1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.0
6 * GDB now uses the GNU MPFR library, if available, to emulate target
7 floating-point arithmetic during expression evaluation when the target
8 uses different floating-point formats than the host. At least version
9 3.1 of GNU MPFR is required.
11 * GDB now supports access to the guarded-storage-control registers and the
12 software-based guarded-storage broadcast control registers on IBM z14.
14 * On Unix systems, GDB now supports transmitting environment variables
15 that are to be set or unset to GDBserver. These variables will
16 affect the environment to be passed to the remote inferior.
18 To inform GDB of environment variables that are to be transmitted to
19 GDBserver, use the "set environment" command. Only user set
20 environment variables are sent to GDBserver.
22 To inform GDB of environment variables that are to be unset before
23 the remote inferior is started by the GDBserver, use the "unset
26 * Completion improvements
28 ** GDB can now complete function parameters in linespecs and
29 explicit locations without quoting. When setting breakpoints,
30 quoting around functions names to help with TAB-completion is
31 generally no longer necessary. For example, this now completes
34 (gdb) b function(in[TAB]
37 Related, GDB is no longer confused with completing functions in
38 C++ anonymous namespaces:
41 (gdb) b (anonymous namespace)::[TAB][TAB]
42 (anonymous namespace)::a_function()
43 (anonymous namespace)::b_function()
45 ** GDB now has much improved linespec and explicit locations TAB
46 completion support, that better understands what you're
47 completing and offers better suggestions. For example, GDB no
48 longer offers data symbols as possible completions when you're
51 ** GDB now TAB-completes label symbol names.
53 ** The "complete" command now mimics TAB completion accurately.
55 * Breakpoints on C++ functions are now set on all scopes by default
57 By default, breakpoints on functions/methods are now interpreted as
58 specifying all functions with the given name ignoring missing
59 leading scopes (namespaces and classes).
61 For example, assuming a C++ program with symbols named:
66 both commands "break func()" and "break B::func()" set a breakpoint
69 You can use the new flag "-qualified" to override this. This makes
70 GDB interpret the specified function name as a complete
71 fully-qualified name instead. For example, using the same C++
72 program, the "break -q B::func" command sets a breakpoint on
75 * Breakpoints on functions marked with C++ ABI tags
77 GDB can now set breakpoints on functions marked with C++ ABI tags
78 (e.g., [abi:cxx11]). See here for a description of ABI tags:
79 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
81 Functions with a C++11 abi tag are demangled/displayed like this:
83 function[abi:cxx11](int)
86 You can now set a breakpoint on such functions simply as if they had
91 Or if you need to disambiguate between tags, like:
93 (gdb) b function[abi:other_tag](int)
95 Tab completion was adjusted accordingly as well.
99 ** New events gdb.new_inferior, gdb.inferior_deleted, and
100 gdb.new_thread are emitted. See the manual for further
101 description of these.
103 ** A new command, "rbreak" has been added to the Python API. This
104 command allows the setting of a large number of breakpoints via a
105 regex pattern in Python. See the manual for further details.
107 * New features in the GDB remote stub, GDBserver
109 ** GDBserver is now able to start inferior processes with a
110 specified initial working directory.
112 The user can set the desired working directory to be used from
113 GDB using the new "set cwd" command.
115 ** New "--selftest" command line option runs some GDBserver self
116 tests. These self tests are disabled in releases.
118 ** On Unix systems, GDBserver now does globbing expansion and variable
119 substitution in inferior command line arguments.
121 This is done by starting inferiors using a shell, like GDB does.
122 See "set startup-with-shell" in the user manual for how to disable
123 this from GDB when using "target extended-remote". When using
124 "target remote", you can disable the startup with shell by using the
125 new "--no-startup-with-shell" GDBserver command line option.
127 ** On Unix systems, GDBserver now supports receiving environment
128 variables that are to be set or unset from GDB. These variables
129 will affect the environment to be passed to the inferior.
131 * When catching an Ada exception raised with a message, GDB now prints
132 the message in the catchpoint hit notification. In GDB/MI mode, that
133 information is provided as an extra field named "exception-message"
134 in the *stopped notification.
138 QEnvironmentHexEncoded
139 Inform GDBserver of an environment variable that is to be passed to
140 the inferior when starting it.
143 Inform GDBserver of an environment variable that is to be unset
144 before starting the remote inferior.
147 Inform GDBserver that the environment should be reset (i.e.,
148 user-set environment variables should be unset).
151 Indicates whether the inferior must be started with a shell or not.
154 Tell GDBserver that the inferior to be started should use a specific
157 * The "maintenance print c-tdesc" command now takes an optional
158 argument which is the file name of XML target description.
160 * The "maintenance selftest" command now takes an optional argument to
161 filter the tests to be run.
163 * The "enable", and "disable" commands now accept a range of
164 breakpoint locations, e.g. "enable 1.3-5".
169 Set and show the current working directory for the inferior.
172 Set and show compilation command used for compiling and injecting code
173 with the 'compile' commands.
175 set debug separate-debug-file
176 show debug separate-debug-file
177 Control the display of debug output about separate debug file search.
180 List the registered selftests.
183 Start the debugged program stopping at the first instruction.
185 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
188 * Safer/improved support for debugging with no debug info
190 GDB no longer assumes functions with no debug information return
193 This means that GDB now refuses to call such functions unless you
194 tell it the function's type, by either casting the call to the
195 declared return type, or by casting the function to a function
196 pointer of the right type, and calling that:
198 (gdb) p getenv ("PATH")
199 'getenv' has unknown return type; cast the call to its declared return type
200 (gdb) p (char *) getenv ("PATH")
201 $1 = 0x7fffffffe "/usr/local/bin:/"...
202 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
203 $2 = 0x7fffffffe "/usr/local/bin:/"...
205 Similarly, GDB no longer assumes that global variables with no debug
206 info have type 'int', and refuses to print the variable's value
207 unless you tell it the variable's type:
210 'var' has unknown type; cast it to its declared type
214 * New native configurations
216 FreeBSD/aarch64 aarch64*-*-freebsd*
217 FreeBSD/arm arm*-*-freebsd*
221 FreeBSD/aarch64 aarch64*-*-freebsd*
222 FreeBSD/arm arm*-*-freebsd*
224 * Removed targets and native configurations
226 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
228 *** Changes in GDB 8.0
230 * GDB now supports access to the PKU register on GNU/Linux. The register is
231 added by the Memory Protection Keys for Userspace feature which will be
232 available in future Intel CPUs.
234 * GDB now supports C++11 rvalue references.
238 ** New functions to start, stop and access a running btrace recording.
239 ** Rvalue references are now supported in gdb.Type.
241 * GDB now supports recording and replaying rdrand and rdseed Intel 64
244 * Building GDB and GDBserver now requires a C++11 compiler.
246 For example, GCC 4.8 or later.
248 It is no longer possible to build GDB or GDBserver with a C
249 compiler. The --disable-build-with-cxx configure option has been
252 * Building GDB and GDBserver now requires GNU make >= 3.81.
254 It is no longer supported to build GDB or GDBserver with another
255 implementation of the make program or an earlier version of GNU make.
257 * Native debugging on MS-Windows supports command-line redirection
259 Command-line arguments used for starting programs on MS-Windows can
260 now include redirection symbols supported by native Windows shells,
261 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
262 as "run", "start", and "set args", as well as the corresponding MI
265 * Support for thread names on MS-Windows.
267 GDB now catches and handles the special exception that programs
268 running on MS-Windows use to assign names to threads in the
271 * Support for Java programs compiled with gcj has been removed.
273 * User commands now accept an unlimited number of arguments.
274 Previously, only up to 10 was accepted.
276 * The "eval" command now expands user-defined command arguments.
278 This makes it easier to process a variable number of arguments:
283 eval "print $arg%d", $i
288 * Target descriptions can now describe registers for sparc32 and sparc64.
290 * GDB now supports DWARF version 5 (debug information format).
291 Its .debug_names index is not yet supported.
293 * New native configurations
295 FreeBSD/mips mips*-*-freebsd
299 Synopsys ARC arc*-*-elf32
300 FreeBSD/mips mips*-*-freebsd
302 * Removed targets and native configurations
304 Alpha running FreeBSD alpha*-*-freebsd*
305 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
310 Erases all the flash memory regions reported by the target.
312 maint print arc arc-instruction address
313 Print internal disassembler information about instruction at a given address.
317 set disassembler-options
318 show disassembler-options
319 Controls the passing of target specific information to the disassembler.
320 If it is necessary to specify more than one disassembler option then
321 multiple options can be placed together into a comma separated list.
322 The default value is the empty string. Currently, the only supported
323 targets are ARM, PowerPC and S/390.
328 Erases all the flash memory regions reported by the target. This is
329 equivalent to the CLI command flash-erase.
331 -file-list-shared-libraries
332 List the shared libraries in the program. This is
333 equivalent to the CLI command "info shared".
335 *** Changes in GDB 7.12
337 * GDB and GDBserver now build with a C++ compiler by default.
339 The --enable-build-with-cxx configure option is now enabled by
340 default. One must now explicitly configure with
341 --disable-build-with-cxx in order to build with a C compiler. This
342 option will be removed in a future release.
344 * GDBserver now supports recording btrace without maintaining an active
347 * GDB now supports a negative repeat count in the 'x' command to examine
348 memory backward from the given address. For example:
351 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
352 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
353 (gdb) x/-5i 0x0000000000400580
354 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
355 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
356 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
357 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
358 0x40057b <main(int, char**)+25>:
359 callq 0x400536 <Func1(int, char const*)>
361 * Fortran: Support structures with fields of dynamic types and
362 arrays of dynamic types.
364 * The symbol dumping maintenance commands have new syntax.
365 maint print symbols [-pc address] [--] [filename]
366 maint print symbols [-objfile objfile] [-source source] [--] [filename]
367 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
368 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
369 maint print msymbols [-objfile objfile] [--] [filename]
371 * GDB now supports multibit bitfields and enums in target register
374 * New Python-based convenience function $_as_string(val), which returns
375 the textual representation of a value. This function is especially
376 useful to obtain the text label of an enum value.
378 * Intel MPX bound violation handling.
380 Segmentation faults caused by a Intel MPX boundary violation
381 now display the kind of violation (upper or lower), the memory
382 address accessed and the memory bounds, along with the usual
383 signal received and code location.
387 Program received signal SIGSEGV, Segmentation fault
388 Upper bound violation while accessing address 0x7fffffffc3b3
389 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
390 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
392 * Rust language support.
393 GDB now supports debugging programs written in the Rust programming
394 language. See https://www.rust-lang.org/ for more information about
397 * Support for running interpreters on specified input/output devices
399 GDB now supports a new mechanism that allows frontends to provide
400 fully featured GDB console views, as a better alternative to
401 building such views on top of the "-interpreter-exec console"
402 command. See the new "new-ui" command below. With that command,
403 frontends can now start GDB in the traditional command-line mode
404 running in an embedded terminal emulator widget, and create a
405 separate MI interpreter running on a specified i/o device. In this
406 way, GDB handles line editing, history, tab completion, etc. in the
407 console all by itself, and the GUI uses the separate MI interpreter
408 for its own control and synchronization, invisible to the command
411 * The "catch syscall" command catches groups of related syscalls.
413 The "catch syscall" command now supports catching a group of related
414 syscalls using the 'group:' or 'g:' prefix.
419 skip -gfile file-glob-pattern
420 skip -function function
421 skip -rfunction regular-expression
422 A generalized form of the skip command, with new support for
423 glob-style file names and regular expressions for function names.
424 Additionally, a file spec and a function spec may now be combined.
426 maint info line-table REGEXP
427 Display the contents of GDB's internal line table data struture.
430 Run any GDB unit tests that were compiled in.
433 Start a new user interface instance running INTERP as interpreter,
434 using the TTY file for input/output.
438 ** gdb.Breakpoint objects have a new attribute "pending", which
439 indicates whether the breakpoint is pending.
440 ** Three new breakpoint-related events have been added:
441 gdb.breakpoint_created, gdb.breakpoint_modified, and
442 gdb.breakpoint_deleted.
445 Signal ("set") the given MS-Windows event object. This is used in
446 conjunction with the Windows JIT debugging (AeDebug) support, where
447 the OS suspends a crashing process until a debugger can attach to
448 it. Resuming the crashing process, in order to debug it, is done by
451 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
452 was added in GDBserver, including JIT compiling fast tracepoint's
453 conditional expression bytecode into native code.
455 * Support for various remote target protocols and ROM monitors has
458 target m32rsdi Remote M32R debugging over SDI
459 target mips MIPS remote debugging protocol
460 target pmon PMON ROM monitor
461 target ddb NEC's DDB variant of PMON for Vr4300
462 target rockhopper NEC RockHopper variant of PMON
463 target lsi LSI variant of PMO
465 * Support for tracepoints and fast tracepoints on powerpc-linux,
466 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
467 including JIT compiling fast tracepoint's conditional expression
468 bytecode into native code.
470 * MI async record =record-started now includes the method and format used for
471 recording. For example:
473 =record-started,thread-group="i1",method="btrace",format="bts"
475 * MI async record =thread-selected now includes the frame field. For example:
477 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
481 Andes NDS32 nds32*-*-elf
483 *** Changes in GDB 7.11
485 * GDB now supports debugging kernel-based threads on FreeBSD.
487 * Per-inferior thread numbers
489 Thread numbers are now per inferior instead of global. If you're
490 debugging multiple inferiors, GDB displays thread IDs using a
491 qualified INF_NUM.THR_NUM form. For example:
495 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
496 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
497 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
498 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
500 As consequence, thread numbers as visible in the $_thread
501 convenience variable and in Python's InferiorThread.num attribute
502 are no longer unique between inferiors.
504 GDB now maintains a second thread ID per thread, referred to as the
505 global thread ID, which is the new equivalent of thread numbers in
506 previous releases. See also $_gthread below.
508 For backwards compatibility, MI's thread IDs always refer to global
511 * Commands that accept thread IDs now accept the qualified
512 INF_NUM.THR_NUM form as well. For example:
515 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
518 * In commands that accept a list of thread IDs, you can now refer to
519 all threads of an inferior using a star wildcard. GDB accepts
520 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
521 refer to all threads of the current inferior. For example, "info
524 * You can use "info threads -gid" to display the global thread ID of
527 * The new convenience variable $_gthread holds the global number of
530 * The new convenience variable $_inferior holds the number of the
533 * GDB now displays the ID and name of the thread that hit a breakpoint
534 or received a signal, if your program is multi-threaded. For
537 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
538 Thread 1 "main" received signal SIGINT, Interrupt.
540 * Record btrace now supports non-stop mode.
542 * Support for tracepoints on aarch64-linux was added in GDBserver.
544 * The 'record instruction-history' command now indicates speculative execution
545 when using the Intel Processor Trace recording format.
547 * GDB now allows users to specify explicit locations, bypassing
548 the linespec parser. This feature is also available to GDB/MI
551 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
552 GDB now is able to debug both AArch64 applications and ARM applications
555 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
556 including JIT compiling fast tracepoint's conditional expression bytecode
559 * GDB now supports displaced stepping on AArch64 GNU/Linux.
561 * "info threads", "info inferiors", "info display", "info checkpoints"
562 and "maint info program-spaces" now list the corresponding items in
563 ascending ID order, for consistency with all other "info" commands.
565 * In Ada, the overloads selection menu has been enhanced to display the
566 parameter types and the return types for the matching overloaded subprograms.
570 maint set target-non-stop (on|off|auto)
571 maint show target-non-stop
572 Control whether GDB targets always operate in non-stop mode even if
573 "set non-stop" is "off". The default is "auto", meaning non-stop
574 mode is enabled if supported by the target.
576 maint set bfd-sharing
577 maint show bfd-sharing
578 Control the reuse of bfd objects.
582 Control display of debugging info regarding bfd caching.
586 Control display of debugging info regarding FreeBSD threads.
588 set remote multiprocess-extensions-packet
589 show remote multiprocess-extensions-packet
590 Set/show the use of the remote protocol multiprocess extensions.
592 set remote thread-events
593 show remote thread-events
594 Set/show the use of thread create/exit events.
596 set ada print-signatures on|off
597 show ada print-signatures"
598 Control whether parameter types and return types are displayed in overloads
599 selection menus. It is activaled (@code{on}) by default.
603 Controls the maximum size of memory, in bytes, that GDB will
604 allocate for value contents. Prevents incorrect programs from
605 causing GDB to allocate overly large buffers. Default is 64k.
607 * The "disassemble" command accepts a new modifier: /s.
608 It prints mixed source+disassembly like /m with two differences:
609 - disassembled instructions are now printed in program order, and
610 - and source for all relevant files is now printed.
611 The "/m" option is now considered deprecated: its "source-centric"
612 output hasn't proved useful in practice.
614 * The "record instruction-history" command accepts a new modifier: /s.
615 It behaves exactly like /m and prints mixed source+disassembly.
617 * The "set scheduler-locking" command supports a new mode "replay".
618 It behaves like "off" in record mode and like "on" in replay mode.
620 * Support for various ROM monitors has been removed:
622 target dbug dBUG ROM monitor for Motorola ColdFire
623 target picobug Motorola picobug monitor
624 target dink32 DINK32 ROM monitor for PowerPC
625 target m32r Renesas M32R/D ROM monitor
626 target mon2000 mon2000 ROM monitor
627 target ppcbug PPCBUG ROM monitor for PowerPC
629 * Support for reading/writing memory and extracting values on architectures
630 whose memory is addressable in units of any integral multiple of 8 bits.
635 Indicates that an exec system call was executed.
637 exec-events feature in qSupported
638 The qSupported packet allows GDB to request support for exec
639 events using the new 'gdbfeature' exec-event, and the qSupported
640 response can contain the corresponding 'stubfeature'. Set and
641 show commands can be used to display whether these features are enabled.
644 Equivalent to interrupting with the ^C character, but works in
647 thread created stop reason (T05 create:...)
648 Indicates that the thread was just created and is stopped at entry.
650 thread exit stop reply (w exitcode;tid)
651 Indicates that the thread has terminated.
654 Enables/disables thread create and exit event reporting. For
655 example, this is used in non-stop mode when GDB stops a set of
656 threads and synchronously waits for the their corresponding stop
657 replies. Without exit events, if one of the threads exits, GDB
658 would hang forever not knowing that it should no longer expect a
659 stop for that same thread.
662 Indicates that there are no resumed threads left in the target (all
663 threads are stopped). The remote stub reports support for this stop
664 reply to GDB's qSupported query.
667 Enables/disables catching syscalls from the inferior process.
668 The remote stub reports support for this packet to GDB's qSupported query.
670 syscall_entry stop reason
671 Indicates that a syscall was just called.
673 syscall_return stop reason
674 Indicates that a syscall just returned.
676 * Extended-remote exec events
678 ** GDB now has support for exec events on extended-remote Linux targets.
679 For such targets with Linux kernels 2.5.46 and later, this enables
680 follow-exec-mode and exec catchpoints.
682 set remote exec-event-feature-packet
683 show remote exec-event-feature-packet
684 Set/show the use of the remote exec event feature.
686 * Thread names in remote protocol
688 The reply to qXfer:threads:read may now include a name attribute for each
691 * Target remote mode fork and exec events
693 ** GDB now has support for fork and exec events on target remote mode
694 Linux targets. For such targets with Linux kernels 2.5.46 and later,
695 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
696 fork and exec catchpoints.
698 * Remote syscall events
700 ** GDB now has support for catch syscall on remote Linux targets,
701 currently enabled on x86/x86_64 architectures.
703 set remote catch-syscall-packet
704 show remote catch-syscall-packet
705 Set/show the use of the remote catch syscall feature.
709 ** The -var-set-format command now accepts the zero-hexadecimal
710 format. It outputs data in hexadecimal format with zero-padding on the
715 ** gdb.InferiorThread objects have a new attribute "global_num",
716 which refers to the thread's global thread ID. The existing
717 "num" attribute now refers to the thread's per-inferior number.
718 See "Per-inferior thread numbers" above.
719 ** gdb.InferiorThread objects have a new attribute "inferior", which
720 is the Inferior object the thread belongs to.
722 *** Changes in GDB 7.10
724 * Support for process record-replay and reverse debugging on aarch64*-linux*
725 targets has been added. GDB now supports recording of A64 instruction set
726 including advance SIMD instructions.
728 * Support for Sun's version of the "stabs" debug file format has been removed.
730 * GDB now honors the content of the file /proc/PID/coredump_filter
731 (PID is the process ID) on GNU/Linux systems. This file can be used
732 to specify the types of memory mappings that will be included in a
733 corefile. For more information, please refer to the manual page of
734 "core(5)". GDB also has a new command: "set use-coredump-filter
735 on|off". It allows to set whether GDB will read the content of the
736 /proc/PID/coredump_filter file when generating a corefile.
738 * The "info os" command on GNU/Linux can now display information on
740 "info os cpus" Listing of all cpus/cores on the system
742 * GDB has two new commands: "set serial parity odd|even|none" and
743 "show serial parity". These allows to set or show parity for the
746 * The "info source" command now displays the producer string if it was
747 present in the debug info. This typically includes the compiler version
748 and may include things like its command line arguments.
750 * The "info dll", an alias of the "info sharedlibrary" command,
751 is now available on all platforms.
753 * Directory names supplied to the "set sysroot" commands may be
754 prefixed with "target:" to tell GDB to access shared libraries from
755 the target system, be it local or remote. This replaces the prefix
756 "remote:". The default sysroot has been changed from "" to
757 "target:". "remote:" is automatically converted to "target:" for
758 backward compatibility.
760 * The system root specified by "set sysroot" will be prepended to the
761 filename of the main executable (if reported to GDB as absolute by
762 the operating system) when starting processes remotely, and when
763 attaching to already-running local or remote processes.
765 * GDB now supports automatic location and retrieval of executable
766 files from remote targets. Remote debugging can now be initiated
767 using only a "target remote" or "target extended-remote" command
768 (no "set sysroot" or "file" commands are required). See "New remote
771 * The "dump" command now supports verilog hex format.
773 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
775 * On GNU/Linux, GDB and gdbserver are now able to access executable
776 and shared library files without a "set sysroot" command when
777 attaching to processes running in different mount namespaces from
778 the debugger. This makes it possible to attach to processes in
779 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
780 See "New remote packets" below.
782 * The "tui reg" command now provides completion for all of the
783 available register groups, including target specific groups.
785 * The HISTSIZE environment variable is no longer read when determining
786 the size of GDB's command history. GDB now instead reads the dedicated
787 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
788 disables truncation of command history. Non-numeric values of GDBHISTSIZE
793 ** Memory ports can now be unbuffered.
797 ** gdb.Objfile objects have a new attribute "username",
798 which is the name of the objfile as specified by the user,
799 without, for example, resolving symlinks.
800 ** You can now write frame unwinders in Python.
801 ** gdb.Type objects have a new method "optimized_out",
802 returning optimized out gdb.Value instance of this type.
803 ** gdb.Value objects have new methods "reference_value" and
804 "const_value" which return a reference to the value and a
805 "const" version of the value respectively.
809 maint print symbol-cache
810 Print the contents of the symbol cache.
812 maint print symbol-cache-statistics
813 Print statistics of symbol cache usage.
815 maint flush-symbol-cache
816 Flush the contents of the symbol cache.
820 Start branch trace recording using Branch Trace Store (BTS) format.
823 Evaluate expression by using the compiler and print result.
827 Explicit commands for enabling and disabling tui mode.
830 set mpx bound on i386 and amd64
831 Support for bound table investigation on Intel MPX enabled applications.
835 Start branch trace recording using Intel Processor Trace format.
838 Print information about branch tracing internals.
840 maint btrace packet-history
841 Print the raw branch tracing data.
843 maint btrace clear-packet-history
844 Discard the stored raw branch tracing data.
847 Discard all branch tracing data. It will be fetched and processed
848 anew by the next "record" command.
853 Renamed from "set debug dwarf2-die".
855 Renamed from "show debug dwarf2-die".
858 Renamed from "set debug dwarf2-read".
859 show debug dwarf-read
860 Renamed from "show debug dwarf2-read".
862 maint set dwarf always-disassemble
863 Renamed from "maint set dwarf2 always-disassemble".
864 maint show dwarf always-disassemble
865 Renamed from "maint show dwarf2 always-disassemble".
867 maint set dwarf max-cache-age
868 Renamed from "maint set dwarf2 max-cache-age".
869 maint show dwarf max-cache-age
870 Renamed from "maint show dwarf2 max-cache-age".
873 show debug dwarf-line
874 Control display of debugging info regarding DWARF line processing.
878 Set the maximum number of candidates to be considered during
879 completion. The default value is 200. This limit allows GDB
880 to avoid generating large completion lists, the computation of
881 which can cause the debugger to become temporarily unresponsive.
883 set history remove-duplicates
884 show history remove-duplicates
885 Control the removal of duplicate history entries.
887 maint set symbol-cache-size
888 maint show symbol-cache-size
889 Control the size of the symbol cache.
891 set|show record btrace bts buffer-size
892 Set and show the size of the ring buffer used for branch tracing in
894 The obtained size may differ from the requested size. Use "info
895 record" to see the obtained buffer size.
897 set debug linux-namespaces
898 show debug linux-namespaces
899 Control display of debugging info regarding Linux namespaces.
901 set|show record btrace pt buffer-size
902 Set and show the size of the ring buffer used for branch tracing in
903 Intel Processor Trace format.
904 The obtained size may differ from the requested size. Use "info
905 record" to see the obtained buffer size.
907 maint set|show btrace pt skip-pad
908 Set and show whether PAD packets are skipped when computing the
911 * The command 'thread apply all' can now support new option '-ascending'
912 to call its specified command for all threads in ascending order.
914 * Python/Guile scripting
916 ** GDB now supports auto-loading of Python/Guile scripts contained in the
917 special section named `.debug_gdb_scripts'.
