
3571 NetBSD/hppa hppa*-*-netbsd*
3572 Xtensa GNU/Lunux xtensa*-*-linux*
3574 * Change in command line behavior -- corefiles vs. process ids.
3576 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3577 attaching to process NUMBER fails, GDB no longer attempts to open a
3578 core file named NUMBER. Attaching to a program using the -c option
3579 is no longer supported. Instead, use the '-p' or '--pid' options.
3581 * GDB can now be built as a native debugger for debugging Windows x86
3582 (mingw32) Portable Executable (PE) programs.
3584 * Pending breakpoints no longer change their number when their address
3587 * GDB now supports breakpoints with multiple locations,
3588 including breakpoints on C++ constructors, inside C++ templates,
3589 and in inlined functions.
3591 * GDB's ability to debug optimized code has been improved. GDB more
3592 accurately identifies function bodies and lexical blocks that occupy
3593 more than one contiguous range of addresses.
3595 * Target descriptions can now describe registers for PowerPC.
3597 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3598 registers on PowerPC targets.
3600 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3601 targets even when the libthread_db library is not available.
3603 * The GDB remote stub, gdbserver, now supports the new file transfer
3604 commands (remote put, remote get, and remote delete).
3606 * The GDB remote stub, gdbserver, now supports run and attach in
3607 extended-remote mode.
3609 * hppa*64*-*-hpux11* target broken
3610 The debugger is unable to start a program and fails with the following
3611 error: "Error trying to get information about dynamic linker".
3612 The gdb-6.7 release is also affected.
3614 * GDB now supports the --enable-targets= configure option to allow
3615 building a single GDB executable that supports multiple remote
3616 target architectures.
3618 * GDB now supports debugging C and C++ programs which use the
3619 Decimal Floating Point extension. In addition, the PowerPC target
3620 now has a set of pseudo-registers to inspect decimal float values
3621 stored in two consecutive float registers.
3623 * The -break-insert MI command can optionally create pending
3626 * Improved support for debugging Ada
3627 Many improvements to the Ada language support have been made. These
3629 - Better support for Ada2005 interface types
3630 - Improved handling of arrays and slices in general
3631 - Better support for Taft-amendment types
3632 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3634 - Improved command completion in Ada
3637 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3642 set print frame-arguments (all|scalars|none)
3643 show print frame-arguments
3644 The value of this variable can be changed to control which argument
3645 values should be printed by the debugger when displaying a frame.
3650 Transfer files to and from a remote target, and delete remote files.
3657 Transfer files to and from a remote target, and delete remote files.
3659 * New remote packets
3666 Open, close, read, write, and delete files on the remote system.
3669 Attach to an existing process on the remote system, in extended-remote
3673 Run a new process on the remote system, in extended-remote mode.
3675 *** Changes in GDB 6.7
3677 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3678 bfd, libiberty and opcodes, as revealed by static analysis donated by
3679 Coverity, Inc. (http://scan.coverity.com).
3681 * When looking up multiply-defined global symbols, GDB will now prefer the
3682 symbol definition in the current shared library if it was built using the
3683 -Bsymbolic linker option.
3685 * When the Text User Interface (TUI) is not configured, GDB will now
3686 recognize the -tui command-line option and print a message that the TUI
3689 * The GDB remote stub, gdbserver, now has lower overhead for high
3690 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3692 * GDB for MIPS targets now autodetects whether a remote target provides
3693 32-bit or 64-bit register values.
3695 * Support for C++ member pointers has been improved.
3697 * GDB now understands XML target descriptions, which specify the
3698 target's overall architecture. GDB can read a description from
3699 a local file or over the remote serial protocol.
3701 * Vectors of single-byte data use a new integer type which is not
3702 automatically displayed as character or string data.
3704 * The /s format now works with the print command. It displays
3705 arrays of single-byte integers and pointers to single-byte integers
3708 * Target descriptions can now describe target-specific registers,
3709 for architectures which have implemented the support (currently
3710 only ARM, M68K, and MIPS).
3712 * GDB and the GDB remote stub, gdbserver, now support the XScale
3715 * The GDB remote stub, gdbserver, has been updated to support
3716 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3717 has been rewritten to use the standard GDB remote protocol.
3719 * GDB can now step into C++ functions which are called through thunks.
3721 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3723 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3724 layout. It also supports a TextSeg= and DataSeg= response when only
3725 segment base addresses (rather than offsets) are available.
3727 * The /i format now outputs any trailing branch delay slot instructions
3728 immediately following the last instruction within the count specified.
3730 * The GDB remote protocol "T" stop reply packet now supports a
3731 "library" response. Combined with the new "qXfer:libraries:read"
3732 packet, this response allows GDB to debug shared libraries on targets
3733 where the operating system manages the list of loaded libraries (e.g.
3734 Windows and SymbianOS).
3736 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3737 (DLLs) on Windows and Windows CE targets.
3739 * GDB now supports a faster verification that a .debug file matches its binary
3740 according to its build-id signature, if the signature is present.
3746 Enable or disable hardware flow control (RTS/CTS) on the serial port
3747 when debugging using remote targets.
3749 set mem inaccessible-by-default
3750 show mem inaccessible-by-default
3751 If the target supplies a memory map, for instance via the remote
3752 protocol's "qXfer:memory-map:read" packet, setting this variable
3753 prevents GDB from accessing memory outside the memory map. This
3754 is useful for targets with memory mapped registers or which react
3755 badly to accesses of unmapped address space.
3757 set breakpoint auto-hw
3758 show breakpoint auto-hw
3759 If the target supplies a memory map, for instance via the remote
3760 protocol's "qXfer:memory-map:read" packet, setting this variable
3761 lets GDB use hardware breakpoints automatically for memory regions
3762 where it can not use software breakpoints. This covers both the
3763 "break" command and internal breakpoints used for other commands
3764 including "next" and "finish".
3767 catch exception unhandled
3768 Stop the program execution when Ada exceptions are raised.
3771 Stop the program execution when an Ada assertion failed.
3775 Set an alternate system root for target files. This is a more
3776 general version of "set solib-absolute-prefix", which is now
3777 an alias to "set sysroot".
3780 Provide extended SPU facility status information. This set of
3781 commands is available only when debugging the Cell/B.E. SPU
3784 * New native configurations
3786 OpenBSD/sh sh*-*openbsd*
3789 unset tdesc filename
3791 Use the specified local file as an XML target description, and do
3792 not query the target for its built-in description.
3796 OpenBSD/sh sh*-*-openbsd*
3797 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3798 Toshiba Media Processor mep-elf
3800 * New remote packets
3803 Ignore the specified signals; pass them directly to the debugged program
3804 without stopping other threads or reporting them to GDB.
3806 qXfer:features:read:
3807 Read an XML target description from the target, which describes its
3812 Read or write contents of an spufs file on the target system. These
3813 packets are available only on the Cell/B.E. SPU architecture.
3815 qXfer:libraries:read:
3816 Report the loaded shared libraries. Combined with new "T" packet
3817 response, this packet allows GDB to debug shared libraries on
3818 targets where the operating system manages the list of loaded
3819 libraries (e.g. Windows and SymbianOS).
3823 Support for these obsolete configurations has been removed.
3831 i[34567]86-*-lynxos*
3832 i[34567]86-*-netware*
3833 i[34567]86-*-sco3.2v5*
3834 i[34567]86-*-sco3.2v4*
3836 i[34567]86-*-sysv4.2*
3839 i[34567]86-*-unixware2*
3840 i[34567]86-*-unixware*
3849 * Other removed features
3856 Various m68k-only ROM monitors.
3863 Various Renesas ROM monitors and debugging interfaces for SH and
3868 Support for a Macraigor serial interface to on-chip debugging.
3869 GDB does not directly support the newer parallel or USB
3874 A debug information format. The predecessor to DWARF 2 and
3875 DWARF 3, which are still supported.
3877 Support for the HP aCC compiler on HP-UX/PA-RISC
3879 SOM-encapsulated symbolic debugging information, automatic
3880 invocation of pxdb, and the aCC custom C++ ABI. This does not
3881 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3882 with aCC can still be debugged on an assembly level.
3884 MIPS ".pdr" sections
3886 A MIPS-specific format used to describe stack frame layout
3887 in debugging information.
3891 GDB could work with an older version of Guile to debug
3892 the interpreter and Scheme programs running in it.
3894 set mips stack-arg-size
3895 set mips saved-gpreg-size
3897 Use "set mips abi" to control parameter passing for MIPS.
3899 *** Changes in GDB 6.6
3904 Cell Broadband Engine SPU spu-elf
3906 * GDB can now be configured as a cross-debugger targeting native Windows
3907 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3908 running on a Windows system over TCP/IP to debug Windows programs.
3910 * The GDB remote stub, gdbserver, has been updated to support Windows and
3911 Cygwin debugging. Both single-threaded and multi-threaded programs are
3914 * The "set trust-readonly-sections" command works again. This command was
3915 broken in GDB 6.3, 6.4, and 6.5.
3917 * The "load" command now supports writing to flash memory, if the remote
3918 stub provides the required support.
3920 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3921 longer requires symbolic debug information (e.g. DWARF-2).
3926 unset substitute-path
3927 show substitute-path
3928 Manage a list of substitution rules that GDB uses to rewrite the name
3929 of the directories where the sources are located. This can be useful
3930 for instance when the sources were moved to a different location
3931 between compilation and debugging.
3935 Print each CLI command as it is executed. Each command is prefixed with
3936 a number of `+' symbols representing the nesting depth.
3937 The source command now has a `-v' option to enable the same feature.
3941 The ARM Demon monitor support (RDP protocol, "target rdp").
3943 Kernel Object Display, an embedded debugging feature which only worked with
3944 an obsolete version of Cisco IOS.
3946 The 'set download-write-size' and 'show download-write-size' commands.
3948 * New remote packets
3951 Tell a stub about GDB client features, and request remote target features.
3952 The first feature implemented is PacketSize, which allows the target to
3953 specify the size of packets it can handle - to minimize the number of
3954 packets required and improve performance when connected to a remote
3958 Fetch an OS auxilliary vector from the remote stub. This packet is a
3959 more efficient replacement for qPart:auxv:read.
3961 qXfer:memory-map:read:
3962 Fetch a memory map from the remote stub, including information about
3963 RAM, ROM, and flash memory devices.
3968 Erase and program a flash memory device.
3970 * Removed remote packets
3973 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3974 used it, and only gdbserver implemented it.
3976 *** Changes in GDB 6.5
3980 Renesas M32C/M16C m32c-elf
3982 Morpho Technologies ms1 ms1-elf
3986 init-if-undefined Initialize a convenience variable, but
3987 only if it doesn't already have a value.
3989 The following commands are presently only implemented for native GNU/Linux:
3991 checkpoint Save a snapshot of the program state.
3993 restart <n> Return the program state to a
3994 previously saved state.
3996 info checkpoints List currently saved checkpoints.
3998 delete-checkpoint <n> Delete a previously saved checkpoint.
4000 set|show detach-on-fork Tell gdb whether to detach from a newly
4001 forked process, or to keep debugging it.
4003 info forks List forks of the user program that
4004 are available to be debugged.
4006 fork <n> Switch to debugging one of several
4007 forks of the user program that are
4008 available to be debugged.
4010 delete-fork <n> Delete a fork from the list of forks
4011 that are available to be debugged (and
4012 kill the forked process).
4014 detach-fork <n> Delete a fork from the list of forks
4015 that are available to be debugged (and
4016 allow the process to continue).
4020 Morpho Technologies ms2 ms1-elf
4022 * Improved Windows host support
4024 GDB now builds as a cross debugger hosted on i686-mingw32, including
4025 native console support, and remote communications using either
4026 network sockets or serial ports.
4028 * Improved Modula-2 language support
4030 GDB can now print most types in the Modula-2 syntax. This includes:
4031 basic types, set types, record types, enumerated types, range types,
4032 pointer types and ARRAY types. Procedure var parameters are correctly
4033 printed and hexadecimal addresses and character constants are also
4034 written in the Modula-2 syntax. Best results can be obtained by using
4035 GNU Modula-2 together with the -gdwarf-2 command line option.
4039 The ARM rdi-share module.
4041 The Netware NLM debug server.
4043 *** Changes in GDB 6.4
4045 * New native configurations
4047 OpenBSD/arm arm*-*-openbsd*
4048 OpenBSD/mips64 mips64-*-openbsd*
4052 Morpho Technologies ms1 ms1-elf
4054 * New command line options
4056 --batch-silent As for --batch, but totally silent.
