1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.0
6 * GDB now supports access to the guarded-storage-control registers and the
7 software-based guarded-storage broadcast control registers on IBM z14.
9 * On Unix systems, GDB now supports transmitting environment variables
10 that are to be set or unset to GDBserver. These variables will
11 affect the environment to be passed to the remote inferior.
13 To inform GDB of environment variables that are to be transmitted to
14 GDBserver, use the "set environment" command. Only user set
15 environment variables are sent to GDBserver.
17 To inform GDB of environment variables that are to be unset before
18 the remote inferior is started by the GDBserver, use the "unset
23 ** New events gdb.new_inferior, gdb.inferior_deleted, and
24 gdb.new_thread are emitted. See the manual for further
27 * New features in the GDB remote stub, GDBserver
29 ** GDBserver is now able to start inferior processes with a
30 specified initial working directory.
32 The user can set the desired working directory to be used from
33 GDB using the new "set cwd" command.
35 ** New "--selftest" command line option runs some GDBserver self
36 tests. These self tests are disabled in releases.
38 ** On Unix systems, GDBserver now does globbing expansion and variable
39 substitution in inferior command line arguments.
41 This is done by starting inferiors using a shell, like GDB does.
42 See "set startup-with-shell" in the user manual for how to disable
43 this from GDB when using "target extended-remote". When using
44 "target remote", you can disable the startup with shell by using the
45 new "--no-startup-with-shell" GDBserver command line option.
47 ** On Unix systems, GDBserver now supports receiving environment
48 variables that are to be set or unset from GDB. These variables
49 will affect the environment to be passed to the inferior.
53 QEnvironmentHexEncoded
54 Inform GDBserver of an environment variable that is to be passed to
55 the inferior when starting it.
58 Inform GDBserver of an environment variable that is to be unset
59 before starting the remote inferior.
62 Inform GDBserver that the environment should be reset (i.e.,
63 user-set environment variables should be unset).
66 Indicates whether the inferior must be started with a shell or not.
69 Tell GDBserver that the inferior to be started should use a specific
72 * The "maintenance print c-tdesc" command now takes an optional
73 argument which is the file name of XML target description.
75 * The "maintenance selftest" command now takes an optional argument to
76 filter the tests to be run.
81 Set and show the current working directory for the inferior.
84 Set and show compilation command used for compiling and injecting code
85 with the 'compile' commands.
87 set debug separate-debug-file
88 show debug separate-debug-file
89 Control the display of debug output about separate debug file search.
92 List the registered selftests.
95 Start the debugged program stopping at the first instruction.
97 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
100 * Safer/improved support for debugging with no debug info
102 GDB no longer assumes functions with no debug information return
105 This means that GDB now refuses to call such functions unless you
106 tell it the function's type, by either casting the call to the
107 declared return type, or by casting the function to a function
108 pointer of the right type, and calling that:
110 (gdb) p getenv ("PATH")
111 'getenv' has unknown return type; cast the call to its declared return type
112 (gdb) p (char *) getenv ("PATH")
113 $1 = 0x7fffffffe "/usr/local/bin:/"...
114 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
115 $2 = 0x7fffffffe "/usr/local/bin:/"...
117 Similarly, GDB no longer assumes that global variables with no debug
118 info have type 'int', and refuses to print the variable's value
119 unless you tell it the variable's type:
122 'var' has unknown type; cast it to its declared type
126 * New native configurations
128 FreeBSD/aarch64 aarch64*-*-freebsd*
132 FreeBSD/aarch64 aarch64*-*-freebsd*
134 * Removed targets and native configurations
136 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
138 *** Changes in GDB 8.0
140 * GDB now supports access to the PKU register on GNU/Linux. The register is
141 added by the Memory Protection Keys for Userspace feature which will be
142 available in future Intel CPUs.
144 * GDB now supports C++11 rvalue references.
148 ** New functions to start, stop and access a running btrace recording.
149 ** Rvalue references are now supported in gdb.Type.
151 * GDB now supports recording and replaying rdrand and rdseed Intel 64
154 * Building GDB and GDBserver now requires a C++11 compiler.
156 For example, GCC 4.8 or later.
158 It is no longer possible to build GDB or GDBserver with a C
159 compiler. The --disable-build-with-cxx configure option has been
162 * Building GDB and GDBserver now requires GNU make >= 3.81.
164 It is no longer supported to build GDB or GDBserver with another
165 implementation of the make program or an earlier version of GNU make.
167 * Native debugging on MS-Windows supports command-line redirection
169 Command-line arguments used for starting programs on MS-Windows can
170 now include redirection symbols supported by native Windows shells,
171 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
172 as "run", "start", and "set args", as well as the corresponding MI
175 * Support for thread names on MS-Windows.
177 GDB now catches and handles the special exception that programs
178 running on MS-Windows use to assign names to threads in the
181 * Support for Java programs compiled with gcj has been removed.
183 * User commands now accept an unlimited number of arguments.
184 Previously, only up to 10 was accepted.
186 * The "eval" command now expands user-defined command arguments.
188 This makes it easier to process a variable number of arguments:
193 eval "print $arg%d", $i
198 * Target descriptions can now describe registers for sparc32 and sparc64.
200 * GDB now supports DWARF version 5 (debug information format).
201 Its .debug_names index is not yet supported.
203 * New native configurations
205 FreeBSD/mips mips*-*-freebsd
209 Synopsys ARC arc*-*-elf32
210 FreeBSD/mips mips*-*-freebsd
212 * Removed targets and native configurations
214 Alpha running FreeBSD alpha*-*-freebsd*
215 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
220 Erases all the flash memory regions reported by the target.
222 maint print arc arc-instruction address
223 Print internal disassembler information about instruction at a given address.
227 set disassembler-options
228 show disassembler-options
229 Controls the passing of target specific information to the disassembler.
230 If it is necessary to specify more than one disassembler option then
231 multiple options can be placed together into a comma separated list.
232 The default value is the empty string. Currently, the only supported
233 targets are ARM, PowerPC and S/390.
238 Erases all the flash memory regions reported by the target. This is
239 equivalent to the CLI command flash-erase.
241 -file-list-shared-libraries
242 List the shared libraries in the program. This is
243 equivalent to the CLI command "info shared".
245 *** Changes in GDB 7.12
247 * GDB and GDBserver now build with a C++ compiler by default.
249 The --enable-build-with-cxx configure option is now enabled by
250 default. One must now explicitly configure with
251 --disable-build-with-cxx in order to build with a C compiler. This
252 option will be removed in a future release.
254 * GDBserver now supports recording btrace without maintaining an active
257 * GDB now supports a negative repeat count in the 'x' command to examine
258 memory backward from the given address. For example:
261 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
262 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
263 (gdb) x/-5i 0x0000000000400580
264 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
265 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
266 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
267 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
268 0x40057b <main(int, char**)+25>:
269 callq 0x400536 <Func1(int, char const*)>
271 * Fortran: Support structures with fields of dynamic types and
272 arrays of dynamic types.
274 * The symbol dumping maintenance commands have new syntax.
275 maint print symbols [-pc address] [--] [filename]
276 maint print symbols [-objfile objfile] [-source source] [--] [filename]
277 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
278 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
279 maint print msymbols [-objfile objfile] [--] [filename]
281 * GDB now supports multibit bitfields and enums in target register
284 * New Python-based convenience function $_as_string(val), which returns
285 the textual representation of a value. This function is especially
286 useful to obtain the text label of an enum value.
288 * Intel MPX bound violation handling.
290 Segmentation faults caused by a Intel MPX boundary violation
291 now display the kind of violation (upper or lower), the memory
292 address accessed and the memory bounds, along with the usual
293 signal received and code location.
297 Program received signal SIGSEGV, Segmentation fault
298 Upper bound violation while accessing address 0x7fffffffc3b3
299 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
300 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
302 * Rust language support.
303 GDB now supports debugging programs written in the Rust programming
304 language. See https://www.rust-lang.org/ for more information about
307 * Support for running interpreters on specified input/output devices
309 GDB now supports a new mechanism that allows frontends to provide
310 fully featured GDB console views, as a better alternative to
311 building such views on top of the "-interpreter-exec console"
312 command. See the new "new-ui" command below. With that command,
313 frontends can now start GDB in the traditional command-line mode
314 running in an embedded terminal emulator widget, and create a
315 separate MI interpreter running on a specified i/o device. In this
316 way, GDB handles line editing, history, tab completion, etc. in the
317 console all by itself, and the GUI uses the separate MI interpreter
318 for its own control and synchronization, invisible to the command
321 * The "catch syscall" command catches groups of related syscalls.
323 The "catch syscall" command now supports catching a group of related
324 syscalls using the 'group:' or 'g:' prefix.
329 skip -gfile file-glob-pattern
330 skip -function function
331 skip -rfunction regular-expression
332 A generalized form of the skip command, with new support for
333 glob-style file names and regular expressions for function names.
334 Additionally, a file spec and a function spec may now be combined.
336 maint info line-table REGEXP
337 Display the contents of GDB's internal line table data struture.
340 Run any GDB unit tests that were compiled in.
343 Start a new user interface instance running INTERP as interpreter,
344 using the TTY file for input/output.
348 ** gdb.Breakpoint objects have a new attribute "pending", which
349 indicates whether the breakpoint is pending.
350 ** Three new breakpoint-related events have been added:
351 gdb.breakpoint_created, gdb.breakpoint_modified, and
352 gdb.breakpoint_deleted.
355 Signal ("set") the given MS-Windows event object. This is used in
356 conjunction with the Windows JIT debugging (AeDebug) support, where
357 the OS suspends a crashing process until a debugger can attach to
358 it. Resuming the crashing process, in order to debug it, is done by
361 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
362 was added in GDBserver, including JIT compiling fast tracepoint's
363 conditional expression bytecode into native code.
365 * Support for various remote target protocols and ROM monitors has
368 target m32rsdi Remote M32R debugging over SDI
369 target mips MIPS remote debugging protocol
370 target pmon PMON ROM monitor
371 target ddb NEC's DDB variant of PMON for Vr4300
372 target rockhopper NEC RockHopper variant of PMON
373 target lsi LSI variant of PMO
375 * Support for tracepoints and fast tracepoints on powerpc-linux,
376 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
377 including JIT compiling fast tracepoint's conditional expression
378 bytecode into native code.
380 * MI async record =record-started now includes the method and format used for
381 recording. For example:
383 =record-started,thread-group="i1",method="btrace",format="bts"
385 * MI async record =thread-selected now includes the frame field. For example:
387 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
391 Andes NDS32 nds32*-*-elf
393 *** Changes in GDB 7.11
395 * GDB now supports debugging kernel-based threads on FreeBSD.
397 * Per-inferior thread numbers
399 Thread numbers are now per inferior instead of global. If you're
400 debugging multiple inferiors, GDB displays thread IDs using a
401 qualified INF_NUM.THR_NUM form. For example:
405 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
406 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
407 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
408 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
410 As consequence, thread numbers as visible in the $_thread
411 convenience variable and in Python's InferiorThread.num attribute
412 are no longer unique between inferiors.
414 GDB now maintains a second thread ID per thread, referred to as the
415 global thread ID, which is the new equivalent of thread numbers in
416 previous releases. See also $_gthread below.
418 For backwards compatibility, MI's thread IDs always refer to global
421 * Commands that accept thread IDs now accept the qualified
422 INF_NUM.THR_NUM form as well. For example:
425 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
428 * In commands that accept a list of thread IDs, you can now refer to
429 all threads of an inferior using a star wildcard. GDB accepts
430 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
431 refer to all threads of the current inferior. For example, "info
434 * You can use "info threads -gid" to display the global thread ID of
437 * The new convenience variable $_gthread holds the global number of
440 * The new convenience variable $_inferior holds the number of the
443 * GDB now displays the ID and name of the thread that hit a breakpoint
444 or received a signal, if your program is multi-threaded. For
447 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
448 Thread 1 "main" received signal SIGINT, Interrupt.
450 * Record btrace now supports non-stop mode.
452 * Support for tracepoints on aarch64-linux was added in GDBserver.
454 * The 'record instruction-history' command now indicates speculative execution
455 when using the Intel Processor Trace recording format.
457 * GDB now allows users to specify explicit locations, bypassing
458 the linespec parser. This feature is also available to GDB/MI
461 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
462 GDB now is able to debug both AArch64 applications and ARM applications
465 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
466 including JIT compiling fast tracepoint's conditional expression bytecode
469 * GDB now supports displaced stepping on AArch64 GNU/Linux.
471 * "info threads", "info inferiors", "info display", "info checkpoints"
472 and "maint info program-spaces" now list the corresponding items in
473 ascending ID order, for consistency with all other "info" commands.
475 * In Ada, the overloads selection menu has been enhanced to display the
476 parameter types and the return types for the matching overloaded subprograms.
480 maint set target-non-stop (on|off|auto)
481 maint show target-non-stop
482 Control whether GDB targets always operate in non-stop mode even if
483 "set non-stop" is "off". The default is "auto", meaning non-stop
484 mode is enabled if supported by the target.
486 maint set bfd-sharing
487 maint show bfd-sharing
488 Control the reuse of bfd objects.
492 Control display of debugging info regarding bfd caching.
496 Control display of debugging info regarding FreeBSD threads.
498 set remote multiprocess-extensions-packet
499 show remote multiprocess-extensions-packet
500 Set/show the use of the remote protocol multiprocess extensions.
502 set remote thread-events
503 show remote thread-events
504 Set/show the use of thread create/exit events.
506 set ada print-signatures on|off
507 show ada print-signatures"
508 Control whether parameter types and return types are displayed in overloads
509 selection menus. It is activaled (@code{on}) by default.
513 Controls the maximum size of memory, in bytes, that GDB will
514 allocate for value contents. Prevents incorrect programs from
515 causing GDB to allocate overly large buffers. Default is 64k.
517 * The "disassemble" command accepts a new modifier: /s.
518 It prints mixed source+disassembly like /m with two differences:
519 - disassembled instructions are now printed in program order, and
520 - and source for all relevant files is now printed.
521 The "/m" option is now considered deprecated: its "source-centric"
522 output hasn't proved useful in practice.
524 * The "record instruction-history" command accepts a new modifier: /s.
525 It behaves exactly like /m and prints mixed source+disassembly.
527 * The "set scheduler-locking" command supports a new mode "replay".
528 It behaves like "off" in record mode and like "on" in replay mode.
530 * Support for various ROM monitors has been removed:
532 target dbug dBUG ROM monitor for Motorola ColdFire
533 target picobug Motorola picobug monitor
534 target dink32 DINK32 ROM monitor for PowerPC
535 target m32r Renesas M32R/D ROM monitor
536 target mon2000 mon2000 ROM monitor
537 target ppcbug PPCBUG ROM monitor for PowerPC
539 * Support for reading/writing memory and extracting values on architectures
540 whose memory is addressable in units of any integral multiple of 8 bits.
545 Indicates that an exec system call was executed.
547 exec-events feature in qSupported
548 The qSupported packet allows GDB to request support for exec
549 events using the new 'gdbfeature' exec-event, and the qSupported
550 response can contain the corresponding 'stubfeature'. Set and
551 show commands can be used to display whether these features are enabled.
554 Equivalent to interrupting with the ^C character, but works in
557 thread created stop reason (T05 create:...)
558 Indicates that the thread was just created and is stopped at entry.
560 thread exit stop reply (w exitcode;tid)
561 Indicates that the thread has terminated.
564 Enables/disables thread create and exit event reporting. For
565 example, this is used in non-stop mode when GDB stops a set of
566 threads and synchronously waits for the their corresponding stop
567 replies. Without exit events, if one of the threads exits, GDB
568 would hang forever not knowing that it should no longer expect a
569 stop for that same thread.
572 Indicates that there are no resumed threads left in the target (all
573 threads are stopped). The remote stub reports support for this stop
574 reply to GDB's qSupported query.
577 Enables/disables catching syscalls from the inferior process.
578 The remote stub reports support for this packet to GDB's qSupported query.
580 syscall_entry stop reason
581 Indicates that a syscall was just called.
583 syscall_return stop reason
584 Indicates that a syscall just returned.
586 * Extended-remote exec events
588 ** GDB now has support for exec events on extended-remote Linux targets.
589 For such targets with Linux kernels 2.5.46 and later, this enables
590 follow-exec-mode and exec catchpoints.
592 set remote exec-event-feature-packet
593 show remote exec-event-feature-packet
594 Set/show the use of the remote exec event feature.
596 * Thread names in remote protocol
598 The reply to qXfer:threads:read may now include a name attribute for each
601 * Target remote mode fork and exec events
603 ** GDB now has support for fork and exec events on target remote mode
604 Linux targets. For such targets with Linux kernels 2.5.46 and later,
605 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
606 fork and exec catchpoints.
608 * Remote syscall events
610 ** GDB now has support for catch syscall on remote Linux targets,
611 currently enabled on x86/x86_64 architectures.
613 set remote catch-syscall-packet
614 show remote catch-syscall-packet
615 Set/show the use of the remote catch syscall feature.
619 ** The -var-set-format command now accepts the zero-hexadecimal
620 format. It outputs data in hexadecimal format with zero-padding on the
625 ** gdb.InferiorThread objects have a new attribute "global_num",
626 which refers to the thread's global thread ID. The existing
627 "num" attribute now refers to the thread's per-inferior number.
628 See "Per-inferior thread numbers" above.
629 ** gdb.InferiorThread objects have a new attribute "inferior", which
630 is the Inferior object the thread belongs to.
632 *** Changes in GDB 7.10
634 * Support for process record-replay and reverse debugging on aarch64*-linux*
635 targets has been added. GDB now supports recording of A64 instruction set
636 including advance SIMD instructions.
638 * Support for Sun's version of the "stabs" debug file format has been removed.
640 * GDB now honors the content of the file /proc/PID/coredump_filter
641 (PID is the process ID) on GNU/Linux systems. This file can be used
642 to specify the types of memory mappings that will be included in a
643 corefile. For more information, please refer to the manual page of
644 "core(5)". GDB also has a new command: "set use-coredump-filter
645 on|off". It allows to set whether GDB will read the content of the
646 /proc/PID/coredump_filter file when generating a corefile.
648 * The "info os" command on GNU/Linux can now display information on
650 "info os cpus" Listing of all cpus/cores on the system
652 * GDB has two new commands: "set serial parity odd|even|none" and
653 "show serial parity". These allows to set or show parity for the
656 * The "info source" command now displays the producer string if it was
657 present in the debug info. This typically includes the compiler version
658 and may include things like its command line arguments.
660 * The "info dll", an alias of the "info sharedlibrary" command,
661 is now available on all platforms.
663 * Directory names supplied to the "set sysroot" commands may be
664 prefixed with "target:" to tell GDB to access shared libraries from
665 the target system, be it local or remote. This replaces the prefix
666 "remote:". The default sysroot has been changed from "" to
667 "target:". "remote:" is automatically converted to "target:" for
668 backward compatibility.
670 * The system root specified by "set sysroot" will be prepended to the
671 filename of the main executable (if reported to GDB as absolute by
672 the operating system) when starting processes remotely, and when
673 attaching to already-running local or remote processes.
675 * GDB now supports automatic location and retrieval of executable
676 files from remote targets. Remote debugging can now be initiated
677 using only a "target remote" or "target extended-remote" command
678 (no "set sysroot" or "file" commands are required). See "New remote
681 * The "dump" command now supports verilog hex format.
683 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
685 * On GNU/Linux, GDB and gdbserver are now able to access executable
686 and shared library files without a "set sysroot" command when
687 attaching to processes running in different mount namespaces from
688 the debugger. This makes it possible to attach to processes in
689 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
690 See "New remote packets" below.
692 * The "tui reg" command now provides completion for all of the
693 available register groups, including target specific groups.
695 * The HISTSIZE environment variable is no longer read when determining
696 the size of GDB's command history. GDB now instead reads the dedicated
697 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
698 disables truncation of command history. Non-numeric values of GDBHISTSIZE
703 ** Memory ports can now be unbuffered.
707 ** gdb.Objfile objects have a new attribute "username",
708 which is the name of the objfile as specified by the user,
709 without, for example, resolving symlinks.
710 ** You can now write frame unwinders in Python.
711 ** gdb.Type objects have a new method "optimized_out",
712 returning optimized out gdb.Value instance of this type.
713 ** gdb.Value objects have new methods "reference_value" and
714 "const_value" which return a reference to the value and a
715 "const" version of the value respectively.
719 maint print symbol-cache
720 Print the contents of the symbol cache.
722 maint print symbol-cache-statistics
723 Print statistics of symbol cache usage.
725 maint flush-symbol-cache
726 Flush the contents of the symbol cache.
730 Start branch trace recording using Branch Trace Store (BTS) format.
733 Evaluate expression by using the compiler and print result.
737 Explicit commands for enabling and disabling tui mode.
740 set mpx bound on i386 and amd64
741 Support for bound table investigation on Intel MPX enabled applications.
745 Start branch trace recording using Intel Processor Trace format.
748 Print information about branch tracing internals.
750 maint btrace packet-history
751 Print the raw branch tracing data.
753 maint btrace clear-packet-history
754 Discard the stored raw branch tracing data.
757 Discard all branch tracing data. It will be fetched and processed
758 anew by the next "record" command.
763 Renamed from "set debug dwarf2-die".
765 Renamed from "show debug dwarf2-die".
768 Renamed from "set debug dwarf2-read".
769 show debug dwarf-read
770 Renamed from "show debug dwarf2-read".
772 maint set dwarf always-disassemble
773 Renamed from "maint set dwarf2 always-disassemble".
774 maint show dwarf always-disassemble
775 Renamed from "maint show dwarf2 always-disassemble".
777 maint set dwarf max-cache-age
778 Renamed from "maint set dwarf2 max-cache-age".
779 maint show dwarf max-cache-age
780 Renamed from "maint show dwarf2 max-cache-age".
783 show debug dwarf-line
784 Control display of debugging info regarding DWARF line processing.
788 Set the maximum number of candidates to be considered during
789 completion. The default value is 200. This limit allows GDB
790 to avoid generating large completion lists, the computation of
791 which can cause the debugger to become temporarily unresponsive.
793 set history remove-duplicates
794 show history remove-duplicates
795 Control the removal of duplicate history entries.
797 maint set symbol-cache-size
798 maint show symbol-cache-size
799 Control the size of the symbol cache.
801 set|show record btrace bts buffer-size
802 Set and show the size of the ring buffer used for branch tracing in
804 The obtained size may differ from the requested size. Use "info
805 record" to see the obtained buffer size.
807 set debug linux-namespaces
808 show debug linux-namespaces
809 Control display of debugging info regarding Linux namespaces.
811 set|show record btrace pt buffer-size
812 Set and show the size of the ring buffer used for branch tracing in
813 Intel Processor Trace format.
814 The obtained size may differ from the requested size. Use "info
815 record" to see the obtained buffer size.
817 maint set|show btrace pt skip-pad
818 Set and show whether PAD packets are skipped when computing the
821 * The command 'thread apply all' can now support new option '-ascending'
822 to call its specified command for all threads in ascending order.
824 * Python/Guile scripting
826 ** GDB now supports auto-loading of Python/Guile scripts contained in the
827 special section named `.debug_gdb_scripts'.
831 qXfer:btrace-conf:read
832 Return the branch trace configuration for the current thread.
834 Qbtrace-conf:bts:size
835 Set the requested ring buffer size for branch tracing in BTS format.
838 Enable Intel Procesor Trace-based branch tracing for the current
839 process. The remote stub reports support for this packet to GDB's
843 Set the requested ring buffer size for branch tracing in Intel Processor
847 Indicates a memory breakpoint instruction was executed, irrespective
848 of whether it was GDB that planted the breakpoint or the breakpoint
849 is hardcoded in the program. This is required for correct non-stop
853 Indicates the target stopped for a hardware breakpoint. This is
854 required for correct non-stop mode operation.
857 Return information about files on the remote system.
860 Return the full absolute name of the file that was executed to
861 create a process running on the remote system.
864 Select the filesystem on which vFile: operations with filename
865 arguments will operate. This is required for GDB to be able to
866 access files on remote targets where the remote stub does not
867 share a common filesystem with the inferior(s).
870 Indicates that a fork system call was executed.
873 Indicates that a vfork system call was executed.
875 vforkdone stop reason
876 Indicates that a vfork child of the specified process has executed
877 an exec or exit, allowing the vfork parent to resume execution.
879 fork-events and vfork-events features in qSupported
880 The qSupported packet allows GDB to request support for fork and
881 vfork events using new 'gdbfeatures' fork-events and vfork-events,
882 and the qSupported response can contain the corresponding
883 'stubfeatures'. Set and show commands can be used to display
884 whether these features are enabled.
886 * Extended-remote fork events
888 ** GDB now has support for fork events on extended-remote Linux
889 targets. For targets with Linux kernels 2.5.60 and later, this
890 enables follow-fork-mode and detach-on-fork for both fork and
891 vfork, as well as fork and vfork catchpoints.
893 * The info record command now shows the recording format and the
894 branch tracing configuration for the current thread when using
895 the btrace record target.
896 For the BTS format, it shows the ring buffer size.
898 * GDB now has support for DTrace USDT (Userland Static Defined
899 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
901 * GDB now supports access to vector registers on S/390 GNU/Linux
904 * Removed command line options
906 -xdb HP-UX XDB compatibility mode.
908 * Removed targets and native configurations
910 HP/PA running HP-UX hppa*-*-hpux*
911 Itanium running HP-UX ia64-*-hpux*
913 * New configure options
916 This configure option allows the user to build GDB with support for
917 Intel Processor Trace (default: auto). This requires libipt.
919 --with-libipt-prefix=PATH
920 Specify the path to the version of libipt that GDB should use.
921 $PATH/include should contain the intel-pt.h header and
922 $PATH/lib should contain the libipt.so library.