921 qXfer:btrace-conf:read
922 Return the branch trace configuration for the current thread.
924 Qbtrace-conf:bts:size
925 Set the requested ring buffer size for branch tracing in BTS format.
928 Enable Intel Procesor Trace-based branch tracing for the current
929 process. The remote stub reports support for this packet to GDB's
933 Set the requested ring buffer size for branch tracing in Intel Processor
937 Indicates a memory breakpoint instruction was executed, irrespective
938 of whether it was GDB that planted the breakpoint or the breakpoint
939 is hardcoded in the program. This is required for correct non-stop
943 Indicates the target stopped for a hardware breakpoint. This is
944 required for correct non-stop mode operation.
947 Return information about files on the remote system.
950 Return the full absolute name of the file that was executed to
951 create a process running on the remote system.
954 Select the filesystem on which vFile: operations with filename
955 arguments will operate. This is required for GDB to be able to
956 access files on remote targets where the remote stub does not
957 share a common filesystem with the inferior(s).
960 Indicates that a fork system call was executed.
963 Indicates that a vfork system call was executed.
965 vforkdone stop reason
966 Indicates that a vfork child of the specified process has executed
967 an exec or exit, allowing the vfork parent to resume execution.
969 fork-events and vfork-events features in qSupported
970 The qSupported packet allows GDB to request support for fork and
971 vfork events using new 'gdbfeatures' fork-events and vfork-events,
972 and the qSupported response can contain the corresponding
973 'stubfeatures'. Set and show commands can be used to display
974 whether these features are enabled.
976 * Extended-remote fork events
978 ** GDB now has support for fork events on extended-remote Linux
979 targets. For targets with Linux kernels 2.5.60 and later, this
980 enables follow-fork-mode and detach-on-fork for both fork and
981 vfork, as well as fork and vfork catchpoints.
983 * The info record command now shows the recording format and the
984 branch tracing configuration for the current thread when using
985 the btrace record target.
986 For the BTS format, it shows the ring buffer size.
988 * GDB now has support for DTrace USDT (Userland Static Defined
989 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
991 * GDB now supports access to vector registers on S/390 GNU/Linux
994 * Removed command line options
996 -xdb HP-UX XDB compatibility mode.
998 * Removed targets and native configurations
1000 HP/PA running HP-UX hppa*-*-hpux*
1001 Itanium running HP-UX ia64-*-hpux*
1003 * New configure options
1006 This configure option allows the user to build GDB with support for
1007 Intel Processor Trace (default: auto). This requires libipt.
1009 --with-libipt-prefix=PATH
1010 Specify the path to the version of libipt that GDB should use.
1011 $PATH/include should contain the intel-pt.h header and
1012 $PATH/lib should contain the libipt.so library.
1014 *** Changes in GDB 7.9.1
1018 ** Xmethods can now specify a result type.
1020 *** Changes in GDB 7.9
1022 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1026 ** You can now access frame registers from Python scripts.
1027 ** New attribute 'producer' for gdb.Symtab objects.
1028 ** gdb.Objfile objects have a new attribute "progspace",
1029 which is the gdb.Progspace object of the containing program space.
1030 ** gdb.Objfile objects have a new attribute "owner".
1031 ** gdb.Objfile objects have a new attribute "build_id",
1032 which is the build ID generated when the file was built.
1033 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1034 ** A new event "gdb.clear_objfiles" has been added, triggered when
1035 selecting a new file to debug.
1036 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1037 ** New function gdb.lookup_objfile.
1039 New events which are triggered when GDB modifies the state of the
1042 ** gdb.events.inferior_call_pre: Function call is about to be made.
1043 ** gdb.events.inferior_call_post: Function call has just been made.
1044 ** gdb.events.memory_changed: A memory location has been altered.
1045 ** gdb.events.register_changed: A register has been altered.
1047 * New Python-based convenience functions:
1049 ** $_caller_is(name [, number_of_frames])
1050 ** $_caller_matches(regexp [, number_of_frames])
1051 ** $_any_caller_is(name [, number_of_frames])
1052 ** $_any_caller_matches(regexp [, number_of_frames])
1054 * GDB now supports the compilation and injection of source code into
1055 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1056 to compile the source code to object code, and if successful, inject
1057 and execute that code within the current context of the inferior.
1058 Currently the C language is supported. The commands used to
1059 interface with this new feature are:
1061 compile code [-raw|-r] [--] [source code]
1062 compile file [-raw|-r] filename
1066 demangle [-l language] [--] name
1067 Demangle "name" in the specified language, or the current language
1068 if elided. This command is renamed from the "maint demangle" command.
1069 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1070 as "maint demangler-warning".
1072 queue-signal signal-name-or-number
1073 Queue a signal to be delivered to the thread when it is resumed.
1075 add-auto-load-scripts-directory directory
1076 Add entries to the list of directories from which to load auto-loaded
1079 maint print user-registers
1080 List all currently available "user" registers.
1082 compile code [-r|-raw] [--] [source code]
1083 Compile, inject, and execute in the inferior the executable object
1084 code produced by compiling the provided source code.
1086 compile file [-r|-raw] filename
1087 Compile and inject into the inferior the executable object code
1088 produced by compiling the source code stored in the filename
1091 * On resume, GDB now always passes the signal the program had stopped
1092 for to the thread the signal was sent to, even if the user changed
1093 threads before resuming. Previously GDB would often (but not
1094 always) deliver the signal to the thread that happens to be current
1097 * Conversely, the "signal" command now consistently delivers the
1098 requested signal to the current thread. GDB now asks for
1099 confirmation if the program had stopped for a signal and the user
1100 switched threads meanwhile.
1102 * "breakpoint always-inserted" modes "off" and "auto" merged.
1104 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1105 won't remove breakpoints from the target until all threads stop,
1106 even in non-stop mode. The "auto" mode has been removed, and "off"
1107 is now the default mode.
1111 set debug symbol-lookup
1112 show debug symbol-lookup
1113 Control display of debugging info regarding symbol lookup.
1117 ** The -list-thread-groups command outputs an exit-code field for
1118 inferiors that have exited.
1122 MIPS SDE mips*-sde*-elf*
1126 Support for these obsolete configurations has been removed.
1128 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1129 SGI Irix-5.x mips-*-irix5*
1130 SGI Irix-6.x mips-*-irix6*
1131 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1132 VAX running Ultrix vax-*-ultrix*
1134 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1135 and "assf"), have been removed. Use the "sharedlibrary" command, or
1136 its alias "share", instead.
1138 *** Changes in GDB 7.8
1140 * New command line options
1143 This is an alias for the --data-directory option.
1145 * GDB supports printing and modifying of variable length automatic arrays
1146 as specified in ISO C99.
1148 * The ARM simulator now supports instruction level tracing
1149 with or without disassembly.
1153 GDB now has support for scripting using Guile. Whether this is
1154 available is determined at configure time.
1155 Guile version 2.0 or greater is required.
1156 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1158 * New commands (for set/show, see "New options" below)
1162 Invoke CODE by passing it to the Guile interpreter.
1166 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1168 info auto-load guile-scripts [regexp]
1169 Print the list of automatically loaded Guile scripts.
1171 * The source command is now capable of sourcing Guile scripts.
1172 This feature is dependent on the debugger being built with Guile support.
1176 set print symbol-loading (off|brief|full)
1177 show print symbol-loading
1178 Control whether to print informational messages when loading symbol
1179 information for a file. The default is "full", but when debugging
1180 programs with large numbers of shared libraries the amount of output
1181 becomes less useful.
1183 set guile print-stack (none|message|full)
1184 show guile print-stack
1185 Show a stack trace when an error is encountered in a Guile script.
1187 set auto-load guile-scripts (on|off)
1188 show auto-load guile-scripts
1189 Control auto-loading of Guile script files.
1191 maint ada set ignore-descriptive-types (on|off)
1192 maint ada show ignore-descriptive-types
1193 Control whether the debugger should ignore descriptive types in Ada
1194 programs. The default is not to ignore the descriptive types. See
1195 the user manual for more details on descriptive types and the intended
1196 usage of this option.
1198 set auto-connect-native-target
1200 Control whether GDB is allowed to automatically connect to the
1201 native target for the run, attach, etc. commands when not connected
1202 to any target yet. See also "target native" below.
1204 set record btrace replay-memory-access (read-only|read-write)
1205 show record btrace replay-memory-access
1206 Control what memory accesses are allowed during replay.
1208 maint set target-async (on|off)
1209 maint show target-async
1210 This controls whether GDB targets operate in synchronous or
1211 asynchronous mode. Normally the default is asynchronous, if it is
1212 available; but this can be changed to more easily debug problems
1213 occurring only in synchronous mode.
1215 set mi-async (on|off)
1217 Control whether MI asynchronous mode is preferred. This supersedes
1218 "set target-async" of previous GDB versions.
1220 * "set target-async" is deprecated as a CLI option and is now an alias
1221 for "set mi-async" (only puts MI into async mode).
1223 * Background execution commands (e.g., "c&", "s&", etc.) are now
1224 possible ``out of the box'' if the target supports them. Previously
1225 the user would need to explicitly enable the possibility with the
1226 "set target-async on" command.
1228 * New features in the GDB remote stub, GDBserver
1230 ** New option --debug-format=option1[,option2,...] allows one to add
1231 additional text to each output. At present only timestamps
1232 are supported: --debug-format=timestamps.
1233 Timestamps can also be turned on with the
1234 "monitor set debug-format timestamps" command from GDB.
1236 * The 'record instruction-history' command now starts counting instructions
1237 at one. This also affects the instruction ranges reported by the
1238 'record function-call-history' command when given the /i modifier.
1240 * The command 'record function-call-history' supports a new modifier '/c' to
1241 indent the function names based on their call stack depth.
1242 The fields for the '/i' and '/l' modifier have been reordered.
1243 The source line range is now prefixed with 'at'.
1244 The instruction range is now prefixed with 'inst'.
1245 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1246 "record instruction-history" and "list" commands.
1248 * The ranges given as arguments to the 'record function-call-history' and
1249 'record instruction-history' commands are now inclusive.
1251 * The btrace record target now supports the 'record goto' command.
1252 For locations inside the execution trace, the back trace is computed
1253 based on the information stored in the execution trace.
1255 * The btrace record target supports limited reverse execution and replay.
1256 The target does not record data and therefore does not allow reading
1257 memory or registers.
1259 * The "catch syscall" command now works on s390*-linux* targets.
1261 * The "compare-sections" command is no longer specific to target
1262 remote. It now works with all targets.
1264 * All native targets are now consistently called "native".
1265 Consequently, the "target child", "target GNU", "target djgpp",
1266 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1267 commands have been replaced with "target native". The QNX/NTO port
1268 leaves the "procfs" target in place and adds a "native" target for
1269 consistency with other ports. The impact on users should be minimal
1270 as these commands previously either throwed an error, or were
1271 no-ops. The target's name is visible in the output of the following
1272 commands: "help target", "info target", "info files", "maint print
1275 * The "target native" command now connects to the native target. This
1276 can be used to launch native programs even when "set
1277 auto-connect-native-target" is set to off.
1279 * GDB now supports access to Intel MPX registers on GNU/Linux.
1281 * Support for Intel AVX-512 registers on GNU/Linux.
1282 Support displaying and modifying Intel AVX-512 registers
1283 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1285 * New remote packets
1287 qXfer:btrace:read's annex
1288 The qXfer:btrace:read packet supports a new annex 'delta' to read
1289 branch trace incrementally.
1293 ** Valid Python operations on gdb.Value objects representing
1294 structs/classes invoke the corresponding overloaded operators if
1296 ** New `Xmethods' feature in the Python API. Xmethods are
1297 additional methods or replacements for existing methods of a C++
1298 class. This feature is useful for those cases where a method
1299 defined in C++ source code could be inlined or optimized out by
1300 the compiler, making it unavailable to GDB.
1303 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1305 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1306 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1307 its alias "share", instead.
1309 * The commands "set remotebaud" and "show remotebaud" are no longer
1310 supported. Use "set serial baud" and "show serial baud" (respectively)
1315 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1316 target-async". The latter is left as a deprecated alias of the
1317 former for backward compatibility. If the target supports it,
1318 CLI background execution commands are now always possible by
1319 default, independently of whether the frontend stated a
1320 preference for asynchronous execution with "-gdb-set mi-async".
1321 Previously "-gdb-set target-async off" affected both MI execution
1322 commands and CLI execution commands.
1324 *** Changes in GDB 7.7
1326 * Improved support for process record-replay and reverse debugging on
1327 arm*-linux* targets. Support for thumb32 and syscall instruction
1328 recording has been added.
1330 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1332 * GDB now supports Fission DWP file format version 2.
1333 http://gcc.gnu.org/wiki/DebugFission
1335 * New convenience function "$_isvoid", to check whether an expression
1336 is void. A void expression is an expression where the type of the
1337 result is "void". For example, some convenience variables may be
1338 "void" when evaluated (e.g., "$_exitcode" before the execution of
1339 the program being debugged; or an undefined convenience variable).
1340 Another example, when calling a function whose return type is
1343 * The "maintenance print objfiles" command now takes an optional regexp.
1345 * The "catch syscall" command now works on arm*-linux* targets.
1347 * GDB now consistently shows "<not saved>" when printing values of
1348 registers the debug info indicates have not been saved in the frame
1349 and there's nowhere to retrieve them from
1350 (callee-saved/call-clobbered registers):
1355 (gdb) info registers rax
1358 Before, the former would print "<optimized out>", and the latter
1359 "*value not available*".
1361 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1366 ** Frame filters and frame decorators have been added.
1367 ** Temporary breakpoints are now supported.
1368 ** Line tables representation has been added.
1369 ** New attribute 'parent_type' for gdb.Field objects.
1370 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1371 ** New attribute 'name' for gdb.Type objects.
1375 Nios II ELF nios2*-*-elf
1376 Nios II GNU/Linux nios2*-*-linux
1377 Texas Instruments MSP430 msp430*-*-elf
1379 * Removed native configurations
1381 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1382 been removed. ELF variants of these configurations are kept supported.
1384 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1385 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1386 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1387 i[34567]86-*-openbsd3.[0-3]
1388 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1389 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1390 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1394 Like "catch throw", but catches a re-thrown exception.
1395 maint check-psymtabs
1396 Renamed from old "maint check-symtabs".
1398 Perform consistency checks on symtabs.
1399 maint expand-symtabs
1400 Expand symtabs matching an optional regexp.
1403 Display the details of GDB configure-time options.
1405 maint set|show per-command
1406 maint set|show per-command space
1407 maint set|show per-command time
1408 maint set|show per-command symtab
1409 Enable display of per-command gdb resource usage.
1411 remove-symbol-file FILENAME
1412 remove-symbol-file -a ADDRESS
1413 Remove a symbol file added via add-symbol-file. The file to remove
1414 can be identified by its filename or by an address that lies within
1415 the boundaries of this symbol file in memory.
1418 info exceptions REGEXP
1419 Display the list of Ada exceptions defined in the program being
1420 debugged. If provided, only the exceptions whose names match REGEXP
1425 set debug symfile off|on
1427 Control display of debugging info regarding reading symbol files and
1428 symbol tables within those files
1430 set print raw frame-arguments
1431 show print raw frame-arguments
1432 Set/show whether to print frame arguments in raw mode,
1433 disregarding any defined pretty-printers.
1435 set remote trace-status-packet
1436 show remote trace-status-packet
1437 Set/show the use of remote protocol qTStatus packet.
1441 Control display of debugging messages related to Nios II targets.
1445 Control whether target-assisted range stepping is enabled.
1447 set startup-with-shell
1448 show startup-with-shell
1449 Specifies whether Unix child processes are started via a shell or
1454 Use the target memory cache for accesses to the code segment. This
1455 improves performance of remote debugging (particularly disassembly).
1457 * You can now use a literal value 'unlimited' for options that
1458 interpret 0 or -1 as meaning "unlimited". E.g., "set
1459 trace-buffer-size unlimited" is now an alias for "set
1460 trace-buffer-size -1" and "set height unlimited" is now an alias for
1463 * The "set debug symtab-create" debugging option of GDB has been changed to
1464 accept a verbosity level. 0 means "off", 1 provides basic debugging
1465 output, and values of 2 or greater provides more verbose output.
1467 * New command-line options
1469 Display the details of GDB configure-time options.
1471 * The command 'tsave' can now support new option '-ctf' to save trace
1472 buffer in Common Trace Format.
1474 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1477 * GDB now implements the the C++ 'typeid' operator.
1479 * The new convenience variable $_exception holds the exception being
1480 thrown or caught at an exception-related catchpoint.
1482 * The exception-related catchpoints, like "catch throw", now accept a
1483 regular expression which can be used to filter exceptions by type.
1485 * The new convenience variable $_exitsignal is automatically set to
1486 the terminating signal number when the program being debugged dies
1487 due to an uncaught signal.
1491 ** All MI commands now accept an optional "--language" option.
1492 Support for this feature can be verified by using the "-list-features"
1493 command, which should contain "language-option".
1495 ** The new command -info-gdb-mi-command allows the user to determine
1496 whether a GDB/MI command is supported or not.
1498 ** The "^error" result record returned when trying to execute an undefined
1499 GDB/MI command now provides a variable named "code" whose content is the
1500 "undefined-command" error code. Support for this feature can be verified
1501 by using the "-list-features" command, which should contain
1502 "undefined-command-error-code".
1504 ** The -trace-save MI command can optionally save trace buffer in Common
1507 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1509 ** The command -data-list-register-values now accepts an optional
1510 "--skip-unavailable" option. When used, only the available registers
1513 ** The new command -trace-frame-collected dumps collected variables,
1514 computed expressions, tvars, memory and registers in a traceframe.
1516 ** The commands -stack-list-locals, -stack-list-arguments and
1517 -stack-list-variables now accept an option "--skip-unavailable".
1518 When used, only the available locals or arguments are displayed.
1520 ** The -exec-run command now accepts an optional "--start" option.
1521 When used, the command follows the same semantics as the "start"
1522 command, stopping the program's execution at the start of its
1523 main subprogram. Support for this feature can be verified using
1524 the "-list-features" command, which should contain
1525 "exec-run-start-option".
1527 ** The new commands -catch-assert and -catch-exceptions insert
1528 catchpoints stopping the program when Ada exceptions are raised.
1530 ** The new command -info-ada-exceptions provides the equivalent of
1531 the new "info exceptions" command.
1533 * New system-wide configuration scripts
1534 A GDB installation now provides scripts suitable for use as system-wide
1535 configuration scripts for the following systems:
1539 * GDB now supports target-assigned range stepping with remote targets.
1540 This improves the performance of stepping source lines by reducing
1541 the number of control packets from/to GDB. See "New remote packets"
1544 * GDB now understands the element 'tvar' in the XML traceframe info.
1545 It has the id of the collected trace state variables.
1547 * On S/390 targets that provide the transactional-execution feature,
1548 the program interruption transaction diagnostic block (TDB) is now
1549 represented as a number of additional "registers" in GDB.
1551 * New remote packets
1555 The vCont packet supports a new 'r' action, that tells the remote
1556 stub to step through an address range itself, without GDB
1557 involvemement at each single-step.
1559 qXfer:libraries-svr4:read's annex
1560 The previously unused annex of the qXfer:libraries-svr4:read packet
1561 is now used to support passing an argument list. The remote stub
1562 reports support for this argument list to GDB's qSupported query.
1563 The defined arguments are "start" and "prev", used to reduce work
1564 necessary for library list updating, resulting in significant
1567 * New features in the GDB remote stub, GDBserver
1569 ** GDBserver now supports target-assisted range stepping. Currently
1570 enabled on x86/x86_64 GNU/Linux targets.
1572 ** GDBserver now adds element 'tvar' in the XML in the reply to
1573 'qXfer:traceframe-info:read'. It has the id of the collected
1574 trace state variables.
1576 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1579 * New 'z' formatter for printing and examining memory, this displays the
1580 value as hexadecimal zero padded on the left to the size of the type.
1582 * GDB can now use Windows x64 unwinding data.
1584 * The "set remotebaud" command has been replaced by "set serial baud".
1585 Similarly, "show remotebaud" has been replaced by "show serial baud".
1586 The "set remotebaud" and "show remotebaud" commands are still available
1587 to provide backward compatibility with older versions of GDB.
1589 *** Changes in GDB 7.6
1591 * Target record has been renamed to record-full.
1592 Record/replay is now enabled with the "record full" command.
1593 This also affects settings that are associated with full record/replay
1594 that have been moved from "set/show record" to "set/show record full":
1596 set|show record full insn-number-max
1597 set|show record full stop-at-limit
1598 set|show record full memory-query
1600 * A new record target "record-btrace" has been added. The new target
1601 uses hardware support to record the control-flow of a process. It
1602 does not support replaying the execution, but it implements the
1603 below new commands for investigating the recorded execution log.
1604 This new recording method can be enabled using:
1608 The "record-btrace" target is only available on Intel Atom processors
1609 and requires a Linux kernel 2.6.32 or later.
1611 * Two new commands have been added for record/replay to give information
1612 about the recorded execution without having to replay the execution.
1613 The commands are only supported by "record btrace".
1615 record instruction-history prints the execution history at
1616 instruction granularity
1618 record function-call-history prints the execution history at
1619 function granularity
1621 * New native configurations
1623 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1624 FreeBSD/powerpc powerpc*-*-freebsd
1625 x86_64/Cygwin x86_64-*-cygwin*
1626 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1630 ARM AArch64 aarch64*-*-elf
1631 ARM AArch64 GNU/Linux aarch64*-*-linux
1632 Lynx 178 PowerPC powerpc-*-lynx*178
1633 x86_64/Cygwin x86_64-*-cygwin*
1634 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1636 * If the configured location of system.gdbinit file (as given by the
1637 --with-system-gdbinit option at configure time) is in the
1638 data-directory (as specified by --with-gdb-datadir at configure
1639 time) or in one of its subdirectories, then GDB will look for the
1640 system-wide init file in the directory specified by the
1641 --data-directory command-line option.
1643 * New command line options:
1645 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1646 other initialization files, unlike -nx which disables all of them.
1648 * Removed command line options
1650 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1653 * The 'ptype' and 'whatis' commands now accept an argument to control
1656 * 'info proc' now works on some core files.
1660 ** Vectors can be created with gdb.Type.vector.
1662 ** Python's atexit.register now works in GDB.
1664 ** Types can be pretty-printed via a Python API.
1666 ** Python 3 is now supported (in addition to Python 2.4 or later)
1668 ** New class gdb.Architecture exposes GDB's internal representation
1669 of architecture in the Python API.
1671 ** New method Frame.architecture returns the gdb.Architecture object
1672 corresponding to the frame's architecture.
1674 * New Python-based convenience functions:
1676 ** $_memeq(buf1, buf2, length)
1677 ** $_streq(str1, str2)
1679 ** $_regex(str, regex)
1681 * The 'cd' command now defaults to using '~' (the home directory) if not
1684 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1685 default for GCC since November 2000.
1687 * The command 'forward-search' can now be abbreviated as 'fo'.
1689 * The command 'info tracepoints' can now display 'installed on target'
1690 or 'not installed on target' for each non-pending location of tracepoint.
1692 * New configure options
1694 --enable-libmcheck/--disable-libmcheck
1695 By default, development versions are built with -lmcheck on hosts
1696 that support it, in order to help track memory corruption issues.
1697 Release versions, on the other hand, are built without -lmcheck
1698 by default. The --enable-libmcheck/--disable-libmcheck configure
1699 options allow the user to override that default.
1700 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1701 This configure option allows the user to build GDB with
1702 libbabeltrace using which GDB can read Common Trace Format data.
1704 * New commands (for set/show, see "New options" below)
1707 Catch signals. This is similar to "handle", but allows commands and
1708 conditions to be attached.
1711 List the BFDs known to GDB.
1713 python-interactive [command]
1715 Start a Python interactive prompt, or evaluate the optional command
1716 and print the result of expressions.
1719 "py" is a new alias for "python".
1721 enable type-printer [name]...
1722 disable type-printer [name]...
1723 Enable or disable type printers.
1727 ** For the Renesas Super-H architecture, the "regs" command has been removed
1728 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1733 set print type methods (on|off)
1734 show print type methods
1735 Control whether method declarations are displayed by "ptype".
1736 The default is to show them.
1738 set print type typedefs (on|off)
1739 show print type typedefs
1740 Control whether typedef definitions are displayed by "ptype".
1741 The default is to show them.
1743 set filename-display basename|relative|absolute
1744 show filename-display
1745 Control the way in which filenames is displayed.
1746 The default is "relative", which preserves previous behavior.
1748 set trace-buffer-size
1749 show trace-buffer-size
1750 Request target to change the size of trace buffer.
1752 set remote trace-buffer-size-packet auto|on|off
1753 show remote trace-buffer-size-packet
1754 Control the use of the remote protocol `QTBuffer:size' packet.
1758 Control display of debugging messages related to ARM AArch64.
1761 set debug coff-pe-read
1762 show debug coff-pe-read
1763 Control display of debugging messages related to reading of COFF/PE
1768 Control display of debugging messages related to Mach-O symbols
1771 set debug notification
1772 show debug notification
1773 Control display of debugging info for async remote notification.
1777 ** Command parameter changes are now notified using new async record
1778 "=cmd-param-changed".
1779 ** Trace frame changes caused by command "tfind" are now notified using
1780 new async record "=traceframe-changed".
1781 ** The creation, deletion and modification of trace state variables
1782 are now notified using new async records "=tsv-created",
1783 "=tsv-deleted" and "=tsv-modified".
1784 ** The start and stop of process record are now notified using new
1785 async record "=record-started" and "=record-stopped".
1786 ** Memory changes are now notified using new async record
1788 ** The data-disassemble command response will include a "fullname" field
1789 containing the absolute file name when source has been requested.
1790 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1791 command, to allow pattern filling of memory areas.
1792 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1793 library load/unload events.