4057 --return-child-result The debugger will exist with the same value
4058 the child (debugged) program exited with.
4059 --eval-command COMMAND, -ex COMMAND
4060 Execute a single GDB CLI command. This may be
4061 specified multiple times and in conjunction
4062 with the --command (-x) option.
4064 * Deprecated commands removed
4066 The following commands, that were deprecated in 2000, have been
4070 set|show arm disassembly-flavor set|show arm disassembler
4071 othernames set arm disassembler
4072 set|show remotedebug set|show debug remote
4073 set|show archdebug set|show debug arch
4074 set|show eventdebug set|show debug event
4077 * New BSD user-level threads support
4079 It is now possible to debug programs using the user-level threads
4080 library on OpenBSD and FreeBSD. Currently supported (target)
4083 FreeBSD/amd64 x86_64-*-freebsd*
4084 FreeBSD/i386 i386-*-freebsd*
4085 OpenBSD/i386 i386-*-openbsd*
4087 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4088 are not yet supported.
4090 * New support for Matsushita MN10300 w/sim added
4091 (Work in progress). mn10300-elf.
4093 * REMOVED configurations and files
4095 VxWorks and the XDR protocol *-*-vxworks
4096 Motorola MCORE mcore-*-*
4097 National Semiconductor NS32000 ns32k-*-*
4099 * New "set print array-indexes" command
4101 After turning this setting "on", GDB prints the index of each element
4102 when displaying arrays. The default is "off" to preserve the previous
4105 * VAX floating point support
4107 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4109 * User-defined command support
4111 In addition to using $arg0..$arg9 for argument passing, it is now possible
4112 to use $argc to determine now many arguments have been passed. See the
4113 section on user-defined commands in the user manual for more information.
4115 *** Changes in GDB 6.3:
4117 * New command line option
4119 GDB now accepts -l followed by a number to set the timeout for remote
4122 * GDB works with GCC -feliminate-dwarf2-dups
4124 GDB now supports a more compact representation of DWARF-2 debug
4125 information using DW_FORM_ref_addr references. These are produced
4126 by GCC with the option -feliminate-dwarf2-dups and also by some
4127 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4128 to use -feliminate-dwarf2-dups.
4130 * Internationalization
4132 When supported by the host system, GDB will be built with
4133 internationalization (libintl). The task of marking up the sources is
4134 continued, we're looking forward to our first translation.
4138 Initial support for debugging programs compiled with the GNAT
4139 implementation of the Ada programming language has been integrated
4140 into GDB. In this release, support is limited to expression evaluation.
4142 * New native configurations
4144 GNU/Linux/m32r m32r-*-linux-gnu
4148 GDB's remote protocol now includes support for the 'p' packet. This
4149 packet is used to fetch individual registers from a remote inferior.
4151 * END-OF-LIFE registers[] compatibility module
4153 GDB's internal register infrastructure has been completely rewritten.
4154 The new infrastructure making possible the implementation of key new
4155 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4158 GDB 6.3 will be the last release to include the the registers[]
4159 compatibility module that allowed out-of-date configurations to
4160 continue to work. This change directly impacts the following
4170 powerpc bdm protocol
4172 Unless there is activity to revive these configurations, they will be
4173 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4175 * OBSOLETE configurations and files
4177 Configurations that have been declared obsolete in this release have
4178 been commented out. Unless there is activity to revive these
4179 configurations, the next release of GDB will have their sources
4180 permanently REMOVED.
4189 *** Changes in GDB 6.2.1:
4191 * MIPS `break main; run' gave an heuristic-fence-post warning
4193 When attempting to run even a simple program, a warning about
4194 heuristic-fence-post being hit would be reported. This problem has
4197 * MIPS IRIX 'long double' crashed GDB
4199 When examining a long double variable, GDB would get a segmentation
4200 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4201 IRIX long double values).
4205 A bug in the VAX stack code was causing problems with the "next"
4206 command. This problem has been fixed.
4208 *** Changes in GDB 6.2:
4210 * Fix for ``many threads''
4212 On GNU/Linux systems that use the NPTL threads library, a program
4213 rapidly creating and deleting threads would confuse GDB leading to the
4216 ptrace: No such process.
4217 thread_db_get_info: cannot get thread info: generic error
4219 This problem has been fixed.
4221 * "-async" and "-noasync" options removed.
4223 Support for the broken "-noasync" option has been removed (it caused
4226 * New ``start'' command.
4228 This command runs the program until the begining of the main procedure.
4230 * New BSD Kernel Data Access Library (libkvm) interface
4232 Using ``target kvm'' it is now possible to debug kernel core dumps and
4233 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4234 platforms. Currently supported (native-only) configurations are:
4236 FreeBSD/amd64 x86_64-*-freebsd*
4237 FreeBSD/i386 i?86-*-freebsd*
4238 NetBSD/i386 i?86-*-netbsd*
4239 NetBSD/m68k m68*-*-netbsd*
4240 NetBSD/sparc sparc-*-netbsd*
4241 OpenBSD/amd64 x86_64-*-openbsd*
4242 OpenBSD/i386 i?86-*-openbsd*
4243 OpenBSD/m68k m68*-openbsd*
4244 OpenBSD/sparc sparc-*-openbsd*
4246 * Signal trampoline code overhauled
4248 Many generic problems with GDB's signal handling code have been fixed.
4249 These include: backtraces through non-contiguous stacks; recognition
4250 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4251 call; backtrace through a signal trampoline; step into and out of
4252 signal handlers; and single-stepping in the signal trampoline.
4254 Please note that kernel bugs are a limiting factor here. These
4255 features have been shown to work on an s390 GNU/Linux system that
4256 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4258 * Cygwin support for DWARF 2 added.
4260 * New native configurations
4262 GNU/Linux/hppa hppa*-*-linux*
4263 OpenBSD/hppa hppa*-*-openbsd*
4264 OpenBSD/m68k m68*-*-openbsd*
4265 OpenBSD/m88k m88*-*-openbsd*
4266 OpenBSD/powerpc powerpc-*-openbsd*
4267 NetBSD/vax vax-*-netbsd*
4268 OpenBSD/vax vax-*-openbsd*
4270 * END-OF-LIFE frame compatibility module
4272 GDB's internal frame infrastructure has been completely rewritten.
4273 The new infrastructure making it possible to support key new features
4274 including DWARF 2 Call Frame Information. To aid in the task of
4275 migrating old configurations to this new infrastructure, a
4276 compatibility module, that allowed old configurations to continue to
4277 work, was also included.
4279 GDB 6.2 will be the last release to include this frame compatibility
4280 module. This change directly impacts the following configurations:
4290 Unless there is activity to revive these configurations, they will be
4291 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4293 * REMOVED configurations and files
4295 Sun 3, running SunOS 3 m68*-*-sunos3*
4296 Sun 3, running SunOS 4 m68*-*-sunos4*
4297 Sun 2, running SunOS 3 m68000-*-sunos3*
4298 Sun 2, running SunOS 4 m68000-*-sunos4*
4299 Motorola 680x0 running LynxOS m68*-*-lynxos*
4300 AT&T 3b1/Unix pc m68*-att-*
4301 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4302 decstation mips-dec-* mips-little-*
4303 riscos mips-*-riscos* mips-*-sysv*
4304 sonymips mips-sony-*
4305 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4307 *** Changes in GDB 6.1.1:
4309 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4311 The TUI (Text-mode User Interface) is now built as part of a default
4312 GDB configuration. It is enabled by either selecting the TUI with the
4313 command line option "-i=tui" or by running the separate "gdbtui"
4314 program. For more information on the TUI, see the manual "Debugging
4317 * Pending breakpoint support (also included in GDB 6.1)
4319 Support has been added to allow you to specify breakpoints in shared
4320 libraries that have not yet been loaded. If a breakpoint location
4321 cannot be found, and the "breakpoint pending" option is set to auto,
4322 GDB queries you if you wish to make the breakpoint pending on a future
4323 shared-library load. If and when GDB resolves the breakpoint symbol,
4324 the pending breakpoint is removed as one or more regular breakpoints
4327 Pending breakpoints are very useful for GCJ Java debugging.
4329 * Fixed ISO-C build problems
4331 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4332 non ISO-C code that stopped them being built using a more strict ISO-C
4333 compiler (e.g., IBM's C compiler).
4335 * Fixed build problem on IRIX 5
4337 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4338 wasn't able to compile compile on an IRIX 5 system.
4340 * Added execute permission to gdb/gdbserver/configure
4342 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4343 permission. This bug would cause configure to fail on a number of
4344 systems (Solaris, IRIX). Ref: server/519.
4346 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4348 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4349 has been updated to use constant array sizes.
4351 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4353 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4354 its generated DWARF Call Frame Info. This encoding was causing GDB to
4355 panic, that panic has been fixed. Ref: gdb/1628.
4357 * Fixed a problem when examining parameters in shared library code.
4359 When examining parameters in optimized shared library code generated
4360 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4361 not available''. GDB now correctly displays the variable's value.
4363 *** Changes in GDB 6.1:
4365 * Removed --with-mmalloc
4367 Support for the mmalloc memory manager has been removed, as it
4368 conflicted with the internal gdb byte cache.
4370 * Changes in AMD64 configurations
4372 The AMD64 target now includes the %cs and %ss registers. As a result
4373 the AMD64 remote protocol has changed; this affects the floating-point
4374 and SSE registers. If you rely on those registers for your debugging,
4375 you should upgrade gdbserver on the remote side.
4377 * Revised SPARC target
4379 The SPARC target has been completely revised, incorporating the
4380 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4381 support for LynxOS and SunOS 4 has been dropped. Calling functions
4382 from within GDB on operating systems with a non-executable stack
4383 (Solaris, OpenBSD) now works.
4387 GDB has a new C++ demangler which does a better job on the mangled
4388 names generated by current versions of g++. It also runs faster, so
4389 with this and other changes gdb should now start faster on large C++
4392 * DWARF 2 Location Expressions
4394 GDB support for location expressions has been extended to support function
4395 arguments and frame bases. Older versions of GDB could crash when they
4398 * C++ nested types and namespaces
4400 GDB's support for nested types and namespaces in C++ has been
4401 improved, especially if you use the DWARF 2 debugging format. (This
4402 is the default for recent versions of GCC on most platforms.)
4403 Specifically, if you have a class "Inner" defined within a class or
4404 namespace "Outer", then GDB realizes that the class's name is
4405 "Outer::Inner", not simply "Inner". This should greatly reduce the
4406 frequency of complaints about not finding RTTI symbols. In addition,
4407 if you are stopped at inside of a function defined within a namespace,
4408 GDB modifies its name lookup accordingly.
4410 * New native configurations
4412 NetBSD/amd64 x86_64-*-netbsd*
4413 OpenBSD/amd64 x86_64-*-openbsd*
4414 OpenBSD/alpha alpha*-*-openbsd*
4415 OpenBSD/sparc sparc-*-openbsd*
4416 OpenBSD/sparc64 sparc64-*-openbsd*
4418 * New debugging protocols
4420 M32R with SDI protocol m32r-*-elf*
4422 * "set prompt-escape-char" command deleted.
4424 The command "set prompt-escape-char" has been deleted. This command,
4425 and its very obscure effet on GDB's prompt, was never documented,
4426 tested, nor mentioned in the NEWS file.
4428 * OBSOLETE configurations and files
4430 Configurations that have been declared obsolete in this release have
4431 been commented out. Unless there is activity to revive these
4432 configurations, the next release of GDB will have their sources
4433 permanently REMOVED.