924 *** Changes in GDB 7.9.1
928 ** Xmethods can now specify a result type.
930 *** Changes in GDB 7.9
932 * GDB now supports hardware watchpoints on x86 GNU Hurd.
936 ** You can now access frame registers from Python scripts.
937 ** New attribute 'producer' for gdb.Symtab objects.
938 ** gdb.Objfile objects have a new attribute "progspace",
939 which is the gdb.Progspace object of the containing program space.
940 ** gdb.Objfile objects have a new attribute "owner".
941 ** gdb.Objfile objects have a new attribute "build_id",
942 which is the build ID generated when the file was built.
943 ** gdb.Objfile objects have a new method "add_separate_debug_file".
944 ** A new event "gdb.clear_objfiles" has been added, triggered when
945 selecting a new file to debug.
946 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
947 ** New function gdb.lookup_objfile.
949 New events which are triggered when GDB modifies the state of the
952 ** gdb.events.inferior_call_pre: Function call is about to be made.
953 ** gdb.events.inferior_call_post: Function call has just been made.
954 ** gdb.events.memory_changed: A memory location has been altered.
955 ** gdb.events.register_changed: A register has been altered.
957 * New Python-based convenience functions:
959 ** $_caller_is(name [, number_of_frames])
960 ** $_caller_matches(regexp [, number_of_frames])
961 ** $_any_caller_is(name [, number_of_frames])
962 ** $_any_caller_matches(regexp [, number_of_frames])
964 * GDB now supports the compilation and injection of source code into
965 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
966 to compile the source code to object code, and if successful, inject
967 and execute that code within the current context of the inferior.
968 Currently the C language is supported. The commands used to
969 interface with this new feature are:
971 compile code [-raw|-r] [--] [source code]
972 compile file [-raw|-r] filename
976 demangle [-l language] [--] name
977 Demangle "name" in the specified language, or the current language
978 if elided. This command is renamed from the "maint demangle" command.
979 The latter is kept as a no-op to avoid "maint demangle" being interpreted
980 as "maint demangler-warning".
982 queue-signal signal-name-or-number
983 Queue a signal to be delivered to the thread when it is resumed.
985 add-auto-load-scripts-directory directory
986 Add entries to the list of directories from which to load auto-loaded
989 maint print user-registers
990 List all currently available "user" registers.
992 compile code [-r|-raw] [--] [source code]
993 Compile, inject, and execute in the inferior the executable object
994 code produced by compiling the provided source code.
996 compile file [-r|-raw] filename
997 Compile and inject into the inferior the executable object code
998 produced by compiling the source code stored in the filename
1001 * On resume, GDB now always passes the signal the program had stopped
1002 for to the thread the signal was sent to, even if the user changed
1003 threads before resuming. Previously GDB would often (but not
1004 always) deliver the signal to the thread that happens to be current
1007 * Conversely, the "signal" command now consistently delivers the
1008 requested signal to the current thread. GDB now asks for
1009 confirmation if the program had stopped for a signal and the user
1010 switched threads meanwhile.
1012 * "breakpoint always-inserted" modes "off" and "auto" merged.
1014 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1015 won't remove breakpoints from the target until all threads stop,
1016 even in non-stop mode. The "auto" mode has been removed, and "off"
1017 is now the default mode.
1021 set debug symbol-lookup
1022 show debug symbol-lookup
1023 Control display of debugging info regarding symbol lookup.
1027 ** The -list-thread-groups command outputs an exit-code field for
1028 inferiors that have exited.
1032 MIPS SDE mips*-sde*-elf*
1036 Support for these obsolete configurations has been removed.
1038 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1039 SGI Irix-5.x mips-*-irix5*
1040 SGI Irix-6.x mips-*-irix6*
1041 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1042 VAX running Ultrix vax-*-ultrix*
1044 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1045 and "assf"), have been removed. Use the "sharedlibrary" command, or
1046 its alias "share", instead.
1048 *** Changes in GDB 7.8
1050 * New command line options
1053 This is an alias for the --data-directory option.
1055 * GDB supports printing and modifying of variable length automatic arrays
1056 as specified in ISO C99.
1058 * The ARM simulator now supports instruction level tracing
1059 with or without disassembly.
1063 GDB now has support for scripting using Guile. Whether this is
1064 available is determined at configure time.
1065 Guile version 2.0 or greater is required.
1066 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1068 * New commands (for set/show, see "New options" below)
1072 Invoke CODE by passing it to the Guile interpreter.
1076 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1078 info auto-load guile-scripts [regexp]
1079 Print the list of automatically loaded Guile scripts.
1081 * The source command is now capable of sourcing Guile scripts.
1082 This feature is dependent on the debugger being built with Guile support.
1086 set print symbol-loading (off|brief|full)
1087 show print symbol-loading
1088 Control whether to print informational messages when loading symbol
1089 information for a file. The default is "full", but when debugging
1090 programs with large numbers of shared libraries the amount of output
1091 becomes less useful.
1093 set guile print-stack (none|message|full)
1094 show guile print-stack
1095 Show a stack trace when an error is encountered in a Guile script.
1097 set auto-load guile-scripts (on|off)
1098 show auto-load guile-scripts
1099 Control auto-loading of Guile script files.
1101 maint ada set ignore-descriptive-types (on|off)
1102 maint ada show ignore-descriptive-types
1103 Control whether the debugger should ignore descriptive types in Ada
1104 programs. The default is not to ignore the descriptive types. See
1105 the user manual for more details on descriptive types and the intended
1106 usage of this option.
1108 set auto-connect-native-target
1110 Control whether GDB is allowed to automatically connect to the
1111 native target for the run, attach, etc. commands when not connected
1112 to any target yet. See also "target native" below.
1114 set record btrace replay-memory-access (read-only|read-write)
1115 show record btrace replay-memory-access
1116 Control what memory accesses are allowed during replay.
1118 maint set target-async (on|off)
1119 maint show target-async
1120 This controls whether GDB targets operate in synchronous or
1121 asynchronous mode. Normally the default is asynchronous, if it is
1122 available; but this can be changed to more easily debug problems
1123 occurring only in synchronous mode.
1125 set mi-async (on|off)
1127 Control whether MI asynchronous mode is preferred. This supersedes
1128 "set target-async" of previous GDB versions.
1130 * "set target-async" is deprecated as a CLI option and is now an alias
1131 for "set mi-async" (only puts MI into async mode).
1133 * Background execution commands (e.g., "c&", "s&", etc.) are now
1134 possible ``out of the box'' if the target supports them. Previously
1135 the user would need to explicitly enable the possibility with the
1136 "set target-async on" command.
1138 * New features in the GDB remote stub, GDBserver
1140 ** New option --debug-format=option1[,option2,...] allows one to add
1141 additional text to each output. At present only timestamps
1142 are supported: --debug-format=timestamps.
1143 Timestamps can also be turned on with the
1144 "monitor set debug-format timestamps" command from GDB.
1146 * The 'record instruction-history' command now starts counting instructions
1147 at one. This also affects the instruction ranges reported by the
1148 'record function-call-history' command when given the /i modifier.
1150 * The command 'record function-call-history' supports a new modifier '/c' to
1151 indent the function names based on their call stack depth.
1152 The fields for the '/i' and '/l' modifier have been reordered.
1153 The source line range is now prefixed with 'at'.
1154 The instruction range is now prefixed with 'inst'.
1155 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1156 "record instruction-history" and "list" commands.
1158 * The ranges given as arguments to the 'record function-call-history' and
1159 'record instruction-history' commands are now inclusive.
1161 * The btrace record target now supports the 'record goto' command.
1162 For locations inside the execution trace, the back trace is computed
1163 based on the information stored in the execution trace.
1165 * The btrace record target supports limited reverse execution and replay.
1166 The target does not record data and therefore does not allow reading
1167 memory or registers.
1169 * The "catch syscall" command now works on s390*-linux* targets.
1171 * The "compare-sections" command is no longer specific to target
1172 remote. It now works with all targets.
1174 * All native targets are now consistently called "native".
1175 Consequently, the "target child", "target GNU", "target djgpp",
1176 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1177 commands have been replaced with "target native". The QNX/NTO port
1178 leaves the "procfs" target in place and adds a "native" target for
1179 consistency with other ports. The impact on users should be minimal
1180 as these commands previously either throwed an error, or were
1181 no-ops. The target's name is visible in the output of the following
1182 commands: "help target", "info target", "info files", "maint print
1185 * The "target native" command now connects to the native target. This
1186 can be used to launch native programs even when "set
1187 auto-connect-native-target" is set to off.
1189 * GDB now supports access to Intel MPX registers on GNU/Linux.
1191 * Support for Intel AVX-512 registers on GNU/Linux.
1192 Support displaying and modifying Intel AVX-512 registers
1193 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1195 * New remote packets
1197 qXfer:btrace:read's annex
1198 The qXfer:btrace:read packet supports a new annex 'delta' to read
1199 branch trace incrementally.
1203 ** Valid Python operations on gdb.Value objects representing
1204 structs/classes invoke the corresponding overloaded operators if
1206 ** New `Xmethods' feature in the Python API. Xmethods are
1207 additional methods or replacements for existing methods of a C++
1208 class. This feature is useful for those cases where a method
1209 defined in C++ source code could be inlined or optimized out by
1210 the compiler, making it unavailable to GDB.
1213 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1215 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1216 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1217 its alias "share", instead.
1219 * The commands "set remotebaud" and "show remotebaud" are no longer
1220 supported. Use "set serial baud" and "show serial baud" (respectively)
1225 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1226 target-async". The latter is left as a deprecated alias of the
1227 former for backward compatibility. If the target supports it,
1228 CLI background execution commands are now always possible by
1229 default, independently of whether the frontend stated a
1230 preference for asynchronous execution with "-gdb-set mi-async".
1231 Previously "-gdb-set target-async off" affected both MI execution
1232 commands and CLI execution commands.
1234 *** Changes in GDB 7.7
1236 * Improved support for process record-replay and reverse debugging on
1237 arm*-linux* targets. Support for thumb32 and syscall instruction
1238 recording has been added.
1240 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1242 * GDB now supports Fission DWP file format version 2.
1243 http://gcc.gnu.org/wiki/DebugFission
1245 * New convenience function "$_isvoid", to check whether an expression
1246 is void. A void expression is an expression where the type of the
1247 result is "void". For example, some convenience variables may be
1248 "void" when evaluated (e.g., "$_exitcode" before the execution of
1249 the program being debugged; or an undefined convenience variable).
1250 Another example, when calling a function whose return type is
1253 * The "maintenance print objfiles" command now takes an optional regexp.
1255 * The "catch syscall" command now works on arm*-linux* targets.
1257 * GDB now consistently shows "<not saved>" when printing values of
1258 registers the debug info indicates have not been saved in the frame
1259 and there's nowhere to retrieve them from
1260 (callee-saved/call-clobbered registers):
1265 (gdb) info registers rax
1268 Before, the former would print "<optimized out>", and the latter
1269 "*value not available*".
1271 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1276 ** Frame filters and frame decorators have been added.
1277 ** Temporary breakpoints are now supported.
1278 ** Line tables representation has been added.
1279 ** New attribute 'parent_type' for gdb.Field objects.
1280 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1281 ** New attribute 'name' for gdb.Type objects.
1285 Nios II ELF nios2*-*-elf
1286 Nios II GNU/Linux nios2*-*-linux
1287 Texas Instruments MSP430 msp430*-*-elf
1289 * Removed native configurations
1291 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1292 been removed. ELF variants of these configurations are kept supported.
1294 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1295 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1296 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1297 i[34567]86-*-openbsd3.[0-3]
1298 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1299 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1300 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1304 Like "catch throw", but catches a re-thrown exception.
1305 maint check-psymtabs
1306 Renamed from old "maint check-symtabs".
1308 Perform consistency checks on symtabs.
1309 maint expand-symtabs
1310 Expand symtabs matching an optional regexp.
1313 Display the details of GDB configure-time options.
1315 maint set|show per-command
1316 maint set|show per-command space
1317 maint set|show per-command time
1318 maint set|show per-command symtab
1319 Enable display of per-command gdb resource usage.
1321 remove-symbol-file FILENAME
1322 remove-symbol-file -a ADDRESS
1323 Remove a symbol file added via add-symbol-file. The file to remove
1324 can be identified by its filename or by an address that lies within
1325 the boundaries of this symbol file in memory.
1328 info exceptions REGEXP
1329 Display the list of Ada exceptions defined in the program being
1330 debugged. If provided, only the exceptions whose names match REGEXP
1335 set debug symfile off|on
1337 Control display of debugging info regarding reading symbol files and
1338 symbol tables within those files
1340 set print raw frame-arguments
1341 show print raw frame-arguments
1342 Set/show whether to print frame arguments in raw mode,
1343 disregarding any defined pretty-printers.
1345 set remote trace-status-packet
1346 show remote trace-status-packet
1347 Set/show the use of remote protocol qTStatus packet.
1351 Control display of debugging messages related to Nios II targets.
1355 Control whether target-assisted range stepping is enabled.
1357 set startup-with-shell
1358 show startup-with-shell
1359 Specifies whether Unix child processes are started via a shell or
1364 Use the target memory cache for accesses to the code segment. This
1365 improves performance of remote debugging (particularly disassembly).
1367 * You can now use a literal value 'unlimited' for options that
1368 interpret 0 or -1 as meaning "unlimited". E.g., "set
1369 trace-buffer-size unlimited" is now an alias for "set
1370 trace-buffer-size -1" and "set height unlimited" is now an alias for
1373 * The "set debug symtab-create" debugging option of GDB has been changed to
1374 accept a verbosity level. 0 means "off", 1 provides basic debugging
1375 output, and values of 2 or greater provides more verbose output.
1377 * New command-line options
1379 Display the details of GDB configure-time options.
1381 * The command 'tsave' can now support new option '-ctf' to save trace
1382 buffer in Common Trace Format.
1384 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1387 * GDB now implements the the C++ 'typeid' operator.
1389 * The new convenience variable $_exception holds the exception being
1390 thrown or caught at an exception-related catchpoint.
1392 * The exception-related catchpoints, like "catch throw", now accept a
1393 regular expression which can be used to filter exceptions by type.
1395 * The new convenience variable $_exitsignal is automatically set to
1396 the terminating signal number when the program being debugged dies
1397 due to an uncaught signal.
1401 ** All MI commands now accept an optional "--language" option.
1402 Support for this feature can be verified by using the "-list-features"
1403 command, which should contain "language-option".
1405 ** The new command -info-gdb-mi-command allows the user to determine
1406 whether a GDB/MI command is supported or not.
1408 ** The "^error" result record returned when trying to execute an undefined
1409 GDB/MI command now provides a variable named "code" whose content is the
1410 "undefined-command" error code. Support for this feature can be verified
1411 by using the "-list-features" command, which should contain
1412 "undefined-command-error-code".
1414 ** The -trace-save MI command can optionally save trace buffer in Common
1417 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1419 ** The command -data-list-register-values now accepts an optional
1420 "--skip-unavailable" option. When used, only the available registers
1423 ** The new command -trace-frame-collected dumps collected variables,
1424 computed expressions, tvars, memory and registers in a traceframe.
1426 ** The commands -stack-list-locals, -stack-list-arguments and
1427 -stack-list-variables now accept an option "--skip-unavailable".
1428 When used, only the available locals or arguments are displayed.
1430 ** The -exec-run command now accepts an optional "--start" option.
1431 When used, the command follows the same semantics as the "start"
1432 command, stopping the program's execution at the start of its
1433 main subprogram. Support for this feature can be verified using
1434 the "-list-features" command, which should contain
1435 "exec-run-start-option".
1437 ** The new commands -catch-assert and -catch-exceptions insert
1438 catchpoints stopping the program when Ada exceptions are raised.
1440 ** The new command -info-ada-exceptions provides the equivalent of
1441 the new "info exceptions" command.
1443 * New system-wide configuration scripts
1444 A GDB installation now provides scripts suitable for use as system-wide
1445 configuration scripts for the following systems:
1449 * GDB now supports target-assigned range stepping with remote targets.
1450 This improves the performance of stepping source lines by reducing
1451 the number of control packets from/to GDB. See "New remote packets"
1454 * GDB now understands the element 'tvar' in the XML traceframe info.
1455 It has the id of the collected trace state variables.
1457 * On S/390 targets that provide the transactional-execution feature,
1458 the program interruption transaction diagnostic block (TDB) is now
1459 represented as a number of additional "registers" in GDB.
1461 * New remote packets
1465 The vCont packet supports a new 'r' action, that tells the remote
1466 stub to step through an address range itself, without GDB
1467 involvemement at each single-step.
1469 qXfer:libraries-svr4:read's annex
1470 The previously unused annex of the qXfer:libraries-svr4:read packet
1471 is now used to support passing an argument list. The remote stub
1472 reports support for this argument list to GDB's qSupported query.
1473 The defined arguments are "start" and "prev", used to reduce work
1474 necessary for library list updating, resulting in significant
1477 * New features in the GDB remote stub, GDBserver
1479 ** GDBserver now supports target-assisted range stepping. Currently
1480 enabled on x86/x86_64 GNU/Linux targets.
1482 ** GDBserver now adds element 'tvar' in the XML in the reply to
1483 'qXfer:traceframe-info:read'. It has the id of the collected
1484 trace state variables.
1486 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1489 * New 'z' formatter for printing and examining memory, this displays the
1490 value as hexadecimal zero padded on the left to the size of the type.
1492 * GDB can now use Windows x64 unwinding data.
1494 * The "set remotebaud" command has been replaced by "set serial baud".
1495 Similarly, "show remotebaud" has been replaced by "show serial baud".
1496 The "set remotebaud" and "show remotebaud" commands are still available
1497 to provide backward compatibility with older versions of GDB.
1499 *** Changes in GDB 7.6
1501 * Target record has been renamed to record-full.
1502 Record/replay is now enabled with the "record full" command.
1503 This also affects settings that are associated with full record/replay
1504 that have been moved from "set/show record" to "set/show record full":
1506 set|show record full insn-number-max
1507 set|show record full stop-at-limit
1508 set|show record full memory-query
1510 * A new record target "record-btrace" has been added. The new target
1511 uses hardware support to record the control-flow of a process. It
1512 does not support replaying the execution, but it implements the
1513 below new commands for investigating the recorded execution log.
1514 This new recording method can be enabled using:
1518 The "record-btrace" target is only available on Intel Atom processors
1519 and requires a Linux kernel 2.6.32 or later.
1521 * Two new commands have been added for record/replay to give information
1522 about the recorded execution without having to replay the execution.
1523 The commands are only supported by "record btrace".
1525 record instruction-history prints the execution history at
1526 instruction granularity
1528 record function-call-history prints the execution history at
1529 function granularity
1531 * New native configurations
1533 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1534 FreeBSD/powerpc powerpc*-*-freebsd
1535 x86_64/Cygwin x86_64-*-cygwin*
1536 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1540 ARM AArch64 aarch64*-*-elf
1541 ARM AArch64 GNU/Linux aarch64*-*-linux
1542 Lynx 178 PowerPC powerpc-*-lynx*178
1543 x86_64/Cygwin x86_64-*-cygwin*
1544 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1546 * If the configured location of system.gdbinit file (as given by the
1547 --with-system-gdbinit option at configure time) is in the
1548 data-directory (as specified by --with-gdb-datadir at configure
1549 time) or in one of its subdirectories, then GDB will look for the
1550 system-wide init file in the directory specified by the
1551 --data-directory command-line option.
1553 * New command line options:
1555 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1556 other initialization files, unlike -nx which disables all of them.
1558 * Removed command line options
1560 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1563 * The 'ptype' and 'whatis' commands now accept an argument to control
1566 * 'info proc' now works on some core files.
1570 ** Vectors can be created with gdb.Type.vector.
1572 ** Python's atexit.register now works in GDB.
1574 ** Types can be pretty-printed via a Python API.
1576 ** Python 3 is now supported (in addition to Python 2.4 or later)
1578 ** New class gdb.Architecture exposes GDB's internal representation
1579 of architecture in the Python API.
1581 ** New method Frame.architecture returns the gdb.Architecture object
1582 corresponding to the frame's architecture.
1584 * New Python-based convenience functions:
1586 ** $_memeq(buf1, buf2, length)
1587 ** $_streq(str1, str2)
1589 ** $_regex(str, regex)
1591 * The 'cd' command now defaults to using '~' (the home directory) if not
1594 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1595 default for GCC since November 2000.
1597 * The command 'forward-search' can now be abbreviated as 'fo'.
1599 * The command 'info tracepoints' can now display 'installed on target'
1600 or 'not installed on target' for each non-pending location of tracepoint.
1602 * New configure options
1604 --enable-libmcheck/--disable-libmcheck
1605 By default, development versions are built with -lmcheck on hosts
1606 that support it, in order to help track memory corruption issues.
1607 Release versions, on the other hand, are built without -lmcheck
1608 by default. The --enable-libmcheck/--disable-libmcheck configure
1609 options allow the user to override that default.
1610 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1611 This configure option allows the user to build GDB with
1612 libbabeltrace using which GDB can read Common Trace Format data.
1614 * New commands (for set/show, see "New options" below)
1617 Catch signals. This is similar to "handle", but allows commands and
1618 conditions to be attached.
1621 List the BFDs known to GDB.
1623 python-interactive [command]
1625 Start a Python interactive prompt, or evaluate the optional command
1626 and print the result of expressions.
1629 "py" is a new alias for "python".
1631 enable type-printer [name]...
1632 disable type-printer [name]...
1633 Enable or disable type printers.
1637 ** For the Renesas Super-H architecture, the "regs" command has been removed
1638 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1643 set print type methods (on|off)
1644 show print type methods
1645 Control whether method declarations are displayed by "ptype".
1646 The default is to show them.
1648 set print type typedefs (on|off)
1649 show print type typedefs
1650 Control whether typedef definitions are displayed by "ptype".
1651 The default is to show them.
1653 set filename-display basename|relative|absolute
1654 show filename-display
1655 Control the way in which filenames is displayed.
1656 The default is "relative", which preserves previous behavior.
1658 set trace-buffer-size
1659 show trace-buffer-size
1660 Request target to change the size of trace buffer.
1662 set remote trace-buffer-size-packet auto|on|off
1663 show remote trace-buffer-size-packet
1664 Control the use of the remote protocol `QTBuffer:size' packet.
1668 Control display of debugging messages related to ARM AArch64.
1671 set debug coff-pe-read
1672 show debug coff-pe-read
1673 Control display of debugging messages related to reading of COFF/PE
1678 Control display of debugging messages related to Mach-O symbols
1681 set debug notification
1682 show debug notification
1683 Control display of debugging info for async remote notification.
1687 ** Command parameter changes are now notified using new async record
1688 "=cmd-param-changed".
1689 ** Trace frame changes caused by command "tfind" are now notified using
1690 new async record "=traceframe-changed".
1691 ** The creation, deletion and modification of trace state variables
1692 are now notified using new async records "=tsv-created",
1693 "=tsv-deleted" and "=tsv-modified".
1694 ** The start and stop of process record are now notified using new
1695 async record "=record-started" and "=record-stopped".
1696 ** Memory changes are now notified using new async record
1698 ** The data-disassemble command response will include a "fullname" field
1699 containing the absolute file name when source has been requested.
1700 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1701 command, to allow pattern filling of memory areas.
1702 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1703 library load/unload events.
1704 ** The response to breakpoint commands and breakpoint async records
1705 includes an "installed" field containing a boolean state about each
1706 non-pending tracepoint location is whether installed on target or not.
1707 ** Output of the "-trace-status" command includes a "trace-file" field
1708 containing the name of the trace file being examined. This field is
1709 optional, and only present when examining a trace file.
1710 ** The "fullname" field is now always present along with the "file" field,
1711 even if the file cannot be found by GDB.
1713 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1714 You must have the LZMA library available when configuring GDB for this
1715 feature to be enabled. For more information, see:
1716 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1718 * New remote packets
1721 Set the size of trace buffer. The remote stub reports support for this
1722 packet to gdb's qSupported query.
1725 Enable Branch Trace Store (BTS)-based branch tracing for the current
1726 thread. The remote stub reports support for this packet to gdb's
1730 Disable branch tracing for the current thread. The remote stub reports
1731 support for this packet to gdb's qSupported query.
1734 Read the traced branches for the current thread. The remote stub
1735 reports support for this packet to gdb's qSupported query.
1737 *** Changes in GDB 7.5
1739 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1740 for more x32 ABI info.
1742 * GDB now supports access to MIPS DSP registers on Linux targets.
1744 * GDB now supports debugging microMIPS binaries.
1746 * The "info os" command on GNU/Linux can now display information on
1747 several new classes of objects managed by the operating system:
1748 "info os procgroups" lists process groups
1749 "info os files" lists file descriptors
1750 "info os sockets" lists internet-domain sockets
1751 "info os shm" lists shared-memory regions
1752 "info os semaphores" lists semaphores
1753 "info os msg" lists message queues
1754 "info os modules" lists loaded kernel modules
1756 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1757 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1758 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1759 options and inspect the probe arguments using the new $_probe_arg family
1760 of convenience variables. You can obtain more information about SystemTap
1761 in <http://sourceware.org/systemtap/>.
1763 * GDB now supports reversible debugging on ARM, it allows you to
1764 debug basic ARM and THUMB instructions, and provides
1765 record/replay support.