1794 ** The response to breakpoint commands and breakpoint async records
1795 includes an "installed" field containing a boolean state about each
1796 non-pending tracepoint location is whether installed on target or not.
1797 ** Output of the "-trace-status" command includes a "trace-file" field
1798 containing the name of the trace file being examined. This field is
1799 optional, and only present when examining a trace file.
1800 ** The "fullname" field is now always present along with the "file" field,
1801 even if the file cannot be found by GDB.
1803 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1804 You must have the LZMA library available when configuring GDB for this
1805 feature to be enabled. For more information, see:
1806 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1808 * New remote packets
1811 Set the size of trace buffer. The remote stub reports support for this
1812 packet to gdb's qSupported query.
1815 Enable Branch Trace Store (BTS)-based branch tracing for the current
1816 thread. The remote stub reports support for this packet to gdb's
1820 Disable branch tracing for the current thread. The remote stub reports
1821 support for this packet to gdb's qSupported query.
1824 Read the traced branches for the current thread. The remote stub
1825 reports support for this packet to gdb's qSupported query.
1827 *** Changes in GDB 7.5
1829 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1830 for more x32 ABI info.
1832 * GDB now supports access to MIPS DSP registers on Linux targets.
1834 * GDB now supports debugging microMIPS binaries.
1836 * The "info os" command on GNU/Linux can now display information on
1837 several new classes of objects managed by the operating system:
1838 "info os procgroups" lists process groups
1839 "info os files" lists file descriptors
1840 "info os sockets" lists internet-domain sockets
1841 "info os shm" lists shared-memory regions
1842 "info os semaphores" lists semaphores
1843 "info os msg" lists message queues
1844 "info os modules" lists loaded kernel modules
1846 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1847 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1848 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1849 options and inspect the probe arguments using the new $_probe_arg family
1850 of convenience variables. You can obtain more information about SystemTap
1851 in <http://sourceware.org/systemtap/>.
1853 * GDB now supports reversible debugging on ARM, it allows you to
1854 debug basic ARM and THUMB instructions, and provides
1855 record/replay support.
1857 * The option "symbol-reloading" has been deleted as it is no longer used.
1861 ** GDB commands implemented in Python can now be put in command class
1864 ** The "maint set python print-stack on|off" is now deleted.
1866 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1867 apply "flag enum"-style pretty-printing to any enum.
1869 ** gdb.lookup_symbol can now work when there is no current frame.
1871 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1872 the source at which the symbol was defined.
1874 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1875 method 'value'. The former indicates whether the symbol needs a
1876 frame in order to compute its value, and the latter computes the
1879 ** A new method 'referenced_value' on gdb.Value objects which can
1880 dereference pointer as well as C++ reference values.
1882 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1883 which return the global and static blocks (as gdb.Block objects),
1884 of the underlying symbol table, respectively.
1886 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1887 object associated with a PC value.
1889 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1890 of the address range occupied by code for the current source line.
1892 * Go language support.
1893 GDB now supports debugging programs written in the Go programming
1896 * GDBserver now supports stdio connections.
1897 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1899 * The binary "gdbtui" can no longer be built or installed.
1900 Use "gdb -tui" instead.
1902 * GDB will now print "flag" enums specially. A flag enum is one where
1903 all the enumerator values have no bits in common when pairwise
1904 "and"ed. When printing a value whose type is a flag enum, GDB will
1905 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1906 (gdb) print (enum E) 3
1909 * The filename part of a linespec will now match trailing components
1910 of a source file name. For example, "break gcc/expr.c:1000" will
1911 now set a breakpoint in build/gcc/expr.c, but not
1912 build/libcpp/expr.c.
1914 * The "info proc" and "generate-core-file" commands will now also
1915 work on remote targets connected to GDBserver on Linux.
1917 * The command "info catch" has been removed. It has been disabled
1918 since December 2007.
1920 * The "catch exception" and "catch assert" commands now accept
1921 a condition at the end of the command, much like the "break"
1922 command does. For instance:
1924 (gdb) catch exception Constraint_Error if Barrier = True
1926 Previously, it was possible to add a condition to such catchpoints,
1927 but it had to be done as a second step, after the catchpoint had been
1928 created, using the "condition" command.
1930 * The "info static-tracepoint-marker" command will now also work on
1931 native Linux targets with in-process agent.
1933 * GDB can now set breakpoints on inlined functions.
1935 * The .gdb_index section has been updated to include symbols for
1936 inlined functions. GDB will ignore older .gdb_index sections by
1937 default, which could cause symbol files to be loaded more slowly
1938 until their .gdb_index sections can be recreated. The new command
1939 "set use-deprecated-index-sections on" will cause GDB to use any older
1940 .gdb_index sections it finds. This will restore performance, but the
1941 ability to set breakpoints on inlined functions will be lost in symbol
1942 files with older .gdb_index sections.
1944 The .gdb_index section has also been updated to record more information
1945 about each symbol. This speeds up the "info variables", "info functions"
1946 and "info types" commands when used with programs having the .gdb_index
1947 section, as well as speeding up debugging with shared libraries using
1948 the .gdb_index section.
1950 * Ada support for GDB/MI Variable Objects has been added.
1952 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1957 ** New command -info-os is the MI equivalent of "info os".
1959 ** Output logs ("set logging" and related) now include MI output.
1963 ** "set use-deprecated-index-sections on|off"
1964 "show use-deprecated-index-sections on|off"
1965 Controls the use of deprecated .gdb_index sections.
1967 ** "catch load" and "catch unload" can be used to stop when a shared
1968 library is loaded or unloaded, respectively.
1970 ** "enable count" can be used to auto-disable a breakpoint after
1973 ** "info vtbl" can be used to show the virtual method tables for
1974 C++ and Java objects.
1976 ** "explore" and its sub commands "explore value" and "explore type"
1977 can be used to recursively explore values and types of
1978 expressions. These commands are available only if GDB is
1979 configured with '--with-python'.
1981 ** "info auto-load" shows status of all kinds of auto-loaded files,
1982 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1983 sequences of commands files, "info auto-load python-scripts"
1984 shows status of auto-loading Python script files,
1985 "info auto-load local-gdbinit" shows status of loading init file
1986 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1987 status of inferior specific thread debugging shared library loading.
1989 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1990 and "show auto-load-scripts" commands have been deprecated, use their
1991 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1992 and "show auto-load python-scripts" counterparts instead.
1994 ** "dprintf location,format,args..." creates a dynamic printf, which
1995 is basically a breakpoint that does a printf and immediately
1996 resumes your program's execution, so it is like a printf that you
1997 can insert dynamically at runtime instead of at compiletime.
1999 ** "set print symbol"
2001 Controls whether GDB attempts to display the symbol, if any,
2002 corresponding to addresses it prints. This defaults to "on", but
2003 you can set it to "off" to restore GDB's previous behavior.
2005 * Deprecated commands
2007 ** For the Renesas Super-H architecture, the "regs" command has been
2008 deprecated, and "info all-registers" should be used instead.
2012 Renesas RL78 rl78-*-elf
2013 HP OpenVMS ia64 ia64-hp-openvms*
2015 * GDBserver supports evaluation of breakpoint conditions. When
2016 support is advertised by GDBserver, GDB may be told to send the
2017 breakpoint conditions in bytecode form to GDBserver. GDBserver
2018 will only report the breakpoint trigger to GDB when its condition
2023 set mips compression
2024 show mips compression
2025 Select the compressed ISA encoding used in functions that have no symbol
2026 information available. The encoding can be set to either of:
2029 and is updated automatically from ELF file flags if available.
2031 set breakpoint condition-evaluation
2032 show breakpoint condition-evaluation
2033 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2034 GDBserver ("target"). Default option "auto" chooses the most efficient
2036 This option can improve debugger efficiency depending on the speed of the
2040 Disable auto-loading globally.
2043 Show auto-loading setting of all kinds of auto-loaded files.
2045 set auto-load gdb-scripts on|off
2046 show auto-load gdb-scripts
2047 Control auto-loading of GDB canned sequences of commands files.
2049 set auto-load python-scripts on|off
2050 show auto-load python-scripts
2051 Control auto-loading of Python script files.
2053 set auto-load local-gdbinit on|off
2054 show auto-load local-gdbinit
2055 Control loading of init file (.gdbinit) from current directory.
2057 set auto-load libthread-db on|off
2058 show auto-load libthread-db
2059 Control auto-loading of inferior specific thread debugging shared library.
2061 set auto-load scripts-directory <dir1>[:<dir2>...]
2062 show auto-load scripts-directory
2063 Set a list of directories from which to load auto-loaded scripts.
2064 Automatically loaded Python scripts and GDB scripts are located in one
2065 of the directories listed by this option.
2066 The delimiter (':' above) may differ according to the host platform.
2068 set auto-load safe-path <dir1>[:<dir2>...]
2069 show auto-load safe-path
2070 Set a list of directories from which it is safe to auto-load files.
2071 The delimiter (':' above) may differ according to the host platform.
2073 set debug auto-load on|off
2074 show debug auto-load
2075 Control display of debugging info for auto-loading the files above.
2077 set dprintf-style gdb|call|agent
2079 Control the way in which a dynamic printf is performed; "gdb"
2080 requests a GDB printf command, while "call" causes dprintf to call a
2081 function in the inferior. "agent" requests that the target agent
2082 (such as GDBserver) do the printing.
2084 set dprintf-function <expr>
2085 show dprintf-function
2086 set dprintf-channel <expr>
2087 show dprintf-channel
2088 Set the function and optional first argument to the call when using
2089 the "call" style of dynamic printf.
2091 set disconnected-dprintf on|off
2092 show disconnected-dprintf
2093 Control whether agent-style dynamic printfs continue to be in effect
2094 after GDB disconnects.
2096 * New configure options
2098 --with-auto-load-dir
2099 Configure default value for the 'set auto-load scripts-directory'
2100 setting above. It defaults to '$debugdir:$datadir/auto-load',
2101 $debugdir representing global debugging info directories (available
2102 via 'show debug-file-directory') and $datadir representing GDB's data
2103 directory (available via 'show data-directory').
2105 --with-auto-load-safe-path
2106 Configure default value for the 'set auto-load safe-path' setting
2107 above. It defaults to the --with-auto-load-dir setting.
2109 --without-auto-load-safe-path
2110 Set 'set auto-load safe-path' to '/', effectively disabling this
2113 * New remote packets
2115 z0/z1 conditional breakpoints extension
2117 The z0/z1 breakpoint insertion packets have been extended to carry
2118 a list of conditional expressions over to the remote stub depending on the
2119 condition evaluation mode. The use of this extension can be controlled
2120 via the "set remote conditional-breakpoints-packet" command.
2124 Specify the signals which the remote stub may pass to the debugged
2125 program without GDB involvement.
2127 * New command line options
2129 --init-command=FILE, -ix Like --command, -x but execute it
2130 before loading inferior.
2131 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2132 execute it before loading inferior.
2134 *** Changes in GDB 7.4
2136 * GDB now handles ambiguous linespecs more consistently; the existing
2137 FILE:LINE support has been expanded to other types of linespecs. A
2138 breakpoint will now be set on all matching locations in all
2139 inferiors, and locations will be added or removed according to
2142 * GDB now allows you to skip uninteresting functions and files when
2143 stepping with the "skip function" and "skip file" commands.
2145 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2146 and "show remote hardware-watchpoint-length-limit". These allows to
2147 set or show the maximum length limit (in bytes) of a remote
2148 target hardware watchpoint.
2150 This allows e.g. to use "unlimited" hardware watchpoints with the
2151 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2152 watchpoints are slower than real hardware watchpoints but are
2153 significantly faster than gdb software watchpoints.
2157 ** The register_pretty_printer function in module gdb.printing now takes
2158 an optional `replace' argument. If True, the new printer replaces any
2161 ** The "maint set python print-stack on|off" command has been
2162 deprecated and will be deleted in GDB 7.5.
2163 A new command: "set python print-stack none|full|message" has
2164 replaced it. Additionally, the default for "print-stack" is
2165 now "message", which just prints the error message without
2168 ** A prompt substitution hook (prompt_hook) is now available to the
2171 ** A new Python module, gdb.prompt has been added to the GDB Python
2172 modules library. This module provides functionality for
2173 escape sequences in prompts (used by set/show
2174 extended-prompt). These escape sequences are replaced by their
2175 corresponding value.
2177 ** Python commands and convenience-functions located in
2178 'data-directory'/python/gdb/command and
2179 'data-directory'/python/gdb/function are now automatically loaded
2182 ** Blocks now provide four new attributes. global_block and
2183 static_block will return the global and static blocks
2184 respectively. is_static and is_global are boolean attributes
2185 that indicate if the block is one of those two types.
2187 ** Symbols now provide the "type" attribute, the type of the symbol.
2189 ** The "gdb.breakpoint" function has been deprecated in favor of
2192 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2193 of a function. This class is based on the "finish" command
2194 available in the CLI.
2196 ** Type objects for struct and union types now allow access to
2197 the fields using standard Python dictionary (mapping) methods.
2198 For example, "some_type['myfield']" now works, as does
2199 "some_type.items()".
2201 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2204 ** A new function, "deep_items" has been added to the gdb.types
2205 module in the GDB Python modules library. This function returns
2206 an iterator over the fields of a struct or union type. Unlike
2207 the standard Python "iteritems" method, it will recursively traverse
2208 any anonymous fields.
2212 ** "*stopped" events can report several new "reason"s, such as
2215 ** Breakpoint changes are now notified using new async records, like
2216 "=breakpoint-modified".
2218 ** New command -ada-task-info.
2220 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2221 $sdir specifies the default system locations of shared libraries.
2222 $pdir specifies the directory where the libpthread used by the application
2225 GDB no longer looks in $sdir and $pdir after it has searched the directories
2226 mentioned in libthread-db-search-path. If you want to search those
2227 directories, they must be specified in libthread-db-search-path.
2228 The default value of libthread-db-search-path on GNU/Linux and Solaris
2229 systems is now "$sdir:$pdir".
2231 $pdir is not supported by gdbserver, it is currently ignored.
2232 $sdir is supported by gdbserver.
2234 * New configure option --with-iconv-bin.
2235 When using the internationalization support like the one in the GNU C
2236 library, GDB will invoke the "iconv" program to get a list of supported
2237 character sets. If this program lives in a non-standard location, one can
2238 use this option to specify where to find it.
2240 * When natively debugging programs on PowerPC BookE processors running
2241 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2242 watchpoints, which specify a mask in addition to an address to watch.
2243 The mask specifies that some bits of an address (the bits which are
2244 reset in the mask) should be ignored when matching the address accessed
2245 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2246 section in the user manual for more details.
2248 * The new option --once causes GDBserver to stop listening for connections once
2249 the first connection is made. The listening port used by GDBserver will
2250 become available after that.
2252 * New commands "info macros" and "alias" have been added.
2254 * New function parameters suffix @entry specifies value of function parameter
2255 at the time the function got called. Entry values are available only since
2261 "!" is now an alias of the "shell" command.
2262 Note that no space is needed between "!" and SHELL COMMAND.
2266 watch EXPRESSION mask MASK_VALUE
2267 The watch command now supports the mask argument which allows creation
2268 of masked watchpoints, if the current architecture supports this feature.
2270 info auto-load-scripts [REGEXP]
2271 This command was formerly named "maintenance print section-scripts".
2272 It is now generally useful and is no longer a maintenance-only command.
2274 info macro [-all] [--] MACRO
2275 The info macro command has new options `-all' and `--'. The first for
2276 printing all definitions of a macro. The second for explicitly specifying
2277 the end of arguments and the beginning of the macro name in case the macro
2278 name starts with a hyphen.
2280 collect[/s] EXPRESSIONS
2281 The tracepoint collect command now takes an optional modifier "/s"
2282 that directs it to dereference pointer-to-character types and
2283 collect the bytes of memory up to a zero byte. The behavior is
2284 similar to what you see when you use the regular print command on a
2285 string. An optional integer following the "/s" sets a bound on the
2286 number of bytes that will be collected.
2289 The trace start command now interprets any supplied arguments as a
2290 note to be recorded with the trace run, with an effect similar to
2291 setting the variable trace-notes.
2294 The trace stop command now interprets any arguments as a note to be
2295 mentioned along with the tstatus report that the trace was stopped
2296 with a command. The effect is similar to setting the variable
2299 * Tracepoints can now be enabled and disabled at any time after a trace
2300 experiment has been started using the standard "enable" and "disable"
2301 commands. It is now possible to start a trace experiment with no enabled
2302 tracepoints; GDB will display a warning, but will allow the experiment to
2303 begin, assuming that tracepoints will be enabled as needed while the trace
2306 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2307 locations with 4-byte instructions, when they were previously
2308 limited to locations with instructions of 5 bytes or longer.
2312 set debug dwarf2-read
2313 show debug dwarf2-read
2314 Turns on or off display of debugging messages related to reading
2315 DWARF debug info. The default is off.
2317 set debug symtab-create
2318 show debug symtab-create
2319 Turns on or off display of debugging messages related to symbol table
2320 creation. The default is off.
2323 show extended-prompt
2324 Set the GDB prompt, and allow escape sequences to be inserted to
2325 display miscellaneous information (see 'help set extended-prompt'
2326 for the list of sequences). This prompt (and any information
2327 accessed through the escape sequences) is updated every time the
2328 prompt is displayed.
2330 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2331 show print entry-values
2332 Set printing of frame argument values at function entry. In some cases
2333 GDB can determine the value of function argument which was passed by the
2334 function caller, even if the value was modified inside the called function.
2336 set debug entry-values
2337 show debug entry-values
2338 Control display of debugging info for determining frame argument values at
2339 function entry and virtual tail call frames.
2341 set basenames-may-differ
2342 show basenames-may-differ
2343 Set whether a source file may have multiple base names.
2344 (A "base name" is the name of a file with the directory part removed.
2345 Example: The base name of "/home/user/hello.c" is "hello.c".)
2346 If set, GDB will canonicalize file names (e.g., expand symlinks)
2347 before comparing them. Canonicalization is an expensive operation,
2348 but it allows the same file be known by more than one base name.
2349 If not set (the default), all source files are assumed to have just
2350 one base name, and gdb will do file name comparisons more efficiently.
2356 Set a user name and notes for the current and any future trace runs.
2357 This is useful for long-running and/or disconnected traces, to
2358 inform others (or yourself) as to who is running the trace, supply
2359 contact information, or otherwise explain what is going on.
2361 set trace-stop-notes
2362 show trace-stop-notes
2363 Set a note attached to the trace run, that is displayed when the
2364 trace has been stopped by a tstop command. This is useful for
2365 instance as an explanation, if you are stopping a trace run that was
2366 started by someone else.
2368 * New remote packets
2372 Dynamically enable a tracepoint in a started trace experiment.
2376 Dynamically disable a tracepoint in a started trace experiment.
2380 Set the user and notes of the trace run.
2384 Query the current status of a tracepoint.
2388 Query the minimum length of instruction at which a fast tracepoint may
2391 * Dcache size (number of lines) and line-size are now runtime-configurable
2392 via "set dcache line" and "set dcache line-size" commands.
2396 Texas Instruments TMS320C6x tic6x-*-*
2400 Renesas RL78 rl78-*-elf
2402 *** Changes in GDB 7.3.1
2404 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2406 *** Changes in GDB 7.3
2408 * GDB has a new command: "thread find [REGEXP]".
2409 It finds the thread id whose name, target id, or thread extra info
2410 matches the given regular expression.
2412 * The "catch syscall" command now works on mips*-linux* targets.
2414 * The -data-disassemble MI command now supports modes 2 and 3 for
2415 dumping the instruction opcodes.
2417 * New command line options
2419 -data-directory DIR Specify DIR as the "data-directory".
2420 This is mostly for testing purposes.
2422 * The "maint set python auto-load on|off" command has been renamed to
2423 "set auto-load-scripts on|off".
2425 * GDB has a new command: "set directories".
2426 It is like the "dir" command except that it replaces the
2427 source path list instead of augmenting it.
2429 * GDB now understands thread names.
2431 On GNU/Linux, "info threads" will display the thread name as set by
2432 prctl or pthread_setname_np.
2434 There is also a new command, "thread name", which can be used to
2435 assign a name internally for GDB to display.
2438 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2439 has been integrated into GDB.
2443 ** The function gdb.Write now accepts an optional keyword 'stream'.
2444 This keyword, when provided, will direct the output to either
2445 stdout, stderr, or GDB's logging output.
2447 ** Parameters can now be be sub-classed in Python, and in particular
2448 you may implement the get_set_doc and get_show_doc functions.
2449 This improves how Parameter set/show documentation is processed
2450 and allows for more dynamic content.
2452 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2453 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2454 have an is_valid method.
2456 ** Breakpoints can now be sub-classed in Python, and in particular
2457 you may implement a 'stop' function that is executed each time
2458 the inferior reaches that breakpoint.
2460 ** New function gdb.lookup_global_symbol looks up a global symbol.
2462 ** GDB values in Python are now callable if the value represents a
2463 function. For example, if 'some_value' represents a function that
2464 takes two integer parameters and returns a value, you can call
2465 that function like so:
2467 result = some_value (10,20)
2469 ** Module gdb.types has been added.
2470 It contains a collection of utilities for working with gdb.Types objects:
2471 get_basic_type, has_field, make_enum_dict.
2473 ** Module gdb.printing has been added.
2474 It contains utilities for writing and registering pretty-printers.
2475 New classes: PrettyPrinter, SubPrettyPrinter,
2476 RegexpCollectionPrettyPrinter.
2477 New function: register_pretty_printer.
2479 ** New commands "info pretty-printers", "enable pretty-printer" and
2480 "disable pretty-printer" have been added.
2482 ** gdb.parameter("directories") is now available.
2484 ** New function gdb.newest_frame returns the newest frame in the
2487 ** The gdb.InferiorThread class has a new "name" attribute. This
2488 holds the thread's name.
2490 ** Python Support for Inferior events.
2491 Python scripts can add observers to be notified of events
2492 occurring in the process being debugged.
2493 The following events are currently supported:
2494 - gdb.events.cont Continue event.
2495 - gdb.events.exited Inferior exited event.
2496 - gdb.events.stop Signal received, and Breakpoint hit events.
2500 ** GDB now puts template parameters in scope when debugging in an
2501 instantiation. For example, if you have:
2503 template<int X> int func (void) { return X; }
2505 then if you step into func<5>, "print X" will show "5". This
2506 feature requires proper debuginfo support from the compiler; it
2507 was added to GCC 4.5.
2509 ** The motion commands "next", "finish", "until", and "advance" now
2510 work better when exceptions are thrown. In particular, GDB will
2511 no longer lose control of the inferior; instead, the GDB will
2512 stop the inferior at the point at which the exception is caught.
2513 This functionality requires a change in the exception handling
2514 code that was introduced in GCC 4.5.
2516 * GDB now follows GCC's rules on accessing volatile objects when
2517 reading or writing target state during expression evaluation.
2518 One notable difference to prior behavior is that "print x = 0"
2519 no longer generates a read of x; the value of the assignment is
2520 now always taken directly from the value being assigned.
2522 * GDB now has some support for using labels in the program's source in
2523 linespecs. For instance, you can use "advance label" to continue
2524 execution to a label.
2526 * GDB now has support for reading and writing a new .gdb_index
2527 section. This section holds a fast index of DWARF debugging
2528 information and can be used to greatly speed up GDB startup and
2529 operation. See the documentation for `save gdb-index' for details.
2531 * The "watch" command now accepts an optional "-location" argument.
2532 When used, this causes GDB to watch the memory referred to by the
2533 expression. Such a watchpoint is never deleted due to it going out
2536 * GDB now supports thread debugging of core dumps on GNU/Linux.
2538 GDB now activates thread debugging using the libthread_db library
2539 when debugging GNU/Linux core dumps, similarly to when debugging
2540 live processes. As a result, when debugging a core dump file, GDB
2541 is now able to display pthread_t ids of threads. For example, "info
2542 threads" shows the same output as when debugging the process when it
2543 was live. In earlier releases, you'd see something like this:
2546 * 1 LWP 6780 main () at main.c:10
2548 While now you see this:
2551 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2553 It is also now possible to inspect TLS variables when debugging core
2556 When debugging a core dump generated on a machine other than the one
2557 used to run GDB, you may need to point GDB at the correct
2558 libthread_db library with the "set libthread-db-search-path"
2559 command. See the user manual for more details on this command.
2561 * When natively debugging programs on PowerPC BookE processors running
2562 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2563 which stop execution of the inferior whenever it executes an instruction
2564 at any address within the specified range. See the "PowerPC Embedded"
2565 section in the user manual for more details.
2567 * New features in the GDB remote stub, GDBserver
2569 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2570 and i686 LynxOS (version 5.x).
2572 ** GDBserver is now supported on Blackfin Linux.
2574 * New native configurations
2576 ia64 HP-UX ia64-*-hpux*
2580 Analog Devices, Inc. Blackfin Processor bfin-*
2582 * Ada task switching is now supported on sparc-elf targets when
2583 debugging a program using the Ravenscar Profile. For more information,
2584 see the "Tasking Support when using the Ravenscar Profile" section
2585 in the GDB user manual.
2587 * Guile support was removed.
2589 * New features in the GNU simulator
2591 ** The --map-info flag lists all known core mappings.
2593 ** CFI flashes may be simulated via the "cfi" device.
2595 *** Changes in GDB 7.2
2597 * Shared library support for remote targets by default
2599 When GDB is configured for a generic, non-OS specific target, like
2600 for example, --target=arm-eabi or one of the many *-*-elf targets,
2601 GDB now queries remote stubs for loaded shared libraries using the
2602 `qXfer:libraries:read' packet. Previously, shared library support
2603 was always disabled for such configurations.
2607 ** Argument Dependent Lookup (ADL)
2609 In C++ ADL lookup directs function search to the namespaces of its
2610 arguments even if the namespace has not been imported.