4435 Sun 3, running SunOS 3 m68*-*-sunos3*
4436 Sun 3, running SunOS 4 m68*-*-sunos4*
4437 Sun 2, running SunOS 3 m68000-*-sunos3*
4438 Sun 2, running SunOS 4 m68000-*-sunos4*
4439 Motorola 680x0 running LynxOS m68*-*-lynxos*
4440 AT&T 3b1/Unix pc m68*-att-*
4441 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4442 decstation mips-dec-* mips-little-*
4443 riscos mips-*-riscos* mips-*-sysv*
4444 sonymips mips-sony-*
4445 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4447 * REMOVED configurations and files
4449 SGI Irix-4.x mips-sgi-irix4 or iris4
4450 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4451 Z8000 simulator z8k-zilog-none or z8ksim
4452 Matsushita MN10200 w/simulator mn10200-*-*
4453 H8/500 simulator h8500-hitachi-hms or h8500hms
4454 HP/PA running BSD hppa*-*-bsd*
4455 HP/PA running OSF/1 hppa*-*-osf*
4456 HP/PA Pro target hppa*-*-pro*
4457 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4458 386BSD i[3456]86-*-bsd*
4459 Sequent family i[3456]86-sequent-sysv4*
4460 i[3456]86-sequent-sysv*
4461 i[3456]86-sequent-bsd*
4462 SPARC running LynxOS sparc-*-lynxos*
4463 SPARC running SunOS 4 sparc-*-sunos4*
4464 Tsqware Sparclet sparclet-*-*
4465 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4467 *** Changes in GDB 6.0:
4471 Support for debugging the Objective-C programming language has been
4472 integrated into GDB.
4474 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4476 DWARF 2's Call Frame Information makes available compiler generated
4477 information that more exactly describes the program's run-time stack.
4478 By using this information, GDB is able to provide more robust stack
4481 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4482 have been updated to use a new backtrace mechanism which includes
4483 DWARF 2 CFI support.
4487 GDB's remote protocol has been extended to include support for hosted
4488 file I/O (where the remote target uses GDB's file system). See GDB's
4489 remote protocol documentation for details.
4491 * All targets using the new architecture framework.
4493 All of GDB's targets have been updated to use the new internal
4494 architecture framework. The way is now open for future GDB releases
4495 to include cross-architecture native debugging support (i386 on amd64,
4498 * GNU/Linux's Thread Local Storage (TLS)
4500 GDB now includes support for for the GNU/Linux implementation of
4501 per-thread variables.
4503 * GNU/Linux's Native POSIX Thread Library (NPTL)
4505 GDB's thread code has been updated to work with either the new
4506 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4508 * Separate debug info.
4510 GDB, in conjunction with BINUTILS, now supports a mechanism for
4511 automatically loading debug information from a separate file. Instead
4512 of shipping full debug and non-debug versions of system libraries,
4513 system integrators can now instead ship just the stripped libraries
4514 and optional debug files.
4516 * DWARF 2 Location Expressions
4518 DWARF 2 Location Expressions allow the compiler to more completely
4519 describe the location of variables (even in optimized code) to the
4522 GDB now includes preliminary support for location expressions (support
4523 for DW_OP_piece is still missing).
4527 A number of long standing bugs that caused GDB to die while starting a
4528 Java application have been fixed. GDB's Java support is now
4529 considered "useable".
4531 * GNU/Linux support for fork, vfork, and exec.
4533 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4534 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4537 * GDB supports logging output to a file
4539 There are two new commands, "set logging" and "show logging", which can be
4540 used to capture GDB's output to a file.
4542 * The meaning of "detach" has changed for gdbserver
4544 The "detach" command will now resume the application, as documented. To
4545 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4548 * d10v, m68hc11 `regs' command deprecated
4550 The `info registers' command has been updated so that it displays the
4551 registers using a format identical to the old `regs' command.
4555 A new command, "maint set profile on/off", has been added. This command can
4556 be used to enable or disable profiling while running GDB, to profile a
4557 session or a set of commands. In addition there is a new configure switch,
4558 "--enable-profiling", which will cause GDB to be compiled with profiling
4559 data, for more informative profiling results.
4561 * Default MI syntax changed to "mi2".
4563 The default MI (machine interface) syntax, enabled by the command line
4564 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4565 "mi1", can be enabled by specifying the option "-i=mi1".
4567 Support for the original "mi0" syntax (included in GDB 5.0) has been
4570 Fix for gdb/192: removed extraneous space when displaying frame level.
4571 Fix for gdb/672: update changelist is now output in mi list format.
4572 Fix for gdb/702: a -var-assign that updates the value now shows up
4573 in a subsequent -var-update.
4575 * New native configurations.
4577 FreeBSD/amd64 x86_64-*-freebsd*
4579 * Multi-arched targets.
4581 HP/PA HPUX11 hppa*-*-hpux*
4582 Renesas M32R/D w/simulator m32r-*-elf*
4584 * OBSOLETE configurations and files
4586 Configurations that have been declared obsolete in this release have
4587 been commented out. Unless there is activity to revive these
4588 configurations, the next release of GDB will have their sources
4589 permanently REMOVED.
4591 Z8000 simulator z8k-zilog-none or z8ksim
4592 Matsushita MN10200 w/simulator mn10200-*-*
4593 H8/500 simulator h8500-hitachi-hms or h8500hms
4594 HP/PA running BSD hppa*-*-bsd*
4595 HP/PA running OSF/1 hppa*-*-osf*
4596 HP/PA Pro target hppa*-*-pro*
4597 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4598 Sequent family i[3456]86-sequent-sysv4*
4599 i[3456]86-sequent-sysv*
4600 i[3456]86-sequent-bsd*
4601 Tsqware Sparclet sparclet-*-*
4602 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4604 * REMOVED configurations and files
4607 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4608 IBM AIX PS/2 i[3456]86-*-aix
4609 i386 running Mach 3.0 i[3456]86-*-mach3*
4610 i386 running Mach i[3456]86-*-mach*
4611 i386 running OSF/1 i[3456]86-*osf1mk*
4612 HP/Apollo 68k Family m68*-apollo*-sysv*,
4614 m68*-hp-bsd*, m68*-hp-hpux*
4615 Argonaut Risc Chip (ARC) arc-*-*
4616 Mitsubishi D30V d30v-*-*
4617 Fujitsu FR30 fr30-*-elf*
4618 OS/9000 i[34]86-*-os9k
4619 I960 with MON960 i960-*-coff
4621 * MIPS $fp behavior changed
4623 The convenience variable $fp, for the MIPS, now consistently returns
4624 the address of the current frame's base. Previously, depending on the
4625 context, $fp could refer to either $sp or the current frame's base
4626 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4627 The GNU Source-Level Debugger''.
4629 *** Changes in GDB 5.3:
4631 * GNU/Linux shared library multi-threaded performance improved.
4633 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4634 `/proc', in preference to `ptrace' for memory reads. This may result
4635 in an improvement in the start-up time of multi-threaded, shared
4636 library applications when run under GDB. One GDB user writes: ``loads
4637 shared libs like mad''.
4639 * ``gdbserver'' now supports multi-threaded applications on some targets
4641 Support for debugging multi-threaded applications which use
4642 the GNU/Linux LinuxThreads package has been added for
4643 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4644 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4646 * GDB now supports C/C++ preprocessor macros.
4648 GDB now expands preprocessor macro invocations in C/C++ expressions,
4649 and provides various commands for showing macro definitions and how
4652 The new command `macro expand EXPRESSION' expands any macro
4653 invocations in expression, and shows the result.
4655 The new command `show macro MACRO-NAME' shows the definition of the
4656 macro named MACRO-NAME, and where it was defined.
4658 Most compilers don't include information about macros in the debugging
4659 information by default. In GCC 3.1, for example, you need to compile
4660 your program with the options `-gdwarf-2 -g3'. If the macro
4661 information is present in the executable, GDB will read it.
4663 * Multi-arched targets.
4665 DEC Alpha (partial) alpha*-*-*
4666 DEC VAX (partial) vax-*-*
4668 National Semiconductor NS32000 (partial) ns32k-*-*
4669 Motorola 68000 (partial) m68k-*-*
4670 Motorola MCORE mcore-*-*
4674 Fujitsu FRV architecture added by Red Hat frv*-*-*
4677 * New native configurations
4679 Alpha NetBSD alpha*-*-netbsd*
4680 SH NetBSD sh*-*-netbsdelf*
4681 MIPS NetBSD mips*-*-netbsd*
4682 UltraSPARC NetBSD sparc64-*-netbsd*
4684 * OBSOLETE configurations and files
4686 Configurations that have been declared obsolete in this release have
4687 been commented out. Unless there is activity to revive these
4688 configurations, the next release of GDB will have their sources
4689 permanently REMOVED.
4691 Mitsubishi D30V d30v-*-*
4692 OS/9000 i[34]86-*-os9k
4693 IBM AIX PS/2 i[3456]86-*-aix
4694 Fujitsu FR30 fr30-*-elf*
4695 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4696 Argonaut Risc Chip (ARC) arc-*-*
4697 i386 running Mach 3.0 i[3456]86-*-mach3*
4698 i386 running Mach i[3456]86-*-mach*
4699 i386 running OSF/1 i[3456]86-*osf1mk*
4700 HP/Apollo 68k Family m68*-apollo*-sysv*,
4702 m68*-hp-bsd*, m68*-hp-hpux*
4703 I960 with MON960 i960-*-coff
4705 * OBSOLETE languages
4707 CHILL, a Pascal like language used by telecommunications companies.
4709 * REMOVED configurations and files
4711 AMD 29k family via UDI a29k-amd-udi, udi29k
4712 A29K VxWorks a29k-*-vxworks
4713 AMD 29000 embedded, using EBMON a29k-none-none
4714 AMD 29000 embedded with COFF a29k-none-coff
4715 AMD 29000 embedded with a.out a29k-none-aout
4717 testsuite/gdb.hp/gdb.threads-hp/ directory
4719 * New command "set max-user-call-depth <nnn>"
4721 This command allows the user to limit the call depth of user-defined
4722 commands. The default is 1024.
4724 * Changes in FreeBSD/i386 native debugging.
4726 Support for the "generate-core-file" has been added.
4728 * New commands "dump", "append", and "restore".
4730 These commands allow data to be copied from target memory
4731 to a bfd-format or binary file (dump and append), and back
4732 from a file into memory (restore).
4734 * Improved "next/step" support on multi-processor Alpha Tru64.
4736 The previous single-step mechanism could cause unpredictable problems,
4737 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4738 of a software single-step mechanism prevents this.
4740 *** Changes in GDB 5.2.1:
4748 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4749 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4750 Fix, by Joel Brobecker imported from mainline.
4752 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4753 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4754 Fix, by Fred Fish, imported from mainline.
4756 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4757 Surprisingly enough, it works now.
4758 By Michal Ludvig, imported from mainline.
4760 i386 hardware watchpoint support:
4761 avoid misses on second run for some targets.
4762 By Pierre Muller, imported from mainline.
4764 *** Changes in GDB 5.2:
4766 * New command "set trust-readonly-sections on[off]".
4768 This command is a hint that tells gdb that read-only sections
4769 really are read-only (ie. that their contents will not change).
4770 In this mode, gdb will go to the object file rather than the
4771 target to read memory from read-only sections (such as ".text").
4772 This can be a significant performance improvement on some
4773 (notably embedded) targets.
4775 * New command "generate-core-file" (or "gcore").
4777 This new gdb command allows the user to drop a core file of the child
4778 process state at any time. So far it's been implemented only for
4779 GNU/Linux and Solaris, but should be relatively easily ported to other
4780 hosts. Argument is core file name (defaults to core.<pid>).
4782 * New command line option
4784 GDB now accepts --pid or -p followed by a process id.
4786 * Change in command line behavior -- corefiles vs. process ids.
4788 There is a subtle behavior in the way in which GDB handles
4789 command line arguments. The first non-flag argument is always
4790 a program to debug, but the second non-flag argument may either
4791 be a corefile or a process id. Previously, GDB would attempt to
4792 open the second argument as a corefile, and if that failed, would
4793 issue a superfluous error message and then attempt to attach it as
4794 a process. Now, if the second argument begins with a non-digit,
4795 it will be treated as a corefile. If it begins with a digit,
4796 GDB will attempt to attach it as a process, and if no such process
4797 is found, will then attempt to open it as a corefile.
4799 * Changes in ARM configurations.
4801 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4802 configuration is fully multi-arch.
4804 * New native configurations
4806 ARM NetBSD arm*-*-netbsd*
4807 x86 OpenBSD i[3456]86-*-openbsd*
4808 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4809 Sparc64 running FreeBSD sparc64-*-freebsd*
4813 Sanyo XStormy16 xstormy16-elf
4815 * OBSOLETE configurations and files
4817 Configurations that have been declared obsolete in this release have
4818 been commented out. Unless there is activity to revive these
4819 configurations, the next release of GDB will have their sources
4820 permanently REMOVED.