1767 * The option "symbol-reloading" has been deleted as it is no longer used.
1771 ** GDB commands implemented in Python can now be put in command class
1774 ** The "maint set python print-stack on|off" is now deleted.
1776 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1777 apply "flag enum"-style pretty-printing to any enum.
1779 ** gdb.lookup_symbol can now work when there is no current frame.
1781 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1782 the source at which the symbol was defined.
1784 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1785 method 'value'. The former indicates whether the symbol needs a
1786 frame in order to compute its value, and the latter computes the
1789 ** A new method 'referenced_value' on gdb.Value objects which can
1790 dereference pointer as well as C++ reference values.
1792 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1793 which return the global and static blocks (as gdb.Block objects),
1794 of the underlying symbol table, respectively.
1796 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1797 object associated with a PC value.
1799 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1800 of the address range occupied by code for the current source line.
1802 * Go language support.
1803 GDB now supports debugging programs written in the Go programming
1806 * GDBserver now supports stdio connections.
1807 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1809 * The binary "gdbtui" can no longer be built or installed.
1810 Use "gdb -tui" instead.
1812 * GDB will now print "flag" enums specially. A flag enum is one where
1813 all the enumerator values have no bits in common when pairwise
1814 "and"ed. When printing a value whose type is a flag enum, GDB will
1815 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1816 (gdb) print (enum E) 3
1819 * The filename part of a linespec will now match trailing components
1820 of a source file name. For example, "break gcc/expr.c:1000" will
1821 now set a breakpoint in build/gcc/expr.c, but not
1822 build/libcpp/expr.c.
1824 * The "info proc" and "generate-core-file" commands will now also
1825 work on remote targets connected to GDBserver on Linux.
1827 * The command "info catch" has been removed. It has been disabled
1828 since December 2007.
1830 * The "catch exception" and "catch assert" commands now accept
1831 a condition at the end of the command, much like the "break"
1832 command does. For instance:
1834 (gdb) catch exception Constraint_Error if Barrier = True
1836 Previously, it was possible to add a condition to such catchpoints,
1837 but it had to be done as a second step, after the catchpoint had been
1838 created, using the "condition" command.
1840 * The "info static-tracepoint-marker" command will now also work on
1841 native Linux targets with in-process agent.
1843 * GDB can now set breakpoints on inlined functions.
1845 * The .gdb_index section has been updated to include symbols for
1846 inlined functions. GDB will ignore older .gdb_index sections by
1847 default, which could cause symbol files to be loaded more slowly
1848 until their .gdb_index sections can be recreated. The new command
1849 "set use-deprecated-index-sections on" will cause GDB to use any older
1850 .gdb_index sections it finds. This will restore performance, but the
1851 ability to set breakpoints on inlined functions will be lost in symbol
1852 files with older .gdb_index sections.
1854 The .gdb_index section has also been updated to record more information
1855 about each symbol. This speeds up the "info variables", "info functions"
1856 and "info types" commands when used with programs having the .gdb_index
1857 section, as well as speeding up debugging with shared libraries using
1858 the .gdb_index section.
1860 * Ada support for GDB/MI Variable Objects has been added.
1862 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1867 ** New command -info-os is the MI equivalent of "info os".
1869 ** Output logs ("set logging" and related) now include MI output.
1873 ** "set use-deprecated-index-sections on|off"
1874 "show use-deprecated-index-sections on|off"
1875 Controls the use of deprecated .gdb_index sections.
1877 ** "catch load" and "catch unload" can be used to stop when a shared
1878 library is loaded or unloaded, respectively.
1880 ** "enable count" can be used to auto-disable a breakpoint after
1883 ** "info vtbl" can be used to show the virtual method tables for
1884 C++ and Java objects.
1886 ** "explore" and its sub commands "explore value" and "explore type"
1887 can be used to recursively explore values and types of
1888 expressions. These commands are available only if GDB is
1889 configured with '--with-python'.
1891 ** "info auto-load" shows status of all kinds of auto-loaded files,
1892 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1893 sequences of commands files, "info auto-load python-scripts"
1894 shows status of auto-loading Python script files,
1895 "info auto-load local-gdbinit" shows status of loading init file
1896 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1897 status of inferior specific thread debugging shared library loading.
1899 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1900 and "show auto-load-scripts" commands have been deprecated, use their
1901 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1902 and "show auto-load python-scripts" counterparts instead.
1904 ** "dprintf location,format,args..." creates a dynamic printf, which
1905 is basically a breakpoint that does a printf and immediately
1906 resumes your program's execution, so it is like a printf that you
1907 can insert dynamically at runtime instead of at compiletime.
1909 ** "set print symbol"
1911 Controls whether GDB attempts to display the symbol, if any,
1912 corresponding to addresses it prints. This defaults to "on", but
1913 you can set it to "off" to restore GDB's previous behavior.
1915 * Deprecated commands
1917 ** For the Renesas Super-H architecture, the "regs" command has been
1918 deprecated, and "info all-registers" should be used instead.
1922 Renesas RL78 rl78-*-elf
1923 HP OpenVMS ia64 ia64-hp-openvms*
1925 * GDBserver supports evaluation of breakpoint conditions. When
1926 support is advertised by GDBserver, GDB may be told to send the
1927 breakpoint conditions in bytecode form to GDBserver. GDBserver
1928 will only report the breakpoint trigger to GDB when its condition
1933 set mips compression
1934 show mips compression
1935 Select the compressed ISA encoding used in functions that have no symbol
1936 information available. The encoding can be set to either of:
1939 and is updated automatically from ELF file flags if available.
1941 set breakpoint condition-evaluation
1942 show breakpoint condition-evaluation
1943 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1944 GDBserver ("target"). Default option "auto" chooses the most efficient
1946 This option can improve debugger efficiency depending on the speed of the
1950 Disable auto-loading globally.
1953 Show auto-loading setting of all kinds of auto-loaded files.
1955 set auto-load gdb-scripts on|off
1956 show auto-load gdb-scripts
1957 Control auto-loading of GDB canned sequences of commands files.
1959 set auto-load python-scripts on|off
1960 show auto-load python-scripts
1961 Control auto-loading of Python script files.
1963 set auto-load local-gdbinit on|off
1964 show auto-load local-gdbinit
1965 Control loading of init file (.gdbinit) from current directory.
1967 set auto-load libthread-db on|off
1968 show auto-load libthread-db
1969 Control auto-loading of inferior specific thread debugging shared library.
1971 set auto-load scripts-directory <dir1>[:<dir2>...]
1972 show auto-load scripts-directory
1973 Set a list of directories from which to load auto-loaded scripts.
1974 Automatically loaded Python scripts and GDB scripts are located in one
1975 of the directories listed by this option.
1976 The delimiter (':' above) may differ according to the host platform.
1978 set auto-load safe-path <dir1>[:<dir2>...]
1979 show auto-load safe-path
1980 Set a list of directories from which it is safe to auto-load files.
1981 The delimiter (':' above) may differ according to the host platform.
1983 set debug auto-load on|off
1984 show debug auto-load
1985 Control display of debugging info for auto-loading the files above.
1987 set dprintf-style gdb|call|agent
1989 Control the way in which a dynamic printf is performed; "gdb"
1990 requests a GDB printf command, while "call" causes dprintf to call a
1991 function in the inferior. "agent" requests that the target agent
1992 (such as GDBserver) do the printing.
1994 set dprintf-function <expr>
1995 show dprintf-function
1996 set dprintf-channel <expr>
1997 show dprintf-channel
1998 Set the function and optional first argument to the call when using
1999 the "call" style of dynamic printf.
2001 set disconnected-dprintf on|off
2002 show disconnected-dprintf
2003 Control whether agent-style dynamic printfs continue to be in effect
2004 after GDB disconnects.
2006 * New configure options
2008 --with-auto-load-dir
2009 Configure default value for the 'set auto-load scripts-directory'
2010 setting above. It defaults to '$debugdir:$datadir/auto-load',
2011 $debugdir representing global debugging info directories (available
2012 via 'show debug-file-directory') and $datadir representing GDB's data
2013 directory (available via 'show data-directory').
2015 --with-auto-load-safe-path
2016 Configure default value for the 'set auto-load safe-path' setting
2017 above. It defaults to the --with-auto-load-dir setting.
2019 --without-auto-load-safe-path
2020 Set 'set auto-load safe-path' to '/', effectively disabling this
2023 * New remote packets
2025 z0/z1 conditional breakpoints extension
2027 The z0/z1 breakpoint insertion packets have been extended to carry
2028 a list of conditional expressions over to the remote stub depending on the
2029 condition evaluation mode. The use of this extension can be controlled
2030 via the "set remote conditional-breakpoints-packet" command.
2034 Specify the signals which the remote stub may pass to the debugged
2035 program without GDB involvement.
2037 * New command line options
2039 --init-command=FILE, -ix Like --command, -x but execute it
2040 before loading inferior.
2041 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2042 execute it before loading inferior.
2044 *** Changes in GDB 7.4
2046 * GDB now handles ambiguous linespecs more consistently; the existing
2047 FILE:LINE support has been expanded to other types of linespecs. A
2048 breakpoint will now be set on all matching locations in all
2049 inferiors, and locations will be added or removed according to
2052 * GDB now allows you to skip uninteresting functions and files when
2053 stepping with the "skip function" and "skip file" commands.
2055 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2056 and "show remote hardware-watchpoint-length-limit". These allows to
2057 set or show the maximum length limit (in bytes) of a remote
2058 target hardware watchpoint.
2060 This allows e.g. to use "unlimited" hardware watchpoints with the
2061 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2062 watchpoints are slower than real hardware watchpoints but are
2063 significantly faster than gdb software watchpoints.
2067 ** The register_pretty_printer function in module gdb.printing now takes
2068 an optional `replace' argument. If True, the new printer replaces any
2071 ** The "maint set python print-stack on|off" command has been
2072 deprecated and will be deleted in GDB 7.5.
2073 A new command: "set python print-stack none|full|message" has
2074 replaced it. Additionally, the default for "print-stack" is
2075 now "message", which just prints the error message without
2078 ** A prompt substitution hook (prompt_hook) is now available to the
2081 ** A new Python module, gdb.prompt has been added to the GDB Python
2082 modules library. This module provides functionality for
2083 escape sequences in prompts (used by set/show
2084 extended-prompt). These escape sequences are replaced by their
2085 corresponding value.
2087 ** Python commands and convenience-functions located in
2088 'data-directory'/python/gdb/command and
2089 'data-directory'/python/gdb/function are now automatically loaded
2092 ** Blocks now provide four new attributes. global_block and
2093 static_block will return the global and static blocks
2094 respectively. is_static and is_global are boolean attributes
2095 that indicate if the block is one of those two types.
2097 ** Symbols now provide the "type" attribute, the type of the symbol.
2099 ** The "gdb.breakpoint" function has been deprecated in favor of
2102 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2103 of a function. This class is based on the "finish" command
2104 available in the CLI.
2106 ** Type objects for struct and union types now allow access to
2107 the fields using standard Python dictionary (mapping) methods.
2108 For example, "some_type['myfield']" now works, as does
2109 "some_type.items()".
2111 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2114 ** A new function, "deep_items" has been added to the gdb.types
2115 module in the GDB Python modules library. This function returns
2116 an iterator over the fields of a struct or union type. Unlike
2117 the standard Python "iteritems" method, it will recursively traverse
2118 any anonymous fields.
2122 ** "*stopped" events can report several new "reason"s, such as
2125 ** Breakpoint changes are now notified using new async records, like
2126 "=breakpoint-modified".
2128 ** New command -ada-task-info.
2130 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2131 $sdir specifies the default system locations of shared libraries.
2132 $pdir specifies the directory where the libpthread used by the application
2135 GDB no longer looks in $sdir and $pdir after it has searched the directories
2136 mentioned in libthread-db-search-path. If you want to search those
2137 directories, they must be specified in libthread-db-search-path.
2138 The default value of libthread-db-search-path on GNU/Linux and Solaris
2139 systems is now "$sdir:$pdir".
2141 $pdir is not supported by gdbserver, it is currently ignored.
2142 $sdir is supported by gdbserver.
2144 * New configure option --with-iconv-bin.
2145 When using the internationalization support like the one in the GNU C
2146 library, GDB will invoke the "iconv" program to get a list of supported
2147 character sets. If this program lives in a non-standard location, one can
2148 use this option to specify where to find it.
2150 * When natively debugging programs on PowerPC BookE processors running
2151 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2152 watchpoints, which specify a mask in addition to an address to watch.
2153 The mask specifies that some bits of an address (the bits which are
2154 reset in the mask) should be ignored when matching the address accessed
2155 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2156 section in the user manual for more details.
2158 * The new option --once causes GDBserver to stop listening for connections once
2159 the first connection is made. The listening port used by GDBserver will
2160 become available after that.
2162 * New commands "info macros" and "alias" have been added.
2164 * New function parameters suffix @entry specifies value of function parameter
2165 at the time the function got called. Entry values are available only since
2171 "!" is now an alias of the "shell" command.
2172 Note that no space is needed between "!" and SHELL COMMAND.
2176 watch EXPRESSION mask MASK_VALUE
2177 The watch command now supports the mask argument which allows creation
2178 of masked watchpoints, if the current architecture supports this feature.
2180 info auto-load-scripts [REGEXP]
2181 This command was formerly named "maintenance print section-scripts".
2182 It is now generally useful and is no longer a maintenance-only command.
2184 info macro [-all] [--] MACRO
2185 The info macro command has new options `-all' and `--'. The first for
2186 printing all definitions of a macro. The second for explicitly specifying
2187 the end of arguments and the beginning of the macro name in case the macro
2188 name starts with a hyphen.
2190 collect[/s] EXPRESSIONS
2191 The tracepoint collect command now takes an optional modifier "/s"
2192 that directs it to dereference pointer-to-character types and
2193 collect the bytes of memory up to a zero byte. The behavior is
2194 similar to what you see when you use the regular print command on a
2195 string. An optional integer following the "/s" sets a bound on the
2196 number of bytes that will be collected.
2199 The trace start command now interprets any supplied arguments as a
2200 note to be recorded with the trace run, with an effect similar to
2201 setting the variable trace-notes.
2204 The trace stop command now interprets any arguments as a note to be
2205 mentioned along with the tstatus report that the trace was stopped
2206 with a command. The effect is similar to setting the variable
2209 * Tracepoints can now be enabled and disabled at any time after a trace
2210 experiment has been started using the standard "enable" and "disable"
2211 commands. It is now possible to start a trace experiment with no enabled
2212 tracepoints; GDB will display a warning, but will allow the experiment to
2213 begin, assuming that tracepoints will be enabled as needed while the trace
2216 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2217 locations with 4-byte instructions, when they were previously
2218 limited to locations with instructions of 5 bytes or longer.
2222 set debug dwarf2-read
2223 show debug dwarf2-read
2224 Turns on or off display of debugging messages related to reading
2225 DWARF debug info. The default is off.
2227 set debug symtab-create
2228 show debug symtab-create
2229 Turns on or off display of debugging messages related to symbol table
2230 creation. The default is off.
2233 show extended-prompt
2234 Set the GDB prompt, and allow escape sequences to be inserted to
2235 display miscellaneous information (see 'help set extended-prompt'
2236 for the list of sequences). This prompt (and any information
2237 accessed through the escape sequences) is updated every time the
2238 prompt is displayed.
2240 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2241 show print entry-values
2242 Set printing of frame argument values at function entry. In some cases
2243 GDB can determine the value of function argument which was passed by the
2244 function caller, even if the value was modified inside the called function.
2246 set debug entry-values
2247 show debug entry-values
2248 Control display of debugging info for determining frame argument values at
2249 function entry and virtual tail call frames.
2251 set basenames-may-differ
2252 show basenames-may-differ
2253 Set whether a source file may have multiple base names.
2254 (A "base name" is the name of a file with the directory part removed.
2255 Example: The base name of "/home/user/hello.c" is "hello.c".)
2256 If set, GDB will canonicalize file names (e.g., expand symlinks)
2257 before comparing them. Canonicalization is an expensive operation,
2258 but it allows the same file be known by more than one base name.
2259 If not set (the default), all source files are assumed to have just
2260 one base name, and gdb will do file name comparisons more efficiently.
2266 Set a user name and notes for the current and any future trace runs.
2267 This is useful for long-running and/or disconnected traces, to
2268 inform others (or yourself) as to who is running the trace, supply
2269 contact information, or otherwise explain what is going on.
2271 set trace-stop-notes
2272 show trace-stop-notes
2273 Set a note attached to the trace run, that is displayed when the
2274 trace has been stopped by a tstop command. This is useful for
2275 instance as an explanation, if you are stopping a trace run that was
2276 started by someone else.
2278 * New remote packets
2282 Dynamically enable a tracepoint in a started trace experiment.
2286 Dynamically disable a tracepoint in a started trace experiment.
2290 Set the user and notes of the trace run.
2294 Query the current status of a tracepoint.
2298 Query the minimum length of instruction at which a fast tracepoint may
2301 * Dcache size (number of lines) and line-size are now runtime-configurable
2302 via "set dcache line" and "set dcache line-size" commands.
2306 Texas Instruments TMS320C6x tic6x-*-*
2310 Renesas RL78 rl78-*-elf
2312 *** Changes in GDB 7.3.1
2314 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2316 *** Changes in GDB 7.3
2318 * GDB has a new command: "thread find [REGEXP]".
2319 It finds the thread id whose name, target id, or thread extra info
2320 matches the given regular expression.
2322 * The "catch syscall" command now works on mips*-linux* targets.
2324 * The -data-disassemble MI command now supports modes 2 and 3 for
2325 dumping the instruction opcodes.
2327 * New command line options
2329 -data-directory DIR Specify DIR as the "data-directory".
2330 This is mostly for testing purposes.
2332 * The "maint set python auto-load on|off" command has been renamed to
2333 "set auto-load-scripts on|off".
2335 * GDB has a new command: "set directories".
2336 It is like the "dir" command except that it replaces the
2337 source path list instead of augmenting it.
2339 * GDB now understands thread names.
2341 On GNU/Linux, "info threads" will display the thread name as set by
2342 prctl or pthread_setname_np.
2344 There is also a new command, "thread name", which can be used to
2345 assign a name internally for GDB to display.
2348 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2349 has been integrated into GDB.
2353 ** The function gdb.Write now accepts an optional keyword 'stream'.
2354 This keyword, when provided, will direct the output to either
2355 stdout, stderr, or GDB's logging output.
2357 ** Parameters can now be be sub-classed in Python, and in particular
2358 you may implement the get_set_doc and get_show_doc functions.
2359 This improves how Parameter set/show documentation is processed
2360 and allows for more dynamic content.
2362 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2363 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2364 have an is_valid method.
2366 ** Breakpoints can now be sub-classed in Python, and in particular
2367 you may implement a 'stop' function that is executed each time
2368 the inferior reaches that breakpoint.
2370 ** New function gdb.lookup_global_symbol looks up a global symbol.
2372 ** GDB values in Python are now callable if the value represents a
2373 function. For example, if 'some_value' represents a function that
2374 takes two integer parameters and returns a value, you can call
2375 that function like so:
2377 result = some_value (10,20)
2379 ** Module gdb.types has been added.
2380 It contains a collection of utilities for working with gdb.Types objects:
2381 get_basic_type, has_field, make_enum_dict.
2383 ** Module gdb.printing has been added.
2384 It contains utilities for writing and registering pretty-printers.
2385 New classes: PrettyPrinter, SubPrettyPrinter,
2386 RegexpCollectionPrettyPrinter.
2387 New function: register_pretty_printer.
2389 ** New commands "info pretty-printers", "enable pretty-printer" and
2390 "disable pretty-printer" have been added.
2392 ** gdb.parameter("directories") is now available.
2394 ** New function gdb.newest_frame returns the newest frame in the
2397 ** The gdb.InferiorThread class has a new "name" attribute. This
2398 holds the thread's name.
2400 ** Python Support for Inferior events.
2401 Python scripts can add observers to be notified of events
2402 occurring in the process being debugged.
2403 The following events are currently supported:
2404 - gdb.events.cont Continue event.
2405 - gdb.events.exited Inferior exited event.
2406 - gdb.events.stop Signal received, and Breakpoint hit events.
2410 ** GDB now puts template parameters in scope when debugging in an
2411 instantiation. For example, if you have:
2413 template<int X> int func (void) { return X; }
2415 then if you step into func<5>, "print X" will show "5". This
2416 feature requires proper debuginfo support from the compiler; it
2417 was added to GCC 4.5.
2419 ** The motion commands "next", "finish", "until", and "advance" now
2420 work better when exceptions are thrown. In particular, GDB will
2421 no longer lose control of the inferior; instead, the GDB will
2422 stop the inferior at the point at which the exception is caught.
2423 This functionality requires a change in the exception handling
2424 code that was introduced in GCC 4.5.
2426 * GDB now follows GCC's rules on accessing volatile objects when
2427 reading or writing target state during expression evaluation.
2428 One notable difference to prior behavior is that "print x = 0"
2429 no longer generates a read of x; the value of the assignment is
2430 now always taken directly from the value being assigned.
2432 * GDB now has some support for using labels in the program's source in
2433 linespecs. For instance, you can use "advance label" to continue
2434 execution to a label.
2436 * GDB now has support for reading and writing a new .gdb_index
2437 section. This section holds a fast index of DWARF debugging
2438 information and can be used to greatly speed up GDB startup and
2439 operation. See the documentation for `save gdb-index' for details.
2441 * The "watch" command now accepts an optional "-location" argument.
2442 When used, this causes GDB to watch the memory referred to by the
2443 expression. Such a watchpoint is never deleted due to it going out
2446 * GDB now supports thread debugging of core dumps on GNU/Linux.
2448 GDB now activates thread debugging using the libthread_db library
2449 when debugging GNU/Linux core dumps, similarly to when debugging
2450 live processes. As a result, when debugging a core dump file, GDB
2451 is now able to display pthread_t ids of threads. For example, "info
2452 threads" shows the same output as when debugging the process when it
2453 was live. In earlier releases, you'd see something like this:
2456 * 1 LWP 6780 main () at main.c:10
2458 While now you see this:
2461 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2463 It is also now possible to inspect TLS variables when debugging core
2466 When debugging a core dump generated on a machine other than the one
2467 used to run GDB, you may need to point GDB at the correct
2468 libthread_db library with the "set libthread-db-search-path"
2469 command. See the user manual for more details on this command.
2471 * When natively debugging programs on PowerPC BookE processors running
2472 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2473 which stop execution of the inferior whenever it executes an instruction
2474 at any address within the specified range. See the "PowerPC Embedded"
2475 section in the user manual for more details.
2477 * New features in the GDB remote stub, GDBserver
2479 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2480 and i686 LynxOS (version 5.x).
2482 ** GDBserver is now supported on Blackfin Linux.
2484 * New native configurations
2486 ia64 HP-UX ia64-*-hpux*
2490 Analog Devices, Inc. Blackfin Processor bfin-*
2492 * Ada task switching is now supported on sparc-elf targets when
2493 debugging a program using the Ravenscar Profile. For more information,
2494 see the "Tasking Support when using the Ravenscar Profile" section
2495 in the GDB user manual.
2497 * Guile support was removed.
2499 * New features in the GNU simulator
2501 ** The --map-info flag lists all known core mappings.
2503 ** CFI flashes may be simulated via the "cfi" device.
2505 *** Changes in GDB 7.2
2507 * Shared library support for remote targets by default
2509 When GDB is configured for a generic, non-OS specific target, like
2510 for example, --target=arm-eabi or one of the many *-*-elf targets,
2511 GDB now queries remote stubs for loaded shared libraries using the
2512 `qXfer:libraries:read' packet. Previously, shared library support
2513 was always disabled for such configurations.
2517 ** Argument Dependent Lookup (ADL)
2519 In C++ ADL lookup directs function search to the namespaces of its
2520 arguments even if the namespace has not been imported.
2530 Here the compiler will search for `foo' in the namespace of 'b'
2531 and find A::foo. GDB now supports this. This construct is commonly
2532 used in the Standard Template Library for operators.
2534 ** Improved User Defined Operator Support
2536 In addition to member operators, GDB now supports lookup of operators
2537 defined in a namespace and imported with a `using' directive, operators
2538 defined in the global scope, operators imported implicitly from an
2539 anonymous namespace, and the ADL operators mentioned in the previous
2541 GDB now also supports proper overload resolution for all the previously
2542 mentioned flavors of operators.
2544 ** static const class members
2546 Printing of static const class members that are initialized in the
2547 class definition has been fixed.
2549 * Windows Thread Information Block access.
2551 On Windows targets, GDB now supports displaying the Windows Thread
2552 Information Block (TIB) structure. This structure is visible either
2553 by using the new command `info w32 thread-information-block' or, by
2554 dereferencing the new convenience variable named `$_tlb', a
2555 thread-specific pointer to the TIB. This feature is also supported
2556 when remote debugging using GDBserver.
2558 * Static tracepoints
2560 Static tracepoints are calls in the user program into a tracing
2561 library. One such library is a port of the LTTng kernel tracer to
2562 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2563 When debugging with GDBserver, GDB now supports combining the GDB
2564 tracepoint machinery with such libraries. For example: the user can
2565 use GDB to probe a static tracepoint marker (a call from the user
2566 program into the tracing library) with the new "strace" command (see
2567 "New commands" below). This creates a "static tracepoint" in the
2568 breakpoint list, that can be manipulated with the same feature set
2569 as fast and regular tracepoints. E.g., collect registers, local and
2570 global variables, collect trace state variables, and define
2571 tracepoint conditions. In addition, the user can collect extra
2572 static tracepoint marker specific data, by collecting the new
2573 $_sdata internal variable. When analyzing the trace buffer, you can
2574 inspect $_sdata like any other variable available to GDB. For more
2575 information, see the "Tracepoints" chapter in GDB user manual. New
2576 remote packets have been defined to support static tracepoints, see
2577 the "New remote packets" section below.