2620 Here the compiler will search for `foo' in the namespace of 'b'
2621 and find A::foo. GDB now supports this. This construct is commonly
2622 used in the Standard Template Library for operators.
2624 ** Improved User Defined Operator Support
2626 In addition to member operators, GDB now supports lookup of operators
2627 defined in a namespace and imported with a `using' directive, operators
2628 defined in the global scope, operators imported implicitly from an
2629 anonymous namespace, and the ADL operators mentioned in the previous
2631 GDB now also supports proper overload resolution for all the previously
2632 mentioned flavors of operators.
2634 ** static const class members
2636 Printing of static const class members that are initialized in the
2637 class definition has been fixed.
2639 * Windows Thread Information Block access.
2641 On Windows targets, GDB now supports displaying the Windows Thread
2642 Information Block (TIB) structure. This structure is visible either
2643 by using the new command `info w32 thread-information-block' or, by
2644 dereferencing the new convenience variable named `$_tlb', a
2645 thread-specific pointer to the TIB. This feature is also supported
2646 when remote debugging using GDBserver.
2648 * Static tracepoints
2650 Static tracepoints are calls in the user program into a tracing
2651 library. One such library is a port of the LTTng kernel tracer to
2652 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2653 When debugging with GDBserver, GDB now supports combining the GDB
2654 tracepoint machinery with such libraries. For example: the user can
2655 use GDB to probe a static tracepoint marker (a call from the user
2656 program into the tracing library) with the new "strace" command (see
2657 "New commands" below). This creates a "static tracepoint" in the
2658 breakpoint list, that can be manipulated with the same feature set
2659 as fast and regular tracepoints. E.g., collect registers, local and
2660 global variables, collect trace state variables, and define
2661 tracepoint conditions. In addition, the user can collect extra
2662 static tracepoint marker specific data, by collecting the new
2663 $_sdata internal variable. When analyzing the trace buffer, you can
2664 inspect $_sdata like any other variable available to GDB. For more
2665 information, see the "Tracepoints" chapter in GDB user manual. New
2666 remote packets have been defined to support static tracepoints, see
2667 the "New remote packets" section below.
2669 * Better reconstruction of tracepoints after disconnected tracing
2671 GDB will attempt to download the original source form of tracepoint
2672 definitions when starting a trace run, and then will upload these
2673 upon reconnection to the target, resulting in a more accurate
2674 reconstruction of the tracepoints that are in use on the target.
2678 You can now exercise direct control over the ways that GDB can
2679 affect your program. For instance, you can disallow the setting of
2680 breakpoints, so that the program can run continuously (assuming
2681 non-stop mode). In addition, the "observer" variable is available
2682 to switch all of the different controls; in observer mode, GDB
2683 cannot affect the target's behavior at all, which is useful for
2684 tasks like diagnosing live systems in the field.
2686 * The new convenience variable $_thread holds the number of the
2689 * New remote packets
2693 Return the address of the Windows Thread Information Block of a given thread.
2697 In response to several of the tracepoint packets, the target may now
2698 also respond with a number of intermediate `qRelocInsn' request
2699 packets before the final result packet, to have GDB handle
2700 relocating an instruction to execute at a different address. This
2701 is particularly useful for stubs that support fast tracepoints. GDB
2702 reports support for this feature in the qSupported packet.
2706 List static tracepoint markers in the target program.
2710 List static tracepoint markers at a given address in the target
2713 qXfer:statictrace:read
2715 Read the static trace data collected (by a `collect $_sdata'
2716 tracepoint action). The remote stub reports support for this packet
2717 to gdb's qSupported query.
2721 Send the current settings of GDB's permission flags.
2725 Send part of the source (textual) form of a tracepoint definition,
2726 which includes location, conditional, and action list.
2728 * The source command now accepts a -s option to force searching for the
2729 script in the source search path even if the script name specifies
2732 * New features in the GDB remote stub, GDBserver
2734 - GDBserver now support tracepoints (including fast tracepoints, and
2735 static tracepoints). The feature is currently supported by the
2736 i386-linux and amd64-linux builds. See the "Tracepoints support
2737 in gdbserver" section in the manual for more information.
2739 GDBserver JIT compiles the tracepoint's conditional agent
2740 expression bytecode into native code whenever possible for low
2741 overhead dynamic tracepoints conditionals. For such tracepoints,
2742 an expression that examines program state is evaluated when the
2743 tracepoint is reached, in order to determine whether to capture
2744 trace data. If the condition is simple and false, processing the
2745 tracepoint finishes very quickly and no data is gathered.
2747 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2748 for static tracepoints support.
2750 - GDBserver now supports x86_64 Windows 64-bit debugging.
2752 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2753 it understands register description.
2755 * The --batch flag now disables pagination and queries.
2757 * X86 general purpose registers
2759 GDB now supports reading/writing byte, word and double-word x86
2760 general purpose registers directly. This means you can use, say,
2761 $ah or $ax to refer, respectively, to the byte register AH and
2762 16-bit word register AX that are actually portions of the 32-bit
2763 register EAX or 64-bit register RAX.
2765 * The `commands' command now accepts a range of breakpoints to modify.
2766 A plain `commands' following a command that creates multiple
2767 breakpoints affects all the breakpoints set by that command. This
2768 applies to breakpoints set by `rbreak', and also applies when a
2769 single `break' command creates multiple breakpoints (e.g.,
2770 breakpoints on overloaded c++ functions).
2772 * The `rbreak' command now accepts a filename specification as part of
2773 its argument, limiting the functions selected by the regex to those
2774 in the specified file.
2776 * Support for remote debugging Windows and SymbianOS shared libraries
2777 from Unix hosts has been improved. Non Windows GDB builds now can
2778 understand target reported file names that follow MS-DOS based file
2779 system semantics, such as file names that include drive letters and
2780 use the backslash character as directory separator. This makes it
2781 possible to transparently use the "set sysroot" and "set
2782 solib-search-path" on Unix hosts to point as host copies of the
2783 target's shared libraries. See the new command "set
2784 target-file-system-kind" described below, and the "Commands to
2785 specify files" section in the user manual for more information.
2789 eval template, expressions...
2790 Convert the values of one or more expressions under the control
2791 of the string template to a command line, and call it.
2793 set target-file-system-kind unix|dos-based|auto
2794 show target-file-system-kind
2795 Set or show the assumed file system kind for target reported file
2798 save breakpoints <filename>
2799 Save all current breakpoint definitions to a file suitable for use
2800 in a later debugging session. To read the saved breakpoint
2801 definitions, use the `source' command.
2803 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2806 info static-tracepoint-markers
2807 Display information about static tracepoint markers in the target.
2809 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2810 Define a static tracepoint by probing a marker at the given
2811 function, line, address, or marker ID.
2815 Enable and disable observer mode.
2817 set may-write-registers on|off
2818 set may-write-memory on|off
2819 set may-insert-breakpoints on|off
2820 set may-insert-tracepoints on|off
2821 set may-insert-fast-tracepoints on|off
2822 set may-interrupt on|off
2823 Set individual permissions for GDB effects on the target. Note that
2824 some of these settings can have undesirable or surprising
2825 consequences, particularly when changed in the middle of a session.
2826 For instance, disabling the writing of memory can prevent
2827 breakpoints from being inserted, cause single-stepping to fail, or
2828 even crash your program, if you disable after breakpoints have been
2829 inserted. However, GDB should not crash.
2831 set record memory-query on|off
2832 show record memory-query
2833 Control whether to stop the inferior if memory changes caused
2834 by an instruction cannot be recorded.
2839 The disassemble command now supports "start,+length" form of two arguments.
2843 ** GDB now provides a new directory location, called the python directory,
2844 where Python scripts written for GDB can be installed. The location
2845 of that directory is <data-directory>/python, where <data-directory>
2846 is the GDB data directory. For more details, see section `Scripting
2847 GDB using Python' in the manual.
2849 ** The GDB Python API now has access to breakpoints, symbols, symbol
2850 tables, program spaces, inferiors, threads and frame's code blocks.
2851 Additionally, GDB Parameters can now be created from the API, and
2852 manipulated via set/show in the CLI.
2854 ** New functions gdb.target_charset, gdb.target_wide_charset,
2855 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2857 ** New exception gdb.GdbError.
2859 ** Pretty-printers are now also looked up in the current program space.
2861 ** Pretty-printers can now be individually enabled and disabled.
2863 ** GDB now looks for names of Python scripts to auto-load in a
2864 special section named `.debug_gdb_scripts', in addition to looking
2865 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2867 * Tracepoint actions were unified with breakpoint commands. In particular,
2868 there are no longer differences in "info break" output for breakpoints and
2869 tracepoints and the "commands" command can be used for both tracepoints and
2870 regular breakpoints.
2874 ARM Symbian arm*-*-symbianelf*
2876 * D language support.
2877 GDB now supports debugging programs written in the D programming
2880 * GDB now supports the extended ptrace interface for PowerPC which is
2881 available since Linux kernel version 2.6.34. This automatically enables
2882 any hardware breakpoints and additional hardware watchpoints available in
2883 the processor. The old ptrace interface exposes just one hardware
2884 watchpoint and no hardware breakpoints.
2886 * GDB is now able to use the Data Value Compare (DVC) register available on
2887 embedded PowerPC processors to implement in hardware simple watchpoint
2888 conditions of the form:
2890 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2892 This works in native GDB running on Linux kernels with the extended ptrace
2893 interface mentioned above.
2895 *** Changes in GDB 7.1
2899 ** Namespace Support
2901 GDB now supports importing of namespaces in C++. This enables the
2902 user to inspect variables from imported namespaces. Support for
2903 namepace aliasing has also been added. So, if a namespace is
2904 aliased in the current scope (e.g. namepace C=A; ) the user can
2905 print variables using the alias (e.g. (gdb) print C::x).
2909 All known bugs relating to the printing of virtual base class were
2910 fixed. It is now possible to call overloaded static methods using a
2915 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2916 and reinterpret_cast<> are now handled by the C++ expression parser.
2920 Xilinx MicroBlaze microblaze-*-*
2925 Xilinx MicroBlaze microblaze
2928 * Multi-program debugging.
2930 GDB now has support for multi-program (a.k.a. multi-executable or
2931 multi-exec) debugging. This allows for debugging multiple inferiors
2932 simultaneously each running a different program under the same GDB
2933 session. See "Debugging Multiple Inferiors and Programs" in the
2934 manual for more information. This implied some user visible changes
2935 in the multi-inferior support. For example, "info inferiors" now
2936 lists inferiors that are not running yet or that have exited
2937 already. See also "New commands" and "New options" below.
2939 * New tracing features
2941 GDB's tracepoint facility now includes several new features:
2943 ** Trace state variables
2945 GDB tracepoints now include support for trace state variables, which
2946 are variables managed by the target agent during a tracing
2947 experiment. They are useful for tracepoints that trigger each
2948 other, so for instance one tracepoint can count hits in a variable,
2949 and then a second tracepoint has a condition that is true when the
2950 count reaches a particular value. Trace state variables share the
2951 $-syntax of GDB convenience variables, and can appear in both
2952 tracepoint actions and condition expressions. Use the "tvariable"
2953 command to create, and "info tvariables" to view; see "Trace State
2954 Variables" in the manual for more detail.
2958 GDB now includes an option for defining fast tracepoints, which
2959 targets may implement more efficiently, such as by installing a jump
2960 into the target agent rather than a trap instruction. The resulting
2961 speedup can be by two orders of magnitude or more, although the
2962 tradeoff is that some program locations on some target architectures
2963 might not allow fast tracepoint installation, for instance if the
2964 instruction to be replaced is shorter than the jump. To request a
2965 fast tracepoint, use the "ftrace" command, with syntax identical to
2966 the regular trace command.
2968 ** Disconnected tracing
2970 It is now possible to detach GDB from the target while it is running
2971 a trace experiment, then reconnect later to see how the experiment
2972 is going. In addition, a new variable disconnected-tracing lets you
2973 tell the target agent whether to continue running a trace if the
2974 connection is lost unexpectedly.
2978 GDB now has the ability to save the trace buffer into a file, and
2979 then use that file as a target, similarly to you can do with
2980 corefiles. You can select trace frames, print data that was
2981 collected in them, and use tstatus to display the state of the
2982 tracing run at the moment that it was saved. To create a trace
2983 file, use "tsave <filename>", and to use it, do "target tfile
2986 ** Circular trace buffer
2988 You can ask the target agent to handle the trace buffer as a
2989 circular buffer, discarding the oldest trace frames to make room for
2990 newer ones, by setting circular-trace-buffer to on. This feature may
2991 not be available for all target agents.
2996 The disassemble command, when invoked with two arguments, now requires
2997 the arguments to be comma-separated.
3000 The info variables command now displays variable definitions. Files
3001 which only declare a variable are not shown.
3004 The source command is now capable of sourcing Python scripts.
3005 This feature is dependent on the debugger being build with Python
3008 Related to this enhancement is also the introduction of a new command
3009 "set script-extension" (see below).
3011 * New commands (for set/show, see "New options" below)
3013 record save [<FILENAME>]
3014 Save a file (in core file format) containing the process record
3015 execution log for replay debugging at a later time.
3017 record restore <FILENAME>
3018 Restore the process record execution log that was saved at an
3019 earlier time, for replay debugging.
3021 add-inferior [-copies <N>] [-exec <FILENAME>]
3024 clone-inferior [-copies <N>] [ID]
3025 Make a new inferior ready to execute the same program another
3026 inferior has loaded.
3031 maint info program-spaces
3032 List the program spaces loaded into GDB.
3034 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3035 show remote interrupt-sequence
3036 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3037 as the sequence to the remote target in order to interrupt the execution.
3038 Ctrl-C is a default. Some system prefers BREAK which is high level of
3039 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3040 Magic SysRq g. It is BREAK signal and character 'g'.
3042 set remote interrupt-on-connect [on | off]
3043 show remote interrupt-on-connect
3044 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3045 remote target when gdb connects to it. This is needed when you debug
3048 set remotebreak [on | off]
3050 Deprecated. Use "set/show remote interrupt-sequence" instead.
3052 tvariable $NAME [ = EXP ]
3053 Create or modify a trace state variable.
3056 List trace state variables and their values.
3058 delete tvariable $NAME ...
3059 Delete one or more trace state variables.
3062 Evaluate the given expressions without collecting anything into the
3063 trace buffer. (Valid in tracepoint actions only.)
3065 ftrace FN / FILE:LINE / *ADDR
3066 Define a fast tracepoint at the given function, line, or address.
3068 * New expression syntax
3070 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3071 GDB now parses 0b101010 identically with 42.
3075 set follow-exec-mode new|same
3076 show follow-exec-mode
3077 Control whether GDB reuses the same inferior across an exec call or
3078 creates a new one. This is useful to be able to restart the old
3079 executable after the inferior having done an exec call.
3081 set default-collect EXPR, ...
3082 show default-collect
3083 Define a list of expressions to be collected at each tracepoint.
3084 This is a useful way to ensure essential items are not overlooked,
3085 such as registers or a critical global variable.
3087 set disconnected-tracing
3088 show disconnected-tracing
3089 If set to 1, the target is instructed to continue tracing if it
3090 loses its connection to GDB. If 0, the target is to stop tracing
3093 set circular-trace-buffer
3094 show circular-trace-buffer
3095 If set to on, the target is instructed to use a circular trace buffer
3096 and discard the oldest trace frames instead of stopping the trace due
3097 to a full trace buffer. If set to off, the trace stops when the buffer
3098 fills up. Some targets may not support this.
3100 set script-extension off|soft|strict
3101 show script-extension
3102 If set to "off", the debugger does not perform any script language
3103 recognition, and all sourced files are assumed to be GDB scripts.
3104 If set to "soft" (the default), files are sourced according to
3105 filename extension, falling back to GDB scripts if the first
3107 If set to "strict", files are sourced according to filename extension.
3109 set ada trust-PAD-over-XVS on|off
3110 show ada trust-PAD-over-XVS
3111 If off, activate a workaround against a bug in the debugging information
3112 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3113 the GCC sources for more information about the GNAT encoding and
3114 PAD types in particular). It is always safe to set this option to
3115 off, but this introduces a slight performance penalty. The default
3118 * Python API Improvements
3120 ** GDB provides the new class gdb.LazyString. This is useful in
3121 some pretty-printing cases. The new method gdb.Value.lazy_string
3122 provides a simple way to create objects of this type.
3124 ** The fields returned by gdb.Type.fields now have an
3125 `is_base_class' attribute.
3127 ** The new method gdb.Type.range returns the range of an array type.
3129 ** The new method gdb.parse_and_eval can be used to parse and
3130 evaluate an expression.
3132 * New remote packets
3135 Define a trace state variable.
3138 Get the current value of a trace state variable.
3141 Set desired tracing behavior upon disconnection.
3144 Set the trace buffer to be linear or circular.
3147 Get data about the tracepoints currently in use.
3151 Process record now works correctly with hardware watchpoints.
3153 Multiple bug fixes have been made to the mips-irix port, making it
3154 much more reliable. In particular:
3155 - Debugging threaded applications is now possible again. Previously,
3156 GDB would hang while starting the program, or while waiting for
3157 the program to stop at a breakpoint.
3158 - Attaching to a running process no longer hangs.
3159 - An error occurring while loading a core file has been fixed.
3160 - Changing the value of the PC register now works again. This fixes
3161 problems observed when using the "jump" command, or when calling
3162 a function from GDB, or even when assigning a new value to $pc.
3163 - With the "finish" and "return" commands, the return value for functions
3164 returning a small array is now correctly printed.
3165 - It is now possible to break on shared library code which gets executed
3166 during a shared library init phase (code executed while executing
3167 their .init section). Previously, the breakpoint would have no effect.
3168 - GDB is now able to backtrace through the signal handler for
3169 non-threaded programs.
3171 PIE (Position Independent Executable) programs debugging is now supported.
3172 This includes debugging execution of PIC (Position Independent Code) shared
3173 libraries although for that, it should be possible to run such libraries as an
3176 *** Changes in GDB 7.0
3178 * GDB now has an interface for JIT compilation. Applications that
3179 dynamically generate code can create symbol files in memory and register
3180 them with GDB. For users, the feature should work transparently, and
3181 for JIT developers, the interface is documented in the GDB manual in the
3182 "JIT Compilation Interface" chapter.
3184 * Tracepoints may now be conditional. The syntax is as for
3185 breakpoints; either an "if" clause appended to the "trace" command,
3186 or the "condition" command is available. GDB sends the condition to
3187 the target for evaluation using the same bytecode format as is used
3188 for tracepoint actions.
3190 * The disassemble command now supports: an optional /r modifier, print the
3191 raw instructions in hex as well as in symbolic form, and an optional /m
3192 modifier to print mixed source+assembly.
3194 * Process record and replay
3196 In a architecture environment that supports ``process record and
3197 replay'', ``process record and replay'' target can record a log of
3198 the process execution, and replay it with both forward and reverse
3201 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3202 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3203 set execution-direction {forward|reverse}, for targets that support
3206 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3207 feature is available with a native GDB running on kernel version
3210 * GDB now has support for multi-byte and wide character sets on the
3211 target. Strings whose character type is wchar_t, char16_t, or
3212 char32_t are now correctly printed. GDB supports wide- and unicode-
3213 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3214 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3215 `printf'. This feature requires iconv to work properly; if your
3216 system does not have a working iconv, GDB can use GNU libiconv. See
3217 the installation instructions for more information.
3219 * GDB now supports automatic retrieval of shared library files from
3220 remote targets. To use this feature, specify a system root that begins
3221 with the `remote:' prefix, either via the `set sysroot' command or via
3222 the `--with-sysroot' configure-time option.
3224 * "info sharedlibrary" now takes an optional regex of libraries to show,
3225 and it now reports if a shared library has no debugging information.
3227 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3228 now complete on file names.
3230 * When completing in expressions, gdb will attempt to limit
3231 completions to allowable structure or union fields, where appropriate.
3232 For instance, consider:
3234 # struct example { int f1; double f2; };
3235 # struct example variable;
3238 If the user types TAB at the end of this command line, the available
3239 completions will be "f1" and "f2".
3241 * Inlined functions are now supported. They show up in backtraces, and
3242 the "step", "next", and "finish" commands handle them automatically.
3244 * GDB now supports the token-splicing (##) and stringification (#)
3245 operators when expanding macros. It also supports variable-arity
3248 * GDB now supports inspecting extra signal information, exported by
3249 the new $_siginfo convenience variable. The feature is currently
3250 implemented on linux ARM, i386 and amd64.
3252 * GDB can now display the VFP floating point registers and NEON vector
3253 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3254 can provide these registers (requires Linux 2.6.30 or later). Remote
3255 and simulator targets may also provide them.
3257 * New remote packets
3260 Search memory for a sequence of bytes.
3263 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3264 operation over reliable transport links. Use of this packet is
3265 controlled by the `set remote noack-packet' command.
3268 Kill the process with the specified process ID. Use this in preference
3269 to `k' when multiprocess protocol extensions are supported.
3272 Obtains additional operating system information
3276 Read or write additional signal information.
3278 * Removed remote protocol undocumented extension
3280 An undocumented extension to the remote protocol's `S' stop reply
3281 packet that permited the stub to pass a process id was removed.
3282 Remote servers should use the `T' stop reply packet instead.
3284 * GDB now supports multiple function calling conventions according to the
3285 DWARF-2 DW_AT_calling_convention function attribute.
3287 * The SH target utilizes the aforementioned change to distinguish between gcc
3288 and Renesas calling convention. It also adds the new CLI commands
3289 `set/show sh calling-convention'.
3291 * GDB can now read compressed debug sections, as produced by GNU gold
3292 with the --compress-debug-sections=zlib flag.
3294 * 64-bit core files are now supported on AIX.
3296 * Thread switching is now supported on Tru64.
3298 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3299 which will be allocated using malloc later in program execution.
3301 * The qXfer:libraries:read remote procotol packet now allows passing a
3302 list of section offsets.
3304 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3305 conditions handling signals delivered during attach or thread creation
3306 have also been fixed.
3308 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3309 From the user's standpoint, all unqualified instances of True and False
3310 are treated as the standard definitions, regardless of context.
3312 * GDB now parses C++ symbol and type names more flexibly. For
3315 template<typename T> class C { };
3318 GDB will now correctly handle all of:
3320 ptype C<char const *>
3321 ptype C<char const*>
3322 ptype C<const char *>
3323 ptype C<const char*>
3325 * New features in the GDB remote stub, gdbserver
3327 - The "--wrapper" command-line argument tells gdbserver to use a
3328 wrapper program to launch programs for debugging.
3330 - On PowerPC and S/390 targets, it is now possible to use a single
3331 gdbserver executable to debug both 32-bit and 64-bit programs.
3332 (This requires gdbserver itself to be built as a 64-bit executable.)
3334 - gdbserver uses the new noack protocol mode for TCP connections to
3335 reduce communications latency, if also supported and enabled in GDB.
3337 - Support for the sparc64-linux-gnu target is now included in
3340 - The amd64-linux build of gdbserver now supports debugging both
3341 32-bit and 64-bit programs.
3343 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3344 now support hardware watchpoints, and will use them automatically
3349 GDB now has support for scripting using Python. Whether this is
3350 available is determined at configure time.
3352 New GDB commands can now be written in Python.
3354 * Ada tasking support
3356 Ada tasks can now be inspected in GDB. The following commands have
3360 Print the list of Ada tasks.
3362 Print detailed information about task number N.
3364 Print the task number of the current task.
3366 Switch the context of debugging to task number N.
3368 * Support for user-defined prefixed commands. The "define" command can
3369 add new commands to existing prefixes, e.g. "target".
3371 * Multi-inferior, multi-process debugging.
3373 GDB now has generalized support for multi-inferior debugging. See
3374 "Debugging Multiple Inferiors" in the manual for more information.
3375 Although availability still depends on target support, the command
3376 set is more uniform now. The GNU/Linux specific multi-forks support
3377 has been migrated to this new framework. This implied some user
3378 visible changes; see "New commands" and also "Removed commands"
3381 * Target descriptions can now describe the target OS ABI. See the
3382 "Target Description Format" section in the user manual for more
3385 * Target descriptions can now describe "compatible" architectures
3386 to indicate that the target can execute applications for a different
3387 architecture in addition to those for the main target architecture.
3388 See the "Target Description Format" section in the user manual for
3391 * Multi-architecture debugging.
3393 GDB now includes general supports for debugging applications on
3394 hybrid systems that use more than one single processor architecture
3395 at the same time. Each such hybrid architecture still requires
3396 specific support to be added. The only hybrid architecture supported
3397 in this version of GDB is the Cell Broadband Engine.
3399 * GDB now supports integrated debugging of Cell/B.E. applications that
3400 use both the PPU and SPU architectures. To enable support for hybrid
3401 Cell/B.E. debugging, you need to configure GDB to support both the
3402 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3403 --enable-targets configure option.
3405 * Non-stop mode debugging.
3407 For some targets, GDB now supports an optional mode of operation in
3408 which you can examine stopped threads while other threads continue
3409 to execute freely. This is referred to as non-stop mode, with the
3410 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3411 section in the user manual for more information.
3413 To be able to support remote non-stop debugging, a remote stub needs
3414 to implement the non-stop mode remote protocol extensions, as
3415 described in the "Remote Non-Stop" section of the user manual. The
3416 GDB remote stub, gdbserver, has been adjusted to support these
3417 extensions on linux targets.
3419 * New commands (for set/show, see "New options" below)
3421 catch syscall [NAME(S) | NUMBER(S)]
3422 Catch system calls. Arguments, which should be names of system
3423 calls or their numbers, mean catch only those syscalls. Without
3424 arguments, every syscall will be caught. When the inferior issues
3425 any of the specified syscalls, GDB will stop and announce the system
3426 call, both when it is called and when its call returns. This
3427 feature is currently available with a native GDB running on the
3428 Linux Kernel, under the following architectures: x86, x86_64,
3429 PowerPC and PowerPC64.
3431 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3433 Search memory for a sequence of bytes.