4822 AMD 29k family via UDI a29k-amd-udi, udi29k
4823 A29K VxWorks a29k-*-vxworks
4824 AMD 29000 embedded, using EBMON a29k-none-none
4825 AMD 29000 embedded with COFF a29k-none-coff
4826 AMD 29000 embedded with a.out a29k-none-aout
4828 testsuite/gdb.hp/gdb.threads-hp/ directory
4830 * REMOVED configurations and files
4832 TI TMS320C80 tic80-*-*
4834 PowerPC Solaris powerpcle-*-solaris*
4835 PowerPC Windows NT powerpcle-*-cygwin32
4836 PowerPC Netware powerpc-*-netware*
4837 Harris/CXUX m88k m88*-harris-cxux*
4838 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4839 ns32k-utek-sysv* ns32k-utek-*
4840 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4841 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4842 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4843 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4844 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4846 * Changes to command line processing
4848 The new `--args' feature can be used to specify command-line arguments
4849 for the inferior from gdb's command line.
4851 * Changes to key bindings
4853 There is a new `operate-and-get-next' function bound to `C-o'.
4855 *** Changes in GDB 5.1.1
4857 Fix compile problem on DJGPP.
4859 Fix a problem with floating-point registers on the i386 being
4862 Fix to stop GDB crashing on .debug_str debug info.
4864 Numerous documentation fixes.
4866 Numerous testsuite fixes.
4868 *** Changes in GDB 5.1:
4870 * New native configurations
4872 Alpha FreeBSD alpha*-*-freebsd*
4873 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4874 MIPS GNU/Linux mips*-*-linux*
4875 MIPS SGI Irix 6.x mips*-sgi-irix6*
4876 ia64 AIX ia64-*-aix*
4877 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4881 Motorola 68HC11 and 68HC12 m68hc11-elf
4883 UltraSparc running GNU/Linux sparc64-*-linux*
4885 * OBSOLETE configurations and files
4887 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4888 Harris/CXUX m88k m88*-harris-cxux*
4889 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4890 ns32k-utek-sysv* ns32k-utek-*
4891 TI TMS320C80 tic80-*-*
4893 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4894 PowerPC Solaris powerpcle-*-solaris*
4895 PowerPC Windows NT powerpcle-*-cygwin32
4896 PowerPC Netware powerpc-*-netware*
4897 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4898 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4899 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4900 Apple Macintosh (MPW) host N/A
4902 stuff.c (Program to stuff files into a specially prepared space in kdb)
4903 kdb-start.c (Main loop for the standalone kernel debugger)
4905 Configurations that have been declared obsolete in this release have
4906 been commented out. Unless there is activity to revive these
4907 configurations, the next release of GDB will have their sources
4908 permanently REMOVED.
4910 * REMOVED configurations and files
4912 Altos 3068 m68*-altos-*
4913 Convex c1-*-*, c2-*-*
4915 ARM RISCix arm-*-* (as host)
4919 * GDB has been converted to ISO C.
4921 GDB's source code has been converted to ISO C. In particular, the
4922 sources are fully protoized, and rely on standard headers being
4927 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4929 * The MI enabled by default.
4931 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4932 revised and enabled by default. Packages which use GDB as a debugging
4933 engine behind a UI or another front end are encouraged to switch to
4934 using the GDB/MI interface, instead of the old annotations interface
4935 which is now deprecated.
4937 * Support for debugging Pascal programs.
4939 GDB now includes support for debugging Pascal programs. The following
4940 main features are supported:
4942 - Pascal-specific data types such as sets;
4944 - automatic recognition of Pascal sources based on file-name
4947 - Pascal-style display of data types, variables, and functions;
4949 - a Pascal expression parser.
4951 However, some important features are not yet supported.
4953 - Pascal string operations are not supported at all;
4955 - there are some problems with boolean types;
4957 - Pascal type hexadecimal constants are not supported
4958 because they conflict with the internal variables format;
4960 - support for Pascal objects and classes is not full yet;
4962 - unlike Pascal, GDB is case-sensitive for symbol names.
4964 * Changes in completion.
4966 Commands such as `shell', `run' and `set args', which pass arguments
4967 to inferior programs, now complete on file names, similar to what
4968 users expect at the shell prompt.
4970 Commands which accept locations, such as `disassemble', `print',
4971 `breakpoint', `until', etc. now complete on filenames as well as
4972 program symbols. Thus, if you type "break foob TAB", and the source
4973 files linked into the programs include `foobar.c', that file name will
4974 be one of the candidates for completion. However, file names are not
4975 considered for completion after you typed a colon that delimits a file
4976 name from a name of a function in that file, as in "break foo.c:bar".
4978 `set demangle-style' completes on available demangling styles.
4980 * New platform-independent commands:
4982 It is now possible to define a post-hook for a command as well as a
4983 hook that runs before the command. For more details, see the
4984 documentation of `hookpost' in the GDB manual.
4986 * Changes in GNU/Linux native debugging.
4988 Support for debugging multi-threaded programs has been completely
4989 revised for all platforms except m68k and sparc. You can now debug as
4990 many threads as your system allows you to have.
4992 Attach/detach is supported for multi-threaded programs.
4994 Support for SSE registers was added for x86. This doesn't work for
4995 multi-threaded programs though.
4997 * Changes in MIPS configurations.
4999 Multi-arch support is enabled for all MIPS configurations.
5001 GDB can now be built as native debugger on SGI Irix 6.x systems for
5002 debugging n32 executables. (Debugging 64-bit executables is not yet
5005 * Unified support for hardware watchpoints in all x86 configurations.
5007 Most (if not all) native x86 configurations support hardware-assisted
5008 breakpoints and watchpoints in a unified manner. This support
5009 implements debug register sharing between watchpoints, which allows to
5010 put a virtually infinite number of watchpoints on the same address,
5011 and also supports watching regions up to 16 bytes with several debug
5014 The new maintenance command `maintenance show-debug-regs' toggles
5015 debugging print-outs in functions that insert, remove, and test
5016 watchpoints and hardware breakpoints.
5018 * Changes in the DJGPP native configuration.
5020 New command ``info dos sysinfo'' displays assorted information about
5021 the CPU, OS, memory, and DPMI server.
5023 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5024 display information about segment descriptors stored in GDT, LDT, and
5027 New commands ``info dos pde'' and ``info dos pte'' display entries
5028 from Page Directory and Page Tables (for now works with CWSDPMI only).
5029 New command ``info dos address-pte'' displays the Page Table entry for
5030 a given linear address.
5032 GDB can now pass command lines longer than 126 characters to the
5033 program being debugged (requires an update to the libdbg.a library
5034 which is part of the DJGPP development kit).
5036 DWARF2 debug info is now supported.
5038 It is now possible to `step' and `next' through calls to `longjmp'.
5040 * Changes in documentation.
5042 All GDB documentation was converted to GFDL, the GNU Free
5043 Documentation License.
5045 Tracepoints-related commands are now fully documented in the GDB
5048 TUI, the Text-mode User Interface, is now documented in the manual.
5050 Tracepoints-related commands are now fully documented in the GDB
5053 The "GDB Internals" manual now has an index. It also includes
5054 documentation of `ui_out' functions, GDB coding standards, x86
5055 hardware watchpoints, and memory region attributes.
5057 * GDB's version number moved to ``version.in''
5059 The Makefile variable VERSION has been replaced by the file
5060 ``version.in''. People creating GDB distributions should update the
5061 contents of this file.
5065 GUD support is now a standard part of the EMACS distribution.
5067 *** Changes in GDB 5.0:
5069 * Improved support for debugging FP programs on x86 targets
5071 Unified and much-improved support for debugging floating-point
5072 programs on all x86 targets. In particular, ``info float'' now
5073 displays the FP registers in the same format on all x86 targets, with
5074 greater level of detail.
5076 * Improvements and bugfixes in hardware-assisted watchpoints
5078 It is now possible to watch array elements, struct members, and
5079 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5080 on x86 targets no longer erroneously trigger when the address is
5083 * Improvements in the native DJGPP version of GDB
5085 The distribution now includes all the scripts and auxiliary files
5086 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5087 machines ``out of the box''.
5089 The DJGPP version can now debug programs that use signals. It is
5090 possible to catch signals that happened in the debuggee, deliver
5091 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5092 would kill the program being debugged.) Programs that hook hardware
5093 interrupts (keyboard, timer, etc.) can also be debugged.
5095 It is now possible to debug DJGPP programs that redirect their
5096 standard handles or switch them to raw (as opposed to cooked) mode, or
5097 even close them. The command ``run < foo > bar'' works as expected,
5098 and ``info terminal'' reports useful information about the debuggee's
5099 terminal, including raw/cooked mode, redirection, etc.
5101 The DJGPP version now uses termios functions for console I/O, which
5102 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5105 DOS-style file names with drive letters are now fully supported by
5108 It is now possible to debug DJGPP programs that switch their working
5109 directory. It is also possible to rerun the debuggee any number of
5110 times without restarting GDB; thus, you can use the same setup,
5111 breakpoints, etc. for many debugging sessions.
5113 * New native configurations
5115 ARM GNU/Linux arm*-*-linux*
5116 PowerPC GNU/Linux powerpc-*-linux*
5120 Motorola MCore mcore-*-*
5121 x86 VxWorks i[3456]86-*-vxworks*
5122 PowerPC VxWorks powerpc-*-vxworks*
5123 TI TMS320C80 tic80-*-*
5125 * OBSOLETE configurations
5127 Altos 3068 m68*-altos-*
5128 Convex c1-*-*, c2-*-*
5130 ARM RISCix arm-*-* (as host)
5133 Configurations that have been declared obsolete will be commented out,
5134 but the code will be left in place. If there is no activity to revive
5135 these configurations before the next release of GDB, the sources will
5136 be permanently REMOVED.
5138 * Gould support removed
5140 Support for the Gould PowerNode and NP1 has been removed.
5142 * New features for SVR4
5144 On SVR4 native platforms (such as Solaris), if you attach to a process
5145 without first loading a symbol file, GDB will now attempt to locate and
5146 load symbols from the running process's executable file.
5148 * Many C++ enhancements
5150 C++ support has been greatly improved. Overload resolution now works properly
5151 in almost all cases. RTTI support is on the way.
5153 * Remote targets can connect to a sub-program
5155 A popen(3) style serial-device has been added. This device starts a
5156 sub-process (such as a stand-alone simulator) and then communicates
5157 with that. The sub-program to run is specified using the syntax
5158 ``|<program> <args>'' vis:
5160 (gdb) set remotedebug 1
5161 (gdb) target extended-remote |mn10300-elf-sim program-args
5163 * MIPS 64 remote protocol
5165 A long standing bug in the mips64 remote protocol where by GDB
5166 expected certain 32 bit registers (ex SR) to be transfered as 32
5167 instead of 64 bits has been fixed.
5169 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5170 added to provide backward compatibility with older versions of GDB.
5172 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5174 The command ``set remotebinarydownload'' command has been replaced by
5175 ``set remote X-packet''. Other commands in ``set remote'' family
5176 include ``set remote P-packet''.
5178 * Breakpoint commands accept ranges.
5180 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5181 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5182 ``tracepoint passcount'' also accepts a range of tracepoints.
5184 * ``apropos'' command added.
5186 The ``apropos'' command searches through command names and
5187 documentation strings, printing out matches, making it much easier to
5188 try to find a command that does what you are looking for.
5192 A new machine oriented interface (MI) has been added to GDB. This
5193 interface is designed for debug environments running GDB as a separate
5194 process. This is part of the long term libGDB project. See the
5195 "GDB/MI" chapter of the GDB manual for further information. It can be
5196 enabled by configuring with:
5198 .../configure --enable-gdbmi
5200 *** Changes in GDB-4.18:
5202 * New native configurations
5204 HP-UX 10.20 hppa*-*-hpux10.20
5205 HP-UX 11.x hppa*-*-hpux11.0*
5206 M68K GNU/Linux m68*-*-linux*
5210 Fujitsu FR30 fr30-*-elf*
5211 Intel StrongARM strongarm-*-*
5212 Mitsubishi D30V d30v-*-*
5214 * OBSOLETE configurations
5216 Gould PowerNode, NP1 np1-*-*, pn-*-*
5218 Configurations that have been declared obsolete will be commented out,
5219 but the code will be left in place. If there is no activity to revive
5220 these configurations before the next release of GDB, the sources will
5221 be permanently REMOVED.
