1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.1
6 * 'info proc' now works on running processes on FreeBSD systems and core
7 files created on FreeBSD systems.
13 Control display of debugging info regarding the FreeBSD native target.
15 set|show varsize-limit
16 This new setting allows the user to control the maximum size of Ada
17 objects being printed when those objects have a variable type,
18 instead of that maximum size being hardcoded to 65536 bytes.
22 RiscV ELF riscv*-*-elf
24 *** Changes in GDB 8.1
26 * GDB now supports dynamically creating arbitrary register groups specified
27 in XML target descriptions. This allows for finer grain grouping of
28 registers on systems with a large amount of registers.
30 * The 'ptype' command now accepts a '/o' flag, which prints the
31 offsets and sizes of fields in a struct, like the pahole(1) tool.
33 * New "--readnever" command line option instructs GDB to not read each
34 symbol file's symbolic debug information. This makes startup faster
35 but at the expense of not being able to perform symbolic debugging.
36 This option is intended for use cases where symbolic debugging will
37 not be used, e.g., when you only need to dump the debuggee's core.
39 * GDB now uses the GNU MPFR library, if available, to emulate target
40 floating-point arithmetic during expression evaluation when the target
41 uses different floating-point formats than the host. At least version
42 3.1 of GNU MPFR is required.
44 * GDB now supports access to the guarded-storage-control registers and the
45 software-based guarded-storage broadcast control registers on IBM z14.
47 * On Unix systems, GDB now supports transmitting environment variables
48 that are to be set or unset to GDBserver. These variables will
49 affect the environment to be passed to the remote inferior.
51 To inform GDB of environment variables that are to be transmitted to
52 GDBserver, use the "set environment" command. Only user set
53 environment variables are sent to GDBserver.
55 To inform GDB of environment variables that are to be unset before
56 the remote inferior is started by the GDBserver, use the "unset
59 * Completion improvements
61 ** GDB can now complete function parameters in linespecs and
62 explicit locations without quoting. When setting breakpoints,
63 quoting around functions names to help with TAB-completion is
64 generally no longer necessary. For example, this now completes
67 (gdb) b function(in[TAB]
70 Related, GDB is no longer confused with completing functions in
71 C++ anonymous namespaces:
74 (gdb) b (anonymous namespace)::[TAB][TAB]
75 (anonymous namespace)::a_function()
76 (anonymous namespace)::b_function()
78 ** GDB now has much improved linespec and explicit locations TAB
79 completion support, that better understands what you're
80 completing and offers better suggestions. For example, GDB no
81 longer offers data symbols as possible completions when you're
84 ** GDB now TAB-completes label symbol names.
86 ** The "complete" command now mimics TAB completion accurately.
88 * New command line options (gcore)
91 Dump all memory mappings.
93 * Breakpoints on C++ functions are now set on all scopes by default
95 By default, breakpoints on functions/methods are now interpreted as
96 specifying all functions with the given name ignoring missing
97 leading scopes (namespaces and classes).
99 For example, assuming a C++ program with symbols named:
104 both commands "break func()" and "break B::func()" set a breakpoint
107 You can use the new flag "-qualified" to override this. This makes
108 GDB interpret the specified function name as a complete
109 fully-qualified name instead. For example, using the same C++
110 program, the "break -q B::func" command sets a breakpoint on
111 "B::func", only. A parameter has been added to the Python
112 gdb.Breakpoint constructor to achieve the same result when creating
113 a breakpoint from Python.
115 * Breakpoints on functions marked with C++ ABI tags
117 GDB can now set breakpoints on functions marked with C++ ABI tags
118 (e.g., [abi:cxx11]). See here for a description of ABI tags:
119 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
121 Functions with a C++11 abi tag are demangled/displayed like this:
123 function[abi:cxx11](int)
126 You can now set a breakpoint on such functions simply as if they had
129 (gdb) b function(int)
131 Or if you need to disambiguate between tags, like:
133 (gdb) b function[abi:other_tag](int)
135 Tab completion was adjusted accordingly as well.
139 ** New events gdb.new_inferior, gdb.inferior_deleted, and
140 gdb.new_thread are emitted. See the manual for further
141 description of these.
143 ** A new function, "gdb.rbreak" has been added to the Python API.
144 This function allows the setting of a large number of breakpoints
145 via a regex pattern in Python. See the manual for further details.
147 ** Python breakpoints can now accept explicit locations. See the
148 manual for a further description of this feature.
151 * New features in the GDB remote stub, GDBserver
153 ** GDBserver is now able to start inferior processes with a
154 specified initial working directory.
156 The user can set the desired working directory to be used from
157 GDB using the new "set cwd" command.
159 ** New "--selftest" command line option runs some GDBserver self
160 tests. These self tests are disabled in releases.
162 ** On Unix systems, GDBserver now does globbing expansion and variable
163 substitution in inferior command line arguments.
165 This is done by starting inferiors using a shell, like GDB does.
166 See "set startup-with-shell" in the user manual for how to disable
167 this from GDB when using "target extended-remote". When using
168 "target remote", you can disable the startup with shell by using the
169 new "--no-startup-with-shell" GDBserver command line option.
171 ** On Unix systems, GDBserver now supports receiving environment
172 variables that are to be set or unset from GDB. These variables
173 will affect the environment to be passed to the inferior.
175 * When catching an Ada exception raised with a message, GDB now prints
176 the message in the catchpoint hit notification. In GDB/MI mode, that
177 information is provided as an extra field named "exception-message"
178 in the *stopped notification.
180 * Trait objects can now be inspected When debugging Rust code. This
181 requires compiler support which will appear in Rust 1.24.
185 QEnvironmentHexEncoded
186 Inform GDBserver of an environment variable that is to be passed to
187 the inferior when starting it.
190 Inform GDBserver of an environment variable that is to be unset
191 before starting the remote inferior.
194 Inform GDBserver that the environment should be reset (i.e.,
195 user-set environment variables should be unset).
198 Indicates whether the inferior must be started with a shell or not.
201 Tell GDBserver that the inferior to be started should use a specific
204 * The "maintenance print c-tdesc" command now takes an optional
205 argument which is the file name of XML target description.
207 * The "maintenance selftest" command now takes an optional argument to
208 filter the tests to be run.
210 * The "enable", and "disable" commands now accept a range of
211 breakpoint locations, e.g. "enable 1.3-5".
216 Set and show the current working directory for the inferior.
219 Set and show compilation command used for compiling and injecting code
220 with the 'compile' commands.
222 set debug separate-debug-file
223 show debug separate-debug-file
224 Control the display of debug output about separate debug file search.
226 set dump-excluded-mappings
227 show dump-excluded-mappings
228 Control whether mappings marked with the VM_DONTDUMP flag should be
229 dumped when generating a core file.
232 List the registered selftests.
235 Start the debugged program stopping at the first instruction.
238 Control display of debugging messages related to OpenRISC targets.
240 set|show print type nested-type-limit
241 Set and show the limit of nesting level for nested types that the
242 type printer will show.
244 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
247 * Safer/improved support for debugging with no debug info
249 GDB no longer assumes functions with no debug information return
252 This means that GDB now refuses to call such functions unless you
253 tell it the function's type, by either casting the call to the
254 declared return type, or by casting the function to a function
255 pointer of the right type, and calling that:
257 (gdb) p getenv ("PATH")
258 'getenv' has unknown return type; cast the call to its declared return type
259 (gdb) p (char *) getenv ("PATH")
260 $1 = 0x7fffffffe "/usr/local/bin:/"...
261 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
262 $2 = 0x7fffffffe "/usr/local/bin:/"...
264 Similarly, GDB no longer assumes that global variables with no debug
265 info have type 'int', and refuses to print the variable's value
266 unless you tell it the variable's type:
269 'var' has unknown type; cast it to its declared type
273 * New native configurations
275 FreeBSD/aarch64 aarch64*-*-freebsd*
276 FreeBSD/arm arm*-*-freebsd*
280 FreeBSD/aarch64 aarch64*-*-freebsd*
281 FreeBSD/arm arm*-*-freebsd*
282 OpenRISC ELF or1k*-*-elf
284 * Removed targets and native configurations
286 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
288 *** Changes in GDB 8.0
290 * GDB now supports access to the PKU register on GNU/Linux. The register is
291 added by the Memory Protection Keys for Userspace feature which will be
292 available in future Intel CPUs.
294 * GDB now supports C++11 rvalue references.
298 ** New functions to start, stop and access a running btrace recording.
299 ** Rvalue references are now supported in gdb.Type.
301 * GDB now supports recording and replaying rdrand and rdseed Intel 64
304 * Building GDB and GDBserver now requires a C++11 compiler.
306 For example, GCC 4.8 or later.
308 It is no longer possible to build GDB or GDBserver with a C
309 compiler. The --disable-build-with-cxx configure option has been
312 * Building GDB and GDBserver now requires GNU make >= 3.81.
314 It is no longer supported to build GDB or GDBserver with another
315 implementation of the make program or an earlier version of GNU make.
317 * Native debugging on MS-Windows supports command-line redirection
319 Command-line arguments used for starting programs on MS-Windows can
320 now include redirection symbols supported by native Windows shells,
321 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
322 as "run", "start", and "set args", as well as the corresponding MI
325 * Support for thread names on MS-Windows.
327 GDB now catches and handles the special exception that programs
328 running on MS-Windows use to assign names to threads in the
331 * Support for Java programs compiled with gcj has been removed.
333 * User commands now accept an unlimited number of arguments.
334 Previously, only up to 10 was accepted.
336 * The "eval" command now expands user-defined command arguments.
338 This makes it easier to process a variable number of arguments:
343 eval "print $arg%d", $i
348 * Target descriptions can now describe registers for sparc32 and sparc64.
350 * GDB now supports DWARF version 5 (debug information format).
351 Its .debug_names index is not yet supported.
353 * New native configurations
355 FreeBSD/mips mips*-*-freebsd
359 Synopsys ARC arc*-*-elf32
360 FreeBSD/mips mips*-*-freebsd
362 * Removed targets and native configurations
364 Alpha running FreeBSD alpha*-*-freebsd*
365 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
370 Erases all the flash memory regions reported by the target.
372 maint print arc arc-instruction address
373 Print internal disassembler information about instruction at a given address.
377 set disassembler-options
378 show disassembler-options
379 Controls the passing of target specific information to the disassembler.
380 If it is necessary to specify more than one disassembler option then
381 multiple options can be placed together into a comma separated list.
382 The default value is the empty string. Currently, the only supported
383 targets are ARM, PowerPC and S/390.
388 Erases all the flash memory regions reported by the target. This is
389 equivalent to the CLI command flash-erase.
391 -file-list-shared-libraries
392 List the shared libraries in the program. This is
393 equivalent to the CLI command "info shared".
396 Catchpoints stopping the program when Ada exceptions are
397 handled. This is equivalent to the CLI command "catch handlers".
399 *** Changes in GDB 7.12
401 * GDB and GDBserver now build with a C++ compiler by default.
403 The --enable-build-with-cxx configure option is now enabled by
404 default. One must now explicitly configure with
405 --disable-build-with-cxx in order to build with a C compiler. This
406 option will be removed in a future release.
408 * GDBserver now supports recording btrace without maintaining an active
411 * GDB now supports a negative repeat count in the 'x' command to examine
412 memory backward from the given address. For example:
415 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
416 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
417 (gdb) x/-5i 0x0000000000400580
418 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
419 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
420 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
421 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
422 0x40057b <main(int, char**)+25>:
423 callq 0x400536 <Func1(int, char const*)>
425 * Fortran: Support structures with fields of dynamic types and
426 arrays of dynamic types.
428 * The symbol dumping maintenance commands have new syntax.
429 maint print symbols [-pc address] [--] [filename]
430 maint print symbols [-objfile objfile] [-source source] [--] [filename]
431 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
432 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
433 maint print msymbols [-objfile objfile] [--] [filename]
435 * GDB now supports multibit bitfields and enums in target register
438 * New Python-based convenience function $_as_string(val), which returns
439 the textual representation of a value. This function is especially
440 useful to obtain the text label of an enum value.
442 * Intel MPX bound violation handling.
444 Segmentation faults caused by a Intel MPX boundary violation
445 now display the kind of violation (upper or lower), the memory
446 address accessed and the memory bounds, along with the usual
447 signal received and code location.
451 Program received signal SIGSEGV, Segmentation fault
452 Upper bound violation while accessing address 0x7fffffffc3b3
453 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
454 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
456 * Rust language support.
457 GDB now supports debugging programs written in the Rust programming
458 language. See https://www.rust-lang.org/ for more information about
461 * Support for running interpreters on specified input/output devices
463 GDB now supports a new mechanism that allows frontends to provide
464 fully featured GDB console views, as a better alternative to
465 building such views on top of the "-interpreter-exec console"
466 command. See the new "new-ui" command below. With that command,
467 frontends can now start GDB in the traditional command-line mode
468 running in an embedded terminal emulator widget, and create a
469 separate MI interpreter running on a specified i/o device. In this
470 way, GDB handles line editing, history, tab completion, etc. in the
471 console all by itself, and the GUI uses the separate MI interpreter
472 for its own control and synchronization, invisible to the command
475 * The "catch syscall" command catches groups of related syscalls.
477 The "catch syscall" command now supports catching a group of related
478 syscalls using the 'group:' or 'g:' prefix.
483 skip -gfile file-glob-pattern
484 skip -function function
485 skip -rfunction regular-expression
486 A generalized form of the skip command, with new support for
487 glob-style file names and regular expressions for function names.
488 Additionally, a file spec and a function spec may now be combined.
490 maint info line-table REGEXP
491 Display the contents of GDB's internal line table data struture.
494 Run any GDB unit tests that were compiled in.
497 Start a new user interface instance running INTERP as interpreter,
498 using the TTY file for input/output.
502 ** gdb.Breakpoint objects have a new attribute "pending", which
503 indicates whether the breakpoint is pending.
504 ** Three new breakpoint-related events have been added:
505 gdb.breakpoint_created, gdb.breakpoint_modified, and
506 gdb.breakpoint_deleted.
509 Signal ("set") the given MS-Windows event object. This is used in
510 conjunction with the Windows JIT debugging (AeDebug) support, where
511 the OS suspends a crashing process until a debugger can attach to
512 it. Resuming the crashing process, in order to debug it, is done by
515 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
516 was added in GDBserver, including JIT compiling fast tracepoint's
517 conditional expression bytecode into native code.
519 * Support for various remote target protocols and ROM monitors has
522 target m32rsdi Remote M32R debugging over SDI
523 target mips MIPS remote debugging protocol
524 target pmon PMON ROM monitor
525 target ddb NEC's DDB variant of PMON for Vr4300
526 target rockhopper NEC RockHopper variant of PMON
527 target lsi LSI variant of PMO
529 * Support for tracepoints and fast tracepoints on powerpc-linux,
530 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
531 including JIT compiling fast tracepoint's conditional expression
532 bytecode into native code.
534 * MI async record =record-started now includes the method and format used for
535 recording. For example:
537 =record-started,thread-group="i1",method="btrace",format="bts"
539 * MI async record =thread-selected now includes the frame field. For example:
541 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
545 Andes NDS32 nds32*-*-elf
547 *** Changes in GDB 7.11
549 * GDB now supports debugging kernel-based threads on FreeBSD.
551 * Per-inferior thread numbers
553 Thread numbers are now per inferior instead of global. If you're
554 debugging multiple inferiors, GDB displays thread IDs using a
555 qualified INF_NUM.THR_NUM form. For example:
559 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
560 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
561 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
562 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
564 As consequence, thread numbers as visible in the $_thread
565 convenience variable and in Python's InferiorThread.num attribute
566 are no longer unique between inferiors.
568 GDB now maintains a second thread ID per thread, referred to as the
569 global thread ID, which is the new equivalent of thread numbers in
570 previous releases. See also $_gthread below.
572 For backwards compatibility, MI's thread IDs always refer to global
575 * Commands that accept thread IDs now accept the qualified
576 INF_NUM.THR_NUM form as well. For example:
579 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
582 * In commands that accept a list of thread IDs, you can now refer to
583 all threads of an inferior using a star wildcard. GDB accepts
584 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
585 refer to all threads of the current inferior. For example, "info
588 * You can use "info threads -gid" to display the global thread ID of
591 * The new convenience variable $_gthread holds the global number of
594 * The new convenience variable $_inferior holds the number of the
597 * GDB now displays the ID and name of the thread that hit a breakpoint
598 or received a signal, if your program is multi-threaded. For
601 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
602 Thread 1 "main" received signal SIGINT, Interrupt.
604 * Record btrace now supports non-stop mode.
606 * Support for tracepoints on aarch64-linux was added in GDBserver.
608 * The 'record instruction-history' command now indicates speculative execution
609 when using the Intel Processor Trace recording format.
611 * GDB now allows users to specify explicit locations, bypassing
612 the linespec parser. This feature is also available to GDB/MI
615 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
616 GDB now is able to debug both AArch64 applications and ARM applications
619 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
620 including JIT compiling fast tracepoint's conditional expression bytecode
623 * GDB now supports displaced stepping on AArch64 GNU/Linux.
625 * "info threads", "info inferiors", "info display", "info checkpoints"
626 and "maint info program-spaces" now list the corresponding items in
627 ascending ID order, for consistency with all other "info" commands.
629 * In Ada, the overloads selection menu has been enhanced to display the
630 parameter types and the return types for the matching overloaded subprograms.
634 maint set target-non-stop (on|off|auto)
635 maint show target-non-stop
636 Control whether GDB targets always operate in non-stop mode even if
637 "set non-stop" is "off". The default is "auto", meaning non-stop
638 mode is enabled if supported by the target.
640 maint set bfd-sharing
641 maint show bfd-sharing
642 Control the reuse of bfd objects.
646 Control display of debugging info regarding bfd caching.
650 Control display of debugging info regarding FreeBSD threads.
652 set remote multiprocess-extensions-packet
653 show remote multiprocess-extensions-packet
654 Set/show the use of the remote protocol multiprocess extensions.
656 set remote thread-events
657 show remote thread-events
658 Set/show the use of thread create/exit events.
660 set ada print-signatures on|off
661 show ada print-signatures"
662 Control whether parameter types and return types are displayed in overloads
663 selection menus. It is activaled (@code{on}) by default.
667 Controls the maximum size of memory, in bytes, that GDB will
668 allocate for value contents. Prevents incorrect programs from
669 causing GDB to allocate overly large buffers. Default is 64k.
671 * The "disassemble" command accepts a new modifier: /s.
672 It prints mixed source+disassembly like /m with two differences:
673 - disassembled instructions are now printed in program order, and
674 - and source for all relevant files is now printed.
675 The "/m" option is now considered deprecated: its "source-centric"
676 output hasn't proved useful in practice.
678 * The "record instruction-history" command accepts a new modifier: /s.
679 It behaves exactly like /m and prints mixed source+disassembly.
681 * The "set scheduler-locking" command supports a new mode "replay".
682 It behaves like "off" in record mode and like "on" in replay mode.
684 * Support for various ROM monitors has been removed:
686 target dbug dBUG ROM monitor for Motorola ColdFire
687 target picobug Motorola picobug monitor
688 target dink32 DINK32 ROM monitor for PowerPC
689 target m32r Renesas M32R/D ROM monitor
690 target mon2000 mon2000 ROM monitor
691 target ppcbug PPCBUG ROM monitor for PowerPC
693 * Support for reading/writing memory and extracting values on architectures
694 whose memory is addressable in units of any integral multiple of 8 bits.
697 Allows to break when an Ada exception is handled.
702 Indicates that an exec system call was executed.
704 exec-events feature in qSupported
705 The qSupported packet allows GDB to request support for exec
706 events using the new 'gdbfeature' exec-event, and the qSupported
707 response can contain the corresponding 'stubfeature'. Set and
708 show commands can be used to display whether these features are enabled.
711 Equivalent to interrupting with the ^C character, but works in
714 thread created stop reason (T05 create:...)
715 Indicates that the thread was just created and is stopped at entry.
717 thread exit stop reply (w exitcode;tid)
718 Indicates that the thread has terminated.
721 Enables/disables thread create and exit event reporting. For
722 example, this is used in non-stop mode when GDB stops a set of
723 threads and synchronously waits for the their corresponding stop
724 replies. Without exit events, if one of the threads exits, GDB
725 would hang forever not knowing that it should no longer expect a
726 stop for that same thread.
729 Indicates that there are no resumed threads left in the target (all
730 threads are stopped). The remote stub reports support for this stop
731 reply to GDB's qSupported query.
734 Enables/disables catching syscalls from the inferior process.
735 The remote stub reports support for this packet to GDB's qSupported query.
737 syscall_entry stop reason
738 Indicates that a syscall was just called.
740 syscall_return stop reason
741 Indicates that a syscall just returned.
743 * Extended-remote exec events
745 ** GDB now has support for exec events on extended-remote Linux targets.
746 For such targets with Linux kernels 2.5.46 and later, this enables
747 follow-exec-mode and exec catchpoints.
749 set remote exec-event-feature-packet
750 show remote exec-event-feature-packet
751 Set/show the use of the remote exec event feature.
753 * Thread names in remote protocol
755 The reply to qXfer:threads:read may now include a name attribute for each
758 * Target remote mode fork and exec events
760 ** GDB now has support for fork and exec events on target remote mode
761 Linux targets. For such targets with Linux kernels 2.5.46 and later,
762 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
763 fork and exec catchpoints.
765 * Remote syscall events
767 ** GDB now has support for catch syscall on remote Linux targets,
768 currently enabled on x86/x86_64 architectures.
770 set remote catch-syscall-packet
771 show remote catch-syscall-packet
772 Set/show the use of the remote catch syscall feature.
776 ** The -var-set-format command now accepts the zero-hexadecimal
777 format. It outputs data in hexadecimal format with zero-padding on the
782 ** gdb.InferiorThread objects have a new attribute "global_num",
783 which refers to the thread's global thread ID. The existing
784 "num" attribute now refers to the thread's per-inferior number.
785 See "Per-inferior thread numbers" above.
786 ** gdb.InferiorThread objects have a new attribute "inferior", which
787 is the Inferior object the thread belongs to.
789 *** Changes in GDB 7.10
791 * Support for process record-replay and reverse debugging on aarch64*-linux*
792 targets has been added. GDB now supports recording of A64 instruction set
793 including advance SIMD instructions.
795 * Support for Sun's version of the "stabs" debug file format has been removed.
797 * GDB now honors the content of the file /proc/PID/coredump_filter
798 (PID is the process ID) on GNU/Linux systems. This file can be used
799 to specify the types of memory mappings that will be included in a
800 corefile. For more information, please refer to the manual page of
801 "core(5)". GDB also has a new command: "set use-coredump-filter
802 on|off". It allows to set whether GDB will read the content of the
803 /proc/PID/coredump_filter file when generating a corefile.
805 * The "info os" command on GNU/Linux can now display information on
807 "info os cpus" Listing of all cpus/cores on the system
809 * GDB has two new commands: "set serial parity odd|even|none" and
810 "show serial parity". These allows to set or show parity for the
813 * The "info source" command now displays the producer string if it was
814 present in the debug info. This typically includes the compiler version
815 and may include things like its command line arguments.
817 * The "info dll", an alias of the "info sharedlibrary" command,
818 is now available on all platforms.
820 * Directory names supplied to the "set sysroot" commands may be
821 prefixed with "target:" to tell GDB to access shared libraries from
822 the target system, be it local or remote. This replaces the prefix
823 "remote:". The default sysroot has been changed from "" to
824 "target:". "remote:" is automatically converted to "target:" for
825 backward compatibility.
827 * The system root specified by "set sysroot" will be prepended to the
828 filename of the main executable (if reported to GDB as absolute by
829 the operating system) when starting processes remotely, and when
830 attaching to already-running local or remote processes.
832 * GDB now supports automatic location and retrieval of executable
833 files from remote targets. Remote debugging can now be initiated
834 using only a "target remote" or "target extended-remote" command
835 (no "set sysroot" or "file" commands are required). See "New remote
838 * The "dump" command now supports verilog hex format.
840 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
842 * On GNU/Linux, GDB and gdbserver are now able to access executable
843 and shared library files without a "set sysroot" command when
844 attaching to processes running in different mount namespaces from
845 the debugger. This makes it possible to attach to processes in
846 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
847 See "New remote packets" below.
849 * The "tui reg" command now provides completion for all of the
850 available register groups, including target specific groups.
852 * The HISTSIZE environment variable is no longer read when determining
853 the size of GDB's command history. GDB now instead reads the dedicated
854 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
855 disables truncation of command history. Non-numeric values of GDBHISTSIZE
860 ** Memory ports can now be unbuffered.
864 ** gdb.Objfile objects have a new attribute "username",
865 which is the name of the objfile as specified by the user,
866 without, for example, resolving symlinks.
867 ** You can now write frame unwinders in Python.
868 ** gdb.Type objects have a new method "optimized_out",
869 returning optimized out gdb.Value instance of this type.
870 ** gdb.Value objects have new methods "reference_value" and
871 "const_value" which return a reference to the value and a
872 "const" version of the value respectively.
876 maint print symbol-cache
877 Print the contents of the symbol cache.
879 maint print symbol-cache-statistics
880 Print statistics of symbol cache usage.
882 maint flush-symbol-cache
883 Flush the contents of the symbol cache.
887 Start branch trace recording using Branch Trace Store (BTS) format.
890 Evaluate expression by using the compiler and print result.
894 Explicit commands for enabling and disabling tui mode.
897 set mpx bound on i386 and amd64
898 Support for bound table investigation on Intel MPX enabled applications.
902 Start branch trace recording using Intel Processor Trace format.
905 Print information about branch tracing internals.
907 maint btrace packet-history
908 Print the raw branch tracing data.
910 maint btrace clear-packet-history
911 Discard the stored raw branch tracing data.
914 Discard all branch tracing data. It will be fetched and processed
915 anew by the next "record" command.