3435 maint set python print-stack
3436 maint show python print-stack
3437 Show a stack trace when an error is encountered in a Python script.
3440 Invoke CODE by passing it to the Python interpreter.
3445 These allow macros to be defined, undefined, and listed
3449 Show operating system information about processes.
3452 List the inferiors currently under GDB's control.
3455 Switch focus to inferior number NUM.
3458 Detach from inferior number NUM.
3461 Kill inferior number NUM.
3465 set spu stop-on-load
3466 show spu stop-on-load
3467 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3469 set spu auto-flush-cache
3470 show spu auto-flush-cache
3471 Control whether to automatically flush the software-managed cache
3472 during Cell/B.E. debugging.
3474 set sh calling-convention
3475 show sh calling-convention
3476 Control the calling convention used when calling SH target functions.
3479 show debug timestamp
3480 Control display of timestamps with GDB debugging output.
3482 set disassemble-next-line
3483 show disassemble-next-line
3484 Control display of disassembled source lines or instructions when
3487 set remote noack-packet
3488 show remote noack-packet
3489 Set/show the use of remote protocol QStartNoAckMode packet. See above
3490 under "New remote packets."
3492 set remote query-attached-packet
3493 show remote query-attached-packet
3494 Control use of remote protocol `qAttached' (query-attached) packet.
3496 set remote read-siginfo-object
3497 show remote read-siginfo-object
3498 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3501 set remote write-siginfo-object
3502 show remote write-siginfo-object
3503 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3506 set remote reverse-continue
3507 show remote reverse-continue
3508 Control use of remote protocol 'bc' (reverse-continue) packet.
3510 set remote reverse-step
3511 show remote reverse-step
3512 Control use of remote protocol 'bs' (reverse-step) packet.
3514 set displaced-stepping
3515 show displaced-stepping
3516 Control displaced stepping mode. Displaced stepping is a way to
3517 single-step over breakpoints without removing them from the debuggee.
3518 Also known as "out-of-line single-stepping".
3521 show debug displaced
3522 Control display of debugging info for displaced stepping.
3524 maint set internal-error
3525 maint show internal-error
3526 Control what GDB does when an internal error is detected.
3528 maint set internal-warning
3529 maint show internal-warning
3530 Control what GDB does when an internal warning is detected.
3535 Use a wrapper program to launch programs for debugging.
3537 set multiple-symbols (all|ask|cancel)
3538 show multiple-symbols
3539 The value of this variable can be changed to adjust the debugger behavior
3540 when an expression or a breakpoint location contains an ambiguous symbol
3541 name (an overloaded function name, for instance).
3543 set breakpoint always-inserted
3544 show breakpoint always-inserted
3545 Keep breakpoints always inserted in the target, as opposed to inserting
3546 them when resuming the target, and removing them when the target stops.
3547 This option can improve debugger performance on slow remote targets.
3549 set arm fallback-mode (arm|thumb|auto)
3550 show arm fallback-mode
3551 set arm force-mode (arm|thumb|auto)
3553 These commands control how ARM GDB determines whether instructions
3554 are ARM or Thumb. The default for both settings is auto, which uses
3555 the current CPSR value for instructions without symbols; previous
3556 versions of GDB behaved as if "set arm fallback-mode arm".
3558 set disable-randomization
3559 show disable-randomization
3560 Standalone programs run with the virtual address space randomization enabled
3561 by default on some platforms. This option keeps the addresses stable across
3562 multiple debugging sessions.
3566 Control whether other threads are stopped or not when some thread hits
3571 Requests that asynchronous execution is enabled in the target, if available.
3572 In this case, it's possible to resume target in the background, and interact
3573 with GDB while the target is running. "show target-async" displays the
3574 current state of asynchronous execution of the target.
3576 set target-wide-charset
3577 show target-wide-charset
3578 The target-wide-charset is the name of the character set that GDB
3579 uses when printing characters whose type is wchar_t.
3581 set tcp auto-retry (on|off)
3583 set tcp connect-timeout
3584 show tcp connect-timeout
3585 These commands allow GDB to retry failed TCP connections to a remote stub
3586 with a specified timeout period; this is useful if the stub is launched
3587 in parallel with GDB but may not be ready to accept connections immediately.
3589 set libthread-db-search-path
3590 show libthread-db-search-path
3591 Control list of directories which GDB will search for appropriate
3594 set schedule-multiple (on|off)
3595 show schedule-multiple
3596 Allow GDB to resume all threads of all processes or only threads of
3597 the current process.
3601 Use more aggressive caching for accesses to the stack. This improves
3602 performance of remote debugging (particularly backtraces) without
3603 affecting correctness.
3605 set interactive-mode (on|off|auto)
3606 show interactive-mode
3607 Control whether GDB runs in interactive mode (on) or not (off).
3608 When in interactive mode, GDB waits for the user to answer all
3609 queries. Otherwise, GDB does not wait and assumes the default
3610 answer. When set to auto (the default), GDB determines which
3611 mode to use based on the stdin settings.
3616 For program forks, this is replaced by the new more generic `info
3617 inferiors' command. To list checkpoints, you can still use the
3618 `info checkpoints' command, which was an alias for the `info forks'
3622 Replaced by the new `inferior' command. To switch between
3623 checkpoints, you can still use the `restart' command, which was an
3624 alias for the `fork' command.
3627 This is removed, since some targets don't have a notion of
3628 processes. To switch between processes, you can still use the
3629 `inferior' command using GDB's own inferior number.
3632 For program forks, this is replaced by the new more generic `kill
3633 inferior' command. To delete a checkpoint, you can still use the
3634 `delete checkpoint' command, which was an alias for the `delete
3638 For program forks, this is replaced by the new more generic `detach
3639 inferior' command. To detach a checkpoint, you can still use the
3640 `detach checkpoint' command, which was an alias for the `detach
3643 * New native configurations
3645 x86/x86_64 Darwin i[34567]86-*-darwin*
3647 x86_64 MinGW x86_64-*-mingw*
3651 Lattice Mico32 lm32-*
3652 x86 DICOS i[34567]86-*-dicos*
3653 x86_64 DICOS x86_64-*-dicos*
3656 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3657 (mingw32ce) debugging.
3663 These commands were actually not implemented on any target.
3665 *** Changes in GDB 6.8
3667 * New native configurations
3669 NetBSD/hppa hppa*-*netbsd*
3670 Xtensa GNU/Linux xtensa*-*-linux*
3674 NetBSD/hppa hppa*-*-netbsd*
3675 Xtensa GNU/Lunux xtensa*-*-linux*
3677 * Change in command line behavior -- corefiles vs. process ids.
3679 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3680 attaching to process NUMBER fails, GDB no longer attempts to open a
3681 core file named NUMBER. Attaching to a program using the -c option
3682 is no longer supported. Instead, use the '-p' or '--pid' options.
3684 * GDB can now be built as a native debugger for debugging Windows x86
3685 (mingw32) Portable Executable (PE) programs.
3687 * Pending breakpoints no longer change their number when their address
3690 * GDB now supports breakpoints with multiple locations,
3691 including breakpoints on C++ constructors, inside C++ templates,
3692 and in inlined functions.
3694 * GDB's ability to debug optimized code has been improved. GDB more
3695 accurately identifies function bodies and lexical blocks that occupy
3696 more than one contiguous range of addresses.
3698 * Target descriptions can now describe registers for PowerPC.
3700 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3701 registers on PowerPC targets.
3703 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3704 targets even when the libthread_db library is not available.
3706 * The GDB remote stub, gdbserver, now supports the new file transfer
3707 commands (remote put, remote get, and remote delete).
3709 * The GDB remote stub, gdbserver, now supports run and attach in
3710 extended-remote mode.
3712 * hppa*64*-*-hpux11* target broken
3713 The debugger is unable to start a program and fails with the following
3714 error: "Error trying to get information about dynamic linker".
3715 The gdb-6.7 release is also affected.
3717 * GDB now supports the --enable-targets= configure option to allow
3718 building a single GDB executable that supports multiple remote
3719 target architectures.
3721 * GDB now supports debugging C and C++ programs which use the
3722 Decimal Floating Point extension. In addition, the PowerPC target
3723 now has a set of pseudo-registers to inspect decimal float values
3724 stored in two consecutive float registers.
3726 * The -break-insert MI command can optionally create pending
3729 * Improved support for debugging Ada
3730 Many improvements to the Ada language support have been made. These
3732 - Better support for Ada2005 interface types
3733 - Improved handling of arrays and slices in general
3734 - Better support for Taft-amendment types
3735 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3737 - Improved command completion in Ada
3740 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3745 set print frame-arguments (all|scalars|none)
3746 show print frame-arguments
3747 The value of this variable can be changed to control which argument
3748 values should be printed by the debugger when displaying a frame.
3753 Transfer files to and from a remote target, and delete remote files.
3760 Transfer files to and from a remote target, and delete remote files.
3762 * New remote packets
3769 Open, close, read, write, and delete files on the remote system.
3772 Attach to an existing process on the remote system, in extended-remote
3776 Run a new process on the remote system, in extended-remote mode.
3778 *** Changes in GDB 6.7
3780 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3781 bfd, libiberty and opcodes, as revealed by static analysis donated by
3782 Coverity, Inc. (http://scan.coverity.com).
3784 * When looking up multiply-defined global symbols, GDB will now prefer the
3785 symbol definition in the current shared library if it was built using the
3786 -Bsymbolic linker option.
3788 * When the Text User Interface (TUI) is not configured, GDB will now
3789 recognize the -tui command-line option and print a message that the TUI
3792 * The GDB remote stub, gdbserver, now has lower overhead for high
3793 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3795 * GDB for MIPS targets now autodetects whether a remote target provides
3796 32-bit or 64-bit register values.
3798 * Support for C++ member pointers has been improved.
3800 * GDB now understands XML target descriptions, which specify the
3801 target's overall architecture. GDB can read a description from
3802 a local file or over the remote serial protocol.
3804 * Vectors of single-byte data use a new integer type which is not
3805 automatically displayed as character or string data.
3807 * The /s format now works with the print command. It displays
3808 arrays of single-byte integers and pointers to single-byte integers
3811 * Target descriptions can now describe target-specific registers,
3812 for architectures which have implemented the support (currently
3813 only ARM, M68K, and MIPS).
3815 * GDB and the GDB remote stub, gdbserver, now support the XScale
3818 * The GDB remote stub, gdbserver, has been updated to support
3819 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3820 has been rewritten to use the standard GDB remote protocol.
3822 * GDB can now step into C++ functions which are called through thunks.
3824 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3826 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3827 layout. It also supports a TextSeg= and DataSeg= response when only
3828 segment base addresses (rather than offsets) are available.
3830 * The /i format now outputs any trailing branch delay slot instructions
3831 immediately following the last instruction within the count specified.
3833 * The GDB remote protocol "T" stop reply packet now supports a
3834 "library" response. Combined with the new "qXfer:libraries:read"
3835 packet, this response allows GDB to debug shared libraries on targets
3836 where the operating system manages the list of loaded libraries (e.g.
3837 Windows and SymbianOS).
3839 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3840 (DLLs) on Windows and Windows CE targets.
3842 * GDB now supports a faster verification that a .debug file matches its binary
3843 according to its build-id signature, if the signature is present.
3849 Enable or disable hardware flow control (RTS/CTS) on the serial port
3850 when debugging using remote targets.
3852 set mem inaccessible-by-default
3853 show mem inaccessible-by-default
3854 If the target supplies a memory map, for instance via the remote
3855 protocol's "qXfer:memory-map:read" packet, setting this variable
3856 prevents GDB from accessing memory outside the memory map. This
3857 is useful for targets with memory mapped registers or which react
3858 badly to accesses of unmapped address space.
3860 set breakpoint auto-hw
3861 show breakpoint auto-hw
3862 If the target supplies a memory map, for instance via the remote
3863 protocol's "qXfer:memory-map:read" packet, setting this variable
3864 lets GDB use hardware breakpoints automatically for memory regions
3865 where it can not use software breakpoints. This covers both the
3866 "break" command and internal breakpoints used for other commands
3867 including "next" and "finish".
3870 catch exception unhandled
3871 Stop the program execution when Ada exceptions are raised.
3874 Stop the program execution when an Ada assertion failed.
3878 Set an alternate system root for target files. This is a more
3879 general version of "set solib-absolute-prefix", which is now
3880 an alias to "set sysroot".
3883 Provide extended SPU facility status information. This set of
3884 commands is available only when debugging the Cell/B.E. SPU
3887 * New native configurations
3889 OpenBSD/sh sh*-*openbsd*
3892 unset tdesc filename
3894 Use the specified local file as an XML target description, and do
3895 not query the target for its built-in description.
3899 OpenBSD/sh sh*-*-openbsd*
3900 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3901 Toshiba Media Processor mep-elf
3903 * New remote packets
3906 Ignore the specified signals; pass them directly to the debugged program
3907 without stopping other threads or reporting them to GDB.
3909 qXfer:features:read:
3910 Read an XML target description from the target, which describes its
3915 Read or write contents of an spufs file on the target system. These
3916 packets are available only on the Cell/B.E. SPU architecture.
3918 qXfer:libraries:read:
3919 Report the loaded shared libraries. Combined with new "T" packet
3920 response, this packet allows GDB to debug shared libraries on
3921 targets where the operating system manages the list of loaded
3922 libraries (e.g. Windows and SymbianOS).
3926 Support for these obsolete configurations has been removed.
3934 i[34567]86-*-lynxos*
3935 i[34567]86-*-netware*
3936 i[34567]86-*-sco3.2v5*
3937 i[34567]86-*-sco3.2v4*
3939 i[34567]86-*-sysv4.2*
3942 i[34567]86-*-unixware2*
3943 i[34567]86-*-unixware*
3952 * Other removed features
3959 Various m68k-only ROM monitors.
3966 Various Renesas ROM monitors and debugging interfaces for SH and
3971 Support for a Macraigor serial interface to on-chip debugging.
3972 GDB does not directly support the newer parallel or USB
3977 A debug information format. The predecessor to DWARF 2 and
3978 DWARF 3, which are still supported.
3980 Support for the HP aCC compiler on HP-UX/PA-RISC
3982 SOM-encapsulated symbolic debugging information, automatic
3983 invocation of pxdb, and the aCC custom C++ ABI. This does not
3984 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3985 with aCC can still be debugged on an assembly level.
3987 MIPS ".pdr" sections
3989 A MIPS-specific format used to describe stack frame layout
3990 in debugging information.
3994 GDB could work with an older version of Guile to debug
3995 the interpreter and Scheme programs running in it.
3997 set mips stack-arg-size
3998 set mips saved-gpreg-size
4000 Use "set mips abi" to control parameter passing for MIPS.
4002 *** Changes in GDB 6.6
4007 Cell Broadband Engine SPU spu-elf
4009 * GDB can now be configured as a cross-debugger targeting native Windows
4010 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4011 running on a Windows system over TCP/IP to debug Windows programs.
4013 * The GDB remote stub, gdbserver, has been updated to support Windows and
4014 Cygwin debugging. Both single-threaded and multi-threaded programs are
4017 * The "set trust-readonly-sections" command works again. This command was
4018 broken in GDB 6.3, 6.4, and 6.5.
4020 * The "load" command now supports writing to flash memory, if the remote
4021 stub provides the required support.
4023 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4024 longer requires symbolic debug information (e.g. DWARF-2).
4029 unset substitute-path
4030 show substitute-path
4031 Manage a list of substitution rules that GDB uses to rewrite the name
4032 of the directories where the sources are located. This can be useful
4033 for instance when the sources were moved to a different location
4034 between compilation and debugging.
4038 Print each CLI command as it is executed. Each command is prefixed with
4039 a number of `+' symbols representing the nesting depth.
4040 The source command now has a `-v' option to enable the same feature.
4044 The ARM Demon monitor support (RDP protocol, "target rdp").
4046 Kernel Object Display, an embedded debugging feature which only worked with
4047 an obsolete version of Cisco IOS.
4049 The 'set download-write-size' and 'show download-write-size' commands.
4051 * New remote packets
4054 Tell a stub about GDB client features, and request remote target features.
4055 The first feature implemented is PacketSize, which allows the target to
4056 specify the size of packets it can handle - to minimize the number of
4057 packets required and improve performance when connected to a remote
4061 Fetch an OS auxilliary vector from the remote stub. This packet is a
4062 more efficient replacement for qPart:auxv:read.
4064 qXfer:memory-map:read:
4065 Fetch a memory map from the remote stub, including information about
4066 RAM, ROM, and flash memory devices.
4071 Erase and program a flash memory device.
4073 * Removed remote packets
4076 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4077 used it, and only gdbserver implemented it.
4079 *** Changes in GDB 6.5
4083 Renesas M32C/M16C m32c-elf
4085 Morpho Technologies ms1 ms1-elf
4089 init-if-undefined Initialize a convenience variable, but
4090 only if it doesn't already have a value.
4092 The following commands are presently only implemented for native GNU/Linux:
4094 checkpoint Save a snapshot of the program state.
4096 restart <n> Return the program state to a
4097 previously saved state.
4099 info checkpoints List currently saved checkpoints.
4101 delete-checkpoint <n> Delete a previously saved checkpoint.
4103 set|show detach-on-fork Tell gdb whether to detach from a newly
4104 forked process, or to keep debugging it.
4106 info forks List forks of the user program that
4107 are available to be debugged.
4109 fork <n> Switch to debugging one of several
4110 forks of the user program that are
4111 available to be debugged.
4113 delete-fork <n> Delete a fork from the list of forks
4114 that are available to be debugged (and
4115 kill the forked process).
4117 detach-fork <n> Delete a fork from the list of forks
4118 that are available to be debugged (and
4119 allow the process to continue).
4123 Morpho Technologies ms2 ms1-elf
4125 * Improved Windows host support
4127 GDB now builds as a cross debugger hosted on i686-mingw32, including
4128 native console support, and remote communications using either
4129 network sockets or serial ports.
4131 * Improved Modula-2 language support
4133 GDB can now print most types in the Modula-2 syntax. This includes:
4134 basic types, set types, record types, enumerated types, range types,
4135 pointer types and ARRAY types. Procedure var parameters are correctly
4136 printed and hexadecimal addresses and character constants are also
4137 written in the Modula-2 syntax. Best results can be obtained by using
4138 GNU Modula-2 together with the -gdwarf-2 command line option.
4142 The ARM rdi-share module.
4144 The Netware NLM debug server.
4146 *** Changes in GDB 6.4
4148 * New native configurations
4150 OpenBSD/arm arm*-*-openbsd*
4151 OpenBSD/mips64 mips64-*-openbsd*
4155 Morpho Technologies ms1 ms1-elf
4157 * New command line options
4159 --batch-silent As for --batch, but totally silent.
4160 --return-child-result The debugger will exist with the same value
4161 the child (debugged) program exited with.
4162 --eval-command COMMAND, -ex COMMAND
4163 Execute a single GDB CLI command. This may be
4164 specified multiple times and in conjunction
4165 with the --command (-x) option.
4167 * Deprecated commands removed
4169 The following commands, that were deprecated in 2000, have been
4173 set|show arm disassembly-flavor set|show arm disassembler
4174 othernames set arm disassembler
4175 set|show remotedebug set|show debug remote
4176 set|show archdebug set|show debug arch
4177 set|show eventdebug set|show debug event
4180 * New BSD user-level threads support
4182 It is now possible to debug programs using the user-level threads
4183 library on OpenBSD and FreeBSD. Currently supported (target)
4186 FreeBSD/amd64 x86_64-*-freebsd*
4187 FreeBSD/i386 i386-*-freebsd*
4188 OpenBSD/i386 i386-*-openbsd*
4190 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4191 are not yet supported.
4193 * New support for Matsushita MN10300 w/sim added
4194 (Work in progress). mn10300-elf.
4196 * REMOVED configurations and files
4198 VxWorks and the XDR protocol *-*-vxworks
4199 Motorola MCORE mcore-*-*
4200 National Semiconductor NS32000 ns32k-*-*
4202 * New "set print array-indexes" command
4204 After turning this setting "on", GDB prints the index of each element
4205 when displaying arrays. The default is "off" to preserve the previous
4208 * VAX floating point support
4210 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4212 * User-defined command support
4214 In addition to using $arg0..$arg9 for argument passing, it is now possible
4215 to use $argc to determine now many arguments have been passed. See the
4216 section on user-defined commands in the user manual for more information.
4218 *** Changes in GDB 6.3:
4220 * New command line option
4222 GDB now accepts -l followed by a number to set the timeout for remote
4225 * GDB works with GCC -feliminate-dwarf2-dups
4227 GDB now supports a more compact representation of DWARF-2 debug
4228 information using DW_FORM_ref_addr references. These are produced
4229 by GCC with the option -feliminate-dwarf2-dups and also by some
4230 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4231 to use -feliminate-dwarf2-dups.
4233 * Internationalization
4235 When supported by the host system, GDB will be built with
4236 internationalization (libintl). The task of marking up the sources is
4237 continued, we're looking forward to our first translation.
4241 Initial support for debugging programs compiled with the GNAT
4242 implementation of the Ada programming language has been integrated
4243 into GDB. In this release, support is limited to expression evaluation.
4245 * New native configurations
4247 GNU/Linux/m32r m32r-*-linux-gnu
4251 GDB's remote protocol now includes support for the 'p' packet. This
4252 packet is used to fetch individual registers from a remote inferior.
4254 * END-OF-LIFE registers[] compatibility module
4256 GDB's internal register infrastructure has been completely rewritten.
4257 The new infrastructure making possible the implementation of key new
4258 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4261 GDB 6.3 will be the last release to include the the registers[]
4262 compatibility module that allowed out-of-date configurations to
4263 continue to work. This change directly impacts the following
4273 powerpc bdm protocol
4275 Unless there is activity to revive these configurations, they will be
4276 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4278 * OBSOLETE configurations and files
4280 Configurations that have been declared obsolete in this release have
4281 been commented out. Unless there is activity to revive these
4282 configurations, the next release of GDB will have their sources
4283 permanently REMOVED.
4292 *** Changes in GDB 6.2.1:
4294 * MIPS `break main; run' gave an heuristic-fence-post warning
4296 When attempting to run even a simple program, a warning about
4297 heuristic-fence-post being hit would be reported. This problem has
4300 * MIPS IRIX 'long double' crashed GDB
4302 When examining a long double variable, GDB would get a segmentation
4303 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4304 IRIX long double values).
4308 A bug in the VAX stack code was causing problems with the "next"
4309 command. This problem has been fixed.
4311 *** Changes in GDB 6.2:
4313 * Fix for ``many threads''
4315 On GNU/Linux systems that use the NPTL threads library, a program
4316 rapidly creating and deleting threads would confuse GDB leading to the
4319 ptrace: No such process.
4320 thread_db_get_info: cannot get thread info: generic error
4322 This problem has been fixed.
4324 * "-async" and "-noasync" options removed.
4326 Support for the broken "-noasync" option has been removed (it caused
4329 * New ``start'' command.
4331 This command runs the program until the begining of the main procedure.
4333 * New BSD Kernel Data Access Library (libkvm) interface
4335 Using ``target kvm'' it is now possible to debug kernel core dumps and
4336 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4337 platforms. Currently supported (native-only) configurations are:
4339 FreeBSD/amd64 x86_64-*-freebsd*
4340 FreeBSD/i386 i?86-*-freebsd*
4341 NetBSD/i386 i?86-*-netbsd*
4342 NetBSD/m68k m68*-*-netbsd*
4343 NetBSD/sparc sparc-*-netbsd*
4344 OpenBSD/amd64 x86_64-*-openbsd*
4345 OpenBSD/i386 i?86-*-openbsd*
4346 OpenBSD/m68k m68*-openbsd*
4347 OpenBSD/sparc sparc-*-openbsd*
4349 * Signal trampoline code overhauled
4351 Many generic problems with GDB's signal handling code have been fixed.
4352 These include: backtraces through non-contiguous stacks; recognition
4353 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4354 call; backtrace through a signal trampoline; step into and out of
4355 signal handlers; and single-stepping in the signal trampoline.
4357 Please note that kernel bugs are a limiting factor here. These
4358 features have been shown to work on an s390 GNU/Linux system that
4359 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4361 * Cygwin support for DWARF 2 added.
4363 * New native configurations
4365 GNU/Linux/hppa hppa*-*-linux*
4366 OpenBSD/hppa hppa*-*-openbsd*
4367 OpenBSD/m68k m68*-*-openbsd*
4368 OpenBSD/m88k m88*-*-openbsd*
4369 OpenBSD/powerpc powerpc-*-openbsd*
4370 NetBSD/vax vax-*-netbsd*
4371 OpenBSD/vax vax-*-openbsd*
4373 * END-OF-LIFE frame compatibility module
4375 GDB's internal frame infrastructure has been completely rewritten.
4376 The new infrastructure making it possible to support key new features
4377 including DWARF 2 Call Frame Information. To aid in the task of
4378 migrating old configurations to this new infrastructure, a
4379 compatibility module, that allowed old configurations to continue to
4380 work, was also included.