5225 As a compatibility experiment, GDB's source files buildsym.h and
5226 buildsym.c have been converted to pure standard C, no longer
5227 containing any K&R compatibility code. We believe that all systems in
5228 use today either come with a standard C compiler, or have a GCC port
5229 available. If this is not true, please report the affected
5230 configuration to bug-gdb@gnu.org immediately. See the README file for
5231 information about getting a standard C compiler if you don't have one
5236 GDB now uses readline 2.2.
5238 * set extension-language
5240 You can now control the mapping between filename extensions and source
5241 languages by using the `set extension-language' command. For instance,
5242 you can ask GDB to treat .c files as C++ by saying
5243 set extension-language .c c++
5244 The command `info extensions' lists all of the recognized extensions
5245 and their associated languages.
5247 * Setting processor type for PowerPC and RS/6000
5249 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5250 you can use the `set processor' command to specify what variant of the
5251 PowerPC family you are debugging. The command
5255 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5256 following PowerPC and RS6000 variants:
5258 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5259 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5261 403GC IBM PowerPC 403GC
5262 505 Motorola PowerPC 505
5263 860 Motorola PowerPC 860 or 850
5264 601 Motorola PowerPC 601
5265 602 Motorola PowerPC 602
5266 603 Motorola/IBM PowerPC 603 or 603e
5267 604 Motorola PowerPC 604 or 604e
5268 750 Motorola/IBM PowerPC 750 or 750
5270 At the moment, this command just tells GDB what to name the
5271 special-purpose processor registers. Since almost all the affected
5272 registers are inaccessible to user-level programs, this command is
5273 only useful for remote debugging in its present form.
5277 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5278 more extensive support for HP-UX. Added features include shared
5279 library support, kernel threads and hardware watchpoints for 11.00,
5280 support for HP's ANSI C and C++ compilers, and a compatibility mode
5281 for xdb and dbx commands.
5285 HP's donation includes the new concept of catchpoints, which is a
5286 generalization of the old catch command. On HP-UX, it is now possible
5287 to catch exec, fork, and vfork, as well as library loading.
5289 This means that the existing catch command has changed; its first
5290 argument now specifies the type of catch to be set up. See the
5291 output of "help catch" for a list of catchpoint types.
5293 * Debugging across forks
5295 On HP-UX, you can choose which process to debug when a fork() happens
5300 HP has donated a curses-based terminal user interface (TUI). To get
5301 it, build with --enable-tui. Although this can be enabled for any
5302 configuration, at present it only works for native HP debugging.
5304 * GDB remote protocol additions
5306 A new protocol packet 'X' that writes binary data is now available.
5307 Default behavior is to try 'X', then drop back to 'M' if the stub
5308 fails to respond. The settable variable `remotebinarydownload'
5309 allows explicit control over the use of 'X'.
5311 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5312 full 64-bit address. The command
5314 set remoteaddresssize 32
5316 can be used to revert to the old behaviour. For existing remote stubs
5317 the change should not be noticed, as the additional address information
5320 In order to assist in debugging stubs, you may use the maintenance
5321 command `packet' to send any text string to the stub. For instance,
5323 maint packet heythere
5325 sends the packet "$heythere#<checksum>". Note that it is very easy to
5326 disrupt a debugging session by sending the wrong packet at the wrong
5329 The compare-sections command allows you to compare section data on the
5330 target to what is in the executable file without uploading or
5331 downloading, by comparing CRC checksums.
5333 * Tracing can collect general expressions
5335 You may now collect general expressions at tracepoints. This requires
5336 further additions to the target-side stub; see tracepoint.c and
5337 doc/agentexpr.texi for further details.
5339 * mask-address variable for Mips
5341 For Mips targets, you may control the zeroing of the upper 32 bits of
5342 a 64-bit address by entering `set mask-address on'. This is mainly
5343 of interest to users of embedded R4xxx and R5xxx processors.
5345 * Higher serial baud rates
5347 GDB's serial code now allows you to specify baud rates 57600, 115200,
5348 230400, and 460800 baud. (Note that your host system may not be able
5349 to achieve all of these rates.)
5353 The i960 configuration now includes an initial implementation of a
5354 builtin simulator, contributed by Jim Wilson.
5357 *** Changes in GDB-4.17:
5359 * New native configurations
5361 Alpha GNU/Linux alpha*-*-linux*
5362 Unixware 2.x i[3456]86-unixware2*
5363 Irix 6.x mips*-sgi-irix6*
5364 PowerPC GNU/Linux powerpc-*-linux*
5365 PowerPC Solaris powerpcle-*-solaris*
5366 Sparc GNU/Linux sparc-*-linux*
5367 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5371 Argonaut Risc Chip (ARC) arc-*-*
5372 Hitachi H8/300S h8300*-*-*
5373 Matsushita MN10200 w/simulator mn10200-*-*
5374 Matsushita MN10300 w/simulator mn10300-*-*
5375 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5376 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5377 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5378 Mitsubishi D10V w/simulator d10v-*-*
5379 Mitsubishi M32R/D w/simulator m32r-*-elf*
5380 Tsqware Sparclet sparclet-*-*
5381 NEC V850 w/simulator v850-*-*
5383 * New debugging protocols
5385 ARM with RDI protocol arm*-*-*
5386 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5387 DDB and LSI variants of PMON protocol mips*-*-*
5388 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5389 PowerPC with SDS protocol powerpc{,le}-*-eabi
5390 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5394 All configurations can now understand and use the DWARF 2 debugging
5395 format. The choice is automatic, if the symbol file contains DWARF 2
5400 GDB now includes basic Java language support. This support is
5401 only useful with Java compilers that produce native machine code.
5403 * solib-absolute-prefix and solib-search-path
5405 For SunOS and SVR4 shared libraries, you may now set the prefix for
5406 loading absolute shared library symbol files, and the search path for
5407 locating non-absolute shared library symbol files.
5409 * Live range splitting
5411 GDB can now effectively debug code for which GCC has performed live
5412 range splitting as part of its optimization. See gdb/doc/LRS for
5413 more details on the expected format of the stabs information.
5417 GDB's support for the GNU Hurd, including thread debugging, has been
5418 updated to work with current versions of the Hurd.
5422 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5423 instruction set. ARM GDB automatically detects when Thumb
5424 instructions are in use, and adjusts disassembly and backtracing
5429 GDB's MIPS target configurations now handle the MIP16 16-bit
5434 GDB now includes support for overlays; if an executable has been
5435 linked such that multiple sections are based at the same address, GDB
5436 will decide which section to use for symbolic info. You can choose to
5437 control the decision manually, using overlay commands, or implement
5438 additional target-side support and use "overlay load-target" to bring
5439 in the overlay mapping. Do "help overlay" for more detail.
5443 The command "info symbol <address>" displays information about
5444 the symbol at the specified address.
5448 The standard remote protocol now includes an extension that allows
5449 asynchronous collection and display of trace data. This requires
5450 extensive support in the target-side debugging stub. Tracing mode
5451 includes a new interaction mode in GDB and new commands: see the
5452 file tracepoint.c for more details.
5456 Configurations for embedded MIPS now include a simulator contributed
5457 by Cygnus Solutions. The simulator supports the instruction sets
5458 of most MIPS variants.
5462 Sparc configurations may now include the ERC32 simulator contributed
5463 by the European Space Agency. The simulator is not built into
5464 Sparc targets by default; configure with --enable-sim to include it.
5468 For target configurations that may include multiple variants of a
5469 basic architecture (such as MIPS and SH), you may now set the
5470 architecture explicitly. "set arch" sets, "info arch" lists
5471 the possible architectures.
5473 *** Changes in GDB-4.16:
5475 * New native configurations
5477 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5478 M68K NetBSD m68k-*-netbsd*
5479 PowerPC AIX 4.x powerpc-*-aix*
5480 PowerPC MacOS powerpc-*-macos*
5481 PowerPC Windows NT powerpcle-*-cygwin32
5482 RS/6000 AIX 4.x rs6000-*-aix4*
5486 ARM with RDP protocol arm-*-*
5487 I960 with MON960 i960-*-coff
5488 MIPS VxWorks mips*-*-vxworks*
5489 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5490 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5492 Matra Sparclet sparclet-*-*
5496 The powerpc-eabi configuration now includes the PSIM simulator,
5497 contributed by Andrew Cagney, with assistance from Mike Meissner.
5498 PSIM is a very elaborate model of the PowerPC, including not only
5499 basic instruction set execution, but also details of execution unit
5500 performance and I/O hardware. See sim/ppc/README for more details.
5504 GDB now works with Solaris 2.5.
5506 * Windows 95/NT native
5508 GDB will now work as a native debugger on Windows 95 and Windows NT.
5509 To build it from source, you must use the "gnu-win32" environment,
5510 which uses a DLL to emulate enough of Unix to run the GNU tools.
5511 Further information, binaries, and sources are available at
5512 ftp.cygnus.com, under pub/gnu-win32.
5514 * dont-repeat command
5516 If a user-defined command includes the command `dont-repeat', then the
5517 command will not be repeated if the user just types return. This is
5518 useful if the command is time-consuming to run, so that accidental
5519 extra keystrokes don't run the same command many times.
5521 * Send break instead of ^C
5523 The standard remote protocol now includes an option to send a break
5524 rather than a ^C to the target in order to interrupt it. By default,
5525 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5527 * Remote protocol timeout
5529 The standard remote protocol includes a new variable `remotetimeout'
5530 that allows you to set the number of seconds before GDB gives up trying
5531 to read from the target. The default value is 2.
5533 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5535 By default GDB will automatically keep track of objects as they are
5536 loaded and unloaded by the dynamic linker. By using the command `set
5537 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5538 when shared library events occur, thus allowing you to set breakpoints
5539 in shared libraries which are explicitly loaded by the inferior.
5541 Note this feature does not work on hpux8. On hpux9 you must link
5542 /usr/lib/end.o into your program. This feature should work
5543 automatically on hpux10.
5545 * Irix 5.x hardware watchpoint support
5547 Irix 5 configurations now support the use of hardware watchpoints.
5549 * Mips protocol "SYN garbage limit"
5551 When debugging a Mips target using the `target mips' protocol, you
5552 may set the number of characters that GDB will ignore by setting
5553 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5554 every character. The default value is 1050.
5556 * Recording and replaying remote debug sessions
5558 If you set `remotelogfile' to the name of a file, gdb will write to it
5559 a recording of a remote debug session. This recording may then be
5560 replayed back to gdb using "gdbreplay". See gdbserver/README for
5561 details. This is useful when you have a problem with GDB while doing
5562 remote debugging; you can make a recording of the session and send it
5563 to someone else, who can then recreate the problem.
5565 * Speedups for remote debugging
5567 GDB includes speedups for downloading and stepping MIPS systems using
5568 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5569 and more efficient S-record downloading.
5571 * Memory use reductions and statistics collection
5573 GDB now uses less memory and reports statistics about memory usage.
5574 Try the `maint print statistics' command, for example.
5576 *** Changes in GDB-4.15:
5578 * Psymtabs for XCOFF
5580 The symbol reader for AIX GDB now uses partial symbol tables. This
5581 can greatly improve startup time, especially for large executables.
5583 * Remote targets use caching
5585 Remote targets now use a data cache to speed up communication with the
5586 remote side. The data cache could lead to incorrect results because
5587 it doesn't know about volatile variables, thus making it impossible to
5588 debug targets which use memory mapped I/O devices. `set remotecache
5589 off' turns the the data cache off.
5591 * Remote targets may have threads
5593 The standard remote protocol now includes support for multiple threads
5594 in the target system, using new protocol commands 'H' and 'T'. See
5595 gdb/remote.c for details.