920 Renamed from "set debug dwarf2-die".
922 Renamed from "show debug dwarf2-die".
925 Renamed from "set debug dwarf2-read".
926 show debug dwarf-read
927 Renamed from "show debug dwarf2-read".
929 maint set dwarf always-disassemble
930 Renamed from "maint set dwarf2 always-disassemble".
931 maint show dwarf always-disassemble
932 Renamed from "maint show dwarf2 always-disassemble".
934 maint set dwarf max-cache-age
935 Renamed from "maint set dwarf2 max-cache-age".
936 maint show dwarf max-cache-age
937 Renamed from "maint show dwarf2 max-cache-age".
940 show debug dwarf-line
941 Control display of debugging info regarding DWARF line processing.
945 Set the maximum number of candidates to be considered during
946 completion. The default value is 200. This limit allows GDB
947 to avoid generating large completion lists, the computation of
948 which can cause the debugger to become temporarily unresponsive.
950 set history remove-duplicates
951 show history remove-duplicates
952 Control the removal of duplicate history entries.
954 maint set symbol-cache-size
955 maint show symbol-cache-size
956 Control the size of the symbol cache.
958 set|show record btrace bts buffer-size
959 Set and show the size of the ring buffer used for branch tracing in
961 The obtained size may differ from the requested size. Use "info
962 record" to see the obtained buffer size.
964 set debug linux-namespaces
965 show debug linux-namespaces
966 Control display of debugging info regarding Linux namespaces.
968 set|show record btrace pt buffer-size
969 Set and show the size of the ring buffer used for branch tracing in
970 Intel Processor Trace format.
971 The obtained size may differ from the requested size. Use "info
972 record" to see the obtained buffer size.
974 maint set|show btrace pt skip-pad
975 Set and show whether PAD packets are skipped when computing the
978 * The command 'thread apply all' can now support new option '-ascending'
979 to call its specified command for all threads in ascending order.
981 * Python/Guile scripting
983 ** GDB now supports auto-loading of Python/Guile scripts contained in the
984 special section named `.debug_gdb_scripts'.
988 qXfer:btrace-conf:read
989 Return the branch trace configuration for the current thread.
991 Qbtrace-conf:bts:size
992 Set the requested ring buffer size for branch tracing in BTS format.
995 Enable Intel Procesor Trace-based branch tracing for the current
996 process. The remote stub reports support for this packet to GDB's
1000 Set the requested ring buffer size for branch tracing in Intel Processor
1004 Indicates a memory breakpoint instruction was executed, irrespective
1005 of whether it was GDB that planted the breakpoint or the breakpoint
1006 is hardcoded in the program. This is required for correct non-stop
1010 Indicates the target stopped for a hardware breakpoint. This is
1011 required for correct non-stop mode operation.
1014 Return information about files on the remote system.
1016 qXfer:exec-file:read
1017 Return the full absolute name of the file that was executed to
1018 create a process running on the remote system.
1021 Select the filesystem on which vFile: operations with filename
1022 arguments will operate. This is required for GDB to be able to
1023 access files on remote targets where the remote stub does not
1024 share a common filesystem with the inferior(s).
1027 Indicates that a fork system call was executed.
1030 Indicates that a vfork system call was executed.
1032 vforkdone stop reason
1033 Indicates that a vfork child of the specified process has executed
1034 an exec or exit, allowing the vfork parent to resume execution.
1036 fork-events and vfork-events features in qSupported
1037 The qSupported packet allows GDB to request support for fork and
1038 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1039 and the qSupported response can contain the corresponding
1040 'stubfeatures'. Set and show commands can be used to display
1041 whether these features are enabled.
1043 * Extended-remote fork events
1045 ** GDB now has support for fork events on extended-remote Linux
1046 targets. For targets with Linux kernels 2.5.60 and later, this
1047 enables follow-fork-mode and detach-on-fork for both fork and
1048 vfork, as well as fork and vfork catchpoints.
1050 * The info record command now shows the recording format and the
1051 branch tracing configuration for the current thread when using
1052 the btrace record target.
1053 For the BTS format, it shows the ring buffer size.
1055 * GDB now has support for DTrace USDT (Userland Static Defined
1056 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1058 * GDB now supports access to vector registers on S/390 GNU/Linux
1061 * Removed command line options
1063 -xdb HP-UX XDB compatibility mode.
1065 * Removed targets and native configurations
1067 HP/PA running HP-UX hppa*-*-hpux*
1068 Itanium running HP-UX ia64-*-hpux*
1070 * New configure options
1073 This configure option allows the user to build GDB with support for
1074 Intel Processor Trace (default: auto). This requires libipt.
1076 --with-libipt-prefix=PATH
1077 Specify the path to the version of libipt that GDB should use.
1078 $PATH/include should contain the intel-pt.h header and
1079 $PATH/lib should contain the libipt.so library.
1081 *** Changes in GDB 7.9.1
1085 ** Xmethods can now specify a result type.
1087 *** Changes in GDB 7.9
1089 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1093 ** You can now access frame registers from Python scripts.
1094 ** New attribute 'producer' for gdb.Symtab objects.
1095 ** gdb.Objfile objects have a new attribute "progspace",
1096 which is the gdb.Progspace object of the containing program space.
1097 ** gdb.Objfile objects have a new attribute "owner".
1098 ** gdb.Objfile objects have a new attribute "build_id",
1099 which is the build ID generated when the file was built.
1100 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1101 ** A new event "gdb.clear_objfiles" has been added, triggered when
1102 selecting a new file to debug.
1103 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1104 ** New function gdb.lookup_objfile.
1106 New events which are triggered when GDB modifies the state of the
1109 ** gdb.events.inferior_call_pre: Function call is about to be made.
1110 ** gdb.events.inferior_call_post: Function call has just been made.
1111 ** gdb.events.memory_changed: A memory location has been altered.
1112 ** gdb.events.register_changed: A register has been altered.
1114 * New Python-based convenience functions:
1116 ** $_caller_is(name [, number_of_frames])
1117 ** $_caller_matches(regexp [, number_of_frames])
1118 ** $_any_caller_is(name [, number_of_frames])
1119 ** $_any_caller_matches(regexp [, number_of_frames])
1121 * GDB now supports the compilation and injection of source code into
1122 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1123 to compile the source code to object code, and if successful, inject
1124 and execute that code within the current context of the inferior.
1125 Currently the C language is supported. The commands used to
1126 interface with this new feature are:
1128 compile code [-raw|-r] [--] [source code]
1129 compile file [-raw|-r] filename
1133 demangle [-l language] [--] name
1134 Demangle "name" in the specified language, or the current language
1135 if elided. This command is renamed from the "maint demangle" command.
1136 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1137 as "maint demangler-warning".
1139 queue-signal signal-name-or-number
1140 Queue a signal to be delivered to the thread when it is resumed.
1142 add-auto-load-scripts-directory directory
1143 Add entries to the list of directories from which to load auto-loaded
1146 maint print user-registers
1147 List all currently available "user" registers.
1149 compile code [-r|-raw] [--] [source code]
1150 Compile, inject, and execute in the inferior the executable object
1151 code produced by compiling the provided source code.
1153 compile file [-r|-raw] filename
1154 Compile and inject into the inferior the executable object code
1155 produced by compiling the source code stored in the filename
1158 * On resume, GDB now always passes the signal the program had stopped
1159 for to the thread the signal was sent to, even if the user changed
1160 threads before resuming. Previously GDB would often (but not
1161 always) deliver the signal to the thread that happens to be current
1164 * Conversely, the "signal" command now consistently delivers the
1165 requested signal to the current thread. GDB now asks for
1166 confirmation if the program had stopped for a signal and the user
1167 switched threads meanwhile.
1169 * "breakpoint always-inserted" modes "off" and "auto" merged.
1171 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1172 won't remove breakpoints from the target until all threads stop,
1173 even in non-stop mode. The "auto" mode has been removed, and "off"
1174 is now the default mode.
1178 set debug symbol-lookup
1179 show debug symbol-lookup
1180 Control display of debugging info regarding symbol lookup.
1184 ** The -list-thread-groups command outputs an exit-code field for
1185 inferiors that have exited.
1189 MIPS SDE mips*-sde*-elf*
1193 Support for these obsolete configurations has been removed.
1195 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1196 SGI Irix-5.x mips-*-irix5*
1197 SGI Irix-6.x mips-*-irix6*
1198 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1199 VAX running Ultrix vax-*-ultrix*
1201 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1202 and "assf"), have been removed. Use the "sharedlibrary" command, or
1203 its alias "share", instead.
1205 *** Changes in GDB 7.8
1207 * New command line options
1210 This is an alias for the --data-directory option.
1212 * GDB supports printing and modifying of variable length automatic arrays
1213 as specified in ISO C99.
1215 * The ARM simulator now supports instruction level tracing
1216 with or without disassembly.
1220 GDB now has support for scripting using Guile. Whether this is
1221 available is determined at configure time.
1222 Guile version 2.0 or greater is required.
1223 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1225 * New commands (for set/show, see "New options" below)
1229 Invoke CODE by passing it to the Guile interpreter.
1233 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1235 info auto-load guile-scripts [regexp]
1236 Print the list of automatically loaded Guile scripts.
1238 * The source command is now capable of sourcing Guile scripts.
1239 This feature is dependent on the debugger being built with Guile support.
1243 set print symbol-loading (off|brief|full)
1244 show print symbol-loading
1245 Control whether to print informational messages when loading symbol
1246 information for a file. The default is "full", but when debugging
1247 programs with large numbers of shared libraries the amount of output
1248 becomes less useful.
1250 set guile print-stack (none|message|full)
1251 show guile print-stack
1252 Show a stack trace when an error is encountered in a Guile script.
1254 set auto-load guile-scripts (on|off)
1255 show auto-load guile-scripts
1256 Control auto-loading of Guile script files.
1258 maint ada set ignore-descriptive-types (on|off)
1259 maint ada show ignore-descriptive-types
1260 Control whether the debugger should ignore descriptive types in Ada
1261 programs. The default is not to ignore the descriptive types. See
1262 the user manual for more details on descriptive types and the intended
1263 usage of this option.
1265 set auto-connect-native-target
1267 Control whether GDB is allowed to automatically connect to the
1268 native target for the run, attach, etc. commands when not connected
1269 to any target yet. See also "target native" below.
1271 set record btrace replay-memory-access (read-only|read-write)
1272 show record btrace replay-memory-access
1273 Control what memory accesses are allowed during replay.
1275 maint set target-async (on|off)
1276 maint show target-async
1277 This controls whether GDB targets operate in synchronous or
1278 asynchronous mode. Normally the default is asynchronous, if it is
1279 available; but this can be changed to more easily debug problems
1280 occurring only in synchronous mode.
1282 set mi-async (on|off)
1284 Control whether MI asynchronous mode is preferred. This supersedes
1285 "set target-async" of previous GDB versions.
1287 * "set target-async" is deprecated as a CLI option and is now an alias
1288 for "set mi-async" (only puts MI into async mode).
1290 * Background execution commands (e.g., "c&", "s&", etc.) are now
1291 possible ``out of the box'' if the target supports them. Previously
1292 the user would need to explicitly enable the possibility with the
1293 "set target-async on" command.
1295 * New features in the GDB remote stub, GDBserver
1297 ** New option --debug-format=option1[,option2,...] allows one to add
1298 additional text to each output. At present only timestamps
1299 are supported: --debug-format=timestamps.
1300 Timestamps can also be turned on with the
1301 "monitor set debug-format timestamps" command from GDB.
1303 * The 'record instruction-history' command now starts counting instructions
1304 at one. This also affects the instruction ranges reported by the
1305 'record function-call-history' command when given the /i modifier.
1307 * The command 'record function-call-history' supports a new modifier '/c' to
1308 indent the function names based on their call stack depth.
1309 The fields for the '/i' and '/l' modifier have been reordered.
1310 The source line range is now prefixed with 'at'.
1311 The instruction range is now prefixed with 'inst'.
1312 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1313 "record instruction-history" and "list" commands.
1315 * The ranges given as arguments to the 'record function-call-history' and
1316 'record instruction-history' commands are now inclusive.
1318 * The btrace record target now supports the 'record goto' command.
1319 For locations inside the execution trace, the back trace is computed
1320 based on the information stored in the execution trace.
1322 * The btrace record target supports limited reverse execution and replay.
1323 The target does not record data and therefore does not allow reading
1324 memory or registers.
1326 * The "catch syscall" command now works on s390*-linux* targets.
1328 * The "compare-sections" command is no longer specific to target
1329 remote. It now works with all targets.
1331 * All native targets are now consistently called "native".
1332 Consequently, the "target child", "target GNU", "target djgpp",
1333 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1334 commands have been replaced with "target native". The QNX/NTO port
1335 leaves the "procfs" target in place and adds a "native" target for
1336 consistency with other ports. The impact on users should be minimal
1337 as these commands previously either throwed an error, or were
1338 no-ops. The target's name is visible in the output of the following
1339 commands: "help target", "info target", "info files", "maint print
1342 * The "target native" command now connects to the native target. This
1343 can be used to launch native programs even when "set
1344 auto-connect-native-target" is set to off.
1346 * GDB now supports access to Intel MPX registers on GNU/Linux.
1348 * Support for Intel AVX-512 registers on GNU/Linux.
1349 Support displaying and modifying Intel AVX-512 registers
1350 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1352 * New remote packets
1354 qXfer:btrace:read's annex
1355 The qXfer:btrace:read packet supports a new annex 'delta' to read
1356 branch trace incrementally.
1360 ** Valid Python operations on gdb.Value objects representing
1361 structs/classes invoke the corresponding overloaded operators if
1363 ** New `Xmethods' feature in the Python API. Xmethods are
1364 additional methods or replacements for existing methods of a C++
1365 class. This feature is useful for those cases where a method
1366 defined in C++ source code could be inlined or optimized out by
1367 the compiler, making it unavailable to GDB.
1370 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1372 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1373 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1374 its alias "share", instead.
1376 * The commands "set remotebaud" and "show remotebaud" are no longer
1377 supported. Use "set serial baud" and "show serial baud" (respectively)
1382 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1383 target-async". The latter is left as a deprecated alias of the
1384 former for backward compatibility. If the target supports it,
1385 CLI background execution commands are now always possible by
1386 default, independently of whether the frontend stated a
1387 preference for asynchronous execution with "-gdb-set mi-async".
1388 Previously "-gdb-set target-async off" affected both MI execution
1389 commands and CLI execution commands.
1391 *** Changes in GDB 7.7
1393 * Improved support for process record-replay and reverse debugging on
1394 arm*-linux* targets. Support for thumb32 and syscall instruction
1395 recording has been added.
1397 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1399 * GDB now supports Fission DWP file format version 2.
1400 http://gcc.gnu.org/wiki/DebugFission
1402 * New convenience function "$_isvoid", to check whether an expression
1403 is void. A void expression is an expression where the type of the
1404 result is "void". For example, some convenience variables may be
1405 "void" when evaluated (e.g., "$_exitcode" before the execution of
1406 the program being debugged; or an undefined convenience variable).
1407 Another example, when calling a function whose return type is
1410 * The "maintenance print objfiles" command now takes an optional regexp.
1412 * The "catch syscall" command now works on arm*-linux* targets.
1414 * GDB now consistently shows "<not saved>" when printing values of
1415 registers the debug info indicates have not been saved in the frame
1416 and there's nowhere to retrieve them from
1417 (callee-saved/call-clobbered registers):
1422 (gdb) info registers rax
1425 Before, the former would print "<optimized out>", and the latter
1426 "*value not available*".
1428 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1433 ** Frame filters and frame decorators have been added.
1434 ** Temporary breakpoints are now supported.
1435 ** Line tables representation has been added.
1436 ** New attribute 'parent_type' for gdb.Field objects.
1437 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1438 ** New attribute 'name' for gdb.Type objects.
1442 Nios II ELF nios2*-*-elf
1443 Nios II GNU/Linux nios2*-*-linux
1444 Texas Instruments MSP430 msp430*-*-elf
1446 * Removed native configurations
1448 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1449 been removed. ELF variants of these configurations are kept supported.
1451 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1452 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1453 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1454 i[34567]86-*-openbsd3.[0-3]
1455 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1456 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1457 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1461 Like "catch throw", but catches a re-thrown exception.
1462 maint check-psymtabs
1463 Renamed from old "maint check-symtabs".
1465 Perform consistency checks on symtabs.
1466 maint expand-symtabs
1467 Expand symtabs matching an optional regexp.
1470 Display the details of GDB configure-time options.
1472 maint set|show per-command
1473 maint set|show per-command space
1474 maint set|show per-command time
1475 maint set|show per-command symtab
1476 Enable display of per-command gdb resource usage.
1478 remove-symbol-file FILENAME
1479 remove-symbol-file -a ADDRESS
1480 Remove a symbol file added via add-symbol-file. The file to remove
1481 can be identified by its filename or by an address that lies within
1482 the boundaries of this symbol file in memory.
1485 info exceptions REGEXP
1486 Display the list of Ada exceptions defined in the program being
1487 debugged. If provided, only the exceptions whose names match REGEXP
1492 set debug symfile off|on
1494 Control display of debugging info regarding reading symbol files and
1495 symbol tables within those files
1497 set print raw frame-arguments
1498 show print raw frame-arguments
1499 Set/show whether to print frame arguments in raw mode,
1500 disregarding any defined pretty-printers.
1502 set remote trace-status-packet
1503 show remote trace-status-packet
1504 Set/show the use of remote protocol qTStatus packet.
1508 Control display of debugging messages related to Nios II targets.
1512 Control whether target-assisted range stepping is enabled.
1514 set startup-with-shell
1515 show startup-with-shell
1516 Specifies whether Unix child processes are started via a shell or
1521 Use the target memory cache for accesses to the code segment. This
1522 improves performance of remote debugging (particularly disassembly).
1524 * You can now use a literal value 'unlimited' for options that
1525 interpret 0 or -1 as meaning "unlimited". E.g., "set
1526 trace-buffer-size unlimited" is now an alias for "set
1527 trace-buffer-size -1" and "set height unlimited" is now an alias for
1530 * The "set debug symtab-create" debugging option of GDB has been changed to
1531 accept a verbosity level. 0 means "off", 1 provides basic debugging
1532 output, and values of 2 or greater provides more verbose output.
1534 * New command-line options
1536 Display the details of GDB configure-time options.
1538 * The command 'tsave' can now support new option '-ctf' to save trace
1539 buffer in Common Trace Format.
1541 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1544 * GDB now implements the the C++ 'typeid' operator.
1546 * The new convenience variable $_exception holds the exception being
1547 thrown or caught at an exception-related catchpoint.
1549 * The exception-related catchpoints, like "catch throw", now accept a
1550 regular expression which can be used to filter exceptions by type.
1552 * The new convenience variable $_exitsignal is automatically set to
1553 the terminating signal number when the program being debugged dies
1554 due to an uncaught signal.
1558 ** All MI commands now accept an optional "--language" option.
1559 Support for this feature can be verified by using the "-list-features"
1560 command, which should contain "language-option".
1562 ** The new command -info-gdb-mi-command allows the user to determine
1563 whether a GDB/MI command is supported or not.
1565 ** The "^error" result record returned when trying to execute an undefined
1566 GDB/MI command now provides a variable named "code" whose content is the
1567 "undefined-command" error code. Support for this feature can be verified
1568 by using the "-list-features" command, which should contain
1569 "undefined-command-error-code".
1571 ** The -trace-save MI command can optionally save trace buffer in Common
1574 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1576 ** The command -data-list-register-values now accepts an optional
1577 "--skip-unavailable" option. When used, only the available registers
1580 ** The new command -trace-frame-collected dumps collected variables,
1581 computed expressions, tvars, memory and registers in a traceframe.
1583 ** The commands -stack-list-locals, -stack-list-arguments and
1584 -stack-list-variables now accept an option "--skip-unavailable".
1585 When used, only the available locals or arguments are displayed.
1587 ** The -exec-run command now accepts an optional "--start" option.
1588 When used, the command follows the same semantics as the "start"
1589 command, stopping the program's execution at the start of its
1590 main subprogram. Support for this feature can be verified using
1591 the "-list-features" command, which should contain
1592 "exec-run-start-option".
1594 ** The new commands -catch-assert and -catch-exceptions insert
1595 catchpoints stopping the program when Ada exceptions are raised.
1597 ** The new command -info-ada-exceptions provides the equivalent of
1598 the new "info exceptions" command.
1600 * New system-wide configuration scripts
1601 A GDB installation now provides scripts suitable for use as system-wide
1602 configuration scripts for the following systems:
1606 * GDB now supports target-assigned range stepping with remote targets.
1607 This improves the performance of stepping source lines by reducing
1608 the number of control packets from/to GDB. See "New remote packets"
1611 * GDB now understands the element 'tvar' in the XML traceframe info.
1612 It has the id of the collected trace state variables.
1614 * On S/390 targets that provide the transactional-execution feature,
1615 the program interruption transaction diagnostic block (TDB) is now
1616 represented as a number of additional "registers" in GDB.
1618 * New remote packets
1622 The vCont packet supports a new 'r' action, that tells the remote
1623 stub to step through an address range itself, without GDB
1624 involvemement at each single-step.
1626 qXfer:libraries-svr4:read's annex
1627 The previously unused annex of the qXfer:libraries-svr4:read packet
1628 is now used to support passing an argument list. The remote stub
1629 reports support for this argument list to GDB's qSupported query.
1630 The defined arguments are "start" and "prev", used to reduce work
1631 necessary for library list updating, resulting in significant
1634 * New features in the GDB remote stub, GDBserver
1636 ** GDBserver now supports target-assisted range stepping. Currently
1637 enabled on x86/x86_64 GNU/Linux targets.
1639 ** GDBserver now adds element 'tvar' in the XML in the reply to
1640 'qXfer:traceframe-info:read'. It has the id of the collected
1641 trace state variables.
1643 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1646 * New 'z' formatter for printing and examining memory, this displays the
1647 value as hexadecimal zero padded on the left to the size of the type.
1649 * GDB can now use Windows x64 unwinding data.
1651 * The "set remotebaud" command has been replaced by "set serial baud".
1652 Similarly, "show remotebaud" has been replaced by "show serial baud".
1653 The "set remotebaud" and "show remotebaud" commands are still available
1654 to provide backward compatibility with older versions of GDB.
1656 *** Changes in GDB 7.6
1658 * Target record has been renamed to record-full.
1659 Record/replay is now enabled with the "record full" command.
1660 This also affects settings that are associated with full record/replay
1661 that have been moved from "set/show record" to "set/show record full":
1663 set|show record full insn-number-max
1664 set|show record full stop-at-limit
1665 set|show record full memory-query
1667 * A new record target "record-btrace" has been added. The new target
1668 uses hardware support to record the control-flow of a process. It
1669 does not support replaying the execution, but it implements the
1670 below new commands for investigating the recorded execution log.
1671 This new recording method can be enabled using:
1675 The "record-btrace" target is only available on Intel Atom processors
1676 and requires a Linux kernel 2.6.32 or later.
1678 * Two new commands have been added for record/replay to give information
1679 about the recorded execution without having to replay the execution.
1680 The commands are only supported by "record btrace".
1682 record instruction-history prints the execution history at
1683 instruction granularity
1685 record function-call-history prints the execution history at
1686 function granularity
1688 * New native configurations
1690 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1691 FreeBSD/powerpc powerpc*-*-freebsd
1692 x86_64/Cygwin x86_64-*-cygwin*
1693 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1697 ARM AArch64 aarch64*-*-elf
1698 ARM AArch64 GNU/Linux aarch64*-*-linux
1699 Lynx 178 PowerPC powerpc-*-lynx*178
1700 x86_64/Cygwin x86_64-*-cygwin*
1701 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1703 * If the configured location of system.gdbinit file (as given by the
1704 --with-system-gdbinit option at configure time) is in the
1705 data-directory (as specified by --with-gdb-datadir at configure
1706 time) or in one of its subdirectories, then GDB will look for the
1707 system-wide init file in the directory specified by the
1708 --data-directory command-line option.
1710 * New command line options:
1712 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1713 other initialization files, unlike -nx which disables all of them.
1715 * Removed command line options
1717 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1720 * The 'ptype' and 'whatis' commands now accept an argument to control
1723 * 'info proc' now works on some core files.
1727 ** Vectors can be created with gdb.Type.vector.
1729 ** Python's atexit.register now works in GDB.
1731 ** Types can be pretty-printed via a Python API.
1733 ** Python 3 is now supported (in addition to Python 2.4 or later)
1735 ** New class gdb.Architecture exposes GDB's internal representation
1736 of architecture in the Python API.
1738 ** New method Frame.architecture returns the gdb.Architecture object
1739 corresponding to the frame's architecture.
1741 * New Python-based convenience functions:
1743 ** $_memeq(buf1, buf2, length)
1744 ** $_streq(str1, str2)
1746 ** $_regex(str, regex)
1748 * The 'cd' command now defaults to using '~' (the home directory) if not
1751 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1752 default for GCC since November 2000.
1754 * The command 'forward-search' can now be abbreviated as 'fo'.
1756 * The command 'info tracepoints' can now display 'installed on target'
1757 or 'not installed on target' for each non-pending location of tracepoint.
1759 * New configure options
1761 --enable-libmcheck/--disable-libmcheck
1762 By default, development versions are built with -lmcheck on hosts
1763 that support it, in order to help track memory corruption issues.
1764 Release versions, on the other hand, are built without -lmcheck
1765 by default. The --enable-libmcheck/--disable-libmcheck configure
1766 options allow the user to override that default.
1767 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1768 This configure option allows the user to build GDB with
1769 libbabeltrace using which GDB can read Common Trace Format data.
1771 * New commands (for set/show, see "New options" below)
1774 Catch signals. This is similar to "handle", but allows commands and
1775 conditions to be attached.
1778 List the BFDs known to GDB.
1780 python-interactive [command]
1782 Start a Python interactive prompt, or evaluate the optional command
1783 and print the result of expressions.
1786 "py" is a new alias for "python".
1788 enable type-printer [name]...
1789 disable type-printer [name]...