4382 GDB 6.2 will be the last release to include this frame compatibility
4383 module. This change directly impacts the following configurations:
4393 Unless there is activity to revive these configurations, they will be
4394 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4396 * REMOVED configurations and files
4398 Sun 3, running SunOS 3 m68*-*-sunos3*
4399 Sun 3, running SunOS 4 m68*-*-sunos4*
4400 Sun 2, running SunOS 3 m68000-*-sunos3*
4401 Sun 2, running SunOS 4 m68000-*-sunos4*
4402 Motorola 680x0 running LynxOS m68*-*-lynxos*
4403 AT&T 3b1/Unix pc m68*-att-*
4404 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4405 decstation mips-dec-* mips-little-*
4406 riscos mips-*-riscos* mips-*-sysv*
4407 sonymips mips-sony-*
4408 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4410 *** Changes in GDB 6.1.1:
4412 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4414 The TUI (Text-mode User Interface) is now built as part of a default
4415 GDB configuration. It is enabled by either selecting the TUI with the
4416 command line option "-i=tui" or by running the separate "gdbtui"
4417 program. For more information on the TUI, see the manual "Debugging
4420 * Pending breakpoint support (also included in GDB 6.1)
4422 Support has been added to allow you to specify breakpoints in shared
4423 libraries that have not yet been loaded. If a breakpoint location
4424 cannot be found, and the "breakpoint pending" option is set to auto,
4425 GDB queries you if you wish to make the breakpoint pending on a future
4426 shared-library load. If and when GDB resolves the breakpoint symbol,
4427 the pending breakpoint is removed as one or more regular breakpoints
4430 Pending breakpoints are very useful for GCJ Java debugging.
4432 * Fixed ISO-C build problems
4434 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4435 non ISO-C code that stopped them being built using a more strict ISO-C
4436 compiler (e.g., IBM's C compiler).
4438 * Fixed build problem on IRIX 5
4440 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4441 wasn't able to compile compile on an IRIX 5 system.
4443 * Added execute permission to gdb/gdbserver/configure
4445 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4446 permission. This bug would cause configure to fail on a number of
4447 systems (Solaris, IRIX). Ref: server/519.
4449 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4451 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4452 has been updated to use constant array sizes.
4454 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4456 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4457 its generated DWARF Call Frame Info. This encoding was causing GDB to
4458 panic, that panic has been fixed. Ref: gdb/1628.
4460 * Fixed a problem when examining parameters in shared library code.
4462 When examining parameters in optimized shared library code generated
4463 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4464 not available''. GDB now correctly displays the variable's value.
4466 *** Changes in GDB 6.1:
4468 * Removed --with-mmalloc
4470 Support for the mmalloc memory manager has been removed, as it
4471 conflicted with the internal gdb byte cache.
4473 * Changes in AMD64 configurations
4475 The AMD64 target now includes the %cs and %ss registers. As a result
4476 the AMD64 remote protocol has changed; this affects the floating-point
4477 and SSE registers. If you rely on those registers for your debugging,
4478 you should upgrade gdbserver on the remote side.
4480 * Revised SPARC target
4482 The SPARC target has been completely revised, incorporating the
4483 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4484 support for LynxOS and SunOS 4 has been dropped. Calling functions
4485 from within GDB on operating systems with a non-executable stack
4486 (Solaris, OpenBSD) now works.
4490 GDB has a new C++ demangler which does a better job on the mangled
4491 names generated by current versions of g++. It also runs faster, so
4492 with this and other changes gdb should now start faster on large C++
4495 * DWARF 2 Location Expressions
4497 GDB support for location expressions has been extended to support function
4498 arguments and frame bases. Older versions of GDB could crash when they
4501 * C++ nested types and namespaces
4503 GDB's support for nested types and namespaces in C++ has been
4504 improved, especially if you use the DWARF 2 debugging format. (This
4505 is the default for recent versions of GCC on most platforms.)
4506 Specifically, if you have a class "Inner" defined within a class or
4507 namespace "Outer", then GDB realizes that the class's name is
4508 "Outer::Inner", not simply "Inner". This should greatly reduce the
4509 frequency of complaints about not finding RTTI symbols. In addition,
4510 if you are stopped at inside of a function defined within a namespace,
4511 GDB modifies its name lookup accordingly.
4513 * New native configurations
4515 NetBSD/amd64 x86_64-*-netbsd*
4516 OpenBSD/amd64 x86_64-*-openbsd*
4517 OpenBSD/alpha alpha*-*-openbsd*
4518 OpenBSD/sparc sparc-*-openbsd*
4519 OpenBSD/sparc64 sparc64-*-openbsd*
4521 * New debugging protocols
4523 M32R with SDI protocol m32r-*-elf*
4525 * "set prompt-escape-char" command deleted.
4527 The command "set prompt-escape-char" has been deleted. This command,
4528 and its very obscure effet on GDB's prompt, was never documented,
4529 tested, nor mentioned in the NEWS file.
4531 * OBSOLETE configurations and files
4533 Configurations that have been declared obsolete in this release have
4534 been commented out. Unless there is activity to revive these
4535 configurations, the next release of GDB will have their sources
4536 permanently REMOVED.
4538 Sun 3, running SunOS 3 m68*-*-sunos3*
4539 Sun 3, running SunOS 4 m68*-*-sunos4*
4540 Sun 2, running SunOS 3 m68000-*-sunos3*
4541 Sun 2, running SunOS 4 m68000-*-sunos4*
4542 Motorola 680x0 running LynxOS m68*-*-lynxos*
4543 AT&T 3b1/Unix pc m68*-att-*
4544 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4545 decstation mips-dec-* mips-little-*
4546 riscos mips-*-riscos* mips-*-sysv*
4547 sonymips mips-sony-*
4548 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4550 * REMOVED configurations and files
4552 SGI Irix-4.x mips-sgi-irix4 or iris4
4553 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4554 Z8000 simulator z8k-zilog-none or z8ksim
4555 Matsushita MN10200 w/simulator mn10200-*-*
4556 H8/500 simulator h8500-hitachi-hms or h8500hms
4557 HP/PA running BSD hppa*-*-bsd*
4558 HP/PA running OSF/1 hppa*-*-osf*
4559 HP/PA Pro target hppa*-*-pro*
4560 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4561 386BSD i[3456]86-*-bsd*
4562 Sequent family i[3456]86-sequent-sysv4*
4563 i[3456]86-sequent-sysv*
4564 i[3456]86-sequent-bsd*
4565 SPARC running LynxOS sparc-*-lynxos*
4566 SPARC running SunOS 4 sparc-*-sunos4*
4567 Tsqware Sparclet sparclet-*-*
4568 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4570 *** Changes in GDB 6.0:
4574 Support for debugging the Objective-C programming language has been
4575 integrated into GDB.
4577 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4579 DWARF 2's Call Frame Information makes available compiler generated
4580 information that more exactly describes the program's run-time stack.
4581 By using this information, GDB is able to provide more robust stack
4584 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4585 have been updated to use a new backtrace mechanism which includes
4586 DWARF 2 CFI support.
4590 GDB's remote protocol has been extended to include support for hosted
4591 file I/O (where the remote target uses GDB's file system). See GDB's
4592 remote protocol documentation for details.
4594 * All targets using the new architecture framework.
4596 All of GDB's targets have been updated to use the new internal
4597 architecture framework. The way is now open for future GDB releases
4598 to include cross-architecture native debugging support (i386 on amd64,
4601 * GNU/Linux's Thread Local Storage (TLS)
4603 GDB now includes support for for the GNU/Linux implementation of
4604 per-thread variables.
4606 * GNU/Linux's Native POSIX Thread Library (NPTL)
4608 GDB's thread code has been updated to work with either the new
4609 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4611 * Separate debug info.
4613 GDB, in conjunction with BINUTILS, now supports a mechanism for
4614 automatically loading debug information from a separate file. Instead
4615 of shipping full debug and non-debug versions of system libraries,
4616 system integrators can now instead ship just the stripped libraries
4617 and optional debug files.
4619 * DWARF 2 Location Expressions
4621 DWARF 2 Location Expressions allow the compiler to more completely
4622 describe the location of variables (even in optimized code) to the
4625 GDB now includes preliminary support for location expressions (support
4626 for DW_OP_piece is still missing).
4630 A number of long standing bugs that caused GDB to die while starting a
4631 Java application have been fixed. GDB's Java support is now
4632 considered "useable".
4634 * GNU/Linux support for fork, vfork, and exec.
4636 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4637 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4640 * GDB supports logging output to a file
4642 There are two new commands, "set logging" and "show logging", which can be
4643 used to capture GDB's output to a file.
4645 * The meaning of "detach" has changed for gdbserver
4647 The "detach" command will now resume the application, as documented. To
4648 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4651 * d10v, m68hc11 `regs' command deprecated
4653 The `info registers' command has been updated so that it displays the
4654 registers using a format identical to the old `regs' command.
4658 A new command, "maint set profile on/off", has been added. This command can
4659 be used to enable or disable profiling while running GDB, to profile a
4660 session or a set of commands. In addition there is a new configure switch,
4661 "--enable-profiling", which will cause GDB to be compiled with profiling
4662 data, for more informative profiling results.
4664 * Default MI syntax changed to "mi2".
4666 The default MI (machine interface) syntax, enabled by the command line
4667 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4668 "mi1", can be enabled by specifying the option "-i=mi1".
4670 Support for the original "mi0" syntax (included in GDB 5.0) has been
4673 Fix for gdb/192: removed extraneous space when displaying frame level.
4674 Fix for gdb/672: update changelist is now output in mi list format.
4675 Fix for gdb/702: a -var-assign that updates the value now shows up
4676 in a subsequent -var-update.
4678 * New native configurations.
4680 FreeBSD/amd64 x86_64-*-freebsd*
4682 * Multi-arched targets.
4684 HP/PA HPUX11 hppa*-*-hpux*
4685 Renesas M32R/D w/simulator m32r-*-elf*
4687 * OBSOLETE configurations and files
4689 Configurations that have been declared obsolete in this release have
4690 been commented out. Unless there is activity to revive these
4691 configurations, the next release of GDB will have their sources
4692 permanently REMOVED.
4694 Z8000 simulator z8k-zilog-none or z8ksim
4695 Matsushita MN10200 w/simulator mn10200-*-*
4696 H8/500 simulator h8500-hitachi-hms or h8500hms
4697 HP/PA running BSD hppa*-*-bsd*
4698 HP/PA running OSF/1 hppa*-*-osf*
4699 HP/PA Pro target hppa*-*-pro*
4700 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4701 Sequent family i[3456]86-sequent-sysv4*
4702 i[3456]86-sequent-sysv*
4703 i[3456]86-sequent-bsd*
4704 Tsqware Sparclet sparclet-*-*
4705 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4707 * REMOVED configurations and files
4710 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4711 IBM AIX PS/2 i[3456]86-*-aix
4712 i386 running Mach 3.0 i[3456]86-*-mach3*
4713 i386 running Mach i[3456]86-*-mach*
4714 i386 running OSF/1 i[3456]86-*osf1mk*
4715 HP/Apollo 68k Family m68*-apollo*-sysv*,
4717 m68*-hp-bsd*, m68*-hp-hpux*
4718 Argonaut Risc Chip (ARC) arc-*-*
4719 Mitsubishi D30V d30v-*-*
4720 Fujitsu FR30 fr30-*-elf*
4721 OS/9000 i[34]86-*-os9k
4722 I960 with MON960 i960-*-coff
4724 * MIPS $fp behavior changed
4726 The convenience variable $fp, for the MIPS, now consistently returns
4727 the address of the current frame's base. Previously, depending on the
4728 context, $fp could refer to either $sp or the current frame's base
4729 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4730 The GNU Source-Level Debugger''.
4732 *** Changes in GDB 5.3:
4734 * GNU/Linux shared library multi-threaded performance improved.
4736 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4737 `/proc', in preference to `ptrace' for memory reads. This may result
4738 in an improvement in the start-up time of multi-threaded, shared
4739 library applications when run under GDB. One GDB user writes: ``loads
4740 shared libs like mad''.
4742 * ``gdbserver'' now supports multi-threaded applications on some targets
4744 Support for debugging multi-threaded applications which use
4745 the GNU/Linux LinuxThreads package has been added for
4746 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4747 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4749 * GDB now supports C/C++ preprocessor macros.
4751 GDB now expands preprocessor macro invocations in C/C++ expressions,
4752 and provides various commands for showing macro definitions and how
4755 The new command `macro expand EXPRESSION' expands any macro
4756 invocations in expression, and shows the result.
4758 The new command `show macro MACRO-NAME' shows the definition of the
4759 macro named MACRO-NAME, and where it was defined.
4761 Most compilers don't include information about macros in the debugging
4762 information by default. In GCC 3.1, for example, you need to compile
4763 your program with the options `-gdwarf-2 -g3'. If the macro
4764 information is present in the executable, GDB will read it.
4766 * Multi-arched targets.
4768 DEC Alpha (partial) alpha*-*-*
4769 DEC VAX (partial) vax-*-*
4771 National Semiconductor NS32000 (partial) ns32k-*-*
4772 Motorola 68000 (partial) m68k-*-*
4773 Motorola MCORE mcore-*-*
4777 Fujitsu FRV architecture added by Red Hat frv*-*-*
4780 * New native configurations
4782 Alpha NetBSD alpha*-*-netbsd*
4783 SH NetBSD sh*-*-netbsdelf*
4784 MIPS NetBSD mips*-*-netbsd*
4785 UltraSPARC NetBSD sparc64-*-netbsd*
4787 * OBSOLETE configurations and files
4789 Configurations that have been declared obsolete in this release have
4790 been commented out. Unless there is activity to revive these
4791 configurations, the next release of GDB will have their sources
4792 permanently REMOVED.
4794 Mitsubishi D30V d30v-*-*
4795 OS/9000 i[34]86-*-os9k
4796 IBM AIX PS/2 i[3456]86-*-aix
4797 Fujitsu FR30 fr30-*-elf*
4798 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4799 Argonaut Risc Chip (ARC) arc-*-*
4800 i386 running Mach 3.0 i[3456]86-*-mach3*
4801 i386 running Mach i[3456]86-*-mach*
4802 i386 running OSF/1 i[3456]86-*osf1mk*
4803 HP/Apollo 68k Family m68*-apollo*-sysv*,
4805 m68*-hp-bsd*, m68*-hp-hpux*
4806 I960 with MON960 i960-*-coff
4808 * OBSOLETE languages
4810 CHILL, a Pascal like language used by telecommunications companies.
4812 * REMOVED configurations and files
4814 AMD 29k family via UDI a29k-amd-udi, udi29k
4815 A29K VxWorks a29k-*-vxworks
4816 AMD 29000 embedded, using EBMON a29k-none-none
4817 AMD 29000 embedded with COFF a29k-none-coff
4818 AMD 29000 embedded with a.out a29k-none-aout
4820 testsuite/gdb.hp/gdb.threads-hp/ directory
4822 * New command "set max-user-call-depth <nnn>"
4824 This command allows the user to limit the call depth of user-defined
4825 commands. The default is 1024.
4827 * Changes in FreeBSD/i386 native debugging.
4829 Support for the "generate-core-file" has been added.
4831 * New commands "dump", "append", and "restore".
4833 These commands allow data to be copied from target memory
4834 to a bfd-format or binary file (dump and append), and back
4835 from a file into memory (restore).
4837 * Improved "next/step" support on multi-processor Alpha Tru64.
4839 The previous single-step mechanism could cause unpredictable problems,
4840 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4841 of a software single-step mechanism prevents this.
4843 *** Changes in GDB 5.2.1:
4851 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4852 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4853 Fix, by Joel Brobecker imported from mainline.
4855 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4856 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4857 Fix, by Fred Fish, imported from mainline.
4859 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4860 Surprisingly enough, it works now.
4861 By Michal Ludvig, imported from mainline.
4863 i386 hardware watchpoint support:
4864 avoid misses on second run for some targets.
4865 By Pierre Muller, imported from mainline.
4867 *** Changes in GDB 5.2:
4869 * New command "set trust-readonly-sections on[off]".
4871 This command is a hint that tells gdb that read-only sections
4872 really are read-only (ie. that their contents will not change).
4873 In this mode, gdb will go to the object file rather than the
4874 target to read memory from read-only sections (such as ".text").
4875 This can be a significant performance improvement on some
4876 (notably embedded) targets.
4878 * New command "generate-core-file" (or "gcore").
4880 This new gdb command allows the user to drop a core file of the child
4881 process state at any time. So far it's been implemented only for
4882 GNU/Linux and Solaris, but should be relatively easily ported to other
4883 hosts. Argument is core file name (defaults to core.<pid>).
4885 * New command line option
4887 GDB now accepts --pid or -p followed by a process id.
4889 * Change in command line behavior -- corefiles vs. process ids.
4891 There is a subtle behavior in the way in which GDB handles
4892 command line arguments. The first non-flag argument is always
4893 a program to debug, but the second non-flag argument may either
4894 be a corefile or a process id. Previously, GDB would attempt to
4895 open the second argument as a corefile, and if that failed, would
4896 issue a superfluous error message and then attempt to attach it as
4897 a process. Now, if the second argument begins with a non-digit,
4898 it will be treated as a corefile. If it begins with a digit,
4899 GDB will attempt to attach it as a process, and if no such process
4900 is found, will then attempt to open it as a corefile.
4902 * Changes in ARM configurations.
4904 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4905 configuration is fully multi-arch.
4907 * New native configurations
4909 ARM NetBSD arm*-*-netbsd*
4910 x86 OpenBSD i[3456]86-*-openbsd*
4911 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4912 Sparc64 running FreeBSD sparc64-*-freebsd*
4916 Sanyo XStormy16 xstormy16-elf
4918 * OBSOLETE configurations and files
4920 Configurations that have been declared obsolete in this release have
4921 been commented out. Unless there is activity to revive these
4922 configurations, the next release of GDB will have their sources
4923 permanently REMOVED.
4925 AMD 29k family via UDI a29k-amd-udi, udi29k
4926 A29K VxWorks a29k-*-vxworks
4927 AMD 29000 embedded, using EBMON a29k-none-none
4928 AMD 29000 embedded with COFF a29k-none-coff
4929 AMD 29000 embedded with a.out a29k-none-aout
4931 testsuite/gdb.hp/gdb.threads-hp/ directory
4933 * REMOVED configurations and files
4935 TI TMS320C80 tic80-*-*
4937 PowerPC Solaris powerpcle-*-solaris*
4938 PowerPC Windows NT powerpcle-*-cygwin32
4939 PowerPC Netware powerpc-*-netware*
4940 Harris/CXUX m88k m88*-harris-cxux*
4941 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4942 ns32k-utek-sysv* ns32k-utek-*
4943 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4944 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4945 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4946 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4947 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4949 * Changes to command line processing
4951 The new `--args' feature can be used to specify command-line arguments
4952 for the inferior from gdb's command line.
4954 * Changes to key bindings
4956 There is a new `operate-and-get-next' function bound to `C-o'.
4958 *** Changes in GDB 5.1.1
4960 Fix compile problem on DJGPP.
4962 Fix a problem with floating-point registers on the i386 being
4965 Fix to stop GDB crashing on .debug_str debug info.
4967 Numerous documentation fixes.
4969 Numerous testsuite fixes.
4971 *** Changes in GDB 5.1:
4973 * New native configurations
4975 Alpha FreeBSD alpha*-*-freebsd*
4976 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4977 MIPS GNU/Linux mips*-*-linux*
4978 MIPS SGI Irix 6.x mips*-sgi-irix6*
4979 ia64 AIX ia64-*-aix*
4980 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4984 Motorola 68HC11 and 68HC12 m68hc11-elf
4986 UltraSparc running GNU/Linux sparc64-*-linux*
4988 * OBSOLETE configurations and files
4990 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4991 Harris/CXUX m88k m88*-harris-cxux*
4992 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4993 ns32k-utek-sysv* ns32k-utek-*
4994 TI TMS320C80 tic80-*-*
4996 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4997 PowerPC Solaris powerpcle-*-solaris*
4998 PowerPC Windows NT powerpcle-*-cygwin32
4999 PowerPC Netware powerpc-*-netware*
5000 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5001 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5002 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5003 Apple Macintosh (MPW) host N/A
5005 stuff.c (Program to stuff files into a specially prepared space in kdb)
5006 kdb-start.c (Main loop for the standalone kernel debugger)
5008 Configurations that have been declared obsolete in this release have
5009 been commented out. Unless there is activity to revive these
5010 configurations, the next release of GDB will have their sources
5011 permanently REMOVED.
5013 * REMOVED configurations and files
5015 Altos 3068 m68*-altos-*
5016 Convex c1-*-*, c2-*-*
5018 ARM RISCix arm-*-* (as host)
5022 * GDB has been converted to ISO C.
5024 GDB's source code has been converted to ISO C. In particular, the
5025 sources are fully protoized, and rely on standard headers being
5030 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5032 * The MI enabled by default.
5034 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5035 revised and enabled by default. Packages which use GDB as a debugging
5036 engine behind a UI or another front end are encouraged to switch to
5037 using the GDB/MI interface, instead of the old annotations interface
5038 which is now deprecated.
5040 * Support for debugging Pascal programs.
5042 GDB now includes support for debugging Pascal programs. The following
5043 main features are supported:
5045 - Pascal-specific data types such as sets;
5047 - automatic recognition of Pascal sources based on file-name
5050 - Pascal-style display of data types, variables, and functions;
5052 - a Pascal expression parser.
5054 However, some important features are not yet supported.
5056 - Pascal string operations are not supported at all;
5058 - there are some problems with boolean types;
5060 - Pascal type hexadecimal constants are not supported
5061 because they conflict with the internal variables format;
5063 - support for Pascal objects and classes is not full yet;
5065 - unlike Pascal, GDB is case-sensitive for symbol names.
5067 * Changes in completion.
5069 Commands such as `shell', `run' and `set args', which pass arguments
5070 to inferior programs, now complete on file names, similar to what
5071 users expect at the shell prompt.
5073 Commands which accept locations, such as `disassemble', `print',
5074 `breakpoint', `until', etc. now complete on filenames as well as
5075 program symbols. Thus, if you type "break foob TAB", and the source
5076 files linked into the programs include `foobar.c', that file name will
5077 be one of the candidates for completion. However, file names are not
5078 considered for completion after you typed a colon that delimits a file
5079 name from a name of a function in that file, as in "break foo.c:bar".
5081 `set demangle-style' completes on available demangling styles.
5083 * New platform-independent commands:
5085 It is now possible to define a post-hook for a command as well as a
5086 hook that runs before the command. For more details, see the
5087 documentation of `hookpost' in the GDB manual.
5089 * Changes in GNU/Linux native debugging.
5091 Support for debugging multi-threaded programs has been completely
5092 revised for all platforms except m68k and sparc. You can now debug as
5093 many threads as your system allows you to have.
5095 Attach/detach is supported for multi-threaded programs.
5097 Support for SSE registers was added for x86. This doesn't work for
5098 multi-threaded programs though.
5100 * Changes in MIPS configurations.
5102 Multi-arch support is enabled for all MIPS configurations.
5104 GDB can now be built as native debugger on SGI Irix 6.x systems for
5105 debugging n32 executables. (Debugging 64-bit executables is not yet
5108 * Unified support for hardware watchpoints in all x86 configurations.
5110 Most (if not all) native x86 configurations support hardware-assisted
5111 breakpoints and watchpoints in a unified manner. This support
5112 implements debug register sharing between watchpoints, which allows to
5113 put a virtually infinite number of watchpoints on the same address,
5114 and also supports watching regions up to 16 bytes with several debug
5117 The new maintenance command `maintenance show-debug-regs' toggles
5118 debugging print-outs in functions that insert, remove, and test
5119 watchpoints and hardware breakpoints.
5121 * Changes in the DJGPP native configuration.
5123 New command ``info dos sysinfo'' displays assorted information about
5124 the CPU, OS, memory, and DPMI server.
5126 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5127 display information about segment descriptors stored in GDT, LDT, and
5130 New commands ``info dos pde'' and ``info dos pte'' display entries
5131 from Page Directory and Page Tables (for now works with CWSDPMI only).
5132 New command ``info dos address-pte'' displays the Page Table entry for
5133 a given linear address.
5135 GDB can now pass command lines longer than 126 characters to the
5136 program being debugged (requires an update to the libdbg.a library
5137 which is part of the DJGPP development kit).
5139 DWARF2 debug info is now supported.
5141 It is now possible to `step' and `next' through calls to `longjmp'.
5143 * Changes in documentation.
5145 All GDB documentation was converted to GFDL, the GNU Free
5146 Documentation License.
5148 Tracepoints-related commands are now fully documented in the GDB
5151 TUI, the Text-mode User Interface, is now documented in the manual.
5153 Tracepoints-related commands are now fully documented in the GDB
5156 The "GDB Internals" manual now has an index. It also includes
5157 documentation of `ui_out' functions, GDB coding standards, x86
5158 hardware watchpoints, and memory region attributes.
5160 * GDB's version number moved to ``version.in''
5162 The Makefile variable VERSION has been replaced by the file
5163 ``version.in''. People creating GDB distributions should update the
5164 contents of this file.
5168 GUD support is now a standard part of the EMACS distribution.
5170 *** Changes in GDB 5.0:
5172 * Improved support for debugging FP programs on x86 targets
5174 Unified and much-improved support for debugging floating-point
5175 programs on all x86 targets. In particular, ``info float'' now
5176 displays the FP registers in the same format on all x86 targets, with
5177 greater level of detail.
5179 * Improvements and bugfixes in hardware-assisted watchpoints
5181 It is now possible to watch array elements, struct members, and
5182 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5183 on x86 targets no longer erroneously trigger when the address is
5186 * Improvements in the native DJGPP version of GDB
5188 The distribution now includes all the scripts and auxiliary files
5189 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5190 machines ``out of the box''.
5192 The DJGPP version can now debug programs that use signals. It is
5193 possible to catch signals that happened in the debuggee, deliver
5194 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5195 would kill the program being debugged.) Programs that hook hardware
5196 interrupts (keyboard, timer, etc.) can also be debugged.
5198 It is now possible to debug DJGPP programs that redirect their
5199 standard handles or switch them to raw (as opposed to cooked) mode, or
5200 even close them. The command ``run < foo > bar'' works as expected,
5201 and ``info terminal'' reports useful information about the debuggee's
5202 terminal, including raw/cooked mode, redirection, etc.
5204 The DJGPP version now uses termios functions for console I/O, which
5205 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5208 DOS-style file names with drive letters are now fully supported by
5211 It is now possible to debug DJGPP programs that switch their working
5212 directory. It is also possible to rerun the debuggee any number of
5213 times without restarting GDB; thus, you can use the same setup,
5214 breakpoints, etc. for many debugging sessions.