2579 * Better reconstruction of tracepoints after disconnected tracing
2581 GDB will attempt to download the original source form of tracepoint
2582 definitions when starting a trace run, and then will upload these
2583 upon reconnection to the target, resulting in a more accurate
2584 reconstruction of the tracepoints that are in use on the target.
2588 You can now exercise direct control over the ways that GDB can
2589 affect your program. For instance, you can disallow the setting of
2590 breakpoints, so that the program can run continuously (assuming
2591 non-stop mode). In addition, the "observer" variable is available
2592 to switch all of the different controls; in observer mode, GDB
2593 cannot affect the target's behavior at all, which is useful for
2594 tasks like diagnosing live systems in the field.
2596 * The new convenience variable $_thread holds the number of the
2599 * New remote packets
2603 Return the address of the Windows Thread Information Block of a given thread.
2607 In response to several of the tracepoint packets, the target may now
2608 also respond with a number of intermediate `qRelocInsn' request
2609 packets before the final result packet, to have GDB handle
2610 relocating an instruction to execute at a different address. This
2611 is particularly useful for stubs that support fast tracepoints. GDB
2612 reports support for this feature in the qSupported packet.
2616 List static tracepoint markers in the target program.
2620 List static tracepoint markers at a given address in the target
2623 qXfer:statictrace:read
2625 Read the static trace data collected (by a `collect $_sdata'
2626 tracepoint action). The remote stub reports support for this packet
2627 to gdb's qSupported query.
2631 Send the current settings of GDB's permission flags.
2635 Send part of the source (textual) form of a tracepoint definition,
2636 which includes location, conditional, and action list.
2638 * The source command now accepts a -s option to force searching for the
2639 script in the source search path even if the script name specifies
2642 * New features in the GDB remote stub, GDBserver
2644 - GDBserver now support tracepoints (including fast tracepoints, and
2645 static tracepoints). The feature is currently supported by the
2646 i386-linux and amd64-linux builds. See the "Tracepoints support
2647 in gdbserver" section in the manual for more information.
2649 GDBserver JIT compiles the tracepoint's conditional agent
2650 expression bytecode into native code whenever possible for low
2651 overhead dynamic tracepoints conditionals. For such tracepoints,
2652 an expression that examines program state is evaluated when the
2653 tracepoint is reached, in order to determine whether to capture
2654 trace data. If the condition is simple and false, processing the
2655 tracepoint finishes very quickly and no data is gathered.
2657 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2658 for static tracepoints support.
2660 - GDBserver now supports x86_64 Windows 64-bit debugging.
2662 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2663 it understands register description.
2665 * The --batch flag now disables pagination and queries.
2667 * X86 general purpose registers
2669 GDB now supports reading/writing byte, word and double-word x86
2670 general purpose registers directly. This means you can use, say,
2671 $ah or $ax to refer, respectively, to the byte register AH and
2672 16-bit word register AX that are actually portions of the 32-bit
2673 register EAX or 64-bit register RAX.
2675 * The `commands' command now accepts a range of breakpoints to modify.
2676 A plain `commands' following a command that creates multiple
2677 breakpoints affects all the breakpoints set by that command. This
2678 applies to breakpoints set by `rbreak', and also applies when a
2679 single `break' command creates multiple breakpoints (e.g.,
2680 breakpoints on overloaded c++ functions).
2682 * The `rbreak' command now accepts a filename specification as part of
2683 its argument, limiting the functions selected by the regex to those
2684 in the specified file.
2686 * Support for remote debugging Windows and SymbianOS shared libraries
2687 from Unix hosts has been improved. Non Windows GDB builds now can
2688 understand target reported file names that follow MS-DOS based file
2689 system semantics, such as file names that include drive letters and
2690 use the backslash character as directory separator. This makes it
2691 possible to transparently use the "set sysroot" and "set
2692 solib-search-path" on Unix hosts to point as host copies of the
2693 target's shared libraries. See the new command "set
2694 target-file-system-kind" described below, and the "Commands to
2695 specify files" section in the user manual for more information.
2699 eval template, expressions...
2700 Convert the values of one or more expressions under the control
2701 of the string template to a command line, and call it.
2703 set target-file-system-kind unix|dos-based|auto
2704 show target-file-system-kind
2705 Set or show the assumed file system kind for target reported file
2708 save breakpoints <filename>
2709 Save all current breakpoint definitions to a file suitable for use
2710 in a later debugging session. To read the saved breakpoint
2711 definitions, use the `source' command.
2713 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2716 info static-tracepoint-markers
2717 Display information about static tracepoint markers in the target.
2719 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2720 Define a static tracepoint by probing a marker at the given
2721 function, line, address, or marker ID.
2725 Enable and disable observer mode.
2727 set may-write-registers on|off
2728 set may-write-memory on|off
2729 set may-insert-breakpoints on|off
2730 set may-insert-tracepoints on|off
2731 set may-insert-fast-tracepoints on|off
2732 set may-interrupt on|off
2733 Set individual permissions for GDB effects on the target. Note that
2734 some of these settings can have undesirable or surprising
2735 consequences, particularly when changed in the middle of a session.
2736 For instance, disabling the writing of memory can prevent
2737 breakpoints from being inserted, cause single-stepping to fail, or
2738 even crash your program, if you disable after breakpoints have been
2739 inserted. However, GDB should not crash.
2741 set record memory-query on|off
2742 show record memory-query
2743 Control whether to stop the inferior if memory changes caused
2744 by an instruction cannot be recorded.
2749 The disassemble command now supports "start,+length" form of two arguments.
2753 ** GDB now provides a new directory location, called the python directory,
2754 where Python scripts written for GDB can be installed. The location
2755 of that directory is <data-directory>/python, where <data-directory>
2756 is the GDB data directory. For more details, see section `Scripting
2757 GDB using Python' in the manual.
2759 ** The GDB Python API now has access to breakpoints, symbols, symbol
2760 tables, program spaces, inferiors, threads and frame's code blocks.
2761 Additionally, GDB Parameters can now be created from the API, and
2762 manipulated via set/show in the CLI.
2764 ** New functions gdb.target_charset, gdb.target_wide_charset,
2765 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2767 ** New exception gdb.GdbError.
2769 ** Pretty-printers are now also looked up in the current program space.
2771 ** Pretty-printers can now be individually enabled and disabled.
2773 ** GDB now looks for names of Python scripts to auto-load in a
2774 special section named `.debug_gdb_scripts', in addition to looking
2775 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2777 * Tracepoint actions were unified with breakpoint commands. In particular,
2778 there are no longer differences in "info break" output for breakpoints and
2779 tracepoints and the "commands" command can be used for both tracepoints and
2780 regular breakpoints.
2784 ARM Symbian arm*-*-symbianelf*
2786 * D language support.
2787 GDB now supports debugging programs written in the D programming
2790 * GDB now supports the extended ptrace interface for PowerPC which is
2791 available since Linux kernel version 2.6.34. This automatically enables
2792 any hardware breakpoints and additional hardware watchpoints available in
2793 the processor. The old ptrace interface exposes just one hardware
2794 watchpoint and no hardware breakpoints.
2796 * GDB is now able to use the Data Value Compare (DVC) register available on
2797 embedded PowerPC processors to implement in hardware simple watchpoint
2798 conditions of the form:
2800 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2802 This works in native GDB running on Linux kernels with the extended ptrace
2803 interface mentioned above.
2805 *** Changes in GDB 7.1
2809 ** Namespace Support
2811 GDB now supports importing of namespaces in C++. This enables the
2812 user to inspect variables from imported namespaces. Support for
2813 namepace aliasing has also been added. So, if a namespace is
2814 aliased in the current scope (e.g. namepace C=A; ) the user can
2815 print variables using the alias (e.g. (gdb) print C::x).
2819 All known bugs relating to the printing of virtual base class were
2820 fixed. It is now possible to call overloaded static methods using a
2825 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2826 and reinterpret_cast<> are now handled by the C++ expression parser.
2830 Xilinx MicroBlaze microblaze-*-*
2835 Xilinx MicroBlaze microblaze
2838 * Multi-program debugging.
2840 GDB now has support for multi-program (a.k.a. multi-executable or
2841 multi-exec) debugging. This allows for debugging multiple inferiors
2842 simultaneously each running a different program under the same GDB
2843 session. See "Debugging Multiple Inferiors and Programs" in the
2844 manual for more information. This implied some user visible changes
2845 in the multi-inferior support. For example, "info inferiors" now
2846 lists inferiors that are not running yet or that have exited
2847 already. See also "New commands" and "New options" below.
2849 * New tracing features
2851 GDB's tracepoint facility now includes several new features:
2853 ** Trace state variables
2855 GDB tracepoints now include support for trace state variables, which
2856 are variables managed by the target agent during a tracing
2857 experiment. They are useful for tracepoints that trigger each
2858 other, so for instance one tracepoint can count hits in a variable,
2859 and then a second tracepoint has a condition that is true when the
2860 count reaches a particular value. Trace state variables share the
2861 $-syntax of GDB convenience variables, and can appear in both
2862 tracepoint actions and condition expressions. Use the "tvariable"
2863 command to create, and "info tvariables" to view; see "Trace State
2864 Variables" in the manual for more detail.
2868 GDB now includes an option for defining fast tracepoints, which
2869 targets may implement more efficiently, such as by installing a jump
2870 into the target agent rather than a trap instruction. The resulting
2871 speedup can be by two orders of magnitude or more, although the
2872 tradeoff is that some program locations on some target architectures
2873 might not allow fast tracepoint installation, for instance if the
2874 instruction to be replaced is shorter than the jump. To request a
2875 fast tracepoint, use the "ftrace" command, with syntax identical to
2876 the regular trace command.
2878 ** Disconnected tracing
2880 It is now possible to detach GDB from the target while it is running
2881 a trace experiment, then reconnect later to see how the experiment
2882 is going. In addition, a new variable disconnected-tracing lets you
2883 tell the target agent whether to continue running a trace if the
2884 connection is lost unexpectedly.
2888 GDB now has the ability to save the trace buffer into a file, and
2889 then use that file as a target, similarly to you can do with
2890 corefiles. You can select trace frames, print data that was
2891 collected in them, and use tstatus to display the state of the
2892 tracing run at the moment that it was saved. To create a trace
2893 file, use "tsave <filename>", and to use it, do "target tfile
2896 ** Circular trace buffer
2898 You can ask the target agent to handle the trace buffer as a
2899 circular buffer, discarding the oldest trace frames to make room for
2900 newer ones, by setting circular-trace-buffer to on. This feature may
2901 not be available for all target agents.
2906 The disassemble command, when invoked with two arguments, now requires
2907 the arguments to be comma-separated.
2910 The info variables command now displays variable definitions. Files
2911 which only declare a variable are not shown.
2914 The source command is now capable of sourcing Python scripts.
2915 This feature is dependent on the debugger being build with Python
2918 Related to this enhancement is also the introduction of a new command
2919 "set script-extension" (see below).
2921 * New commands (for set/show, see "New options" below)
2923 record save [<FILENAME>]
2924 Save a file (in core file format) containing the process record
2925 execution log for replay debugging at a later time.
2927 record restore <FILENAME>
2928 Restore the process record execution log that was saved at an
2929 earlier time, for replay debugging.
2931 add-inferior [-copies <N>] [-exec <FILENAME>]
2934 clone-inferior [-copies <N>] [ID]
2935 Make a new inferior ready to execute the same program another
2936 inferior has loaded.
2941 maint info program-spaces
2942 List the program spaces loaded into GDB.
2944 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2945 show remote interrupt-sequence
2946 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2947 as the sequence to the remote target in order to interrupt the execution.
2948 Ctrl-C is a default. Some system prefers BREAK which is high level of
2949 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2950 Magic SysRq g. It is BREAK signal and character 'g'.
2952 set remote interrupt-on-connect [on | off]
2953 show remote interrupt-on-connect
2954 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2955 remote target when gdb connects to it. This is needed when you debug
2958 set remotebreak [on | off]
2960 Deprecated. Use "set/show remote interrupt-sequence" instead.
2962 tvariable $NAME [ = EXP ]
2963 Create or modify a trace state variable.
2966 List trace state variables and their values.
2968 delete tvariable $NAME ...
2969 Delete one or more trace state variables.
2972 Evaluate the given expressions without collecting anything into the
2973 trace buffer. (Valid in tracepoint actions only.)
2975 ftrace FN / FILE:LINE / *ADDR
2976 Define a fast tracepoint at the given function, line, or address.
2978 * New expression syntax
2980 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2981 GDB now parses 0b101010 identically with 42.
2985 set follow-exec-mode new|same
2986 show follow-exec-mode
2987 Control whether GDB reuses the same inferior across an exec call or
2988 creates a new one. This is useful to be able to restart the old
2989 executable after the inferior having done an exec call.
2991 set default-collect EXPR, ...
2992 show default-collect
2993 Define a list of expressions to be collected at each tracepoint.
2994 This is a useful way to ensure essential items are not overlooked,
2995 such as registers or a critical global variable.
2997 set disconnected-tracing
2998 show disconnected-tracing
2999 If set to 1, the target is instructed to continue tracing if it
3000 loses its connection to GDB. If 0, the target is to stop tracing
3003 set circular-trace-buffer
3004 show circular-trace-buffer
3005 If set to on, the target is instructed to use a circular trace buffer
3006 and discard the oldest trace frames instead of stopping the trace due
3007 to a full trace buffer. If set to off, the trace stops when the buffer
3008 fills up. Some targets may not support this.
3010 set script-extension off|soft|strict
3011 show script-extension
3012 If set to "off", the debugger does not perform any script language
3013 recognition, and all sourced files are assumed to be GDB scripts.
3014 If set to "soft" (the default), files are sourced according to
3015 filename extension, falling back to GDB scripts if the first
3017 If set to "strict", files are sourced according to filename extension.
3019 set ada trust-PAD-over-XVS on|off
3020 show ada trust-PAD-over-XVS
3021 If off, activate a workaround against a bug in the debugging information
3022 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3023 the GCC sources for more information about the GNAT encoding and
3024 PAD types in particular). It is always safe to set this option to
3025 off, but this introduces a slight performance penalty. The default
3028 * Python API Improvements
3030 ** GDB provides the new class gdb.LazyString. This is useful in
3031 some pretty-printing cases. The new method gdb.Value.lazy_string
3032 provides a simple way to create objects of this type.
3034 ** The fields returned by gdb.Type.fields now have an
3035 `is_base_class' attribute.
3037 ** The new method gdb.Type.range returns the range of an array type.
3039 ** The new method gdb.parse_and_eval can be used to parse and
3040 evaluate an expression.
3042 * New remote packets
3045 Define a trace state variable.
3048 Get the current value of a trace state variable.
3051 Set desired tracing behavior upon disconnection.
3054 Set the trace buffer to be linear or circular.
3057 Get data about the tracepoints currently in use.
3061 Process record now works correctly with hardware watchpoints.
3063 Multiple bug fixes have been made to the mips-irix port, making it
3064 much more reliable. In particular:
3065 - Debugging threaded applications is now possible again. Previously,
3066 GDB would hang while starting the program, or while waiting for
3067 the program to stop at a breakpoint.
3068 - Attaching to a running process no longer hangs.
3069 - An error occurring while loading a core file has been fixed.
3070 - Changing the value of the PC register now works again. This fixes
3071 problems observed when using the "jump" command, or when calling
3072 a function from GDB, or even when assigning a new value to $pc.
3073 - With the "finish" and "return" commands, the return value for functions
3074 returning a small array is now correctly printed.
3075 - It is now possible to break on shared library code which gets executed
3076 during a shared library init phase (code executed while executing
3077 their .init section). Previously, the breakpoint would have no effect.
3078 - GDB is now able to backtrace through the signal handler for
3079 non-threaded programs.
3081 PIE (Position Independent Executable) programs debugging is now supported.
3082 This includes debugging execution of PIC (Position Independent Code) shared
3083 libraries although for that, it should be possible to run such libraries as an
3086 *** Changes in GDB 7.0
3088 * GDB now has an interface for JIT compilation. Applications that
3089 dynamically generate code can create symbol files in memory and register
3090 them with GDB. For users, the feature should work transparently, and
3091 for JIT developers, the interface is documented in the GDB manual in the
3092 "JIT Compilation Interface" chapter.
3094 * Tracepoints may now be conditional. The syntax is as for
3095 breakpoints; either an "if" clause appended to the "trace" command,
3096 or the "condition" command is available. GDB sends the condition to
3097 the target for evaluation using the same bytecode format as is used
3098 for tracepoint actions.
3100 * The disassemble command now supports: an optional /r modifier, print the
3101 raw instructions in hex as well as in symbolic form, and an optional /m
3102 modifier to print mixed source+assembly.
3104 * Process record and replay
3106 In a architecture environment that supports ``process record and
3107 replay'', ``process record and replay'' target can record a log of
3108 the process execution, and replay it with both forward and reverse
3111 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3112 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3113 set execution-direction {forward|reverse}, for targets that support
3116 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3117 feature is available with a native GDB running on kernel version
3120 * GDB now has support for multi-byte and wide character sets on the
3121 target. Strings whose character type is wchar_t, char16_t, or
3122 char32_t are now correctly printed. GDB supports wide- and unicode-
3123 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3124 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3125 `printf'. This feature requires iconv to work properly; if your
3126 system does not have a working iconv, GDB can use GNU libiconv. See
3127 the installation instructions for more information.
3129 * GDB now supports automatic retrieval of shared library files from
3130 remote targets. To use this feature, specify a system root that begins
3131 with the `remote:' prefix, either via the `set sysroot' command or via
3132 the `--with-sysroot' configure-time option.
3134 * "info sharedlibrary" now takes an optional regex of libraries to show,
3135 and it now reports if a shared library has no debugging information.
3137 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3138 now complete on file names.
3140 * When completing in expressions, gdb will attempt to limit
3141 completions to allowable structure or union fields, where appropriate.
3142 For instance, consider:
3144 # struct example { int f1; double f2; };
3145 # struct example variable;
3148 If the user types TAB at the end of this command line, the available
3149 completions will be "f1" and "f2".
3151 * Inlined functions are now supported. They show up in backtraces, and
3152 the "step", "next", and "finish" commands handle them automatically.
3154 * GDB now supports the token-splicing (##) and stringification (#)
3155 operators when expanding macros. It also supports variable-arity
3158 * GDB now supports inspecting extra signal information, exported by
3159 the new $_siginfo convenience variable. The feature is currently
3160 implemented on linux ARM, i386 and amd64.
3162 * GDB can now display the VFP floating point registers and NEON vector
3163 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3164 can provide these registers (requires Linux 2.6.30 or later). Remote
3165 and simulator targets may also provide them.
3167 * New remote packets
3170 Search memory for a sequence of bytes.
3173 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3174 operation over reliable transport links. Use of this packet is
3175 controlled by the `set remote noack-packet' command.
3178 Kill the process with the specified process ID. Use this in preference
3179 to `k' when multiprocess protocol extensions are supported.
3182 Obtains additional operating system information
3186 Read or write additional signal information.
3188 * Removed remote protocol undocumented extension
3190 An undocumented extension to the remote protocol's `S' stop reply
3191 packet that permited the stub to pass a process id was removed.
3192 Remote servers should use the `T' stop reply packet instead.
3194 * GDB now supports multiple function calling conventions according to the
3195 DWARF-2 DW_AT_calling_convention function attribute.
3197 * The SH target utilizes the aforementioned change to distinguish between gcc
3198 and Renesas calling convention. It also adds the new CLI commands
3199 `set/show sh calling-convention'.
3201 * GDB can now read compressed debug sections, as produced by GNU gold
3202 with the --compress-debug-sections=zlib flag.
3204 * 64-bit core files are now supported on AIX.
3206 * Thread switching is now supported on Tru64.
3208 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3209 which will be allocated using malloc later in program execution.
3211 * The qXfer:libraries:read remote procotol packet now allows passing a
3212 list of section offsets.
3214 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3215 conditions handling signals delivered during attach or thread creation
3216 have also been fixed.
3218 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3219 From the user's standpoint, all unqualified instances of True and False
3220 are treated as the standard definitions, regardless of context.
3222 * GDB now parses C++ symbol and type names more flexibly. For
3225 template<typename T> class C { };
3228 GDB will now correctly handle all of:
3230 ptype C<char const *>
3231 ptype C<char const*>
3232 ptype C<const char *>
3233 ptype C<const char*>
3235 * New features in the GDB remote stub, gdbserver
3237 - The "--wrapper" command-line argument tells gdbserver to use a
3238 wrapper program to launch programs for debugging.
3240 - On PowerPC and S/390 targets, it is now possible to use a single
3241 gdbserver executable to debug both 32-bit and 64-bit programs.
3242 (This requires gdbserver itself to be built as a 64-bit executable.)
3244 - gdbserver uses the new noack protocol mode for TCP connections to
3245 reduce communications latency, if also supported and enabled in GDB.
3247 - Support for the sparc64-linux-gnu target is now included in
3250 - The amd64-linux build of gdbserver now supports debugging both
3251 32-bit and 64-bit programs.
3253 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3254 now support hardware watchpoints, and will use them automatically
3259 GDB now has support for scripting using Python. Whether this is
3260 available is determined at configure time.
3262 New GDB commands can now be written in Python.
3264 * Ada tasking support
3266 Ada tasks can now be inspected in GDB. The following commands have
3270 Print the list of Ada tasks.
3272 Print detailed information about task number N.
3274 Print the task number of the current task.
3276 Switch the context of debugging to task number N.
3278 * Support for user-defined prefixed commands. The "define" command can
3279 add new commands to existing prefixes, e.g. "target".
3281 * Multi-inferior, multi-process debugging.
3283 GDB now has generalized support for multi-inferior debugging. See
3284 "Debugging Multiple Inferiors" in the manual for more information.
3285 Although availability still depends on target support, the command
3286 set is more uniform now. The GNU/Linux specific multi-forks support
3287 has been migrated to this new framework. This implied some user
3288 visible changes; see "New commands" and also "Removed commands"
3291 * Target descriptions can now describe the target OS ABI. See the
3292 "Target Description Format" section in the user manual for more
3295 * Target descriptions can now describe "compatible" architectures
3296 to indicate that the target can execute applications for a different
3297 architecture in addition to those for the main target architecture.
3298 See the "Target Description Format" section in the user manual for
3301 * Multi-architecture debugging.
3303 GDB now includes general supports for debugging applications on
3304 hybrid systems that use more than one single processor architecture
3305 at the same time. Each such hybrid architecture still requires
3306 specific support to be added. The only hybrid architecture supported
3307 in this version of GDB is the Cell Broadband Engine.
3309 * GDB now supports integrated debugging of Cell/B.E. applications that
3310 use both the PPU and SPU architectures. To enable support for hybrid
3311 Cell/B.E. debugging, you need to configure GDB to support both the
3312 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3313 --enable-targets configure option.
3315 * Non-stop mode debugging.
3317 For some targets, GDB now supports an optional mode of operation in
3318 which you can examine stopped threads while other threads continue
3319 to execute freely. This is referred to as non-stop mode, with the
3320 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3321 section in the user manual for more information.
3323 To be able to support remote non-stop debugging, a remote stub needs
3324 to implement the non-stop mode remote protocol extensions, as
3325 described in the "Remote Non-Stop" section of the user manual. The
3326 GDB remote stub, gdbserver, has been adjusted to support these
3327 extensions on linux targets.
3329 * New commands (for set/show, see "New options" below)
3331 catch syscall [NAME(S) | NUMBER(S)]
3332 Catch system calls. Arguments, which should be names of system
3333 calls or their numbers, mean catch only those syscalls. Without
3334 arguments, every syscall will be caught. When the inferior issues
3335 any of the specified syscalls, GDB will stop and announce the system
3336 call, both when it is called and when its call returns. This
3337 feature is currently available with a native GDB running on the
3338 Linux Kernel, under the following architectures: x86, x86_64,
3339 PowerPC and PowerPC64.
3341 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3343 Search memory for a sequence of bytes.
3345 maint set python print-stack
3346 maint show python print-stack
3347 Show a stack trace when an error is encountered in a Python script.
3350 Invoke CODE by passing it to the Python interpreter.
3355 These allow macros to be defined, undefined, and listed
3359 Show operating system information about processes.
3362 List the inferiors currently under GDB's control.
3365 Switch focus to inferior number NUM.
3368 Detach from inferior number NUM.
3371 Kill inferior number NUM.
3375 set spu stop-on-load
3376 show spu stop-on-load
3377 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3379 set spu auto-flush-cache
3380 show spu auto-flush-cache
3381 Control whether to automatically flush the software-managed cache
3382 during Cell/B.E. debugging.
3384 set sh calling-convention
3385 show sh calling-convention
3386 Control the calling convention used when calling SH target functions.
3389 show debug timestamp
3390 Control display of timestamps with GDB debugging output.
3392 set disassemble-next-line
3393 show disassemble-next-line
3394 Control display of disassembled source lines or instructions when
3397 set remote noack-packet
3398 show remote noack-packet
3399 Set/show the use of remote protocol QStartNoAckMode packet. See above
3400 under "New remote packets."