1790 Enable or disable type printers.
1794 ** For the Renesas Super-H architecture, the "regs" command has been removed
1795 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1800 set print type methods (on|off)
1801 show print type methods
1802 Control whether method declarations are displayed by "ptype".
1803 The default is to show them.
1805 set print type typedefs (on|off)
1806 show print type typedefs
1807 Control whether typedef definitions are displayed by "ptype".
1808 The default is to show them.
1810 set filename-display basename|relative|absolute
1811 show filename-display
1812 Control the way in which filenames is displayed.
1813 The default is "relative", which preserves previous behavior.
1815 set trace-buffer-size
1816 show trace-buffer-size
1817 Request target to change the size of trace buffer.
1819 set remote trace-buffer-size-packet auto|on|off
1820 show remote trace-buffer-size-packet
1821 Control the use of the remote protocol `QTBuffer:size' packet.
1825 Control display of debugging messages related to ARM AArch64.
1828 set debug coff-pe-read
1829 show debug coff-pe-read
1830 Control display of debugging messages related to reading of COFF/PE
1835 Control display of debugging messages related to Mach-O symbols
1838 set debug notification
1839 show debug notification
1840 Control display of debugging info for async remote notification.
1844 ** Command parameter changes are now notified using new async record
1845 "=cmd-param-changed".
1846 ** Trace frame changes caused by command "tfind" are now notified using
1847 new async record "=traceframe-changed".
1848 ** The creation, deletion and modification of trace state variables
1849 are now notified using new async records "=tsv-created",
1850 "=tsv-deleted" and "=tsv-modified".
1851 ** The start and stop of process record are now notified using new
1852 async record "=record-started" and "=record-stopped".
1853 ** Memory changes are now notified using new async record
1855 ** The data-disassemble command response will include a "fullname" field
1856 containing the absolute file name when source has been requested.
1857 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1858 command, to allow pattern filling of memory areas.
1859 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1860 library load/unload events.
1861 ** The response to breakpoint commands and breakpoint async records
1862 includes an "installed" field containing a boolean state about each
1863 non-pending tracepoint location is whether installed on target or not.
1864 ** Output of the "-trace-status" command includes a "trace-file" field
1865 containing the name of the trace file being examined. This field is
1866 optional, and only present when examining a trace file.
1867 ** The "fullname" field is now always present along with the "file" field,
1868 even if the file cannot be found by GDB.
1870 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1871 You must have the LZMA library available when configuring GDB for this
1872 feature to be enabled. For more information, see:
1873 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1875 * New remote packets
1878 Set the size of trace buffer. The remote stub reports support for this
1879 packet to gdb's qSupported query.
1882 Enable Branch Trace Store (BTS)-based branch tracing for the current
1883 thread. The remote stub reports support for this packet to gdb's
1887 Disable branch tracing for the current thread. The remote stub reports
1888 support for this packet to gdb's qSupported query.
1891 Read the traced branches for the current thread. The remote stub
1892 reports support for this packet to gdb's qSupported query.
1894 *** Changes in GDB 7.5
1896 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1897 for more x32 ABI info.
1899 * GDB now supports access to MIPS DSP registers on Linux targets.
1901 * GDB now supports debugging microMIPS binaries.
1903 * The "info os" command on GNU/Linux can now display information on
1904 several new classes of objects managed by the operating system:
1905 "info os procgroups" lists process groups
1906 "info os files" lists file descriptors
1907 "info os sockets" lists internet-domain sockets
1908 "info os shm" lists shared-memory regions
1909 "info os semaphores" lists semaphores
1910 "info os msg" lists message queues
1911 "info os modules" lists loaded kernel modules
1913 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1914 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1915 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1916 options and inspect the probe arguments using the new $_probe_arg family
1917 of convenience variables. You can obtain more information about SystemTap
1918 in <http://sourceware.org/systemtap/>.
1920 * GDB now supports reversible debugging on ARM, it allows you to
1921 debug basic ARM and THUMB instructions, and provides
1922 record/replay support.
1924 * The option "symbol-reloading" has been deleted as it is no longer used.
1928 ** GDB commands implemented in Python can now be put in command class
1931 ** The "maint set python print-stack on|off" is now deleted.
1933 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1934 apply "flag enum"-style pretty-printing to any enum.
1936 ** gdb.lookup_symbol can now work when there is no current frame.
1938 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1939 the source at which the symbol was defined.
1941 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1942 method 'value'. The former indicates whether the symbol needs a
1943 frame in order to compute its value, and the latter computes the
1946 ** A new method 'referenced_value' on gdb.Value objects which can
1947 dereference pointer as well as C++ reference values.
1949 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1950 which return the global and static blocks (as gdb.Block objects),
1951 of the underlying symbol table, respectively.
1953 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1954 object associated with a PC value.
1956 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1957 of the address range occupied by code for the current source line.
1959 * Go language support.
1960 GDB now supports debugging programs written in the Go programming
1963 * GDBserver now supports stdio connections.
1964 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1966 * The binary "gdbtui" can no longer be built or installed.
1967 Use "gdb -tui" instead.
1969 * GDB will now print "flag" enums specially. A flag enum is one where
1970 all the enumerator values have no bits in common when pairwise
1971 "and"ed. When printing a value whose type is a flag enum, GDB will
1972 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1973 (gdb) print (enum E) 3
1976 * The filename part of a linespec will now match trailing components
1977 of a source file name. For example, "break gcc/expr.c:1000" will
1978 now set a breakpoint in build/gcc/expr.c, but not
1979 build/libcpp/expr.c.
1981 * The "info proc" and "generate-core-file" commands will now also
1982 work on remote targets connected to GDBserver on Linux.
1984 * The command "info catch" has been removed. It has been disabled
1985 since December 2007.
1987 * The "catch exception" and "catch assert" commands now accept
1988 a condition at the end of the command, much like the "break"
1989 command does. For instance:
1991 (gdb) catch exception Constraint_Error if Barrier = True
1993 Previously, it was possible to add a condition to such catchpoints,
1994 but it had to be done as a second step, after the catchpoint had been
1995 created, using the "condition" command.
1997 * The "info static-tracepoint-marker" command will now also work on
1998 native Linux targets with in-process agent.
2000 * GDB can now set breakpoints on inlined functions.
2002 * The .gdb_index section has been updated to include symbols for
2003 inlined functions. GDB will ignore older .gdb_index sections by
2004 default, which could cause symbol files to be loaded more slowly
2005 until their .gdb_index sections can be recreated. The new command
2006 "set use-deprecated-index-sections on" will cause GDB to use any older
2007 .gdb_index sections it finds. This will restore performance, but the
2008 ability to set breakpoints on inlined functions will be lost in symbol
2009 files with older .gdb_index sections.
2011 The .gdb_index section has also been updated to record more information
2012 about each symbol. This speeds up the "info variables", "info functions"
2013 and "info types" commands when used with programs having the .gdb_index
2014 section, as well as speeding up debugging with shared libraries using
2015 the .gdb_index section.
2017 * Ada support for GDB/MI Variable Objects has been added.
2019 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2024 ** New command -info-os is the MI equivalent of "info os".
2026 ** Output logs ("set logging" and related) now include MI output.
2030 ** "set use-deprecated-index-sections on|off"
2031 "show use-deprecated-index-sections on|off"
2032 Controls the use of deprecated .gdb_index sections.
2034 ** "catch load" and "catch unload" can be used to stop when a shared
2035 library is loaded or unloaded, respectively.
2037 ** "enable count" can be used to auto-disable a breakpoint after
2040 ** "info vtbl" can be used to show the virtual method tables for
2041 C++ and Java objects.
2043 ** "explore" and its sub commands "explore value" and "explore type"
2044 can be used to recursively explore values and types of
2045 expressions. These commands are available only if GDB is
2046 configured with '--with-python'.
2048 ** "info auto-load" shows status of all kinds of auto-loaded files,
2049 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2050 sequences of commands files, "info auto-load python-scripts"
2051 shows status of auto-loading Python script files,
2052 "info auto-load local-gdbinit" shows status of loading init file
2053 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2054 status of inferior specific thread debugging shared library loading.
2056 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2057 and "show auto-load-scripts" commands have been deprecated, use their
2058 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2059 and "show auto-load python-scripts" counterparts instead.
2061 ** "dprintf location,format,args..." creates a dynamic printf, which
2062 is basically a breakpoint that does a printf and immediately
2063 resumes your program's execution, so it is like a printf that you
2064 can insert dynamically at runtime instead of at compiletime.
2066 ** "set print symbol"
2068 Controls whether GDB attempts to display the symbol, if any,
2069 corresponding to addresses it prints. This defaults to "on", but
2070 you can set it to "off" to restore GDB's previous behavior.
2072 * Deprecated commands
2074 ** For the Renesas Super-H architecture, the "regs" command has been
2075 deprecated, and "info all-registers" should be used instead.
2079 Renesas RL78 rl78-*-elf
2080 HP OpenVMS ia64 ia64-hp-openvms*
2082 * GDBserver supports evaluation of breakpoint conditions. When
2083 support is advertised by GDBserver, GDB may be told to send the
2084 breakpoint conditions in bytecode form to GDBserver. GDBserver
2085 will only report the breakpoint trigger to GDB when its condition
2090 set mips compression
2091 show mips compression
2092 Select the compressed ISA encoding used in functions that have no symbol
2093 information available. The encoding can be set to either of:
2096 and is updated automatically from ELF file flags if available.
2098 set breakpoint condition-evaluation
2099 show breakpoint condition-evaluation
2100 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2101 GDBserver ("target"). Default option "auto" chooses the most efficient
2103 This option can improve debugger efficiency depending on the speed of the
2107 Disable auto-loading globally.
2110 Show auto-loading setting of all kinds of auto-loaded files.
2112 set auto-load gdb-scripts on|off
2113 show auto-load gdb-scripts
2114 Control auto-loading of GDB canned sequences of commands files.
2116 set auto-load python-scripts on|off
2117 show auto-load python-scripts
2118 Control auto-loading of Python script files.
2120 set auto-load local-gdbinit on|off
2121 show auto-load local-gdbinit
2122 Control loading of init file (.gdbinit) from current directory.
2124 set auto-load libthread-db on|off
2125 show auto-load libthread-db
2126 Control auto-loading of inferior specific thread debugging shared library.
2128 set auto-load scripts-directory <dir1>[:<dir2>...]
2129 show auto-load scripts-directory
2130 Set a list of directories from which to load auto-loaded scripts.
2131 Automatically loaded Python scripts and GDB scripts are located in one
2132 of the directories listed by this option.
2133 The delimiter (':' above) may differ according to the host platform.
2135 set auto-load safe-path <dir1>[:<dir2>...]
2136 show auto-load safe-path
2137 Set a list of directories from which it is safe to auto-load files.
2138 The delimiter (':' above) may differ according to the host platform.
2140 set debug auto-load on|off
2141 show debug auto-load
2142 Control display of debugging info for auto-loading the files above.
2144 set dprintf-style gdb|call|agent
2146 Control the way in which a dynamic printf is performed; "gdb"
2147 requests a GDB printf command, while "call" causes dprintf to call a
2148 function in the inferior. "agent" requests that the target agent
2149 (such as GDBserver) do the printing.
2151 set dprintf-function <expr>
2152 show dprintf-function
2153 set dprintf-channel <expr>
2154 show dprintf-channel
2155 Set the function and optional first argument to the call when using
2156 the "call" style of dynamic printf.
2158 set disconnected-dprintf on|off
2159 show disconnected-dprintf
2160 Control whether agent-style dynamic printfs continue to be in effect
2161 after GDB disconnects.
2163 * New configure options
2165 --with-auto-load-dir
2166 Configure default value for the 'set auto-load scripts-directory'
2167 setting above. It defaults to '$debugdir:$datadir/auto-load',
2168 $debugdir representing global debugging info directories (available
2169 via 'show debug-file-directory') and $datadir representing GDB's data
2170 directory (available via 'show data-directory').
2172 --with-auto-load-safe-path
2173 Configure default value for the 'set auto-load safe-path' setting
2174 above. It defaults to the --with-auto-load-dir setting.
2176 --without-auto-load-safe-path
2177 Set 'set auto-load safe-path' to '/', effectively disabling this
2180 * New remote packets
2182 z0/z1 conditional breakpoints extension
2184 The z0/z1 breakpoint insertion packets have been extended to carry
2185 a list of conditional expressions over to the remote stub depending on the
2186 condition evaluation mode. The use of this extension can be controlled
2187 via the "set remote conditional-breakpoints-packet" command.
2191 Specify the signals which the remote stub may pass to the debugged
2192 program without GDB involvement.
2194 * New command line options
2196 --init-command=FILE, -ix Like --command, -x but execute it
2197 before loading inferior.
2198 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2199 execute it before loading inferior.
2201 *** Changes in GDB 7.4
2203 * GDB now handles ambiguous linespecs more consistently; the existing
2204 FILE:LINE support has been expanded to other types of linespecs. A
2205 breakpoint will now be set on all matching locations in all
2206 inferiors, and locations will be added or removed according to
2209 * GDB now allows you to skip uninteresting functions and files when
2210 stepping with the "skip function" and "skip file" commands.
2212 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2213 and "show remote hardware-watchpoint-length-limit". These allows to
2214 set or show the maximum length limit (in bytes) of a remote
2215 target hardware watchpoint.
2217 This allows e.g. to use "unlimited" hardware watchpoints with the
2218 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2219 watchpoints are slower than real hardware watchpoints but are
2220 significantly faster than gdb software watchpoints.
2224 ** The register_pretty_printer function in module gdb.printing now takes
2225 an optional `replace' argument. If True, the new printer replaces any
2228 ** The "maint set python print-stack on|off" command has been
2229 deprecated and will be deleted in GDB 7.5.
2230 A new command: "set python print-stack none|full|message" has
2231 replaced it. Additionally, the default for "print-stack" is
2232 now "message", which just prints the error message without
2235 ** A prompt substitution hook (prompt_hook) is now available to the
2238 ** A new Python module, gdb.prompt has been added to the GDB Python
2239 modules library. This module provides functionality for
2240 escape sequences in prompts (used by set/show
2241 extended-prompt). These escape sequences are replaced by their
2242 corresponding value.
2244 ** Python commands and convenience-functions located in
2245 'data-directory'/python/gdb/command and
2246 'data-directory'/python/gdb/function are now automatically loaded
2249 ** Blocks now provide four new attributes. global_block and
2250 static_block will return the global and static blocks
2251 respectively. is_static and is_global are boolean attributes
2252 that indicate if the block is one of those two types.
2254 ** Symbols now provide the "type" attribute, the type of the symbol.
2256 ** The "gdb.breakpoint" function has been deprecated in favor of
2259 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2260 of a function. This class is based on the "finish" command
2261 available in the CLI.
2263 ** Type objects for struct and union types now allow access to
2264 the fields using standard Python dictionary (mapping) methods.
2265 For example, "some_type['myfield']" now works, as does
2266 "some_type.items()".
2268 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2271 ** A new function, "deep_items" has been added to the gdb.types
2272 module in the GDB Python modules library. This function returns
2273 an iterator over the fields of a struct or union type. Unlike
2274 the standard Python "iteritems" method, it will recursively traverse
2275 any anonymous fields.
2279 ** "*stopped" events can report several new "reason"s, such as
2282 ** Breakpoint changes are now notified using new async records, like
2283 "=breakpoint-modified".
2285 ** New command -ada-task-info.
2287 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2288 $sdir specifies the default system locations of shared libraries.
2289 $pdir specifies the directory where the libpthread used by the application
2292 GDB no longer looks in $sdir and $pdir after it has searched the directories
2293 mentioned in libthread-db-search-path. If you want to search those
2294 directories, they must be specified in libthread-db-search-path.
2295 The default value of libthread-db-search-path on GNU/Linux and Solaris
2296 systems is now "$sdir:$pdir".
2298 $pdir is not supported by gdbserver, it is currently ignored.
2299 $sdir is supported by gdbserver.
2301 * New configure option --with-iconv-bin.
2302 When using the internationalization support like the one in the GNU C
2303 library, GDB will invoke the "iconv" program to get a list of supported
2304 character sets. If this program lives in a non-standard location, one can
2305 use this option to specify where to find it.
2307 * When natively debugging programs on PowerPC BookE processors running
2308 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2309 watchpoints, which specify a mask in addition to an address to watch.
2310 The mask specifies that some bits of an address (the bits which are
2311 reset in the mask) should be ignored when matching the address accessed
2312 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2313 section in the user manual for more details.
2315 * The new option --once causes GDBserver to stop listening for connections once
2316 the first connection is made. The listening port used by GDBserver will
2317 become available after that.
2319 * New commands "info macros" and "alias" have been added.
2321 * New function parameters suffix @entry specifies value of function parameter
2322 at the time the function got called. Entry values are available only since
2328 "!" is now an alias of the "shell" command.
2329 Note that no space is needed between "!" and SHELL COMMAND.
2333 watch EXPRESSION mask MASK_VALUE
2334 The watch command now supports the mask argument which allows creation
2335 of masked watchpoints, if the current architecture supports this feature.
2337 info auto-load-scripts [REGEXP]
2338 This command was formerly named "maintenance print section-scripts".
2339 It is now generally useful and is no longer a maintenance-only command.
2341 info macro [-all] [--] MACRO
2342 The info macro command has new options `-all' and `--'. The first for
2343 printing all definitions of a macro. The second for explicitly specifying
2344 the end of arguments and the beginning of the macro name in case the macro
2345 name starts with a hyphen.
2347 collect[/s] EXPRESSIONS
2348 The tracepoint collect command now takes an optional modifier "/s"
2349 that directs it to dereference pointer-to-character types and
2350 collect the bytes of memory up to a zero byte. The behavior is
2351 similar to what you see when you use the regular print command on a
2352 string. An optional integer following the "/s" sets a bound on the
2353 number of bytes that will be collected.
2356 The trace start command now interprets any supplied arguments as a
2357 note to be recorded with the trace run, with an effect similar to
2358 setting the variable trace-notes.
2361 The trace stop command now interprets any arguments as a note to be
2362 mentioned along with the tstatus report that the trace was stopped
2363 with a command. The effect is similar to setting the variable
2366 * Tracepoints can now be enabled and disabled at any time after a trace
2367 experiment has been started using the standard "enable" and "disable"
2368 commands. It is now possible to start a trace experiment with no enabled
2369 tracepoints; GDB will display a warning, but will allow the experiment to
2370 begin, assuming that tracepoints will be enabled as needed while the trace
2373 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2374 locations with 4-byte instructions, when they were previously
2375 limited to locations with instructions of 5 bytes or longer.
2379 set debug dwarf2-read
2380 show debug dwarf2-read
2381 Turns on or off display of debugging messages related to reading
2382 DWARF debug info. The default is off.
2384 set debug symtab-create
2385 show debug symtab-create
2386 Turns on or off display of debugging messages related to symbol table
2387 creation. The default is off.
2390 show extended-prompt
2391 Set the GDB prompt, and allow escape sequences to be inserted to
2392 display miscellaneous information (see 'help set extended-prompt'
2393 for the list of sequences). This prompt (and any information
2394 accessed through the escape sequences) is updated every time the
2395 prompt is displayed.
2397 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2398 show print entry-values
2399 Set printing of frame argument values at function entry. In some cases
2400 GDB can determine the value of function argument which was passed by the
2401 function caller, even if the value was modified inside the called function.
2403 set debug entry-values
2404 show debug entry-values
2405 Control display of debugging info for determining frame argument values at
2406 function entry and virtual tail call frames.
2408 set basenames-may-differ
2409 show basenames-may-differ
2410 Set whether a source file may have multiple base names.
2411 (A "base name" is the name of a file with the directory part removed.
2412 Example: The base name of "/home/user/hello.c" is "hello.c".)
2413 If set, GDB will canonicalize file names (e.g., expand symlinks)
2414 before comparing them. Canonicalization is an expensive operation,
2415 but it allows the same file be known by more than one base name.
2416 If not set (the default), all source files are assumed to have just
2417 one base name, and gdb will do file name comparisons more efficiently.
2423 Set a user name and notes for the current and any future trace runs.
2424 This is useful for long-running and/or disconnected traces, to
2425 inform others (or yourself) as to who is running the trace, supply
2426 contact information, or otherwise explain what is going on.
2428 set trace-stop-notes
2429 show trace-stop-notes
2430 Set a note attached to the trace run, that is displayed when the
2431 trace has been stopped by a tstop command. This is useful for
2432 instance as an explanation, if you are stopping a trace run that was
2433 started by someone else.
2435 * New remote packets
2439 Dynamically enable a tracepoint in a started trace experiment.
2443 Dynamically disable a tracepoint in a started trace experiment.
2447 Set the user and notes of the trace run.
2451 Query the current status of a tracepoint.
2455 Query the minimum length of instruction at which a fast tracepoint may
2458 * Dcache size (number of lines) and line-size are now runtime-configurable
2459 via "set dcache line" and "set dcache line-size" commands.
2463 Texas Instruments TMS320C6x tic6x-*-*
2467 Renesas RL78 rl78-*-elf
2469 *** Changes in GDB 7.3.1
2471 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2473 *** Changes in GDB 7.3
2475 * GDB has a new command: "thread find [REGEXP]".
2476 It finds the thread id whose name, target id, or thread extra info
2477 matches the given regular expression.
2479 * The "catch syscall" command now works on mips*-linux* targets.
2481 * The -data-disassemble MI command now supports modes 2 and 3 for
2482 dumping the instruction opcodes.
2484 * New command line options
2486 -data-directory DIR Specify DIR as the "data-directory".
2487 This is mostly for testing purposes.
2489 * The "maint set python auto-load on|off" command has been renamed to
2490 "set auto-load-scripts on|off".
2492 * GDB has a new command: "set directories".
2493 It is like the "dir" command except that it replaces the
2494 source path list instead of augmenting it.
2496 * GDB now understands thread names.
2498 On GNU/Linux, "info threads" will display the thread name as set by
2499 prctl or pthread_setname_np.
2501 There is also a new command, "thread name", which can be used to
2502 assign a name internally for GDB to display.
2505 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2506 has been integrated into GDB.
2510 ** The function gdb.Write now accepts an optional keyword 'stream'.
2511 This keyword, when provided, will direct the output to either
2512 stdout, stderr, or GDB's logging output.
2514 ** Parameters can now be be sub-classed in Python, and in particular
2515 you may implement the get_set_doc and get_show_doc functions.
2516 This improves how Parameter set/show documentation is processed
2517 and allows for more dynamic content.
2519 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2520 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2521 have an is_valid method.
2523 ** Breakpoints can now be sub-classed in Python, and in particular
2524 you may implement a 'stop' function that is executed each time
2525 the inferior reaches that breakpoint.
2527 ** New function gdb.lookup_global_symbol looks up a global symbol.
2529 ** GDB values in Python are now callable if the value represents a
2530 function. For example, if 'some_value' represents a function that
2531 takes two integer parameters and returns a value, you can call
2532 that function like so:
2534 result = some_value (10,20)
2536 ** Module gdb.types has been added.
2537 It contains a collection of utilities for working with gdb.Types objects:
2538 get_basic_type, has_field, make_enum_dict.
2540 ** Module gdb.printing has been added.
2541 It contains utilities for writing and registering pretty-printers.
2542 New classes: PrettyPrinter, SubPrettyPrinter,
2543 RegexpCollectionPrettyPrinter.
2544 New function: register_pretty_printer.
2546 ** New commands "info pretty-printers", "enable pretty-printer" and
2547 "disable pretty-printer" have been added.
2549 ** gdb.parameter("directories") is now available.
2551 ** New function gdb.newest_frame returns the newest frame in the
2554 ** The gdb.InferiorThread class has a new "name" attribute. This
2555 holds the thread's name.
2557 ** Python Support for Inferior events.
2558 Python scripts can add observers to be notified of events
2559 occurring in the process being debugged.
2560 The following events are currently supported:
2561 - gdb.events.cont Continue event.
2562 - gdb.events.exited Inferior exited event.
2563 - gdb.events.stop Signal received, and Breakpoint hit events.
2567 ** GDB now puts template parameters in scope when debugging in an
2568 instantiation. For example, if you have:
2570 template<int X> int func (void) { return X; }
2572 then if you step into func<5>, "print X" will show "5". This
2573 feature requires proper debuginfo support from the compiler; it
2574 was added to GCC 4.5.
2576 ** The motion commands "next", "finish", "until", and "advance" now
2577 work better when exceptions are thrown. In particular, GDB will
2578 no longer lose control of the inferior; instead, the GDB will
2579 stop the inferior at the point at which the exception is caught.
2580 This functionality requires a change in the exception handling
2581 code that was introduced in GCC 4.5.
2583 * GDB now follows GCC's rules on accessing volatile objects when
2584 reading or writing target state during expression evaluation.
2585 One notable difference to prior behavior is that "print x = 0"
2586 no longer generates a read of x; the value of the assignment is
2587 now always taken directly from the value being assigned.
2589 * GDB now has some support for using labels in the program's source in
2590 linespecs. For instance, you can use "advance label" to continue
2591 execution to a label.
2593 * GDB now has support for reading and writing a new .gdb_index
2594 section. This section holds a fast index of DWARF debugging
2595 information and can be used to greatly speed up GDB startup and
2596 operation. See the documentation for `save gdb-index' for details.
2598 * The "watch" command now accepts an optional "-location" argument.
2599 When used, this causes GDB to watch the memory referred to by the
2600 expression. Such a watchpoint is never deleted due to it going out
2603 * GDB now supports thread debugging of core dumps on GNU/Linux.
2605 GDB now activates thread debugging using the libthread_db library
2606 when debugging GNU/Linux core dumps, similarly to when debugging
2607 live processes. As a result, when debugging a core dump file, GDB
2608 is now able to display pthread_t ids of threads. For example, "info
2609 threads" shows the same output as when debugging the process when it
2610 was live. In earlier releases, you'd see something like this:
2613 * 1 LWP 6780 main () at main.c:10
2615 While now you see this:
2618 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2620 It is also now possible to inspect TLS variables when debugging core
2623 When debugging a core dump generated on a machine other than the one
2624 used to run GDB, you may need to point GDB at the correct
2625 libthread_db library with the "set libthread-db-search-path"
2626 command. See the user manual for more details on this command.
2628 * When natively debugging programs on PowerPC BookE processors running
2629 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2630 which stop execution of the inferior whenever it executes an instruction
2631 at any address within the specified range. See the "PowerPC Embedded"
2632 section in the user manual for more details.