5216 * New native configurations
5218 ARM GNU/Linux arm*-*-linux*
5219 PowerPC GNU/Linux powerpc-*-linux*
5223 Motorola MCore mcore-*-*
5224 x86 VxWorks i[3456]86-*-vxworks*
5225 PowerPC VxWorks powerpc-*-vxworks*
5226 TI TMS320C80 tic80-*-*
5228 * OBSOLETE configurations
5230 Altos 3068 m68*-altos-*
5231 Convex c1-*-*, c2-*-*
5233 ARM RISCix arm-*-* (as host)
5236 Configurations that have been declared obsolete will be commented out,
5237 but the code will be left in place. If there is no activity to revive
5238 these configurations before the next release of GDB, the sources will
5239 be permanently REMOVED.
5241 * Gould support removed
5243 Support for the Gould PowerNode and NP1 has been removed.
5245 * New features for SVR4
5247 On SVR4 native platforms (such as Solaris), if you attach to a process
5248 without first loading a symbol file, GDB will now attempt to locate and
5249 load symbols from the running process's executable file.
5251 * Many C++ enhancements
5253 C++ support has been greatly improved. Overload resolution now works properly
5254 in almost all cases. RTTI support is on the way.
5256 * Remote targets can connect to a sub-program
5258 A popen(3) style serial-device has been added. This device starts a
5259 sub-process (such as a stand-alone simulator) and then communicates
5260 with that. The sub-program to run is specified using the syntax
5261 ``|<program> <args>'' vis:
5263 (gdb) set remotedebug 1
5264 (gdb) target extended-remote |mn10300-elf-sim program-args
5266 * MIPS 64 remote protocol
5268 A long standing bug in the mips64 remote protocol where by GDB
5269 expected certain 32 bit registers (ex SR) to be transfered as 32
5270 instead of 64 bits has been fixed.
5272 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5273 added to provide backward compatibility with older versions of GDB.
5275 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5277 The command ``set remotebinarydownload'' command has been replaced by
5278 ``set remote X-packet''. Other commands in ``set remote'' family
5279 include ``set remote P-packet''.
5281 * Breakpoint commands accept ranges.
5283 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5284 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5285 ``tracepoint passcount'' also accepts a range of tracepoints.
5287 * ``apropos'' command added.
5289 The ``apropos'' command searches through command names and
5290 documentation strings, printing out matches, making it much easier to
5291 try to find a command that does what you are looking for.
5295 A new machine oriented interface (MI) has been added to GDB. This
5296 interface is designed for debug environments running GDB as a separate
5297 process. This is part of the long term libGDB project. See the
5298 "GDB/MI" chapter of the GDB manual for further information. It can be
5299 enabled by configuring with:
5301 .../configure --enable-gdbmi
5303 *** Changes in GDB-4.18:
5305 * New native configurations
5307 HP-UX 10.20 hppa*-*-hpux10.20
5308 HP-UX 11.x hppa*-*-hpux11.0*
5309 M68K GNU/Linux m68*-*-linux*
5313 Fujitsu FR30 fr30-*-elf*
5314 Intel StrongARM strongarm-*-*
5315 Mitsubishi D30V d30v-*-*
5317 * OBSOLETE configurations
5319 Gould PowerNode, NP1 np1-*-*, pn-*-*
5321 Configurations that have been declared obsolete will be commented out,
5322 but the code will be left in place. If there is no activity to revive
5323 these configurations before the next release of GDB, the sources will
5324 be permanently REMOVED.
5328 As a compatibility experiment, GDB's source files buildsym.h and
5329 buildsym.c have been converted to pure standard C, no longer
5330 containing any K&R compatibility code. We believe that all systems in
5331 use today either come with a standard C compiler, or have a GCC port
5332 available. If this is not true, please report the affected
5333 configuration to bug-gdb@gnu.org immediately. See the README file for
5334 information about getting a standard C compiler if you don't have one
5339 GDB now uses readline 2.2.
5341 * set extension-language
5343 You can now control the mapping between filename extensions and source
5344 languages by using the `set extension-language' command. For instance,
5345 you can ask GDB to treat .c files as C++ by saying
5346 set extension-language .c c++
5347 The command `info extensions' lists all of the recognized extensions
5348 and their associated languages.
5350 * Setting processor type for PowerPC and RS/6000
5352 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5353 you can use the `set processor' command to specify what variant of the
5354 PowerPC family you are debugging. The command
5358 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5359 following PowerPC and RS6000 variants:
5361 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5362 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5364 403GC IBM PowerPC 403GC
5365 505 Motorola PowerPC 505
5366 860 Motorola PowerPC 860 or 850
5367 601 Motorola PowerPC 601
5368 602 Motorola PowerPC 602
5369 603 Motorola/IBM PowerPC 603 or 603e
5370 604 Motorola PowerPC 604 or 604e
5371 750 Motorola/IBM PowerPC 750 or 750
5373 At the moment, this command just tells GDB what to name the
5374 special-purpose processor registers. Since almost all the affected
5375 registers are inaccessible to user-level programs, this command is
5376 only useful for remote debugging in its present form.
5380 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5381 more extensive support for HP-UX. Added features include shared
5382 library support, kernel threads and hardware watchpoints for 11.00,
5383 support for HP's ANSI C and C++ compilers, and a compatibility mode
5384 for xdb and dbx commands.
5388 HP's donation includes the new concept of catchpoints, which is a
5389 generalization of the old catch command. On HP-UX, it is now possible
5390 to catch exec, fork, and vfork, as well as library loading.
5392 This means that the existing catch command has changed; its first
5393 argument now specifies the type of catch to be set up. See the
5394 output of "help catch" for a list of catchpoint types.
5396 * Debugging across forks
5398 On HP-UX, you can choose which process to debug when a fork() happens
5403 HP has donated a curses-based terminal user interface (TUI). To get
5404 it, build with --enable-tui. Although this can be enabled for any
5405 configuration, at present it only works for native HP debugging.
5407 * GDB remote protocol additions
5409 A new protocol packet 'X' that writes binary data is now available.
5410 Default behavior is to try 'X', then drop back to 'M' if the stub
5411 fails to respond. The settable variable `remotebinarydownload'
5412 allows explicit control over the use of 'X'.
5414 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5415 full 64-bit address. The command
5417 set remoteaddresssize 32
5419 can be used to revert to the old behaviour. For existing remote stubs
5420 the change should not be noticed, as the additional address information
5423 In order to assist in debugging stubs, you may use the maintenance
5424 command `packet' to send any text string to the stub. For instance,
5426 maint packet heythere
5428 sends the packet "$heythere#<checksum>". Note that it is very easy to
5429 disrupt a debugging session by sending the wrong packet at the wrong
5432 The compare-sections command allows you to compare section data on the
5433 target to what is in the executable file without uploading or
5434 downloading, by comparing CRC checksums.
5436 * Tracing can collect general expressions
5438 You may now collect general expressions at tracepoints. This requires
5439 further additions to the target-side stub; see tracepoint.c and
5440 doc/agentexpr.texi for further details.
5442 * mask-address variable for Mips
5444 For Mips targets, you may control the zeroing of the upper 32 bits of
5445 a 64-bit address by entering `set mask-address on'. This is mainly
5446 of interest to users of embedded R4xxx and R5xxx processors.
5448 * Higher serial baud rates
5450 GDB's serial code now allows you to specify baud rates 57600, 115200,
5451 230400, and 460800 baud. (Note that your host system may not be able
5452 to achieve all of these rates.)
5456 The i960 configuration now includes an initial implementation of a
5457 builtin simulator, contributed by Jim Wilson.
5460 *** Changes in GDB-4.17:
5462 * New native configurations
5464 Alpha GNU/Linux alpha*-*-linux*
5465 Unixware 2.x i[3456]86-unixware2*
5466 Irix 6.x mips*-sgi-irix6*
5467 PowerPC GNU/Linux powerpc-*-linux*
5468 PowerPC Solaris powerpcle-*-solaris*
5469 Sparc GNU/Linux sparc-*-linux*
5470 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5474 Argonaut Risc Chip (ARC) arc-*-*
5475 Hitachi H8/300S h8300*-*-*
5476 Matsushita MN10200 w/simulator mn10200-*-*
5477 Matsushita MN10300 w/simulator mn10300-*-*
5478 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5479 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5480 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5481 Mitsubishi D10V w/simulator d10v-*-*
5482 Mitsubishi M32R/D w/simulator m32r-*-elf*
5483 Tsqware Sparclet sparclet-*-*
5484 NEC V850 w/simulator v850-*-*
5486 * New debugging protocols
5488 ARM with RDI protocol arm*-*-*
5489 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5490 DDB and LSI variants of PMON protocol mips*-*-*
5491 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5492 PowerPC with SDS protocol powerpc{,le}-*-eabi
5493 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5497 All configurations can now understand and use the DWARF 2 debugging
5498 format. The choice is automatic, if the symbol file contains DWARF 2
5503 GDB now includes basic Java language support. This support is
5504 only useful with Java compilers that produce native machine code.
5506 * solib-absolute-prefix and solib-search-path
5508 For SunOS and SVR4 shared libraries, you may now set the prefix for
5509 loading absolute shared library symbol files, and the search path for
5510 locating non-absolute shared library symbol files.
5512 * Live range splitting
5514 GDB can now effectively debug code for which GCC has performed live
5515 range splitting as part of its optimization. See gdb/doc/LRS for
5516 more details on the expected format of the stabs information.
5520 GDB's support for the GNU Hurd, including thread debugging, has been
5521 updated to work with current versions of the Hurd.
5525 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5526 instruction set. ARM GDB automatically detects when Thumb
5527 instructions are in use, and adjusts disassembly and backtracing
5532 GDB's MIPS target configurations now handle the MIP16 16-bit
5537 GDB now includes support for overlays; if an executable has been
5538 linked such that multiple sections are based at the same address, GDB
5539 will decide which section to use for symbolic info. You can choose to
5540 control the decision manually, using overlay commands, or implement
5541 additional target-side support and use "overlay load-target" to bring
5542 in the overlay mapping. Do "help overlay" for more detail.
5546 The command "info symbol <address>" displays information about
5547 the symbol at the specified address.
5551 The standard remote protocol now includes an extension that allows
5552 asynchronous collection and display of trace data. This requires
5553 extensive support in the target-side debugging stub. Tracing mode
5554 includes a new interaction mode in GDB and new commands: see the
5555 file tracepoint.c for more details.
5559 Configurations for embedded MIPS now include a simulator contributed
5560 by Cygnus Solutions. The simulator supports the instruction sets
5561 of most MIPS variants.
5565 Sparc configurations may now include the ERC32 simulator contributed
5566 by the European Space Agency. The simulator is not built into
5567 Sparc targets by default; configure with --enable-sim to include it.
5571 For target configurations that may include multiple variants of a
5572 basic architecture (such as MIPS and SH), you may now set the
5573 architecture explicitly. "set arch" sets, "info arch" lists
5574 the possible architectures.
5576 *** Changes in GDB-4.16:
5578 * New native configurations
5580 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5581 M68K NetBSD m68k-*-netbsd*
5582 PowerPC AIX 4.x powerpc-*-aix*
5583 PowerPC MacOS powerpc-*-macos*
5584 PowerPC Windows NT powerpcle-*-cygwin32
5585 RS/6000 AIX 4.x rs6000-*-aix4*
5589 ARM with RDP protocol arm-*-*
5590 I960 with MON960 i960-*-coff
5591 MIPS VxWorks mips*-*-vxworks*
5592 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5593 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5595 Matra Sparclet sparclet-*-*
5599 The powerpc-eabi configuration now includes the PSIM simulator,
5600 contributed by Andrew Cagney, with assistance from Mike Meissner.
5601 PSIM is a very elaborate model of the PowerPC, including not only
5602 basic instruction set execution, but also details of execution unit
5603 performance and I/O hardware. See sim/ppc/README for more details.
5607 GDB now works with Solaris 2.5.
5609 * Windows 95/NT native
5611 GDB will now work as a native debugger on Windows 95 and Windows NT.
5612 To build it from source, you must use the "gnu-win32" environment,
5613 which uses a DLL to emulate enough of Unix to run the GNU tools.
5614 Further information, binaries, and sources are available at
5615 ftp.cygnus.com, under pub/gnu-win32.
5617 * dont-repeat command
5619 If a user-defined command includes the command `dont-repeat', then the
5620 command will not be repeated if the user just types return. This is
5621 useful if the command is time-consuming to run, so that accidental
5622 extra keystrokes don't run the same command many times.
5624 * Send break instead of ^C
5626 The standard remote protocol now includes an option to send a break
5627 rather than a ^C to the target in order to interrupt it. By default,
5628 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5630 * Remote protocol timeout
5632 The standard remote protocol includes a new variable `remotetimeout'
5633 that allows you to set the number of seconds before GDB gives up trying
5634 to read from the target. The default value is 2.
5636 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5638 By default GDB will automatically keep track of objects as they are
5639 loaded and unloaded by the dynamic linker. By using the command `set
5640 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5641 when shared library events occur, thus allowing you to set breakpoints
5642 in shared libraries which are explicitly loaded by the inferior.
5644 Note this feature does not work on hpux8. On hpux9 you must link
5645 /usr/lib/end.o into your program. This feature should work
5646 automatically on hpux10.
5648 * Irix 5.x hardware watchpoint support
5650 Irix 5 configurations now support the use of hardware watchpoints.
5652 * Mips protocol "SYN garbage limit"
5654 When debugging a Mips target using the `target mips' protocol, you
5655 may set the number of characters that GDB will ignore by setting
5656 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5657 every character. The default value is 1050.
5659 * Recording and replaying remote debug sessions
5661 If you set `remotelogfile' to the name of a file, gdb will write to it
5662 a recording of a remote debug session. This recording may then be
5663 replayed back to gdb using "gdbreplay". See gdbserver/README for
5664 details. This is useful when you have a problem with GDB while doing
5665 remote debugging; you can make a recording of the session and send it
5666 to someone else, who can then recreate the problem.
5668 * Speedups for remote debugging
5670 GDB includes speedups for downloading and stepping MIPS systems using
5671 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5672 and more efficient S-record downloading.
5674 * Memory use reductions and statistics collection
5676 GDB now uses less memory and reports statistics about memory usage.
5677 Try the `maint print statistics' command, for example.
5679 *** Changes in GDB-4.15:
5681 * Psymtabs for XCOFF
5683 The symbol reader for AIX GDB now uses partial symbol tables. This
5684 can greatly improve startup time, especially for large executables.
5686 * Remote targets use caching
5688 Remote targets now use a data cache to speed up communication with the
5689 remote side. The data cache could lead to incorrect results because
5690 it doesn't know about volatile variables, thus making it impossible to
5691 debug targets which use memory mapped I/O devices. `set remotecache
5692 off' turns the the data cache off.
5694 * Remote targets may have threads
5696 The standard remote protocol now includes support for multiple threads
5697 in the target system, using new protocol commands 'H' and 'T'. See
5698 gdb/remote.c for details.
5702 If GDB is configured with `--enable-netrom', then it will include
5703 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5704 acts as though it is a bank of ROM on the target board, but you can
5705 write into it over the network. GDB's support consists only of
5706 support for fast loading into the emulated ROM; to debug, you must use
5707 another protocol, such as standard remote protocol. The usual
5708 sequence is something like
5710 target nrom <netrom-hostname>
5712 target remote <netrom-hostname>:1235
5716 GDB now includes support for the Apple Macintosh, as a host only. It
5717 may be run as either an MPW tool or as a standalone application, and
5718 it can debug through the serial port. All the usual GDB commands are
5719 available, but to the target command, you must supply "serial" as the
5720 device type instead of "/dev/ttyXX". See mpw-README in the main
5721 directory for more information on how to build. The MPW configuration
5722 scripts */mpw-config.in support only a few targets, and only the
5723 mips-idt-ecoff target has been tested.
5727 GDB configuration now uses autoconf. This is not user-visible,
5728 but does simplify configuration and building.
5732 GDB now supports hpux10.
5734 *** Changes in GDB-4.14:
5736 * New native configurations
5738 x86 FreeBSD i[345]86-*-freebsd
5739 x86 NetBSD i[345]86-*-netbsd
5740 NS32k NetBSD ns32k-*-netbsd
5741 Sparc NetBSD sparc-*-netbsd
5745 A29K VxWorks a29k-*-vxworks
5746 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5747 CPU32 EST-300 emulator m68*-*-est*
5748 PowerPC ELF powerpc-*-elf
5751 * Alpha OSF/1 support for procfs
5753 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5754 possible to attach to running processes. As the mounting of the /proc
5755 filesystem is optional on the Alpha, GDB automatically determines
5756 the availability of /proc during startup. This can lead to problems
5757 if /proc is unmounted after GDB has been started.
5759 * Arguments to user-defined commands
5761 User commands may accept up to 10 arguments separated by whitespace.
5762 Arguments are accessed within the user command via $arg0..$arg9. A
5765 print $arg0 + $arg1 + $arg2
5767 To execute the command use:
5770 Defines the command "adder" which prints the sum of its three arguments.
5771 Note the arguments are text substitutions, so they may reference variables,
5772 use complex expressions, or even perform inferior function calls.
5774 * New `if' and `while' commands
5776 This makes it possible to write more sophisticated user-defined
5777 commands. Both commands take a single argument, which is the
5778 expression to evaluate, and must be followed by the commands to
5779 execute, one per line, if the expression is nonzero, the list being
5780 terminated by the word `end'. The `if' command list may include an
5781 `else' word, which causes the following commands to be executed only
5782 if the expression is zero.
5784 * Fortran source language mode
5786 GDB now includes partial support for Fortran 77. It will recognize
5787 Fortran programs and can evaluate a subset of Fortran expressions, but
5788 variables and functions may not be handled correctly. GDB will work
5789 with G77, but does not yet know much about symbols emitted by other
5792 * Better HPUX support
5794 Most debugging facilities now work on dynamic executables for HPPAs
5795 running hpux9 or later. You can attach to running dynamically linked
5796 processes, but by default the dynamic libraries will be read-only, so
5797 for instance you won't be able to put breakpoints in them. To change
5798 that behavior do the following before running the program:
5804 This will cause the libraries to be mapped private and read-write.
5805 To revert to the normal behavior, do this:
5811 You cannot set breakpoints or examine data in the library until after
5812 the library is loaded if the function/data symbols do not have
5815 GDB can now also read debug symbols produced by the HP C compiler on
5816 HPPAs (sorry, no C++, Fortran or 68k support).
5818 * Target byte order now dynamically selectable
5820 You can choose which byte order to use with a target system, via the
5821 commands "set endian big" and "set endian little", and you can see the
5822 current setting by using "show endian". You can also give the command
5823 "set endian auto", in which case GDB will use the byte order
5824 associated with the executable. Currently, only embedded MIPS
5825 configurations support dynamic selection of target byte order.
5827 * New DOS host serial code
5829 This version uses DPMI interrupts to handle buffered I/O, so you
5830 no longer need to run asynctsr when debugging boards connected to
5833 *** Changes in GDB-4.13:
5835 * New "complete" command
5837 This lists all the possible completions for the rest of the line, if it
5838 were to be given as a command itself. This is intended for use by emacs.
5840 * Trailing space optional in prompt
5842 "set prompt" no longer adds a space for you after the prompt you set. This
5843 allows you to set a prompt which ends in a space or one that does not.
5845 * Breakpoint hit counts
5847 "info break" now displays a count of the number of times the breakpoint
5848 has been hit. This is especially useful in conjunction with "ignore"; you
5849 can ignore a large number of breakpoint hits, look at the breakpoint info
5850 to see how many times the breakpoint was hit, then run again, ignoring one
5851 less than that number, and this will get you quickly to the last hit of
5854 * Ability to stop printing at NULL character
5856 "set print null-stop" will cause GDB to stop printing the characters of
5857 an array when the first NULL is encountered. This is useful when large
5858 arrays actually contain only short strings.
5860 * Shared library breakpoints
5862 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5863 breakpoints in shared libraries before the executable is run.
5865 * Hardware watchpoints
5867 There is a new hardware breakpoint for the watch command for sparclite
5868 targets. See gdb/sparclite/hw_breakpoint.note.
5870 Hardware watchpoints are also now supported under GNU/Linux.
5874 Annotations have been added. These are for use with graphical interfaces,
5875 and are still experimental. Currently only gdba.el uses these.
5877 * Improved Irix 5 support
5879 GDB now works properly with Irix 5.2.
5881 * Improved HPPA support
5883 GDB now works properly with the latest GCC and GAS.
5885 * New native configurations
5887 Sequent PTX4 i[34]86-sequent-ptx4
5888 HPPA running OSF/1 hppa*-*-osf*
5889 Atari TT running SVR4 m68*-*-sysv4*
5890 RS/6000 LynxOS rs6000-*-lynxos*
5894 OS/9000 i[34]86-*-os9k
5895 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5898 * Hitachi SH7000 and E7000-PC ICE support
5900 There is now support for communicating with the Hitachi E7000-PC ICE.
5901 This is available automatically when GDB is configured for the SH.
5905 As usual, a variety of small fixes and improvements, both generic
5906 and configuration-specific. See the ChangeLog for more detail.
5908 *** Changes in GDB-4.12:
5910 * Irix 5 is now supported
5914 GDB-4.12 on the HPPA has a number of changes which make it unable
5915 to debug the output from the currently released versions of GCC and
5916 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5917 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5918 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5921 *** Changes in GDB-4.11:
5923 * User visible changes:
5927 The "set remotedebug" option is now consistent between the mips remote
5928 target, remote targets using the gdb-specific protocol, UDI (AMD's
5929 debug protocol for the 29k) and the 88k bug monitor. It is now an
5930 integer specifying a debug level (normally 0 or 1, but 2 means more
5931 debugging info for the mips target).
5933 * DEC Alpha native support
5935 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5936 debug info, but GDB works fairly well with the DEC compiler and should
5937 work with a future GCC release. See the README file for a few
5938 Alpha-specific notes.
5940 * Preliminary thread implementation
5942 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5944 * LynxOS native and target support for 386
5946 This release has been hosted on LynxOS 2.2, and also can be configured
5947 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5950 * Improvements in C++ mangling/demangling.
5952 This release has much better g++ debugging, specifically in name
5953 mangling/demangling, virtual function calls, print virtual table,
5954 call methods, ...etc.
5956 *** Changes in GDB-4.10:
5958 * User visible changes:
5960 Remote debugging using the GDB-specific (`target remote') protocol now
5961 supports the `load' command. This is only useful if you have some
5962 other way of getting the stub to the target system, and you can put it
5963 somewhere in memory where it won't get clobbered by the download.
5965 Filename completion now works.
5967 When run under emacs mode, the "info line" command now causes the
5968 arrow to point to the line specified. Also, "info line" prints
5969 addresses in symbolic form (as well as hex).
5971 All vxworks based targets now support a user settable option, called
5972 vxworks-timeout. This option represents the number of seconds gdb
5973 should wait for responses to rpc's. You might want to use this if
5974 your vxworks target is, perhaps, a slow software simulator or happens
5975 to be on the far side of a thin network line.
5979 This release contains support for using a DEC alpha as a GDB host for
5980 cross debugging. Native alpha debugging is not supported yet.
5983 *** Changes in GDB-4.9:
5987 This is the first GDB release which is accompanied by a matching testsuite.
5988 The testsuite requires installation of dejagnu, which should be available
5989 via ftp from most sites that carry GNU software.
5993 'Cfront' style demangling has had its name changed to 'ARM' style, to
5994 emphasize that it was written from the specifications in the C++ Annotated
5995 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5996 disclaimers, it still generated too much confusion with users attempting to
5997 use gdb with AT&T cfront.
6001 GDB now uses a standard remote interface to a simulator library.
6002 So far, the library contains simulators for the Zilog Z8001/2, the
6003 Hitachi H8/300, H8/500 and Super-H.
6005 * New targets supported
6007 H8/300 simulator h8300-hitachi-hms or h8300hms
6008 H8/500 simulator h8500-hitachi-hms or h8500hms
6009 SH simulator sh-hitachi-hms or sh
6010 Z8000 simulator z8k-zilog-none or z8ksim
6011 IDT MIPS board over serial line mips-idt-ecoff
6013 Cross-debugging to GO32 targets is supported. It requires a custom
6014 version of the i386-stub.c module which is integrated with the
6015 GO32 memory extender.
6017 * New remote protocols
6019 MIPS remote debugging protocol.
6021 * New source languages supported
6023 This version includes preliminary support for Chill, a Pascal like language
6024 used by telecommunications companies. Chill support is also being integrated
6025 into the GNU compiler, but we don't know when it will be publically available.
6028 *** Changes in GDB-4.8:
6030 * HP Precision Architecture supported
6032 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6033 version of this support was available as a set of patches from the
6034 University of Utah. GDB does not support debugging of programs
6035 compiled with the HP compiler, because HP will not document their file
6036 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6037 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6039 Many problems in the preliminary version have been fixed.
6041 * Faster and better demangling
6043 We have improved template demangling and fixed numerous bugs in the GNU style
6044 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6045 character types (wchar_t) are now supported. Demangling of each symbol is now
6046 only done once, and is cached when the symbol table for a file is read in.
6047 This results in a small increase in memory usage for C programs, a moderate
6048 increase in memory usage for C++ programs, and a fantastic speedup in
6051 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6052 from the specifications in the Annotated Reference Manual, which AT&T's
6053 compiler does not actually implement.
6055 * G++ multiple inheritance compiler problem
6057 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6058 inheritance lattices was reworked to properly discover ambiguities. We
6059 recently found an example which causes this new algorithm to fail in a
6060 very subtle way, producing bad debug information for those classes.
6061 The file 'gcc.patch' (in this directory) can be applied to gcc to
6062 circumvent the problem. A future GCC release will contain a complete
6065 The previous G++ debug info problem (mentioned below for the gdb-4.7
6066 release) is fixed in gcc version 2.3.2.