3402 set remote query-attached-packet
3403 show remote query-attached-packet
3404 Control use of remote protocol `qAttached' (query-attached) packet.
3406 set remote read-siginfo-object
3407 show remote read-siginfo-object
3408 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3411 set remote write-siginfo-object
3412 show remote write-siginfo-object
3413 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3416 set remote reverse-continue
3417 show remote reverse-continue
3418 Control use of remote protocol 'bc' (reverse-continue) packet.
3420 set remote reverse-step
3421 show remote reverse-step
3422 Control use of remote protocol 'bs' (reverse-step) packet.
3424 set displaced-stepping
3425 show displaced-stepping
3426 Control displaced stepping mode. Displaced stepping is a way to
3427 single-step over breakpoints without removing them from the debuggee.
3428 Also known as "out-of-line single-stepping".
3431 show debug displaced
3432 Control display of debugging info for displaced stepping.
3434 maint set internal-error
3435 maint show internal-error
3436 Control what GDB does when an internal error is detected.
3438 maint set internal-warning
3439 maint show internal-warning
3440 Control what GDB does when an internal warning is detected.
3445 Use a wrapper program to launch programs for debugging.
3447 set multiple-symbols (all|ask|cancel)
3448 show multiple-symbols
3449 The value of this variable can be changed to adjust the debugger behavior
3450 when an expression or a breakpoint location contains an ambiguous symbol
3451 name (an overloaded function name, for instance).
3453 set breakpoint always-inserted
3454 show breakpoint always-inserted
3455 Keep breakpoints always inserted in the target, as opposed to inserting
3456 them when resuming the target, and removing them when the target stops.
3457 This option can improve debugger performance on slow remote targets.
3459 set arm fallback-mode (arm|thumb|auto)
3460 show arm fallback-mode
3461 set arm force-mode (arm|thumb|auto)
3463 These commands control how ARM GDB determines whether instructions
3464 are ARM or Thumb. The default for both settings is auto, which uses
3465 the current CPSR value for instructions without symbols; previous
3466 versions of GDB behaved as if "set arm fallback-mode arm".
3468 set disable-randomization
3469 show disable-randomization
3470 Standalone programs run with the virtual address space randomization enabled
3471 by default on some platforms. This option keeps the addresses stable across
3472 multiple debugging sessions.
3476 Control whether other threads are stopped or not when some thread hits
3481 Requests that asynchronous execution is enabled in the target, if available.
3482 In this case, it's possible to resume target in the background, and interact
3483 with GDB while the target is running. "show target-async" displays the
3484 current state of asynchronous execution of the target.
3486 set target-wide-charset
3487 show target-wide-charset
3488 The target-wide-charset is the name of the character set that GDB
3489 uses when printing characters whose type is wchar_t.
3491 set tcp auto-retry (on|off)
3493 set tcp connect-timeout
3494 show tcp connect-timeout
3495 These commands allow GDB to retry failed TCP connections to a remote stub
3496 with a specified timeout period; this is useful if the stub is launched
3497 in parallel with GDB but may not be ready to accept connections immediately.
3499 set libthread-db-search-path
3500 show libthread-db-search-path
3501 Control list of directories which GDB will search for appropriate
3504 set schedule-multiple (on|off)
3505 show schedule-multiple
3506 Allow GDB to resume all threads of all processes or only threads of
3507 the current process.
3511 Use more aggressive caching for accesses to the stack. This improves
3512 performance of remote debugging (particularly backtraces) without
3513 affecting correctness.
3515 set interactive-mode (on|off|auto)
3516 show interactive-mode
3517 Control whether GDB runs in interactive mode (on) or not (off).
3518 When in interactive mode, GDB waits for the user to answer all
3519 queries. Otherwise, GDB does not wait and assumes the default
3520 answer. When set to auto (the default), GDB determines which
3521 mode to use based on the stdin settings.
3526 For program forks, this is replaced by the new more generic `info
3527 inferiors' command. To list checkpoints, you can still use the
3528 `info checkpoints' command, which was an alias for the `info forks'
3532 Replaced by the new `inferior' command. To switch between
3533 checkpoints, you can still use the `restart' command, which was an
3534 alias for the `fork' command.
3537 This is removed, since some targets don't have a notion of
3538 processes. To switch between processes, you can still use the
3539 `inferior' command using GDB's own inferior number.
3542 For program forks, this is replaced by the new more generic `kill
3543 inferior' command. To delete a checkpoint, you can still use the
3544 `delete checkpoint' command, which was an alias for the `delete
3548 For program forks, this is replaced by the new more generic `detach
3549 inferior' command. To detach a checkpoint, you can still use the
3550 `detach checkpoint' command, which was an alias for the `detach
3553 * New native configurations
3555 x86/x86_64 Darwin i[34567]86-*-darwin*
3557 x86_64 MinGW x86_64-*-mingw*
3561 Lattice Mico32 lm32-*
3562 x86 DICOS i[34567]86-*-dicos*
3563 x86_64 DICOS x86_64-*-dicos*
3566 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3567 (mingw32ce) debugging.
3573 These commands were actually not implemented on any target.
3575 *** Changes in GDB 6.8
3577 * New native configurations
3579 NetBSD/hppa hppa*-*netbsd*
3580 Xtensa GNU/Linux xtensa*-*-linux*
3584 NetBSD/hppa hppa*-*-netbsd*
3585 Xtensa GNU/Lunux xtensa*-*-linux*
3587 * Change in command line behavior -- corefiles vs. process ids.
3589 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3590 attaching to process NUMBER fails, GDB no longer attempts to open a
3591 core file named NUMBER. Attaching to a program using the -c option
3592 is no longer supported. Instead, use the '-p' or '--pid' options.
3594 * GDB can now be built as a native debugger for debugging Windows x86
3595 (mingw32) Portable Executable (PE) programs.
3597 * Pending breakpoints no longer change their number when their address
3600 * GDB now supports breakpoints with multiple locations,
3601 including breakpoints on C++ constructors, inside C++ templates,
3602 and in inlined functions.
3604 * GDB's ability to debug optimized code has been improved. GDB more
3605 accurately identifies function bodies and lexical blocks that occupy
3606 more than one contiguous range of addresses.
3608 * Target descriptions can now describe registers for PowerPC.
3610 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3611 registers on PowerPC targets.
3613 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3614 targets even when the libthread_db library is not available.
3616 * The GDB remote stub, gdbserver, now supports the new file transfer
3617 commands (remote put, remote get, and remote delete).
3619 * The GDB remote stub, gdbserver, now supports run and attach in
3620 extended-remote mode.
3622 * hppa*64*-*-hpux11* target broken
3623 The debugger is unable to start a program and fails with the following
3624 error: "Error trying to get information about dynamic linker".
3625 The gdb-6.7 release is also affected.
3627 * GDB now supports the --enable-targets= configure option to allow
3628 building a single GDB executable that supports multiple remote
3629 target architectures.
3631 * GDB now supports debugging C and C++ programs which use the
3632 Decimal Floating Point extension. In addition, the PowerPC target
3633 now has a set of pseudo-registers to inspect decimal float values
3634 stored in two consecutive float registers.
3636 * The -break-insert MI command can optionally create pending
3639 * Improved support for debugging Ada
3640 Many improvements to the Ada language support have been made. These
3642 - Better support for Ada2005 interface types
3643 - Improved handling of arrays and slices in general
3644 - Better support for Taft-amendment types
3645 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3647 - Improved command completion in Ada
3650 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3655 set print frame-arguments (all|scalars|none)
3656 show print frame-arguments
3657 The value of this variable can be changed to control which argument
3658 values should be printed by the debugger when displaying a frame.
3663 Transfer files to and from a remote target, and delete remote files.
3670 Transfer files to and from a remote target, and delete remote files.
3672 * New remote packets
3679 Open, close, read, write, and delete files on the remote system.
3682 Attach to an existing process on the remote system, in extended-remote
3686 Run a new process on the remote system, in extended-remote mode.
3688 *** Changes in GDB 6.7
3690 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3691 bfd, libiberty and opcodes, as revealed by static analysis donated by
3692 Coverity, Inc. (http://scan.coverity.com).
3694 * When looking up multiply-defined global symbols, GDB will now prefer the
3695 symbol definition in the current shared library if it was built using the
3696 -Bsymbolic linker option.
3698 * When the Text User Interface (TUI) is not configured, GDB will now
3699 recognize the -tui command-line option and print a message that the TUI
3702 * The GDB remote stub, gdbserver, now has lower overhead for high
3703 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3705 * GDB for MIPS targets now autodetects whether a remote target provides
3706 32-bit or 64-bit register values.
3708 * Support for C++ member pointers has been improved.
3710 * GDB now understands XML target descriptions, which specify the
3711 target's overall architecture. GDB can read a description from
3712 a local file or over the remote serial protocol.
3714 * Vectors of single-byte data use a new integer type which is not
3715 automatically displayed as character or string data.
3717 * The /s format now works with the print command. It displays
3718 arrays of single-byte integers and pointers to single-byte integers
3721 * Target descriptions can now describe target-specific registers,
3722 for architectures which have implemented the support (currently
3723 only ARM, M68K, and MIPS).
3725 * GDB and the GDB remote stub, gdbserver, now support the XScale
3728 * The GDB remote stub, gdbserver, has been updated to support
3729 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3730 has been rewritten to use the standard GDB remote protocol.
3732 * GDB can now step into C++ functions which are called through thunks.
3734 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3736 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3737 layout. It also supports a TextSeg= and DataSeg= response when only
3738 segment base addresses (rather than offsets) are available.
3740 * The /i format now outputs any trailing branch delay slot instructions
3741 immediately following the last instruction within the count specified.
3743 * The GDB remote protocol "T" stop reply packet now supports a
3744 "library" response. Combined with the new "qXfer:libraries:read"
3745 packet, this response allows GDB to debug shared libraries on targets
3746 where the operating system manages the list of loaded libraries (e.g.
3747 Windows and SymbianOS).
3749 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3750 (DLLs) on Windows and Windows CE targets.
3752 * GDB now supports a faster verification that a .debug file matches its binary
3753 according to its build-id signature, if the signature is present.
3759 Enable or disable hardware flow control (RTS/CTS) on the serial port
3760 when debugging using remote targets.
3762 set mem inaccessible-by-default
3763 show mem inaccessible-by-default
3764 If the target supplies a memory map, for instance via the remote
3765 protocol's "qXfer:memory-map:read" packet, setting this variable
3766 prevents GDB from accessing memory outside the memory map. This
3767 is useful for targets with memory mapped registers or which react
3768 badly to accesses of unmapped address space.
3770 set breakpoint auto-hw
3771 show breakpoint auto-hw
3772 If the target supplies a memory map, for instance via the remote
3773 protocol's "qXfer:memory-map:read" packet, setting this variable
3774 lets GDB use hardware breakpoints automatically for memory regions
3775 where it can not use software breakpoints. This covers both the
3776 "break" command and internal breakpoints used for other commands
3777 including "next" and "finish".
3780 catch exception unhandled
3781 Stop the program execution when Ada exceptions are raised.
3784 Stop the program execution when an Ada assertion failed.
3788 Set an alternate system root for target files. This is a more
3789 general version of "set solib-absolute-prefix", which is now
3790 an alias to "set sysroot".
3793 Provide extended SPU facility status information. This set of
3794 commands is available only when debugging the Cell/B.E. SPU
3797 * New native configurations
3799 OpenBSD/sh sh*-*openbsd*
3802 unset tdesc filename
3804 Use the specified local file as an XML target description, and do
3805 not query the target for its built-in description.
3809 OpenBSD/sh sh*-*-openbsd*
3810 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3811 Toshiba Media Processor mep-elf
3813 * New remote packets
3816 Ignore the specified signals; pass them directly to the debugged program
3817 without stopping other threads or reporting them to GDB.
3819 qXfer:features:read:
3820 Read an XML target description from the target, which describes its
3825 Read or write contents of an spufs file on the target system. These
3826 packets are available only on the Cell/B.E. SPU architecture.
3828 qXfer:libraries:read:
3829 Report the loaded shared libraries. Combined with new "T" packet
3830 response, this packet allows GDB to debug shared libraries on
3831 targets where the operating system manages the list of loaded
3832 libraries (e.g. Windows and SymbianOS).
3836 Support for these obsolete configurations has been removed.
3844 i[34567]86-*-lynxos*
3845 i[34567]86-*-netware*
3846 i[34567]86-*-sco3.2v5*
3847 i[34567]86-*-sco3.2v4*
3849 i[34567]86-*-sysv4.2*
3852 i[34567]86-*-unixware2*
3853 i[34567]86-*-unixware*
3862 * Other removed features
3869 Various m68k-only ROM monitors.
3876 Various Renesas ROM monitors and debugging interfaces for SH and
3881 Support for a Macraigor serial interface to on-chip debugging.
3882 GDB does not directly support the newer parallel or USB
3887 A debug information format. The predecessor to DWARF 2 and
3888 DWARF 3, which are still supported.
3890 Support for the HP aCC compiler on HP-UX/PA-RISC
3892 SOM-encapsulated symbolic debugging information, automatic
3893 invocation of pxdb, and the aCC custom C++ ABI. This does not
3894 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3895 with aCC can still be debugged on an assembly level.
3897 MIPS ".pdr" sections
3899 A MIPS-specific format used to describe stack frame layout
3900 in debugging information.
3904 GDB could work with an older version of Guile to debug
3905 the interpreter and Scheme programs running in it.
3907 set mips stack-arg-size
3908 set mips saved-gpreg-size
3910 Use "set mips abi" to control parameter passing for MIPS.
3912 *** Changes in GDB 6.6
3917 Cell Broadband Engine SPU spu-elf
3919 * GDB can now be configured as a cross-debugger targeting native Windows
3920 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3921 running on a Windows system over TCP/IP to debug Windows programs.
3923 * The GDB remote stub, gdbserver, has been updated to support Windows and
3924 Cygwin debugging. Both single-threaded and multi-threaded programs are
3927 * The "set trust-readonly-sections" command works again. This command was
3928 broken in GDB 6.3, 6.4, and 6.5.
3930 * The "load" command now supports writing to flash memory, if the remote
3931 stub provides the required support.
3933 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3934 longer requires symbolic debug information (e.g. DWARF-2).
3939 unset substitute-path
3940 show substitute-path
3941 Manage a list of substitution rules that GDB uses to rewrite the name
3942 of the directories where the sources are located. This can be useful
3943 for instance when the sources were moved to a different location
3944 between compilation and debugging.
3948 Print each CLI command as it is executed. Each command is prefixed with
3949 a number of `+' symbols representing the nesting depth.
3950 The source command now has a `-v' option to enable the same feature.
3954 The ARM Demon monitor support (RDP protocol, "target rdp").
3956 Kernel Object Display, an embedded debugging feature which only worked with
3957 an obsolete version of Cisco IOS.
3959 The 'set download-write-size' and 'show download-write-size' commands.
3961 * New remote packets
3964 Tell a stub about GDB client features, and request remote target features.
3965 The first feature implemented is PacketSize, which allows the target to
3966 specify the size of packets it can handle - to minimize the number of
3967 packets required and improve performance when connected to a remote
3971 Fetch an OS auxilliary vector from the remote stub. This packet is a
3972 more efficient replacement for qPart:auxv:read.
3974 qXfer:memory-map:read:
3975 Fetch a memory map from the remote stub, including information about
3976 RAM, ROM, and flash memory devices.
3981 Erase and program a flash memory device.
3983 * Removed remote packets
3986 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3987 used it, and only gdbserver implemented it.
3989 *** Changes in GDB 6.5
3993 Renesas M32C/M16C m32c-elf
3995 Morpho Technologies ms1 ms1-elf
3999 init-if-undefined Initialize a convenience variable, but
4000 only if it doesn't already have a value.
4002 The following commands are presently only implemented for native GNU/Linux:
4004 checkpoint Save a snapshot of the program state.
4006 restart <n> Return the program state to a
4007 previously saved state.
4009 info checkpoints List currently saved checkpoints.
4011 delete-checkpoint <n> Delete a previously saved checkpoint.
4013 set|show detach-on-fork Tell gdb whether to detach from a newly
4014 forked process, or to keep debugging it.
4016 info forks List forks of the user program that
4017 are available to be debugged.
4019 fork <n> Switch to debugging one of several
4020 forks of the user program that are
4021 available to be debugged.
4023 delete-fork <n> Delete a fork from the list of forks
4024 that are available to be debugged (and
4025 kill the forked process).
4027 detach-fork <n> Delete a fork from the list of forks
4028 that are available to be debugged (and
4029 allow the process to continue).
4033 Morpho Technologies ms2 ms1-elf
4035 * Improved Windows host support
4037 GDB now builds as a cross debugger hosted on i686-mingw32, including
4038 native console support, and remote communications using either
4039 network sockets or serial ports.
4041 * Improved Modula-2 language support
4043 GDB can now print most types in the Modula-2 syntax. This includes:
4044 basic types, set types, record types, enumerated types, range types,
4045 pointer types and ARRAY types. Procedure var parameters are correctly
4046 printed and hexadecimal addresses and character constants are also
4047 written in the Modula-2 syntax. Best results can be obtained by using
4048 GNU Modula-2 together with the -gdwarf-2 command line option.
4052 The ARM rdi-share module.
4054 The Netware NLM debug server.
4056 *** Changes in GDB 6.4
4058 * New native configurations
4060 OpenBSD/arm arm*-*-openbsd*
4061 OpenBSD/mips64 mips64-*-openbsd*
4065 Morpho Technologies ms1 ms1-elf
4067 * New command line options
4069 --batch-silent As for --batch, but totally silent.
4070 --return-child-result The debugger will exist with the same value
4071 the child (debugged) program exited with.
4072 --eval-command COMMAND, -ex COMMAND
4073 Execute a single GDB CLI command. This may be
4074 specified multiple times and in conjunction
4075 with the --command (-x) option.
4077 * Deprecated commands removed
4079 The following commands, that were deprecated in 2000, have been
4083 set|show arm disassembly-flavor set|show arm disassembler
4084 othernames set arm disassembler
4085 set|show remotedebug set|show debug remote
4086 set|show archdebug set|show debug arch
4087 set|show eventdebug set|show debug event
4090 * New BSD user-level threads support
4092 It is now possible to debug programs using the user-level threads
4093 library on OpenBSD and FreeBSD. Currently supported (target)
4096 FreeBSD/amd64 x86_64-*-freebsd*
4097 FreeBSD/i386 i386-*-freebsd*
4098 OpenBSD/i386 i386-*-openbsd*
4100 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4101 are not yet supported.
4103 * New support for Matsushita MN10300 w/sim added
4104 (Work in progress). mn10300-elf.
4106 * REMOVED configurations and files
4108 VxWorks and the XDR protocol *-*-vxworks
4109 Motorola MCORE mcore-*-*
4110 National Semiconductor NS32000 ns32k-*-*
4112 * New "set print array-indexes" command
4114 After turning this setting "on", GDB prints the index of each element
4115 when displaying arrays. The default is "off" to preserve the previous
4118 * VAX floating point support
4120 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4122 * User-defined command support
4124 In addition to using $arg0..$arg9 for argument passing, it is now possible
4125 to use $argc to determine now many arguments have been passed. See the
4126 section on user-defined commands in the user manual for more information.
4128 *** Changes in GDB 6.3:
4130 * New command line option
4132 GDB now accepts -l followed by a number to set the timeout for remote
4135 * GDB works with GCC -feliminate-dwarf2-dups
4137 GDB now supports a more compact representation of DWARF-2 debug
4138 information using DW_FORM_ref_addr references. These are produced
4139 by GCC with the option -feliminate-dwarf2-dups and also by some
4140 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4141 to use -feliminate-dwarf2-dups.
4143 * Internationalization
4145 When supported by the host system, GDB will be built with
4146 internationalization (libintl). The task of marking up the sources is
4147 continued, we're looking forward to our first translation.
4151 Initial support for debugging programs compiled with the GNAT
4152 implementation of the Ada programming language has been integrated
4153 into GDB. In this release, support is limited to expression evaluation.
4155 * New native configurations
4157 GNU/Linux/m32r m32r-*-linux-gnu
4161 GDB's remote protocol now includes support for the 'p' packet. This
4162 packet is used to fetch individual registers from a remote inferior.
4164 * END-OF-LIFE registers[] compatibility module
4166 GDB's internal register infrastructure has been completely rewritten.
4167 The new infrastructure making possible the implementation of key new
4168 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4171 GDB 6.3 will be the last release to include the the registers[]
4172 compatibility module that allowed out-of-date configurations to
4173 continue to work. This change directly impacts the following
4183 powerpc bdm protocol
4185 Unless there is activity to revive these configurations, they will be
4186 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4188 * OBSOLETE configurations and files
4190 Configurations that have been declared obsolete in this release have
4191 been commented out. Unless there is activity to revive these
4192 configurations, the next release of GDB will have their sources
4193 permanently REMOVED.
4202 *** Changes in GDB 6.2.1:
4204 * MIPS `break main; run' gave an heuristic-fence-post warning
4206 When attempting to run even a simple program, a warning about
4207 heuristic-fence-post being hit would be reported. This problem has
4210 * MIPS IRIX 'long double' crashed GDB
4212 When examining a long double variable, GDB would get a segmentation
4213 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4214 IRIX long double values).
4218 A bug in the VAX stack code was causing problems with the "next"
4219 command. This problem has been fixed.
4221 *** Changes in GDB 6.2:
4223 * Fix for ``many threads''
4225 On GNU/Linux systems that use the NPTL threads library, a program
4226 rapidly creating and deleting threads would confuse GDB leading to the
4229 ptrace: No such process.
4230 thread_db_get_info: cannot get thread info: generic error
4232 This problem has been fixed.
4234 * "-async" and "-noasync" options removed.
4236 Support for the broken "-noasync" option has been removed (it caused
4239 * New ``start'' command.
4241 This command runs the program until the begining of the main procedure.
4243 * New BSD Kernel Data Access Library (libkvm) interface
4245 Using ``target kvm'' it is now possible to debug kernel core dumps and
4246 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4247 platforms. Currently supported (native-only) configurations are:
4249 FreeBSD/amd64 x86_64-*-freebsd*
4250 FreeBSD/i386 i?86-*-freebsd*
4251 NetBSD/i386 i?86-*-netbsd*
4252 NetBSD/m68k m68*-*-netbsd*
4253 NetBSD/sparc sparc-*-netbsd*
4254 OpenBSD/amd64 x86_64-*-openbsd*
4255 OpenBSD/i386 i?86-*-openbsd*
4256 OpenBSD/m68k m68*-openbsd*
4257 OpenBSD/sparc sparc-*-openbsd*
4259 * Signal trampoline code overhauled
4261 Many generic problems with GDB's signal handling code have been fixed.
4262 These include: backtraces through non-contiguous stacks; recognition
4263 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4264 call; backtrace through a signal trampoline; step into and out of
4265 signal handlers; and single-stepping in the signal trampoline.
4267 Please note that kernel bugs are a limiting factor here. These
4268 features have been shown to work on an s390 GNU/Linux system that
4269 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4271 * Cygwin support for DWARF 2 added.
4273 * New native configurations
4275 GNU/Linux/hppa hppa*-*-linux*
4276 OpenBSD/hppa hppa*-*-openbsd*
4277 OpenBSD/m68k m68*-*-openbsd*
4278 OpenBSD/m88k m88*-*-openbsd*
4279 OpenBSD/powerpc powerpc-*-openbsd*
4280 NetBSD/vax vax-*-netbsd*
4281 OpenBSD/vax vax-*-openbsd*
4283 * END-OF-LIFE frame compatibility module
4285 GDB's internal frame infrastructure has been completely rewritten.
4286 The new infrastructure making it possible to support key new features
4287 including DWARF 2 Call Frame Information. To aid in the task of
4288 migrating old configurations to this new infrastructure, a
4289 compatibility module, that allowed old configurations to continue to
4290 work, was also included.
4292 GDB 6.2 will be the last release to include this frame compatibility
4293 module. This change directly impacts the following configurations:
4303 Unless there is activity to revive these configurations, they will be
4304 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4306 * REMOVED configurations and files
4308 Sun 3, running SunOS 3 m68*-*-sunos3*
4309 Sun 3, running SunOS 4 m68*-*-sunos4*
4310 Sun 2, running SunOS 3 m68000-*-sunos3*
4311 Sun 2, running SunOS 4 m68000-*-sunos4*
4312 Motorola 680x0 running LynxOS m68*-*-lynxos*
4313 AT&T 3b1/Unix pc m68*-att-*
4314 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4315 decstation mips-dec-* mips-little-*
4316 riscos mips-*-riscos* mips-*-sysv*
4317 sonymips mips-sony-*
4318 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4320 *** Changes in GDB 6.1.1:
4322 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4324 The TUI (Text-mode User Interface) is now built as part of a default
4325 GDB configuration. It is enabled by either selecting the TUI with the
4326 command line option "-i=tui" or by running the separate "gdbtui"
4327 program. For more information on the TUI, see the manual "Debugging
4330 * Pending breakpoint support (also included in GDB 6.1)
4332 Support has been added to allow you to specify breakpoints in shared
4333 libraries that have not yet been loaded. If a breakpoint location
4334 cannot be found, and the "breakpoint pending" option is set to auto,
4335 GDB queries you if you wish to make the breakpoint pending on a future
4336 shared-library load. If and when GDB resolves the breakpoint symbol,
4337 the pending breakpoint is removed as one or more regular breakpoints
4340 Pending breakpoints are very useful for GCJ Java debugging.
4342 * Fixed ISO-C build problems
4344 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4345 non ISO-C code that stopped them being built using a more strict ISO-C
4346 compiler (e.g., IBM's C compiler).