2634 * New features in the GDB remote stub, GDBserver
2636 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2637 and i686 LynxOS (version 5.x).
2639 ** GDBserver is now supported on Blackfin Linux.
2641 * New native configurations
2643 ia64 HP-UX ia64-*-hpux*
2647 Analog Devices, Inc. Blackfin Processor bfin-*
2649 * Ada task switching is now supported on sparc-elf targets when
2650 debugging a program using the Ravenscar Profile. For more information,
2651 see the "Tasking Support when using the Ravenscar Profile" section
2652 in the GDB user manual.
2654 * Guile support was removed.
2656 * New features in the GNU simulator
2658 ** The --map-info flag lists all known core mappings.
2660 ** CFI flashes may be simulated via the "cfi" device.
2662 *** Changes in GDB 7.2
2664 * Shared library support for remote targets by default
2666 When GDB is configured for a generic, non-OS specific target, like
2667 for example, --target=arm-eabi or one of the many *-*-elf targets,
2668 GDB now queries remote stubs for loaded shared libraries using the
2669 `qXfer:libraries:read' packet. Previously, shared library support
2670 was always disabled for such configurations.
2674 ** Argument Dependent Lookup (ADL)
2676 In C++ ADL lookup directs function search to the namespaces of its
2677 arguments even if the namespace has not been imported.
2687 Here the compiler will search for `foo' in the namespace of 'b'
2688 and find A::foo. GDB now supports this. This construct is commonly
2689 used in the Standard Template Library for operators.
2691 ** Improved User Defined Operator Support
2693 In addition to member operators, GDB now supports lookup of operators
2694 defined in a namespace and imported with a `using' directive, operators
2695 defined in the global scope, operators imported implicitly from an
2696 anonymous namespace, and the ADL operators mentioned in the previous
2698 GDB now also supports proper overload resolution for all the previously
2699 mentioned flavors of operators.
2701 ** static const class members
2703 Printing of static const class members that are initialized in the
2704 class definition has been fixed.
2706 * Windows Thread Information Block access.
2708 On Windows targets, GDB now supports displaying the Windows Thread
2709 Information Block (TIB) structure. This structure is visible either
2710 by using the new command `info w32 thread-information-block' or, by
2711 dereferencing the new convenience variable named `$_tlb', a
2712 thread-specific pointer to the TIB. This feature is also supported
2713 when remote debugging using GDBserver.
2715 * Static tracepoints
2717 Static tracepoints are calls in the user program into a tracing
2718 library. One such library is a port of the LTTng kernel tracer to
2719 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2720 When debugging with GDBserver, GDB now supports combining the GDB
2721 tracepoint machinery with such libraries. For example: the user can
2722 use GDB to probe a static tracepoint marker (a call from the user
2723 program into the tracing library) with the new "strace" command (see
2724 "New commands" below). This creates a "static tracepoint" in the
2725 breakpoint list, that can be manipulated with the same feature set
2726 as fast and regular tracepoints. E.g., collect registers, local and
2727 global variables, collect trace state variables, and define
2728 tracepoint conditions. In addition, the user can collect extra
2729 static tracepoint marker specific data, by collecting the new
2730 $_sdata internal variable. When analyzing the trace buffer, you can
2731 inspect $_sdata like any other variable available to GDB. For more
2732 information, see the "Tracepoints" chapter in GDB user manual. New
2733 remote packets have been defined to support static tracepoints, see
2734 the "New remote packets" section below.
2736 * Better reconstruction of tracepoints after disconnected tracing
2738 GDB will attempt to download the original source form of tracepoint
2739 definitions when starting a trace run, and then will upload these
2740 upon reconnection to the target, resulting in a more accurate
2741 reconstruction of the tracepoints that are in use on the target.
2745 You can now exercise direct control over the ways that GDB can
2746 affect your program. For instance, you can disallow the setting of
2747 breakpoints, so that the program can run continuously (assuming
2748 non-stop mode). In addition, the "observer" variable is available
2749 to switch all of the different controls; in observer mode, GDB
2750 cannot affect the target's behavior at all, which is useful for
2751 tasks like diagnosing live systems in the field.
2753 * The new convenience variable $_thread holds the number of the
2756 * New remote packets
2760 Return the address of the Windows Thread Information Block of a given thread.
2764 In response to several of the tracepoint packets, the target may now
2765 also respond with a number of intermediate `qRelocInsn' request
2766 packets before the final result packet, to have GDB handle
2767 relocating an instruction to execute at a different address. This
2768 is particularly useful for stubs that support fast tracepoints. GDB
2769 reports support for this feature in the qSupported packet.
2773 List static tracepoint markers in the target program.
2777 List static tracepoint markers at a given address in the target
2780 qXfer:statictrace:read
2782 Read the static trace data collected (by a `collect $_sdata'
2783 tracepoint action). The remote stub reports support for this packet
2784 to gdb's qSupported query.
2788 Send the current settings of GDB's permission flags.
2792 Send part of the source (textual) form of a tracepoint definition,
2793 which includes location, conditional, and action list.
2795 * The source command now accepts a -s option to force searching for the
2796 script in the source search path even if the script name specifies
2799 * New features in the GDB remote stub, GDBserver
2801 - GDBserver now support tracepoints (including fast tracepoints, and
2802 static tracepoints). The feature is currently supported by the
2803 i386-linux and amd64-linux builds. See the "Tracepoints support
2804 in gdbserver" section in the manual for more information.
2806 GDBserver JIT compiles the tracepoint's conditional agent
2807 expression bytecode into native code whenever possible for low
2808 overhead dynamic tracepoints conditionals. For such tracepoints,
2809 an expression that examines program state is evaluated when the
2810 tracepoint is reached, in order to determine whether to capture
2811 trace data. If the condition is simple and false, processing the
2812 tracepoint finishes very quickly and no data is gathered.
2814 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2815 for static tracepoints support.
2817 - GDBserver now supports x86_64 Windows 64-bit debugging.
2819 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2820 it understands register description.
2822 * The --batch flag now disables pagination and queries.
2824 * X86 general purpose registers
2826 GDB now supports reading/writing byte, word and double-word x86
2827 general purpose registers directly. This means you can use, say,
2828 $ah or $ax to refer, respectively, to the byte register AH and
2829 16-bit word register AX that are actually portions of the 32-bit
2830 register EAX or 64-bit register RAX.
2832 * The `commands' command now accepts a range of breakpoints to modify.
2833 A plain `commands' following a command that creates multiple
2834 breakpoints affects all the breakpoints set by that command. This
2835 applies to breakpoints set by `rbreak', and also applies when a
2836 single `break' command creates multiple breakpoints (e.g.,
2837 breakpoints on overloaded c++ functions).
2839 * The `rbreak' command now accepts a filename specification as part of
2840 its argument, limiting the functions selected by the regex to those
2841 in the specified file.
2843 * Support for remote debugging Windows and SymbianOS shared libraries
2844 from Unix hosts has been improved. Non Windows GDB builds now can
2845 understand target reported file names that follow MS-DOS based file
2846 system semantics, such as file names that include drive letters and
2847 use the backslash character as directory separator. This makes it
2848 possible to transparently use the "set sysroot" and "set
2849 solib-search-path" on Unix hosts to point as host copies of the
2850 target's shared libraries. See the new command "set
2851 target-file-system-kind" described below, and the "Commands to
2852 specify files" section in the user manual for more information.
2856 eval template, expressions...
2857 Convert the values of one or more expressions under the control
2858 of the string template to a command line, and call it.
2860 set target-file-system-kind unix|dos-based|auto
2861 show target-file-system-kind
2862 Set or show the assumed file system kind for target reported file
2865 save breakpoints <filename>
2866 Save all current breakpoint definitions to a file suitable for use
2867 in a later debugging session. To read the saved breakpoint
2868 definitions, use the `source' command.
2870 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2873 info static-tracepoint-markers
2874 Display information about static tracepoint markers in the target.
2876 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2877 Define a static tracepoint by probing a marker at the given
2878 function, line, address, or marker ID.
2882 Enable and disable observer mode.
2884 set may-write-registers on|off
2885 set may-write-memory on|off
2886 set may-insert-breakpoints on|off
2887 set may-insert-tracepoints on|off
2888 set may-insert-fast-tracepoints on|off
2889 set may-interrupt on|off
2890 Set individual permissions for GDB effects on the target. Note that
2891 some of these settings can have undesirable or surprising
2892 consequences, particularly when changed in the middle of a session.
2893 For instance, disabling the writing of memory can prevent
2894 breakpoints from being inserted, cause single-stepping to fail, or
2895 even crash your program, if you disable after breakpoints have been
2896 inserted. However, GDB should not crash.
2898 set record memory-query on|off
2899 show record memory-query
2900 Control whether to stop the inferior if memory changes caused
2901 by an instruction cannot be recorded.
2906 The disassemble command now supports "start,+length" form of two arguments.
2910 ** GDB now provides a new directory location, called the python directory,
2911 where Python scripts written for GDB can be installed. The location
2912 of that directory is <data-directory>/python, where <data-directory>
2913 is the GDB data directory. For more details, see section `Scripting
2914 GDB using Python' in the manual.
2916 ** The GDB Python API now has access to breakpoints, symbols, symbol
2917 tables, program spaces, inferiors, threads and frame's code blocks.
2918 Additionally, GDB Parameters can now be created from the API, and
2919 manipulated via set/show in the CLI.
2921 ** New functions gdb.target_charset, gdb.target_wide_charset,
2922 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2924 ** New exception gdb.GdbError.
2926 ** Pretty-printers are now also looked up in the current program space.
2928 ** Pretty-printers can now be individually enabled and disabled.
2930 ** GDB now looks for names of Python scripts to auto-load in a
2931 special section named `.debug_gdb_scripts', in addition to looking
2932 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2934 * Tracepoint actions were unified with breakpoint commands. In particular,
2935 there are no longer differences in "info break" output for breakpoints and
2936 tracepoints and the "commands" command can be used for both tracepoints and
2937 regular breakpoints.
2941 ARM Symbian arm*-*-symbianelf*
2943 * D language support.
2944 GDB now supports debugging programs written in the D programming
2947 * GDB now supports the extended ptrace interface for PowerPC which is
2948 available since Linux kernel version 2.6.34. This automatically enables
2949 any hardware breakpoints and additional hardware watchpoints available in
2950 the processor. The old ptrace interface exposes just one hardware
2951 watchpoint and no hardware breakpoints.
2953 * GDB is now able to use the Data Value Compare (DVC) register available on
2954 embedded PowerPC processors to implement in hardware simple watchpoint
2955 conditions of the form:
2957 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2959 This works in native GDB running on Linux kernels with the extended ptrace
2960 interface mentioned above.
2962 *** Changes in GDB 7.1
2966 ** Namespace Support
2968 GDB now supports importing of namespaces in C++. This enables the
2969 user to inspect variables from imported namespaces. Support for
2970 namepace aliasing has also been added. So, if a namespace is
2971 aliased in the current scope (e.g. namepace C=A; ) the user can
2972 print variables using the alias (e.g. (gdb) print C::x).
2976 All known bugs relating to the printing of virtual base class were
2977 fixed. It is now possible to call overloaded static methods using a
2982 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2983 and reinterpret_cast<> are now handled by the C++ expression parser.
2987 Xilinx MicroBlaze microblaze-*-*
2992 Xilinx MicroBlaze microblaze
2995 * Multi-program debugging.
2997 GDB now has support for multi-program (a.k.a. multi-executable or
2998 multi-exec) debugging. This allows for debugging multiple inferiors
2999 simultaneously each running a different program under the same GDB
3000 session. See "Debugging Multiple Inferiors and Programs" in the
3001 manual for more information. This implied some user visible changes
3002 in the multi-inferior support. For example, "info inferiors" now
3003 lists inferiors that are not running yet or that have exited
3004 already. See also "New commands" and "New options" below.
3006 * New tracing features
3008 GDB's tracepoint facility now includes several new features:
3010 ** Trace state variables
3012 GDB tracepoints now include support for trace state variables, which
3013 are variables managed by the target agent during a tracing
3014 experiment. They are useful for tracepoints that trigger each
3015 other, so for instance one tracepoint can count hits in a variable,
3016 and then a second tracepoint has a condition that is true when the
3017 count reaches a particular value. Trace state variables share the
3018 $-syntax of GDB convenience variables, and can appear in both
3019 tracepoint actions and condition expressions. Use the "tvariable"
3020 command to create, and "info tvariables" to view; see "Trace State
3021 Variables" in the manual for more detail.
3025 GDB now includes an option for defining fast tracepoints, which
3026 targets may implement more efficiently, such as by installing a jump
3027 into the target agent rather than a trap instruction. The resulting
3028 speedup can be by two orders of magnitude or more, although the
3029 tradeoff is that some program locations on some target architectures
3030 might not allow fast tracepoint installation, for instance if the
3031 instruction to be replaced is shorter than the jump. To request a
3032 fast tracepoint, use the "ftrace" command, with syntax identical to
3033 the regular trace command.
3035 ** Disconnected tracing
3037 It is now possible to detach GDB from the target while it is running
3038 a trace experiment, then reconnect later to see how the experiment
3039 is going. In addition, a new variable disconnected-tracing lets you
3040 tell the target agent whether to continue running a trace if the
3041 connection is lost unexpectedly.
3045 GDB now has the ability to save the trace buffer into a file, and
3046 then use that file as a target, similarly to you can do with
3047 corefiles. You can select trace frames, print data that was
3048 collected in them, and use tstatus to display the state of the
3049 tracing run at the moment that it was saved. To create a trace
3050 file, use "tsave <filename>", and to use it, do "target tfile
3053 ** Circular trace buffer
3055 You can ask the target agent to handle the trace buffer as a
3056 circular buffer, discarding the oldest trace frames to make room for
3057 newer ones, by setting circular-trace-buffer to on. This feature may
3058 not be available for all target agents.
3063 The disassemble command, when invoked with two arguments, now requires
3064 the arguments to be comma-separated.
3067 The info variables command now displays variable definitions. Files
3068 which only declare a variable are not shown.
3071 The source command is now capable of sourcing Python scripts.
3072 This feature is dependent on the debugger being build with Python
3075 Related to this enhancement is also the introduction of a new command
3076 "set script-extension" (see below).
3078 * New commands (for set/show, see "New options" below)
3080 record save [<FILENAME>]
3081 Save a file (in core file format) containing the process record
3082 execution log for replay debugging at a later time.
3084 record restore <FILENAME>
3085 Restore the process record execution log that was saved at an
3086 earlier time, for replay debugging.
3088 add-inferior [-copies <N>] [-exec <FILENAME>]
3091 clone-inferior [-copies <N>] [ID]
3092 Make a new inferior ready to execute the same program another
3093 inferior has loaded.
3098 maint info program-spaces
3099 List the program spaces loaded into GDB.
3101 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3102 show remote interrupt-sequence
3103 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3104 as the sequence to the remote target in order to interrupt the execution.
3105 Ctrl-C is a default. Some system prefers BREAK which is high level of
3106 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3107 Magic SysRq g. It is BREAK signal and character 'g'.
3109 set remote interrupt-on-connect [on | off]
3110 show remote interrupt-on-connect
3111 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3112 remote target when gdb connects to it. This is needed when you debug
3115 set remotebreak [on | off]
3117 Deprecated. Use "set/show remote interrupt-sequence" instead.
3119 tvariable $NAME [ = EXP ]
3120 Create or modify a trace state variable.
3123 List trace state variables and their values.
3125 delete tvariable $NAME ...
3126 Delete one or more trace state variables.
3129 Evaluate the given expressions without collecting anything into the
3130 trace buffer. (Valid in tracepoint actions only.)
3132 ftrace FN / FILE:LINE / *ADDR
3133 Define a fast tracepoint at the given function, line, or address.
3135 * New expression syntax
3137 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3138 GDB now parses 0b101010 identically with 42.
3142 set follow-exec-mode new|same
3143 show follow-exec-mode
3144 Control whether GDB reuses the same inferior across an exec call or
3145 creates a new one. This is useful to be able to restart the old
3146 executable after the inferior having done an exec call.
3148 set default-collect EXPR, ...
3149 show default-collect
3150 Define a list of expressions to be collected at each tracepoint.
3151 This is a useful way to ensure essential items are not overlooked,
3152 such as registers or a critical global variable.
3154 set disconnected-tracing
3155 show disconnected-tracing
3156 If set to 1, the target is instructed to continue tracing if it
3157 loses its connection to GDB. If 0, the target is to stop tracing
3160 set circular-trace-buffer
3161 show circular-trace-buffer
3162 If set to on, the target is instructed to use a circular trace buffer
3163 and discard the oldest trace frames instead of stopping the trace due
3164 to a full trace buffer. If set to off, the trace stops when the buffer
3165 fills up. Some targets may not support this.
3167 set script-extension off|soft|strict
3168 show script-extension
3169 If set to "off", the debugger does not perform any script language
3170 recognition, and all sourced files are assumed to be GDB scripts.
3171 If set to "soft" (the default), files are sourced according to
3172 filename extension, falling back to GDB scripts if the first
3174 If set to "strict", files are sourced according to filename extension.
3176 set ada trust-PAD-over-XVS on|off
3177 show ada trust-PAD-over-XVS
3178 If off, activate a workaround against a bug in the debugging information
3179 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3180 the GCC sources for more information about the GNAT encoding and
3181 PAD types in particular). It is always safe to set this option to
3182 off, but this introduces a slight performance penalty. The default
3185 * Python API Improvements
3187 ** GDB provides the new class gdb.LazyString. This is useful in
3188 some pretty-printing cases. The new method gdb.Value.lazy_string
3189 provides a simple way to create objects of this type.
3191 ** The fields returned by gdb.Type.fields now have an
3192 `is_base_class' attribute.
3194 ** The new method gdb.Type.range returns the range of an array type.
3196 ** The new method gdb.parse_and_eval can be used to parse and
3197 evaluate an expression.
3199 * New remote packets
3202 Define a trace state variable.
3205 Get the current value of a trace state variable.
3208 Set desired tracing behavior upon disconnection.
3211 Set the trace buffer to be linear or circular.
3214 Get data about the tracepoints currently in use.
3218 Process record now works correctly with hardware watchpoints.
3220 Multiple bug fixes have been made to the mips-irix port, making it
3221 much more reliable. In particular:
3222 - Debugging threaded applications is now possible again. Previously,
3223 GDB would hang while starting the program, or while waiting for
3224 the program to stop at a breakpoint.
3225 - Attaching to a running process no longer hangs.
3226 - An error occurring while loading a core file has been fixed.
3227 - Changing the value of the PC register now works again. This fixes
3228 problems observed when using the "jump" command, or when calling
3229 a function from GDB, or even when assigning a new value to $pc.
3230 - With the "finish" and "return" commands, the return value for functions
3231 returning a small array is now correctly printed.
3232 - It is now possible to break on shared library code which gets executed
3233 during a shared library init phase (code executed while executing
3234 their .init section). Previously, the breakpoint would have no effect.
3235 - GDB is now able to backtrace through the signal handler for
3236 non-threaded programs.
3238 PIE (Position Independent Executable) programs debugging is now supported.
3239 This includes debugging execution of PIC (Position Independent Code) shared
3240 libraries although for that, it should be possible to run such libraries as an
3243 *** Changes in GDB 7.0
3245 * GDB now has an interface for JIT compilation. Applications that
3246 dynamically generate code can create symbol files in memory and register
3247 them with GDB. For users, the feature should work transparently, and
3248 for JIT developers, the interface is documented in the GDB manual in the
3249 "JIT Compilation Interface" chapter.
3251 * Tracepoints may now be conditional. The syntax is as for
3252 breakpoints; either an "if" clause appended to the "trace" command,
3253 or the "condition" command is available. GDB sends the condition to
3254 the target for evaluation using the same bytecode format as is used
3255 for tracepoint actions.
3257 * The disassemble command now supports: an optional /r modifier, print the
3258 raw instructions in hex as well as in symbolic form, and an optional /m
3259 modifier to print mixed source+assembly.
3261 * Process record and replay
3263 In a architecture environment that supports ``process record and
3264 replay'', ``process record and replay'' target can record a log of
3265 the process execution, and replay it with both forward and reverse
3268 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3269 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3270 set execution-direction {forward|reverse}, for targets that support
3273 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3274 feature is available with a native GDB running on kernel version
3277 * GDB now has support for multi-byte and wide character sets on the
3278 target. Strings whose character type is wchar_t, char16_t, or
3279 char32_t are now correctly printed. GDB supports wide- and unicode-
3280 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3281 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3282 `printf'. This feature requires iconv to work properly; if your
3283 system does not have a working iconv, GDB can use GNU libiconv. See
3284 the installation instructions for more information.
3286 * GDB now supports automatic retrieval of shared library files from
3287 remote targets. To use this feature, specify a system root that begins
3288 with the `remote:' prefix, either via the `set sysroot' command or via
3289 the `--with-sysroot' configure-time option.
3291 * "info sharedlibrary" now takes an optional regex of libraries to show,
3292 and it now reports if a shared library has no debugging information.
3294 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3295 now complete on file names.
3297 * When completing in expressions, gdb will attempt to limit
3298 completions to allowable structure or union fields, where appropriate.
3299 For instance, consider:
3301 # struct example { int f1; double f2; };
3302 # struct example variable;
3305 If the user types TAB at the end of this command line, the available
3306 completions will be "f1" and "f2".
3308 * Inlined functions are now supported. They show up in backtraces, and
3309 the "step", "next", and "finish" commands handle them automatically.
3311 * GDB now supports the token-splicing (##) and stringification (#)
3312 operators when expanding macros. It also supports variable-arity
3315 * GDB now supports inspecting extra signal information, exported by
3316 the new $_siginfo convenience variable. The feature is currently
3317 implemented on linux ARM, i386 and amd64.
3319 * GDB can now display the VFP floating point registers and NEON vector
3320 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3321 can provide these registers (requires Linux 2.6.30 or later). Remote
3322 and simulator targets may also provide them.
3324 * New remote packets
3327 Search memory for a sequence of bytes.
3330 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3331 operation over reliable transport links. Use of this packet is
3332 controlled by the `set remote noack-packet' command.
3335 Kill the process with the specified process ID. Use this in preference
3336 to `k' when multiprocess protocol extensions are supported.
3339 Obtains additional operating system information
3343 Read or write additional signal information.
3345 * Removed remote protocol undocumented extension
3347 An undocumented extension to the remote protocol's `S' stop reply
3348 packet that permited the stub to pass a process id was removed.
3349 Remote servers should use the `T' stop reply packet instead.
3351 * GDB now supports multiple function calling conventions according to the
3352 DWARF-2 DW_AT_calling_convention function attribute.
3354 * The SH target utilizes the aforementioned change to distinguish between gcc
3355 and Renesas calling convention. It also adds the new CLI commands
3356 `set/show sh calling-convention'.
3358 * GDB can now read compressed debug sections, as produced by GNU gold
3359 with the --compress-debug-sections=zlib flag.
3361 * 64-bit core files are now supported on AIX.
3363 * Thread switching is now supported on Tru64.
3365 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3366 which will be allocated using malloc later in program execution.
3368 * The qXfer:libraries:read remote procotol packet now allows passing a
3369 list of section offsets.
3371 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3372 conditions handling signals delivered during attach or thread creation
3373 have also been fixed.
3375 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3376 From the user's standpoint, all unqualified instances of True and False
3377 are treated as the standard definitions, regardless of context.
3379 * GDB now parses C++ symbol and type names more flexibly. For
3382 template<typename T> class C { };
3385 GDB will now correctly handle all of:
3387 ptype C<char const *>
3388 ptype C<char const*>
3389 ptype C<const char *>
3390 ptype C<const char*>
3392 * New features in the GDB remote stub, gdbserver
3394 - The "--wrapper" command-line argument tells gdbserver to use a
3395 wrapper program to launch programs for debugging.
3397 - On PowerPC and S/390 targets, it is now possible to use a single
3398 gdbserver executable to debug both 32-bit and 64-bit programs.
3399 (This requires gdbserver itself to be built as a 64-bit executable.)
3401 - gdbserver uses the new noack protocol mode for TCP connections to
3402 reduce communications latency, if also supported and enabled in GDB.
3404 - Support for the sparc64-linux-gnu target is now included in
3407 - The amd64-linux build of gdbserver now supports debugging both
3408 32-bit and 64-bit programs.
3410 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3411 now support hardware watchpoints, and will use them automatically
3416 GDB now has support for scripting using Python. Whether this is
3417 available is determined at configure time.
3419 New GDB commands can now be written in Python.
3421 * Ada tasking support
3423 Ada tasks can now be inspected in GDB. The following commands have
3427 Print the list of Ada tasks.
3429 Print detailed information about task number N.
3431 Print the task number of the current task.
3433 Switch the context of debugging to task number N.
3435 * Support for user-defined prefixed commands. The "define" command can
3436 add new commands to existing prefixes, e.g. "target".
3438 * Multi-inferior, multi-process debugging.
3440 GDB now has generalized support for multi-inferior debugging. See
3441 "Debugging Multiple Inferiors" in the manual for more information.
3442 Although availability still depends on target support, the command
3443 set is more uniform now. The GNU/Linux specific multi-forks support
3444 has been migrated to this new framework. This implied some user
3445 visible changes; see "New commands" and also "Removed commands"
3448 * Target descriptions can now describe the target OS ABI. See the
3449 "Target Description Format" section in the user manual for more
3452 * Target descriptions can now describe "compatible" architectures
3453 to indicate that the target can execute applications for a different
3454 architecture in addition to those for the main target architecture.
3455 See the "Target Description Format" section in the user manual for
3458 * Multi-architecture debugging.
3460 GDB now includes general supports for debugging applications on
3461 hybrid systems that use more than one single processor architecture
3462 at the same time. Each such hybrid architecture still requires
3463 specific support to be added. The only hybrid architecture supported
3464 in this version of GDB is the Cell Broadband Engine.
3466 * GDB now supports integrated debugging of Cell/B.E. applications that
3467 use both the PPU and SPU architectures. To enable support for hybrid
3468 Cell/B.E. debugging, you need to configure GDB to support both the
3469 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3470 --enable-targets configure option.
3472 * Non-stop mode debugging.