5599 If GDB is configured with `--enable-netrom', then it will include
5600 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5601 acts as though it is a bank of ROM on the target board, but you can
5602 write into it over the network. GDB's support consists only of
5603 support for fast loading into the emulated ROM; to debug, you must use
5604 another protocol, such as standard remote protocol. The usual
5605 sequence is something like
5607 target nrom <netrom-hostname>
5609 target remote <netrom-hostname>:1235
5613 GDB now includes support for the Apple Macintosh, as a host only. It
5614 may be run as either an MPW tool or as a standalone application, and
5615 it can debug through the serial port. All the usual GDB commands are
5616 available, but to the target command, you must supply "serial" as the
5617 device type instead of "/dev/ttyXX". See mpw-README in the main
5618 directory for more information on how to build. The MPW configuration
5619 scripts */mpw-config.in support only a few targets, and only the
5620 mips-idt-ecoff target has been tested.
5624 GDB configuration now uses autoconf. This is not user-visible,
5625 but does simplify configuration and building.
5629 GDB now supports hpux10.
5631 *** Changes in GDB-4.14:
5633 * New native configurations
5635 x86 FreeBSD i[345]86-*-freebsd
5636 x86 NetBSD i[345]86-*-netbsd
5637 NS32k NetBSD ns32k-*-netbsd
5638 Sparc NetBSD sparc-*-netbsd
5642 A29K VxWorks a29k-*-vxworks
5643 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5644 CPU32 EST-300 emulator m68*-*-est*
5645 PowerPC ELF powerpc-*-elf
5648 * Alpha OSF/1 support for procfs
5650 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5651 possible to attach to running processes. As the mounting of the /proc
5652 filesystem is optional on the Alpha, GDB automatically determines
5653 the availability of /proc during startup. This can lead to problems
5654 if /proc is unmounted after GDB has been started.
5656 * Arguments to user-defined commands
5658 User commands may accept up to 10 arguments separated by whitespace.
5659 Arguments are accessed within the user command via $arg0..$arg9. A
5662 print $arg0 + $arg1 + $arg2
5664 To execute the command use:
5667 Defines the command "adder" which prints the sum of its three arguments.
5668 Note the arguments are text substitutions, so they may reference variables,
5669 use complex expressions, or even perform inferior function calls.
5671 * New `if' and `while' commands
5673 This makes it possible to write more sophisticated user-defined
5674 commands. Both commands take a single argument, which is the
5675 expression to evaluate, and must be followed by the commands to
5676 execute, one per line, if the expression is nonzero, the list being
5677 terminated by the word `end'. The `if' command list may include an
5678 `else' word, which causes the following commands to be executed only
5679 if the expression is zero.
5681 * Fortran source language mode
5683 GDB now includes partial support for Fortran 77. It will recognize
5684 Fortran programs and can evaluate a subset of Fortran expressions, but
5685 variables and functions may not be handled correctly. GDB will work
5686 with G77, but does not yet know much about symbols emitted by other
5689 * Better HPUX support
5691 Most debugging facilities now work on dynamic executables for HPPAs
5692 running hpux9 or later. You can attach to running dynamically linked
5693 processes, but by default the dynamic libraries will be read-only, so
5694 for instance you won't be able to put breakpoints in them. To change
5695 that behavior do the following before running the program:
5701 This will cause the libraries to be mapped private and read-write.
5702 To revert to the normal behavior, do this:
5708 You cannot set breakpoints or examine data in the library until after
5709 the library is loaded if the function/data symbols do not have
5712 GDB can now also read debug symbols produced by the HP C compiler on
5713 HPPAs (sorry, no C++, Fortran or 68k support).
5715 * Target byte order now dynamically selectable
5717 You can choose which byte order to use with a target system, via the
5718 commands "set endian big" and "set endian little", and you can see the
5719 current setting by using "show endian". You can also give the command
5720 "set endian auto", in which case GDB will use the byte order
5721 associated with the executable. Currently, only embedded MIPS
5722 configurations support dynamic selection of target byte order.
5724 * New DOS host serial code
5726 This version uses DPMI interrupts to handle buffered I/O, so you
5727 no longer need to run asynctsr when debugging boards connected to
5730 *** Changes in GDB-4.13:
5732 * New "complete" command
5734 This lists all the possible completions for the rest of the line, if it
5735 were to be given as a command itself. This is intended for use by emacs.
5737 * Trailing space optional in prompt
5739 "set prompt" no longer adds a space for you after the prompt you set. This
5740 allows you to set a prompt which ends in a space or one that does not.
5742 * Breakpoint hit counts
5744 "info break" now displays a count of the number of times the breakpoint
5745 has been hit. This is especially useful in conjunction with "ignore"; you
5746 can ignore a large number of breakpoint hits, look at the breakpoint info
5747 to see how many times the breakpoint was hit, then run again, ignoring one
5748 less than that number, and this will get you quickly to the last hit of
5751 * Ability to stop printing at NULL character
5753 "set print null-stop" will cause GDB to stop printing the characters of
5754 an array when the first NULL is encountered. This is useful when large
5755 arrays actually contain only short strings.
5757 * Shared library breakpoints
5759 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5760 breakpoints in shared libraries before the executable is run.
5762 * Hardware watchpoints
5764 There is a new hardware breakpoint for the watch command for sparclite
5765 targets. See gdb/sparclite/hw_breakpoint.note.
5767 Hardware watchpoints are also now supported under GNU/Linux.
5771 Annotations have been added. These are for use with graphical interfaces,
5772 and are still experimental. Currently only gdba.el uses these.
5774 * Improved Irix 5 support
5776 GDB now works properly with Irix 5.2.
5778 * Improved HPPA support
5780 GDB now works properly with the latest GCC and GAS.
5782 * New native configurations
5784 Sequent PTX4 i[34]86-sequent-ptx4
5785 HPPA running OSF/1 hppa*-*-osf*
5786 Atari TT running SVR4 m68*-*-sysv4*
5787 RS/6000 LynxOS rs6000-*-lynxos*
5791 OS/9000 i[34]86-*-os9k
5792 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5795 * Hitachi SH7000 and E7000-PC ICE support
5797 There is now support for communicating with the Hitachi E7000-PC ICE.
5798 This is available automatically when GDB is configured for the SH.
5802 As usual, a variety of small fixes and improvements, both generic
5803 and configuration-specific. See the ChangeLog for more detail.
5805 *** Changes in GDB-4.12:
5807 * Irix 5 is now supported
5811 GDB-4.12 on the HPPA has a number of changes which make it unable
5812 to debug the output from the currently released versions of GCC and
5813 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5814 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5815 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5818 *** Changes in GDB-4.11:
5820 * User visible changes:
5824 The "set remotedebug" option is now consistent between the mips remote
5825 target, remote targets using the gdb-specific protocol, UDI (AMD's
5826 debug protocol for the 29k) and the 88k bug monitor. It is now an
5827 integer specifying a debug level (normally 0 or 1, but 2 means more
5828 debugging info for the mips target).
5830 * DEC Alpha native support
5832 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5833 debug info, but GDB works fairly well with the DEC compiler and should
5834 work with a future GCC release. See the README file for a few
5835 Alpha-specific notes.
5837 * Preliminary thread implementation
5839 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5841 * LynxOS native and target support for 386
5843 This release has been hosted on LynxOS 2.2, and also can be configured
5844 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5847 * Improvements in C++ mangling/demangling.
5849 This release has much better g++ debugging, specifically in name
5850 mangling/demangling, virtual function calls, print virtual table,
5851 call methods, ...etc.
5853 *** Changes in GDB-4.10:
5855 * User visible changes:
5857 Remote debugging using the GDB-specific (`target remote') protocol now
5858 supports the `load' command. This is only useful if you have some
5859 other way of getting the stub to the target system, and you can put it
5860 somewhere in memory where it won't get clobbered by the download.
5862 Filename completion now works.
5864 When run under emacs mode, the "info line" command now causes the
5865 arrow to point to the line specified. Also, "info line" prints
5866 addresses in symbolic form (as well as hex).
5868 All vxworks based targets now support a user settable option, called
5869 vxworks-timeout. This option represents the number of seconds gdb
5870 should wait for responses to rpc's. You might want to use this if
5871 your vxworks target is, perhaps, a slow software simulator or happens
5872 to be on the far side of a thin network line.
5876 This release contains support for using a DEC alpha as a GDB host for
5877 cross debugging. Native alpha debugging is not supported yet.
5880 *** Changes in GDB-4.9:
5884 This is the first GDB release which is accompanied by a matching testsuite.
5885 The testsuite requires installation of dejagnu, which should be available
5886 via ftp from most sites that carry GNU software.
5890 'Cfront' style demangling has had its name changed to 'ARM' style, to
5891 emphasize that it was written from the specifications in the C++ Annotated
5892 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5893 disclaimers, it still generated too much confusion with users attempting to
5894 use gdb with AT&T cfront.
5898 GDB now uses a standard remote interface to a simulator library.
5899 So far, the library contains simulators for the Zilog Z8001/2, the
5900 Hitachi H8/300, H8/500 and Super-H.
5902 * New targets supported
5904 H8/300 simulator h8300-hitachi-hms or h8300hms
5905 H8/500 simulator h8500-hitachi-hms or h8500hms
5906 SH simulator sh-hitachi-hms or sh
5907 Z8000 simulator z8k-zilog-none or z8ksim
5908 IDT MIPS board over serial line mips-idt-ecoff
5910 Cross-debugging to GO32 targets is supported. It requires a custom
5911 version of the i386-stub.c module which is integrated with the
5912 GO32 memory extender.
5914 * New remote protocols
5916 MIPS remote debugging protocol.
5918 * New source languages supported
5920 This version includes preliminary support for Chill, a Pascal like language
5921 used by telecommunications companies. Chill support is also being integrated
5922 into the GNU compiler, but we don't know when it will be publically available.
5925 *** Changes in GDB-4.8:
5927 * HP Precision Architecture supported
5929 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5930 version of this support was available as a set of patches from the
5931 University of Utah. GDB does not support debugging of programs
5932 compiled with the HP compiler, because HP will not document their file
5933 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5934 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5936 Many problems in the preliminary version have been fixed.
5938 * Faster and better demangling
5940 We have improved template demangling and fixed numerous bugs in the GNU style
5941 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5942 character types (wchar_t) are now supported. Demangling of each symbol is now
5943 only done once, and is cached when the symbol table for a file is read in.
5944 This results in a small increase in memory usage for C programs, a moderate
5945 increase in memory usage for C++ programs, and a fantastic speedup in
5948 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5949 from the specifications in the Annotated Reference Manual, which AT&T's
5950 compiler does not actually implement.
5952 * G++ multiple inheritance compiler problem
5954 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5955 inheritance lattices was reworked to properly discover ambiguities. We
5956 recently found an example which causes this new algorithm to fail in a
5957 very subtle way, producing bad debug information for those classes.
5958 The file 'gcc.patch' (in this directory) can be applied to gcc to
5959 circumvent the problem. A future GCC release will contain a complete
5962 The previous G++ debug info problem (mentioned below for the gdb-4.7
5963 release) is fixed in gcc version 2.3.2.
5965 * Improved configure script
5967 The `configure' script will now attempt to guess your system type if
5968 you don't supply a host system type. The old scheme of supplying a
5969 host system triplet is preferable over using this. All the magic is
5970 done in the new `config.guess' script. Examine it for details.
5972 We have also brought our configure script much more in line with the FSF's
5973 version. It now supports the --with-xxx options. In particular,
5974 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5975 The resulting GDB will not be able to read arbitrary object file formats --
5976 only the format ``expected'' to be used on the configured target system.
5977 We hope to make this the default in a future release.
5979 * Documentation improvements
5981 There's new internal documentation on how to modify GDB, and how to
5982 produce clean changes to the code. We implore people to read it
5983 before submitting changes.
5985 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5986 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5987 `info' files are also provided. To build `info' files from scratch,
5988 you will need the latest `makeinfo' release, which will be available in
5989 a future texinfo-X.Y release.
5991 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5992 We're not sure exactly which versions have this problem, but it has
5993 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5994 or better. If that isn't possible, there is a patch in
5995 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5996 around this problem.
6000 GDB now supports array constants that can be used in expressions typed in by
6001 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6002 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6005 The new directory `gdb/sparclite' contains a program that demonstrates
6006 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6008 * New native hosts supported
6010 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6011 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6013 * New targets supported
6015 AMD 29k family via UDI a29k-amd-udi or udi29k
6017 * New file formats supported
6019 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6020 HPUX core files, and SCO 3.2v2 core files.