4348 * Fixed build problem on IRIX 5
4350 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4351 wasn't able to compile compile on an IRIX 5 system.
4353 * Added execute permission to gdb/gdbserver/configure
4355 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4356 permission. This bug would cause configure to fail on a number of
4357 systems (Solaris, IRIX). Ref: server/519.
4359 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4361 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4362 has been updated to use constant array sizes.
4364 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4366 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4367 its generated DWARF Call Frame Info. This encoding was causing GDB to
4368 panic, that panic has been fixed. Ref: gdb/1628.
4370 * Fixed a problem when examining parameters in shared library code.
4372 When examining parameters in optimized shared library code generated
4373 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4374 not available''. GDB now correctly displays the variable's value.
4376 *** Changes in GDB 6.1:
4378 * Removed --with-mmalloc
4380 Support for the mmalloc memory manager has been removed, as it
4381 conflicted with the internal gdb byte cache.
4383 * Changes in AMD64 configurations
4385 The AMD64 target now includes the %cs and %ss registers. As a result
4386 the AMD64 remote protocol has changed; this affects the floating-point
4387 and SSE registers. If you rely on those registers for your debugging,
4388 you should upgrade gdbserver on the remote side.
4390 * Revised SPARC target
4392 The SPARC target has been completely revised, incorporating the
4393 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4394 support for LynxOS and SunOS 4 has been dropped. Calling functions
4395 from within GDB on operating systems with a non-executable stack
4396 (Solaris, OpenBSD) now works.
4400 GDB has a new C++ demangler which does a better job on the mangled
4401 names generated by current versions of g++. It also runs faster, so
4402 with this and other changes gdb should now start faster on large C++
4405 * DWARF 2 Location Expressions
4407 GDB support for location expressions has been extended to support function
4408 arguments and frame bases. Older versions of GDB could crash when they
4411 * C++ nested types and namespaces
4413 GDB's support for nested types and namespaces in C++ has been
4414 improved, especially if you use the DWARF 2 debugging format. (This
4415 is the default for recent versions of GCC on most platforms.)
4416 Specifically, if you have a class "Inner" defined within a class or
4417 namespace "Outer", then GDB realizes that the class's name is
4418 "Outer::Inner", not simply "Inner". This should greatly reduce the
4419 frequency of complaints about not finding RTTI symbols. In addition,
4420 if you are stopped at inside of a function defined within a namespace,
4421 GDB modifies its name lookup accordingly.
4423 * New native configurations
4425 NetBSD/amd64 x86_64-*-netbsd*
4426 OpenBSD/amd64 x86_64-*-openbsd*
4427 OpenBSD/alpha alpha*-*-openbsd*
4428 OpenBSD/sparc sparc-*-openbsd*
4429 OpenBSD/sparc64 sparc64-*-openbsd*
4431 * New debugging protocols
4433 M32R with SDI protocol m32r-*-elf*
4435 * "set prompt-escape-char" command deleted.
4437 The command "set prompt-escape-char" has been deleted. This command,
4438 and its very obscure effet on GDB's prompt, was never documented,
4439 tested, nor mentioned in the NEWS file.
4441 * OBSOLETE configurations and files
4443 Configurations that have been declared obsolete in this release have
4444 been commented out. Unless there is activity to revive these
4445 configurations, the next release of GDB will have their sources
4446 permanently REMOVED.
4448 Sun 3, running SunOS 3 m68*-*-sunos3*
4449 Sun 3, running SunOS 4 m68*-*-sunos4*
4450 Sun 2, running SunOS 3 m68000-*-sunos3*
4451 Sun 2, running SunOS 4 m68000-*-sunos4*
4452 Motorola 680x0 running LynxOS m68*-*-lynxos*
4453 AT&T 3b1/Unix pc m68*-att-*
4454 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4455 decstation mips-dec-* mips-little-*
4456 riscos mips-*-riscos* mips-*-sysv*
4457 sonymips mips-sony-*
4458 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4460 * REMOVED configurations and files
4462 SGI Irix-4.x mips-sgi-irix4 or iris4
4463 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4464 Z8000 simulator z8k-zilog-none or z8ksim
4465 Matsushita MN10200 w/simulator mn10200-*-*
4466 H8/500 simulator h8500-hitachi-hms or h8500hms
4467 HP/PA running BSD hppa*-*-bsd*
4468 HP/PA running OSF/1 hppa*-*-osf*
4469 HP/PA Pro target hppa*-*-pro*
4470 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4471 386BSD i[3456]86-*-bsd*
4472 Sequent family i[3456]86-sequent-sysv4*
4473 i[3456]86-sequent-sysv*
4474 i[3456]86-sequent-bsd*
4475 SPARC running LynxOS sparc-*-lynxos*
4476 SPARC running SunOS 4 sparc-*-sunos4*
4477 Tsqware Sparclet sparclet-*-*
4478 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4480 *** Changes in GDB 6.0:
4484 Support for debugging the Objective-C programming language has been
4485 integrated into GDB.
4487 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4489 DWARF 2's Call Frame Information makes available compiler generated
4490 information that more exactly describes the program's run-time stack.
4491 By using this information, GDB is able to provide more robust stack
4494 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4495 have been updated to use a new backtrace mechanism which includes
4496 DWARF 2 CFI support.
4500 GDB's remote protocol has been extended to include support for hosted
4501 file I/O (where the remote target uses GDB's file system). See GDB's
4502 remote protocol documentation for details.
4504 * All targets using the new architecture framework.
4506 All of GDB's targets have been updated to use the new internal
4507 architecture framework. The way is now open for future GDB releases
4508 to include cross-architecture native debugging support (i386 on amd64,
4511 * GNU/Linux's Thread Local Storage (TLS)
4513 GDB now includes support for for the GNU/Linux implementation of
4514 per-thread variables.
4516 * GNU/Linux's Native POSIX Thread Library (NPTL)
4518 GDB's thread code has been updated to work with either the new
4519 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4521 * Separate debug info.
4523 GDB, in conjunction with BINUTILS, now supports a mechanism for
4524 automatically loading debug information from a separate file. Instead
4525 of shipping full debug and non-debug versions of system libraries,
4526 system integrators can now instead ship just the stripped libraries
4527 and optional debug files.
4529 * DWARF 2 Location Expressions
4531 DWARF 2 Location Expressions allow the compiler to more completely
4532 describe the location of variables (even in optimized code) to the
4535 GDB now includes preliminary support for location expressions (support
4536 for DW_OP_piece is still missing).
4540 A number of long standing bugs that caused GDB to die while starting a
4541 Java application have been fixed. GDB's Java support is now
4542 considered "useable".
4544 * GNU/Linux support for fork, vfork, and exec.
4546 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4547 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4550 * GDB supports logging output to a file
4552 There are two new commands, "set logging" and "show logging", which can be
4553 used to capture GDB's output to a file.
4555 * The meaning of "detach" has changed for gdbserver
4557 The "detach" command will now resume the application, as documented. To
4558 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4561 * d10v, m68hc11 `regs' command deprecated
4563 The `info registers' command has been updated so that it displays the
4564 registers using a format identical to the old `regs' command.
4568 A new command, "maint set profile on/off", has been added. This command can
4569 be used to enable or disable profiling while running GDB, to profile a
4570 session or a set of commands. In addition there is a new configure switch,
4571 "--enable-profiling", which will cause GDB to be compiled with profiling
4572 data, for more informative profiling results.
4574 * Default MI syntax changed to "mi2".
4576 The default MI (machine interface) syntax, enabled by the command line
4577 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4578 "mi1", can be enabled by specifying the option "-i=mi1".
4580 Support for the original "mi0" syntax (included in GDB 5.0) has been
4583 Fix for gdb/192: removed extraneous space when displaying frame level.
4584 Fix for gdb/672: update changelist is now output in mi list format.
4585 Fix for gdb/702: a -var-assign that updates the value now shows up
4586 in a subsequent -var-update.
4588 * New native configurations.
4590 FreeBSD/amd64 x86_64-*-freebsd*
4592 * Multi-arched targets.
4594 HP/PA HPUX11 hppa*-*-hpux*
4595 Renesas M32R/D w/simulator m32r-*-elf*
4597 * OBSOLETE configurations and files
4599 Configurations that have been declared obsolete in this release have
4600 been commented out. Unless there is activity to revive these
4601 configurations, the next release of GDB will have their sources
4602 permanently REMOVED.
4604 Z8000 simulator z8k-zilog-none or z8ksim
4605 Matsushita MN10200 w/simulator mn10200-*-*
4606 H8/500 simulator h8500-hitachi-hms or h8500hms
4607 HP/PA running BSD hppa*-*-bsd*
4608 HP/PA running OSF/1 hppa*-*-osf*
4609 HP/PA Pro target hppa*-*-pro*
4610 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4611 Sequent family i[3456]86-sequent-sysv4*
4612 i[3456]86-sequent-sysv*
4613 i[3456]86-sequent-bsd*
4614 Tsqware Sparclet sparclet-*-*
4615 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4617 * REMOVED configurations and files
4620 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4621 IBM AIX PS/2 i[3456]86-*-aix
4622 i386 running Mach 3.0 i[3456]86-*-mach3*
4623 i386 running Mach i[3456]86-*-mach*
4624 i386 running OSF/1 i[3456]86-*osf1mk*
4625 HP/Apollo 68k Family m68*-apollo*-sysv*,
4627 m68*-hp-bsd*, m68*-hp-hpux*
4628 Argonaut Risc Chip (ARC) arc-*-*
4629 Mitsubishi D30V d30v-*-*
4630 Fujitsu FR30 fr30-*-elf*
4631 OS/9000 i[34]86-*-os9k
4632 I960 with MON960 i960-*-coff
4634 * MIPS $fp behavior changed
4636 The convenience variable $fp, for the MIPS, now consistently returns
4637 the address of the current frame's base. Previously, depending on the
4638 context, $fp could refer to either $sp or the current frame's base
4639 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4640 The GNU Source-Level Debugger''.
4642 *** Changes in GDB 5.3:
4644 * GNU/Linux shared library multi-threaded performance improved.
4646 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4647 `/proc', in preference to `ptrace' for memory reads. This may result
4648 in an improvement in the start-up time of multi-threaded, shared
4649 library applications when run under GDB. One GDB user writes: ``loads
4650 shared libs like mad''.
4652 * ``gdbserver'' now supports multi-threaded applications on some targets
4654 Support for debugging multi-threaded applications which use
4655 the GNU/Linux LinuxThreads package has been added for
4656 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4657 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4659 * GDB now supports C/C++ preprocessor macros.
4661 GDB now expands preprocessor macro invocations in C/C++ expressions,
4662 and provides various commands for showing macro definitions and how
4665 The new command `macro expand EXPRESSION' expands any macro
4666 invocations in expression, and shows the result.
4668 The new command `show macro MACRO-NAME' shows the definition of the
4669 macro named MACRO-NAME, and where it was defined.
4671 Most compilers don't include information about macros in the debugging
4672 information by default. In GCC 3.1, for example, you need to compile
4673 your program with the options `-gdwarf-2 -g3'. If the macro
4674 information is present in the executable, GDB will read it.
4676 * Multi-arched targets.
4678 DEC Alpha (partial) alpha*-*-*
4679 DEC VAX (partial) vax-*-*
4681 National Semiconductor NS32000 (partial) ns32k-*-*
4682 Motorola 68000 (partial) m68k-*-*
4683 Motorola MCORE mcore-*-*
4687 Fujitsu FRV architecture added by Red Hat frv*-*-*
4690 * New native configurations
4692 Alpha NetBSD alpha*-*-netbsd*
4693 SH NetBSD sh*-*-netbsdelf*
4694 MIPS NetBSD mips*-*-netbsd*
4695 UltraSPARC NetBSD sparc64-*-netbsd*
4697 * OBSOLETE configurations and files
4699 Configurations that have been declared obsolete in this release have
4700 been commented out. Unless there is activity to revive these
4701 configurations, the next release of GDB will have their sources
4702 permanently REMOVED.
4704 Mitsubishi D30V d30v-*-*
4705 OS/9000 i[34]86-*-os9k
4706 IBM AIX PS/2 i[3456]86-*-aix
4707 Fujitsu FR30 fr30-*-elf*
4708 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4709 Argonaut Risc Chip (ARC) arc-*-*
4710 i386 running Mach 3.0 i[3456]86-*-mach3*
4711 i386 running Mach i[3456]86-*-mach*
4712 i386 running OSF/1 i[3456]86-*osf1mk*
4713 HP/Apollo 68k Family m68*-apollo*-sysv*,
4715 m68*-hp-bsd*, m68*-hp-hpux*
4716 I960 with MON960 i960-*-coff
4718 * OBSOLETE languages
4720 CHILL, a Pascal like language used by telecommunications companies.
4722 * REMOVED configurations and files
4724 AMD 29k family via UDI a29k-amd-udi, udi29k
4725 A29K VxWorks a29k-*-vxworks
4726 AMD 29000 embedded, using EBMON a29k-none-none
4727 AMD 29000 embedded with COFF a29k-none-coff
4728 AMD 29000 embedded with a.out a29k-none-aout
4730 testsuite/gdb.hp/gdb.threads-hp/ directory
4732 * New command "set max-user-call-depth <nnn>"
4734 This command allows the user to limit the call depth of user-defined
4735 commands. The default is 1024.
4737 * Changes in FreeBSD/i386 native debugging.
4739 Support for the "generate-core-file" has been added.
4741 * New commands "dump", "append", and "restore".
4743 These commands allow data to be copied from target memory
4744 to a bfd-format or binary file (dump and append), and back
4745 from a file into memory (restore).
4747 * Improved "next/step" support on multi-processor Alpha Tru64.
4749 The previous single-step mechanism could cause unpredictable problems,
4750 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4751 of a software single-step mechanism prevents this.
4753 *** Changes in GDB 5.2.1:
4761 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4762 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4763 Fix, by Joel Brobecker imported from mainline.
4765 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4766 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4767 Fix, by Fred Fish, imported from mainline.
4769 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4770 Surprisingly enough, it works now.
4771 By Michal Ludvig, imported from mainline.
4773 i386 hardware watchpoint support:
4774 avoid misses on second run for some targets.
4775 By Pierre Muller, imported from mainline.
4777 *** Changes in GDB 5.2:
4779 * New command "set trust-readonly-sections on[off]".
4781 This command is a hint that tells gdb that read-only sections
4782 really are read-only (ie. that their contents will not change).
4783 In this mode, gdb will go to the object file rather than the
4784 target to read memory from read-only sections (such as ".text").
4785 This can be a significant performance improvement on some
4786 (notably embedded) targets.
4788 * New command "generate-core-file" (or "gcore").
4790 This new gdb command allows the user to drop a core file of the child
4791 process state at any time. So far it's been implemented only for
4792 GNU/Linux and Solaris, but should be relatively easily ported to other
4793 hosts. Argument is core file name (defaults to core.<pid>).
4795 * New command line option
4797 GDB now accepts --pid or -p followed by a process id.
4799 * Change in command line behavior -- corefiles vs. process ids.
4801 There is a subtle behavior in the way in which GDB handles
4802 command line arguments. The first non-flag argument is always
4803 a program to debug, but the second non-flag argument may either
4804 be a corefile or a process id. Previously, GDB would attempt to
4805 open the second argument as a corefile, and if that failed, would
4806 issue a superfluous error message and then attempt to attach it as
4807 a process. Now, if the second argument begins with a non-digit,
4808 it will be treated as a corefile. If it begins with a digit,
4809 GDB will attempt to attach it as a process, and if no such process
4810 is found, will then attempt to open it as a corefile.
4812 * Changes in ARM configurations.
4814 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4815 configuration is fully multi-arch.
4817 * New native configurations
4819 ARM NetBSD arm*-*-netbsd*
4820 x86 OpenBSD i[3456]86-*-openbsd*
4821 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4822 Sparc64 running FreeBSD sparc64-*-freebsd*
4826 Sanyo XStormy16 xstormy16-elf
4828 * OBSOLETE configurations and files
4830 Configurations that have been declared obsolete in this release have
4831 been commented out. Unless there is activity to revive these
4832 configurations, the next release of GDB will have their sources
4833 permanently REMOVED.
4835 AMD 29k family via UDI a29k-amd-udi, udi29k
4836 A29K VxWorks a29k-*-vxworks
4837 AMD 29000 embedded, using EBMON a29k-none-none
4838 AMD 29000 embedded with COFF a29k-none-coff
4839 AMD 29000 embedded with a.out a29k-none-aout
4841 testsuite/gdb.hp/gdb.threads-hp/ directory
4843 * REMOVED configurations and files
4845 TI TMS320C80 tic80-*-*
4847 PowerPC Solaris powerpcle-*-solaris*
4848 PowerPC Windows NT powerpcle-*-cygwin32
4849 PowerPC Netware powerpc-*-netware*
4850 Harris/CXUX m88k m88*-harris-cxux*
4851 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4852 ns32k-utek-sysv* ns32k-utek-*
4853 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4854 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4855 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4856 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4857 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4859 * Changes to command line processing
4861 The new `--args' feature can be used to specify command-line arguments
4862 for the inferior from gdb's command line.
4864 * Changes to key bindings
4866 There is a new `operate-and-get-next' function bound to `C-o'.
4868 *** Changes in GDB 5.1.1
4870 Fix compile problem on DJGPP.
4872 Fix a problem with floating-point registers on the i386 being
4875 Fix to stop GDB crashing on .debug_str debug info.
4877 Numerous documentation fixes.
4879 Numerous testsuite fixes.
4881 *** Changes in GDB 5.1:
4883 * New native configurations
4885 Alpha FreeBSD alpha*-*-freebsd*
4886 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4887 MIPS GNU/Linux mips*-*-linux*
4888 MIPS SGI Irix 6.x mips*-sgi-irix6*
4889 ia64 AIX ia64-*-aix*
4890 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4894 Motorola 68HC11 and 68HC12 m68hc11-elf
4896 UltraSparc running GNU/Linux sparc64-*-linux*
4898 * OBSOLETE configurations and files
4900 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4901 Harris/CXUX m88k m88*-harris-cxux*
4902 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4903 ns32k-utek-sysv* ns32k-utek-*
4904 TI TMS320C80 tic80-*-*
4906 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4907 PowerPC Solaris powerpcle-*-solaris*
4908 PowerPC Windows NT powerpcle-*-cygwin32
4909 PowerPC Netware powerpc-*-netware*
4910 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4911 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4912 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4913 Apple Macintosh (MPW) host N/A
4915 stuff.c (Program to stuff files into a specially prepared space in kdb)
4916 kdb-start.c (Main loop for the standalone kernel debugger)
4918 Configurations that have been declared obsolete in this release have
4919 been commented out. Unless there is activity to revive these
4920 configurations, the next release of GDB will have their sources
4921 permanently REMOVED.
4923 * REMOVED configurations and files
4925 Altos 3068 m68*-altos-*
4926 Convex c1-*-*, c2-*-*
4928 ARM RISCix arm-*-* (as host)
4932 * GDB has been converted to ISO C.
4934 GDB's source code has been converted to ISO C. In particular, the
4935 sources are fully protoized, and rely on standard headers being
4940 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4942 * The MI enabled by default.
4944 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4945 revised and enabled by default. Packages which use GDB as a debugging
4946 engine behind a UI or another front end are encouraged to switch to
4947 using the GDB/MI interface, instead of the old annotations interface
4948 which is now deprecated.
4950 * Support for debugging Pascal programs.
4952 GDB now includes support for debugging Pascal programs. The following
4953 main features are supported:
4955 - Pascal-specific data types such as sets;
4957 - automatic recognition of Pascal sources based on file-name
4960 - Pascal-style display of data types, variables, and functions;
4962 - a Pascal expression parser.
4964 However, some important features are not yet supported.
4966 - Pascal string operations are not supported at all;
4968 - there are some problems with boolean types;
4970 - Pascal type hexadecimal constants are not supported
4971 because they conflict with the internal variables format;
4973 - support for Pascal objects and classes is not full yet;
4975 - unlike Pascal, GDB is case-sensitive for symbol names.
4977 * Changes in completion.
4979 Commands such as `shell', `run' and `set args', which pass arguments
4980 to inferior programs, now complete on file names, similar to what
4981 users expect at the shell prompt.
4983 Commands which accept locations, such as `disassemble', `print',
4984 `breakpoint', `until', etc. now complete on filenames as well as
4985 program symbols. Thus, if you type "break foob TAB", and the source
4986 files linked into the programs include `foobar.c', that file name will
4987 be one of the candidates for completion. However, file names are not
4988 considered for completion after you typed a colon that delimits a file
4989 name from a name of a function in that file, as in "break foo.c:bar".
4991 `set demangle-style' completes on available demangling styles.
4993 * New platform-independent commands:
4995 It is now possible to define a post-hook for a command as well as a
4996 hook that runs before the command. For more details, see the
4997 documentation of `hookpost' in the GDB manual.
4999 * Changes in GNU/Linux native debugging.
5001 Support for debugging multi-threaded programs has been completely
5002 revised for all platforms except m68k and sparc. You can now debug as
5003 many threads as your system allows you to have.
5005 Attach/detach is supported for multi-threaded programs.
5007 Support for SSE registers was added for x86. This doesn't work for
5008 multi-threaded programs though.
5010 * Changes in MIPS configurations.
5012 Multi-arch support is enabled for all MIPS configurations.
5014 GDB can now be built as native debugger on SGI Irix 6.x systems for
5015 debugging n32 executables. (Debugging 64-bit executables is not yet
5018 * Unified support for hardware watchpoints in all x86 configurations.
5020 Most (if not all) native x86 configurations support hardware-assisted
5021 breakpoints and watchpoints in a unified manner. This support
5022 implements debug register sharing between watchpoints, which allows to
5023 put a virtually infinite number of watchpoints on the same address,
5024 and also supports watching regions up to 16 bytes with several debug
5027 The new maintenance command `maintenance show-debug-regs' toggles
5028 debugging print-outs in functions that insert, remove, and test
5029 watchpoints and hardware breakpoints.
5031 * Changes in the DJGPP native configuration.
5033 New command ``info dos sysinfo'' displays assorted information about
5034 the CPU, OS, memory, and DPMI server.
5036 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5037 display information about segment descriptors stored in GDT, LDT, and
5040 New commands ``info dos pde'' and ``info dos pte'' display entries
5041 from Page Directory and Page Tables (for now works with CWSDPMI only).
5042 New command ``info dos address-pte'' displays the Page Table entry for
5043 a given linear address.
5045 GDB can now pass command lines longer than 126 characters to the
5046 program being debugged (requires an update to the libdbg.a library
5047 which is part of the DJGPP development kit).
5049 DWARF2 debug info is now supported.
5051 It is now possible to `step' and `next' through calls to `longjmp'.
5053 * Changes in documentation.
5055 All GDB documentation was converted to GFDL, the GNU Free
5056 Documentation License.
5058 Tracepoints-related commands are now fully documented in the GDB
5061 TUI, the Text-mode User Interface, is now documented in the manual.
5063 Tracepoints-related commands are now fully documented in the GDB
5066 The "GDB Internals" manual now has an index. It also includes
5067 documentation of `ui_out' functions, GDB coding standards, x86
5068 hardware watchpoints, and memory region attributes.
5070 * GDB's version number moved to ``version.in''
5072 The Makefile variable VERSION has been replaced by the file
5073 ``version.in''. People creating GDB distributions should update the
5074 contents of this file.
5078 GUD support is now a standard part of the EMACS distribution.
5080 *** Changes in GDB 5.0:
5082 * Improved support for debugging FP programs on x86 targets
5084 Unified and much-improved support for debugging floating-point
5085 programs on all x86 targets. In particular, ``info float'' now
5086 displays the FP registers in the same format on all x86 targets, with
5087 greater level of detail.
5089 * Improvements and bugfixes in hardware-assisted watchpoints
5091 It is now possible to watch array elements, struct members, and
5092 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5093 on x86 targets no longer erroneously trigger when the address is
5096 * Improvements in the native DJGPP version of GDB
5098 The distribution now includes all the scripts and auxiliary files
5099 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5100 machines ``out of the box''.
5102 The DJGPP version can now debug programs that use signals. It is
5103 possible to catch signals that happened in the debuggee, deliver
5104 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5105 would kill the program being debugged.) Programs that hook hardware
5106 interrupts (keyboard, timer, etc.) can also be debugged.
5108 It is now possible to debug DJGPP programs that redirect their
5109 standard handles or switch them to raw (as opposed to cooked) mode, or
5110 even close them. The command ``run < foo > bar'' works as expected,
5111 and ``info terminal'' reports useful information about the debuggee's
5112 terminal, including raw/cooked mode, redirection, etc.
5114 The DJGPP version now uses termios functions for console I/O, which
5115 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5118 DOS-style file names with drive letters are now fully supported by
5121 It is now possible to debug DJGPP programs that switch their working
5122 directory. It is also possible to rerun the debuggee any number of
5123 times without restarting GDB; thus, you can use the same setup,
5124 breakpoints, etc. for many debugging sessions.
5126 * New native configurations
5128 ARM GNU/Linux arm*-*-linux*
5129 PowerPC GNU/Linux powerpc-*-linux*
5133 Motorola MCore mcore-*-*
5134 x86 VxWorks i[3456]86-*-vxworks*
5135 PowerPC VxWorks powerpc-*-vxworks*
5136 TI TMS320C80 tic80-*-*
5138 * OBSOLETE configurations
5140 Altos 3068 m68*-altos-*
5141 Convex c1-*-*, c2-*-*
5143 ARM RISCix arm-*-* (as host)
5146 Configurations that have been declared obsolete will be commented out,
5147 but the code will be left in place. If there is no activity to revive
5148 these configurations before the next release of GDB, the sources will
5149 be permanently REMOVED.