3474 For some targets, GDB now supports an optional mode of operation in
3475 which you can examine stopped threads while other threads continue
3476 to execute freely. This is referred to as non-stop mode, with the
3477 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3478 section in the user manual for more information.
3480 To be able to support remote non-stop debugging, a remote stub needs
3481 to implement the non-stop mode remote protocol extensions, as
3482 described in the "Remote Non-Stop" section of the user manual. The
3483 GDB remote stub, gdbserver, has been adjusted to support these
3484 extensions on linux targets.
3486 * New commands (for set/show, see "New options" below)
3488 catch syscall [NAME(S) | NUMBER(S)]
3489 Catch system calls. Arguments, which should be names of system
3490 calls or their numbers, mean catch only those syscalls. Without
3491 arguments, every syscall will be caught. When the inferior issues
3492 any of the specified syscalls, GDB will stop and announce the system
3493 call, both when it is called and when its call returns. This
3494 feature is currently available with a native GDB running on the
3495 Linux Kernel, under the following architectures: x86, x86_64,
3496 PowerPC and PowerPC64.
3498 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3500 Search memory for a sequence of bytes.
3502 maint set python print-stack
3503 maint show python print-stack
3504 Show a stack trace when an error is encountered in a Python script.
3507 Invoke CODE by passing it to the Python interpreter.
3512 These allow macros to be defined, undefined, and listed
3516 Show operating system information about processes.
3519 List the inferiors currently under GDB's control.
3522 Switch focus to inferior number NUM.
3525 Detach from inferior number NUM.
3528 Kill inferior number NUM.
3532 set spu stop-on-load
3533 show spu stop-on-load
3534 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3536 set spu auto-flush-cache
3537 show spu auto-flush-cache
3538 Control whether to automatically flush the software-managed cache
3539 during Cell/B.E. debugging.
3541 set sh calling-convention
3542 show sh calling-convention
3543 Control the calling convention used when calling SH target functions.
3546 show debug timestamp
3547 Control display of timestamps with GDB debugging output.
3549 set disassemble-next-line
3550 show disassemble-next-line
3551 Control display of disassembled source lines or instructions when
3554 set remote noack-packet
3555 show remote noack-packet
3556 Set/show the use of remote protocol QStartNoAckMode packet. See above
3557 under "New remote packets."
3559 set remote query-attached-packet
3560 show remote query-attached-packet
3561 Control use of remote protocol `qAttached' (query-attached) packet.
3563 set remote read-siginfo-object
3564 show remote read-siginfo-object
3565 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3568 set remote write-siginfo-object
3569 show remote write-siginfo-object
3570 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3573 set remote reverse-continue
3574 show remote reverse-continue
3575 Control use of remote protocol 'bc' (reverse-continue) packet.
3577 set remote reverse-step
3578 show remote reverse-step
3579 Control use of remote protocol 'bs' (reverse-step) packet.
3581 set displaced-stepping
3582 show displaced-stepping
3583 Control displaced stepping mode. Displaced stepping is a way to
3584 single-step over breakpoints without removing them from the debuggee.
3585 Also known as "out-of-line single-stepping".
3588 show debug displaced
3589 Control display of debugging info for displaced stepping.
3591 maint set internal-error
3592 maint show internal-error
3593 Control what GDB does when an internal error is detected.
3595 maint set internal-warning
3596 maint show internal-warning
3597 Control what GDB does when an internal warning is detected.
3602 Use a wrapper program to launch programs for debugging.
3604 set multiple-symbols (all|ask|cancel)
3605 show multiple-symbols
3606 The value of this variable can be changed to adjust the debugger behavior
3607 when an expression or a breakpoint location contains an ambiguous symbol
3608 name (an overloaded function name, for instance).
3610 set breakpoint always-inserted
3611 show breakpoint always-inserted
3612 Keep breakpoints always inserted in the target, as opposed to inserting
3613 them when resuming the target, and removing them when the target stops.
3614 This option can improve debugger performance on slow remote targets.
3616 set arm fallback-mode (arm|thumb|auto)
3617 show arm fallback-mode
3618 set arm force-mode (arm|thumb|auto)
3620 These commands control how ARM GDB determines whether instructions
3621 are ARM or Thumb. The default for both settings is auto, which uses
3622 the current CPSR value for instructions without symbols; previous
3623 versions of GDB behaved as if "set arm fallback-mode arm".
3625 set disable-randomization
3626 show disable-randomization
3627 Standalone programs run with the virtual address space randomization enabled
3628 by default on some platforms. This option keeps the addresses stable across
3629 multiple debugging sessions.
3633 Control whether other threads are stopped or not when some thread hits
3638 Requests that asynchronous execution is enabled in the target, if available.
3639 In this case, it's possible to resume target in the background, and interact
3640 with GDB while the target is running. "show target-async" displays the
3641 current state of asynchronous execution of the target.
3643 set target-wide-charset
3644 show target-wide-charset
3645 The target-wide-charset is the name of the character set that GDB
3646 uses when printing characters whose type is wchar_t.
3648 set tcp auto-retry (on|off)
3650 set tcp connect-timeout
3651 show tcp connect-timeout
3652 These commands allow GDB to retry failed TCP connections to a remote stub
3653 with a specified timeout period; this is useful if the stub is launched
3654 in parallel with GDB but may not be ready to accept connections immediately.
3656 set libthread-db-search-path
3657 show libthread-db-search-path
3658 Control list of directories which GDB will search for appropriate
3661 set schedule-multiple (on|off)
3662 show schedule-multiple
3663 Allow GDB to resume all threads of all processes or only threads of
3664 the current process.
3668 Use more aggressive caching for accesses to the stack. This improves
3669 performance of remote debugging (particularly backtraces) without
3670 affecting correctness.
3672 set interactive-mode (on|off|auto)
3673 show interactive-mode
3674 Control whether GDB runs in interactive mode (on) or not (off).
3675 When in interactive mode, GDB waits for the user to answer all
3676 queries. Otherwise, GDB does not wait and assumes the default
3677 answer. When set to auto (the default), GDB determines which
3678 mode to use based on the stdin settings.
3683 For program forks, this is replaced by the new more generic `info
3684 inferiors' command. To list checkpoints, you can still use the
3685 `info checkpoints' command, which was an alias for the `info forks'
3689 Replaced by the new `inferior' command. To switch between
3690 checkpoints, you can still use the `restart' command, which was an
3691 alias for the `fork' command.
3694 This is removed, since some targets don't have a notion of
3695 processes. To switch between processes, you can still use the
3696 `inferior' command using GDB's own inferior number.
3699 For program forks, this is replaced by the new more generic `kill
3700 inferior' command. To delete a checkpoint, you can still use the
3701 `delete checkpoint' command, which was an alias for the `delete
3705 For program forks, this is replaced by the new more generic `detach
3706 inferior' command. To detach a checkpoint, you can still use the
3707 `detach checkpoint' command, which was an alias for the `detach
3710 * New native configurations
3712 x86/x86_64 Darwin i[34567]86-*-darwin*
3714 x86_64 MinGW x86_64-*-mingw*
3718 Lattice Mico32 lm32-*
3719 x86 DICOS i[34567]86-*-dicos*
3720 x86_64 DICOS x86_64-*-dicos*
3723 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3724 (mingw32ce) debugging.
3730 These commands were actually not implemented on any target.
3732 *** Changes in GDB 6.8
3734 * New native configurations
3736 NetBSD/hppa hppa*-*netbsd*
3737 Xtensa GNU/Linux xtensa*-*-linux*
3741 NetBSD/hppa hppa*-*-netbsd*
3742 Xtensa GNU/Lunux xtensa*-*-linux*
3744 * Change in command line behavior -- corefiles vs. process ids.
3746 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3747 attaching to process NUMBER fails, GDB no longer attempts to open a
3748 core file named NUMBER. Attaching to a program using the -c option
3749 is no longer supported. Instead, use the '-p' or '--pid' options.
3751 * GDB can now be built as a native debugger for debugging Windows x86
3752 (mingw32) Portable Executable (PE) programs.
3754 * Pending breakpoints no longer change their number when their address
3757 * GDB now supports breakpoints with multiple locations,
3758 including breakpoints on C++ constructors, inside C++ templates,
3759 and in inlined functions.
3761 * GDB's ability to debug optimized code has been improved. GDB more
3762 accurately identifies function bodies and lexical blocks that occupy
3763 more than one contiguous range of addresses.
3765 * Target descriptions can now describe registers for PowerPC.
3767 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3768 registers on PowerPC targets.
3770 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3771 targets even when the libthread_db library is not available.
3773 * The GDB remote stub, gdbserver, now supports the new file transfer
3774 commands (remote put, remote get, and remote delete).
3776 * The GDB remote stub, gdbserver, now supports run and attach in
3777 extended-remote mode.
3779 * hppa*64*-*-hpux11* target broken
3780 The debugger is unable to start a program and fails with the following
3781 error: "Error trying to get information about dynamic linker".
3782 The gdb-6.7 release is also affected.
3784 * GDB now supports the --enable-targets= configure option to allow
3785 building a single GDB executable that supports multiple remote
3786 target architectures.
3788 * GDB now supports debugging C and C++ programs which use the
3789 Decimal Floating Point extension. In addition, the PowerPC target
3790 now has a set of pseudo-registers to inspect decimal float values
3791 stored in two consecutive float registers.
3793 * The -break-insert MI command can optionally create pending
3796 * Improved support for debugging Ada
3797 Many improvements to the Ada language support have been made. These
3799 - Better support for Ada2005 interface types
3800 - Improved handling of arrays and slices in general
3801 - Better support for Taft-amendment types
3802 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3804 - Improved command completion in Ada
3807 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3812 set print frame-arguments (all|scalars|none)
3813 show print frame-arguments
3814 The value of this variable can be changed to control which argument
3815 values should be printed by the debugger when displaying a frame.
3820 Transfer files to and from a remote target, and delete remote files.
3827 Transfer files to and from a remote target, and delete remote files.
3829 * New remote packets
3836 Open, close, read, write, and delete files on the remote system.
3839 Attach to an existing process on the remote system, in extended-remote
3843 Run a new process on the remote system, in extended-remote mode.
3845 *** Changes in GDB 6.7
3847 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3848 bfd, libiberty and opcodes, as revealed by static analysis donated by
3849 Coverity, Inc. (http://scan.coverity.com).
3851 * When looking up multiply-defined global symbols, GDB will now prefer the
3852 symbol definition in the current shared library if it was built using the
3853 -Bsymbolic linker option.
3855 * When the Text User Interface (TUI) is not configured, GDB will now
3856 recognize the -tui command-line option and print a message that the TUI
3859 * The GDB remote stub, gdbserver, now has lower overhead for high
3860 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3862 * GDB for MIPS targets now autodetects whether a remote target provides
3863 32-bit or 64-bit register values.
3865 * Support for C++ member pointers has been improved.
3867 * GDB now understands XML target descriptions, which specify the
3868 target's overall architecture. GDB can read a description from
3869 a local file or over the remote serial protocol.
3871 * Vectors of single-byte data use a new integer type which is not
3872 automatically displayed as character or string data.
3874 * The /s format now works with the print command. It displays
3875 arrays of single-byte integers and pointers to single-byte integers
3878 * Target descriptions can now describe target-specific registers,
3879 for architectures which have implemented the support (currently
3880 only ARM, M68K, and MIPS).
3882 * GDB and the GDB remote stub, gdbserver, now support the XScale
3885 * The GDB remote stub, gdbserver, has been updated to support
3886 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3887 has been rewritten to use the standard GDB remote protocol.
3889 * GDB can now step into C++ functions which are called through thunks.
3891 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3893 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3894 layout. It also supports a TextSeg= and DataSeg= response when only
3895 segment base addresses (rather than offsets) are available.
3897 * The /i format now outputs any trailing branch delay slot instructions
3898 immediately following the last instruction within the count specified.
3900 * The GDB remote protocol "T" stop reply packet now supports a
3901 "library" response. Combined with the new "qXfer:libraries:read"
3902 packet, this response allows GDB to debug shared libraries on targets
3903 where the operating system manages the list of loaded libraries (e.g.
3904 Windows and SymbianOS).
3906 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3907 (DLLs) on Windows and Windows CE targets.
3909 * GDB now supports a faster verification that a .debug file matches its binary
3910 according to its build-id signature, if the signature is present.
3916 Enable or disable hardware flow control (RTS/CTS) on the serial port
3917 when debugging using remote targets.
3919 set mem inaccessible-by-default
3920 show mem inaccessible-by-default
3921 If the target supplies a memory map, for instance via the remote
3922 protocol's "qXfer:memory-map:read" packet, setting this variable
3923 prevents GDB from accessing memory outside the memory map. This
3924 is useful for targets with memory mapped registers or which react
3925 badly to accesses of unmapped address space.
3927 set breakpoint auto-hw
3928 show breakpoint auto-hw
3929 If the target supplies a memory map, for instance via the remote
3930 protocol's "qXfer:memory-map:read" packet, setting this variable
3931 lets GDB use hardware breakpoints automatically for memory regions
3932 where it can not use software breakpoints. This covers both the
3933 "break" command and internal breakpoints used for other commands
3934 including "next" and "finish".
3937 catch exception unhandled
3938 Stop the program execution when Ada exceptions are raised.
3941 Stop the program execution when an Ada assertion failed.
3945 Set an alternate system root for target files. This is a more
3946 general version of "set solib-absolute-prefix", which is now
3947 an alias to "set sysroot".
3950 Provide extended SPU facility status information. This set of
3951 commands is available only when debugging the Cell/B.E. SPU
3954 * New native configurations
3956 OpenBSD/sh sh*-*openbsd*
3959 unset tdesc filename
3961 Use the specified local file as an XML target description, and do
3962 not query the target for its built-in description.
3966 OpenBSD/sh sh*-*-openbsd*
3967 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3968 Toshiba Media Processor mep-elf
3970 * New remote packets
3973 Ignore the specified signals; pass them directly to the debugged program
3974 without stopping other threads or reporting them to GDB.
3976 qXfer:features:read:
3977 Read an XML target description from the target, which describes its
3982 Read or write contents of an spufs file on the target system. These
3983 packets are available only on the Cell/B.E. SPU architecture.
3985 qXfer:libraries:read:
3986 Report the loaded shared libraries. Combined with new "T" packet
3987 response, this packet allows GDB to debug shared libraries on
3988 targets where the operating system manages the list of loaded
3989 libraries (e.g. Windows and SymbianOS).
3993 Support for these obsolete configurations has been removed.
4001 i[34567]86-*-lynxos*
4002 i[34567]86-*-netware*
4003 i[34567]86-*-sco3.2v5*
4004 i[34567]86-*-sco3.2v4*
4006 i[34567]86-*-sysv4.2*
4009 i[34567]86-*-unixware2*
4010 i[34567]86-*-unixware*
4019 * Other removed features
4026 Various m68k-only ROM monitors.
4033 Various Renesas ROM monitors and debugging interfaces for SH and
4038 Support for a Macraigor serial interface to on-chip debugging.
4039 GDB does not directly support the newer parallel or USB
4044 A debug information format. The predecessor to DWARF 2 and
4045 DWARF 3, which are still supported.
4047 Support for the HP aCC compiler on HP-UX/PA-RISC
4049 SOM-encapsulated symbolic debugging information, automatic
4050 invocation of pxdb, and the aCC custom C++ ABI. This does not
4051 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4052 with aCC can still be debugged on an assembly level.
4054 MIPS ".pdr" sections
4056 A MIPS-specific format used to describe stack frame layout
4057 in debugging information.
4061 GDB could work with an older version of Guile to debug
4062 the interpreter and Scheme programs running in it.
4064 set mips stack-arg-size
4065 set mips saved-gpreg-size
4067 Use "set mips abi" to control parameter passing for MIPS.
4069 *** Changes in GDB 6.6
4074 Cell Broadband Engine SPU spu-elf
4076 * GDB can now be configured as a cross-debugger targeting native Windows
4077 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4078 running on a Windows system over TCP/IP to debug Windows programs.
4080 * The GDB remote stub, gdbserver, has been updated to support Windows and
4081 Cygwin debugging. Both single-threaded and multi-threaded programs are
4084 * The "set trust-readonly-sections" command works again. This command was
4085 broken in GDB 6.3, 6.4, and 6.5.
4087 * The "load" command now supports writing to flash memory, if the remote
4088 stub provides the required support.
4090 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4091 longer requires symbolic debug information (e.g. DWARF-2).
4096 unset substitute-path
4097 show substitute-path
4098 Manage a list of substitution rules that GDB uses to rewrite the name
4099 of the directories where the sources are located. This can be useful
4100 for instance when the sources were moved to a different location
4101 between compilation and debugging.
4105 Print each CLI command as it is executed. Each command is prefixed with
4106 a number of `+' symbols representing the nesting depth.
4107 The source command now has a `-v' option to enable the same feature.
4111 The ARM Demon monitor support (RDP protocol, "target rdp").
4113 Kernel Object Display, an embedded debugging feature which only worked with
4114 an obsolete version of Cisco IOS.
4116 The 'set download-write-size' and 'show download-write-size' commands.
4118 * New remote packets
4121 Tell a stub about GDB client features, and request remote target features.
4122 The first feature implemented is PacketSize, which allows the target to
4123 specify the size of packets it can handle - to minimize the number of
4124 packets required and improve performance when connected to a remote
4128 Fetch an OS auxilliary vector from the remote stub. This packet is a
4129 more efficient replacement for qPart:auxv:read.
4131 qXfer:memory-map:read:
4132 Fetch a memory map from the remote stub, including information about
4133 RAM, ROM, and flash memory devices.
4138 Erase and program a flash memory device.
4140 * Removed remote packets
4143 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4144 used it, and only gdbserver implemented it.
4146 *** Changes in GDB 6.5
4150 Renesas M32C/M16C m32c-elf
4152 Morpho Technologies ms1 ms1-elf
4156 init-if-undefined Initialize a convenience variable, but
4157 only if it doesn't already have a value.
4159 The following commands are presently only implemented for native GNU/Linux:
4161 checkpoint Save a snapshot of the program state.
4163 restart <n> Return the program state to a
4164 previously saved state.
4166 info checkpoints List currently saved checkpoints.
4168 delete-checkpoint <n> Delete a previously saved checkpoint.
4170 set|show detach-on-fork Tell gdb whether to detach from a newly
4171 forked process, or to keep debugging it.
4173 info forks List forks of the user program that
4174 are available to be debugged.
4176 fork <n> Switch to debugging one of several
4177 forks of the user program that are
4178 available to be debugged.
4180 delete-fork <n> Delete a fork from the list of forks
4181 that are available to be debugged (and
4182 kill the forked process).
4184 detach-fork <n> Delete a fork from the list of forks
4185 that are available to be debugged (and
4186 allow the process to continue).
4190 Morpho Technologies ms2 ms1-elf
4192 * Improved Windows host support
4194 GDB now builds as a cross debugger hosted on i686-mingw32, including
4195 native console support, and remote communications using either
4196 network sockets or serial ports.
4198 * Improved Modula-2 language support
4200 GDB can now print most types in the Modula-2 syntax. This includes:
4201 basic types, set types, record types, enumerated types, range types,
4202 pointer types and ARRAY types. Procedure var parameters are correctly
4203 printed and hexadecimal addresses and character constants are also
4204 written in the Modula-2 syntax. Best results can be obtained by using
4205 GNU Modula-2 together with the -gdwarf-2 command line option.
4209 The ARM rdi-share module.
4211 The Netware NLM debug server.
4213 *** Changes in GDB 6.4
4215 * New native configurations
4217 OpenBSD/arm arm*-*-openbsd*
4218 OpenBSD/mips64 mips64-*-openbsd*
4222 Morpho Technologies ms1 ms1-elf
4224 * New command line options
4226 --batch-silent As for --batch, but totally silent.
4227 --return-child-result The debugger will exist with the same value
4228 the child (debugged) program exited with.
4229 --eval-command COMMAND, -ex COMMAND
4230 Execute a single GDB CLI command. This may be
4231 specified multiple times and in conjunction
4232 with the --command (-x) option.
4234 * Deprecated commands removed
4236 The following commands, that were deprecated in 2000, have been
4240 set|show arm disassembly-flavor set|show arm disassembler
4241 othernames set arm disassembler
4242 set|show remotedebug set|show debug remote
4243 set|show archdebug set|show debug arch
4244 set|show eventdebug set|show debug event
4247 * New BSD user-level threads support
4249 It is now possible to debug programs using the user-level threads
4250 library on OpenBSD and FreeBSD. Currently supported (target)
4253 FreeBSD/amd64 x86_64-*-freebsd*
4254 FreeBSD/i386 i386-*-freebsd*
4255 OpenBSD/i386 i386-*-openbsd*
4257 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4258 are not yet supported.
4260 * New support for Matsushita MN10300 w/sim added
4261 (Work in progress). mn10300-elf.
4263 * REMOVED configurations and files
4265 VxWorks and the XDR protocol *-*-vxworks
4266 Motorola MCORE mcore-*-*
4267 National Semiconductor NS32000 ns32k-*-*
4269 * New "set print array-indexes" command
4271 After turning this setting "on", GDB prints the index of each element
4272 when displaying arrays. The default is "off" to preserve the previous
4275 * VAX floating point support
4277 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4279 * User-defined command support
4281 In addition to using $arg0..$arg9 for argument passing, it is now possible
4282 to use $argc to determine now many arguments have been passed. See the
4283 section on user-defined commands in the user manual for more information.
4285 *** Changes in GDB 6.3:
4287 * New command line option
4289 GDB now accepts -l followed by a number to set the timeout for remote
4292 * GDB works with GCC -feliminate-dwarf2-dups
4294 GDB now supports a more compact representation of DWARF-2 debug
4295 information using DW_FORM_ref_addr references. These are produced
4296 by GCC with the option -feliminate-dwarf2-dups and also by some
4297 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4298 to use -feliminate-dwarf2-dups.
4300 * Internationalization
4302 When supported by the host system, GDB will be built with
4303 internationalization (libintl). The task of marking up the sources is
4304 continued, we're looking forward to our first translation.
4308 Initial support for debugging programs compiled with the GNAT
4309 implementation of the Ada programming language has been integrated
4310 into GDB. In this release, support is limited to expression evaluation.
4312 * New native configurations
4314 GNU/Linux/m32r m32r-*-linux-gnu
4318 GDB's remote protocol now includes support for the 'p' packet. This
4319 packet is used to fetch individual registers from a remote inferior.
4321 * END-OF-LIFE registers[] compatibility module
4323 GDB's internal register infrastructure has been completely rewritten.
4324 The new infrastructure making possible the implementation of key new
4325 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4328 GDB 6.3 will be the last release to include the the registers[]
4329 compatibility module that allowed out-of-date configurations to
4330 continue to work. This change directly impacts the following
4340 powerpc bdm protocol
4342 Unless there is activity to revive these configurations, they will be
4343 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4345 * OBSOLETE configurations and files
4347 Configurations that have been declared obsolete in this release have
4348 been commented out. Unless there is activity to revive these
4349 configurations, the next release of GDB will have their sources
4350 permanently REMOVED.
4359 *** Changes in GDB 6.2.1:
4361 * MIPS `break main; run' gave an heuristic-fence-post warning
4363 When attempting to run even a simple program, a warning about
4364 heuristic-fence-post being hit would be reported. This problem has
4367 * MIPS IRIX 'long double' crashed GDB
4369 When examining a long double variable, GDB would get a segmentation
4370 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4371 IRIX long double values).
4375 A bug in the VAX stack code was causing problems with the "next"
4376 command. This problem has been fixed.
4378 *** Changes in GDB 6.2:
4380 * Fix for ``many threads''
4382 On GNU/Linux systems that use the NPTL threads library, a program
4383 rapidly creating and deleting threads would confuse GDB leading to the
4386 ptrace: No such process.
4387 thread_db_get_info: cannot get thread info: generic error
4389 This problem has been fixed.
4391 * "-async" and "-noasync" options removed.
4393 Support for the broken "-noasync" option has been removed (it caused
4396 * New ``start'' command.
4398 This command runs the program until the begining of the main procedure.
4400 * New BSD Kernel Data Access Library (libkvm) interface
4402 Using ``target kvm'' it is now possible to debug kernel core dumps and
4403 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4404 platforms. Currently supported (native-only) configurations are:
4406 FreeBSD/amd64 x86_64-*-freebsd*
4407 FreeBSD/i386 i?86-*-freebsd*
4408 NetBSD/i386 i?86-*-netbsd*
4409 NetBSD/m68k m68*-*-netbsd*
4410 NetBSD/sparc sparc-*-netbsd*
4411 OpenBSD/amd64 x86_64-*-openbsd*
4412 OpenBSD/i386 i?86-*-openbsd*
4413 OpenBSD/m68k m68*-openbsd*
4414 OpenBSD/sparc sparc-*-openbsd*
4416 * Signal trampoline code overhauled
4418 Many generic problems with GDB's signal handling code have been fixed.
4419 These include: backtraces through non-contiguous stacks; recognition
4420 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4421 call; backtrace through a signal trampoline; step into and out of
4422 signal handlers; and single-stepping in the signal trampoline.
4424 Please note that kernel bugs are a limiting factor here. These
4425 features have been shown to work on an s390 GNU/Linux system that
4426 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4428 * Cygwin support for DWARF 2 added.
4430 * New native configurations
4432 GNU/Linux/hppa hppa*-*-linux*
4433 OpenBSD/hppa hppa*-*-openbsd*
4434 OpenBSD/m68k m68*-*-openbsd*
4435 OpenBSD/m88k m88*-*-openbsd*
4436 OpenBSD/powerpc powerpc-*-openbsd*
4437 NetBSD/vax vax-*-netbsd*
4438 OpenBSD/vax vax-*-openbsd*
4440 * END-OF-LIFE frame compatibility module
4442 GDB's internal frame infrastructure has been completely rewritten.
4443 The new infrastructure making it possible to support key new features
4444 including DWARF 2 Call Frame Information. To aid in the task of
4445 migrating old configurations to this new infrastructure, a
4446 compatibility module, that allowed old configurations to continue to
4447 work, was also included.