6024 Attaching to processes now works again; thanks for the many bug reports.
6026 We have also stomped on a bunch of core dumps caused by
6027 printf_filtered("%s") problems.
6029 We eliminated a copyright problem on the rpc and ptrace header files
6030 for VxWorks, which was discovered at the last minute during the 4.7
6031 release. You should now be able to build a VxWorks GDB.
6033 You can now interrupt gdb while an attached process is running. This
6034 will cause the attached process to stop, and give control back to GDB.
6036 We fixed problems caused by using too many file descriptors
6037 for reading symbols from object files and libraries. This was
6038 especially a problem for programs that used many (~100) shared
6041 The `step' command now only enters a subroutine if there is line number
6042 information for the subroutine. Otherwise it acts like the `next'
6043 command. Previously, `step' would enter subroutines if there was
6044 any debugging information about the routine. This avoids problems
6045 when using `cc -g1' on MIPS machines.
6047 * Internal improvements
6049 GDB's internal interfaces have been improved to make it easier to support
6050 debugging of multiple languages in the future.
6052 GDB now uses a common structure for symbol information internally.
6053 Minimal symbols (derived from linkage symbols in object files), partial
6054 symbols (from a quick scan of debug information), and full symbols
6055 contain a common subset of information, making it easier to write
6056 shared code that handles any of them.
6058 * New command line options
6060 We now accept --silent as an alias for --quiet.
6064 The memory-mapped-malloc library is now licensed under the GNU Library
6065 General Public License.
6067 *** Changes in GDB-4.7:
6069 * Host/native/target split
6071 GDB has had some major internal surgery to untangle the support for
6072 hosts and remote targets. Now, when you configure GDB for a remote
6073 target, it will no longer load in all of the support for debugging
6074 local programs on the host. When fully completed and tested, this will
6075 ensure that arbitrary host/target combinations are possible.
6077 The primary conceptual shift is to separate the non-portable code in
6078 GDB into three categories. Host specific code is required any time GDB
6079 is compiled on that host, regardless of the target. Target specific
6080 code relates to the peculiarities of the target, but can be compiled on
6081 any host. Native specific code is everything else: it can only be
6082 built when the host and target are the same system. Child process
6083 handling and core file support are two common `native' examples.
6085 GDB's use of /proc for controlling Unix child processes is now cleaner.
6086 It has been split out into a single module under the `target_ops' vector,
6087 plus two native-dependent functions for each system that uses /proc.
6089 * New hosts supported
6091 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6092 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6093 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6095 * New targets supported
6097 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6098 68030 and CPU32 m68030-*-*, m68332-*-*
6100 * New native hosts supported
6102 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6103 (386bsd is not well tested yet)
6104 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6106 * New file formats supported
6108 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6109 supports reading of `a.out.adobe' object files, which are an a.out
6110 format extended with minimal information about multiple sections.
6114 `show copying' is the same as the old `info copying'.
6115 `show warranty' is the same as `info warrantee'.
6116 These were renamed for consistency. The old commands continue to work.
6118 `info handle' is a new alias for `info signals'.
6120 You can now define pre-command hooks, which attach arbitrary command
6121 scripts to any command. The commands in the hook will be executed
6122 prior to the user's command. You can also create a hook which will be
6123 executed whenever the program stops. See gdb.texinfo.
6127 We now deal with Cfront style name mangling, and can even extract type
6128 info from mangled symbols. GDB can automatically figure out which
6129 symbol mangling style your C++ compiler uses.
6131 Calling of methods and virtual functions has been improved as well.
6135 The crash that occured when debugging Sun Ansi-C compiled binaries is
6136 fixed. This was due to mishandling of the extra N_SO stabs output
6139 We also finally got Ultrix 4.2 running in house, and fixed core file
6140 support, with help from a dozen people on the net.
6142 John M. Farrell discovered that the reason that single-stepping was so
6143 slow on all of the Mips based platforms (primarily SGI and DEC) was
6144 that we were trying to demangle and lookup a symbol used for internal
6145 purposes on every instruction that was being stepped through. Changing
6146 the name of that symbol so that it couldn't be mistaken for a C++
6147 mangled symbol sped things up a great deal.
6149 Rich Pixley sped up symbol lookups in general by getting much smarter
6150 about when C++ symbol mangling is necessary. This should make symbol
6151 completion (TAB on the command line) much faster. It's not as fast as
6152 we'd like, but it's significantly faster than gdb-4.6.
6156 A new user controllable variable 'call_scratch_address' can
6157 specify the location of a scratch area to be used when GDB
6158 calls a function in the target. This is necessary because the
6159 usual method of putting the scratch area on the stack does not work
6160 in systems that have separate instruction and data spaces.
6162 We integrated changes to support the 29k UDI (Universal Debugger
6163 Interface), but discovered at the last minute that we didn't have all
6164 of the appropriate copyright paperwork. We are working with AMD to
6165 resolve this, and hope to have it available soon.
6169 We have sped up the remote serial line protocol, especially for targets
6170 with lots of registers. It now supports a new `expedited status' ('T')
6171 message which can be used in place of the existing 'S' status message.
6172 This allows the remote stub to send only the registers that GDB
6173 needs to make a quick decision about single-stepping or conditional
6174 breakpoints, eliminating the need to fetch the entire register set for
6175 each instruction being stepped through.
6177 The GDB remote serial protocol now implements a write-through cache for
6178 registers, only re-reading the registers if the target has run.
6180 There is also a new remote serial stub for SPARC processors. You can
6181 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6182 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6183 processor with a serial port.
6187 Configure.in files have become much easier to read and modify. A new
6188 `table driven' format makes it more obvious what configurations are
6189 supported, and what files each one uses.
6193 There is a new opcodes library which will eventually contain all of the
6194 disassembly routines and opcode tables. At present, it only contains
6195 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6196 disassembler (binutils/objdump) to share these routines.
6198 The libiberty library is now copylefted under the GNU Library General
6199 Public License. This allows more liberal use, and was done so libg++
6200 can use it. This makes no difference to GDB, since the Library License
6201 grants all the rights from the General Public License.
6205 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6206 reference to the stabs symbol info used by the debugger. It is (as far
6207 as we know) the only published document on this fascinating topic. We
6208 encourage you to read it, compare it to the stabs information on your
6209 system, and send improvements on the document in general (to
6210 bug-gdb@prep.ai.mit.edu).
6212 And, of course, many bugs have been fixed.
6215 *** Changes in GDB-4.6:
6217 * Better support for C++ function names
6219 GDB now accepts as input the "demangled form" of C++ overloaded function
6220 names and member function names, and can do command completion on such names
6221 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6222 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6223 Make use of command completion, it is your friend.
6225 GDB also now accepts a variety of C++ mangled symbol formats. They are
6226 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6227 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6228 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6229 for the list of formats.
6231 * G++ symbol mangling problem
6233 Recent versions of gcc have a bug in how they emit debugging information for
6234 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6235 directory) can be applied to gcc to fix the problem. Alternatively, if you
6236 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6237 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6238 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6241 * New 'maintenance' command
6243 All of the commands related to hacking GDB internals have been moved out of
6244 the main command set, and now live behind the 'maintenance' command. This
6245 can also be abbreviated as 'mt'. The following changes were made:
6247 dump-me -> maintenance dump-me
6248 info all-breakpoints -> maintenance info breakpoints
6249 printmsyms -> maintenance print msyms
6250 printobjfiles -> maintenance print objfiles
6251 printpsyms -> maintenance print psymbols
6252 printsyms -> maintenance print symbols
6254 The following commands are new:
6256 maintenance demangle Call internal GDB demangler routine to
6257 demangle a C++ link name and prints the result.
6258 maintenance print type Print a type chain for a given symbol
6260 * Change to .gdbinit file processing
6262 We now read the $HOME/.gdbinit file before processing the argv arguments
6263 (e.g. reading symbol files or core files). This allows global parameters to
6264 be set, which will apply during the symbol reading. The ./.gdbinit is still
6265 read after argv processing.
6267 * New hosts supported
6269 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6271 GNU/Linux support i386-unknown-linux or linux
6273 We are also including code to support the HP/PA running BSD and HPUX. This
6274 is almost guaranteed not to work, as we didn't have time to test or build it
6275 for this release. We are including it so that the more adventurous (or
6276 masochistic) of you can play with it. We also had major problems with the
6277 fact that the compiler that we got from HP doesn't support the -g option.
6280 * New targets supported
6282 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6284 * More smarts about finding #include files
6286 GDB now remembers the compilation directory for all include files, and for
6287 all files from which C is generated (like yacc and lex sources). This
6288 greatly improves GDB's ability to find yacc/lex sources, and include files,
6289 especially if you are debugging your program from a directory different from
6290 the one that contains your sources.
6292 We also fixed a bug which caused difficulty with listing and setting
6293 breakpoints in include files which contain C code. (In the past, you had to
6294 try twice in order to list an include file that you hadn't looked at before.)
6296 * Interesting infernals change
6298 GDB now deals with arbitrary numbers of sections, where the symbols for each
6299 section must be relocated relative to that section's landing place in the
6300 target's address space. This work was needed to support ELF with embedded
6301 stabs used by Solaris-2.0.
6303 * Bug fixes (of course!)
6305 There have been loads of fixes for the following things:
6306 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6307 i960, stabs, DOS(GO32), procfs, etc...
6309 See the ChangeLog for details.
6311 *** Changes in GDB-4.5:
6313 * New machines supported (host and target)
6315 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6317 SGI Irix-4.x mips-sgi-irix4 or iris4
6319 * New malloc package
6321 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6322 Mmalloc is capable of handling mutiple heaps of memory. It is also
6323 capable of saving a heap to a file, and then mapping it back in later.
6324 This can be used to greatly speedup the startup of GDB by using a
6325 pre-parsed symbol table which lives in a mmalloc managed heap. For
6326 more details, please read mmalloc/mmalloc.texi.
6330 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6331 'help info proc' for details.
6333 * MIPS ecoff symbol table format
6335 The code that reads MIPS symbol table format is now supported on all hosts.
6336 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6339 * File name changes for MS-DOS
6341 Many files in the config directories have been renamed to make it easier to
6342 support GDB on MS-DOSe systems (which have very restrictive file name
6343 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6344 environment) is close to working but has some remaining problems. Note
6345 that debugging of DOS programs is not supported, due to limitations
6346 in the ``operating system'', but it can be used to host cross-debugging.
6348 * Cross byte order fixes
6350 Many fixes have been made to support cross debugging of Sparc and MIPS
6351 targets from hosts whose byte order differs.
6353 * New -mapped and -readnow options
6355 If memory-mapped files are available on your system through the 'mmap'
6356 system call, you can use the -mapped option on the `file' or
6357 `symbol-file' commands to cause GDB to write the symbols from your
6358 program into a reusable file. If the program you are debugging is
6359 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6360 Future GDB debugging sessions will notice the presence of this file,
6361 and will quickly map in symbol information from it, rather than reading
6362 the symbol table from the executable program. Using the '-mapped'
6363 option in a GDB `file' or `symbol-file' command has the same effect as
6364 starting GDB with the '-mapped' command-line option.
6366 You can cause GDB to read the entire symbol table immediately by using
6367 the '-readnow' option with any of the commands that load symbol table
6368 information (or on the GDB command line). This makes the command
6369 slower, but makes future operations faster.
6371 The -mapped and -readnow options are typically combined in order to
6372 build a `fred.syms' file that contains complete symbol information.
6373 A simple GDB invocation to do nothing but build a `.syms' file for future
6376 gdb -batch -nx -mapped -readnow programname
6378 The `.syms' file is specific to the host machine on which GDB is run.
6379 It holds an exact image of GDB's internal symbol table. It cannot be
6380 shared across multiple host platforms.
6382 * longjmp() handling
6384 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6385 siglongjmp() without losing control. This feature has not yet been ported to
6386 all systems. It currently works on many 386 platforms, all MIPS-based
6387 platforms (SGI, DECstation, etc), and Sun3/4.
6391 Preliminary work has been put in to support the new Solaris OS from Sun. At
6392 this time, it can control and debug processes, but it is not capable of
6397 As always, many many bug fixes. The major areas were with g++, and mipsread.
6398 People using the MIPS-based platforms should experience fewer mysterious
6399 crashes and trashed symbol tables.