5151 * Gould support removed
5153 Support for the Gould PowerNode and NP1 has been removed.
5155 * New features for SVR4
5157 On SVR4 native platforms (such as Solaris), if you attach to a process
5158 without first loading a symbol file, GDB will now attempt to locate and
5159 load symbols from the running process's executable file.
5161 * Many C++ enhancements
5163 C++ support has been greatly improved. Overload resolution now works properly
5164 in almost all cases. RTTI support is on the way.
5166 * Remote targets can connect to a sub-program
5168 A popen(3) style serial-device has been added. This device starts a
5169 sub-process (such as a stand-alone simulator) and then communicates
5170 with that. The sub-program to run is specified using the syntax
5171 ``|<program> <args>'' vis:
5173 (gdb) set remotedebug 1
5174 (gdb) target extended-remote |mn10300-elf-sim program-args
5176 * MIPS 64 remote protocol
5178 A long standing bug in the mips64 remote protocol where by GDB
5179 expected certain 32 bit registers (ex SR) to be transfered as 32
5180 instead of 64 bits has been fixed.
5182 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5183 added to provide backward compatibility with older versions of GDB.
5185 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5187 The command ``set remotebinarydownload'' command has been replaced by
5188 ``set remote X-packet''. Other commands in ``set remote'' family
5189 include ``set remote P-packet''.
5191 * Breakpoint commands accept ranges.
5193 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5194 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5195 ``tracepoint passcount'' also accepts a range of tracepoints.
5197 * ``apropos'' command added.
5199 The ``apropos'' command searches through command names and
5200 documentation strings, printing out matches, making it much easier to
5201 try to find a command that does what you are looking for.
5205 A new machine oriented interface (MI) has been added to GDB. This
5206 interface is designed for debug environments running GDB as a separate
5207 process. This is part of the long term libGDB project. See the
5208 "GDB/MI" chapter of the GDB manual for further information. It can be
5209 enabled by configuring with:
5211 .../configure --enable-gdbmi
5213 *** Changes in GDB-4.18:
5215 * New native configurations
5217 HP-UX 10.20 hppa*-*-hpux10.20
5218 HP-UX 11.x hppa*-*-hpux11.0*
5219 M68K GNU/Linux m68*-*-linux*
5223 Fujitsu FR30 fr30-*-elf*
5224 Intel StrongARM strongarm-*-*
5225 Mitsubishi D30V d30v-*-*
5227 * OBSOLETE configurations
5229 Gould PowerNode, NP1 np1-*-*, pn-*-*
5231 Configurations that have been declared obsolete will be commented out,
5232 but the code will be left in place. If there is no activity to revive
5233 these configurations before the next release of GDB, the sources will
5234 be permanently REMOVED.
5238 As a compatibility experiment, GDB's source files buildsym.h and
5239 buildsym.c have been converted to pure standard C, no longer
5240 containing any K&R compatibility code. We believe that all systems in
5241 use today either come with a standard C compiler, or have a GCC port
5242 available. If this is not true, please report the affected
5243 configuration to bug-gdb@gnu.org immediately. See the README file for
5244 information about getting a standard C compiler if you don't have one
5249 GDB now uses readline 2.2.
5251 * set extension-language
5253 You can now control the mapping between filename extensions and source
5254 languages by using the `set extension-language' command. For instance,
5255 you can ask GDB to treat .c files as C++ by saying
5256 set extension-language .c c++
5257 The command `info extensions' lists all of the recognized extensions
5258 and their associated languages.
5260 * Setting processor type for PowerPC and RS/6000
5262 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5263 you can use the `set processor' command to specify what variant of the
5264 PowerPC family you are debugging. The command
5268 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5269 following PowerPC and RS6000 variants:
5271 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5272 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5274 403GC IBM PowerPC 403GC
5275 505 Motorola PowerPC 505
5276 860 Motorola PowerPC 860 or 850
5277 601 Motorola PowerPC 601
5278 602 Motorola PowerPC 602
5279 603 Motorola/IBM PowerPC 603 or 603e
5280 604 Motorola PowerPC 604 or 604e
5281 750 Motorola/IBM PowerPC 750 or 750
5283 At the moment, this command just tells GDB what to name the
5284 special-purpose processor registers. Since almost all the affected
5285 registers are inaccessible to user-level programs, this command is
5286 only useful for remote debugging in its present form.
5290 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5291 more extensive support for HP-UX. Added features include shared
5292 library support, kernel threads and hardware watchpoints for 11.00,
5293 support for HP's ANSI C and C++ compilers, and a compatibility mode
5294 for xdb and dbx commands.
5298 HP's donation includes the new concept of catchpoints, which is a
5299 generalization of the old catch command. On HP-UX, it is now possible
5300 to catch exec, fork, and vfork, as well as library loading.
5302 This means that the existing catch command has changed; its first
5303 argument now specifies the type of catch to be set up. See the
5304 output of "help catch" for a list of catchpoint types.
5306 * Debugging across forks
5308 On HP-UX, you can choose which process to debug when a fork() happens
5313 HP has donated a curses-based terminal user interface (TUI). To get
5314 it, build with --enable-tui. Although this can be enabled for any
5315 configuration, at present it only works for native HP debugging.
5317 * GDB remote protocol additions
5319 A new protocol packet 'X' that writes binary data is now available.
5320 Default behavior is to try 'X', then drop back to 'M' if the stub
5321 fails to respond. The settable variable `remotebinarydownload'
5322 allows explicit control over the use of 'X'.
5324 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5325 full 64-bit address. The command
5327 set remoteaddresssize 32
5329 can be used to revert to the old behaviour. For existing remote stubs
5330 the change should not be noticed, as the additional address information
5333 In order to assist in debugging stubs, you may use the maintenance
5334 command `packet' to send any text string to the stub. For instance,
5336 maint packet heythere
5338 sends the packet "$heythere#<checksum>". Note that it is very easy to
5339 disrupt a debugging session by sending the wrong packet at the wrong
5342 The compare-sections command allows you to compare section data on the
5343 target to what is in the executable file without uploading or
5344 downloading, by comparing CRC checksums.
5346 * Tracing can collect general expressions
5348 You may now collect general expressions at tracepoints. This requires
5349 further additions to the target-side stub; see tracepoint.c and
5350 doc/agentexpr.texi for further details.
5352 * mask-address variable for Mips
5354 For Mips targets, you may control the zeroing of the upper 32 bits of
5355 a 64-bit address by entering `set mask-address on'. This is mainly
5356 of interest to users of embedded R4xxx and R5xxx processors.
5358 * Higher serial baud rates
5360 GDB's serial code now allows you to specify baud rates 57600, 115200,
5361 230400, and 460800 baud. (Note that your host system may not be able
5362 to achieve all of these rates.)
5366 The i960 configuration now includes an initial implementation of a
5367 builtin simulator, contributed by Jim Wilson.
5370 *** Changes in GDB-4.17:
5372 * New native configurations
5374 Alpha GNU/Linux alpha*-*-linux*
5375 Unixware 2.x i[3456]86-unixware2*
5376 Irix 6.x mips*-sgi-irix6*
5377 PowerPC GNU/Linux powerpc-*-linux*
5378 PowerPC Solaris powerpcle-*-solaris*
5379 Sparc GNU/Linux sparc-*-linux*
5380 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5384 Argonaut Risc Chip (ARC) arc-*-*
5385 Hitachi H8/300S h8300*-*-*
5386 Matsushita MN10200 w/simulator mn10200-*-*
5387 Matsushita MN10300 w/simulator mn10300-*-*
5388 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5389 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5390 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5391 Mitsubishi D10V w/simulator d10v-*-*
5392 Mitsubishi M32R/D w/simulator m32r-*-elf*
5393 Tsqware Sparclet sparclet-*-*
5394 NEC V850 w/simulator v850-*-*
5396 * New debugging protocols
5398 ARM with RDI protocol arm*-*-*
5399 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5400 DDB and LSI variants of PMON protocol mips*-*-*
5401 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5402 PowerPC with SDS protocol powerpc{,le}-*-eabi
5403 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5407 All configurations can now understand and use the DWARF 2 debugging
5408 format. The choice is automatic, if the symbol file contains DWARF 2
5413 GDB now includes basic Java language support. This support is
5414 only useful with Java compilers that produce native machine code.
5416 * solib-absolute-prefix and solib-search-path
5418 For SunOS and SVR4 shared libraries, you may now set the prefix for
5419 loading absolute shared library symbol files, and the search path for
5420 locating non-absolute shared library symbol files.
5422 * Live range splitting
5424 GDB can now effectively debug code for which GCC has performed live
5425 range splitting as part of its optimization. See gdb/doc/LRS for
5426 more details on the expected format of the stabs information.
5430 GDB's support for the GNU Hurd, including thread debugging, has been
5431 updated to work with current versions of the Hurd.
5435 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5436 instruction set. ARM GDB automatically detects when Thumb
5437 instructions are in use, and adjusts disassembly and backtracing
5442 GDB's MIPS target configurations now handle the MIP16 16-bit
5447 GDB now includes support for overlays; if an executable has been
5448 linked such that multiple sections are based at the same address, GDB
5449 will decide which section to use for symbolic info. You can choose to
5450 control the decision manually, using overlay commands, or implement
5451 additional target-side support and use "overlay load-target" to bring
5452 in the overlay mapping. Do "help overlay" for more detail.
5456 The command "info symbol <address>" displays information about
5457 the symbol at the specified address.
5461 The standard remote protocol now includes an extension that allows
5462 asynchronous collection and display of trace data. This requires
5463 extensive support in the target-side debugging stub. Tracing mode
5464 includes a new interaction mode in GDB and new commands: see the
5465 file tracepoint.c for more details.
5469 Configurations for embedded MIPS now include a simulator contributed
5470 by Cygnus Solutions. The simulator supports the instruction sets
5471 of most MIPS variants.
5475 Sparc configurations may now include the ERC32 simulator contributed
5476 by the European Space Agency. The simulator is not built into
5477 Sparc targets by default; configure with --enable-sim to include it.
5481 For target configurations that may include multiple variants of a
5482 basic architecture (such as MIPS and SH), you may now set the
5483 architecture explicitly. "set arch" sets, "info arch" lists
5484 the possible architectures.
5486 *** Changes in GDB-4.16:
5488 * New native configurations
5490 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5491 M68K NetBSD m68k-*-netbsd*
5492 PowerPC AIX 4.x powerpc-*-aix*
5493 PowerPC MacOS powerpc-*-macos*
5494 PowerPC Windows NT powerpcle-*-cygwin32
5495 RS/6000 AIX 4.x rs6000-*-aix4*
5499 ARM with RDP protocol arm-*-*
5500 I960 with MON960 i960-*-coff
5501 MIPS VxWorks mips*-*-vxworks*
5502 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5503 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5505 Matra Sparclet sparclet-*-*
5509 The powerpc-eabi configuration now includes the PSIM simulator,
5510 contributed by Andrew Cagney, with assistance from Mike Meissner.
5511 PSIM is a very elaborate model of the PowerPC, including not only
5512 basic instruction set execution, but also details of execution unit
5513 performance and I/O hardware. See sim/ppc/README for more details.
5517 GDB now works with Solaris 2.5.
5519 * Windows 95/NT native
5521 GDB will now work as a native debugger on Windows 95 and Windows NT.
5522 To build it from source, you must use the "gnu-win32" environment,
5523 which uses a DLL to emulate enough of Unix to run the GNU tools.
5524 Further information, binaries, and sources are available at
5525 ftp.cygnus.com, under pub/gnu-win32.
5527 * dont-repeat command
5529 If a user-defined command includes the command `dont-repeat', then the
5530 command will not be repeated if the user just types return. This is
5531 useful if the command is time-consuming to run, so that accidental
5532 extra keystrokes don't run the same command many times.
5534 * Send break instead of ^C
5536 The standard remote protocol now includes an option to send a break
5537 rather than a ^C to the target in order to interrupt it. By default,
5538 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5540 * Remote protocol timeout
5542 The standard remote protocol includes a new variable `remotetimeout'
5543 that allows you to set the number of seconds before GDB gives up trying
5544 to read from the target. The default value is 2.
5546 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5548 By default GDB will automatically keep track of objects as they are
5549 loaded and unloaded by the dynamic linker. By using the command `set
5550 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5551 when shared library events occur, thus allowing you to set breakpoints
5552 in shared libraries which are explicitly loaded by the inferior.
5554 Note this feature does not work on hpux8. On hpux9 you must link
5555 /usr/lib/end.o into your program. This feature should work
5556 automatically on hpux10.
5558 * Irix 5.x hardware watchpoint support
5560 Irix 5 configurations now support the use of hardware watchpoints.
5562 * Mips protocol "SYN garbage limit"
5564 When debugging a Mips target using the `target mips' protocol, you
5565 may set the number of characters that GDB will ignore by setting
5566 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5567 every character. The default value is 1050.
5569 * Recording and replaying remote debug sessions
5571 If you set `remotelogfile' to the name of a file, gdb will write to it
5572 a recording of a remote debug session. This recording may then be
5573 replayed back to gdb using "gdbreplay". See gdbserver/README for
5574 details. This is useful when you have a problem with GDB while doing
5575 remote debugging; you can make a recording of the session and send it
5576 to someone else, who can then recreate the problem.
5578 * Speedups for remote debugging
5580 GDB includes speedups for downloading and stepping MIPS systems using
5581 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5582 and more efficient S-record downloading.
5584 * Memory use reductions and statistics collection
5586 GDB now uses less memory and reports statistics about memory usage.
5587 Try the `maint print statistics' command, for example.
5589 *** Changes in GDB-4.15:
5591 * Psymtabs for XCOFF
5593 The symbol reader for AIX GDB now uses partial symbol tables. This
5594 can greatly improve startup time, especially for large executables.
5596 * Remote targets use caching
5598 Remote targets now use a data cache to speed up communication with the
5599 remote side. The data cache could lead to incorrect results because
5600 it doesn't know about volatile variables, thus making it impossible to
5601 debug targets which use memory mapped I/O devices. `set remotecache
5602 off' turns the the data cache off.
5604 * Remote targets may have threads
5606 The standard remote protocol now includes support for multiple threads
5607 in the target system, using new protocol commands 'H' and 'T'. See
5608 gdb/remote.c for details.
5612 If GDB is configured with `--enable-netrom', then it will include
5613 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5614 acts as though it is a bank of ROM on the target board, but you can
5615 write into it over the network. GDB's support consists only of
5616 support for fast loading into the emulated ROM; to debug, you must use
5617 another protocol, such as standard remote protocol. The usual
5618 sequence is something like
5620 target nrom <netrom-hostname>
5622 target remote <netrom-hostname>:1235
5626 GDB now includes support for the Apple Macintosh, as a host only. It
5627 may be run as either an MPW tool or as a standalone application, and
5628 it can debug through the serial port. All the usual GDB commands are
5629 available, but to the target command, you must supply "serial" as the
5630 device type instead of "/dev/ttyXX". See mpw-README in the main
5631 directory for more information on how to build. The MPW configuration
5632 scripts */mpw-config.in support only a few targets, and only the
5633 mips-idt-ecoff target has been tested.
5637 GDB configuration now uses autoconf. This is not user-visible,
5638 but does simplify configuration and building.
5642 GDB now supports hpux10.
5644 *** Changes in GDB-4.14:
5646 * New native configurations
5648 x86 FreeBSD i[345]86-*-freebsd
5649 x86 NetBSD i[345]86-*-netbsd
5650 NS32k NetBSD ns32k-*-netbsd
5651 Sparc NetBSD sparc-*-netbsd
5655 A29K VxWorks a29k-*-vxworks
5656 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5657 CPU32 EST-300 emulator m68*-*-est*
5658 PowerPC ELF powerpc-*-elf
5661 * Alpha OSF/1 support for procfs
5663 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5664 possible to attach to running processes. As the mounting of the /proc
5665 filesystem is optional on the Alpha, GDB automatically determines
5666 the availability of /proc during startup. This can lead to problems
5667 if /proc is unmounted after GDB has been started.
5669 * Arguments to user-defined commands
5671 User commands may accept up to 10 arguments separated by whitespace.
5672 Arguments are accessed within the user command via $arg0..$arg9. A
5675 print $arg0 + $arg1 + $arg2
5677 To execute the command use:
5680 Defines the command "adder" which prints the sum of its three arguments.
5681 Note the arguments are text substitutions, so they may reference variables,
5682 use complex expressions, or even perform inferior function calls.
5684 * New `if' and `while' commands
5686 This makes it possible to write more sophisticated user-defined
5687 commands. Both commands take a single argument, which is the
5688 expression to evaluate, and must be followed by the commands to
5689 execute, one per line, if the expression is nonzero, the list being
5690 terminated by the word `end'. The `if' command list may include an
5691 `else' word, which causes the following commands to be executed only
5692 if the expression is zero.
5694 * Fortran source language mode
5696 GDB now includes partial support for Fortran 77. It will recognize
5697 Fortran programs and can evaluate a subset of Fortran expressions, but
5698 variables and functions may not be handled correctly. GDB will work
5699 with G77, but does not yet know much about symbols emitted by other
5702 * Better HPUX support
5704 Most debugging facilities now work on dynamic executables for HPPAs
5705 running hpux9 or later. You can attach to running dynamically linked
5706 processes, but by default the dynamic libraries will be read-only, so
5707 for instance you won't be able to put breakpoints in them. To change
5708 that behavior do the following before running the program:
5714 This will cause the libraries to be mapped private and read-write.
5715 To revert to the normal behavior, do this:
5721 You cannot set breakpoints or examine data in the library until after
5722 the library is loaded if the function/data symbols do not have
5725 GDB can now also read debug symbols produced by the HP C compiler on
5726 HPPAs (sorry, no C++, Fortran or 68k support).
5728 * Target byte order now dynamically selectable
5730 You can choose which byte order to use with a target system, via the
5731 commands "set endian big" and "set endian little", and you can see the
5732 current setting by using "show endian". You can also give the command
5733 "set endian auto", in which case GDB will use the byte order
5734 associated with the executable. Currently, only embedded MIPS
5735 configurations support dynamic selection of target byte order.
5737 * New DOS host serial code
5739 This version uses DPMI interrupts to handle buffered I/O, so you
5740 no longer need to run asynctsr when debugging boards connected to
5743 *** Changes in GDB-4.13:
5745 * New "complete" command
5747 This lists all the possible completions for the rest of the line, if it
5748 were to be given as a command itself. This is intended for use by emacs.
5750 * Trailing space optional in prompt
5752 "set prompt" no longer adds a space for you after the prompt you set. This
5753 allows you to set a prompt which ends in a space or one that does not.
5755 * Breakpoint hit counts
5757 "info break" now displays a count of the number of times the breakpoint
5758 has been hit. This is especially useful in conjunction with "ignore"; you
5759 can ignore a large number of breakpoint hits, look at the breakpoint info
5760 to see how many times the breakpoint was hit, then run again, ignoring one
5761 less than that number, and this will get you quickly to the last hit of
5764 * Ability to stop printing at NULL character
5766 "set print null-stop" will cause GDB to stop printing the characters of
5767 an array when the first NULL is encountered. This is useful when large
5768 arrays actually contain only short strings.
5770 * Shared library breakpoints
5772 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5773 breakpoints in shared libraries before the executable is run.
5775 * Hardware watchpoints
5777 There is a new hardware breakpoint for the watch command for sparclite
5778 targets. See gdb/sparclite/hw_breakpoint.note.
5780 Hardware watchpoints are also now supported under GNU/Linux.
5784 Annotations have been added. These are for use with graphical interfaces,
5785 and are still experimental. Currently only gdba.el uses these.
5787 * Improved Irix 5 support
5789 GDB now works properly with Irix 5.2.
5791 * Improved HPPA support
5793 GDB now works properly with the latest GCC and GAS.
5795 * New native configurations
5797 Sequent PTX4 i[34]86-sequent-ptx4
5798 HPPA running OSF/1 hppa*-*-osf*
5799 Atari TT running SVR4 m68*-*-sysv4*
5800 RS/6000 LynxOS rs6000-*-lynxos*
5804 OS/9000 i[34]86-*-os9k
5805 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5808 * Hitachi SH7000 and E7000-PC ICE support
5810 There is now support for communicating with the Hitachi E7000-PC ICE.
5811 This is available automatically when GDB is configured for the SH.
5815 As usual, a variety of small fixes and improvements, both generic
5816 and configuration-specific. See the ChangeLog for more detail.
5818 *** Changes in GDB-4.12:
5820 * Irix 5 is now supported
5824 GDB-4.12 on the HPPA has a number of changes which make it unable
5825 to debug the output from the currently released versions of GCC and
5826 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5827 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5828 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5831 *** Changes in GDB-4.11:
5833 * User visible changes:
5837 The "set remotedebug" option is now consistent between the mips remote
5838 target, remote targets using the gdb-specific protocol, UDI (AMD's
5839 debug protocol for the 29k) and the 88k bug monitor. It is now an
5840 integer specifying a debug level (normally 0 or 1, but 2 means more
5841 debugging info for the mips target).
5843 * DEC Alpha native support
5845 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5846 debug info, but GDB works fairly well with the DEC compiler and should
5847 work with a future GCC release. See the README file for a few
5848 Alpha-specific notes.
5850 * Preliminary thread implementation
5852 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5854 * LynxOS native and target support for 386
5856 This release has been hosted on LynxOS 2.2, and also can be configured
5857 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5860 * Improvements in C++ mangling/demangling.
5862 This release has much better g++ debugging, specifically in name
5863 mangling/demangling, virtual function calls, print virtual table,
5864 call methods, ...etc.
5866 *** Changes in GDB-4.10:
5868 * User visible changes:
5870 Remote debugging using the GDB-specific (`target remote') protocol now
5871 supports the `load' command. This is only useful if you have some
5872 other way of getting the stub to the target system, and you can put it
5873 somewhere in memory where it won't get clobbered by the download.
5875 Filename completion now works.
5877 When run under emacs mode, the "info line" command now causes the
5878 arrow to point to the line specified. Also, "info line" prints
5879 addresses in symbolic form (as well as hex).
5881 All vxworks based targets now support a user settable option, called
5882 vxworks-timeout. This option represents the number of seconds gdb
5883 should wait for responses to rpc's. You might want to use this if
5884 your vxworks target is, perhaps, a slow software simulator or happens
5885 to be on the far side of a thin network line.
5889 This release contains support for using a DEC alpha as a GDB host for
5890 cross debugging. Native alpha debugging is not supported yet.
5893 *** Changes in GDB-4.9:
5897 This is the first GDB release which is accompanied by a matching testsuite.
5898 The testsuite requires installation of dejagnu, which should be available
5899 via ftp from most sites that carry GNU software.
5903 'Cfront' style demangling has had its name changed to 'ARM' style, to
5904 emphasize that it was written from the specifications in the C++ Annotated
5905 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5906 disclaimers, it still generated too much confusion with users attempting to
5907 use gdb with AT&T cfront.
5911 GDB now uses a standard remote interface to a simulator library.
5912 So far, the library contains simulators for the Zilog Z8001/2, the
5913 Hitachi H8/300, H8/500 and Super-H.
5915 * New targets supported
5917 H8/300 simulator h8300-hitachi-hms or h8300hms
5918 H8/500 simulator h8500-hitachi-hms or h8500hms
5919 SH simulator sh-hitachi-hms or sh
5920 Z8000 simulator z8k-zilog-none or z8ksim
5921 IDT MIPS board over serial line mips-idt-ecoff
5923 Cross-debugging to GO32 targets is supported. It requires a custom
5924 version of the i386-stub.c module which is integrated with the
5925 GO32 memory extender.
5927 * New remote protocols
5929 MIPS remote debugging protocol.
5931 * New source languages supported
5933 This version includes preliminary support for Chill, a Pascal like language
5934 used by telecommunications companies. Chill support is also being integrated
5935 into the GNU compiler, but we don't know when it will be publically available.
5938 *** Changes in GDB-4.8:
5940 * HP Precision Architecture supported
5942 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5943 version of this support was available as a set of patches from the
5944 University of Utah. GDB does not support debugging of programs
5945 compiled with the HP compiler, because HP will not document their file
5946 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5947 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5949 Many problems in the preliminary version have been fixed.
5951 * Faster and better demangling
5953 We have improved template demangling and fixed numerous bugs in the GNU style
5954 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5955 character types (wchar_t) are now supported. Demangling of each symbol is now
5956 only done once, and is cached when the symbol table for a file is read in.
5957 This results in a small increase in memory usage for C programs, a moderate
5958 increase in memory usage for C++ programs, and a fantastic speedup in
5961 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5962 from the specifications in the Annotated Reference Manual, which AT&T's
5963 compiler does not actually implement.
5965 * G++ multiple inheritance compiler problem
5967 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5968 inheritance lattices was reworked to properly discover ambiguities. We
5969 recently found an example which causes this new algorithm to fail in a
5970 very subtle way, producing bad debug information for those classes.
5971 The file 'gcc.patch' (in this directory) can be applied to gcc to
5972 circumvent the problem. A future GCC release will contain a complete
5975 The previous G++ debug info problem (mentioned below for the gdb-4.7
5976 release) is fixed in gcc version 2.3.2.
5978 * Improved configure script
5980 The `configure' script will now attempt to guess your system type if
5981 you don't supply a host system type. The old scheme of supplying a
5982 host system triplet is preferable over using this. All the magic is
5983 done in the new `config.guess' script. Examine it for details.