4449 GDB 6.2 will be the last release to include this frame compatibility
4450 module. This change directly impacts the following configurations:
4460 Unless there is activity to revive these configurations, they will be
4461 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4463 * REMOVED configurations and files
4465 Sun 3, running SunOS 3 m68*-*-sunos3*
4466 Sun 3, running SunOS 4 m68*-*-sunos4*
4467 Sun 2, running SunOS 3 m68000-*-sunos3*
4468 Sun 2, running SunOS 4 m68000-*-sunos4*
4469 Motorola 680x0 running LynxOS m68*-*-lynxos*
4470 AT&T 3b1/Unix pc m68*-att-*
4471 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4472 decstation mips-dec-* mips-little-*
4473 riscos mips-*-riscos* mips-*-sysv*
4474 sonymips mips-sony-*
4475 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4477 *** Changes in GDB 6.1.1:
4479 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4481 The TUI (Text-mode User Interface) is now built as part of a default
4482 GDB configuration. It is enabled by either selecting the TUI with the
4483 command line option "-i=tui" or by running the separate "gdbtui"
4484 program. For more information on the TUI, see the manual "Debugging
4487 * Pending breakpoint support (also included in GDB 6.1)
4489 Support has been added to allow you to specify breakpoints in shared
4490 libraries that have not yet been loaded. If a breakpoint location
4491 cannot be found, and the "breakpoint pending" option is set to auto,
4492 GDB queries you if you wish to make the breakpoint pending on a future
4493 shared-library load. If and when GDB resolves the breakpoint symbol,
4494 the pending breakpoint is removed as one or more regular breakpoints
4497 Pending breakpoints are very useful for GCJ Java debugging.
4499 * Fixed ISO-C build problems
4501 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4502 non ISO-C code that stopped them being built using a more strict ISO-C
4503 compiler (e.g., IBM's C compiler).
4505 * Fixed build problem on IRIX 5
4507 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4508 wasn't able to compile compile on an IRIX 5 system.
4510 * Added execute permission to gdb/gdbserver/configure
4512 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4513 permission. This bug would cause configure to fail on a number of
4514 systems (Solaris, IRIX). Ref: server/519.
4516 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4518 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4519 has been updated to use constant array sizes.
4521 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4523 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4524 its generated DWARF Call Frame Info. This encoding was causing GDB to
4525 panic, that panic has been fixed. Ref: gdb/1628.
4527 * Fixed a problem when examining parameters in shared library code.
4529 When examining parameters in optimized shared library code generated
4530 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4531 not available''. GDB now correctly displays the variable's value.
4533 *** Changes in GDB 6.1:
4535 * Removed --with-mmalloc
4537 Support for the mmalloc memory manager has been removed, as it
4538 conflicted with the internal gdb byte cache.
4540 * Changes in AMD64 configurations
4542 The AMD64 target now includes the %cs and %ss registers. As a result
4543 the AMD64 remote protocol has changed; this affects the floating-point
4544 and SSE registers. If you rely on those registers for your debugging,
4545 you should upgrade gdbserver on the remote side.
4547 * Revised SPARC target
4549 The SPARC target has been completely revised, incorporating the
4550 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4551 support for LynxOS and SunOS 4 has been dropped. Calling functions
4552 from within GDB on operating systems with a non-executable stack
4553 (Solaris, OpenBSD) now works.
4557 GDB has a new C++ demangler which does a better job on the mangled
4558 names generated by current versions of g++. It also runs faster, so
4559 with this and other changes gdb should now start faster on large C++
4562 * DWARF 2 Location Expressions
4564 GDB support for location expressions has been extended to support function
4565 arguments and frame bases. Older versions of GDB could crash when they
4568 * C++ nested types and namespaces
4570 GDB's support for nested types and namespaces in C++ has been
4571 improved, especially if you use the DWARF 2 debugging format. (This
4572 is the default for recent versions of GCC on most platforms.)
4573 Specifically, if you have a class "Inner" defined within a class or
4574 namespace "Outer", then GDB realizes that the class's name is
4575 "Outer::Inner", not simply "Inner". This should greatly reduce the
4576 frequency of complaints about not finding RTTI symbols. In addition,
4577 if you are stopped at inside of a function defined within a namespace,
4578 GDB modifies its name lookup accordingly.
4580 * New native configurations
4582 NetBSD/amd64 x86_64-*-netbsd*
4583 OpenBSD/amd64 x86_64-*-openbsd*
4584 OpenBSD/alpha alpha*-*-openbsd*
4585 OpenBSD/sparc sparc-*-openbsd*
4586 OpenBSD/sparc64 sparc64-*-openbsd*
4588 * New debugging protocols
4590 M32R with SDI protocol m32r-*-elf*
4592 * "set prompt-escape-char" command deleted.
4594 The command "set prompt-escape-char" has been deleted. This command,
4595 and its very obscure effet on GDB's prompt, was never documented,
4596 tested, nor mentioned in the NEWS file.
4598 * OBSOLETE configurations and files
4600 Configurations that have been declared obsolete in this release have
4601 been commented out. Unless there is activity to revive these
4602 configurations, the next release of GDB will have their sources
4603 permanently REMOVED.
4605 Sun 3, running SunOS 3 m68*-*-sunos3*
4606 Sun 3, running SunOS 4 m68*-*-sunos4*
4607 Sun 2, running SunOS 3 m68000-*-sunos3*
4608 Sun 2, running SunOS 4 m68000-*-sunos4*
4609 Motorola 680x0 running LynxOS m68*-*-lynxos*
4610 AT&T 3b1/Unix pc m68*-att-*
4611 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4612 decstation mips-dec-* mips-little-*
4613 riscos mips-*-riscos* mips-*-sysv*
4614 sonymips mips-sony-*
4615 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4617 * REMOVED configurations and files
4619 SGI Irix-4.x mips-sgi-irix4 or iris4
4620 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4621 Z8000 simulator z8k-zilog-none or z8ksim
4622 Matsushita MN10200 w/simulator mn10200-*-*
4623 H8/500 simulator h8500-hitachi-hms or h8500hms
4624 HP/PA running BSD hppa*-*-bsd*
4625 HP/PA running OSF/1 hppa*-*-osf*
4626 HP/PA Pro target hppa*-*-pro*
4627 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4628 386BSD i[3456]86-*-bsd*
4629 Sequent family i[3456]86-sequent-sysv4*
4630 i[3456]86-sequent-sysv*
4631 i[3456]86-sequent-bsd*
4632 SPARC running LynxOS sparc-*-lynxos*
4633 SPARC running SunOS 4 sparc-*-sunos4*
4634 Tsqware Sparclet sparclet-*-*
4635 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4637 *** Changes in GDB 6.0:
4641 Support for debugging the Objective-C programming language has been
4642 integrated into GDB.
4644 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4646 DWARF 2's Call Frame Information makes available compiler generated
4647 information that more exactly describes the program's run-time stack.
4648 By using this information, GDB is able to provide more robust stack
4651 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4652 have been updated to use a new backtrace mechanism which includes
4653 DWARF 2 CFI support.
4657 GDB's remote protocol has been extended to include support for hosted
4658 file I/O (where the remote target uses GDB's file system). See GDB's
4659 remote protocol documentation for details.
4661 * All targets using the new architecture framework.
4663 All of GDB's targets have been updated to use the new internal
4664 architecture framework. The way is now open for future GDB releases
4665 to include cross-architecture native debugging support (i386 on amd64,
4668 * GNU/Linux's Thread Local Storage (TLS)
4670 GDB now includes support for for the GNU/Linux implementation of
4671 per-thread variables.
4673 * GNU/Linux's Native POSIX Thread Library (NPTL)
4675 GDB's thread code has been updated to work with either the new
4676 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4678 * Separate debug info.
4680 GDB, in conjunction with BINUTILS, now supports a mechanism for
4681 automatically loading debug information from a separate file. Instead
4682 of shipping full debug and non-debug versions of system libraries,
4683 system integrators can now instead ship just the stripped libraries
4684 and optional debug files.
4686 * DWARF 2 Location Expressions
4688 DWARF 2 Location Expressions allow the compiler to more completely
4689 describe the location of variables (even in optimized code) to the
4692 GDB now includes preliminary support for location expressions (support
4693 for DW_OP_piece is still missing).
4697 A number of long standing bugs that caused GDB to die while starting a
4698 Java application have been fixed. GDB's Java support is now
4699 considered "useable".
4701 * GNU/Linux support for fork, vfork, and exec.
4703 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4704 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4707 * GDB supports logging output to a file
4709 There are two new commands, "set logging" and "show logging", which can be
4710 used to capture GDB's output to a file.
4712 * The meaning of "detach" has changed for gdbserver
4714 The "detach" command will now resume the application, as documented. To
4715 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4718 * d10v, m68hc11 `regs' command deprecated
4720 The `info registers' command has been updated so that it displays the
4721 registers using a format identical to the old `regs' command.
4725 A new command, "maint set profile on/off", has been added. This command can
4726 be used to enable or disable profiling while running GDB, to profile a
4727 session or a set of commands. In addition there is a new configure switch,
4728 "--enable-profiling", which will cause GDB to be compiled with profiling
4729 data, for more informative profiling results.
4731 * Default MI syntax changed to "mi2".
4733 The default MI (machine interface) syntax, enabled by the command line
4734 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4735 "mi1", can be enabled by specifying the option "-i=mi1".
4737 Support for the original "mi0" syntax (included in GDB 5.0) has been
4740 Fix for gdb/192: removed extraneous space when displaying frame level.
4741 Fix for gdb/672: update changelist is now output in mi list format.
4742 Fix for gdb/702: a -var-assign that updates the value now shows up
4743 in a subsequent -var-update.
4745 * New native configurations.
4747 FreeBSD/amd64 x86_64-*-freebsd*
4749 * Multi-arched targets.
4751 HP/PA HPUX11 hppa*-*-hpux*
4752 Renesas M32R/D w/simulator m32r-*-elf*
4754 * OBSOLETE configurations and files
4756 Configurations that have been declared obsolete in this release have
4757 been commented out. Unless there is activity to revive these
4758 configurations, the next release of GDB will have their sources
4759 permanently REMOVED.
4761 Z8000 simulator z8k-zilog-none or z8ksim
4762 Matsushita MN10200 w/simulator mn10200-*-*
4763 H8/500 simulator h8500-hitachi-hms or h8500hms
4764 HP/PA running BSD hppa*-*-bsd*
4765 HP/PA running OSF/1 hppa*-*-osf*
4766 HP/PA Pro target hppa*-*-pro*
4767 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4768 Sequent family i[3456]86-sequent-sysv4*
4769 i[3456]86-sequent-sysv*
4770 i[3456]86-sequent-bsd*
4771 Tsqware Sparclet sparclet-*-*
4772 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4774 * REMOVED configurations and files
4777 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4778 IBM AIX PS/2 i[3456]86-*-aix
4779 i386 running Mach 3.0 i[3456]86-*-mach3*
4780 i386 running Mach i[3456]86-*-mach*
4781 i386 running OSF/1 i[3456]86-*osf1mk*
4782 HP/Apollo 68k Family m68*-apollo*-sysv*,
4784 m68*-hp-bsd*, m68*-hp-hpux*
4785 Argonaut Risc Chip (ARC) arc-*-*
4786 Mitsubishi D30V d30v-*-*
4787 Fujitsu FR30 fr30-*-elf*
4788 OS/9000 i[34]86-*-os9k
4789 I960 with MON960 i960-*-coff
4791 * MIPS $fp behavior changed
4793 The convenience variable $fp, for the MIPS, now consistently returns
4794 the address of the current frame's base. Previously, depending on the
4795 context, $fp could refer to either $sp or the current frame's base
4796 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4797 The GNU Source-Level Debugger''.
4799 *** Changes in GDB 5.3:
4801 * GNU/Linux shared library multi-threaded performance improved.
4803 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4804 `/proc', in preference to `ptrace' for memory reads. This may result
4805 in an improvement in the start-up time of multi-threaded, shared
4806 library applications when run under GDB. One GDB user writes: ``loads
4807 shared libs like mad''.
4809 * ``gdbserver'' now supports multi-threaded applications on some targets
4811 Support for debugging multi-threaded applications which use
4812 the GNU/Linux LinuxThreads package has been added for
4813 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4814 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4816 * GDB now supports C/C++ preprocessor macros.
4818 GDB now expands preprocessor macro invocations in C/C++ expressions,
4819 and provides various commands for showing macro definitions and how
4822 The new command `macro expand EXPRESSION' expands any macro
4823 invocations in expression, and shows the result.
4825 The new command `show macro MACRO-NAME' shows the definition of the
4826 macro named MACRO-NAME, and where it was defined.
4828 Most compilers don't include information about macros in the debugging
4829 information by default. In GCC 3.1, for example, you need to compile
4830 your program with the options `-gdwarf-2 -g3'. If the macro
4831 information is present in the executable, GDB will read it.
4833 * Multi-arched targets.
4835 DEC Alpha (partial) alpha*-*-*
4836 DEC VAX (partial) vax-*-*
4838 National Semiconductor NS32000 (partial) ns32k-*-*
4839 Motorola 68000 (partial) m68k-*-*
4840 Motorola MCORE mcore-*-*
4844 Fujitsu FRV architecture added by Red Hat frv*-*-*
4847 * New native configurations
4849 Alpha NetBSD alpha*-*-netbsd*
4850 SH NetBSD sh*-*-netbsdelf*
4851 MIPS NetBSD mips*-*-netbsd*
4852 UltraSPARC NetBSD sparc64-*-netbsd*
4854 * OBSOLETE configurations and files
4856 Configurations that have been declared obsolete in this release have
4857 been commented out. Unless there is activity to revive these
4858 configurations, the next release of GDB will have their sources
4859 permanently REMOVED.
4861 Mitsubishi D30V d30v-*-*
4862 OS/9000 i[34]86-*-os9k
4863 IBM AIX PS/2 i[3456]86-*-aix
4864 Fujitsu FR30 fr30-*-elf*
4865 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4866 Argonaut Risc Chip (ARC) arc-*-*
4867 i386 running Mach 3.0 i[3456]86-*-mach3*
4868 i386 running Mach i[3456]86-*-mach*
4869 i386 running OSF/1 i[3456]86-*osf1mk*
4870 HP/Apollo 68k Family m68*-apollo*-sysv*,
4872 m68*-hp-bsd*, m68*-hp-hpux*
4873 I960 with MON960 i960-*-coff
4875 * OBSOLETE languages
4877 CHILL, a Pascal like language used by telecommunications companies.
4879 * REMOVED configurations and files
4881 AMD 29k family via UDI a29k-amd-udi, udi29k
4882 A29K VxWorks a29k-*-vxworks
4883 AMD 29000 embedded, using EBMON a29k-none-none
4884 AMD 29000 embedded with COFF a29k-none-coff
4885 AMD 29000 embedded with a.out a29k-none-aout
4887 testsuite/gdb.hp/gdb.threads-hp/ directory
4889 * New command "set max-user-call-depth <nnn>"
4891 This command allows the user to limit the call depth of user-defined
4892 commands. The default is 1024.
4894 * Changes in FreeBSD/i386 native debugging.
4896 Support for the "generate-core-file" has been added.
4898 * New commands "dump", "append", and "restore".
4900 These commands allow data to be copied from target memory
4901 to a bfd-format or binary file (dump and append), and back
4902 from a file into memory (restore).
4904 * Improved "next/step" support on multi-processor Alpha Tru64.
4906 The previous single-step mechanism could cause unpredictable problems,
4907 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4908 of a software single-step mechanism prevents this.
4910 *** Changes in GDB 5.2.1:
4918 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4919 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4920 Fix, by Joel Brobecker imported from mainline.
4922 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4923 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4924 Fix, by Fred Fish, imported from mainline.
4926 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4927 Surprisingly enough, it works now.
4928 By Michal Ludvig, imported from mainline.
4930 i386 hardware watchpoint support:
4931 avoid misses on second run for some targets.
4932 By Pierre Muller, imported from mainline.
4934 *** Changes in GDB 5.2:
4936 * New command "set trust-readonly-sections on[off]".
4938 This command is a hint that tells gdb that read-only sections
4939 really are read-only (ie. that their contents will not change).
4940 In this mode, gdb will go to the object file rather than the
4941 target to read memory from read-only sections (such as ".text").
4942 This can be a significant performance improvement on some
4943 (notably embedded) targets.
4945 * New command "generate-core-file" (or "gcore").
4947 This new gdb command allows the user to drop a core file of the child
4948 process state at any time. So far it's been implemented only for
4949 GNU/Linux and Solaris, but should be relatively easily ported to other
4950 hosts. Argument is core file name (defaults to core.<pid>).
4952 * New command line option
4954 GDB now accepts --pid or -p followed by a process id.
4956 * Change in command line behavior -- corefiles vs. process ids.
4958 There is a subtle behavior in the way in which GDB handles
4959 command line arguments. The first non-flag argument is always
4960 a program to debug, but the second non-flag argument may either
4961 be a corefile or a process id. Previously, GDB would attempt to
4962 open the second argument as a corefile, and if that failed, would
4963 issue a superfluous error message and then attempt to attach it as
4964 a process. Now, if the second argument begins with a non-digit,
4965 it will be treated as a corefile. If it begins with a digit,
4966 GDB will attempt to attach it as a process, and if no such process
4967 is found, will then attempt to open it as a corefile.
4969 * Changes in ARM configurations.
4971 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4972 configuration is fully multi-arch.
4974 * New native configurations
4976 ARM NetBSD arm*-*-netbsd*
4977 x86 OpenBSD i[3456]86-*-openbsd*
4978 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4979 Sparc64 running FreeBSD sparc64-*-freebsd*
4983 Sanyo XStormy16 xstormy16-elf
4985 * OBSOLETE configurations and files
4987 Configurations that have been declared obsolete in this release have
4988 been commented out. Unless there is activity to revive these
4989 configurations, the next release of GDB will have their sources
4990 permanently REMOVED.
4992 AMD 29k family via UDI a29k-amd-udi, udi29k
4993 A29K VxWorks a29k-*-vxworks
4994 AMD 29000 embedded, using EBMON a29k-none-none
4995 AMD 29000 embedded with COFF a29k-none-coff
4996 AMD 29000 embedded with a.out a29k-none-aout
4998 testsuite/gdb.hp/gdb.threads-hp/ directory
5000 * REMOVED configurations and files
5002 TI TMS320C80 tic80-*-*
5004 PowerPC Solaris powerpcle-*-solaris*
5005 PowerPC Windows NT powerpcle-*-cygwin32
5006 PowerPC Netware powerpc-*-netware*
5007 Harris/CXUX m88k m88*-harris-cxux*
5008 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5009 ns32k-utek-sysv* ns32k-utek-*
5010 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5011 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5012 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5013 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5014 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5016 * Changes to command line processing
5018 The new `--args' feature can be used to specify command-line arguments
5019 for the inferior from gdb's command line.
5021 * Changes to key bindings
5023 There is a new `operate-and-get-next' function bound to `C-o'.
5025 *** Changes in GDB 5.1.1
5027 Fix compile problem on DJGPP.
5029 Fix a problem with floating-point registers on the i386 being
5032 Fix to stop GDB crashing on .debug_str debug info.
5034 Numerous documentation fixes.
5036 Numerous testsuite fixes.
5038 *** Changes in GDB 5.1:
5040 * New native configurations
5042 Alpha FreeBSD alpha*-*-freebsd*
5043 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5044 MIPS GNU/Linux mips*-*-linux*
5045 MIPS SGI Irix 6.x mips*-sgi-irix6*
5046 ia64 AIX ia64-*-aix*
5047 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5051 Motorola 68HC11 and 68HC12 m68hc11-elf
5053 UltraSparc running GNU/Linux sparc64-*-linux*
5055 * OBSOLETE configurations and files
5057 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5058 Harris/CXUX m88k m88*-harris-cxux*
5059 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5060 ns32k-utek-sysv* ns32k-utek-*
5061 TI TMS320C80 tic80-*-*
5063 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5064 PowerPC Solaris powerpcle-*-solaris*
5065 PowerPC Windows NT powerpcle-*-cygwin32
5066 PowerPC Netware powerpc-*-netware*
5067 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5068 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5069 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5070 Apple Macintosh (MPW) host N/A
5072 stuff.c (Program to stuff files into a specially prepared space in kdb)
5073 kdb-start.c (Main loop for the standalone kernel debugger)
5075 Configurations that have been declared obsolete in this release have
5076 been commented out. Unless there is activity to revive these
5077 configurations, the next release of GDB will have their sources
5078 permanently REMOVED.
5080 * REMOVED configurations and files
5082 Altos 3068 m68*-altos-*
5083 Convex c1-*-*, c2-*-*
5085 ARM RISCix arm-*-* (as host)
5089 * GDB has been converted to ISO C.
5091 GDB's source code has been converted to ISO C. In particular, the
5092 sources are fully protoized, and rely on standard headers being
5097 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5099 * The MI enabled by default.
5101 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5102 revised and enabled by default. Packages which use GDB as a debugging
5103 engine behind a UI or another front end are encouraged to switch to
5104 using the GDB/MI interface, instead of the old annotations interface
5105 which is now deprecated.
5107 * Support for debugging Pascal programs.
5109 GDB now includes support for debugging Pascal programs. The following
5110 main features are supported:
5112 - Pascal-specific data types such as sets;
5114 - automatic recognition of Pascal sources based on file-name
5117 - Pascal-style display of data types, variables, and functions;
5119 - a Pascal expression parser.
5121 However, some important features are not yet supported.
5123 - Pascal string operations are not supported at all;
5125 - there are some problems with boolean types;
5127 - Pascal type hexadecimal constants are not supported
5128 because they conflict with the internal variables format;
5130 - support for Pascal objects and classes is not full yet;
5132 - unlike Pascal, GDB is case-sensitive for symbol names.
5134 * Changes in completion.
5136 Commands such as `shell', `run' and `set args', which pass arguments
5137 to inferior programs, now complete on file names, similar to what
5138 users expect at the shell prompt.
5140 Commands which accept locations, such as `disassemble', `print',
5141 `breakpoint', `until', etc. now complete on filenames as well as
5142 program symbols. Thus, if you type "break foob TAB", and the source
5143 files linked into the programs include `foobar.c', that file name will
5144 be one of the candidates for completion. However, file names are not
5145 considered for completion after you typed a colon that delimits a file
5146 name from a name of a function in that file, as in "break foo.c:bar".
5148 `set demangle-style' completes on available demangling styles.
5150 * New platform-independent commands:
5152 It is now possible to define a post-hook for a command as well as a
5153 hook that runs before the command. For more details, see the
5154 documentation of `hookpost' in the GDB manual.
5156 * Changes in GNU/Linux native debugging.
5158 Support for debugging multi-threaded programs has been completely
5159 revised for all platforms except m68k and sparc. You can now debug as
5160 many threads as your system allows you to have.
5162 Attach/detach is supported for multi-threaded programs.
5164 Support for SSE registers was added for x86. This doesn't work for
5165 multi-threaded programs though.
5167 * Changes in MIPS configurations.
5169 Multi-arch support is enabled for all MIPS configurations.
5171 GDB can now be built as native debugger on SGI Irix 6.x systems for
5172 debugging n32 executables. (Debugging 64-bit executables is not yet
5175 * Unified support for hardware watchpoints in all x86 configurations.
5177 Most (if not all) native x86 configurations support hardware-assisted
5178 breakpoints and watchpoints in a unified manner. This support
5179 implements debug register sharing between watchpoints, which allows to
5180 put a virtually infinite number of watchpoints on the same address,
5181 and also supports watching regions up to 16 bytes with several debug
5184 The new maintenance command `maintenance show-debug-regs' toggles
5185 debugging print-outs in functions that insert, remove, and test
5186 watchpoints and hardware breakpoints.
5188 * Changes in the DJGPP native configuration.
5190 New command ``info dos sysinfo'' displays assorted information about
5191 the CPU, OS, memory, and DPMI server.
5193 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5194 display information about segment descriptors stored in GDT, LDT, and
5197 New commands ``info dos pde'' and ``info dos pte'' display entries
5198 from Page Directory and Page Tables (for now works with CWSDPMI only).
5199 New command ``info dos address-pte'' displays the Page Table entry for
5200 a given linear address.
5202 GDB can now pass command lines longer than 126 characters to the
5203 program being debugged (requires an update to the libdbg.a library
5204 which is part of the DJGPP development kit).
5206 DWARF2 debug info is now supported.
5208 It is now possible to `step' and `next' through calls to `longjmp'.
5210 * Changes in documentation.
5212 All GDB documentation was converted to GFDL, the GNU Free
5213 Documentation License.
5215 Tracepoints-related commands are now fully documented in the GDB
5218 TUI, the Text-mode User Interface, is now documented in the manual.
5220 Tracepoints-related commands are now fully documented in the GDB
5223 The "GDB Internals" manual now has an index. It also includes
5224 documentation of `ui_out' functions, GDB coding standards, x86
5225 hardware watchpoints, and memory region attributes.
5227 * GDB's version number moved to ``version.in''
5229 The Makefile variable VERSION has been replaced by the file
5230 ``version.in''. People creating GDB distributions should update the
5231 contents of this file.
5235 GUD support is now a standard part of the EMACS distribution.
5237 *** Changes in GDB 5.0:
5239 * Improved support for debugging FP programs on x86 targets
5241 Unified and much-improved support for debugging floating-point
5242 programs on all x86 targets. In particular, ``info float'' now
5243 displays the FP registers in the same format on all x86 targets, with
5244 greater level of detail.
5246 * Improvements and bugfixes in hardware-assisted watchpoints
5248 It is now possible to watch array elements, struct members, and
5249 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5250 on x86 targets no longer erroneously trigger when the address is
5253 * Improvements in the native DJGPP version of GDB
5255 The distribution now includes all the scripts and auxiliary files
5256 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5257 machines ``out of the box''.
5259 The DJGPP version can now debug programs that use signals. It is
5260 possible to catch signals that happened in the debuggee, deliver
5261 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5262 would kill the program being debugged.) Programs that hook hardware
5263 interrupts (keyboard, timer, etc.) can also be debugged.