6068 * Improved configure script
6070 The `configure' script will now attempt to guess your system type if
6071 you don't supply a host system type. The old scheme of supplying a
6072 host system triplet is preferable over using this. All the magic is
6073 done in the new `config.guess' script. Examine it for details.
6075 We have also brought our configure script much more in line with the FSF's
6076 version. It now supports the --with-xxx options. In particular,
6077 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6078 The resulting GDB will not be able to read arbitrary object file formats --
6079 only the format ``expected'' to be used on the configured target system.
6080 We hope to make this the default in a future release.
6082 * Documentation improvements
6084 There's new internal documentation on how to modify GDB, and how to
6085 produce clean changes to the code. We implore people to read it
6086 before submitting changes.
6088 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6089 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6090 `info' files are also provided. To build `info' files from scratch,
6091 you will need the latest `makeinfo' release, which will be available in
6092 a future texinfo-X.Y release.
6094 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6095 We're not sure exactly which versions have this problem, but it has
6096 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6097 or better. If that isn't possible, there is a patch in
6098 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6099 around this problem.
6103 GDB now supports array constants that can be used in expressions typed in by
6104 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6105 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6108 The new directory `gdb/sparclite' contains a program that demonstrates
6109 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6111 * New native hosts supported
6113 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6114 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6116 * New targets supported
6118 AMD 29k family via UDI a29k-amd-udi or udi29k
6120 * New file formats supported
6122 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6123 HPUX core files, and SCO 3.2v2 core files.
6127 Attaching to processes now works again; thanks for the many bug reports.
6129 We have also stomped on a bunch of core dumps caused by
6130 printf_filtered("%s") problems.
6132 We eliminated a copyright problem on the rpc and ptrace header files
6133 for VxWorks, which was discovered at the last minute during the 4.7
6134 release. You should now be able to build a VxWorks GDB.
6136 You can now interrupt gdb while an attached process is running. This
6137 will cause the attached process to stop, and give control back to GDB.
6139 We fixed problems caused by using too many file descriptors
6140 for reading symbols from object files and libraries. This was
6141 especially a problem for programs that used many (~100) shared
6144 The `step' command now only enters a subroutine if there is line number
6145 information for the subroutine. Otherwise it acts like the `next'
6146 command. Previously, `step' would enter subroutines if there was
6147 any debugging information about the routine. This avoids problems
6148 when using `cc -g1' on MIPS machines.
6150 * Internal improvements
6152 GDB's internal interfaces have been improved to make it easier to support
6153 debugging of multiple languages in the future.
6155 GDB now uses a common structure for symbol information internally.
6156 Minimal symbols (derived from linkage symbols in object files), partial
6157 symbols (from a quick scan of debug information), and full symbols
6158 contain a common subset of information, making it easier to write
6159 shared code that handles any of them.
6161 * New command line options
6163 We now accept --silent as an alias for --quiet.
6167 The memory-mapped-malloc library is now licensed under the GNU Library
6168 General Public License.
6170 *** Changes in GDB-4.7:
6172 * Host/native/target split
6174 GDB has had some major internal surgery to untangle the support for
6175 hosts and remote targets. Now, when you configure GDB for a remote
6176 target, it will no longer load in all of the support for debugging
6177 local programs on the host. When fully completed and tested, this will
6178 ensure that arbitrary host/target combinations are possible.
6180 The primary conceptual shift is to separate the non-portable code in
6181 GDB into three categories. Host specific code is required any time GDB
6182 is compiled on that host, regardless of the target. Target specific
6183 code relates to the peculiarities of the target, but can be compiled on
6184 any host. Native specific code is everything else: it can only be
6185 built when the host and target are the same system. Child process
6186 handling and core file support are two common `native' examples.
6188 GDB's use of /proc for controlling Unix child processes is now cleaner.
6189 It has been split out into a single module under the `target_ops' vector,
6190 plus two native-dependent functions for each system that uses /proc.
6192 * New hosts supported
6194 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6195 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6196 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6198 * New targets supported
6200 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6201 68030 and CPU32 m68030-*-*, m68332-*-*
6203 * New native hosts supported
6205 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6206 (386bsd is not well tested yet)
6207 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6209 * New file formats supported
6211 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6212 supports reading of `a.out.adobe' object files, which are an a.out
6213 format extended with minimal information about multiple sections.
6217 `show copying' is the same as the old `info copying'.
6218 `show warranty' is the same as `info warrantee'.
6219 These were renamed for consistency. The old commands continue to work.
6221 `info handle' is a new alias for `info signals'.
6223 You can now define pre-command hooks, which attach arbitrary command
6224 scripts to any command. The commands in the hook will be executed
6225 prior to the user's command. You can also create a hook which will be
6226 executed whenever the program stops. See gdb.texinfo.
6230 We now deal with Cfront style name mangling, and can even extract type
6231 info from mangled symbols. GDB can automatically figure out which
6232 symbol mangling style your C++ compiler uses.
6234 Calling of methods and virtual functions has been improved as well.
6238 The crash that occured when debugging Sun Ansi-C compiled binaries is
6239 fixed. This was due to mishandling of the extra N_SO stabs output
6242 We also finally got Ultrix 4.2 running in house, and fixed core file
6243 support, with help from a dozen people on the net.
6245 John M. Farrell discovered that the reason that single-stepping was so
6246 slow on all of the Mips based platforms (primarily SGI and DEC) was
6247 that we were trying to demangle and lookup a symbol used for internal
6248 purposes on every instruction that was being stepped through. Changing
6249 the name of that symbol so that it couldn't be mistaken for a C++
6250 mangled symbol sped things up a great deal.
6252 Rich Pixley sped up symbol lookups in general by getting much smarter
6253 about when C++ symbol mangling is necessary. This should make symbol
6254 completion (TAB on the command line) much faster. It's not as fast as
6255 we'd like, but it's significantly faster than gdb-4.6.
6259 A new user controllable variable 'call_scratch_address' can
6260 specify the location of a scratch area to be used when GDB
6261 calls a function in the target. This is necessary because the
6262 usual method of putting the scratch area on the stack does not work
6263 in systems that have separate instruction and data spaces.
6265 We integrated changes to support the 29k UDI (Universal Debugger
6266 Interface), but discovered at the last minute that we didn't have all
6267 of the appropriate copyright paperwork. We are working with AMD to
6268 resolve this, and hope to have it available soon.
6272 We have sped up the remote serial line protocol, especially for targets
6273 with lots of registers. It now supports a new `expedited status' ('T')
6274 message which can be used in place of the existing 'S' status message.
6275 This allows the remote stub to send only the registers that GDB
6276 needs to make a quick decision about single-stepping or conditional
6277 breakpoints, eliminating the need to fetch the entire register set for
6278 each instruction being stepped through.
6280 The GDB remote serial protocol now implements a write-through cache for
6281 registers, only re-reading the registers if the target has run.
6283 There is also a new remote serial stub for SPARC processors. You can
6284 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6285 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6286 processor with a serial port.
6290 Configure.in files have become much easier to read and modify. A new
6291 `table driven' format makes it more obvious what configurations are
6292 supported, and what files each one uses.
6296 There is a new opcodes library which will eventually contain all of the
6297 disassembly routines and opcode tables. At present, it only contains
6298 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6299 disassembler (binutils/objdump) to share these routines.
6301 The libiberty library is now copylefted under the GNU Library General
6302 Public License. This allows more liberal use, and was done so libg++
6303 can use it. This makes no difference to GDB, since the Library License
6304 grants all the rights from the General Public License.
6308 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6309 reference to the stabs symbol info used by the debugger. It is (as far
6310 as we know) the only published document on this fascinating topic. We
6311 encourage you to read it, compare it to the stabs information on your
6312 system, and send improvements on the document in general (to
6313 bug-gdb@prep.ai.mit.edu).
6315 And, of course, many bugs have been fixed.
6318 *** Changes in GDB-4.6:
6320 * Better support for C++ function names
6322 GDB now accepts as input the "demangled form" of C++ overloaded function
6323 names and member function names, and can do command completion on such names
6324 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6325 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6326 Make use of command completion, it is your friend.
6328 GDB also now accepts a variety of C++ mangled symbol formats. They are
6329 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6330 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6331 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6332 for the list of formats.
6334 * G++ symbol mangling problem
6336 Recent versions of gcc have a bug in how they emit debugging information for
6337 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6338 directory) can be applied to gcc to fix the problem. Alternatively, if you
6339 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6340 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6341 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6344 * New 'maintenance' command
6346 All of the commands related to hacking GDB internals have been moved out of
6347 the main command set, and now live behind the 'maintenance' command. This
6348 can also be abbreviated as 'mt'. The following changes were made:
6350 dump-me -> maintenance dump-me
6351 info all-breakpoints -> maintenance info breakpoints
6352 printmsyms -> maintenance print msyms
6353 printobjfiles -> maintenance print objfiles
6354 printpsyms -> maintenance print psymbols
6355 printsyms -> maintenance print symbols
6357 The following commands are new:
6359 maintenance demangle Call internal GDB demangler routine to
6360 demangle a C++ link name and prints the result.
6361 maintenance print type Print a type chain for a given symbol
6363 * Change to .gdbinit file processing
6365 We now read the $HOME/.gdbinit file before processing the argv arguments
6366 (e.g. reading symbol files or core files). This allows global parameters to
6367 be set, which will apply during the symbol reading. The ./.gdbinit is still
6368 read after argv processing.
6370 * New hosts supported
6372 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6374 GNU/Linux support i386-unknown-linux or linux
6376 We are also including code to support the HP/PA running BSD and HPUX. This
6377 is almost guaranteed not to work, as we didn't have time to test or build it
6378 for this release. We are including it so that the more adventurous (or
6379 masochistic) of you can play with it. We also had major problems with the
6380 fact that the compiler that we got from HP doesn't support the -g option.
6383 * New targets supported
6385 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6387 * More smarts about finding #include files
6389 GDB now remembers the compilation directory for all include files, and for
6390 all files from which C is generated (like yacc and lex sources). This
6391 greatly improves GDB's ability to find yacc/lex sources, and include files,
6392 especially if you are debugging your program from a directory different from
6393 the one that contains your sources.
6395 We also fixed a bug which caused difficulty with listing and setting
6396 breakpoints in include files which contain C code. (In the past, you had to
6397 try twice in order to list an include file that you hadn't looked at before.)
6399 * Interesting infernals change
6401 GDB now deals with arbitrary numbers of sections, where the symbols for each
6402 section must be relocated relative to that section's landing place in the
6403 target's address space. This work was needed to support ELF with embedded
6404 stabs used by Solaris-2.0.
6406 * Bug fixes (of course!)
6408 There have been loads of fixes for the following things:
6409 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6410 i960, stabs, DOS(GO32), procfs, etc...
6412 See the ChangeLog for details.
6414 *** Changes in GDB-4.5:
6416 * New machines supported (host and target)
6418 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6420 SGI Irix-4.x mips-sgi-irix4 or iris4
6422 * New malloc package
6424 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6425 Mmalloc is capable of handling mutiple heaps of memory. It is also
6426 capable of saving a heap to a file, and then mapping it back in later.
6427 This can be used to greatly speedup the startup of GDB by using a
6428 pre-parsed symbol table which lives in a mmalloc managed heap. For
6429 more details, please read mmalloc/mmalloc.texi.
6433 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6434 'help info proc' for details.
6436 * MIPS ecoff symbol table format
6438 The code that reads MIPS symbol table format is now supported on all hosts.
6439 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6442 * File name changes for MS-DOS
6444 Many files in the config directories have been renamed to make it easier to
6445 support GDB on MS-DOSe systems (which have very restrictive file name
6446 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6447 environment) is close to working but has some remaining problems. Note
6448 that debugging of DOS programs is not supported, due to limitations
6449 in the ``operating system'', but it can be used to host cross-debugging.
6451 * Cross byte order fixes
6453 Many fixes have been made to support cross debugging of Sparc and MIPS
6454 targets from hosts whose byte order differs.
6456 * New -mapped and -readnow options
6458 If memory-mapped files are available on your system through the 'mmap'
6459 system call, you can use the -mapped option on the `file' or
6460 `symbol-file' commands to cause GDB to write the symbols from your
6461 program into a reusable file. If the program you are debugging is
6462 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6463 Future GDB debugging sessions will notice the presence of this file,
6464 and will quickly map in symbol information from it, rather than reading
6465 the symbol table from the executable program. Using the '-mapped'
6466 option in a GDB `file' or `symbol-file' command has the same effect as
6467 starting GDB with the '-mapped' command-line option.
6469 You can cause GDB to read the entire symbol table immediately by using
6470 the '-readnow' option with any of the commands that load symbol table
6471 information (or on the GDB command line). This makes the command
6472 slower, but makes future operations faster.
6474 The -mapped and -readnow options are typically combined in order to
6475 build a `fred.syms' file that contains complete symbol information.
6476 A simple GDB invocation to do nothing but build a `.syms' file for future
6479 gdb -batch -nx -mapped -readnow programname
6481 The `.syms' file is specific to the host machine on which GDB is run.
6482 It holds an exact image of GDB's internal symbol table. It cannot be
6483 shared across multiple host platforms.
6485 * longjmp() handling
6487 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6488 siglongjmp() without losing control. This feature has not yet been ported to
6489 all systems. It currently works on many 386 platforms, all MIPS-based
6490 platforms (SGI, DECstation, etc), and Sun3/4.
6494 Preliminary work has been put in to support the new Solaris OS from Sun. At
6495 this time, it can control and debug processes, but it is not capable of
6500 As always, many many bug fixes. The major areas were with g++, and mipsread.
6501 People using the MIPS-based platforms should experience fewer mysterious
6502 crashes and trashed symbol tables.
6504 *** Changes in GDB-4.4:
6506 * New machines supported (host and target)
6508 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6510 BSD Reno on Vax vax-dec-bsd
6511 Ultrix on Vax vax-dec-ultrix
6513 * New machines supported (target)
6515 AMD 29000 embedded, using EBMON a29k-none-none
6519 GDB continues to improve its handling of C++. `References' work better.
6520 The demangler has also been improved, and now deals with symbols mangled as
6521 per the Annotated C++ Reference Guide.
6523 GDB also now handles `stabs' symbol information embedded in MIPS
6524 `ecoff' symbol tables. Since the ecoff format was not easily
6525 extensible to handle new languages such as C++, this appeared to be a
6526 good way to put C++ debugging info into MIPS binaries. This option
6527 will be supported in the GNU C compiler, version 2, when it is
6530 * New features for SVR4
6532 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6533 shared libraries. Debugging dynamically linked programs should present
6534 only minor differences from debugging statically linked programs.
6536 The `info proc' command will print out information about any process
6537 on an SVR4 system (including the one you are debugging). At the moment,
6538 it prints the address mappings of the process.
6540 If you bring up GDB on another SVR4 system, please send mail to
6541 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6543 * Better dynamic linking support in SunOS
6545 Reading symbols from shared libraries which contain debugging symbols
6546 now works properly. However, there remain issues such as automatic
6547 skipping of `transfer vector' code during function calls, which
6548 make it harder to debug code in a shared library, than to debug the
6549 same code linked statically.
6553 GDB is now using the latest `getopt' routines from the FSF. This
6554 version accepts the -- prefix for options with long names. GDB will
6555 continue to accept the old forms (-option and +option) as well.
6556 Various single letter abbreviations for options have been explicity
6557 added to the option table so that they won't get overshadowed in the
6558 future by other options that begin with the same letter.
6562 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6563 Many assorted bugs have been handled. Many more remain to be handled.
6564 See the various ChangeLog files (primarily in gdb and bfd) for details.
6567 *** Changes in GDB-4.3:
6569 * New machines supported (host and target)
6571 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6572 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6573 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6575 * Almost SCO Unix support
6577 We had hoped to support:
6578 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6579 (except for core file support), but we discovered very late in the release
6580 that it has problems with process groups that render gdb unusable. Sorry
6581 about that. I encourage people to fix it and post the fixes.
6583 * Preliminary ELF and DWARF support
6585 GDB can read ELF object files on System V Release 4, and can handle
6586 debugging records for C, in DWARF format, in ELF files. This support
6587 is preliminary. If you bring up GDB on another SVR4 system, please
6588 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6593 GDB now uses the latest `readline' library. One user-visible change
6594 is that two tabs will list possible command completions, which previously
6595 required typing M-? (meta-question mark, or ESC ?).
6599 The `stepi' bug that many of you noticed has been squashed.
6600 Many bugs in C++ have been handled. Many more remain to be handled.
6601 See the various ChangeLog files (primarily in gdb and bfd) for details.
6603 * State of the MIPS world (in case you wondered):
6605 GDB can understand the symbol tables emitted by the compilers
6606 supplied by most vendors of MIPS-based machines, including DEC. These
6607 symbol tables are in a format that essentially nobody else uses.
6609 Some versions of gcc come with an assembler post-processor called
6610 mips-tfile. This program is required if you want to do source-level
6611 debugging of gcc-compiled programs. I believe FSF does not ship
6612 mips-tfile with gcc version 1, but it will eventually come with gcc
6615 Debugging of g++ output remains a problem. g++ version 1.xx does not
6616 really support it at all. (If you're lucky, you should be able to get
6617 line numbers and stack traces to work, but no parameters or local
6618 variables.) With some work it should be possible to improve the
6621 When gcc version 2 is released, you will have somewhat better luck.
6622 However, even then you will get confusing results for inheritance and
6625 We will eventually provide full debugging of g++ output on
6626 DECstations. This will probably involve some kind of stabs-in-ecoff
6627 encapulation, but the details have not been worked out yet.
6630 *** Changes in GDB-4.2:
6632 * Improved configuration
6634 Only one copy of `configure' exists now, and it is not self-modifying.
6635 Porting BFD is simpler.
6639 The `step' and `next' commands now only stop at the first instruction
6640 of a source line. This prevents the multiple stops that used to occur
6641 in switch statements, for-loops, etc. `Step' continues to stop if a
6642 function that has debugging information is called within the line.
6646 Lots of small bugs fixed. More remain.
6648 * New host supported (not target)
6650 Intel 386 PC clone running Mach i386-none-mach
6653 *** Changes in GDB-4.1:
6655 * Multiple source language support
6657 GDB now has internal scaffolding to handle several source languages.
6658 It determines the type of each source file from its filename extension,
6659 and will switch expression parsing and number formatting to match the
6660 language of the function in the currently selected stack frame.
6661 You can also specifically set the language to be used, with
6662 `set language c' or `set language modula-2'.
6666 GDB now has preliminary support for the GNU Modula-2 compiler,
6667 currently under development at the State University of New York at
6668 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6669 continue through the fall of 1991 and into 1992.
6671 Other Modula-2 compilers are currently not supported, and attempting to
6672 debug programs compiled with them will likely result in an error as the
6673 symbol table is read. Feel free to work on it, though!
6675 There are hooks in GDB for strict type checking and range checking,
6676 in the `Modula-2 philosophy', but they do not currently work.
6680 GDB can now write to executable and core files (e.g. patch
6681 a variable's value). You must turn this switch on, specify
6682 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6683 by assigning a new value to a variable. Modifications take
6686 * Automatic SunOS shared library reading
6688 When you run your program, GDB automatically determines where its
6689 shared libraries (if any) have been loaded, and reads their symbols.
6690 The `share' command is no longer needed. This also works when
6691 examining core files.
6695 You can specify the number of lines that the `list' command shows.
6698 * New machines supported (host and target)
6700 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6701 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6702 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6704 * New hosts supported (not targets)
6706 IBM RT/PC: romp-ibm-aix or rtpc
6708 * New targets supported (not hosts)
6710 AMD 29000 embedded with COFF a29k-none-coff
6711 AMD 29000 embedded with a.out a29k-none-aout
6712 Ultracomputer remote kernel debug a29k-nyu-kern
6714 * New remote interfaces
6720 *** Changes in GDB-4.0:
6724 Wide output is wrapped at good places to make the output more readable.
6726 Gdb now supports cross-debugging from a host machine of one type to a
6727 target machine of another type. Communication with the target system
6728 is over serial lines. The ``target'' command handles connecting to the
6729 remote system; the ``load'' command will download a program into the
6730 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6731 also supports debugging of realtime processes running under VxWorks,
6732 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6733 stub on the target system.
6735 New CPUs supported include the AMD 29000 and Intel 960.
6737 GDB now reads object files and symbol tables via a ``binary file''
6738 library, which allows a single copy of GDB to debug programs of multiple
6739 object file types such as a.out and coff.
6741 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6742 refcard.dvi and refcard.ps are available to format it).
6745 * Control-Variable user interface simplified
6747 All variables that control the operation of the debugger can be set
6748 by the ``set'' command, and displayed by the ``show'' command.
6750 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6751 ``Show prompt'' produces the response:
6752 Gdb's prompt is new-gdb=>.
6754 What follows are the NEW set commands. The command ``help set'' will
6755 print a complete list of old and new set commands. ``help set FOO''
6756 will give a longer description of the variable FOO. ``show'' will show
6757 all of the variable descriptions and their current settings.
6759 confirm on/off: Enables warning questions for operations that are
6760 hard to recover from, e.g. rerunning the program while
6761 it is already running. Default is ON.
6763 editing on/off: Enables EMACS style command line editing
6764 of input. Previous lines can be recalled with
6765 control-P, the current line can be edited with control-B,
6766 you can search for commands with control-R, etc.
6769 history filename NAME: NAME is where the gdb command history
6770 will be stored. The default is .gdb_history,
6771 or the value of the environment variable
6774 history size N: The size, in commands, of the command history. The
6775 default is 256, or the value of the environment variable
6778 history save on/off: If this value is set to ON, the history file will
6779 be saved after exiting gdb. If set to OFF, the
6780 file will not be saved. The default is OFF.
6782 history expansion on/off: If this value is set to ON, then csh-like
6783 history expansion will be performed on
6784 command line input. The default is OFF.
6786 radix N: Sets the default radix for input and output. It can be set
6787 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6788 in the current radix, so "set radix 10" is always a no-op.
6790 height N: This integer value is the number of lines on a page. Default
6791 is 24, the current `stty rows'' setting, or the ``li#''
6792 setting from the termcap entry matching the environment
6795 width N: This integer value is the number of characters on a line.
6796 Default is 80, the current `stty cols'' setting, or the ``co#''
6797 setting from the termcap entry matching the environment
6800 Note: ``set screensize'' is obsolete. Use ``set height'' and
6801 ``set width'' instead.
6803 print address on/off: Print memory addresses in various command displays,
6804 such as stack traces and structure values. Gdb looks
6805 more ``symbolic'' if you turn this off; it looks more
6806 ``machine level'' with it on. Default is ON.
6808 print array on/off: Prettyprint arrays. New convenient format! Default
6811 print demangle on/off: Print C++ symbols in "source" form if on,
6814 print asm-demangle on/off: Same, for assembler level printouts
6817 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6820 * Support for Epoch Environment.
6822 The epoch environment is a version of Emacs v18 with windowing. One
6823 new command, ``inspect'', is identical to ``print'', except that if you
6824 are running in the epoch environment, the value is printed in its own
6828 * Support for Shared Libraries
6830 GDB can now debug programs and core files that use SunOS shared libraries.
6831 Symbols from a shared library cannot be referenced
6832 before the shared library has been linked with the program (this
6833 happens after you type ``run'' and before the function main() is entered).
6834 At any time after this linking (including when examining core files
6835 from dynamically linked programs), gdb reads the symbols from each
6836 shared library when you type the ``sharedlibrary'' command.
6837 It can be abbreviated ``share''.
6839 sharedlibrary REGEXP: Load shared object library symbols for files
6840 matching a unix regular expression. No argument
6841 indicates to load symbols for all shared libraries.
6843 info sharedlibrary: Status of loaded shared libraries.
6848 A watchpoint stops execution of a program whenever the value of an
6849 expression changes. Checking for this slows down execution
6850 tremendously whenever you are in the scope of the expression, but is
6851 quite useful for catching tough ``bit-spreader'' or pointer misuse
6852 problems. Some machines such as the 386 have hardware for doing this
6853 more quickly, and future versions of gdb will use this hardware.
6855 watch EXP: Set a watchpoint (breakpoint) for an expression.
6857 info watchpoints: Information about your watchpoints.
6859 delete N: Deletes watchpoint number N (same as breakpoints).
6860 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6861 enable N: Re-enables watchpoint number N (same as breakpoints).
6864 * C++ multiple inheritance
6866 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6869 * C++ exception handling
6871 Gdb now supports limited C++ exception handling. Besides the existing
6872 ability to breakpoint on an exception handler, gdb can breakpoint on
6873 the raising of an exception (before the stack is peeled back to the
6876 catch FOO: If there is a FOO exception handler in the dynamic scope,
6877 set a breakpoint to catch exceptions which may be raised there.
6878 Multiple exceptions (``catch foo bar baz'') may be caught.
6880 info catch: Lists all exceptions which may be caught in the
6881 current stack frame.
6884 * Minor command changes
6886 The command ``call func (arg, arg, ...)'' now acts like the print
6887 command, except it does not print or save a value if the function's result
6888 is void. This is similar to dbx usage.
6890 The ``up'' and ``down'' commands now always print the frame they end up
6891 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6892 frames without printing.
6894 * New directory command
6896 'dir' now adds directories to the FRONT of the source search path.
6897 The path starts off empty. Source files that contain debug information
6898 about the directory in which they were compiled can be found even
6899 with an empty path; Sun CC and GCC include this information. If GDB can't
6900 find your source file in the current directory, type "dir .".
6902 * Configuring GDB for compilation
6904 For normal use, type ``./configure host''. See README or gdb.texinfo
6907 GDB now handles cross debugging. If you are remotely debugging between
6908 two different machines, type ``./configure host -target=targ''.
6909 Host is the machine where GDB will run; targ is the machine
6910 where the program that you are debugging will run.