6401 *** Changes in GDB-4.4:
6403 * New machines supported (host and target)
6405 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6407 BSD Reno on Vax vax-dec-bsd
6408 Ultrix on Vax vax-dec-ultrix
6410 * New machines supported (target)
6412 AMD 29000 embedded, using EBMON a29k-none-none
6416 GDB continues to improve its handling of C++. `References' work better.
6417 The demangler has also been improved, and now deals with symbols mangled as
6418 per the Annotated C++ Reference Guide.
6420 GDB also now handles `stabs' symbol information embedded in MIPS
6421 `ecoff' symbol tables. Since the ecoff format was not easily
6422 extensible to handle new languages such as C++, this appeared to be a
6423 good way to put C++ debugging info into MIPS binaries. This option
6424 will be supported in the GNU C compiler, version 2, when it is
6427 * New features for SVR4
6429 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6430 shared libraries. Debugging dynamically linked programs should present
6431 only minor differences from debugging statically linked programs.
6433 The `info proc' command will print out information about any process
6434 on an SVR4 system (including the one you are debugging). At the moment,
6435 it prints the address mappings of the process.
6437 If you bring up GDB on another SVR4 system, please send mail to
6438 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6440 * Better dynamic linking support in SunOS
6442 Reading symbols from shared libraries which contain debugging symbols
6443 now works properly. However, there remain issues such as automatic
6444 skipping of `transfer vector' code during function calls, which
6445 make it harder to debug code in a shared library, than to debug the
6446 same code linked statically.
6450 GDB is now using the latest `getopt' routines from the FSF. This
6451 version accepts the -- prefix for options with long names. GDB will
6452 continue to accept the old forms (-option and +option) as well.
6453 Various single letter abbreviations for options have been explicity
6454 added to the option table so that they won't get overshadowed in the
6455 future by other options that begin with the same letter.
6459 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6460 Many assorted bugs have been handled. Many more remain to be handled.
6461 See the various ChangeLog files (primarily in gdb and bfd) for details.
6464 *** Changes in GDB-4.3:
6466 * New machines supported (host and target)
6468 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6469 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6470 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6472 * Almost SCO Unix support
6474 We had hoped to support:
6475 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6476 (except for core file support), but we discovered very late in the release
6477 that it has problems with process groups that render gdb unusable. Sorry
6478 about that. I encourage people to fix it and post the fixes.
6480 * Preliminary ELF and DWARF support
6482 GDB can read ELF object files on System V Release 4, and can handle
6483 debugging records for C, in DWARF format, in ELF files. This support
6484 is preliminary. If you bring up GDB on another SVR4 system, please
6485 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6490 GDB now uses the latest `readline' library. One user-visible change
6491 is that two tabs will list possible command completions, which previously
6492 required typing M-? (meta-question mark, or ESC ?).
6496 The `stepi' bug that many of you noticed has been squashed.
6497 Many bugs in C++ have been handled. Many more remain to be handled.
6498 See the various ChangeLog files (primarily in gdb and bfd) for details.
6500 * State of the MIPS world (in case you wondered):
6502 GDB can understand the symbol tables emitted by the compilers
6503 supplied by most vendors of MIPS-based machines, including DEC. These
6504 symbol tables are in a format that essentially nobody else uses.
6506 Some versions of gcc come with an assembler post-processor called
6507 mips-tfile. This program is required if you want to do source-level
6508 debugging of gcc-compiled programs. I believe FSF does not ship
6509 mips-tfile with gcc version 1, but it will eventually come with gcc
6512 Debugging of g++ output remains a problem. g++ version 1.xx does not
6513 really support it at all. (If you're lucky, you should be able to get
6514 line numbers and stack traces to work, but no parameters or local
6515 variables.) With some work it should be possible to improve the
6518 When gcc version 2 is released, you will have somewhat better luck.
6519 However, even then you will get confusing results for inheritance and
6522 We will eventually provide full debugging of g++ output on
6523 DECstations. This will probably involve some kind of stabs-in-ecoff
6524 encapulation, but the details have not been worked out yet.
6527 *** Changes in GDB-4.2:
6529 * Improved configuration
6531 Only one copy of `configure' exists now, and it is not self-modifying.
6532 Porting BFD is simpler.
6536 The `step' and `next' commands now only stop at the first instruction
6537 of a source line. This prevents the multiple stops that used to occur
6538 in switch statements, for-loops, etc. `Step' continues to stop if a
6539 function that has debugging information is called within the line.
6543 Lots of small bugs fixed. More remain.
6545 * New host supported (not target)
6547 Intel 386 PC clone running Mach i386-none-mach
6550 *** Changes in GDB-4.1:
6552 * Multiple source language support
6554 GDB now has internal scaffolding to handle several source languages.
6555 It determines the type of each source file from its filename extension,
6556 and will switch expression parsing and number formatting to match the
6557 language of the function in the currently selected stack frame.
6558 You can also specifically set the language to be used, with
6559 `set language c' or `set language modula-2'.
6563 GDB now has preliminary support for the GNU Modula-2 compiler,
6564 currently under development at the State University of New York at
6565 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6566 continue through the fall of 1991 and into 1992.
6568 Other Modula-2 compilers are currently not supported, and attempting to
6569 debug programs compiled with them will likely result in an error as the
6570 symbol table is read. Feel free to work on it, though!
6572 There are hooks in GDB for strict type checking and range checking,
6573 in the `Modula-2 philosophy', but they do not currently work.
6577 GDB can now write to executable and core files (e.g. patch
6578 a variable's value). You must turn this switch on, specify
6579 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6580 by assigning a new value to a variable. Modifications take
6583 * Automatic SunOS shared library reading
6585 When you run your program, GDB automatically determines where its
6586 shared libraries (if any) have been loaded, and reads their symbols.
6587 The `share' command is no longer needed. This also works when
6588 examining core files.
6592 You can specify the number of lines that the `list' command shows.
6595 * New machines supported (host and target)
6597 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6598 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6599 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6601 * New hosts supported (not targets)
6603 IBM RT/PC: romp-ibm-aix or rtpc
6605 * New targets supported (not hosts)
6607 AMD 29000 embedded with COFF a29k-none-coff
6608 AMD 29000 embedded with a.out a29k-none-aout
6609 Ultracomputer remote kernel debug a29k-nyu-kern
6611 * New remote interfaces
6617 *** Changes in GDB-4.0:
6621 Wide output is wrapped at good places to make the output more readable.
6623 Gdb now supports cross-debugging from a host machine of one type to a
6624 target machine of another type. Communication with the target system
6625 is over serial lines. The ``target'' command handles connecting to the
6626 remote system; the ``load'' command will download a program into the
6627 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6628 also supports debugging of realtime processes running under VxWorks,
6629 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6630 stub on the target system.
6632 New CPUs supported include the AMD 29000 and Intel 960.
6634 GDB now reads object files and symbol tables via a ``binary file''
6635 library, which allows a single copy of GDB to debug programs of multiple
6636 object file types such as a.out and coff.
6638 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6639 refcard.dvi and refcard.ps are available to format it).
6642 * Control-Variable user interface simplified
6644 All variables that control the operation of the debugger can be set
6645 by the ``set'' command, and displayed by the ``show'' command.
6647 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6648 ``Show prompt'' produces the response:
6649 Gdb's prompt is new-gdb=>.
6651 What follows are the NEW set commands. The command ``help set'' will
6652 print a complete list of old and new set commands. ``help set FOO''
6653 will give a longer description of the variable FOO. ``show'' will show
6654 all of the variable descriptions and their current settings.
6656 confirm on/off: Enables warning questions for operations that are
6657 hard to recover from, e.g. rerunning the program while
6658 it is already running. Default is ON.
6660 editing on/off: Enables EMACS style command line editing
6661 of input. Previous lines can be recalled with
6662 control-P, the current line can be edited with control-B,
6663 you can search for commands with control-R, etc.
6666 history filename NAME: NAME is where the gdb command history
6667 will be stored. The default is .gdb_history,
6668 or the value of the environment variable
6671 history size N: The size, in commands, of the command history. The
6672 default is 256, or the value of the environment variable
6675 history save on/off: If this value is set to ON, the history file will
6676 be saved after exiting gdb. If set to OFF, the
6677 file will not be saved. The default is OFF.
6679 history expansion on/off: If this value is set to ON, then csh-like
6680 history expansion will be performed on
6681 command line input. The default is OFF.
6683 radix N: Sets the default radix for input and output. It can be set
6684 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6685 in the current radix, so "set radix 10" is always a no-op.
6687 height N: This integer value is the number of lines on a page. Default
6688 is 24, the current `stty rows'' setting, or the ``li#''
6689 setting from the termcap entry matching the environment
6692 width N: This integer value is the number of characters on a line.
6693 Default is 80, the current `stty cols'' setting, or the ``co#''
6694 setting from the termcap entry matching the environment
6697 Note: ``set screensize'' is obsolete. Use ``set height'' and
6698 ``set width'' instead.
6700 print address on/off: Print memory addresses in various command displays,
6701 such as stack traces and structure values. Gdb looks
6702 more ``symbolic'' if you turn this off; it looks more
6703 ``machine level'' with it on. Default is ON.
6705 print array on/off: Prettyprint arrays. New convenient format! Default
6708 print demangle on/off: Print C++ symbols in "source" form if on,
6711 print asm-demangle on/off: Same, for assembler level printouts
6714 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6717 * Support for Epoch Environment.
6719 The epoch environment is a version of Emacs v18 with windowing. One
6720 new command, ``inspect'', is identical to ``print'', except that if you
6721 are running in the epoch environment, the value is printed in its own
6725 * Support for Shared Libraries
6727 GDB can now debug programs and core files that use SunOS shared libraries.
6728 Symbols from a shared library cannot be referenced
6729 before the shared library has been linked with the program (this
6730 happens after you type ``run'' and before the function main() is entered).
6731 At any time after this linking (including when examining core files
6732 from dynamically linked programs), gdb reads the symbols from each
6733 shared library when you type the ``sharedlibrary'' command.
6734 It can be abbreviated ``share''.
6736 sharedlibrary REGEXP: Load shared object library symbols for files
6737 matching a unix regular expression. No argument
6738 indicates to load symbols for all shared libraries.
6740 info sharedlibrary: Status of loaded shared libraries.
6745 A watchpoint stops execution of a program whenever the value of an
6746 expression changes. Checking for this slows down execution
6747 tremendously whenever you are in the scope of the expression, but is
6748 quite useful for catching tough ``bit-spreader'' or pointer misuse
6749 problems. Some machines such as the 386 have hardware for doing this
6750 more quickly, and future versions of gdb will use this hardware.
6752 watch EXP: Set a watchpoint (breakpoint) for an expression.
6754 info watchpoints: Information about your watchpoints.
6756 delete N: Deletes watchpoint number N (same as breakpoints).
6757 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6758 enable N: Re-enables watchpoint number N (same as breakpoints).
6761 * C++ multiple inheritance
6763 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6766 * C++ exception handling
6768 Gdb now supports limited C++ exception handling. Besides the existing
6769 ability to breakpoint on an exception handler, gdb can breakpoint on
6770 the raising of an exception (before the stack is peeled back to the
6773 catch FOO: If there is a FOO exception handler in the dynamic scope,
6774 set a breakpoint to catch exceptions which may be raised there.
6775 Multiple exceptions (``catch foo bar baz'') may be caught.
6777 info catch: Lists all exceptions which may be caught in the
6778 current stack frame.
6781 * Minor command changes
6783 The command ``call func (arg, arg, ...)'' now acts like the print
6784 command, except it does not print or save a value if the function's result
6785 is void. This is similar to dbx usage.
6787 The ``up'' and ``down'' commands now always print the frame they end up
6788 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6789 frames without printing.
6791 * New directory command
6793 'dir' now adds directories to the FRONT of the source search path.
6794 The path starts off empty. Source files that contain debug information
6795 about the directory in which they were compiled can be found even
6796 with an empty path; Sun CC and GCC include this information. If GDB can't
6797 find your source file in the current directory, type "dir .".
6799 * Configuring GDB for compilation
6801 For normal use, type ``./configure host''. See README or gdb.texinfo
6804 GDB now handles cross debugging. If you are remotely debugging between
6805 two different machines, type ``./configure host -target=targ''.
6806 Host is the machine where GDB will run; targ is the machine
6807 where the program that you are debugging will run.