5265 It is now possible to debug DJGPP programs that redirect their
5266 standard handles or switch them to raw (as opposed to cooked) mode, or
5267 even close them. The command ``run < foo > bar'' works as expected,
5268 and ``info terminal'' reports useful information about the debuggee's
5269 terminal, including raw/cooked mode, redirection, etc.
5271 The DJGPP version now uses termios functions for console I/O, which
5272 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5275 DOS-style file names with drive letters are now fully supported by
5278 It is now possible to debug DJGPP programs that switch their working
5279 directory. It is also possible to rerun the debuggee any number of
5280 times without restarting GDB; thus, you can use the same setup,
5281 breakpoints, etc. for many debugging sessions.
5283 * New native configurations
5285 ARM GNU/Linux arm*-*-linux*
5286 PowerPC GNU/Linux powerpc-*-linux*
5290 Motorola MCore mcore-*-*
5291 x86 VxWorks i[3456]86-*-vxworks*
5292 PowerPC VxWorks powerpc-*-vxworks*
5293 TI TMS320C80 tic80-*-*
5295 * OBSOLETE configurations
5297 Altos 3068 m68*-altos-*
5298 Convex c1-*-*, c2-*-*
5300 ARM RISCix arm-*-* (as host)
5303 Configurations that have been declared obsolete will be commented out,
5304 but the code will be left in place. If there is no activity to revive
5305 these configurations before the next release of GDB, the sources will
5306 be permanently REMOVED.
5308 * Gould support removed
5310 Support for the Gould PowerNode and NP1 has been removed.
5312 * New features for SVR4
5314 On SVR4 native platforms (such as Solaris), if you attach to a process
5315 without first loading a symbol file, GDB will now attempt to locate and
5316 load symbols from the running process's executable file.
5318 * Many C++ enhancements
5320 C++ support has been greatly improved. Overload resolution now works properly
5321 in almost all cases. RTTI support is on the way.
5323 * Remote targets can connect to a sub-program
5325 A popen(3) style serial-device has been added. This device starts a
5326 sub-process (such as a stand-alone simulator) and then communicates
5327 with that. The sub-program to run is specified using the syntax
5328 ``|<program> <args>'' vis:
5330 (gdb) set remotedebug 1
5331 (gdb) target extended-remote |mn10300-elf-sim program-args
5333 * MIPS 64 remote protocol
5335 A long standing bug in the mips64 remote protocol where by GDB
5336 expected certain 32 bit registers (ex SR) to be transfered as 32
5337 instead of 64 bits has been fixed.
5339 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5340 added to provide backward compatibility with older versions of GDB.
5342 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5344 The command ``set remotebinarydownload'' command has been replaced by
5345 ``set remote X-packet''. Other commands in ``set remote'' family
5346 include ``set remote P-packet''.
5348 * Breakpoint commands accept ranges.
5350 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5351 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5352 ``tracepoint passcount'' also accepts a range of tracepoints.
5354 * ``apropos'' command added.
5356 The ``apropos'' command searches through command names and
5357 documentation strings, printing out matches, making it much easier to
5358 try to find a command that does what you are looking for.
5362 A new machine oriented interface (MI) has been added to GDB. This
5363 interface is designed for debug environments running GDB as a separate
5364 process. This is part of the long term libGDB project. See the
5365 "GDB/MI" chapter of the GDB manual for further information. It can be
5366 enabled by configuring with:
5368 .../configure --enable-gdbmi
5370 *** Changes in GDB-4.18:
5372 * New native configurations
5374 HP-UX 10.20 hppa*-*-hpux10.20
5375 HP-UX 11.x hppa*-*-hpux11.0*
5376 M68K GNU/Linux m68*-*-linux*
5380 Fujitsu FR30 fr30-*-elf*
5381 Intel StrongARM strongarm-*-*
5382 Mitsubishi D30V d30v-*-*
5384 * OBSOLETE configurations
5386 Gould PowerNode, NP1 np1-*-*, pn-*-*
5388 Configurations that have been declared obsolete will be commented out,
5389 but the code will be left in place. If there is no activity to revive
5390 these configurations before the next release of GDB, the sources will
5391 be permanently REMOVED.
5395 As a compatibility experiment, GDB's source files buildsym.h and
5396 buildsym.c have been converted to pure standard C, no longer
5397 containing any K&R compatibility code. We believe that all systems in
5398 use today either come with a standard C compiler, or have a GCC port
5399 available. If this is not true, please report the affected
5400 configuration to bug-gdb@gnu.org immediately. See the README file for
5401 information about getting a standard C compiler if you don't have one
5406 GDB now uses readline 2.2.
5408 * set extension-language
5410 You can now control the mapping between filename extensions and source
5411 languages by using the `set extension-language' command. For instance,
5412 you can ask GDB to treat .c files as C++ by saying
5413 set extension-language .c c++
5414 The command `info extensions' lists all of the recognized extensions
5415 and their associated languages.
5417 * Setting processor type for PowerPC and RS/6000
5419 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5420 you can use the `set processor' command to specify what variant of the
5421 PowerPC family you are debugging. The command
5425 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5426 following PowerPC and RS6000 variants:
5428 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5429 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5431 403GC IBM PowerPC 403GC
5432 505 Motorola PowerPC 505
5433 860 Motorola PowerPC 860 or 850
5434 601 Motorola PowerPC 601
5435 602 Motorola PowerPC 602
5436 603 Motorola/IBM PowerPC 603 or 603e
5437 604 Motorola PowerPC 604 or 604e
5438 750 Motorola/IBM PowerPC 750 or 750
5440 At the moment, this command just tells GDB what to name the
5441 special-purpose processor registers. Since almost all the affected
5442 registers are inaccessible to user-level programs, this command is
5443 only useful for remote debugging in its present form.
5447 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5448 more extensive support for HP-UX. Added features include shared
5449 library support, kernel threads and hardware watchpoints for 11.00,
5450 support for HP's ANSI C and C++ compilers, and a compatibility mode
5451 for xdb and dbx commands.
5455 HP's donation includes the new concept of catchpoints, which is a
5456 generalization of the old catch command. On HP-UX, it is now possible
5457 to catch exec, fork, and vfork, as well as library loading.
5459 This means that the existing catch command has changed; its first
5460 argument now specifies the type of catch to be set up. See the
5461 output of "help catch" for a list of catchpoint types.
5463 * Debugging across forks
5465 On HP-UX, you can choose which process to debug when a fork() happens
5470 HP has donated a curses-based terminal user interface (TUI). To get
5471 it, build with --enable-tui. Although this can be enabled for any
5472 configuration, at present it only works for native HP debugging.
5474 * GDB remote protocol additions
5476 A new protocol packet 'X' that writes binary data is now available.
5477 Default behavior is to try 'X', then drop back to 'M' if the stub
5478 fails to respond. The settable variable `remotebinarydownload'
5479 allows explicit control over the use of 'X'.
5481 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5482 full 64-bit address. The command
5484 set remoteaddresssize 32
5486 can be used to revert to the old behaviour. For existing remote stubs
5487 the change should not be noticed, as the additional address information
5490 In order to assist in debugging stubs, you may use the maintenance
5491 command `packet' to send any text string to the stub. For instance,
5493 maint packet heythere
5495 sends the packet "$heythere#<checksum>". Note that it is very easy to
5496 disrupt a debugging session by sending the wrong packet at the wrong
5499 The compare-sections command allows you to compare section data on the
5500 target to what is in the executable file without uploading or
5501 downloading, by comparing CRC checksums.
5503 * Tracing can collect general expressions
5505 You may now collect general expressions at tracepoints. This requires
5506 further additions to the target-side stub; see tracepoint.c and
5507 doc/agentexpr.texi for further details.
5509 * mask-address variable for Mips
5511 For Mips targets, you may control the zeroing of the upper 32 bits of
5512 a 64-bit address by entering `set mask-address on'. This is mainly
5513 of interest to users of embedded R4xxx and R5xxx processors.
5515 * Higher serial baud rates
5517 GDB's serial code now allows you to specify baud rates 57600, 115200,
5518 230400, and 460800 baud. (Note that your host system may not be able
5519 to achieve all of these rates.)
5523 The i960 configuration now includes an initial implementation of a
5524 builtin simulator, contributed by Jim Wilson.
5527 *** Changes in GDB-4.17:
5529 * New native configurations
5531 Alpha GNU/Linux alpha*-*-linux*
5532 Unixware 2.x i[3456]86-unixware2*
5533 Irix 6.x mips*-sgi-irix6*
5534 PowerPC GNU/Linux powerpc-*-linux*
5535 PowerPC Solaris powerpcle-*-solaris*
5536 Sparc GNU/Linux sparc-*-linux*
5537 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5541 Argonaut Risc Chip (ARC) arc-*-*
5542 Hitachi H8/300S h8300*-*-*
5543 Matsushita MN10200 w/simulator mn10200-*-*
5544 Matsushita MN10300 w/simulator mn10300-*-*
5545 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5546 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5547 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5548 Mitsubishi D10V w/simulator d10v-*-*
5549 Mitsubishi M32R/D w/simulator m32r-*-elf*
5550 Tsqware Sparclet sparclet-*-*
5551 NEC V850 w/simulator v850-*-*
5553 * New debugging protocols
5555 ARM with RDI protocol arm*-*-*
5556 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5557 DDB and LSI variants of PMON protocol mips*-*-*
5558 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5559 PowerPC with SDS protocol powerpc{,le}-*-eabi
5560 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5564 All configurations can now understand and use the DWARF 2 debugging
5565 format. The choice is automatic, if the symbol file contains DWARF 2
5570 GDB now includes basic Java language support. This support is
5571 only useful with Java compilers that produce native machine code.
5573 * solib-absolute-prefix and solib-search-path
5575 For SunOS and SVR4 shared libraries, you may now set the prefix for
5576 loading absolute shared library symbol files, and the search path for
5577 locating non-absolute shared library symbol files.
5579 * Live range splitting
5581 GDB can now effectively debug code for which GCC has performed live
5582 range splitting as part of its optimization. See gdb/doc/LRS for
5583 more details on the expected format of the stabs information.
5587 GDB's support for the GNU Hurd, including thread debugging, has been
5588 updated to work with current versions of the Hurd.
5592 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5593 instruction set. ARM GDB automatically detects when Thumb
5594 instructions are in use, and adjusts disassembly and backtracing
5599 GDB's MIPS target configurations now handle the MIP16 16-bit
5604 GDB now includes support for overlays; if an executable has been
5605 linked such that multiple sections are based at the same address, GDB
5606 will decide which section to use for symbolic info. You can choose to
5607 control the decision manually, using overlay commands, or implement
5608 additional target-side support and use "overlay load-target" to bring
5609 in the overlay mapping. Do "help overlay" for more detail.
5613 The command "info symbol <address>" displays information about
5614 the symbol at the specified address.
5618 The standard remote protocol now includes an extension that allows
5619 asynchronous collection and display of trace data. This requires
5620 extensive support in the target-side debugging stub. Tracing mode
5621 includes a new interaction mode in GDB and new commands: see the
5622 file tracepoint.c for more details.
5626 Configurations for embedded MIPS now include a simulator contributed
5627 by Cygnus Solutions. The simulator supports the instruction sets
5628 of most MIPS variants.
5632 Sparc configurations may now include the ERC32 simulator contributed
5633 by the European Space Agency. The simulator is not built into
5634 Sparc targets by default; configure with --enable-sim to include it.
5638 For target configurations that may include multiple variants of a
5639 basic architecture (such as MIPS and SH), you may now set the
5640 architecture explicitly. "set arch" sets, "info arch" lists
5641 the possible architectures.
5643 *** Changes in GDB-4.16:
5645 * New native configurations
5647 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5648 M68K NetBSD m68k-*-netbsd*
5649 PowerPC AIX 4.x powerpc-*-aix*
5650 PowerPC MacOS powerpc-*-macos*
5651 PowerPC Windows NT powerpcle-*-cygwin32
5652 RS/6000 AIX 4.x rs6000-*-aix4*
5656 ARM with RDP protocol arm-*-*
5657 I960 with MON960 i960-*-coff
5658 MIPS VxWorks mips*-*-vxworks*
5659 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5660 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5662 Matra Sparclet sparclet-*-*
5666 The powerpc-eabi configuration now includes the PSIM simulator,
5667 contributed by Andrew Cagney, with assistance from Mike Meissner.
5668 PSIM is a very elaborate model of the PowerPC, including not only
5669 basic instruction set execution, but also details of execution unit
5670 performance and I/O hardware. See sim/ppc/README for more details.
5674 GDB now works with Solaris 2.5.
5676 * Windows 95/NT native
5678 GDB will now work as a native debugger on Windows 95 and Windows NT.
5679 To build it from source, you must use the "gnu-win32" environment,
5680 which uses a DLL to emulate enough of Unix to run the GNU tools.
5681 Further information, binaries, and sources are available at
5682 ftp.cygnus.com, under pub/gnu-win32.
5684 * dont-repeat command
5686 If a user-defined command includes the command `dont-repeat', then the
5687 command will not be repeated if the user just types return. This is
5688 useful if the command is time-consuming to run, so that accidental
5689 extra keystrokes don't run the same command many times.
5691 * Send break instead of ^C
5693 The standard remote protocol now includes an option to send a break
5694 rather than a ^C to the target in order to interrupt it. By default,
5695 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5697 * Remote protocol timeout
5699 The standard remote protocol includes a new variable `remotetimeout'
5700 that allows you to set the number of seconds before GDB gives up trying
5701 to read from the target. The default value is 2.
5703 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5705 By default GDB will automatically keep track of objects as they are
5706 loaded and unloaded by the dynamic linker. By using the command `set
5707 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5708 when shared library events occur, thus allowing you to set breakpoints
5709 in shared libraries which are explicitly loaded by the inferior.
5711 Note this feature does not work on hpux8. On hpux9 you must link
5712 /usr/lib/end.o into your program. This feature should work
5713 automatically on hpux10.
5715 * Irix 5.x hardware watchpoint support
5717 Irix 5 configurations now support the use of hardware watchpoints.
5719 * Mips protocol "SYN garbage limit"
5721 When debugging a Mips target using the `target mips' protocol, you
5722 may set the number of characters that GDB will ignore by setting
5723 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5724 every character. The default value is 1050.
5726 * Recording and replaying remote debug sessions
5728 If you set `remotelogfile' to the name of a file, gdb will write to it
5729 a recording of a remote debug session. This recording may then be
5730 replayed back to gdb using "gdbreplay". See gdbserver/README for
5731 details. This is useful when you have a problem with GDB while doing
5732 remote debugging; you can make a recording of the session and send it
5733 to someone else, who can then recreate the problem.
5735 * Speedups for remote debugging
5737 GDB includes speedups for downloading and stepping MIPS systems using
5738 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5739 and more efficient S-record downloading.
5741 * Memory use reductions and statistics collection
5743 GDB now uses less memory and reports statistics about memory usage.
5744 Try the `maint print statistics' command, for example.
5746 *** Changes in GDB-4.15:
5748 * Psymtabs for XCOFF
5750 The symbol reader for AIX GDB now uses partial symbol tables. This
5751 can greatly improve startup time, especially for large executables.
5753 * Remote targets use caching
5755 Remote targets now use a data cache to speed up communication with the
5756 remote side. The data cache could lead to incorrect results because
5757 it doesn't know about volatile variables, thus making it impossible to
5758 debug targets which use memory mapped I/O devices. `set remotecache
5759 off' turns the the data cache off.
5761 * Remote targets may have threads
5763 The standard remote protocol now includes support for multiple threads
5764 in the target system, using new protocol commands 'H' and 'T'. See
5765 gdb/remote.c for details.
5769 If GDB is configured with `--enable-netrom', then it will include
5770 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5771 acts as though it is a bank of ROM on the target board, but you can
5772 write into it over the network. GDB's support consists only of
5773 support for fast loading into the emulated ROM; to debug, you must use
5774 another protocol, such as standard remote protocol. The usual
5775 sequence is something like
5777 target nrom <netrom-hostname>
5779 target remote <netrom-hostname>:1235
5783 GDB now includes support for the Apple Macintosh, as a host only. It
5784 may be run as either an MPW tool or as a standalone application, and
5785 it can debug through the serial port. All the usual GDB commands are
5786 available, but to the target command, you must supply "serial" as the
5787 device type instead of "/dev/ttyXX". See mpw-README in the main
5788 directory for more information on how to build. The MPW configuration
5789 scripts */mpw-config.in support only a few targets, and only the
5790 mips-idt-ecoff target has been tested.
5794 GDB configuration now uses autoconf. This is not user-visible,
5795 but does simplify configuration and building.
5799 GDB now supports hpux10.
5801 *** Changes in GDB-4.14:
5803 * New native configurations
5805 x86 FreeBSD i[345]86-*-freebsd
5806 x86 NetBSD i[345]86-*-netbsd
5807 NS32k NetBSD ns32k-*-netbsd
5808 Sparc NetBSD sparc-*-netbsd
5812 A29K VxWorks a29k-*-vxworks
5813 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5814 CPU32 EST-300 emulator m68*-*-est*
5815 PowerPC ELF powerpc-*-elf
5818 * Alpha OSF/1 support for procfs
5820 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5821 possible to attach to running processes. As the mounting of the /proc
5822 filesystem is optional on the Alpha, GDB automatically determines
5823 the availability of /proc during startup. This can lead to problems
5824 if /proc is unmounted after GDB has been started.
5826 * Arguments to user-defined commands
5828 User commands may accept up to 10 arguments separated by whitespace.
5829 Arguments are accessed within the user command via $arg0..$arg9. A
5832 print $arg0 + $arg1 + $arg2
5834 To execute the command use:
5837 Defines the command "adder" which prints the sum of its three arguments.
5838 Note the arguments are text substitutions, so they may reference variables,
5839 use complex expressions, or even perform inferior function calls.
5841 * New `if' and `while' commands
5843 This makes it possible to write more sophisticated user-defined
5844 commands. Both commands take a single argument, which is the
5845 expression to evaluate, and must be followed by the commands to
5846 execute, one per line, if the expression is nonzero, the list being
5847 terminated by the word `end'. The `if' command list may include an
5848 `else' word, which causes the following commands to be executed only
5849 if the expression is zero.
5851 * Fortran source language mode
5853 GDB now includes partial support for Fortran 77. It will recognize
5854 Fortran programs and can evaluate a subset of Fortran expressions, but
5855 variables and functions may not be handled correctly. GDB will work
5856 with G77, but does not yet know much about symbols emitted by other
5859 * Better HPUX support
5861 Most debugging facilities now work on dynamic executables for HPPAs
5862 running hpux9 or later. You can attach to running dynamically linked
5863 processes, but by default the dynamic libraries will be read-only, so
5864 for instance you won't be able to put breakpoints in them. To change
5865 that behavior do the following before running the program:
5871 This will cause the libraries to be mapped private and read-write.
5872 To revert to the normal behavior, do this:
5878 You cannot set breakpoints or examine data in the library until after
5879 the library is loaded if the function/data symbols do not have
5882 GDB can now also read debug symbols produced by the HP C compiler on
5883 HPPAs (sorry, no C++, Fortran or 68k support).
5885 * Target byte order now dynamically selectable
5887 You can choose which byte order to use with a target system, via the
5888 commands "set endian big" and "set endian little", and you can see the
5889 current setting by using "show endian". You can also give the command
5890 "set endian auto", in which case GDB will use the byte order
5891 associated with the executable. Currently, only embedded MIPS
5892 configurations support dynamic selection of target byte order.
5894 * New DOS host serial code
5896 This version uses DPMI interrupts to handle buffered I/O, so you
5897 no longer need to run asynctsr when debugging boards connected to
5900 *** Changes in GDB-4.13:
5902 * New "complete" command
5904 This lists all the possible completions for the rest of the line, if it
5905 were to be given as a command itself. This is intended for use by emacs.
5907 * Trailing space optional in prompt
5909 "set prompt" no longer adds a space for you after the prompt you set. This
5910 allows you to set a prompt which ends in a space or one that does not.
5912 * Breakpoint hit counts
5914 "info break" now displays a count of the number of times the breakpoint
5915 has been hit. This is especially useful in conjunction with "ignore"; you
5916 can ignore a large number of breakpoint hits, look at the breakpoint info
5917 to see how many times the breakpoint was hit, then run again, ignoring one
5918 less than that number, and this will get you quickly to the last hit of
5921 * Ability to stop printing at NULL character
5923 "set print null-stop" will cause GDB to stop printing the characters of
5924 an array when the first NULL is encountered. This is useful when large
5925 arrays actually contain only short strings.
5927 * Shared library breakpoints
5929 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5930 breakpoints in shared libraries before the executable is run.
5932 * Hardware watchpoints
5934 There is a new hardware breakpoint for the watch command for sparclite
5935 targets. See gdb/sparclite/hw_breakpoint.note.
5937 Hardware watchpoints are also now supported under GNU/Linux.
5941 Annotations have been added. These are for use with graphical interfaces,
5942 and are still experimental. Currently only gdba.el uses these.
5944 * Improved Irix 5 support
5946 GDB now works properly with Irix 5.2.
5948 * Improved HPPA support
5950 GDB now works properly with the latest GCC and GAS.
5952 * New native configurations
5954 Sequent PTX4 i[34]86-sequent-ptx4
5955 HPPA running OSF/1 hppa*-*-osf*
5956 Atari TT running SVR4 m68*-*-sysv4*
5957 RS/6000 LynxOS rs6000-*-lynxos*
5961 OS/9000 i[34]86-*-os9k
5962 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5965 * Hitachi SH7000 and E7000-PC ICE support
5967 There is now support for communicating with the Hitachi E7000-PC ICE.
5968 This is available automatically when GDB is configured for the SH.
5972 As usual, a variety of small fixes and improvements, both generic
5973 and configuration-specific. See the ChangeLog for more detail.
5975 *** Changes in GDB-4.12:
5977 * Irix 5 is now supported
5981 GDB-4.12 on the HPPA has a number of changes which make it unable
5982 to debug the output from the currently released versions of GCC and
5983 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5984 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5985 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5988 *** Changes in GDB-4.11:
5990 * User visible changes:
5994 The "set remotedebug" option is now consistent between the mips remote
5995 target, remote targets using the gdb-specific protocol, UDI (AMD's
5996 debug protocol for the 29k) and the 88k bug monitor. It is now an
5997 integer specifying a debug level (normally 0 or 1, but 2 means more
5998 debugging info for the mips target).
6000 * DEC Alpha native support
6002 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6003 debug info, but GDB works fairly well with the DEC compiler and should
6004 work with a future GCC release. See the README file for a few
6005 Alpha-specific notes.
6007 * Preliminary thread implementation
6009 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6011 * LynxOS native and target support for 386
6013 This release has been hosted on LynxOS 2.2, and also can be configured
6014 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6017 * Improvements in C++ mangling/demangling.
6019 This release has much better g++ debugging, specifically in name
6020 mangling/demangling, virtual function calls, print virtual table,
6021 call methods, ...etc.
6023 *** Changes in GDB-4.10:
6025 * User visible changes:
6027 Remote debugging using the GDB-specific (`target remote') protocol now
6028 supports the `load' command. This is only useful if you have some
6029 other way of getting the stub to the target system, and you can put it
6030 somewhere in memory where it won't get clobbered by the download.
6032 Filename completion now works.
6034 When run under emacs mode, the "info line" command now causes the
6035 arrow to point to the line specified. Also, "info line" prints
6036 addresses in symbolic form (as well as hex).
6038 All vxworks based targets now support a user settable option, called
6039 vxworks-timeout. This option represents the number of seconds gdb
6040 should wait for responses to rpc's. You might want to use this if
6041 your vxworks target is, perhaps, a slow software simulator or happens
6042 to be on the far side of a thin network line.
6046 This release contains support for using a DEC alpha as a GDB host for
6047 cross debugging. Native alpha debugging is not supported yet.
6050 *** Changes in GDB-4.9:
6054 This is the first GDB release which is accompanied by a matching testsuite.
6055 The testsuite requires installation of dejagnu, which should be available
6056 via ftp from most sites that carry GNU software.
6060 'Cfront' style demangling has had its name changed to 'ARM' style, to
6061 emphasize that it was written from the specifications in the C++ Annotated
6062 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6063 disclaimers, it still generated too much confusion with users attempting to
6064 use gdb with AT&T cfront.
6068 GDB now uses a standard remote interface to a simulator library.
6069 So far, the library contains simulators for the Zilog Z8001/2, the
6070 Hitachi H8/300, H8/500 and Super-H.
6072 * New targets supported
6074 H8/300 simulator h8300-hitachi-hms or h8300hms
6075 H8/500 simulator h8500-hitachi-hms or h8500hms
6076 SH simulator sh-hitachi-hms or sh
6077 Z8000 simulator z8k-zilog-none or z8ksim
6078 IDT MIPS board over serial line mips-idt-ecoff
6080 Cross-debugging to GO32 targets is supported. It requires a custom
6081 version of the i386-stub.c module which is integrated with the
6082 GO32 memory extender.
6084 * New remote protocols
6086 MIPS remote debugging protocol.
6088 * New source languages supported
6090 This version includes preliminary support for Chill, a Pascal like language
6091 used by telecommunications companies. Chill support is also being integrated
6092 into the GNU compiler, but we don't know when it will be publically available.
6095 *** Changes in GDB-4.8:
6097 * HP Precision Architecture supported
6099 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6100 version of this support was available as a set of patches from the
6101 University of Utah. GDB does not support debugging of programs
6102 compiled with the HP compiler, because HP will not document their file
6103 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6104 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6106 Many problems in the preliminary version have been fixed.
6108 * Faster and better demangling
6110 We have improved template demangling and fixed numerous bugs in the GNU style
6111 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6112 character types (wchar_t) are now supported. Demangling of each symbol is now
6113 only done once, and is cached when the symbol table for a file is read in.
6114 This results in a small increase in memory usage for C programs, a moderate
6115 increase in memory usage for C++ programs, and a fantastic speedup in
6118 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6119 from the specifications in the Annotated Reference Manual, which AT&T's
6120 compiler does not actually implement.
6122 * G++ multiple inheritance compiler problem
6124 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6125 inheritance lattices was reworked to properly discover ambiguities. We
6126 recently found an example which causes this new algorithm to fail in a
6127 very subtle way, producing bad debug information for those classes.