5985 We have also brought our configure script much more in line with the FSF's
5986 version. It now supports the --with-xxx options. In particular,
5987 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5988 The resulting GDB will not be able to read arbitrary object file formats --
5989 only the format ``expected'' to be used on the configured target system.
5990 We hope to make this the default in a future release.
5992 * Documentation improvements
5994 There's new internal documentation on how to modify GDB, and how to
5995 produce clean changes to the code. We implore people to read it
5996 before submitting changes.
5998 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5999 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6000 `info' files are also provided. To build `info' files from scratch,
6001 you will need the latest `makeinfo' release, which will be available in
6002 a future texinfo-X.Y release.
6004 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6005 We're not sure exactly which versions have this problem, but it has
6006 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6007 or better. If that isn't possible, there is a patch in
6008 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6009 around this problem.
6013 GDB now supports array constants that can be used in expressions typed in by
6014 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6015 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6018 The new directory `gdb/sparclite' contains a program that demonstrates
6019 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6021 * New native hosts supported
6023 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6024 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6026 * New targets supported
6028 AMD 29k family via UDI a29k-amd-udi or udi29k
6030 * New file formats supported
6032 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6033 HPUX core files, and SCO 3.2v2 core files.
6037 Attaching to processes now works again; thanks for the many bug reports.
6039 We have also stomped on a bunch of core dumps caused by
6040 printf_filtered("%s") problems.
6042 We eliminated a copyright problem on the rpc and ptrace header files
6043 for VxWorks, which was discovered at the last minute during the 4.7
6044 release. You should now be able to build a VxWorks GDB.
6046 You can now interrupt gdb while an attached process is running. This
6047 will cause the attached process to stop, and give control back to GDB.
6049 We fixed problems caused by using too many file descriptors
6050 for reading symbols from object files and libraries. This was
6051 especially a problem for programs that used many (~100) shared
6054 The `step' command now only enters a subroutine if there is line number
6055 information for the subroutine. Otherwise it acts like the `next'
6056 command. Previously, `step' would enter subroutines if there was
6057 any debugging information about the routine. This avoids problems
6058 when using `cc -g1' on MIPS machines.
6060 * Internal improvements
6062 GDB's internal interfaces have been improved to make it easier to support
6063 debugging of multiple languages in the future.
6065 GDB now uses a common structure for symbol information internally.
6066 Minimal symbols (derived from linkage symbols in object files), partial
6067 symbols (from a quick scan of debug information), and full symbols
6068 contain a common subset of information, making it easier to write
6069 shared code that handles any of them.
6071 * New command line options
6073 We now accept --silent as an alias for --quiet.
6077 The memory-mapped-malloc library is now licensed under the GNU Library
6078 General Public License.
6080 *** Changes in GDB-4.7:
6082 * Host/native/target split
6084 GDB has had some major internal surgery to untangle the support for
6085 hosts and remote targets. Now, when you configure GDB for a remote
6086 target, it will no longer load in all of the support for debugging
6087 local programs on the host. When fully completed and tested, this will
6088 ensure that arbitrary host/target combinations are possible.
6090 The primary conceptual shift is to separate the non-portable code in
6091 GDB into three categories. Host specific code is required any time GDB
6092 is compiled on that host, regardless of the target. Target specific
6093 code relates to the peculiarities of the target, but can be compiled on
6094 any host. Native specific code is everything else: it can only be
6095 built when the host and target are the same system. Child process
6096 handling and core file support are two common `native' examples.
6098 GDB's use of /proc for controlling Unix child processes is now cleaner.
6099 It has been split out into a single module under the `target_ops' vector,
6100 plus two native-dependent functions for each system that uses /proc.
6102 * New hosts supported
6104 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6105 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6106 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6108 * New targets supported
6110 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6111 68030 and CPU32 m68030-*-*, m68332-*-*
6113 * New native hosts supported
6115 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6116 (386bsd is not well tested yet)
6117 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6119 * New file formats supported
6121 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6122 supports reading of `a.out.adobe' object files, which are an a.out
6123 format extended with minimal information about multiple sections.
6127 `show copying' is the same as the old `info copying'.
6128 `show warranty' is the same as `info warrantee'.
6129 These were renamed for consistency. The old commands continue to work.
6131 `info handle' is a new alias for `info signals'.
6133 You can now define pre-command hooks, which attach arbitrary command
6134 scripts to any command. The commands in the hook will be executed
6135 prior to the user's command. You can also create a hook which will be
6136 executed whenever the program stops. See gdb.texinfo.
6140 We now deal with Cfront style name mangling, and can even extract type
6141 info from mangled symbols. GDB can automatically figure out which
6142 symbol mangling style your C++ compiler uses.
6144 Calling of methods and virtual functions has been improved as well.
6148 The crash that occured when debugging Sun Ansi-C compiled binaries is
6149 fixed. This was due to mishandling of the extra N_SO stabs output
6152 We also finally got Ultrix 4.2 running in house, and fixed core file
6153 support, with help from a dozen people on the net.
6155 John M. Farrell discovered that the reason that single-stepping was so
6156 slow on all of the Mips based platforms (primarily SGI and DEC) was
6157 that we were trying to demangle and lookup a symbol used for internal
6158 purposes on every instruction that was being stepped through. Changing
6159 the name of that symbol so that it couldn't be mistaken for a C++
6160 mangled symbol sped things up a great deal.
6162 Rich Pixley sped up symbol lookups in general by getting much smarter
6163 about when C++ symbol mangling is necessary. This should make symbol
6164 completion (TAB on the command line) much faster. It's not as fast as
6165 we'd like, but it's significantly faster than gdb-4.6.
6169 A new user controllable variable 'call_scratch_address' can
6170 specify the location of a scratch area to be used when GDB
6171 calls a function in the target. This is necessary because the
6172 usual method of putting the scratch area on the stack does not work
6173 in systems that have separate instruction and data spaces.
6175 We integrated changes to support the 29k UDI (Universal Debugger
6176 Interface), but discovered at the last minute that we didn't have all
6177 of the appropriate copyright paperwork. We are working with AMD to
6178 resolve this, and hope to have it available soon.
6182 We have sped up the remote serial line protocol, especially for targets
6183 with lots of registers. It now supports a new `expedited status' ('T')
6184 message which can be used in place of the existing 'S' status message.
6185 This allows the remote stub to send only the registers that GDB
6186 needs to make a quick decision about single-stepping or conditional
6187 breakpoints, eliminating the need to fetch the entire register set for
6188 each instruction being stepped through.
6190 The GDB remote serial protocol now implements a write-through cache for
6191 registers, only re-reading the registers if the target has run.
6193 There is also a new remote serial stub for SPARC processors. You can
6194 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6195 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6196 processor with a serial port.
6200 Configure.in files have become much easier to read and modify. A new
6201 `table driven' format makes it more obvious what configurations are
6202 supported, and what files each one uses.
6206 There is a new opcodes library which will eventually contain all of the
6207 disassembly routines and opcode tables. At present, it only contains
6208 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6209 disassembler (binutils/objdump) to share these routines.
6211 The libiberty library is now copylefted under the GNU Library General
6212 Public License. This allows more liberal use, and was done so libg++
6213 can use it. This makes no difference to GDB, since the Library License
6214 grants all the rights from the General Public License.
6218 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6219 reference to the stabs symbol info used by the debugger. It is (as far
6220 as we know) the only published document on this fascinating topic. We
6221 encourage you to read it, compare it to the stabs information on your
6222 system, and send improvements on the document in general (to
6223 bug-gdb@prep.ai.mit.edu).
6225 And, of course, many bugs have been fixed.
6228 *** Changes in GDB-4.6:
6230 * Better support for C++ function names
6232 GDB now accepts as input the "demangled form" of C++ overloaded function
6233 names and member function names, and can do command completion on such names
6234 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6235 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6236 Make use of command completion, it is your friend.
6238 GDB also now accepts a variety of C++ mangled symbol formats. They are
6239 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6240 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6241 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6242 for the list of formats.
6244 * G++ symbol mangling problem
6246 Recent versions of gcc have a bug in how they emit debugging information for
6247 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6248 directory) can be applied to gcc to fix the problem. Alternatively, if you
6249 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6250 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6251 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6254 * New 'maintenance' command
6256 All of the commands related to hacking GDB internals have been moved out of
6257 the main command set, and now live behind the 'maintenance' command. This
6258 can also be abbreviated as 'mt'. The following changes were made:
6260 dump-me -> maintenance dump-me
6261 info all-breakpoints -> maintenance info breakpoints
6262 printmsyms -> maintenance print msyms
6263 printobjfiles -> maintenance print objfiles
6264 printpsyms -> maintenance print psymbols
6265 printsyms -> maintenance print symbols
6267 The following commands are new:
6269 maintenance demangle Call internal GDB demangler routine to
6270 demangle a C++ link name and prints the result.
6271 maintenance print type Print a type chain for a given symbol
6273 * Change to .gdbinit file processing
6275 We now read the $HOME/.gdbinit file before processing the argv arguments
6276 (e.g. reading symbol files or core files). This allows global parameters to
6277 be set, which will apply during the symbol reading. The ./.gdbinit is still
6278 read after argv processing.
6280 * New hosts supported
6282 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6284 GNU/Linux support i386-unknown-linux or linux
6286 We are also including code to support the HP/PA running BSD and HPUX. This
6287 is almost guaranteed not to work, as we didn't have time to test or build it
6288 for this release. We are including it so that the more adventurous (or
6289 masochistic) of you can play with it. We also had major problems with the
6290 fact that the compiler that we got from HP doesn't support the -g option.
6293 * New targets supported
6295 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6297 * More smarts about finding #include files
6299 GDB now remembers the compilation directory for all include files, and for
6300 all files from which C is generated (like yacc and lex sources). This
6301 greatly improves GDB's ability to find yacc/lex sources, and include files,
6302 especially if you are debugging your program from a directory different from
6303 the one that contains your sources.
6305 We also fixed a bug which caused difficulty with listing and setting
6306 breakpoints in include files which contain C code. (In the past, you had to
6307 try twice in order to list an include file that you hadn't looked at before.)
6309 * Interesting infernals change
6311 GDB now deals with arbitrary numbers of sections, where the symbols for each
6312 section must be relocated relative to that section's landing place in the
6313 target's address space. This work was needed to support ELF with embedded
6314 stabs used by Solaris-2.0.
6316 * Bug fixes (of course!)
6318 There have been loads of fixes for the following things:
6319 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6320 i960, stabs, DOS(GO32), procfs, etc...
6322 See the ChangeLog for details.
6324 *** Changes in GDB-4.5:
6326 * New machines supported (host and target)
6328 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6330 SGI Irix-4.x mips-sgi-irix4 or iris4
6332 * New malloc package
6334 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6335 Mmalloc is capable of handling mutiple heaps of memory. It is also
6336 capable of saving a heap to a file, and then mapping it back in later.
6337 This can be used to greatly speedup the startup of GDB by using a
6338 pre-parsed symbol table which lives in a mmalloc managed heap. For
6339 more details, please read mmalloc/mmalloc.texi.
6343 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6344 'help info proc' for details.
6346 * MIPS ecoff symbol table format
6348 The code that reads MIPS symbol table format is now supported on all hosts.
6349 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6352 * File name changes for MS-DOS
6354 Many files in the config directories have been renamed to make it easier to
6355 support GDB on MS-DOSe systems (which have very restrictive file name
6356 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6357 environment) is close to working but has some remaining problems. Note
6358 that debugging of DOS programs is not supported, due to limitations
6359 in the ``operating system'', but it can be used to host cross-debugging.
6361 * Cross byte order fixes
6363 Many fixes have been made to support cross debugging of Sparc and MIPS
6364 targets from hosts whose byte order differs.
6366 * New -mapped and -readnow options
6368 If memory-mapped files are available on your system through the 'mmap'
6369 system call, you can use the -mapped option on the `file' or
6370 `symbol-file' commands to cause GDB to write the symbols from your
6371 program into a reusable file. If the program you are debugging is
6372 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6373 Future GDB debugging sessions will notice the presence of this file,
6374 and will quickly map in symbol information from it, rather than reading
6375 the symbol table from the executable program. Using the '-mapped'
6376 option in a GDB `file' or `symbol-file' command has the same effect as
6377 starting GDB with the '-mapped' command-line option.
6379 You can cause GDB to read the entire symbol table immediately by using
6380 the '-readnow' option with any of the commands that load symbol table
6381 information (or on the GDB command line). This makes the command
6382 slower, but makes future operations faster.
6384 The -mapped and -readnow options are typically combined in order to
6385 build a `fred.syms' file that contains complete symbol information.
6386 A simple GDB invocation to do nothing but build a `.syms' file for future
6389 gdb -batch -nx -mapped -readnow programname
6391 The `.syms' file is specific to the host machine on which GDB is run.
6392 It holds an exact image of GDB's internal symbol table. It cannot be
6393 shared across multiple host platforms.
6395 * longjmp() handling
6397 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6398 siglongjmp() without losing control. This feature has not yet been ported to
6399 all systems. It currently works on many 386 platforms, all MIPS-based
6400 platforms (SGI, DECstation, etc), and Sun3/4.
6404 Preliminary work has been put in to support the new Solaris OS from Sun. At
6405 this time, it can control and debug processes, but it is not capable of
6410 As always, many many bug fixes. The major areas were with g++, and mipsread.
6411 People using the MIPS-based platforms should experience fewer mysterious
6412 crashes and trashed symbol tables.
6414 *** Changes in GDB-4.4:
6416 * New machines supported (host and target)
6418 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6420 BSD Reno on Vax vax-dec-bsd
6421 Ultrix on Vax vax-dec-ultrix
6423 * New machines supported (target)
6425 AMD 29000 embedded, using EBMON a29k-none-none
6429 GDB continues to improve its handling of C++. `References' work better.
6430 The demangler has also been improved, and now deals with symbols mangled as
6431 per the Annotated C++ Reference Guide.
6433 GDB also now handles `stabs' symbol information embedded in MIPS
6434 `ecoff' symbol tables. Since the ecoff format was not easily
6435 extensible to handle new languages such as C++, this appeared to be a
6436 good way to put C++ debugging info into MIPS binaries. This option
6437 will be supported in the GNU C compiler, version 2, when it is
6440 * New features for SVR4
6442 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6443 shared libraries. Debugging dynamically linked programs should present
6444 only minor differences from debugging statically linked programs.
6446 The `info proc' command will print out information about any process
6447 on an SVR4 system (including the one you are debugging). At the moment,
6448 it prints the address mappings of the process.
6450 If you bring up GDB on another SVR4 system, please send mail to
6451 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6453 * Better dynamic linking support in SunOS
6455 Reading symbols from shared libraries which contain debugging symbols
6456 now works properly. However, there remain issues such as automatic
6457 skipping of `transfer vector' code during function calls, which
6458 make it harder to debug code in a shared library, than to debug the
6459 same code linked statically.
6463 GDB is now using the latest `getopt' routines from the FSF. This
6464 version accepts the -- prefix for options with long names. GDB will
6465 continue to accept the old forms (-option and +option) as well.
6466 Various single letter abbreviations for options have been explicity
6467 added to the option table so that they won't get overshadowed in the
6468 future by other options that begin with the same letter.
6472 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6473 Many assorted bugs have been handled. Many more remain to be handled.
6474 See the various ChangeLog files (primarily in gdb and bfd) for details.
6477 *** Changes in GDB-4.3:
6479 * New machines supported (host and target)
6481 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6482 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6483 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6485 * Almost SCO Unix support
6487 We had hoped to support:
6488 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6489 (except for core file support), but we discovered very late in the release
6490 that it has problems with process groups that render gdb unusable. Sorry
6491 about that. I encourage people to fix it and post the fixes.
6493 * Preliminary ELF and DWARF support
6495 GDB can read ELF object files on System V Release 4, and can handle
6496 debugging records for C, in DWARF format, in ELF files. This support
6497 is preliminary. If you bring up GDB on another SVR4 system, please
6498 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6503 GDB now uses the latest `readline' library. One user-visible change
6504 is that two tabs will list possible command completions, which previously
6505 required typing M-? (meta-question mark, or ESC ?).
6509 The `stepi' bug that many of you noticed has been squashed.
6510 Many bugs in C++ have been handled. Many more remain to be handled.
6511 See the various ChangeLog files (primarily in gdb and bfd) for details.
6513 * State of the MIPS world (in case you wondered):
6515 GDB can understand the symbol tables emitted by the compilers
6516 supplied by most vendors of MIPS-based machines, including DEC. These
6517 symbol tables are in a format that essentially nobody else uses.
6519 Some versions of gcc come with an assembler post-processor called
6520 mips-tfile. This program is required if you want to do source-level
6521 debugging of gcc-compiled programs. I believe FSF does not ship
6522 mips-tfile with gcc version 1, but it will eventually come with gcc
6525 Debugging of g++ output remains a problem. g++ version 1.xx does not
6526 really support it at all. (If you're lucky, you should be able to get
6527 line numbers and stack traces to work, but no parameters or local
6528 variables.) With some work it should be possible to improve the
6531 When gcc version 2 is released, you will have somewhat better luck.
6532 However, even then you will get confusing results for inheritance and
6535 We will eventually provide full debugging of g++ output on
6536 DECstations. This will probably involve some kind of stabs-in-ecoff
6537 encapulation, but the details have not been worked out yet.
6540 *** Changes in GDB-4.2:
6542 * Improved configuration
6544 Only one copy of `configure' exists now, and it is not self-modifying.
6545 Porting BFD is simpler.
6549 The `step' and `next' commands now only stop at the first instruction
6550 of a source line. This prevents the multiple stops that used to occur
6551 in switch statements, for-loops, etc. `Step' continues to stop if a
6552 function that has debugging information is called within the line.
6556 Lots of small bugs fixed. More remain.
6558 * New host supported (not target)
6560 Intel 386 PC clone running Mach i386-none-mach
6563 *** Changes in GDB-4.1:
6565 * Multiple source language support
6567 GDB now has internal scaffolding to handle several source languages.
6568 It determines the type of each source file from its filename extension,
6569 and will switch expression parsing and number formatting to match the
6570 language of the function in the currently selected stack frame.
6571 You can also specifically set the language to be used, with
6572 `set language c' or `set language modula-2'.
6576 GDB now has preliminary support for the GNU Modula-2 compiler,
6577 currently under development at the State University of New York at
6578 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6579 continue through the fall of 1991 and into 1992.
6581 Other Modula-2 compilers are currently not supported, and attempting to
6582 debug programs compiled with them will likely result in an error as the
6583 symbol table is read. Feel free to work on it, though!
6585 There are hooks in GDB for strict type checking and range checking,
6586 in the `Modula-2 philosophy', but they do not currently work.
6590 GDB can now write to executable and core files (e.g. patch
6591 a variable's value). You must turn this switch on, specify
6592 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6593 by assigning a new value to a variable. Modifications take
6596 * Automatic SunOS shared library reading
6598 When you run your program, GDB automatically determines where its
6599 shared libraries (if any) have been loaded, and reads their symbols.
6600 The `share' command is no longer needed. This also works when
6601 examining core files.
6605 You can specify the number of lines that the `list' command shows.
6608 * New machines supported (host and target)
6610 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6611 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6612 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6614 * New hosts supported (not targets)
6616 IBM RT/PC: romp-ibm-aix or rtpc
6618 * New targets supported (not hosts)
6620 AMD 29000 embedded with COFF a29k-none-coff
6621 AMD 29000 embedded with a.out a29k-none-aout
6622 Ultracomputer remote kernel debug a29k-nyu-kern
6624 * New remote interfaces
6630 *** Changes in GDB-4.0:
6634 Wide output is wrapped at good places to make the output more readable.
6636 Gdb now supports cross-debugging from a host machine of one type to a
6637 target machine of another type. Communication with the target system
6638 is over serial lines. The ``target'' command handles connecting to the
6639 remote system; the ``load'' command will download a program into the
6640 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6641 also supports debugging of realtime processes running under VxWorks,
6642 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6643 stub on the target system.
6645 New CPUs supported include the AMD 29000 and Intel 960.
6647 GDB now reads object files and symbol tables via a ``binary file''
6648 library, which allows a single copy of GDB to debug programs of multiple
6649 object file types such as a.out and coff.
6651 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6652 refcard.dvi and refcard.ps are available to format it).
6655 * Control-Variable user interface simplified
6657 All variables that control the operation of the debugger can be set
6658 by the ``set'' command, and displayed by the ``show'' command.
6660 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6661 ``Show prompt'' produces the response:
6662 Gdb's prompt is new-gdb=>.
6664 What follows are the NEW set commands. The command ``help set'' will
6665 print a complete list of old and new set commands. ``help set FOO''
6666 will give a longer description of the variable FOO. ``show'' will show
6667 all of the variable descriptions and their current settings.
6669 confirm on/off: Enables warning questions for operations that are
6670 hard to recover from, e.g. rerunning the program while
6671 it is already running. Default is ON.
6673 editing on/off: Enables EMACS style command line editing
6674 of input. Previous lines can be recalled with
6675 control-P, the current line can be edited with control-B,
6676 you can search for commands with control-R, etc.
6679 history filename NAME: NAME is where the gdb command history
6680 will be stored. The default is .gdb_history,
6681 or the value of the environment variable
6684 history size N: The size, in commands, of the command history. The
6685 default is 256, or the value of the environment variable
6688 history save on/off: If this value is set to ON, the history file will
6689 be saved after exiting gdb. If set to OFF, the
6690 file will not be saved. The default is OFF.
6692 history expansion on/off: If this value is set to ON, then csh-like
6693 history expansion will be performed on
6694 command line input. The default is OFF.
6696 radix N: Sets the default radix for input and output. It can be set
6697 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6698 in the current radix, so "set radix 10" is always a no-op.
6700 height N: This integer value is the number of lines on a page. Default
6701 is 24, the current `stty rows'' setting, or the ``li#''
6702 setting from the termcap entry matching the environment
6705 width N: This integer value is the number of characters on a line.
6706 Default is 80, the current `stty cols'' setting, or the ``co#''
6707 setting from the termcap entry matching the environment
6710 Note: ``set screensize'' is obsolete. Use ``set height'' and
6711 ``set width'' instead.
6713 print address on/off: Print memory addresses in various command displays,
6714 such as stack traces and structure values. Gdb looks
6715 more ``symbolic'' if you turn this off; it looks more
6716 ``machine level'' with it on. Default is ON.
6718 print array on/off: Prettyprint arrays. New convenient format! Default
6721 print demangle on/off: Print C++ symbols in "source" form if on,
6724 print asm-demangle on/off: Same, for assembler level printouts
6727 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6730 * Support for Epoch Environment.
6732 The epoch environment is a version of Emacs v18 with windowing. One
6733 new command, ``inspect'', is identical to ``print'', except that if you
6734 are running in the epoch environment, the value is printed in its own
6738 * Support for Shared Libraries
6740 GDB can now debug programs and core files that use SunOS shared libraries.
6741 Symbols from a shared library cannot be referenced
6742 before the shared library has been linked with the program (this
6743 happens after you type ``run'' and before the function main() is entered).
6744 At any time after this linking (including when examining core files
6745 from dynamically linked programs), gdb reads the symbols from each
6746 shared library when you type the ``sharedlibrary'' command.
6747 It can be abbreviated ``share''.
6749 sharedlibrary REGEXP: Load shared object library symbols for files
6750 matching a unix regular expression. No argument
6751 indicates to load symbols for all shared libraries.
6753 info sharedlibrary: Status of loaded shared libraries.
6758 A watchpoint stops execution of a program whenever the value of an
6759 expression changes. Checking for this slows down execution
6760 tremendously whenever you are in the scope of the expression, but is
6761 quite useful for catching tough ``bit-spreader'' or pointer misuse
6762 problems. Some machines such as the 386 have hardware for doing this
6763 more quickly, and future versions of gdb will use this hardware.
6765 watch EXP: Set a watchpoint (breakpoint) for an expression.
6767 info watchpoints: Information about your watchpoints.
6769 delete N: Deletes watchpoint number N (same as breakpoints).
6770 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6771 enable N: Re-enables watchpoint number N (same as breakpoints).
6774 * C++ multiple inheritance
6776 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6779 * C++ exception handling
6781 Gdb now supports limited C++ exception handling. Besides the existing
6782 ability to breakpoint on an exception handler, gdb can breakpoint on
6783 the raising of an exception (before the stack is peeled back to the
6786 catch FOO: If there is a FOO exception handler in the dynamic scope,
6787 set a breakpoint to catch exceptions which may be raised there.
6788 Multiple exceptions (``catch foo bar baz'') may be caught.
6790 info catch: Lists all exceptions which may be caught in the
6791 current stack frame.
6794 * Minor command changes
6796 The command ``call func (arg, arg, ...)'' now acts like the print
6797 command, except it does not print or save a value if the function's result
6798 is void. This is similar to dbx usage.
6800 The ``up'' and ``down'' commands now always print the frame they end up
6801 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6802 frames without printing.
6804 * New directory command
6806 'dir' now adds directories to the FRONT of the source search path.
6807 The path starts off empty. Source files that contain debug information
6808 about the directory in which they were compiled can be found even
6809 with an empty path; Sun CC and GCC include this information. If GDB can't
6810 find your source file in the current directory, type "dir .".
6812 * Configuring GDB for compilation
6814 For normal use, type ``./configure host''. See README or gdb.texinfo
6817 GDB now handles cross debugging. If you are remotely debugging between
6818 two different machines, type ``./configure host -target=targ''.
6819 Host is the machine where GDB will run; targ is the machine
6820 where the program that you are debugging will run.