6128 The file 'gcc.patch' (in this directory) can be applied to gcc to
6129 circumvent the problem. A future GCC release will contain a complete
6132 The previous G++ debug info problem (mentioned below for the gdb-4.7
6133 release) is fixed in gcc version 2.3.2.
6135 * Improved configure script
6137 The `configure' script will now attempt to guess your system type if
6138 you don't supply a host system type. The old scheme of supplying a
6139 host system triplet is preferable over using this. All the magic is
6140 done in the new `config.guess' script. Examine it for details.
6142 We have also brought our configure script much more in line with the FSF's
6143 version. It now supports the --with-xxx options. In particular,
6144 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6145 The resulting GDB will not be able to read arbitrary object file formats --
6146 only the format ``expected'' to be used on the configured target system.
6147 We hope to make this the default in a future release.
6149 * Documentation improvements
6151 There's new internal documentation on how to modify GDB, and how to
6152 produce clean changes to the code. We implore people to read it
6153 before submitting changes.
6155 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6156 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6157 `info' files are also provided. To build `info' files from scratch,
6158 you will need the latest `makeinfo' release, which will be available in
6159 a future texinfo-X.Y release.
6161 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6162 We're not sure exactly which versions have this problem, but it has
6163 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6164 or better. If that isn't possible, there is a patch in
6165 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6166 around this problem.
6170 GDB now supports array constants that can be used in expressions typed in by
6171 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6172 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6175 The new directory `gdb/sparclite' contains a program that demonstrates
6176 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6178 * New native hosts supported
6180 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6181 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6183 * New targets supported
6185 AMD 29k family via UDI a29k-amd-udi or udi29k
6187 * New file formats supported
6189 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6190 HPUX core files, and SCO 3.2v2 core files.
6194 Attaching to processes now works again; thanks for the many bug reports.
6196 We have also stomped on a bunch of core dumps caused by
6197 printf_filtered("%s") problems.
6199 We eliminated a copyright problem on the rpc and ptrace header files
6200 for VxWorks, which was discovered at the last minute during the 4.7
6201 release. You should now be able to build a VxWorks GDB.
6203 You can now interrupt gdb while an attached process is running. This
6204 will cause the attached process to stop, and give control back to GDB.
6206 We fixed problems caused by using too many file descriptors
6207 for reading symbols from object files and libraries. This was
6208 especially a problem for programs that used many (~100) shared
6211 The `step' command now only enters a subroutine if there is line number
6212 information for the subroutine. Otherwise it acts like the `next'
6213 command. Previously, `step' would enter subroutines if there was
6214 any debugging information about the routine. This avoids problems
6215 when using `cc -g1' on MIPS machines.
6217 * Internal improvements
6219 GDB's internal interfaces have been improved to make it easier to support
6220 debugging of multiple languages in the future.
6222 GDB now uses a common structure for symbol information internally.
6223 Minimal symbols (derived from linkage symbols in object files), partial
6224 symbols (from a quick scan of debug information), and full symbols
6225 contain a common subset of information, making it easier to write
6226 shared code that handles any of them.
6228 * New command line options
6230 We now accept --silent as an alias for --quiet.
6234 The memory-mapped-malloc library is now licensed under the GNU Library
6235 General Public License.
6237 *** Changes in GDB-4.7:
6239 * Host/native/target split
6241 GDB has had some major internal surgery to untangle the support for
6242 hosts and remote targets. Now, when you configure GDB for a remote
6243 target, it will no longer load in all of the support for debugging
6244 local programs on the host. When fully completed and tested, this will
6245 ensure that arbitrary host/target combinations are possible.
6247 The primary conceptual shift is to separate the non-portable code in
6248 GDB into three categories. Host specific code is required any time GDB
6249 is compiled on that host, regardless of the target. Target specific
6250 code relates to the peculiarities of the target, but can be compiled on
6251 any host. Native specific code is everything else: it can only be
6252 built when the host and target are the same system. Child process
6253 handling and core file support are two common `native' examples.
6255 GDB's use of /proc for controlling Unix child processes is now cleaner.
6256 It has been split out into a single module under the `target_ops' vector,
6257 plus two native-dependent functions for each system that uses /proc.
6259 * New hosts supported
6261 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6262 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6263 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6265 * New targets supported
6267 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6268 68030 and CPU32 m68030-*-*, m68332-*-*
6270 * New native hosts supported
6272 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6273 (386bsd is not well tested yet)
6274 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6276 * New file formats supported
6278 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6279 supports reading of `a.out.adobe' object files, which are an a.out
6280 format extended with minimal information about multiple sections.
6284 `show copying' is the same as the old `info copying'.
6285 `show warranty' is the same as `info warrantee'.
6286 These were renamed for consistency. The old commands continue to work.
6288 `info handle' is a new alias for `info signals'.
6290 You can now define pre-command hooks, which attach arbitrary command
6291 scripts to any command. The commands in the hook will be executed
6292 prior to the user's command. You can also create a hook which will be
6293 executed whenever the program stops. See gdb.texinfo.
6297 We now deal with Cfront style name mangling, and can even extract type
6298 info from mangled symbols. GDB can automatically figure out which
6299 symbol mangling style your C++ compiler uses.
6301 Calling of methods and virtual functions has been improved as well.
6305 The crash that occured when debugging Sun Ansi-C compiled binaries is
6306 fixed. This was due to mishandling of the extra N_SO stabs output
6309 We also finally got Ultrix 4.2 running in house, and fixed core file
6310 support, with help from a dozen people on the net.
6312 John M. Farrell discovered that the reason that single-stepping was so
6313 slow on all of the Mips based platforms (primarily SGI and DEC) was
6314 that we were trying to demangle and lookup a symbol used for internal
6315 purposes on every instruction that was being stepped through. Changing
6316 the name of that symbol so that it couldn't be mistaken for a C++
6317 mangled symbol sped things up a great deal.
6319 Rich Pixley sped up symbol lookups in general by getting much smarter
6320 about when C++ symbol mangling is necessary. This should make symbol
6321 completion (TAB on the command line) much faster. It's not as fast as
6322 we'd like, but it's significantly faster than gdb-4.6.
6326 A new user controllable variable 'call_scratch_address' can
6327 specify the location of a scratch area to be used when GDB
6328 calls a function in the target. This is necessary because the
6329 usual method of putting the scratch area on the stack does not work
6330 in systems that have separate instruction and data spaces.
6332 We integrated changes to support the 29k UDI (Universal Debugger
6333 Interface), but discovered at the last minute that we didn't have all
6334 of the appropriate copyright paperwork. We are working with AMD to
6335 resolve this, and hope to have it available soon.
6339 We have sped up the remote serial line protocol, especially for targets
6340 with lots of registers. It now supports a new `expedited status' ('T')
6341 message which can be used in place of the existing 'S' status message.
6342 This allows the remote stub to send only the registers that GDB
6343 needs to make a quick decision about single-stepping or conditional
6344 breakpoints, eliminating the need to fetch the entire register set for
6345 each instruction being stepped through.
6347 The GDB remote serial protocol now implements a write-through cache for
6348 registers, only re-reading the registers if the target has run.
6350 There is also a new remote serial stub for SPARC processors. You can
6351 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6352 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6353 processor with a serial port.
6357 Configure.in files have become much easier to read and modify. A new
6358 `table driven' format makes it more obvious what configurations are
6359 supported, and what files each one uses.
6363 There is a new opcodes library which will eventually contain all of the
6364 disassembly routines and opcode tables. At present, it only contains
6365 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6366 disassembler (binutils/objdump) to share these routines.
6368 The libiberty library is now copylefted under the GNU Library General
6369 Public License. This allows more liberal use, and was done so libg++
6370 can use it. This makes no difference to GDB, since the Library License
6371 grants all the rights from the General Public License.
6375 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6376 reference to the stabs symbol info used by the debugger. It is (as far
6377 as we know) the only published document on this fascinating topic. We
6378 encourage you to read it, compare it to the stabs information on your
6379 system, and send improvements on the document in general (to
6380 bug-gdb@prep.ai.mit.edu).
6382 And, of course, many bugs have been fixed.
6385 *** Changes in GDB-4.6:
6387 * Better support for C++ function names
6389 GDB now accepts as input the "demangled form" of C++ overloaded function
6390 names and member function names, and can do command completion on such names
6391 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6392 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6393 Make use of command completion, it is your friend.
6395 GDB also now accepts a variety of C++ mangled symbol formats. They are
6396 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6397 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6398 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6399 for the list of formats.
6401 * G++ symbol mangling problem
6403 Recent versions of gcc have a bug in how they emit debugging information for
6404 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6405 directory) can be applied to gcc to fix the problem. Alternatively, if you
6406 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6407 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6408 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6411 * New 'maintenance' command
6413 All of the commands related to hacking GDB internals have been moved out of
6414 the main command set, and now live behind the 'maintenance' command. This
6415 can also be abbreviated as 'mt'. The following changes were made:
6417 dump-me -> maintenance dump-me
6418 info all-breakpoints -> maintenance info breakpoints
6419 printmsyms -> maintenance print msyms
6420 printobjfiles -> maintenance print objfiles
6421 printpsyms -> maintenance print psymbols
6422 printsyms -> maintenance print symbols
6424 The following commands are new:
6426 maintenance demangle Call internal GDB demangler routine to
6427 demangle a C++ link name and prints the result.
6428 maintenance print type Print a type chain for a given symbol
6430 * Change to .gdbinit file processing
6432 We now read the $HOME/.gdbinit file before processing the argv arguments
6433 (e.g. reading symbol files or core files). This allows global parameters to
6434 be set, which will apply during the symbol reading. The ./.gdbinit is still
6435 read after argv processing.
6437 * New hosts supported
6439 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6441 GNU/Linux support i386-unknown-linux or linux
6443 We are also including code to support the HP/PA running BSD and HPUX. This
6444 is almost guaranteed not to work, as we didn't have time to test or build it
6445 for this release. We are including it so that the more adventurous (or
6446 masochistic) of you can play with it. We also had major problems with the
6447 fact that the compiler that we got from HP doesn't support the -g option.
6450 * New targets supported
6452 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6454 * More smarts about finding #include files
6456 GDB now remembers the compilation directory for all include files, and for
6457 all files from which C is generated (like yacc and lex sources). This
6458 greatly improves GDB's ability to find yacc/lex sources, and include files,
6459 especially if you are debugging your program from a directory different from
6460 the one that contains your sources.
6462 We also fixed a bug which caused difficulty with listing and setting
6463 breakpoints in include files which contain C code. (In the past, you had to
6464 try twice in order to list an include file that you hadn't looked at before.)
6466 * Interesting infernals change
6468 GDB now deals with arbitrary numbers of sections, where the symbols for each
6469 section must be relocated relative to that section's landing place in the
6470 target's address space. This work was needed to support ELF with embedded
6471 stabs used by Solaris-2.0.
6473 * Bug fixes (of course!)
6475 There have been loads of fixes for the following things:
6476 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6477 i960, stabs, DOS(GO32), procfs, etc...
6479 See the ChangeLog for details.
6481 *** Changes in GDB-4.5:
6483 * New machines supported (host and target)
6485 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6487 SGI Irix-4.x mips-sgi-irix4 or iris4
6489 * New malloc package
6491 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6492 Mmalloc is capable of handling mutiple heaps of memory. It is also
6493 capable of saving a heap to a file, and then mapping it back in later.
6494 This can be used to greatly speedup the startup of GDB by using a
6495 pre-parsed symbol table which lives in a mmalloc managed heap. For
6496 more details, please read mmalloc/mmalloc.texi.
6500 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6501 'help info proc' for details.
6503 * MIPS ecoff symbol table format
6505 The code that reads MIPS symbol table format is now supported on all hosts.
6506 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6509 * File name changes for MS-DOS
6511 Many files in the config directories have been renamed to make it easier to
6512 support GDB on MS-DOSe systems (which have very restrictive file name
6513 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6514 environment) is close to working but has some remaining problems. Note
6515 that debugging of DOS programs is not supported, due to limitations
6516 in the ``operating system'', but it can be used to host cross-debugging.
6518 * Cross byte order fixes
6520 Many fixes have been made to support cross debugging of Sparc and MIPS
6521 targets from hosts whose byte order differs.
6523 * New -mapped and -readnow options
6525 If memory-mapped files are available on your system through the 'mmap'
6526 system call, you can use the -mapped option on the `file' or
6527 `symbol-file' commands to cause GDB to write the symbols from your
6528 program into a reusable file. If the program you are debugging is
6529 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6530 Future GDB debugging sessions will notice the presence of this file,
6531 and will quickly map in symbol information from it, rather than reading
6532 the symbol table from the executable program. Using the '-mapped'
6533 option in a GDB `file' or `symbol-file' command has the same effect as
6534 starting GDB with the '-mapped' command-line option.
6536 You can cause GDB to read the entire symbol table immediately by using
6537 the '-readnow' option with any of the commands that load symbol table
6538 information (or on the GDB command line). This makes the command
6539 slower, but makes future operations faster.
6541 The -mapped and -readnow options are typically combined in order to
6542 build a `fred.syms' file that contains complete symbol information.
6543 A simple GDB invocation to do nothing but build a `.syms' file for future
6546 gdb -batch -nx -mapped -readnow programname
6548 The `.syms' file is specific to the host machine on which GDB is run.
6549 It holds an exact image of GDB's internal symbol table. It cannot be
6550 shared across multiple host platforms.
6552 * longjmp() handling
6554 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6555 siglongjmp() without losing control. This feature has not yet been ported to
6556 all systems. It currently works on many 386 platforms, all MIPS-based
6557 platforms (SGI, DECstation, etc), and Sun3/4.
6561 Preliminary work has been put in to support the new Solaris OS from Sun. At
6562 this time, it can control and debug processes, but it is not capable of
6567 As always, many many bug fixes. The major areas were with g++, and mipsread.
6568 People using the MIPS-based platforms should experience fewer mysterious
6569 crashes and trashed symbol tables.
6571 *** Changes in GDB-4.4:
6573 * New machines supported (host and target)
6575 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6577 BSD Reno on Vax vax-dec-bsd
6578 Ultrix on Vax vax-dec-ultrix
6580 * New machines supported (target)
6582 AMD 29000 embedded, using EBMON a29k-none-none
6586 GDB continues to improve its handling of C++. `References' work better.
6587 The demangler has also been improved, and now deals with symbols mangled as
6588 per the Annotated C++ Reference Guide.
6590 GDB also now handles `stabs' symbol information embedded in MIPS
6591 `ecoff' symbol tables. Since the ecoff format was not easily
6592 extensible to handle new languages such as C++, this appeared to be a
6593 good way to put C++ debugging info into MIPS binaries. This option
6594 will be supported in the GNU C compiler, version 2, when it is
6597 * New features for SVR4
6599 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6600 shared libraries. Debugging dynamically linked programs should present
6601 only minor differences from debugging statically linked programs.
6603 The `info proc' command will print out information about any process
6604 on an SVR4 system (including the one you are debugging). At the moment,
6605 it prints the address mappings of the process.
6607 If you bring up GDB on another SVR4 system, please send mail to
6608 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6610 * Better dynamic linking support in SunOS
6612 Reading symbols from shared libraries which contain debugging symbols
6613 now works properly. However, there remain issues such as automatic
6614 skipping of `transfer vector' code during function calls, which
6615 make it harder to debug code in a shared library, than to debug the
6616 same code linked statically.
6620 GDB is now using the latest `getopt' routines from the FSF. This
6621 version accepts the -- prefix for options with long names. GDB will
6622 continue to accept the old forms (-option and +option) as well.
6623 Various single letter abbreviations for options have been explicity
6624 added to the option table so that they won't get overshadowed in the
6625 future by other options that begin with the same letter.
6629 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6630 Many assorted bugs have been handled. Many more remain to be handled.
6631 See the various ChangeLog files (primarily in gdb and bfd) for details.
6634 *** Changes in GDB-4.3:
6636 * New machines supported (host and target)
6638 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6639 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6640 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6642 * Almost SCO Unix support
6644 We had hoped to support:
6645 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6646 (except for core file support), but we discovered very late in the release
6647 that it has problems with process groups that render gdb unusable. Sorry
6648 about that. I encourage people to fix it and post the fixes.
6650 * Preliminary ELF and DWARF support
6652 GDB can read ELF object files on System V Release 4, and can handle
6653 debugging records for C, in DWARF format, in ELF files. This support
6654 is preliminary. If you bring up GDB on another SVR4 system, please
6655 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6660 GDB now uses the latest `readline' library. One user-visible change
6661 is that two tabs will list possible command completions, which previously
6662 required typing M-? (meta-question mark, or ESC ?).
6666 The `stepi' bug that many of you noticed has been squashed.
6667 Many bugs in C++ have been handled. Many more remain to be handled.
6668 See the various ChangeLog files (primarily in gdb and bfd) for details.
6670 * State of the MIPS world (in case you wondered):
6672 GDB can understand the symbol tables emitted by the compilers
6673 supplied by most vendors of MIPS-based machines, including DEC. These
6674 symbol tables are in a format that essentially nobody else uses.
6676 Some versions of gcc come with an assembler post-processor called
6677 mips-tfile. This program is required if you want to do source-level
6678 debugging of gcc-compiled programs. I believe FSF does not ship
6679 mips-tfile with gcc version 1, but it will eventually come with gcc
6682 Debugging of g++ output remains a problem. g++ version 1.xx does not
6683 really support it at all. (If you're lucky, you should be able to get
6684 line numbers and stack traces to work, but no parameters or local
6685 variables.) With some work it should be possible to improve the
6688 When gcc version 2 is released, you will have somewhat better luck.
6689 However, even then you will get confusing results for inheritance and
6692 We will eventually provide full debugging of g++ output on
6693 DECstations. This will probably involve some kind of stabs-in-ecoff
6694 encapulation, but the details have not been worked out yet.
6697 *** Changes in GDB-4.2:
6699 * Improved configuration
6701 Only one copy of `configure' exists now, and it is not self-modifying.
6702 Porting BFD is simpler.
6706 The `step' and `next' commands now only stop at the first instruction
6707 of a source line. This prevents the multiple stops that used to occur
6708 in switch statements, for-loops, etc. `Step' continues to stop if a
6709 function that has debugging information is called within the line.
6713 Lots of small bugs fixed. More remain.
6715 * New host supported (not target)
6717 Intel 386 PC clone running Mach i386-none-mach
6720 *** Changes in GDB-4.1:
6722 * Multiple source language support
6724 GDB now has internal scaffolding to handle several source languages.
6725 It determines the type of each source file from its filename extension,
6726 and will switch expression parsing and number formatting to match the
6727 language of the function in the currently selected stack frame.
6728 You can also specifically set the language to be used, with
6729 `set language c' or `set language modula-2'.
6733 GDB now has preliminary support for the GNU Modula-2 compiler,
6734 currently under development at the State University of New York at
6735 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6736 continue through the fall of 1991 and into 1992.
6738 Other Modula-2 compilers are currently not supported, and attempting to
6739 debug programs compiled with them will likely result in an error as the
6740 symbol table is read. Feel free to work on it, though!
6742 There are hooks in GDB for strict type checking and range checking,
6743 in the `Modula-2 philosophy', but they do not currently work.
6747 GDB can now write to executable and core files (e.g. patch
6748 a variable's value). You must turn this switch on, specify
6749 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6750 by assigning a new value to a variable. Modifications take
6753 * Automatic SunOS shared library reading
6755 When you run your program, GDB automatically determines where its
6756 shared libraries (if any) have been loaded, and reads their symbols.
6757 The `share' command is no longer needed. This also works when
6758 examining core files.
6762 You can specify the number of lines that the `list' command shows.
6765 * New machines supported (host and target)
6767 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6768 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6769 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6771 * New hosts supported (not targets)
6773 IBM RT/PC: romp-ibm-aix or rtpc
6775 * New targets supported (not hosts)
6777 AMD 29000 embedded with COFF a29k-none-coff
6778 AMD 29000 embedded with a.out a29k-none-aout
6779 Ultracomputer remote kernel debug a29k-nyu-kern
6781 * New remote interfaces
6787 *** Changes in GDB-4.0:
6791 Wide output is wrapped at good places to make the output more readable.
6793 Gdb now supports cross-debugging from a host machine of one type to a
6794 target machine of another type. Communication with the target system
6795 is over serial lines. The ``target'' command handles connecting to the
6796 remote system; the ``load'' command will download a program into the
6797 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6798 also supports debugging of realtime processes running under VxWorks,
6799 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6800 stub on the target system.
6802 New CPUs supported include the AMD 29000 and Intel 960.
6804 GDB now reads object files and symbol tables via a ``binary file''
6805 library, which allows a single copy of GDB to debug programs of multiple
6806 object file types such as a.out and coff.
6808 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6809 refcard.dvi and refcard.ps are available to format it).
6812 * Control-Variable user interface simplified
6814 All variables that control the operation of the debugger can be set
6815 by the ``set'' command, and displayed by the ``show'' command.
6817 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6818 ``Show prompt'' produces the response:
6819 Gdb's prompt is new-gdb=>.
6821 What follows are the NEW set commands. The command ``help set'' will
6822 print a complete list of old and new set commands. ``help set FOO''
6823 will give a longer description of the variable FOO. ``show'' will show
6824 all of the variable descriptions and their current settings.
6826 confirm on/off: Enables warning questions for operations that are
6827 hard to recover from, e.g. rerunning the program while
6828 it is already running. Default is ON.
6830 editing on/off: Enables EMACS style command line editing
6831 of input. Previous lines can be recalled with
6832 control-P, the current line can be edited with control-B,
6833 you can search for commands with control-R, etc.
6836 history filename NAME: NAME is where the gdb command history
6837 will be stored. The default is .gdb_history,
6838 or the value of the environment variable
6841 history size N: The size, in commands, of the command history. The
6842 default is 256, or the value of the environment variable
6845 history save on/off: If this value is set to ON, the history file will
6846 be saved after exiting gdb. If set to OFF, the
6847 file will not be saved. The default is OFF.
6849 history expansion on/off: If this value is set to ON, then csh-like
6850 history expansion will be performed on
6851 command line input. The default is OFF.
6853 radix N: Sets the default radix for input and output. It can be set
6854 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6855 in the current radix, so "set radix 10" is always a no-op.
6857 height N: This integer value is the number of lines on a page. Default
6858 is 24, the current `stty rows'' setting, or the ``li#''
6859 setting from the termcap entry matching the environment
6862 width N: This integer value is the number of characters on a line.
6863 Default is 80, the current `stty cols'' setting, or the ``co#''
6864 setting from the termcap entry matching the environment
6867 Note: ``set screensize'' is obsolete. Use ``set height'' and
6868 ``set width'' instead.
6870 print address on/off: Print memory addresses in various command displays,
6871 such as stack traces and structure values. Gdb looks
6872 more ``symbolic'' if you turn this off; it looks more
6873 ``machine level'' with it on. Default is ON.
6875 print array on/off: Prettyprint arrays. New convenient format! Default
6878 print demangle on/off: Print C++ symbols in "source" form if on,
6881 print asm-demangle on/off: Same, for assembler level printouts
6884 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6887 * Support for Epoch Environment.
6889 The epoch environment is a version of Emacs v18 with windowing. One
6890 new command, ``inspect'', is identical to ``print'', except that if you
6891 are running in the epoch environment, the value is printed in its own
6895 * Support for Shared Libraries
6897 GDB can now debug programs and core files that use SunOS shared libraries.
6898 Symbols from a shared library cannot be referenced
6899 before the shared library has been linked with the program (this
6900 happens after you type ``run'' and before the function main() is entered).
6901 At any time after this linking (including when examining core files
6902 from dynamically linked programs), gdb reads the symbols from each
6903 shared library when you type the ``sharedlibrary'' command.
6904 It can be abbreviated ``share''.
6906 sharedlibrary REGEXP: Load shared object library symbols for files
6907 matching a unix regular expression. No argument
6908 indicates to load symbols for all shared libraries.
6910 info sharedlibrary: Status of loaded shared libraries.
6915 A watchpoint stops execution of a program whenever the value of an
6916 expression changes. Checking for this slows down execution
6917 tremendously whenever you are in the scope of the expression, but is
6918 quite useful for catching tough ``bit-spreader'' or pointer misuse
6919 problems. Some machines such as the 386 have hardware for doing this
6920 more quickly, and future versions of gdb will use this hardware.
6922 watch EXP: Set a watchpoint (breakpoint) for an expression.
6924 info watchpoints: Information about your watchpoints.
6926 delete N: Deletes watchpoint number N (same as breakpoints).
6927 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6928 enable N: Re-enables watchpoint number N (same as breakpoints).
6931 * C++ multiple inheritance
6933 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6936 * C++ exception handling
6938 Gdb now supports limited C++ exception handling. Besides the existing
6939 ability to breakpoint on an exception handler, gdb can breakpoint on
6940 the raising of an exception (before the stack is peeled back to the
6943 catch FOO: If there is a FOO exception handler in the dynamic scope,
6944 set a breakpoint to catch exceptions which may be raised there.
6945 Multiple exceptions (``catch foo bar baz'') may be caught.
6947 info catch: Lists all exceptions which may be caught in the
6948 current stack frame.
6951 * Minor command changes
6953 The command ``call func (arg, arg, ...)'' now acts like the print
6954 command, except it does not print or save a value if the function's result
6955 is void. This is similar to dbx usage.
6957 The ``up'' and ``down'' commands now always print the frame they end up
6958 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6959 frames without printing.
6961 * New directory command
6963 'dir' now adds directories to the FRONT of the source search path.
6964 The path starts off empty. Source files that contain debug information
6965 about the directory in which they were compiled can be found even
6966 with an empty path; Sun CC and GCC include this information. If GDB can't
6967 find your source file in the current directory, type "dir .".
6969 * Configuring GDB for compilation
6971 For normal use, type ``./configure host''. See README or gdb.texinfo
6974 GDB now handles cross debugging. If you are remotely debugging between
6975 two different machines, type ``./configure host -target=targ''.
6976 Host is the machine where GDB will run; targ is the machine
6977 where the program that you are debugging will run.